JPH0543907B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a fluid pressure actuator for an automatic transmission that includes an annular cylinder portion that is stacked in the radial direction to form a two-layer structure. (Prior Art) Conventionally, automatic transmissions installed in vehicles etc. have a gear transmission mechanism and components of the gear transmission mechanism are selectively attached to other components or an automatic transmission case (transmission case). A plurality of friction engagement elements such as a multi-disc clutch or a multi-disc brake for engagement, a fluid pressure actuator such as a hydraulic servo for engaging and disengaging the friction engagement elements, and shifting of the fluid pressure actuator. lever setting position,
The hydraulic control device is selectively operated depending on vehicle speed, engine load, etc. to achieve a predetermined gear position. By the way, among the above-mentioned frictional engagement elements, a multi-plate clutch for achieving forward running requires a particularly high transmission torque capacity, for example, in first gear. The fluid pressure actuator for this purpose has two annular cylinders arranged in parallel in the radial direction, and a piston part is slidably attached to each of the two annular cylinder parts. That is, a two-layer cylinder is formed by an inner annular cylinder part and an outer annular cylinder part arranged in parallel on the outer periphery of the inner annular cylinder part, and an inner annular piston part is slidably fitted into the inner annular cylinder part, and the outer annular cylinder part is slidably fitted into the inner annular cylinder part. An outer annular piston portion is slidably fitted into the portion. A hydraulic oil supply passage connecting the inner annular cylinder portion and the outer annular cylinder portion is formed, and hydraulic oil is supplied to and discharged from the outer annular cylinder portion via the hydraulic oil supply passage. It's summery. (Problem to be Solved by the Invention) However, in the hydraulic actuator of the automatic transmission configured as described above, the supply of hydraulic oil to each of the two annular cylinder parts is started almost simultaneously, and after the start of supply, Since only the supply speed of the hydraulic oil is adjusted, a peak occurs in the torque characteristics and a shift shock occurs. That is, for example, in a hydraulic servo of a multi-disc clutch that is engaged to achieve forward travel, the pressure increase characteristics of the hydraulic pressure in each annular cylinder part and the output shaft torque of the automatic transmission are as shown by the solid line in Fig. 3. Change. In FIG. 3, P _2A is the hydraulic oil pressure in the inner annular cylinder section, and P _2B is the hydraulic oil pressure in the outer annular cylinder section. When the oil pressure increases in this way, peaks m1 and m2 occur in the output shaft torque curve, and a shift shock occurs during the N-D shift. The present invention solves the above-mentioned problems of the conventional hydraulic actuator for automatic transmissions, and provides near-ideal torque characteristics and hydraulic servo boost characteristics in the hydraulic actuator for automatic transmissions having two-layer cylinders. It is an object of the present invention to provide a hydraulic actuator for an automatic transmission that can reduce the shift shock. (Means for Solving the Problems) For this purpose, in the fluid pressure actuator for an automatic transmission of the present invention, a two-layer cylinder having an inner annular cylinder portion and an outer annular cylinder portion arranged in parallel on the outer periphery of the inner annular cylinder portion. A piston is provided. The piston includes an inner annular piston portion and an outer annular piston portion, the inner annular piston portion being slidably fitted into the inner annular cylinder portion, and the outer annular piston portion being slidable into the outer annular cylinder portion. It will be inserted into. Further, an oil hole is provided for supplying and discharging hydraulic oil to either one of the inner annular cylinder part and the outer annular cylinder part, and the inner annular cylinder part and the outer annular cylinder part are connected to the inner and outer cylinders. connected to the road. The inner and outer cylinder communication oil passages are provided at positions where they communicate when the piston is displaced by a set distance from the innermost stopping point. (Operations and Effects of the Invention) According to the present invention, as described above, the piston is disposed in a two-layer cylinder having an inner annular cylinder portion and an outer annular cylinder portion arranged in parallel on the outer periphery of the inner annular cylinder portion. The piston includes an inner annular piston portion and an outer annular piston portion, the inner annular piston portion being slidably fitted into the inner annular cylinder portion, and the outer annular piston portion being slidable into the outer annular cylinder portion. It will be inserted into. Therefore, since the frictional engagement element is engaged and disengaged by the inner annular cylinder portion and the outer annular cylinder portion, the transmission torque capacity is increased. Further, an oil hole is provided for supplying and discharging hydraulic oil to either one of the inner annular cylinder part and the outer annular cylinder part, and the inner annular cylinder part and the outer annular cylinder part are connected to the inner and outer cylinders. The roads are connected. Therefore, the hydraulic oil supplied to either the inner annular cylinder portion or the outer annular cylinder portion through the oil hole is supplied to the other annular cylinder portion via the inner/outer cylinder communication oil passage. At this time, since the above-mentioned inner and outer cylinder communication oil passages are provided at positions where they communicate when the above-mentioned piston is displaced by a set distance from the innermost stopping point, the inner and outer cylinder parts communicate with each other through the oil holes. When the supply of hydraulic oil to either one of the cylinder sections is started, the other annular cylinder section is not supplied with hydraulic oil, and after the piston has been displaced by the set distance, the other annular cylinder section is operated. Oil will be supplied. Therefore, fluctuations in the transmission torque capacity of the friction engagement element are smoothed by the delay in the rise of the hydraulic pressure, and it is possible to obtain near-ideal torque characteristics and pressure increase characteristics of the hydraulic servo, and to reduce shift shock. I can do it. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Reference numeral 14 indicates an intermediate transmission shaft of a transmission of an automatic transmission for a vehicle, C1 indicates a clutch which is a multi-plate friction engagement element, and C-1 indicates a hydraulic servo which is a hydraulic actuator thereof. A collar-shaped portion 14A having a large outer diameter is provided on the outer periphery of the rear portion (the right side portion in the figure) of the transmission shaft 14, and a rear end portion 15 at the rear of the collar portion 14A has a center hole 16 with a slightly larger outer diameter. It has a cylindrical shape. Said collar-shaped part 14
At the front end of the outer periphery 14C of A, there is a bottom wall portion 1A that is flush with the front surface 14D of the collar portion 14A, an outer cylindrical portion 1B extending from the outer periphery of the bottom wall portion 1A, and an outer cylindrical portion 1B further extending from the outer cylindrical portion 1B. Spline 1 on the inner circumference
A cylinder drum 1 consisting of a clutch drum portion 1C provided with D is welded. The hydraulic servo C-1 is a two-layer cylinder having an inner annular cylinder portion (hereinafter referred to as the inner cylinder) 2A and an outer annular cylinder portion (hereinafter referred to as the outer cylinder) 2B provided on the outer periphery thereof. 2, an inner annular piston part (hereinafter referred to as "inner piston") 3A that is slidably fitted in the inner cylinder 2A, and an outer annular piston part (hereinafter referred to as "outer piston") that is slidably fitted in the outer cylinder. The piston 3 is composed of a piston 3 having an intermediate cylindrical portion 3C provided at the connecting portion between the inner piston and the outer piston, and return biasing means 4 for the piston 3. In this embodiment, the inner cylinder 2A of the two-layer cylinder has a rear end outer peripheral surface 14E of the transmission shaft,
In this embodiment, the outer circumferential surface 14C of the collar-shaped portion of the transmission shaft is
It is formed by the inner circumferential surface 3D of the intermediate cylindrical portion 3C of the piston that slides on the piston, and the rear surface 14F of the brim portion 14A. Further, the outer cylinder 2A of the two-layer cylinder has an outer circumferential surface 14 of the brim portion 14A.
C, an inner circumferential surface 1E of the outer cylindrical portion 1B of the drum 1, and an inner surface 1F of the bottom wall portion 1A. The inner piston 3A of the piston has an inner periphery 3E that slides on the outer periphery 14C of the rear end of the transmission shaft, and the outer periphery is connected to the rear end of the inner periphery 3D of the intermediate cylindrical portion 3C of the piston, Said outer piston 3B
has an inner periphery 3F surrounding the outer periphery 14 of the collar-shaped part of the transmission shaft and an outer periphery 3G slidingly in contact with the inner periphery 1E of the outer cylindrical part of the drum, and has an inner periphery 3F and an outer periphery 3B. A protrusion 3H is provided around the middle rear surface. A relief valve 3e consisting of an orifice-equipped plug 3a and a ball valve 3b is attached to the outer annular piston portion 3B of the piston 3. The return biasing means 4 includes a snap spring 4B fitted into a groove 4A provided on the outer periphery of the rear end of the transmission shaft 14, and a rear end portion 14B of the transmission shaft whose inner peripheral portion is locked by the snap spring 4B. The externally fitted annular plate-shaped spring retainer 4C, the piston protrusion 3H and the spring retainer 4
A turn spring 4D is interposed between the outer circumferential portion of C and the outer peripheral portion of C. The transmission shaft 14 is provided with a hole 14K forming a lubricating oil supply path and an oil hole 6 for supplying hydraulic oil to the inner cylinder 2A. In this embodiment, the oil hole 6 includes an axial hole 6A formed from the center hole 16 and into which a ball stopper 6a is fitted, a radial hole 6B connecting the axial hole 6A and the outside of the axis, and It consists of an axial hole 6A and an oblique hole 6C that communicates with the inner cylinder 2A. Further, the flange-like portion 14A of the transmission shaft 14 is provided with an inner/outer cylinder communication oil passage that communicates the inner cylinder 2A and the outer cylinder 2B. In this embodiment, the inner and outer cylinder communication oil passages are connected to an axial hole 7A provided from the rear surface 14F of the flange-shaped portion and an outer circumferential surface 1 of the flange-shaped portion.
4C, a hydraulic oil supply oil passage 7 consisting of a radial hole 7B opened at an intermediate position, a shaft hole 8A formed in the axial direction from the rear surface 14F of the collar, and a shaft hole 8A formed in the front of the outer peripheral surface of the collar. It is comprised of a hydraulic oil discharge passage 8 consisting of a radial hole 8B opened at a horizontal position and a check ball 8C provided in the shaft hole 8A. Importing the oil passage 7 to the outer cylinder 7
C is set to open when the piston 3 is displaced to the position indicated by the dashed-dotted line, and the oil passage 8 has an opening 8D substantially at the innermost part of the outer cylinder. The clutch C1 includes an outer friction plate 9A meshed with a spline 1D of the clutch drum 1C, a clutch hub 9B provided coaxially with the clutch drum and connected to an output member (not shown), and a clutch hub 9B provided on the outer periphery of the clutch hub. The inner friction plate 9D is meshed with the spline 9C and overlapped with the outer friction plate 9A. When hydraulic oil is supplied from the oil passage 6 in a state where the piston 3 is stopped at the innermost part of the cylinder 2 (the position indicated by the solid line in Fig. 1), this hydraulic servo C-1 first moves inside. Pressure oil enters cylinder 2A.
This causes the piston 3 to move to the return spring 4D.
is compressed and quickly displaced by the play gap L between the piston 3 and the friction plates 9A, 9D. Next, as the working oil pressure increases, the frictional force between the friction plates 9A and 9D is increased. In this state, the import 7C of the oil passage 7 opens and hydraulic oil begins to be supplied to the outer cylinder 3B. As a result, the transmission torque capacity of the clutch C1 changes as shown by the one-dot chain line in FIG. 3, reducing shift shock during gear changes. FIG. 2 shows an automatic transmission for a vehicle using the hydraulic actuator of the automatic transmission of the present invention. In this embodiment, the cylinder drum 1 is applied to a third hydraulic servo drum 46 forming the hydraulic servo C-1 of the clutch C1. The automatic transmission 100 includes a hydraulic torque converter 200, a transmission 300, and a hydraulic control device 400. The transmission 300 includes a first planetary gear set p1, one multi-disc clutch C0 operated by a hydraulic servo, one multi-disc brake B0,
and an overdrive planetary gear transmission 10 with one one-way clutch F0, a second planetary gear set p2, a third planetary gear set p3, two multi-disc clutches C1, C2 operated by hydraulic servo, one belt brake B1,
3 forward gears reverse 1 with two multi-disc brakes B2, B3 and two one-way clutches F1, F2
The underdrive planetary gear transmission 40 is comprised of a two-stage underdrive planetary gear transmission 40. An automatic transmission case 110 includes a torque converter housing 120 that houses a torque converter 200 and an overdrive planetary gear transmission 10.
and an underdrive planetary gear transmission 40, an extension housing 140 that covers the rear side of the automatic transmission 100, and the torque converter housing 120, the transmission case 130, Extension housing 140
and are each fastened with a large number of bolts so that they have coaxial centers. Torque converter 200 is located at the front (engine side)
is housed in the open torque converter chamber 121,
A front cover 111 connected to an engine output shaft (not shown), an annular plate-shaped rear cover 112 welded to the front cover 111 at its outer periphery, and a pump impeller 205 installed around the inner wall of the rear cover 112. , a turbine runner 206 disposed opposite the pump impeller 205, a turbine shell 207 holding the turbine runner 206, and a fixed shaft 2 via a one-way clutch 202.
03, a friction surface 20 provided on the inner surface of the front cover 111, and an annular plate-shaped clutch disk 50 whose inner circumference is connected to a turbine hub 208 which is an output member.
The front cover 111 and the turbine hub 208
A lock-up clutch 80 is provided to connect between the two. A cylindrical transmission chamber 1 continuous to the rear of the torque converter chamber 121
32 and the torque converter chamber 121, an oil pump front cover 151 having an annular plate shape and a cylindrical portion 152 projecting forward in the center and housing the oil pump 150 therein is located on the front end surface of the transmission case 130. The oil pump front cover 15
An oil pump cover 154 having a cylindrical front support 153 that is coaxial with the cylindrical portion 152 and protrudes rearward is fastened to the rear side of the oil pump cover 1. The oil pump front cover 151 and the oil pump cover 154 form an oil pump housing 155, and the torque converter chamber 121
It serves as a partition between the transmission chamber 132 and the transmission chamber 132. Further, in the middle of the transmission chamber 132, an intermediate support wall 159 having a cylindrical center support 158 that partitions the overdrive mechanism chamber 133 and the underdrive mechanism chamber 134 and projects rearward is separately cast and fitted. There is. At the rear part, a rear support wall 157 having a cylindrical rear support 156 that projects forward is provided by integral casting. The transmission chamber 13 is located between the partition wall 155 and the rear support wall 157.
2, and the output shaft chamber 141 of the transmission is located between the rear support wall 157 and the extension housing 140.
An electronically controlled sensor rotor 143 and a speedometer drive gear 144 are provided in the output shaft chamber 141, and a sleeve yoke (not shown) coaxial with the front support 153 is inserted through the rear end. . A fixed shaft 203 of the one-way clutch 202 that supports the stator 201 of the torque converter 200 is fitted inside the front support 153.
A torque converter 200 is installed inside the fixed shaft 203.
The input shaft 11 of the transmission is the output shaft of
is rotatably supported. The input shaft 11 has a flange portion 12a at the rear of the front support 153.
A center hole 13 is formed in the center of the rear end portion 12 having a large diameter. At the rear of the input shaft 11, an intermediate transmission shaft 14 is rotatably mounted, the tip of which slides into the center hole 13 and is arranged in series with the input shaft 11. Output shaft 36 in the center
A center hole 16 is formed into which the tip of the holder slides.
The output shaft 36 is spline-fitted at an intermediate portion 37 with a flange plate 82 provided with a rearwardly protruding shaft support 81 that meshes with the ring gear R2 of the third planetary gear set p3, and at a rear portion 38 is spline-fitted with the sleeve yoke. They are mated. In the overdrive mechanism chamber 133, a first planetary gear set p is provided on the rear side of the input shaft 11.
1 is provided, the ring gear R0 is connected to the intermediate transmission shaft 14 via a flange plate 22, and the planetary carrier P0 is connected to the flange portion 12 of the input shaft 11.
a, and the sun gear S0 is connected to the inner race shaft 2.
It is formed in 3. On the front side of the first planetary gear set p1, a first hydraulic servo drum 24 that opens rearward is fixed to an inner race shaft 23, and an annular piston 25 is fitted between the outer peripheral wall of the drum and the inner race shaft 23, and the clutch C0 A return spring 26 is attached to the inner race shaft 23 side, and a clutch C0 is attached to the inner side of the outer peripheral wall, and is connected to the carrier P0 via the clutch C0. A one-way clutch F0 having the inner race shaft 23 as an inner race is provided on the inner periphery of the first hydraulic servo drum 24, and a clutch C0 and a brake B0 are provided on the outer periphery between the outer race 27 and the transmission case 130.
A piston 29 is fitted into the front side of the intermediate support wall 159 on the rear side to form a hydraulic servo B-0 of the brake B0, and a return spring 32 is fitted into the inner periphery 31 of the outer cylinder part of the intermediate support wall 159. . Inside the underdrive mechanism chamber 134, at the front, a second hydraulic servo drum 41 that opens rearward is rotatably fitted onto the center support 158, and an annular piston 42 is fitted between its inner and outer circumferential walls to drive the clutch C2. A hydraulic servo C-2 is formed and a return spring 4 is installed on the inner peripheral wall side.
4. A clutch C2 is installed inside the outer peripheral wall. On the rear side of the second hydraulic servo drum 41,
A cylindrical clutch hub 3 opens at the rear and at the front.
A third hydraulic servo drum 1 for forming a cylinder of a hydraulic actuator of an automatic transmission according to the present invention is fixed to a rear end portion 15 of an intermediate transmission shaft 14, to which a third hydraulic servo drum 1 is welded. An annular piston 3 is fitted between the clutch C1 and a hydraulic servo C-1 of the clutch C1, and a return biasing means 4 is provided on the inner circumferential side, and a cylindrical clutch hub 35
A clutch C2 is attached to the outer periphery of the clutch C2.
The second and third hydraulic servo drums 41 are connected via. A second planetary gear set p2 is provided on the rear side of the third hydraulic servo drum 46,
The ring gear R1 is connected to the third hydraulic servo drum 4 via the cylindrical clutch hub 48 and the clutch C1.
6, the carrier P1 is spline-fitted to the tip of the output shaft 36, and the sun gear S1 is integrally formed with the sun gear shaft 45. Further, a connecting drum 60, which is molded to cover the second and third hydraulic servo drums 41, 46 and the second planetary gear set p2 in a minimum space, is fixed to the outer periphery of the second hydraulic servo drum 41 at its tip, and The end is connected to the sun gear shaft 45 on the rear side of the second planetary gear set p2, and a belt brake B1 is provided on the outer circumferential side. A spline 75 formed inside the transmission case 130 on the rear side of the brake B2.
is the brake disc b of brake B2 from the front.
2. The brake disc b3 of the brake B3 is spline-fitted, and the piston 77 is fitted into the annular hole between the outer peripheral side of the rear support 156 of the rear support wall 157 and the transmission case 130, and the hydraulic servo of the brake B3 is fitted. A return spring 79 of the hydraulic servo B-3 is supported by a flange plate 82 attached to the tip of the rear support 156. A one-way clutch F1 having the sun gear shaft 45 as an inner race is provided inside the brake B2, an outer race 39 is connected to the brake B2, and a return biasing means 90 and an inner race are provided on the rear side of the one-way clutch F1. 83 to the fourth hydraulic servo drum 7
2 and a spline-fitted one-way clutch F2 on the outer inner diameter. In the third planetary gear set p3, the sun gear S2 is connected to the sun gear shaft 4.
5, the carrier P2 is connected to the outer race 86 of the front one-way clutch F2, and the ring gear R2 is connected to the brake B3, and has a parking gear 85 around the outer periphery of the output shaft 3.
6. When the shift lever of the automatic transmission is selected to the parking (P) position, the parking claw 84 engages with the parking gear 85 to fix the output shaft 36. An annular fourth hydraulic servo drum 7 opened at the front.
2, an intermediate cylinder 71 is press-molded, and an annular piston 73 is fitted between the fourth hydraulic servo drum 72 and the intermediate cylinder 71 to form a hydraulic servo B-2 of the brake B2, and a fourth hydraulic servo A return spring 74 is installed between the inner peripheral wall of the drum 72 and the intermediate cylinder 71, and a brake B2 is installed inside the outer peripheral wall. The transmission 300 operates from a hydraulic control device 400 in a valve body 403 built in an oil pan 401 fastened to the lower part of the transmission case 130 with bolts 402, depending on vehicle running conditions such as vehicle speed and throttle opening. The hydraulic pressure selectively output to the hydraulic servo of each frictional engagement device engages or releases each clutch and brake, resulting in four forward speeds or one reverse speed change. Table 1 shows an example of the operation of each clutch, brake, and one-way clutch and the achieved gear position (RANGE).

[Table] In Table 1, E indicates that the corresponding clutch, brake, or one-way clutch is engaged.
(L) indicates that the corresponding one-way clutch is engaged only in engine drive conditions and not in engine brake conditions. Furthermore, the one-way clutch corresponding to L is engaged in the engine drive state, but this engagement is not necessarily required since power transmission is guaranteed by the clutch or brake built in parallel. Indicates that (lock). Furthermore, f indicates that the corresponding one-way clutch is free.
Furthermore, an X indicates that the corresponding clutch and brake are released.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a fluid pressure actuator for an automatic transmission according to the present invention, FIG. 2 is a cross-sectional view of an automatic transmission employing the fluid pressure actuator, and FIG. 3 is a diagram showing hydraulic pressure rise characteristics and It is a graph showing changes in transmission torque capacity. In the figure, 2... cylinder, 3... piston, 10
0... Automatic transmission, 200... Torque converter, 300... Transmission, 400...
Hydraulic control device, C1...Multi-disc clutch, C-1...
...Hydraulic servo, 2A...Inner annular cylinder part,
2B...Outer annular cylinder part, 3A...Inner annular piston part, 3B...Outer annular piston part.

Claims (1)

[Claims] 1. A two-layer cylinder having an inner annular cylinder part and an outer annular cylinder part arranged in parallel on the outer periphery thereof, an inner annular piston part slidably fitted into the inner annular cylinder part, and an outer annular cylinder part that slides on the outer annular cylinder part. A piston having an outer annular piston part fitted into a material, an oil hole for supplying and discharging hydraulic oil to either one of the inner annular cylinder part and the outer annular cylinder part, the inner annular cylinder part and It has an inner and outer cylinder communication oil passage that communicates the outer annular cylinder portion, and the inner and outer cylinder communication oil passage is provided at a position where the communication occurs when the piston is displaced by a set distance from the innermost stopping point. A hydraulic actuator for an automatic transmission, characterized in that: