JPH0932920A - Tandem piston structure for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed pressure oil even to the external surface of an inner piston and allow the reduction of machining cost as well as the improvement of a transmission function by feeding the oil to the second fluid chamber via the first fluid passage formed on a cylinder member and the second fluid passage formed on the first piston. SOLUTION: The external surface of a case 10, and a wall-shaped part 10a and an inner cylindrical part formed on the case 10, form a cylinder member, and the first piston 273 is retained within the cylinder member. Also. pressure oil is fed to an oil chamber 263a for driving the second piston 263, via an oil passage 266 formed on the case 10 and an oil passage 273b formed on the piston 273. Furthermore, a pair of seal members 275 and 276 for separating an annular oil chamber 273c are provided between the case 10 and the cylindrical external surface of the piston 273. Furthermore, the oil passage 266 (first fluid passage) and the oil passage 273b (second fluid passage) communicate with the annular oil chamber 273c, and the oil passages 266 and 273b are connected to each other via the annular fluid chamber 273c. As a result, pressure oil can be supplied to each oil chamber from the external side thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a tandem piston for actuating frictional engagement elements such as a clutch and a brake, which are arranged adjacent to each other in an automatic transmission, and particularly, to reduce the number of parts of the automatic transmission. The present invention relates to a friction engagement device for an automatic transmission that can be downsized.

[0002]

Background General Background of the Invention invention, the automatic transmission for a vehicle, the rotation of the engine and inputted through the torque converter, transmission to the propeller shaft by the auxiliary transmission having a plurality of sets of planetary gears (axle side ) Output is popular. Then, in the auxiliary transmission in this type of automatic transmission, the rotation of the input shaft from the torque converter is transmitted to a specific gear or carrier constituting the planetary gear, or a specific gear or a carrier according to the shift position. In order to transmit the rotation of the carrier to the output shaft as appropriate, or to restrain the rotation of a specific gear or carrier as appropriate, frictional engagement elements consisting of clutches or brakes are provided. Many of these clutches or brakes are of a multi-plate type, which comprises a plurality of friction plates, and an actuator for bringing the friction plates into close contact is a hydraulic type, which comprises a piston slidably held in a cylinder. Usually provided. This piston moves in a direction in which the pressure plate from the oil pump is supplied to an oil chamber formed between the piston and the cylinder so as to press the friction plate and bring them into close contact with each other, thereby supplying the pressure oil to the oil chamber. When is stopped, the restoring force of the return spring causes the friction plate to return to the non-operating position where the friction plate is not pressed. By the way, in recent years, when the living space of the vehicle is expanded and the number of mounted parts such as safety equipment is increased, and the traveling performance is improved, in the situation where further cost performance improvement of the vehicle is required, The automatic transmission is required to have a more detailed and smooth gear shifting operation, and is also required to be downsized to reduce the installation space in the vehicle and to be reduced in the number of parts.

A conventional automatic transmission is disclosed in Japanese Patent Laid-Open No. 62-141343.
As shown in the figure, in this kind of automatic transmission, two pistons of a so-called tandem type in which two pistons are housed and held in series in one cylinder actuate two friction engagement elements arranged in proximity. The structure is often adopted. This is two clutches C1 and C2 having different diameters.
And a cylindrical piston having a bottom for activating the clutch C1 on the large diameter side, and an inner peripheral side held by the piston on the outer peripheral side and sliding as the cylinder on the outer peripheral side. And a return spring disposed on the front side of the piston on the inner peripheral side, the return operation of both pistons is performed. However, conventionally, in this structure, the oil for supplying the pressure oil to each oil chamber for driving each piston is on the inner peripheral side central axis line of each piston as shown in FIG. 1 of the above publication. It is designed to be supplied through an oil passage formed in a boss (which is usually fixed to the case side) located at.

[0004]

Therefore, the conventional tandem piston structure has the following problems. (A) The holes forming the oil passages are located on the inner peripheral side of the component and are difficult to process, which is an obstacle to reducing the machining cost of the component. (B) In order to guide the oil from the valve mounted on the case of the automatic transmission, the oil is guided to the inside of the boss to supply the oil from the inner peripheral side to the oil chamber of each piston. Since the entire length of the oil passage up to the point becomes considerably long and the rise in hydraulic pressure is delayed, it is difficult to achieve high gear shifting performance (rapid gear shifting). The reason why it is necessary to guide the oil to the inside of the boss to supply the oil from the inner peripheral side to the oil chamber of each piston is that in the case of the conventional example of the above publication, the cylinder containing two pistons is a clutch drum. The first is that it rotates with the shaft, but even if the clutch drum is provided integrally with the case, the oil passage is connected from the outer peripheral side (that is, the case side). It has been difficult to form in the past. This is because even in this case, the oil could not be supplied to the piston on the inner peripheral side that is contained in the piston on the outer peripheral side.

Therefore, an object of the present invention is to provide a tandem piston structure of an automatic transmission, which can supply oil to the inner piston from the outer peripheral side and can reduce the processing cost and improve the gear shifting performance. .

[0006]

In order to achieve the above object, a tandem piston structure for an automatic transmission according to claim 1 has a cylinder member formed integrally with a case side of the automatic transmission and an outer circumference of a bottom portion. A cylindrical portion slidably contacting the inner circumference of the cylinder member is formed on the side, is slidably held in the cylinder member, and is pressed by the pressure of the first liquid chamber formed between the bottom portion and the cylinder member. A first piston to be driven, and a second piston slidably held in the cylindrical portion of the first piston and driven by the pressure of a second liquid chamber formed between the bottom portion of the first piston and the second piston. A tandem piston structure for an automatic transmission, comprising: a first liquid passage provided in an outer peripheral portion of the cylinder member; and a second liquid passage provided in a cylindrical portion of the first piston. Second
It is characterized in that a pressure liquid is supplied to the liquid chamber.

According to another aspect of the present invention, there is provided a tandem piston structure for an automatic transmission, wherein a pair of seal members that define an annular liquid chamber are provided between the cylinder member and the outer circumference of the cylindrical portion of the first piston. The first liquid passage and the second liquid passage are communicated with each other in the liquid chamber, and the first liquid passage and the second liquid passage are connected via the annular liquid chamber.

A tandem piston structure for an automatic transmission according to a third aspect of the present invention is characterized in that one of the sealing members also functions as a sealing member that separates the first liquid chamber.

According to the first aspect of the present invention, the second piston for driving the second piston is provided via the first liquid passage provided in the cylinder member and the second liquid passage provided in the cylindrical portion of the first piston.
Since the pressure liquid is supplied to the liquid chamber, the pressure liquid can be supplied to the second liquid chamber of the second piston, which is the inner piston of the tandem piston, by the liquid passage formed on the outer peripheral side of the case. Like

According to the second aspect of the present invention, the first liquid passage and the first liquid passage are provided through an annular liquid chamber defined by a pair of seal members between the inner periphery of the cylinder member and the outer periphery of the cylindrical portion of the first piston. Since the two liquid passages are connected, the liquid pressure can be smoothly supplied between the relatively sliding members (that is, between the cylinder member and the first piston) without leakage. Further, in this case, since the first oil passage and the second oil passage do not have to be arranged at the opposite positions because they are connected via the annular chamber, the hydraulic pressure can be supplied without any problem even when the first piston rotates. Can be done.

According to the third aspect of the invention, one sealing member functions both as a sealing member for partitioning the first liquid chamber and as a sealing member for partitioning the annular liquid chamber.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings as an embodiment applied to an automatic transmission. FIG. 1 is a sectional view of the entire automatic transmission of this embodiment, FIG. 2 is a diagram showing a skeleton of an auxiliary transmission that constitutes this automatic transmission, and FIGS. 3 to 5 are partially enlarged views of FIG. Of these, FIG. 5 shows an essential part of the present invention. 1 to 5, the left side (engine side) is the front side and the right side (the side far from the engine) is the rear side. (A) Overall Configuration As shown in FIG. 1, the automatic transmission according to the present embodiment includes a torque converter 20 and an oil pump 5 in an integrated case 10.
0, the auxiliary transmission 100, and the control valve unit 300 at the bottom of the case 10.

The torque converter 20 is connected to a crankshaft of an engine and rotates with a front cover 21.
A rear cover 22 connected to the rear portion of the front cover 21, a pump impeller 23 formed inside the rear cover 22, a turbine runner 24 arranged to face the pump impeller 23, and a turbine runner 24. A turbine shell 25, a stator 26 arranged between the pump impeller 23 and the turbine runner 24, a one-way clutch 27 supporting the stator 26, and a lock arranged between the front cover 21 and the turbine shell 25. And an up piston 28. The front side end of the input shaft 110 (input shaft) of the auxiliary transmission 100 is inserted through the central axis of the torque converter 20, and the turbine shell 25 and the lockup piston 28 have the input shaft at their inner peripheral portions. 110
Is connected to the front end of the. The inner circumference of the stator 26 is connected to the outer race of the one-way clutch 27, and the inner race of the one-way clutch 27 is connected to the outer circumference of the front boss 53 of the oil pump cover 52, which will be described later, and is in a fixed state. A boss 29 is fixedly mounted on the rear cover 22 and is fitted around the outer periphery of the front boss 53 with a gap.

The oil pump 50 is a vane type pump in which the rotor and the like are housed in an outer frame composed of an oil pump housing 51 and an oil pump cover 52. The rotor is connected to the tip of the boss 29 of the torque converter 20. The oil pan 3 that is driven and attached to the lower surface side of the case 10
The oil in 01 is sucked to generate a predetermined hydraulic pressure. The oil pump cover 52 is formed with a front boss 53 extending to the front side along the outer circumference of the input shaft 110 and a rear boss 54 extending to the rear side along the outer circumference of the input shaft 110. As described above, the inner race of the one-way clutch 27 is connected to the tip portion of the. The oil pump housing 51 and the oil pump cover 52 of the oil pump 50 are
It is fixed to the case 10 with bolts 55.

As shown in FIGS. 1 and 2, the auxiliary transmission 100 includes an input shaft 110 and an intermediate shaft 12.
0, output shaft 130, first planetary gear 140, second planetary gear 150, third planetary gear 160, low clutch (L / C) 170, high clutch (H / C) 180, reverse clutch (R /
C) 190, third brake (3rd / B) 200, third one-way clutch (3rd / OWC) 210, overdrive brake (OD / B) 220, second brake (2nd / B) 230, second one-way clutch (2nd / OWC) 240, reverse brake (R / B) 250, low coast brake (LOW coast / B) 260, low brake (LOW / B) 27
0 and low one way clutch (LOW / OWC) 2
80.

As shown in FIG. 1, the input shaft 110, the intermediate shaft 120 and the output shaft 130 are sequentially arranged on the central axis of the case 10 from the front side to the rear side and can rotate independently. Is supported. On the outer peripheral side of the intermediate shaft 120, as shown in FIGS. 2 and 4, the hollow shaft members 121, 1
22 are sequentially arranged concentrically and are supported so as to rotate independently. Here, the front side of the hollow shaft member 121 is connected to a hub 182 described later, and the first carrier 144 described later is connected to the rear side thereof by a spline. The front side of the hollow shaft member 122 is connected to hubs 192 and 222 described later and also functions as an inner race of the third one-way clutch 210, and the rear side thereof is integrated with a first sun gear 141 described later. Is formed in.

The rear end of the output shaft 130 extends to the rear side through the inside of the rear case 11 attached to the rear side of the case 10, and extends through the output flange member 131 to the propeller shaft of the vehicle. Connected to. A parking gear 132 is connected to the outer periphery of the substantially central portion of the output shaft 130 by a spline, and a parking pole (not shown) that works in conjunction with the select lever during parking operation is provided in the parking gear 132.
The output shaft 130 is mechanically locked by meshing with the output shaft 130. A vehicle speed sensor 133, which outputs a pulse signal having a frequency corresponding to the rotation speed of the output shaft 130 by detecting teeth on the outer peripheral surface of the parking gear 132, is attached at a position desired on the outer peripheral surface of the parking gear 132. Has been.

As shown in FIGS. 2 and 4, the first planetary gear 140 includes a first sun gear (S1) 141, a first pinion gear (P1) 142, and a first ring gear (R).
1) 143. As shown in FIG. 4, the first sun gear 141 is integrally formed at the rear end of the hollow shaft member 122 described above. Further, the first carrier (C1) 144 that supports the first pinion gear 142 has its rear end inner circumference connected to the rear end outer circumference of the hollow shaft member 121 by a spline, and its front end. The inner peripheral side of the part is connected to an inner race 241 of the second one-way clutch 240, which will be described later, by a spline, and the outer peripheral side of the front end of the second one-way clutch 240 is connected to a reverse brake drum 251, which will be described later.

As shown in FIGS. 2 and 4, the second planetary gear 150 includes a second sun gear (S2) 151, a second pinion gear (P2) 152, and a second ring gear (R).
2) 153. As shown in FIG. 4, the second sun gear 151 is connected to a later-described third sun gear 161 that constitutes the third planetary gear 160 and rotates integrally.
The rear end of the second carrier (C2) 154 supporting the second pinion gear 152 is integrally connected to a third carrier (C2) 164, which will be described later, and the front end thereof is the first ring. It is integrally connected to the gear 143.

As shown in FIGS. 2 and 4, the third planetary gear 160 includes a third sun gear (S3) 161, a third pinion gear (P3) 162 (shown in FIG. 1), and a third planetary gear 160.
It is composed of a ring gear (R3) 163. Third Sun Gear 1
As shown in FIG. 4, 61 is connected to the intermediate shaft 120 by a spline, and is connected to the second sun gear 151.
It is connected to and rotates integrally. Further, the third carrier (C3) 164 that supports the third pinion gear 162 has its rear end inner circumference connected to the front end outer circumference of the output shaft 130 by a spline, and its front end second. It is connected to the carrier 154.

The low clutch (L / C) 170 (second friction engagement element) has a wall member 17 to be described later, as shown in FIG.
1 is a multi-plate type in which a driven plate connected to the cylindrical portion by a spline and a drive plate connected to the hub 172 by a spline are alternately laminated, and slides left and right (in the axial direction) in FIG. Piston 173 (second
The wall member 171 and the hub 172 are connected by a frictional force generated by pressing each plate in a close contact direction by a piston). The wall member 171 is the input shaft 110.
Since the hub 172 is connected to the intermediate shaft 120, the low clutch 170 eventually has a function of connecting the input shaft 110 and the second sun gear 151 or the third sun gear 161. The piston 173 has an oil chamber 173 a formed between the wall member 171 and the piston 173, and the input shaft 110
When pressure oil is supplied through the oil passage 111 formed in the upper part, it moves to the operating position, and the spring 17 interposed between the retainer 174 and the piston 173 in a compressed state.
The restoring force of 5 restores the non-operating position.

The high clutch (H / C) 180 (first friction engagement element) is, as shown in FIG. 3, an outer peripheral side cylindrical portion 181a (cylindrical extending portion) of the cylinder 181 (first cylinder) described later. 3 is a multi-plate type in which a driven plate connected by a spline and a drive plate connected by a spline to a hub 182 (third cylindrical member) are alternately laminated. In FIG.
The cylinder 181 and the hub 182 are connected by the frictional force generated by pressing the plates in the contact direction by the (first piston). The cylinder 181 is connected to the input shaft 110, and the hub 182 is the hub 18.
It is connected to the first carrier 144 via the above-mentioned hollow shaft member 121 formed integrally with the second carrier 144. Therefore, in the end, the high clutch 180 does not operate on the input shaft 11
0 has a function of connecting the first carrier 144. The piston 183 has an oil chamber 183 a formed between a later-described wall-shaped portion 181 c of the cylinder 181 and the piston 183, and an inner peripheral side cylindrical portion 18 of the cylinder 181 described later.
When pressure oil is supplied through an oil passage 184 formed in 1b, it moves to an operating position, and a spring 187 shown in FIG. 1 interposed in a compressed state between a retainer 188 and this piston 183 is provided. It returns to the non-operating position due to the restoring force. In the oil chamber 171b (centrifugal oil pressure cancel chamber) formed between the wall member 171 and the piston 183, the oil passage 1 formed in the inner peripheral side cylindrical portion 181b of the cylinder 181 is provided.
Oil is supplied via 85. As a result, the wall-shaped portion 18
1c and an oil chamber 183a formed between the piston 183
It is possible to cancel the centrifugal hydraulic pressure generated in the above, and it becomes easy to control the hydraulic pressure for smooth gear shifting.

As shown in FIG. 3, the reverse clutch (R / C) 190 is formed by alternately stacking a driven plate connected to the cylinder 181 by a spline and a drive plate connected to the hub 192 by a spline. A multi-plate type piston 19 that slides left and right in FIG.
The plates are pressed against each other by means of the pressing flange 194 by means of 3, and the frictional force generated thereby connects the cylinder 181 and the hub 192. Here, the cylinder 181 is connected to the input shaft 110,
The hub 192 is connected to the first sun gear 141 via the above-mentioned hollow shaft member 122 integrally formed with the hub 192. Therefore, after all, this reverse clutch 1
90 is the input shaft 110 and the first sun gear 14
It has a function of connecting with 1. Also, the piston 193
Is located in an oil chamber formed between a later-described wall-shaped portion 181c of the cylinder 181 and the piston 193.
Of the return spring interposed between the retainer 195 and the piston 193 in a compressed state by being supplied with pressure oil through the oil passage 186 formed in the inner cylindrical portion 181b of the The restoring force of 196 restores the non-actuated position.

The cylinder 181 for supporting the reverse clutch 190 together with the high clutch 180 includes an outer peripheral side cylindrical portion 181a, an inner peripheral side cylindrical portion 181b, and an outer peripheral side cylindrical portion 181b extending in the outer peripheral direction. Part 1
81a connected to the bottom part 181c,
In order to house the pistons 183 and the like of the high clutch 180 at a high density, the step portion 18 in the direction in which the inner peripheral side extends is provided in the 1c.
1d is formed, and is connected to the input shaft 110 by a spline on the rear side of the inner peripheral side cylindrical portion 181b, and the front side of the inner peripheral side cylindrical portion 181b is slidably contacted with the outer periphery of the rear side boss 54 of the oil pump cover 52. While it is a member that rotates. And this cylinder 181
The front end portion of the outer peripheral side cylindrical portion 181a has a comb-like shape in which a plurality of rectangular notches 181e are formed in the circumferential direction, and the comb-teeth portion constitutes a claw-like portion 181f.

Further, the piston 193 has a comb-like outer peripheral portion, and has a rectangular claw-shaped portion 193a at a position corresponding to the cutout 181e of the cylinder 181.
1 has a step portion 193b along the bottom portion 181c. The oil chamber that operates this piston 193 is the seal rings 193c and 193d.
It is formed between the inner surfaces of the stepped portions 181d and 193b that are slidably contacted with or separated from each other by the space sealed by, that is, the piston 193 moves. On the other hand, as shown in FIG. 3, the front end of the pressing flange 194 has a rectangular cutout 194 at a position corresponding to the cutout 181e of the cylinder 181.
a is formed. The claw-shaped portion 193a of the piston 193 penetrates the notch 181e of the cylinder 181 and is fitted into the notch 194a of the pressing flange 194, and is attached to the front end of the pressing flange 194 by the snap ring 194b. The piston 193 and the pressing flange 194 are integrally connected. Also, as a result, the claw portion 181 of the cylinder 181 is
The f is configured to extend through the opening formed between the adjacent claw-shaped portions 193a of the piston 193 and outward to the front side of the piston 193.

Then, the claw-shaped portion 181 extending outwardly from this
A retainer 195 is attached to the f by a snap ring 195a, and the inner peripheral side of the retainer 195 and the piston 1
A return spring 1 for returning the piston 193 between the upper part of the rear surface of 93 and the outer peripheral side concave portion of the step 193b.
96 is interposed in a compressed state. In this way, the return spring 196 is arranged in the space on the outer peripheral side of the step portion 193b and on the inner side (inner peripheral side) of the outer diameter of the outer peripheral side cylindrical portion 181a of the cylinder 181. They are densely arranged and do not form any extra overhangs in the radial or axial directions.

Further, the outer peripheral side end of the retainer 195 of the return spring 196 is an inverted L-shaped comb tooth-shaped portion 195.
It has a comb-like shape in which a plurality of b are formed, and an inverted L-shaped comb-like portion 195b thereof is formed in the notch 1 of the cylinder 181.
It goes through 81e. The claw-shaped portion 19 is provided at a position desired on the outer peripheral surface of the comb-shaped portion 195b of the retainer 195.
By detecting 5b, the input shaft 110
An input shaft rotation speed sensor 197 that outputs a pulse signal having a frequency corresponding to the rotation speed of the turbine runner 24 is attached. Therefore, the retainer 195
Also functions as a rotor for detecting the input shaft rotation speed.

Further, as shown in FIG. 3, the hub 192 of the reverse clutch 190 is disposed close to the wall member 171 of the low clutch 170 with a slight displacement in the rear direction and the outer peripheral direction, and the hub 192 is further raised. The hub 182 of the clutch 180 is sandwiched between the members of the wall member 171 and the hub 192 so that the hub 182 extends from the outer peripheral side of the cylindrical portion of the wall member 171 to the inner peripheral side of the cylindrical portion of the hub 192 in close proximity. It is arranged. In addition, with such a configuration, at the position between the end faces of the wall member 171 and the hub 192 in the hub 182, the inclined portion 18 oblique to the axial direction is formed.
2a is formed, and the end portions of the wall member 171 and the hub 192 are, as shown in FIG.
It is tapered so as to follow a, and inclined surfaces 171a and 192a are formed on the outer peripheries of the ends thereof, respectively. Thereby, the end faces of the wall member 171 and the hub 192 and the hub 182.
Interference with the hard to occur, these members can be arranged closer to each other, each clutch 170,180,1
90 are arranged in high density.

The third brake (3rd / B) 200 is
As shown in FIG. 4, a multi-plate type in which a driven plate splined to a fixed drum 70 fixed to the case 10 and a drive plate splined to the hub 202 are alternately laminated, Fixed drum 70
Each plate is pressed in the close contact direction by a piston 203 which is housed in a concave portion formed on the front outer peripheral side and slides left and right in FIG. 4, and a braking force is exerted on the hub 202 by a frictional force generated thereby. Here, the hub 202 is fixed to the outer race 211 of the third one-way clutch 210, and thus the third brake 200 is the one direction of the hollow shaft member 122 in which the first sun gear 141 is formed via the third one-way clutch 210. It has the function of exerting braking force on rotation. The piston 203 moves to the operating position by supplying pressure oil to the oil chamber formed between the fixed drum 70 and the piston 203 via the oil passage 71 formed in the fixed drum 70. The restoring force of the spring 204 restores the non-operating position. In addition, the third one-way clutch (3r
The d / OWC) 210 facilitates shift control at the time of upshifting to the 4th speed. As described later, the low clutch 1
When the high clutch 180 is operated while the 70 and the third brake 200 are operated to the third speed, the third one-way clutch 210 is released, and the third brake 200 can be operated to the fourth speed. it can.

Overdrive brake (OD / B) 2
As shown in FIG. 4, 20 is a multi-plate type in which a driven plate connected to the fixed drum 70 fixed to the case 10 by a spline and a drive plate connected to the hub 222 by a spline are alternately laminated. By the piston 223 which is housed in the concave portion formed on the front inner peripheral side of the fixed drum 70 and slides left and right in FIG. 4,
The plates are pressed in the close contact direction, and the frictional force generated thereby exerts a braking force on the hub 222. Here, the hub 222 is connected to the front side end of the hollow shaft member 122 on which the first sun gear 141 is formed, and the overdrive brake 220 eventually has a function of exerting a braking force on the first sun gear 141. Have. The piston 223 moves to the operating position by supplying pressure oil to the oil chamber formed between the fixed drum 70 and the piston 223 via the oil passage 72 formed in the fixed drum 70. The restoring force of the spring 224 restores the non-operating position.

Second brake (2nd / B) 230
As shown in FIG. 4, a driven plate splined to the fixed drum 70 fixed to the case 10 and a drive plate splined to the outer race 242 of the second one-way clutch 240 are alternately laminated. It is a multi-plate type consisting of a fixed drum 70
Each plate is pressed in the close contact direction by a piston 233 which is housed in a recess formed on the rear side and slides left and right in FIG. 4, and a braking force is exerted on the outer race 242 by the frictional force generated thereby. Inner race 241 of the second one-way clutch 240
Is connected to the first carrier 144 as described above, the second brake 230 is eventually connected to the first carrier 144 via the second one-way clutch 240.
Also, the second ring gear 153 has a function of exerting a braking force on the rotation in one direction. The piston 233 is
By supplying pressure oil to the oil chamber formed between the fixed drum 70 and the piston 233 via the oil passage 73 formed in the fixed drum 70, the oil moves to the operating position, and the restoring force of the spring 234 is restored. To return to the inoperative position. Also, a second one-way clutch (2nd / OWC) 240
Is for facilitating the shift control at the time of upshifting to the 3rd speed, and includes the low clutch 170 and the second brake 2
When the third brake 200 is operated when the third brake 200 is operated while the third brake 30 is operated, the second one-way clutch 240 is released, and the third brake 230 can be shifted to the third speed with the second brake 230 being operated.

As shown in FIG. 4, the reverse brake (R / B) 250 is a band type consisting of a brake band wound around the outer circumference of the reverse brake drum 251, and the brake band is formed by a servo piston (not shown). By being tightened, a braking force is exerted on the reverse brake drum 251. Reverse brake drum 2
Since 51 is connected to the first carrier 144 and the second ring gear 153 is integrally formed as described above, the reverse brake 250 is eventually connected to the first carrier 144 and the second ring gear 153. It has the function of activating braking force.

Low Coast Brake (LOW Coast /
B) 260, as shown in FIG. 4 or FIG.
Driven plate splined to the hub 2
62 is a multi-plate type in which drive plates connected to each other by a spline are alternately laminated, and each plate is pressed in a close contact direction by a piston 263 (second piston), and a friction force generated thereby causes a hub to move. Apply braking force to 262. The hub 262 is fixed to the inner race 281 of the rowan way clutch 280,
Further, since the inner race 281 is connected to the third ring gear 163 by a spline, the low coast brake 260 eventually has a function of exerting a braking force on the third ring gear 163. Here piston 263
Is a wall-shaped part 10a formed on the rear side of the case 10 in a direction perpendicular to the axis, and an inner side formed from the inner peripheral end of the wall-shaped part 10a along the outer periphery of the output shaft 130 to the front side. It is housed in a recess surrounded by the cylindrical portion 10b in series with a piston 273 of a low brake 270, which will be described later, and slides left and right in FIG. 4 or 5.
Then, the piston 263 is provided with a pressure oil via an oil passage 273a (second liquid passage) formed in the piston 273 in an oil chamber 263a (second liquid chamber) formed between the piston 273 and the piston 263. Is supplied to move to the operating position, and the restoring force of the spring 265 interposed between the retainer 264 and the piston 263 restores the non-operating position.

As shown in FIG. 4, the low brake (LOW / B) 270 includes a driven plate connected to the case 10 by a spline and a drive plate connected to the outer race 282 of the low one-way clutch 280 by a spline. It is a multi-plate type in which the plates are alternately laminated, and a braking force is exerted on the outer race 282 by a frictional force generated by the pistons 273 (first pistons) pressing each plate in the close contact direction. Since the inner race 281 of the low one-way clutch 280 is connected to the third ring gear 163 as described above, the low brake 270 is eventually connected to the low one-way clutch 280.
The third ring gear 163 has a function of exerting a braking force on the rotation of the third ring gear 163 in one direction. Piston 273 here
Is the aforementioned wall-shaped portion 10a and inner cylindrical portion 1 of the case 10.
0b, which is housed in a recess surrounded by 0b and slides left and right in FIG. 4 or FIG. 5, and is formed between the wall-shaped portion 10a and the piston 273 (oil chamber 273d (first liquid chamber)). ), The pressure oil is supplied through the oil passage 274 formed in the wall-shaped portion 10a to move to the operating position,
The restoring force of the spring 265 restores the non-operating position. The pressing portion (a portion that presses each plate) 273b of the piston 273 penetrates the gap between the plates of the low coast brake 260 and contacts the plate side surface of the low brake 270 (strictly, the dish plate side surface). In addition, low one way clutch (LOW / O
WC) 280 is for facilitating the shift control at the time of upshifting to the 2nd speed, and operates the second brake 230 when the low clutch 170 and the low brake 270 are operated to become the 1st speed. Then, this low one way clutch 280 is released, and the low brake 2
It is possible to shift to the second speed with 70 still operating.

The control valve unit 300 has various solenoid valves controlled by a control unit (electrical circuit) (not shown) in a body in which a control oil passage is formed, and a manual valve which operates according to the operation of a select lever. A plurality of valves including valves are attached to form a hydraulic control circuit, which is attached to the lower surface of the case 10 in a state of being covered with an oil pan 301.
Based on the operation of the select lever or the control of the control unit, the pressure of the hydraulic oil generated by the hydraulic pump 50 is adjusted as needed, and the torque converter is appropriately passed through a predetermined oil passage formed in the case 10 or the like. 20 and a predetermined oil chamber of the auxiliary transmission 100. As a result, lubrication, cooling, and the like of each part of the auxiliary transmission 100 are performed, and the lockup piston 28 of the torque converter 20 and each clutch or brake piston of the auxiliary transmission 100 are appropriately operated. . In this case, the operating state of each clutch or brake of the auxiliary transmission 100 with respect to the main operation position (range) of the select lever or the shift position in the D range is set as shown in FIG.

(B) Detailed Configuration of Main Part Next, the detailed configuration of the main part to which the present invention is applied will be described with reference to FIG. In the case of the present embodiment, the present invention is applied to a tandem piston structure (a structure including the piston 263 and the piston 273) that operates the low coast brake (LOW coast / B) 260 and the low brake (LOW / B) 270. . That is, the outer peripheral portion of the case 10, the wall-shaped portion 10a and the inner cylindrical portion 10b formed in the case 10 constitute the cylinder member of the present invention, and the piston 273 is held in the cylinder member. It corresponds to the first piston of the present invention, and the tip 273a of the outer peripheral side cylindrical portion thereof has a low brake (LOW / B) 27.
It is configured to press 0. Also, the piston 263
Corresponds to the second piston of the present invention and is held in the piston 273 to press and operate the low coast brake 260. And the piston 263 (second piston)
As shown in FIG. 5, the oil chamber 263a (second liquid chamber) that drives the oil passage 266 (first liquid passage) formed in the case 10 and the oil passage 273b (second liquid chamber) formed in the piston 273 are arranged in the oil chamber 263a (second liquid chamber). The pressure oil is supplied via the two liquid paths). A pair of seal members 275 and 276 are provided between the case 10 and the outer circumference of the cylindrical portion of the piston 273 to define the annular liquid chamber 273c.
The oil passage 266 and the oil passage 273b are communicated with each other, and the oil passage 266 and the oil passage 273b are connected via the annular liquid chamber 273c. Therefore, oil is supplied from the outer peripheral side to each oil chamber 273.
d, 263a is supplied to the inner peripheral side as in the conventional case, and the oil is guided to the inner peripheral side.
It is possible to avoid the configuration in which the oil is supplied through an oil passage provided in the inner cylindrical portion 10b) of As a result, the drilling of the component for forming the oil passage is a simple process that can be performed from the outer peripheral side of the component to reduce the processing cost, and from the control valve unit 300 to the oil chambers 273d and 273d.
The total length of the oil passage up to 3a can be significantly shortened, and moreover, between the members that relatively slide (that is, the case 10 and the piston 273).
Since the hydraulic pressure can be smoothly supplied during the (interval) period, the piston can be quickly operated and the gear shifting performance is improved.
In this case, as shown in FIG. 5, a concave portion is provided on the outer periphery of the cylindrical portion of the piston 273 so as to expand the diameter of the annular liquid chamber 273c to reduce the flow passage resistance. Even if the piston 273 moves in the entire stroke range, this concave portion
It is preferable that the oil passage 266 is set to have a length in the axial direction so as not to come off to the outside of the recess. Further, in this case, since the annular liquid chamber 273c is formed over the entire circumference, the oil passage 266 and the oil passage 273b are necessarily formed at positions (the same angle in the circumferential direction) facing each other. There is no need, and it can be formed at any position, so there is a high degree of design freedom. Furthermore, for example, the oil passage 273b may be formed at a plurality of positions in the circumferential direction, and by doing so, the flow passage resistance (pressure loss) at the time of oil supply can be further reduced, and a further speed change operation can be performed. This also makes it possible to reduce the discharge pressure of the oil pump. Further, in this case, the pair of seal members 2
One of the seal members 276, 75 and 276 also separates the oil chamber 273d of the piston 273 from the seal member 277. That is, the seal member 276 is the annular liquid chamber 2.
The oil chamber 273 is also used as a seal member that separates 73c.
It also functions as a seal member that is separated by d, and the number of parts is reduced.

(C) Overall Operation Next, the overall operation of the automatic transmission will be outlined. When the select lever is in the P range or the N range, all the clutches or brakes are maintained in the inoperative state by the control of the control unit and the control valve unit 300 as shown in FIG. Therefore, the rotation of the input shaft 110 is not transmitted to the output shaft 130, and the vehicle is maintained in a stopped state. When the select lever is operated to the P range, the parking ball (not shown) meshes with the parking gear 132 as described above, and the output shaft 1
30 is mechanically fixed.

Next, when the select lever is in the D range, the control unit receives a vehicle speed signal based on the vehicle speed sensor 133 and the like, a throttle opening signal from a throttle sensor attached to the engine of the vehicle, and the like, The shift position (1st speed to 5th speed) is determined based on the preset gear shift characteristic pattern, and by the control of the control unit and the control valve unit 300,
As shown in FIG. 5, a predetermined clutch or brake of the auxiliary transmission 100 is operated according to each shift position.

That is, in the first speed, the low clutch (L /
C) 170 and low brake (LOW / B) 270 and low one-way clutch (LOW / OWC) 280 are operated unconditionally, and when a predetermined engine brake operating condition is satisfied, low coast brake (LOW)
Activate Coast / B) 260. As a result, the driving force of the input shaft 110 is increased by the intermediate shaft 120.
Is transmitted to the third sun gear 161 via the third sun gear 161 and the third pinion gear 162 revolves with the rotation of the third sun gear 161 when the third ring gear 163 is stopped (third carrier 1
As a revolution of 64), the torque is greatly amplified (decelerated) and output to the output shaft 130. FIG.
Is a collinear chart showing the rotation speed of each element of each planetary gear on the vertical axis when the rotation speed of the input (input shaft 110) is constant, and the output shaft (output shaft for this first speed) The rotation number of 130) is represented by the point indicated by the reference numeral D1.

At this time, the low coast brake (LO
If W Coast / B) 260 is inactive, the third
Since the reverse drive force from the output shaft 130 is not transmitted to the input shaft 110 due to the idling of the ring gear 163 in one direction, so-called engine braking does not work, and this downshift to the first speed is smoothly performed without shock. However, if the engine brake operating condition is satisfied and the low coast brake 260 is activated, the third
Since the ring gear 163 is braked in either direction,
Depending on the driving condition and operating condition of the vehicle, the engine brake will work. The engine brake operating condition is, for example, a case where a special mode such as a power mode is set to the control unit by a power switch provided on the select lever and the accelerator opening is equal to or less than a predetermined value.

In the second speed, the low clutch (L / C)
170, second brake (2nd / B) 230 and second one-way clutch (2nd / OWC) 240
Are operated unconditionally, and if the predetermined engine brake operating conditions are satisfied, the reverse brake (R /
B) Activate 250. As a result, the driving force of the input shaft 110 is transmitted to the second sun gear 151 via the intermediate shaft 120, and the second sun gear 151 rotates with the second sun gear 151 stopped.
As the revolution of the pinion gear 152 (revolution of the second carrier 154), the torque is amplified (decelerated) to some extent and output to the output shaft 130. In the collinear chart of FIG. 6, the number of revolutions of the output shaft (output shaft 130) in the case of the second speed is indicated by a point D2.

At this time, the reverse brake (R / B)
When 250 is inactive, the second ring gear 153
Output shaft 130 by idling in one direction
Since the reverse driving force from the engine is not transmitted to the input shaft 110, so-called engine braking does not work.
Shifting down to high speed is also performed smoothly without shock. However, when the engine brake operating condition is satisfied and the reverse brake (R / B) 250 is operated, the second ring gear 153 is braked in either direction, and therefore the engine brake is activated depending on the running condition and the operating condition of the vehicle. Like

Next, in the third speed, the low clutch (L / C)
170 and the third brake (3rd / B) 200 and the third one-way clutch (3rd / OWC) 210 are operated unconditionally, and when the predetermined engine brake operating condition is satisfied, the overdrive brake (O
D / B) 220 is activated. As a result, the driving force of the input shaft 110 is transmitted to the second sun gear 151 via the intermediate shaft 120 and the first sun gear 141.
As the revolution of the second pinion gear 152 (the rotation of the first ring gear 143, the rotation of the second carrier 154) accompanying the rotation of the second sun gear 151 in the state where the rotation is stopped, a slight torque amplification (deceleration) is applied to the output shaft 130. Is output. In the collinear chart of FIG. 6, the number of revolutions of the output shaft (output shaft 130) in the case of the third speed is indicated by a point D3.

At this time, when the overdrive brake (OD / B) 220 is in the non-operating state, the reverse drive force from the output shaft 130 is generated by the idling of the first sun gear 141 in one direction.
Since it is not transmitted to, the so-called engine braking does not work, and the downshift to the third speed is performed smoothly without shock. However, when the engine brake operating condition is satisfied and the overdrive brake (OD / B) 220 is operated, the first sun gear 141 is braked in either direction, so that the engine brake works depending on the running condition and the operating condition of the vehicle. Like

In the 4th speed, low clutch (L / C)
170 and the high clutch (H / C) 180 are operated unconditionally. Accordingly, the driving force of the input shaft 110 is transmitted to the second sun gear 151, the third sun gear 161, the first carrier 144, and the second ring gear 153 via the intermediate shaft 120 and the hollow shaft member 121, and the output shaft 130 is directly transmitted. Is output from. At this time, as a result, each planetary gear 140, 150, 16
0 gears and output shaft 130
It will rotate integrally with the input shaft 110. In the collinear chart of FIG. 6, the number of revolutions of the output shaft (output shaft 130) in the case of the fourth speed is indicated by the symbol D4.

In the fifth gear, the high clutch (H / C)
180 and overdrive brake (OD / B) 220
And operate unconditionally. As a result, the driving force of the input shaft 110 passes through the hollow shaft member 121 to the first
The first sun gear 141 is transmitted to the carrier 144 and is rotated by the first pinion gear 142 while the first sun gear 141 is stopped.
Rotation of ring gear 143 (rotation of second carrier 154)
As a result, the torque is reduced (accelerated) and output to the output shaft 130. In addition, in the alignment chart of FIG.
The output shaft (output shaft 13
The rotation speed of 0) is represented by the point indicated by the reference numeral D5.

When a predetermined lockup operating condition is satisfied at each shift speed in the D range, the lockup piston 28 of the torque converter 20 is operated to directly connect the crankshaft of the engine and the input shaft 110. As a result, transmission efficiency and fuel efficiency can be improved. At this time, the hydraulic pressure for operating the lock-up piston 28 is engaged (while the pump impeller 23 and the turbine runner 24 are engaged with each other while detecting the rotation speed of the turbine runner 24 of the torque converter 20 based on the output signal of the input shaft rotation speed sensor 197). It is controlled so that the matching of the rotation speeds) is gradually performed. Also, the lockup operating conditions are
For example, this is a case where the power mode is not set and the speed is equal to or higher than the set vehicle speed and equal to or lower than the set throttle opening.

When the select lever is operated to the R range, the reverse clutch (R) is controlled by the control unit and the control valve unit 300.
/ C) 190 and reverse brake (R / B) 250 operate unconditionally. Then, the input shaft 110
The driving force of the first sun gear 1 is transmitted through the hollow shaft member 122.
41 and the first carrier 144 (the revolution of the first pinion gear 142) is stopped and the first sun gear 14
As the reverse rotation of the first ring gear 143 (reverse rotation of the second carrier 154) due to the rotation of No. 1, the output shaft 13
The rotation direction is reversed to 0 and the torque is amplified (decelerated) and output. Therefore, the vehicle can be moved backward. In the nomographic chart of FIG. 6, the rotational speed of the output shaft (output shaft 130) in the case of this R range is R
The point indicated by.

The present invention is not limited to the above embodiments,
There can be various aspects. For example, the cylinder member of the present invention is not limited to the aspect formed as a part of the case,
A configuration in which separate parts are fixed to the case may be used.

[0050]

According to the first aspect of the present invention, the second piston is provided via the first liquid passage provided in the cylinder member and the second liquid passage provided in the cylindrical portion of the first piston. Since the pressurized liquid is supplied to the driven second liquid chamber, the second liquid chamber of the second piston, which is the inner piston of the tandem piston, is also formed by the liquid passage formed on the outer peripheral side of the case.
The pressure liquid can be supplied. Therefore,
The configuration in which oil is supplied to each liquid chamber from the outer peripheral side is achieved, and it is possible to avoid the conventional configuration in which oil is once introduced to the inner peripheral side and supplied from the inner peripheral side. As a result, drilling of parts for forming oil passages is a simple process that can be performed from the outer peripheral side of the parts, reducing the processing cost and significantly increasing the total length of the oil passage from the control valve to each liquid chamber. Since it can be shortened to, the piston can be moved quickly and the gear shifting performance is improved.

According to the second aspect of the present invention, the first liquid is introduced through the annular liquid chamber defined by the pair of sealing members between the inner periphery of the cylinder member and the outer periphery of the cylindrical portion of the first piston.
Since the liquid passage and the second liquid passage are connected, the liquid pressure can be smoothly supplied between the members that relatively slide (that is, between the cylinder member and the first piston) without leakage, and a more rapid piston operation can be realized. . Further, in this case, since the first oil passage and the second oil passage do not have to be arranged at the opposite positions because they are connected via the annular chamber, the hydraulic pressure can be supplied without any problem even when the first piston rotates. Therefore, the degree of freedom in design is improved.

According to the third aspect of the invention, one sealing member functions both as a sealing member for partitioning the first liquid chamber and as a sealing member for partitioning the annular liquid chamber.
The number of parts is reduced, which contributes to downsizing and cost reduction.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of an automatic transmission according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a skeleton of the auxiliary transmission of the automatic transmission according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part of the automatic transmission according to the first embodiment of the present invention, which is a partially enlarged view of FIG.

FIG. 4 is a partial cross-sectional view of the automatic transmission according to the first embodiment of the present invention, which is a partially enlarged view of FIG.

5 is a partial cross-sectional view of the automatic transmission according to the first embodiment of the present invention, which is a partially enlarged view of FIG.

FIG. 6 is a diagram showing an operating state of each friction engagement element of the automatic transmission according to the first embodiment of the present invention.

FIG. 7 is a collinear chart showing a speed change state (relationship of rotational speeds of respective elements in the planetary gear) of the automatic transmission according to the first embodiment of the present invention.

[Explanation of symbols]

 10 case (cylinder member) 10a wall-shaped part (cylinder member) 10b inner cylindrical part (cylinder member) 263 piston (second piston) 263a oil chamber (second liquid chamber) 266 oil passage (first liquid passage) 273 piston (First piston) 273a Oil passage (second liquid passage) 273d Oil chamber (first liquid chamber) 273c Annular liquid chamber 275 Seal member 276 Seal member (one seal member)

Claims (3)

[Claims] 1. A cylinder member integrally formed with a case side of an automatic transmission, and a cylindrical portion slidably contacting an inner circumference of the cylinder member on an outer peripheral side of a bottom portion, the cylinder member sliding in the cylinder member. A first piston that is freely held and is driven by the pressure of a first liquid chamber formed between the bottom portion and the cylinder member; and a first piston that is slidably held in the cylindrical portion of the first piston. A tandem piston structure for an automatic transmission, comprising a second piston driven by the pressure of a second liquid chamber formed between the bottom of one piston and a first piston provided on an outer peripheral portion of the cylinder member. A tandem piston structure for an automatic transmission, characterized in that a pressure liquid is supplied to the second liquid chamber via a liquid passage and a second liquid passage provided in the cylindrical portion of the first piston. . 2. A pair of seal members that define an annular liquid chamber are provided between the cylinder member and the outer circumference of the cylindrical portion of the first piston, and the first liquid passage and the second liquid are provided in the annular liquid chamber. 2. The tandem piston structure for an automatic transmission according to claim 1, wherein the first liquid passage and the second liquid passage are connected to each other through the annular liquid chamber by connecting the passages to each other. 3. The tandem piston structure for an automatic transmission according to claim 2, wherein one of the seal members also functions as a seal member that separates the first liquid chamber.