JPS628658B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements in hydraulic control devices for automatic transmissions, and is intended to reduce shift shock, prevent slippage of frictional engagement devices, etc., and improve durability. Various automatic transmissions are used to transmit desired values of the output torque and rotational speed of a prime mover such as an internal combustion engine to a driven machine, and many are controlled using hydraulic control devices. Automatic transmissions for automobiles, which have been widely used recently, are configured to selectively engage multiple frictional engagement devices such as clutches and brakes using a hydraulic control device to obtain a predetermined gear position. . Each frictional engagement device is supplied with hydraulic pressure obtained by controlling the discharge pressure of the oil pump with an actuator that is a combination of a solenoid valve and a hydraulic pressure regulating valve. However, when a friction element, such as a clutch, is engaged in two or more consecutive gears,
When the oil pump discharge pressure is reduced to the initial engagement pressure in order to engage other frictional engagement devices to prevent shift shock, the oil pressure supplied to the already engaged clutch is also reduced, causing slippage. There are problems such as causing damage or deteriorating durability.
There is a problem in that if the pressure reduction control is made slightly to prevent this slippage, a shift shock will occur. The present invention eliminates such conventional drawbacks and makes it possible to supply two systems of hydraulic pressure to friction elements that are engaged in two or more consecutive gear stages, so that slipping occurs even when other friction engagement devices are engaged. The purpose of the present invention is to provide a hydraulic control device for an automatic transmission that avoids The structure of the present invention that achieves this object is achieved by selectively hydraulically engaging a plurality of friction engagement devices including friction elements that are engaged in at least two or more consecutive gear stages. In automatic transmissions,
a hydraulic source providing a first hydraulic fluid at a constant pressure;
A hydraulic pressure adjustment device that adjusts the pressure of the first hydraulic fluid to a desired low hydraulic pressure and supplies it as a second hydraulic fluid; communicates with the hydraulic pressure supply source, the hydraulic pressure adjustment device, and the friction element, and provides the friction element with the first operation. a switching valve having a first position that supplies oil and cuts off the supply of the second hydraulic oil; and a second position that supplies the second hydraulic oil to the friction element and cuts off the supply of the first hydraulic oil. , the switching valve is operated to switch from the second hydraulic oil supply state at the second position to the first position due to an increase in the oil pressure of the second hydraulic oil by the oil pressure adjusting device, and the oil pressure of the first hydraulic oil is increased. It is characterized in that it is configured to be held at the first position in a state where it does not fall below a predetermined value. Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. First, the schematic structure of the automatic transmission to be controlled will be explained using the power train diagram shown in FIG. 1. Crankshaft 2 of engine 1, which is the power source of the vehicle
is directly connected to the pump 4 of the torque converter 3. The torque converter 3 has a pump 4, a turbine 5, a stator 6, a one-way clutch 7,
The stator 6 is connected to a case 8 via a one-way clutch 7, which allows the stator 6 to rotate in the same direction as the crankshaft 2, but is not allowed to rotate in the opposite direction. A direct coupling clutch 9 is provided between the crankshaft 2 and the turbine 5, and the clutch 9 engages with a predetermined slip ratio when engaged. Therefore, the output of the engine 1 is the output of the direct coupling clutch 9.
Alternatively, the torque is transmitted to the turbine 5 via the torque converter 3. The torque transmitted to the turbine 5 is transmitted by an input shaft 10 to a transmission gear train 100 disposed at the rear thereof that achieves four forward speeds and one reverse speed. The transmission gear train 100 includes three clutches 11,1
2, 13, two brakes 14, 15, one one-way clutch 16, and one set of Ravignio type planetary gear set 17. The planetary gear set 17 includes an annulus gear 18, a reverse sun gear 19, a forward sun gear 20, a long pinion 21, a short pinion 22, and a carrier 23. The annulus gear 18 is fixed to the output shaft 24,
Reverse sun gear 19 is a kick down drum 25
The drum 25 is fixed to the case 8 via the kickdown brake 14, and is also integrated to the input shaft 10 via the front clutch 11, while the forward sun gear 20 is connected to the input shaft via the rear clutch 12. integrated into the shaft 10, and
The carrier 23 that holds the long pinion 21 and short pinion 22 is a one-way clutch 16.
It is fixed to the case 8 via the transmission gear train 100, is integrated with the input shaft 10 via the 4-speed clutch 13 provided at the rear end of the transmission gear train 100, and is further fixed to the cake 8 via the low reverse brake 15. Ru. One-way clutch 16 is provided to prevent reverse rotation of carrier 23. The three clutches 11, 12, 13 and the two brakes 14, 15 are hydraulic friction engagement devices, and the oil pressure supplied to each hydraulic piston that operates these friction engagement devices is generated by an oil pump 26. be done. The output passing through the speed change gear train 100 is transmitted to the output shaft 24.
The transmission is transmitted from the transfer drive gear 27 fixed to the transfer idle gear 28 to the transfer driven gear 29, and further to the transfer shaft 30 integrated with the driven gear 29.
The signal is transmitted from the helical gear 31 to the differential gear 32 . The driver's seat select lever (not shown) and the
Selective engagement of each frictional engagement device is performed in accordance with the operation of an auxiliary switch that selects D ₄ , D ₃ , 2, and L and the driving state of the vehicle detected by various driving detection devices described later. , various gears are achieved. The selection patterns are P (parking), R (reverse),
N (neutral), D ₄ (4 forward automatic transmission), D ₃ (3 forward automatic transmission), 2 (2 forward automatic transmission), L (1
(fixed speed), and the select lever is set to P,
It has four positions: R, N, and D. When the same lever is set to the D position and an auxiliary switch consisting of an inhibitor switch and a changeover switch is selected, the positions are L, 2,
The structure is such that D ₃ or D ₄ is selected. How each frictional engagement device works when the select lever and auxiliary switch are placed in each position of the above selection pattern is as shown in the operating element diagram in Figure 2. By selectively combining the coupling devices, a gear ratio of four forward speeds and one reverse speed can be obtained. In this figure, the O mark indicates a friction engagement device that is engaged by hydraulic operation, and the ● mark indicates a friction engagement device that is engaged by the one-way clutch 16 just before the low reverse brake 15 is engaged during gear shifting.
3 is stopped, and the select lever and auxiliary switch positions are D ₄ , D ₃ , 2, 1st in the L column,
2nd, 3rd, and 4th are 1st gear, 2nd gear, and 3rd gear, respectively.
The case of 4th speed is shown. As is clear from the figure, the rear clutch 12 as a friction element is not used during any of the three consecutive forward gears of 1st, 2nd, and 3rd gears. When the engagement is made, in order to achieve the second speed, the kickdown brake 14, which is another frictional engagement device, is engaged, and the third gear is engaged.
To achieve speed, the front clutch 11 is engaged. Next, the direct coupling clutch 9 will be explained with reference to FIG. This direct coupling clutch 9 is a slip type clutch that transmits power while constantly slipping. When the clutch 9 is in operation, the power from the engine 1 is mainly transmitted to the input shaft 10 via the clutch 9, and some of the power is transmitted to the input shaft 10. is transmitted via the torque converter 3,
This reduces the slip of the torque converter 3 and improves fuel efficiency.
It has an effect (damping effect) of alleviating the impact torque caused by the shock. The torque converter 3 and the direct coupling clutch 9 are integrally formed, and a drive plate 33 is fixed to the crankshaft 2, and the drive plate 33 is connected to the outer shell 34 of the pump 4 of the torque converter 3 and the friction plate 35 of the direct coupling clutch 9. The turbine 5 is spline-fitted to the input shaft 10 and rotates integrally with the input shaft 10, and is also connected to the piston 38 via a transfer ring 37 so as to rotate integrally with the piston 38.
is slidably and rotatably fitted in the input shaft 10 in the axial direction, and is arranged opposite to the plate 36,
It has a friction surface 39 that comes into contact with the friction plate 35,
A hydraulic chamber 4 is provided between the piston 38 and the plate 36.
1 is formed, and a hydraulic chamber 42 is formed between the outer peripheral surface of the outer shell 40 of the turbine 5 and the piston 38. Friction plate 35 and friction surface 39 of the direct coupling clutch 9
The coefficient of dynamic friction is set so that the rate of change due to speed difference is small. A plurality of grooves are appropriately provided on the surface of the friction plate 35 along the radial direction, circumferential direction, or a combination of the two, and the friction plate 35 and the friction surface 39 are formed by oil passing through the grooves. Overheating is prevented. Oil is supplied to the torque converter 3 and the direct coupling clutch 9 with oil pressure regulated by hydraulic control, which will be described later. The oil is guided into the torque converter 3 through an oil passage 44 formed inside a sleeve 43 fitted over the input shaft 10 of the pump 4, as indicated by the arrow in FIG. After that, the hydraulic chamber 4 passes through the gap between the friction plate 35 and the friction surface 39 of the direct coupling clutch 9.
1 and is further discharged through an oil passage 45 bored in the input shaft 10, or is circulated in the opposite direction. Next, a hydraulic control system for controlling each friction engagement device of the automatic transmission and a hydraulic control system for a rear clutch applied thereto will be explained with reference to FIG. 4. The hydraulic control device is connected to the oil filter 4 from the oil sump 46.
7. The oil discharged from the oil pump 26 through the oil passage 402 is transferred to the torque converter 3, the direct coupling clutch 9, the front clutch 11, the rear clutch 12 as a friction element, the kickdown brake 14, the low reverse brake 15, and the 4-speed clutch 13. In order to operate the hydraulic piston, the hydraulic pressure supplied to each hydraulic chamber is controlled according to the operating state, and mainly includes a pressure regulating valve 50, a torque converter control valve 70, a direct clutch control valve 90, a pressure reducing valve 110, and a shift control valve. Valve 130, manual valve 150, 1st-2nd speed shift valve 17
0, 2nd speed - 3rd speed and 4th speed - 3rd speed shift valve 190,
N-D control valve 210 as a switching valve, 4-speed clutch control valve 230, hydraulic control valve 250 during gear shifting, N
-R control valve 270, rear clutch control valve 280,
It has three solenoid valves 300, 310, 320 and a solenoid valve 325 as components, and among these valves, the N-D control valve 210, the hydraulic control valve 250 as a hydraulic pressure adjustment device, and the solenoid valve 325 are the fourth In the figure, a hydraulic control device 340 for the rear clutch 12 shown surrounded by a broken line is configured,
Each element is connected by an oil passage. Solenoid valve 300, 310, 320, 325
have the same structure, and are non-energized closed type solenoid valves that control the opening and closing of orifices 301, 311, 321, and 326, respectively, based on electrical signals from the electronic control device 290. 322 and 327, each orifice 301, 3 is arranged in the same solenoid.
Valve bodies 303, 3 that open and close 11, 321, 326
13, 323, and 328, and springs 304, 314, 324, and 329 that bias the valve bodies in the closing direction. The electronic control device 290 has a built-in shift detection device for detecting the start of a shift, and a solenoid valve 30 that detects the operating state of the vehicle and performs duty control.
0,325 actuation, stop, and control the single pulse current width of the pulse current of several to several tens of Hz, for example 50 Hz, supplied to the solenoid valve, change the valve opening time, control the oil pressure, and turn on the solenoid valve. It controls the opening and closing of solenoid valves 310 and 320 that are subjected to OFF control, and its main input element is an engine load detection device 33 that detects the throttle valve opening (not shown) of the engine 1 or the intake manifold negative pressure.
0, a rotation speed detection device 331 of the engine 1, a rotation speed detection device 332 of the kickdown drum 25 shown in FIG. 1, and a rotation speed detection device of the transfer driven gear 29 provided to detect the rotation speed of the output shaft 24. 333, oil temperature detection device 334 for detecting lubricating oil temperature, select lever selection position detection device 341, and auxiliary switch selection position detection device 34
It consists of 2nd class. The oil discharged from the oil pump 26 flows through the oil path 40.
1 to a pressure regulating valve 50, a manual valve 150, a direct clutch control valve 90, and a pressure reducing valve 110. The pressure regulating valve 50 has a spool 53 and a spring 54, which have pressure receiving surfaces 51 and 52, and a manual valve 150 is connected to the pressure receiving surface 51 by operating a select lever.
Or when the D position is selected, the same manual valve 15
0, the oil pressure in the oil passage 401 acts from the oil passage 403 through the orifice 404, and as a result, the oil passage 4
The oil pressure of 01 is regulated to a constant pressure of 6 kg/cm ² (this pressure is called line pressure), and when the manual valve 150 is in the R position on the pressure receiving surface 52, the oil passage is connected through the manual valve 150. Oil pressure 401 acts from oil passage 405 through orifice 406, and as a result, the oil pressure in oil passage 401 is regulated to 14.6 kg/cm ² . In addition, the oil path 40
The relief valve 407 provided at 1 is a relief valve when high pressure oil is discharged from the oil pump 26. The oil led to the pressure reducing valve 110 through the oil passage 401 is regulated to 2.4 kg/cm ² by the same valve 110 and is led to the oil passages 408 and 410. The pressure reducing valve 110 has a spool 111 and a spring 1.
12, and the pressure is regulated by the balance between the hydraulic pressure due to the area difference between pressure receiving surfaces 114 and 115 formed opposite to the spool 111 and the spring 112. The pressure regulating oil led to this oil passage 408 is control oil at a constant pressure to the control side that is supplied to the hydraulic control device 340 of the rear clutch, and is supplied to the control side of the hydraulic control valve 250 via an orifice 426. The control side of the control valve 270 and the orifice 326 of the solenoid valve 325 are connected to the oil passage 40 by the operation of the solenoid valve 325 controlled by the electronic control device 290.
The control pressure downstream of the orifice 426 of No. 8 is changed to generate an output oil pressure in the oil passage 422 or the oil passage 409 according to the operating state during gear shifting. 217 with a spool 211 and a spring 212, the land 2
The spool 211 is moved to the left end shown in FIG. The position can be selectively switched between the position and the right end position (not shown). The hydraulic control valve 250 has pressure receiving surfaces 251, 252, 2
Spool 254 with 53 and spring 255
The hydraulic pressure in the oil passage 422 is regulated to a predetermined pressure by the balance between the hydraulic pressure acting on the pressure receiving surface 251, the hydraulic pressure due to the area difference between the pressure receiving surfaces 252 and 253, and the resultant force of the biasing force of the spring 255. be done. The N-R control valve 270 has pressure receiving surfaces 271, 272,
Spool 274 with 273 and spring 27
5, and the hydraulic pressure in the oil passage 409 is adjusted to a predetermined pressure by the balance between the hydraulic pressure acting on the pressure receiving surface 271, the hydraulic pressure due to the area difference between the pressure receiving surfaces 272 and 273, and the resultant force of the urging force of the spring 275. be pressured. The oil pressure control valve 250 and the N-R control valve 270 are configured so that while one is regulating the pressure, the other is not regulating the pressure.
The pulsation of the control pressure downstream of the orifice 426 is applied to the hydraulic pressure from the pressure receiving surface 251 or 271 and the spring 25.
5 or 275 as an accumulator. The output hydraulic pressure led to the oil passage 422 controls the front clutch 11, rear clutch 12, kickdown brake 14, and low reverse brake 15 during forward movement, while the output oil pressure led to the oil passage 409 controls the front clutch 11, rear clutch 12, kickdown brake 14, and low reverse brake 15 during forward movement. The low reverse brake 15 is controlled at the time. The solenoid valve 325 includes an engine load detection device 330 and rotation speed detection devices 331, 332, 333.
The electronic control unit 290 detects the operating state in response to signals from the oil temperature detection device 334 and the like, and changes the pulse width of the orifice 326 by duty control at several to several tens of Hz, for example, 50 Hz, depending on the operating state. control the opening/closing time. Pressure receiving surface 251 of hydraulic control valve 250 by this solenoid valve 325
Alternatively, the control hydraulic pressure Ps acting on the pressure receiving surface 271 of the N-R control valve 270 is controlled by the orifice 426.
is set to 0.8φ, and the orifice 326 is set to 1.4φ, and the pressure is regulated between approximately 0.3 and 2.1 Kg/cm ² . Therefore, in the hydraulic control valve 250, the line pressure 6, which is the constant pressure hydraulic oil (hydraulic supply source) supplied from the oil passage 414 by this control hydraulic pressure Ps.
When the oil pressure of Kg/cm ² becomes the output pressure Pa and is output to the oil passage 422, the pressure is 0 to 6 as shown in Fig. 5.
The pressure is regulated in the range of Kg/ ^cm2 , and in the N-R control valve 270, the line pressure of 14.6Kg/ ^cm2 supplied from the oil passage 421 by this control hydraulic pressure Ps becomes the output pressure Pb. When output from the line 409, the pressure is regulated in the range of 0 to 14.6 kg/cm ² as shown in FIG. In addition, the start of operation and the operation period of the solenoid valve 325 are determined by the various detection devices 330, 333, and 3 described above.
34, a shift detection device built into the electronic control unit 290 that detects the start of a shift, an engagement timing detection device consisting of two rotational speed detection devices 332 and 333, and the like. The shift control valve 130 is controlled ON-OFF2
It is controlled by a combination of opening and closing of solenoid valves 310 and 320 to obtain each of four forward gears. This shift control valve 130 has spools 131, 132, 133 divided into three and two stoppers 134, 135.
1 is provided with two lands 136, 137 and an oil hole 139 that communicates between the hydraulic chamber 138 outside the land 136 and the lands 136, 137, and the spool 132 is provided with two lands 136, 137 with different diameters. 140, 141 are provided, and pressing portions that come into contact with the spools 131, 133 are provided at both ends.
Two lands 142 and 143 are provided, and a hydraulic chamber 144 outside the land 143 and a land 14 are provided.
An oil hole 145 is provided that communicates between the parts 2 and 143. And spool 131 and spool 132
A stopper 134 is interposed between the spool 1
A hole is formed through which the pressing part at the end of 32 passes and is fixed to the casing, and the spool 132 and spool 1
A stopper 135 is interposed between the spool 132 and the spool 132, and a hole is formed through which a pressing portion at the end of the spool 132 passes, and is fixed to the casing. Two lands 140, 141 of spool 132
The oil passage 470 that is always in communication with the oil passage 414 of the manual valve 150 also communicates with the orifice 47.
1 to an orifice 311 that is opened and closed by a solenoid valve 310, and further communicates to a hydraulic chamber 138 and a hydraulic chamber 144.
Further, the oil passage 470 is communicated via an orifice 472 with an orifice 321 that is opened and closed by a solenoid valve 320, and is also communicated between the spools 131 and 132 in the state shown in FIG. and two solenoid valves 310 and 3
The three spools 131, 132, 133 are controlled to obtain the first to fourth gears by opening and closing the solenoid valves 310, 320.
The relationship between opening/closing and each gear stage is as shown in Table 1. In addition, in the table, ○ mark indicates ON, and × mark indicates OFF.

[Table] The 1st-2nd speed shift valve 170 has a spool 171 and a spring 172, and the spool 1
71 is selectively switched between the left end position shown in FIG. 4 and the right end position (not shown). The 2nd speed-3rd speed and the 4th speed-3rd speed shift valve 190 and the 4th speed clutch control valve 230 similarly have spools 191, 231 and springs 192, 232, respectively, and the left side of each spool has a hydraulic pressure to which line pressure is introduced. Chambers 193, 233 are provided, and hydraulic chambers 194, 234 are provided on the right side, and each spool is selectively switched between a left end position shown in FIG. 4 and a right end position (not shown). The rear clutch control valve 280 has five lands 28.
1,282, 283, 284, 285 and a spring 292, the diameter of the land 281 is slightly larger than that of the land 285, and the diameter of the land 281 is slightly larger than that of the land 285. The hydraulic pressure led to the hydraulic chamber 293 is the land 2
a force acting on the pressure receiving surface of the land 281; and a force acting on the pressure receiving surface of the land 285 due to the hydraulic pressure led to the hydraulic chamber 294 on the outside of the land 285 (on the right side in FIG. 4).
Depending on the balance with the biasing force of the spring 292, the spool 291 is selectively switched between the left end position shown in FIG. 4 and the right end position (not shown). Next, shift control based on selective engagement of each frictional engagement device will be explained together with the operation of the hydraulic control device and the rear clutch hydraulic control device 340. When the manual valve 150 is switched from N to D shown in FIG. 4, the line pressure regulated to 6 kg/cm ² is guided from the oil passage 401 to the oil passage 414. The line pressure of the oil passage 414 is controlled by the hydraulic control valve 250,
Oil passage 422, N-D control valve 210, oil passage 416,
It is led to the hydraulic chamber of the rear clutch 12 via the rear clutch control valve 280, oil passage 417, and the oil passage 422, the 1st-2nd speed shift valve 170, and the oil passage 4.
53 to the hydraulic chamber of the low reverse brake 15, and the first gear is achieved by engaging the rear clutch 12 and the low reverse brake 15. During this shift, the hydraulic pressure control valve 25
0, the hydraulic pressure supplied to the rear clutch 12 is adjusted to prevent a shock. That is, when the start of a shift is detected by a shift detection device that detects the start of a shift built in an electronic control device 290 such as a computer, the oil passage 408 is opened by duty control of the solenoid valve 325 controlled by the electronic control device 290. The control hydraulic pressure Ps downstream of the orifice 426 is adjusted to change the output pressure Pa output from the oil passage 414 to the oil passage 422, thereby preventing a sudden rise in oil pressure in the hydraulic chamber of the rear clutch 12 and preventing shock during gear shifting. To prevent. At this time,
N communicating with the downstream of the orifice 426 of the oil passage 408
- The spool 274 of the R control valve 270 is the pressure receiving surface 27
1 and the spring 275, it functions as an accumulator and absorbs the pulsation of the control hydraulic pressure Ps. FIGS. 7 and 8 show the characteristics of the output oil pressure Pa of the oil passage 422, which is controlled at startup by the oil pressure control valve 250, with respect to time and engine rotation speed. In the figure, Pao indicates the output oil pressure at the start of the shift, and Pae indicates the output oil pressure at the end of the shift. Next, the relationship between the change in the output oil pressure Pa from the oil pressure control valve 250 and the operation of the ND control valve 210 will be explained in more detail. First, the manual valve 150 is operated from the N range to the D range.
When switched to the range, 6 kg/
Line pressure as hydraulic oil with a constant pressure regulated to cm ² is supplied to the N-D control valve 210 and the hydraulic control valve 250. In the N-D control valve 210, the oil passage 414 is closed by the land 216, but in the hydraulic control valve 250, when the manual valve 150 is operated, the solenoid valve 325 is activated, and the hydraulic pressure acting on the pressure receiving surface 251 is The spool 254 moves leftward from the right end position, and the oil passage 414 and the oil passage 422 communicate with each other, and the pressing force due to the area difference between the pressure receiving surfaces 252 and 253, the pressing force acting on the pressure receiving surface 251, and the spring 255 are reduced. The oil whose pressure is reduced by the balance is transferred from the oil path 422 to the N
- Directed to the D control valve 210. As a result, the reduced pressure oil is introduced into the oil passage 416 between the two lands 216 and 217, and the reduced pressure oil is further supplied to the rear clutch 12 via the rear clutch control valve 280 for initial engagement. The above land 216,
Since there is a pressure receiving area difference between the hydraulic control valves 217 and 217, following the initial engagement of the rear clutch 12, the hydraulic control valve 25
When the output oil pressure of the oil passage 422 is increased by the operation of the 0 and solenoid valves 325, the spool 211 moves to the right against the biasing force of the spring 212, and the oil passage to which line pressure has been supplied is moved. 414 communicates with oil passage 416 via orifice 473, and line pressure is supplied to rear clutch 12 with a certain delay due to orifice 473. When the spool 211 moves to the right end position, the line pressure from the oil passage 414 acts on the left end pressure receiving surface 213 of the spool 211, and the line pressure also acts on the left pressure receiving surface 215 of the land 217, causing the spool 211 to move to the right end position. While holding the oil passage 422 in position, the land 216 closes the oil passage 422. As a result, line pressure is transferred from the oil passage 414 to the two pressure receiving surfaces 21.
The rear clutch 12 is fully engaged by being supplied to the oil passage 416 through the oil passage communicating with the rear clutch 12. On the other hand, the oil passage 422 is closed by the land 216 (at this time, the solenoid 3
5 is in the closed state), so the hydraulic control valve 250
Even if the output pressure Pa changes, the rear clutch 12 remains engaged until the line pressure from the oil passage 414 is discharged, that is, until the manual valve 150 is returned to the N range. It is. Therefore, as long as the manual valve 150 is held at the D position, the oil passage 414 is communicated with the oil passage 416 without going through the hydraulic control valve 250, and the rear clutch 12
The hydraulic pressure chamber is not affected by the hydraulic pressure reduction control during gear shifting by the hydraulic control valve 250 and the solenoid valve 325, and problems such as gear shifting shock due to slipping of the rear clutch 12 and engine racing during gear shifting are prevented. Prevented. By the way, when the manual valve 150 is switched from N to D, oil pressure is also guided to the shift control valve 130 from the oil passage 414, but the solenoid valves 310, 32
0 is energized and the orifices 311 and 321 are open to achieve 1st speed, the orifice 47
With the intervention of 1,472, the same orifice 471,
The hydraulic pressure on the downstream side of 472 is approximately 0 kg/cm ² , and due to the high hydraulic pressure generated between the lands 140 and 141 of the spool 132, a pressing force is applied to the left due to the difference in pressure receiving area between the lands 141 and 142. Spool 1
32 stops at the leftmost position shown in FIG. Further, when the accelerator is depressed and the vehicle speed increases, the electronic control unit 290 sends a signal to the solenoid valve 31.
0 and 320 are issued, the solenoid valve 310 is de-energized, and the solenoid valve 3
20 is kept energized. By this switching, the high pressure oil in the oil passage 470 is passed through the orifice 471 between the two lands 136 and 137 of the spool 131, into the oil hole 139, and into the hydraulic chamber 138.
and is guided between the hydraulic chamber 144 and the two lands 142 and 143 of the spool 133, and the spool 131
moves to the right together with the spool 132 and stops with the spool 131 in contact with the stopper 134. Then, the line pressure in the oil passage 414 is guided to the oil passage 412 through between the two lands 140 and 141 of the spool 132, and the line pressure acts on the hydraulic chamber 173 of the 1st-2nd speed shift valve 170 to shift the spool. 171 to the rightmost position in Fig. 4, and 4
It also acts on the hydraulic chamber 233 of the speed clutch control valve 230 to move the spool 231 to the right end position in FIG. 428 to the engaging-side hydraulic chamber 423 of the kick-down brake 14, and the rod 424 moves to the left against the spring 425 to engage a brake band (not shown) with the kick-down drum 25. Road 4
The hydraulic pressure 53 is discharged through an oil passage 409 communicating with the NR control valve 270, and the low reverse brake 15 is disengaged to achieve second speed. Even during this shift to the second speed, the hydraulic control valve 25
0 is controlled by the control oil pressure of the solenoid valve 325, which reduces the oil pressure in the oil passage 422 to prevent a shift shock, and the rear clutch 12 is not affected by this pressure reduction. Next, when power to the solenoid valves 310 and 320 is cut off in order to achieve third speed according to a command from the electronic control unit 290, the line pressure is increased between the outside of the land 137 of the spool 131 of the shift control valve 130 and the stopper 134. Spool 1 is supplied between
32 is moved to the right in FIG. 4 by the line pressure acting on the pressure receiving surface of the land 140, and the spool 133
It stops with the pressing part in contact with the oil passage 414.
is newly communicated with the oil passage 430, and the line pressure is transferred to the hydraulic chamber 1 of the 2nd speed-3rd speed and 4th speed-3rd speed shift valve 190.
93, the spool 191 of the 2nd speed-3rd speed and 4th speed-3rd speed shift valve 190 is switched to the right end. At this time, the oil passage 42 communicating with the shift valve 190
8 is communicated with an oil passage 432 via an orifice 429. The oil passage 432 reaches the hydraulic chamber 234 at the right end of the 4-speed clutch control valve 230 via a switching valve 452 and communicates with the hydraulic chamber of the front clutch 11 via the release side hydraulic chamber 433 of the kickdown brake 14 and the switching valve 434. do. Due to the structure in which this oil passage 432 is communicated with the release side hydraulic chamber 433 of the kick-down brake 14 and the hydraulic chamber of the front clutch 11, engagement and release of the two are performed with overlap. During this shift from 2nd speed to 3rd speed, the hydraulic control valve 250 operates in exactly the same way as during the shift from 1st speed to 2nd speed, and the oil pressure supplied to the oil passage 422 is maintained low for a short time, but the rear clutch 12 is not affected by this pressure reduction. In addition, an orifice 429 is installed in the oil passage 428.
During the operation of the hydraulic control valve 250, the hydraulic chamber 4
33 and the hydraulic chambers of the front clutch 11 are maintained at the same low oil pressure, and the front clutch 11 is engaged in parallel with the release of the kick-down brake 14. Thereafter, when the hydraulic pressure is increased to 6 kg/cm ² by stopping the operation of the hydraulic control valve 250, the engagement of the front clutch 11 is completed and the third speed is achieved, but when this third speed is achieved, the input shaft 10 and the rotational speed of the kick-down drum 25 approach the rotational speed of the output shaft 24, resulting in a synchronous rotation state. Therefore, the rotational speed detecting devices 332 and 333 detect this matched state or immediately before that as the completion of the shift. Hydraulic control valve 250 by detection
operation is stopped and the supply pressure to the front clutch 11 is increased to 6 kg/cm ² . Due to this pressure increase, 4
The oil pressure in the right end hydraulic chamber 234 of the quick clutch control valve 230 is also increased, the spool 231 is switched to the left end position in FIG.
is supplied to the 4-speed clutch 13 via the 4-speed clutch 13, and the 4-speed clutch is held in an engaged state. The oil passage 445 communicates with the oil pressure chamber 234 from the oil passage 451 via a switching valve 452, and once oil pressure is supplied to the oil passage 445, the 4-speed clutch control valve 230 is closed until the oil pressure in the oil passage 445 is discharged. The spool 231 is held at the left end position in FIG. 4 to prevent the 4th gear clutch 13 from releasing or slipping during shifting between 3rd and 4th gears, resulting in an inability to shift or a neutral state. . Next, with the auxiliary switch set to D ₄ , the solenoid valve 310 is energized and the solenoid valve 320 is kept de-energized in order to achieve 4th speed according to a command from the electronic control unit 290, and the shift control valve The hydraulic pressure in the hydraulic chamber 144 of 130 decreases, and the spool 133 moves to the right together with the spool 132 to the rightmost position in FIG. As a result, oil line 4
14 line pressure is supplied to the hydraulic chamber 293 of the rear clutch control valve 280 and the check valve 2 through the oil passage 436.
35 to an oil passage 445. The spool 291 of the rear clutch control valve 280 is moved to the right end position in FIG. 4 by the line pressure supplied to the hydraulic chamber 293, and the oil passage 436 and the oil passage 456 are communicated, and the 2nd speed - 3rd speed and the 4th speed - 3rd speed are established. shift valve 19
Line pressure is supplied to the hydraulic chamber 194 of the valve 19
0 spool 191 is switched to the left end position shown in FIG. At this time, the oil in the hydraulic chamber of the rear clutch 12 is immediately discharged from the oil drain port 295 of the rear clutch control valve 280, the rear clutch 12 is immediately released, and the hydraulic chamber of the front clutch 11 and the hydraulic chamber 433 of the kick-down brake 14 are also discharged. Oil drains from the oil drain port 1 of the 2nd speed-3rd speed and 4th speed-3rd speed shift valve 190
95 through the orifice 196, the front clutch 11 is released, and the kick-down brake 14 is engaged, but from the first gear to the second gear,
Alternatively, the hydraulic pressure control valve 250 is operated in the same way as when shifting from 2nd to 3rd gear, and the hydraulic pressure in the oil passage 422 is reduced for a short period of time during gear shifting, thereby acting on the hydraulic chamber 423 of the kick-down brake 14. Smooth engagement is achieved by lowering the engagement oil pressure, and then when the engagement oil pressure rises to 6Kg/ ^cm2 , engagement is achieved and 4
Speed is completed. Next, to explain the downshift, the switching of the hydraulic operating system is the reverse of the above-mentioned upshift. First, in order to shift from 4th gear to 3rd gear, both solenoid valves 31
0,320 becomes de-energized, the line pressure in the oil passage 436 is discharged and the rear clutch control valve 280
The spool 291 of the 2nd speed-3rd speed and 4th speed-3rd speed shift valve 190 is switched to the right end, and hydraulic pressure is supplied to the oil passages 417 and 432. At this time, oil is smoothly supplied to the hydraulic chamber 433 of the kickdown brake 14 and the hydraulic chamber of the front clutch 11 via the orifice 429, and is supplied to the hydraulic chamber of the rear clutch 12 via the orifice 473 compared to the front clutch 11. It is fed gradually with sufficient delay. Therefore, the downbrake 14 is immediately released, but
Even during this deceleration shift, the hydraulic pressure control valve 250 operates for a short time during the shift, and the hydraulic pressure supplied to the oil passages 428 and 432 is maintained at a low pressure. This is a rear clutch 12 with a large torque capacity.
This is done to prevent gear shifting shocks due to engagement from the outside. When shifting from 3rd gear to 2nd gear, solenoid valve 3
10 is de-energized, the solenoid valve 320 is energized, and the spools 131 and 1 of the shift control valve 130 are
32 decreases, the spool 132 moves one step to the left in FIG. 4, and the oil pressure in the oil passage 430 is discharged. The spool 191 moves to the left end, and the hydraulic pressure in the oil passage 432 is discharged, and the spool 231 of the 4-speed clutch control valve 230 moves to the right end, and the hydraulic pressure in the oil passage 445 is also discharged, and the 4-speed clutch 1
3 is immediately released, and the front clutch 1
The release of the first gear engagement and the engagement of the kick-down brake 14 are carried out gradually by the operation of the hydraulic control valve 250 at the time of gear change, as in the shift from the fourth gear to the third gear, and the second gear is smoothly achieved. When shifting from 2nd speed to 1st speed, both solenoid valves 310 and 320 are energized, and shift control valve 130 is placed in the leftmost position with spool 131,
132 moves, the hydraulic pressure in the oil passage 412 is discharged, and the spool 171 of the 1st-2nd speed shift valve 170
and spool 231 of 4-speed clutch control valve 230
moves to the left end, the oil in the hydraulic chamber of the kick-down brake 14 is discharged, and the brake 14 is disengaged, while the low reverse brake 15 is engaged and the first speed is achieved. By operating the select lever and auxiliary switch
D When selecting ₃ or 2 positions, manual valve 150
The oil passage is not switched at all by the select lever selection position detection device 341 and the auxiliary switch selection position detection device 342, and the position is detected by the select lever selection position detection device 341 and the auxiliary switch selection position detection device 342. The solenoid valves 310 and 320 are controlled so that gear changes are not performed. When the manual valve 150 is selected to the L position, the position is detected by the selection lever selection position detection device 341, and if the vehicle speed is above a predetermined value such as 50 km/h at the initial stage of selection, the vehicle is held at 2nd gear, and thereafter the vehicle speed is increased. When the value is below a predetermined value, the first speed is fixed by controlling the solenoid valves 310 and 320. Incidentally, as in each of the above-mentioned gear shifts, by operating the hydraulic pressure control valve 250, the supplied hydraulic pressure is maintained at a low pressure at the time of switching (shifting), thereby preventing a shock. Next, the case of moving backward will be explained. When the manual valve 150 is selected to the R position, the oil passage 4
01 is connected to the oil passage 421, and the oil passage 421 is connected to the N-
The oil passage 401 is led to the low reverse brake 15 via the R control valve 270, the oil passage 409, the 1st-2nd gear shift valve 170, and the oil passage 453.
05 to the switching valve 434, oil is also supplied to the hydraulic chamber of the front clutch 11, and retraction is achieved by engagement of the clutch 11 and brake 15. Even during this gear change during reverse, the N-R control valve 2
70 operates as a hydraulic pressure regulating valve, and the hydraulic control valve 25
0 spool 254 and spring 255 function as an accumulator for pulsation mitigation, and the oil path 4
The output pressure Pd from 09 is changed as shown in FIGS. 9 and 10. By the way, the oil led to the torque converter control valve 70 from the oil passage 459 through the pressure regulating valve 50 is as follows.
The pressure is regulated to 2.5 kg/cm ² due to the balance between the control hydraulic pressure acting on the right end pressure receiving surface of the spool 71 in FIG. Further, the oil in the oil passage 460 is supplied to the lubrication system on the opposite side of the engine 1 via an orifice 463. Representative examples of the hydraulic control characteristics of the hydraulic control device in the upshift and downshift described above are shown in FIGS. 11 to 13. Figures 11 to 13 show 1st gear → 2nd gear in the case of power ON upshift, which is a normal upshift.
The gears shift from 2nd to 3rd gear and 3rd to 4th gear, where Ni indicates the input shaft rotation speed, No indicates the output shaft rotation speed, Nk indicates the kickdown drum rotation speed, and Pa indicates the output oil pressure. Next, control of the direct coupling clutch 9 provided to reduce slippage within the torque converter 3 will be explained. The oil whose pressure is regulated to 2.4 kg/cm ² by the pressure reducing valve 110 and led to the oil passage 410 reaches the orifice 301 via the orifice 464 and which is controlled to open and close by the solenoid valve 300. The direct coupling clutch control valve 90 has four lands 92,
It has a spool 91 with 93, 94, 95,
While the control hydraulic pressure regulated by duty control between 0.3 and 1.9 kg/cm ² by the solenoid valve 300 acts on the pressure receiving surface 96 on the outside of the land 92,
The oil passage 410 communicates between the lands 94 and 95, and the pressure regulating oil regulated by the pressure reducing valve 110 flows between the lands 94 and 95.
95, and due to the pressure receiving area difference, a pressing force to the left in FIG. The pressing force to the left in FIG. 4 caused by the hydraulic pressure acting on the right side in FIG. 4 and the hydraulic pressure between the lands 94 and 95,
The flow direction of the oil supplied to the torque converter 3 and the direct coupling clutch 9 and its oil pressure are controlled by the balance with the pressing force to the right in FIG. An oil passage 44 following the torque converter 3 is connected to an oil passage 465, and a direct coupling clutch 9
The oil passage 45 that follows is connected to an oil passage 466, and by switching control of the direct coupling clutch control valve 90, the oil passage 465 is connected to the discharge oil connected from the supply oil passage 401 or the oil cooler 462 to the lubrication system on the engine 1 side of the transmission. The oil passage 466 is selectively communicated with the supply oil passage 460 or the discharge oil passage 467. The solenoid valve 300 is controlled by the electronic control device 290.
When an engagement command for the direct coupling clutch 9 is given to the direct coupling clutch 9, oil pressure regulated by the direct coupling clutch control valve 90 is supplied from the oil passage 401 to 465 as shown by the solid line arrow in FIG. is hydraulic chamber 4
The piston 38 is pushed leftward by the hydraulic pressure acting on the piston 2 and is engaged with a predetermined amount of slip. The hydraulic characteristics due to the direct coupling clutch control valve 90 are
Shown in Figure 4. The output oil pressure Pc generated in the oil passage 465 with respect to the control oil pressure Ps acting on the pressure receiving surface 96 of the spool 91 has the characteristics shown in FIG. If the hydraulic pressure acting on the piston 38 is controlled by a computer to provide a slip amount that is slightly below the range of speed fluctuations of the crankshaft 2 caused by the fluctuating torque of the engine 1, most of the fluctuating torque of the crankshaft 2 can be transmitted. This results in highly efficient power transmission and improved fuel efficiency. By the way, when starting or suddenly accelerating, the direct coupling clutch 9 is activated to utilize the characteristics of the torque converter 3 on the feeling.
It is necessary to remove the electronic control unit 29.
0, the energization of the solenoid valve 300 is stopped, and the direct coupling clutch control valve 90 is switched to allow oil to flow in the opposite direction to that indicated by the dashed arrow in FIG.
That is, the torque converter control valve 70
Low oil pressure oil of 2.5Kg/cm ² flows from oil path 460 to 466.
The piston 38 of the direct coupling clutch 9 moves to the right by the hydraulic pressure acting on the hydraulic chamber 41, and the engagement thereof is released. As described above in detail with the embodiments, according to the present invention, once a friction element that is engaged in at least two or more consecutive gears, such as a rear clutch, is engaged, other frictional elements are engaged. Due to the initial engagement of the device, even if the supplied hydraulic pressure is reduced, the fully engaged state is maintained without being affected by it, which prevents problems such as gear shift shock due to slippage and engine revving. At the same time, durability also improves.

[Brief explanation of the drawing]

Fig. 1 is a power train diagram of a vehicle automatic transmission to which the present invention is applied, and Fig. 2 shows the engagement state of each frictional engagement device in the automatic transmission in relation to the select lever position. FIG. 3 is a sectional view of the torque converter and the direct coupling clutch; FIG. 4 is a system diagram showing the hydraulic control device for the automatic transmission equipped with the hydraulic control device for the rear clutch according to an embodiment of the present invention; Figures 5 and 6
The figure shows the control pressure in the rear clutch hydraulic control system.
Graphs showing the relationship between output pressure Pa during forward movement and output pressure Pb during backward movement with respect to Ps, Figures 7 to 1
Figure 0 is a graph showing the characteristics of hydraulic control by the rear clutch hydraulic control device over time and engine speed, Figures 11 to 13 are graphs showing the hydraulic control characteristics at each upshift gear stage, and Figure 14. is a graph showing hydraulic characteristics due to a direct coupling clutch control valve. In the drawing, 1 is an engine, 3 is a torque converter, 9 is a direct coupling clutch, 12 is a rear clutch (friction element), 11, 13, 14, 15 are friction engagement devices, 17 is a planetary gear set, 50 is a pressure regulating valve, 70 1 is a torque converter control valve, 90 is a direct clutch control valve, 110 is a pressure reducing valve, 130 is a shift control valve, 1
50 is a manual valve, 170 is a 1st-2nd speed shift valve, 1
90 is a 2nd speed - 3rd speed and 4th speed - 3rd speed shift valve, 21
0 is the N-D control valve (switching valve), 230 is the 4-speed clutch control valve, 250 is the hydraulic control valve, 270 is the N-
R control valve, 280 is rear clutch control valve, 290
300, 310, 320 are solenoid valves, 325 is a solenoid valve, and 340 is a rear clutch hydraulic control device.

Claims (1)

[Claims] 1 In an automatic transmission in which a plurality of gears are achieved by selectively hydraulically engaging a plurality of friction engagement devices including friction elements that are engaged in at least two or more consecutive gears, a constant pressure a hydraulic pressure supply source that supplies a first hydraulic fluid, a hydraulic pressure adjustment device that adjusts the pressure of the first hydraulic fluid to a desired low hydraulic pressure and supplies it as a second hydraulic fluid, the hydraulic pressure supply source, the hydraulic pressure adjustment device, and the friction element. a first position that supplies the first hydraulic oil to the friction element and cuts off the supply of the second hydraulic oil; and a first position that supplies the second hydraulic oil to the friction element and supplies the first hydraulic oil. a switching valve having a second position where the switching valve shuts off the second hydraulic fluid, and the switching valve is configured to switch from the supply state of the second hydraulic fluid at the second position to the first hydraulic fluid by increasing the hydraulic pressure of the second hydraulic fluid by the hydraulic pressure adjusting device. When the oil pressure of the first hydraulic fluid does not drop below a predetermined value, the first
A hydraulic control device for an automatic transmission, characterized in that it is configured to be held in position.