JP4655635B2 - Hydraulic control device with opposed connection of oil flow control valve - Google Patents

Description

  The present invention relates to a hydraulic control device, and in particular, when oil is supplied from a first port and oil is discharged from a second port, the operating state is changed in a first direction, and oil is supplied from a second port. The present invention relates to a hydraulic control device for a hydraulic servo device that changes an operating state in a second direction opposite to the first direction when oil is discharged from the first port.

  When the oil is supplied from the first port and the oil is discharged from the second port, the operating state is changed in the first direction, and conversely, the oil is supplied from the second port. A servomechanism that changes its operating state in a second direction opposite to the first direction when oil is supplied and discharged from the first port is, for example, in the field of vehicle technology a transmission, particularly a toroidal It is known in many machine configurations, such as in a type or belt type continuously variable transmission.

In order to operate the servo mechanism as described above, the oil supply from the pressure oil source is switched between the first and second ports, and at the same time, the second and first ports are connected to the oil drain passage. A hydraulic circuit device having a servo valve for switching is provided. The servo valve in such a hydraulic circuit device generally has two hydraulic supply ports, one of which is connected to the pressure oil supply passage according to the switching movement of the valve spool, and one of them connected to the oil discharge passage. This is a so-called 4-port type servo valve having two drain ports. Examples of a hydraulic circuit including such a 4-port servo valve for a toroidal-type continuously variable transmission are shown in Patent Documents 1 and 2 below.
JP2002-276786 JP-A-10-252878

  In the structure in which the operation of the servo mechanism is controlled by the 4-port type servo valve as described above, if a stick or the like is generated in the servo valve and the supply of hydraulic pressure to one port does not stop, one direction of the servo mechanism If the device incorporating the servo mechanism is a vehicle transmission, it becomes difficult to control the transmission ratio, and the transmission remains fixed at a high transmission ratio or a low transmission ratio. Such inconvenience may occur.

  In response to such a problem, according to Japanese Patent Application No. 2003-276598, when the oil is supplied from the first port and the oil is discharged from the second port, the operating state is changed in the first direction, and the oil is supplied from the second port. And a hydraulic control device for a hydraulic servo device that changes an operating state in a second direction opposite to the first direction when oil is supplied and discharged from the first port. First and second oil flow control valves having an oil supply control unit for controlling the supply of oil from the oil and an oil discharge control unit for controlling conduction to the oil discharge passage, and the first and second oil flows Control valve operation control means for controlling the operation of the control valve, wherein the first port can be supplied with oil from the oil supply control unit of the first oil flow control valve and Oil is discharged through the oil discharge control part of the second oil flow control valve. The second port can be supplied with oil from the oil supply control unit of the second oil flow control valve and the oil of the first oil flow control valve. Oil can be discharged through a discharge control unit, and the operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the control valve operation control means. A hydraulic control device is proposed which is characterized by

  According to the hydraulic control device having the first and second oil flow control valves as described above, as long as the first and second oil flow control valves are operating normally, the operating state of the hydraulic servo device is When changing to the first direction, set the second oil flow control valve to the state where the supply of oil from the pressure oil source is shut off and the conduction to the drain oil passage is shut off, and only the first oil flow control valve When the hydraulic servo device operating state should be changed to the second direction, the first oil flow control valve shuts off the oil supply from the pressure oil source and supplies the oil to the oil discharge passage. It is possible to do so by operating only the second oil flow control valve with the continuity cut off, and the first or second oil flow control valve has failed to stop supplying oil flow Occasionally, the operation of the second or first oil flow control valve causes the excess from the first or second oil flow control valve. You can escape the supply of such oil. However, when there is a failure that does not stop the supply of oil flow to the first or second oil flow control valve, at the same time, a failure that does not stop the conduction to the oil discharge passage from the first or second oil flow control valve. It is also when this happens. Therefore, when a failure that does not stop the supply of oil flow occurs in the first or second oil flow control valve, the other oil flow control valve in which the failure is not caused to flow from the oil flow control valve in which the failure has occurred However, the oil sent from the oil flow control valve which has not failed is released by the oil flow control valve in which the failure has occurred. There is a problem that the hydraulic pressure cannot be controlled. In many cases, the hydraulic servo device is acted upon by a load that tends to bias its operating state in one direction during its operation, such as the driving force in the case of a transmission control device for a transmission. If the hydraulic pressure is no longer controlled, the operating state of the hydraulic servo device may deviate in one direction to its end.

  The present invention addresses this problem and changes the operating state in the first direction when oil is supplied from the first port and discharged from the second port, and oil is supplied from the second port. When oil is discharged from the first port, a hydraulic control device for a hydraulic servo device that changes its operating state in a second direction opposite to the first direction, each of which is supplied with oil from a pressure oil source First and second oil flow control valves each having an oil supply control unit that controls supply of oil and an oil discharge control unit that controls conduction to the oil discharge passage, and the first and second oil flow control valves Control valve operation control means for controlling the operation, wherein the first port can be supplied with oil from the oil supply control unit of the first oil flow control valve and the second port. Oil can be discharged through the oil discharge control part of the oil flow control valve, The second port can be supplied with oil from the oil supply control unit of the second oil flow control valve, and the oil is discharged through the oil discharge control unit of the first oil flow control valve. A hydraulic control device configured to control an operating state of the hydraulic servo device by operating control of the first and second oil flow control valves by the control valve operation control means; When one of the first and second oil flow control valves fails to stop being connected to the oil discharge passage, the operating state of the hydraulic servo device is changed in the first or second direction to its end. The problem is to improve the system so that it will not end up.

  In order to solve the above problems, the present invention changes the operating state in the first direction when oil is supplied from the first port and discharged from the second port, and the oil is supplied from the second port. And a hydraulic control device for a hydraulic servo device that changes an operating state in a second direction opposite to the first direction when oil is supplied and discharged from the first port. First and second oil flow control valves having an oil supply control unit for controlling the supply of oil from the oil and an oil discharge control unit for controlling conduction to the oil discharge passage, and the first and second oil flows Control valve operation control means for controlling the operation of the control valve, wherein the first port can be supplied with oil from the oil supply control unit of the first oil flow control valve and The oil can be discharged through the oil discharge control unit of the second oil flow control valve. And the second port is adapted to be supplied with oil from the oil supply control unit of the second oil flow control valve, and the oil discharge control unit of the first oil flow control valve. Through which oil can be discharged, the operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the control valve operation control means, Further, the temporary discharge that can selectively prevent the oil discharge from the first port through the oil discharge control unit of the second oil flow control valve independently of the operation of the second oil flow control valve. The present invention provides a hydraulic control device having oil flow blocking means. In the present invention, the oil discharge from the second port through the oil discharge control unit of the first oil flow control valve is selected independently of the operation of the first oil flow control valve. It is not excluded to simultaneously provide a temporary oil flow blocking means capable of blocking.

  In the hydraulic control apparatus as described above, when the operation state of the hydraulic servo apparatus is to be changed to the first direction, the control valve operation control means moves the second oil flow control valve from the pressure oil source. This is done by operating only the first oil flow control valve in a state in which the oil supply is shut off and the conduction to the drainage passage is shut off. When the oil flow control valve does not cut off the conduction to the oil discharge passage due to some failure, the temporary oil flow blocking means may cut off the passage. Further, a throttle passage that bypasses the temporary oil flow blocking means may be provided.

  Further, the hydraulic control device includes the first oil flow prevention means that prevents the first oil from being discharged from the first port through the oil discharge control portion of the second oil flow control valve. Temporary oil supply means for supplying hydraulic pressure to the first port without passing through the oil supply control unit of the oil flow control valve may be provided. When such a temporary oil supply means is operated, a load such as a torque input to the hydraulic servo device may be controlled in accordance with the hydraulic pressure supplied from the temporary oil supply means.

  The hydraulic servo device may be a vehicle transmission, and the first port may be a port to which hydraulic pressure is supplied when the operating state of the vehicle transmission is changed to the upshift side, and the vehicle transmission is It may be a toroidal continuously variable transmission.

  Alternatively, according to the present invention, when the oil is supplied from the first port and the oil is discharged from the second port, the operating state is changed in the first direction, and the second port When the oil is supplied from the first port and discharged from the first port, the hydraulic control device for the hydraulic servo device changes the operating state in the second direction opposite to the first direction. First and second oil flow control valves each having an oil supply control unit that controls supply of oil from an oil source and an oil discharge control unit that controls conduction to an oil discharge passage; and Control valve operation control means for controlling the operation of the oil flow control valve, and the first port can be supplied with oil from the oil supply control unit of the first oil flow control valve. In addition, the oil can be discharged through the oil discharge control unit of the second oil flow control valve. The second port can be supplied with oil from the oil supply control unit of the second oil flow control valve and passes through the oil discharge control unit of the first oil flow control valve. The oil can be discharged, and the operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the control valve operation control means, and Temporary oil capable of selectively blocking the supply of oil to the second port via the oil supply control unit of the second oil flow control valve independently of the operation of the second oil flow control valve It is also achieved by a hydraulic control device characterized by having a flow blocking means.

  Also in this case, when the operating state of the hydraulic servo device is to be changed to the first direction, the control valve operation control means causes the second oil flow control valve to supply oil from the pressure oil source. It is in a state where it is shut off and the conduction to the oil drainage passage is shut off, and only the first oil flow control valve is operated to do so. In this case, the second oil flow control valve is When the supply of oil from the pressure oil source is not cut off due to some failure, the temporary oil flow blocking means may block it. Further, a throttle passage that bypasses the temporary oil flow blocking means may be provided.

  As described above, when the oil is supplied from the first port and the oil is discharged from the second port, the operating state is changed in the first direction, the oil is supplied from the second port, and the oil is supplied from the first port. In a hydraulic control device for a hydraulic servo device that changes an operating state in a second direction opposite to the first direction when oil is discharged, each oil supply controls oil supply from a pressure oil source First and second oil flow control valves having a control unit and an oil discharge control unit for controlling conduction to the oil discharge passage, and control valve operation for controlling the operation of the first and second oil flow control valves Control means, wherein the first port can be supplied with oil from the oil supply control section of the first oil flow control valve and the oil of the second oil flow control valve. The oil can be discharged through the discharge control unit, and the second port Is configured such that oil can be supplied from the oil supply control unit of the second oil flow control valve, and oil can be discharged through the oil discharge control unit of the first oil flow control valve. The operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the control valve operation control means, and further from the first port. Temporary oil flow blocking means capable of selectively blocking oil discharge through the oil discharge control unit of the second oil flow control valve independently of the operation of the second oil flow control valve is provided. Therefore, when the first and second oil flow control valves are operating normally, only the first or second oil flow control valve is operated to change the operating state of the hydraulic servo device in the first direction or the second direction. It can be changed in two directions, and the operating state of the hydraulic servo When the second oil flow control valve is to be changed in the first direction, or when the operating state of the hydraulic servo device should be prevented from excessively changing in the second direction, the second oil flow control valve is When the continuity of one port to the oil drain passage is not cut off, the temporary oil flow blocking means cuts it off, thereby preventing the operating state of the hydraulic servo device from being abnormally biased in the second direction. Or can be further biased in the first direction.

  That is, when the first and second oil flow control valves are operating normally, the second oil flow control valve is supplied from the pressure oil source when the operating state of the hydraulic servo device is to be changed to the first direction. When the oil supply is cut off and the conduction to the oil discharge passage is cut off, only the first oil flow control valve is controlled to do so, and the operating state of the hydraulic servo device should be changed to the second direction The first oil flow control valve shuts off the supply of oil from the pressure oil source and shuts off the conduction to the drain oil passage, and controls only the second oil flow control valve to perform it. All the operating states of the hydraulic servo device can be dealt with by controlling one oil flow control valve at a time each time, even if one 4-port control valve is divided into two. There is no complication in control.

  In addition, basically, when a stick occurs in the first oil flow control valve and the supply of oil from the first oil flow control valve does not stop, the second oil flow control valve is opened in the opening direction. When operated, the hydraulic servo device can be prevented from going beyond a predetermined target position in the first direction by appropriately releasing oil from the first oil flow control valve to the oil discharge passage. It is also possible to return the overshoot in the first direction of the hydraulic servo device to the original position. In this case, the first oil flow control is performed by appropriately increasing the opening of the second oil flow control valve unless the supply of oil from the first oil flow control valve does not stop fully opening. The function of changing the state of the hydraulic servo device in the second direction by overcoming the supply of oil that has stopped from the valve can be prevented from being lost. When a stick occurs in the second oil flow control valve and the supply of oil from the second oil flow control valve cannot be stopped, the same auxiliary control is obtained by the first oil flow control valve.

  However, when the hydraulic servo device receives a large load load that biases the operating state of the hydraulic servo device in one direction during operation, such as a shift control device of a toroidal type continuously variable transmission for a vehicle, the load If the oil discharge control part of the oil flow control valve that stops discharging oil from the port that receives the load does not close, the hydraulic servo unit will be able to supply oil to the port from the oil supply control part of the other oil flow control valve. There is a risk of being biased in the one direction by being pushed by the load. In this case, such a port is used as the first port, and an oil flow control valve that provides an oil discharge unit that discharges oil from the first port is used as the second oil flow control valve. Provided with temporary oil blocking means capable of selectively stopping oil discharge through the oil discharge control section of the second oil flow control valve independently of the operation of the second oil flow control valve. By operating it, it is possible to reliably prevent the hydraulic servo apparatus from being biased in the one direction even under the action of a large load.

  Further, if a throttle passage that bypasses the temporary oil flow blocking means is provided, an open stick is generated in the second oil flow control valve, and the first oil flow blocking means is activated even when the temporary oil flow blocking means is activated. Since a state in which oil is gradually and gradually removed from the port through the throttle passage is obtained, oil is being supplied to the other second port from the second oil flow control valve stuck in the open state In this case, the other first oil flow control valve is opened to supply oil to the first port, and at the same time the oil is discharged from the second port, and the first oil flow control valve is closed and the second oil flow control valve is closed. The oil pressure at the first port is controlled by controlling the execution time ratio (duty ratio) when oil supply to one port is stopped and oil discharge from the second port is stopped at the same time. Hydraulic pressure while maintaining the pressure required for effective operation of the servo device It is possible to change the operating states of the first and second directions of the turbo device.

  When the temporary oil flow blocking means prevents the oil from being discharged from the first port through the oil discharge control unit of the second oil flow control valve, the oil supply control unit of the first oil flow control valve is If the temporary oil supply means for supplying the hydraulic pressure from the pressure oil source to the first port without passing through is provided, the hydraulic pressure from the temporary oil supply means appropriately maintains the hydraulic pressure of the first port, and The hydraulic pressure at one port can be maintained at a pressure required for effective operation of the hydraulic servo device. In this case, if the load load such as torque input to the hydraulic servo device is controlled according to the hydraulic pressure supplied from the temporary oil supply means, the controlled input load load to the hydraulic servo device and the temporary oil supply means The operating state of the hydraulic servo device in the first and second directions can also be changed by balancing with the supplied hydraulic pressure.

  If the hydraulic servo device is a vehicle transmission and the first port is a port to which hydraulic pressure is supplied when the operating state of the vehicle transmission is changed to the upshift side, the hydraulic pressure is applied to the first port. Since the transmission cannot be obtained, it is avoided that the transmission is downshifted to the lowest speed, and shift controllability is ensured.

  When the hydraulic servo device is a shift control device for a toroidal-type continuously variable transmission, the control hydraulic pressure is required to be supplied as an individual hydraulic pressure only when the transmission is to be upshifted or downshifted. Therefore, the present invention in which individual hydraulic pressures are controlled by individual oil flow control valves is well suited for this.

  Further, when oil is supplied from the first port and oil is discharged from the second port, the operating state is changed in the first direction, oil is supplied from the second port, and oil is supplied from the first port. In a hydraulic control device for a hydraulic servo device that changes its operating state in a second direction opposite to the first direction when discharged, each oil supply controls the supply of oil from a pressure oil source First and second oil flow control valves having a control unit and an oil discharge control unit for controlling conduction to the oil discharge passage, and control valve operation for controlling the operation of the first and second oil flow control valves Control means, and the first port can be supplied with oil from the oil supply control section of the first oil flow control valve, and the oil of the second oil flow control valve. Oil can be discharged through a discharge control unit, and the second port is connected to the second port. The oil can be supplied from the oil supply control unit of the oil flow control valve and the oil can be discharged through the oil discharge control unit of the first oil flow control valve, The operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the control valve operation control means, and the oil of the second oil flow control valve is further controlled. If temporary oil flow blocking means capable of selectively blocking the supply of oil to the second port via the supply control unit independently of the operation of the second oil flow control valve is provided, When the first and second oil flow control valves are operating normally, only the first or second oil flow control valve is operated to change the operating state of the hydraulic servo device in the first direction or the second direction. Can change the operating state of the hydraulic servo device in the first direction. When it is to be changed, or when the operating state of the hydraulic servo device is to be prevented from excessively changing in the second direction, the second oil flow control valve may be brought into the second port due to some failure. When the supply of oil is not stopped, the temporary oil flow prevention means prevents the oil supply, and the supply of oil to the first port by the first oil flow control valve can effectively exert its effect. As a result, it is possible to prevent the operating state of the hydraulic servo device from being abnormally biased in the second direction, or to further bias it in the first direction.

  Also in this case, if a throttle passage that bypasses the temporary oil flow blocking means is provided, even if the supply of oil to the second port is blocked by the temporary oil flow blocking means, After that, since the gradual oil supply to the second port is performed, the first oil flow control valve faces the first port by facing the oil supply to the second port passing through the throttle passage. By controlling the oil supply, the operating state of the hydraulic servo device in the first and second directions is changed while maintaining the hydraulic pressure at the first port at a pressure necessary for effective operation of the hydraulic servo device. be able to.

  FIG. 1 attached herewith is a schematic diagram showing one embodiment in which the present invention is applied to a hydraulic control device for shift control of a toroidal-type continuously variable transmission. In the figure, reference numeral 10 denotes a power roller having a well-known structure as a toroidal-type continuously variable transmission, which is supported by a trunnion 12 via an eccentric shaft 14 between a pair of disks not shown in the figure. It is arranged in a state of being crushed and changes the gear ratio of the rotational power transmitted between the pair of disks by changing the tilt angle with respect to the pair of disks. The change of the tilt angle of the power roller with respect to the pair of disks is brought about by the trunnion 12 being temporarily displaced up and down in the drawing by the hydraulic actuator 16.

  That is, when the central axis of the power roller intersects the central axis of the disk, the driving disk exerts an influence on the power roller at the contact point with the power roller regardless of the tilt angle of the power roller with respect to the disk. The force acts parallel to the tilting axis of the power roller, and therefore the force that changes the tilting angle does not act on the power roller, but when the center axis of the power roller is displaced either up or down with respect to the center axis of the disc. If the displacement direction is a direction along the rotation direction of the disk as seen from the contact point between the power roller and the driving disk, a force in the direction of moving the power roller toward the center of the driving disk acts on the power roller. The power roller is tilted in the direction that increases the gear ratio (ie, the downshift direction), and conversely, the displacement direction is opposite to the disc rotation direction. If, in the power roller from acting the direction of the force away from the center of the drive-side disk it, the power roller is tilted in a direction to decrease small gear ratio (i.e. upshift direction).

  Thus, when the speed ratio should be kept constant, the trunnion is given a force that resists the driving force exerted on the power roller from the driving side disk, and the center axis of the power roller is the center of the driving disk (and hence the driven disk). When the gear ratio should be changed while maintaining the position intersecting the axis, the gear ratio can be increased or decreased by temporarily displacing the center axis of the power roller with respect to the center axis of the disk as needed. In the illustrated embodiment, the power roller 10 is driven downward at a contact point with a drive disk (not shown), and the power roller 10 drives its central axis. The gear ratio is changed to an increase side (i.e., downshifted) when displaced downward from a neutral position intersecting the central axis of the disk, and the gear ratio decreases when the power roller 10 is displaced upward from the neutral position. It is changed to the side (that is, upshifted).

  The hydraulic actuator 16 has a piston 18 connected to the lower end of the trunnion 12, a hydraulic chamber 20 formed below the piston, and a hydraulic chamber 22 formed above the piston. Oil is supplied into the hydraulic chamber 20, and the oil in the hydraulic chamber 22 is discharged from the port 26, so that the piston 18 is displaced upward to cause an upshift, and conversely the oil from the port 26 into the hydraulic chamber 22. Is supplied, and the oil in the hydraulic chamber 20 is discharged from the port 24, whereby the piston 18 is displaced downward to cause a downshift.

  A strong pressing force is applied between the power roller, the drive disk, and the driven disk so as to generate a frictional force sufficient to transmit the necessary rotational power. As described above, the power roller 10 is applied with a downward driving force from the drive side disk, and the trunnion and other gravitational forces are acting on the piston 18, so that these forces are required to displace the trunnion 12 upward. The power to resist is necessary. Oil treatment to bias the trunnion up and down is a so-called hydraulic control, but the shift control in the toroidal continuously variable transmission is essentially a control of the vertical displacement of the power roller, and the oil is not compressed. Therefore, the operation of the hydraulic control device that is the subject of the present invention is essentially the control of the amount of oil withdrawn into and out of the hydraulic chambers 20 and 22.

  The illustrated hydraulic control device for controlling oil supply / discharge to the hydraulic chambers 20 and 22 includes a pressure oil source 28 composed of a hydraulic pump or the like, two oil flow control valves 30 and 32, and a drain oil reservoir 34. It is out. The oil flow control valve 30 includes a valve housing 44 having an oil supply intake port 36, an oil supply extraction port 38, an oil discharge intake port 40, and an oil discharge port 42, and communication or blocking between the ports 36 and 38 and the port 40. A valve spool 46 that controls the communication or blocking between 42, a compression coil spring 48 that biases the valve spool to a position that blocks between ports 36 and 38 and between ports 40 and 42; An electromagnetic driving device 50 is included which drives the spool 46 to a position where it communicates between the ports 36 and 38 and between the ports 40 and 42 against the spring force of the compression coil spring 48.

  Similarly, the oil flow control valve 32 communicates or shuts off between the valve housing 60 including the oil supply intake port 52, the oil supply extraction port 54, the oil discharge intake port 56, and the oil discharge port 58, and the ports 52 and 54. A valve spool 62 that controls communication between the ports 56 and 58, and a compression coil spring 64 that biases the spool to a position that blocks between the ports 52 and 54 and blocks between the ports 56 and 58; And an electromagnetic drive device 66 for driving the valve spool 62 to a position where it communicates between the ports 52 and 54 and communicates between the ports 56 and 58 against the spring force of the compression coil spring 64.

  On the one hand, the pressure oil source 28 is connected to the oil supply intake port 36 of the oil flow control valve 30 through the oil passages 68 and 70, and the corresponding oil supply outlet port 38 is connected to the oil passages 72 and 74 through the toroidal type continuously variable. It is connected to the port 24 of the transmission. Corresponding to the oil supply path, the port 26 of the toroidal type continuously variable transmission is connected to the oil intake port 40 of the oil flow control valve 30 through the oil paths 76 and 78, and the oil discharge port 42 corresponding thereto is It is connected to the oil sump 34 through oil passages 80 and 82.

  On the other hand, the pressure oil source 28 is connected to the oil supply intake port 52 of the oil flow control valve 32 through the oil passages 68 and 84, and the corresponding oil supply outlet port 54 is connected to the toroidal type through the oil passages 86 and 76. It is connected to the port 26 of the continuously variable transmission. Corresponding to such an oil supply path, the port 24 of the toroidal-type continuously variable transmission is connected to an oil intake port 56 of the oil flow control valve 32 via oil paths 74 and 88, and a corresponding oil discharge port 58 corresponding thereto. Is connected to the oil sump 34 through oil passages 90 and 82. Energization of the oil flow control valves 30 and 32 to the electromagnetic driving devices 50 and 66 is controlled by a control valve operation control means 92 having a microcomputer.

  In the middle of the oil passage 90, the oil passage 90 is normally in a switching state as shown in FIG. 1, and the oil passage 90 is communicated. When the switching state is reversed, the switching valve 94 that shuts off the oil passage 90 is cut off. Is provided. Note that the switching valve 94 may be provided in the middle of the oil passage 88 as indicated by a virtual line in the drawing. The switching of the switching valve 94 to the shut-off position is a reduction in the hydraulic pressure in the passages 74 and 88 for discharging the oil from the port 24 when the hydraulic pressure in the hydraulic chamber 20 drops at a speed exceeding a predetermined reduction speed. The hydraulic pressure drop rate sensor 96 detects from the rate, the end position sensor 98 detects that the trunnion 12 is lowered to the lower end position, the power roller deflection angle sensor not shown in the figure, and the other oil flow control valve 32. May be performed in response to actuation of any sensor that senses that the user has stuck in the open position.

  In the above-described configuration, when an arbitrary speed change ratio should be reduced to a predetermined target value, the current Iu is first supplied only to the electromagnetic drive device 50 of the oil flow control valve 30 under the control of the control valve operation control means 92. Is supplied. As shown in FIG. 2A, when the current value becomes equal to or greater than Iuo, communication between the oil supply intake port 36 and the oil supply extraction 38 starts, and the supply hydraulic pressure to the piston chamber 20 of the toroidal continuously variable transmission reaches the maximum hydraulic pressure Pu1. Increases rapidly. However, since there is some oil leakage between the adjacent ports 36 and 38, the amount of oil Q (L / min) supplied to the piston chamber 20 of the toroidal continuously variable transmission is B in FIG. As shown in FIG. 6, the current Iu increases in proportion to the magnitude of the current Iu. In addition, the current supply to the electromagnetic drive devices 50 and 66 of the oil flow control valve may be performed by so-called duty control that repeats on / off at a relatively short cycle. In this case, Iu is proportional to the duty ratio, so in any case. Even so, the amount of oil Q supplied to the piston chamber 20 of the toroidal type continuously variable transmission is controlled in accordance with the current Iu. At this time, the port 26 on the opposite side is communicated with the oil sump 34 by communication between the oil removal port 40 and the oil removal port 42. The values of Id and the corresponding values of Pd and Q in A and B of FIG. 2 are supplied between the oil supply intake port 52 and the oil supply extraction 54 by supplying current to the electromagnetic drive device 66 of the oil flow control valve 32. The relationship between the electric current, the supply hydraulic pressure, and the oil amount with respect to the communication of.

  When the piston 18 is displaced upward in this manner, the power roller is deflected in a direction (upshift direction) to reduce the transmission gear ratio, and the resulting change in the transmission gear ratio is not shown in the figure. Is detected by a sensor or the like that detects the deflection angle, and the signal is sent to the control valve operation control means 92. As the speed ratio changes, the control valve operation control means 92 executes appropriate feedback control, and stops the supply current to the electromagnetic drive device 50 when a desired tilting occurs or is expected to occur in the power roller 10. Next, the current Id is supplied only to the electromagnetic drive device 66 of the oil flow control valve 32 to return the piston 18 to the neutral position. At this time, the hydraulic pressure Pd rapidly rises to the maximum value Pd1 when the current Id exceeds Ido. The piston chamber 22 of the toroidal type continuously variable transmission is supplied with an oil amount Q (L / min) corresponding to the current Id (however, considering the flow direction -Q (L / min)). Further, at this time, the port 24 on the opposite side is communicated with the oil sump 34 by the communication of the oil removal port 56 and the oil removal port 58.

  In the downshift control for increasing the transmission ratio of the continuously variable transmission, in contrast to the above, only the oil flow control valve 32 is first operated to displace the power roller 10 downward, and then only the oil flow control valve 30 is operated. The power rotor 10 is displaced upward and returned to the original neutral position.

  In such a configuration, during the downshift control in which the oil flow control valve 32 is operated to increase the transmission ratio of the continuously variable transmission, a stick caused by a foreign matter biting into the oil flow control valve 32 is being performed. Suppose that the valve spool 62 does not return to the fully closed position even when the electromagnetic drive device 66 is turned off. In this case, downshifting may continue and there may be a problem of being fixed at the maximum gear ratio.

  Therefore, such a stick in the open state of the oil flow control valve 32 is generated, which is detected by the oil pressure decrease rate sensor 96, the trunnion end position sensor 98, or a power roller deflection angle sensor not shown in the drawing. In this case, if the switching valve 94 is switched to the shut-off position to prevent the oil from being discharged from the port 24, the oil pressure opposite to the oil pressure Pd1 appearing at the oil supply take-out port 54 of the oil flow control valve 32 (-in FIG. The hydraulic pressure corresponding to the sum of the hydraulic pressure corresponding to the downward load load can be generated in the hydraulic chamber 20 in the diagram of Pd1) and the trunnion 12, and the abnormal speed ratio increase of the continuously variable transmission is immediately stopped. be able to. The oil flow control valve 32 sticks to the open position, and the oil pressure in the oil passages 74 and 88 drops suddenly. Accordingly, the trunnion 12 falls to the lower end position, thereby causing the power roller 10 to increase the speed ratio. Therefore, the switching valve 94 is immediately switched in response to the operation of the hydraulic pressure drop rate sensor 96 and the trunnion end position sensor 98, and the oil flow control valve 30 is controlled to open if necessary. Thus, a rapid increase in the gear ratio can be prevented.

  In addition, during the upshift control in which the oil flow control valve 30 is operated to reduce the gear ratio of the continuously variable transmission, a stick due to foreign matter biting or the like occurs in the oil flow control valve 30 and electromagnetic drive is performed. If the valve spool 46 does not return to the fully closed position even when the power to the device 50 is cut off, the trunnion 12 will face downward in the drawing applied to the hydraulic chamber 20 of the continuously variable transmission. There is a fear that the continuously variable transmission will be in a state of being fixed at the minimum gear ratio by rising against the load. If the transmission is fixed to the minimum transmission ratio, there is a possibility that the vehicle cannot be restarted, but there is no danger due to the occurrence during running. In this case, if the oil flow control valve 32 is appropriately opened to supply oil to the hydraulic chamber 22 and the oil is allowed to escape from the hydraulic chamber 20 before the vehicle restarts, it can be temporarily dealt with. .

  Further, the oil flow control valves 30 and 32 may be energized to the electromagnetic drive device 50 or 66 due to a failure of the electrical system related to the electromagnetic drive device 50 or 66 or the entry of foreign matter in the valve seat. There is also a possibility that the intended displacement of the valve spool does not occur, and the desired pressure oil does not appear at the oil supply outlet port 38 or 54.

  If the oil flow control valve 30 is not opened, the upshift cannot be performed, and the continuously variable transmission is finally downshifted to the maximum reduction ratio by applying a downward load to the trunnion 12 in the figure. However, when the oil flow control valve 32 does not open, it is possible to perform shift control by the oil flow control valve 30 using the action of a load applied to the trunnion 12 downward in the drawing.

  FIG. 3 is a view similar to FIG. 1 showing an embodiment in which a bypass passage 102 having a restriction 100 for bypassing the switching valve 94 in the embodiment shown in FIG. 1 is provided. If such a throttle bypass passage is provided, an open stick is generated in the oil flow control valve 32, and even when the switching valve 94 is closed, the oil is gradually discharged from the port 24 through the throttle passage. Therefore, even when oil is being supplied to the port 22 from the oil flow control valve 32 that is stuck in the open state, the oil flow control valve 30 is opened and oil is supplied to the port 24 at the same time. Controlling the operating time ratio (duty ratio) in a state in which more oil is discharged and in a state in which oil supply to the port 24 is stopped by closing the oil flow control valve 30 and oil discharge from the port 26 is also stopped. Thus, the gear ratio can be changed in the upshift direction or the downshift direction while maintaining the hydraulic pressure at the port 24 at a pressure necessary to support the load applied to the trunnion.

  FIG. 4 shows that when an open stick is generated in the oil flow control valve 32 in place of the switching valve 94 in the embodiment shown in FIG. 1, the oil flow control valve 32 passes through the discharge ports 56 and 58. FIG. 2 is a view similar to FIG. 1 showing an embodiment in which a switching valve 104 is provided that can shut off an oil discharge passage of the port 24 and supply an appropriate hydraulic pressure Pm from another hydraulic source toward the port 24. . In this way, when the oil is prevented from being discharged from the port 24 through the discharge ports 56 and 58 of the oil flow control valve 32, if temporary oil supply means for supplying oil from another pressure oil source to the port 24 is provided, The hydraulic pressure at the port 24 is appropriately maintained by the hydraulic pressure from the temporary oil supply means, and the gear ratio is increased or decreased in the upshift direction while maintaining the hydraulic pressure at the port 24 at a pressure necessary to support the load applied to the trunnion. Changing to the shift direction can be performed more appropriately. In this case, if the load torque acting on the transmission is controlled in accordance with the hydraulic pressure Pm supplied from the temporary oil supply means, it is possible to control the upshift or the downshift.

  FIG. 5 is a view similar to FIG. 4 showing an embodiment in which a bypass passage 102 including a throttle 100 for bypassing the switching valve 104 in the embodiment shown in FIG. 4 is provided. Even when the temporary oil supply means by the switching valve 104 is provided, if the throttle bypass passage is provided for the switching valve 104, an open stick is generated in the oil flow control valve 32, and the temporary oil supply means is When in operation, a state is obtained in which the oil is continuously and gradually discharged from the port 24 through the throttle passage, so that the oil is being supplied to the port 22 from the oil flow control valve 32 that is stuck in the open state. Even if there is, the oil flow control valve 30 is opened while the oil is supplied to the port 24 by the temporary oil supply means, the oil is supplied to the port 24 and at the same time the oil is discharged from the port 22, and the oil flow control valve 30 is closed. By controlling the duty ratio in a state where the oil supply to the port 24 is stopped but the oil discharge from the port 26 is also stopped, the hydraulic pressure at the port 24 is applied to the trunnion. While maintaining the pressure required to support the weight, it is possible to suitably perform varying the gear ratio to the upshift direction or downshift direction.

  6 is replaced with the switching valve 94 in the embodiment shown in FIG. 1, and passes through the oil supply ports 52 and 54 of the oil flow control valve 32 when an open stick is generated in the oil flow control valve 32. FIG. 2 is a view similar to FIG. 1 showing an embodiment in which a switching valve 106 capable of blocking oil supply from a port 26 is provided in the middle of an oil passage 86. In this way, when an open stick is generated in the oil flow control valve 32, if the oil supply to the port 26 of the hydraulic actuator 16 through the oil supply ports 52 and 54 is blocked, the oil flow control valve 30 is controlled. Thus, by supplying hydraulic pressure to the port 24 of the hydraulic actuator 16, the piston 18 can be prevented from being lowered too much by the open state stick of the oil flow control valve 32, and the piston 18 can be pushed back upward if necessary. . This is possible even when the downward force is applied to the piston 18 by the driving torque from the roller 10 in the figure. The switching valve 106 may be provided in the middle of the oil passage 84 as indicated by a virtual line in the drawing.

  FIG. 7 is a view similar to FIG. 6 showing an embodiment in which a bypass passage 110 provided with a throttle 108 for bypassing the switching valve 106 in the embodiment shown in FIG. 6 is provided. If such a throttle bypass passage is provided, an open stick is generated in the oil flow control valve 32 and oil is continuously supplied to the port 26 through the throttle passage even when the switching valve 106 is closed. Therefore, even when oil is being supplied to the port 26 from the oil flow control valve 32 that is stuck in the open state, the oil flow control valve 30 is opened and oil is supplied to the port 24, and at the same time, the oil is supplied from the port 26. By controlling the operating time ratio (duty ratio) in a state in which the oil flow control valve 30 is closed and the oil supply to the port 24 is stopped, and the oil discharge from the port 26 is stopped at the same time, The gear ratio can be changed in the upshift direction or the downshift direction while maintaining the hydraulic pressure at the port 24 at a pressure necessary to support the load applied to the trunnion.

  While the present invention has been described in detail with respect to several embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention. .

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows one embodiment which applied this invention to the hydraulic control apparatus for shift control of a toroidal type continuously variable transmission. 2 is a graph showing the operation of the hydraulic control device shown in FIG. 1, and FIG. A shows the supply currents Iu and Id to the electromagnetic drive devices 50 and 66 of the oil flow control valves 30 and 32 and the pressure supplied to the hydraulic chambers 20 and 22. FIG. B shows the relationship between the currents Iu and Id and the pressures Pu and Pd of the pressure oil supplied to the hydraulic chambers 20 and 22. FIG. 3 is a schematic view showing another embodiment in which a throttle bypass passage 102 is provided in the switching valve 94 of the hydraulic control device shown in FIG. 1. Schematic which shows another one Embodiment which replaced with the switching valve 94 of the hydraulic control apparatus shown in FIG. 1, and provided the switching valve 104. FIG. FIG. 6 is a schematic view showing another embodiment in which a throttle bypass passage 102 is provided in the switching valve 104 of the hydraulic control device shown in FIG. 4. Schematic which shows another one Embodiment which replaced with the switching valve 94 of the hydraulic control apparatus shown in FIG. 1, and provided the switching valve 106. FIG. FIG. 7 is a schematic view showing another embodiment in which a throttle bypass passage 110 is provided in the switching valve 106 of the hydraulic control device shown in FIG. 6.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Power roller, 12 ... Trunnion, 14 ... Eccentric shaft, 16 ... Hydraulic actuator, 18 ... Piston, 20, 22 ... Hydraulic chamber, 24, 26 ... Port, 28 ... Pressure oil source, 30, 32 ... Oil flow control valve , 34 ... Oil reservoir, 36 ... Oil supply port, 38 ... Oil supply port, 40 ... Oil supply port, 42 ... Oil discharge port, 44 ... Valve housing, 46 ... Valve spool, 48 ... Compression coil spring, 50 ... Electromagnetic drive device, 52 ... Oil supply port, 54 ... Oil supply port, 56 ... Oil supply port, 58 ... Oil extraction port, 60 ... Valve housing, 62 ... Valve spool, 64 ... Compression coil spring, 66 ... Electromagnetic Drive device, 68 to 90 ... oil passage, 92 ... control valve operation control means, 94 ... switching valve, 96 ... hydraulic pressure drop rate sensor, 98 ... trunnion end position sensor, 100 ... throttle, 02 ... bypass passage, 104, 106 ... switching valve, 108 ... aperture, 110 ... bypass passage

Claims (5)

When the oil is supplied from the first port and the oil is discharged from the second port, the operating state is changed in the first direction, the oil is supplied from the second port, and the oil is discharged from the first port. An oil supply control unit for a hydraulic servo device that changes an operating state in a second direction opposite to the first direction, each of which controls an oil supply from a pressure oil source; A first and second oil flow control valve having an oil discharge control unit for controlling conduction to the oil drain passage, and a control valve operation control means for controlling the operation of the first and second oil flow control valves; The first port can be supplied with oil from the oil supply control unit of the first oil flow control valve and the oil discharge control unit of the second oil flow control valve Oil can be discharged via the second port and the second port is connected to the second oil stream. Oil can be supplied from the oil supply control unit of the control valve, and oil can be discharged through the oil discharge control unit of the first oil flow control valve. The operation state of the hydraulic servo device is controlled by the operation control of the first and second oil flow control valves by the operation control means, and further the second oil flow control from the first port. A temporary oil flow blocking means capable of selectively blocking oil discharge through the oil discharge control section of the valve independently of the operation of the second oil flow control valve; and the temporary oil flow blocking means Without passing through the oil supply control unit of the first oil flow control valve when the oil discharge from the first port through the oil discharge control unit of the second oil flow control valve is blocked. this has a temporary oil supply means for supplying hydraulic pressure to the first port Hydraulic control device according to claim.   The control valve operation control means shuts off the supply of oil from the pressure oil source and discharges the second oil flow control valve when the operating state of the hydraulic servo device is to be changed to the first direction. This is done by operating only the first oil flow control valve in a state in which conduction to the oil passage is cut off, and at this time, the second oil flow control valve is not discharged due to some failure. 2. The hydraulic control device according to claim 1, wherein when the conduction to the oil passage is not cut off, the temporary oil flow blocking means cuts off the passage.   3. The hydraulic control apparatus according to claim 1, further comprising a throttle passage that bypasses the temporary oil flow blocking means.   The hydraulic servo device is a vehicle transmission, and the first port is a port to which hydraulic pressure is supplied when the operating state of the vehicle transmission is changed to the upshift side. The hydraulic control apparatus in any one of -3.   5. The hydraulic control apparatus according to claim 4, wherein the vehicle transmission is a toroidal continuously variable transmission.

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