JP5476525B2 - Continuously variable transmission - Google Patents

Description

  The present invention relates to a continuously variable transmission.

  Conventionally, in a belt-type continuously variable transmission, Patent Document 1 discloses that a line pressure is increased and a slip of a belt stretched between pulleys is suppressed when a solenoid for controlling a hydraulic pressure supplied to the pulley fails. It is disclosed.

JP-A-6-207664

  However, when the hydraulic pressure supplied to the pulley is drained, for example, when a failure occurs in an actuator such as a solenoid, in the above invention, torque is transmitted to the pulley whose hydraulic pressure has decreased, causing the belt to slip. There is a problem that the pulley and the belt deteriorate.

  The present invention has been invented to solve such problems, and it is possible to suppress the transmission of torque to a pulley with reduced hydraulic pressure to cause slippage of the belt, and to suppress the deterioration of the pulley and the belt. The purpose is to do.

  A continuously variable transmission according to an aspect of the present invention is wound around an input-side primary pulley that changes the groove width by hydraulic pressure, an output-side secondary pulley that changes the groove width by hydraulic pressure, a primary pulley, and a secondary pulley. And a first hydraulic control means for supplying and discharging oil to and from the primary pulley or the secondary pulley, and by transmitting the power of the drive source to the drive wheel by fastening and driving wheel by releasing it. The first clutch mechanism that cuts off the transmission of power from the drive source to the engine and a part of the oil that is supplied and discharged by the first hydraulic control means are introduced, and the engagement force of the first clutch mechanism decreases as the pressure by the introduced oil decreases. And a second hydraulic control means for reducing the pressure.

  According to this aspect, when the pulley oil is discharged and the pulley pressure is reduced, the fastening force of the first clutch mechanism is reduced in conjunction with the reduction of the pulley pressure, so that torque is transmitted to the pulley whose hydraulic pressure has decreased. It is possible to suppress the occurrence of slippage in the belt and to suppress the deterioration of the pulley or the belt.

It is a schematic block diagram of the vehicle provided with the continuously variable transmission of 1st Embodiment of this invention. It is a figure which shows the relationship between the gear ratio in 1st Embodiment, a primary pulley pressure, and a secondary pulley pressure. 3 is a time chart showing a torque change or the like when an accelerator pedal is depressed in the first embodiment. In a 1st embodiment, it is a time chart which shows torque change etc. when a brake pedal is depressed. It is a schematic block diagram of the vehicle provided with the continuously variable transmission of 2nd Embodiment of this invention. In 2nd Embodiment, it is a time chart which shows the torque change etc. when a brake pedal is depressed. It is a schematic block diagram of the vehicle provided with the continuously variable transmission of 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A vehicle including a continuously variable transmission according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a vehicle having a continuously variable transmission according to the present embodiment.

  The vehicle includes an engine 1, a torque converter 2, and a continuously variable transmission 3.

  The engine 1 is a drive source for moving the vehicle forward and backward, and the rotation generated by the engine 1 is transmitted in the order of the torque converter 2, the continuously variable transmission 3, and the drive wheels (not shown).

  The continuously variable transmission 3 includes a forward / reverse switching mechanism 4, a variator 5, a first valve 6, a second valve 7, and a solenoid 8.

  The forward / reverse switching mechanism 4 includes a forward clutch 4 a and a reverse brake 4 b and is provided between the torque converter 2 and the variator 5. By controlling the oil supplied to and discharged from the forward clutch 4a and the reverse brake 4b, the forward / reverse switching mechanism 4 switches between the engaged state and the released state of the forward clutch 4a and the reverse brake 4b.

  When the forward clutch 4a is engaged and the reverse brake 4b is released, the rotation input via the torque converter 2 is transmitted to the variator 5 without reversing the rotation direction. On the other hand, when the forward clutch 4a is disengaged and the reverse brake 4b is engaged, the input rotation is transmitted to the variator 5 with its rotational direction reversed. The oil supplied to and discharged from the forward clutch 4a or the reverse brake 4b is controlled by a second valve 7 which will be described in detail. When oil is discharged from the forward clutch 4a or the reverse brake 4b by the second valve 7, the forward movement The clutch 4a or the reverse brake 4b is released. Therefore, transmission of rotation from the engine 1 to the variator 5 is interrupted.

  The forward clutch 4a or the reverse brake 4b is also supplied and discharged by another valve (not shown) arranged between the second valve and the forward / reverse switching mechanism 4, and the second valve 7 Even when is supplied, the fastening and releasing states are switched by other valves.

  The variator 5 includes a primary pulley 10, a secondary pulley 11, and a belt 12.

  The primary pulley 10 includes a fixed conical plate 10a and a movable conical plate 10b. The movable conical plate 10b moves along the axial direction by supplying and discharging oil adjusted to the primary pulley chamber 10c using the line pressure as the original pressure. As a result, the V-groove width formed by the fixed conical plate 10a and the movable conical plate 10b is changed. The rotation generated by the engine 1 is transmitted to the primary pulley 10 via the forward / reverse switching mechanism 4.

  The secondary pulley 11 includes a fixed conical plate 11a and a movable conical plate 11b. The movable conical plate 11b moves along the axial direction by supplying and discharging the oil regulated by the first valve 6 to the secondary pulley chamber 11c using the line pressure as the original pressure. As a result, like the primary pulley 10, the width of the V-groove between the fixed conical plate 11a and the movable conical plate 11b is changed. The rotation of the primary pulley 10 is transmitted to the secondary pulley 11 via the belt 12. The rotation of the secondary pulley 11 is transmitted to the drive wheels, and the vehicle moves forward and backward. In the present embodiment, the pressure receiving area of the secondary pulley 11 is smaller than the pressure receiving area of the primary pulley 10.

  The belt 12 is wound around the V groove of the primary pulley 10 and the V groove of the secondary pulley 11, and the fixed conical plate 10 a and the movable conical plate 10 b of the primary pulley 10, and the fixed conical plate 11 a and the movable conical plate of the secondary pulley 11. Frictionally engages 11b. The belt 12 transmits the rotation transmitted to the primary pulley 10 to the secondary pulley 11.

  The primary pulley pressure and the secondary pressure are controlled based on the operation state such as the accelerator pedal depression amount and the vehicle speed, and the variator 5 is continuously changed by changing the winding arc diameter of the belt 12 with respect to the primary pulley 10 and the secondary pulley 11. Shifting in is performed.

  The first valve 6 includes a spool (not shown) that moves based on the difference between the biasing force of the spring and the pressure controlled by the oil controlled by the solenoid 8, and supplies and discharges oil to and from the secondary pulley chamber 11c. The first valve 6 includes a first outlet port 6a that communicates with the secondary pulley chamber 11c, and a first inlet port 6b that is supplied with line pressure oil or a first discharge port 6c that discharges oil from the secondary pulley chamber 11c. It communicates according to the movement of the spool. The spring biases one end of the spool so that the first outlet port 6a and the first discharge port 6c communicate with each other. Oil is supplied to the other end side of the spool through a solenoid 8, and the spool is moved by controlling the supplied oil by the solenoid 8.

  Specifically, when the pressure of the oil controlled by the solenoid 8 is larger than the biasing force of the spring, the spool causes the first inlet port 6b and the first outlet port 6a to communicate with each other to the secondary pulley chamber 11c. Oil is supplied. When the urging force of the spring is larger than the oil pressure controlled by the solenoid 8, the spool communicates the first outlet port 6a and the first discharge port 6c, and the oil in the secondary pulley chamber 11c is discharged from the first. It is discharged through the port 6c.

  The second valve 7 is a spool that moves based on the difference between the biasing force of the spring and the pressure adjusted by the first valve 6, that is, the pressure by a part of the oil supplied to and discharged from the secondary pulley chamber 11 c (see FIG. (Not shown) for supplying and discharging oil to the forward / reverse switching mechanism 4. The second valve 7 includes a second outlet port 7a that communicates with the forward / reverse switching mechanism 4, a second inlet port 7b that is supplied with line pressure oil, or a second discharge port 7c that discharges the oil of the forward / reverse switching mechanism 4. Are communicated according to the movement of the spool. The spring biases one end of the spool so that the second outlet port 7a and the second discharge port 7c communicate with each other. A part of the oil that communicates with the secondary pulley chamber 11c and is supplied to and discharged from the secondary pulley chamber 11c flows into the other end of the spool. Therefore, the spool moves according to the hydraulic pressure in the secondary pulley chamber 11c.

  Specifically, when the pressure of the oil supplied to the end portion communicating with the secondary pulley chamber 11c is larger than the urging force of the spring, the spool connects the second outlet port 7a and the second inlet port 7b. The oil is supplied to the forward clutch 4 a or the reverse brake 4 b of the forward / reverse switching mechanism 4. When the urging force of the spring is larger than the pressure of the oil supplied to the end side communicating with the secondary pulley chamber 11c, the spool communicates the second outlet port 7a and the second discharge port 7c, and moves forward and backward. The oil supplied to the forward clutch 4a or the reverse brake 4b of the switching mechanism 4 is discharged through the second discharge port 7c.

  For example, the oil in the secondary pulley chamber 11c is discharged due to a valve stick due to contamination, a failure of the solenoid 8 (hereinafter referred to as an actuator failure), and the secondary pulley 11 has a hydraulic pressure that may cause the belt 12 to slip. When the pulley pressure decreases, the urging force of the spring becomes larger than the pressure of the oil supplied to the end side communicating with the secondary pulley chamber 11c of the second valve 7. As a result, the spool of the second valve communicates the second outlet port 7a and the second discharge port 7c, and the forward clutch 4a or the reverse brake 4b in the engaged state is discharged, and the forward clutch 4a in the engaged state is discharged. Alternatively, the reverse brake 4b is released.

  In the present embodiment, when the secondary pulley pressure decreases, the forward clutch 4a or the reverse brake 4b of the forward / reverse switching mechanism 4 is released by the second valve 7 in conjunction with the decrease of the secondary pulley pressure. .

  In this embodiment, since the pressure receiving area of the secondary pulley 11 is smaller than the pressure receiving area of the primary pulley 10, the hydraulic pressure for realizing the transmission ratio of the variator 5 has a relationship as shown in FIG. FIG. 2 is a diagram illustrating a relationship among the transmission ratio, the primary pulley pressure, and the secondary pulley pressure. In FIG. 2, the gear ratio is a value obtained by dividing the rotational speed of the primary pulley 10 by the secondary rotational speed, and becomes high when the gear ratio is small, and is low when the gear ratio is large.

  As shown in FIG. 2, the hydraulic pressure for realizing the gear ratio has a large region where the secondary pulley pressure is higher than the primary pulley pressure. That is, when the hydraulic pressure decreases, the belt 12 slips more easily in the secondary pulley 11 than in the primary pulley 10. For this reason, in the present embodiment, the forward clutch 4a or the reverse brake 4b of the forward / reverse switching mechanism 4 is released by the second valve 7 in conjunction with a decrease in the secondary pulley pressure.

  Next, changes in torque and the like when the actuator breaks down and the oil in the secondary pulley chamber 11c is discharged will be described with reference to time charts of FIGS. 3 and 4, a change in torque when the present embodiment is used is indicated by a solid line, and a change in torque when the present embodiment is not used is indicated by a broken line. Here, it is assumed that the forward clutch 4a of the forward / reverse switching mechanism 4 is engaged and the reverse brake 4b is released.

  First, the case where the accelerator pedal is depressed will be described with reference to FIG.

  At time t0, a failure occurs in the actuator, the first outlet port 6a and the first discharge port 6c communicate with each other in the first valve 6, the oil in the secondary pulley chamber 11c is discharged, and the secondary pulley pressure decreases. When the secondary pulley pressure decreases, in the second valve 7, the pressure on the end side of the spool communicating with the secondary pulley chamber 11c also decreases. Thereafter, when the urging force of the spring of the second valve 7 becomes larger than the pressure, the spool of the second valve 7 causes the second outlet port 7a and the second discharge port 7c to communicate with each other. As a result, the oil of the forward clutch 4a of the forward / reverse switching mechanism 4 is discharged, so the forward clutch 4a is released, the rotation is not transmitted from the engine 1 to the variator 5, and the torque transmitted to the variator 5 is reduced.

  When the accelerator pedal is depressed by the driver at time t1, in this embodiment, the forward clutch 4a of the forward / reverse switching mechanism 4 is released, so that no torque is transmitted from the engine 1 to the variator 5. Since the forward clutch 4a of the forward / reverse switching mechanism 4 is released, the engine torque slightly increases.

  On the other hand, when this embodiment is not used, the engine torque increases as the accelerator pedal is depressed. Further, since the forward clutch 4a of the forward / reverse switching mechanism 4 is engaged and torque is transmitted from the engine 1 to the variator 5, the slippage of the belt 12 occurs in the secondary pulley 11 in which the clamping force of the belt 12 is reduced due to the decrease in hydraulic pressure. Occurs.

  Next, the case where the brake pedal is depressed will be described with reference to FIG.

  If a failure occurs in the actuator at time t0, the secondary pulley pressure is reduced as in FIG. 3, and then the forward clutch 4a of the forward / reverse switching mechanism 4 is released.

  When the brake pedal is depressed at time t1, negative torque is applied to the secondary pulley 11. When this embodiment is not used, since the forward clutch 4a of the forward / reverse switching mechanism 4 is engaged, the negative torque applied to the secondary pulley 11 is increased by the inertia torque of the engine 1. Further, since the clamping force of the belt 12 in the secondary pulley 11 is small, the belt 12 is likely to slip in the secondary pulley 11.

  In this embodiment, the forward clutch 4a of the forward / reverse switching mechanism 4 is released, and the inertia torque of the engine 1 is not applied to the variator 5. Therefore, the negative torque applied to the secondary pulley 11 is compared with the case where this embodiment is not used. Thus, the belt 12 can be prevented from slipping.

  The effect of 1st Embodiment of this invention is demonstrated.

  When the actuator breaks down and the oil in the secondary pulley chamber is discharged, the secondary pulley pressure decreases, slippage occurs between the belt and the secondary pulley, and the secondary pulley or the belt may deteriorate.

  It is also possible to prevent torque from being transmitted to the secondary pulley by detecting the failure of the actuator and releasing the forward clutch and reverse brake of the forward / reverse switching mechanism so that the belt does not slip.

  However, a separate device for detecting the failure of the actuator is required, which increases the cost and makes the control complicated.

  Further, it is possible to detect a failure of the actuator based on the indicated pressure and the actual pressure of the secondary pulley. In this case, for example, it is determined that the actuator has failed when a predetermined time elapses when the differential pressure between the command pressure of the secondary pulley and the actual pressure is greater than a threshold value for determining failure. However, since the forward clutch is in the engaged state for a predetermined time, the torque is transmitted from the engine or the like to the secondary pulley during the predetermined time, and the belt may slip.

  On the other hand, in this embodiment, when the actuator breaks down and the oil in the secondary pulley chamber 11c is discharged and the secondary pulley pressure decreases, the second valve 7 advances the forward / reverse switching mechanism 4 in conjunction with the decrease in oil pressure. The hydraulic pressure of the clutch 4a or the reverse brake 4b is reduced, and the forward clutch 4a or the reverse brake 4b is released. Thereby, the torque transmitted to the variator 5 can be reduced, the slip of the belt 12 in the secondary pulley 11 can be suppressed, and the deterioration of the secondary pulley 11 and the belt 12 can be suppressed (corresponding to claim 1). Effect).

  By disposing the forward / reverse switching mechanism 4 between the engine 1 and the variator 5, the forward clutch 4a or the reverse brake 4b of the forward / reverse switching mechanism 4 is released when the actuator fails and the secondary pulley pressure decreases. . Thereby, the rotation transmitted from the engine 1 can be interrupted. Even when a negative torque is transmitted from the drive wheel side to the variator 5, transmission of rotation between the variator 5 and the engine 1 is interrupted, so that the inertia torque of the engine 1 is not applied to the variator 5, and the secondary pulley 11 can be reduced. Therefore, the slip of the belt 12 in the secondary pulley 11 can be suppressed, and deterioration of the secondary pulley 11 and the belt 12 can be suppressed (effect corresponding to claim 2).

  The slippage of the belt 12 in the variator 5 can be suppressed by releasing the forward clutch 4a or the reverse brake 4b of the forward / reverse switching mechanism 4 in conjunction with the hydraulic pressure of the secondary pulley 11 having a smaller pressure receiving area than the primary pulley 10. And the deterioration of the variator 5 and the belt 12 can be suppressed (effect corresponding to claim 5).

  Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 5 is a schematic configuration diagram of a vehicle including the continuously variable transmission 20 according to the present embodiment. The second embodiment will be described with a focus on differences from the first embodiment.

  The forward / reverse switching mechanism 21 includes a forward clutch 21a and a reverse brake 21b, and is provided between the variator 5 and the drive wheel. The forward / reverse switching mechanism 21 transmits the rotation input via the variator 5 to the drive wheels.

  The oil supplied to and discharged from the forward clutch 21a or the reverse brake 21b of the forward / reverse switching mechanism 21 is controlled by the third valve 22, and when the oil is discharged from the forward clutch 21a or the reverse brake 21b by the third valve 22, The forward clutch 21a or the reverse brake 21b is released.

  The configuration of the third valve 22 is the same as that of the second valve 7 of the first embodiment. The third valve 22 supplies oil to the forward clutch 21a or the reverse brake 21b of the forward / reverse switching mechanism 21 by communicating the third outlet port 22a and the third inlet port 22b. The third valve 22 discharges oil from the forward clutch 21a or the reverse brake 21b of the forward / reverse switching mechanism 21 by communicating the third outlet port and the third discharge port 22c.

  When the actuator fails, the oil in the secondary pulley chamber 11c is discharged, and the secondary pulley pressure decreases, the third valve 22 is interlocked with the forward clutch 21a or the reverse brake of the forward / reverse switching mechanism 21 that is in the engaged state. 21b is released.

  Next, a change in torque when the actuator breaks down, the oil in the secondary pulley chamber 11c is discharged, and the brake pedal is depressed will be described with reference to the time chart of FIG.

  At time t0, a failure occurs in the actuator, and the first outlet port 6a and the first discharge port 6c communicate with each other in the first valve 6, and the oil in the secondary pulley chamber 11c is discharged. When the secondary pulley pressure decreases, the forward clutch 21a is released in conjunction with the decrease of the secondary pulley pressure, and the torque of the secondary pulley 11 decreases.

  When the brake pedal is depressed at time t1, when the present embodiment is not used, the forward clutch 21a of the forward / reverse switching mechanism 21 is engaged, so that a negative torque is applied to the secondary pulley 11.

  When this embodiment is used, since the forward clutch 21a of the forward / reverse switching mechanism 21 is released, no negative torque is applied to the secondary pulley 11.

  The effect of 2nd Embodiment of this invention is demonstrated.

  A forward / reverse switching mechanism 21 is disposed between the engine 1 and the variator 5. When the actuator fails and the secondary pulley pressure decreases, the forward clutch 21a or the reverse brake 21b of the forward / reverse switching mechanism 21 is released. Thereby, when a negative torque is transmitted to the variator 5 from the drive wheel side, it is possible to prevent a negative torque from being applied to the secondary pulley 11. Therefore, slip of the belt 12 in the secondary pulley 11 can be suppressed, and deterioration of the secondary pulley 11 and the belt 12 can be suppressed (effect corresponding to claim 3).

  Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 7 is a schematic configuration diagram of a vehicle including the continuously variable transmission 30 according to the present embodiment. The third embodiment will be described with a focus on differences from the first embodiment.

  The continuously variable transmission 30 further includes an auxiliary transmission mechanism 31 and a fourth valve 32.

  The auxiliary transmission mechanism 31 is provided between the variator 5 and the drive wheel. The subtransmission mechanism 31 includes clutches 31a and 31b that change the subtransmission stage. The clutch 31 a and the clutch 31 b are engaged and disengaged when oil is supplied and discharged via the fourth valve 32.

  The configuration of the fourth valve 32 is the same as that of the second valve 7 of the first embodiment. The fourth valve 32 supplies oil to the clutch 31a or the clutch 31b of the auxiliary transmission mechanism 31 by communicating the fourth outlet port 32a and the fourth inlet port 32b. The fourth valve 32 discharges oil from the clutch 31a or the clutch 31b of the auxiliary transmission mechanism 31 by communicating the fourth outlet port 32a and the fourth discharge port 32c.

  When the actuator breaks down, the oil in the secondary pulley chamber 11c is discharged, and the secondary pulley pressure decreases, the fourth valve 32 releases the clutch 31a or the clutch 31b of the subtransmission mechanism 31 in conjunction with the decrease in the secondary pulley pressure. .

  The effect of the third embodiment of the present invention will be described.

  A forward / reverse switching mechanism 21 is disposed between the engine 1 and the variator 5, and an auxiliary transmission mechanism 31 is disposed between the variator 5 and the drive wheels. When the actuator fails and the secondary pulley pressure decreases, the forward clutch 21a or reverse brake 21b of the forward / reverse switching mechanism 21 and the clutch 31a or clutch 31b of the auxiliary transmission mechanism 31 are interlocked with the decrease of the secondary pulley pressure. release. Thereby, torque transmission from the engine 1 to the variator 5 can be suppressed by the forward / reverse switching mechanism 21, and torque transmission from the drive wheel side to the variator 5 can be suppressed by the auxiliary transmission mechanism 31. Can do. Therefore, the slip of the belt 12 in the secondary pulley 11 can be suppressed, and deterioration of the secondary pulley 11 and the belt 12 can be suppressed (effect corresponding to claim 4).

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

  Instead of the forward / reverse switching mechanism 21 of the second embodiment, a subtransmission mechanism having a forward / reverse switching function may be used.

  In the above embodiment, the clutch mechanism such as the forward / reverse switching mechanism 4 is released by, for example, the second valve 7 in conjunction with the decrease in the hydraulic pressure of the secondary pulley 11, but the present invention is not limited to this. When the pressure receiving area of the primary pulley 10 is smaller than the pressure receiving area of the secondary pulley 11, the clutch mechanism such as the forward / reverse switching mechanism 4 is released by the second valve 7 in conjunction with the decrease in the hydraulic pressure of the primary pulley 10. May be.

  Moreover, although the case where the engine 1 was used as a drive source was demonstrated in the said embodiment, you may apply to the electric vehicle or hybrid vehicle which is not restricted to the engine 1 and uses a motor. In the case of an electric vehicle, for example, a clutch mechanism such as a forward / reverse switching mechanism is disposed between the motor and the continuously variable transmission 3. In the case of a hybrid vehicle, for example, a clutch mechanism is disposed between the engine 1 and the motor.

  In the above-described embodiment, the clutch mechanism such as the forward / reverse switching mechanism is released by the second valve or the like in conjunction with the decrease in the secondary pulley pressure. The fastening force may be reduced.

  Moreover, in the said embodiment, although demonstrated as the power transmission member which wound the belt 12 around the primary pulley 10 and the secondary pulley 11, it is not restricted to this, It is the chain which connected the some link with the pin. Also good.

1 Engine (drive source)
3, 20, 30 Continuously variable transmission 4, 21 Forward / reverse switching mechanism (first clutch mechanism)
5 Variator 6 First valve (first hydraulic control means)
7 Second valve (second hydraulic control means)
10 Primary pulley 11 Secondary pulley 12 Belt (power transmission member)
22 3rd valve (2nd hydraulic control means)
31 Sub-transmission mechanism (second clutch mechanism)
32 4th valve (3rd hydraulic control means)

Claims (5)

A variator having an input-side primary pulley that changes the groove width by hydraulic pressure, an output-side secondary pulley that changes the groove width by hydraulic pressure, and a power transmission member wound around the primary pulley and the secondary pulley;
First hydraulic control means for supplying and discharging oil to the primary pulley or the secondary pulley;
A first clutch mechanism that transmits power of the drive source to the drive wheels by fastening, and interrupts transmission of power of the drive source to the drive wheels by releasing;
A continuously variable transmission comprising: a second hydraulic control unit that introduces a part of the oil to be supplied and discharged by the first hydraulic control unit, and reduces a fastening force of the first clutch mechanism as a pressure by the introduced oil decreases. .   The continuously variable transmission according to claim 1, wherein the first clutch mechanism is disposed between the drive source and the variator.   The continuously variable transmission according to claim 1, wherein the first clutch mechanism is disposed between the variator and the drive wheel. Arranged between the variator and the drive wheel, the rotation is transmitted between the variator and the drive wheel by fastening, and the rotation transmission between the variator and the drive wheel is blocked by releasing. A second clutch mechanism;
A portion of oil to be supplied and discharged by the first hydraulic control means is introduced, and third hydraulic control means for reducing the fastening force of the second clutch mechanism as the pressure by the introduced oil decreases. The continuously variable transmission according to claim 1.   5. The first hydraulic pressure control unit supplies and discharges oil to and from a pulley having a smaller pressure receiving area among the primary pulley and the secondary pulley. 6. Continuously variable transmission.

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