JP2021038767A - Hydraulic circuit - Google Patents

Abstract

To provide a hydraulic circuit to be suitably used for a belt-type continuously variable transmission adopting clutch fuse control.SOLUTION: In an ON-state of an on/off valve 105, a spool 142 of a shift valve 104 is located at a control position so that a linear solenoid pressure output from a linear solenoid valve 103 is input to a second input port 152 of the shift valve 104 and the linear solenoid pressure is output from the shift valve 104 and supplied to a forward clutch 52 or a reverse clutch 54. On the other hand, in an OFF-state of the on/off valve 105, a spool 142 is located at a fail position so that a clutch modulator pressure output from a clutch modulator valve 102 is input to a clutch modulator pressure input port and the clutch modulator pressure is supplied to the forward clutch 52 or the reverse clutch 54.SELECTED DRAWING: Figure 2A

Description

The present invention relates to a hydraulic circuit.

A belt-type continuously variable transmission (CVT) is known as a transmission mounted on a vehicle such as an automobile.

The belt-type continuously variable transmission has a configuration in which an endless belt is wound around a primary pulley and a secondary pulley. Each pulley of the primary pulley and the secondary pulley is supported by a fixed sheave that is fixedly supported by the rotating shaft and is supported by the rotating shaft so as to be movable in the axial direction and not relative to rotation, and faces the fixed sheave with a belt in between. It is equipped with a movable sheave. When the power from the engine is input to the rotating shaft of the primary pulley, the power is transmitted from the primary pulley to the belt, and the power is transmitted from the belt to the secondary pulley. Further, the movement of each movable sheave of the primary pulley and the secondary pulley changes the winding diameter of the belt with respect to the primary pulley and the secondary pulley, and the gear ratio (pulley ratio) continuously and steplessly changes.

In a vehicle equipped with a belt-type continuously variable transmission, for example, when the vehicle gets over a protrusion such as a speed breaker (speed bump) or when the drive wheel regains grip from a state where it is slipping against the road surface. In addition, belt slippage may occur between the pulley and the belt. That is, if the drive wheels of the vehicle rise from the road surface when overcoming the protrusions, or if the drive wheels slip against the road surface, the rotation speed of the output shaft increases, and then the drive wheels grip against the road surface. Occasionally, the torque input to the drive wheels from the road surface causes the rotation speed of the output shaft to decrease sharply, and the inner shuttlek due to the sudden decrease may cause the belt to slip with respect to the pulley.

In order to prevent the occurrence of belt slippage, a clutch is provided on the power transmission path between the secondary pulley and the drive wheels, and the transmission torque capacity (clutch torque capacity) of the clutch is calculated from the transmission torque capacity (belt torque capacity) of the belt. A technique to set the torque small has been proposed. If the clutch torque capacity is smaller than the belt torque capacity, the clutch slips before the belt when an excessive torque is input to the drive wheels from the road surface, so that the occurrence of belt slip can be prevented.

Japanese Unexamined Patent Publication No. 4-231765 Japanese Unexamined Patent Publication No. 2000-193081

However, depending on the hydraulic circuit that supplies the oil pressure to the clutch, a configuration is adopted in which a constant pressure is supplied to the clutch in the engaged state to maintain the engaged state. In the hydraulic circuit adopting this configuration, the hydraulic pressure supplied to the engaged clutch cannot be increased or decreased, and the clutch torque capacity cannot be increased or decreased. Therefore, the hydraulic circuit cannot be used for a continuously variable transmission that employs a control (clutch fuse control) that prevents the occurrence of belt slippage by making the clutch torque capacity smaller than the belt torque capacity.

An object of the present invention is to provide a hydraulic circuit that can be suitably used for a belt-type continuously variable transmission that employs clutch fuse control.

In order to achieve the above object, the hydraulic circuit according to the present invention is a hydraulic circuit of a transmission including an engaging element, in which a source pressure is input and the input source pressure is adjusted to a predetermined modulator pressure. The modulator valve that outputs the data, the modulator pressure that is output from the modulator valve is input, and the input modulator pressure is adjusted to the engaging pressure that engages the engaging element and output. It is provided with a modulator pressure input port for inputting a modulator pressure to be input, an engagement pressure input port for inputting an engagement pressure output from a solenoid valve, and a spool movable between a control position and a fail position. Outputs the engagement pressure input to the engagement pressure input port as the hydraulic pressure supplied to the engagement element when is located in the control position, and is input to the modulator pressure input port when the spool is located in the fail position. The shift valve that outputs the modulator pressure to be supplied as the hydraulic pressure to the engaging element and the modulator pressure output from the modulator valve are input, the input modulator pressure is output in the on state, and the modulator pressure is output in the off state. The shift valve includes when the modulator pressure output from the on / off valve is input, including an on / off valve that stops the output of and is turned on for engagement transients and engagement retention of the engaging elements. The spool is located at the control position, and the spool is located at the fail position when there is no input of the modulator pressure.

According to this configuration, the original pressure is input to the modulator valve, and the modulator valve adjusts the original pressure to the modulator pressure and outputs it. The modulator pressure output from the modulator valve is input to the solenoid valve, and the solenoid valve adjusts the modulator pressure to the engagement pressure and outputs it. The modulator pressure output from the modulator valve is input to the on / off valve.

When the on / off valve is on, the modulator pressure is output from the on / off valve, the modulator pressure is input to the shift valve, and the spool of the shift valve is positioned at the control position. Then, in this state, the engaging pressure output from the solenoid valve is input to the engaging pressure input port of the shift valve, and the engaging pressure is output from the shift valve and supplied to the engaging element.

The engagement pressure can be increased or decreased by controlling the energization of the solenoid valve. The transmission torque capacity of the engaging element can be increased or decreased by increasing or decreasing the engaging pressure. Therefore, this hydraulic circuit is suitable for a continuously variable transmission that employs clutch fuse control that prevents the occurrence of belt slippage by making the transmission torque capacity of the engaging element smaller than the transmission torque capacity of the belt of the continuously variable transmission mechanism. Can be used for.

On the other hand, in the off state of the on / off valve, the output of the modulator pressure from the on / off valve is stopped, so that there is no input of the modulator pressure from the on / off valve to the shift valve. Therefore, the spool is located at the fail position. In this state, the modulator pressure output from the modulator valve is input to the modulator pressure input port, and the modulator pressure is supplied to the engaging element.

When a power loss fail occurs, the on / off valve is turned off so that the shift valve supplies modulator pressure to the engaging element. This engages the engaging elements. Therefore, even if the engaging element is a clutch that transmits / shuts off the power for traveling the vehicle, the clutch is engaged when a power loss fail occurs, so that the clutch is engaged for traveling the vehicle from the transmission. It is possible to output the power of the vehicle and secure the running of the vehicle.

The modulator valve preferably has a feedback port into which the engaging pressure supplied to the engaging element is input, and has a configuration in which the modulator pressure is reduced according to the engaging pressure input to the feedback port. ..

As a result, the modulator pressure input to the solenoid valve is reduced, so that the differential pressure between the modulator pressure and the engaging pressure output from the solenoid valve can be reduced, and the override characteristics of the solenoid valve can be improved.

According to the present invention, it can be suitably used for a belt-type continuously variable transmission that employs clutch fuse control.

It is a skeleton diagram which shows the structure of the drive system of a vehicle. It is a circuit diagram which shows the structure of the hydraulic circuit which concerns on one Embodiment of this invention, and also shows the flow of the oil when the input torque is a high torque state, and the shift range is an R range. It is a circuit diagram which shows the structure of the hydraulic circuit, and also shows the flow of the oil when the input torque is a high torque state, and the shift range is a D range. It is a circuit diagram which shows the structure of the hydraulic circuit, and also shows the flow of the oil when the input torque is a low torque state, and the shift range is an R range. It is a circuit diagram which shows the structure of the hydraulic circuit, and also shows the flow of the oil when the input torque is a low torque state, and the shift range is a D range. It is a figure which shows the relationship between a line pressure (PL pressure) and a clutch modulator pressure. It is a figure which shows the shift range, the running state, the state of a linear solenoid valve, the state of an on / off valve, the state of the output pressure of an engagement clutch and a shift valve in a list. It is a circuit diagram which shows the structure of the hydraulic circuit which concerns on the modification.

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

<Vehicle drive system>
FIG. 1 is a skeleton diagram showing the configuration of the drive system of the vehicle 1.

The vehicle 1 is equipped with an engine 2 as a drive source, and adopts, for example, an FR (Front-engine Rear-wheel-drive) layout. The engine 2 is, for example, a 3-cylinder 4-stroke engine, and the crankshaft 3 is placed vertically in the front portion of the vehicle 1 so as to be vertically oriented with respect to the front-rear direction (hereinafter, simply referred to as “front-rear direction”) of the vehicle 1. It will be installed. The power of the engine 2 is input to the transmission unit 4. The power output from the transmission unit 4 is transmitted to the differential gear 6 via the propeller shaft 5, and is transmitted from the differential gear 6 to the left and right drive wheels (rear wheels) 7L and 7R.

The engine 2 is not limited to a 3-cylinder 4-stroke engine. The number of cylinders of the engine 2 is not limited to 3 cylinders, and may be 4 cylinders or more, or 2 cylinders or less. Further, the number of strokes of the engine 2 is not limited to 4 strokes, and may be 2 strokes.

The transmission unit 4 includes a torque converter 8 and a CVT 9 in a unit case forming an outer shell.

The torque converter 8 is a torque converter with a lockup mechanism, and includes a front cover 11, a pump impeller 12, a turbine runner 13, and a lockup clutch (lockup piston) 14.

The front cover 11 extends in a substantially disk shape around a rotation axis extending in the front-rear direction, and its outer peripheral end portion is bent toward the rear side opposite to the engine 2 side. The crankshaft 3 of the engine 2 is coupled to the central portion of the front cover 11 so as not to rotate relative to each other.

The pump impeller 12 is arranged behind the front cover 11. The outer peripheral end of the pump impeller 12 is connected to the outer peripheral end of the front cover 11, and the pump impeller 12 is provided so as to be rotatable integrally with the front cover 11.

The turbine runner 13 is arranged between the front cover 11 and the pump impeller 12.

The lockup clutch 14 is located between the front cover 11 and the turbine runner 13. When the oil pressure of the engagement side oil chamber 15 on the turbine runner 13 side is higher than the oil pressure of the release side oil chamber 16 on the front cover 11 side with respect to the lockup clutch 14, the lockup clutch 14 is moved to the front cover due to the differential pressure. Moving to the 11 side, the lockup clutch 14 is pressed against the front cover 11, and the pump impeller 12 and the turbine runner 13 are directly connected (lockup on).

On the contrary, when the oil pressure of the release side oil chamber 16 is higher than the oil pressure of the engagement side oil chamber 15, the lockup clutch 14 moves to the turbine runner 13 side due to the differential pressure. When the lockup clutch 14 is separated from the front cover 11, the direct connection between the pump impeller 12 and the turbine runner 13 is released (lockup off). When the pump impeller 12 is rotated by the engine torque in the lock-up-off state, an oil flow from the pump impeller 12 to the turbine runner 13 is generated. This oil flow is received by the turbine runner 13, and the turbine runner 13 rotates. At this time, the amplification action of the torque converter 8 occurs, and a torque larger than the engine torque is generated in the turbine runner 13.

The CVT 9 includes an input shaft 21, a continuously variable transmission mechanism 22, a reverse transmission mechanism 23, and an output shaft 24. The CVT 9 is provided so that the input shaft 21 extends in the front-rear direction in the vertical direction.

The input shaft 21 extends on the rotation axis of the torque converter 8 and is provided so as to be rotatable integrally with the turbine runner 13 of the torque converter 8. The input shaft gear 25 is integrally formed with the input shaft 21, or the input shaft gear 25 formed separately is supported so as not to rotate relative to each other.

The continuously variable transmission mechanism 22 includes a primary shaft 31, a secondary shaft 32, a primary pulley 33, a secondary pulley 34, and a belt 35.

The primary shaft 31 is arranged at a position where its axis is separated from the center of the input shaft 21 to the lower right when viewed from the rear side, and extends parallel to the input shaft 21. The secondary shaft 32 is arranged at a position where its axis is separated from the center of the input shaft 21 toward the upper left when viewed from the rear side, and extends parallel to the input shaft 21. In this way, the primary shaft 31 and the secondary shaft 32 are separately arranged on the left and right sides with respect to the input shaft 21. As a result, the distance between the primary shaft 31 and the secondary shaft 32 in the vertical direction can be shortened, and the size of the CVT 9 in the vertical direction can be reduced. Therefore, even if the vehicle 1 is a vehicle such as a commercial vehicle having a low floor, it is possible to mount the speed change unit 4 on the vehicle 1 while ensuring the minimum ground clearance of the vehicle 1. ..

The primary pulley 33 is arranged to face the primary fixed sheave 41 fixed to the primary shaft 31 with the belt 35 sandwiched between the primary fixed sheave 41, and is supported by the primary shaft 31 so as to be movable in the axial direction and not to rotate relative to each other. It is equipped with a primary movable sheave 42. The primary movable sheave 42 is arranged on the front side with respect to the primary fixed sheave 41.

A cylinder 43 is provided on the side opposite to the primary fixed sheave 41 side with respect to the primary movable sheave 42, that is, on the front side. The inner peripheral end of the cylinder 43 is fixed to the primary shaft 31, extends from the primary shaft 31 in the shaft radial direction, and the outer peripheral end portion bends and extends to the rear side. The outer peripheral end of the primary movable sheave 42 is in liquidtight contact with the outer peripheral end of the cylinder 43 from the inside in the radial direction of rotation. A hydraulic chamber (piston chamber) 44 is formed between the primary movable sheave 42 and the cylinder 43.

The secondary pulley 34 is arranged to face the secondary fixed sheave 45 fixed to the secondary shaft 32 with the belt 35 sandwiched between the secondary fixed sheave 45, and is supported by the secondary shaft 32 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with a secondary movable sheave 46. The secondary movable sheave 46 is arranged on the rear side with respect to the secondary fixed sheave 45, and the positional relationship between the secondary fixed sheave 45 and the secondary movable sheave 46 in the front-rear direction is the primary fixed sheave 41 of the primary pulley 33 and the primary. The positional relationship with the movable sheave 42 is reversed.

A piston 47 is provided on the side opposite to the secondary fixed sheave 45, that is, on the rear side with respect to the secondary movable sheave 46. The inner peripheral end of the piston 47 is fixed to the secondary shaft 32 and extends from the secondary shaft 32 in the shaft radial direction. The outer peripheral end of the secondary movable sheave 46 extends to the rear side, and the outer peripheral end of the piston 47 is in liquidtight contact with the outer peripheral end of the secondary movable sheave 46 from the inside in the radial direction of rotation. A hydraulic chamber 48 is formed between the secondary movable sheave 46 and the piston 47.

In the continuously variable transmission mechanism 22, the hydraulic pressure supplied to the hydraulic chambers 44 and 48 of the primary pulley 33 and the secondary pulley 34 is controlled, and the groove widths of the primary pulley 33 and the secondary pulley 34 are changed to change the belt. The gear ratio (the pulley ratio between the primary pulley 33 and the secondary pulley 34) is continuously and steplessly changed within a constant gear ratio range.

Specifically, when the belt gear ratio is reduced, the oil supply supplied to the hydraulic chamber 44 of the primary pulley 33 is increased. As a result, the primary movable sheave 42 of the primary pulley 33 moves to the primary fixed sheave 41 side, and the distance (groove width) between the primary fixed sheave 41 and the primary movable sheave 42 becomes smaller. Along with this, the winding diameter of the belt 35 with respect to the primary pulley 33 becomes large, and the distance (groove width) between the secondary fixed sheave 45 and the secondary movable sheave 46 of the secondary pulley 34 becomes large. As a result, the belt gear ratio becomes smaller.

When the belt gear ratio is increased, the oil supply to the hydraulic chamber 44 of the primary pulley 33 is reduced. As a result, the thrust of the secondary pulley 34 with respect to the belt 35 becomes larger than the thrust of the primary pulley 33 with respect to the belt 35, the distance between the secondary fixed sheave 45 of the secondary pulley 34 and the secondary movable sheave 46 becomes smaller, and the primary fixed sheave 41 The distance between the and the primary movable sheave 42 becomes large. As a result, the belt gear ratio becomes large.

Although not shown, a bias spring is provided in the hydraulic chamber 48 of the secondary pulley 34. One end of the bias spring is elastically in contact with the secondary movable sheave 46, and the other end is elastically in contact with the piston 47. The elastic force of the bias spring urges the secondary movable sheave 46 and the piston 47 in a direction in which they are separated from each other. The secondary movable sheave 46 is subjected to the urging force of the hydraulic pressure in the hydraulic chamber 48 and the bias spring, and the belt 35 is subjected to the corresponding pinching pressure.

A primary input gear 51 is supported on the front end of the primary shaft 31 so as to be relatively rotatable.

A forward clutch 52 is provided between the primary input gear 51 and the primary pulley 33 arranged on the rear side thereof. The forward clutch 52 is a hydraulic friction clutch, which is hydraulically engaged and prohibits the rotation of the primary input gear 51 with respect to the primary shaft 31. Therefore, in the engaged state of the forward clutch 52, when the primary input gear 51 rotates, the primary shaft 31 rotates integrally with the primary input gear 51. When the oil pressure is released from the forward clutch 52 in this engaged state, the forward clutch 52 is released. The release of the forward clutch 52 allows the rotation of the primary input gear 51 with respect to the primary shaft 31, and even if the primary input gear 51 rotates, the rotation is not transmitted to the primary shaft 31.

A secondary input gear 53 is supported on the front end of the secondary shaft 32 so as to be relatively rotatable.

A reverse clutch 54 is provided between the secondary input gear 53 and the secondary pulley 34 arranged on the rear side. The reverse clutch 54 is a hydraulic friction clutch, which is hydraulically engaged and prohibits the rotation of the secondary input gear 53 with respect to the secondary shaft 32. Therefore, when the secondary input gear 53 rotates, the secondary shaft 32 rotates integrally with the secondary input gear 53. When the oil pressure is released from the reverse clutch 54 in this engaged state, the reverse clutch 54 is released. By releasing the reverse clutch 54, the rotation of the secondary input gear 53 with respect to the secondary shaft 32 is allowed, and even if the secondary input gear 53 rotates, the rotation is not transmitted to the secondary shaft 32.

The reverse transmission mechanism 23 is a mechanism that transmits the power (rotation) of the input shaft 21 to the secondary shaft 32 without passing through the continuously variable transmission mechanism 22. The reverse transmission mechanism 23 includes a reverse idler shaft 55, a first reverse gear 56, and a second reverse gear 57.

The reverse idler shaft 55 extends in the front-rear direction parallel to the input shaft 21.

The first reverse gear 56 is formed integrally with the reverse idler shaft 55 or is formed separately from the reverse idler shaft 55 and is supported by the reverse idler shaft 55 so as not to rotate relative to the reverse idler shaft 55.

The output shaft 24 is arranged on the same axis as the input shaft 21 with a space behind the input shaft 21. An output shaft gear 58 is integrally formed with the output shaft 24, or an output shaft gear 58 formed separately from the output shaft 24 is supported so as not to rotate relative to each other. Correspondingly, the secondary output gear 59 is supported on the secondary shaft 32 so as to be relatively non-rotatable by spline fitting adjacent to the rear side of the piston 47 of the secondary pulley 34. The output shaft gear 58 and the secondary output gear 59 are in mesh with each other.

When the vehicle 1 travels forward, the forward clutch 52 is engaged and the reverse clutch 54 is released. The power input from the engine 2 to the input shaft 21 via the torque converter 8 is transmitted from the input shaft gear 25 to the primary shaft 31 via the primary input gear 51 by the engagement of the forward clutch 52. On the other hand, even if the power input to the input shaft 21 is transmitted from the input shaft gear 25 to the secondary input gear 53 and the secondary input gear 53 rotates, the secondary input gear 53 becomes the secondary shaft 32 due to the release of the reverse clutch 54. The power is not transmitted to the secondary shaft 32.

The power transmitted to the primary shaft 31 is changed at a belt gear ratio corresponding to the pulley ratio between the primary pulley 33 and the secondary pulley 34, and is transmitted to the secondary shaft 32. Then, the power transmitted to the secondary shaft 32 is transmitted from the secondary output gear 59 to the output shaft 24 via the output shaft gear 58, and is transmitted from the output shaft 24 to the propeller shaft 5.

When the vehicle 1 travels backward, the forward clutch 52 is released and the reverse clutch 54 is engaged. The power input from the engine 2 to the input shaft 21 via the torque converter 8 is transmitted from the input shaft gear 25 to the secondary shaft 32 via the reverse transmission mechanism 23 and the secondary input gear 53 by the engagement of the reverse clutch 54. To. At this time, the secondary shaft 32 rotates in the direction opposite to that when the vehicle 1 moves forward. On the other hand, even if the power input to the input shaft 21 is transmitted from the input shaft gear 25 to the primary input gear 51 and the primary input gear 51 rotates, the primary input gear 51 becomes the primary shaft 31 due to the release of the forward clutch 52. The power is not transmitted to the primary shaft 31.

The power transmitted to the secondary shaft 32 is transmitted from the secondary output gear 59 to the output shaft 24 via the output shaft gear 58, and is transmitted from the output shaft 24 to the propeller shaft 5.

<Flood control circuit>
2A, 2B, 2C, and 2D are circuit diagrams showing the configuration of the hydraulic circuit 101 according to the embodiment of the present invention.

The hydraulic circuit 101 is a circuit for supplying oil pressure to the forward clutch 52 and the reverse clutch 54, and is incorporated as a part of the hydraulic circuit of the transmission unit 4.

The hydraulic circuit 101 includes a clutch modulator valve 102, a linear solenoid valve 103, a shift valve 104, an on / off valve 105, and a manual valve 106.

The clutch modulator valve 102 is a valve that regulates the line pressure (PL pressure), which is the original pressure obtained by adjusting the generated oil pressure of an oil pump (not shown), to a predetermined clutch modulator pressure (Pc pressure) and outputs the valve. is there. The clutch modulator valve 102 includes a substantially cylindrical sleeve 111. A spool 112 and a spring 113 are provided in the sleeve 111.

The sleeve 111 has a first inner diameter portion 114, a second inner diameter portion 115, and a third inner diameter portion 116 having different inner diameters. The first inner diameter portion 114, the second inner diameter portion 115, and the third inner diameter portion 116 are formed in this order from one side in the center line direction of the sleeve 111. The inner diameter of the first inner diameter portion 114 is smaller than the inner diameter of the second inner diameter portion 115 and the inner diameter of the third inner diameter portion 116, and the inner diameter of the second inner diameter portion 115 is smaller than the inner diameter of the third inner diameter portion 116.

The spool 112 is provided so as to be movable in the center line direction of the sleeve 111, and is elastically pressed to one side in the center line direction by the spring 113.

The spool 112 is provided with a first land portion 117, a second land portion 118, and a third land portion 119 at intervals from one side in the center line direction in this order. The first land portion 117 is formed in a substantially columnar shape having an outer diameter corresponding to the inner diameter of the first inner diameter portion 114 of the sleeve 111. The second land portion 118 is formed in a substantially columnar shape having an outer diameter corresponding to the inner diameter of the second inner diameter portion 115 of the sleeve 111. The third land portion 119 is formed in a substantially columnar shape having an outer diameter corresponding to the inner diameter of the third inner diameter portion 116 of the sleeve 111. In the movable range of the spool 112, regardless of the position of the spool 112, at least a part of the first land portion 117, the second land portion 118, and the third land portion 119 are the first inner diameter portion 114 of the sleeve 111, respectively. It faces the second inner diameter portion 115 and the third inner diameter portion 116 with almost no gap.

The sleeve 111 is formed with an input port 121, an output port 122, a first feedback port 123, a second feedback port 124, and a third feedback port 125.

Depending on the design of each part of the clutch modulator valve 102, the input port 121 is provided in the third inner diameter part 116, and the area closed by the third land part 119 of the spool 112 changes as the spool 112 moves. Further, the output port 122 is provided in the third inner diameter portion 116 and is not closed by the third land portion 119 regardless of the position of the spool 112 (so that the opening area does not change). The first feedback port 123 is provided in the first inner diameter portion 114 and communicates with the first land portion 117 and one end surface in the center line direction of the sleeve 111 regardless of the position of the spool 112. The second feedback port 124 is provided at a position straddling the first inner diameter portion 114 and the second inner diameter portion 115, and is between the first land portion 117 and the second land portion 118 regardless of the position of the spool 112. Communicate with. The third feedback port 125 is provided at a position straddling the second inner diameter portion 115 and the third inner diameter portion 116, and is between the second land portion 18 and the third land portion 119 regardless of the position of the spool 112. Communicate with.

The linear solenoid valve 103 is a normally closed type linear solenoid valve that is fully closed when no power is applied. The clutch modulator pressure output from the clutch modulator valve 102 is input to the input port 131 of the linear solenoid valve 103. By controlling the energization of the linear solenoid valve 103 (solenoid coil), the clutch modulator pressure input to the input port 131 is adjusted to the linear solenoid pressure, and the linear solenoid pressure is output from the output port 132. ..

The shift valve 104 is a valve that selectively outputs the clutch modulator pressure output from the clutch modulator valve 102 and the linear solenoid pressure output from the linear solenoid valve 103. The shift valve 104 includes a substantially cylindrical sleeve 141. A spool 142 and a spring 143 are provided in the sleeve 141.

The spool 142 is provided so as to be movable between the control position and the fail position in the center line direction of the sleeve 141, and is elastically pressed to one side in the center line direction, that is, to the control position side by the spring 143. The spool 142 is provided with a first land portion 144, a second land portion 145, and a third land portion 146 at intervals from one side in the center line direction in this order. The first land portion 144, the second land portion 145, and the third land portion 146 are formed in a substantially columnar shape having the same outer diameter according to the inner diameter of the sleeve 141.

The sleeve 141 is formed with a first input port 151, a second input port 152, a third input port 153, a fourth input port 154, a first output port 155, and a second output port 156.

Due to the design of each part of the shift valve 104, the first input port 151 communicates between the one end surface of the sleeve 141 in the center line direction and the first land part 144 regardless of the position of the spool 142. The second input port 152 communicates between the first land portion 144 and the second land portion 145 when the spool 142 is in the control position, and the first land when the spool 142 is in the fail position. Closed by section 144. The third input port 153 communicates between the second land portion 145 and the third land portion 146 when the spool 142 is in the control position, and the first land when the spool 142 is in the fail position. It communicates with the section 144 and the second land section 145. The fourth input port 154 communicates between the third land portion 146 and the other end surface of the sleeve 141 in the center line direction regardless of the position of the spool 142. The first output port 155 communicates between the first land portion 144 and the second land portion 145 regardless of the position of the spool 142. The second output port 156 communicates between the second land portion 145 and the third land portion 146 regardless of the position of the spool 142.

The on / off valve 105 is a normally closed type on / off solenoid valve, and is turned on (output state) when energized and turned off (output stopped state) when not energized. The clutch modulator pressure output from the clutch modulator valve 102 is input to the input port 161 of the on / off valve 105. When the on / off valve 105 is on, the clutch modulator pressure is output from the output port 162, and the clutch modulator pressure is input to the fourth input port 154 of the shift valve 104.

The manual valve 106 includes a spool 171 that is displaced according to the manual operation of the shift lever arranged in the vehicle interior, and outputs the oil input to the input port 172 to the forward output port 173 or the reverse output according to the position of the shift lever. It is a valve that outputs from port 174.

Specifically, the CVT 9 has, for example, a shift range including a P (parking) range, an R (reverse) range, an N (neutral) range and a D (drive) range. A shift lever (select lever) is provided in the vehicle interior of the vehicle 1 in order to instruct the switching of the shift range. The range of motion of the shift lever is set to P position, R position, N position and D position according to the shift range.

The oil pressure (clutch modulator pressure or linear solenoid pressure) output from the first output port 155 of the shift valve 104 is input to the input port 172 of the manual valve 106. When the shift lever is in the D position, the oil input to the input port 172 is output from the forward output port 173. Further, when the shift lever is located in the R position, the oil pressure input to the input port 172 is output from the reverse output port 174.

One end of the forward clutch oil passage 175 is connected to the forward output port 173. The other end of the forward clutch oil passage 175 is connected to the forward clutch 52. As a result, the oil pressure output from the forward output port 173 is supplied to the forward clutch 52 through the forward clutch oil passage 175. Further, one end of the branch oil passage 176 is branched and connected in the middle of the forward clutch oil passage 175. The other end of the branch oil passage 176 is connected to the second feedback port 124 of the clutch modulator valve 102. Therefore, the oil pressure output from the forward output port 173 is also input to the second feedback port 124 of the clutch modulator valve 102 from the forward clutch oil passage 175 through the branch oil passage 176.

One end of the reverse clutch oil passage 177 is connected to the reverse output port 174. The other end of the reverse clutch oil passage 177 is connected to the reverse clutch 54. As a result, the flood pressure output from the reverse output port 174 is supplied to the reverse clutch 54 through the reverse clutch oil passage 177.

<Circuit operation>
FIG. 3 is a diagram showing the relationship between the line pressure (PL pressure) and the clutch modulator pressures P1, P2, P3, and P4. FIG. 4 is a diagram showing a list of the shift range, the traveling state, the state of the linear solenoid valve 103, the state of the on / off valve 105, and the state of the output pressure of the engaging clutch and the shift valve 104.

In each of FIGS. 2A to 2D and FIG. 4, the forward clutch 52 is described as "C1" and the reverse clutch 54 is described as "C2".

The vehicle 1 is equipped with a plurality of ECUs having a configuration including a microcomputer in order to control each part. The plurality of ECUs are connected so that bidirectional communication can be performed by a CAN (Controller Area Network) communication protocol. The operation of the hydraulic circuit 101 is controlled by one of the plurality of ECUs according to the shift range and the traveling state.

In the vehicle 1, when the input torque input to the input shaft 21 of the CVT 9 is in a low torque state of less than a predetermined value, the ECU executes clutch fuse control. When the input torque is in a high torque state equal to or higher than a predetermined value, the clutch fuse control is not executed. The clutch fuse control is a control that causes the forward clutch 52 or the reverse clutch 54 to slip before the belt 35 of the continuously variable transmission mechanism 22 when an excessive torque is input to the drive wheels 7L and 7R from the road surface. .. Specifically, in the clutch fuse control, the hydraulic pressure (engagement) supplied to the forward clutch 52 or the reverse clutch 54 so that the transmission torque capacity of the forward clutch 52 or the reverse clutch 54 is smaller than the transmission torque capacity of the belt 35. Pressure), that is, the linear solenoid pressure output by the linear solenoid valve 103 is regulated.

When the input torque is in a high torque state, the energization of the linear solenoid valve 103 and the on / off valve 105 is cut off, and the output of the linear solenoid pressure from the linear solenoid valve 103 and the clutch modulator pressure from the on / off valve 105 is stopped. Will be done.

At this time, as shown by the thick gray lines in FIGS. 2A and 2B, the clutch modulator pressure output from the output port 122 of the clutch modulator valve 102 is input to the first input port 151 and the third input port 153 of the shift valve 104. Will be done. Due to the clutch modulator pressure input to the first input port 151, the spool 142 of the shift valve 104 is positioned at the fail position (high torque, fail) against the elastic force of the spring 143. In this state, the third input port 153 communicates with the first output port 155 via the first land portion 144 and the second land portion 145 of the spool 142. Therefore, the clutch modulator pressure input to the first input port 151 is output from the first output port 155 and input to the input port 172 of the manual valve 106.

When the shift range is the R range, the shift lever is in the R position, so that the clutch modulator pressure input to the input port 172 of the manual valve 106 moves backward from the reverse output port 174, as shown in FIG. 2A. It is output to the clutch oil passage 177. As a result, the clutch modulator pressure is supplied to the reverse clutch 54 through the reverse clutch oil passage 177, and the reverse clutch 54 engages with the clutch modulator pressure.

Further, the clutch modulator pressure output from the output port 122 of the clutch modulator valve 102 is input to the first feedback port 123 of the clutch modulator valve 102. Therefore, the first land portion 117 of the spool 112 of the clutch modulator valve 102 receives the pressure due to the product of the clutch modulator pressure and the pressure receiving area that receives the clutch modulator pressure, and the spool 112 is at a position where the pressure balances with the elastic force of the spring 113. Moves. As a result, the area closed by the third land portion 119 in the input port 121 of the clutch modulator valve 102 is increased, the line pressure is reduced to a constant clutch modulator pressure P1, and the clutch modulator pressure P1 is output from the output port 122. To.

When the shift range is the D range, the shift lever is in the D position, so that the clutch modulator pressure input to the input port 172 of the manual valve 106 advances from the forward output port 173, as shown in FIG. 2B. It is output to the clutch oil passage 175. As a result, the clutch modulator pressure is supplied to the forward clutch 52 through the forward clutch oil passage 175, and the forward clutch 52 engages with the clutch modulator pressure.

Further, the clutch modulator pressure output from the output port 122 of the clutch modulator valve 102 is input to the first feedback port 123 of the clutch modulator valve 102. Therefore, the first land portion 117 of the spool 112 of the clutch modulator valve 102 receives the pressure due to the product of the clutch modulator pressure and the pressure receiving area that receives the clutch modulator pressure. Further, the clutch modulator pressure output to the forward clutch oil passage 175 is input to the third feedback port 125 of the clutch modulator valve 102 through the branch oil passage 176. Therefore, in the clutch modulator valve 102, the second land portion 118 and the third land portion 119 of the spool 112 newly receive the clutch modulator pressure input to the third feedback port 125, and the spool 112 receives the second land portion 118. The pressure of the value obtained by multiplying the difference in the pressure receiving area between the third land portion 119 and the clutch modulator pressure acts. As a result, the area closed by the third land portion 119 at the input port 121 of the clutch modulator valve 102 is increased, the line pressure is reduced to a constant clutch modulator pressure P2 lower than the clutch modulator pressure P1, and the clutch modulator pressure P2 is reduced. Is output from the output port 122.

When a power loss failure occurs in the hydraulic circuit 101, the energization of the linear solenoid valve 103 and the on / off valve 105 is cut off. Therefore, the operation of the hydraulic circuit 101 is when the input torque is in a high torque state. It becomes the same as the operation.

When the input torque is in the low torque state, the energization of the linear solenoid valve 103 is controlled. By controlling this energization, the linear solenoid pressure variably adjusted is output from the output port 132 of the linear solenoid valve 103. The linear solenoid pressure output from the output port 132 is input to the second input port 152 of the shift valve 104. Further, the on / off valve 105 is energized to turn on the on / off valve 105. As a result, the clutch modulator pressure is output from the output port 162 of the on / off valve 105, and the output clutch modulator pressure is input to the fourth input port 154 of the shift valve 104.

At this time, as shown by the thick gray lines in FIGS. 2C and 2D, the clutch modulator pressure output from the output port 122 of the clutch modulator valve 102 is input to the first input port 151 and the third input port 153 of the shift valve 104. Will be done. As a result, the clutch modulator pressure input to the first input port 151 and the clutch modulator pressure input to the fourth input port 154 cancel each other out, and the spool 142 of the shift valve 104 is controlled by the elastic force of the spring 143. Located in position (low torque, engagement transient).

Further, the second input port 152 communicates with the first output port 155 via the first land portion 144 and the second land portion 145 of the spool 142. Therefore, the linear solenoid pressure input to the second input port 152 is output from the first output port 155 and input to the input port 172 of the manual valve 106 as shown by the gray middle line in FIGS. 2C and 2D. Will be done.

When the shift range is the R range, as shown in FIG. 2C, the clutch modulator pressure input to the input port 172 of the manual valve 106 is output from the reverse output port 174 to the reverse clutch oil passage 177. As a result, the linear solenoid pressure is supplied to the reverse clutch 54 through the reverse clutch oil passage 177. By controlling the energization of the linear solenoid valve 103 and increasing or decreasing the linear solenoid pressure, it is possible to switch between engaging and disengaging the reverse clutch 54, and it is also possible to hold the reverse clutch 54 in the engaged state. it can.

Further, the clutch modulator pressure output from the output port 122 of the clutch modulator valve 102 is input to the first feedback port 123 of the clutch modulator valve 102. Therefore, the first land portion 117 of the spool 112 of the clutch modulator valve 102 receives the pressure due to the product of the clutch modulator pressure and the pressure receiving area that receives the clutch modulator pressure. Further, in the shift valve 104, the third input port 153 and the second output port 156 communicate with each other via the second land portion 145 and the third land portion 146 of the spool 142. Therefore, the clutch modulator pressure input to the third input port 153 is output from the second output port 156. The clutch modulator pressure output from the second output port 156 is input to the second feedback port 124 of the clutch modulator valve 102. Therefore, in the clutch modulator valve 102, the first land portion 117 and the second land portion 118 of the spool 112 receive the clutch modulator pressure input to the second feedback port 124, and the spool 112 receives the first land portion 117 and the first land portion 117. The pressure of the value obtained by multiplying the difference in the pressure receiving area from the two land portion 118 by the clutch modulator pressure further acts. As a result, the line pressure is reduced to a constant clutch modulator pressure P3 lower than the clutch modulator pressure P1, and the clutch modulator pressure P3 is output from the output port 122.

When the shift range is the D range, as shown in FIG. 2D, the clutch modulator pressure input to the input port 172 of the manual valve 106 is output from the forward output port 173 to the forward clutch oil passage 175. As a result, the clutch modulator pressure is supplied to the forward clutch 52 through the forward clutch oil passage 175. By controlling the energization of the linear solenoid valve 103 to increase or decrease the linear solenoid pressure, the engagement and disengagement of the forward clutch 52 can be switched, and the forward clutch 52 can be held in the engaged state. it can.

Further, as in the case where the shift range is the R range, the first land portion 117 of the spool 112 of the clutch modulator valve 102 receives the pressure due to the clutch modulator pressure input to the first feedback port 123, and the first land portion 117 And the second land portion 118 receives the clutch modulator pressure input to the second feedback port 124. Further, the linear solenoid pressure output to the forward clutch oil passage 175 is input to the third feedback port 125 of the clutch modulator valve 102 through the branch oil passage 176. Therefore, in the clutch modulator valve 102, the second land portion 118 and the third land portion 119 of the spool 112 receive the linear solenoid pressure input to the third feedback port 125, and the spool 112 receives the second land portion 118 and the second land portion 118. The pressure of the value obtained by multiplying the difference in the pressure receiving area from the 3 land portion 119 by the linear solenoid pressure acts. As a result, the line pressure is reduced to a constant clutch modulator pressure P4 lower than the clutch modulator pressure P3, and the clutch modulator pressure P4 is output from the output port 122.

<Effect>
As described above, the line pressure is input to the clutch modulator valve 102, and the clutch modulator valve 102 adjusts the line pressure to the clutch modulator pressure and outputs the pressure. The clutch modulator pressure output from the clutch modulator valve 102 is input to the linear solenoid valve 103, and the linear solenoid valve 103 adjusts the clutch modulator pressure to the linear solenoid pressure and outputs the pressure. The clutch modulator pressure output from the clutch modulator valve 102 is input to the on / off valve 105.

When the on / off valve 105 is on, the clutch modulator pressure is output from the on / off valve 105, the clutch modulator pressure is input to the shift valve 104, and the spool 142 of the shift valve 104 is located at the control position. In this state, the linear solenoid pressure output from the linear solenoid valve 103 is input to the second input port 152 of the shift valve 104, and the linear solenoid pressure is output from the shift valve 104 to the forward clutch 52 or the reverse clutch 54. Is supplied to.

The linear solenoid pressure can be increased or decreased by controlling the energization of the linear solenoid valve 103. The transmission torque capacity of the forward clutch 52 or the reverse clutch 54 can be increased or decreased by increasing or decreasing the linear solenoid pressure. Therefore, the hydraulic circuit 101 can be suitably used for the transmission unit 4 mounted on the vehicle 1 that employs the clutch fuse control.

On the other hand, in the off state of the on / off valve 105, the output of the clutch modulator pressure from the on / off valve 105 is stopped, so that there is no input of the clutch modulator pressure from the on / off valve 105 to the shift valve 104. Therefore, the spool 142 is located at the fail position. In this state, the clutch modulator pressure output from the clutch modulator valve 102 is input to the clutch modulator pressure input port, and the clutch modulator pressure is supplied to the forward clutch 52 or the reverse clutch 54.

When a power loss fail occurs, the on / off valve 105 is turned off, so that the shift valve 104 supplies the clutch modulator pressure to the forward clutch 52 or the reverse clutch 54. As a result, the forward clutch 52 or the reverse clutch 54 is engaged. Therefore, when the failure of power loss occurs, the forward clutch 52 or the reverse clutch 54 is engaged, so that the transmission unit 4 can output the power for running the vehicle 1 and secure the running of the vehicle 1. can do.

The clutch modulator valve 102 has a second feedback port 124 to which the linear solenoid pressure supplied to the forward clutch 52 or the reverse clutch 54 is input, and the clutch modulator valve 102 is input to the second feedback port 124. The clutch modulator pressure decreases according to the linear solenoid pressure.

As a result, the clutch modulator pressure input to the linear solenoid valve 103 is reduced, so that the differential pressure between the clutch modulator pressure and the linear solenoid pressure output from the linear solenoid valve 103 can be reduced, and the override characteristics of the linear solenoid valve 103 can be reduced. Can be improved.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the hydraulic circuit 101 according to the above-described embodiment, the normally closed type on / off valve 105 is used, and the clutch modulator pressure is output from the output port 162 of the on / off valve 105 while the on / off valve 105 is on. Then, the clutch modulator pressure is input to the fourth input port 154 of the shift valve 104. The configuration of the hydraulic circuit 201 is not limited to this, and the configuration of the hydraulic circuit 201 shown in FIG. 5 may be adopted.

In the hydraulic circuit 101, the normally closed type on / off valve 105 is used, whereas in the hydraulic circuit 101, the normally open type on / off valve 202 is used instead of the normally closed type on / off valve 105. Has been done. The normally open type on / off valve 202 goes into an off state (output stop state) when energized, and goes into an on state (output state) when it is not energized. The clutch modulator pressure output from the clutch modulator valve 102 is input to the input port 203 of the on / off valve 202. When the on / off valve 202 is on, the clutch modulator pressure is output from the output port 204, and the clutch modulator pressure is input to the first input port 151 of the shift valve 104.

When the input torque is in the high torque state and in the fail state, the energization of the on / off valve 105 is cut off. At this time, the clutch modulator pressure is output from the output port 204 of the on / off valve 105, and the clutch modulator pressure is input to the first input port 151 of the shift valve 104. Due to the clutch modulator pressure input to the first input port 151, the spool 142 of the shift valve 104 is positioned at the fail position (high torque, fail) against the elastic force of the spring 143.

When the input torque is in the low torque state, the on / off valve 105 is energized and the on / off valve 105 is turned on. As a result, the output of the clutch modulator pressure from the output port 162 of the on / off valve 105 is stopped, so that the spool 142 of the shift valve 104 is positioned at the control position (low torque, engagement transient) by the elastic force of the spring 143. To do.

Therefore, even with the configuration of the hydraulic circuit 201, the same effects as in the case of the configuration of the hydraulic circuit 101 can be obtained. Moreover, in the configuration of the hydraulic circuit 201, the configuration is simpler than that of the hydraulic circuit 101 because it is not necessary to input the oil pressure by using the fourth input port 154 of the shift valve 104 as the drain port.

Further, in the above-described embodiment, the CVT 9 is vertically installed, but the hydraulic circuit 101 can also be applied to a transmission unit including a transmission whose input shaft is horizontally arranged so as to extend in the left-right direction of the vehicle 1. it can.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

4: Transmission unit (transmission)
9: CVT (transmission)
52: Forward clutch (engagement element)
54: Reverse clutch (engagement element)
101: Hydraulic circuit 102: Clutch modulator valve (modulator valve)
103: Linear solenoid valve (solenoid valve)
104: Shift valve 105: On / off valve 124: Second feedback port (feedback port)
142: Spool 151: 1st input port (modulator pressure input port)
152: Second input port (engagement pressure input port)
153: Third input port (modulator pressure input port)

Claims (2)

A transmission hydraulic circuit with engaging elements
A modulator valve in which the original pressure is input and the input original pressure is adjusted to a predetermined modulator pressure and output.
A solenoid valve to which the modulator pressure output from the modulator valve is input and the input modulator pressure is adjusted to the engaging pressure for engaging the engaging element and output.
The modulator pressure input port to which the modulator pressure output from the modulator valve is input, the engagement pressure input port to which the engagement pressure output from the solenoid valve is input, and the control position and the fail position are moved to each other. With a possible spool, the spool is located at the control position, and the engagement pressure input to the engagement pressure input port is output as a flood control supplied to the engagement element, and the spool A shift valve that outputs the modulator pressure input to the modulator pressure input port as a flood control supplied to the engaging element while being located at the fail position.
The modulator pressure output from the modulator valve is input, the input modulator pressure is output in the on state, the output of the modulator pressure is stopped in the off state, and the engagement transient and engagement of the engagement element are engaged. Includes an on / off valve that is turned on for holding
In the shift valve, the spool is located at the control position when the modulator pressure output from the on / off valve is input, and the spool is located at the fail position when the modulator pressure is not input. A hydraulic circuit that has a configuration. The modulator valve includes a feedback port to which the engaging pressure supplied to the engaging element is input, and has a configuration in which the modulator pressure is reduced according to the engaging pressure input to the feedback port. The hydraulic circuit according to claim 1.