JPH023072B2 - - 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 gear ratio control of a continuously variable transmission has been carried out using a flow rate control valve in which the cam deviation 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 in an opposing relationship. 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 by increasing the cam deflection. 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 that was used, continuously variable speed over a wide range was realized.

Furthermore, especially in mechanical continuously variable transmissions, the operation of the speed ratio control actuator requires an extremely large force due to the reaction force of the torque transmitting part. Therefore, the speed ratio control actuator is generally controlled through 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, the throttle valve response pressure and the vehicle speed response pressure are accompanied by the generation of low and high oil pressures, so it is not desirable to directly operate the speed ratio control actuator. Additionally, when the vehicle suddenly falls into a small depression while the vehicle is running, the reaction force is transmitted from the wheel side through the transmission mechanism to the speed ratio control actuator, causing unnecessary speed ratio changes. You may try to do so.

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. )
is used to operate the speed ratio control actuator. Furthermore, the present invention provides a compact control device that uses the throttle valve response pressure and vehicle speed response pressure to constantly use high-pressure line hydraulic pressure as hydraulic pressure, which has a low pressure section. .

The present invention further provides that the speed ratio is minimized as necessary in order to obtain maximum torque as output from the output shaft of the continuously variable transmission during high loads such as starting, sudden acceleration, and climbing up a slope. It is an object of the present invention to provide a speed ratio control device for a continuously variable transmission that makes it possible to set or move a fixed value range and to set or move a speed ratio maximum value fixed range. At this time, the continuously variable speed ratio region is set or moved between the low speed ratio fixed region and the high speed ratio fixed region as necessary, and is adjusted to match the engine rotational speed N _E at each time under a predetermined speed. We aim to provide a device that enables continuously variable transmission.

A first device provided by the present invention includes a speed ratio changing means, a line oil pressure generating means, a throttle opening responsive pressure generating means, a manually operated response valve, and a vehicle speed responsive pressure generating means, and includes a throttle opening responsive pressure generating means. In a speed ratio control device for a continuously variable transmission for a vehicle that controls a speed ratio according to a vehicle speed response pressure and a vehicle speed response pressure, a speed ratio changing means is provided by controlling a line oil pressure with a valve element that operates according to an input signal pressure. a speed ratio control servo mechanism that controls the speed ratio control servo mechanism, and a kickdown valve that is operated by the throttle opening response pressure from the throttle opening response pressure generating means and that regulates the line oil pressure from the manually operated response valve to generate an output signal pressure. When the line oil pressure is applied from the manually operated response valve, the first vehicle speed response pressure from the vehicle speed response pressure generating means is regulated and output as the second vehicle speed response pressure, and when the line oil pressure is not applied, the first vehicle speed response pressure is output as the second vehicle speed response pressure. a hold valve that conducts the pressure as it is and outputs it as a second vehicle speed response pressure;
The second vehicle speed response pressure is actuated and input by the second vehicle speed response pressure inputted to counteract the spring force and the output signal pressure from the kickdown valve inputted to act additionally on the spring force. A modulator valve that regulates and outputs its own pressure, and a line hydraulic pressure that is input to counteract the output pressure is regulated by the output pressure of this modulator valve and a throttle opening response pressure that is input to counteract the output pressure. and a compensation valve that outputs as the input signal pressure of the speed ratio control servo mechanism, and the output signal pressure of the down valve is additionally acted on the compensation valve so as to oppose the output pressure of the modulator valve. It is said that

The second device also includes a speed ratio changing means, a line oil pressure generating means, a throttle opening response pressure generating means, a manual operation response valve, and a vehicle speed response pressure generating means, and the second device responds to the throttle opening response pressure and the vehicle speed response pressure. In a speed ratio control device for a continuously variable transmission for a vehicle, the speed ratio control servo controls the speed ratio changing means by controlling line oil pressure with a valve element that operates according to input signal pressure. mechanism, a kick-down valve that is activated by the throttle opening response pressure from the throttle opening response pressure generating means, regulates the line oil pressure from the manually operated response valve and generates an output signal pressure, and a vehicle speed responsive pressure generating means. When the line oil pressure is applied from the manually operated response valve, the first vehicle speed response pressure is regulated and output as the second vehicle speed response pressure, and when the line oil pressure is not applied, the first vehicle speed response pressure is adjusted and output as the second vehicle speed response pressure.
a hold valve that conducts the vehicle speed response pressure as it is and outputs it as a second vehicle speed response pressure; the second vehicle speed response pressure that is input to counteract the spring force; and a kickdown that is input to act additionally on the spring force. a modulator valve that is actuated by the output signal pressure from the valve to regulate and output the input second vehicle speed response pressure itself, and to keep the output signal at no pressure until the second vehicle speed response pressure reaches a predetermined value; The input signal pressure of the speed ratio control servo mechanism is adjusted by regulating the line oil pressure input to counteract the output pressure by the output pressure of the modulator valve and the throttle opening response pressure input to counteract the output pressure. and a compensation valve that outputs an output signal as shown in FIG. A speed ratio control servo mechanism is fixed to form a minimum speed ratio fixed region on a low vehicle speed side, and the minimum speed ratio fixed region is expanded each time to a high vehicle speed side by applying the line oil pressure to the hold valve. It is characterized by

Such a device is used each time when starting, sudden or high acceleration, high load (requires high output) such as climbing a slope, or when applying engine braking (during high-speed driving, descending a slope, etc.). This is based on the fact that it is essential for safe and efficient driving to extend the necessary low speed ratio range to the high speed side or to additionally provide downshifting at medium and high speeds in continuously variable transmissions. be.

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
20 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 (RCS) 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 pumps 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. Line P ₉₁ connects 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 discharge amount of the main pump 102 and the line pressure P _L increase, a spring is applied to the piston of port f to the left. 123
A force acts against this, pushing the valve element 121 to the left and opening ports b and d. ports b, d
Upon opening, oil flows to lines P ₉₅ and P ₉₁ , respectively, and the line pressure _PL drops and is 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 it is usually the same as 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 increases 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.

A manual valve (manual operation response valve) 130 has a valve element 131 equipped with a manual switching knob 131a on a body having, from the left, a drain port and the lockup L so as to be shiftable to each position. Line P ₁ is connected to port c, and ports a and b are connected to ports a and b of servo valve 220 via line P ₂ .
d, are connected to port b of the throttle valve 160, port a of the kickdown valve 140, and port a of the compensation valve 150, 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 the manual valve 130 are line
Connected via _P4 to port d of hold valve 180 for additional control (lockup) of governor pressure _P
can be done. 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 1 via line P ₁₀ .
Connect to the actuating means of 03.

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 communicate with port c, and line P ₁ -manual valve 130-
Line pressure P _L is applied to ports a and d of servo valve 220 via line P ₂ , and automatic start clutch 10
3 is line pressure P _L via port a-b-line P ₁₀
is applied to the clutch, and the line pressure P _L applied to the other port d acts additionally on the spring 222 pressure to secure the piston 221 in the 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, ports c-d are communicated and line pressure P _L is supplied to clutch 103 via line P ₁₀ .
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 O, 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.

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).

As the output signal pressure of the compensation valve 150, the line P ₆₀ from port d is connected to the speed ratio control servo (RCS) 200.
Connect to port a of

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 each form an opposing piston surface that is operated by the line _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 further has a valve element 151 to which pressure is applied to the drain port x and the line pressure input port c to regulate the line pressure P _L and output 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), P _K = P _L from line P ₅ to port b.
A signal pressure of
P _C is expressed by equation (4) (for simplicity, it is assumed that the cross-sectional area of the piston portion 151a of the valve element 151=the cross-sectional area _A1 of the valve element 152).
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. . A port b is formed in the body 203 so as to open into a second chamber C formed between both pistons 206a and 206b, and the port b is connected to the discharge side of the main pump 102 through a line _P1 to receive line pressure P _L. Granted. An arm 210 having a link hole 211 extends from the cylinder mouth end of the actuator 205, and is connected to a speed ratio changing means of a continuously variable transmission (for example, a spherical conduction speed ratio changing means shown in FIG. 1) via a link means not shown. The actuator 205 is connected to the means 104) and exerts a braking action on the speed ratio changing means by the back and forth movement between L and H of the actuator 205.

piston 206a of actuator 205,
206b has a predetermined effective cross-sectional area ratio, and a port f communicating with the center hole 207 is opened in the second chamber C between both pistons 206a and 206b, and the hole bottom of the center hole 207 (arm end side) It has a drain 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 part (spring receiving part) 201b having an open end slidably accommodated in the actuator center hole 207 at the opposite end thereof, and an intermediate point thereof. Small holes 212a, 212 are provided in the middle part in the axial direction.
The small hole 212a communicates between ports c and e, and the port 212b communicates between the hollow part of the spring receiving portion 201b and the intermediate port d. In the state shown in FIG. 3, the valve element 20 is connected between ports e and f.
1 is pressed to the right, the port d is placed in open communication, and the port d is arranged to open when the valve element 201 retreats to the left or the actuator 205 moves to the right. Port c opens to the spring 209 storage cylinder 204b in the state shown in FIG. 3, and is spaced at a predetermined distance from port d so that it closes when the valve element 201 is further pressed to the right by a predetermined amount after port d is closed. will be arranged.

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.
The actuator 205 flows through the a-port c into the first chamber C formed on the opposite side of the second chamber C with respect to the piston 206b in the cylinder 240b, 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, ports fe are closed,
Port d opens and pressure oil is released from the left cylinder 204b to the small hole 212b, center hole 207, and drain port The pressing force due to the line pressure P _L corresponding to the pressure receiving area difference (effective pressure receiving area) between 206b and 206a becomes equal, and the movement of the actuator to the right stops. The reciprocating motion 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 is actuated by a predetermined throttle opening response pressure to generate a predetermined output signal pressure, and is connected to drain port x, port a,
b, a body having a drain port x ₂ and a port c sequentially, the port c end is a piston part 141c, the port b-x ₂ communication part 141a is in the middle, and the left drain port part x ₁ is a spool supported by a spring 142 141
It consists of . Port a communicates via line P ₂ to manual valve 130 ports a, b, port b communicates via line P ₅ to compensation valve port b and modulator valve port b, and port c communicates via line P ₅₀ . Communicate with throttle valve ports a and c. Port c no pressure between ports b and x ₂ (P _TH = 0)
When the throttle pressure P TH is constant, the spring 142 is connected to the pressure P _TH corresponding to a constant throttle opening, for example, 7/8 _.
(7/8), the spool 141 is adjusted to move to the left. In other words, throttle opening 7/8 to 8/8
It operates only when the throttle is fully open, and this is set to correspond to the throttle opening during kickdown. Ports a and b are communicated by the left movement of the spool 141, and at the same time drain port x ₂ (port b and x ₂
) is closed. Therefore, when the throttle opening is 7/8 to fully open, the kick-down valve output pressure P _K is applied to line _P5 .
＝P _L occurs, and when the throttle opening is less than 0 to 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 valve P _G is connected to the compensation valve.
A signal pressure P G '' is further modulated from the signal pressure (second vehicle speed response pressure) P _{G ′} whose pressure is controlled by the hold valve 180 .

The force of the spring 192 is the force acting on the piston part 191a due to the input pressure P _G ' of line P ₄₁ to port d at a 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 surface 181d of the piston portion 181c is disposed in the port d. Ports a and c are line
It is connected to the governor valve port b via P ₄₀ and receives the first vehicle speed response pressure _PG as an input signal pressure. Port d is connected to ports d and e of manual valve 130 via line _P4 , and line pressure P _L is applied to manual valve shift knob 131a at L (lockup) and R (reverse) positions. When line pressure P _L is applied to port d, the spool 181 moves to the left to control port c between a closed state (closed between ports b and c, and at the same time communication between ports b and x ₂ ) and a partially open state, When line pressure P _L is above a certain value, port c is closed. This port d is a manual valve N
(neutral), D (drive) position has no pressure, and D
In this position, the spool 181 receives the leftward force of the spring 182 and the force acting on the piston portion 181a (minus 181c) of the output pressure P _G ' in port b which opposes the force acting on the governor pressure P _G on the piston portion 181a (port a). According to equilibrium, port c (between c and b) is held appropriately open, with a signal pressure equal to the input pressure P _G
P _G ′ via line P ₄₁ to modulator valve 190
Send to. Therefore, as far as the D position of the manual valve is concerned, the hold valve 180 does not participate in any special control operation.

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 done in accordance with the pressure applied to each piston portion 181a, 181c of 81 and the acting force of 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.

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

P _G ′=1/S ₁ −S ₃ {(S ₁ −S ₂ )P _G +−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 the pressure regulating valve 120 . Line pressure P _L is also the throttle pressure corresponding to the throttle opening.
By applying _PTH 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
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 this time, port -e opens for communication, and the air flows into the left cylinder 204b through the small hole 212a and port c, and the pressure thereof becomes 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, the port d opens and communicates with the drain X, so the pressure inside the left cylinder 204b drops rapidly, resulting in the initial pressure relationship (left cylinder low)
, and the actuator is moved to the left (L direction) again.
However, it 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 generates the pressure P _C in the line P _60. At this time, the vehicle speed V _MV
defines the vertical line segment m in FIG. 10, and furthermore, V>
When it reaches V _MV , it enters 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. Therefore, the valve element 201 moves slightly to the right (in the H direction) against the spring 208. At this time, RCS port -e is connected, and the line pressure P _L is increased to the left cylinder 20.
4b and slightly presses the actuator in the H direction. Due to this H direction movement, port d
-X is connected and the movement in the H direction is stopped there.

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 vehicle's ellipse. 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 1
Drain X of 50 opens, further lowering P _C ,
Similarly, RCS valve element 201
The speed ratio gradually decreases as the actuator 205 moves backward in the L direction and then the actuator 205 moves backward.

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 kickdown 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 _P5 becomes P _K =P _L. Line P ₅ communicates with port b of compensator valve 150 on the one hand and port b of modulator valve 190 on the other hand, and applies line pressure P _L respectively. First, in the compensation valve 150 port b, the rightward pressing force of P _L・A ₂ is applied to the piston part 151.
It acts on a. 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 vehicle speed V, and as a result, downshifting is performed appropriately at an appropriately high engine speed NE, and as needed. Torque can be easily obtained at 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
It gives a line segment s of ≦8/8 (at high speed), and realizes a downshift by continuously variable speed in the shaded area B1. The vertical portion consisting of line segments O and s corresponds to P _TH = _PL in FIG. 8 7/8≦θ≦8/8. In addition, the widths of the horizontal line segments n and r are the step l at θ=7/8 in FIG. 8 and the piston portion 191b of the spool 190.
This occurs in accordance with the area ratio of 191a to that of 191a.
This step l is the valve element 1 of the throttle valve.
It is basically defined by the spacing d ₂ between 61 and 162 and the setting of the spring 163, and the opposing acting force of the valve port c (pressure receiving area of the piston part 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 boundary 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, a shift characteristic diagram corresponding to the case where V _MV =0 in FIG. 11 is shown.

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 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 P as the vehicle speed response pressure. In contrast, in the present invention, the governor pressure P, which is the conventional vehicle speed response pressure, can be further appropriately modulated 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 (or the optimum automatic transmission output torque T). ) to plot the 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.

That is, first, 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 exceeds a certain value. The limit for maintaining a predetermined speed ratio must be set at a point where N is slightly smaller. When the optimum shift point (e→H) for this purpose 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 the zero or small position 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 without pressure at ~V _MV (i.e. e=L fixed), the curve MV in Figure 9 at V _MV V < Vk
Therefore, the valve element 151 in the compensation valve 150 moves to the left and outputs the output signal pressure P _C to the line P ₆₀ in response to the vehicle speed V (P _{G ″} ). actuator 2 of RCS200 at the appropriate speed ratio e.
Activate 05. In this way, since the throttle pressure P _TH = 0 during the throttle opening θ = 0 to 2/8, the speed ratio upper limit position H is equal to the vehicle speed V within this range.
(P _G ″), and thus appears as line segment P in Figure 10.

In addition, in the region of 2/8θ<7/8 and VVk,
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.

In the R (reverse) position of the manual valve 130, line pressure is applied to the line _P3 through communication between ports c-f, and the servo valve 220 enters the reverse (rightward) state and switches the forward/reverse switching means 108 via the forkshaft 223. Set the vehicle in reverse. Also, the servo valve 220
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 line P ₆₀ and line P ₂ are communicated. Line P ₂ is a manual valve and communicates with the drain. There is 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 at the lowest value L.

At the manual valve parking P position, port f is closed and no pressure is applied to line _P10 , causing clutch 1 to close.
03 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. .

Next, the operation of the hold valve will be explained in detail.

The spool 181 of the manual valve 130 operates according to equation (6). Now, while the vehicle is running, move the manual valve 130 from the D position to the L (lock up) position.
When in position, line pressure P _L is applied to port d via line P ₄ and exerts a leftward pushing force on spool 181 . On the other hand, port a via line P ₄₀
A first vehicle speed response pressure (governor pressure) P _G is applied to the spring 182 to apply a leftward pressing force to the spool 181.
It is also affecting. As a result, the line pressure P _L of the line P ₄ moves the spool 181 of the hold valve 180 to the left against the spring 182 and the pushing force of P _G , acts in the direction of closing the port c of the same valve 180, and the hold valve output pressure It works in the direction of lowering P _G ′. (Furthermore, the output pressure P _G ″ of the modulator valve 190 decreases, and the valve element 151 of the compensation valve 150
(for right-hand operation). As a result, manual valve 1
By manually operating the manual valve 130 to the L position, the hold valve output pressure P _G ′, which was P _G ′ = P _G at the D position of No. 30, becomes equal to the line pressure P _L and the governor pressure P which is the first vehicle speed response pressure. Pressure regulation is controlled according to the opposing action with _G.

This decreased hold valve 130 output signal pressure
P _G ' constitutes a second vehicle speed response pressure, which is further adjusted by the modulator valve 190 to the curve shown in FIG.
The output signal pressure P _G '' represented by MV' acts on the piston portion 151b of the valve element 151 of the compensation valve 150.

On the other hand, if the throttle opening θ is constant (however, 0θ7/8) during this period, the compensation valve 150
The valve element 151 has a descending amount of P _G ″△
It moves to the right in response to P _G '', and correspondingly reduces the output signal pressure P _C of the same valve, making it unpressurized when the vehicle speed V is small (port d-X communication).

The decrease in signal pressure P _C causes the valve element 201 of the RCS 200 to move to the left, causing the RCS actuator 205 to move to the left (move in the L direction) by a considerable amount. Therefore, at a constant vehicle speed V ₁ , manual valve D→
When manual operation is performed to the L position, the predetermined speed ratio e ₁ at the D position is an amount (△e ₁ ) corresponding to the speed V ₁ at that time.
(However, when θ=constant). the result,
The predetermined vehicle speed _VMV , which forms the boundary between the low speed ratio (L) fixed area A and the continuously variable speed area B, has shifted further to the high speed side.
V' _MV , and the speed ratio L fixed area A moves to the high speed side. (Figure 12). Also, when you step on the accelerator and the throttle opening becomes 7/8θ8/8,
Due to the operation of the kickdown valve 140, the line segment o moves toward the high speed side to the position o', and the speed ratio L fixed region is expanded.

As a result, for example, the speed ratio _e1 , which was within the continuously variable speed region B at the manual valve D position, falls within the speed ratio (L) fixed region A, which is expanded toward the high speed side when the vehicle speed V is medium speed. If θ=constant, the vehicle will be accelerated.
When the vehicle speed V is high and within region B, the speed ratio
e ₁ is decreased by a predetermined amount (Δe ₁ ) and shifted down, and assuming θ=constant, the vehicle is accelerated. Furthermore, when V is large and falls within the maximum speed ratio (H) fixed region C, it belongs to region B, which has moved to the high speed side, and is also shifted down by a predetermined amount (Δe ₁ ). Thus,
High torque for sudden acceleration etc. can be obtained as appropriate depending on the vehicle speed at that time.

Note that if θ=0, the engine brake will be downshifted in accordance with the vehicle speed V at that time, and the engine brake will work effectively. This is when the brake is applied.
This is advantageous when going down a slope.

As mentioned above, the hold valve 130 output signal pressure
Although P _G ' is controlled depending on the throttle opening θ via the line pressure _PL , next we will discuss the operation associated with changes in the throttle opening θ.

That is, in FIG. 7, the hold valve output signal pressure
P _G ′ is represented by the curve HV, and this curve HV
is not fixed, and the amount of decrease △ _PG from the hold valve input signal pressure (governor pressure _P
(maximum θ) and curve _PG . Therefore, the amount of drop (ΔP _C ) in the output signal pressure P _C of the modulator valve 150 changes depending not only on the vehicle speed V at that time but also on the increase in the throttle opening θ. This ΔP _C defines the downshift width.

Thus, when the hold valve 180 is not operated, for example, A in the shift characteristic diagram shown in FIG.
The boundary line segments m-n-o and p-q-r-s between the areas -B and B-C are respectively m ₁ ′-m ₂ ′-n′-θ in FIG. 12 when the hold valve is activated. ′ and p′−q′−r′−
s′. In particular, m and q each tilt toward the high speed region as the throttle opening θ increases. The line segment m is divided into a rising line segment m ₁ ′ and an inclined line segment m ₂ ′, and m ₁ ′ corresponds to the no-pressure area k between 0θ2/8 of the throttle pressure P _TH shown in Fig. 8. It is something. Also, horizontal line segment n′,
r′ also increases in accordance with the throttle opening (θ=7/8).

In FIG. 12, the movement widths of m→m ₁ ' and p→p' are defined by the design of each part of the hold valve 180, that is, by the setting of each term on the right side of equation (6).

Thus, the slopes of line segments m ₂ ' and q' and the elongation rates of line segments n' and r' are determined by the relationship (slope) of line pressure P _L with throttle opening θ and the relationship (slope) of line pressure P _L with throttle opening θ. It also depends on the slope etc. Note that from equation (6) it can be seen that an increase in line pressure P _L causes a decrease in hold valve output pressure P _G '.

In this embodiment, as shown in FIG. 6, the line pressure P _L , which increases in accordance with the throttle pressure P _TH , is used as the input signal for the hold valve 180. N _E
In many cases, high torque is required for starting, sudden acceleration, climbing hills, heavy loads, etc. In such cases, it is preferable to keep the speed ratio e as relatively low as possible. be. but,
It is not always essential to make this line pressure P _L dependent on the throttle pressure P _TH . When line pressure P _L is not increased depending on throttle pressure P _TH ,
When the hold valve 180 is in operation, the shift characteristic diagram takes a shape in which region B in FIG. 10 is shifted to the right (high speed side) by a predetermined amount.

Next, the vehicle starts from a state where the speed ratio is fixed within region A as a result of the manual valve D→L position operation. Assuming that θ=a constant intermediate value, the vehicle is accelerated and gradually reaches P _G while maintaining the speed ratio e=L position.
increases, then the P _G acting force at port a and spring 1
The resultant force of 82 is the pressing force of line pressure P _L (port d)
overcoming it. At this point, the spool 181 moves slightly to the right, communicates between ports c and d, and outputs a regulated output pressure (second vehicle speed response pressure) P _G ', and this P _G ' is transmitted through the modulator valve 190. Pressure regulation controlled,
P _G '' (curve MV' in Figure 9), which acts on the compensation valve 150, increases the pressureless P _C , and enters the continuously variable speed region B. Here, the speed ratio e is L-H.
In the meantime, as the vehicle speed increases, the speed increases continuously, and when V further increases, it is fixed at e=H and enters the C region.

At this time, when the throttle opening degree θ=7/8 to 8/8, the area boundary changes as shown in FIG. 12.

In the present invention, a follow-up type actuator other than the one used in the embodiment can be used as the speed ratio control valve RCS.
Furthermore, the control means of the present invention can be used not only for mechanical speed ratio changing means but also for hydraulic type ones.

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. At the same time, by the cooperation of the modulator valve 190 and the kickdown valve 140, the low speed ratio (L)
This is realized as a transmission characteristic diagram that has a fixed region, a continuously variable transmission region, and a high speed ratio (H) fixed region.Furthermore, the L fixed region, the L fixed region, and
It expands the continuously variable transmission range toward higher speeds and provides an effective downshift function according to vehicle speed, effectively realizing various functions essential for vehicle operation.

[Brief explanation of drawings]

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. 6 is a pressure regulating valve characteristic diagram showing the relationship between the throttle pressure (throttle opening response pressure) P _TH and line pressure (line hydraulic means) P _L in the pressure regulating valve,
FIG. 7 is a characteristic diagram showing the relationship between the hold valve output signal (second vehicle speed response pressure) P _G ' and the vehicle speed V (however,
Curve _PG shows the governor pressure (first vehicle speed response pressure), and FIG. 8 shows 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 vehicle speed V and modulator valve 190 output signal pressure _P ), FIG. 11 shows a shift characteristic diagram showing the case where only the low speed ratio fixed area A is defined by the modulator valve 190, together with the case when the additional kickdown valve 140 is activated. FIG. 12 shows the graph when the hold valve is activated. FIG. 1 shows a transmission characteristic diagram in FIG. 1. The one- to two-digit numbers next to the ports in the figure indicate hydraulic line codes. 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. Comprising a speed ratio changing means, a line oil pressure generating means, a throttle opening response pressure generating means, a manual operation response valve, and a vehicle speed response pressure generating means, which responds to the throttle opening response pressure and the vehicle speed response pressure. In a speed ratio control device for a continuously variable transmission for a vehicle, the speed ratio control servo controls the speed ratio changing means by controlling line oil pressure with a valve element that operates according to input signal pressure. a kickdown valve that is operated by the throttle opening response pressure from the throttle opening response pressure generating means and that regulates the line oil pressure from the manually operated response valve to generate an output signal pressure;
When line oil pressure is applied from the manually operated response valve, the first vehicle speed response pressure from the vehicle speed response pressure generating means is regulated and output as the second vehicle speed response pressure, and when no line oil pressure is applied, the first vehicle speed response pressure is output as the first vehicle speed response pressure. a hold valve that conducts as it is and outputs it as a second vehicle speed response pressure, a second vehicle speed response pressure that is inputted to counteract the spring force, and a kickdown valve that is inputted to act additionally on the spring force. a modulator valve that is actuated by the output signal pressure to regulate and output the input second vehicle speed response pressure itself; and a throttle opening response pressure that is input to counteract the output pressure of the modulator valve. Therefore, the output signal pressure of the kickdown valve is provided with a compensation valve that regulates the input line oil pressure so as to counteract the output pressure and outputs it as the input signal pressure of the speed ratio control servo mechanism, and the output signal pressure of the kickdown valve is applied to the compensation valve. A speed ratio control device for a continuously variable transmission for a vehicle, characterized in that the device is additionally operated to counteract the output pressure of a valve. 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 pressure 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, in which the second vehicle speed response pressure is regulated, is applied to one end and to which the throttle opening response pressure is applied in opposition to the opposite end, 2. The apparatus of claim 1, wherein the element regulates line oil pressure and the regulated line oil pressure acts on the valve element to counteract the output pressure of the modulator valve. 4. The device according to claim 3, wherein the valve element of the compensation valve has a piston portion to which the output signal pressure of the kick-down valve is additionally applied to counteract the output pressure of the modulator valve. 5. The hold valve has a spool that receives a back spring force and a first vehicle speed response pressure acting in opposition thereto, and a line hydraulic pressure is applied in a direction opposite to the first vehicle speed response pressure. 2. The device according to claim 1, wherein the first vehicle speed response pressure is controlled to be depressurized or depressurized when the line oil pressure is applied. 6. The device according to any one of claims 1 to 5, wherein the line hydraulic pressure changes in accordance with the throttle opening. 7. Comprising a speed ratio changing means, a line oil pressure generating means, a throttle opening response pressure generating means, a manual operation response valve, and a vehicle speed response pressure generating means, and controlling the speed ratio 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 controls a speed ratio changing means by controlling line oil pressure with a valve element that operates according to input signal pressure, and a throttle opening. a kick-down valve that is activated by the throttle opening response pressure from the response pressure generating means, regulates the line oil pressure from the manually operated response valve, and generates an output signal pressure;
When line oil pressure is applied from the manually operated response valve, the first vehicle speed response pressure from the vehicle speed response pressure generating means is regulated and output as the second vehicle speed response pressure, and when no line oil pressure is applied, the first vehicle speed response pressure is output as the first vehicle speed response pressure. a hold valve that conducts as it is and outputs it as a second vehicle speed response pressure, a second vehicle speed response pressure that is inputted to counteract the spring force, and a kickdown valve that is inputted to act additionally on the spring force. a modulator valve that is actuated by the output signal pressure to regulate and output the input second vehicle speed response pressure itself and makes the output signal pressureless until the second vehicle speed response pressure reaches a predetermined value; and the modulator. The line hydraulic pressure input to counteract the output pressure is regulated by the output pressure of the valve and the throttle opening response pressure input to counteract the output pressure, and outputted as the input signal pressure of the speed ratio control servo mechanism. and a compensation valve, the output signal pressure of the kickdown valve additionally acts on the compensation valve to counteract the output pressure of the modulator valve, and the speed ratio is set to the minimum speed ratio until the vehicle speed reaches a predetermined value. The control servo mechanism is fixed to form a minimum speed ratio fixed region on the low vehicle speed side, and the minimum speed ratio fixed region is expanded each time to the high vehicle speed side by applying the line oil pressure to the hold valve. A speed ratio control device for a continuously variable transmission for vehicles. 8. The device according to claim 7, wherein the kickdown valve is operated by a pressure that responds to a predetermined throttle opening response pressure near a maximum throttle opening. 9. The output signal pressure generated by the operation of the kickdown valve acts on the modulator valve to counteract the second vehicle speed response pressure and simultaneously acts on the compensation valve to counteract the output pressure of the modulator valve, each time increasing the speed ratio. 9. The device according to claim 7 or 8, wherein the lowest speed ratio fixed region of the vehicle is expanded in the direction of increasing vehicle speed. 10. The device according to claim 7 or 9, wherein the output signal pressure of the kickdown valve is generated by regulating line oil pressure. 11. The device according to claim 7, wherein the hold valve controls the first vehicle speed response pressure to be depressurized or depressurized when line oil pressure is applied. 12. The device according to claim 7, wherein the hold valve outputs a pressure equal to the first vehicle speed response pressure as the second vehicle speed response pressure when the line hydraulic pressure is not applied. 13. Claims 7, 10 to 12, wherein the line hydraulic pressure changes in accordance with the throttle opening degree.
Apparatus described in section. 14 The manual operation response valve has a D position and an L position, and in the D position, line oil pressure is not supplied to the hold valve, and the minimum speed ratio fixed region, the variable speed region, and the maximum speed ratio fixed region are sequentially set from the low vehicle speed side. In the L position, line oil pressure is supplied to the hold valve to expand the minimum speed ratio fixed region and the variable speed region to the high vehicle speed side each time according to the vehicle speed. 8. The device according to claim 7 for moving. 15. The device according to claim 14, wherein the manually operated response valve expands or moves the lowest speed ratio fixed region and the continuously variable speed region toward the higher vehicle speed side each time in the L position depending on the vehicle speed and throttle opening.