JPS6324188B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed ratio control device for a continuously variable transmission for a vehicle. Continuously variable transmissions include mechanical and hydraulic continuously variable transmissions, and the present invention particularly relates to a hydraulic control means for the speed ratio changing means of a continuously variable transmission having a mechanical speed ratio changing means.

Conventionally, the speed ratio control of a continuously variable transmission has been carried out using a flow rate control valve in which the cam deflection of a cam interlocked with a throttle valve and the output hydraulic pressure of a hydraulic governor driven by the rotation of the output shaft of the continuously variable transmission are opposed to each other. This is done by applying the speed ratio control hydraulic pressure to the speed ratio control actuator. Since the actuator is directly driven by the differentially amplified hydraulic pressure of the flow control valve, designing each part is extremely difficult. In other words, it is necessary to obtain a sufficient level of governor oil pressure to drive the spool of the flow control valve, make the cam deflection sufficiently large, and precisely determine the strength of the flow control valve spring to make its stroke sufficiently long. This is extremely difficult and requires a strong force to press the accelerator pedal due to the large cam deviation. When adding compensation hydraulic pressure to the actuator's speed ratio control hydraulic pressure for throttle opening differential compensation, compensation at start, etc., connect an additional cam to the throttle valve and use the cam to push the pilot piston to obtain the compensation control hydraulic pressure. However, in this case, a larger force is required to press the accelerator pedal, and a balanced actuator control oil pressure can be achieved by using only one flow control valve and also inputting the compensation control oil pressure. , the design of the flow control valve becomes even more difficult.

The present invention obtains an operating signal for a speed ratio control servo in response to a signal (pressure) responsive to vehicle speed and a signal (pressure) responsive to throttle opening, and transmits this operating signal to a follow-up type actuator. By supplying it to the speed ratio control servo used, continuously variable speed over a corresponding range was realized.

Furthermore, especially in a mechanical continuously variable transmission, the operation of the speed ratio control actuator requires an extremely large force due to the reaction force of the torque transmitting part. For this reason, the speed ratio control actuator is generally operated via hydraulic pressure, and it is desirable that this hydraulic pressure always operate stably without being strong or weak at all speed ratios. Therefore, for example, it is not desirable to directly actuate the speed ratio control actuator because the throttle valve response pressure or the vehicle speed response pressure involves the generation of low and high oil pressures. Also, when the vehicle suddenly falls into a small depression while the vehicle is running, the pressure is transmitted from the wheel side through the transmission mechanism to the speed ratio control actuator, causing unnecessary speed ratio changes. There are cases where

In order to eliminate these drawbacks, the present invention creates an appropriate oil pressure signal corresponding to the speed ratio using the throttle valve response pressure and vehicle speed response pressure, and adjusts the high hydraulic oil pressure (usually line oil pressure) according to this oil pressure signal. This is used to operate the speed ratio control actuator. Furthermore, the present invention provides a compact control device that uses these throttle valve response pressures and vehicle speed response pressures that have low-pressure portions to constantly use high-pressure line oil pressure as hydraulic oil pressure.

The present invention will be described below based on examples.

The speed ratio control device of the present invention provides speed ratio control means for a mechanical continuously variable transmission, which is shown by way of example by the schematic symbols in FIG. The main pump 102 driven by the output shaft 101 of the engine E constitutes the hydraulic pressure source for the line hydraulic means, and then the automatic starting clutch 10
3. A spherical conduction speed ratio changing means 104 and a forward/reverse switching means 108 are sequentially connected to the engine output shaft 101 side, and a governor is connected to the output shaft side of the speed ratio changing means 104 at the end of the forward/reverse switching means 108. Valve 1
70 are arranged.

The main pump 102 is connected to the oil reservoir 10 via line P ₉₉ .
9 supplies pressure oil as line hydraulic means to line _P1 as the engine rotates. Line P ₁ then includes a pressure regulating valve 120, a governor valve 170, a speed ratio control servo (RCR) 200, and a manual valve 130.
is connected to corresponding port 1 of , and supplies line pressure P _L. The main pump 102 can be a known rotary or gear pump, and the discharge amount of these pumps is usually proportional to the rotational speed.

As the pressure regulating valve 120, a known one can be used. The pressure regulating valve 120 has valve elements 121 and 122 that receive pressing force from a spring 123 interposed between the valve elements 121 and 122.
The opposite ends of springs 1 and 122 form pistons in ports f and a, respectively, and port f has an orifice 1.
A line _P1 is connected to the port 24, and an output line _P50 of a throttle valve 160 is connected to port a. This orifice 124 is arranged to damp vibrations caused by a pump or the like in line _P1 . Line P ₁ is connected to ports c and e, and ports b and d
Lines P ₉₅ and P ₉₁ are connected to these ports, respectively, and when the valve element 121 moves to the left, ports c and b and ports c and d communicate with each other, respectively. Line P ₉₅ has a relief valve 230 as a branch and connects to the clutch and other lubrication systems 111a, 111b. The line P ₎₁ is connected to another lubrication system 111c. There is a drain port x on each end plate at both ends of the body.

The pressure regulating valve is for adjusting the line pressure P _L of the line P _1. When the engine speed increases and the main pump 102 discharge amount and line pressure P _L increase, a spring 123 is applied to the piston of port f to the left. A force acts against this, pushing the valve element 121 to the left and opening ports b and d. By opening ports b and d, oil flows to lines P ₉₅ and P ₉₁ , respectively, and line pressure P _L is lowered and adjusted. Preferably, ports b and d are opened at different times, so that when the increase in line pressure P _L is small, only one port is used to adjust the pressure, and when the increase in P _L is large, both ports are opened. The pressure is adjusted by

Usually, the pressure of lines P ₉₅ and P ₉₁ connected to ports b and d is maintained at a low pressure of less than 1 kg/cm ² , and the line
P ₉₅ is maintained below a predetermined value by the relief valve 230. A known relief valve 230 can be used.

Since line P ₅₀ is connected to port a,
A pressure (throttle pressure) P _TH corresponding to the throttle opening degree acts on the piston surface of the valve element 122 via the throttle valve 160 . When the throttle opening is increased by depressing the accelerator, the throttle pressure _PTH increases and presses the valve element 122 to the right, and the valve element 121 is pressed to the right via the spring 123, closing ports b and d. At this time, the valve element 122 is pressed to the right, and the spring force increases by the amount that the spring 123 is compressed, and the line pressure increases accordingly.
An increase in P _L occurs. That is, the line pressure P _L changes according to the throttle pressure P _TH .

The governor valve 170 can be of a known type, but is usually connected to the transmission output shaft 110.
It rotates together with the output shaft to generate hydraulic pressure and generates hydraulic means according to the vehicle speed.

The governor valve 170 has the transmission output shaft 110 as a body and has a large diameter hole and a small diameter hole, and the small diameter hole has a drain port x, an input port a, and an output port b in the portion corresponding to the valve element 171 in order from the center. , a cylindrical weight having a drain port
W ₁ 172 and a cylindrical weight W ₂ 173 that is movable and fitted concentrically around the outer periphery of the output shaft 110 and engages with the weight W ₁ 172 in the radial centrifugal direction of the output shaft 110 via a spring 174 . Weight W ₂ 17
A snap 176 is locked in the large diameter hole with a small clearance t from the outer end of the weight W ₂ to prevent the weight W 2 from moving outward from the output shaft 110 .

As the output shaft 110 rotates, a centrifugal force is generated on the weight, and a force responsive to the output shaft rotational speed, that is, the vehicle speed V acts on the pin 175 in the direction of the arrow. On the other hand, line pressure P _L is applied to port a through line _P1 , and the degree of opening between ports a and b increases in response to an increase in vehicle speed V, and the governor pressure is increased as shown in Fig. 7.
P _G is generated as an output signal corresponding to the vehicle speed V.

Note that port b is connected to input port e of compensation valve 150 via line P ₄₀ and optionally via hold valve 180, line P ₄₁ and modulator valve 190.
_{The governor pressure P G is} further applied to the compensation valve 150 as a modulated and controlled signal pressure.

The weight W ₂ 173 of the governor 170 is locked to the weight W 1 via the spring 173 when a slight centrifugal force is applied in the direction of the arrow, and the weight _{W 1 is} locked to the weight W ₂ by the snap 177, and the weight W 1 is locked to the pin 175. On the other hand, it exerts a centrifugal force proportional to the mass (W ₁ + W ₂ ). Furthermore, as the output shaft rotation speed increases, the weight increases.
W ₂ is locked to pin 176 and transmits centrifugal force to output shaft 1
10, and thereafter (weight W ₁ + pressing force of spring 174) is supported by pin 17 from point c in FIG.
Governor pressure P _G acting on 5 and represented by curve GV
will occur.

The manual valve 130 includes a valve element 131 equipped with a manual switching knob 131a on a body having a drain port x and ports a to f from the left.
are arranged so as to be shiftable to the following switching positions: Park P, Reverse R, Neutral N, Drive D, and Lock Up L. Line P ₁ is connected to port c, and ports a and b are connected via line P ₂ to ports a and b of servo valve 220, port b of throttle valve 160, port a of kickdown valve 140, and port of compensation valve 150. Connect to a respectively.

In the neutral position N, port c is closed, ports a and b communicate with drain x, and ports d to f are in an unpressurized state. At drive position D, port c communicates with ports a and b, drain x is closed, and port d
~f are respectively in a pressureless state. Lockup position L
Then drain x, ports a and e are closed, ports b and d
communicates with port c, and port f is in an unpressurized state.

At reverse position R, ports a and b are drain x (open)
Port c is in communication with port d and is in a no-pressure state.
~f and applies line pressure P _L.

At parking position P, port a is drain x
Port b is closed, port c is connected to ports d and e, and port f is closed.

Ports d and e of manual valve 130 can be connected to port d of hold valve 180 via line _P4 , if desired, to provide additional control (lockup) of governor pressure _PG .
For this purpose, line _P4 is provided. Port f of manual valve 130 is connected to port c of servo valve 220 via line _P3 .

The servo valve 220 has one end pressed by a spring 222 in a body having ports a to d, and a servo piston 221 including a valve element portion 221 moves to the right against the spring 222 by hydraulic pressure applied to port c. It is arranged so that it can be moved by pressing.

The illustrated position (left position) of the piston 221 in FIG. 2 indicates forward movement, and the right position indicates backward movement. The piston 221 is formed integrally with the forkshaft 223 of the forward/reverse switching means 108, or is interlocked with the forkshaft via a link means. Port a communicates with port b in the forward state, and port b communicates with automatic starting clutch 10 via line ₁₀ .
Connect to the actuating means of No. 3.

The servo valve 220 is controlled and operated by the manual valve 130. Manual valve 130 shift knob 1
In the N position of 31a, no pressure from line _P3 is applied to port c of the servo valve, and piston 221
remains in the forward position, and servo valve ports a and b communicate with each other, but no pressure is applied from line _P2 , so the starting clutch is in a released state.

In the D and L positions of the manual valve shift knob 131a, the piston 221 is in the forward position. In position D, ports a and b of manual valve 130 are connected to line P ₁ -manual valve 130- through port c.
Line pressure P _L is applied to ports a and d of the servo 220 via line P ₂ and the automatic start clutch 103
is applied with line pressure P _L via ports a-b-line P ₁₀ and is in a clutch engaged state, while the line pressure P _L applied to port d additionally acts on the spring 222 pressure and causes the piston 221 to move. Secure in forward position.

In the L position, the only difference is that manual valve port a is closed compared to the D position, but the oil line
The flow rate from P ₁ to line P ₂ is slightly restricted, and a slightly lower line pressure _PL is supplied to line P ₁₀ to clutch 103.

In the R position, port c- of manual valve 130
d-Line _P3 -Line pressure P _L is applied to port c of the servo valve 220, and the piston 221 moves to the right against the spring 222 to reach the reverse position.
At the same time, port c-b is communicated and line pressure P _L is supplied to clutch ₁₀₃ via line P10.
At this time, no pressure is applied to the servo valve 220 port d (on the spring side of the piston) because the line P ₂ is opened to communicate with the drains X of the manual valve 130 ports a and b.

As the throttle valve 160, a known one can be used. The throttle valve 160 has a valve element 161 in which one end is pressed by a spring 164 and the other end is pressed by a spring 163, in a body in which drain ports x ₁ , x ₂ and ports a to c are sequentially arranged. The arm 1 is compressed between the valve element 161 by the element 162 and operates in synchronization with the throttle opening.
65 receives a rightward pressing force corresponding to the throttle opening degree. A drain port x ₁ is arranged between the valve elements 162 and 161 (distance d ₂ ), and the drain port x ₂ is located within the movable range of the valve element 161.
Ports a to c are arranged. At the port c portion, the valve element 161 has a piston portion 161a.

Line P2 from ports a and b of the manual valve 130 is connected to port b of the throttle valve 160, and port b- _a is the minimum opening when applying line pressure P _L to port b of line _P2 . The communication port _x2 is in a closed state, and when there is no pressure in the line _P2 , the distance _d1 between the piston portion 161a of the port c portion and the body boundary plate is 0, and they are in contact with each other.

When the accelerator is depressed, the arm 165 presses the valve element 162 in the direction of the arrow via a link means not shown, and further presses the valve element 161 in the same direction as the arrow (to the right) via the spring 163. . As a result, the opening degree of port b-a increases, and a signal pressure (throttle pressure P _TH ) corresponding to the throttle opening degree (accelerator depression amount) is applied to port a.
occurs. Port a communicates with port c, and each time the throttle pressure _PTH increases, it applies a force to the piston portion 161a in a direction that counteracts the increase in the throttle pressure _PTH .
Drain port x ₂ is throttle pressure P _TH is line pressure P ₂
The piston portion 16 is arranged to prevent the pressure from changing (increasing) depending on the throttle opening regardless of the throttle opening.
1a (port c) When the pressing force is overcome, port b- _x2 is communicated to regulate the throttle pressure _PTH that responds to the throttle opening. Port b is further connected to port a of compensation valve 150, pressure regulating valve port a, and port c of kickdown valve 140 via line _P50 .

Compensation valve 150 has two valve elements 15
1,152 in order from the left: a-d, drain x, e
The valve element 152 has its port a end pressed by a spring 153, and its port b portion abuts against and supports the small diameter piston portion 151a of the valve element 151. The valve element 151 is a small diameter piston portion 1
51a, large diameter piston part 151b and intermediate shaft part 1
51c, the cylinder has a port c within the movable range of the small diameter piston part 151a, and ports d, x, and e in the large diameter part, and the port e is in the large diameter piston part 1.
It opens to the right of 51a. By moving the valve element 151 to the right (when P _TH increases), port d
-x is in communication and at the same time, ports c and d are closed.
Also, by moving the valve element 151 to the left,
Ports c and d are communicated, and at the same time, drain port x (therefore, between d and x) is closed.

A line _P50 (from port a of the throttle valve 160) is connected to port a of the compensation valve 150 to apply throttle pressure _PTH , and a line _P5 from port b of the kickdown valve is connected to port b. (It is also connected to port b of modulator 190.) Line P ₂ from ports a and b of manual valve 130 is connected to port c, and line P ₄₂ having a signal source in governor valve 170 is connected to port e. Connected (input signal pressure or higher). Compensation valve 150
As for the output signal pressure, a line P ₆₀ from port d is connected to port a of the speed ratio control servo (RCS) 200.

At the port b portion of the compensation valve 150, the shaft portions of the valve element 152 and the small-diameter piston portion 151a of the valve element 151 are in contact with each other, and form opposing piston surfaces that are actuated by the respective lines _P5 .

That is, the compensation valve 150 has a vehicle speed response pressure (governor pressure P _G or its modulation pressure P ₄₂ ) at one end, and a pressure corresponding to the throttle opening (throttle pressure P _TH ) at the opposite end.
The valve element 151 has a valve element 151 to which pressure is applied in opposition, and the valve element 151 further regulates the line pressure P _L by opening and closing the drain port x and the line pressure input port c, and outputs it from the port d as an output. The pressure is further adjusted by vehicle speed response pressure (P _G
etc.), the valve element 151 is pressed in the opposite direction to achieve a kind of self-balancing.

The balance of the acting force on the valve element 151 in the compensation valve is expressed by the following equation (1) when the throttle opening is less than 0/8 to 7/8, and the output pressure P _C is expressed by the equation (2) (however, A ₁ > A ₂ ).

f + (A ₁ − A ₂ ) P _C + A ₂ P _TH = A ₁ P _G ″ (1) P _C = 1/A ₁ − _{A 2} (A ₁ P _G ″ − _{A 2} P _TH − f) (2) However, f: pressing force of spring 153, A: cross-sectional area of valve element 152, A ₂ : piston portion 15
Cross-sectional area of 1b, P _G : Pressure of line P ₄₂ Also, when the throttle opening is 7/8 to 8/8 (kick down),
A signal pressure of P _K =P _L is applied from line P ₅ to port b, and the valve element 151 moves to the right. At this time, the following equation (3) holds true, and the output pressure P _C is expressed by equation (4). (For simplicity, valve element 151
The cross-sectional area of the piston portion 151a = the cross-sectional area of the valve element 152 _A1 . However, this is not a necessary condition).

A ₂・P _L + (A ₁ − _{A 2} ) P _C = A ₁ P _G ″ (3) P _C = 1/A ₁ − _{A 2} (A ₁ P _G ″ − _{A 2} P _L ) (4) As a result, P _C (0/8 to 7/8) when the throttle opening θ is less than 0/8 to 7/8 is larger than when the throttle opening is (7/8 to 8/8). This relationship is the basic purpose of the kickdown valve 140 and its basic effect on the compensation valve 150 (see the section on the kickdown valve).

A follow-up type servo can be used as the speed ratio control servo 200.

The speed ratio control servo 200 includes cylinders 204 (204a, 204b) formed in the body 203.
The actuator 205 is fitted so as to be movable in the axial direction.
The actuator 205 is fitted into the center hole 207 by being pressed toward the bottom of the cylinder by a compression spring 208 supported at the bottom of the hole, and the body 20
The other end of the valve element 201 is fitted into a small diameter cylinder 204c formed concentrically with the valve element 201.

There is a port a at the bottom of the small diameter cylinder 204a, which receives signal pressure P _C from the compensation valve 150 via line P ₆₀ . The actuator 205 has pistons 206a and 206b spaced apart from each other by a predetermined distance and sliding in cylinders 204a and 204b, respectively, and is pressed toward the cylinder mouth by a spring 209 supported by a bottom spring seat 212 of the cylinder 204b. . There is a port b in the body 203 within the movable range of both pistons 206a and 206b,
Port b is connected to the discharge side of main pump 102 through line P ₁ and is applied with line pressure P _L . The cylinder mouth end of the actuator 205 is connected to the link hole 2.
11 extends, and connects the speed ratio changing means of the continuously variable transmission (for example, the spherical conduction speed ratio changing means 10 in FIG.
4) and L-H of actuator 205.
The back-and-forth movement in between exerts a control action on the speed ratio changing means.

piston 206a of actuator 205,
206b has a predetermined effective cross-sectional area ratio, and has a port f communicating with the center hole 207 in the cylindrical part between both pistons 206a and 206b, and a drain at the bottom of the center hole 207 (on the arm end side). It has port x.

The valve element 201 is a small diameter cylinder 2
A hollow cylindrical portion 201a that is slidably housed in 04c;
It consists of a hollow cylindrical portion (spring receiving portion) 201b having an open end slidably accommodated in the actuator center hole 207 at the opposite end thereof, and an intermediate portion thereof. There are small holes 212a, 212b in the axial direction in the middle part.
, the small hole 212a communicates ports c and e,
The port 212b communicates the hollow portion of the spring receiving portion 201b with the intermediate port d. In the state shown in FIG. 3, ports e and f are open and communicated when the valve element 201 is pushed to the right, and port d is opened when the valve element 201 is moved back to the left or the actuator 205 is moved to the right. Arranged to open. Port c is connected to spring 2 in the state shown in FIG.
09 Opens to the storage cylinder 204b and connects the port d
After the valve element 201 is closed, the valve element 201 is arranged at a predetermined distance from the port d so that the valve element 201 closes when the valve element 201 is further pushed to the right by a predetermined amount.

The piston 206b has a larger pressure-receiving area than the piston 206a, and when sufficient line pressure P _L is applied to the cylinder space 204c, the actuator 205 moves toward the bottom of the cylinder against the pressing force of the spring 209 ( move to the left). This leftward movement connects ports fe and pressurized oil to the hole 212.
It flows into the cylinder 240b (spring 209 side) through the a-port c, and when the left and right pressure balance of the piston 206b is restored, the actuator 205
moves in the opposite direction (to the right) by the force of the spring 209, passing through the original position and moving further to the right. As a result, port fe is closed, port d is open, and pressure oil flows from the left cylinder 204b to the small hole 212b.
- central hole 207 - discharged into drain port x;
The pressure in the left cylinder chamber of the piston 206b decreases again, and the pressing force of the spring 209 and the piston 20
The pressing force due to the line pressure P _L corresponding to the pressure receiving area difference (effective pressure receiving area) between 6b and 206a becomes equal,
Movement of the actuator to the right stops. The reciprocating movement between the L and H positions of the link hole 211 of the actuator 205 can be changed into an angle change α of the roller shaft 107 of the speed ratio changing means 104 by the link means.

Note that the most preferable control accuracy is achieved by opening and closing ports ef and opening and closing ports d simultaneously (zero lap).

The kickdown valve 140 has a body that has drain port x, ports a, _b , drain port
41c, with a port b-x ₂ communication part 141a in the middle, and a spool 141 supported by a spring 142 at the left drain port part _x1 . port a is line
communicates with manual valve 130 ports a and b via line P ₂ ; port b communicates with compensation valve port b and modulator valve port b via line P ₅ ;
Port c communicates with throttle valve ports a and c via line _P50 . Ports b and x ₂ communicate when port c is unpressurized (P _TH = 0), and the spring 142 causes the throttle pressure P _TH to change to the corresponding pressure P _TH (7/8) at a constant throttle opening, for example, 7/8. When reached, spool 1
41 is adjusted to move to the left. That is, it operates only when the throttle opening is 7/8 to 8/8 (fully open), and this is set to correspond to the throttle opening during kickdown. Spool 1 between ports a and b
Connected by left movement of 41 and drain port x ₂ at the same time
(between ports b and x ₂ ) is closed. Therefore, when the throttle opening ranges from 7/8 to fully open, the kickdown valve output pressure P _K =P _L occurs in line _P5 , and when the throttle opening ranges from 0 to 0.
If it is less than 7/8, P _K =0.

The modulator valve 190 has a body that has a drain port x and ports a to d sequentially from the left, and the drain port
The piston part 19 has a piston part 191a on the side and acts on the port b part in opposition to the piston part 191a.
1b, the spool 191 controls the degree of communication opening between ports c and d, and at the same time closes port a. Ports a and c are mutually open and closed in a zero lap, and ports a-
Communication is made between ports a and port a by line P ₄₂ outside the valve, and communication is made between ports a and port a by line P ₄₂ .
Let the signal pressure P _G ″ be zero pressure.

Hold valve 18 via line P ₄₁ to port d
Signal pressure P _G ' from port b of 0 is input, ports a and c communicate with port e of compensation valve 150 via line P ₄₂ , and governor pressure P _G is regulated by hold valve 180 for the compensation valve. Pressure-controlled signal pressure
A signal pressure P _G ″ that is further modulated from P _{G ′} is supplied.

The force of the spring 192 is that the force acting on the piston part 191a due to the input pressure P _G ' of the line P ₄₁ of port d is the predetermined vehicle speed response pressure P _MV (for example, vehicle speed V = approximately 10 Km/h).
is set to hold port c closed until . As a result, the input signal pressure P _G ′ becomes equal to the predetermined vehicle speed V _MV
The modulator valve output signal pressure P _G ″ is kept pressureless until the corresponding pressure P _MV is reached, and when it reaches P _MV ,
With port c open (c-d communication), an output signal pressure P _G ''=P _MV ' is generated in line P ₄₂ , and thereafter increases according to the curve MV in FIG. 9, as an example, as the vehicle speed increases. This produces a modulated pressure that is slightly lower than the input signal pressure P _G ' of the modulator valve 190 (the hold valve output pressure, or the governor pressure P _G when the hold valve is not used).

Port b communicates with port b of the kickdown valve 140 via line _P5 , and inputs kickdown valve output pressure P _K =P _L (line pressure) when the kickdown valve is activated (throttle opening 7/8 to fully open). and exerts pressure on the piston portion 191b, causing the spring 192
The spool 191 is moved to the right by additionally acting on the pressing force of , and port c is closed (ports a and x are open). At this time, the output signal pressure P _G ″ of the line P ₄₂ becomes zero pressure.

The hold valve 180 includes, from the left, drain port x ₁ ,
A spool that is backed by a spring ₁₈₂ to the right on a body having a port a, a drain port 181 is arranged. A working surface of the piston portion 181a is disposed in the port a, a working surface of the piston portions 181a and 181c facing each other is disposed in the port b, and a piston portion 181d is disposed in the port d. Ports a and c are connected to governor valve port b via line P ₄₀ and receive vehicle speed response pressure P _G as input signal pressure. Port d is connected to ports d and e of manual valve 130 via line _P4 , and is connected to L (lockup) of manual valve shift knob 131a.
and line pressure P _L is applied at the R (reverse) position. When line pressure P _L is applied to port d, the spool 181 moves to the left and closes port c (port b
Control is performed between a state in which the line pressure P _L is at least a certain value, and the port C is closed when the line pressure P _L is above a certain value. This port d
In the manual valve N (neutral) and D (drive) positions, there is no pressure, and in the D position, the spool 181 is under the leftward force f of the spring 182 and the acting force of the governor pressure P _G on the piston portion 181a (port a). In accordance with the balance of the force acting on the piston portion 181a and minus 181c of the output pressure P _G ' in port b opposing the output pressure P G ', port c (between c and b) is held at an appropriate open position, and a signal equal to the input pressure P _G is maintained. Pressure P _G ' is delivered to modulator valve 190 via line P ₄₁ . Therefore, as far as the D position of the manual valve is concerned, the hold valve 180
does not involve any special control actions.

On the other hand, L (lock up) of manual valve 130
position, R (reverse) position, line to port d
Line pressure P _L is applied via P ₄ and spool 1
This is performed according to the pressure applied to each piston portion 181a, 181c of 81 and the acting force f of the spring 182.
Now, assuming that the total cross-sectional area of the piston part 181a is S, the cross-sectional area of the spring guide part 181e is _S2 , and the cross-sectional area of the piston inside port d is _S3 , the line pressure P _L is
When the voltage is applied to the spool 181, the following equation (5) holds true.

f + (S ₁ - S ₂ ) P _G = (S ₁ - S ₃ ) P _G '+ S ₃ P _L (5) Therefore, the output pressure of port b of the hold valve 180
P _G ′ is expressed by equation (6).

P _G ′=1/S ₁ −S ₃ {(S ₁ −S ₂ )P _G +f−S ₃ P _L } (6) This P _G ′ becomes the vehicle speed response pressure shown by the curve HV in Figure 7, Furthermore, modulator valve 190
is supplied to its port d as the operating pressure of the spool 191.

The operation of this embodiment will be explained below.

The manual valve 130 is connected to a shift lever (not shown) via a link means and is manually operated. In neutral N position, line P ₁ is manual valve 1
30, the servo valve 220 (for forward/reverse switching control) is in the forward state according to the pressing force of the spring 222.

When engine E is started here, main pump 10
2 starts rotating and line pressure P _L is applied to line P ₁ . The main pump 102 increases its discharge amount in proportion to the engine rotational speed N _E , but produces a line P _L whose pressure is regulated by a pressure regulating valve 120 . Line pressure P _L is also the throttle pressure corresponding to the throttle opening.
By applying P _TH to the pressure regulating valve 120, the pressure is increased in accordance with the amount of accelerator depression (throttle opening) (this relationship is shown in FIG. 6). Line pressure P _L is applied to port b of speed ratio control servo (RCS) 200 via line P ₁ . The throttle is opened by pressing the accelerator when starting the engine, but when the manual valve 130 is in the neutral N position, the throttle valve 1 is opened.
The line P ₂ which is the pressure source of 60 is at zero pressure, the throttle pressure P _TH is zero, and the compensation valve 150 is at zero pressure.
Does not create pressure on P ₆₀ . As a result, the valve element 201 is pressed leftward by the spring 208 and comes into contact with the bottom end of the small cylinder 204c. In this state, the RCS actuator 205 applies the line pressure P _L from port b to the piston 206b.
is applied to the left side (velocity ratio e) in Figure 3.
20 of the left cylinder.
It comes into contact with 4L and stops (L position). At that time, ports fe open for communication, and the flow flows into the left cylinder 204b through the small hole 212a and port c, and the pressure is
is equal to P _L. As a result, the sum of the anti-supporting force of the spring 209 and the force acting on the left cylinder side of the piston 206b (H direction force) exceeds the L direction force and tries to push the actuator 205 back in the H direction.
As a result of this forward movement in the H direction, port d opens and drains
, the pressure inside the left cylinder 204b suddenly drops and becomes the initial pressure relationship (left cylinder low), and the actuator tries to move to the left (in the L direction) again, but is blocked by the stepped portion 204L. and remains at the position L where the speed ratio e is minimum.

On the other hand, the line pressure P _L is applied to the governor valve 170 via the line P ₁ and is in a state where it can output the vehicle speed responsive pressure (governor pressure) P _G as soon as the output shaft 110 starts rotating. The relationship between governor pressure P _G and vehicle speed V is as shown in FIG.

Governor pressure P _G is applied to port c of the hold valve 180 via line P ₄₀ , but in the N position, line P ₄ (port d of the same valve) is unpressurized and the spool 181 is pushed to the right by the spring 182. port c-
b Communication is open, and the output pressure of line P ₄₁ is P _G ′=P _G . Regarding the hold valve 180, even in the manual valve D position, the line P ₄ -port d is similarly pressureless. Therefore, even in the N and D positions, the governor pressure is applied to the modulator valve 190 port d.
_PG is applied via line _P41 .

The output signal pressure P _G '' (line P ₄₂ ) of the modulator valve 190 is generated depending on the input signal P _G ' (N, D position=P _G ) and draws a curve MV shown in FIG.

Spring 192 force and ports c, a, piston part 19
By setting 1a, P _G ″=0 until the vehicle speed reaches the predetermined speed V _MV (corresponding vehicle speed response pressure P _MV ),
After outputting the rising P _G ″=P _MV ′ at V _MV , P _G ″ becomes a curve
Draw MV and increase corresponding to P _G ′. Vehicle speed V=
P _G ″=0 at 0~V _MV defines the rising line segment m at V=V _MV in Figure 10, and the throttle opening 0~
At 7/8, continuously variable speed operation occurs in region B to the right of this line segment m (V > V _MV ), and to the left (V
= 0 to V _MV ), the speed ratio e = L
Fixed in position. In the low speed ratio range, there is no need to perform continuously variable shifting according to the engine rotational speed N _E or throttle angle θ and the vehicle speed V, so it is useful to provide the speed ratio fixed range A (L position fixed) in this way. The predetermined vehicle speed _VMV at which the continuously variable speed range starts is determined by the settings of the various parts of the modulator valve 190, particularly the settings of the spring coefficient of the spring 192 and the arrangement of the port c.

Here, when the manual valve 130 is shifted from the N position to the drive D position, the lines P ₁ -P ₂ are communicated with each other, and the line pressure _PL is applied to the line P ₂ . As a result, the servo valve 220 is held in the forward position, the clutch 103 is engaged through ports a-b and the line _P10 , and the rotational torque of the engine E is transferred from the engine output shaft 101 to the speed ratio changing means 104 and forward/backward switching. The pressure is transmitted to the output shaft 110 via the means 108, and the governor valve 110 rotates to produce a governor pressure P _G corresponding to the vehicle speed. At the same time, line pressure P _L is applied to port b via line P ₂ due to communication between ports c, d, and e of manual valve 130.
The opening degree of ports b-c of the throttle valve 160 increases in accordance with the amount of accelerator depression (throttle opening) and applies a throttle pressure _PTH to the line _P50 . line
By applying pressure to P ₅₀ , throttle pressure P _TH is applied to port a of compensation valve 150, line pressure P _L from line P ₂ is applied to port c, and governor pressure from governor valve 170 is applied to port e. The pressure P _G ″ that modulates the pressure P _G is the modulator valve 19
0 port c line P ₄₂ . As a result, valve element 151 of compensation valve 150
Throttle pressure P _TH (pressure responsive to throttle opening) is applied to one end of P TH (pressure responsive to throttle opening), and modulator valve output signal pressure P _G ″ (pressure corresponding to vehicle speed V) is applied to the other end in opposition to P _TH . The valve element 151 slides left and right according to the difference in the _opposing forces of
(Line P ₂ ) and port d (Line P ₆₀ ) are communicated (when the acting force of P _TH < the acting force of P _G ), or
Communicate between port d and drain x (when the pressure difference is opposite). When starting now, the vehicle speed V0 (P _G
0), and the throttle pressure _PTH increases slightly.
At this time, the valve element 151 of the compensation valve 150
is located at the right end, and due to port d-x communication, line pressure P ₆₀ is 0 and the RCS actuator starts at L. When the vehicle speed increases a little, the governor pressure P _G
increases correspondingly, but the vehicle speed V _MV remains constant according to Fig. 9.
P G ″=0 until P _G ″=0. Therefore, the compensation valve 15
The output pressure P _C at 0 is no pressure, and the actuator 205 of the RCS is fixed at the L position while 0<V<V _MV (region A in FIG. 10). Now the throttle opening is 2/8
If <θ<7/8, the vehicle speed V increases after the start and reaches V _MV , and at this time, the modulator valve 19
0 output pressure P _G '' occurs with a sudden rise (Fig. 9), exerts pressure on the compensation valve 150 port e, and shifts the output pressure P _C to the line P _60. At this time, the vehicle speed V _MV is
Define the vertical line segment m in Figure 10, and furthermore, V>V _MV
Then, it enters the continuously variable speed region B.

Now, assuming that the throttle opening θ is uniform and the throttle pressure _PTH is about the same, the valve element 15
1 moves to the left, drain X closes _, and at the same time, port c _slightly opens (ports c _and Depends on vehicle speed V
Applied to RCS port a. For this purpose, the valve element 201 is moved to the right (H direction) by the spring 208.
move slightly against the At this time, ports fe and e of the RCS are connected, and the line pressure P _L is
04b and slightly presses the actuator in the H direction. This movement in the H direction then connects ports d-X and stops the movement in the H direction.

Thereafter, when the throttle opening degree is kept constant within the above range, the same operation is repeated as the vehicle speed V increases, and the piston 20 of the actuator 205
6b comes into contact with the cylinder stepped portion 204H, and this position is the maximum speed ratio position H, and henceforth e
=H, the vehicle speed V is simultaneously accelerated as long as the output torque overcomes the running resistance (speed ratio fixed region C).
Furthermore, when the accelerator is depressed within the range θ<7/8 for acceleration, continuously variable speed (speed ratio e increases) is performed in the same manner as during start-acceleration.

On the other hand, while driving at a constant speed, if you release the accelerator, the line
P _TH of P ₅₀ drops rapidly, and on the other hand, P _G '' also gradually decreases due to the ellipse of the vehicle. At this time, engine braking is applied, but as the vehicle speed V further decreases, the first
0 From the C (H fixed) area to the B (continuously variable speed) area.

At this time, the valve element 151 is connected to port a.
(to the left), the port c opens, and the line pressure P _L acts on the piston 151b, opening the drain port X. As a result, the line pressure P _C of P ₆₀ suddenly decreases.
The pressure in the cylinder 204c of the RCS rapidly decreases according to P _C via the line P ₆₀ port a, and the valve element 201 retreats to the left (in the L direction). The actuator 205 moves in the L direction, closes the port d again, and stops. As P _G '' gradually decreases, the piston 151b moves to the right and the compensation valve 15
0 drain X opens, P _C is further lowered, and in the same manner, the RCS valve element 201 retreats in the L direction, and then the actuator 205 follows and retreats, causing the speed ratio to gradually decrease.

When decelerating (braking, etc.) to stop,
P _TH is 0, and P _G ″ decreases according to the vehicle speed V.
In this case as well, the operation of the actuator is the same as during elliptical deceleration, but due to the sudden drop in P _G ″, the range of movement of the actuator in the L direction becomes larger, and the engine brake is also applied accordingly.

Note that the clearance d ₂ between the valve elements 161 and 162 of the throttle valve 160 varies between 7/8 and 7/8 of the throttle opening when the accelerator is strongly depressed.
This is to rapidly increase the throttle pressure _PTH in response to 8/8. By closing this clearance _d2 , the valve element 161 receives the pressing force of the arm 165 without the intervention of the spring 163, and
The space between b is fully opened, and P _TH =P _L. This relationship is shown in FIG. In the figure, throttle opening 0 to 2/8
The throttle pressure _PTH up to (one example) no-pressure range k corresponds to play in the throttle, accelerator, and link means.

Next, the operation of the down valve 140 will be described. The kickdown valve 140 operates only in a range close to the throttle opening fully open (θ = 7/8 to 8/8), and does not directly supply the operating pressure P _K to the compensation valve 150 port b.
and at the same time act on the modulator valve 190 port b via the line P ₅ to control the output P _G ″ (line P ₄₂ ) of the modulator valve 190, indirectly exerting a complementary effect on the compensation valve 150.

Fully opening the throttle means that the accelerator is temporarily depressed for downshifting, typically as a preliminary step for acceleration, or a state of rapid acceleration or high load (starting, overtaking, climbing a hill, etc.). .

Assuming that the manual valve 130 is now in the D position, the thick line hydraulic line in FIG. 5 represents the state in which line pressure P _L is applied. In this D position, throttle pressure P _TH is applied to the kickdown valve 140 port c via line P ₂ -throttle valve port ba - line P ₅₀ , while line pressure P _L from line P ₂ to kickdown valve port a is applied. is applied. As shown in FIG. 8, when the throttle opening is 7/8 to 8/8, P _TH = _PL , and _PL itself is increased in pressure according to FIG. 6 in accordance with P _TH . At this time, the spool 141 of the kickdown valve 140 moves to the left due to the action of the throttle pressure P _TH = line pressure P _L applied to its port c, ports a and b are opened, drain port X ₂ is closed, and the line
The output signal pressure of P ₅ becomes P _K =P _L. Line P ₅ communicates with port b of compensation valve 150 on the one hand and port b of modulator valve 190 on the other hand, and applies line pressure P _L to each port. First, compensation valve 150 port b
Then, the rightward pressing force of P _L・A ₂ is the piston part 151a
It acts on On the other hand, in the modulator valve 190, by applying line pressure to the piston part 191b, if the vehicle speed remains momentarily constant, the spool 191 moves to the right, closing port c and opening port a (a-X communication). open), and the output pressure P _G ″ of line P ₄₂ (therefore port e of compensation valve 150) is P _G ′
(vehicle speed V) by a predetermined amount (△
P _G '') does not decrease or becomes no pressure. Therefore, the compensation valve valve element 151 moves rapidly to the right, and the output pressure P _C of line P ₆₀ decreases by a predetermined amount (△P _C ) or becomes no pressure. (When there is no pressure, port c is closed (c-d closed), drain port X is open (d-X open)). Result
The actuator 205 of the RCS200 suddenly moves in the L direction, but depending on the magnitude of the vehicle speed V at this time, when V is small, it reaches L, and when V is large, it moves halfway in the L direction by a predetermined amount. (△L) It moves suddenly and stops. The operation of the actuator 205 is to temporarily reduce the speed ratio e, which provides an operation equivalent to sudden acceleration or downshifting for high loads. Note that when the port d input pressure P _G ′ of the modulator valve 190 is large (vehicle speed V large), the valve spool 191 increases by a predetermined amount (△P _G ″) corresponding to P _G ′ (=P _G , vehicle speed V). ) reduced output pressure
P _G '' is controlled and output, the compensation valve 150 output pressure P _C suddenly decreases by a predetermined amount (△P _C ), and the RCS 200 reduces the speed ratio e by a predetermined ratio (△e) and shifts down according to the vehicle speed. Realize.

In the device of the present invention, the downshift operation is performed by suddenly pressing the accelerator in any range of the vehicle speed V, and as a result, the downshift is performed appropriately at an appropriately high engine speed _N. Accordingly, high torque can be easily obtained on the continuously variable transmission output shaft. Here, the kickdown valve 140
is the valve element 151 of the direct compensation valve 150
modulator valve 190
A predetermined downshift is performed by complementary decreasing control of the vehicle speed response pressure P _G ″ on the opposite side of the valve element 151 of the compensation valve through the compensating valve.

As mentioned above, the kickdown valve 140 is set to operate at the throttle opening θ=7/8, as an example, and as a result, the line segments n and 7 at θ=7/8 in the shift characteristic diagram in FIG. Line segment O with /8<θ≦8/8 (at low speed), line segment r with θ=7/8 and 7/8<θ
This gives a line segment s of ≦8/8 (at high speed), and realizes continuously variable downshifting in the shaded area B1. The vertical part consisting of line segments o and s is shown in Fig. 8 7/
It corresponds to P _TH = _PL when 8≦θ≦8/8. Further, the widths of the horizontal line segments n and r are generated in accordance with the step l at θ=7/8 in FIG. 8 and the area ratio of the piston portion 191b of the spool 190 to the same 191a. This step l is the valve element 16 of the throttle valve.
1,162 and the setting of the spring ₁₆₃ , and the opposing acting force of the valve port c (pressure receiving area of the piston portion 161a x line pressure P _L )
It can be set as appropriate in relation to.

As an example, if you step on the accelerator at point h (θ=6/8) in area B in Fig. 10,
The kick-down valve 140 works and L moves to point i in the fixed area A, and as it accelerates, it reaches the intersection with the line segment s,
Once again, the vehicle speed is increased through continuously variable speed within the B1 area, and the spool 1 of the modulator valve 190
91 moves to the left due to the increased P _G ', crosses the line segment s and reaches point j in the H region. in this way,
Kickdown valve 140 and modulator valve 190
Due to the cooperation of By fixing it to =L, the maximum torque can be obtained at the transmission output shaft, and furthermore, the continuously variable transmission region B1 shown in the figure is formed as the hatched area where the continuously variable transmission region B is expanded toward the high speed side.

Thus, the line segments m, n, and o forming the boundaries between the continuously variable speed region B and the fixed speed ratio region A in FIG. 10 are achieved by the cooperation of the modulator valve 190 and the kickdown valve 140. However, as an embodiment of the present invention, it is possible to add and use only the modulator valve 190 and the kickdown valve 140 independently, and the line segment m in FIG. 2-point line n, o
shows the effect when the kickdown valve 140 is added. In addition, when only the kickdown valve 140 is additionally used without the modulator valve 190, FIG. 11 shows a shift characteristic diagram corresponding to the case where V _MV =0.

The operation of the modulator valve 190 within the automatic transmission range B is as follows. That is, the engine rotational speed N _E (α
The relationship between the vehicle speed (V) and the torque T of the automatic transmission output shaft draws a parabola and decreases as N _E increases after reaching the maximum value. A virtual point is set before the balance point is reached, and the shift is performed by directly using the governor pressure _PG as the vehicle speed response pressure. In contrast, in the present invention, the governor pressure P _G , which is the conventional vehicle speed response pressure, can be further modulated as appropriate by the action of the modulator valve 190, and the setting of this shift point can be adjusted to the optimum engine rotational speed.
N _E (or optimum automatic transmission output torque T) is plotted to enable settings to be drawn to draw an optimum continuously variable shift line.

In particular, the boundary with the high speed ratio fixed region C (e=H) defined by the line segment q in FIG. 10 is set in accordance with the general requirements for transition to the maximum speed ratio e=H. Ru.

Firstly, from the relationship between engine rotational speed N _E and output torque, when the throttle opening θ is small, the engine output torque becomes less than the vehicle running resistance when the rotational speed N _E exceeds a certain value. The point where N _E is slightly smaller than that must be set as the limit for maintaining the specified speed ratio. Therefore, when the optimum shift point (e→H) is plotted, it becomes line segment q in FIG. Second, the engine noise is constant rotational speed N _E
The smaller the vehicle speed V is, the relatively larger it becomes. Therefore, when the vehicle speed is not high (V=medium speed, etc.), it is necessary to appropriately reduce the speed ratio e (automatically change the speed).

The shift signal at this optimum engine speed N _E is the output signal of the modulator valve 190.
As described above, the compensation valve 150 uses P _G '' as one input signal and the other input signal as the throttle pressure P _TH (indirectly responding to N _E ), which is the throttle opening response pressure _. It consists of a compensation valve 150 output signal pressure P _C obtained by regulating the proportional line pressure P _L .

The throttle pressure P _TH no-pressure region k (Fig. 8) corresponds to the rising line segment p (θ
= 0 to 2/8). That is, this no-pressure area k is
At low throttle opening (N _E small), constant vehicle speed V _k
In the following, the speed ratio e is kept relatively low so that it does not reach the H position, and torque shortage (knocking, etc.) does not occur.
In addition, this contributes to eliminating the influence of errors in the throttle pressure _PTH caused by difficulty in accurately detecting zero or minute positions of the accelerator opening. Within this throttle pressure-free region k, on the one hand, the engine is at an appropriate low rotational speed N _E , but on the other hand, the vehicle speed response pressure P _G '' is V = 0.
After being held at no pressure at ~V _MV (i.e., e=L fixed), the modulator valve output signal pressure P _G '' represented by the curve MV in FIG. 9 is issued at V _MV V < V _K. Therefore, the compensation In the valve 150, the valve element 151 moves to the left and generates an output signal pressure P _C on the line P ₆₀ in response to the vehicle speed V (P _G ″), and the actuator 20 of the RCS 200 moves to the appropriate speed ratio e.
Activate 5. In this way, the throttle opening θ
Since the throttle pressure P _TH = 0 between = 0 and 2/8, the speed ratio upper limit position H is equal to the vehicle speed V (P _G ″) within this range.
Therefore, the first
It appears as a 0-figure line segment P.

In addition, in the region of 2/8θ<7/8 and VV _K ,
A line segment q that depends on the throttle pressure P _TH and the vehicle speed response pressure P _G ″ defines the lower limit boundary of the speed ratio e=H fixed region. However, in the present invention, the L position is treated as inactive and the explanation is omitted, but there is an advantage that this hold valve 130 can be additionally configured.

When the manual valve 130 is in the R (reverse) position, line pressure is applied to the line P ₃ through communication between ports c-f, the servo valve 220 is in the reverse (rightward) state, and the forward/reverse switching means 108 is moved via the forkshaft 223. is in the backward state. Also, the servo valve 22
0 port c-b communicates and engages the clutch 103.

On the other hand, line P ₁ governor valve 170, line P ₄₀ ,
Modulator valve output pressure P _G '' is applied to compensation valve port e via hold valve 180 and line P ₄₂ , but line P ₂ is pressureless and throttle pressure is applied to line P ₆₀ even though the throttle is open. Therefore, as the reverse vehicle speed V increases, the valve element 151 is pushed slightly to the left, ports c-d are communicated, and lines P ₆₀ and P ₂ are communicated.
_P2 is a manual valve that communicates with the drain X and has no pressure, and the RCS valve element retreats to the left end L position in accordance with the no pressure of _P60 . Thus, in the manual selection for reverse R, the speed ratio e is fixed to the lowest ratio L.

In the manual valve parking P position, port f is closed, no pressure is applied to line P ₁₀ , and clutch 10 is closed.
3 is in the released state, and line pressure P _L is applied to RCS, but line P ₆₀ is also unpressurized because line P ₂ is unpressurized, and the RCS actuator is in the L position. .

As described above in detail, the continuously variable transmission speed ratio control device of the present invention uses the hydraulic means generated by the opposing actions in the compensation valve of the hydraulic means responsive to the vehicle speed and the hydraulic means responsive to the throttle opening as a signal hydraulic pressure. By using this signal hydraulic pressure to actuate the valve element for actuating the actuator of the speed ratio control servo RCS against the opposing spring force, stepless control of the speed ratio e within the L-H range is achieved. Further, through the cooperation of the modulator valve 190 and the kick-down valve 140, a transmission characteristic diagram having a low speed ratio (L) fixed region, a continuously variable speed region, and a high speed ratio (H) fixed region is realized, and the throttle Each time the opening degree, vehicle speed gradually increases or decreases, or suddenly changes,
It has appropriate responsiveness.

In the present invention, the speed ratio control valve RCS is as follows:
Follow-up type actuators other than those used in the examples can be used. moreover,
Speed ratio changing means are not limited to mechanical ones.
The control means of the present invention can also be used for hydraulic types.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of the relationship between the continuously variable transmission speed ratio control device and the continuously variable transmission of the present invention, FIG. 2 is a hydraulic circuit diagram showing an embodiment of the present invention, and FIG. , Fig. 2 is an enlarged view of the speed ratio control servo, Fig. 4 is an enlarged view including the throttle valve, compensation valve, kickdown valve, modulator valve, and hold valve, and Fig. 5 is the operating state of the hydraulic circuit at the manual valve D position. Figure 6 shows the throttle pressure at the pressure regulating valve.
Figure 7, a pressure regulating valve characteristic diagram showing the relationship between P _TH and line pressure P _L (output pressure), shows the governor pressure P _G of the governor valve.
FIG. 8 is a characteristic diagram showing the relationship between the output signal and the hold valve output signal and the vehicle speed V, and FIG. 8 is a throttle valve characteristic diagram showing the relationship between the throttle opening of the throttle valve and the throttle pressure _PTH . FIG. 9 is a graph showing the relationship between the hold valve 180 output signal pressure P _G ′ (vehicle speed V) and the modulator valve 190 output signal pressure P _G ′, and FIG. 10 is a graph showing the relationship between the vehicle speed V and the throttle opening θ. Shift characteristic diagram FIG. 11 shows a shift characteristic diagram showing the case where only the low speed ratio fixed region A is defined by the modulator valve 190, as well as when the additional kickdown valve 140 is operated. In addition,
In the figure, the 1- to 2-digit numbers next to the ports indicate the hydraulic line code. Further, the thick lines in FIGS. 2 and 5 indicate hydraulic lines to which working pressure is applied. E...Engine, 101...Engine output shaft,
102...Main pump, 103...Clutch, 10
4...Continuously variable transmission, 108...Forward/reverse switching means, 110...Transmission output shaft, 120...Pressure regulating valve, 130...Manual valve, 140...Kickdown valve, 150...Compensation valve, 160... ...Throttle valve, 170...Governor valve, 180...Hold valve, 190...Modulator valve, 200...
...speed ratio control servo mechanism, 220...servo valve,
230...Relief valve.

Claims (1)

[Scope of Claims] 1. A speed ratio changing means, a line hydraulic means, a throttle opening response pressure generation means, and a vehicle speed response pressure generation means, and the speed ratio is controlled according to the throttle opening response pressure and the vehicle speed response pressure. A speed ratio control device for a continuously variable transmission for a vehicle includes a speed ratio control servo mechanism that continuously controls a speed ratio changing means by controlling a line hydraulic means by a valve element that operates according to an input signal pressure, and a predetermined throttle opening. valve means actuated by the pressure response pressure to produce a predetermined output signal pressure;
a modulator valve that is actuated by a vehicle speed response pressure that opposes the spring force and a predetermined output signal pressure of the valve means that acts additionally on the spring force to regulate the vehicle speed response pressure itself; and a compensation valve that regulates the pressure of the line hydraulic means by the throttle opening response pressure, and this pressure regulation itself acts against the output pressure to supply the input signal pressure of the speed ratio control servo mechanism, A speed ratio control device for a continuously variable transmission for a vehicle, characterized in that a predetermined output signal pressure of the valve means additionally acts on the compensation valve in opposition to the modulator valve output pressure. 2. The speed ratio control servo mechanism includes a valve element to which an input signal pressure is applied at one end against a backing spring, and an actuator that is operated by line hydraulic means to control the speed ratio changing means, and Claim 1: The element constitutes a control valve means for the hydraulic pressure of the actuator, and operates the actuator in the direction of increasing or decreasing the speed ratio each time in accordance with the input signal pressure to the valve element. The device described. 3. The compensation valve has a valve element to which the output pressure of the modulator valve as a vehicle speed response pressure is applied to one end and the throttle opening response pressure is applied to the opposite end, and the valve element is connected to the line hydraulic means. 2. The device according to claim 1, wherein the pressure is regulated and the pressure regulation itself acts on the valve element in opposition to the modulator valve output pressure. 4. The valve element of the compensation valve has a piston portion for additionally applying a predetermined output signal pressure of the valve means in opposition to the modulator valve output pressure. equipment. 5. Continuously variable transmission for a vehicle, which is equipped with speed ratio changing means, line hydraulic pressure means, throttle opening response pressure generation means, and vehicle speed response pressure generation means, and controls the speed ratio according to throttle opening response pressure and vehicle speed response pressure. The speed ratio control device includes a speed ratio control servo mechanism that controls the speed ratio changing means by controlling the line hydraulic means by a valve element that operates according to input signal pressure, and a speed ratio control servo mechanism that controls the speed ratio changing means by controlling the line hydraulic means by a valve element that operates according to input signal pressure, and a speed ratio control servo mechanism that operates according to a predetermined throttle opening response pressure and A valve means that generates an output signal pressure, a vehicle speed response pressure that opposes a spring force, and a predetermined output signal pressure of the valve means that acts additionally on the spring force to regulate the vehicle speed response pressure itself and generate a predetermined vehicle speed response pressure. A modulator valve that keeps the output signal at no pressure until reaching the output pressure, and a line hydraulic means is pressure regulated by the output pressure of the modulator valve and the throttle opening response pressure that opposes this, and this pressure regulation itself becomes the output pressure of the modulator valve. a compensation valve acting in opposition to supply an input signal pressure of the speed ratio control servomechanism, wherein a predetermined output signal pressure of the valve means is applied to the compensation valve in opposition to the modulator valve output pressure. A speed ratio control device for a continuously variable transmission for a vehicle, characterized in that the speed ratio control servo mechanism is fixed at the lowest speed ratio until a predetermined vehicle speed is reached, and a speed ratio fixing region is formed on the low vehicle speed side. . 6. The apparatus according to claim 5, wherein said valve means is operated by a pressure that responds to a predetermined throttle opening response pressure near a maximum throttle opening. 7. The predetermined signal pressure generated by the actuation of the valve means acts on the modulator valve against the vehicle speed response pressure and at the same time acts on the compensation valve against the modulator valve output pressure, in each case the lowest speed ratio of the speed ratios. 7. The device according to claim 5 or 6, wherein the fixed area is expanded in the direction of increasing vehicle speed. 8. The apparatus according to any one of claims 5 to 7, wherein the predetermined signal pressure of the valve means comprises line hydraulic means.