JPH0327788B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a hydraulic control system for a vehicle automatic transmission using a V-belt continuously variable transmission. [Prior Art] A V-belt type consisting of an input pulley and an output pulley, which are provided on the input and output shafts, respectively, and whose effective diameters are variable by a hydraulic servo, and a V-belt that transmits power between the input and output pulleys. A continuously variable transmission is used as a continuously variable automatic transmission for a vehicle in combination with a forward/reverse switching mechanism and a coupling such as a fluid coupling, a centrifugal clutch, or a friction clutch. In this type of V-belt continuously variable transmission,
In order to quickly and smoothly increase or decrease the reduction ratio, it is necessary to set the ratio of the load on the input pulley to the load on the output pulley to be around 2. ) At times, it is necessary to supply a higher hydraulic pressure to the hydraulic servo than during steady driving, such as gradual upshift driving, gradual downshift driving, and constant reduction ratio driving. Conventionally, in order to obtain the above load ratio, the effective pressure receiving area of the input pulley's hydraulic servo is set to be twice as large as the effective pressure receiving area of the output pulley's hydraulic servo.
A method has been used in which the operating pressure of the hydraulic servo of the input pulley is made equal to the operating pressure of the hydraulic servo of the output pulley. In order to secure this large effective pressure-receiving area, the hydraulic servo of the input pulley has to be enlarged, which has the disadvantage of reducing the ease of mounting on a vehicle and reducing fuel efficiency due to increased weight. [Problems to be Solved by the Invention] In conventional continuously variable transmissions, it is common for one of the hydraulic servos to generate the clamping force for the V-belt, and the other hydraulic servo to control the reduction ratio. . Therefore, in order to generate a high clamping force on the V-belt when the vehicle starts or suddenly accelerates or decelerates, it is necessary to supply high working pressure to one of the hydraulic servos. However, when changing the reduction ratio during a shift, the other hydraulic servo requires higher working oil pressure, which requires an increase in the capacity of the oil pump, which reduces fuel efficiency and forces more than necessary. There is a problem in that this acts on the V-belt and reduces the durability of the belt. The present invention solves the above problems, and includes:
The purpose of the present invention is to provide a hydraulic control device for a continuously variable automatic transmission for vehicles that can be made compact and lightweight by eliminating excessive hydraulic pressure and ensuring the minimum required belt clamping force, while also enabling upshifts or downshifts. shall be. [Means for Solving the Problem] For this purpose, the hydraulic control device for a continuously variable automatic transmission for vehicles of the present invention includes hydraulic servos 154 and 16, respectively.
4, the input pulley 150 has a variable effective diameter.
and an output pulley 160, and a V-belt 145 that transmits power between the input pulley and the output pulley;
By controlling the hydraulic pressure supplied to both the hydraulic servos, the input pulley 150 and the output pulley 1
60, the hydraulic control device includes a first hydraulic pressure adjusting device 30 that adjusts the discharge hydraulic pressure from the oil pump 20 to a first hydraulic pressure; a second hydraulic pressure adjusting device 35 that adjusts the pressure to a second hydraulic pressure lower than the hydraulic pressure of the input pulley 150 or the output pulley 160; and reduction ratio control means 50, 60 for supplying the first hydraulic pressure or the second hydraulic pressure to the servo 164, and the reduction ratio control means controls the first hydraulic pressure or the second hydraulic pressure to one of the hydraulic servos when changing gears. It is characterized by selectively supplying hydraulic pressure. Note that the numbers added to the above configurations are for comparison with the drawings to facilitate understanding, and the configurations of the present invention are not limited thereby. [Operation and Effects of the Invention] In the present invention, when changing the reduction ratio,
Supplying or discharging a first hydraulic pressure to one hydraulic servo, for example, supplying a lower second hydraulic pressure to the other hydraulic servo in the case of an upshift, and a higher first hydraulic pressure to the other hydraulic servo in the case of a downshift. Since the reduction ratio is changed using the relative load ratio of both hydraulic servos, it is possible to perform upshifts or downshifts while eliminating excessive hydraulic pressure and ensuring the minimum required belt clamping force. , it can be made more compact and lighter. [Example] Next, the present invention will be explained based on an example shown in the drawings. FIG. 1 shows a continuously variable automatic transmission for a vehicle. This continuously variable automatic transmission for a vehicle includes a hydraulic torque converter 100 which is a fluid coupling with a direct coupling clutch, a planetary gear transmission mechanism 120 for forward/reverse switching, a V-belt continuously variable transmission 140, and a differential gear 1.
70. The torque converter 100 includes a front cover 101 connected to the output shaft of the engine, a pump impeller shell 102 welded to the front cover 101 and having an impeller attached to its inner periphery, and a torque converter in the center via a turbine hub 104. Turbine runner 1 connected to output shaft 103
05, consists of a stator 107 fixed to an inner case 110 via a one-way clutch 106, and a direct connection clutch 108 that directly connects the turbine hub 104 and the front cover 101, and between the torque converter 100 and the planetary gear transmission mechanism 120. There is an oil pump 20 driven by the output of the engine.
is provided. The forward/reverse switching planetary gear transmission 120 connects the output shaft 103 of the torque converter to the input shaft 10.
3, and the input shaft 141 of the V-belt type continuously variable transmission 140 connected in series with the input shaft is the output shaft 141,
A multi-disc clutch C1, a hydraulic servo 121 that operates the multi-disc clutch C1, a multi-disc brake B1, a hydraulic servo 122 that operates the multi-disc brake B1,
It consists of a planetary gear set 130. The planetary gear set 130 includes a carrier 131 connected to the input shaft 103 via an annular hydraulic cylinder 123 of a hydraulic servo 121, a multi-disc clutch C1 connected to the hydraulic cylinder 123, and a spline connected to the output shaft 141. The fitted sun gear 132 is rotatably supported by the ring gear 133 fixed to the transmission case 220 and the carrier 131 via the multi-disc brake B1, and the sun gear 132 and ring gear 133 have teeth. combined planetary gear 1
It consists of 34. The V-belt type continuously variable transmission 140 has the input shaft 1
41 and an output shaft 142 arranged parallel to the input shaft 141 are each driven by a hydraulic servo. Input pulley 150 and output pulley 16
0, and these input pulley 150 and output pulley 160 are connected by a V-belt 145, which is formed by attaching a number of metal books 144 to a steel band 143 made of overlapping ring-shaped thin plates. The input pulley 150 includes a fixed flange 151 formed integrally with the input shaft 141 and a double piston 152.
Hydraulic servo 1 of the input pulley with and 153
54 to be displaced in the axial direction to increase or decrease the effective diameter of the input pulley. The output pulley 160 is connected to the output shaft 14
2, and a movable flange 165 that is driven by a hydraulic servo 164 of the output pulley having double pistons 162 and 163 and is displaced in the axial direction to increase or decrease the effective diameter of the output pulley. The differential gear 170 includes a large drive gear 171 as an input gear, a gear box 172, a small differential gear 173, a large differential gear 174, and an output shaft 175 connected to an axle. A governor valve 25 is provided at one end of the output shaft of the V-belt type continuously variable transmission, and an output gear 188 is rotatably supported at the other end, and a reduction planetary gear set 180 is provided at the other end. The planetary gear set 180 for deceleration includes a sun gear 181 connected to the output shaft 142, a ring gear 182 fixed to the transmission case 220, a carrier 183 connected to the output gear 188, and the sun gear 181 and the ring gear 182. An output gear 188 consisting of a planetary gear 184 which meshes with each other and is rotatably supported by a carrier 183 is connected by a chain 190 to the large drive gear 171 of the differential gear. FIG. 2 shows a control device for controlling the speed change of the continuously variable automatic transmission for a vehicle shown in FIG. 1 shows a hydraulic control device in a control device for a continuously variable automatic transmission for a vehicle, which includes a hydraulic control device controlled by the device. The hydraulic control device of this embodiment includes the oil pump 20 which is a hydraulic source and is driven by an engine, the governor valve 25 which outputs a governor pressure corresponding to the vehicle speed or the output shaft rotation speed of the V-belt continuously variable transmission;
A primary regulator valve 30 that supplies primary line pressure to the hydraulic control device, a secondary regulator valve 35 that supplies secondary line pressure to the hydraulic control device, a throttle valve 40 that outputs throttle pressure according to the throttle opening, and a governor. The cutback valve 45 outputs a cutback pressure corresponding to the pressure to the throttle valve, and relates the throttle pressure to the vehicle speed (governor pressure).The cutback valve 45 outputs a throttle control pressure adjusted in relation to the governor pressure to the primary regulator valve. A line pressure adjustment valve 47, a reduction ratio control mechanism 50 that controls the supply and discharge of hydraulic oil to the hydraulic servo of the input pulley and increases or decreases the reduction ratio of the V-belt continuously variable transmission according to vehicle running conditions; A shift sequence mechanism 60 for changing the type of hydraulic pressure supplied to the hydraulic servo of the output pulley of the step-change transmission from the primary line pressure to the secondary line pressure in response to the operation of the reduction ratio control mechanism 50, when the input pulley is running steadily. An input pulley modulator mechanism 66 that balances the oil pressure of the hydraulic servo and compensates for oil pressure leakage of the hydraulic servo, and a planetary gear transmission mechanism 12 that is operated by a shift lever provided at the driver's seat.
Manual valve 70, N that switches between forward and backward movement of 0
→ Operates the shift control mechanism 75 for smooth engagement of the multi-disc clutch or multi-disc brake during D shift and N→R shift, and for inertial running in D range, and the direct coupling clutch 108 of torque converter 100. It has a lockup control mechanism 80 that allows the lockup to be performed. In the oil pump 20, a slide casing 204, which has a spring 202 on one side and a hydraulic servo 203 on the other side, is housed in a body 201 so as to be slidable about a fulcrum 205. 20
This is a variable displacement vane pump equipped with a rotor 207 with a 6-piece rotor 207, and sucks oil from an oil reservoir 208 through an oil strainer 209 and discharges it into the oil passage 1. The governor valve 25 has a known configuration and is attached to the output shaft of the V-belt continuously variable transmission, and controls the line pressure supplied from the oil passage 1 to the output of the V-belt continuously variable transmission corresponding to the vehicle speed. The pressure is regulated according to the shaft rotation speed and output to the oil passage 6 as governor pressure shown in FIG. The primary regulator valve 30 includes a spool 3 having a spring 31 on its back on one side (lower side in the figure).
2, and a regulator plunger 33 which is provided in series at the lower side in the figure, in contact with the spool 32 so as to press the spool 32 from the same direction as the spring 31. The regulator plunger 33 is provided with an upper land 331 of a large diameter and a lower land 332 of a small diameter.
Throttle control pressure outputted from the line pressure regulating valve 47 supplied from the oil passage 7B via the orifice 341 or governor pressure supplied from the oil passage 6A connected to the oil passage 6 via the orifice 341 is applied. Throttle pressure is applied to the side land 332 via the oil passage 7, and the spool 32 is pushed upward in the drawing by a pressing force corresponding to the input oil pressure. The spool 32 is displaced by the feedback of the primary line pressure applied from above in the figure through the orifice 301 to the top end land in the figure, and the spring load of the spring 31 and the pressing force of the regulator plunger 33 received from below in the figure. The communication area between the oil passage 1 and the oil passage 2 is increased or decreased to allow excess oil to flow out into the oil passage 2, and excess oil exceeding the outflow capacity from the oil passage 2 is drained from the drain port 302. As a result, the oil pressure in the oil passage 1 generates a primary line pressure Pl shown in FIG. 4, which is related to vehicle speed (governor pressure) and throttle opening (throttle pressure), which are the driving conditions of the vehicle. The secondary regulator valve 35 has a spool 3 on which a spring 36 is mounted on one side (lower side in the figure).
7 and a plunger 38 provided in series in the lower part of the figure in contact with the spool 37, a first port 371 that outputs secondary line pressure, and a torque converter 100 that outputs excess oil when regulating the secondary line pressure. and a second port 372 that supplies lubricating oil to parts that require lubricating oil in the automatic transmission, a third port 373 that outputs hydraulic pressure to control the amount of oil discharged to the variable displacement oil pump 20, a drain port 352,
353, an input port 354 for throttle pressure, which is input oil pressure according to vehicle operating conditions, and an input port 355 for secondary line pressure. The oil passage 5 communicating with the second port 372 is connected to an orifice 391 having a relatively large diameter.
It communicates with the oil passage 5A that supplies hydraulic oil to the torque converter 100 via the lock-up control valve 81 of the torque converter, and also communicates with the oil passage 5A that supplies hydraulic oil to the torque converter 100 through the lock-up control valve 81 of the torque converter. Oil passage 5B that supplies lubricating oil to parts that require lubrication
is in contact with. The oil passage 2 where the secondary line pressure is generated and the oil passage 5A communicating with the lock-up control valve 81 are connected via a small diameter orifice 393.
In addition, the oil passage 2 and the oil passage 5B for supplying lubricating oil are:
Further communication is provided via a small diameter orifice 394. This secondary regulator valve 35 operates as follows. In this secondary regulator valve 35, the spool 37 receives the feedback of the secondary line pressure of the oil passage 2 applied from the upper side in the figure via the orifice 351 to the upper end land in the figure, and receives the spring load from the spring 36 from the lower side in the figure. and oil road 7
It is displaced in response to the throttle pressure applied to the plunger 38 from above, and increases or decreases the communication area between the first port 371 communicating with the oil passage 2 and the second port 372 communicating with the supply oil passage 5 for lubricating oil, etc. When the primary line pressure is regulated by the primary regulator valve 30, the oil pressure in the oil passage 2, which is the oil passage through which excess oil spills, is regulated in accordance with the input oil pressure, which is the throttle pressure, and the secondary line shown in FIG. Outputs pressure P,
and a third port 373 communicating with the oil passage 8 that outputs control oil pressure to the oil pump hydraulic servo 203.
The communication area between the first port 371 and the drain port 352, which communicate with the oil passage 2, is adjusted to output hydraulic pressure to the hydraulic servo 203, thereby controlling the discharge capacity of the oil pump 20. FIG. 6 shows the displacement of the spool 37 and the characteristics of oil pressure changes in the oil passages 5A, 5B, and 8 when the throttle pressure is constant. When the secondary line pressure is within the set appropriate range (zone A in Figure 6). The first port 371 and the second port 372 communicate with each other to generate hydraulic pressure in the oil passage 5, and the torque converter supply pressure in the oil passage 5A and the lubricating oil pressure in the oil passage 5B are mainly transmitted through orifices 391 and 392, respectively. Hydraulic pressure is sufficiently supplied and at an appropriate value. The engine is running at low rpm and the oil pump 2
0, the amount of oil discharged from the primary regulator valve 30 is small, and the excess oil discharged from the primary regulator valve 30 to the oil path 2 is also small, and the oil temperature is high, resulting in increased oil leakage from various parts of the hydraulic circuit. When the pressure falls below the set appropriate range (zone B in Figure 6). The spool 37 is displaced upward in the drawing to close the second port 372, stopping the discharge of excess oil from the oil passage 5 and maintaining the secondary line pressure. At this time, if no pressure oil is supplied to the oil passage 5A, the direct coupling clutch 10 in the torque converter 100
8 cannot be reliably maintained in the released state, resulting in wear due to the drag of the direct coupling clutch, and insufficient circulation of the hydraulic oil to the oil cooler, which tends to cause excessive temperature rise of the hydraulic oil in the torque converter. In the present invention, the minimum required amount of hydraulic oil is supplied from the oil passage 2 through the small diameter orifice 393 into the oil passage 5A.
The torque is supplied to the torque converter 100 through the direct coupling clutch control valve 81, thereby preventing the direct coupling clutch from dragging and preventing the hydraulic oil from rising in temperature excessively. Also oil road 5
If no lubricating oil is supplied to B, the sliding parts that require lubrication are likely to seize, so the minimum necessary lubricating oil is supplied through an orifice 394 having a smaller diameter. Note that the amount of pressure oil flowing out from the flow path 2 through these small-diameter orifices 393 and 394 is so small that it hardly affects the maintenance of the secondary line pressure in the flow path 2. When the engine is operated in a high rotational speed range and there are many discharge oil passages of the oil pump 20, so that there is a large amount of surplus oil discharged from the primary regulator valve 30 to the oil passage 2 (Zone C in FIG. 6). Since the secondary line pressure becomes higher than the appropriate range, the spool 37 is displaced downward in the figure, the third port 373 and the first port 371 communicate with each other, and pressure oil is supplied from the oil path 8 to the hydraulic servo 203 of the oil pump 20. The amount of oil discharged from the oil pump 20 is reduced,
This reduces the excess oil in the primary regulator valve 30 and lowers the secondary line pressure to a set appropriate range. By reducing the discharge capacity of the oil pump 20, the output torque of the engine consumed by the oil pump 20 is reduced, making it possible to increase the engine output and improve fuel efficiency. Note that this secondary line pressure is approximately 1/2 of the primary regulator pressure outputted to the oil passage 1 by the primary regulator valve 30. The throttle valve 40 has a spool 42 having a spring 41 on its back on one side (upper side in the drawing), and is arranged in series with the spool 42 via a spring 43, and one end 44A (lower end in the drawing) protruding from the valve body is connected to the engine. The throttle plunger 44 is in contact with the operating surface of a throttle cam (not shown) that rotates in accordance with the throttle opening. The throttle plunger 44 is a large diameter land 44 on the upper side in the figure.
In addition to the pressing force from the throttle cam, the throttle pressure of the oil passage 7 is applied to the effective pressure-receiving surface of the large-diameter land 441, thereby increasing the effective pressure-receiving pressure of the lower small-diameter land 442. The surface receives the cutback pressure of the oil passage 7A, is displaced upward in the figure, and is connected to the spool 42 via the spring 43.
Press upward. The spool 42 receives the pressing force from the spring 43 from below, and the spring load from the spring 41 from above is applied to the upper end land 421.
The cutback pressure of the oil passage 7A applied to the effective pressure receiving surface of the intermediate land 4 via the orifice 401
It is displaced in response to the feedback of the throttle pressure applied to the effective pressure-receiving surface of the oil passage 22, increasing or decreasing the communication area between the oil passage 2 and the oil passage 7, and changing the secondary line pressure supplied from the oil passage 2 to the throttle opening and Adjust the throttle pressure as shown in FIG. 7, which changes in relation to the governor pressure (output shaft rotational speed). The cutback valve 45 has a large diameter lower end land 46.
1. A spool 46 having an intermediate land 462 and an upper end land 463 is provided, and when the spool 46 is set downward in the figure, the oil passage 7 and the oil passage 7A communicate with each other, and a cutback pressure Pc is generated in the oil passage 7A. The spool 46 receives governor pressure Pg supplied from above to the effective pressure receiving area S1 of the lower end land 461 via the oil passage 6, and receives cutback pressure Pc from below to the pressure receiving area S2 of the lower end land 461 from below via the orifice 451. Pg×S1=
It is displaced so as to maintain the balance expressed by the balance equation of Pc×S2. As the spool 46 is displaced upward, the area of the oil passage 7A communicating with the oil passage 7 decreases, and the area of the oil passage 7A communicating with the drain port 451 increases, so the cutback pressure Pc decreases and Pg ×S1>Pc×S2, so spool 4
6 is moved downward. In this way, the spool 46 is held at a position determined by the equilibrium equation of Pg x S1 = Pc x S2, and the cutback pressure output to the oil passage 7A is regulated. Figure 8 shows the cutback pressure Pc characteristics. The line pressure regulating valve 47 includes a spool 49 having a spring 48 on its back on one side (lower side in the figure). The spool 49 is connected to the spring 48 from below.
The upper end land 49 shown from above receives the spring load of
1 is displaced in response to the governor pressure Pg of the oil passage 6, and the communication area between the oil passage 7B that outputs the throttle control pressure, the oil passage 7 to which the throttle pressure is supplied, and the drain port 471 is adjusted, and the oil passage Adjust the throttle control pressure output to 7B.
Figure 3 shows the characteristics of the throttle control pressure Psm. The reduction ratio control mechanism 50 connects the hydraulic servo 154 of the input pulley 150 and the oil path 1 or the drain port 5.
Controls communication with 11 and V-belt continuously variable transmission 14
A reduction ratio control valve 51 that changes the reduction ratio of 0, is controlled by an electronic control device that receives vehicle running conditions such as input pulley rotation speed and throttle opening, and is turned ON.
It consists of an upshift electromagnetic solenoid valve 55 (hereinafter referred to as up solenoid 55) and a downshift electromagnetic solenoid valve (hereinafter referred to as down solenoid 56) 56, which are turned off and control the reduction ratio control valve 51. The reduction ratio control valve 51 has a spring 52 installed behind it on one side (lower side in the figure), and an intermediate land 532 between an upper end land 531 and a lower end land 534 in contact with the upper end of the spring 52.
and 533, and the oil chamber 521 between the lands 531 and 532 communicates with the oil passage 9, and when the spool 53 is displaced upward, it communicates with the oil passage 1, and when the spool 53 is displaced downward, it communicates with the oil passage 1. Contact Drainport 511. The oil chamber 522 between the intermediate lands 532 and 533 communicates with the oil passage 12A which communicates with the lower end oil chamber 524, and the land 53
2, the hydraulic pressure of the oil passage 12A is leaked from the drain port 511 whose opening area is adjusted to adjust the pressure and hold the spool at an intermediate position. A notch 511A is provided in the drain port 511, and the oil passage 1
The amount of oil pressure leaking from 2A changes gradually, and the spool is smoothly maintained at the intermediate position. Oil chamber 523 between intermediate land 533 and lower end land 534
communicates with the oil passage 6A via the orifice 512, and when the spool 53 is held at the intermediate position, the oil passage 6A and the drain port 513 are communicated with each other to exhaust pressure in the oil passage 6A, and the spool 53 is displaced upward. At this time, the lower end land 534 closes the communication port 514 with the oil passage 6A to maintain the oil pressure in the oil passage 6A, and also allows the communication port 515 with the oil passage 12A, which communicates with the lower end oil chamber 524, to communicate with the drain port 513. to evacuate the oil passage 12A. The up solenoid 55 is connected to the oil path 2 through the orifice 515.
It is attached to the oil passage 2A that connects to the upper end oil chamber 525 of the reduction ratio control valve 51, and maintains the oil pressure of the oil passage 2A at a high level (equivalent to the secondary line pressure) when it is OFF. When it is ON, the hydraulic pressure in oil passage 2A is exhausted. The down solenoid valve 56 is connected to the orifice 5
61 to the oil passage 12 and to the lower end oil chamber 524 of the reduction ratio control valve 51, and further to the oil chamber 522 of the spool when the spool 53 of the reduction ratio control valve is held at an intermediate position. It is attached to the oil passage 12A that connects to the port 515, and maintains the oil pressure of the oil passage 12A when it is OFF.
When ON, the oil passage 12A is depressurized. In the above configuration, the primary line pressure of the oil passage 1 is controlled as follows. When a shift signal for upshifting or downshifting is issued from an electronic control circuit that receives vehicle running conditions such as the input pulley rotation speed and throttle opening, the up solenoid 55 or down solenoid 56 is turned on, and the reduction ratio control valve 51 is turned on.
The spool 53 is displaced upward or downward from the intermediate position, and as a result, when the spool 53 is in the intermediate position, the drain port 513 and the oil passage 6A communicate with each other, and the oil passage 6A and the drain port are connected to each other. 513 is cut off, the governor pressure in the oil passage 6A is generated as a shift signal oil pressure, and the governor pressure in the oil passage 6A is transmitted as a shift signal oil pressure to the regulator plunger via the check valve 34 and the oil passage 11. 33 and pushes the spool 32 upward. This shift signal oil pressure reduces the communication area between oil passage 1 and oil passage 2 of regulator valve 30. As a result, the line pressure regulated by the regulator valve 30 increases in level as shown in FIG. In this way, during steady running, the input pulley's hydraulic servo is kept constant at a low line pressure, the line pressure is leveled up only when the torque ratio changes, and this level-up line pressure is supplied to the input pulley's hydraulic servo during upshifts. During a downshift, it is supplied to the hydraulic servo of the output pulley to control the reduction ratio. This enables V-belt continuously variable transmissions to perform rapid upshifts and downshifts, providing excellent acceleration and deceleration performance, and requires only a low level of line pressure when not shifting. Output consumption can be reduced. In this embodiment, the shift signal oil pressure is the vehicle speed or the output shaft 1.
The governor pressure is increased as shown in FIG. 3 in response to an increase in the rotational speed of the engine 42. This is because the above-mentioned characteristics of the governor pressure are suitable for obtaining the line pressure required during shift driving.The shift signal oil pressure may be another oil pressure other than the governor pressure. The shift sequence mechanism 60 consists of a shift sequence valve 61 and check valves 64 and 65. The shift sequence valve 61 is located on one side (lower side in the figure).
A spring 62 is provided on the back of the upper end land 6 shown in the figure.
31, a spool 63 having an intermediate land 632, a lower end land 633 shown in the figure with which the upper end of the spring 62 is in contact, and a port 611 communicating with the oil passage 1;
A port 61 that communicates with the oil passage 10 for supplying hydraulic oil to the hydraulic servo 164 of the output pulley 160
2. It has a port 613 communicating with the oil passage 12 and a drain port 614. Check valve 64 is connected to oil line 2
The check valve 65 is inserted into an oil passage communicating between the oil passage 2 and the oil passage 10, and the check valve 65 is inserted into an oil passage communicating between the oil passage 2 and the oil passage 12. The spool 63 of the shift sequence valve 61 is displaced by receiving the spring load of the spring 62 from below and receiving pressure from the oil passage 9 supplied from above through the orifice 601 on the upper end land 631,
When the oil pressure in oil passage 9 is higher than the set value (during steady running or upshifting), the oil pressure in oil passage 1 is set to the lower position in the diagram.
2 and oil passage 10, and oil passage 1 and oil passage 1.
0, and further connects oil passage 1 and oil passage 13. When the oil pressure in oil passage 9 is exhaust pressure (during downshift), the oil passage 1 and oil passage 10 are set upward in the figure.
At the same time, the oil passage 12 is connected to the drain port 614 to discharge pressure, and the oil passage 1 and the oil passage 1
Cut off contact with 3. The check valve 64 functions to supply the secondary line pressure of the oil passage 2 to the oil passage 10 and the oil passage 12 when the spool 63 of the shift sequence valve is set to the lower position in the figure. When the oil pressure becomes higher than the oil pressure in the oil passage 2, the pressure oil in the oil passage 12 is discharged to the oil passage 2. Oil pressure P9 of oil passage 9 relative to output shaft rotation speed,
FIG. 9 shows changes in the oil pressure P10 of the oil passage 10 and the oil pressure P12 of the oil passage 12. The input pulley modulator mechanism 66 consists of a modulator valve 67 and a check valve 69. The modulator valve 67 has a spring 6 on one side (lower in the figure).
A check valve 69 is inserted between the output oil path 13A of the modulator valve 67 and the operation supply oil path 9 to the hydraulic servo 154 of the input pulley. The spool 68 of the modulator valve 67 receives the spring load of the spring 671 and the governor pressure supplied from the oil passage 6 from one side, and receives the output oil pressure of the oil passage 13A through the orifice 672 from the other side to the upper end land shown in the figure. The oil passages 13A and 1 are displaced in response to feedback.
3 and the drain port 673 to adjust the line pressure supplied from the oil passage 13 in relation to the governor pressure to adjust the line modulator pressure.
It is output to the oil passage 13A as Pm. FIG. 10 shows the line modulator pressure Pm and the required pressure Pn required by the input pulley hydraulic servo during steady running. In the conventional reduction ratio control mechanism, in order to maintain a steady running state, the tension of the V-belt pulled by the input pulley and the output pulley is maintained.
It is necessary to supply hydrostatic pressure that takes into account the hydraulic pressure in the hydraulic servo generated by centrifugal force to the hydraulic servo of each pulley, and to balance the clamping force of the V-belt by the hydraulic servo between the input pulley and the output pulley. However, the rotational speeds of the input pulley and output pulley fluctuate according to the reduction ratio (torque ratio), so in order to achieve the above-mentioned balance, the reduction ratio control mechanism must be operated to supply hydraulic oil to the hydraulic servo of the input pulley or the like. It was necessary to drain hydraulic oil from the input pulley's hydraulic servo. Therefore, even during steady driving, the solenoid valve always operates ON and OFF.
This placed a heavy burden on the solenoid valve, which was disadvantageous from the viewpoint of durability of the electromagnetic solenoid valve. The input pulley modulator mechanism 66 determines the speed at which the driving force of the engine and the steady-state running resistance are balanced at each throttle opening, and adjusts the hydraulic servo pressure of the input pulley necessary for that state (in steady state) to the reduction ratio control mechanism. Balances the hydraulic servo pressure of the input pulley by supplying it from the input pulley modulator mechanism without going through the
This turns the downshift and upshift electromagnetic solenoid valves ON and OFF when the reduction ratio control mechanism maintains steady running or downshift.
The number of activations is reduced. Next, the reduction ratio control mechanism 50, the shift sequence mechanism 60, the input pulley modulator mechanism 66, and the primary regulator valve 30 of the hydraulic adjustment device
Explain the effect of When the vehicle starts from a stop, when the manual valve is set to the N position, both the up solenoid valves 5 are in the OFF state.
5 and the down solenoid valve 56, the down solenoid valve 56 is turned ON for a short time by the action of the electronic control circuit that inputs the N-D shift signal of the manual valve.
The spool 53 is set downward in the figure. As a result, the oil passage 9 that supplies hydraulic oil to the hydraulic servo 154 of the input pulley communicates with the drain port 511 and is discharged to reduce the pressure.When the oil pressure in the oil passage 9 decreases and reaches the set value, the shift sequence valve 61 is activated. The spool 63 is displaced upward in the figure by the action of the spring 62, and the hydraulic servo 164 of the oil passage 1 and output pulley
The oil passage 10 is connected to the oil passage 10 that supplies hydraulic oil to the oil passage 10.
At the same time, primary line pressure is supplied to oil line 1.
2 and the drain port 614 to evacuate the oil passage 12. As the primary line pressure is supplied to the oil path 10, the hydraulic servo 164 of the output pulley is activated.
quickly increases the effective diameter of the output pulley to the maximum value, and as the effective diameter of the output pulley increases, V
The movable flange of the input pulley is pushed by the tension of the belt 145, reducing the effective diameter to the minimum value while promoting the discharge pressure of the hydraulic fluid in the hydraulic servo 154. Along with this, the oil passage 12A is connected to the drain port 5.
13 and the pressure is discharged, and the oil passage 12 is also discharged, so the down solenoid valve 56 is turned ON,
The exhaust pressure state is maintained regardless of whether it is OFF. The throttle control pressure in the oil passage 7B is input to the regulator plunger 33 of the primary regulator valve 30 via the oil passage 11 to raise the level of the primary line pressure. This level-up primary line pressure is supplied to the output pulley hydraulic servo 164 as described above, so the output pulley 1
The effective diameter of 60 mm is increased quickly and strongly, making it possible to start the vehicle smoothly. When the vehicle is upshifted after starting or during a rapid upshift while the vehicle is running, the up solenoid valve 55 is turned on and the down solenoid valve 56 is turned off. As a result, the spool 53 of the reduction ratio control valve 51 is set upward in the figure, and the oil passage 9 and the oil passage 1 communicate with each other. Since the primary line pressure is supplied to the oil passage 9, the spool 63 of the shift sequence valve 60 is displaced downward in the figure.
Communication between oil passage 10 and oil passage 1 is cut off, and communication between oil passage 10 and oil passage 12 is established. Therefore, the secondary line pressure of the oil passage 2 is supplied to the oil passage 10 via the check valve 64. In the V-belt type continuously variable transmission, the input pulley's hydraulic servo 154 to which primary line pressure is supplied from the oil passage 9 has a higher load than the output pulley's hydraulic servo 164 to which the secondary line pressure is supplied from the oil passage 10. As a result, the effective diameter of input pulley 150 increases, and the effective diameter of output pulley 160 decreases, resulting in an upshift. The secondary line pressure supplied to the oil passage 10 is guided to the oil passage 12A via the oil passage 12, and allows the down solenoid valve 56 to control the oil pressure of the oil passage 12A. Furthermore, since the spool 53 is set upward in the figure, the communication between the oil passage 6A and the drain port 513 is blocked by the land 534, so the governor pressure of the oil passage 6A is maintained, and the oil passage 6A is
The governor pressure A is input to the regulator plunger 33 of the primary regulator valve 30 to raise the level of the primary line pressure as shown in FIG.
This level-up primary line pressure is supplied to the hydraulic servo 154 of the input pulley as described above, so the effective diameter of the input pulley 150 is quickly and powerfully adjusted, allowing the vehicle to shift up rapidly, resulting in a vehicle with excellent acceleration performance. A continuously variable automatic transmission is obtained. During steady running, both the up solenoid valve 55 and the down solenoid valve 56 are turned off. The spool 53 of the reduction ratio control valve 51 is held at an intermediate position, the oil passage 9 is cut off from both the oil passage 1 and the drain port 511, and the oil pressure is maintained.
As a result, the spool 6 of the shift sequence valve 61
3 is held at the bottom in the figure. In this state, hydraulic oil is supplied to the oil passage 9 from the oil passage 13 through the check valve to replenish the leakage of hydraulic oil in the oil passage 9 or to make a slight change (increase) in the reduction ratio as the output shaft rotational speed increases. This is done by the input pulley modulator valve via the input pulley modulator valve 69, and it is done without turning on or off the up solenoid valve 55 or the downshift valve 56. This improves the durability of the solenoid valves 55 and 56. During normal upshifts and gradual upshifts, the up solenoid valve 55 is intermittently turned ON and OFF by the output of the electronic control device, and the spool 53 of the reduction ratio control valve is vibrated upward, and the oil passages 1 and 9 are connected to each other. be connected with a small communication area. As a result, the oil from the oil path 1 gradually flows into the oil path 9, the oil pressure in the oil path 9 increases, and the hydraulic servo 154 of the input pulley connected to the oil path 9 moves from the oil path 1 to the oil path 9. Upshifting is performed by increasing the effective diameter of the input pulley in accordance with the amount of hydraulic oil supplied. During a normal downshift and a gradual downshift, the down solenoid valve 56 is intermittently turned ON and OFF by the output of the electronic control device, and the spool 53 of the reduction ratio control valve is vibrated downward, and the drain port 511 and oil passage It also communicates with 9 through a small communication area. As a result, the oil pressure in the oil passage 9 decreases, and the oil pressure in the oil passage 9 decreases.
The hydraulic servo 154 of the input pulley connected to the input pulley reduces the effective diameter of the input pulley in accordance with the amount of hydraulic oil discharged from the oil passage 9 to the oil passage 511, thereby performing a downshift. During a sudden downshift, the up solenoid valve 55 is turned OFF, and the down solenoid valve 56 is turned ON or OFF. As a result, the spool 53 of the reduction ratio control valve 51 is set downward in the figure, and the oil passage 9 communicates with the drain port 511. The pressure in the oil passage 9 is exhausted, and as a result, the spool 63 of the shift sequence valve 61 is pressed against the spring 6.
2, the oil passage 10 is set upward in the figure, and the oil passage 1
The primary line pressure is supplied to the hydraulic servo 164 of the output pulley, and the oil passage 12 is connected to the drain port 614 for exhaust pressure. In the V-belt type continuously variable transmission 140, the effective diameter of the output pulley 160 rapidly increases due to the primary line pressure being supplied to the hydraulic servo of the output pulley, and as the effective diameter increases, the V-belt 14
With a tension of 5, the movable flange of the input pulley is pushed and moved, reducing the effective diameter while promoting the discharge pressure of the hydraulic fluid in the hydraulic servo 154. At this time, oil path 1
Since the port 2A communicates with the drain port 513 and is depressurized, the depressurized state is maintained regardless of whether the downshift solenoid valve 56 is turned on or off. Furthermore, since the spool 53 is set downward in the drawing, the communication between the oil passage 6A and the drain port 513 is blocked by the land 533, so the governor pressure of the oil passage 6A is maintained, and the governor pressure of the oil passage 6A is The pressure is input to the regulator plunger 33 of the primary regulator valve 30, and the primary line pressure is leveled up as shown in FIG. This level-up primary line pressure is supplied to the output pulley hydraulic servo 164 as described above, so the output pulley 16
The effective diameter of 0 is rapidly and strongly increased, and the vehicle is rapidly accelerated. The manual valve 70 includes a spool 71 that is manually displaced by a shift lever provided on the driver's seat. ),
L
(Low), and at each shift position, oil passages 1 and 2 are connected to oil passages 3 and 4 as shown in Table 1, and a line is connected to oil passages 3 and 4. pressure or secondary line pressure, or connect oil passage 3 or oil passage 4 with drain port 701 or 702 to exhaust pressure. In addition, the drain port 702 that drains pressure from the oil passage 4 that communicates with the clutch C1 is set so that its opening is above the oil level 712 to prevent the clutch from dragging due to residual oil in the hydraulic servo of the clutch C1. ing. Table 1 P R N D L Oilway 3 × ○ × × × Oilway 4 × × × △ △ In Table 1, ○ indicates communication with oilway 1, △ indicates communication with oilway 2, and × Indicates exhaust pressure. The shift control mechanism 75 includes a shift control valve 76;
Secondary line pressure is supplied from the oil passage 2 via an orifice 91, which is attached to the oil passage 2D that communicates with the oil chamber at the left end in the diagram of the shift control valve 76, and controls the shift control valve 76 according to the output of the electronic control device. It consists of a shift control electromagnetic solenoid valve (hereinafter referred to as shift solenoid valve) 79. The shift control valve 76 is provided with a spring 77 on one side (right side in the figure), and has a left end land 781 in the figure and an intermediate land 78.
2 and 783, and a spool 78 having a small diameter and a right end land 784 in the figure, to which the left end of the spring 77 is abutted. The spool 78 receives the hydraulic pressure of the oil passage 2D on the land 781 from the left side, and receives the spring load of the spring 77 and the hydraulic oil supply/drain passage 3a to the hydraulic servo 122 of the brake B1 from the right side.
From the effective pressure receiving area of land 783 (land 783
(cross-sectional area of the land 784 - cross-sectional area of the land 784) or the feedback of the hydraulic pressure received from the land 784 from the hydraulic oil supply/discharge passage 4a to the hydraulic servo 121 of the clutch C1. Next, the functions of the manual valve 70 and the shift control mechanism 75 will be explained. When the manual valve is shifted from the N position (range) to the D range, the oil passage 3 becomes a discharge pressure state and the secondary line pressure is supplied to the oil passage 4. The N→D shift signal causes the shift solenoid valve 79, which had been turned off during the N range, to be turned on for a set short time, thereby setting the spool 78 to the left in the figure. At this time, the oil passage 4 and the oil passage 4a are cut off, the oil passage 4a is connected to the drain port 761, and the pressure is discharged, and the clutch C1 is released. The duty control turns ON and OFF so that the ON time gradually decreases, and the oil pressure of the oil passage 2D is gradually increased. As a result, the spool 78 is gradually displaced to the right in the figure, and the oil passage 4a has a communication area with the oil passage 4. is increased, and the communication area with the drain port 761 is decreased, and the oil passage 4a is
The oil pressure gradually approaches the secondary line pressure. In this way, a smooth N→D shift is performed. Shift solenoid valve 79 after a certain period of time
is turned off. When the manual valve is shifted from N range to R range, primary line pressure is supplied to oil path 3 and oil path 4
maintains the exhaust pressure state. In response to the N-R shift signal, the shift solenoid valve 79, which was turned off in the N range, is turned on and off so that the off time is gradually reduced by the duty control, whereby the oil pressure in the oil passage 2D gradually decreases. As a result, the spool 78, which had been set to the right in the drawing, is gradually displaced to the left in the drawing, and the oil passage 3a gradually decreases the communication area with the drain port 761, and gradually increases the communication area with the oil passage 3, resulting in a smooth N. →R shift is performed. Shift solenoid valve 79 after a certain period of time
is turned on. When the solenoid valve 77 is turned on, pressure is discharged from the oil passage 2D, so the spool 78 is set to the left in the figure and communicates with the oil passage 3 and the oil passage 3a, and pressurized oil is supplied to the hydraulic servo 122 to brake. When B1 is engaged, the oil passage 4a communicates with the drain port 761 and is discharged, and the clutch C1 is released. As a result, the planetary gear transmission mechanism 120 enters the reverse traveling state. Furthermore, when the solenoid valve 79 is turned OFF, the oil pressure in the oil passage 2D becomes the secondary line pressure, and the spool 78 is set to the right in the figure, and the oil pressure in the oil passage 2D becomes the secondary line pressure.
is connected to the oil passage 4a, and the oil passage 3a is connected to the drain port 761. As a result, pressure oil is supplied to the hydraulic servo 121, pressure is discharged from the hydraulic servo 122, the clutch C1 is engaged, and the brake B1 is released. As a result, the planetary gear transmission mechanism 120
is in the forward state. Furthermore, when the vehicle speed is below the set speed and the throttle opening is below the set throttle opening while driving in the D range, the shift solenoid valve 79 is turned on by the output of the electronic control device, thereby releasing the clutch C1, and connecting the input shaft and output shaft of the planetary gear transmission. By breaking the connection between the two, inertial running can be achieved, thereby improving fuel quality. The lock-up control mechanism 80 includes a lock-up control valve 81, a lock-up signal valve 85, and a lock-up electromagnetic solenoid valve 8 as an auxiliary device.
It has 8. The lock-up control valve 81 has a spool 82 disposed at the bottom in the drawing, and a plunger 84 connected in series with the spool 82 via a spring 83. The spool 82 has a lower end land 821, an intermediate land 822, and an upper end land 823 each having the same diameter, and the plunger 84 is connected to the spool 82.
The outer diameter is set smaller than that of the land. The lock-up signal valve 85 has a spool 87 with a spring 86 on its back. When it receives oil pressure and is displaced by the oil pressure of oil passage 10 from the other side and is set upward in the figure, it connects oil passage 2 and oil passage 2B, and when it is set downward in the figure, it connects oil passage 2B and oil passage 2. The communication is cut off and the oil passage 2B is connected to the drain port 851. The lock-up electromagnetic solenoid valve 88 is connected to the oil path 2.
C, when it is turned ON, the hydraulic pressure of the oil passage 2C is discharged and the spool 87 of the lock-up signal valve 85 can be displaced by the change in the oil pressure of the oil passage 10, and when it is turned OFF, the oil pressure of the oil passage 2C is discharged. Hold it to lock the spool 85 of the lock-up signal valve 85 upward in the figure. Next, the operation of the lockup control mechanism 80 will be explained. The lock-up control valve 81 receives an input signal hydraulic pressure for controlling the release and engagement of the direct coupling clutch through the oil passage 2, the lock-up signal valve 85, and the oil passage 2B on the pressure-receiving surface of the illustrated lower end land 821 of the spool 82. A secondary line Ps is applied to the (pressure receiving area L2), and a hydraulic pressure P10 of the hydraulic servo 164 of the output pulley is applied as a counter hydraulic pressure from the oil passage 10 to the pressure receiving surface (pressure receiving area L1) of the plunger 84. (a) When the hydraulic pressure of the output pulley hydraulic servo 164 is the primary line pressure Pl, this lock-up control valve 81 is set as P10=Pl.
Therefore, the pressure receiving areas of the spool 82 and the plunger 84 are set so that P10.L1>Ps.L2. Therefore, when the oil pressure P10 in the oil passage 10 is the primary line pressure Pl, the spool 82 is fixed to the direct clutch release side, and the input signal oil pressure (secondary line pressure
Ps) oil passage 5A and oil passage 5C regardless of
It also communicates between the oil passage 50 and the oil passage 5F. The hydraulic oil flows in the order of oil passage 2 → secondary regulator valve 35 → oil passage 5 → oil passage 5A → lock-up control valve 81 → oil passage 5C → oil passage 50 → lock-up control valve 81 → oil passage 5F → oil cooler. The direct coupling clutch 108 is released. (b) When the hydraulic pressure of the output pulley hydraulic servo 164 is the secondary line pressure, the spool 82 is set upward in the figure (direct coupling clutch engagement side) due to the relationship of P10=Ps P10・L1<Ps・L2, and the oil path 5A and oil road 5
0 and the oil passage 5C communicates with the drain port 811. Hydraulic oil goes through oil path 2 → secondary regulator valve 35 → oil path 5 → oil path 5A
→ Lockup control valve 81 → Oil passage 50 → Oil passage 5
C→Drain port 81 of lock-up control valve
1, the lock-up clutch engages. FIG. 11 shows the relationship between the position of the spool of the lock-up control valve 81 and the oil pressure P2B in the oil passage 2B and the oil pressure P10 in the oil passage 10, and FIG. 12 shows the characteristics of P2B and P10 with respect to vehicle speed. The lock-up signal valve 85 has a pressure receiving area L
The hydraulic pressure P of the oil passage 10, which is the hydraulic pressure of the hydraulic servo 164 of the output pulley, is shown from above on the spool 87 of the output pulley.
10 is applied, and the spring 86 is applied from below in the figure.
The spring load SP2 and the secondary line pressure Ps of the oil passage 2C connected to the oil passage 2 via the orifice 881 are applied. (c) Oil pressure P10 of oil passage 10 is primary line pressure
When Pl, the spring load is set so that the relationship P10=Pl P10・L>Ps・L+SP2 is established, so the spool 87 is set downward in the figure, and the oil passage 2B and drain port 851 are connected and the oil passage 2B is depressurized. Due to this exhaust pressure in the oil passage 2B, the spool of the lock-up control valve is set to the lower position in the figure, and the direct coupling clutch is released. (d) Oil pressure P10 of oil passage 10 is secondary line pressure
When Ps, P10=Ps P10・L<Ps・L+SP2, so the spool 87 is set upward in the figure, and the oil passage 2B communicates with the oil passage 2 to obtain the secondary line pressure.
Ps is supplied. Therefore, when the oil pressure in the oil passage 10 is the primary line pressure, the input signal oil pressure (the oil pressure in the oil passage 2B) is not supplied to the lock-up control valve 81.
The direct coupling clutch 10 is released regardless of any other conditions. (e) When the lock-up solenoid 88 is turned on, the spool 87 is fixed at the lower position in the figure, regardless of the oil pressure in the oil passage 10, as described above, and the oil passage 2
B is exhausted, no input signal oil pressure is supplied to the lock-up control valve 81, and the direct coupling clutch 108 is released. An orifice 5G is provided between the oil passage 5D and the oil passage 5F to constantly supply the minimum amount of hydraulic oil necessary to prevent the oil temperature from rising excessively to the oil cooler.

[Brief explanation of drawings]

Fig. 1 is a skeleton diagram of a continuously variable automatic transmission for vehicles, Fig. 2 is a hydraulic circuit diagram of its hydraulic control device, and Fig. 3 is a governor pressure characteristic and line output from a governor valve provided in the hydraulic control device. FIG. 4 is a graph showing the characteristics of the throttle control pressure output by the pressure regulating valve, FIG. FIG. 6 is a graph showing the characteristics of the secondary line pressure by the hydraulic pressure adjustment device in the hydraulic control device of the continuously variable automatic transmission for vehicles of the present invention. FIG. 6 is a graph showing the output hydraulic pressure characteristics from each port of the secondary regulator valve. Figure 8 is a graph showing the throttle pressure characteristics output by the throttle valve, Figure 8 is a graph showing the cutback pressure characteristics, Figure 9 is a graph showing the input and output oil pressure characteristics of the shift sequence valve, and Figure 10 is the input pulley module. Graph showing the characteristics of the line modulator pressure Pm output by the rotor valve and the required oil pressure Pn of the input pulley, No. 11
12 is a graph showing the relationship between the spool position of the lock-up control valve and the input signal oil pressure and opposing oil pressure. FIG. 12 is a graph showing the characteristics of the input signal oil pressure and opposing oil pressure of the lock-up control valve with respect to vehicle speed. In the figure, 20...variable volume oil pump, 2
5... Governor valve, 30... Primary regulator valve, 35... Secondary regulator valve,
40... Throttle valve, 45... Cutback valve, 47... Line pressure adjustment valve, 50... Reduction ratio control mechanism, 51... Reduction ratio control valve, 55... Upshift electromagnetic solenoid valve, 56... Downshift electromagnetic Solenoid valve, 60...Shift sequence mechanism, 61...Shift sequence valve, 6
6... Input pulley modulator mechanism, 67...
Modulator valve, 34, 64, 65, 69...
Check valve, 70...Manual valve, 75...
Shift control mechanism, 76...Shift control valve, 79
...Electromagnetic solenoid valve for shift control, 80...
Lock-up control mechanism, 81... Lock-up control valve, 85... Lock-up signal valve, 8
8...Lock-up electromagnetic solenoid valve, 100
... Torque converter, 120 ... Planetary gear transmission mechanism for forward and reverse switching, 140 ... V-belt type continuously variable transmission, 150 ... Input pulley, 160
...Output pulley, 170...Differential gear, 180...Output gear, 190...Chain.

Claims (1)

[Claims] 1. An input pulley and an output pulley whose effective diameters are variable by hydraulic servos, a V-belt that transmits power between these input and output pulleys, and hydraulic pressure supplied to both hydraulic servos. By doing so, it is equipped with a hydraulic control device for controlling the reduction ratio between the input pulley and the output pulley,
The hydraulic control device includes a first hydraulic pressure adjustment device that adjusts the discharge hydraulic pressure from the oil pump to a first hydraulic pressure;
A second hydraulic pressure that adjusts the pressure to a second hydraulic pressure lower than the first hydraulic pressure.
a hydraulic adjustment device, and a reduction ratio control that supplies or discharges the first hydraulic pressure to the hydraulic servo of either the input pulley or the output pulley and supplies the first hydraulic pressure or the second hydraulic pressure to the other hydraulic servo. and the reduction ratio control means applies the first hydraulic pressure or the second hydraulic pressure to one of the hydraulic servos during gear shifting.
A hydraulic control device for a continuously variable automatic transmission for a vehicle, which is characterized by selectively supplying hydraulic pressure. 2. In the case of at least one of upshifting and downshifting, the hydraulic pressure regulated in the first hydraulic pressure adjustment device is increased by the signal hydraulic pressure of the reduction ratio control means. A hydraulic control device for a continuously variable automatic transmission for a vehicle as described above. 3. The reduction ratio control means has a shift sequence mechanism that uses the supply pressure to one hydraulic servo as a signal hydraulic pressure and switches the first hydraulic pressure and the second hydraulic pressure to the other hydraulic servo. A hydraulic control device for a continuously variable automatic transmission for a vehicle according to item 1.