JPH0456174B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a friction engagement device including a hydraulic actuator and an accumulator having two hydraulic chambers. "Conventional technology" For example, in automatic transmissions installed in vehicles,
A transmission mechanism, a plurality of friction engagement elements such as a multi-disc clutch or a multi-disc brake for engaging its components with other components or a transmission case (transmission case), and the friction engagement elements and a hydraulic control device that selectively operates the hydraulic actuator to configure a predetermined gear position. Among the frictional engagement elements, for example, a frictional engagement element that requires a particularly high transmission torque has two hydraulic pressure chambers provided in parallel, and a sliding mechanism in each of the two hydraulic pressure chambers. A hydraulic actuator combined with an attached piston is effective. Furthermore, when the engagement element is engaged, the hydraulic pressure is supplied to the hydraulic pressure chamber from an oil pump whose drive source is the output shaft of the engine, and which is provided in the hydraulic control device, and is connected to the oil pump according to the vehicle running conditions. Pressure oil is regulated to a predetermined oil pressure by a hydraulic pressure adjustment mechanism (regulator valve, etc.) that regulates the discharge pressure, and is supplied via a manual valve and an oil passage switching valve operated by input oil pressure corresponding to vehicle running conditions. , when the friction engagement element is released, it is discharged through these switching valves. The hydraulic oil supply and drainage path to the hydraulic pressure chamber is controlled to adjust the rise (pressure increase characteristic) and fall (pressure drop characteristic) of the hydraulic pressure in the hydraulic pressure chamber, thereby controlling the engagement of the frictional engagement element. In order to adjust the timing of engagement and release and reduce the shock during gear shifting, there is normally a cylinder chamber and an accumulator piston that is slidably fitted into the cylinder chamber and partitions the cylinder chamber into an accumulator chamber and an oil drain chamber. , a return spring, a back pressure, or other means for biasing the return of the accumulator piston. As mentioned above, a friction engagement device using an accumulator as a hydraulic actuator for two hydraulic chambers is
Conventionally, as shown in FIG. 11, a hydraulic actuator 3 drives a piston 33 and engages a friction coefficient element 2 using hydraulic pressure supplied to a first hydraulic chamber 31 and a second hydraulic chamber 32. , a first oil supply and discharge passage 41 having an orifice (restriction) 41A in the flow passage for supplying and discharging hydraulic fluid to and from the first hydraulic pressure chamber 31; Hydraulic pressure chamber 32
An orifice 42 is installed in the flow path for supplying and discharging hydraulic oil.
A second oil drain passage 42 having a diameter of It was set up. "Problems to be Solved by the Invention" As shown above, in the conventional technology, the supply and discharge ports of the hydraulic pressure chamber of the accumulator are provided in communication with the working oil supply and discharge passages on the hydraulic oil supply side of the orifice. Therefore, as shown in FIG. 12, even if an orifice for hydraulic pressure adjustment is provided on the upstream side of the accumulator, the working oil pressure P1 supplied to the first hydraulic pressure chamber will be lower than t1 when the accumulator piston starts due to the action of the accumulator.
The pressure increases linearly from t1 to t2 when the accumulator piston ends, but since the working pressure P2 supplied to the second hydraulic pressure chamber is controlled by the inflow amount of the orifice, the increase increases from t1 at startup to t2 at end. Pressure is not applied linearly, resulting in large oil pressure fluctuations. The torque capacity Tc applied to the piston of the hydraulic actuator is K x (P1 x A1 + P2 x A2) (A1: pressure receiving area of the piston in the first hydraulic pressure chamber, A2: pressure receiving area of the piston in the second hydraulic pressure chamber, K: friction As a result, the torque capacity Tc of the piston has a large torque fluctuation when the accumulator is accumulating pressure (t1 to t2), as shown in FIG. The purpose of the present invention is to
An object of the present invention is to provide a friction engagement device that linearizes torque fluctuations applied to a piston of an actuator having two hydraulic chambers and smoothly engages friction engagement elements. "Means for Solving the Problems" In order to solve the above problems, the frictional engagement device of the present invention drives a piston by hydraulic pressure supplied to a first hydraulic pressure chamber and a second hydraulic pressure chamber, a hydraulic actuator that engages the friction coefficient element; a first supply and discharge path for supplying and discharging hydraulic fluid to and from the first hydraulic pressure chamber; communicating with the first supply and discharge passage via a throttle; It is comprised of a second supply and discharge passage for supplying and discharging the working fluid from the second hydraulic pressure chamber, and an accumulator provided in the second supply and discharge passage. "Operations and Effects of the Invention" The frictional engagement device of the present invention having the above-mentioned configuration is provided with an accumulator that accumulates pressure of the hydraulic fluid supplied to the second hydraulic pressure chamber through the throttle. It is possible to linearly control the rise in hydraulic pressure to the second hydraulic pressure chamber, thereby linearly controlling the torque fluctuations applied to the piston of the accumulator.
The frictional engagement elements can be smoothly engaged. "Effects of the Example" By providing a bypass oil path in parallel with the restriction in the second oil supply/drainage path having a check valve that closes when hydraulic fluid is supplied and opens when hydraulic fluid is supplied/discharged, When discharging the hydraulic fluid, the hydraulic fluid in the accumulator chamber and the hydraulic fluid in the second hydraulic pressure chamber can be quickly discharged via the bypass path. "Embodiment" Next, the frictional engagement device of the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a schematic diagram in which the frictional engagement device of the present invention is applied to a friction clutch mechanism. The frictional engagement device 1 includes a frictional engagement element 2 that transmits power when engaged and cuts off the power when released, and presses the frictional engagement element 2 when supplied with hydraulic oil. First hydraulic chamber 3
1 and a second hydraulic chamber 32, the first hydraulic chamber 31, the second hydraulic chamber 32, and the piston 33 slidably mounted on the first hydraulic chamber 31 and the second hydraulic chamber 32. a hydraulic actuator 3 comprising a first hydraulic chamber 31 and a second hydraulic chamber 32 supplied with hydraulic oil to drive a piston 33 to press and engage the frictional engagement element 2; Said first hydraulic chamber 31
a first oil supply and discharge passage 41 having an orifice 41A that controls the supply flow rate of hydraulic oil to a flow passage for supplying and discharging hydraulic oil; and the first oil supply and discharge passage 4.
1, and has an orifice 42A for controlling the supply flow rate of hydraulic oil to the flow passage for supplying and discharging hydraulic oil from the second hydraulic pressure chamber 32; An accumulator 5 that accumulates pressure of hydraulic oil supplied to the chamber 32 and smoothly engages and releases the frictional engagement element 2, and a piston 33 of the hydraulic actuator 3 are attached in the opposite direction to the frictional engagement element 2. When the hydraulic oil in the first hydraulic chamber 31 and the second hydraulic chamber 32 is drained, the piston 33 is moved in the opposite direction to the frictional engagement element 2, and the first hydraulic chamber 3
and a return biasing means 6 for the piston 33 that prevents the frictional engagement element 2 from dragging when draining oil from the first and second hydraulic pressure chambers 32. When the frictional engagement device 1 configured as described above receives hydraulic oil from the hydraulic oil supply/drainage path 4 to engage the frictional engagement element 2, it is supplied to the first hydraulic pressure chamber as shown in FIG. The first oil supply and drainage passage 41 that supplies and discharges hydraulic oil to the first hydraulic pressure chamber 31 is connected to the second oil supply and drainage passage 42.
P1 = {d ₁ ⁴ / (d ₁ ⁴ +
d ₂ ⁴ )} × P0 + {d ₂ ⁴ / (d ₁ ⁴ + d ₂ ⁴ )} × P2 (P0: hydraulic pressure supplied to the hydraulic oil supply and drainage path 4, P2: operation of the second hydraulic pressure chamber 32 Hydraulic pressure, di: diameter of orifice 41A, d2: diameter of orifice 42A).
Here, the working oil pressure P2 of the second hydraulic pressure chamber 32 is changed from t1 when the accumulator piston starts, because the accumulator 5 accumulates the hydraulic oil supplied through the orifice 42A in response to the inflow pressure. The pressure is increased linearly until the final time t2. As a result, the above (d ₁ ⁴ / d ₁ ⁴ + d ₂ ⁴ )×P0+
The first hydraulic pressure chamber 3 is expressed as (d ₂ ⁴ /d ₁ ⁴ +d ₂ ⁴ )×P2
1's working oil pressure P1 also varies from t1 when the accumulator piston starts to t2 when the accumulator piston ends.
Pressure increases linearly until As a result, the torque capacity applied by the piston 33 of the hydraulic actuator 3
Tc is determined by K x (P1 x A1 + P2 x A2) (A1: pressure receiving area of the piston in the first hydraulic pressure chamber, A2: pressure receiving area of the piston in the second hydraulic pressure chamber, K: number of frictional engagement elements and center diameter) As a result, the torque capacity Tc of the piston 33 increases linearly when the accumulator 5 accumulates pressure (t1 to t2), as shown in FIG. can be done. Next, an embodiment in which the frictional engagement device of the present invention is applied to a brake mechanism of a four-wheel drive transmission consisting of a main transmission and a sub-transmission will be described with reference to FIGS. 4 to 10. Figure 4 is a schematic diagram of a four-wheel drive transmission;
The figure is a sectional view of the sub-transmission shown in Fig. 4, Figs. 8 and 9 are hydraulic circuit diagrams of the hydraulic control device of the main transmission and sub-transmission, and Fig. 10 is a block diagram of the electronic control device of the hydraulic control device. Show the diagram. The main transmission 100 includes a hydraulic torque converter T, an overdrive mechanism OD, and an underdrive mechanism UD with three forward speeds and one reverse speed. The torque converter T includes a pump 111 connected to the output shaft of an engine (not shown), and a turbine 11 connected to the output shaft 112 of the torque converter T.
3, a stator 115 connected to a stationary part via a one-way clutch 114, and a linear clutch 1
16, the output shaft 11 of the torque converter T
2 is the input shaft of the overdrive mechanism OD. The overdrive mechanism OD includes a multi-disc clutch Co, a multi-disc brake Bo, and a one-way clutch Fo, which are friction engagement elements, and the selective engagement of these friction engagement elements causes the components to be attached to a fixed member such as the main transmission case 120. It consists of a planetary gear set Po that is fixed, connected to the input shaft, output shaft, or other components, or released from these fixations or connections. The planetary gear set Po is connected to the output shaft 11.
2, a ring gear 123 connected to the output shaft 122 of the overdrive mechanism OD, and a brake Bo rotatably fitted to the input shaft 112. , a sun gear 124 connected to the carrier 121 via a clutch Co and a one-way clutch Fo parallel to the clutch Co;
and rotatably supported by the carrier 121, and the sun gear 124 and ring gear 123.
It consists of a planetary pinion 125 meshed with. The output shaft 122 of the overdrive mechanism OD also serves as the input shaft of the underdrive mechanism UD, which has three forward stages and one reverse stage. The underdrive mechanism UD includes multi-disc clutches C1 and C2, which are frictional engagement elements, a belt brake B1, multi-disc brakes B2 and B3, one-way clutches F1 and F2, a front planetary gear set P1, and a rear planetary gear. Set P2
And so on. The front planetary gear set P1 is the clutch C.
a ring gear 131 connected to the output shaft 122 via a clutch C2; a carrier 133 connected to the output shaft 132 of the underdrive mechanism UD; and a belt brake connected to the output shaft 122 via a clutch C2. B1, the belt brake B
1 and brake B2 in parallel with
a sun gear 134 fixed to the main transmission case 120 via a one-way clutch F1 in series with the main transmission case 120;
It consists of a planetary pinion 135 that is rotatably supported by the carrier 133 and meshed with a sun gear 134 and a ring gear 131. The rear planetary gear set P2 is the brake B
3, a carrier 136 fixed to the main transmission case 120 via a one-way clutch F2 parallel to the brake B3, a sun gear 137 integrally formed with the sun gear 134 of the preceding planetary gear set P1, and an output A ring gear 138 connected to the shaft 132 and a planetary pinion 139 rotatably supported by the carrier 136 and meshed with the sun gear 137 and the ring gear 138.
It consists of. As shown in FIG.
The output shaft 1 of the planetary gear sets P1 and P2 is equipped with a clutch C3, a brake B4, and a clutch C4, which are frictional engagement elements that do not switch between wheel drive and four-wheel drive, and between a direct connection state and a deceleration state.
32 as an input shaft, and a first output shaft 201 of the transfer 200 arranged in series with the output shaft 132;
A planetary gear set P3 disposed between the output shaft 132 and the first output shaft 201, a four-wheel drive sleeve 202 rotatably fitted on the first output shaft 201, and a four-wheel drive sleeve 202 parallel to the output shaft 132. a second output shaft 203 installed in parallel with the first output shaft 201 to output in the opposite direction; a transmission mechanism 20 between the sleeve 202 and the second output shaft 203;
It has 4. Planetary gear set P3 includes sun gear 2 spline-fitted to the end of output shaft 132.
05, a planetary pinion 206 that meshes with the sun gear 205, a ring gear 207 that meshes with the planetary pinion 206, and a ring gear 207 that rotatably holds the planetary pinion 206 and is attached to the tip of the first output shaft 201 of the transfer shaft 200. It consists of linked carriers 208. carrier 20
A parking gear 210 is provided around the outer circumferential side of the cylinder 209 connected to the cylinder 8.
When the shift lever of the main transmission 100 is selected to the parking position, the pawl 211 moves to the parking gear 2.
10 and fixes the first output shaft 210. Clutch C3 is disposed on the sub-transmission case 212 side of planetary gear set P3, and is connected to sun gear 20.
5 and the carrier 208, the hydraulic cylinder 216 and the clutch cylinders 214, 215 are connected to the carrier 208 via a cylinder 209, and have an inner circumference and an outer circumference forming clutch cylinders 214, 215. A clutch piston 217 installed inside, an inner hydraulic servo C-3i formed by the clutch cylinder 214 and the clutch piston 217, an outer hydraulic servo C-3o formed by the clutch cylinder 215 and the clutch piston 217, and an inner hydraulic servo C- The clutch C is composed of an orifice 218 that communicates between the inner hydraulic servo C-3i and the outer hydraulic servo C-3o.
3 is engaged and disengaged. The brake B4 is a wet multi-plate friction engagement brake for engaging the sub-transmission case 212 of the ring gear 207, and rotatably supports the output shaft 132 and the first output shaft 201 shown in FIGS. 6 and 7. The brake cylinders 220, 221 and the center support 21 are formed with openings toward the main transmission side on the inner and outer circumferential sides of one side of the center support 219.
9, an inner hydraulic servo B-4i formed by the inner brake cylinder 220 and the brake piston 222, and an outer brake cylinder 221 and the brake piston 2.
The center support 219 includes an outer hydraulic servo C-4o formed by the inner hydraulic servo B-4i.
The first oil supply and discharge passage 223, which is a second oil supply and discharge passage that supplies and discharges hydraulic oil from the first oil supply and discharge passage 223 to the outer hydraulic servo B-4o, and the outer hydraulic servo B- Orifice 22 that communicates 4o
4. An accumulator communication oil passage 225 is provided that communicates the inside of the outer hydraulic servo B-4o with the accumulator 700 described below, and 226 and 227 are used to communicate the hydraulic oil in the inner hydraulic servo B-4i and the outer hydraulic servo B-4o. This port is provided with check valves 228 and 229 inside to improve drain performance during supply and discharge. The clutch C4 is a wet multi-plate friction engagement clutch for connecting and disconnecting the first output shaft 201 connected to the carrier 208 and the sleeve 202 of the transmission mechanism 204 for driving the second output shaft 203. A hydraulic cylinder 230 rotatably supported on the outer periphery of an inner cylinder;
The clutch piston 231 is formed between the hydraulic cylinder 230 and the clutch piston 222, and the hydraulic servo C-4 has a large pressure receiving area.
Further, a hydraulic control device 600 for the auxiliary transmission 200 is provided at a lower position to supply hydraulic servo hydraulic oil for the clutches C1, C2, and brake B1. The hydraulic control device 300 of the main transmission 100 includes an oil strainer 301, an oil pump 302, a cooler bypass valve 315 that regulates the pressure of the oil cooler O/C, a pressure relief valve 316, a release clutch control valve 317, and a release brake control valve. A valve 318, a lock-up relay valve 320, a pressure regulating valve (regulator valve) 330 that regulates the pressure of the supply oil supplied from the oil pump 302 and supplies it to the oil passage, a lubricating oil supply oil passage L1 to the main transmission side, and a sub-oil passage L1. Transmission side hydraulic oil supply oil passage 12
a second pressure regulating valve 350, a cutback valve 360, a lockup control valve 370,
The first accumulator control valve 380, the second accumulator control valve 390, and the throttle valve 4 that generates oil pressure in the oil path IA according to the throttle opening degree.
00, the line pressure supplied to the oil passage to the oil passage
A manual valve 410, a 1-2 shift valve 420, a 2-3 shift valve 430, a 3-4 shift valve 440, and an intermediate coast modulator valve that adjusts the hydraulic pressure supplied to the hydraulic servo B-1. 445, a low coast modulator valve 450 that adjusts the hydraulic pressure supplied to the hydraulic servo B-3, an accumulator 460 that smoothly engages the clutch Co, an accumulator that smoothly engages the brake Bo. 470, an accumulator 48 that smoothly engages the clutch C2;
0, Kimyu mullet 490 that smoothly engages the brake B2, clutch C0, C1, C
2 hydraulic servo C-0, C-1, C-2 and brake B0, B1, B2, B3 hydraulic servo B-
0, B-1, B-2, B-3, flow rate post-valve 501 with check valve that controls the flow rate of supplied pressure oil;
503, 504, 505, 506, 507, 50
8,509, shuttle valve 502, oil strainers ST1, ST2, ST3, ST4, first solenoid valve S1, 1 that is opened and closed by the output of the electronic control device (computer) 800 described below and controls the 2-3 shift valve 430. -2 shift valves 420 and 3-4
A second solenoid valve S2 controls both the shift valve 440, and a third solenoid valve S2 controls both the lock-up relay valve 320 and the lock-up control valve 370.
It consists of a solenoid valve S3, an oil passage connecting each valve, and the clutch and brake hydraulic cylinders. The hydraulic control device 600 of the four-wheel drive transfer 200 includes a transfer manual valve 61 that supplies supply oil supplied by a swing path to an oil path and an oil path using a shift lever provided at the driver's seat.
0, relay valve 620, inhibitor valve 640 for switching engagement between clutch C3 and brake B4, third
an orifice control valve 6 that controls the supply flow rate of hydraulic oil to the accumulator control valve 660, shift timing valve 670, and hydraulic servo B-4.
80, an accumulator 690 that smoothly engages the clutch C3, an accumulator 700 that smoothly engages the brake B4, a flow control valve with a check valve 7 that controls the flow rate of the supplied pressure oil.
11,712, oil strainer ST5, ST6,
It consists of a fourth solenoid valve S4 that is opened and closed by the output of an electronic control unit 800, which will be described below, and an oil passage that communicates between each valve and the hydraulic cylinders of the clutch and brake. Electronic control device 8 that controls energization of solenoid valves S1 to S4 of hydraulic control devices 300 and 600
00 is a main transmission shift lever position sensor 810 that detects the position of the setting range of the main transmission 100;
A transfer shift lever position sensor 820 that detects the position of the setting range of the sub-transmission 200, a vehicle speed sensor 830 that converts a signal detected from the output shaft rotation speed of the sub-transmission 200 into vehicle speed, and a throttle opening that detects the amount of accelerator. Sensor 840, main transmission 1
A rotational speed detection sensor 850 that detects the rotational speed of the output shaft 132 of the 00, an I/O port 860 that is an input port from these and an output port to the solenoid valves S1 to S4, a central processing unit CPU, and a shift point. It consists of a random accelerator memory RAM that performs processing, and a read-only memory ROM that stores data on shift patterns such as shift points and lock-up points. A main transmission shift lever (not shown) provided in the driver's seat for driving the manual valve 410 is
P (park), R (reverse), N (neutral),
It has a main shift position MSP for each range of D (drive), S (second), and L (low), and the setting range of this main shift position MSP and the 4th gear
Table 1 shows the operating relationships of the clutch and brake at speed (4), third speed (3), second speed (2), and first speed (1).

[Table] The shift lever (not shown) of the transfer 200 installed in the driver's seat to drive the transfer manual valve 410 is H2 (directly connected to two-wheel drive),
It has a sub-shift position SSP for each range of H4 (4-wheel drive direct connection) and L4 (4-wheel drive deceleration), and the setting range of this sub-shift position SSP and brake B
4. Table 2 shows the operational relationship between the engagement and release of clutches C3 and C4 and the running state of the vehicle.

【table】

[Table] In Tables 1 and 2, ○ in S1, S2, and S4 indicates energization, and × in S1, S2, and S4 indicates non-energization.
◎ in S3 indicates a lock-up state when energized, and × in S3 indicates a lock-up release state.
Once S4 is de-energized, α maintains the directly connected running state even if S4 is energized. β is once S4 is energized.
Even if S4 is de-energized, the decelerated running state is maintained.
E indicates that the corresponding clutch or brake is engaged, and X indicates that the corresponding clutch or brake is released. The corresponding one-way clutch of L is engaged in the engine drive state, but this engagement is not necessarily required as power transmission is guaranteed by the clutch or brake built in parallel. Indicates that (lock). (L) indicates that the corresponding one-way clutch is engaged only in engine drive conditions and not in engine brake conditions. f indicates that the corresponding one-way clutch is free. Table 3 shows the communication state between the oil passage and the oil passage at the shift position of the shift lever of the main transmission.

[Table] Table 4 shows the communication state between the oil passages and the oil passages at the shift positions of the sub-transmission.

[Table] In Tables 3 and 4, ◯ indicates the case where line pressure is supplied through communication, and × indicates the case where the line pressure is exhausted. The transfer manual valve 610 has a spool 611 connected to a shift lever (not shown) provided at the driver's seat, and is connected to the main transmission 10.
An import 612 that connects the oil passage of the main hydraulic control device 300 of No. 0, an out port 613 that connects to the oil passage, an out port 614 that connects to the oil passage,
It has drain ports 615 and 616, and when the spool 611 of the transfer manual valve 610 is set to the two-wheel drive direct connection (H2) position, the oil passage is connected to the oil passage and the oil passage is connected to the drain port 616. When set to the 4-wheel drive direct connection (H4) position, it connects the oil passage and the oil passage, and when it is set to the 4-wheel drive deceleration (L4) position, it connects the oil passage and the oil passage. Connect the oil path to the drain import 615. The relay valve 620 has a spool 621 and a plunger 622 connected in series with the spool 621. The spool 621 has an upper end land 624 and a lower land 625, both of which have the same diameter and have a spring 623 on their backs. Plunger 622
has an illustrated upper end land 626 having the same diameter as the land of the spool 621, and an illustrated lower end land 627 having a larger diameter than the upper end land 626. These spools 6
21 and plunger 622, the illustrated upper end oil chamber 631, upper end land 624, and lower end land 625 are installed.
A first intermediate oil chamber 632 between the spool 621 and the plunger 622, a second intermediate oil chamber 633 between the spool 621 and the plunger 622, and a third intermediate oil chamber 633 between the upper end land 626 and the lower end land 627.
An intermediate oil chamber 634 and a lower end oil pressure 635 are formed. This relay valve 620 is connected to the oil passage A when the oil pressure corresponding to the solenoid valve S4 is supplied to the lower end oil chamber 635 from the oil passage A, and when the spool 621 and the plunger 622 are set upward in the figure. are in communication via the first intermediate oil chamber 632, and by switching the transfer manual valve 610, line pressure can be supplied and discharged to the lower end oil chamber 656 of the inhibitor valve 640, and the oil passage and the line pressure supply oil passage A are connected. Contact and transfer manual valve 6
10, the lower end oil chamber 656 of the inhibitor valve 640
When line pressure is supplied, the second intermediate oil chamber 6
33, the spool 621 is fixed upward in the drawing, and when the hydraulic pressure generated in the oil passage A is discharged from the lower end oil chamber 635, the plunger 622 is set downward in the drawing. , the spool 621 remains fixed upward in the figure, and the lower end oil chamber 65 of the inhibitor valve 640
Maintain line pressure supplied to 6. In this state, when the line pressure in the oil passage is discharged by the transfer manual valve 610, or when the oil passage and the line pressure supply oil passage A are connected, the transfer manual valve 610 releases the inviter valve 640.
When the oil pressure generated in the oil passage A is discharged from the lower end oil chamber 635 while the line pressure is exhausted from the lower end oil chamber 656, the spool 621 and the plunger 622 are set downward in the figure by the force of the spring 623. The line pressure supply oil passage A is connected to the first intermediate oil chamber 63.
2 to the drain port 636. When the spool 621 is set downward in the figure,
Line pressure is not supplied to the lower end oil chamber 656 of the inhibitor valve 640 by the transfer manual valve 610, and the pressure remains discharged, and the spool 641 and plunger 642 of the inhibitor valve 640 are set downward in the drawing. The inhibitor valve 640 has a first set position (lower side in the figure) and a second set position (upper side in the figure),
From the top of the diagram, the first setting position (bottom of the diagram) and the second setting position (from the top of the diagram)
The line pressure oil is supplied to the inner hydraulic servo C-3i and outer hydraulic servo C-3o of the clutch C3, and the inner hydraulic servo B-4i and outer hydraulic servo B-4o of the brake B4. A spool 641, which is a switching valve for supplying and discharging, and a first
A plunger 642 has a set position (lower side in the figure) and a second set position (upper side in the figure), and sets the spool 641 to the second set position when biased to the second set position (upper side in the figure). and has a spool 641
Each has a sleeve-shaped land 645 at the upper end shown, a lower end land 647 shown, and an intermediate land 646, all of which have the same diameter and are backed by a spring 650 which is a means for biasing the spool 641 to the first setting position. The plunger 642 is connected to the spool 641.
The illustrated upper end land 648 has the same diameter as that of the land, and the lower end land 649 has a larger diameter than the upper end land 648. These spool 641 and plunger 642 form an upper end oil chamber 651, a sleeve-shaped land 645, an intermediate land 646, and a lower end land 647.
first and second intermediate oil chambers 652, 653 between;
An oil chamber 654 and a lower end oil chamber 656 are formed between the spool 641 and the plunger 642. This inhibitor valve 640 is connected to the upper end oil chamber 651 when the spool 641 is set downward in the figure.
communicates with the oil passage A via the oil port 643 of the sleeve-shaped land 645, the first intermediate oil chamber 652 communicates the line pressure oil passage and the deceleration oil passage B, and the second intermediate oil chamber 653 connects the line pressure oil passage with the deceleration oil passage B. Oil passage C and drain port 6
57, and when the spool 641 is set upward in the figure, the upper end oil chamber 651 connects to the drain port 65 through the oil port 643 of the sleeve-shaped land 645.
8, the first intermediate oil chamber 652 connects the deceleration oil path B and the drain import 659, the second intermediate oil chamber 653 connects the oil path and the direct connection oil path C,
In addition, the oil chamber 654 always generates hydraulic pressure corresponding to the signal from the solenoid valve S4 that urges the spool 641 to the second set position (upward in the figure) and urges the plunger 642 to the first set position (downward in the figure). The lower end oil chamber 656 always urges the plunger 642 to the second set position (upper side in the figure). The orifice control valve 680 regulates the pressure of the hydraulic oil supplied to the oil passage B, and controls the inner hydraulic servo B-4i and the outer hydraulic servo B-4o.
The control valve supplies the spring 68 upward as shown in the figure.
1, the upper end land 682 is biased from the upper side in the drawing;
It has a spool 685 having an intermediate land 683 and a lower end land 684, and an upper end oil chamber 68 at the upper side in the figure.
6. Upper oil chamber 687 between upper end land 682 and intermediate land 683, lower oil chamber 688 between intermediate land 683 and lower end land 684, spring 681
A lower end oil chamber 689 containing therein is formed, and the spool 685 is provided with an orifice 683A that communicates the upper oil chamber 687 and the lower oil chamber 688.
The upper oil chamber 686 is the oil passage IA of the hydraulic control device 300.
The spool 685 is adjusted by the oil pressure applied to the upper end oil chamber 686 according to the throttle opening degree and the spring 681, and the line oil pressure supplied to the oil path B is communicated with the orifice a provided in the flow path of the oil path B. b is selected and supplied to the first oil supply/drainage path 223. Hydraulic oil is supplied from the inner hydraulic servo B-4i to the outer hydraulic servo B-4o through a second oil supply and discharge passage 224A in which an orifice 224 is disposed in the flow passage.
The accumulator 700 that accumulates the pressure of the hydraulic oil of the outer hydraulic servo B-4o is
Outer hydraulic servo B-4o and accumulator 7
This is done through the accumulator communication oil passage 225 that communicates with the accumulator chamber 701 of No. 00. The first oil supply/drainage passage 223 is communicated with the oil passage B on the inhibitor side of the orifice A without going through the orifice control valve 680, and when hydraulic oil is supplied to the oil passage B, it is closed hydraulically and the oil is drained. The inner hydraulic servo B-4i, the outer hydraulic servo B-4o, and the accumulator chamber 70 of the accumulator 700 are opened through the oil passage 223.
A bypass oil passage 714 having a check valve 713 for quickly draining the hydraulic oil in the first oil supply and drainage passage 223 and an accumulator communication oil passage 225 is provided in parallel with a second oil supply and drainage passage 224A having an orifice 224. When the hydraulic oil is supplied to the first oil supply/drainage passage 223, the oil pressure is closed, and when the oil is drained, the oil pressure is opened and the outer hydraulic servo B-4o and Accumulator 70 of Accumulator 700
Check valve 22 that quickly drains the hydraulic oil from step 1
A bypass oil passage 226 having a diameter of 8 is provided. From the above, the hydraulic oil in the accumulator chamber 701 of the accumulator 700 can be drained without passing through the orifice 224. Therefore, even if the accumulator 700 is provided to accumulate the hydraulic oil of the outer hydraulic servo B-4o, the brake B4 is not activated. Engagement can be quickly released. Solenoid valve S4 is in the gear shift permission range (or low gear L4) from high gear (H2, H4) to low gear (L4).
When within the shift restriction range (to higher gears H2 and H4)
When it is turned ON and the hydraulic pressure in oil passage A is exhausted, and the shift is permitted from low gear (L4) to high gear (H2, H4) (or within the gear shift restriction area from high gear H2, H4 to low gear L4) is turned OFF and generates oil line pressure in oil passage A. As a result, oil path A
Hydraulic pressure related to the shift permission region (or shift restriction region) is generated. The operation of transfer 200 in each setting range will be explained. (A) When the transfer manual valve 610 is set to the H2 range, the oil passage is exhausted, so the exhaust pressure of the hydraulic servo C-4 causes the clutch C to
4 is released, no power is transmitted to the sleeve 202, and the two-wheel drive state is maintained. Further, a line pressure signal, which is a first hydraulic pressure signal, is generated in the oil passage. When the solenoid valve S4 is OFF, hydraulic pressure is supplied to the lower end oil chamber 635 of the relay valve 620, so the spool 621 and plunger 62
2 is set upward in the figure, the oil passage and line pressure supply oil passage A communicate with each other, a line pressure signal is supplied to the lower end oil chamber 656 of the inhibitor valve 640, and the spool 641 and plunger 642 are set at the second setting position (not shown). The oil passage B is connected to the drain port 659 and the pressure is discharged, and the inner hydraulic servo B-4i and the outer hydraulic servo B-4o are thereby discharged, so that the brake B4 is released. Since the spool 641 and plunger 642 of the inhibitor valve 640 are set at the second setting position (upper part in the figure), the oil passage C is connected to the oil passage, and is connected to the oil passage D via the third accumulator control valve 660. , and supplies line pressure to the inner hydraulic servo C-3i and the outer hydraulic servo C-3o to engage the clutch C3. Therefore, transfer 20
0 becomes H2 (two-wheel drive directly connected state). At this time, since feedback pressure is supplied to the second intermediate oil chamber 633 of the relay valve 620, the spool 621 is fixed upward in the figure, so the solenoid valve S4 is turned on and the oil pressure is discharged from the lower end oil chamber 635. If plunger 6
Only the spool 62 is set at the lower side in the figure.
1 remains set upward in the figure, and a line pressure signal is supplied to the lower end oil chamber 656 of the inhibitor valve 640. Therefore, the transfer 200 maintains H2 (two-wheel drive direct connection state). (B) When the transfer manual valve 610 is set to range H4, line pressure is supplied to both the oil passage and the oil passage. When the solenoid valve S4 is OFF, hydraulic pressure is supplied to the lower end oil chamber 635 of the relay valve 620, so the spool 621 and plunger 62
2 is set upward in the figure, the oil passage and line pressure supply oil passage A communicate with each other, a line pressure signal is supplied to the lower end oil chamber 656 of the inhibitor valve 640, and the spool 641 and plunger 642 are set at the second setting position (not shown). The oil passage B is connected to the drain port 659 and the pressure is discharged, and the inner hydraulic servo B-4i and the outer hydraulic servo B-4o are thereby discharged, so that the brake B4 is released. Since the spool 641 and plunger 642 of the inhibitor valve 640 are set at the second setting position (upper part in the figure), the oil passage is connected to the oil passage, and is connected to the oil passage D via the third accumulator control valve 660. The clutch C3 is engaged by supplying line pressure to the inner hydraulic servo C-3i and the outer hydraulic servo C-3o. The line pressure supplied to the oil passage is controlled by hydraulic servo C.
-4 and engages clutch C4. As a result, the transfer force 200 becomes H4 (four-wheel drive direct connection state). At this time, since feedback pressure is supplied to the third intermediate oil chamber 633 of the relay valve 620,
Since the spool 621 is fixed upward in the figure, when the solenoid valve S4 is turned on and the hydraulic pressure is discharged from the lower end oil chamber 635, the plunger 6
Only the spool 62 is set at the lower side in the figure.
1 remains set upward in the figure, and a line pressure signal is supplied to the lower end oil chamber 656 of the inhibitor valve 640. Therefore, the transfer shaft 200 maintains H4 (four-wheel drive direct connection state). (C) When the transfer manual valve 610 is set to the L4 range, the pressure in the oil passage A is exhausted and line pressure is supplied to the oil passage regardless of the setting of the relay valve 620. As a result, clutch C4 is engaged and the four-wheel drive state is maintained. When solenoid valve S4 is turned OFF within the shift restriction range from high gear (H2, H4) to low gear (L4), line pressure is supplied to the oil chamber 654 from oil passage A, and the transfer manual When the valve 610 is set to the L4 range, the line pressure signal that was being supplied to the lower oil chamber 656 is discharged from the oil passage A, so the line pressure applied to the oil chamber 654 causes the inhibitor valve 640 to be activated. Plunger 642 is set at a first setting position (lower in the figure). Solenoid valve S in H2/H4→L4 shift permission area
4 is ON and transfer manual valve 610 is set to L4 range,
Or, when the solenoid valve S4 is OFF in the H2/H4→L4 shift restriction region, the transfer manual valve 610 is in the L4 state and the H2/H4→L4 shift restriction region changes to the H2/H4→L4 shift permission region and the solenoid valve S4 is OFF. When it is turned on from
is exhausted, the spool 641 is moved to the first setting position (lower in the figure) by the action of the spring 650.
As a result, the oil passage and oil passage B communicate with each other, and the oil pressure is controlled by the orifice control valve 680, and the inner hydraulic servo B-4i
Hydraulic oil is supplied to the outer hydraulic servo B-4o, and the oil path C is connected to the drain port 657.
The hydraulic pressure of the inner hydraulic servo C-3i and the outer hydraulic servo C-3o of the clutch C3 is discharged. As a result, the transfer force 200 enters a low-speed four-wheel drive state. After switching to low-speed 4-wheel drive, H2/H4
→L4 shift limit area is reached and solenoid valve S4 is activated.
Even if it is turned OFF, the line pressure of the oil passage A is applied to the oil chamber 654 of the inhibitor valve 640 and at the same time is applied to the upper end oil chamber 651 via the oil port 643 of the sleeve-shaped land 645 of the spool 641. The low-speed four-wheel drive state is maintained without displacement. (D) When the transfer manual valve 610 is set from the L4 range to the H2 or H4 range while the transfer 200 is in a low-speed four-wheel drive state, line pressure is supplied to the oil passage. At this time, when the vehicle running condition is in the L4→H2/H4 shift permission range and the solenoid valve S4 is in the ON state, the relay valve 620
Hydraulic pressure is discharged from the lower end oil chamber 635 of the inhibitor valve 640, and the spool 621 and the plunger 622 are set downward in the drawing due to the force of the spring 623, so the oil passage and the oil passage A do not communicate with each other, and the lower end oil chamber 656 of the inhibitor valve 640 Since the hydraulic pressure is discharged from the drain port 636 of the relay valve 620, the spool 641 and plunger 642 of the inhibitor valve 640 are set downward in the figure by the force of the spring 650, and the clutch C3 is released.
Since the brake B4 is engaged, the transfer 200 is in a low-speed two-wheel drive state or a low-speed four-wheel drive state. Furthermore, when the vehicle running condition is in the L4→H2/H4 shift permission range and the solenoid valve S4 is in the OFF state, oil pressure is supplied to the lower end oil chamber 635 of the relay valve 620, so the spool 621 and plunger 622 move upward in the figure. is set, the oil passage and line pressure supply oil passage A are in communication, and the inhibitor valve 64
A line pressure signal is supplied to the lower end oil chamber 656 of 0, and the spool 641 and plunger 642 are set to the second set position (upper part in the figure), and the oil passage B is connected to the drain port 659 and is depressurized. Brake B4 is released. Oil passage C is the spool 64 of the inhibitor valve 640
1. Since the plunger 642 is set at the second setting position (upper side in the figure), it communicates with the oil passage, and communicates with the oil passage D via the third accumulator control valve 660, thereby engaging the clutch C3. ing. Therefore, the transfer 200 becomes H2 (directly connected to two-wheel drive) or H4 (directly connected to four-wheel drive).

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a frictional engagement device of the present invention;
Figure 2 is a graph where the vertical axis shows the inner hydraulic servo and outer hydraulic servo oil pressure, and the horizontal axis shows time. Figure 3 is a graph where the vertical axis shows piston pressure torque and the horizontal axis shows time. Figure 4 Figure 5 is a schematic skeletal diagram of a four-wheel drive transmission, Figure 5 is a side sectional view of the transfer gear,
Figure 6 is a front view of the center support, Figure 7 is a side sectional view of the center support, Figure 8 is a hydraulic circuit diagram of the hydraulic control device of the main transmission, and Figure 9 is the hydraulic pressure of the hydraulic control device of the auxiliary transmission. A circuit diagram, FIG. 10 is a block diagram of an electronic control device, FIG. 11 is a schematic diagram of a conventional frictional engagement device equipped with an actuator having two hydraulic chambers, and FIG. 12 is a schematic diagram of a conventional frictional engagement device. A graph showing the relationship between the oil pressure of the inner hydraulic servo and the outer hydraulic servo and time. FIG. 13 is a graph showing the relationship between the piston pressing torque of an accumulator driven by the conventional inner hydraulic servo and the outer hydraulic servo and time. In the figure, 1...Frictional engagement device, 2...Frictional engagement element, 3...Actuator, 4...Hydraulic oil supply and drain path, 5...Accumulator, 31...First hydraulic pressure chamber, 32... ...Second hydraulic chamber, 33...Piston, 4
1...First oil supply and drainage path, 42...Second oil supply and drainage path, 4
1A, 42A... Orifice.

Claims (1)

[Scope of Claims] 1. A hydraulic actuator that drives a piston using hydraulic pressure supplied to a first hydraulic pressure chamber and a second hydraulic pressure chamber to engage a frictional engagement element;
a first supply and discharge path for supplying and discharging hydraulic fluid to and from the hydraulic pressure chamber; and a first supply and discharge passage that communicates with the first supply and discharge passage via a throttle and for supplying and discharging hydraulic fluid from the second hydraulic pressure chamber. A friction engagement device comprising a second supply/discharge path and an accumulator provided in the second supply/discharge path. 2. The throttle is provided with a bypass path in parallel with the throttle, which has a check valve that closes when hydraulic fluid is supplied and opens when hydraulic fluid is discharged. frictional engagement device.