JP2017048821A - Torque converter and braking system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel-structure torque converter for functioning as a backup brake.SOLUTION: A torque converter 1 includes a pump shell 11 connected to an output shaft 61 of an engine via a housing 14 and adapted to be rotated integrally with the output shaft 61, a turbine shell 12 connected to an input shaft 51 of a transmission via a carrier 42 of a planetary gear train 41 and adapted to be rotated integrally with the input shaft 51, a lock-up clutch 21 through the engagement of which the pump shell 11 and the turbine shell 12 are connected and then the pump shell 11 and the turbine shell 12 are integrally rotated, the planetary gear train 41 including a fixed sun gear 411, a pinion gear 412, and a ring gear 413, and a retarder operation changeover clutch 44 through the engagement of which the ring gear 413 and the housing 14 are connected and then the ring gear 413 and the housing 14 are integrally rotated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a torque converter having a retarder function and a braking system using the torque converter.

  2. Description of the Related Art Conventionally, in a torque converter, a disk type stator clutch is provided for a stator so that the torque converter can be used as a retarder brake (for example, Patent Document 1). In this torque converter, the stator is usually idled in a locked-up state, and a stator clutch is used to fix the stator and stir the hydraulic oil inside the torque converter to obtain a braking force. Thereby, the braking ability at the time of descent can be improved significantly. In this torque converter, the hydraulic pressure required for the braking operation can be controlled by the same pump hydraulic pressure by adding a switching valve and a solenoid valve.

  A method using a multi-stage transmission as a backup brake is also known (for example, Patent Document 2). In this method, in a plurality of multi-speed automatic transmissions, a clutch of one shift stage selected from the plurality of shift stages is completely engaged, and a clutch of a shift stage connected to the selected shift stage is engaged. A braking force is obtained by generating an interlock by slip engagement.

Japanese Utility Model Publication No. 5-1058 JP 2006-307966 A

  However, in the torque converter of Patent Document 1, it is possible to obtain a braking force by using a torque converter as a fluid type retarder, but in this case, the vehicle cannot be stopped completely. In addition, when traveling at a low speed on a long downward slope, the rotational speed input to the torque converter decreases, so that the braking force by the retarder cannot be obtained sufficiently, and it is necessary to use the brake for a long time after all. There is.

  Further, the method of Patent Document 2 cannot be applied to a transmission having a structure such as CVT because the braking force is generated by using a clutch provided at each shift stage of the multi-stage transmission.

  An object of the present invention is to solve the above problems and provide a torque converter having a novel structure having a function as a backup brake and a braking system using the torque converter.

  A torque converter according to an aspect of the present invention includes a pump shell connected to an output shaft of a drive source via a pump intermediate member and rotating integrally with the output shaft, and connected to an input shaft of a transmission via a turbine intermediate member. A turbine shell that rotates integrally with the input shaft; a lock-up clutch that engages the pump shell and the turbine shell to engage with each other to rotate the pump shell and the turbine shell together; and a fixed sun gear; A ring gear and a planetary gear train having the turbine intermediate member as a carrier, and the ring gear and the pump intermediate member are connected by engaging the ring gear and the pump intermediate member. And a retarder operation switching clutch that rotates together.

  With this configuration, the interlock state is realized in the torque converter by simultaneously engaging the lock-up clutch and the retarder operation switching clutch, so that the torque converter can be used as a backup brake. The torque converter can also be used as a retarder brake by disengaging the lock-up clutch and engaging the retarder operation switching clutch. Further, since the braking force can be generated only by the configuration in the torque converter, the above-described backup brake and retarder brake can be realized regardless of the configuration of the transmission.

  In the above torque converter, a damper may be provided between the lockup clutch and the turbine intermediate member.

  With this configuration, when the lock-up clutch is engaged and the pump shell and the turbine shell are rotated together, a damper is provided between the output shaft and the input shaft. Can absorb vibration.

  A braking system according to an aspect of the present invention includes the torque converter and a control unit that engages the lock-up clutch and the retarder operation switching clutch, and the control unit receives a backup brake operation request. , One of the lockup clutch and the retarder operation switching clutch is engaged, and then the other one of the lockup clutch and the retarder operation switching clutch is engaged while controlling the degree of engagement. have.

  With this configuration, the interlock state is realized in the torque converter by simultaneously engaging the lock-up clutch and the retarder operation switching clutch, and the braking force in the torque converter can be controlled when the torque converter is used as a backup brake. .

  In the above braking system, the control unit may reduce the degree of engagement when a wheel lock is generated.

  With this configuration, it is possible to avoid wheel lock caused by suddenly entering the interlock state.

  In the above braking system, the control unit may reduce the degree of engagement when the generated braking force exceeds a predetermined upper limit value.

  With this configuration, it is possible to avoid or reduce the damage of the lock-up clutch and the retarder operation switching clutch that is engaged later.

  In the above braking system, the control unit engages the retarder operation switching clutch when receiving an operation request for a backup brake, and then engages the lock-up clutch while controlling the degree of engagement. You may let me.

  With this configuration, the retarder brake can function and generate a braking force until the lockup clutch is completely engaged and the interlock state is established.

  The braking system may further include a hydraulic mechanism that operates the lockup clutch and the retarder operation switching clutch, and the control unit controls the hydraulic mechanism to control the lockup clutch and the retarder operation switching. A clutch may be engaged.

  With this configuration, the lockup clutch and the retarder operation switching clutch of the torque converter can be operated using the hydraulic mechanism.

  According to the present invention, since the interlock state is realized in the torque converter by simultaneously engaging the lockup clutch and the retarder operation switching clutch, the torque converter can be used as a backup brake. The torque converter can also be used as a retarder brake by disengaging the lock-up clutch and engaging the retarder operation switching clutch. Further, since the braking force can be generated only by the configuration in the torque converter, the above-described backup brake and retarder brake can be realized regardless of the configuration of the transmission.

Sectional drawing of the torque converter of embodiment of this invention The graph which shows the ratio of the rotation speed of each gear of the planetary gear train of embodiment of this invention The schematic diagram which shows the structure of the torque converter of embodiment of this invention The block diagram which shows the interlock state of embodiment of this invention The block diagram which shows the component of the vehicle which comprises the braking system of embodiment of this invention The flowchart which shows the control method of the backup brake of embodiment of this invention Flow chart of lock-up clutch complete engagement processing according to the embodiment of the present invention

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below shows an example when the present invention is implemented, and the present invention is not limited to the specific configuration described below. In carrying out the present invention, a specific configuration according to the embodiment may be adopted as appropriate.

  FIG. 1 is a cross-sectional view of a torque converter according to an embodiment of the present invention. In FIG. 1, only the upper half portion of the torque converter 1 is shown. The torque converter 1 is integrated with the transmission. The transmission is provided on the left side of the torque converter 1 in FIG. 1, and an engine as a power source is provided on the right side of the torque converter 1 in FIG. The torque converter 1 and the engine output shaft 61 (see FIG. 2) are arranged coaxially with the input shaft 51 of the transmission. In the present embodiment, the term “axial direction”, “radial direction”, and “circumferential direction” refer to a direction based on the axis of the input shaft 51.

  The engine is a prime mover that outputs power generated by fuel combustion. For example, a spark ignition engine such as a gasoline engine or a compression ignition engine such as a diesel engine can be used. The transmission is a speed change mechanism that changes the rotational speed of the input shaft 51 at a predetermined speed ratio and outputs it. The transmission may be a stepped automatic transmission mechanism that is capable of switching a plurality of shift speeds having different speed ratios, or may be an automatic continuously variable transmission mechanism that can change the speed ratio continuously. The torque output from the transmission is distributed and transmitted to the two left and right wheels via the output operating gear mechanism.

  The torque converter 1 is a fluid coupling that transmits engine torque to the transmission. The torque converter 1 is drivingly connected so as to rotate integrally with the input shaft 51 and the pump shell 11 that is driven and connected so as to rotate integrally with the output shaft 61 of the engine by engaging (connecting) a clutch (not shown). The turbine shell 12, a stator 13 provided therebetween, and a housing 14 for housing them are configured. The torque converter 1 transmits torque between the drive-side pump shell 11 and the driven-side turbine shell 12 via oil filled in the housing 14.

  The housing 14 is configured by integrally joining a first housing member 141 on the transmission side and a second housing member 142 on the engine side by welding or the like. The first housing member 141 is a cover member formed so as to cover the transmission side of the torque converter 1. The first housing member 141 is an annular member having an arc-shaped cross-sectional shape in which a radially intermediate portion bulges toward the transmission side. The pump shell 11 is fixed to the first housing member 141. Therefore, the pump shell 11 is connected to the engine output shaft 61 via the housing 14 as a pump intermediate member, and rotates integrally with the output shaft 61.

  The second housing member 142 is a cylindrical member formed so as to cover the engine side of the torque converter 1. The second housing member 142 is a stepped cylindrical member in which a step portion is formed at a radially intermediate portion. That is, the second housing member 142 includes an outer cylindrical portion 142a that is an outer peripheral portion of the housing 14 in the engine side portion, and an intermediate portion that is smaller in diameter than the outer peripheral cylindrical portion 142a and forms a step portion of a radially intermediate portion. And a cylindrical portion 142b. A speed increasing planetary gear train 41, a retarder operation switching clutch 44, etc., which will be described later, are accommodated inside the intermediate cylindrical portion 142b.

  A lock-up clutch 21 is provided on the inner side of the radially extending portion on the outer side of the intermediate cylindrical portion 142 b of the second housing member 142. The lockup clutch 21 is disposed on the engine side in the axial direction with respect to the turbine shell 12. The lockup clutch 21 is a lockup engagement device for selectively locking up the torque converter 1. Specifically, the lock-up clutch 21 selectively engages the pump shell 11 and the turbine shell 12 to stop the transmission of the driving force via the oil and bring them into a directly connected state (lock-up state). To do. That is, when the lockup clutch 21 is engaged, the turbine shell 12 is connected to the housing 14 via the damper 31 and rotates integrally with the housing 14. As described above, since the pump shell 11 is fixed to the housing 14, the pump shell 11 and the turbine shell 12 are connected by lock-up, and the pump shell 11 and the turbine shell 12 rotate integrally. Become.

  A pump drive shaft 15 extending toward the transmission side is integrally provided at the radially inner end of the first housing member 141 on the transmission side portion. The pump drive shaft 15 is a cylindrical shaft portion that rotates integrally with the housing 14 of the torque converter 1, and is disposed on the radially outer side of the input shaft 51 coaxially with the input shaft 51.

  The turbine shell 12 is disposed opposite to the pump shell 11 on the engine side with respect to the pump shell 11 inside the housing 14. The turbine shell 12 is connected to an input shaft 51 via a carrier 42 as a turbine intermediate member, and rotates integrally with the input shaft 51. The radially inner end of the carrier 42 is spline-engaged with the input shaft 51. The stator 13 is disposed between the pump shell 11 and the turbine shell 12 in the axial direction. The stator 13 is supported on a stator shaft 17 via a one-way clutch 16.

  The stator shaft 17 is a cylindrical shaft portion, and is disposed between the input shaft 51 and the pump drive shaft 15 in the radial direction. The stator shaft 17 is fixed so as not to rotate on the transmission side. Thus, the torque converter 1 can transmit torque between the drive-side pump shell 11 and the driven-side turbine shell 12 via the oil filled in the housing 14. .

  The torque converter 1 is a torque converter with a lockup function. That is, the torque converter 1 includes a lockup clutch 21 that engages the pump shell 11 and the turbine shell 12 to lock up the torque converter 1. The pump shell 11 and the turbine shell 12 are drivingly connected via a lock-up clutch 21 so as to selectively rotate integrally.

  The damper 31 is disposed between the lockup clutch 21 and the turbine shell 12 in the axial direction. The damper 31 absorbs the vibration of the driving force transmitted between the pump shell 11 and the turbine shell 12 when the lockup clutch 21 is engaged. The damper 31 engages with the first intermediate member 313 via the drive member 311 as an input element, the plurality of outer peripheral springs 312, and the plurality of outer peripheral springs 312, and constitutes an intermediate element together with the first intermediate member 313. 2 intermediate members 314, a plurality of inner peripheral springs 315, and a driven member 316 as an output element that engages with the second intermediate member 314 via the plurality of inner peripheral springs 315. The driven member 316 is coupled to rotate integrally with the turbine shell 12 and the input shaft 51.

  In the damper 31, the plurality of outer peripheral springs 312 are compressed by the relative rotation of the drive member 311, the first intermediate member 313, and the second intermediate member 314, respectively, and the plurality of inner peripheral springs 315 are driven by the second intermediate member 314. It is compressed by relative rotation with the member 316. Thus, when the lockup clutch 21 is engaged, the torque applied to the drive member 311 from the second housing member 142 that rotates integrally with the output shaft 61 of the engine via the lockup clutch 21 is a plurality of outer peripheral springs. The first intermediate member 313, the second intermediate member 314, and the inner peripheral spring 315 are transmitted in this order, and finally transmitted to the driven member 316 that rotates integrally with the turbine shell 12.

  In the torque converter 1 of the present embodiment, a single pinion speed increasing planetary gear train 41 is added to the stator shaft 17. The speed increasing planetary gear train 41 is provided on the engine side in the axial direction on the radially inner side of the damper 31. The speed increasing planetary gear train 41 is used such that the sun gear 411 is fixed, the plurality of pinion gears 412 revolve around the sun gear 411 together with the carrier 42, and the ring gear 413 rotates. The speed increasing planetary gear train 41 is used when the torque converter 1 is caused to function as a retarder brake and an emergency brake as will be described later. At this time, the sun gear 411 is fixed, so the carrier 42 becomes an input. The ring gear 413 becomes an output.

  The sun gear 411 is fixed to the stator shaft 17 so as not to rotate. The pinion gear 412 engages with the sun gear 411. The carrier 42 passes through the first turbine hub 421 disposed on the transmission side of the speed increasing planetary gear train 41, the second turbine hub disposed on the engine side of the speed increasing planetary gear train 41, and the pinion gear 412. And a connecting shaft 423 for connecting the first turbine hub 421 and the second turbine hub 422.

  The first turbine hub 421 is a donut-shaped member that can rotate with respect to the stator shaft 17. The first turbine hub 421 is fixed to the driven member 316 and the turbine shell 12. The second turbine hub 422 is spline fitted to the input shaft 51 and rotates integrally with the input shaft 51. The connecting shaft 423 is provided corresponding to each of the plurality of pinion gears 412 and penetrates the center of each pinion gear 412. Each connecting shaft 423 is rotatable with respect to each pinion gear 412.

  That is, the first turbine hub 421 that is one end of the carrier 42 is connected to the turbine shell 12, and the second turbine hub 422 that is the other end of the carrier 42 plays the role of a conventional turbine stator. Similarly, the turbine shell 12 and the input shaft 51 are connected via a carrier 42. With the above configuration, the rotational torque around the driven member 316 and the turbine shell 12 is transmitted to the input shaft 51 through the carrier 42 as described above.

FIG. 2 is a graph showing the ratio of the rotational speeds of the sun gear 411, the carrier 42, and the ring gear 413 in the speed increasing planetary gear train 41. As described above, the sun gear 411 is fixed and the rotation speed is always zero. The rotation speed of the carrier 42 (that is, the rotation speed of the turbine shell 12) is Nc, the rotation speed of the ring gear 413 (that is, the rotation speed of the pump shell 11) is Nr, and the number of teeth of the sun gear 411 and the ring gear 413 is respectively Assuming Zs and Zr, the following formula (1) is established.
Nc = Nr (Zr / (Zr + Zs)) (1)

  That is, the ratio of the rotational speed Nr of the ring gear 413 to the rotational speed Nc of the carrier 42 is Nr / Nc = (Zr + Zs) / Zr (> 1), and the rotational speed Nc of the carrier 42 is increased to increase the speed of the ring gear 413. The rotation speed Nr.

  A retarder operation switching clutch 44 is provided on the radially outer side of the ring gear 413. The retarder operation switching clutch 44 is a wet multi-plate clutch, and includes a wear material 441 and a clutch drum 442. The wear material 441 is fixed to the outer periphery of the ring gear 413 and rotates integrally with the ring gear 413. The clutch drum 442 is fixed to the housing 14 and rotates integrally with the housing 14. The clutch drum 442 is provided so as to sandwich the wear material 441 in the axial direction.

  A piston 43 is provided adjacent to the retarder operation switching clutch 44. The piston 43 is operated by the hydraulic pressure in the torque converter 1 and engages (connects) the retarder operation switching clutch 44 by contacting the clutch drum 442 and pressing the clutch drum 442 against the wear material 441. When the retarder operation switching clutch 44 is engaged, the ring gear 413, the housing 14, and the pump shell 11 are connected via the retarder operation switching clutch 44 and integrally rotate.

  FIG. 3 is a schematic diagram showing the configuration of the torque converter 1 described above. In FIG. 3, the illustration of the damper 31 is omitted. The operation of the torque converter 1 will be described with reference to FIG. 3 together with FIG.

  First, when the output shaft 61 of the engine ENG rotates, the housing 14 and the pump shell 11 fixed to the housing 14 rotate together therewith. The turbine shell 12 is rotated by the rotation of the pump shell 11 and the input shaft 51 of the transmission T / M fixed to the turbine shell 12 is rotated. Thereby, the rotational torque of the output shaft 61 of the engine ENG is transmitted to the input shaft 51 of the transmission T / M. When the lockup clutch 21 is engaged (connected), the output shaft 61 is drivingly connected to the input shaft 51 via the carrier 42, and the output shaft 61 and the input shaft 51 rotate integrally.

  When the torque converter 1 is used as a retarder brake, the torque converter 1 operates as follows. That is, when the retarder operation switching clutch 44 is engaged with the lockup clutch 21 disconnected, the input shaft 51 is drivingly connected to the housing 14 via the speed increasing planetary gear train 41. As a result, the housing 14 and the pump shell 11 fixed thereto rotate at a rotational speed greater than the rotational speed of the input shaft 51. Since the rotational speed of the input shaft 51 is the rotational speed of the turbine shell 12, a rotational speed difference is generated between the pump shell 11 and the turbine shell 12, whereby the torque converter 1 exhibits a retarder function as an auxiliary brake. .

  When the lockup clutch 21 is engaged and the retarder operation switching clutch 44 is also engaged, the interlock state is established. FIG. 4 is a block diagram illustrating the interlock state. When both the lockup clutch 21 and the retarder operation switching clutch 44 are engaged, as shown in FIG. 4, the input shaft 51 and the carrier 42 that rotate at the rotational speed Nc due to the inertia of the vehicle via the transmission T / M. Is operated to rotate the housing 14 at the rotational speed Nc through the damper 31 and the lockup clutch 21, and on the other hand, the speed is increased by the speed increasing planetary gear train 41 to switch the ring gear 413 and the retarder operation. The housing 14 is rotated through the clutch 44 at the rotational speed Nr (= ((Zr + Zs) / Zr) Nc).

  As described above, when both the lockup clutch 21 and the retarder operation switching clutch 44 are engaged, a plurality of rotation transmission paths for rotating the housing 14 at different rotational speeds are formed, so that all the members cannot rotate. Thus, the interlock state is realized. Thus, the torque converter 1 in the interlock state can be used as a backup brake in an emergency such as when an abnormality occurs in a normal brake system. Note that the engagement is gradually and completely engaged by controlling the degree of engagement (or engagement force) while slipping at least one of the lockup clutch 21 and the retarder operation switching clutch 44, that is, in a half-clutch state.

  Next, the control of the backup brake will be described. FIG. 5 is a block diagram showing the components of the vehicle constituting the braking system. The braking system 100 includes a torque converter 1, a hydraulic mechanism 70 for driving the torque converter 1, and a control unit 80 that controls the hydraulic mechanism 70. The hydraulic mechanism 70 includes an oil pump 71, a regulator 72, a retarder operation switching hydraulic circuit 73, a lockup hydraulic control circuit 74, an oil cooler 75, and an oil pan 76. The control unit 80 includes a required braking force calculation unit 81, a braking force control unit 82, and a transmission control unit 83. In the braking system 100, the hydraulic mechanism 70 operates the lockup clutch 21 and the retarder operation switching clutch, and the control unit 80 controls the lockup clutch and the retarder operation switching clutch by controlling the hydraulic mechanism 70.

  The oil pump 71 is a hydraulic device that generates hydraulic pressure for sending oil. The regulator 72 is a pressure adjustment valve that adjusts the maximum value of the hydraulic pressure supplied from the oil pump 71. The oil whose hydraulic pressure is adjusted by the regulator 72 is supplied to a retarder operation switching hydraulic circuit 73 and a lockup hydraulic control circuit 74. The retarder operation switching hydraulic circuit 73 is a circuit that controls the hydraulic pressure acting on the piston 43, and presses the piston 43 against the clutch drum 442 of the retarder operation switching clutch 44 in accordance with a retarder control signal provided from the transmission control unit 83. Alternatively, control is performed so as to be separated from the clutch drum 442. The lockup hydraulic pressure control circuit 74 is a circuit that controls the hydraulic pressure acting on the lockup clutch 21, and in accordance with the lockup control signal given from the transmission control unit 83, the degree of engagement (engagement force) of the lockup clutch 21 is completely achieved. Control is arbitrarily performed between engagement and disengagement.

  The oil cooler 75 is a cooling device that cools the oil discharged from the lockup hydraulic control circuit 74. The oil pan 76 is a container that stores the oil cooled by the oil cooler 75.

  The requested braking force calculation unit 81 inputs a brake pedal signal indicating the amount of depression of the brake pedal and vehicle speed information, and calculates a user requested braking force based on them. For this reason, the required braking force calculation unit 81 has a calculation formula that defines the relationship between the amount of depression of the brake pedal, the vehicle speed, and the user required braking force. The user-requested braking force is calculated in the calculation formula. Instead, the required braking force calculation unit 81 has a table that defines the correspondence relationship between the combination of the brake pedal signal and the vehicle speed and the user required braking force, and the set of the brake pedal signal and the vehicle speed is input. The user requested braking force corresponding to the set may be obtained by referring to the table.

  The braking force control unit 82 is necessary based on the user requested braking force obtained by the requested braking force calculation unit 81, transmission control information for controlling the transmission, and engine control information for controlling the engine. Find the braking force. Based on this necessary braking force, the transmission control unit 83 outputs a retarder control signal to the retarder operation switching hydraulic circuit 73 and outputs a lockup control signal to the lockup hydraulic control circuit 74. In addition, the braking force control unit 82 outputs a backup brake operation instruction to the transmission control unit 83 when an abnormal signal is input as a backup brake operation request from the brake system.

  Further, the braking force control unit 82 calculates (estimates) the braking force generated in the lockup clutch 21 when the torque converter 1 is used as a backup brake. Specifically, the braking force control unit 82 determines the slip amount in the lockup clutch 21 (the rotational speed difference between the input shaft 51 and the output shaft 61) and the magnitude of the hydraulic force applied to the lockup clutch 21 ( The generated braking force in the lockup clutch 21 is estimated from the degree of engagement or the engagement force. The generated braking force in the lockup clutch 21 is proportional to the slip amount and the engagement force.

  When a brake system abnormality occurs in a vehicle with the above configuration, or when the braking force decreases due to continuous use of the brake for a long time as requested by the user, it is necessary to stop the vehicle urgently. In response to the backup brake operation request, an interlock is generated in the torque converter 1, thereby generating a braking force.

  FIG. 6 is a flowchart showing a control method of the backup brake. The vehicle 100 operates the backup brake through the backup brake operation determination process shown in FIG. First, the braking force control unit 82 detects an abnormality in the brake system (checks whether there is an abnormality) (step S61), and determines whether there is a backup brake operation request due to an abnormality in the brake system (step S62). If there is no request for operating the backup brake (NO in step S62), the process returns without processing.

  When an abnormality is detected in the brake system and a request for operating the backup brake is input to braking force control unit 82 (YES in step S62), braking force control unit 82 provides backup brake to transmission control unit 83. An operation instruction is output (step S63). When receiving the backup brake operation instruction, the transmission control unit 83 performs a process of completely engaging the retarder clutch (step S64). Specifically, the transmission control unit 83 outputs a retarder control signal for engaging the retarder operation switching clutch 44 to the retarder operation switching hydraulic circuit 73. The retarder operation switching hydraulic circuit 73 controls the hydraulic pressure supplied from the retarder operation switching hydraulic circuit 73 in accordance with the retarder control signal to operate the piston 43 and engage the retarder operation switching clutch 44.

  Next, the vehicle 100 performs a lock-up clutch complete engagement process (step S66). When the lock-up clutch complete engagement processing is completed, as described above, the torque converter 1 is in an interlock state, and all the members are unable to rotate. In this embodiment, the interlock state is realized by first engaging the retarder operation switching clutch 44 and then engaging the lock-up clutch 21. Instead, the lock-up clutch 21 is The interlock state may be realized by engaging the retarder operation switching clutch 44 after the engagement.

  In the lock-up clutch complete engagement process (step S66) for setting the interlock state, if the lock-up clutch 21 is immediately fully engaged, the braking force becomes too large, the wheels are locked, and the vehicle slides. Problems arise such that the steering operation becomes impossible, the various components of the torque converter 1 are damaged due to a heavy load, and the driver cannot maintain the driving posture due to sudden deceleration of the vehicle.

  Therefore, in the present embodiment, the subsequent clutch engagement in the simultaneous engagement of the retarder operation switching clutch 44 and the lockup clutch 21 for realizing the interlock state, that is, the lockup clutch complete engagement processing in the present embodiment. In (Step S66), processing is performed so that the lockup clutch 21 is gradually engaged so as not to cause the above problem.

  FIG. 7 is a flowchart of the lock-up clutch complete engagement process. As shown in FIG. 7, in the lock-up clutch complete engagement process, first, the rotational speed of the wheel is detected (step S71), and it is determined whether or not the wheel lock has occurred (step S72). If the wheel lock has not occurred (YES in step S72), the braking force control unit 82 estimates the generated braking force in the lockup clutch 21 (step S73), and the estimated generated braking force is a predetermined upper limit. It is determined whether or not it is equal to or less than the value α (step S74).

  If the generated braking force is less than or equal to upper limit α (YES in step S74), braking force control unit 82 controls transmission control unit 83 to cause the transmission to shift down, and the lockup clutch after the shift down. The generated braking force at 21 is estimated (step S75), and it is determined whether the generated braking force after the downshift is equal to or less than the upper limit value α (step S76). If the generated braking force does not reach the upper limit value α even after the downshift (YES in step S76), transmission control unit 83 causes lockup control circuit 74 to amplify the hydraulic pressure to be applied to lockup clutch 21. Processing to output a lockup control signal is performed (step S77). Thereafter, the braking force control unit 82 detects the vehicle speed and the acceleration of the vehicle (step S78), and determines whether or not the stop of the vehicle is completed (step S79).

  If the vehicle has completely stopped (YES in step S78), the process returns. If the vehicle has not stopped (NO in step S78), the process returns to step S71 to detect the rotational speed of the wheel. In this way, the process is repeated until the stop of the vehicle is completed.

  If the wheel is locked (NO in step S72) and if the generated power exceeds upper limit α (NO in step S74 or NO in step S86), transmission control unit 83 is Then, the lockup control circuit 74 performs a process of outputting a lockup control signal for reducing the hydraulic pressure applied to the lockup clutch 21 (step S80).

  As described above, when the generated braking force in the lockup clutch 21 exceeds the upper limit value α, the hydraulic force in the lockup clutch 21 is reduced (reducing the engagement force). This is to prevent the lockup clutch 21 and other components from being damaged due to the damage. The reason for downshifting the transmission before increasing the engagement force of the lockup clutch 21 is to use the interlock state as a backup brake after the braking force by the retarder brake is sufficiently generated.

  As described above, according to the torque converter 1 of the present embodiment, when the user requests deceleration, the other one of the retarder operation switching clutch 44 and the lockup clutch 21 is engaged and the other is engaged. Thus, an interlock state can be realized and a braking force can be obtained. The torque converter 1 according to the present embodiment can stop the vehicle by completely engaging both the retarder operation switching clutch 44 and the lockup clutch 21, so that the backup brake in the event of an abnormality in the brake system. Available as

  In addition, since the brake operation is possible only with the configuration within the torque converter, it can be applied to a vehicle having a transmission of various types or specifications as long as the vehicle is equipped with a torque converter regardless of the configuration of the transmission. is there.

  Further, according to the torque converter 1 of the present embodiment, the fluid retarder function can be realized by engaging only the retarder operation switching clutch 44 at the time of deceleration request.

  Furthermore, in the torque converter 1 of the present embodiment, the above advantages can be realized without impairing the function as a torque converter.

  In the present embodiment, in order to realize the interlock state by engaging both the lock-up clutch 21 and the retarder operation switching clutch 44, the retarder operation switching clutch 44 is first completely engaged, Since the up clutch 21 is gradually engaged by the control shown in FIG. 7, the retarder brake can function during this time to generate a braking force.

  In the above embodiment, an example in which the drive source is an engine has been described. However, the drive source may be a motor in addition to the engine or instead of the engine.

DESCRIPTION OF SYMBOLS 1 Torque converter 11 Pump shell 12 Turbine shell 13 Stator 14 Housing 21 Lockup clutch 31 Damper 41 Planetary gear train for acceleration 411 Sun gear 412 Pinion gear 413 Ring gear 42 Carrier 43 Piston 44 Retarder operation switching clutch 51 Input shaft 61 Output shaft 70 Hydraulic mechanism 71 Oil pump 72 Regulator 73 Retarder operation switching hydraulic circuit 74 Lock-up hydraulic control circuit 75 Oil cooler 76 Oil pan 80 Control unit 81 Required braking force calculation unit 82 Braking force control unit 83 Transmission control unit 100 Braking system

Claims (7)

A pump shell connected to the output shaft of the drive source via a pump intermediate member and rotating integrally with the output shaft;
A turbine shell connected to an input shaft of the transmission via a turbine intermediate member and rotating integrally with the input shaft;
A lock-up clutch that connects the pump shell and the turbine shell by engaging to rotate the pump shell and the turbine shell together;
A planetary gear train comprising a fixed sun gear, a pinion gear, and a ring gear, the turbine intermediate member serving as a carrier;
A retarder operation switching clutch that connects the ring gear and the pump intermediate member by engaging to rotate the ring gear and the pump intermediate member integrally;
A torque converter characterized by comprising:   The torque converter according to claim 1, wherein a damper is provided between the lockup clutch and the turbine intermediate member. A torque converter according to claim 1;
A control unit for engaging the lockup clutch and the retarder operation switching clutch;
With
The control unit engages either the lock-up clutch or the retarder operation switching clutch when receiving an operation request for a backup brake, and then either of the lock-up clutch or the retarder operation switching clutch. A braking system characterized in that the other is engaged while controlling the degree of engagement.   The braking system according to claim 3, wherein the control unit reduces the degree of engagement when a wheel lock is generated.   The braking system according to claim 3 or 4, wherein the control unit reduces the degree of engagement when a generated braking force exceeds a predetermined upper limit value.   The control unit engages the retarder operation switching clutch when receiving an operation request for a backup brake, and then engages the lock-up clutch while controlling the degree of engagement. The braking system according to any one of claims 3 to 5. A hydraulic mechanism for operating the lock-up clutch and the retarder operation switching clutch;
The braking system according to any one of claims 3 to 6, wherein the control unit engages the lock-up clutch and the retarder operation switching clutch by controlling the hydraulic mechanism.

Images