JPH10122332A - Continuously variable transmission - Google Patents

Abstract

(57) [Problem] To provide a hydraulic continuously variable transmission that has a small axial dimension, is compact, and can automatically start and shift according to a change in the rotation speed of an input shaft. A radial type which is connected via a hydraulic closed circuit to the input shaft first plunger 14 group and the first hydraulic pump P ₁ of the radial type first hydraulic pump P ₁ to a common cylinder body 12 which is fixed to 1 The second hydraulic pump P ₂ and the second group of plungers 24 are arranged, and the first pump ring 15 for operating the first group of plungers 14 is mounted on the transmission case 5, the eccentric direction of the first pump ring 15 with respect to the cylinder body 12 and The shaft is supported to make the amount of eccentricity variable. Further, a clutch valve 51 for communicating and disconnecting between the low pressure and high pressure oil passages 28 and 29 of the hydraulic closed circuit, and a centrifugal mechanism 60 for sequentially operating the valve and the first pump ring 15 in response to an increase in the rotation speed of the input shaft 1.
Are provided on the cylinder body 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuously variable transmission mainly applied to vehicles such as motorcycles and automobiles.

[0002]

2. Description of the Related Art As a continuously variable transmission, for example, Japanese Patent Publication No. 7-2
As disclosed in Japanese Patent No. 6676, there is known an axial hydraulic pump having a fixed capacity and an axial hydraulic motor having a variable capacity which are coaxially arranged and connected via a hydraulic closed circuit.

[0003]

In the continuously variable transmission as described above, the axial type hydraulic pump and the hydraulic motor, which extend relatively long in the axial direction, are arranged in the axial direction. And it is difficult to make it compact.

The present invention has been made in view of such circumstances, and has a compact configuration in which the axial dimension is greatly reduced, and automatically starts and shifts according to changes in the rotation speed of the input shaft. It is an object of the present invention to provide a continuously variable transmission that can be controlled at a constant speed.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a transmission case in which an input shaft and an output shaft are coaxially supported on a transmission case, and a cylinder body fixed to the input shaft is provided. A plurality of first plungers radially disposed on the body, and surrounding the first plungers so as to relatively movably engage with their outer ends, and reciprocate with each of the first plungers as the cylinder body rotates. Give
In order to adjust the reciprocating stroke, a radial type first hydraulic pump having a variable capacity is constituted by a first pump ring which is rotatably supported by a transmission case. A plurality of second plungers are fixed to the output shaft, surround the second plungers and engage with their outer ends so as to be relatively movable. A second hydraulic pump having a fixed capacity is constituted by a second pump ring that provides a reciprocating motion of a constant stroke to the two plungers, and a first hydraulic pump sucks working oil into the cylinder body and a second hydraulic pump into the cylinder body. And a low-pressure oil passage through which hydraulic oil is discharged from the first hydraulic pump and hydraulic oil is sucked into the second hydraulic pump. A clutch valve that moves between a clutch-off position that connects the high-pressure oil passage to the low-pressure oil passage or the oil reservoir and a clutch-on position that cuts off the communication; To the clutch-on position, and further reduce the gear ratio to the first position.
A first feature is that a centrifugal mechanism that operates a first pump ring to control a reciprocating stroke of the plunger is provided.

In addition to the above features, the present invention provides a driving plate fixed to a cylinder body, a sliding plate slidably connected to the driving plate in an axial direction, and a driving plate and a sliding plate between the driving plate and the sliding plate. A centrifugal mechanism is configured with a centrifugal weight that operates to separate the sliding plate from the driving plate in the axial direction in accordance with an increase in centrifugal force, and a clutch valve is connected to the sliding plate,
Transmission case The clutch valve is moved from the clutch-off position to the clutch-on position while the sliding plate moves a predetermined distance from the closest position to the drive plate via a shift lever pivotally supported by the case, and the sliding plate moves from the closest position to the driving plate. The second feature is that the first pump ring is moved to a side where the gear ratio is decreased by further moving the sliding plate thereafter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an input shaft connected to a motor of a vehicle, and 2 denotes an output shaft connected to drive wheels of the vehicle. Both shafts 1 and 2 are coaxially arranged and have a continuously variable transmission according to the present invention. It is connected via the machine T.

At the inner end of the output shaft 2 is integrally formed a support tube 3 which concentrically surrounds the inner end of the input shaft 1. A ball bearing 4 is provided to allow relative rotation of.

The input and output shafts 1 and 2 are supported at left and right ends of a transmission case 5 accommodating the continuously variable transmission T via ball bearings 6 and 7, respectively. Is supported via a ball bearing 8 at an intermediate portion of the head. Oil seals 9 and 10 are interposed between the input and output shafts 1 and 2 and the transmission case 5 outside the ball bearings 6 and 8.

The continuously variable transmission T is constructed by interconnecting a variable capacity first radial hydraulic pump P ₁ and a constant capacity radial second hydraulic pump P ₂ via a hydraulic closed circuit. .

[0012] As shown in FIGS. 1, 2 and 6, the first hydraulic pump P ₁ is the cylinder body 12 that is coupled coaxially through a spline 11 to the input shaft 1, opened to the outer peripheral surface (Five in the illustrated example) of the first cylinder holes 13 provided in a radial arrangement as shown in FIG.
The first plungers 14 slidably fitted to the respective 3
And a first pump ring 15 surrounding the group of plungers 14 and slidably engaging with the outer ends thereof in the circumferential direction. Each first cylinder hole 13 has a first plunger 14.
1 for urging the spring in the direction of engagement with the first pump ring 15
6 are stored.

The first pump ring 15 has a boss 15a formed on one side thereof supported by the transmission case 5 via a pivot 17 parallel to the input shaft 1. The first pump ring 15 is directed to one side with respect to the cylinder body 12. Distance e ₁ (maximum eccentricity, see FIGS. 2 and 12 (a)) Eccentric first eccentric position A, and a predetermined distance e ₂ (see FIGS. 2 and 15 (a)) eccentric to the other side It can swing between the second eccentric position C and a non-eccentric position which is concentric with the cylinder body 12 between the eccentric positions A and C (see FIG. 14A).
B exists. The first and second eccentric positions A and C of the first pump ring 15 correspond to one and the other of the concave portions 18 formed on the inner peripheral wall of the transmission case 5 by the stopper arm 15 b protruding from the other side of the ring 15. It is defined by contacting the inner end wall. The first pump ring 15 is shifted between the first eccentric position A and the second eccentric position C by a centrifugal mechanism 60 described later. At each eccentric position, when the cylinder body 12 rotates, the amount of eccentricity is twice as large. A reciprocating motion is applied to each first plunger 14 with a stroke, so that the suction and discharge strokes can be repeated.

[0014] The FIGS. 7 to 9 will be described a centrifugal mechanism 60, the mechanism 60 includes a drive plate 62 which is secured by the first hydraulic pump P ₁ side end surface bis 61 of the cylinder body 12, combined with the transmission case 5 A sliding plate 64 rotatably and axially slidably supported via a resin bush 63. The bush 63 has a large diameter provided on the transmission case 5 so as to surround the bearing 6. Is mounted non-rotatably in the support hole 65. A plurality of weight pockets 66 are defined between the drive plate 62 and the slide plate 64 in the circumferential direction thereof. Each of the weight pockets 66 includes a driving plate 62 and a sliding plate 6 facing the pocket 66.
Each of the weight pockets 66 accommodates a roller-shaped centrifugal weight 67.

The transmission case 5 has two arms 7
Bell crank type shift lever 70 having 0a, 70b
And the roller 72 mounted on the first arm 70a is disposed so as to be in contact with the end surface of the cylindrical portion 64a of the sliding plate 64 supported by the bush 63. Therefore, the first arm 70a can interlock with the axial movement of the sliding plate 64 while allowing the sliding plate 64 to rotate. The second arm 70b of the shift lever 70 is arranged so as to be able to push the first pump ring 15 from the first eccentric position A to the second eccentric position C. And this shift lever 70
The lever 72 is urged by a weak spring force of a lever return spring 74 so that the roller 72 comes into contact with the end face of the cylindrical portion 64a. In order to avoid interference between the first arm 70a and the bush 63, the first arm 70a
A notch 73 allowing entry of a is provided.

On the other hand, between the first pump ring 15 and the transmission case 5, a return spring 71 for constantly urging the ring 15 toward the first eccentric position A is contracted. Thus, the centrifugal mechanism 60 is configured.

As shown in FIGS. 1 and 3, the second hydraulic pump P ₂ has a plurality (five in the illustrated example) of radially arranged second openings provided on the outer peripheral surface of the cylinder body 12.
A cylinder hole 23, a second plunger 24 slidably fitted in each of the second cylinder holes 23, and circumferentially slidably engaged with outer ends of the second plungers 24 surrounding the group of the second plungers 24. And a spring 26 that urges each second plunger 24 in the direction of engagement with the second pump ring 25 in each second cylinder hole 23.
Is stored.

The second pump ring 25 is integrally connected to the support cylinder 3 of the output shaft 2 and is a predetermined distance e ₃ (fixed eccentric amount, FIGS. 3 and 14) to one side of the cylinder body 12.
(See (a)) It is arranged to be eccentric. When the cylinder body 12 rotates, the second pump ring 25 reciprocates each second plunger 24 with a stroke twice as much as the eccentric amount of the ring 25 to repeat the suction and discharge strokes. Can be done.

As shown in FIG. 6, the outer diameter d ₁ of the first plunger 14 is set smaller than the outer diameter d ₂ of the second plunger 24. As shown in FIGS. 2 and 3, the maximum eccentricity e ₁ of the first pump ring 15 is
5 is set larger than the fixed eccentric amount e ₃ , that is, the maximum stroke of the first plunger 14 is set larger than the stroke of the second plunger 24. Thus a first maximum displacement of the hydraulic pump P ₁ and fixed capacity of the second hydraulic pump P ₂ is substantially equal to.

As shown in FIG. 1, the first hydraulic pump P ₁ and the second hydraulic pump P ₂ are arranged at one end and the other end of the cylinder body 12 so as to be separated from each other. 1 and an annular high-pressure oil passage 29 further surrounding the low-pressure oil passage 28.

The cylinder body 12 has the same number of the first cylinder holes 13, the first valve holes 31 radially extending adjacent to the inside of the first cylinder holes 13, and the second cylinder holes 23. A second valve hole 32 extending radially adjacent to the inside of the second cylinder hole group 23 is provided. Each first valve hole 31 penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A first pump port 33 extending laterally from the adjacent first cylinder hole 13 is opened on the inner surface of the valve hole 31. Each second valve hole 32 also penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A second pump port 34 extending laterally from the adjacent second cylinder hole 23 opens on the inner surface of the valve hole 32.

As shown in FIGS. 1 and 4, the first valve hole 31
A first switching valve 35 of a spool type is slidably fitted to the first switching valve 35, and a first switching ring 37 surrounding the first switching valve 35 is slidably engaged with the outer end of the first switching valve 35 in the circumferential direction. You. The first switching ring 37 is fixed to the transmission case 5 with bolts 39 at a position eccentric by a predetermined distance e _{4 with} respect to the cylinder body 12 as shown in FIG.

When the cylinder body 12 rotates, each of the first switching valves 35 engages with the first switching ring 37 due to the centrifugal force of the first switching valve 35 and the centrifugal oil pressure of the operating oil in the low-pressure oil passage 28. Kept in state. Therefore, the first switching ring 37
As the cylinder body 12 rotates, each first switching valve 35 is reciprocated between a radially inner position and an outer position of the cylinder body 12 in the radial direction.

At this time, if the first pump ring 15 occupies the first eccentric position A, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is moved by the first switching valve 35 to the low pressure oil passage. , The second pump port 34 corresponding to the second plunger 24 during the suction stroke.
Is connected to the high-pressure oil passage 29 by the first switching valve 37.

If the first pump ring 15 occupies the second eccentric position C, on the contrary, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke becomes the first switching valve 35. While communicating with the high pressure oil passage 29,
The first pump port 33 corresponding to the first plunger 14 during the suction stroke is connected to the low-pressure oil passage 28 by the first switching valve 35.

As shown in FIGS. 1 and 5, the second valve hole 32
A second switching valve 36, which is also of a spool type, is slidably fitted to the second switching valve 36, and a second switching ring 38 surrounding the second switching valve 36 is slidably engaged with the outer end of the second switching valve 36 in the circumferential direction. Is done. The second switching ring 38 is integrally connected to the second pump ring 25 and is connected to the cylinder body 12.
Are disposed so as to be eccentric with respect to a predetermined distance e ₅ .

When the cylinder body 12 rotates, each of the second switching valves 36 engages with the second switching ring 38 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the second switching ring 38
Reciprocates each second switching valve 36 between a radially inner position and an outer position of the cylinder body 12 with the relative rotation with respect to the cylinder body 12. By the second switching valve 36, the second pump port 34 corresponding to the second plunger 24 during the suction stroke is connected to the low-pressure oil passage 28, while the second pump port corresponding to the second plunger 24 during the discharge stroke. Reference numeral 34 communicates with the high-pressure oil passage 29.

In the above, the low pressure oil passage 28 and the high pressure oil passage 2
9, the first and second valve holes 31 and 32 and the first and second pump ports 33 and 34 constitute a closed hydraulic circuit that connects the first and second hydraulic pumps P ₁ and P ₂ .

Referring again to FIG. 1, the low-pressure oil passage 28 is connected to the oil reservoir 4 at the bottom of the transmission case 5 through a series of supply oil passages 40 formed on the input shaft 1 and the side wall of the transmission case 5.
Communicate with 1. An oil filter 42 is installed at the inlet of the replenishing oil passage 40, and a dust reservoir 44 communicating with the oil reservoir 41 through the through hole 43 is provided in the bottom wall of the transmission case 5.
Is provided.

1, 2, 4 and 6, the cylinder body 12 has a central block 12 b having first and second valve holes 31 and 32 and a clutch valve hole 50, and a first cylinder hole 13. The first block 12a is overlapped on the left side of the central block 12b, and the second block 12c is overlapped on the right side of the central block 12b with the second cylinder hole 23. In the illustrated example, the first side block 12 a is connected to the input shaft 1 via a spline 11. And these three blocks 12a, 12b, 12c are provided with seal rings 45, 4
6 are connected by a plurality of bolts 47. At this time, as clearly shown in FIG. 6, the high-pressure oil passage 29 has a pair of first and second annular grooves 29a and 29b formed on both end surfaces of the central block 12b, and adjacent first and second annular grooves 29a and 29b. Valve hole 31,
32, and both annular grooves 29 intersecting with the clutch valve hole 50.
The first and second annular grooves 29a and 29b are closed by the first and second side blocks 12a and 12c, respectively. Further, the first and second pump ports 33, 34 are formed in the respective opposing surfaces of the blocks 12a, 12b, 12c.

On the other hand, the low-pressure oil passage 28 is defined by an annular groove formed on the outer peripheral surface of the input shaft 1 and the inner peripheral surface of the central block 12b.

The plurality of bolts 47 are substantially arranged on an annular arrangement line of the through holes 29c so as to be alternately arranged with the plurality of through holes 29c, and the annular grooves 29a and 29b bypass these bolts 47. Therefore, it is formed in a petal shape partially curved inward in the radial direction (see FIG. 4).

The centrifugal mechanism 60 will now be described with reference to FIGS.
Will be described. The mechanism 60 includes a cylinder body 1
A drive plate 62 which is fixed by screws 61 to the first hydraulic pump P ₁ side end face of the 2, sliding plate 64 to be rotated and axially slidably supported via a synthetic resin bush 63 in the transmission case 5 The bush 63 is non-rotatably mounted in a large-diameter support hole 65 provided in the transmission case 5 so as to surround the bearing 6. A plurality of weight pockets 66 are defined between the drive plate 62 and the slide plate 64 in the circumferential direction thereof. Each weight pocket 66 has a wedge-shaped cross-section so that the distance between the drive plate 62 and the sliding plate 64 facing the pocket 66 becomes smaller toward the outside in the radial direction. Is stored. A clutch valve 51 is fixed to the sliding plate 64 and slidably fitted in an axial clutch valve hole 50 formed in the cylinder body 12. It can rotate with it.

The transmission case 5 has two arms 7
Bell crank type shift lever 70 having 0a, 70b
And the roller 72 mounted on the first arm 70a is disposed so as to be in contact with the end surface of the cylindrical portion 64a of the sliding plate 64 supported by the bush 63. The second arm 70b of the shift lever 70 is connected to the first pump ring 1
5 is arranged to be able to be pushed from the first eccentric position A to the second eccentric position C. The shift lever 70 has a first plate urging the slide plate 64 toward the drive plate 62 through a roller 72.
Return spring ₇₁₁ is connected. Therefore, the shift lever 70 allows the rotation of the slide plate 64 and swings the first pump ring 15 in conjunction with the axial movement of the plate 64. A predetermined gap 52 is provided between the second arm 70b and the ring 15 so as not to swing the ring 15 while a predetermined distance from the closest position to the second arm 70b.

The first arm 70a and the bush 63
The bush 63 is provided with a notch 73 that allows the first arm 70a to enter into the bush 63 in order to avoid interference.

On the other hand, the first pump ring 15, ₂ second return spring 71 to constantly urge the ring 15 to the first eccentric position A side connected.

The clutch valve hole 50 extends so as to intersect with the first annular groove 29 a of the high-pressure oil passage 29 and communicates with the low-pressure oil passage 28 through a bypass hole 53. The clutch valve 51 which is slidably fitted in the clutch valve hole 50 is of a spool type, and has an annular groove 54 on its outer periphery, a blind hole 55 with its open end facing the bypass hole 53 in the center, and a peripheral wall. Is provided with a horizontal hole 56 connecting the annular groove 54 and the blind hole 55, and these constitute a short-circuit path 57.

When the sliding plate 64 is closest to the driving plate 62, the clutch valve 51 makes the annular groove 54 coincide with the first annular groove 29 a of the high-pressure oil passage 29, so that the short-circuit 8 occupies a clutch-off position (the state shown in FIG. 8) for communicating between the low-pressure and high-pressure oil passages 28 and 29 via the bypass hole 53 and the shift plate 70. When the pump ring 15 starts to swing, the clutch valve 51 is
Is shifted from the first annular groove 29a of the high-pressure oil passage 29 so as to occupy a clutch-on position (the state shown in FIG. 10) in which the low-pressure and high-pressure oil passages 28 and 29 are disconnected.

Next, the operation of this embodiment will be described.

When the input shaft 1 rotates, the cylinder body 1
2, the driving plate 62, the sliding plate 64, and the centrifugal weight 67 rotate.
The centrifugal weight 67 is turned by its centrifugal force into a weight pocket.
66 in the radial direction to move the sliding plate 64 to the driving plate 6.
Idling the input shaft 1
In the region, the first return spring 71 has a small centrifugal force. ₁To
It is held at the position closest to the drive plate 62 and
Accordingly, the clutch valve 51 is in the clutch off position shown in FIG.
And a low pressure is applied through the short circuit path 57 and the bypass hole 53.
And the high pressure oil passages 28 and 29 communicate with each other.
Second hydraulic pump P₁, P_TwoNo hydraulic transmission between
No. Therefore, the handling of the vehicle by hand pushing is free
It can be carried out. This is the same when the input shaft 1 is stopped.
It is.

When the rotation of the input shaft 1 rises and exceeds the idle rotation range, the centrifugal weight 67 starts to move radially outward in the weight pocket 66 due to the increased centrifugal force.
The sliding plate 64 is moved away from the driving plate 62 against the urging force of the first return spring 71 ₁ .
Moves from the clutch-off position to the clutch-on position shown in FIG. 10, disconnects the communication between the low-pressure and high-pressure oil passages 28 and 29, and transmits the hydraulic pressure between the first and second hydraulic pumps P ₁ and P _2. To start.

At that time, the gap 52 between the second arm 70b of the shift lever 70 operated by the sliding plate 64 and the first pump ring 14 disappears, and the shift lever 70
, The operation of the first pump ring 14 becomes possible.

When the rotation of the input shaft 1 further increases, the slide plate 64 swings the shift lever 70 clockwise in FIG.
The first pump ring 15 swings toward the second eccentric position against the spring biasing force of the return spring 71, and the first pump ring 15 receives the centrifugal force of the centrifugal weight 67 and the first and second return springs 71. _1, 71 ₂ and the urging force of the stops its swing where the balance. Therefore, the first pump ring 15 is automatically shifted from the first eccentric position A to the second eccentric position C in accordance with an increase in the rotation speed of the input shaft 1.

The relationship between the eccentric position of the first pump ring 15 and the gear ratio between the input and output shafts 1 and 2 will be described with reference to FIGS. In each of the drawings, (a) is a schematic cross-sectional view of the first and second hydraulic pumps,
(B) is a development schematic diagram of the first and second hydraulic pumps P ₁ and P ₂ .

<State where the gear ratio is steplessly large (see FIG. 11)>
In this state, the first pump ring 15 is in the first eccentric position A
Is held (see FIG. 2), the capacity of the first hydraulic pump P ₁ at this time is equal to that of the second hydraulic pump P _2.

Therefore, when the input shaft 1 is rotated, the cylinder body 12 which rotates integrally therewith causes relative rotation between the first pump ring 15 and the second pump ring 25. At this time, the corresponding first plunger 14 in the discharge stroke as the first in the hydraulic pump P ₁ above 1
The pump port 33 communicates with the low-pressure oil passage 28, and the first pump port 33 corresponding to the first plunger 14 during the suction stroke communicates with the high-pressure oil passage 29.
The hydraulic oil is sucked into the low pressure oil passage 28 and discharged.

On the other hand, in the second hydraulic pump P ₂ , the second pump port 3 corresponding to the second plunger 24 during the suction stroke
4 is connected to the low-pressure oil passage 28, and the second pump port 34 corresponding to the second plunger 24 during the discharge stroke is connected to the high-pressure oil passage 29. The hydraulic oil is discharged to the passage 29.

In addition, since the capacity of both hydraulic pumps P ₁ and P ₂ is equal, the entire amount of hydraulic oil discharged from the first hydraulic pump P ₁ to the low-pressure oil passage 28 during one rotation of the cylinder body 12 is reduced by the _second hydraulic pump P _1. P ₂ and the second hydraulic pump P ₂
There will be the total amount of the hydraulic oil to be discharged to the high pressure oil passage 29 is sucked into the first hydraulic pump P _1. Therefore, the first and second plungers 14 and 24 repeat reciprocating motions, respectively. The first and second plungers 14 and 24 merely slide on the inner peripheral surfaces of the first and second pump rings 15 and 25 and do not generate a rotational torque, so that the output shaft is not generated. 2 keeps the stopped state.

<State where the gear ratio is 2, for example (see FIG. 12)> The first pump ring 15 is at an intermediate position between the first eccentric position A (see FIG. 2) and the non-eccentric position B, that is, the position where the eccentric amount is en. Once shifted, the capacity of the first hydraulic pump P ₁ is controlled to half the capacity of the second hydraulic pump P _2. As a result, during one rotation of the cylinder body 12, the first
Amount of hydraulic oil hydraulic pump P ₁ is sucked from the high-pressure oil passage 29, second because hydraulic pump P ₂ is half of the amount of hydraulic oil to discharge the high pressure oil passage 29, the second hydraulic pump P ₂ is the other half The reaction force generated when the hydraulic oil is discharged acts on the second pump ring 25 from the second plunger 24 during the discharge stroke, and rotates the output shaft 2 via the ring 25. As a result, during one rotation of the input shaft 1, the output shaft 2 makes a half rotation.

<State where the gear ratio is 1 (see FIG. 13)>
When the pump ring 15 is shifted to the non-eccentric position B (see FIG. 2), the first volume of the hydraulic pump P ₁ is controlled to zero. When this occurs, hydraulic fluid second hydraulic pump P ₂ is discharged to the high pressure oil passage 29 is not at all taken into the first hydraulic pump P _1, to lose nowhere to go, all the second plunger 24
Is in a hydraulic lock state, and the cylinder body 12 and the second
As a result, the input and output shafts 1 and 2 are integrally connected by the pump ring 25, so that both shafts 1 and 2 rotate at the same speed.

<State where the gear ratio is 0.66 (FIG. 14)
The first pump ring 15 is in the second eccentric position C (see FIG. 2).
When shifted to the reference), the suction region and the discharge region of the first hydraulic pump P _1, together with the reverse of the past, its capacity is controlled to half the capacity of the second hydraulic pump P ₂ You. If this occurs, during one rotation of the cylinder body 12, with a capacity of 2 minutes of the first hydraulic pump P ₁ in the second hydraulic pump P _2, the first plunger 14 in the discharge stroke
From the corresponding first pump port 33 to the high-pressure oil passage 29
Discharging hydraulic oil to the second corresponding to the second plunger 24 that were in the discharge stroke in the second hydraulic pump P ₂ until it
Since the second plunger 24 is supplied to the pump port 34, the second plunger 24 moves to the expansion stroke, and the second pump ring 25 is accelerated by a half rotation in the rotation direction of the cylinder body 12 by the expansion thrust. After all, the gear ratio is 1: 1.
5 = 0.66, and the vehicle is in the speed increasing state.

As is clear from the above, the centrifugal mechanism 60
Since the clutch valve 51 and the first pump ring 15 are sequentially operated in accordance with the increase in the rotation speed of the input shaft 1, the start and the speed change can be performed automatically and accurately. Moreover, by shifting the first pump ring 15 from the first eccentric position A to the second eccentric position C steplessly, the speed ratio can be steplessly controlled from infinity (neutral state) to a speed increasing state. At high speeds, overdrive is enabled to reduce fuel consumption.

While the cylinder body 12 is rotating, the oil sump 41
Is sucked from the replenishing oil passage 40 to the low-pressure oil passage 28 by the action of centrifugal force and is stored. Therefore, leaks of hydraulic oil from the sliding surfaces of the first and second plungers 14 and 24 and the first and second switching valves 35 and 36 are immediately supplied from the low-pressure oil passage 28.

Incidentally, the continuously variable transmission T is
Al-type first and second hydraulic pumps P ₁, P_TwoThe common
Since it is constructed on the Linda body 12,
Combination of conventional axial type hydraulic pump and motor
Compared with, the axial dimension is greatly reduced, making it more compact.
Can be planned. Moreover, as described above, the first pump
Gear ratio can be increased from infinity by simply shifting ring 15
Since it can be controlled in a continuous manner up to the speed state,
The range of application to both is extremely wide.

The support cylinder 3 formed at the inner end of the output shaft 2 is supported by a transmission case 5 via a ball bearing 4, and the support cylinder 3 connects the inner end of the input shaft 1 via a ball bearing 7. Since the bearings are supported, the inner ends of the two shafts 1 and 2 can be firmly supported by the transmission case 5 within a small axial space, and the supporting rigidity can be increased. In addition, since the second pump ring 25 is integrally connected to the support cylinder 3, the thrust of the second plunger 24 and its reaction force can be supported between the support cylinder 3 and the input shaft 1. 5 can be reduced, and its thickness and weight can be reduced.

Further, the cylinder body 12 has first and second cylinder bodies.
The central block 12b having the valve holes 31 and 32 and the clutch valve hole 50, the first block 12a having the first cylinder hole 13, and the second block 12c having the second cylinder hole 23 are divided into three blocks. First and second annular grooves 29a and 29b formed on the joint surface of the block
And a plurality of annularly arranged through holes 2 formed in the central block 12b so as to communicate between the annular grooves 29a and 29b and to intersect the first and second valve holes 31 and 32 and the clutch valve hole 50.
9c, an annular high-pressure oil passage 29 is formed, and the first and second pump ports 33, 34 are formed in the joint surfaces of the three blocks 12a, 12b, 12c. , 34 can be easily formed and no blind plug is required.

On the other hand, since the low-pressure oil passage 28 is formed by an annular groove formed on the peripheral surface of the input shaft 1 and the central block 12b opposed to each other, the formation can be easily performed.

The three blocks 12a, 12b, 12
c are joined to each other by a plurality of bolts 39 substantially arranged on the annular arrangement line of the plurality of through holes 29c.
Since the second annular grooves 29a and 29b are partially formed in a petal shape curved inward in the radial direction, the cylinder body 12
Can be prevented from interfering with the bolt 39 and the high-pressure oil passage 29.

FIG. 15 shows another embodiment of the present invention. The structure of the clutch valve 51 and the oil passage opened and closed by the clutch valve 51 are different from those of the previous embodiment. That is, the first high pressure oil passage 29
A relief hole 58 that opens to the outside of the cylinder body 5, that is, the oil reservoir 41, intersects an intermediate portion of the clutch valve hole 50 communicating with the annular groove 29 a. The clutch valve 51 is provided with a blind hole 55 whose open end faces the first annular groove 29a, and a lateral hole 56 penetrating the peripheral wall. Thus, the sliding plate 6
At the clutch off position occupied by the clutch valve 51 when the valve 4 is closest to the drive plate 62, the horizontal hole 56 communicates with the escape hole 58 to discharge the high pressure in the high pressure oil passage 29 to the oil reservoir 41, and the first and the second The hydraulic transmission between the hydraulic pumps P ₁ and P ₂ is disabled, and when the sliding plate 64 is separated from the driving plate 62 by a predetermined distance, the lateral hole 56 is located at the clutch-on position occupied by the clutch valve 51.
The communication between the first and second hydraulic pumps P ₁ and P ₂ is enabled by interrupting the communication between the first and second hydraulic pumps P ₁ and P ₂ by blocking the communication between the first and second hydraulic pumps P ₁ and P ₂ by interrupting the communication between the first and second hydraulic pumps.

Since other structures are the same as those of the previous embodiment, the same reference numerals in the drawings denote the same parts as in the previous embodiment, and a description thereof will be omitted.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention. For example, the centrifugal weight 67 is
It is also possible to adopt a pendulum type that is pivotally supported at 2. Further, the first side block 12a can be formed integrally with the input shaft 1.

[0062]

As described above, according to the first aspect of the present invention, the input shaft and the output shaft are coaxially supported on the transmission case, and the cylinder body fixed to the input shaft is provided. And a plurality of first plungers radially disposed around the first plungers, the first plungers surround the first plungers and are relatively movably engaged with their outer ends, and reciprocate each first plunger with rotation of the cylinder body. In addition, in order to adjust the reciprocating stroke, a first pump ring rotatably supported by a transmission case constitutes a radial type first hydraulic pump having a variable capacity. A plurality of second plungers radially arranged, and a plurality of second plungers fixed to the output shaft;
A second pump ring which surrounds the plungers and movably engages with the outer ends thereof, and reciprocates a fixed stroke to each second plunger with the relative rotation with the cylinder body. 2 constitute a hydraulic pump,
The cylinder body has a high-pressure oil passage through which hydraulic oil is sucked into the first hydraulic pump and hydraulic oil is discharged from the second hydraulic pump, and a hydraulic oil is discharged from the first hydraulic pump to the second hydraulic pump. The provision of the low-pressure oil passage through which the hydraulic oil is sucked allows the provision of a compact continuously variable transmission having a smaller axial dimension as compared with a conventional combination of an axial hydraulic pump and a hydraulic motor. .

The cylinder body further includes a clutch valve that moves between a clutch-off position that connects the high-pressure oil passage to the low-pressure oil passage or the oil reservoir and a clutch-on position that disconnects the communication.
A centrifugal mechanism that operates the clutch valve from the clutch-off position to the clutch-on position in response to an increase in the rotation speed of the input shaft, and further operates the first pump ring to control the reciprocating stroke of the first plunger in a direction in which the gear ratio decreases. Is provided, the starting and shifting can be automatically performed by one centrifugal mechanism in accordance with an increase in the rotation speed of the input shaft. According to the second aspect of the present invention, the starting and shifting are fixed to the cylinder body. A driving plate, a sliding plate connected to the driving plate in an axially slidable manner, and a sliding plate provided between the driving plate and the sliding plate. A centrifugal mechanism is constituted by a centrifugal weight that operates so as to be separated from the first pump ring via a shift lever pivotally supported by a transmission case, while connecting a clutch valve to a sliding plate, Sliding plate The clutch valve is moved from the clutch-off position to the clutch-on position while moving a predetermined distance from the closest position to the moving plate, and then the first pump ring is actuated to a lower gear ratio side by further movement of the sliding plate. Since the clutch valve and the first pump ring are sequentially operated by a simple centrifugal mechanism, starting and shifting can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a continuously variable transmission according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional front view taken along line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a partially enlarged view of FIG. 1;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 1;

FIG. 8 is an enlarged view of a portion 8 in FIG. 1 showing a clutch-off state.

9 is a sectional view taken along line 9-9 in FIG.

FIG. 10 is an enlarged view of a portion 8 in FIG. 1 showing a clutch-on state.

FIG. 11 is an explanatory diagram of an operation in an infinite speed ratio state.

FIG. 12 is an explanatory diagram of an operation in a state of a gear ratio 2;

FIG. 13 is an explanatory diagram of an operation in a state of a gear ratio 1;

FIG. 14 is an operation explanatory view in a state of a gear ratio of 0.66.

FIG. 15 is a sectional view showing another embodiment of the present invention and corresponding to FIG. 8;

[Explanation of symbols]

1 ... input shaft 2 ... output shaft 3 ... support cylinder 5 ... transmission case 12 ... cylinder body 13 ... first cylinder hole 14 ... ... 1st plunger 15 ... 1st pump ring 23 ... 2nd cylinder hole 24 ... 2nd plunger 28 ... low pressure oil passage 29 ... high pressure oil passage 41 ··· Oil reservoir 51 ··· Clutch valve 60 ··· Centrifugal mechanism 62 ··· Driving plate 64 ··· Sliding plate 66 ··· Weight pocket 67 ··· Centrifugal weight 70 shift lever 71 ₁ first return spring 71 ₂ second return spring P ₁ first hydraulic pump P ₂ second hydraulic pump T・ Continuously variable transmission

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 30, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Continuously variable transmission

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuously variable transmission mainly applied to vehicles such as motorcycles and automobiles.

[0002]

2. Description of the Related Art As a continuously variable transmission, for example, Japanese Patent Publication No. 7-2
As disclosed in Japanese Patent No. 6676, there is known an axial hydraulic pump having a fixed capacity and an axial hydraulic motor having a variable capacity which are coaxially arranged and connected via a hydraulic closed circuit.

[0003]

In the continuously variable transmission as described above, the axial type hydraulic pump and the hydraulic motor, which extend relatively long in the axial direction, are arranged in the axial direction. And it is difficult to make it compact.

The present invention has been made in view of such circumstances, and has a compact configuration in which the axial dimension is greatly reduced, and automatically starts and shifts according to changes in the rotation speed of the input shaft. It is an object of the present invention to provide a continuously variable transmission that can be controlled at a constant speed.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a transmission case in which an input shaft and an output shaft are coaxially supported on a transmission case, and a cylinder body fixed to the input shaft is provided. A plurality of first plungers radially disposed on the body, and surrounding the first plungers so as to relatively movably engage with their outer ends, and reciprocate with each of the first plungers as the cylinder body rotates. Give
In order to adjust the reciprocating stroke, a radial type first hydraulic pump having a variable capacity is constituted by a first pump ring which is rotatably supported by a transmission case. A plurality of second plungers are fixed to the output shaft, surround the second plungers and engage with their outer ends so as to be relatively movable. A second hydraulic pump having a fixed capacity is constituted by a second pump ring that provides a reciprocating motion of a constant stroke to the two plungers, and a first hydraulic pump sucks working oil into the cylinder body and a second hydraulic pump into the cylinder body. And a low-pressure oil passage through which hydraulic oil is discharged from the first hydraulic pump and hydraulic oil is sucked into the second hydraulic pump. A clutch valve that moves between a clutch-off position that connects the high-pressure oil passage to the low-pressure oil passage or the oil reservoir and a clutch-on position that cuts off the communication; To the clutch-on position, and further reduce the gear ratio to the first position.
A first feature is that a centrifugal mechanism that operates a first pump ring to control a reciprocating stroke of the plunger is provided.

In addition to the above features, the present invention provides a driving plate fixed to a cylinder body, a sliding plate slidably connected to the driving plate in an axial direction, and a driving plate and a sliding plate between the driving plate and the sliding plate. A centrifugal mechanism is configured with a centrifugal weight that operates to separate the sliding plate from the driving plate in the axial direction in accordance with an increase in centrifugal force, and a clutch valve is connected to the sliding plate,
Transmission case The clutch valve is moved from the clutch-off position to the clutch-on position while the sliding plate moves a predetermined distance from the closest position to the drive plate via a shift lever pivotally supported by the case, and the sliding plate moves from the closest position to the driving plate. The second feature is that the first pump ring is moved to a side where the gear ratio is decreased by further moving the sliding plate thereafter.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an input shaft connected to a motor of a vehicle, and 2 denotes an output shaft connected to drive wheels of the vehicle. Both shafts 1 and 2 are coaxially arranged and have a continuously variable transmission according to the present invention. It is connected via the machine T.

At the inner end of the output shaft 2 is integrally formed a support tube 3 which concentrically surrounds the inner end of the input shaft 1. A ball bearing 4 is provided to allow relative rotation of.

The input and output shafts 1 and 2 are supported at left and right ends of a transmission case 5 accommodating the continuously variable transmission T via ball bearings 6 and 7, respectively. Is supported via a ball bearing 8 at an intermediate portion of the head. Oil seals 9 and 10 are interposed between the input and output shafts 1 and 2 and the transmission case 5 outside the ball bearings 6 and 8.

The continuously variable transmission T is constructed by interconnecting a variable capacity first radial hydraulic pump P ₁ and a constant capacity radial second hydraulic pump P ₂ via a hydraulic closed circuit. .

[0012] As shown in FIGS. 1, 2 and 6, the first hydraulic pump P ₁ is the cylinder body 12 that is coupled coaxially through a spline 11 to the input shaft 1, opened to the outer peripheral surface (Five in the illustrated example) of the first cylinder holes 13 provided in a radial arrangement as shown in FIG.
The first plungers 14 slidably fitted to the respective 3
And a first pump ring 15 surrounding the group of plungers 14 and slidably engaging with the outer ends thereof in the circumferential direction. Each first cylinder hole 13 has a first plunger 14.
1 for urging the spring in the direction of engagement with the first pump ring 15
6 are stored.

The first pump ring 15 has a boss 15a formed on one side thereof supported by the transmission case 5 via a pivot 17 parallel to the input shaft 1. The first pump ring 15 is directed to one side with respect to the cylinder body 12. Distance e ₁ (maximum eccentricity, see FIGS. 2 and 12 (a)) Eccentric first eccentric position A, and a predetermined distance e ₂ (see FIGS. 2 and 15 (a)) eccentric to the other side It can swing between the second eccentric position C and a non-eccentric position which is concentric with the cylinder body 12 between the eccentric positions A and C (see FIG. 14A).
B exists. The first and second eccentric positions A and C of the first pump ring 15 correspond to one and the other of the concave portions 18 formed on the inner peripheral wall of the transmission case 5 by the stopper arm 15 b protruding from the other side of the ring 15. It is defined by contacting the inner end wall. The first pump ring 15 is shifted between the first eccentric position A and the second eccentric position C by a centrifugal mechanism 60 described later. At each eccentric position, when the cylinder body 12 rotates, the amount of eccentricity is twice as large. with stroke gives reciprocate in the first plunger 14, Ru can be repeating give a suction and discharge stroke.

As shown in FIGS. 1 and 3, the second hydraulic pump P ₂ has a plurality (five in the illustrated example) of radially arranged second openings provided on the outer peripheral surface of the cylinder body 12.
A cylinder hole 23, a second plunger 24 slidably fitted in each of the second cylinder holes 23, and circumferentially slidably engaged with outer ends of the second plungers 24 surrounding the group of the second plungers 24. And a spring 26 that urges each second plunger 24 in the direction of engagement with the second pump ring 25 in each second cylinder hole 23.
Is stored.

The second pump ring 25 is integrally connected to the support cylinder 3 of the output shaft 2 and is a predetermined distance e ₃ (fixed eccentricity, FIGS. 3 and 14) to one side of the cylinder body 12.
(See (a)) It is arranged to be eccentric. When the cylinder body 12 rotates, the second pump ring 25 reciprocates each second plunger 24 with a stroke twice as much as the eccentric amount of the ring 25 to repeat the suction and discharge strokes. Can be done.

As shown in FIG. 6, the outer diameter d ₁ of the first plunger 14 is set smaller than the outer diameter d ₂ of the second plunger 24. As shown in FIGS. 2 and 3, the maximum eccentricity e ₁ of the first pump ring 15 is
5 is set larger than the fixed eccentric amount e ₃ , that is, the maximum stroke of the first plunger 14 is set larger than the stroke of the second plunger 24. Thus a first maximum displacement of the hydraulic pump P ₁ and fixed capacity of the second hydraulic pump P ₂ is substantially equal to.

As shown in FIG. 1, the first hydraulic pump P ₁ and the second hydraulic pump P ₂ are arranged at one end and the other end of the cylinder body 12 so as to be separated from each other. 1 and an annular high-pressure oil passage 29 further surrounding the low-pressure oil passage 28.

The cylinder body 12 has the same number of the first cylinder holes 13 as the first valve holes 31 radially extending adjacent to the inside of the first cylinder hole 13 group and the second cylinder holes 23. A second valve hole 32 extending radially adjacent to the inside of the second cylinder hole group 23 is provided. Each first valve hole 31 penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A first pump port 33 extending laterally from the adjacent first cylinder hole 13 is opened on the inner surface of the valve hole 31. Each second valve hole 32 also penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A second pump port 34 extending laterally from the adjacent second cylinder hole 23 opens on the inner surface of the valve hole 32.

As shown in FIGS. 1 and 4, the first valve hole 31
A first switching valve 35 of a spool type is slidably fitted to the first switching valve 35, and a first switching ring 37 surrounding the first switching valve 35 is slidably engaged with the outer end of the first switching valve 35 in the circumferential direction. You. The first switching ring 37 is fixed to the transmission case 5 with bolts 39 at a position eccentric by a predetermined distance e _{4 with} respect to the cylinder body 12 as shown in FIG.

When the cylinder body 12 rotates, each of the first switching valves 35 engages with the first switching ring 37 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the first switching ring 37
As the cylinder body 12 rotates, each first switching valve 35 is reciprocated between a radially inner position and an outer position of the cylinder body 12 in the radial direction.

At this time, if the first pump ring 15 occupies the first eccentric position A, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is moved by the first switching valve 35 to the low pressure oil passage. , The second pump port 34 corresponding to the second plunger 24 during the suction stroke.
Is connected to the high-pressure oil passage 29 by the first switching valve 37.

If the first pump ring 15 occupies the second eccentric position C, on the contrary, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is connected to the first switching valve 35. While communicating with the high pressure oil passage 29,
The first pump port 33 corresponding to the first plunger 14 during the suction stroke is connected to the low-pressure oil passage 28 by the first switching valve 35.

As shown in FIGS. 1 and 5, the second valve hole 32
A second switching valve 36, which is also of a spool type, is slidably fitted to the second switching valve 36, and a second switching ring 38 surrounding the second switching valve 36 is slidably engaged with the outer end of the second switching valve 36 in the circumferential direction. Is done. The second switching ring 38 is integrally connected to the second pump ring 25 and is connected to the cylinder body 12.
Are disposed so as to be eccentric with respect to a predetermined distance e ₅ .

When the cylinder body 12 rotates, each second switching valve 36 engages with the second switching ring 38 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the second switching ring 38
Reciprocates each second switching valve 36 between a radially inner position and an outer position of the cylinder body 12 with the relative rotation with respect to the cylinder body 12. By the second switching valve 36, the second pump port 34 corresponding to the second plunger 24 during the suction stroke is connected to the low-pressure oil passage 28, while the second pump port corresponding to the second plunger 24 during the discharge stroke. Reference numeral 34 communicates with the high-pressure oil passage 29.

In the above, the low pressure oil passage 28 and the high pressure oil passage 2
9, the first and second valve holes 31 and 32 and the first and second pump ports 33 and 34 constitute a closed hydraulic circuit that connects the first and second hydraulic pumps P ₁ and P ₂ .

Referring again to FIG. 1, the low-pressure oil passage 28 is connected to the oil reservoir 4 at the bottom of the transmission case 5 through a series of supply oil passages 40 formed on the input shaft 1 and the side wall of the transmission case 5.
Communicate with 1. An oil filter 42 is installed at the inlet of the replenishing oil passage 40, and a dust reservoir 44 communicating with the oil reservoir 41 through the through hole 43 is provided in the bottom wall of the transmission case 5.
Is Ru provided.

[0027] is, the centrifugal mechanism 60 by 7 to 9
Will be described. The mechanism 60 includes a cylinder body 1
A drive plate 62 which is fixed by screws 61 to the first hydraulic pump P ₁ side end face of the 2, sliding plate 64 to be rotated and axially slidably supported via a synthetic resin bush 63 in the transmission case 5 The bush 63 is non-rotatably mounted in a large-diameter support hole 65 provided in the transmission case 5 so as to surround the bearing 6. A plurality of weight pockets 66 are defined between the drive plate 62 and the slide plate 64 in the circumferential direction thereof. Each weight pocket 66 has a wedge-shaped cross-section so that the distance between the drive plate 62 and the sliding plate 64 facing the pocket 66 becomes smaller toward the outside in the radial direction. Is stored. A clutch valve 51 is fixed to the sliding plate 64 and slidably fitted in an axial clutch valve hole 50 formed in the cylinder body 12. It can rotate with it.

The transmission case 5 includes two arms 7
Bell crank type shift lever 70 having 0a, 70b
And the roller 72 mounted on the first arm 70a is disposed so as to be in contact with the end surface of the cylindrical portion 64a of the sliding plate 64 supported by the bush 63. The second arm 70b of the shift lever 70 is connected to the first pump ring 1
5 is arranged to be able to be pushed from the first eccentric position A to the second eccentric position C. The shift lever 70 has a first plate urging the slide plate 64 toward the drive plate 62 through a roller 72.
Return spring ₇₁₁ is connected. Therefore, the shift lever 70 allows the rotation of the slide plate 64 and swings the first pump ring 15 in conjunction with the axial movement of the plate 64. A predetermined gap 52 is provided between the second arm 70b and the ring 15 so as not to swing the ring 15 while a predetermined distance from the closest position to the second arm 70b.

The first arm 70a and the bush 63
The bush 63 is provided with a notch 73 that allows the first arm 70a to enter into the bush 63 in order to avoid interference.

On the other hand, the first pump ring 15, ₂ second return spring 71 to constantly urge the ring 15 to the first eccentric position A side connected.

The clutch valve hole 50 extends so as to intersect with the first annular groove 29 a of the high-pressure oil passage 29 and communicates with the low-pressure oil passage 28 via a bypass hole 53. The clutch valve 51 which is slidably fitted in the clutch valve hole 50 is of a spool type, and has an annular groove 54 on its outer periphery, a blind hole 55 with its open end facing the bypass hole 53 in the center, and a peripheral wall. Is provided with a horizontal hole 56 connecting the annular groove 54 and the blind hole 55, and these constitute a short-circuit path 57.

When the sliding plate 64 is closest to the driving plate 62, the clutch valve 51 makes the annular groove 54 coincide with the first annular groove 29 a of the high-pressure oil passage 29, so that the short-circuit 8 occupies a clutch-off position (the state shown in FIG. 8) for communicating between the low-pressure and high-pressure oil passages 28 and 29 via the bypass hole 53 and the shift plate 70. When the pump ring 15 starts to swing, the clutch valve 51 is
Is shifted from the first annular groove 29a of the high-pressure oil passage 29 so as to occupy a clutch-on position (the state shown in FIG. 10) in which the low-pressure and high-pressure oil passages 28 and 29 are interrupted.

In FIG . 1, FIG. 2, FIG. 4 and FIG.
The body 12 is provided with first and second valve holes 31 and 32 and a clutch.
H. Central block 12b having valve hole 50, first cylinder
It has a hole 13 and is superimposed on the left side of the central block 12b.
Having a first side block 12 a and a second cylinder hole 23.
And the second side block superimposed on the right side of the central block 12b.
Lock 12c is divided into three blocks.
In the illustrated example, the first side block 12a is connected to the input shaft 1.
They are connected via splines 11. And these three
The locks 12a, 12b, 12c are seal rings 45, 4
6 are connected by a plurality of bolts 47. That
At this time, as clearly shown in FIG.
A pair of first and second rings formed on both end surfaces of the lock 12b.
Grooves 29a, 29b and adjacent first and second valve holes 31,
32, and both annular grooves 29 intersecting with the clutch valve hole 50.
a, 29b and a plurality of through holes 29c in an annular arrangement communicating with each other.
And open surfaces of the first and second annular grooves 29a and 29b.
By the first and second side blocks 12a and 12c, respectively.
Closed. Also, the first and second pump ports 33, 34
Drilled on each opposing surface of the blocks 12a, 12b, 12c
You.

On the other hand, the low-pressure oil passage 28 is provided on the outer peripheral surface of the input shaft 1.
Between the annular groove formed in the center block and the inner peripheral surface of the central block 12b.
Is done.

The plurality of bolts 47 are connected to the plurality of through holes.
The annular arrangement of these through holes 29c is alternately arranged with the through holes 29c.
The annular grooves 29a and 29b are substantially arranged on the
Partially radially inward to bypass these bolts 47
It is formed in a curved petal shape (see FIG. 4).

Next, the operation of this embodiment will be described.

When the input shaft 1 rotates, the cylinder body 1
2, the driving plate 62, the sliding plate 64, and the centrifugal weight 67 rotate.
The centrifugal weight 67 is turned by its centrifugal force into a weight pocket.
66 in the radial direction to move the sliding plate 64 to the driving plate 6.
Idling the input shaft 1
In the region, the first return spring 71 has a small centrifugal force. ₁To
It is held at the position closest to the drive plate 62 and
Accordingly, the clutch valve 51 is in the clutch off position shown in FIG.
And a low pressure is applied through the short circuit path 57 and the bypass hole 53.
And the high pressure oil passages 28 and 29 communicate with each other.
Second hydraulic pump P₁, P_TwoNo hydraulic transmission between
No. Therefore, the handling of the vehicle by hand pushing is free
It can be carried out. This is the same when the input shaft 1 is stopped.
It is.

When the rotation of the input shaft 1 rises and exceeds the idle rotation range, the centrifugal weight 67 starts moving radially outward in the weight pocket 66 due to the increased centrifugal force.
The sliding plate 64 is moved away from the driving plate 62 against the urging force of the first return spring 71 ₁ .
Moves from the clutch-off position to the clutch-on position shown in FIG. 10, disconnects the communication between the low-pressure and high-pressure oil passages 28 and 29, and transmits the hydraulic pressure between the first and second hydraulic pumps P ₁ and P _2. To start.

At that time, the gap 52 between the second arm 70b of the shift lever 70 operated by the sliding plate 64 and the first pump ring 14 disappears, and the shift lever 70
, The operation of the first pump ring 14 becomes possible.

When the rotation of the input shaft 1 further increases, the slide plate 64 swings the shift lever 70 clockwise in FIG.
The first pump ring 15 swings toward the second eccentric position against the spring biasing force of the return spring 71, and the first pump ring 15 receives the centrifugal force of the centrifugal weight 67 and the first and second return springs 71. _1, 71 ₂ and the urging force of the stops its swing where the balance. Therefore, the first pump ring 15 is automatically shifted from the first eccentric position A to the second eccentric position C in accordance with an increase in the rotation speed of the input shaft 1.

The relationship between the eccentric position of the first pump ring 15 and the gear ratio between the input and output shafts 1 and 2 will be described with reference to FIGS. In each of the drawings, (a) is a schematic cross-sectional view of the first and second hydraulic pumps,
(B) is a development schematic diagram of the first and second hydraulic pumps P ₁ and P ₂ .

<State where the gear ratio is steplessly large (see FIG. 11)>
In this state, the first pump ring 15 is in the first eccentric position A
Is held (see FIG. 2), the capacity of the first hydraulic pump P ₁ at this time is equal to that of the second hydraulic pump P _2.

Therefore, when the input shaft 1 is rotated, the cylinder body 12 which rotates integrally therewith causes relative rotation between the first pump ring 15 and the second pump ring 25. At this time, the corresponding first plunger 14 in the discharge stroke as the first in the hydraulic pump P ₁ above 1
The pump port 33 communicates with the low-pressure oil passage 28, and the first pump port 33 corresponding to the first plunger 14 during the suction stroke communicates with the high-pressure oil passage 29.
The hydraulic oil is sucked into the low pressure oil passage 28 and discharged.

On the other hand, in the second hydraulic pump P ₂ , the second pump port 3 corresponding to the second plunger 24 during the suction stroke
4 is connected to the low-pressure oil passage 28, and the second pump port 34 corresponding to the second plunger 24 during the discharge stroke is connected to the high-pressure oil passage 29. The hydraulic oil is discharged to the passage 29.

In addition, since the capacities of the two hydraulic pumps P ₁ and P ₂ are equal, the entire hydraulic oil discharged from the first hydraulic pump P ₁ to the low-pressure oil passage 28 during one rotation of the cylinder body 12 is reduced by the _second hydraulic pump P _1. P ₂ and the second hydraulic pump P ₂
There will be the total amount of the hydraulic oil to be discharged to the high pressure oil passage 29 is sucked into the first hydraulic pump P _1. Therefore, the first and second plungers 14 and 24 repeat reciprocating motions, respectively. The first and second plungers 14 and 24 merely slide on the inner peripheral surfaces of the first and second pump rings 15 and 25 and do not generate a rotational torque, so that the output shaft is not generated. 2 keeps the stopped state.

<State where the gear ratio is 2, for example (see FIG. 12)> The first pump ring 15 is at an intermediate position between the first eccentric position A (see FIG. 2) and the non-eccentric position B, that is, the position where the eccentric amount is en. Once shifted, the capacity of the first hydraulic pump P ₁ is controlled to half the capacity of the second hydraulic pump P _2. As a result, during one rotation of the cylinder body 12, the first
Amount of hydraulic oil hydraulic pump P ₁ is sucked from the high-pressure oil passage 29, second because hydraulic pump P ₂ is half of the amount of hydraulic oil to discharge the high pressure oil passage 29, the second hydraulic pump P ₂ is the other half The reaction force generated when the hydraulic oil is discharged acts on the second pump ring 25 from the second plunger 24 during the discharge stroke, and rotates the output shaft 2 via the ring 25. As a result, during one rotation of the input shaft 1, the output shaft 2 makes a half rotation.

<State where the gear ratio is 1 (see FIG. 13)>
When the pump ring 15 is shifted to the non-eccentric position B (see FIG. 2), the first volume of the hydraulic pump P ₁ is controlled to zero. When this occurs, hydraulic fluid second hydraulic pump P ₂ is discharged to the high pressure oil passage 29 is not at all taken into the first hydraulic pump P _1, to lose nowhere to go, all the second plunger 24
Is in a hydraulic lock state, and the cylinder body 12 and the second
As a result, the input and output shafts 1 and 2 are integrally connected by the pump ring 25, so that both shafts 1 and 2 rotate at the same speed.

<A state where the gear ratio is, for example, 0.66 (FIG. 14)
The first pump ring 15 is in the second eccentric position C (see FIG. 2).
When shifted to the reference), the suction region and the discharge region of the first hydraulic pump P _1, together with the reverse of the past, its capacity is controlled to half the capacity of the second hydraulic pump P ₂ You. If this occurs, during one rotation of the cylinder body 12, with a capacity of 2 minutes of the first hydraulic pump P ₁ in the second hydraulic pump P _2, the first plunger 14 in the discharge stroke
From the corresponding first pump port 33 to the high-pressure oil passage 29
Discharging hydraulic oil to the second corresponding to the second plunger 24 that were in the discharge stroke in the second hydraulic pump P ₂ until it
Since the second plunger 24 is supplied to the pump port 34, the second plunger 24 moves to the expansion stroke, and the second pump ring 25 is accelerated by a half rotation in the rotation direction of the cylinder body 12 by the expansion thrust. After all, the gear ratio is 1: 1.
5 = 0.66, and the vehicle is in the speed increasing state.

As is clear from the above, the centrifugal mechanism 60
Since the clutch valve 51 and the first pump ring 15 are sequentially operated in accordance with the increase in the rotation speed of the input shaft 1, the start and the speed change can be performed automatically and accurately. Moreover, by shifting the first pump ring 15 from the first eccentric position A to the second eccentric position C steplessly, the speed ratio can be steplessly controlled from infinity (neutral state) to a speed increasing state. At high speeds, overdrive is enabled to reduce fuel consumption.

While the cylinder body 12 is rotating, the oil sump 41
Is sucked from the replenishing oil passage 40 to the low-pressure oil passage 28 by the action of centrifugal force and is stored. Therefore, leaks of hydraulic oil from the sliding surfaces of the first and second plungers 14 and 24 and the first and second switching valves 35 and 36 are immediately supplied from the low-pressure oil passage 28.

Incidentally, the continuously variable transmission T is
Al-type first and second hydraulic pumps P ₁, P_TwoThe common
Since it is constructed on the Linda body 12,
Combination of conventional axial type hydraulic pump and motor
Compared with, the axial dimension is greatly reduced, making it more compact.
Can be planned. Moreover, as described above, the first pump
Gear ratio can be increased from infinity by simply shifting ring 15
Since it can be controlled in a continuous manner up to the speed state,
The range of application to both is extremely wide.

The support cylinder 3 formed at the inner end of the output shaft 2 is supported by a transmission case 5 via a ball bearing 4, and the support cylinder 3 connects the inner end of the input shaft 1 via a ball bearing 7. Since the bearings are supported, the inner ends of the two shafts 1 and 2 can be firmly supported by the transmission case 5 within a small axial space, and the supporting rigidity can be increased. In addition, since the second pump ring 25 is integrally connected to the support cylinder 3, the thrust of the second plunger 24 and its reaction force can be supported between the support cylinder 3 and the input shaft 1. 5 can be reduced, and its thickness and weight can be reduced.

Further, the cylinder body 12 includes first and second cylinders.
The central block 12b having the valve holes 31 and 32 and the clutch valve hole 50, the first block 12a having the first cylinder hole 13, and the second block 12c having the second cylinder hole 23 are divided into three blocks. First and second annular grooves 29a and 29b formed on the joint surface of the block
And a plurality of annularly arranged through holes 2 formed in the central block 12b so as to communicate between the annular grooves 29a and 29b and to intersect the first and second valve holes 31 and 32 and the clutch valve hole 50.
9c, an annular high-pressure oil passage 29 is formed, and the first and second pump ports 33, 34 are formed in the joint surfaces of the three blocks 12a, 12b, 12c. , 34 can be easily formed and no blind plug is required.

On the other hand, since the low-pressure oil passage 28 is formed by an annular groove formed on the peripheral surface of the input shaft 1 and the central block 12b facing each other, it can be easily formed.

The three blocks 12a, 12b, 12
c are joined to each other by a plurality of bolts 39 substantially arranged on the annular arrangement line of the plurality of through holes 29c.
Since the second annular grooves 29a and 29b are partially formed in a petal shape curved inward in the radial direction, the cylinder body 12
Can be prevented from interfering with the bolt 39 and the high-pressure oil passage 29.

FIG. 15 shows another embodiment of the present invention. The structure of the clutch valve 51 and the oil passage opened and closed by the clutch valve 51 are different from those of the previous embodiment. That is, the first high pressure oil passage 29
A relief hole 58 that opens to the outside of the cylinder body 5, that is, the oil reservoir 41, intersects an intermediate portion of the clutch valve hole 50 communicating with the annular groove 29 a. The clutch valve 51 is provided with a blind hole 55 whose open end faces the first annular groove 29a, and a lateral hole 56 penetrating the peripheral wall. Thus, the sliding plate 6
At the clutch off position occupied by the clutch valve 51 when the valve 4 is closest to the drive plate 62, the horizontal hole 56 communicates with the escape hole 58 to discharge the high pressure of the high pressure oil passage 29 to the oil reservoir 41, and the first and the second The hydraulic transmission between the hydraulic pumps P ₁ and P ₂ is disabled, and when the sliding plate 64 is separated from the driving plate 62 by a predetermined distance, the horizontal hole 56 is occupied by the clutch-on position occupied by the clutch valve 51.
The communication between the first and second hydraulic pumps P ₁ and P ₂ is enabled by interrupting the communication between the first and second hydraulic pumps P ₁ and P ₂ by blocking the communication between the first and second hydraulic pumps P ₁ and P ₂ by interrupting the communication between the first and second hydraulic pumps P ₁ and P ₂ .

Since other structures are the same as those of the previous embodiment, the same reference numerals are given to the parts corresponding to those of the previous embodiment, and the description thereof will be omitted.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the gist of the present invention. For example, the centrifugal weight 67 is
It is also possible to adopt a pendulum type that is pivotally supported at 2. Further, the first side block 12a can be formed integrally with the input shaft 1.

[0059]

As described above, according to the first aspect of the present invention, the input shaft and the output shaft are coaxially supported on the transmission case, and the cylinder body fixed to the input shaft is provided. And a plurality of first plungers radially disposed around the first plungers, the first plungers surround the first plungers and are relatively movably engaged with their outer ends, and reciprocate each first plunger with rotation of the cylinder body. In addition, in order to adjust the reciprocating stroke, a first pump ring rotatably supported by a transmission case constitutes a radial type first hydraulic pump having a variable capacity. A plurality of second plungers radially arranged, and a plurality of second plungers fixed to the output shaft;
A second pump ring which surrounds the plungers and movably engages with the outer ends thereof, and reciprocates a fixed stroke to each second plunger with the relative rotation with the cylinder body. 2 constitute a hydraulic pump,
The cylinder body has a high-pressure oil passage through which hydraulic oil is sucked into the first hydraulic pump and hydraulic oil is discharged from the second hydraulic pump, and a hydraulic oil is discharged from the first hydraulic pump to the second hydraulic pump. The provision of the low-pressure oil passage through which the hydraulic oil is sucked allows the provision of a compact continuously variable transmission having a smaller axial dimension as compared with a conventional combination of an axial hydraulic pump and a hydraulic motor. .

The cylinder body further includes a clutch valve that moves between a clutch-off position that connects the high-pressure oil passage to the low-pressure oil passage or the oil reservoir and a clutch-on position that disconnects the communication.
A centrifugal mechanism that operates the clutch valve from the clutch-off position to the clutch-on position in response to an increase in the rotation speed of the input shaft, and further operates the first pump ring to control the reciprocating stroke of the first plunger in a direction in which the gear ratio decreases. Is provided, the starting and shifting can be automatically performed by one centrifugal mechanism in accordance with an increase in the rotation speed of the input shaft. According to the second aspect of the present invention, the starting and shifting are fixed to the cylinder body. A driving plate, a sliding plate connected to the driving plate in an axially slidable manner, and a sliding plate provided between the driving plate and the sliding plate. A centrifugal mechanism is constituted by a centrifugal weight that operates so as to be separated from the first pump ring via a shift lever pivotally supported by a transmission case, while connecting a clutch valve to a sliding plate, Sliding plate The clutch valve is moved from the clutch-off position to the clutch-on position while moving a predetermined distance from the closest position to the moving plate, and then the first pump ring is actuated to a lower gear ratio side by further movement of the sliding plate. Since the clutch valve and the first pump ring are sequentially operated by a simple centrifugal mechanism, starting and shifting can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a continuously variable transmission according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional front view taken along line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a partially enlarged view of FIG. 1;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 1;

FIG. 8 is an enlarged view of a portion 8 in FIG. 1 showing a clutch-off state.

9 is a sectional view taken along line 9-9 in FIG.

FIG. 10 is an enlarged view of a portion 8 in FIG. 1 showing a clutch-on state.

FIG. 11 is an explanatory diagram of an operation in an infinite speed ratio state.

FIG. 12 is an explanatory diagram of an operation in a state of a gear ratio 2;

FIG. 13 is an explanatory diagram of an operation in a state of a gear ratio 1;

FIG. 14 is an operation explanatory view in a state of a gear ratio of 0.66.

FIG. 15 is a sectional view showing another embodiment of the present invention and corresponding to FIG. 8;

[Explanation of Signs] 1... Input shaft 2... Output shaft 3... Support cylinder 5... Mission case 12. 1 cylinder hole 14 first plunger 15 first pump ring 23 second cylinder hole 24 second plunger 28 low-pressure oil passage 29 High pressure oil passage 41 Oil reservoir 51 Clutch valve 60 Centrifugal mechanism 62 Driving plate 64 Sliding plate 66 Weight pocket 67 ··· Centrifugal weight 70 ··· Shift lever 71 ₁ ··· First return spring 71 ₂ ··· Second return spring P ₁ ··· First hydraulic pump P ₂ ··· Second hydraulic pump T ... continuously variable transmission

Claims (2)

[Claims] An input shaft (1) is mounted on a transmission case (5).
And the output shaft (2) is coaxially supported, and its input shaft (1)
A cylinder body (12), a plurality of first plungers (14) radially disposed on the cylinder body (12), and outer ends thereof surrounding the first plungers (14). To reciprocate the first plunger (14) with the rotation of the cylinder body (12), and can rotate to the transmission case (5) to adjust the reciprocating stroke. radially arranged constitutes a radial type first hydraulic pump of the variable displacement out the first pump ring (15) supported (P _1), also with the cylinder body (12), to the cylinder body (12) A plurality of second plungers (24), which are fixed to the output shaft (2), and
4) and movably engage with their outer ends around
A second reciprocation of a constant stroke to each second plunger (24) with relative rotation with respect to the cylinder body (12).
A radial second hydraulic pump (P ₂ ) having a fixed capacity is constituted by the pump ring (25). The hydraulic oil is sucked into the first hydraulic pump (P ₁ ) and the second hydraulic pump is sucked into the cylinder body (12). high pressure oil passage discharged hydraulic oil from the hydraulic pump (P ₂₎ and (29), sucks the hydraulic oil to the second hydraulic pump (P ₂₎ with discharged hydraulic fluid from the first hydraulic pump (P ₁₎ A low-pressure oil passage (28), and the high-pressure oil passage (29) is connected to the low-pressure oil passage (28) or the oil reservoir (41).
A clutch valve (51) that moves between a clutch-off position communicating with the clutch and a clutch-on position that interrupts the communication, and the clutch valve (51) is turned on from the clutch-off position in response to an increase in the rotation speed of the input shaft (1). And a centrifugal mechanism (60) for operating the first pump ring (15) to control the reciprocating stroke of the first plunger (14) in the direction of decreasing the gear ratio. Continuously variable transmission. 2. The drive plate according to claim 1, wherein the drive plate is fixed to the cylinder body.
A sliding plate (64) slidably connected to the driving plate (62) in the axial direction; and a sliding plate (64) provided between the driving plate (62) and the sliding plate (64). A centrifugal mechanism (60) is constituted by a centrifugal weight (67) which operates to separate the sliding plate (64) from the driving plate (62) in the axial direction, and a clutch valve (60) is provided on the sliding plate (64). 51) and a first pump ring (15) via a shift lever (70) pivotally supported by the transmission case (5).
The clutch valve (51) is moved from the clutch-off position to the clutch-on position while the sliding plate (64) moves a predetermined distance from the closest position to the driving plate (62). A continuously variable transmission, wherein the first pump ring (15) is actuated to the side of decreasing the gear ratio by further movement of (64).