Vehicle power transmission device

Abstract

To provide a vehicular power transmission device that has a clutch function and a damper function capable of changing the extent of damping action, and can reduce the number of components.SOLUTION: A vehicular power transmission device (10) comprises: a first member (111), a second member (112), and a third member (113) to which rotational motion is transmitted; a cushioning mechanism (120) including a cushioning member (121) for cushioning an impact between the first member and the second member, and a damping member (122) for damping the energy of the impact; a clutch part (130) capable of switching a transmission state of power between the second member and the third member; an actuator (140) for switching the transmission state of the power in the clutch part; and a transmission member (141) for transmitting a driving force of the actuator to the damping member. The damping member (122) changes the extent of damping action depending on the driving force of the actuator transmitted via the transmission member (141).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power transmission device for a vehicle.

Background Art

[0002] Patent Document 1 discloses a clutch device having a damper function with a variable attenuation effect by hydraulic pressure.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a clutch device capable of switching a power transmission state by hydraulic or electrical control. When a damper function with a variable attenuation effect is added to such a clutch device, two systems of drive units, i.e., a drive unit for switching the power transmission state and a drive unit for increasing or decreasing the attenuation effect, are required, and the number of parts increases.

[0005] An object of the present invention is to provide a power transmission device for a vehicle that has a clutch function and a damper function with a variable attenuation effect and can reduce the number of parts.

Means for Solving the Problems

[0006] (1) A power transmission device for a vehicle according to one aspect of the present invention includes a first member, a second member, and a third member to which rotational motion is transmitted, a buffer mechanism including a buffer member that buffers an impact between the first member and the second member, and a damping member that damps the energy of the impact, a clutch portion capable of switching a power transmission state between the second member and the third member, An actuator that switches the power transmission state of the clutch unit, A transmission member that transmits the driving force of the actuator to the damping member, and is provided with, The first member includes an input shaft, The third member includes an output shaft, The rotational motion input to the first member via the input shaft is transmitted to the third member via the second member, and the rotational motion is output from the output shaft, The damping member, The first member includes a first surface and a second surface whose relative rotation with the second member is restricted, and the energy of the impact is attenuated by the friction between the first surface and the second surface, and changes the magnitude of the damping action according to the driving force of the actuator transmitted through the transmission member, The clutch unit is configured to cut off power transmission while the actuator is not driven. 、 The transmission member transmits the driving force of the actuator By transmitting, the pressure of the contact surface between the first surface and the second surface is increased or decreased . (2) A vehicle power transmission device according to another aspect of the present invention includes a first member, a second member, and a third member to which rotational motion is transmitted, a buffer mechanism including a buffer member that buffers an impact between the first member and the second member, and a damping member that damps the energy of the impact, a clutch unit capable of switching a power transmission state between the second member and the third member, an actuator that switches the power transmission state of the clutch unit, a transmission member that transmits the driving force of the actuator to the damping member, an acting member that applies the driving force of the actuator to the clutch unit, a damping portion that generates a damping action when the clutch unit and the acting member rotate relative to each other while the clutch unit transmits power, and is provided with, The damping member changes the magnitude of the damping action according to the driving force of the actuator transmitted through the transmission member, The buffer mechanism exerts a buffer action between the first member and the second member when the first member and the second member rotate relative to each other, The relatively rotatable angle between the first member and the actuating member is smaller than the relatively rotatable angle between the first member and the second member.

Advantages of the Invention

[0007] According to the present invention, the damping action of the buffer mechanism can be increased or decreased by using the driving force of the actuator that switches the clutch portion. Therefore, compared with a configuration having two systems of drive units, namely, switching of the clutch portion and increase or decrease of the damping action, the number of components can be reduced.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an example of a vehicle equipped with a power transmission device for a vehicle according to an embodiment of the present invention.

[0010] The vehicle 1 in FIG. 1 is, for example, a HEV (Hybrid Electric Vehicle), and includes drive wheels 2, an engine 4 which is an internal combustion engine, an auxiliary machine 5 for driving the engine 4, an electric motor 6 for generating driving power, a battery 8 for storing driving electric power, an inverter 7 for driving the electric motor 6 using the electric power of the battery 8, a transmission 9 for transmitting power to the drive wheels 2, a power transmission device 10 disposed between the engine 4 and the transmission 9, a driving operation unit 20 for the driver to perform driving operations, and a control unit 31 for controlling the auxiliary machine 5, the inverter 7, and the power transmission device 10 according to driving operations and the like. The driving operation unit 20 includes a steering wheel 21, an accelerator pedal 22, and a brake pedal 23, and signals indicating the operation amounts of these are sent to the control unit 31. The electric motor 6 may generate electricity by regenerative operation and charge the battery 8.

[0011] The power transmission device 10 according to the embodiment of the present invention switches the power transmission state (a state in which power is transmitted and a state in which power transmission is interrupted) between the engine 4 and the transmission 9. The crankshaft 4a of the engine 4 and the input shaft 9i of the transmission 9 are connected to the power transmission device 10. Hereinafter, the state in which power is transmitted is also referred to as "clutch on", and the state in which power transmission is interrupted is also referred to as "clutch off".

[0012] The power transmission device 10 has the crankshaft 4a of the engine 4 connected to the input side and the input shaft 9i of the transmission 9 connected to the output side. Further, the motor shaft of the electric motor 6 is connected to the output side of the power transmission device 10 via a chain and a sprocket.

[0013] The power transmission device 10 switches the power transmission state by driving the actuator 140, and increases or decreases the attenuation effect of the impact energy in the buffering function. When the power transmission device 10 is in the clutch-off state, the input shaft 9i of the transmission 9 is disconnected from the engine 4 and connected to the electric motor 6. When the power transmission device 10 is in the clutch-on state, the input shaft 9i of the transmission 9 and the electric motor 6 are connected to the crankshaft 4a of the engine 4. By such switching, the vehicle 1 can run using the power of the engine 4 and the power of the electric motor 6.

[0014] The control unit 31 is composed of one ECU (Electronic Control Unit) or a plurality of ECUs that operate in cooperation with each other via communication. The control unit 31 realizes the running of the vehicle 1 by driving the auxiliary machine 5, the inverter 7, and the actuator 140 according to the driving operation and the vehicle state (running speed, output torque, remaining battery charge, etc.).

[0015] <Power Transmission Device> FIG. 2 is a longitudinal sectional view of the upper half of the power transmission device 10. FIG. 3 is a plan view showing the inside of the power transmission device 10. Hereinafter, the direction along the rotation axis O1 of the power transmission device 10 is referred to as the axial direction, the direction perpendicular to the rotation axis O1 is referred to as the radial direction, and the rotation direction centered on the rotation axis O1 is referred to as the circumferential direction. Also, the side where power is output in the axial direction (the right side in FIG. 2) is referred to as the output side, and the opposite side is referred to as the input side. FIG. 3 corresponds to a plan view seen from the output side, excluding the covers 151 and 152, the third member 113, the front plate 111c, and the plurality of clutch plates 131. FIG. 4 is a plan view showing the disk portion 111b of the first member 111. FIG. 5 is a plan view showing the second member 112. FIG. 6 is a plan view showing the acting member 142.

[0016] The power transmission device 10 includes a first member 111, a second member 112, and a third member 113 that are rotatable about a rotation axis O1, a buffer mechanism 120 that exerts a buffering action between the first member 111 and the second member 112, a clutch portion 130 that can switch the power transmission state between the second member 112 and the third member 113, an actuator 140 that switches the state of the power transmission device 10, an action member 142 that transmits the driving force of the actuator 140 to the clutch portion 130, a transmission member 141 that transmits the driving force of the actuator 140 to the friction plate 122, and covers 151, 152 that cover the surroundings. The first member 111 and the second member 112 are relatively rotatable by a predetermined angle in the circumferential direction, and the second member 112 and the third member 113 are relatively rotatable when the clutch is off.

[0017] The first member 111 includes an input shaft 111a, a disk portion (back plate) 111b connected to the input shaft 111a, and a ring-shaped front plate 111c connected to the disk portion 111b. The input shaft 111a is connected to the crankshaft 4a of the engine 4. The input shaft 111a may be one end of the crankshaft 4a. As shown in FIG. 4, the disk portion 111b is a member that extends in the radial direction (rotation radius direction) in a plate shape, and has a holding hole HR1 for holding the spring spring 121 and a plurality of long holes HL1a, HL1b. The front plate 111c (FIG. 2) is connected to the disk portion 111b via a connecting pin 111d (FIG. 3) and holds the spring spring 121 from the output side.

[0018] The third member 113 includes an output shaft 113a, a connecting portion 113b connected to the inner peripheral portion of the clutch portion 130, and a sprocket 113c integrated with the output shaft 113a. The sprocket 113c may be connected to the output shaft 113a outside the power transmission device 10. The output shaft 113a is connected to the input shaft 9i of the transmission 9, and the sprocket 113c is connected to the motor shaft of the electric motor 6 via a chain.

[0019] The second member 112 is a ring-shaped plate member (intermediate plate) connected to the outer peripheral member 132 of the clutch portion 130, and is positioned between the disk portion (back plate) 111b and the front plate 111c of the first member 111. The second member 112 has an engagement portion 112a that engages with both ends of the spring spring 121, a through-hole H2 through which the transmission member 141 passes, and a long hole HL2 through which the connecting pin 111d passes.

[0020] The clutch portion 130 has a plurality of clutch plates 131 and an outer peripheral member 132. When the plurality of clutch plates 131 are pressed against each other, the connecting portion 113b of the third member 113 connected to the inner peripheral portion of the clutch portion 130 and the outer peripheral member 132 are connected so as to be able to transmit power. The outer peripheral member 132 is connected to the second member 112 via the transmission member 141. The clutch portion 130 disconnects the connection between the connecting portion 113b of the third member 113 on the inner peripheral portion and the outer peripheral member 132 when the pressing of the plurality of clutch plates 131 is released. The clutch portion 130 is disposed on the output side of the disk portion 111b.

[0021] The actuator 140 is driven by hydraulic pressure or electrically, outputs a driving force for pushing out the plunger during operation, and stops the output of the driving force during non-operation. The driving force of the actuator 140 is transmitted to the clutch portion 130 via the acting member 142, and presses the plurality of clutch plates 131. The actuator 140 is supported by the input-side cover 152, and outputs a driving force to the acting member 142 via a thrust bearing 143 such as a needle bearing. Due to the thrust bearing 143, even when the disk portion 111b, the clutch portion 130, and the acting member 142 rotate in the circumferential direction, the driving force can be output from the actuator 140 to the clutch portion 130 via the acting member 142. The actuator 140 is disposed on the input side of the disk portion 111b.

[0022] As shown in FIG. 6, the acting member 142 has a ring plate portion 142a that contacts the clutch portion 130 and a plurality of support columns 142b that extend axially from the ring plate portion 142a. The ring plate portion 142a and the plurality of support columns 142b are integrated. The acting member 142 is interposed between the actuator 140 and the clutch portion 130 and transmits the driving force of the actuator 140 to the clutch portion 130. Although the disk portion 111b of the first member 111 is positioned between the actuator 140 and the clutch portion 130, the support columns 142b of the acting member 142 are passed through the long hole HL1b of the disk portion 111b, so that the acting member 142 can be interposed between the actuator 140 and the clutch portion 130.

[0023] The buffer mechanism 120 has a spring (corresponding to a buffer member) 121 that exerts a buffering action and a friction plate (corresponding to a damping member) 122 that exerts a damping action on the energy of the impact. The spring 121 is held compressibly within the holding hole HR1 of the disk portion 111b. Further, the pair of engaging portions 112a of the second member 112 can abut against both ends of the spring 121. Therefore, when the disk portion 111b of the first member 111 and the second member 112 rotate relative to each other in the circumferential direction, the spring 121 contracts to exert a buffering action.

[0024] The friction plate 122 is a ring-shaped and plate-shaped member and is disposed on the input side of the disk portion 111b of the first member 111. The friction plate 122 has a through hole H22 (FIGS. 2 and 3) through which the shaft portion of the transmission member 141 passes. The friction plate 122 is in surface contact with the back surface (corresponding to the receiving surface) of the disk portion 111b and generates a frictional force on the contact surface when the disk portion 111b rotates relatively, thereby exerting a damping action on the energy of the impact.

[0025] The transmission member 141 holds the friction plate 122 on one side of the disk portion 111b and transmits the driving force of the actuator 140 to the friction plate 122. The transmission member 141 has a shaft portion and a head portion, and is passed through the through-hole H22 of the friction plate 122, the long hole HL1a of the disk portion 111b, and the through-hole H2 of the second member 112. The tip of the shaft portion is connected to the outer peripheral member 132 of the clutch portion 130, and the head portion is positioned on the input side of the friction plate 122 to hold the friction plate 122. Since the transmission member 141 is passed through the long hole HL1a of the disk portion 111b, it does not inhibit the relative rotation between the disk portion 111b and the second member 112. On the other hand, the transmission member 141 is passed through the through-hole H22 of the friction plate 122 and the through-hole H2 of the second member 112, so that the relative rotation between the second member 112 and the friction plate 122 is restricted. Therefore, when the first member 111 and the second member 112 rotate relative to each other, similarly, the disk portion 111b and the friction plate 122 rotate relative to each other, and frictional force can be generated at the contact surface between the two.

[0026] Furthermore, the head portion of the transmission member 141 has a dimension that cannot enter the through-hole H22 of the friction plate 122. In addition, the tip of the shaft portion of the transmission member 141 is connected (or may be engaged) to the outer peripheral member 132 of the clutch portion 130. Therefore, when a force in the direction toward the output side is applied to the outer peripheral member 132 of the clutch portion 130, the force is transmitted to the friction plate 122 via the transmission member 141, and the contact surface pressure between the friction plate 122 and the disk portion 111b can be increased.

[0027] <Clutch switching operation and increase / decrease operation of damping action> When the driving force of the actuator 140 is not output, since the acting member 142 does not apply pressure to the clutch portion 130, the plurality of clutch plates 131 are not in pressure contact and the clutch is off. Due to the clutch being off, the transmission of power is interrupted between the first member 111 and the second member 112 and the third member 113. When the clutch is off, with the engine 4 connected to the first member 111 stopped, power can be transmitted between the electric motor 6 and the transmission 9 via the third member 113.

[0028] When the driving force is output from the actuator 140 and pressure is applied from the acting member 142 to the clutch portion 130, the plurality of clutch plates 131 are in pressure contact and the clutch is on. Due to the clutch being on, the second member 112 and the third member 113 are connected so as to be able to transmit power. Further, when an impact in the rotational direction is applied to the first member 111, or when an impact is applied to the relative rotational movement between the first member 111 and the third member 113, the first member 111 and the second member 112 rotate relative to each other. Then, the spring 121 contracts and the impact applied to the second member 112 is alleviated. Further, when the first member 111 and the second member 112 rotate relative to each other due to the expansion and contraction of the spring 121, the friction plate 122 slides on the disk portion 111b of the first member 111, attenuating the energy of the impact.

[0029] When the driving force is output from the actuator 140 and the clutch is turned on, when the driving force of the actuator 140 increases or decreases, the increase or decrease of the driving force is transmitted to the friction plate 122 via the acting member 142, the clutch portion 130, and the transmission member 141. Then, the above driving force is transmitted to the contact surface between the friction plate 122 and the disk portion 111b, increasing or decreasing the pressure of the contact surface. Therefore, the magnitude of the attenuation action by the friction plate 122 can be increased or decreased.

[0030] <Second attenuation configuration> As shown in FIG. 6, on the ring plate portion 142a of the acting member 142, a friction material R1 (corresponding to the damping portion) is provided on the surface on the clutch portion 130 side. When the ring plate portion 142a and the clutch portion 130 rotate relative to each other, a frictional force is generated on the contact surface between the two, and by this frictional force, the relative rotational energy between the first member 111 and the second member 112 can be attenuated.

[0031] As shown in FIG. 3, the angle W1 at which the friction plate 122 and the disk portion 111b can rotate relative to each other corresponds to the angle at which the first member 111 and the second member 112 can rotate relative to each other. The angle W1 corresponds to the angular range within which the transmission member 141 can move from one end to the other end of the long hole HL1a of the disk portion 111b. Alternatively, the above-mentioned rotatable angle W1 corresponds to the angular range from the angle of the second member 112 when the disk portion 111b is fixed and the spring 121 is most contracted in the left rotation direction to the angle of the second member 112 when the spring 121 is most contracted in the right rotation direction. When the above two angular ranges are different, the smaller of these two angular ranges corresponds to the above-mentioned rotatable angle W1.

[0032] On the other hand, the angle W2 at which the acting member 142 and the disk portion 111b can rotate relative to each other corresponds to the angular range within which the support portion 142b of the acting member 142 can move from one end to the other end of the long hole HL1b of the disk portion 111b.

[0033] The angle W2 at which the acting member 142 and the disk portion 111b can rotate relative to each other is smaller than the angle W1 at which the first member 111 and the second member 112 can rotate relative to each other. Therefore, when the torque change applied to the power transmission device 10 is large and the relative rotation amount between the first member 111 and the second member 112 exceeds the angle W2 due to the action of the buffer mechanism 120, the support portion 142b of the acting member 142 contacts one end or the other end of the long hole HL1b of the disk portion 111b. Then, by receiving a circumferential force from the disk portion 111b, the acting member 142 rotates relative to the clutch portion 130. Then, the ring plate portion 142a of the acting member 142 slides relative to the clutch portion 130, and an action of attenuating the rotational energy between the first member 111 and the second member 112 is exerted.

[0034] That is, when the first member 111 and the second member 112 rotate relative to each other, the friction plate 122 slides relative to the disc portion 111b, and the first damping action is exerted by the friction based on the sliding. Further, when the relative rotation amount between the first member 111 and the second member 112 becomes large and exceeds the angle W2, the ring plate portion 142a of the acting member 142 slides relative to the clutch portion 130. And the second damping action is exerted by the friction based on the sliding. When the second damping action occurs, the support portion 142b of the acting member 142 deviates from the center in the long hole HL1b, and after the second damping action occurs, the support portion 142b of the acting member 142 stops at the deviated position. Therefore, next, when the support portion 142b of the acting member 142 contacts one end or the other end of the long hole HL1b, the rotation amount (the relative rotation amount between the first member 111 and the second member 112) at which the second damping action occurs is different from when the support portion 142b is located at the center of the long hole HL1b.

[0035] <Damper characteristics> FIG. 7 is a graph showing the characteristics of the damper function of the power transmission device. The graph in FIG. 7 shows the relationship between the torsional angle and the axial torque of the power transmission device 10 when the clutch is on. The torsional angle means the relative rotation angle between the first member 111 and the third member 113, and the axial torque means the torque generated between the first member 111 and the third member 113. The graph line shows the axial torque when the torsional angle changes in the direction of the arrow, and the areas of the regions E1, E2, and E3 surrounded by the graph line when the return angle changes in the forward rotation direction and the graph line when it changes in the reverse rotation direction represent the magnitude of the attenuation in the damper action.

[0036] When the power transmission device 10 is on the clutch, when the driving force of the actuator 140 is small, as shown by the dashed line, a small damping action occurs, and when the driving force of the actuator 140 is large, as shown by the solid line, a large damping action occurs.

[0037] Furthermore, when the torsional angle becomes larger than the angle W2 during torque fluctuations and the second damping action comes into play, as shown by the two-dot chain line, the absolute value of the shaft torque increases due to the friction between the acting member 142 and the clutch portion 130, and accordingly, a greater damping action can be produced. The torsional angle at which the second damping action starts to rise varies depending on where the support portion 142b of the acting member 142 stops in the long hole HL1b.

[0038] <Control Example of Power Transmission Device> Subsequently, the control process of the power transmission device 10 will be described. FIG. 8 is a flowchart showing an example of clutch switching control processing executed by the control unit.

[0039] The clutch switching control process is always executed during the operation of the vehicle 1. When the power transmission device 10 is in the clutch-off state during the operation of the vehicle 1, the control unit 31 repeatedly performs a determination process (step S1) to check whether the predetermined clutch-on condition is satisfied until the condition is met. The determination process in step S1 is performed based on the driving operation, vehicle state (travel speed, output torque, remaining battery charge, etc.) or both. When the clutch-on condition is satisfied, the control unit 31 controls the actuator 140 to be turned on and outputs a driving force F1 from the actuator 140. By outputting the driving force F1, the clutch is turned on, and the friction plate 122 is pressed against the disk portion 111b with the first pressing force F11. In this state, a damping action of normal magnitude occurs in the damper function of the power transmission device 10. The driving force F1 may be the minimum driving force that does not cause slippage in the clutch portion 130 due to the torque output from the engine 4 after the clutch is turned on and the buffering and damping actions of the power transmission device 10 occur, and the control unit 31 may be configured to have a function of calculating the driving force.

[0040] When the driving force F1 is output from the actuator 140, next, the control unit 31 determines whether or not it meets the conditions (resonance conditions) for resonance to occur around the power transmission path of the engine 4 based on the driving operation, vehicle state, or both (step S3), and determines whether or not it meets the clutch-off conditions (step S5), and repeats until it matches any of the conditions. As a result, if it meets the resonance conditions, the control unit 31 controls the actuator 140 to increase the output of the actuator 140 to the driving force F2 (step S4). The driving force F2 is greater than the driving force F1 output in steps S2 and S7. By outputting the driving force F2, the friction plate 122 is pressed against the disk portion 111b with a second pressing force F12 that is greater than the above-described first pressing force F11, and the damping action of the damper function of the power transmission device 10 increases. Due to the increase in the damping action, even when it meets the resonance conditions, resonance around the path through which the power of the engine 4 is transmitted can be suppressed.

[0041] When the driving force F2 is output from the actuator 140, next, the control unit 31 determines whether or not the conditions for resonance to occur around the power transmission path of the engine 4 have been released based on the driving operation, vehicle state, or both (step S6), and determines whether or not it meets the clutch-off conditions (step S8), and repeats until it matches any of the conditions. As a result, if the resonance conditions are released, the control unit 31 controls the actuator 140 to decrease the actuator 140 output to the driving force F1 (step S7). By outputting the driving force F1, the pressing force of the friction plate 122 against the disk portion 111b decreases to the first pressing force F11, and the damping action of the damper function of the power transmission device 10 returns to its normal magnitude. By such control, it is possible to suppress the damping action of the damper function from becoming unnecessarily large and suppress a decrease in power transmission efficiency.

[0042] On one hand, in the discrimination loop of steps S3 and S5, or the discrimination loop of steps S6 and S8, if it is determined that the clutch-off condition is satisfied, the control unit 31 turns off the actuator 140 (step S9). Then, the clutch unit 130 is clutched off, and the crankshaft 4a of the engine 4 is disconnected from the power train that transmits power to the drive wheels 2. And the control unit 31 returns the process to step S1.

[0043] According to such clutch switching control processing, by the drive control of one system of the actuator 140, it is possible to switch the clutch on and off of the power transmission device 10 and increase and decrease the damping action of the damper function.

[0044] As described above, according to the power transmission device 10 of the present embodiment, it is possible to switch between clutch on and clutch off by the driving force of the actuator 140. Further, the driving force of the actuator 140 is transmitted to the friction plate 122 via the transmission member 141. Therefore, by increasing and decreasing the driving force of the actuator 140, the magnitude of the damping action of the buffer mechanism 120 generated in the friction plate 122 can be increased and decreased. Therefore, the switching of the clutch unit 130 and the increase and decrease of the magnitude of the damping action of the buffer mechanism 120 are realized by the driving of the common actuator 140, and the number of components can be reduced as compared with the case of using separate driving parts for these controls.

[0045] Furthermore, according to the vehicle 1 in which the power transmission device 10 of the present embodiment is arranged between the engine 4 and the transmission 9, by driving the actuator 140 that switches between clutch on and off, the magnitude of the damping action of the damper function of the power transmission device 10 can be increased and decreased. Therefore, when the vibration becomes large in the power transmission path of the engine 4, the damping action can be increased to suppress the vibration. Also, during light load or in an operating region where vibration generation is small, by reducing the damping action, energy loss due to damping can be reduced, and the power transmission efficiency and energy efficiency can be improved.

[0046] Furthermore, according to the vehicle 1 in which the power transmission device 10 of the present embodiment is disposed between the engine 4 and the transmission 9, a large damping action can be obtained in the power transmission device 10 by driving the actuator 140 that switches the clutch on and off. Therefore, without using a large and heavy flywheel, a large buffering action can be obtained in the power transmission device 10 against torque fluctuations, rotational speed fluctuations, etc. of the engine 4 during high load. Therefore, compared with the case where a large and heavy flywheel is applied, weight reduction of the vehicle 1, compactification of the drive mechanism, and improvement of the response of the driving force can be achieved.

[0047] Furthermore, according to the power transmission device 10 of the present embodiment, the clutch portion 130 has a normally open configuration that cuts off power transmission while the actuator 140 is not driven. Further, the transmission member 141 is configured to transmit the driving force of the actuator 140 to the contact surface so as to increase the contact surface pressure between the friction plate 122 and the disk portion 111b. With such a configuration, by increasing the driving force of the actuator 140 from zero, the power transmission state can be switched in the order of clutch off and damper function off, small damping action when the clutch is on, and large damping action when the clutch is on. Therefore, corresponding to the normal state transition in which the power transmission device 10 starts to receive an impact when the clutch is engaged, the power transmission device 10 can be switched to the required state by stepwise switching or continuous switching of the driving force of the actuator 140. Therefore, the control of the power transmission device 10 becomes easy. In addition, since the magnitude of the damping action changes by applying the driving force of the actuator 140 to the contact surface between the friction plate 122 and the disk portion 111b, stable increase and decrease of the damping action can be realized by controlling the actuator 140.

[0048] Furthermore, according to the power transmission device 10 of the present embodiment, a friction material R1 is provided between the ring plate portion 142a of the acting member 142 and the clutch portion 130. Further, an angle W2 at which the first member 111 and the acting member 142 can rotate relative to each other is smaller than an angle W1 at which the first member 111 and the second member 112 can rotate relative to each other. Therefore, when torque fluctuation increases the relative rotation amount between the first member 111 and the second member 112, friction can be generated between the ring plate portion 142a and the clutch portion 130 to increase the damping effect. That is, in this way, the damping effect of the damper function can be automatically increased in accordance with torque fluctuation at which the amplitude of the buffer mechanism 120 becomes large.

[0049] Furthermore, according to the power transmission device 10 of the present embodiment, the actuator 140 and the clutch portion 130 are arranged with the disk portion 111b of the first member 111 interposed therebetween. Further, the acting member 142 that transmits the driving force of the actuator 140 to the clutch portion 130 is interposed between the actuator 140 and the clutch portion 130 through the through hole (long hole HL1b) of the disk portion 111b. Therefore, the angle W2 at which the first member 111 and the acting member 142 can rotate relative to each other can be easily set according to the angular range of the long hole HL1b, and a configuration for relatively rotating the acting member 142 and the clutch portion 130 during torque fluctuation can be realized with a simple configuration and a small number of parts.

[0050] Furthermore, according to the power transmission device 10 of the present embodiment, the control unit 31 switches the clutch portion 130 and increases or decreases the damping effect of the buffer mechanism 120 by controlling one actuator 140. Therefore, both of these controls can be unified into one system, and reduction of control signal lines and simplification of the control configuration (software configuration) can be achieved.

[0051] The above describes each embodiment of the present invention. However, the present invention is not limited to the above embodiments. For example, the configuration of the transmission member that transmits the driving force of the actuator to the damping member is not limited to the illustrated configuration, and any configuration in which the driving force is transmitted through any path and any mechanism may be used. Further, in the above embodiment, a ring-shaped friction plate 122 is adopted as the damping member, and an example in which a damping action is generated by friction is shown. However, the damping member may be, for example, a flow path member that generates a damping action by the movement of hydraulic oil, or a configuration in which the magnitude of the damping action is changed by changing the cross-sectional area of the flow path by the driving force of the actuator may be adopted. The damping member can be variously modified. Further, the clutch portion may adopt a normally closed configuration instead of a normally open configuration, or the configuration in which a damping action is generated by the friction between the actuating member and the clutch portion may be omitted.

[0052] Further, in the above embodiment, the actuator 140 is provided on the fixed side (cover 152), and the actuating member 142 is configured to transmit the driving force of the actuator 140 to the clutch portion 130. However, the actuator according to the present invention may be provided on the rotating side (for example, the second member or the third member), and the actuating member receives a repulsive force from another member (for example, the cover 152) by the driving force of the actuator, so that the driving force acts on the clutch portion. Even in such a configuration, a damping action can be generated by the relative rotation between the actuating member and the clutch portion. Further, in the above embodiment, an example in which the friction material R1 is applied as the damping portion that generates a damping action by the relative rotation between the actuating member and the clutch portion is shown. However, the specific configuration of the damping portion can be variously modified, for example, it may be a flow path member that generates a damping action by the movement of hydraulic oil.

[0053] In the above-described embodiment, an example where the power transmission device is located between the engine and the transmission has been shown. However, the power transmission device according to the present invention may be applied to various power transmission locations in a vehicle, such as being applied to a torque converter with a clutch. Further, the vehicle to which the power transmission device is applied is not limited to an HEV, and may be an EV (Electric Vehicle) or an engine vehicle. In addition, the details shown in the embodiment can be appropriately changed without departing from the gist of the invention.

Explanation of Reference Numerals

[0054] 1 Vehicle 2 Driving wheel 4 Engine 6 Electric motor 9 Transmission 10 Power transmission device 31 Control unit 111 First member 111b Disk portion HR1 Holding hole HL1a, HL1b, HL2 Long hole 112 Second member H2 Through hole 113 Third member 120 Buffer mechanism 121 Spring spring (buffer member) 122 Friction plate (damping member) H22 Through hole 130 Clutch portion 140 Actuator 141 Transmission member 142 Actuating member R1 Friction material (damping portion)

Claims

1. a first member, a second member, and a third member to which rotational motion is transmitted; a buffer mechanism including a buffer member that absorbs an impact between the first member and the second member, and a damping member that damps the energy of the impact; a clutch unit capable of switching a power transmission state between the second member and the third member; an actuator for switching a power transmission state of the clutch unit; a transmission member that transmits a driving force of the actuator to the damping member; Equipped with the first member includes an input shaft; the third member includes an output shaft; A rotational motion input to the first member via the input shaft is transmitted to the third member via the second member, thereby outputting a rotational motion from the output shaft, the damping member includes a first surface included in the first member and a second surface whose rotation relative to the second member is restricted, and is configured to dampen energy of the impact by friction between the first surface and the second surface, and changes a magnitude of the damping action in response to the driving force of the actuator transmitted via the transmission member; The clutch portion is configured to interrupt the transmission of power while the actuator is not driven, a transmission member for transmitting a driving force of the actuator, the transmission member increasing or decreasing a pressure on a contact surface between the first surface and the second surface.

2. a first member, a second member, and a third member to which rotational motion is transmitted; a buffer mechanism including a buffer member that absorbs an impact between the first member and the second member, and a damping member that damps the energy of the impact; a clutch unit capable of switching a power transmission state between the second member and the third member; an actuator for switching a power transmission state of the clutch unit; a transmission member that transmits a driving force of the actuator to the damping member; an acting member for applying a driving force of the actuator to the clutch portion; a damping unit that generates a damping effect by rotating the clutch unit and the working member relative to each other in a state in which the clutch unit transmits power; Equipped with the damping member changes a magnitude of a damping action in response to the driving force of the actuator transmitted via the transmission member, the buffer mechanism exerts a buffering effect between the first member and the second member by the first member and the second member rotating relative to each other, A power transmission device for a vehicle, wherein an angle by which the first member and the acting member can rotate relatively to each other is smaller than an angle by which the first member and the second member can rotate relatively to each other.

3. The first member includes a disk portion extending in a radial direction of rotation and having a long hole, The actuator is disposed on the opposite side of the disk portion from the clutch portion, 3. The power transmission device for a vehicle according to claim 2, wherein the action member passes through the long hole and is interposed between the actuator and the clutch portion.

4. 4. The power transmission device for a vehicle according to claim 1, further comprising a control unit that controls both the switching of the clutch unit and the increase and decrease of the damping action by controlling the actuator.

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