JPH0193661A - Static hydraulic type continuously variable transmission for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention A0 Objective of the Invention (1) Industrial Application Field The present invention relates to a hydraulic pump connected to an engine, a hydraulic motor connected to a wheel, and a hydraulic closed circuit connecting these hydraulic pumps and hydraulic motors. The present invention relates to a hydrostatic continuously variable transmission for vehicles, comprising:

(2) Prior Art Conventionally, in this type of transmission, in order to cut off power transmission between the hydraulic pump and the hydraulic motor,
It is known that a short-circuit oil path connecting a high-pressure oil path and a low-pressure oil path in a hydraulic closed circuit is provided, and a clutch valve is interposed therein, which opens when power needs to be cut off (for example, Japanese Patent Publication No. 41-3
(See Publication No. 208).

(3) Problems to be solved by the invention Firstly, when the vehicle is running at high speed, even if the clutch valve is opened in an attempt to coast, a large amount of hydraulic fluid is discharged from the hydraulic motor that is driven at high speed from the wheel side. , due to the flow resistance of the short-circuited oil passage, a considerable amount of that oil pressure is transmitted to the hydraulic pump, and this is transmitted to the engine as a reverse load, so the engine brake may be applied to some extent, giving the operator a sense of discomfort. . Furthermore, even if the clutch valve is opened when manually moving a vehicle with the engine stopped, the engine will be under some load for the same reason.

The present invention has been made in view of the above circumstances, and is a vehicle static system that reliably blocks hydraulic pressure transmission from the hydraulic motor to the hydraulic pump and enables the hydraulic motor to idle when driven from the wheel side. The purpose is to provide a hydraulic continuously variable transmission.

B0 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a method for solving problems in a hydraulic closed circuit.
It is characterized in that the oil passage connecting the suction side of the hydraulic pump to the discharge side of the hydraulic motor communicates with the oil reservoir via a valve that can be opened and closed as desired.

(2) Operation The oil passage connecting the suction side of the hydraulic pump and the discharge side of the hydraulic motor becomes high-pressure due to the pumping action of the hydraulic motor when the hydraulic motor is driven from the wheel side. When the valve is opened in such a case, the oil passage is opened to the oil sump, so the high-pressure hydraulic oil discharged from the hydraulic motor immediately flows into the oil sump.
Hydraulic pressure transmission to the hydraulic pump can be reliably shut off.

(3) Examples An embodiment of the present invention will be described below with reference to the drawings.

First, in Figure 1, the power unit l-U of a motorcycle
consists of an engine E and a hydrostatic continuously variable transmission T, and the crankshaft 1 of the engine E and the transmission T are housed and supported in a common casing 4. The continuously variable transmission T is arranged with an input cylinder shaft 5 and an output shaft 31 parallel to the crankshaft 1, the crankshaft 1 drives the input cylinder shaft 5 via the primary reduction gear 2, and the output shaft 31 drives the input cylinder shaft 5 through the primary reduction gear 2. It is arranged to drive a rear wheel (not shown) of a motorcycle via a secondary reduction gear 3.

A kick starter St is installed adjacent to the right end of the crankshaft 1.

In FIGS. 2 and 3, the continuously variable transmission T includes a constant displacement swash plate type hydraulic pump P and a variable displacement swash plate type hydraulic motor M.

The hydraulic pump P is connected to the output sprocket 2 of the primary reduction gear 2.
A is connected to a human-powered cylinder shaft 5 connected by a rivet 16, a pump cylinder 7 fitted to the inner circumferential wall of the input cylinder shaft 5 via a needle bearing 6 so as to be relatively rotatable, and a pump cylinder 7 whose rotation A large number of pump plungers 9.9... which are respectively slidably engaged with a large number of odd numbered cylinder holes 8.8... provided in an annular arrangement surrounding the axis, and these pump plungers 9.9... A pump swash plate 10 whose front surface is brought into contact with the outer end, and a virtual trunnion axis 'M that is orthogonal to the axis of the pump cylinder 7.
The pump swash plate holder 12 supports the back surface of the swash plate 10 via an angular contact bearing 11 so as to maintain the swash plate 10 tilted at a constant angle with respect to the axis of the pump cylinder 7 with AO+ as the center. The pump swash plate holder 12 is also fixed to the input cylinder shaft 5 by the rivet 16. The angular contact bearing 11 is configured to cooperate with the pump swash plate holder 12 to provide an alignment effect to the pump swash plate 10.

Thus, the pump swash plate 10 can cause the pump plungers 9, 9, . . . to reciprocate and repeat the suction and discharge strokes when the input sleeve rotates 50 times.

In order to improve the ability of the pump plunger 9 to follow the pump swash plate 10, a coil spring 15 that biases the pump plunger 9 in the direction of extension is housed in the cylinder hole 8.

On the other hand, the hydraulic motor M includes a motor cylinder 17 disposed on the same axis as the pump cylinder 7 and to the left thereof, and a large number of odd number of cylinder holes arranged in an annular manner surrounding the rotation axis of the motor cylinder 17. A large number of motor plungers 19.19 each slidably connected to 18.18...
..., a motor swash plate 20 that abuts the front surfaces of the outer ends of these motor plungers 19, 19, and a motor swash plate holder 22 that supports the back surface of this motor swash plate 20 via an angular contact bearing 21. and a motor swash plate anchor 2 that supports the back surface of this motor swash plate holder 22.
It consists of 3.

As clearly shown in FIG. 14, the opposing surfaces f+, f of the motor swash plate holder 22 and the motor swash plate anchor 23 that are in contact with each other
g is the axis of the motor cylinder 17 and the trunnion axis 08
It is formed into a spherical surface centered at the intersection with

Further, the motor swash plate holder 22 is integrally provided with a pair of semi-cylindrical trunnion shafts 22a, 22a at both ends, which are disposed on the trunnion axis 0□ orthogonal to the rotation axis of the motor cylinder 17, and these are attached to the motor swash plate anchor. It is rotatably engaged with a pair of semi-cylindrical recesses 23a, 23a formed at both ends of 23, respectively. Note that the trunnion shaft 22a and the recess 23a are connected to the motor swash plate holder 2.
2, the trunnion may have a shape other than a semi-cylindrical shape, as long as it can prevent rotation about an axis other than the trunnion axis O1, for example, it may have a semi-conical shape.

The angular contact bearing 21 is configured to cooperate with the motor swash plate holder 22 to provide an alignment effect to the motor swash plate 20.

The motor swash plate anchor 23 is attached to a bolt 2 on the left side wall of the casing 4 together with a cylindrical cylinder holder 24 connected to its right end.
Fixed at 7. This cylinder holder 24 rotatably supports the outer peripheral surface of the motor cylinder 17 via a needle bearing 25 and a ball bearing 26.

The motor swash plate 20 is configured to move between an upright position perpendicular to the axis of the motor cylinder 17 and a maximum tilt position where it is tilted at an angle by the rotation of the motor swash plate holder 22. In the tilted state, as the motor cylinder 17 rotates, the motor plungers 19, 19, .

In order to improve the ability of the motor plunger 19 to follow the motor swash plate 20, a coil spring 30 that biases the motor plunger 19 in the extension direction is housed in the cylinder hole 18.

The pump cylinder 7 and the motor cylinder 17 are integrally connected to each other to form a cylinder block B, and the output shaft 31 is passed through the center of the cylinder block B. Then, the outer end of the pump cylinder 7 is abutted against the two-split stopper ring 33 that is locked on the outer periphery of the output shaft 31, and the motor cylinder 17 is spline-fitted 3 to the output shaft 31.
2, the cylinder block B is fixed to the output shaft 31 by locking the circlip 35 which contacts the outer end of the motor cylinder 17 via the seat plate 34 to the output shaft 31.

The right end of the output shaft 31 also passes through the pump swash plate 10 and the pump swash plate holder 12, and integrally has a highly rigid flange 37 that supports the back surface of the pump swash plate holder 22 via a thrust roller bearing 40. We are prepared. The output shaft 31 also connects the pump swash plate holder 22 to the needle bearing 4.
It is rotatably supported via 2.

The left end of the output shaft 31 extends through the motor swash plate 20, the motor swash plate holder 22, and the motor swash plate anchor 23, and is connected to the outer periphery of this left end by a spline 43 and fixed with a splitter 44. A retainer 46 and a thrust roller bearing 47 are sequentially interposed between the support cylinder 45 and the motor swash plate anchor 23 from the swash plate anchor 23 side. Further, the output shaft 31 is rotatably supported by the swash plate anchor 23 via a needle bearing 48 and the retainer 46.

In this way, all the components of the transmission T, from the outlet block block 2a to the splitter 44, are assembled as one assembly on the output shaft 31, so that the transmission T can be attached to and removed from the casing 4. can be easily done.

When the transmission T is assembled to the casing 4, the pump swash plate holder 12 is supported on the right side wall of the casing 4 via a ball bearing 41, and the input cylinder shaft 5 is supported on the separable intermediate support wall 4a of the casing 4. The motor swash plate anchor 23 is supported via a ball bearing 39 and fixed to the left side wall of the casing 4 by a bolt 27. And casing 4
A cap 50 that closes a maintenance hole 49 opening there is fixed with a bolt 51 to the right side wall of the casing 4.
An oil seal 56 that closely contacts the outer peripheral surface of the support tube 45 is fitted on the left side wall of the support tube 45 . Further, on the outside of the casing 4, the inlet block block 3a of the secondary reduction gear 3 is connected to the bolt 3B.
It is fixed in place. At this time, the input block (3a) presses the outer periphery of the two-split bracket 44 to prevent it from coming off.

In order to rotate the pump swash plate 10 synchronously with the pump cylinder 7, the pump swash plate IO is formed with a spherical recess 10a in which the spherical end 9a of the corresponding pump plunger 9 engages.

Further, in order to rotate the motor swash plate 20 synchronously with the motor cylinder 17, the motor swash plate 20 is formed with a spherical recess 20a into which the spherical end 19a of the corresponding motor plunger 19 engages.

Each of the spherical recesses 10a, 20a is formed with a radius larger than the radius of the corresponding spherical end 9a, 19a, so that the spherical end 9a,
19a is ensured.

Furthermore, in the hydraulic motor M, during motor plunge 19
In order to particularly ensure the mutual torque transmission between the motor swash plates 20, the partition wall 20b between each of the spherical recesses 20a and 2Qa is formed in a mountain shape that protrudes toward the center (see FIGS. 11 to 13). Incidentally, such a structure may also be adopted on the hydraulic pump P side.

2 to 5, the cylinder block B has an output shaft 31 between the cylinder holes 8, 8... groups of the pump cylinder 7 and the cylinder holes 18, 18... group of the motor cylinder 17. An annular inner oil passage 52 and an outer oil passage 53 lined up concentrically around the center, a cylinder hole 8°8, which radially penetrates the annular partition wall between both oil passages 52 and 53 and the outer circumferential wall of the outer oil passage 53. ... and 18,18... and the same number of first valve holes 54,54... and second valve holes 55, respectively.
, 55... and a pump bow that interconnects the adjacent cylinder holes 8, 8... and the first valve holes 54, 54...)
a, a..., and a large number of motor bows b, b... which communicate with each other the adjacent cylinder holes 18, 18... and the second valve holes 55, 55... are provided.

The inner oil passage 52 is formed as an annular groove on the inner peripheral surface of the cylinder block B, and its open surface is closed by the outer peripheral surface of the output shaft 31.

Spool-type first distribution valves 6i, 61... are installed in the first valve holes 54, 54, and the second valve holes 55, 55, .
... also has a spool-type second distribution valve 62°62.
... are rubbed together. Then, the first distribution valve 61.
At the outer ends of the second distribution valves 62, 62..., there are first eccentric wheels 63 surrounding them, and at the outer ends of the second distribution valves 62, 62, there are second eccentric wheels 64 surrounding them, respectively.
The outer ends of the first distribution valves 61, 61, . The outer end of the second distribution valve 62, 62... is connected to the second eccentric wheel 62.
．． 62... are mutually connected by a second forcing ring 68 in a concentric relationship.

The first eccentric wheel 63 is fixed to the outer periphery of the input cylinder shaft 5 via a connecting pin 69, and is located eccentrically by a predetermined distance from the center of the output shaft 31 along the virtual trunnion axis O8, as shown in FIG. is maintained. .

Thus, when relative rotation occurs between the input cylinder shaft 5 and the pump cylinder 7, each first distribution valve 61 has an eccentric amount ε in the first valve hole 54 due to the first eccentric wheel 63.

The pump cylinder 7 is reciprocated between a radially inner position and an outer position with a stroke that is twice the distance of the pump cylinder 7. As shown in FIG. 4, in the discharge area of the hydraulic pump P, the first distribution valve 61 moves to the inner position side, communicates the corresponding pump valve (a) with the outer oil passage 53, and connects the inner side. The pump plunger 9 is disconnected from the oil passage 52 and is in the discharge stroke.
The hydraulic oil is force-fed from the cylinder hole 8 to the outer oil passage 53, and in the suction region S, the first distribution valve 61 moves to the outer position side and connects the corresponding pump port a to the inner oil passage 5.
2 and disconnected from the outer oil passage 53, and hydraulic oil is sucked into the cylinder hole 8 from the inner oil passage 52 by the pump plunger 9 during the suction stroke.

As shown in FIGS. 5 and 6, the second eccentric wheel 64 has a pivot 3 parallel to the output shaft 31 on the cylinder holder 24.
0 so as to be able to swing between a clutch-on position n and a clutch-off position f. In the clutch-on position n, the second eccentric wheel 64 is aligned with the trunnion axis Ot.
occupies a position that is eccentric by a predetermined distance ε2 from the center of the output shaft 31 along the clutch-off position f, and is located at a distance 8. from the center of the output shaft 31 that is larger than the eccentricity ε2. It occupies an eccentric position, and in order to regulate its position, a notch 71 is provided on the outer peripheral surface of the second eccentric ring 64, and a stopper 72 that can come into contact with the inner end surface of the stomach of this notch 71 is integrated into the casing 4. is formed.

That is, when this stopper 72 comes into contact with one inner end surface of the notch 71, the clutch-on position n of the second eccentric wheel 64 is
However, by contacting the other inner end surface of the notch 71, the clutch-off position f of the second eccentric wheel 64 is regulated.

A camshaft 74 arranged parallel to the output shaft 31 is inserted into a through-hole 73 formed in an example part of the second eccentric wheel 64, and a slipper plate 75 that engages with this camshaft 74 is inserted through the through-hole 73. It is fixed to the second eccentric wheel 64 with a bolt 76 so as to cover one side of the inside 73.

As shown in FIG. 3, the camshaft 74 is supported by the casing 4 via a pair of left and right ball bearings 77, and a lever (not shown) at the outer end is attached to a steering handle H of the motorcycle. Connect the operating wire Wl to the clutch lever Cl.
connected via.

When the camshaft 74 is rotated by operating the clutch lever CIl, it can push the slipper plate 75 and swing the second eccentric wheel 64 to the clutch-off position f.

Further, as shown in FIG. 5, a clutch spring 78 is connected to the second eccentric wheel 64 to bias it toward the clutch-on position n. Therefore, if the camshaft 74 is operated to retreat from the slipper plate 75, the second eccentric wheel 64 can be swung to the clutch-on position n by the force of the clutch spring 78.

Thus, when the second eccentric wheel 64 occupies the clutch-on position n (see FIG. 5), when the motor cylinder 17 rotates, each second distribution valve 62 is caused to close to the second valve hole by the second eccentric wheel 64. At 55, the eccentricity ε.

The motor cylinder 17 is reciprocated between a radially inner position and an outer position with a stroke that is twice the distance of the motor cylinder 17. In the fat swelling region Ex of the hydraulic motor M, the second distribution valve 62
moves to the inner position side and the corresponding motor boat b
is communicated with the outer oil passage 53 and the inner oil passage 52 is disconnected, and the motor plunger 1 during the fat expansion stroke is communicated with the outer oil passage 53.
High-pressure hydraulic oil is supplied to the cylinder hole 18 of No. 9, and in the contraction region sh, the second distribution valve 62 moves to the outer position side and communicates the corresponding motor boat b with the inner oil passage 52. The outer oil passage 53 is disconnected, and hydraulic oil is discharged from the cylinder hole 18 of the motor plunger 19 during the contraction stroke to the inner oil passage 52.

Further, when the second eccentric wheel 64 occupies the clutch-off position f (see FIG. 6), when the motor cylinder 17 rotates,
Each second distribution valve 62 is reciprocated between an inner position and an outer position in the radial direction of the motor cylinder 17 by a second eccentric wheel 64 with a stroke of twice the eccentricity ε3 in the second valve hole 55. , at its inner and outer positions, the second distribution valve 62 opens the outer oil passage 53 to the outside of the cylinder block B.

In the above configuration, when the input cylinder shaft 5 of the hydraulic pump P is rotated from the primary reduction gear 2 while the second eccentric wheel 64 is held at the clutch-on position n, the pump swash plate 10 causes the pump plungers 9, 9, . . . Exhalation and suction strokes are applied alternately.

The pump plunger 9 pumps hydraulic oil from the cylinder hole 8 to the outer oil passage 53 while passing through the discharge area, and pumps hydraulic oil from the inner oil passage 52 to the cylinder hole 8 while passing through the suction area S. Inhale.

The high pressure hydraulic oil sent to the outer oil passage 53 is supplied to the hydraulic motor M.
Hydraulic oil is supplied to the cylinder hole 18 of the motor plunger 19 in the expansion area Ex, while the hydraulic oil is discharged from the cylinder hole 18 to the inner oil passage 52 by the motor plunger 19 in the contraction area sh.

During this period, the pump cylinder 7 receives reaction torque from the pump swash plate 10 via the pump plunger 9 in the discharge stroke, and the motor cylinder 17 receives the reaction torque from the pump plunger 1 in the expansion stroke.
The cylinder block B is rotated by the sum of the reaction torque received from the motor swash plate 20 via the motor 9, and the rotational torque is transmitted from the output shaft 31 to the secondary reduction gear 3.

In this case, the gear ratio of the output shaft 31 to the input cylinder shaft 5 is given by the following equation.

Capacity of Hydraulic Pump P Therefore, if the capacity of hydraulic motor M is changed to a value consisting of zero, the transmission ratio can be changed to a required value consisting of one. Moreover, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, by tilting the motor swash plate 20 from the upright position to the inclined position, the gear ratio can be controlled steplessly up to a value of 1. Can be done.

During operation of the transmission T, the pump swash plate 10 receives thrust loads in opposite directions from the pump plungers 9, 9, etc., and the motor swash plate 20 receives thrust loads in opposite directions from the motor plungers 19, 19, . The thrust load that the swash plate 10 receives is supported by the output shaft 31 via the angular contact bearing 11, the pump swash plate holder 12, the thrust roller bearing 40, and the flange 37, and the thrust load that the motor swash plate 20 receives is supported by the angular contact bearing 21. , the motor swash plate holder 22 , the motor swash plate anchor 23 , the thrust roller bearing 47 , the support tube 45 , and the shaft 44 are supported by the output shaft 31 . Therefore, the above-mentioned thrust load only causes a tensile stress on the output shaft 31 and does not act on the casing 4 that supports the shaft 31 at all.

In this case, the motor swash plate holder 22 supports the motor swash plate 20 on the front side via the thrust roller bearing 21, and is supported on the back side on the motor swash plate anchor 23, so that the motor swash plate holder 22 supports the motor swash plate 20 at the front side via the thrust roller bearing 21, and the back side is supported by the motor swash plate anchor 23. Even if a thrust load is applied from the motor group via the motor swash plate 20, no deflection occurs. Moreover, the motor swash plate holder 22 and the motor swash plate anchor 23 are aligned with the axis of the motor cylinder 17 and the trunnion axis 0! Since the spherical surfaces f, , f, centered at the intersection with the spherical surfaces f, , f, are opposed to each other, the motor swash plate holder 22 exhibits an alignment function due to the interaction of these spherical surfaces. As a result, the motor swash plate holder 22 has a trunnion axis of 0! The motor swash plate 20 can be rotated smoothly and the inclination angle of the motor swash plate 20 can be easily controlled. At this time, the engagement between the trunnion shaft 22a of the motor swash plate holder 22 and the recess 23a of the motor swash plate anchor 23 prevents the motor swash plate holder 22 from rotating around axes other than the trunnion axis 0. Further, the motor swash plate anchor 23 having a concave spherical surface f becomes thicker from the center toward the periphery and has high rigidity, so it can withstand a large load from the motor swash plate holder 22 and the thrust roller bearing 47. be able to.

Furthermore, each spherical recess 20a on the motor swash plate 20.

Since the partition wall 20b between 20a is formed in a chevron shape, the effective engagement depth between the spherical recess 20a and the spherical end 19a of the motor plunger 19 can be increased without making the entire motor swash plate 20 thick. Therefore, even under high load, the motor plunger 19 can be set as
The motor swash plate 20 can be reliably rotated without slipping.

Furthermore, in the hydraulic pump P and the hydraulic motor M, each swash plate 10.20 receives centering action from the front and back by the spherical ends 9a, 19a of the corresponding plunger 9.19 and the angular contact bearing 11.21. , the cylinder block B remains in its fixed position even in any inclined state.
It is possible to perform accurate synchronous rotation.

When the second eccentric wheel 64 is swung to the clutch-off position f when the vehicle is stopped, the high-pressure outer oil passage 53 is opened to the outside of the cylinder block B by the second distribution valve 62. Hydraulic oil is no longer supplied, and power transmission from hydraulic pump P to hydraulic motor M is cut off. That is, a so-called clutch-off state is obtained.

1, 2, and 10, a speed change control device C for controlling the angle of the motor swash plate 20 is connected to the trunnion shaft 22a.

This speed change control device C includes an electric motor 80 capable of forward and reverse rotation, such as a pulse motor, a DC motor, etc.
0, and a pole nut mechanism 82 that is connected to the reduction gear device 81. The pole nut mechanism 82 consists of a screw shaft 83 and a nut 85 that is screwed onto the screw shaft 83 via a circulation ball 84.The screw shaft 83 is connected to the output gear of the reduction gear device 81 and has both ends. Ball bearing 86°8
It is rotatably supported by the casing 4 via 6'. The nut 85 has a connecting arm 87 on one side, and this connecting arm 87 and a pair of connecting arms 88 and 88 that protrude from one side of the motor swash plate holder 22 and sandwich the connecting arm 87 are parallel to the trunnion axis 08. They are connected to each other by a connecting pin 89. Such a connection prevents the nut 85 from rotating around the screw shaft 83.

Then, if the screw shaft 83 is rotated in the normal direction by rotating the electric motor 80 in the normal direction, what happens? 85 moves to the left in FIG. 2, rotates the motor swash plate holder 22 around the trunnion axis 03 via the connecting arms 87 and 88, and allows the motor swash plate 20 to stand up. When the motor 80 is reversed, the nut 85 moves to the right and the motor swash plate 20 can be tilted.

3 and 10, a rotary potentiometer 111 is attached to the casing 4 to detect the inclination angle of the motor swash plate 20 and send control signals to various control devices. This potency type meter 111 is equipped with a lever 113 at the tip of a rotating shaft 112, and this lever 113 is engaged with a retaining groove 114 formed in one trunnion shaft 22a of the motor swash plate holder 22. Therefore, when the motor swash plate holder 22 is rotated to tilt the motor swash plate 20, the rotating shaft 112 is rotated via the lever 113, and the angle of the motor swash plate 20 is determined by the potentiometer 111. A control signal is output.

In FIGS. 2, 3, and 9, a central oil passage 90 is bored in the center of the output shaft 31, its left end is closed by a bushing rod 96, which will be described later, and its right end is opened as an inlet. An oil filter 91 facing the cap 50 is attached to the cap 50 .

The entrance of the central oil passage 90 is communicated with an oil reservoir 93 at the bottom of the casing 4 via an oil passage 92 formed in the casing 4.
A replenishment pump 95 driven by a gear 94 fixed to the pump swash plate holder 22 is interposed in the middle of the oil passage 92 . Therefore, while the engine E is rotating, the supply pump 95 continues to supply oil from the oil reservoir 93 to the central oil passage 90.

A valve cylinder 100 with both ends open is fitted in the center of the central oil passage 90, and the valve cylinder 100 is fixed to the output shaft 31 by passing through a fixing pin 101 that is press-fitted on its diameter line. The fixing pin 101 has a hollow portion 102 that opens both ends to the inner oil passage 52, and this hollow portion 102 is connected to the valve cylinder 100.
It has a plurality of through holes 103, 103, . . . communicating therein. Therefore, the center oil passage 90 and the inner oil passage 52 are communicated with each other via the valve cylinder 100 and the fixing pin 101.

Chamfered portions 104 and 104 are formed on the outer circumferential surface of the valve cylinder 100 to communicate the upstream and downstream sides of the central oil passage 90.

In addition, inside the valve cylinder 100, there is a central oil passage 90 from the inner oil passage 52.
a pair of left and right first check valves 105 that prevent backflow of oil to the
105' are arranged symmetrically across the fixing pin 101,
These check valves 105, 105' have valve springs 106, 106
' is always biased in the valve closing direction.

Further, the output shaft 31 and the cylinder block B have a valve cylinder 1
A series of replenishment oil passages 107 are provided that connect the central oil passage 90 on the upstream side of 00 and the outer oil passage 53, and this replenishment oil passage 1
A second check valve 108 that prevents oil from flowing backward from the outer oil passage 53 to the central oil passage 90 is interposed in the middle of the oil passage 07, and this check valve 108 is always urged in the closing direction by a valve spring 109. Forced.

Furthermore, the output shaft 31 has a radial orifice hole 1 for supplying lubricating oil from a central oil passage 90 to each part of the transmission T.
10 are drilled in place.

During normal load operation in which the hydraulic motor M is hydraulically driven from the hydraulic pump P, the pressure in the inner oil passage 52 on the low pressure side increases to the pressure in the central oil passage 90 due to oil leakage from the hydraulic closed circuit between the two. When the oil pressure drops below this level, the first check valves 105 and 105' open, and hydraulic oil is replenished from the central oil passage 90 to the inner oil passage 52. On the other hand, at this time, the hydraulic oil in the outer oil passage 53 on the high pressure side is prevented from flowing into the central oil passage 90 by the second check valve 108 .

Furthermore, during reverse load operation, that is, during engine braking, the hydraulic motor M performs a pumping action, and the hydraulic pump P performs a motor action, thus changing the outer oil passage 53 to low pressure and the inner oil passage 52 to high pressure. Therefore, if the pressure in the outer oil passage 53 drops below the pressure in the central oil passage 90 due to oil leakage,
The second check valve 10 is opened and the center oil passage 90 is opened to the outer oil passage 5.
Hydraulic oil is supplied to 3, and the center oil passage 90 is supplied from the inner oil passage 52.
The hydraulic oil is prevented from flowing out to the first check valves 105, 105'.

Furthermore, since the oil in the central oil passage 90 is supplied to each part of the transmission T while its flow rate is restricted by the orifice hole 110,
Due to this supply, the pressure in the central oil passage 90 does not drop excessively, and therefore, there is no problem in supplying hydraulic oil from the central oil passage 90 to the inner oil passage 52 and the outer oil passage 53.

A guide hole 97 connected to the central oil passage 90 is provided at the left end of the output shaft 31, and a guide hole 97 is provided at the center of the bolt 38.
A through hole 98 communicating with the through hole 98 is formed respectively.
A bushing rod 9 is disposed in the central oil passage 90 through the bushing rod 9.
6 is slidably supported in the guide hole 97 via a seal member 99. The inner end of this bushing rod 96 is opposed to the left first check valve 105 so as to be able to forcibly open the valve 105, and the outer end thereof is opposed to the camshaft 115.

A return spring 116 is attached to the bushing rod 96 to bias it in the direction of engagement with the camshaft 115.

The cam shaft 115 is rotatably supported by a side cover 119 that covers the side surface of the sprocket 3a and is fixed to the casing 4, and a lever 129 fixed to the shaft 115 is connected to the clutch lever C via an operating wire W8. ! connected to.

Therefore, when the clutch lever 02 is operated, the camshaft 11
5 to push the bushing rod 96 through the first check valve 1.
05 can be forcibly opened, and as a result, the inner oil passage 52 is opened to the central oil passage 90. When such an operation is performed during engine braking, the hydraulic motor M performs a pumping action and makes the inner oil passage 52 high pressure during engine braking as described above, so that high pressure hydraulic oil is immediately transferred to the low pressure central oil passage 90. The oil flows out and passes through the lubricating parts of each part to the oil sump 9.
3, the hydraulic motor M transmits the hydraulic pressure to the hydraulic pump P and becomes idling, and the engine brake is released and the vehicle can coast.

Furthermore, when the vehicle is moved manually with the engine E stopped, if the clutch lever C2 is operated, the hydraulic motor M is driven from the rear wheel side. This enables smooth manual movement of vehicles.

In FIG. 9, the cylinder block B is also provided with a pressure regulating valve 120 that prevents the oil pressure in the outer oil passage 53 from rising excessively.

This pressure regulating valve 120 consists of a valve cylinder 121, a valve body 122, and a valve spring 123.

The valve cylinder 121 is press-fitted into the partition wall between the inner and outer oil passages 52 and 53 and the peripheral wall of the outer oil passage 53 so as to penetrate them in the radial direction. This valve cylinder 121 has a horizontal hole 124 that opens to the outer oil passage 53, a vertical valve hole 125 that communicates between this horizontal hole 124 and the outer oil passage 53, and a horizontal hole that has a slightly larger diameter than this valve hole 125. It has a guide hole 126 extending from 124 in the opposite direction to the valve hole 125, and a large diameter spring chamber 127 connected to the guide hole 126.

The valve body 122 faces the horizontal hole 124 and also faces the valve hole 125.
It has a valve part 122a that slides into the guide hole 126, a valve rod part 122b that slides into the guide hole 126, and a flange-shaped stopper part 122c that can come into contact with the step between the guide hole 126 and the spring chamber 127. is normally held in the abutting position with the stepped portion by a valve spring 123 housed in a spring chamber 127. The spring chamber 127 communicates with the inner oil passage 52 so as not to interfere with the operation of the valve body 122.

Therefore, the oil pressure of the outer oil passage 53 is applied to the step surface between the valve portion 122a and the valve rod portion 122b, and applies a valve opening force to the valve body 122, but the oil pressure of the outer oil passage 53 is below a specified value. In normal operating conditions, the force of the valve spring 123 that biases the valve body 122 in the valve closing direction is greater than the valve opening force, so the valve body 122 is in the closed state, that is, the valve hole 125 is closed. held in state. When the oil pressure in the outer oil passage 53 exceeds a specified value, the valve opening force increases more than the force of the valve spring 123, so the valve body 122 slides and opens the valve while compressing the valve spring 123, that is, the valve opens. Open the hole 125 and remove the excessive oil pressure in the outer oil passage 53 from the valve hole 1.
25 to the outside of the cylinder block B. Then, when the oil pressure in the outer oil passage 53 returns to the specified value, the valve spring 123
The force causes the valve body 122 to return to the closed state again. Therefore, even when the vehicle suddenly starts or accelerates, an excessive increase in the oil pressure in the outer oil passage 53 can be suppressed.

The cylinder block B further includes an inner oil passage 52 and a center oil passage 90 in order to prevent an excessive rise in the oil pressure in the inner oil passage 52.
A throttle hole 128 is provided that communicates between the two. therefore,
Even during sudden engine braking, the oil pressure in the inner oil passage 52 can be prevented from increasing excessively.

Referring again to FIG. 2, the flange 37 integrated with the output shaft 31
has a large number of teeth 117 carved on its outer periphery and is also used as a signal rotor, and a pickup coil 1 facing the outer periphery.
1B is screwed onto the casing 4. The pickup coil 118 generates pulses according to the rotation of the output shaft 31,
This is converted into current or voltage and displayed as the vehicle speed on a speedometer (not shown).

2, 15 to 18, the starter St has a kick shaft 130 that is rotatably supported by the casing 4 via a needle bearing 131 on the same axis as the crankshaft 1 of the engine E. A kick pedal 132 is connected to the outer end of the shaft 130.

A carrier 134 supported by the casing 4 via a ball bearing 133 is integrally connected to the inner end of the kick shaft 130.
The planetary gears 135... each include a ring gear 136 surrounding them, and a sun gear 13 surrounding them.
7 meshes with each other.

The ring gear 136 is fixed to the casing 4 with bolts 138, and the sun gear 137 is integrally formed with a starting shaft 140 that is slidably fitted into a guide hole 139 provided at the center of the kick shaft 130. sun gear 1
37 is slidable in the axial direction with respect to the planetary gears 135.

A drive ratchet 141 is fixed to the tip of the sun gear 137 and is detachable from a driven ratchet 142 fixed to the right end of the crankshaft 1 . An annular groove 143 is provided on the outer periphery of this drive ratchet 141, and a control plate 144 is engaged with this groove 143 so as to be relatively rotatable. Such attachment is achieved through a large cutout 145 extending from the outer peripheral surface of the control plate 144 to its center. Further, three small notches 146 are provided at equal intervals on the outer periphery of the control plate 144, and the carrier 1 is provided in these small notches 146...
Three leg pieces 147 protruding from 34 are engaged so as to be slidable in the axial direction.

Further, the control plate 144 has an arm portion 1 projecting radially outward.
44a, which is connected to the cam surface 14 of the cam plate 148.
8a. The cam plate 148 is fixed to the inner wall of the casing 4 with the bolts 148, and the cam surface 148a of the cam plate 148 is fixed to the inner wall of the casing 4.
As the control plate 144 rotates in the cranking direction R,
The slope is such that it allows axial movement of the crankshaft 1 toward the crankshaft 1 side.

The kick shaft 130 has this in the anti-cranking direction R.
A return spring 150 is connected to rotate the kick shaft 130 and the starting shaft 140, and an extrusion spring 151 is compressed between the kick shaft 130 and the starting shaft 140 to urge the starting shaft 140 toward the crankshaft 1 side.

Therefore, by operating the kick pedal 132, the kick shaft 13
0 is returned and rotated in the cranking direction R against the force of the spring 150, as the carrier 134 rotates, the planetary gears 135... rotate on their own axis while revolving along the ring gear 136, thereby cranking the sun gear 137. Ranking direction R
Since the speed is increased, the starting shaft 140 and the drive ratchet 141 are also driven in the same way.

On the other hand, when the control plate 144 rotates in the cranking direction R together with the carrier 134 and the arm portion 144a is separated from the cam surface 148a of the cam plate 148, the starting shaft 140 moves forward toward the crankshaft 1 by the force of the extrusion spring 151. Then, the driving ratchet 141 is engaged with the driven ratchet 142. The torque of the starting shaft 140 is transmitted to the crankshaft 1 via both ratchets 141 and 142 and cranks it, so that the engine E can be started.

When the engine E starts, the driven ratchet 142 rebounds the drive ratchet 141 in the axial direction, so the rotation of the crankshaft 1 is not transmitted to the starting shaft 140 side.Afterwards, when the kick pedal 132 is released, the return spring 150
The kick shaft 130, the carrier 134, and the control plate 144 are rotated in the anti-cranking direction by the return force of the control plate 1.
When the arm portion 144a of 44 engages with the cam surface 148a, the control plate 144 retreats due to the guiding action of the cam surface 148a, and at the same time, the drive ratchet 141 and the starting shaft 14
Since the drive ratchet 141 is moved backward against the force of the push-out spring 151, the drive ratchet 141 can be completely separated from the driven ratchet 142.

In this way, by employing the planetary gear mechanism 152 consisting of the planetary gear 135, the sun gear 137, and the ring gear 136, the kick shaft 130 coaxially arranged with the crankshaft 1 can drive the crankshaft l at an increased speed. can be laid out compactly on one side of the engine E without interfering with the continuously variable transmission T.

C0 Effects of the Invention As described above, according to the present invention, during a hydraulic closed circuit, the oil passage connecting the suction side of the hydraulic pump to the discharge side of the hydraulic motor is communicated with the oil sump via a valve that can be opened and closed arbitrarily. Therefore, when the hydraulic motor is driven from the rear wheel side, by opening the valve, the hydraulic fluid discharged from the hydraulic motor immediately flows into the oil sump, and the hydraulic pressure transmission from the hydraulic motor to the hydraulic pump is reliably interrupted. This enables high-speed coasting of vehicles and smooth human-powered movement.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view of a power unit for a motorcycle, FIG. 2 is an enlarged vertical sectional plan view of the main part of FIG. 1, and FIG. −■ line cross-sectional view,
Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3, Fig. 5 is a sectional view taken along the line ■-V in Fig. 3, showing the clutch-on state, and Fig. 6
The figure is a sectional view similar to Fig. 5 shown in the clutch-off state, Fig. 7 is a front view of the second distribution valve, Fig. 8 is a sectional view taken along the line ■-■ in Fig. 7, and Fig. 9 is the same as Fig. 3. 1O is an enlarged view of the main part of FIG. 3, FIG. 11 is a plan view of the motor swash plate, and FIGS. 14 is an exploded perspective view of the main part of FIG. 2, FIGS. 15 and 16 are sectional views along the xv-xv and XVI-XVI lines of FIG. 2, and FIG. X in Figure 16
18 is an exploded perspective view of the main parts of FIGS. 15 and 16. C2...Clutch lever-1E...Engine, M...
- Hydraulic motor, P...Hydraulic pump, T...Continuously variable transmission 52...Oil passage connecting the suction side of hydraulic pump P to the discharge side of hydraulic motor M, 105...Valve Fig. 4 Figure 7 Figure 6 Figure 5 Figure 18 Figure 17 Figure 15 jllS diagram

Claims (1)

[Claims] In a vehicle hydrostatic continuously variable transmission consisting of a hydraulic pump connected to the engine, a hydraulic motor connected to the wheels, and a hydraulic closed circuit connecting these hydraulic pumps and hydraulic motors, during the hydraulic closed circuit, the hydraulic pump is inhaled. A hydrostatic continuously variable transmission for a vehicle, characterized in that an oil passage whose side is connected to the discharge side of a hydraulic motor is communicated with an oil reservoir via a valve that can be opened and closed arbitrarily.