JP6311580B2 - Fluid transmission device - Google Patents

Description

  The present invention relates to a fluid transmission device mounted on a vehicle, and more particularly to a fluid transmission device including a lock-up clutch.

  A fluid power transmission device such as a torque converter that is incorporated in a transmission such as an automatic transmission or a continuously variable transmission mounted on a vehicle and transmits an output of a driving source such as an engine to a transmission mechanism is connected to an engine as a driving source. A pump as an input member that rotates integrally with the drive source, and a turbine as an output member that is disposed opposite to the pump and to which power is transmitted by the pump via a fluid. ing.

  In the fluid transmission device, in order to improve the fuel consumption performance of the engine in the driving state excluding when the vehicle is stopped in the traveling range where the relative rotation of the pump and the turbine needs to be permitted or when shifting during traveling, etc., One having a lock-up clutch directly connected to a turbine is known.

  The lock-up clutch is configured to press the piston by supplying the fastening fluid pressure to the fluid pressure chamber to directly connect the pump and the turbine, and to supply the fastening fluid pressure to the fluid pressure chamber. And is released by discharging the fastening fluid pressure from the fluid pressure chamber.

  In recent years, for example, a balance chamber has been provided on the opposite side of the fluid pressure chamber across the piston for the purpose of reducing the influence of centrifugal pressure when the lockup clutch is engaged or for reducing the engagement pressure when the lockup clutch is engaged. A technique is known (for example, Patent Document 1).

German Patent Application Publication No. 10104346

  However, as described in Patent Document 1, in a fluid transmission device including a lock-up clutch having a balance chamber, when the fastening fluid pressure is discharged from the fluid pressure chamber when the lock-up clutch is released, There is a possibility that the centrifugal force acting on the fluid becomes larger than the centrifugal force acting on the fluid remaining in the fluid pressure chamber, and the piston is urged in the release direction and moved.

  If the piston is urged and moved in the release direction when the lockup clutch is released, the piston is urged in the engagement direction when the fastening fluid pressure is supplied to the fluid pressure chamber when the lockup clutch is engaged. Since the movement is delayed, the responsiveness when the lock-up clutch is engaged is lowered.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a fluid transmission device that can suppress the piston of the lockup clutch from being urged and moved in the release direction when the lockup clutch is released, and can fasten the lockup clutch with high responsiveness. The task is to do.

  In order to solve the above problems, the fluid transmission device according to the present invention is configured as follows.

According to the first aspect of the present invention, in the case connected to the drive source, the input member that rotates integrally with the drive source, and the power is transmitted from the input member via the power transmission fluid. An output member, and a lock-up clutch that presses the piston with a fastening fluid pressure supplied to the fluid pressure chamber to directly connect the input member and the output member. A fluid transmission device having a balance chamber formed on the opposite side, wherein the piston is moved in the release direction by centrifugal force acting on the fluid in the balance chamber in the fluid pressure chamber when the engagement condition of the lockup clutch is not satisfied. comprises a fluid pressure supply means for supplying a predetermined fluid pressure suppressing Rukoto, said fluid pressure supply means, the transition to the time not satisfied the holds, the fastening condition of the lock-up clutch The first predetermined fluid pressure that is lower than the fastening fluid pressure and is set to correspond to the centrifugal force acting on the fluid in the balance chamber when the lockup clutch is released is applied to the fluid pressure chamber. And the fluid pressure supply means supplies the first predetermined fluid pressure to the fluid pressure chamber when the engagement condition of the lockup clutch is not established, and the input member via the lockup clutch. When power is transmitted to and from the output member, a second predetermined fluid pressure obtained by reducing the first predetermined fluid pressure supplied to the fluid pressure chamber by a predetermined pressure is supplied to the fluid pressure chamber. To do.

According to a second aspect of the present invention, in the fluid transmission device according to the first aspect, the fluid pressure supply means supplies the first predetermined fluid pressure to the fluid pressure when a fastening condition of the lockup clutch is not established. When power is transmitted between the input member and the output member via the lock-up clutch during supply to the chamber, the first predetermined fluid pressure supplied to the fluid pressure chamber is set to a predetermined pressure. The lowered second predetermined fluid pressure is supplied to the fluid pressure chamber, and the fluid pressure supply means is configured to supply the second predetermined fluid pressure to the fluid pressure chamber via the lock-up clutch even after supplying the second predetermined fluid pressure to the fluid pressure chamber. When power is transmitted between the input member and the output member, the fluid pressure supplied to the fluid pressure chamber is decreased by a predetermined pressure, and the fluid pressure supplied to the fluid pressure chamber becomes smaller than a predetermined lower limit value. Fluid pressure at that time Maintained, characterized in that to be supplied to the fluid pressure chamber.

With the above configuration, according to the first aspect of the present invention, the piston is moved in the release direction by the centrifugal force acting on the fluid in the balance chamber in the fluid pressure chamber when the fastening condition of the lockup clutch is not satisfied. When the lockup clutch is released, the piston is biased in the release direction by the centrifugal force acting on the fluid in the balance chamber by the predetermined fluid pressure supplied to the fluid pressure chamber when the lockup clutch is released. Thus, the lockup clutch can be suppressed with high responsiveness when the fastening fluid pressure is supplied to the fluid pressure chamber when the lockup clutch is fastened.
When the lockup clutch is engaged from the time when the engagement condition is established to when it is not established, the pressure is lower than the engagement fluid pressure, and is set to correspond to the centrifugal force acting on the fluid in the balance chamber when the lockup clutch is released. When the first predetermined fluid pressure of the pressure is supplied to the fluid pressure chamber and the first predetermined fluid pressure is supplied, when power is transmitted between the input member and the output member via the lockup clutch, By supplying the second predetermined fluid pressure obtained by reducing the first predetermined fluid pressure by a predetermined pressure to the fluid pressure chamber, the above effect can be effectively achieved.

According to the second aspect of the present invention, when the first predetermined fluid pressure is supplied to the fluid pressure chamber when the fastening condition of the lockup clutch is not satisfied, the input member and the output member are interposed via the lockup clutch. When power is transmitted between the first and second fluid pressure chambers, the second predetermined fluid pressure obtained by lowering the first predetermined fluid pressure supplied to the fluid pressure chamber by a predetermined pressure is supplied to the fluid pressure chamber and the second predetermined fluid pressure is supplied. However, when power is transmitted between the input member and the output member via the lock-up clutch, the fluid pressure supplied to the fluid pressure chamber is decreased by a predetermined pressure, and when the pressure decreases below a predetermined lower limit value, Since the fluid pressure is maintained and supplied to the fluid pressure chamber, when the lockup clutch is released, the lockup clutch can be prevented from being engaged by the fluid pressure supplied to the fluid pressure chamber, and the above effect is effective. Play Door can be.

It is sectional drawing of the fluid transmission apparatus which concerns on embodiment of this invention. It is sectional drawing to which the principal part of the fluid transmission apparatus shown in FIG. 1 was expanded. It is a control system figure of an automatic transmission provided with the fluid transmission device. It is a flowchart which shows control operation | movement of the lockup clutch of the said fluid power transmission apparatus. It is a time chart for demonstrating an example of control of the lockup clutch of the said fluid power transmission apparatus.

  Hereinafter, an embodiment in which the present invention is applied to a torque converter of an automatic transmission will be described.

  1 is a cross-sectional view of a fluid transmission device according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of the fluid transmission device shown in FIG. A torque converter 1 as a fluid transmission device according to an embodiment of the present invention is incorporated in an automatic transmission, and has a case 10 that forms an outer shell thereof as shown in FIGS. 1 and 2. .

  The case 10 is an engine as a drive source, specifically an output shaft of the engine, via a connecting portion 12 fixed at the radial center of the front cover 11 that constitutes the engine side surface that is the drive source side. Is connected to a crankshaft (not shown). As a result, the entire torque converter 1 is driven by the engine.

  In the following description, for the sake of convenience, the engine side (the right side in the figure) is the front, and the non-engine side (the left side in the figure) is the rear.

  The torque converter 1 includes, as main components, a donut-shaped torus T, a one-way clutch OWC, a lock-up clutch (hereinafter referred to as “clutch” as appropriate) formed by a pump 20 as an input member and a turbine and a stator as an output member. 60) and a lock-up damper (hereinafter referred to as “damper” as appropriate) LD, which are housed in the case 10 and filled with hydraulic oil as a power transmission fluid. It is like that.

  In FIG. 1, the pump 20, the turbine and stator, the one-way clutch OWC, and the damper LD, which are constituent members of the torus T, are not shown in detail for easy understanding of the invention.

  The pump 20 has a pump shell 21 that constitutes a surface of the case 10 on the side opposite to the engine, and the pump shell 21 is formed such that an outer peripheral portion thereof bulges rearward and has a predetermined interval in the circumferential direction therein. A large number of blades (not shown) are provided. The pump 20 rotates integrally with the case 10 so that the hydraulic oil filled in the case 10 is swirled around the shaft center by the inner surface of the pump shell 21 and the blade, and a flow from the rear to the front is generated. It has become.

  A pump-type oil pump (not shown) is connected to an inner peripheral end of the pump shell 21 and extends to the transmission mechanism side of the automatic transmission, and the tip of the pump sleeve 23 is disposed behind the torque converter 1. ) Is engaged. Accordingly, the oil pump is driven via the case 10 and the pump sleeve 23 by the rotation of the crankshaft.

  The turbine includes a turbine shell (not shown) disposed on the engine side of the pump shell 21 and a turbine hub 30 coupled to an inner peripheral end of the turbine shell, and is disposed opposite to the front of the pump 20. In the case 10 so as to be rotatable.

  The turbine shell has an outer peripheral portion that bulges forward, and a plurality of blades (not shown) are disposed in the turbine shell at predetermined intervals in the circumferential direction. The outer peripheral portion of the pump shell 21 on which the blades are disposed and the outer peripheral portion of the turbine shell on which the blades are disposed are arranged to face each other, so that the flow of hydraulic oil generated by the rotation of the pump 20 flows into the turbine shell. Introduced, an inward flow of hydraulic oil is formed by the inner surface of the turbine shell and the blades, and the flow of the hydraulic oil presses the blades, whereby the turbine receives a circumferential force, and the pump 20 Are driven in the same direction.

  This driving force is transmitted to the transmission mechanism by a turbine shaft 25 extending to the transmission mechanism side of the automatic transmission connected to the turbine. The turbine is connected to the turbine shaft 25 by spline fitting the inner peripheral end of the turbine hub 30 to the turbine shaft 25.

  The stator includes a large number of blades (not shown) disposed at a predetermined interval in the circumferential direction and disposed inside a facing portion of the pump 20 and the turbine. The blades are integrated as a whole. It is made into the structure. The blade is disposed between an inner peripheral end of the blade of the pump 20 and an inner peripheral end of the turbine blade, whereby the flow of hydraulic oil that has driven the turbine is transferred to the turbine side. A flow of hydraulic oil that is introduced through and passes between the blades of the stator is formed.

  Then, the flow of the hydraulic oil is introduced into the inner surface of the pump shell 21 from the inner peripheral side and becomes the flow of the hydraulic oil from the rear to the front by the inner surface of the pump shell 21 and the blades, and the pump 20, the turbine, and the stator A hydraulic oil flow that circulates between the blades is formed, and the torque converter 1 as a whole forms a donut-shaped space in which this circulating flow is formed, that is, a torus T. .

  The one-way clutch OWC supports the stator and realizes a torque increasing action by the stator, and is disposed inside the stator. The one-way clutch OWC is assembled to the stator shaft 24 by spline fitting the inner peripheral surface of the inner race 36 to the stator shaft 24 extending from the transmission case of the automatic transmission.

  When the stator receives a rotational force in one direction due to the flow of hydraulic oil in the torus T, the stator rotates freely as the one-way clutch OWC idles, and when the stator receives a rotational force in the other direction, The one-way clutch OWC is fixed by being locked. At this time, a torque increasing action occurs, the torque input from the engine to the pump 20 is increased, and the torque is output from the turbine to the turbine shaft 25.

  The hydraulic oil supplied into the torus T is supplied into the case 10 through an oil passage 24a formed between the stator shaft 24 and the turbine shaft 25, and formed between the pump sleeve 23 and the stator shaft 24. The oil is discharged from the case 10 through the oil passage 23a.

  On the other hand, the clutch 60 includes a clutch hub 61 and a clutch drum 62 that are concentrically disposed, and a plurality of friction plates 63 that are disposed between the hub 61 and the drum 62 and are alternately engaged with these. And a piston 65 that presses the plurality of friction plates 63.

  The clutch drum 62 includes an outer cylindrical portion 62a extending in the axial direction with the friction plate 63 engaged, a bottom portion 62b extending radially from the engine side of the outer cylindrical portion 62a, and an inner side of the bottom portion 62b from the inner side to the anti-engine side. An inner cylindrical portion 62c extending in the axial direction is provided, and the bottom portion 62b is fixed to the inner surface of the front cover 11 by welding and coupled to the case 10.

  An oil passage component member 40 extending in the radial direction along the front cover 11 is fixed to the front cover 11 by welding on the inner peripheral side of the clutch drum 62 and the outer peripheral side of the turbine hub 30. In addition, welding with the oil-path structural member 40 and the front cover 11 is performed in the multiple places of the circumferential direction, for example.

  The piston 65 of the clutch 60 is fitted between the inner cylindrical portion 62 c of the clutch drum 62 and the outer peripheral portion 41 of the oil passage constituting member 40, and between the inner cylindrical portion 62 c of the clutch drum 62 and the piston 65. An annular seal member 46 is interposed, and an annular seal member 47 is interposed between the outer peripheral portion 41 of the oil passage constituting member 40 and the piston 65.

  The piston 65 includes an outer cylindrical portion 71 that extends in the axial direction fitted to the inner cylindrical portion 62c of the clutch drum 62, a hydraulic pressure receiving portion 72 that extends radially inward from the engine side of the outer cylindrical portion 71, and a hydraulic pressure. The inner cylindrical portion 73 extends in the axial direction from the inner side of the receiving portion 72 to the opposite engine side and is fitted to the outer peripheral portion 41 of the oil passage component member 40, and has a diameter on the opposite engine side of the outer cylindrical portion 71. A pressing portion 74 extending outward in the direction is provided.

  The hydraulic chamber 4 as a fluid pressure chamber is supplied with a fastening hydraulic pressure as a fastening fluid pressure of the lockup clutch between the back portion of the piston 65, that is, between the piston 65 and the case 10, specifically, the front cover 11. Is formed.

  From the oil passage 25a provided in the hydraulic chamber 4 to the inside of the turbine shaft 25, the oil passage 40a provided between the front cover 11 and the oil passage component 40 fixed to the inner surface of the front cover 11 is passed through a predetermined passage. When hydraulic fluid is supplied with the fastening hydraulic pressure, the plurality of friction plates 63 are pressed against the retainer 68 by the piston 65, and the clutch 60 is fastened.

  A plurality of groove portions 42 extending in a substantially radial direction are formed on the surface of the oil path constituent member 40 on the front cover 11 side, and the hydraulic chamber 4 is formed between the oil path constituent member 40 and the front cover 11 by the groove portions 42. An oil passage 40a communicating with the oil passage 40a is formed.

  FIG. 1 also shows a part of a hydraulic control circuit of an automatic transmission provided with a torque converter 1. The hydraulic control circuit 100 has a predetermined hydraulic pressure at which the discharge pressure of the oil pump 101 includes various valves. Via the circuit 102, each frictional engagement element of the speed change mechanism, the case internal pressure chamber 2 filled with hydraulic oil of the torque converter 1, the hydraulic chamber 4 of the lockup clutch 60, and the like are supplied.

  As shown in FIG. 1, the hydraulic control circuit 100 includes a lock-up clutch linear solenoid valve 103 that controls the hydraulic pressure supplied to the hydraulic chamber 4 of the clutch 60 through oil passages 25a, 40a, and the like. It operates by a control signal from the control unit 150, which will be described later, adjusts the hydraulic pressure input to the original pressure port a to a predetermined hydraulic pressure and outputs it to the output port b, or shuts off both ports and drains the output port b. It operates to communicate with port c. In this way, the fastening hydraulic pressure can be supplied to the hydraulic chamber 4 of the clutch 60 or the fastening hydraulic pressure can be discharged.

  Further, a seal ring 81 is interposed between the inner peripheral portion 43 of the oil passage component member 40 and the turbine hub 30, and the seal ring 81 is placed in a seal ring groove portion formed on the outer peripheral surface of the turbine hub 30. It is installed.

  The clutch 60 also includes a plate member 50 disposed on the non-engine side of the piston 65, and the plate member 50 forms a balance chamber 6 with the piston 65. The balance chamber 6 is formed on the opposite side of the hydraulic chamber 4 with the piston 65 interposed therebetween.

  The plate member 50 includes an outer plate portion 51 extending in the radial direction substantially along the hydraulic pressure receiving portion 72 of the piston 65, a cylindrical portion 52 extending in the axial direction from the inner peripheral side of the outer plate portion 51 to the opposite engine side, and a cylindrical portion. 52, an inner plate portion 53 extending radially inward from the non-engine side, and the inner plate portion 53 is fixed to the case 10 by being fixed to the oil passage component member 40 by welding. The welding of the inner plate portion 53 and the oil passage component member 40 is performed at, for example, a plurality of locations in the circumferential direction.

  The plate member 50 includes a seal member 55 at an end portion on the outer peripheral side in the radial direction of the outer plate portion 51, and the seal member 55 is between the outer cylindrical portion 71 of the piston 65 and the outer plate portion 51 of the plate member 50. To seal.

  Further, a seal ring 83 is interposed between the inner peripheral portion 54 of the plate member 50 that is an end portion on the inner peripheral side in the radial direction of the inner plate portion 53 and the turbine hub 30, and the seal ring 83 is connected to the turbine hub. It is mounted in a seal ring groove formed on the outer peripheral surface of 30.

  The balance chamber 6 is formed between the plate member 50 arranged in this way and the hydraulic pressure receiving portion 72 of the piston 65. By introducing the hydraulic oil into the balance chamber 6, the centrifugal force acting on the hydraulic oil in the hydraulic chamber 4 is canceled by the centrifugal force acting on the hydraulic oil in the balance chamber 6.

  As shown in FIG. 2, the balance chamber 6 communicates with the case internal pressure chamber 2 through a communication hole 75 provided in the outer cylindrical portion 71 of the piston 65, and transmits power between the pump 20 and the turbine. Part of the hydraulic fluid is introduced from the case internal pressure chamber 2 filled with the hydraulic fluid for the purpose.

  The case internal pressure chamber 2 refers to a space in the case 10 excluding the hydraulic chamber 4 and the balance chamber 6 and the oil passage 40a connected thereto. In the present embodiment, the case 10 is more anti-engine than the plate member 50 in the case 10. It is formed by a space on the side and a space radially outward from the outer cylindrical portion 71 of the piston 65.

  The balance chamber 6 is also connected to the outer oil inside the turbine shaft 25 via a communication hole 35 provided in the turbine hub 30 in the radial direction and a communication hole 26 provided in the turbine shaft 25 in the radial direction. The hydraulic fluid in the balance chamber 6 communicates with the passage 25b and is discharged through the communication holes 35 and 26.

  An oil hole 27 penetrating in the axial direction is provided inside the turbine shaft 25, and the oil hole 27 is connected to the hydraulic chamber 4 by a pipe member 28 fitted in the oil hole 27. The passage 25 a is partitioned into an outer oil passage 25 b communicating with the balance chamber 6.

  Further, the damper LD has a plurality of damper springs (not shown) for absorbing a shock when the clutch 60 is engaged, and one end of the damper spring is connected to the clutch hub 61 of the clutch 60, and the damper The other end of the spring is connected to the turbine.

  When the clutch 60 is engaged, the damper LD receives the rotation of the front cover 11, that is, the rotation of the crankshaft, through the clutch 60 and compresses the damper spring of the damper LD while compressing the damper spring. It is transmitted to the turbine.

  Here, the operation of the torque converter 1 will be described. First, when the clutch 60 is not engaged, the turbine is driven via the hydraulic oil circulating in the torus T by the pump 20 that rotates integrally with the crankshaft of the engine. Then, power is transmitted to the transmission mechanism via the turbine shaft 25. In that case, the output torque of the engine is increased and output to the speed change mechanism at the speed ratio at which the torque increasing action of the stator is obtained.

  When the clutch 60 is engaged, if a predetermined engagement hydraulic pressure is supplied to the hydraulic chamber 4 of the clutch 60 via the oil passages 25a, 40a, the piston 65 is pressed by the engagement hydraulic pressure, and the clutch 60 is engaged. The case 10 and the turbine are connected via the damper LD, and the engine output torque is directly transmitted from the crankshaft to the turbine via the case 10, the clutch 60, and the damper LD. . In this case, the power is transmitted to the transmission mechanism without passing through the hydraulic oil, so that the torque transmission efficiency is improved compared to when the clutch 60 is not engaged, and the fuel efficiency of the engine is improved.

  When the clutch 60 is engaged, the hydraulic oil supplied to the hydraulic chamber 4 is controlled to be in a slip state and then completely engaged in order to suppress a shock when the clutch 60 is engaged. When the torque transmission is started when the plurality of friction plates 63 of the clutch 60 start to contact, the shock at the start of torque transmission is absorbed by the compression of the damper spring of the damper LD.

  In the clutch 60, the friction plate 63 and the retainer 68 are elastically deformed by the pressing force of the piston 65 when the clutch 60 is engaged. When the clutch 60 is released, the hydraulic chamber 4 When the locking hydraulic pressure for the lockup clutch is discharged, the piston 65 is moved in the releasing direction by the elastic restoring force of the friction plate 63, the retainer 68 and the like.

  As described above, when the clutch 60 has the balance chamber 6, when the fastening hydraulic pressure is discharged from the hydraulic chamber 4 when the clutch 60 is released, the piston 65 is biased in the release direction and moved. Although the responsiveness when 60 is engaged may be reduced, in the present embodiment, such a problem is avoided by supplying a predetermined hydraulic pressure to the hydraulic chamber 4 when the clutch 60 is released.

  As shown in FIG. 3, the automatic transmission including the torque converter 1 selectively supplies hydraulic pressure to each friction engagement element of the transmission mechanism to form each shift stage, and the case internal pressure chamber 2 of the torque converter 1 and the like. A hydraulic control circuit 100 for supplying hydraulic pressure to the hydraulic chamber 4 of the clutch 60 is provided. The hydraulic control circuit 100 engages the friction engagement element solenoid valve 104 and the clutch 60 for performing engagement control of each friction engagement element. A lock-up clutch solenoid valve 103 and the like for performing control are provided.

  In addition, the automatic transmission includes a control unit 150 as a control device that controls each solenoid valve in the hydraulic control circuit 100 to form a gear stage according to an operating state. The control unit 150 includes the vehicle. A signal from a vehicle speed sensor 151 that detects the vehicle speed, a signal from an accelerator position sensor 152 that detects the amount of depression of the accelerator pedal (accelerator position) by the driver, and a range that is selected by the driver's selection A signal from the sensor 153, a signal from the engine speed sensor 154 that detects the engine speed, a signal from the turbine speed sensor 155 that detects the speed of the turbine, and the like are input.

  Based on these signals, the control unit 150 provides control signals to the friction engagement element solenoid valve 104, the lock-up clutch solenoid valve 103 in the hydraulic control circuit 100, and other solenoid valves included in the hydraulic control circuit 100. Is output to selectively supply a hydraulic pressure to a predetermined frictional engagement element to form a gear position according to an operating state and to control the clutch 60. The control unit 150 includes a microcomputer as a main part.

  In the present embodiment, the control unit 150 supplies the engagement hydraulic pressure to the hydraulic chamber 4 when the engagement condition of the clutch 60 is satisfied, and supplies the predetermined hydraulic pressure to the hydraulic chamber 4 when the engagement condition of the clutch 60 is not satisfied. The lockup clutch solenoid valve 103 is controlled.

  Further, the control unit 150 reduces the predetermined fluid pressure supplied to the hydraulic chamber 4 when power is transmitted between the pump 20 and the turbine via the clutch 60 when the engagement condition of the clutch 60 is not established. The solenoid valve 103 for the lockup clutch is controlled so that

  FIG. 4 is a flowchart showing the control operation of the lockup clutch. The control operation of the lock-up clutch 60 is executed by the control unit 150. As shown in FIG. 4, the control unit 150 includes a vehicle speed sensor 151, an accelerator opening sensor 152, a range sensor 153, an engine speed sensor 154, and a turbine speed. Based on various signals read from the number sensor 155 or the like, it is determined whether or not the lock-up clutch 60 is under engagement control (step S1), and the engagement condition of the lock-up clutch 60 is satisfied and the lock-up clutch 60 is satisfied. It is determined whether or not the fastening control is in progress.

  As an engagement condition of the lock-up clutch 60, in this embodiment, the vehicle speed of the vehicle on which the automatic transmission is mounted is a predetermined vehicle speed, for example, 10 km / h or less, the accelerator pedal is depressed, and the accelerator is ON. It is used that the D (forward) range is selected.

  When the determination result in step S1 is YES, that is, when the engagement condition of the lockup clutch 60 is established and the engagement control of the lockup clutch 60 is being performed, the engagement control of the lockup clutch 60 according to the operation state is performed. Specifically, a control signal is output to the lockup clutch solenoid valve 103 so as to supply a predetermined fastening hydraulic pressure to the hydraulic chamber 4 (step S2). Note that the lock-up clutch 60 may be slip-controlled according to the operating state.

  On the other hand, when the determination result in step S1 is NO, that is, when the engagement condition of the lockup clutch 60 is not satisfied and the lockup clutch 60 is not in the engagement control, the lockup clutch 60 is shifted to the non-engagement control. It is determined whether or not there is (step S3). In step S3, it is determined whether or not it is a transition from when the lockup clutch 60 engagement condition is established to when it is not established, and whether or not it is the first time that the lockup clutch 60 engagement condition is not established. It is determined whether or not.

  When the determination result in step S3 is YES, that is, when the lockup clutch 60 is shifted to the non-engagement control, the lockup clutch 60 is supplied so that the first predetermined hydraulic pressure lower than the engagement hydraulic pressure is supplied to the lockup clutch 60. A control signal is output to the solenoid valve 103 (step S4). The first predetermined hydraulic pressure is set to a predetermined constant pressure lower than the fastening hydraulic pressure, and is set in advance to correspond to a centrifugal force acting on the hydraulic oil introduced into the balance chamber 6 when the lockup clutch 60 is released. .

  When the first predetermined hydraulic pressure is supplied to the lockup clutch 60, it is determined whether or not slip has occurred in the lockup clutch 60 (step S5), and the lockup in which the engagement condition of the lockup clutch 60 is not satisfied. It is determined whether or not power is transmitted through the lockup clutch 60 when the clutch 60 is released. Whether or not slip has occurred in the lockup clutch 60 can be determined based on a change in the turbine rotational speed, and it can be determined that slip has occurred when the turbine rotational speed has rapidly increased. The slip determination of the lock-up clutch 60 can also be determined based on a change in differential rotation between the engine speed and the turbine speed.

  If the determination result in step S5 is NO, that is, if slip has not occurred in the lock-up clutch 60, steps S1 and S3 are repeated. In the next step S3, the lock-up clutch 60 is switched to non-engagement control. Since the determination result at step S3 is not at the time of transition, it is determined whether slip has occurred in the lockup clutch 60 in step S5 in a state where the first predetermined hydraulic pressure is supplied to the lockup clutch 60. Is done.

  Next, when the determination result in step S5 is YES, that is, when slip occurs in the lockup clutch 60, it is determined whether or not the hydraulic pressure supplied to the lockup clutch 60 is equal to or greater than a predetermined lower limit value (step). S6). A predetermined lower limit value higher than zero is set in advance for the hydraulic pressure supplied to the lockup clutch 60.

  If the determination result in step S6 is YES, that is, if the hydraulic pressure supplied to the lockup clutch 60 is greater than or equal to a predetermined lower limit value, the lockup clutch is configured to reduce the hydraulic pressure supplied to the lockup clutch 60 by a predetermined pressure. A control signal is output to the solenoid valve 103 (step S7). When the first predetermined hydraulic pressure is supplied, the second predetermined hydraulic pressure is controlled by reducing the predetermined pressure.

  Then, steps S1, S3, and S5 are repeated, and if the determination result in step S5 is NO, that is, if the slip-up does not occur in the lock-up clutch 60, the second predetermined hydraulic pressure is continuously supplied. A control signal is output to the up-clutch solenoid valve 103. If the determination result in step S5 is YES, that is, if the slip is still occurring in the lock-up clutch 60, the control signal is supplied to the lock-up clutch 60 in step S6. It is determined whether the hydraulic pressure is equal to or greater than a predetermined lower limit value.

  If the determination result in step S6 is YES, that is, if the hydraulic pressure supplied to the lockup clutch 60 is greater than or equal to a predetermined lower limit value, the hydraulic pressure supplied to the lockup clutch 60 is locked up so as to further reduce the predetermined pressure. A control signal is output to the clutch solenoid valve 103 (step S7). When the second predetermined hydraulic pressure is supplied, control is performed to reduce the predetermined pressure and supply the third predetermined hydraulic pressure.

  When slip is generated in the lockup clutch 60, if the determination result in step S6 is YES, that is, if the hydraulic pressure supplied to the lockup clutch 60 is greater than or equal to a predetermined lower limit value, the lockup is sequentially performed in step S7. The hydraulic pressure supplied to the clutch 60 is controlled to sequentially reduce the predetermined pressure. When the determination result in step S6 is NO, that is, when the hydraulic pressure supplied to the lockup clutch 60 is smaller than a predetermined lower limit value, Control is performed to maintain the hydraulic pressure supplied to the lockup clutch 60.

FIG. 5 is a time chart for explaining an example of control of the lockup clutch. As shown in FIG. 5, when the engagement condition of the lockup clutch 60 is satisfied and the lockup clutch 60 is under the engagement control, the engagement control determination of the lockup clutch 60 is turned on and supplied to the lockup clutch 60. hydraulic pressure of the command pressure to be is set to the fastening hydraulic P ₀ in accordance with the operating state.

At time t1, when the engagement condition of the lockup clutch 60 is not satisfied and the lockup clutch 60 is not under the engagement control, the engagement control determination of the lockup clutch 60 is turned off and supplied to the lockup clutch 60. that command pressure of the hydraulic pressure is set to a first supply pressure P ₁ is lower than the fastening hydraulic.

  If the lockup clutch 60 is no longer engaged and the lockup clutch 60 is not under engagement control, it is determined whether slip has occurred during the non-engagement control of the lockup clutch 60, and the lockup clutch 60 is It is determined whether power is transmitted between the pump 20 and the turbine.

At time t2, when slip is generated during the non-engagement control of the lock-up clutch 60, the slip determination during the non-engagement control of the lock-up clutch is changed from the OFF state where the slip is not generated to the ON state where the slip is generated. Then, the hydraulic pressure supplied to the lockup clutch 60 is reduced by a predetermined pressure. If it is first set to a predetermined pressure P ₁ at time t2 before, it reduces a predetermined pressure is set to the second predetermined fluid pressure P ₂ in.

In Figure 5, by reducing the first predetermined pressure P ₁ at time t2 the second predetermined fluid pressure P _2, when slip lock-up clutch 60 is not yet occurred, that slipping yet occurred, the second A predetermined pressure is further reduced from the predetermined oil pressure. When slip occurs in the lock-up clutch 60, the hydraulic pressure supplied to the lock-up clutch 60 is controlled to be decreased by a predetermined pressure, but when the pressure is smaller than a predetermined lower limit value _PMIN , the hydraulic pressure at that time is maintained. To be controlled.

  As described above, the torque converter 1 according to the present embodiment includes a hydraulic pressure supply unit that supplies a predetermined hydraulic pressure to the hydraulic chamber 4 when the engagement condition of the lockup clutch 60 is not satisfied. The hydraulic pressure supply means includes a lockup clutch solenoid valve 103 and a control unit 150.

  Thereby, when the lockup clutch 60 is released, the piston 65 is urged and moved in the release direction by the centrifugal force acting on the hydraulic oil in the balance chamber 6 by the predetermined hydraulic pressure supplied to the hydraulic chamber 4. When the lockup clutch 60 is fastened, the lockup clutch 60 can be fastened with good responsiveness when the fastening hydraulic pressure is supplied to the hydraulic chamber 4.

  In addition, when power is transmitted between the pump 20 and the turbine via the lock-up clutch 60 when the fastening condition of the lock-up clutch 60 is not established, the predetermined hydraulic pressure supplied to the hydraulic chamber 4 is reduced. Thereby, when the lockup clutch 60 is released, the lockup clutch 60 can be suppressed from being fastened by the hydraulic pressure supplied to the hydraulic chamber 4.

  Further, the hydraulic pressure supplied to the hydraulic chamber 4 is controlled from the engagement hydraulic pressure at the time when the lockup clutch 60 is established to the predetermined oil pressure when the engagement condition of the lockup clutch 60 is established to when it is not established. This prevents the piston 65 from being biased in the release direction and moved by the centrifugal force acting on the hydraulic oil in the balance chamber 6 when the lockup clutch 60 is shifted from the time of engagement to the time of release. it can.

  In the present embodiment, hydraulic oil is supplied to the balance chamber 6 from the case internal pressure chamber 2, but the present invention is not limited to this. For example, hydraulic oil may be supplied from the hydraulic chamber 4, The hydraulic oil may be supplied from an oil passage provided in the turbine shaft 25.

  In the present embodiment, a predetermined hydraulic pressure lower than the engagement hydraulic pressure is supplied when the engagement condition of the lock-up clutch 60 is not established, but the engagement is performed when the engagement condition of the lock-up clutch 60 is established as the predetermined oil pressure. A constant pressure that is the same as or higher than the working hydraulic pressure may be supplied, or may be variably controlled according to the engine speed or turbine speed. The predetermined hydraulic pressure is appropriately set to a hydraulic pressure that can reduce the influence of the centrifugal hydraulic pressure generated in the balance chamber 6 when the lockup clutch 60 is released.

  In the embodiment described above, a predetermined hydraulic pressure is supplied to the lockup clutch 60 over the entire period of the non-engagement control of the lockup clutch 60 when the engagement condition of the lockup clutch 60 is not satisfied. The predetermined hydraulic pressure may be supplied to the lockup clutch 60 during a predetermined period from the transition from the engagement control to the non-engagement control of the lockup clutch 60, and after the transition from the engagement control to the non-engagement control of the lockup clutch 60. Supply of a predetermined hydraulic pressure to the lockup clutch 60 may be started.

  In the above-described embodiment, the case where the lockup clutch 60 is moved from the engaged state to the released state is described, but the case where the lockup clutch 60 is moved from the slip control state to the released state is also described. By controlling in the same manner as the form, the same effect can be obtained. Moreover, although the torque converter is described as the fluid transmission device, it can be similarly applied to other fluid transmission devices that transmit power from the pump to the turbine via the fluid.

  The present invention is not limited to the illustrated embodiments, and various improvements and design changes can be made without departing from the scope of the present invention.

  As described above, according to the present invention, when the lockup clutch is released, it is possible to suppress the piston of the lockup clutch from being biased in the release direction and move the lockup clutch with high responsiveness. Therefore, there is a possibility of being suitably used in the technical field of manufacturing a fluid transmission device having a lock-up clutch or a vehicle equipped with the fluid transmission device.

DESCRIPTION OF SYMBOLS 1 Torque converter 2 Case internal pressure chamber 4 Hydraulic chamber 6 Balance chamber 10 Case 20 Pump 60 Lock-up clutch 65 Piston 100 Hydraulic control circuit 103 Solenoid valve 150 for lock-up clutch Control unit

Claims (2)

In a case connected to the drive source, an input member that rotates integrally with the drive source, an output member that transmits power from the input member via a power transmission fluid, and a fastening member that is supplied to the fluid pressure chamber A fluid transmission device including a lockup clutch that presses a piston by fluid pressure to directly connect the input member and the output member, and a balance chamber is formed on the opposite side of the fluid pressure chamber across the piston; There,
Fluid pressure supply means for supplying a predetermined fluid pressure to the fluid pressure chamber to prevent the piston from moving in the release direction by centrifugal force acting on the fluid in the balance chamber when the lockup clutch engagement condition is not established. equipped with a,
The fluid pressure supplying means is lower than the fastening fluid pressure when acting on the fluid in the balance chamber when the lockup clutch is released, when transitioning from when the lockup clutch is engaged to when it is not established. Supplying a first predetermined fluid pressure of a constant pressure set corresponding to the centrifugal force to the fluid pressure chamber;
The fluid pressure supply means supplies the first predetermined fluid pressure to the fluid pressure chamber when the engagement condition of the lockup clutch is not established, and the input member and the output member via the lockup clutch. When power is transmitted between the first and second fluid pressure chambers, a second predetermined fluid pressure obtained by reducing the first predetermined fluid pressure supplied to the fluid pressure chamber by a predetermined pressure is supplied to the fluid pressure chamber.
A fluid transmission device characterized by that. The fluid pressure supply means supplies the first predetermined fluid pressure to the fluid pressure chamber when the engagement condition of the lockup clutch is not established, and the input member and the output member via the lockup clutch. When the power is transmitted between the first and second fluid pressure chambers, the second predetermined fluid pressure obtained by lowering the first predetermined fluid pressure supplied to the fluid pressure chamber by a predetermined pressure is supplied to the fluid pressure chamber,
The fluid pressure supply means is configured to transmit power between the input member and the output member via the lockup clutch even after supplying the second predetermined fluid pressure to the fluid pressure chamber. The fluid pressure supplied to the fluid pressure chamber is decreased by a predetermined pressure, and when the fluid pressure supplied to the fluid pressure chamber becomes smaller than a predetermined lower limit value, the fluid pressure at that time is maintained and supplied to the fluid pressure chamber.
The fluid transmission device according to claim 1.

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