JPH056054B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to a control device for a continuously variable transmission for a vehicle, which is used in a vehicle such as an automobile and is equipped with a V-belt type continuously variable transmission mechanism that performs continuously variable transmission using a V-belt. . [Prior Art] A continuously variable transmission equipped with a V-belt type continuously variable transmission mechanism used in vehicles such as automobiles is used in combination with a fluid transmission mechanism such as a torque converter or a fluid coupling, and a forward/reverse switching mechanism. There is.
In such a continuously variable transmission, a hydraulic control device inputs vehicle running conditions such as vehicle speed and throttle opening and frictionally engages the friction engagement elements of the V-belt continuously variable transmission mechanism and the forward/reverse switching mechanism. The supply and discharge of hydraulic oil or the supply of lubricating oil to the hydraulic servo means and the fluid transmission mechanism are controlled. By the way, such a hydraulic control device generally includes a hydraulic adjustment device that generates line pressure in response to the input. Conventionally, the hydraulic servo means of the V-belt type continuously variable transmission mechanism and the forward/reverse switching mechanism are operated by the line pressure generated by this hydraulic adjustment device. [Problems to be Solved by the Invention] However, the above-mentioned line pressure is set at a relatively high pressure to prevent the V-belt from slipping when operating the engine brake even when the engine is idling. ing. However, when the line pressure is set to a high value in this way, as described above, this line pressure is also supplied to the hydraulic servo means of the forward/reverse switching mechanism, so this high pressure reduces the friction of the forward/reverse switching mechanism. The engagement elements become frictionally engaged. For this reason, when switching from a neutral range (N range) to a driving range such as a drive range (D range) or a low range (L range), the forward multi-plate clutch, which is one of the frictional engagement elements, suddenly This caused a large shock to occur when switching ranges. Therefore, the conventional V-belt type continuously variable transmission cannot provide a good driving feeling. In addition, such high pressure is supplied to hydraulic drive means that do not require such high pressure, such as hydraulic servo means for operating the forward multi-plate clutch, and to a hydraulic circuit that supplies hydraulic pressure to the hydraulic drive means. In this case, the seal must be made better than necessary, and the sealing member for this purpose becomes expensive. Also, if the sealing material is made cheap, it will deteriorate relatively quickly due to the high pressure.
This results in poor sealing properties. The present invention has been made in view of the above circumstances, and provides hydraulic pressure supplied to the hydraulic servo that drives the variable pulley of the V-belt type continuously variable transmission mechanism and hydraulic pressure that drives the frictional engagement element of the forward/reverse switching mechanism. By using a simple structure, the hydraulic pressure supplied to the servo is suitably controlled in accordance with the throttle opening, reducing the shift shock caused by the engagement of the frictional engagement element when changing the selection of the shift range, and reducing the hydraulic pressure. It is an object of the present invention to provide a control device for a continuously variable transmission for a vehicle that can improve the durability of a sealing member of a circuit. [Means for Solving the Problems] The control device for a continuously variable transmission for a vehicle according to the present invention operates between a forward gear and a reverse gear by selectively engaging a frictional engagement element driven by a hydraulic servo. A continuously variable transmission for vehicles equipped with a switchable forward/reverse switching mechanism and a V-belt type continuously variable transmission mechanism in which a belt is wound between input and output pulleys whose effective diameter is variable by a hydraulic servo. The control device includes a pressure regulating valve that regulates hydraulic pressure discharged from the oil pump to a predetermined line pressure, and a reduction ratio control mechanism that selectively supplies and discharges the line pressure to at least one of the hydraulic servos of the input and output pulleys. , a throttle valve that regulates the line pressure according to the throttle opening, generates a throttle pressure that increases from a predetermined engagement pressure as the throttle opening increases, and causes the throttle pressure to act on the pressure regulating valve; a shift valve for supplying and discharging throttle pressure to the forward hydraulic servo of the forward/reverse switching mechanism; and a flow rate adjustment valve provided in an oil passage connecting the shift valve and the forward hydraulic servo of the forward/reverse switching mechanism. It is characterized by being prepared. [Operations and Effects of the Invention] According to the control device for a continuously variable transmission for vehicles of the present invention, the hydraulic pressure discharged from the oil pump is controlled by the pressure regulating valve to the high pressure required for the hydraulic servo of the pulley in accordance with the throttle pressure. The line pressure is regulated to line pressure, and the line pressure is selectively supplied to and discharged from the hydraulic servo of the pulley via the reduction ratio control mechanism. On the other hand, the throttle pressure is a pressure that is lower than the line pressure by regulating the line pressure according to the throttle opening by a throttle valve, and increases from a predetermined engagement pressure as the throttle opening increases. The characteristics correspond to the transmission torque capacity of the friction engagement element of the forward/reverse switching mechanism. The throttle pressure is supplied and discharged by the shift valve to the forward hydraulic servo of the forward/reverse switching mechanism via the flow rate adjustment valve. Therefore, according to the present invention, the throttle pressure regulated by the throttle valve in accordance with the throttle opening is supplied to the hydraulic servo that drives the frictional engagement element of the forward/reverse switching mechanism, and the V-belt type stepless By supplying line pressure regulated by a pressure regulating valve according to the throttle pressure to the hydraulic servo that drives the variable pulley of the transmission mechanism, it is applied to the hydraulic servo of the forward/reverse switching mechanism and the V-belt continuously variable transmission mechanism. With a simple structure, it is possible to suitably control the supply oil pressure of each of the valves in accordance with the throttle opening. Therefore, when selecting a shift range, the shift valve gradually supplies throttle pressure with characteristics corresponding to the transmission torque capacity of the frictional engagement element to the forward hydraulic servo of the forward/reverse switching mechanism via the flow rate adjustment valve. The frictional engagement elements of the forward/reverse switching mechanism engage smoothly to reduce shift shock, and the hydraulic circuit to the forward hydraulic servo of the forward/reverse switching mechanism has a pressure lower than the line pressure to reduce the friction described above. Since a throttle pressure having characteristics corresponding to the transmission torque capacity of the engagement element is supplied, the durability of the seal member is improved. [Example] Hereinafter, an example of the present invention will be described using the drawings. FIG. 1 shows an embodiment of a continuously variable transmission for a vehicle according to the present invention. In FIG. 1, reference numeral 100 has a fastening surface 100A with the engine open, a fluid transmission mechanism room 110 in which a fluid transmission mechanism 400 such as a fluid coupling and a torque converter is housed, and a side opposite to the engine open and a differential. allencial gear 700
The differential room 120 houses the differential gear 700 and supports one output shaft of the differential gear 700. Similarly, the side opposite to the engine is open and houses the idler gear and supports one of the shafts of the idler gear. Idragia room 13
A torque converter case 200 has a transmission room 210 that opens on the engine side and houses a V-belt continuously variable transmission, and a torque converter case 200 that covers the opening surface of the differential room 120 of the torque converter case 100 and a transmission room 210 that opens on the engine side and houses the V-belt continuously variable transmission. It consists of a differential room 220 that supports the other output shaft of the differential gear 700, and an idler gear room 230 that covers the side opposite to the engine side of the idler gear room 130 of the torque converter case 100, Side surface 100 of the torque converter case 100 opposite to the engine
A transmission case is fastened to B with bolts, and forms an outer shell (case) of a vehicle automatic transmission together with the torque converter case 100 and an intermediate case to be described later. Reference numeral 300 denotes a center case that pivotally supports the transmission shaft between the fluid transmission mechanism 400 and the transmission.
It has a structure of a center case that is fastened to B with bolts. In this embodiment, the automatic transmission includes a fluid coupling 400 of a fluid transmission mechanism disposed within the torque converter case 100 and connected to the output shaft of the engine.
and a transmission provided within the torque converter case 200. The transmission has a hollow shaft center, and the input shaft 510, in which the hollow portion 511 is used as an oil supply/discharge path for hydraulic oil and lubricating oil of the hydraulic servo, is arranged so that it has the same axis as the fluid coupling 400. The output shaft 550, which has a hollow shaft center and the hollow portion 551 serves as an oil supply and drainage path for hydraulic oil of a hydraulic servo, is connected to the input shaft 51.
V-belt type continuously variable transmission 50 arranged in parallel with 0
0. Input shaft 5 of this V-belt type continuously variable transmission 500
10 and the output shaft 42 of the fluid coupling 400
0, a differential 700 in which the input shaft 510 and output shaft 710 of the V-belt continuously variable transmission 500 are connected to an axle, and the differential 700 is inserted between the input large gear 720 of the V-belt continuously variable transmission 500 and the output gear 590 of the V-belt continuously variable transmission 500 provided at the engine side end of the output shaft 550 of the V-belt continuously variable transmission 500. axis 55
0, an idler gear shaft 810 is provided with one end being pivotally supported by the torque converter case 100 and the other end being pivotally supported by the center case 300 serving as an inner case, and this idler gear shaft 80
Input gear 802 and output gear 8 provided in 1
It consists of an idler gear 800 consisting of 03. The V-belt continuously variable transmission 500 and the planetary gear transmission mechanism 600 are subject to predetermined control such as reduction ratio, forward movement, and reverse movement by a hydraulic control device according to vehicle running conditions such as vehicle speed and throttle opening. 900 is fastened to the engine side (fluid coupling side) wall of the center case, and has a hollow shaft 4 integrated with the fluid coupling 400 inside.
This is an oil pump cover in which an oil pump driven by a motor 10 is housed. Output shaft 420 of fluid coupling 400
is rotatably supported by a sleeve 310 fitted in the center of the center case 300 via a metal bearing 320, and has a hub 440 of a lock-up clutch 430 and a hub 460 of a fluid coupling turbine 450 at the end on the engine side. are spline-fitted, and the other end has a stepped larger diameter, and this larger diameter portion is connected to the input shaft 60 of the planetary gear transmission mechanism 600.
1 and is supported by the center case 300 via a bearing 330. The output shaft 420 of the fluid coupling and the input shaft 601 of the planetary gear transmission mechanism 600 are formed hollow, and this hollow part is provided with an oil passage 421 and fitted with a plug. The engine side end of the sleeve 422 fixed to the input shaft 510 of the 500 is rotatably fitted. The planetary gear transmission mechanism 600 includes an input shaft 6 that is integrated with the output shaft 420 of the fluid coupling 400.
01, and a carrier 620 which is connected to a fixed flange 520A of a V-belt continuously variable transmission 500 (to be described later) via a forward multi-plate clutch 630 which is a frictional engagement element, and a reverse gear which is a frictional engagement element. The ring gear 660 is engaged with the center case 300 via the multi-disc brake 650, and the output shaft 6 of the planetary gear transmission mechanism 600 is integrally formed with the input shaft 510 of the V-belt continuously variable transmission 500.
10, a sun gear 670 provided on the outer periphery; a planetary gear 640 that is pivotally supported by the carrier 620 and meshed with the sun gear 670 and the ring gear 660;
A hydraulic servo 680 is formed on the wall of the center case 300 to operate the multi-disc brake 650, and a multi-disc clutch 6 is formed on the fixed flange wall.
30 and a hydraulic servo 690 that operates the hydraulic servo 690. This planetary gear transmission mechanism 600 constitutes a forward/reverse switching mechanism. The V-belt continuously variable transmission 500 has an input shaft 510 that is integrated with an output shaft 610 of the planetary gear transmission mechanism 600.
A fixed flange 520A integrally formed with the fixed flange 520A and a hydraulic servo 530
An input pulley 520 consisting of a movable flange 520B driven in the 0A direction, a fixed flange 560A formed integrally with the output shaft 550 of the V-belt type continuously variable transmission, and a hydraulic servo 570 driven in the fixed flange 560A direction. The output pulley 560 includes a movable flange 560B, and a V-belt 580 transmits power between the input pulley 520 and the output pulley 560. Input shaft 510 of V-belt continuously variable transmission 500
In this case, the engine side end 510A, which is the output shaft 610 of the planetary gear transmission mechanism 600, is connected to the bearing 34.
0 to the input shaft 601 of the planetary gear transmission mechanism.
The other end 510B is supported by the center case 300 via the input shaft 601 and the bearing 340, and the other end 510B is supported by the side wall 250 of the transmission case opposite to the engine via the bearing 350. 510C
is in contact with a lid 260 fastened to the side wall 250 via a needle (roller) bearing 270. The sleeve 422 is fitted to the engine side in a hollow part 511 formed at the axis of the input shaft 510 of the V-belt continuously variable transmission 500, and the engine side 511A is connected to the center case 300 and the oil passage 301.
The oil pressure supplied from the oil passage 421 is transferred to an oil passage 513 formed at the base of the fixed flange 520A.
The opposite side portion 511B is an oil path for supplying hydraulic pressure to the hydraulic servo 690 through the input shaft 5 of the side wall 250 of the transmission case.
The transmission case 200 is fitted with a pipe-shaped protrusion 261 of a lid 260 that is fitted with a lid so as to close a hole 520A formed in a corresponding part with the lid 260, and the entire space is hydraulically controlled. Pressure oil is supplied from the oil passage 514 communicating with the device through the protrusion 261 of the lid 260 to the hydraulic servo 5.
It acts as an oil passage for supplying oil to 30. The output gear 590 is formed integrally with a hollow support shaft 591, and this support shaft 591 is connected to the engine side end 591.
Roller bearing 59 with A forming one fulcrum
2, the other end 591B is supported by the center case 300 via a roller bearing 593, and the engine side side surface 590A of the output gear 590 is supported via a needle bearing 595 forming an intermediate fulcrum. An inner spline 596 is formed on the transmission side of the support shaft 591 and is in contact with the side surface of the center case 300 . The output shaft 550 of the V-belt type continuously variable transmission has an outer spline 550A formed at the end on the engine side that fits into the inner spline 596 formed on the support shaft 591 of the output gear. It is supported by the center case 300 via a support shaft 591, and the other end 550B is supported by the side wall 250 of the transmission case opposite to the engine via a ball bearing 920 forming the other support. Output shaft 55 of this V-belt type continuously variable transmission 500
A sensing valve body 552 is fitted in the middle part of an oil passage 551 formed at the axis of 0, and an engine side part 552A of this valve body 552 is an oil passage communicating with a hydraulic control device formed in a transmission case. The oil pressure supplied from the valve body 552 is an oil passage leading to the hydraulic servo 570, and the valve body 552 is connected to a portion 552B of the valve body 552 on the side opposite to the engine.
The distal end of the transmission case and The hydraulic pressure is adjusted by a reduction ratio detection valve 50 that detects the displacement position of the movable flange 560B from a hydraulic control device formed on a lid 553 fastened to this transmission. In the reduction ratio detection valve 50, an engagement pin 51A attached to the right end of the detection rod 51 in the drawing is engaged with a step 561 formed on the inner circumference of the movable flange 560B, and the spool is displaced in accordance with the displacement of the movable flange 560B. The oil pressure of the oil passage 3 is adjusted by. FIG. 2 shows a hydraulic control device for controlling the continuously variable automatic transmission for a vehicle shown in FIG. 20 is an oil pump that is driven by the engine and discharges the hydraulic oil sucked from the oil reservoir 21 into the oil passage 1; 30 is a pressure regulating valve that adjusts the oil pressure of the oil passage 1 according to the input oil pressure and makes it line pressure; 40 is a pressure regulating valve; The line pressure supplied from the oil passage 1 is regulated according to the throttle opening degree, and is output from the oil passage 2 as a first throttle pressure, and the output of the reduction ratio detection valve is supplied from the oil passage 3 via the orifice 22. When the throttle opening is set to 01, the reduction ratio pressure is
In the above case, a throttle valve 50 outputs the second throttle pressure from the oil passage 3a, and 50 is a movable flange of the output side pulley of the V-belt type continuously variable transmission. 56
The reduction ratio detection valve 60, which regulates the pressure according to the amount of displacement of 0B, communicates with the oil passage 1 via the orifice 24, and regulates the oil pressure of the oil passage 4 from which excess oil from the pressure regulation valve 30 is discharged, and also controls the excess oil. A second pressure regulating valve 65, which supplies lubricating oil from the oil passage 5 to parts that require lubrication of the continuously variable automatic transmission, is operated by a shift lever installed in the driver's seat, and the line pressure of the oil passage 1 is controlled by the driver. 70 is a lock-up control mechanism that supplies the hydraulic pressure of the oil passage 4 to the fluid transmission mechanism 400 in accordance with the input and controls the engagement and release of the lock-up clutch 430; 80 is the lock-up control mechanism that controls the engagement and release of the lock-up clutch 430; Accordingly, the reduction ratio (torque ratio) of the V-belt continuously variable transmission 500 outputs the hydraulic pressure of the oil passage 1a, which communicates with the oil passage 1 via the large-diameter orifice 86, from the oil passage 1b to the hydraulic servo 530 of the input pulley. ) control mechanism, 10 is a manual valve 65
A low modulator valve 12 is provided in the oil path 1c that communicates with the oil path 1 when the is shifted to the L range, and regulates the line pressure and supplies it to the oil path 2 as a low modulator pressure. Relief valve 25 is a relief valve provided in the oil passage 1, 26 is a flow rate adjustment valve with a check valve provided in the hydraulic oil supply oil passage 6 to the hydraulic servo 680 of the multi-disc brake of the planetary gear transmission mechanism 300, 27 is a flow rate adjustment valve with a check valve provided in the hydraulic oil supply passage 7 to the forward hydraulic servo 690 of the multi-plate clutch of the planetary gear transmission mechanism 300. The reduction ratio detection valve 50 includes a detection rod 51 having an engagement pin 51A fixed to one end that engages with a movable flange 560B of an output pulley of a V-belt type continuously variable transmission, and a spring 52 disposed at the other end; This detection rod 5
1 and a spool 54 having lands 54A and 54B arranged in series via a spring 53, a port 55 communicating with the oil passage 3, and a drain port 5.
6. An oil passage 57 is provided in the spool 55 and communicates between the port 55 and the oil chamber 54a between the lands 54A and 54B, and the hydraulic pressure P is adjusted as shown in FIG. 3 according to the displacement of the movable flange 560B. _i to oil path 3
to occur. The throttle valve 40 includes a throttle plunger 42 that is displaced in contact with a throttle cam 41 linked to an accelerator pedal at the driver's seat, and a spool 44 that is arranged in series with the throttle plunger 42 via a spring 43. When the throttle is fully open (θ=0), the spool 44 is urged to the right in the figure by the load of the spring 43 in the attached state, and this urging force and the orifice 4
The communication area between the oil passage 1 and the oil passage 2 is changed by the balance with the oil pressure of the oil passage 2 fed back to the land 44a via the land 44a through the oil passage 5, thereby producing a predetermined minimum throttle ratio (P _thp ) in the oil passage 2. . When the throttle opening degree θ increases, the movement of the throttle cam 41 is transmitted to the plunger 42, and the plunger 42
is displaced to the right in the figure and compresses the spring 43,
The biasing force acting on the spool 44 on the right side in the drawing is increased. As a result, the throttle pressure P _th generated in the oil passage 2 is adjusted to a predetermined minimum throttle pressure (P _thp ) as shown in FIGS.
The pressure is adjusted so that it increases in accordance with the increase in . When the throttle opening reaches a set value θ ₁ or more (θ>θ ₁ ), the plunger 42 connects the oil passage 3 and the oil passage 3a to generate the reduction specific pressure in the oil passage 3a,
When the throttle opening is less than the set value θ ₁ (θ<θ ₁ ), the oil pressure in the oil passage 3a is discharged from the drain port 40a, and the second throttle pressure P _j is applied to the oil passage 3a as shown in FIG. generate. The pressure regulating valve 30 has a spring 31 disposed on one side (left side in the drawing) and lands 32A, 32B, 32C.
a first regulator plunger 33 disposed in series with the spool 32 and having a small-diameter land 33A and a large-diameter land 33B; It has a second regulator plunger 34 arranged therein, a port 34a that communicates with the oil passage 1, a port 34b to which line pressure is fed back via an orifice 35, a drain port 34c, and a drain port 34c for directing excess oil to the oil passage 4. A drain port 34d drains oil leaking from between the land and the valve wall.
4e, an input port 34f to which the reduction ratio pressure is input from the oil passage 3, an input port 34g to which the first throttle pressure is input from the oil passage 2, and an input port 34h to which the second throttle pressure is input from the oil passage 3. Become. The low modulator valve 10 outputs a low modulator pressure P _lpw shown in FIG. 7 that is independent of the throttle opening when the manual valve 65 is set to the L range. Here, neither the low modulator pressure 10 nor the throttle valve 40 has a discharge pressure oil passage for pressure regulation, and the throttle pressure P _th is
The pressure is regulated by taking advantage of the fact that the pressure is constantly exhausted from 0, and both of these valves are arranged in parallel.
As shown in the figure, the larger hydraulic pressure of P _lpw and P _th is generated. Therefore, as shown in FIG. 9, the line pressure P _l in the L range low throttle opening is higher than in the D range. This pressure regulating valve 30 is configured to control a reduced specific pressure input from a port 34f and applied to the second plunger 34, a first throttle pressure input from a port 34g and applied to the land 33B of the first plunger 33, and a first throttle pressure input from a port 34h and applied to the land 33B of the first plunger 33. The second throttle pressure is applied to the land 33A of the first plunger 33, and the second throttle pressure is applied to the land 33A of the spool from the port 34b, which is connected to the oil passage 1 via the spring 31 and the orifice 35.
The spool 42 is displaced by the line pressure fed back to the port 34 connected to the oil path 1.
a. Adjust the opening area of the port 34d and drain port 34c that communicate with the oil passage 4 to increase or decrease the amount of pressure oil leaking from the oil passage 1, and adjust the line pressure P shown in Figs. 9, 10, and 11. cause _l . In L range, it is necessary to downshift to obtain strong engine braking. In a V-belt type continuously variable transmission, when a downshift is performed, the oil path to the hydraulic servo 530 of the input pulley is connected to the discharge pressure oil path, thereby draining the oil in the servo oil chamber and realizing a downshift. let However, in order to obtain strong engine braking, the primary sheave must be rotated at high rotation speeds, but the hydraulic pressure caused by the centrifugal force generated by this rotation may prevent oil drainage. Therefore, when a quick downshift is required, it is necessary to make the hydraulic pressure applied to the output pulley's hydraulic servo 570 higher than usual, and this is especially important when the throttle opening is low. To this end, in the L range, the throttle pressure P _th is increased by the low modulator valve when the throttle opening θ is small, and the line pressure P _l (line pressure = hydraulic servo supply pressure of the output pulley) is increased. The manual valve 65 is a spool that is moved by a shift lever provided on the driver's seat and is set to each shift position of P (park), R (reverse), N (neutral), D (drive), and L (low). 66, and when set at each shift position, oil passage 1 or oil passage 2 communicates with oil passage 1c, oil passage 6, and oil passage 7 as shown in Table 1.

[Table] In Table 1, ○ indicates connection with oil passage 1, △ indicates oil passage 2
- indicates blockage of oil passage, × indicates exhaust pressure. As shown in Table 1, in the R range, line pressure is supplied to the hydraulic servo 680 of the reverse brake 650 of the planetary gear transmission mechanism, and in the D and L ranges, line pressure is supplied to the forward hydraulic servo 690 of the forward clutch 630.
Throttle pressure (or low modulator pressure) of the oil passage 2 is supplied to switch between forward and backward movement. In that case, the second throttle pressure, which is the pressure of the hydraulic fluid that operates the forward clutch 630, is lower than the line pressure, so when the manual valve 65 is set to the D or L range to move the vehicle forward, The clutch 630 becomes a gentle frictional engagement. Therefore, the shock when changing the shift range is small and the drive feeling is good. The second pressure regulating valve 60 has a spool 62 with a spring 61 disposed on one side and lands 62A, 62B, and 62C.
land 62 through the spring load and orifice 63
A is displaced by the oil pressure applied to A to change the flow resistance of the oil passages 4 and 5 and the drain port 60A, thereby regulating the oil pressure of the oil passage 4, and supplying excess lubrication from the oil passage 5 to parts that require lubrication. Drain the oil from drain port 60A. The reduction ratio control mechanism 80 includes a reduction ratio control valve 81, orifices 82 and 83, an upshift electromagnetic solenoid valve 84, and a downshift electromagnetic solenoid valve 85. The reduction ratio control valve 81 has a first land 812A, a second land 812B, and a third land 812C, and a spool 812 with a spring 811 disposed on one land 812C;
Side end oil chambers 815 and 81 at both ends to which throttle pressure or low modulator pressure is supplied from oil passage 2 via orifices 82 and 83, respectively.
6. Intermediate oil chamber 810 between land 812B and land 812, oil passage 2A connecting oil chamber 815 and oil chamber 816, communicating with oil passage 1 to which line pressure is supplied, and responding to movement of spool 812. A pressure regulating oil chamber 819 and a spool 8 are provided with an input port 817 whose opening area increases and decreases, and an output port 818 that communicates with the hydraulic servo 530 of the input pulley 520 of the V-belt continuously variable transmission 500 via the oil path 1b.
A drain port 814 that evacuates the oil chamber 819 according to the movement of the spool 812, and a drain port 813 that evacuates the oil chamber 810 and 815 according to the movement of the spool 812 are provided. The upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 are the oil chamber 8 of the reduction ratio control valve 81, respectively.
15 and an oil chamber 816, both of which are operated by the output of an electric control circuit to be described later to evacuate the pressure of the oil chamber 815 and the oil chamber 816, respectively. As shown in FIGS. 2 and 12, the lock-up control mechanism 70 includes a lock-up control valve 71.
, an orifice 77, and an electromagnetic solenoid valve 76 that controls the oil pressure of the oil passage 4a that communicates with the oil passage 4 via the orifice 77. The lock-up control 71 has a spring 72 disposed on one side (right side in the figure), and lands 73A, 73 having the same diameter.
The spool 73 includes a spool 73 provided with spools B and 73C, and a sleeve 75 which is provided in series with the spool 73, has a spring 74 disposed on the other side (left side in the figure), and has a diameter larger than the land of the spool 73. . In FIG. 12, the oil pressure P ₄ of the oil passage 4 applied to the land 73C and the spring load F s1 of the spring 72 are received from one side through the input port 71A connected to the oil passage 4, and the sleeve 75 receives the spring load F _s1 of the spring 72 from the other side. The solenoid pressure P _s of the oil passage 4a controlled by the solenoid valve 76 or the land 7 via the port 71D
The spool 73 is displaced in response to the hydraulic pressure P ₂ of the release side oil passage 8 of the lock up clutch 430 applied to the lock up clutch 430 and the spring load F _s2 by the spring 74, and the spool 73 is displaced between the oil passage 4 and the release side oil passage 8 or the lock up clutch 430. Controls the communication of the up clutch 430 with the engagement side oil passage 9. When the solenoid valve 76 is energized and turned on, the hydraulic pressure in the oil passage 4a is discharged, the spool 73 is fixed to the left in the figure, the oil passage 4 and the oil passage 9 are in communication, and the hydraulic oil is The fluid flows in the order of passage 9 - lockup clutch 430 - oil passage 8 - drain port 71C, and lockup clutch 430 is in an engaged state. When the solenoid valve 76 is de-energized and the valve port is closed (OFF), the oil pressure in the oil passage 4a is maintained, the spool 73 is fixed to the right in the figure, and the oil passage 4
is in communication with oil passage 8, and the hydraulic oil flows in the order of oil passage 8, lock up clutch 430, oil passage 9, and communication oil passage 10 to the oil cooler.
30 are released. As is clear from the above description, according to the control device for a continuously variable transmission for a vehicle according to the present invention, the line pressure is used as the hydraulic pressure to be supplied to the hydraulic servo means for operating the frictional engagement element. Since the throttle pressure is regulated to a lower pressure than this line pressure according to the opening degree, the shock associated with the gear change operation is alleviated. Therefore,
You will be able to get a comfortable driving feeling. Furthermore, the relatively low operating pressure of the hydraulic servo means not only improves the durability of the seal, but also allows for a simpler seal.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of a control device for a continuously variable transmission for vehicles according to the present invention, Fig. 2 is a circuit diagram of the control device, and Fig. 3 is a diagram showing the output characteristics of the reduction ratio control valve. , FIG. 4 is a diagram showing the second throttle pressure characteristics output by the throttle valve, FIGS. 5 and 6 are diagrams showing the first throttle pressure characteristics output by the throttle valve, and FIG. A diagram showing the output low modulator pressure characteristics, FIG. 8 is a diagram showing the hydraulic characteristics occurring in the oil passage 2, FIGS. 9 and 10.
11 is a diagram showing the line pressure characteristics output by the pressure regulating valve, and FIGS. 12A, B, C, and D are explanatory diagrams of the operation of the lock-up control mechanism. 20...Oil pump, 27...Flow rate adjustment valve,
30...pressure regulating valve, 40...throttle valve, 65...
...Manual shift valve, 80...Reduction ratio control mechanism, 400...Fluid coupling (fluid transmission mechanism), 500...V-belt type continuously variable transmission mechanism, 6
00... Planetary gear transmission mechanism (forward/forward switching mechanism),
630...Advance multi-plate clutch (frictional engagement element),
690...Forward hydraulic servo.

Claims (1)

[Claims] 1. A forward/reverse switching mechanism capable of switching between a forward gear and a reverse gear by selective engagement of a frictional engagement element driven by a hydraulic servo; In a control system for a vehicle continuously variable transmission equipped with a V-belt type continuously variable transmission mechanism in which a belt is wound between variable input and output pulleys, the hydraulic pressure discharged from the oil pump is adjusted to a predetermined line pressure. a pressure regulating valve that selectively supplies and discharges the line pressure to at least one of the hydraulic servos of the input/output pulley, and a reduction ratio control mechanism that regulates the line pressure according to the throttle opening degree to achieve a predetermined engagement. a throttle valve that generates a throttle pressure that increases in response to an increase in throttle opening and causes the throttle pressure to act on the pressure regulating valve; and a throttle valve that supplies and discharges the throttle pressure to a forward hydraulic servo of the forward/reverse switching mechanism. A control device for a continuously variable transmission for a vehicle, comprising: a shift valve; and a flow rate adjustment valve provided in an oil path that communicates the shift valve with a forward hydraulic servo of the forward/reverse switching mechanism. 2. The throttle valve includes a spool to which the throttle pressure is fed back to regulate the throttle pressure, and urging means to apply a predetermined urging force to the spool in opposition to the throttle pressure to generate a predetermined minimum throttle pressure. The continuously variable transmission for a vehicle according to claim 1, further comprising means for applying a biasing force to the spool according to the throttle opening and increasing the throttle pressure as the throttle opening increases. Machine control device.