JP2004293650A - Transmission hydraulic control device - Google Patents

Abstract

Provided is a hydraulic control device for a transmission that can suppress a decrease in controllability of an oil amount in a hydraulic chamber.
A transmission (2) whose transmission ratio is controlled based on the amount of oil in a hydraulic chamber (6), the amount of oil supplied to the hydraulic chamber (6), and the amount of oil supplied to the hydraulic chamber (6) and discharged from the hydraulic chamber (6). In a hydraulic control device for a transmission having a flow control valve 11 for controlling an oil amount, an oil passage 10 formed between a flow control valve 11 and a hydraulic And the amount of oil supplied from the flow control valve 11 to the hydraulic chamber 6 or the amount of oil discharged from the hydraulic chamber 6 via the flow control valve 11 based on the correspondence between the hydraulic pressure and the hydraulic pressure at a location remote from the hydraulic chamber. Among them, oil amount control mechanisms 19, 20, 25, and 26 for controlling at least one oil amount are provided.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic control device for a transmission configured to control the power transmission state of the transmission by hydraulic pressure.
[0002]
[Prior art]
2. Description of the Related Art In a hydraulically controlled transmission, there is known a technology of controlling a speed ratio of the transmission by controlling an amount of oil supplied to a hydraulic chamber. One example of such a hydraulically controlled transmission is described in Japanese Patent Application Laid-Open No. 2001-12590 (Patent Document 1). The transmission described in this publication is a belt-type continuously variable transmission, which has a primary pulley and a secondary pulley, and a belt wound around the primary pulley and the secondary pulley. ing. Further, a hydraulic actuator is arranged corresponding to the primary pulley, and the hydraulic actuator has a hydraulic chamber.
[0003]
The hydraulic circuit of the transmission is provided with a primary regulator valve, a secondary regulator valve, and a ratio control valve. The primary regulator valve regulates the line pressure, and the secondary regulator valve regulates the secondary pressure. The ratio control valve is controlled by the signal pressure from the linear solenoid valve for the ratio control valve, and the hydraulic pressure from the output port of the ratio control valve is supplied to the hydraulic chamber of the hydraulic actuator of the primary pulley to change the CVT speed. The ratio is controlled.
[0004]
[Patent Document 1]
JP 2001-12590A (Paragraph Nos. 0020 to 0033, FIGS. 1 and 3)
[0005]
[Problems to be solved by the invention]
However, in the hydraulic control device described in the above publication, the hydraulic pressure is supplied to the hydraulic chamber due to the correspondence between the hydraulic chamber of the hydraulic actuator of the primary pulley and the hydraulic pressure of the oil passage communicating with the hydraulic chamber. There is a possibility that the amount of oil discharged from the hydraulic chamber or the amount of oil discharged from the hydraulic chamber does not become the amount of oil corresponding to the signal pressure of the solenoid valve for the ratio control valve. As a result, the controllability of the amount of oil supplied to the hydraulic chamber or the controllability of the amount of oil discharged from the hydraulic chamber may be reduced.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic control device for a transmission that can suppress a decrease in controllability of an oil amount in a hydraulic chamber.
[0007]
Means for Solving the Problems and Their Functions
In order to achieve the above object, an invention according to claim 1 is provided with a transmission in which a power transmission state is controlled based on an oil amount in a hydraulic chamber, and a communication with the hydraulic chamber and supply to the hydraulic chamber. An oil passage formed between the flow control valve and the hydraulic chamber, the hydraulic control device having a flow control valve for controlling an amount of oil flowing and an amount of oil discharged from the hydraulic chamber. The amount of oil supplied from the flow control valve to the hydraulic chamber, or the flow rate control from the hydraulic chamber, based on the correspondence between the hydraulic pressure at a location near the hydraulic chamber and the hydraulic pressure at a location distant from the hydraulic chamber. The invention is characterized in that an oil amount control mechanism for controlling at least one of the oil amounts discharged through the valve is provided.
[0008]
According to the first aspect of the present invention, the amount of oil supplied from the flow control valve to the hydraulic chamber or the amount of oil supplied from the hydraulic chamber is determined based on the correspondence between the hydraulic pressure at a location near the hydraulic chamber and the hydraulic pressure at a location far from the hydraulic chamber. At least one of the oil amounts discharged through the flow control valve is controlled.
[0009]
According to a second aspect of the present invention, in addition to the configuration of the first aspect, the flow control valve has a valve body that can operate in a forward / reverse direction. In this case, while the amount of oil supplied to the hydraulic chamber increases and the amount of oil discharged from the hydraulic chamber decreases, when the valve element operates in the opposite direction, the amount of oil supplied to the hydraulic chamber increases. The amount of oil to be discharged is reduced, and the amount of oil discharged from the hydraulic chamber is configured to increase, and an orifice is provided between a portion of the oil passage near and far from the hydraulic chamber. An urging force that is arranged and applies an urging force corresponding to a hydraulic pressure at a location near the hydraulic chamber and an urging force corresponding to a hydraulic pressure at a location far from the hydraulic chamber in opposite directions to the valve body. The invention is characterized in that a mechanism is provided.
[0010]
According to the second aspect of the invention, in addition to the same effect as the first aspect of the invention, when the valve element operates in the forward direction, the amount of oil supplied to the hydraulic chamber increases, and The amount of oil discharged from the pump decreases. On the other hand, when the valve element operates in the reverse direction, the amount of oil supplied to the hydraulic chamber decreases, and the amount of oil discharged from the hydraulic chamber increases. An orifice is arranged between a near point and a distant point in the oil passage, and an urging force corresponding to the oil pressure at the near point and an urging force corresponding to the oil pressure at the far point are applied to the valve body. It works in the opposite direction.
[0011]
According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the transmission is a belt-type continuously variable transmission in which a belt is wound around a primary pulley and a secondary pulley. The gear ratio of the belt-type continuously variable transmission is included, and the belt-type continuously variable transmission is configured such that the gear ratio is controlled by controlling the groove width of the primary pulley. The groove width of the primary pulley changes based on the amount of oil.
[0012]
According to the third aspect of the invention, in addition to the same effect as the first or second aspect of the invention, the speed ratio of the belt-type continuously variable transmission is controlled based on the oil amount in the hydraulic chamber.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described based on specific examples. FIG. 1 is a conceptual diagram of a case in which a hydraulic control device 1 of the present invention controls a belt-type continuously variable transmission 2 for a vehicle. The belt-type continuously variable transmission 2 has a primary pulley 3 and a secondary pulley 4, and a belt 5 is wound around the primary pulley 3 and the secondary pulley 4. A driving force source (not shown) is connected to the primary pulley 3 so as to transmit power, and wheels (not shown) are connected to the secondary pulley 4 so as to transmit power. The primary pulley 3 has a movable sheave that can move in the axial direction and a fixed sheave that does not move in the axial direction. A first hydraulic chamber 6 for controlling the groove width of the primary pulley 3 is provided. The secondary pulley 4 has a movable sheave that can move in the axial direction and a fixed sheave that does not move in the axial direction. A second hydraulic chamber 7 for controlling the groove width of the secondary pulley 4 is provided.
[0014]
In the above configuration, when the torque of the driving force source is transmitted to the primary pulley 3, the torque of the primary pulley 3 is transmitted to the secondary pulley 4 via the belt 5, and the torque of the secondary pulley 4 is transmitted to the wheels for driving. Force is generated. Further, the groove width of the primary pulley 3 is controlled based on the amount of oil in the first hydraulic chamber 6, and the winding diameter of the belt 5 on the primary pulley 3 changes, thereby changing the speed of the belt-type continuously variable transmission 2. The ratio is controlled. Further, the clamping force applied from the secondary pulley 4 to the belt 5 changes based on the hydraulic pressure in the second hydraulic chamber 7, and the torque capacity transmitted by the belt-type continuously variable transmission 2 is controlled.
[0015]
The hydraulic control device 1 has a function of controlling the amount of oil supplied to the first hydraulic chamber 6 and the hydraulic pressure transmitted to the second hydraulic chamber 7. Hereinafter, the configuration of the hydraulic control device 1 will be described. The hydraulic control device 1 has an oil passage 8, which is connected to a discharge port of an oil pump (not shown). A configuration in which this oil pump is driven by a driving force source, for example, an engine or an electric motor can be adopted. The oil passage 8 and the second hydraulic chamber 7 are connected by an oil passage 9. Further, an oil passage 10 connected to the first hydraulic chamber 6 is formed, and a ratio control valve 11 is provided at a connection portion between the oil passage 10 and the oil passage 8.
[0016]
The ratio control valve 11 has a spool 12 that can move in the vertical direction in FIG. 1 and elastic members 13 and 14 that apply a biasing force to the spool 12. One elastic member 13 generates an urging force F1 for urging the spool 12 downward, and the other elastic member 14 generates an urging force F2 for urging the spool 12 upward. That is, the direction of the urging force F1 is opposite to the direction of the urging force F2. When springs are used as the elastic members 13 and 14, their spring constants are set to be the same.
[0017]
Further, the ratio control valve 11 has a first signal pressure port 15 and a second signal pressure port 16. Then, the signal pressure of the first linear solenoid valve 17 is input to the first signal pressure port 15. The first linear solenoid valve 17 is a valve configured so that the output signal pressure becomes a minimum when the value of the current supplied to the electromagnetic coil is controlled to the minimum value, that is, a so-called normally closed valve. is there. The signal pressure input to the first port 15 generates an urging force F1 for urging the spool 12 downward.
[0018]
On the other hand, the signal pressure of the second linear solenoid valve 18 is input to the second signal pressure port 16. The second linear solenoid valve 18 is a valve that is configured so that the output signal pressure becomes minimum when the value of the current supplied to the electromagnetic coil is controlled to the minimum value, that is, a valve of a so-called normally closed type. is there. The signal pressure input to the second signal pressure port 16 generates an urging force F2 for urging the spool 12 upward.
[0019]
Further, the ratio control valve 11 has a first feedback port 19 and a second feedback port 20, and the ratio control valve 11 has an input port 21, an output port 22, and a drain port 23. . The oil passage 8 and the input port 21 are connected, and the output port 22 and the oil passage 10 are connected. Further, an oil pan is connected to the drain port 23.
[0020]
An orifice 24 is provided in the oil passage 10, and an oil passage 25 is formed in the oil passage 10 to connect a portion between the output port 22 and the orifice 24 and the first feedback port 19. Have been. An urging force F1 for urging the spool 12 downward is generated according to the hydraulic pressure of the first feedback port 19. In addition, an oil passage 26 is formed in the oil passage 10 and connects the second feedback port 20 to a location between the first hydraulic chamber 6 and the orifice 24. In accordance with the hydraulic pressure of the second feedback port 20, an urging force F2 for urging the spool 12 upward is generated.
[0021]
The function of the hydraulic control device 1 having the above configuration will be described. First, oil from an oil pan (not shown) is sucked by an oil pump, and oil discharged from the oil pump is supplied to an oil passage 8. The hydraulic pressure (line pressure) PL of the oil passage 8 is regulated by a pressure regulating valve. Part of the oil in the oil passage 8 is supplied to the oil passage 9, and the oil pressure is adjusted by a pressure adjusting valve (not shown), and the oil pressure is transmitted to the second oil pressure chamber 7. Thus, the torque capacity of the belt-type continuously variable transmission 2 is controlled. Although the torque capacity of the belt-type continuously variable transmission 2 is controlled by the hydraulic pressure of the second hydraulic chamber 7, the hydraulic pressure of the second hydraulic chamber 7 is changed by the oil. Can be said to be related to the torque capacity.
[0022]
On the other hand, the shift control of the belt-type continuously variable transmission 2 is performed by the ratio control valve 12. First, in the case of executing deceleration control, that is, shift control in which the speed ratio of the belt-type continuously variable transmission 2 is increased, the signal pressure input to the first signal pressure port 15 is changed to the second signal pressure. It is set higher than the signal pressure input to port 16. Then, the spool 12 operates downward in FIG. 1, and the communication area between the input port 21 and the output port 22 decreases, and the communication area between the output port 22 and the drain port 23 increases. As a result, the oil in the first hydraulic chamber 6 is drained, the groove width of the primary pulley 3 increases, the winding radius of the belt 5 on the primary pulley 3 decreases, and the gear ratio of the belt type continuously variable transmission 2 decreases. A shift that increases is executed.
[0023]
Next, when performing speed increase control, that is, speed change control in which the speed ratio of the belt-type continuously variable transmission 2 is reduced, the signal pressure input to the second signal pressure port 16 is changed to the first signal pressure. The signal pressure is set higher than the signal pressure input to the signal pressure port 15. Then, the spool 12 moves upward in FIG. 1, so that the communication area between the input port 21 and the output port 22 increases, and the communication area between the output port 22 and the drain port 23 decreases. As a result, the amount of oil supplied from the oil passage 8 to the first hydraulic chamber 6 increases, the groove width of the primary pulley 3 decreases, the winding radius of the belt 5 around the primary pulley 3 increases, and the belt type The shift is performed such that the gear ratio of the continuously variable transmission 2 becomes smaller.
[0024]
Further, when the gear ratio is controlled to be substantially constant, the signal pressure input to the first signal pressure port 15 and the signal pressure input to the second signal pressure port 16 are controlled to be the same. For example, if control is performed to supply no current to both the first linear solenoid valve 17 and the second linear solenoid valve 18, the signal pressure input to the first signal pressure port 15 and the second signal The signal pressure input to the pressure port 16 is the same, specifically, the lowest pressure.
[0025]
In this way, when the signal pressure input to the first signal pressure port 15 and the signal pressure input to the second signal pressure port 16 are controlled to be the same, the urging force generated by the elastic member 13 F1 and the biasing force F2 generated by the elastic member 14 cancel each other, and the spool 12 stops at the predetermined neutral position. Then, all the ports 21, 22 and 23 are shut off, the oil in the oil passage 8 is not supplied to the first hydraulic chamber 6, and the oil in the first hydraulic chamber 6 is not drained from the drain port 23. . Therefore, the oil amount in the first hydraulic chamber 6 is controlled to be substantially constant, and the speed ratio of the belt-type continuously variable transmission 2 is fixed. Control for controlling the amount of oil in the first hydraulic chamber 6 to be substantially constant is referred to as “binding control”.
[0026]
As described above, the amount of oil in the first hydraulic chamber 6, specifically, the amount of oil supplied to the first hydraulic chamber 6 and the amount of oil discharged from the first hydraulic chamber 6, are basically Control is performed based on signal pressures output from the first linear solenoid valve 17 and the second linear solenoid valve 18. By the way, depending on the oil pressure in the oil passage 8 and the oil pressure in the first hydraulic chamber 6, there is a possibility that the oil amount in the first hydraulic chamber 6 cannot be properly controlled by the above signal pressure.
[0027]
For example, when the speed increase control is executed, if the oil pressure in the first hydraulic chamber 6 is equal to or more than a predetermined value, the oil in the first hydraulic chamber 6 is independent of the communication area between the input port 21 and the output port 22. The amount is less likely to increase. As a result, the speed increase speed may decrease. On the other hand, when the deceleration control is performed, if the oil pressure in the first hydraulic chamber 6 is equal to or more than a predetermined value, the oil amount in the first hydraulic chamber 6 is independent of the communication area between the output port 22 and the drain port 23. Decreases sharply. As a result, the deceleration speed may increase sharply.
[0028]
On the other hand, even when the speed ratio of the belt-type continuously variable transmission 2 is fixed, a predetermined amount of oil leaks from the seal portion of the first hydraulic chamber 6, and in order to control the speed ratio constant, Similarly to the above, it is possible to supply oil from the oil passage 8 to the first hydraulic chamber 6 and execute control to make the amount of oil leakage substantially equal to the amount of supplied oil. However, also in this case, it is difficult to supply the oil to the first hydraulic chamber 6 for the same reason as that at the time of the speed increase control, and the gear ratio may change.
[0029]
On the other hand, according to the hydraulic control device 1 of FIG. 1, such a problem can be solved. First, during deceleration control of the belt-type continuously variable transmission 2, the oil in the first hydraulic chamber 6 is drained to the oil pan. Here, if the oil pressure Pin2 of the oil passage between the orifice 24 and the first hydraulic chamber 6 is higher than the oil pressure Pin1 of the oil passage between the output port 22 and the orifice 24, the first hydraulic chamber The amount of oil discharged from 6 tends to increase. When the hydraulic pressure Pin2 transmitted to the second feedback port 20 is higher than the hydraulic pressure Pin1 transmitted to the first feedback port 19, the spool 12 is urged upward in FIG. It is possible to suppress a rapid decrease in the oil amount in the hydraulic chamber 6.
[0030]
Further, during the deceleration control of the belt-type continuously variable transmission 2, the oil pressure Pin2 in the oil passage between the orifice 24 and the first hydraulic chamber 6 is higher than the oil pressure Pin1 in the oil passage between the output port 22 and the orifice 24. Is lower, the amount of oil discharged from the first hydraulic chamber 6 tends to decrease. When the hydraulic pressure Pin2 transmitted to the second feedback port 20 is lower than the hydraulic pressure Pin1 transmitted to the first feedback port 19, the spool 12 is urged downward in FIG. An increase in the amount of oil discharged from the hydraulic chamber 6 can be promoted.
[0031]
On the other hand, at the time of speed-up control of the belt-type continuously variable transmission 2, the oil pressure Pin1 of the oil passage between the output port 22 and the orifice 24 is greater than that of the oil passage between the orifice 24 and the first hydraulic chamber 6. If it is higher than the hydraulic pressure Pin2, the amount of oil supplied to the first hydraulic chamber 6 tends to increase. When the hydraulic pressure Pin1 transmitted to the first feedback port 19 is higher than the hydraulic pressure Pin2 transmitted to the second feedback port 20, the spool 12 is biased downward in FIG. It is possible to suppress a sudden increase in the amount of oil in the hydraulic chamber 6.
[0032]
Further, during the speed-up control of the belt-type continuously variable transmission 2, the hydraulic pressure in the oil passage between the orifice 24 and the first hydraulic chamber 6 is higher than the hydraulic pressure Pin 1 in the oil passage between the output port 22 and the orifice 24. If Pin2 is higher, the amount of oil supplied to the first hydraulic chamber 6 tends to decrease. When the hydraulic pressure Pin2 transmitted to the second feedback port 20 is higher than the hydraulic pressure Pin1 transmitted to the first feedback port 19, the spool 12 is urged upward in FIG. An increase in the amount of oil supplied to the hydraulic chamber 6 can be promoted.
[0033]
As described above, the amount of oil supplied to the first hydraulic chamber 6 and the amount of oil discharged from the first hydraulic chamber 6 depend on the signal pressures Psol 1 and Psol 1 output from the first linear solenoid valve 17. In addition to the signal pressure Psol 2 output from the linear solenoid valve 18 of the first embodiment, the pressure is also changed by the hydraulic pressure transmitted to the first feedback port 19 and the second feedback port 20. Therefore, during the deceleration control, the value obtained by subtracting the oil pressure Pin1 from the oil pressure Pin2 becomes a desired value (a value such that the amount of oil discharged from the first hydraulic chamber 6 becomes an expected amount). By controlling the correspondence between the signal pressure Psol 1 of the first linear solenoid valve 17 and the signal pressure Psol 2 of the second linear solenoid valve 17, the deceleration speed during the deceleration control can be set to an arbitrary value. And drivability is improved.
[0034]
At the time of the speed increase control, a value obtained by subtracting the oil pressure Pin2 from the oil pressure Pin1 becomes a desired value (a value such that the amount of oil supplied to the first hydraulic chamber 6 becomes an expected amount). By controlling the correspondence between the signal pressure Psol 1 of the first linear solenoid valve 17 and the signal pressure Psol 2 of the second linear solenoid valve 17, the speed increase speed at the time of speed increase control can be set to an arbitrary value. Can be set, and drivability is improved.
[0035]
Further, when the speed ratio of the belt-type continuously variable transmission 2 is fixed, the amount of oil leaking from the first hydraulic chamber 6 and the amount of oil supplied to the first hydraulic chamber 6 are supplied for the same reason as that in the speed increasing control. Can be substantially matched with the amount of oil. Therefore, it is possible to reduce waste of oil consumption caused by the stroke of the movable sheave of the primary pulley 3 being more than necessary. When the oil pump is driven by the power of the engine, it is possible to suppress a decrease in fuel consumption due to waste of the oil discharge amount of the oil pump. As described above, in this embodiment, the amount of oil supplied to the first hydraulic chamber 6 without being affected by the hydraulic pressure of the first hydraulic chamber 6 or the hydraulic pressure PL of the oil passage 8, The amount of oil discharged from the hydraulic chamber 6 can be controlled, and the shift controllability of the belt-type continuously variable transmission 2 is improved.
[0036]
In the embodiment of FIG. 1, the amount of oil supplied to the first hydraulic chamber 6 for controlling the speed ratio of the belt-type continuously variable transmission 2 or the amount of oil discharged from the first hydraulic chamber 6 is controlled. The case where the amount of oil supplied to the second hydraulic chamber 7 for controlling the torque capacity of the belt-type continuously variable transmission 2 or the amount of oil discharged from the second hydraulic chamber 7 is controlled has been described. It is also possible to apply this embodiment.
[0037]
Explaining the correspondence between the configuration of this embodiment and the configuration of the present invention, the first hydraulic chamber 6 and the second hydraulic chamber 7 correspond to the hydraulic chamber of the present invention, and the belt type continuously variable transmission. 2 corresponds to the power transmission state of the present invention, the ratio control valve 11 corresponds to the flow control valve of the present invention, and the belt type continuously variable transmission 2 corresponds to the transmission of the present invention. The oil passage 10 corresponds to the "oil passage formed between the flow control valve and the hydraulic chamber" of the present invention, and the hydraulic pressure Pin2 corresponds to the "oil pressure near the hydraulic chamber" of the present invention. , The hydraulic pressure Pin1 corresponds to the “hydraulic pressure at a location far from the hydraulic chamber” in the present invention, and includes a first feedback oil passage 25, a second feedback oil passage 26, a first feedback port 19, and a second feedback port 20. However, the present invention The spool 12 corresponds to the valve body of the present invention, and “when the spool 12 moves upward in FIG. 1” corresponds to “the valve body moves in the forward direction” in the present invention. "When the spool 12 operates downward in FIG. 1" corresponds to "when the valve element operates in the reverse direction" of the present invention.
[0038]
【The invention's effect】
As described above, according to the first aspect of the present invention, the oil supplied from the flow control valve to the hydraulic chamber based on the correspondence between the hydraulic pressure near the hydraulic chamber and the hydraulic pressure far from the hydraulic chamber. At least one of the amount and the amount of oil discharged from the hydraulic chamber via the flow control valve can be appropriately controlled, and a decrease in controllability of the power transmission state of the transmission can be suppressed.
[0039]
According to the second aspect of the invention, in addition to obtaining the same effect as the first aspect of the invention, when the valve element operates in the forward direction, the amount of oil supplied to the hydraulic chamber increases, and As a result, the amount of oil discharged from the hydraulic chamber decreases. On the other hand, when the valve element operates in the reverse direction, the amount of oil supplied to the hydraulic chamber decreases, and the amount of oil discharged from the hydraulic chamber increases.
[0040]
According to the third aspect of the invention, the same effect as that of the first or second aspect of the invention can be obtained, and in addition, the speed ratio control accuracy can be improved based on the oil amount of the hydraulic chamber.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hydraulic control apparatus, 2 ... Belt type continuously variable transmission, 3 ... Primary pulley, 6 and 7 ... Hydraulic chamber, 10 ... Oil passage, 11 ... Ratio control valve, 12 ... Spool, 19 ... First feedback port, Reference numeral 20: second feedback port, 24: orifice, 25: first feedback oil passage, 26: second feedback oil passage, F1, F2: biasing force, Pin1, Pin2: hydraulic pressure.

Claims (3)

A transmission whose power transmission state is controlled based on the amount of oil in the hydraulic chamber, and which controls the amount of oil communicated with the hydraulic chamber and supplied to the hydraulic chamber, and the amount of oil discharged from the hydraulic chamber. A hydraulic control device for a transmission having a flow control valve;
An oil passage formed between the flow control valve and the hydraulic chamber, wherein the flow control is performed based on a correspondence relationship between a hydraulic pressure at a location near the hydraulic chamber and a hydraulic pressure at a location far from the hydraulic chamber. An oil amount control mechanism is provided for controlling at least one of an oil amount supplied from a valve to the hydraulic chamber and an oil amount discharged from the hydraulic chamber via the flow control valve. A hydraulic control device for a transmission. The flow control valve has a valve body that can operate in the forward and reverse directions, and the flow control valve increases the amount of oil supplied to the hydraulic chamber when the valve body operates in the forward direction. And, while the amount of oil discharged from the hydraulic chamber decreases, when the valve element operates in the opposite direction, the amount of oil supplied to the hydraulic chamber decreases, and is discharged from the hydraulic chamber. And an orifice is arranged between the oil passage and a portion near and far from the hydraulic chamber, corresponding to the oil pressure at a portion near the hydraulic chamber. 2. An urging force applying mechanism for applying an urging force and an urging force corresponding to a hydraulic pressure at a location far from the hydraulic chamber to the valve body in a reverse direction is provided. Transmission hydraulic control device. The transmission is a belt-type continuously variable transmission in which a belt is wound around a primary pulley and a secondary pulley, and the power transmission state includes a gear ratio of the belt-type continuously variable transmission. The step transmission is configured such that the gear ratio is controlled by controlling the groove width of the primary pulley, and the groove width of the primary pulley changes based on the amount of oil in the hydraulic chamber. The hydraulic control device for a transmission according to claim 1 or 2, wherein

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