JP6252521B2 - Brake control system for transmission - Google Patents

Description

  The present invention relates to a brake control system for a transmission mounted on a vehicle, and belongs to the technical field of a vehicle transmission.

  In general, an automatic transmission mounted on a vehicle such as an automobile includes a transmission mechanism having a plurality of planetary gear mechanisms and a plurality of frictional engagement elements, and each planetary gear mechanism is selectively engaged by selectively fastening these frictional engagement elements. The power transmission path through which the vehicle passes is switched to form a predetermined gear stage according to the driving state of the vehicle. Each shift stage is basically formed by the engagement of two frictional engagement elements, but conventionally, the first speed in the D range is usually formed by the engagement of a low clutch and the locking of a one-way clutch. It was.

  However, the one-way clutch is expensive, and at the time other than the first speed in the D range, the improvement of the fuel consumption performance of the engine is hindered by the rotational resistance caused by the idling of the one-way clutch. It has been put into practical use.

  For example, in Patent Document 1, in an automatic transmission with 6 forward speeds and 1 reverse speed, a low clutch that is fastened at 1st to 4th speed, a high clutch that is fastened at 4th to 6th speed, and a fast clutch that is fastened at 1st speed and reverse speed. LR (low reverse) brakes, 26 brakes engaged at 2nd and 6th speeds, and R35 brakes engaged at 3rd, 5th and reverse speeds, with the one-way clutch abolished Yes.

  In the automatic transmission of Patent Document 1, when shifting down from the second speed in which the low clutch and 26 brake are engaged to the first speed in which the low clutch and LR brake are engaged, the engagement of the low clutch is maintained. Thus, the 26 brake is released and the LR brake is engaged. For the frictional engagement element newly engaged at the time of shifting, it is necessary to precisely control the increase in the hydraulic pressure supplied for the engagement. In particular, since the LR brake that is engaged when shifting down to the first speed has a large capacity and the pressure receiving area of the piston is large, the engagement force is large when a small error occurs in the hydraulic pressure supplied for engagement. Since an error will occur, the hydraulic pressure supply for fastening the LR brake is required to be particularly precisely controlled.

  In order to enable such precise fastening control, FIG. 4 of Patent Document 1 discloses a tandem piston type LR brake having a fastening piston and a clearance adjusting piston. In this LR brake, a clearance adjusting hydraulic chamber is formed between the inner surface of the case of the automatic transmission and the back surface of the clearance adjusting piston. The fastening piston is fitted on the front side of the clearance adjusting piston, and a fastening hydraulic chamber is formed between these pistons. The fitting portion between the fastening piston and the clearance adjustment piston is provided with a seal member that seals the fastening hydraulic chamber. When no hydraulic pressure is supplied to the fastening hydraulic chamber, the sealing member is adjusted by friction of the seal member. The positional relationship of the fastening piston with respect to the piston is maintained.

  When fastening such a tandem piston type LR brake, first, the clearance adjustment piston strokes to a predetermined position against the biasing force of the return spring by supplying hydraulic pressure to the clearance adjustment hydraulic chamber. At this time, the fastening piston strokes with the piston while maintaining the positional relationship with the clearance adjustment piston, and the fastening piston is in contact with or substantially in contact with the friction plate without pressing the friction plate (hereinafter referred to as the piston). This state is referred to as “zero clearance state”, and the position of the fastening piston in this state is referred to as “zero clearance position”).

  Next, when the hydraulic pressure is supplied to the fastening hydraulic chamber in this zero clearance state, the fastening piston has already almost finished the stroke for fastening, so the friction plate is pressed almost simultaneously with the supply of hydraulic pressure, The LR brake is fastened with good responsiveness. Thus, by adopting a tandem piston type as the LR brake, it is possible to perform precise fastening control through a zero clearance state.

  When the hydraulic pressure is discharged from the fastening hydraulic chamber in the engaged state of the LR brake, the pressing force of the fastening piston against the friction plate is released, and the state returns to the zero clearance state. In this state, when the hydraulic pressure is further discharged from the clearance adjusting hydraulic chamber, the clearance adjusting piston is stroked by the urging force of the return spring until it returns to the original position. At this time, the fastening piston strokes away from the friction plate while maintaining the positional relationship with the clearance adjustment piston, whereby the LR brake is completely released.

JP2013-224716A

  In the tandem piston type brake as described above, as long as the positional relationship between the fastening piston and the clearance adjustment piston is maintained, the zero clearance state can be formed with high accuracy, thereby achieving a precise and excellent responsiveness. Fastening control becomes possible.

  However, when the hydraulic oil is discharged from the fastening hydraulic chamber for releasing the brake, the fastening piston is moved to the anti-friction plate side with respect to the clearance adjustment piston due to the negative pressure generated in the fastening hydraulic chamber. It can shift. When the hydraulic pressure is supplied to the clearance adjusting hydraulic chamber in such a brake released state where the positional relationship is broken, the fastening piston strokes only to a position shifted from the zero clearance position to the side opposite to the friction plate. . Therefore, the hydraulic pressure is supplied to the fastening hydraulic chamber in a state where the stroke of the fastening piston is not completed, and when the supply of the hydraulic pressure is started, the fastening piston may press the friction plate immediately. This is not possible and the fastening timing is delayed.

  In general single-piston brakes, the piston is engaged by the stroke against the urging force of the return spring. To improve the response, however, the fastening hydraulic pressure is not affected by the piston stroke. There is also a single piston type brake in which the friction plate is fastened or released only by supplying and discharging hydraulic pressure to the chamber. Since this type of brake is not provided with a return spring, at the time of release, the piston does not retract due to the urging force of the return spring. Therefore, the same problem as described above may occur with respect to the responsiveness and denseness of the fastening control.

  Incidentally, an electromagnetic hydraulic control valve such as a linear solenoid valve is generally used for hydraulic supply / discharge control for the brake. As indicated by the symbol a in FIG. 4, as a characteristic of the electromagnetic hydraulic control valve, originally, in a region where the command value (current) and the output value (hydraulic pressure) are small, the value between the target value X and the actual output value Y There is a tendency for the output to become unstable with a large deviation. For this reason, when the brake is engaged with a relatively low oil pressure, the hydraulic control valve is controlled in an unstable output region, so that it is easily affected by the viscosity of the hydraulic oil, etc. There is also a problem that it is difficult to do.

  Therefore, the present invention suppresses the displacement of the engagement piston in the non-engaged state in the brake of the transmission, and always uses the output pressure belonging to the stable output region of the hydraulic control valve, thereby controlling the engagement of the brake. It is an object to improve the denseness and responsiveness in the above.

  In order to solve the above problems, a brake control system for a transmission according to the present invention is configured as follows.

First, in the invention according to claim 1 of the present application, a brake including a rotating element and a case that accommodates the rotating element is provided with a brake that connects and disconnects the rotating element and the case. The fastening hydraulic chamber is supplied with the hydraulic pressure output from the electromagnetic hydraulic control valve, the fastening piston has a pressure receiving portion facing the fastening hydraulic chamber, and is fastened by being pressed by the fastening piston. A transmission brake control system comprising a plurality of friction plates,
A back pressure chamber disposed adjacent to the opposite side of the fastening hydraulic chamber across the pressure receiving portion;
A first oil passage for guiding the hydraulic pressure output from the hydraulic control valve to the fastening hydraulic chamber;
A second oil passage branched from the first oil passage;
An input port through which the hydraulic pressure output from the hydraulic control valve is input via the second oil passage, and when the output pressure of the hydraulic control valve is less than a predetermined pressure, the output pressure is set to the predetermined pressure. a regulating valve having an output port for output the said predetermined constant pressure when it is higher,
And a third oil passage for guiding the hydraulic pressure output from the output port to the back pressure chamber .

A transmission brake control system according to a second aspect of the present invention provides the transmission brake control system according to the first aspect of the present invention.
A partition for partitioning the back pressure chamber and the space adjacent to the radially inner side of the friction plate is disposed at an axial position between the friction plate and the pressure receiving portion of the fastening piston. And

Furthermore, the brake control system for a transmission according to the invention of claim 3 is the invention according to claim 1 or 2,
Comprising a drain oil passage for communicating oil discharged from the hydraulic control valve to an oil pan;
A pressure holding valve is provided on the drain oil passage, and is opened when a hydraulic pressure equal to or higher than a predetermined drain pressure lower than the predetermined pressure is input.

  First, according to the first aspect of the invention, when the output pressure of the hydraulic control valve is less than a predetermined pressure, the pressure regulating valve operates so that the output pressure of the hydraulic control valve is supplied to the back pressure chamber as it is. As a result, since the same hydraulic pressure is supplied to both the fastening hydraulic chamber and the back pressure chamber, the pressure applied to the pressure receiving portion of the fastening piston from the fastening hydraulic chamber side and the back pressure chamber side is offset. The As a result, the fastening piston can be reliably held at a predetermined position when the brake is not fastened.

When the output pressure of the hydraulic control valve rises above the predetermined pressure, only the hydraulic pressure in the fastening hydraulic chamber rises while the hydraulic pressure in the back pressure chamber is maintained at the predetermined pressure by the pressure regulating valve. Since a differential pressure is generated between the hydraulic chamber and the hydraulic chamber, the friction plate is pressed by the fastening piston. Therefore, if the fastening hydraulic chamber is precharged while maintaining the output pressure of the hydraulic control valve below a predetermined pressure and the fastening piston is held at a predetermined position, the output pressure of the hydraulic control valve is set to a predetermined value. When the pressure is increased above the pressure, the fastening force by the fastening piston can be immediately applied to the friction plate, whereby the brake can be fastened with good responsiveness.

  In addition, since the brake is engaged when the output pressure of the hydraulic control valve is equal to or higher than the predetermined pressure, the engagement of the brake can be precisely controlled by always using the output pressure belonging to the stable output region of the hydraulic control valve. .

  Furthermore, when the output pressure of the hydraulic control valve is lowered below a predetermined pressure in the brake engaged state, the hydraulic pressure applied to the pressure receiving portion of the fastening piston from the fastening hydraulic chamber side and the back pressure chamber side is offset, The pressing state of the friction plate by the fastening piston is released, and the brake can be released. Thus, even when a negative pressure is generated in the fastening hydraulic chamber when the brake is released, the pressures in the fastening hydraulic chamber and the back pressure chamber are offset. Therefore, the stroke position of the fastening piston can be reliably held at a predetermined position in the non-engaged state of the brake, thereby realizing good precision and responsiveness in the subsequent fastening control.

  According to the second aspect of the present invention, the partition portion that partitions the space adjacent to the radially inner side of the friction plate of the brake and the back pressure chamber is provided. The lubricating oil supplied to the plate is blocked, and thereby the contact area where the lubricating oil hits the fastening piston can be reduced. For this reason, it is possible to suppress the displacement of the fastening piston toward the anti-friction plate due to the influence of the lubricating oil, thereby further improving the precision and responsiveness of the brake fastening control.

  According to the third aspect of the present invention, if the hydraulic pressure input from the hydraulic control valve to the pressure holding valve on the drain oil passage is equal to or higher than the predetermined drain pressure, the pressure holding valve is opened, Oil is drained through the passage, but when the hydraulic pressure input to the pressure holding valve is lower than the drain pressure, the oil holding is regulated by closing the pressure holding valve. Therefore, it is possible to always maintain a state in which the hydraulic oil for fastening is filled with the hydraulic oil regardless of the output pressure of the hydraulic control valve. Therefore, a quick brake engagement can be reliably realized by always being in a precharged state when the brake is not engaged.

1 is a skeleton diagram of an automatic transmission including a brake control system according to an embodiment of the present invention. It is a fastening table | surface which shows the relationship between the fastening combination of the friction fastening element of the automatic transmission, and a gear stage. It is a mimetic diagram showing a brake control system concerning an embodiment of the present invention. It is a graph which shows the relationship between the command value to a linear solenoid valve, and the output value of the valve, and the relationship between the command value and the pressing force by the fastening piston.

  Embodiments of the present invention will be described below.

[Configuration of automatic transmission]
FIG. 1 is a skeleton diagram showing an example of an automatic transmission 4 provided with a brake control system according to an embodiment of the present invention. The automatic transmission 4 includes an input shaft 7 and an output gear in a transmission case 5. 8 is a horizontal automatic transmission.

  The input shaft 7 is arranged so as to extend in the vehicle body width direction, and the right end portion of the input shaft 7 in the figure is connected to the crankshaft 2 of the engine 1 via the torque converter 3. The output gear 8 is disposed on the same axis as the input shaft 7. The output gear 8 is connected to an axle (not shown) via a differential mechanism (not shown), whereby the power of the engine 1 is changed by the automatic transmission 4 and then according to the driving situation. Is transmitted to the left and right axles by the difference in rotation.

  The torque converter 3 includes a case 3a connected to the crankshaft 2, a pump 3b fixed in the case 3a, and a turbine 3c that is disposed opposite to the pump 3b and driven by the pump 3b via hydraulic oil. And a stator 3e interposed between the pump 3b and the turbine 3c and supported by the transmission case 5 via the one-way clutch 3d to increase the torque, and between the case 3a and the turbine 3c. And a lockup clutch 3f that directly connects the crankshaft 2 and the turbine 3c via the case 3a. The rotation of the turbine 3 c is transmitted to the automatic transmission 4 via the input shaft 7.

  A mechanical oil pump 6 driven by the engine 1 via the torque converter 3 is disposed between the automatic transmission 4 and the torque converter 3. The oil pump 6 is provided so as to be driven by rotation of the crankshaft 2, and hydraulic pressure is supplied by the oil pump 6 to a hydraulic circuit for controlling the automatic transmission 4 while the engine 1 is being driven. The

  First, second, and third planetary gear sets (hereinafter referred to as “first, second, and third gear sets”) 10 are provided on the input shaft 7 of the automatic transmission 4 from the engine 1 side (torque converter 3 side). , 20, 30 are arranged.

  On the input shaft 7, the power from the input shaft 7 is selectively transmitted to the gear set 10, 20, 30 side as a frictional engagement element for switching the power transmission path constituted by the gear sets 10, 20, 30. A low clutch 40 and a high clutch 50 are disposed. Furthermore, on the input shaft 7, LR (low reverse) brakes 60, 26 brakes 70, and R35 brakes 80 for fixing predetermined rotating elements of the respective gear sets 10, 20, 30 are arranged in this order from the engine 1 side. Has been placed.

  Of the first to third gear sets 10, 20, 30, the first gear set 10 and the second gear set 20 are single pinion type planetary gear sets, and are engaged with the sun gears 11, 21 and these sun gears 11, 21. The plurality of pinions 12 and 22, the carriers 13 and 23 that respectively support the pinions 12 and 22, and the ring gears 14 and 24 that mesh with the pinions 12 and 22.

  The third gear set 30 is a double pinion type planetary gear set, and includes a sun gear 31, a plurality of first pinions 32a meshed with the sun gear 31, a second pinion 32b meshed with the first pinion 32a, and these The carrier 33 supports the pinions 32a and 32b, and the ring gear 34 meshed with the second pinion 32b.

  The input shaft 7 is directly connected to the sun gear 31 of the third gear set 30. The sun gear 11 of the first gear set 10 and the sun gear 21 of the second gear set 20 are coupled to each other and connected to the output member 41 of the low clutch 40. The output member 51 of the high clutch 50 is connected to the carrier 23 of the second gear set 20.

  Further, the ring gear 14 of the first gear set 10 and the carrier 23 of the second gear set 20 are coupled to each other and connected to the transmission case 5 via the LR brake 60 so as to be connectable and detachable. The ring gear 24 of the second gear set 20 and the ring gear 34 of the third gear set 30 are coupled to each other, and are connected to the transmission case 5 via a 26 brake 70 so as to be connected and disconnected. The carrier 33 of the third gear set 30 is connected to the transmission case 5 via an R35 brake 80 so as to be connectable and detachable. The output gear 8 is connected to the carrier 13 of the first gear set 10.

  With the above-described configuration, the automatic transmission 4 is arranged in the engagement table of FIG. 2 according to the combination of the engagement states of the friction engagement elements (low clutch 40, high clutch 50, LR brake 60, 26 brake 70, and R35 brake 80). As shown, the first to sixth speeds in the D range and the reverse speed in the R range are formed.

  The low clutch 40, the high clutch 50, the 26 brake 70, and the R35 brake 80 are single piston type frictional engagement elements. However, the LR brake 60 is a clutch clearance for improving the response at the time of engagement as will be described later. It is a tandem piston type frictional engagement element having an adjustment function, and includes a clearance adjusting hydraulic chamber (hereinafter referred to as “clearance adjusting chamber”) 64 and a fastening hydraulic chamber (hereinafter referred to as “fastening chamber”) 65. (See FIG. 3).

  Therefore, as shown in the fastening table of FIG. 2, when the LR brake 60 is fastened to form the first speed in the D range or the reverse speed in the R range, both the clearance adjusting chamber 64 and the fastening chamber 65 are used. In the neutral state in the N range, the hydraulic pressure is supplied to the clearance adjustment chamber 64 of the LR brake 60, so that the LR brake 60 is brought into an engagement preparation state described later.

[Tandem piston type LR brake]
FIG. 3 is a schematic diagram in which a cross-sectional view schematically showing a configuration of the LR brake 60 and a circuit diagram showing a hydraulic circuit 100 used for hydraulic control related to the LR brake 60 are combined.

  As shown in FIG. 3, the LR brake 60 includes a fixed friction plate 61 engaged with the inner periphery of the transmission case 5, the ring gear 14 of the first gear set 10, and the carrier 23 of the second gear set 20 (see FIG. 1). ) And a rotation-side friction plate 62 engaged with the outer periphery of the braked rotating member 63 connected to the ring gear 14 and the carrier 23.

  The fixed friction plate 61 and the rotation side friction plate 62 are alternately arranged in the axial direction. Lubrication between the adjacent friction plates 61 and 62 is performed by, for example, lubricating oil supplied from the axial center side in the transmission case 5 to the radially outer side.

  A clearance adjusting piston 67 is disposed on one side in the axial direction with the friction plates 61 and 62 interposed therebetween, and a fastening piston 69 is disposed on the other side.

  The clearance adjustment piston 67 is fitted in a cylinder 5 a provided in the transmission case 5 so as to be movable in the axial direction. The back of the clearance adjustment piston 67 in the cylinder 5 a is connected to the clearance adjustment chamber 64. Has been.

  The fastening piston 69 is fitted in another cylinder 5b provided in the transmission case 5 so as to be movable in the axial direction, and the back portion of the fastening piston 69 in the cylinder 5b serves as a fastening chamber 65. ing.

  The fastening piston 69 includes a pressure receiving portion 69 a that faces the fastening chamber 65 and a pressing portion 69 b that presses the friction plates 61 and 62. On the opposite side of the fastening chamber 65 across the pressure receiving portion 69a of the fastening piston 69, a back pressure chamber 66 is disposed adjacently.

  A partition 91 that partitions the space 90 adjacent to the radially inner side of the friction plates 61 and the back pressure chamber 66 is disposed at a position in the axial direction between the pressure receiving portion 69 a and the friction plates 61 and 62. . The outer peripheral surface of the partition part 91 is disposed so as to oppose the inner peripheral surface of the pressing part 69b. The partition portion 91 is fixed to the transmission case 5 or provided integrally.

  Seal members 93 and 94 are respectively attached to both ends in the radial direction of the pressure receiving portion 69a to seal between the cylinder 5b and the inner peripheral surface of the pressing portion 69b is connected to the outer peripheral surface of the partition portion 91. A seal member 92 that seals the gap is attached. The shaft of the fastening piston 69 when not in operation is caused by the frictional force acting on the seal members 92, 93, 94 and the hydraulic pressure supplied to the fastening chamber 65 and the back pressure chamber 66 using the hydraulic circuit 100 described later. Directional movement is restricted.

  When not operating, the fastening piston 69 is disposed at an axial position where the pressing portion 69b is in contact with or substantially in contact with the friction plates 61 and 62. On the other hand, the clearance adjusting piston 67 is stroked toward the friction plates 61 and 62 in the axial direction until hydraulic pressure is supplied to the clearance adjusting chamber 64 until it abuts against the stopper 99 against the urging force of the return spring 68. Sometimes, it is in contact with or nearly in contact with the friction plates 61 and 62.

  At this time, the friction plates 61 and 62 are sandwiched without being pressed by the clearance adjusting piston 67 and the fastening piston 69, so that a clutch preparation state (small clearance state) in which the clutch clearance is packed in a minute amount is obtained. . The “clutch clearance” here refers to the clearances between the pistons 67 and 69 and the friction plates 61 and 62 and the clearances between the friction plates 61 and 62 when the LR brake 60 is not engaged. This means the total dimension of the axial dimensions.

  When the hydraulic pressure in the fastening chamber 65 is increased by hydraulic pressure control described later in this fastening preparation state, the fastening piston 69 that has already almost finished the fastening stroke presses the friction plates 61 and 62 quickly. As a result, the friction plates 61 and 62 are clamped from both sides in the axial direction by the fastening piston 69 and the clearance adjusting piston 67 so that the friction plates 61 and 62 cannot be rotated relative to each other, whereby the LR brake 60 is fastened with good responsiveness. become.

  On the other hand, when the hydraulic oil is discharged from the clearance adjustment chamber 64 in the state where the LR brake 60 is ready to be engaged, the clearance adjustment piston 67 moves backward toward the anti-friction plates 61 and 62, thereby increasing the clutch clearance. The LR brake 60 is completely released.

As described above, by adopting a tandem piston type brake as the LR brake 60, when the LR brake 60 is released, a large clearance state is obtained, so that the rotational resistance due to the viscosity of the lubricating oil is suppressed. in Rukoto reacted with fastening force to the friction plates 61 and 62 by fastening the piston 69 in the clearance state, it is possible to be entered into the control dense and responsive.

[Hydraulic circuit]
Next, the configuration of the hydraulic circuit 100 that supplies the hydraulic pressure from the oil pump 6 to the clearance adjustment chamber 64, the fastening chamber 65, and the back pressure chamber 66 of the LR brake 60 will be described.

  Here, the case where a mechanical oil pump 6 driven by the engine 1 to generate hydraulic pressure is described as the hydraulic pressure source, but an electric pump driven by a motor to generate hydraulic pressure may be used. Further, the hydraulic circuit 100 may be configured so that the hydraulic pressure source can be switched between the electric pump and the mechanical oil pump 6. In this case, for example, a mechanical oil pump is driven while the engine 1 is being driven. 6, the electric pump can be used while the engine 1 is stopped.

  The hydraulic circuit 100 includes an open / close valve 112 that opens and closes a clearance adjustment line 114 connected to the clearance adjustment chamber 64, an on / off solenoid valve (hereinafter referred to as “on / off SV”) 110 that controls the open / close valve 112, a fastening chamber A linear solenoid valve (hereinafter referred to as “linear SV”) 120 that outputs hydraulic pressure to a fastening line 121 connected to 65, and an output pressure to the back pressure chamber 66 after reducing the output pressure of the linear SV 120 to a predetermined pressure P1. A pressure valve 130 and a predetermined hydraulic circuit 102 provided with various other valves are provided.

  The oil pump 6 is driven by the engine 1 to suck oil stored in the oil pan 150 of the automatic transmission 4 and generate hydraulic pressure. The hydraulic pressure generated by the oil pump 6 is input to the first input line 104 connected to the linear SV 120, the second input line 106 connected to the on / off SV 110, and the opening / closing valve 112 via the predetermined hydraulic circuit 102. The signals are respectively supplied to the third input lines 108 connected to the port B1.

  The on / off SV 110 is a normally open type solenoid valve that can control only opening and closing. Thus, when the on / off SV 110 is off, the hydraulic pressure supplied to the second input line 106 is input to the control port A1 provided at one end of the on-off valve 112 via the open on / off SV 110 and the output line 107. Is done.

  When the hydraulic pressure is input to the control port A1 of the on-off valve 112 by turning off the on / off SV 110, the spool 113 moves to the right side in the figure, and the input port B1 and the output port C1 are in communication. As a result, the hydraulic pressure supplied from the oil pump 6 to the third input line 108 is guided to the clearance adjustment chamber 64 via the clearance adjustment line 114, so that the clearance adjustment piston 67 is operated and the above-described fastening is performed. It becomes possible to form a preparation state (small clearance state).

  On the other hand, when the on / off SV 110 is turned on and closed, the hydraulic pressure supply to the control port A1 of the on-off valve 112 is cut off, so that the spool 113 is positioned on the left side in the figure, and thus the input port B1 is While being closed, the drain port D1 communicates with the output port C1. As a result, the hydraulic oil is discharged from the clearance adjustment chamber 64, whereby the above-described large clearance state can be formed.

  The linear SV 120 is an electromagnetic valve that can control output pressure as well as opening and closing. The output pressure of the linear SV 120 is supplied to the fastening chamber 65 via the fastening line 121. Further, the output pressure of the linear SV 120 is back pressure via a fourth input line 122 branched from the fastening line 121 and a back pressure supply line 132 that can be connected to the fourth input line 122 via the pressure regulating valve 130. Can be led to chamber 66.

  The fourth input line 122 is connected to the input port E1 of the pressure regulating valve 130, and the back pressure supply line 132 is connected to the output port F1 of the pressure regulating valve 130. A feedback port 133 branched from the back pressure supply line 132 is connected to the control port G1 provided at one end of the pressure regulating valve 130. Thereby, the hydraulic pressure input to the input port E1 can be temporarily output from the output port F1 and re-input to the control port G1. Further, the pressure regulating valve 130 is provided with a drain port H1 for discharging oil to the oil pan 150.

  In the pressure regulating valve 130, when the hydraulic pressure input to the control port G1 is less than the predetermined pressure P1, the spool 131 is positioned relatively on the left side in the drawing so that the input port E1 is opened and the drain port H1 is closed. When a hydraulic pressure equal to or higher than a predetermined pressure P1 is input to the port G1, the spool 131 is configured to be positioned on the relatively right side in the drawing so that the input port E1 is closed and the drain port H1 is opened.

  With such a configuration of the pressure regulating valve 130, when the output pressure of the linear SV 120 is less than the predetermined pressure P1, the hydraulic pressure input to the input port E1 and the control port G1 of the pressure regulating valve 130 is maintained below the predetermined pressure P1. As a result, the state in which the input port E1 communicates with the output port F1 is maintained, whereby the output pressure of the linear SV 120 is supplied to the back pressure chamber 66 as it is.

  On the other hand, when the output pressure of the linear SV 120 rises to the predetermined pressure P1 or higher, the hydraulic pressure of the predetermined pressure P1 or higher is input to the control port G1, and the spool 131 moves to the right side in the figure, thereby causing the input port E1 and the output port to The connection with F1 is interrupted. As a result, the supply of hydraulic pressure to the control port G1 via the input port E1 and the output port F1 is cut off, thereby reducing the input pressure of the control port G1. When the input pressure of the control port G1 is slightly lower than the predetermined pressure P1, the spool 131 moves to the left side in the figure, so that the input port E1 communicates with the output port F1. As a result, when a hydraulic pressure equal to or higher than the predetermined pressure P1 is input to the input port E1 and the control port G1, the spool 131 moves to the right side in the figure and closes the input port E1.

  While the operation of the spool 131 is repeated, a hydraulic pressure substantially equal to the predetermined pressure P1 is always output from the output port F1. Therefore, when the output pressure of the linear SV 120 is equal to or higher than the predetermined pressure P1, the hydraulic pressure at the predetermined pressure P1 is always supplied to the back pressure chamber 66.

  As shown in FIG. 4, the target value X of the output pressure of the linear SV 120 is set to a value proportional to the command value in the entire region where the command value (current) is I1 or more. However, as a characteristic of the linear SV 120, in a low output pressure region less than the predetermined pressure P1 (an output region corresponding to a command value that is greater than or equal to I1 and less than I2), an output value proportional to the command value is stabilized as indicated by the symbol a. It is difficult to obtain, and there is a tendency that a deviation tends to occur between the target value X of the output pressure and the actual output value Y. Therefore, if the LR brake 60 is engaged in a state where the hydraulic pressure less than the predetermined pressure P1 is output by the linear SV 120, this engagement control may not be performed precisely.

  With respect to this problem, according to the configuration of the present embodiment, when the output pressure of the linear SV 120 is less than the predetermined pressure P1, the output pressure of the linear SV 120 is supplied as it is to both the fastening chamber 65 and the back pressure chamber 66. Will be. At this time, the pressure applied to the pressure receiving portion 69a of the fastening piston 69 from the fastening chamber 65 side and the back pressure chamber 66 side is canceled out, whereby the stroke of the fastening piston 69 is surely restricted and the LR brake 60 is fastened. It will never be done. Therefore, the unstable output region of the linear SV 120 can be avoided from being used for fastening the LR brake 60, and the fastening piston 69 is securely held at the predetermined zero clearance position when the LR brake 60 is not fastened. be able to.

On the other hand, when the output pressure of the linear SV 120 rises above the predetermined pressure P1, only the hydraulic pressure in the fastening chamber 65 rises while the hydraulic pressure in the back pressure chamber 66 is maintained at the predetermined pressure P1 by the pressure regulating valve 130. Since a differential pressure is generated between the chamber 66 and the fastening chamber 65, the fastening piston 69 applies a fastening force to the friction plates 61 and 62 so as to press the friction plates 61 and 62, and thereby the LR brake 60. Can be concluded.

  When the LR brake 60 is thus engaged, the output pressure of the linear SV 120 belongs to a stable output region (see FIG. 4) that is equal to or higher than the predetermined pressure P1, and therefore the output pressure of the linear SV 120 that is controlled with high accuracy. , The fastening of the LR brake 60 can be precisely controlled.

In addition, according to the present embodiment, in the state where the LR brake 60 is ready to be engaged, the output pressure of the linear SV 120 is maintained below the predetermined pressure P1, and thereby the engagement chamber 69 is held in the zero clearance position. By precharging 65, when the output pressure of the linear SV 120 is increased to a predetermined pressure P1 or more, the fastening force by the fastening piston 69 can be applied to the friction plates 61 and 62 immediately. The LR brake 60 can be fastened with good responsiveness.

Furthermore, when reducing the output pressure of the linear SV120 below the predetermined pressure P1 in the engagement state of the LR brake 60, by the hydraulic pressure in the apply chamber 65 is decreased to the same hydraulic back pressure chamber 66, the friction plates by fastening the piston 69 The action of the fastening force on 61, 62 is stopped, whereby the LR brake 60 is released. At this time, it is possible to suppress a negative pressure from being generated in the fastening chamber 65 by maintaining the state in which the fastening chamber 65 and the back pressure chamber 66 are filled with hydraulic oil at a low hydraulic pressure. Regardless of whether or not negative pressure is generated in the fastening chamber 65, when the LR brake 60 is released, the pressure in the fastening chamber 65 and the back pressure chamber 66 cancels out, so that the displacement and inclination of the fastening piston 69 are reduced. Can be suppressed.

  Further, when the release of the LR brake 60 is started, a relatively high hydraulic pressure equal to or higher than the predetermined pressure P1 is supplied to the fastening chamber 65, and the pressure difference from the atmosphere is large. Quick release using pressure is possible.

  Furthermore, since the space 90 adjacent to the radially inner side of the friction plates 61 and 62 of the LR brake 60 and the back pressure chamber 66 are partitioned by the partition portion 91, the partition portion 91 causes the space 90 from the radially inner side. The lubricating oil supplied to the friction plates 61 and 62 is blocked. Therefore, the contact area where the lubricating oil hits the fastening piston 69 from the back pressure chamber 66 side can be reduced, and this also suppresses the displacement of the fastening piston 69 toward the anti-friction plates 61 and 62 side. .

  Therefore, in the non-engaged state of the LR brake 60, the stroke position of the fastening piston 69 can be reliably held at the zero clearance position, thereby realizing good precision and responsiveness in the subsequent fastening control. it can.

  Further, the hydraulic circuit 100 includes a drain line 140 that communicates oil discharged from the linear SV 120 to the oil pan 150. On the drain line 140, there is provided a pressure holding valve 142 that is opened when a hydraulic pressure equal to or higher than a predetermined drain pressure P2 (see FIG. 4) lower than the predetermined pressure P1 is input. The pressure holding valve 142 is always disposed so as to be immersed in the oil, thereby preventing air from entering the drain line 140 when the pressure holding valve 142 is opened.

  If the hydraulic pressure input to the pressure holding valve 142 is equal to or higher than the drain pressure P2, the pressure holding valve 142 is opened, and oil is discharged from the linear SV 120 to the oil pan 150 via the drain line 140. When the hydraulic pressure input to 142 is less than the drain pressure P2, the oil pressure is regulated by closing the pressure holding valve 142.

  In this way, by restricting the oil discharge below the drain pressure P2, as long as the hydraulic pressure is supplied from the first input line 104 to the linear SV 120, the hydraulic pressure in the upstream portion of the drain line 140 from the pressure holding valve 142, In addition, the hydraulic pressure of the fastening line 121 is maintained at the drain pressure P2 or more, and thus, it is possible to always maintain the state in which the fastening chamber 65 is filled with the hydraulic oil.

Further, if the hydraulic pressure of the fastening line 121 is equal to or higher than the drain pressure P2 and less than the predetermined pressure P1, the same hydraulic pressure as that of the fastening chamber 65 is also supplied to the back pressure chamber 66 as described above. The effect of the fastening force on the friction plates 61 and 62 by the piston 69 is restricted. For this reason, in the present embodiment, the pressure holding valve 142 is provided so that the hydraulic oil is filled in the fastening chamber 65, and the fastening piston 69 is erroneously caused by the hydraulic oil filled in the fastening chamber 65. It is possible to suppress the operation, thereby preventing erroneous fastening of the LR brake 60.

  Therefore, when the LR brake 60 is not engaged, the engagement chamber 65 and the back pressure chamber 66 are always in a precharged state, so that it is possible to reliably realize the engagement of the LR brake 60 with high accuracy and high responsiveness.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the LR brake 60 provided in the stepped automatic transmission 4 configured as described above has been described. However, the present invention is not limited to the LR brake 60 in the automatic transmission 4. The present invention can also be applied to brakes, brakes provided in all types of stepped automatic transmissions different from the automatic transmission 4, or continuously variable transmissions or manual transmissions.

  Further, the present invention is not limited to a tandem piston type brake, and a single piston type brake can be used as long as it is a type that is fastened / released only by hydraulic pressure supply / discharge without stroke of a fastening piston. Is also applicable.

  As described above, according to the present invention, in the brake of the transmission, the position displacement of the fastening piston in the non-engaged state is suppressed, and the output pressure belonging to the stable output region of the hydraulic control valve is always used. Since it becomes possible to improve the preciseness and responsiveness in the brake engagement control, a shift having a brake that is engaged by supplying the output pressure of the hydraulic control valve regardless of the stroke of the engagement piston. And may be suitably used in the field of manufacturing industries of vehicles equipped with this type of transmission.

DESCRIPTION OF SYMBOLS 1 Engine 2 Crankshaft 3 Torque converter 3f Lock-up clutch 4 Automatic transmission 5 Transmission case (case)
6 Oil Pump 40 Low Clutch 50 High Clutch 60 LR Brake 61 Fixed Friction Plate 62 Rotation Friction Plate 63 Brake Rotating Member (Rotating Element)
64 Hydraulic chamber for clearance adjustment (clearance adjustment chamber)
65 Hydraulic room for fastening (fastening room)
66 Back pressure chamber 67 Clearance adjusting piston 69 Fastening piston 69a Pressure receiving portion 69b Pressing portion 70 26 Brake 80 R35 brake 90 Space adjacent to the radial inside of the friction plate 91 Partition portion 100 Hydraulic circuit 102 Predetermined hydraulic circuit 104 First input Line 106 Second input line 107 Output line 108 Third input line 110 On-off SV
112 Open / close valve 114 Clearance adjustment line 120 Linear SV (hydraulic control valve)
121 fastening line 122 fourth input line 130 pressure regulating valve 132 back pressure supply line 140 drain line (drain oil passage)
142 Holding valve 150 Oil pan

Claims (3)

A transmission including a rotating element and a case that accommodates the rotating element is provided with a brake that connects and disconnects the rotating element and the case. The brake is supplied with hydraulic pressure output from an electromagnetic hydraulic control valve. Brake of a transmission comprising: a fastening hydraulic chamber, a fastening piston having a pressure receiving portion facing the fastening hydraulic chamber, and a plurality of friction plates fastened by being pressed by the fastening piston A control system,
A back pressure chamber disposed adjacent to the opposite side of the fastening hydraulic chamber across the pressure receiving portion;
A first oil passage for guiding the hydraulic pressure output from the hydraulic control valve to the fastening hydraulic chamber;
A second oil passage branched from the first oil passage;
An input port through which the hydraulic pressure output from the hydraulic control valve is input via the second oil passage, and when the output pressure of the hydraulic control valve is less than a predetermined pressure, the output pressure is set to the predetermined pressure. a regulating valve having an output port for output the said predetermined constant pressure when it is higher,
A brake control system for a transmission , further comprising a third oil passage for guiding the hydraulic pressure output from the output port to the back pressure chamber .   A partition for partitioning the back pressure chamber and the space adjacent to the radially inner side of the friction plate is disposed at an axial position between the friction plate and the pressure receiving portion of the fastening piston. The brake control system for a transmission according to claim 1. Comprising a drain oil passage for communicating oil discharged from the hydraulic control valve to an oil pan;
The pressure holding valve that opens when a hydraulic pressure equal to or higher than a predetermined drain pressure that is lower than the predetermined pressure is provided on the drain oil passage. Brake control system for transmission.

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