JPH10246317A - Oil pressure control device for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the oil pressure required for quick down-shift operation of a continuously variable transmission by regulating the flowing-out of oil from a line pressure oil path to a secondary pressure oil path when quick down- shift operation by quick braking, etc., is required, and thereby ensuring the pressure required for a torque converter with a lock-up. SOLUTION: When a direct clutch is in a state of engagement during forward travel of a vehicle, the engaging pressure of the clutch is supplied to a control oil chamber L, and a by-pass control valve 97 is in a right half-position to connect a line pressure oil path (h) and a secondary pressure oil path (p) through an orifice 111. When a continuously variable transmission is quickly speed- changed by quick brake operation, etc., the direct clutch is declutched, the engaging pressure acting on the control oil chamber L is released, the control oil pressure from a linear solenoid valve for speed changing acts on a control oil chamber K, and the valve 97 is switched to the right half-position to cut off the connection of the line pressure oil path (h) and the secondary pressure oil path (p).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission used in a vehicle, and more particularly, to a hydraulic control of a continuously variable transmission having a fluid transmission with a lock-up clutch and a belt-type continuously variable transmission. Related to the device.

[0002]

2. Description of the Related Art In general, a hydraulic circuit of an automatic transmission having a torque converter with a lock-up as a starting device includes:
The orifice connects the line pressure oil passage supplied to the hydraulic servo for the friction engagement element, which switches the transmission path to change the speed, with the secondary pressure oil passage supplied to the torque converter. When the discharge amount of the pump is small and the secondary pressure is insufficient, the secondary pressure is secured by replenishment from the line pressure oil passage, and the release pressure of the lock-up clutch is maintained. This prevents the lock-up clutch from being dragged due to insufficient lock-up clutch release pressure during idling or the like, thereby preventing the engine from stopping.

[0003]

When the hydraulic circuit for an automatic transmission described above is applied to a continuously variable transmission having a torque converter with a lock-up clutch, the continuously variable transmission is
In particular, when a downshift is performed quickly with a brake or the like, the pulley ratio suddenly moves toward the underdrive (U / D) side, so it is necessary to increase the supply pressure for changing the pulley ratio from the line pressure oil passage.

However, in the above hydraulic circuit, when the discharge amount of the oil pump during idling or the like does not increase to the set pressure due to a small amount, the flow of the primary regulator valve to the secondary pressure oil passage is greatly reduced. Due to the communication between the oil passage and the secondary pressure oil passage, a flow corresponding to the differential pressure between the line pressure and the secondary pressure flows through the secondary pressure oil passage, so that the flow rate of the line pressure oil passage cannot be sufficiently secured, There is a concern that the quick downshift operation required for the continuously variable transmission may be hindered.

It is also conceivable to increase the discharge capacity of the oil pump so that the oil flow does not become insufficient. In this case, however, an increase in the discharge capacity of the oil pump results in an increase in the engine load. In such a case, the oil discharge amount becomes excessively large, which leads to a decrease in fuel efficiency.

Therefore, the present invention regulates the outflow from the line pressure oil passage to the secondary pressure oil passage when a quick downshift operation is required due to a sudden braking or the like, and the required pressure of the fluid transmission device with lock-up is controlled. It is also an object of the present invention to provide a hydraulic control device for a continuously variable transmission, which secures the required pressure for a rapid downshift operation while ensuring the above, and thereby solves the above-mentioned problems.

[0007]

According to the first aspect of the present invention, there is provided a continuously variable transmission (2) whose gear ratio can be changed by hydraulic pressure.
And a fluid transmission (6) interposed between the continuously variable transmission and the engine output shaft (10) and having a lock-up clutch (5). The discharge pressure of the pump (21) is adjusted by the line pressure adjusting means (72), and the adjusted line pressure (P _L ) is adjusted.
To the gear ratio changing means (92, 33, 3) of the continuously variable transmission.
5) the supply line pressure oil passage and (h), the line pressure by regulating in the secondary pressure regulating means (73), the fluid power transmission device a secondary pressure (P _S) whose pressure該調(2 ), A communication oil passage (Z) communicating the line pressure oil passage (h) and the secondary pressure oil passage (p), and a communication oil passage (Z) interposed in the communication oil passage. changing means for changing the amount of oil flowing through the communicating oil passage and (97, 97 _2, 97 _3), lying in the hydraulic control system of the continuously variable transmission, characterized in that comprises a.

According to a second aspect of the present invention, when the speed change ratio of the continuously variable transmission (2) is high, the changing means regulates the amount of oil flowing through the communication oil passage (Z). The hydraulic control device for a continuously variable transmission according to claim 1, wherein the hydraulic control device is changed to:

According to a third aspect of the present invention, in the control oil chamber (K), the changing means includes the speed ratio changing means (92).
When a control oil pressure is supplied from a shift linear solenoid valve (SLR) for controlling the speed, and the control oil pressure controls the speed ratio changing speed by the speed ratio changing means faster, the amount of oil flowing through the communication oil passage is regulated. _3. The hydraulic control device for a continuously variable transmission according to claim ₂ , wherein said control valve is a switching valve (97, 97 ₂ , 97 ₃ ) for switching the operation.

The present invention according to claim 4 is interposed between the engine output shaft (10) and the continuously variable transmission (2), and is connected when the vehicle is traveling forward so that the power of the engine is transmitted to the drive wheels. An input clutch (C1) for transmitting is provided, and the changing means (97, 97 ₂ ) is provided with the input clutch (C1).
The hydraulic control device for a continuously variable transmission according to claim 1, wherein when the pressure is released, a change is made so as to regulate an amount of oil flowing through the communication oil passage.

According to a fifth aspect of the present invention, the changing means communicates the control oil chamber (L) with a hydraulic servo (C1) of the input clutch, and a hydraulic pressure applied to the hydraulic servo controls the input clutch. 5. The hydraulic control device for a continuously variable transmission according to claim 4, wherein said switching valve is a switching valve (97, 97 ₂ ) for switching the amount of oil flowing through said communication oil passage so as to be regulated when said oil passage is released.

According to a sixth aspect of the present invention, there is provided a transmission linear solenoid valve (SLR) for controlling the transmission ratio changing means (92), which is engaged when the vehicle is running to transmit engine power to driving wheels. A clutch (C1), wherein the changing means includes a spool (97a), a spring (97b) for urging the spool in one direction, and a hydraulic servo of the input clutch disposed on a side of the spring. A first control oil chamber (L) that communicates with (C1), and a second control oil chamber that is disposed on a side of the spool that opposes a spring and that is supplied with control oil pressure of the speed-changing linear solenoid valve (SLR). (K). The hydraulic control device for the continuously variable transmission according to claim 1, wherein the switching valve has a switching valve (97, 97 ₂ ).

According to a seventh aspect of the present invention, there is provided a lock-up control linear solenoid valve (SLU) for controlling the lock-up clutch (5), and the input clutch (C1) is provided with the lock-up control linear solenoid. 7. The hydraulic control apparatus for a continuously variable transmission according to claim 4, wherein the control oil pressure of the valve is controlled to release the gear ratio changing means when changing the gear ratio at a high speed. It is in.

According to an eighth aspect of the present invention, the changing means is a solenoid valve (S5) which is controlled to be on / off.
The hydraulic control device for a continuously variable transmission according to claim 1, further comprising: a switching valve (97 ₃ ) that is switched by an output pressure of the solenoid valve.

According to a ninth aspect of the present invention, the changing means includes the line pressure oil passage (h) and the secondary pressure oil passage (p).
And a switch valve (97) for switching between communication and disconnection through an orifice (111). 9. The hydraulic control device for a continuously variable transmission according to claim 1, wherein

According to a tenth aspect of the present invention, the change means includes the line pressure oil passage (h) and the secondary pressure oil passage (p).
And a plurality of orifices (11
1) A switching valve (97 ₂ , 97 ₃ ) for switching to communicate via any one of (113).
9. The hydraulic control device for a continuously variable transmission according to any one of items 1 to 8.

[Operation] Based on the above structure, the changing means (for example, the bypass control valve 97) is used to engage the first clutch (C1) when the first clutch (C1) is in the engaged state, for example, during forward running of the vehicle. The pressure is supplied to the first control oil chamber (L) and communicates, for example, between the line pressure oil passage (h) and the secondary pressure oil passage (p) via the orifice (111). In this state, the line pressure (P _L ) of the line pressure oil passage (h) is supplied to the secondary pressure oil passage (p), so that the secondary pressure such that the lock-up clutch (5) does not drag can be secured.

When the speed ratio changing means (92) rapidly changes the speed ratio of the continuously variable transmission due to, for example, sudden braking, the first clutch (C1) is released. Then, for example, the engagement pressure of the first clutch acting on the first control oil chamber (L) is released and, for example, the speed-changing linear solenoid valve (SLR) is transferred to the second control oil chamber (K). The control oil pressure from the valve acts to change the changing means (97), and the communication between the line pressure oil passage (h) and the secondary pressure oil passage (p) is, for example, shut off or the orifice (113) having a small orifice diameter. It is regulated by intermediation. As a result, the line pressure (P _L ) of the line pressure oil passage (h), which requires a large amount of oil for a rapid gear ratio change, is secured, and the continuously variable transmission (2) is rapidly shifted. .

The reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

[0020]

According to the present invention, the amount of oil flowing between the oil passages communicating the line pressure oil passage and the secondary pressure oil passage can be changed, so that the lock-up clutch is not dragged. As well as secondary pressure
The amount of oil in the line pressure oil passage required for rapid shifting of the continuously variable transmission can also be secured, and the reliability of the continuously variable transmission including the fluid transmission with the lock-up clutch can be improved.

According to the second aspect of the present invention, when a rapid shift is required due to a sudden brake or the like, the amount of oil in the communication oil passage is regulated to prevent the oil from flowing out of the line pressure oil passage. Can be performed reliably and accurately.

According to the third aspect of the present invention, by the shift control of the continuously variable transmission, the switching valve is reliably switched to restrict the outflow from the line pressure oil passage, and the shift operation of the continuously variable transmission is performed. It can be done reliably.

According to the present invention, the continuously variable transmission can be downshifted rapidly without being affected by the engine speed by releasing the input clutch. The rapid downshift can be reliably and accurately performed by restricting outflow from the line pressure oil passage.

According to the fifth aspect of the present invention, since the engagement pressure of the input clutch is input to the control oil chamber, the switching valve is automatically switched by releasing the input clutch.

According to the present invention, the switching valve is switched by the control hydraulic pressure of the linear solenoid valve for shifting when the input clutch is disengaged during a rapid shifting operation. Is
The above-mentioned rapid shifting operation can be reliably performed by reliably controlling the outflow from the line pressure oil passage, and at other times, the line pressure of the line pressure oil passage is supplied to the secondary pressure oil passage. By ensuring the secondary pressure, the lock-up clutch can be reliably prevented from being dragged.

According to the present invention, since the control of the lock-up clutch and the release control of the input clutch in response to the rapid shift operation are not simultaneously controlled, the two controls are performed by one. This is done with a linear solenoid valve, reducing the number of expensive linear solenoid valves and reducing costs.Also, even when the input clutch is released, it can be in a low pressure standby state in preparation for re-starting. It becomes possible.

According to the eighth aspect of the present invention, since the switching valve is switched by the solenoid valve, the structure of the hydraulic circuit can be simplified, and the solenoid valve is controlled by a signal from the control unit, so that various operations can be performed. Highly flexible control according to the mode becomes possible.

According to the ninth aspect of the present invention, the switching valve can be switched to the shutoff position to completely shut out the outflow from the line pressure oil passage to the secondary pressure oil passage.

According to the tenth aspect of the present invention, the switching valve is switched so as to pass through the orifice having a different flow rate so that the communication from the line pressure oil passage to the secondary pressure oil passage is not completely interrupted, and the speed is changed. In addition, the minimum secondary pressure can be maintained at the same time while ensuring the line pressure necessary for the above.

[0030]

FIG. 1 is a diagram showing a continuously variable automatic transmission 1 for a vehicle to which the present invention can be applied. The continuously variable automatic transmission includes a belt-type continuously variable transmission (CVT) 2, The apparatus includes a forward / reverse switching device 3, a torque converter 6 including a lock-up clutch 5, a counter shaft 7, and a differential device 9, and these devices are housed in a split case.

[0031] The torque converter 6 includes
0, a pump impeller 11 connected via a front cover 17, a turbine runner 13 connected to an input shaft 12, and a stator 16 supported via a one-way clutch 15. The lock-up clutch 5 is interposed between the front cover 17 and the front cover 17. In the drawing, reference numeral 20 denotes a damper spring interposed between the lock-up clutch plate and the input shaft,
An oil pump 21 is connected to and driven by the pump impeller 11.

The CVT (belt type continuously variable transmission) 2 includes a fixed sheave 23 fixed to a primary shaft 22 and a movable sheave 2 supported only slidably on the shaft.
5, a secondary pulley 31 comprising a fixed sheave 29 fixed to a secondary shaft 27 and a movable sheave 30 supported only slidably on the shaft, and a primary pulley 26 wound around these pulleys. And a metal belt 32.

Further, a hydraulic actuator 33 composed of a double piston is disposed on the back of the primary movable sheave 25, and a hydraulic actuator 3 composed of a single piston is disposed on the rear of the secondary movable sheave 30.
5 are arranged. The primary hydraulic actuator 33 includes a cylinder member 36 and a reaction force support member 37 fixed to the primary shaft 22, and a movable sheave 25.
And a first hydraulic chamber 41 is formed on the back surface of the cylindrical member 39, the reaction force support member 37, and the movable sheave 25,
The second hydraulic chamber 42 is constituted by the cylinder member 36 and the piston member 40. The first hydraulic chamber 41 and the second hydraulic chamber 42 communicate with each other through a communication hole 37a, and generate an axial force substantially doubled as compared with the secondary hydraulic actuator 35 by the same hydraulic pressure. I do. on the other hand,
The secondary-side hydraulic actuator 35 has a reaction force support member 43 fixed to the secondary shaft 27 and a tubular member 45 fixed to the back of the movable sheave 30. These two members constitute one hydraulic chamber. A preload spring 47 is contracted between the movable sheave 30 and the reaction force support member 43.

The forward / reverse switching device 3 has a double pinion planetary gear 50, a reverse brake B1, and a direct clutch C1. The planetary gear 50
Is a carrier C whose sun gear S is connected to the input shaft 12 and which supports the first and second pinions P1 and P2.
R is connected to the primary fixed sheave 23, the ring gear R is connected to the reverse brake B1, and the direct clutch C1 is interposed between the carrier CR and the ring gear R.

A large gear 51 and a small gear 52 are fixed to the counter shaft 7. The large gear 51 meshes with a gear 53 fixed to the secondary shaft 27, and the small gear 52 is a gear 55 of the differential device 9. Is engaged. The differential device 9 is configured such that rotation of a differential gear 56 supported by a differential case 66 having the gear 55 is controlled by left and right axles 60, 6 via left and right side gears 57, 59.
1 is transmitted.

A number of uneven portions 23a are formed on the outer peripheral portion of the primary fixed sheave 23 at regular intervals by gear cutting, and are fixed to a case (not shown) so as to face the uneven portions. An electromagnetic pickup 62 is disposed. Similarly, on the outer peripheral portion of the secondary side fixed sheave 29, a large number of concave and convex portions 29a are formed at regular intervals by gear cutting, and an electromagnetic pickup 63 is fixed to the case so as to face the concave and convex portions. ing. The electromagnetic pickups 62 and 63 have their detection surfaces arranged close to the irregularities, and constitute a primary (input) rotational speed sensor and a secondary (output) rotational speed (ie, vehicle speed) sensor for detecting the irregularities. doing. An electromagnetic pickup 65 is arranged near the front cover 17, and the electromagnetic pickup constitutes an engine speed sensor. Then, the input torque is obtained by calculating the engine torque based on the throttle opening and the engine speed from the map, further calculating the speed ratio from the input / output speed of the torque converter, obtaining the torque ratio from the map based on the speed ratio, It is determined by multiplying the torque by the torque ratio.

Next, the hydraulic circuit of the continuously variable transmission will be described with reference to FIG. In the figure, 21 is the oil pump, 70 is an oil pump control valve, S
2 is a solenoid valve for the control valve.
72 is a primary regulator valve, 73 is a secondary regulator valve, SLT is a linear solenoid valve for line pressure control, SLU is a linear solenoid valve for lock-up control, SLR is a linear solenoid valve for ratio control, and 76 is a solenoid valve Modulator valve.

Reference numeral 77 denotes a manual valve. As shown in the table, the hydraulic pressure of the port 1 to which a predetermined pressure regulated by the clutch modulator valve 79 described later is supplied is switched to the port 2 or 3 by manual operation. 79
Is a clutch modulator valve, 80 is a C1 control valve, 81 is a neutral relay valve, 82 is a reverse inhibit valve, and S1 is a solenoid valve for forward / reverse control. C1 is a hydraulic servo for the direct clutch C1, B1 is a hydraulic servo for the brake B1, and 90 and 91 are accumulators for B1 and C1, respectively.

Reference numeral 92 denotes a ratio control valve, and reference numerals 33 and 35 denote the primary and secondary hydraulic actuators. 95 is a lock-up control valve, 96 is a lock-up relay valve, and S3 is a lock-up switching solenoid valve. In the figure, E
x is a drain port.

Reference numeral 97 denotes a bypass control valve according to the present invention, and 99 denotes a secondary control pressure modulator valve.

Next, the operation based on the above configuration will be described. A predetermined hydraulic pressure is generated by the rotation of the oil pump 21 based on the engine rotation, and the hydraulic pressure is controlled by a primary solenoid valve 72 based on a linear solenoid valve SLT controlled by a signal from a control unit calculated based on a pulley ratio and an input torque. Is controlled,
The pressure is adjusted to the line pressure, and the secondary pressure is further adjusted by the secondary regulator valve 73. When a high line pressure is not required, such as in a stopped state, the solenoid valve S2 is controlled based on a signal from the control unit, and the oil pump control valve 70 is operated to the right half position to directly reduce the hydraulic pressure from the pump 21. Circulate.

In the D range and the L range of the manual valve 77, the hydraulic pressure adjusted by the clutch module valve 79 is supplied from the port 1 to the hydraulic servo C1 for the direct clutch via the port 2 and the clutch C1 Connecting. In this state, the rotation of the engine output shaft 10 is transmitted to the primary pulley 26 via the torque converter 6, the input shaft 12 and the planetary gear 50 which is directly connected by the direct clutch C1, and further via the CVT 2 which is appropriately shifted. And transmitted to the left and right axles 60 and 61 via the counter gear and the differential device 9.

When the manual valve 77 is operated in the reverse range, the hydraulic pressure from the port 1 is supplied to the brake hydraulic servo B1 via the port 3. In this state, the ring gear R of the planetary gear 50 is locked,
The rotation of the sun gear S from the input shaft 12 is taken out by the carrier CR as a reverse rotation, and the reverse rotation is applied to the primary pulley 2.
6 is transmitted.

The CVT 2 is supplied with the line pressure from the primary regulator valve 72 to the hydraulic actuator 35 of the secondary pulley 31, and exerts a belt clamping force according to the load torque. On the other hand, the ratio control linear solenoid valve SLR is controlled based on the shift signal from the control unit, and the ratio control valve 9 is controlled by the output pressure from the output port i of the solenoid valve.
2 is controlled, and the pressure regulation from the output port is supplied to the hydraulic actuator 33 composed of the double piston of the primary pulley, whereby the gear ratio of the CVT 2 is appropriately controlled.

Then, the torque of the engine output shaft 10 is
The torque is transmitted to the input shaft 12 via the torque converter 6, and particularly at the time of starting, the speed is changed by the torque converter 6 so that the torque ratio is increased and transmitted to the input shaft 12, and the vehicle starts smoothly. The torque converter 6
Has a lock-up clutch 5, and when the vehicle is running at high speed and stable, the lock-up clutch is engaged,
The engine output shaft 10 and the input shaft 12 are in a directly connected state, and the loss due to the oil flow of the torque converter is reduced. Further, the output pressure from the linear solenoid valve SLU is adjusted so that the rotation difference between the input side and the output side of the lock-up clutch becomes a predetermined value in the low / medium speed region until the clutch is completely engaged. Slip control is performed based on this.

That is, a map is selected by the position sensor depending on whether the manual valve 77 is in the D range or the L range, and the accelerator opening and the input rotation speed sensor 6 are selected.
The input number of revolutions read from the map 2 is read from the map, and the control unit outputs a lock-up OFF signal or an ON signal to the solenoid valve S3. When the solenoid valve S3 outputs the lock-up OFF pressure (zero pressure), the lock-up relay valve 96 is at the right half position. In this state, the secondary pressure of the oil passage p from the secondary regulator valve 73 is supplied to the torque converter 6 from the lockup OFF port 6a via the ports a and b of the relay valve 96, and from the lockup ON port 6b to the relay valve. Cooler 1 through 96 ports e and f
00, whereby the lock-up clutch 5 is held in the disconnected state.

On the other hand, when the solenoid valve S3 inputs the lock-up ON signal from the control unit, the lock-up relay valve 96 is switched to the left half position. In this state, the secondary pressure of the oil passage p is set to the lock-up ON port 6b via the ports a and e of the relay valve 96.
From the lock-up OFF port 6a to the port d of the control valve 95 via the ports b and c of the relay valve 96 and discharged from the drain port, whereby the lock-up clutch 5 is connected. Held in state.

When the lock-up clutch is slipped, the control unit receives the input-side and output-side rotation speeds of the lock-up clutch, that is, a signal from the engine speed sensor 65 and a signal from the input speed engine 62. , And outputs a signal such that the difference becomes a predetermined value. Based on the signal, the linear solenoid valve SLU outputs a control oil pressure from the output port A. The control oil pressure acts on the control oil chamber k of the control valve 95, and the valve 95
The port d communicates with the secondary pressure input port g and the drain port Ex at a predetermined ratio, balanced by the oil pressure of the feedback oil chamber j and the control oil chamber of the control oil chamber k. As a result, the hydraulic pressure from the lock-up OFF-side port 6a becomes a predetermined pressure, the ON-side oil chamber 5b and the OFF-side oil chamber 5a of the torque converter 6 are balanced, and the lock-up clutch 5 enters a predetermined slip state.

Further, control of the direct clutch C1 will be described. When the manual valve 77 is switched from the N range or from N to D, the solenoid valve S1 is turned on, the reverse inhibit valve 82 is at the right half position, and the neutral relay valve 81 is at the right half position. The lock-up clutch control solenoid valve SLU is in a state where a predetermined control oil pressure is output from its output port A, and the control oil pressure acts on the control oil chamber B of the C1 control valve 80 to move the valve 80 to the right. Hold in half position. Therefore, in this state, the hydraulic pressure from the port 2 of the manual valve 77 is applied to the direct clutch hydraulic servo C1 via the ports D and E of the C1 control valve 80 and the ports H and G of the check valve 110 or the neutral relay valve 81. Supplied. When the engagement of the direct clutch C1 is completed, the solenoid valve S1 is switched to the OFF pressure state, and the neutral relay valve 81 is switched to the left half position. In this state, the hydraulic pressure from the port 2 is supplied and held to the direct clutch hydraulic servo C1 via the ports Y and G of the relay valve 81, and the ports G and
H is shut off. Therefore, in this state, the check valve 110 does not affect the hydraulic servo C1 regardless of the position of the C1 control valve 80. Therefore, as described above, the linear solenoid valve S
The LU can output a required control oil pressure for slip control of the lock-up clutch.

During forward running of the vehicle with the direct clutch C1 engaged, signals such as accelerator off and brake on are input, and if the control unit determines that rapid downshifting is performed, the solenoid valve S1 is switched to ON pressure. The neutral relay valve 81 is switched to the right half position, and the lock-up clutch control linear solenoid valve SLU is controlled so as to reduce the control oil pressure. As a result, the C1 control valve 80 acts on the upper end chamber F thereof. The position becomes the left half position based on the feedback pressure, and the port E communicates with the drain port Ex.
In this state, the hydraulic pressure of the direct clutch hydraulic servo C1 is changed to the neutral relay valve 81 in the right half position.
Through ports G, H and port E. As a result, the connection between the input shaft 2 and the primary pulley 26 is disconnected, and the CVT 2 can rapidly downshift without being affected by the engine speed.

At this time, the linear solenoid valve SLU controls the control oil pressure so as to balance the feedback pressure, and adjusts the oil pressure of the hydraulic servo so that the direct clutch C1 is in contact with the friction material but has a torque capacity. (A state immediately before the engagement) to prepare for a quick response at the time of re-acceleration. Further, in the lock-up clutch linear solenoid valve SLU, the lock-up control does not function when the direct clutch C1 is controlled during the traveling, and the lock-up clutch 5 is held by switching the solenoid valve S3. , The linear solenoid valve SLU is
It can be used for both control of the direct clutch and the lock-up clutch.

Next, the adjustment of the secondary pressure will be described with reference to FIG. Primary regulator valve 7
A spring 72b is contracted in one end chamber 1 of the valve 2 and a control oil pressure from an output port m of the linear solenoid valve SLT acts via an orifice 101. An orifice 102 is provided in the other end chamber n of the valve 72. via the line pressure P _L acts. Therefore, the spool 72a has one end chamber.
The pressure supplied from the oil pump 21 to the port o of the primary regulator valve 72 is balanced by the control oil pressure acting on the valve l and the feedback pressure acting on the other end chamber n. pressure regulated by communicating at a predetermined ratio to q, thereby the line pressure P _L is calculated based on the speed ratio of the input torque and CVT2 is led to the oil passage h.

On the other hand, the secondary regulator valve 73
A spring 73b is contracted in one end chamber r, and the output pressure from the output port s of the secondary control pressure modulator valve 99 acts via the orifice 103, and the other end chamber t through the orifice 105. secondary pressure P _S acts. Therefore, the spool 73a is balanced by the control oil pressure acting on the one end chamber r and the feedback pressure acting on the other end chamber t, and the port u is regulated by communicating with the drain port Ex at a predetermined ratio, and the primary pressure is adjusted. Port q of regulator valve 72
Hydraulic pressure supplied to the port u of the secondary regulator valve 73 from the become secondary pressure P _S which is based on pressure from the output port s of the secondary control pressure modulator valve 99 is led to the oil passage p. Further, a lubricating oil pressure is supplied from the port v of the secondary regulator valve 73 to the lubricating device 107 via the orifice 109.

The modulator valve 99 is
The spring 99b is contracted in one end chamber w, and the output pressure from the output port s acts on the other end chamber x via the orifice 106. Further, the modulator valve 99 has an input port y, an output port s, and a drain port Ex to which a control oil pressure from the line pressure control linear solenoid valve SLT is supplied through an orifice 104, and has an output port. The port s communicates with the input port y and the drain port Ex at a predetermined ratio, and the input port y is formed with a V notch y '.

Therefore, the spool 99a of the modulator valve 99 is balanced by the output pressure acting on the upper end thereof as a feedback pressure and the biasing force of the spring 99b acting on the lower end.
The biasing force of the spring 99b is large with respect to the feedback pressure acting on the upper end chamber x, and the control hydraulic pressure from the input port y is output to the output port s as it is at the right half position. When the control oil pressure from the linear solenoid valve SLT becomes equal to or higher than a predetermined pressure, the spool 99a is balanced by the feedback pressure and the spring urging force, so that the output pressure from the output port s is constant even if the control oil pressure increases. Retained by value.

Therefore, the line pressure control linear solenoid valve SLT is controlled by the input torque from the control unit and the CVT2.
Output port m of the modulator pressure P _M from the solenoid modulator valve 79 by a control signal based on the speed ratio of
To the control oil chamber l.
Based acts on the primary regulator valve 72 outputs the line pressure P _L which is proportional to the input torque between CVT2 the U / D (under drive) and O / D (overdrive).

On the other hand, the linear solenoid valve SLT
When the control oil pressure from the controller is within a predetermined pressure, the secondary control pressure modulator valve 99 outputs the control oil pressure as it is, and the output pressure acts on the control oil chamber r, so that the secondary regulator valve 73 operates the U / D
And outputs the secondary pressure P _S which is proportional to the input torque at the time and O / D o'clock. Secondary pressure P _S at the time of O / D
(U / D) is set so as to match the required pressure of the torque converter 6, and the secondary pressure P _S during U / D is set.
There is no shortage.

The output pressure from the output port s of the modulator valve 99 is equal to the linear solenoid valve S
When the control hydraulic pressure of the LT becomes equal to or higher than a predetermined pressure, it is kept constant. Therefore, the line pressure P _L rises in proportion to the control oil pressure, the secondary pressure P _S, the upper limit on the basis of the output pressure consisting of constant pressure (control pressure) is regulated to a constant value. The upper limit of the secondary pressure P _S is a lower limit pressure of the torque converter 5, and to substantially match the required maximum pressure.

Next, the bypass control valve 97 according to the main part of the present invention will be described with reference to FIG.

The bypass control valve 97 is interposed in a communication oil passage Z that connects the line pressure oil passage h and the secondary pressure oil passage p (see FIG. 2), and is connected to an output port of the ratio control linear solenoid valve SLR. An oil passage J from the oil clutch J communicates with a control oil chamber K at an upper end thereof, and a spring 97b is contracted in an oil chamber L at a lower end thereof. Communicate with each other (see FIG. 2). Further, the valve 97 has a port Q communicating with the line pressure oil passage h through the orifice 111, and a check valve 112 (see FIG. 2).
And a port T that communicates with the secondary pressure oil passage p through the port 97. These ports Q and T are communicated or blocked by the movement of the spool 97a.

Therefore, when the oil pressure is not supplied to both the upper oil chamber K and the lower oil chamber L, the bypass control valve 97 is at the left half position by the spring 97b, T communicates, and the line pressure P _L of the line pressure oil passage h is supplied to the secondary pressure oil passage p via the orifice 111, the ports Q and T, and the check valve 112. Therefore, when the manual valve 77 is in the N or R state and the hydraulic pressure of the direct clutch hydraulic servo C1 is in the released state, the engine is in the idling state and the discharge amount of the oil pump 21 is small,
Although the secondary pressure is insufficient, the lock-up clutch release pressure of the torque converter 6 can be secured by supplying the line pressure to the secondary pressure oil passage p through the orifice 112 through the communication between the ports Q and T.

On the other hand, when the ratio control linear solenoid valve SLR outputs control oil pressure from its output port i in order to control the ratio control valve 92 and change the pulley ratio, the control oil pressure is transmitted through the oil passage J It is supplied to the upper control oil chamber K of the bypass control valve 97. When the control hydraulic pressure overcomes the urging force acting on the lower end of the spool 97a and moves the spool to the right half position, the ports Q and T are shut off, and the communication between the line pressure oil passage h and the secondary oil passage p is cut off. Dripping.

During the forward running of the vehicle, the direct clutch C1 is in the engaged state, the hydraulic servo C1 is in the supply state, and the hydraulic pressure is applied via the oil passage M to the bypass control valve 97. Is supplied to the lower end oil chamber L. In this state, even if the linear solenoid valve SLR outputs the control oil pressure to change the pulley ratio and the control oil pressure acts on the upper oil chamber K, the lower oil chamber L
Bypass control valve 97 by the urging force of the hydraulic and spring 97b acting on In the communicating position (left half position), the line pressure P _L of the line pressure oil passage h to the secondary pressure oil passage p via the orifice 111 Supply. Therefore, even when the pulley ratio is changed at a normal speed while the vehicle is traveling, the line pressure is supplied to the secondary pressure oil passage p, and the release pressure of the lock-up clutch 5 is secured. At this time, the supply of the line pressure to the hydraulic servos 33 and 35 of the pulley by the ratio control valve 92 is
While the vehicle is running, the discharge amount of the oil pump 21 is kept to a minimum, the line pressure by the primary regulator valve 72 is maintained, and the speed change is not abrupt, and the speed of the oil pressure to the pulley hydraulic servos 33 and 35 is increased. The amount of oil is secured.

When the vehicle shifts down rapidly due to the brake on during forward running of the vehicle, the neutral relay valve 81 is switched to the right half position based on the solenoid valve S1 and the linear solenoid valve SLU is switched.
, The C1 control valve 80 is switched to the left half position, and the direct clutch hydraulic servo C1 is released. Then, the hydraulic pressure from the hydraulic servo C1 acting on the lower end oil chamber L of the bypass control valve 97 disappears, and the control oil pressure from the linear solenoid valve SLR output for the downshift operation is changed to the upper end oil chamber K. , The bypass control valve 97 is switched to the right half position, and the ports Q and T are shut off. Therefore, the hydraulic servos 33, 35 for pulleys require a large amount of hydraulic pressure for the rapid downshift, but the line pressure is not supplied to the secondary pressure oil passage p. The amount of the line pressure oil passage h
, And a quick downshift of the CVT 2 can be reliably performed.

FIG. 5 is a diagram showing a partially modified embodiment, and the same parts as those in FIG. 4 are denoted by the same reference numerals. The bypass control valve 97 ₂ according to this embodiment
Has a port U in addition to the above-described upper end oil chamber K, lower end oil chamber L, and ports Q and T. The port U communicates with the line pressure oil passage h and has a second orifice 113 having a smaller orifice diameter than the orifice 111 communicating with the port Q.

Therefore, the bypass control valve 97
_{When 2} is at the left half position, the ports Q and T communicate with each other, and the line pressure P _L of the line pressure oil passage h is supplied to the secondary pressure oil passage p via the orifice 111 having a large hole,
Secondary pressure is ensured. Moreover, the rapid downshift bypass control valve 97 ₂ When in the right half position, the port U and T are communicated. In this state,
The line pressure P _L of the line pressure oil passage h is supplied to the secondary pressure oil passage p through the orifice 113 having a small hole, and a large amount of oil accompanying the rapid downshift is secured in the line pressure oil passage h. together, also to ensure the minimum required secondary pressure P _S in the release of the lock-up clutch.

FIG. 6 is a diagram showing a further modified embodiment. Similarly, the same portions are denoted by the same reference numerals and description thereof is omitted. This bypass control valve 97 ₃ is controlled by a solenoid valve S5. That is, the upper end oil chamber K
, A control oil pressure that is turned on and off by the solenoid valve S5 acts on the lower oil chamber L, and the lower oil chamber L is released with only the spring 97 ₃ b interposed therebetween.

[0068] Therefore, when the release solenoid valve S5, the bypass control valve 97 ₃ In the left half position, communicates and the port Q and T, the line pressure oil passage h is
When the solenoid valve S5 is closed, it communicates with the secondary pressure oil passage p through the orifice 111 having a large hole.
The valve 97 ₃ In the right half position, communicates with the port U and T is the line pressure oil passage h is small hole orifice 11
3 and communicate with the secondary pressure oil passage p.

Although the above embodiment has been described with reference to the continuously variable transmission shown in FIGS. 1 and 2, the present invention is not limited to the belt type continuously variable transmission and the torque converter. It is needless to say that the present invention can be similarly applied to a device including another fluid transmission device such as a continuously variable transmission and a fluid coupling.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a continuously variable transmission according to the present invention.

FIG. 2 is a diagram showing the hydraulic circuit.

FIG. 3 is a partially enlarged view of FIG. 2 showing pressure regulation of a line pressure and a secondary pressure.

FIG. 4 is a partially enlarged view of FIG. 2 showing a main part of the embodiment according to the present invention.

FIG. 5 illustrates another embodiment.

FIG. 6 is a diagram showing a further modified embodiment.

[Explanation of symbols]

Reference Signs List 1 continuously variable transmission 2 (belt type) continuously variable transmission (CVT) 5 lock-up clutch 6 fluid transmission device (torque converter) 10 engine output shaft 12 input shaft 21 oil pump 33, 35 gear ratio changing means (pulley hydraulic pressure) Servo) 72 Line pressure adjusting means (primary regulator valve) 73 Secondary pressure adjusting means (secondary regulator valve) 92 Gear ratio changing means (ratio control valve) 97, 97 ₂ , 97 ₃ Changing means (switching valve, bypass control valve) 97a Spool 97b Spring 111 Orifice 113 (of large orifice diameter) 113 Orifice (of small orifice diameter) C1 First (direct) clutch, hydraulic servo h Line pressure oil path p Secondary pressure oil path Z Communication oil path P _L line pressure P _S secondary Pressure L First control oil chamber K Second control oil chamber SLR Linear solenoid valve for speed change (for ratio control) SLU Linear solenoid valve for lock-up control S5 Solenoid valve

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Junichi Tokunaga 10 Takane, Fujii-cho, Anjo-shi, Aichi, Japan Aisin AW Co., Ltd.

Claims (10)

[Claims] 1. A continuously variable transmission comprising a continuously variable transmission capable of changing a gear ratio by a hydraulic pressure, and a fluid transmission having a lock-up clutch interposed between the continuously variable transmission and an engine output shaft. A line pressure oil passage that regulates a discharge pressure of an oil pump by a line pressure regulating unit and supplies the regulated line pressure to a speed ratio changing unit of the continuously variable transmission; Is adjusted by secondary pressure adjusting means to supply the adjusted secondary pressure to the fluid transmission device; and a communication oil passage communicating the line pressure oil passage and the secondary pressure oil passage. And a changing means interposed in the communication oil passage for changing an amount of oil flowing through the communication oil passage. A hydraulic control device for a continuously variable transmission, comprising: 2. The continuously variable transmission according to claim 1, wherein the changing unit changes the amount of oil flowing through the communication oil passage when the speed ratio changing speed of the continuously variable transmission is high. Hydraulic control device. 3. The change means is supplied with a control oil pressure from a speed-changing linear solenoid valve for controlling the speed ratio change means to a control oil chamber thereof, and the control oil pressure is changed by a speed ratio change speed by the speed ratio change means. 3. The hydraulic control device for a continuously variable transmission according to claim 2, wherein the control valve is a switching valve that switches so that the amount of oil flowing through the communication oil passage is regulated when the speed is controlled quickly. 4. An input clutch interposed between the engine output shaft and the continuously variable transmission, connected to the vehicle when the vehicle is traveling forward, and transmitting an engine power to driving wheels. The hydraulic control device for a continuously variable transmission according to claim 1, wherein when the input clutch is released, a change is made so as to regulate an amount of oil flowing through the communication oil passage. 5. The control device according to claim 1, wherein the control oil chamber communicates with a hydraulic servo of the input clutch, and when a hydraulic pressure applied to the hydraulic servo releases the input clutch,
The hydraulic control device for a continuously variable transmission according to claim 4, wherein the control valve is a switching valve that switches the amount of oil flowing through the communication oil passage so as to be regulated. 6. A shift linear solenoid valve for controlling the speed ratio changing means, and an input clutch engaged when the vehicle is running to transmit power of an engine to driving wheels, wherein the changing means includes a spool and A spring for urging the spool in one direction, a first control oil chamber communicating with a hydraulic servo of the input clutch disposed on a side where the spring is located, and a spring disposed on a side of the spool opposed to the spring. The hydraulic control device for a continuously variable transmission according to claim 1, wherein the control valve is a switching valve having a second control oil chamber to which a control hydraulic pressure of the shift linear solenoid valve is supplied. 7. A lock-up control linear solenoid valve for controlling the lock-up clutch, wherein the input clutch shifts the gear ratio changing means at a high speed by a control oil pressure of the lock-up control linear solenoid valve. The hydraulic control device for a continuously variable transmission according to claim 4, wherein the hydraulic pressure control device is controlled so as to be released when the ratio is changed. 8. The continuously variable transmission according to claim 1, wherein the changing unit includes a solenoid valve that is controlled to be turned on and off, and a switching valve that is switched by an output pressure of the solenoid valve. Hydraulic control device. 9. The switching valve according to claim 1, wherein the changing unit is a switching valve that switches between the line pressure oil passage and the secondary pressure oil passage via an orifice or a cutoff. Hydraulic control device in the continuously variable transmission. 10. The switching valve for switching the line pressure oil passage and the secondary pressure oil passage so as to communicate with each other through one of a plurality of orifices having different orifice diameters. 8. The hydraulic control device for a continuously variable transmission according to any one of items 8 to 8.