JP2005337482A - Power transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission capable of eliminating the need of installing a dedicated transmission mechanism on the output side of a power source. <P>SOLUTION: This power transmission comprises an input member 6 and an output member 2 for power transmission and an oil pump discharging an oil by rotating a first rotating member 8 and a second rotating member 9 relative to each other. Either of the first rotating member 8 and the second rotating member 9 is connected to the input member 6 and the other is connected to the output member 2. The oil pump of radial piston type connects the first rotating member 6 to the second rotating member 2 so that a power can be transmitted therebetween and comprises a piston 11 radially operating perpendicularly to a rotating axis. The oil pump comprises a plurality of radial piston type pumps 7 and 7A capable of individually controlling the delivery state of the oil and a control valves 27 and 27A controlling the state of power transmission between the first rotating member 6 and the second rotating member 2 by controlling the delivery state of the oil by the plurality of radial piston type pumps 7 and 7A. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power transmission device disposed on the output side of a power source.

  Conventionally, a power source is mounted on a vehicle, and a power transmission device is disposed on the output side of the power source. This power transmission device includes elements such as a clutch, a transmission, and a forward / reverse switching device, and the type and arrangement position of each element are arbitrarily selected according to specifications such as vehicle performance and vehicle specifications. An example of a vehicle having such a power transmission device is described in Patent Document 1. The vehicle described in Patent Document 1 includes an engine, and a forward / reverse switching device, a belt-type continuously variable transmission, and a final reduction gear are disposed on the output side of the engine. This forward / reverse switching device has a planetary gear device, a clutch, and a brake, and is provided with a hydraulic control device that controls engagement / release of the clutch and the brake.

  The belt-type continuously variable transmission has a primary pulley, a secondary pulley, and a belt, and the hydraulic pressure in the hydraulic chamber of the primary pulley and the hydraulic chamber of the secondary pulley is controlled by a hydraulic control device. . Furthermore, a torque converter and a lock-up clutch are provided in parallel in a power transmission path between the crankshaft of the engine and the input shaft connected to the forward / reverse switching device. The torque converter has a pump impeller connected to a crankshaft and a turbine runner connected to an input shaft. The oil amount supplied to the torque converter and the engagement hydraulic pressure of the lockup clutch are also controlled by the hydraulic control device. Furthermore, the hydraulic control device has a hydraulic circuit and a solenoid valve, and an oil pump that supplies oil to the hydraulic circuit is provided. This oil pump has a body and a rotor, the body is fixed to a transaxle case, and the rotor is connected to rotate integrally with a pump impeller.

With the above configuration, engine power is transmitted to the rotor via the pump impeller, and the oil pump is driven to discharge oil. When the lockup clutch is released, when the engine power is transmitted to the torque converter, the power is transmitted by the kinetic energy of the fluid. When the lockup clutch is engaged, when the engine power is transmitted to the torque converter, the power is transmitted by the frictional force. In this way, engine power is transmitted to the forward / reverse switching device. An example of a power transmission device having an oil pump is also described in Patent Document 2, while an example of a radial hydraulic pump is described in Patent Document 3.
JP 2001-323978 A Japanese Patent Laid-Open No. 10-220557 JP 2000-186664 A

  However, the power transmission device described in Patent Document 1 is configured such that engine power is transmitted to the wheels via a fluid transmission mechanism, a forward / reverse switching device, and a belt-type continuously variable transmission. In addition, it is necessary to separately provide an oil pump for discharging oil supplied to the fluid transmission mechanism, the forward / reverse switching device, and the belt type continuously variable transmission. For this reason, there has been room for improvement in the case where the overall configuration of the power transmission device or the overall configuration including the devices attached to the power transmission device is increased in size and the on-vehicle performance is improved.

  The present invention has been made against the background of the above circumstances, and it is an object of the present invention to provide a power transmission device that can be reduced in size as a whole and that can be mounted on a vehicle.

  In order to achieve the above object, an invention according to claim 1 is an oil pump that sucks and discharges oil by relative rotation of an input member and an output member for transmitting power, and a first rotating member and a second rotating member. In the power transmission device in which either one of the first rotating member or the second rotating member is connected to the input member, and the other is connected to the output member, the oil pump includes: A piston that connects the first rotating member and the second rotating member so as to be able to transmit power, and operates in a radial direction perpendicular to the rotation axis of the first rotating member and the second rotating member. And a plurality of the radial piston pumps capable of separately controlling the oil discharge state. The plurality of radial piston pumps are provided. By controlling the oil discharge state that is characterized in that the control valve is provided for controlling the power transmission state between the first rotary member and the second rotary member.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, either the first rotating member or the second rotating member is formed in a circumferential direction around the rotation axis, and When a plurality of cam surfaces displaced in the radial direction are provided and the first rotating member and the second rotating member rotate relative to each other, the pistons of the plurality of radial piston pumps are A plurality of cam surfaces are configured to operate in a radial direction along a plurality of cam surfaces to suck and discharge oil, and the plurality of cam surfaces are arranged side by side in the rotation axis direction. Is.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect, a radius of a predetermined cam surface is different from a radius of another cam surface among the plurality of cam surfaces.

  According to the invention of claim 4, in addition to the configuration of claim 2 or 3, in accordance with the displacement in such a manner that the radius of the predetermined cam surface is increased on the circumferential phase around the rotation axis. The other cam surface is configured to be displaced so that the radius becomes smaller. In the invention of each claim, the input member means a member arranged upstream of the output member in the power transmission direction. Further, in claims 3 and 4, “predetermined” and “other” are described, but this is a term for distinguishing each cam surface, and “predetermined” and “predetermined” The term “other” itself has no particular technical meaning.

  According to the first aspect of the present invention, power is transmitted between the input member and the output member via the first rotating member and the second rotating member. Moreover, it is possible to control the power transmission state between the input member and the output member by controlling the oil discharge state in the plurality of radial piston pumps. That is, since the radial piston pump has both a function as an oil pressure feeding device and a function as a transmission mechanism, it is not necessary to provide a transmission mechanism in addition to the oil pump on the output side of the power source. Therefore, the number of parts of the power transmission device is reduced, the power transmission device can be reduced in size, and the in-vehicle performance is improved. Furthermore, since a plurality of radial piston pumps are provided, the total control mode of the oil discharge state increases.

  According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, it is possible to arrange a plurality of radial piston pumps at different positions in the rotational axis direction.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 2, it is possible to vary the oil discharge capacities of the plurality of radial piston pumps.

  According to the invention of claim 4, in addition to obtaining the same effect as that of the invention of claim 2 or 3, when the input member and the output member have a predetermined relative positional relationship in the circumferential direction, a plurality of radials are provided. Oil discharge amount of piston type pump is different. For this reason, even when the relative positional relationship between the input member and the output member changes in the circumferential direction, it is possible to suppress an increase in the fluctuation amount of the total discharge amount of the plurality of radial piston pumps. Therefore, even when the relative positional relationship between the input member and the output member changes in the circumferential direction, it is possible to suppress an increase in the amount of torque fluctuation transmitted between the input member and the output member. It is possible to reduce vibration and noise in the path.

  Next, the present invention will be described based on specific examples. The present invention is a power transmission device having a configuration in which an oil pump has both an oil discharge function and a power transmission function, and various embodiments will be sequentially described.

  FIG. 1 schematically shows an example of a power train and a control system of a vehicle Ve having the power transmission device of the present invention. First, the power train of the vehicle Ve will be described. The engine 1 is provided as a power source, and the engine torque is transmitted to the wheels 5 via the input shaft 2, the belt type continuously variable transmission 3, and the differential 4. It becomes the composition which is done. The input shaft 2, the belt type continuously variable transmission 3 and the differential 4 are disposed in a casing 60.

  In addition, the shaft 6 connected to the crankshaft (not shown) of the engine 1 and the input shaft 2 are arranged around the rotation axis A1, and the power transmission path from the shaft 6 to the input shaft 2 is An oil pump 7 as a first oil pump and an oil pump 7A as a second oil pump are provided. In this embodiment, radial piston pumps are used as the two oil pumps 7 and 7A. The configuration of the oil pumps 7 and 7A will be described with reference to FIG. FIG. 2 is a front sectional view in a plane including the rotation axis A1. First, the structure of the oil pump 7 will be described. The oil pump 7 has an inner race 8 provided on the shaft 6. The inner race 8 is formed at the end of the shaft 6 on the input shaft 2 side, and the inner race 8 has a disk shape centered on the rotation axis A1. The inner race 8 is formed with a plurality of cylinders 10 at predetermined intervals in the circumferential direction. Each cylinder 10 is arranged at intervals of 45 degrees, for example. Each cylinder 10 is a substantially cylindrical recess opened on the outer peripheral surface of the inner race 8, and as shown in FIG. 2, the axis B1 of each cylinder 10 and the rotation axis A1 are substantially orthogonal to each other. Yes.

  Each cylinder 10 is provided with a cylindrical piston 11, and each piston 11 is configured to reciprocate in the direction of the axis B1. That is, the piston 11 is movable in the radial direction of the inner race 8. A recess 12 is formed on the outer end face of each piston 11. The recess 12 is formed in a hemispherical shape, and the ball 13 is held by the recess 12. The ball 13 can roll in the recess 12. On the other hand, an oil chamber 14 is formed between the back end face 10 </ b> A of the cylinder 10 and the piston 11. The oil chamber 14 is provided with an elastic member 15, and a force that pushes the piston 11 out of the cylinder 10 is applied from the elastic member 15 to the piston 11.

  On the other hand, the shaft 6 is provided with a suction oil passage 16 and discharge oil passages 17 and 17D in the rotation axis direction, and three annular grooves 16A, 17A and 17C are formed on the outer peripheral surface of the shaft 6. Yes. The annular grooves 16A, 17A, and 17C are arranged at different positions in the rotation axis direction. The suction oil passage 16 and the annular groove 16A are connected, the discharge oil passage 17 and the annular groove 17A are connected, and the discharge oil passage 17D and the annular groove 17C are connected. Incidentally, a partition wall 61 extending in the radial direction of the rotation axis A <b> 1 is provided in the casing 60, and the shaft hole 20 is formed in the partition wall 61. The partition wall 61 is disposed between the engine 1 and the oil pump 7 in the rotational axis direction. The partition wall 61 is provided with an intake oil passage 18 and discharge oil passages 19 and 19A. The partition wall 61 extends in a direction intersecting the rotation axis A <b> 1, and the shaft 6 is rotatably disposed in the shaft hole 20 of the partition wall 61. The suction oil passage 18 and the discharge oil passages 19 and 19A are opened in the shaft hole 20, the suction oil passage 18 and the annular groove 16A are connected, the discharge oil passage 19 and the annular groove 17A are connected, and the discharge oil passage. 19A and the annular groove 17C are connected.

  As described above, the suction oil passage 16 and the suction oil passage 18 are connected and the discharge oil passage 17 and the discharge oil passage 19 are connected regardless of whether the shaft 6 is rotating or stopped. Thus, the discharge oil passage 19A and the annular groove 17C are connected. Further, the oil passes through the connecting portion between the suction oil passage 16 and the suction oil passage 18, the connection portion between the discharge oil passage 17 and the discharge oil passage 19, and the connection portion between the discharge oil passage 17D and the discharge oil passage 19A. A sealing device 20 </ b> A is provided to prevent leakage. Further, as shown in FIG. 1, an oil pan 21 is provided, and the suction oil passage 18 is connected to the oil pan 21.

  Further, an oil passage 22 that connects the suction oil passage 16 and the oil chamber 14 is provided, and an oil passage 23 that connects the discharge oil passage 17 and the oil chamber 14 is provided. 24 is provided, and a check valve 25 is provided in the oil passage 23. The check valve 24 has a function of allowing the oil in the suction oil passage 16 to be sucked into the oil chamber 14 and preventing the oil in the oil chamber 14 from flowing back into the suction oil passage 16. On the other hand, the check valve 25 has a function of allowing the oil in the oil chamber 14 to be discharged into the discharge oil passage 17 and preventing the oil in the discharge oil passage 17 from flowing back into the oil chamber 14. doing.

  On the other hand, an outer race 9 is formed on the input shaft 2. The outer race 9 has an outward flange 35 and a cylindrical portion 35 </ b> A continuous with the outward flange 35. The cylindrical portion 35A is disposed so as to surround the outer side of the inner race 8, and a cam surface 36 as a first cam surface is formed on the inner periphery of the cylindrical portion 35A. FIG. 3 is a side view of the outer race 9, and the cam surface 36 is formed in an annular shape centering on the rotation axis A1 and is formed in a substantially waveform. In other words, convex portions curved so as to project outward in the radial direction and concave portions curved so as to project inward in the radial direction are alternately and continuously arranged in the circumferential direction. ing. For example, the convex portions are arranged at intervals of 45 degrees, and the concave portions are arranged at intervals of 45 degrees. The diameter of the inscribed circle (not shown) of the cam surface 36 is set larger than the diameter of the inner race 8. The cam surface 36 and the ball 13 held by the piston 11 are in contact with each other, and the ball 13 is configured to roll along the cam surface 36 in the circumferential direction.

  Next, the configuration of the oil pump 7A will be described. The oil pump 7 </ b> A has a disk-shaped plate 80 fixed to the end surface of the inner race 8. The plate 80 is disposed between the outward flange 35 and the inner race 8 in the rotational axis direction. The outer diameter of the plate 80 is set to be less than the outer diameter of the inner race 80. Further, the suction oil passage 16 is extended in the plate 80, and a discharge oil passage 17 </ b> B extended in the rotation axis direction is formed in the plate 80. The discharge oil passage 17B is connected to a discharge oil passage 17D formed in the shaft 6.

  A plurality of cylinders 10 are formed on the plate 80 at predetermined intervals in the circumferential direction. For example, the cylinders 10 are arranged at intervals of 45 degrees. Each cylinder 10 is a substantially cylindrical recess opened on the outer peripheral surface of the plate 9, and as shown in FIG. 2, the axis B1 of each cylinder 10 and the rotation axis A1 are substantially orthogonal to each other. . Each cylinder 10 is provided with a cylindrical piston 11, and each piston 11 is configured to reciprocate in the direction of the axis B <b> 1. That is, the piston 11 can move in the radial direction of the plate 80.

  Furthermore, the outer diameter of the piston 11 and the inner diameter of the cylinder 10 of the oil pump 7 are set larger than the outer diameter of the piston 11 and the inner diameter of the cylinder 10 of the oil pump 7A. A recess 12 is formed on the outer end face of each piston 11. The recess 12 is formed in a hemispherical shape, and the ball 13 is held by the recess 12. The ball 13 can roll in the recess 12. On the other hand, an oil chamber 14 </ b> A is formed between the rear end surface 10 </ b> A of the cylinder 10 and the piston 11. The oil chamber 14 </ b> A is provided with an elastic member 15, and a force that pushes the piston 11 out of the cylinder 10 is applied from the elastic member 15 to the piston 11.

  A cam surface 36A as a second cam surface is formed on the inner periphery of the cylindrical portion 35A. Here, the cam surface 36 and the cam surface 36A are arranged side by side in the rotation axis direction. In other words, the cam surface 36 and the cam surface 36A have different arrangement regions in the rotation axis direction. Further, the cam surface 36A is formed in an annular shape centering on the rotation axis A1, and has a substantially waveform. In other words, convex portions curved so as to project outward in the radial direction and concave portions curved so as to project inward in the radial direction are alternately and continuously arranged in the circumferential direction. ing. For example, the convex portions are arranged at intervals of 45 degrees, and the concave portions are arranged at intervals of 45 degrees. Thus, the cam surface 36 and the cam surface 36A have a similar shape in a plane orthogonal to the rotation axis A1.

  The diameter of the circumscribed circle (not shown) of the cam surface 36A is set to be equal to or smaller than the diameter of the inscribed circle (not shown) of the cam surface 36. The diameter of the inscribed circle of the cam surface 36 is set larger than the diameter of the inner race 8. The cam surface 36 and the ball 13 held on the piston 11 are in contact with each other, and the ball 13 is configured to roll along the cam surface 36 in the circumferential direction. Furthermore, the difference between the circumscribed circle and the inscribed circle of the cam surface 36 is set larger than the difference between the circumscribed circle and the inscribed circle of the cam surface 36A. Therefore, the stroke amount of the piston 11 of the oil pump 7 is larger than the stroke amount of the piston 11 of the oil pump 7A.

  Furthermore, on the circumferential phase centered on the rotation axis A1, for example, the cam surface is displaced from the base line C1 in the clockwise direction in FIG. 3 so that the radius of the cam surface 36 increases. The configuration is such that the radius of 36A is reduced. In other words, the minimum radius R1 of the cam surface 36 and the maximum radius R2 of the cam surface 36A are located on the same phase in the circumferential direction, and the maximum radius of the cam surface 36 is on the same phase in the circumferential direction. The phase of the concave and convex portions of the cam surfaces 36 and 36A is set so that the portion R3 and the minimum radius portion R4 of the cam surface 36A are located.

  Further, the suction oil passage 16 and the oil chamber 14 </ b> A are connected by an oil passage 22, and the discharge oil passage 17 </ b> B and the oil chamber 14 </ b> A are connected by an oil passage 23. The oil passage 22 is provided with a check valve 24, and the oil passage 23 is provided with a check valve 25. The check valve 24 has a function of allowing the oil in the suction oil passage 16 to be sucked into the oil chamber 14 </ b> A and preventing the oil in the oil chamber 14 </ b> A from flowing back into the suction oil passage 16. On the other hand, the check valve 25 has a function of allowing the oil in the oil chamber 14A to be discharged into the discharge oil passage 17B and preventing the oil in the discharge oil passage 17B from flowing back into the oil chamber 14A. doing.

  Next, a device for controlling the oil discharge state of the oil pump 7 will be described. A control valve 27 is provided in a path from the discharge oil passage 19 connected to the oil pump 7 to the hydraulic control device 26. As shown in FIG. 4, the control valve 27 includes a spool 28, an elastic member 29, a solenoid 30, and a plunger 30A that can reciprocate substantially linearly. From the elastic member 29, a force is applied to urge the spool 28 in a predetermined direction, for example, upward in FIG. Further, when electric power is supplied to the solenoid 30, a magnetic attractive force is generated, and the plunger 30A is urged in the direction opposite to the force of the elastic member 29.

  Further, a land 31 is formed in the spool 28, and the control valve 27 has a suction port 32 and a discharge port 33. The suction port 32 is connected to the discharge oil passage 19, and the discharge port 33 is connected to the hydraulic control device 26 via the oil passage 34. Further, a port C <b> 1 is formed between the valve body and the outer peripheral surface of the land 31. The operation of the spool 28 is controlled by the correspondence between the force applied to the spool 28 from the elastic member 29 and the force applied to the spool 28 from the plunger 30A. By the operation of the spool 28, the cross-sectional area of the port C1 is controlled, and the flow rate of oil discharged from the suction port 32 to the discharge port 33 is controlled.

  Further, a device for controlling the oil discharge state of the oil pump 7A will be described with reference to FIG. 4. A control valve 27A is provided in a path from the discharge oil passage 19A connected to the oil pump 7A to the hydraulic control device 26. Yes. Since the configuration of the control valve 27A is the same as that of the control valve 27, in FIG. 4, for convenience, the control valve 27 and the control valve 27A are shown in common, and the discharge oil passage 19A is connected to the suction port 32. It is connected. The operating principle of the control valve 27A is the same as the operating principle of the control valve 27.

  The engine 1 is a power unit that converts thermal energy from fuel combustion into kinetic energy. As the engine 1, for example, an internal combustion engine, specifically, a gasoline engine, a diesel engine, an LPG engine, or the like can be used. . The engine 1 has an intake / exhaust device, a fuel injection device, and the like.

  A forward / reverse switching device 37 is provided on the path from the input shaft 2 to the belt type continuously variable transmission 3. The forward / reverse switching device 37 is a mechanism that is employed when the rotational direction of the engine 1 is limited to one direction, and has a function of switching the rotational direction of the primary shaft 38 with respect to the rotational direction of the input shaft 2. I have. In the example shown in FIG. 1, a double pinion type planetary gear mechanism is employed as the forward / reverse switching device 37. That is, a sun gear 39 that rotates integrally with the input shaft 2, a ring gear 40 that is arranged concentrically with the sun gear 39, a pinion gear 41 that meshes with the sun gear 39, and another pinion gear 42 that meshes with the pinion gear 41 and the ring gear 40 are provided. The pinion gears 41 and 42 are held by the carrier 43 so as to rotate and revolve freely. The carrier 43 and the primary shaft 38 are connected to rotate integrally.

  Further, a forward clutch 44 for selectively connecting and releasing the input shaft 2 and the carrier 43 is provided. Further, a reverse brake 45 that reverses the rotation direction of the primary shaft 38 with respect to the rotation direction of the input shaft 2 by selectively fixing the ring gear 40 is provided. Engagement / release of the forward clutch 44 and the reverse brake 45 is controlled by the hydraulic control device 26.

  The belt-type continuously variable transmission 3 includes a primary pulley 46 and a secondary pulley 47 arranged in parallel to each other, and a belt 48 is wound around the primary pulley 46 and the secondary pulley 47. Further, a hydraulic servo mechanism 49 that controls the clamping pressure applied from the primary pulley 46 to the belt 48 and a hydraulic servo mechanism 50 that controls the clamping pressure applied from the secondary pulley 47 to the belt 48 are provided. The hydraulic pressure of the pressure oil supplied to the hydraulic servo mechanisms 49 and 50 is controlled by the hydraulic control device 26.

  The primary pulley 46 is configured to rotate integrally with the primary shaft 38, and the secondary pulley 47 is configured to rotate integrally with the secondary shaft 51. The primary shaft 38 and the secondary shaft 51 are arranged in parallel to each other, and the torque of the secondary shaft 51 is transmitted to the wheels 5 via the transmission mechanism 52 and the differential 4.

  Next, the control system of the vehicle Ve shown in FIG. 1 will be described. An electronic control device 53 is provided as a controller for controlling the entire vehicle Ve. The electronic control device 53 receives signals such as acceleration request, braking request, engine speed, throttle opening, input shaft 2 speed, primary shaft 38 speed, secondary shaft 51 speed, shift position, and the like. Is done. In contrast, the electronic control unit 53 outputs a signal for controlling the hydraulic control unit 26, a signal for controlling the control valves 27 and 27A, a signal for controlling the engine 1, and the like.

  First, when the engine 1 is operated, the torque of the shaft 6 is transmitted to the input shaft 2 via the oil pumps 7 and 7A. The torque transmission principle through the oil pumps 7 and 7A will be described later. Here, when the forward position is selected as the shift position, the forward / reverse switching device 37 engages the forward clutch 44 and releases the reverse brake 45. As a result, the input shaft 2 and the carrier 43 are coupled so as to be integrally rotatable, and the torque of the input shaft 2 is transmitted to the primary shaft 38. In this case, the rotation direction of the input shaft 2 and the rotation direction of the primary shaft 38 are the same. On the other hand, when the reverse position is selected as the shift position, the reverse brake 45 is engaged and the forward clutch 44 is released. As a result, the ring gear 40 becomes a reaction force element, and the torque of the input shaft 2 is transmitted to the primary shaft 38. In this case, the rotation direction of the primary shaft 38 is opposite to the rotation direction of the input shaft 2.

  On the other hand, in the belt type continuously variable transmission 3, the supply state of pressure oil in the hydraulic servo mechanisms 49 and 50 is controlled by the hydraulic control device 26. Specifically, the flow rate of the pressure oil supplied to the hydraulic servo mechanism 49 is controlled, and the winding radius of the belt 48 in the primary pulley 46 and the winding radius of the belt 48 in the secondary pulley 47 are controlled. The gear ratio of the continuously variable transmission 3, that is, the ratio between the rotational speed of the primary shaft 38 and the rotational speed of the secondary shaft 51 can be controlled steplessly (continuously). In addition to this shift control, the clamping force applied from the secondary pulley 47 to the belt 48 is adjusted, and the torque capacity of the belt type continuously variable transmission 3 is controlled.

  For example, the required driving force in the vehicle is determined based on the vehicle speed and acceleration request (for example, accelerator opening), and the target engine output is determined based on the determination result. The target engine speed and target engine torque that achieve this target engine output with optimum fuel efficiency are determined, and the gear ratio of the belt-type continuously variable transmission 3 is controlled so that the actual engine speed approaches the target engine speed. . Further, in parallel with the control of the gear ratio of the belt-type continuously variable transmission 3, the electronic throttle valve and the like are controlled to bring the actual engine torque closer to the target engine torque. As described above, the torque of the input shaft 2 is transmitted to the transmission mechanism 52 via the forward / reverse switching device 37 and the belt-type continuously variable transmission 3, and the torque of the transmission mechanism 52 passes through the differential 4. And transmitted to the wheel 5.

  Next, the principle of torque transmission between the input shaft 2 and the shaft 6 and the torque control method, in other words, the principle of torque transmission in the oil pumps 7 and 7A, and the method of controlling the transmission torque in the oil pumps 7 and 7A will be described. And control of the oil discharge amount of the oil pumps 7 and 7A will be described. When the engine 1 is operated, torque is generated in a direction that rotates the shaft 6 in a predetermined direction of FIG. 3, for example, clockwise. In this embodiment, the torque transmitted between the shaft 6 and the input shaft 2 is controlled as follows.

  First, the oil pump 7 will be described. The ball 13 attached to the inner race 8 is urged toward the outside of the cylinder 10 by the urging force of the elastic member 15. When the inner race 8 and the outer race 9 rotate relative to each other, the ball 13 rolls along the cam surface 36 of the outer race 9, and the ball 13 and the piston 11 are formed by the uneven shape in the radial direction of the cam surface 36. However, it reciprocates within the cylinder 10 in the direction of the axis B1. In this embodiment, in the oil pump 7, the cylinders 10 are arranged at intervals of 45 degrees, the convex portions of the cam surface 36 are arranged at intervals of 45 degrees, and the concave portions are arranged at intervals of 45 degrees. Among all the pistons 11 constituting the pump 7, the operation strokes of the pistons 11 located on the same axis coincide with each other.

  Thus, when the piston 11 reciprocates in the cylinder 10, the volume of the oil chamber 14 changes. That is, when the piston 11 moves outward along the axis B1, the volume of the oil chamber 14 is expanded, and when the piston 11 moves inward along the axis B1, the volume of the oil chamber 14 is reduced. When the volume of the oil chamber 14 is enlarged, the oil chamber 14 becomes negative pressure. Then, the check valve 24 is opened, and the oil in the oil pan 21 is sucked into the oil chamber 14 via the suction oil passage 18 and the suction oil passage 16. In this case, since the check valve 25 is closed, the oil in the discharge oil passage 17 does not flow back into the oil chamber 14.

  Next, when the piston 11 moves inward with the relative rotation of the inner race 8 and the outer race 9, the volume of the oil chamber 14 is reduced, and the internal hydraulic pressure rises. When the hydraulic pressure in the oil chamber 14 becomes higher than the hydraulic pressure in the suction oil passage 16, the check valve 24 is closed. As a result, the oil in the suction oil passage 16 is not sucked into the oil chamber 14 and the oil in the oil chamber 14 is prevented from flowing back into the suction oil passage 16. On the other hand, the check valve 25 is opened when the oil pressure in the oil chamber 14 becomes higher than the oil pressure in the discharge oil passage 17 due to the reduction in the volume of the oil chamber 14. As a result, the oil in the oil chamber 14 is supplied to the control valve 27 via the discharge oil passage 17 and the discharge oil passage 19. Thereafter, the oil is discharged from the oil pump 7 by the piston 11 repeating the reciprocating motion.

  On the other hand, in the control valve 27, the cross-sectional area of the port C1 formed between the suction port 32 and the discharge port 33 is controlled, and according to the cross-sectional area of the port C1, the oil discharge amount in the oil pump 7, The amount of oil supplied from the oil pump 7 to the hydraulic control device 26 is controlled. In this embodiment, the operation of the spool 28 is controlled by the current value of the power supplied to the solenoid 30, and the cross-sectional area of the port C1 is adjusted. The flow resistance of oil discharged from the discharge oil passage 19 to the oil passage 34 changes according to the cross-sectional area of the port C1. Specifically, the greater the cross-sectional area of the port C1, the lower the oil flow resistance, and the smaller the cross-sectional area of the port C1, the greater the oil flow resistance.

  The flow resistance of the oil discharged from the discharge oil passage 19 to the oil passage 34 affects the operation characteristics of the piston 11 in the cylinder 10. That is, when the force that presses the piston 11 inward is the same, and the piston 11 operates inward to reduce the volume of the oil chamber 14, the flow of oil discharged from the discharge oil passage 19 to the oil passage 34 The higher the resistance, the lower the amount of oil per unit time discharged from the oil chamber 14 to the discharge oil passage 17. On the other hand, the lower the flow resistance of the oil discharged from the discharge oil passage 19 to the oil passage 34, the greater the amount of oil per unit time discharged from the oil chamber 14 to the discharge oil passage 17.

  Further, as the flow resistance of the oil discharged from the discharge oil passage 19 to the oil passage 34 is higher, the oil pressure in the oil chamber 14 is less likely to decrease, and the load necessary to operate the piston 11 inward increases. On the other hand, the lower the flow resistance of the oil discharged from the discharge oil passage 19 to the oil passage 34, the lower the oil pressure in the oil chamber 14, and the lower the load required to operate the piston 11 inward. In this embodiment, the inner race 8 and the outer race 9 rotate relative to each other, whereby the ball 13 rolls on the cam surface 36 and a load that presses the piston 11 inward from the outer race 9 is applied. It has become. Therefore, the higher the load required to move the piston 11 inward, the higher the circumferential load required to rotate the inner race 8 and the outer race 9 relative to each other. In other words, the torque transmitted by the oil pump 7 increases. On the contrary, the lower the load required to move the piston 11 inward, the lower the circumferential load required to rotate the inner race 8 and the outer race 9 relative to each other. The transmission torque due to decreases.

  Next, the oil pump 7A will be described. The operation principle and torque control principle of the oil pump 7A are the same as those of the oil pump 7. The ball 13 attached to the plate 80 is urged toward the outside of the cylinder 10 by the urging force of the elastic member 15. When the inner race 8 and the plate 80 rotate together and the input shaft 2 and the plate 80 rotate relative to each other, the ball 13 rolls along the cam surface 36A of the outer race 9 and the radius of the cam surface 36A. Due to the concavo-convex shape of the direction, the ball 13 and the piston 11 reciprocate in the cylinder 10 in the direction of the axis B1.

  In this embodiment, in the oil pump 7A, the cylinders 10 are arranged at intervals of 45 degrees, the convex portions of the cam surface 36A are arranged at intervals of 45 degrees, and the concave portions are arranged at intervals of 45 degrees. Among all the pistons 11 constituting the pump 7A, the operation strokes of the pistons 11 located on the same axis coincide with each other. Here, when the piston 11 moves outward, the hydraulic chamber 14 </ b> A becomes negative pressure, and the check valve 24 is opened, the oil in the oil pan 21 passes through the suction oil passage 18 and the suction oil passage 16. Sucked into the chamber 14A. In this case, since the check valve 25 is closed, the oil in the discharge oil passage 17B does not flow back into the oil chamber 14A.

Next, when the piston 11 moves inward with the relative rotation between the plate 80 and the outer race 9 and the oil pressure in the oil chamber 14A becomes higher than the oil pressure in the suction oil passage 16, the check valve 24 is turned on. Closed. As a result, the oil in the suction oil passage 16 is not sucked into the oil chamber 14A, and the oil in the oil chamber 14A is prevented from flowing back into the suction oil passage 16. On the other hand, when the oil pressure in the oil chamber 14A is reduced to be higher than the oil pressure in the discharge oil passage 17B, the check valve 25 is opened. As a result, the oil in the oil chamber 14A is supplied to the control valve 27A via the discharge oil passages 17B and 17D and the discharge oil passage 19A. Thereafter, the oil is discharged from the oil pump 7A as the piston 11 repeats the reciprocating motion. The oil discharged from the oil pump 7A is sent to the control valve 27A. The amount of oil supplied from the oil pump 7A to the hydraulic control device 26 is controlled by the control valve 27A. The operating principle of the control valve 27A is the same as the operating principle of the control valve 27, and the transmission torque in the oil pump 7A is controlled by the function of the control valve 27A.
To do.

  As described above, in this embodiment, since the oil pumps 7 and 7A have both the function as an oil pressure feeding device and the function as a transmission mechanism (starting device), on the output side of the engine 1, It is not necessary to provide a transmission mechanism in addition to the oil pumps 7 and 7A. Therefore, the number of parts of the power transmission device is reduced, the power transmission device can be reduced in size, and the in-vehicle performance is improved. Further, the oil pumps 7 and 7A can be arranged at different positions in the rotation axis direction.

  Further, on the phase in the circumferential direction centered on the rotation axis A1, the cam surface 36A is displaced so that the radius of the cam surface 36A is increased and the radius of the cam surface 36A is decreased. Yes. That is, when the piston 11 of the oil pump 7 operates toward the outside, the piston 11 of the oil pump 7A operates toward the inside. On the other hand, when the piston 11 of the oil pump 7 operates toward the inside, the piston 11 of the oil pump 7A operates toward the outside. As a result, when oil is discharged from the oil pump 7, the oil is sucked by the oil pump 7A, and when oil is sucked by the oil pump 7, the oil is discharged by the oil pump 7A. .

  As described above, when the shaft 6 and the input shaft 2 have a predetermined relative positional relationship in the circumferential direction, the oil discharge amounts of the oil pump 7 and the oil pump 7A are different. For this reason, even when the relative positional relationship between the shaft 6 and the input shaft 2 changes in the circumferential direction, it is possible to suppress an increase in the fluctuation amount of the total oil discharge amount in the oil pumps 7 and 7A. Furthermore, even when the relative positional relationship between the shaft 6 and the input shaft 2 changes in the circumferential direction, it is possible to suppress an increase in the amount of fluctuation in torque transmitted between the shaft 6 and the input shaft 2, thereby transmitting power. It is possible to reduce vibration and noise in the path.

  Furthermore, in this embodiment, the cross-sectional areas of the piston 11 and the cylinder 10 in the oil pump 7 are set wider than the cross-sectional areas of the piston 11 and the cylinder 10 in the oil pump 7A, and the stroke amount of the piston 11 in the oil pump 7 is It becomes larger than the stroke amount of the piston 11 in the oil pump 7A. Therefore, the oil discharge capacity in the oil pump 7 is larger than the oil discharge capacity in the oil pump 7A.

  As described above, the oil pumps 7 and 7A have different oil discharge capacities, and selectively switch a plurality of control modes as modes for controlling the oil discharge state of the oil pumps 7 and 7A according to the operation state of the vehicle Ve. Is possible. An example of switching the control mode will be described based on the flowchart of FIG. First, it is determined whether or not the vehicle Ve is starting (step S1). If the determination is affirmative in step S1, the oil is discharged from the oil pump 7 and the oil is discharged from the oil pump 7A. The process which stops is performed (step S2). Following this step S2, it is determined whether or not the required oil flow rate is secured by the hydraulic control device 26 (step S3). If the determination in step S3 is affirmative, the control routine shown in FIG. finish. On the other hand, when a negative determination is made in step S3, a process of discharging oil from the oil pump 7 and the oil pump 7A is performed (step S4), and the process returns.

  On the other hand, if a negative determination is made in step S1, it is determined whether at least one of a condition for sudden shifting with the belt-type continuously variable transmission 3 or a high load condition is satisfied (step S5). . Here, the high load condition means that the target engine output is not less than a predetermined value. If a positive determination is made in step S5, the process proceeds to step S2. On the other hand, if a negative determination is made in step S5, it is determined whether or not at least one of a steady running condition or a low load condition is established (step S6). Here, steady running means running such that the gear ratio is maintained substantially constant, and low load means that the target engine output is less than a predetermined value. If the determination in step S6 is affirmative, a process of discharging oil from the oil pump 7A and stopping oil discharge in the oil pump 7 is executed (step S7), and this control routine is terminated. . Note that if the determination in step S6 is negative, the process directly returns. As described above, according to the control example of FIG. 5, the three control modes can be selectively switched as the control modes of the oil pumps 7 and 7A.

  Here, the manufacturing process of the outer race 9 will be described. The workpiece can be machined using a milling machine or the like to form the outer race 9 having the cam surfaces 36 and 36A. Here, when the outer race 9 in which the radius of the inscribed circle of the cam surface 36 and the radius of the circumscribed circle of the cam surface 36A are set to be the same is formed, the cam surface 36 is processed first, and then the cam surface If the cam surface 36A is processed using the minimum radius portion R1 of 39 as a reference, the cam surface 36 and the cam surface 36A can be held with high concentricity and the workability of the outer race 9 is improved.

  Next, another configuration example of the control valve for controlling the discharge state of the oil pumps 7 and 7A will be described with reference to FIG. The control valve 110 shown in FIG. 6 can be used in place of the control valve 27 shown in FIGS. The control valve 110 includes a spool 111 that can reciprocate in the axial direction, an elastic member 112 that applies a force in a predetermined direction in the axial direction to the spool 111, a suction port 113, a discharge port 114, a control port 115, and a feedback port 116. have. The discharge oil passage 19 is connected to the suction port 113 and the feedback port 116, and the oil passage 34 is connected to the discharge oil passage 114.

  On the other hand, lands 117, 118, and 119 are formed on the spool 111, and a force that biases the spool 111 in a direction opposite to the force of the elastic member 112 is generated according to the hydraulic pressure of the feedback port 116. Further, the hydraulic pressure of the control port 115 generates a force that biases the spool 111 in the same direction as the elastic member 112. Note that the control hydraulic pressure input to the control port 115 via the oil passage 120 is regulated by the hydraulic control device 26.

  In the control valve 110 configured as described above, the force applied to the spool 111 according to the hydraulic pressure transmitted from the discharge oil passage 19 to the feedback port 116, the force applied from the elastic member 112 to the spool 111, and the control port 115. The operation of the spool 111 in the axial direction is controlled by the correspondence relationship with the force applied to the spool 111 according to the oil pressure of the oil, and the cross-sectional area of the port D1 formed between the discharge oil passage 19 and the oil passage 34 is also In addition, the flow rate of the oil supplied from the discharge oil passage 19 to the oil passage 34 is adjusted. That is, when the oil pressure in the discharge oil passage 19 increases, the oil pressure in the feedback port 116 increases, and the spool 111 operates upward in FIG.

  For this reason, the cross-sectional area of the port D1 is enlarged, the flow rate of the oil discharged from the discharge oil passage 19 to the oil passage 34 is increased, and the increase in the discharge pressure of the oil pump 7 is suppressed. On the other hand, when the hydraulic pressure of the discharge oil passage 19 decreases, the hydraulic pressure of the feedback port 116 decreases, and the spool 111 operates downward in FIG. For this reason, the cross-sectional area of the port D1 is reduced, the flow rate of the oil discharged from the discharge oil passage 19 to the oil passage 34 is reduced, and the drop in the discharge pressure of the oil pump 7 is suppressed. When the control hydraulic pressure input to the control port 115 is increased, the cross-sectional area of the port D1 is difficult to increase, and the discharge pressure of the oil pump 7 is suppressed from decreasing or the discharge pressure of the oil pump 7 is increased. To do. On the contrary, if the control hydraulic pressure input to the control port 115 is reduced, the cross-sectional area of the port D1 is easily enlarged, and the discharge pressure of the oil pump 7 is suppressed from increasing, or the oil pump 7 The discharge pressure decreases.

  Furthermore, it is possible to use the control valve 110A shown in FIG. 6 instead of the control valve 7A. In the case of this control valve 110 </ b> A, the discharge oil passage 19 </ b> A is connected to the suction port 113 and the feedback port 116. Other configurations and functions of the control valve 110A are almost the same as those of the control valve 110. Therefore, in FIG. 6, the control valve 110 and the control valve 110A are shown in common for convenience. With the function of the control valve 110A, the discharge pressure of the oil pump 7A can be controlled based on the same principle as described above. Even when the control valves 110 and 110A are used, the oil discharge state of the oil pumps 7 and 7A can be controlled based on the flowchart shown in FIG. In this case, of course, the control valves 110 and 110A are controlled by the electronic control unit 53.

  Although not particularly shown, the outer race and a plurality of cam surfaces are formed on the shaft 6, the inner race and the plate are provided on the input shaft 2, and a plurality of cylinders, pistons, hydraulic chambers and the like are provided on the inner race and the plate, respectively. It is also possible to adopt a configuration in which the input shaft 2 is provided with an intake oil passage and a discharge oil passage connected to these hydraulic chambers. It is also possible to use a rolling element instead of the ball 13, for example, a radial piston pump having a roller.

  Here, the correspondence between the configurations of the first and second embodiments and the configuration of the present invention will be described. The shaft 6 corresponds to the input member of the present invention, and the input shaft 2 corresponds to the output member of the present invention. The inner race 8 and the plate 80 correspond to the first rotating member of the present invention, the outer race 9 corresponds to the second rotating member of the present invention, and the oil pumps 7 and 7A correspond to the present invention. It corresponds to a plurality of radial piston pumps, the oil discharge flow rate and the discharge hydraulic pressure in the oil pumps 7 and 7A correspond to the oil discharge state of the present invention, and the cam surface 36 corresponds to the predetermined cam surface of the present invention. The cam surface 36A corresponds to another cam surface of the present invention, and the “power transmission state” of the present invention includes torque transmitted between the shaft 6 and the input shaft 2.

It is a conceptual diagram which shows the vehicle which has the power transmission device of this invention, and its control system. It is front sectional drawing which shows the structural example of the oil pump shown by FIG. It is a side view which shows the structural example of the oil pump shown by FIG. It is a figure which shows the structure of the control valve shown by FIG. It is a flowchart which shows the example of control which can be performed with the vehicle of FIG. It is a figure which shows the other structure of the control valve shown by FIG.

Explanation of symbols

  2 ... Input shaft, 6 ... Shaft, 7,7A ... Oil pump, 8 ... Inner race, 9 ... Outer race, 11 ... Piston, 27,27A, 110,110A ... Control valve, 36,36A ... Cam surface.

Claims (4)

An input member and an output member that transmit power, and an oil pump that sucks and discharges oil by the relative rotation of the first rotating member and the second rotating member, and the first rotating member or the first rotating member In the power transmission device in which any one of the two rotating members is connected to the input member and the other is connected to the output member,
The oil pump connects the first rotating member and the second rotating member so that power can be transmitted, and has a radius perpendicular to the rotation axis of the first rotating member and the second rotating member. This is a radial piston pump with a piston that moves in the direction, and there are multiple radial piston pumps that can control the oil discharge state separately, and control the oil discharge state in these multiple radial piston pumps By doing so, a control valve for controlling a power transmission state between the first rotating member and the second rotating member is provided.   Either one of the first rotating member or the second rotating member is provided with a plurality of cam surfaces formed in a circumferential direction around the rotation axis and displaced in the radial direction. When the first rotating member and the second rotating member rotate relative to each other, the pistons of the plurality of radial piston pumps operate in the radial direction along the plurality of cam surfaces, respectively. 2. The power transmission device according to claim 1, wherein the power transmission device has a configuration for sucking and discharging, and the plurality of cam surfaces are arranged side by side in the rotation axis direction.   The power transmission device according to claim 2, wherein a radius of a predetermined cam surface is different from a radius of another cam surface among the plurality of cam surfaces.   A configuration in which a predetermined cam surface is displaced so that a radius of the predetermined cam surface is increased on a phase in a circumferential direction centering on the rotation axis, and the radius of the other cam surface is decreased. The power transmission device according to claim 2, wherein the power transmission device is provided.

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