JP2013185599A - Hydraulic control device of clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a protective property and reliability of a hydraulic circuit, regarding a hydraulic control device of a clutch.SOLUTION: In a hydraulic control device related to connection/disconnection of a clutch 3 mounted on a vehicle, a bidirectional pump 2a rotated in conjunction with drive wheels 8 of the vehicle in a forward direction or reverse direction and generating hydraulic pressure is interposed in a first passage 21 and the generated hydraulic pressure is transmitted to the clutch 3. Further, a second passage 22 is provided which connects an upstream side and a downstream side of the bidirectional pump 2a interposed in the first passage 21. Further, a check valve 24 is interposed in the second passage 22 to allow flowing of hydraulic fluid to the clutch 3 side and to shut off flowing of hydraulic fluid from the clutch 3 side.

Description

  The present invention relates to a hydraulic control device for a clutch mounted on a vehicle.

  Conventionally, hybrid vehicles that drive a vehicle using an engine (internal combustion engine) and a motor (electric motor) together are widely known. In the hybrid vehicle, the output distribution of the drive source is controlled in various ways according to the output characteristics of the mounted engine and motor, the running state, and the like. For example, a mild hybrid type hybrid vehicle has a function of traveling only with an engine according to the traveling state of the vehicle, a function of performing regenerative power generation, a function of assisting the driving force of the engine with a driving force of a motor, and the like. ing. This method has the advantage that the output performance required for the motor is relatively small, and a good fuel efficiency performance (fuel saving ratio) can be obtained as compared with vehicles other than the hybrid method.

  On the other hand, in the strong hybrid system vehicle, in addition to the above functions, a function of running only with a motor is added. That is, pure electric power traveling is realized by driving the motor with the engine completely stopped. The merit of this method is that if the motor output and the power source are secured, the fuel efficiency can be remarkably improved as compared with the mild hybrid method.

  The Strong Hybrid system includes a series system in which a generator is driven by an engine and a motor is driven by the generated energy, and a parallel hybrid that distributes engine power to drive wheels and uses both engine and motor drive power. There are methods.

  By the way, when the vehicle is driven with the driving force of only the motor while the engine is stopped, the power transmission between the engine and the driving wheels may be interrupted so that the driving force of the motor is not transmitted to the engine side. Desired. For example, in a power train provided with a clutch on the power transmission path from the engine to the drive wheels, the clutch is disconnected when the motor is running. On the other hand, it is not possible to take out the power related to the clutch connection / disconnection from the stopped engine. Therefore, in a vehicle that performs motor running, a power source other than the engine is required to drive an actuator related to the control of the clutch connection / disconnection state.

  In order to deal with such a problem, a method of driving an oil pump for a clutch using the power of a motor or battery power has been studied. For example, it has been proposed to connect a mechanical oil pump to the output shaft of a travel motor and operate a clutch with hydraulic oil discharged from the mechanical oil pump (see Patent Document 1). With such a configuration, it becomes possible to operate the oil pump by utilizing the rotation of the drive wheel during motor traveling, and unnecessary power consumption can be prevented.

JP 2008-230281 A

  However, the motor mounted on the strong hybrid type hybrid vehicle can be driven not only in the forward rotation direction but also in the reverse rotation direction when the vehicle is reverse. That is, in the conventional engine-driven oil pump, the rotational direction of the engine is always constant, so the rotational direction of the rotating body built in the oil pump is also constant, but the rotational direction of the drive wheels is the forward direction of the vehicle. Or it reverses by retreat, and the direction of rotation does not become constant.

  Therefore, when the mechanical oil pump is connected to the output shaft of the motor or the rotation shaft (drive shaft) of the drive wheel, the hydraulic oil discharge direction is reversed according to the traveling direction of the vehicle, and the clutch is connected or disconnected. It may become impossible to control correctly. In addition, the flow direction of the hydraulic oil in the hydraulic circuit is reversed, so that excessive pressure may act on the valves and filters in the circuit, making it difficult to improve the protection and reliability of the hydraulic circuit. There is a problem.

One of the objects of the present case is to provide a clutch hydraulic control device that has been developed in view of the above-described problems and can improve the protection and reliability of the hydraulic circuit.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

  (1) A hydraulic control device for a clutch disclosed herein is a hydraulic control device related to connection / disconnection of a clutch mounted on a vehicle, and rotates in a forward direction or a reverse direction in conjunction with a drive wheel of the vehicle, A bi-directional pump that generates hydraulic pressure is provided. Further, a first passage that is provided with the bidirectional pump and transmits the hydraulic pressure to the clutch, and a second passage that connects an upstream side and a downstream side of the bidirectional pump interposed in the first passage. With. In addition, a check valve is provided in the second passage and allows a flow of hydraulic oil to the clutch side and blocks a flow of hydraulic oil from the clutch side.

(2) Moreover, it is preferable to provide the pressure regulation valve which adjusts the pressure of the hydraulic fluid which is interposed on the said 1st channel | path and is transmitted to the said clutch.
(3) Moreover, it is preferable to provide the electromagnetic valve which is interposed on the said 1st channel | path, and accept | permits or interrupts | blocks the distribution | circulation of the said hydraulic oil.

  (4) It is preferable that the vehicle has a switching means for switching between the EV mode or the series hybrid mode and the parallel hybrid mode. In this case, it is preferable to provide a clutch control means for controlling the opening degree of the electromagnetic valve in the opening direction when the switching means is in the parallel hybrid mode.

In the disclosed hydraulic control device for a clutch, a check valve is provided in the second passage so that backflow from the second passage can be prevented in a state where hydraulic pressure is transmitted to the clutch through the first passage. Can be activated. On the other hand, when the rotation direction of the bidirectional pump is reversed, the hydraulic oil flows through the second passage and again through the first passage via the check valve. That is, the hydraulic oil can be circulated in an annular circuit composed of the first passage and the second passage. As a result, the protection and reliability of the hydraulic circuit can be improved.
For example, it is preferable to engage a clutch when the vehicle speed of the vehicle is equal to or higher than a predetermined vehicle speed and shift from series hybrid travel or EV travel to parallel hybrid travel.

It is a top view which illustrates the internal structure of the vehicle carrying the power train which concerns on the hydraulic control apparatus as one Embodiment. It is a schematic diagram of the power transmission path | route formed in the transaxle of the power train of FIG. 2 is a graph illustrating the relationship between the driving state of the vehicle in FIG. 1 and a travel mode. It is a perspective view of the transaxle provided in the power train of FIG. It is a side view for demonstrating the power transmission path | route of the transaxle of FIG. FIG. 2 is a schematic diagram of the power train of FIG. 1. It is a circuit diagram which illustrates the hydraulic circuit built in the pump of the power train of FIG.

  A power train of a hybrid vehicle will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment, and can be selected or combined as necessary.

[1. Power train]
The power train 7 of this embodiment is applied to the vehicle 10 shown in FIG. The vehicle 10 is a plug-in hybrid vehicle (PHEV) that travels using the engine 6 and the motor 4 (electric motor) as drive sources, and functionally belongs to the strong hybrid system. In addition to the engine 6 and the motor 4, the power train 7 is provided with a generator 5 (generator), a transaxle 1, a clutch 3 (power connection / disconnection device), and a pump 2. The driving force of the engine 6 and the motor 4 is transmitted to the driving wheel 8 via the transaxle 1 to cause the vehicle 10 to travel. The vehicle 10 shown in FIG. 1 is an FF type vehicle 10 having the front wheels as drive wheels 8.

  The engine 6 is an internal combustion engine (gasoline engine, diesel engine) that burns gasoline or light oil. This engine 6 is a so-called horizontal engine, and is disposed sideways so that the direction of the crankshaft 6 a coincides with the vehicle width direction of the vehicle 10, and is fixed to the right side surface of the transaxle 1. The crankshaft 6 a is disposed in parallel to the drive shaft 9 of the drive wheel 8. The operating state of the engine 6 is controlled by the electronic control unit 40.

  The motor 4 (electric motor) is, for example, a high-output permanent magnet synchronous motor, and generates electric power using the function of rotating the rotor (rotor) by receiving the electric power stored in the power storage device and the inertial power of the vehicle 10. It also has a function to perform. A power supply source of the motor 4 is a driving battery device mounted on the vehicle 10. The driving battery device is, for example, a lithium ion battery or a nickel metal hydride battery, and supplies a high-voltage direct current of several hundred volts to the motor 4.

  An inverter that converts a direct current supplied from the drive battery device into an alternating current is provided around (or inside) the motor 4. The rotation speed of the motor 4 is proportional to the AC frequency of the current converted by the inverter. Therefore, the rotational speed of the motor 4 can be adjusted by controlling the inverter. The external shape of the general motor 4 is determined according to the shape of the rotating body when the rotor is rotated. For example, it is formed in a cylindrical shape with the rotating shaft of the rotor as a cylinder axis, and is fixed to the left side surface of the transaxle 1 with the bottom surface facing the transaxle 1 side. The operating state of the motor 4 and the inverter is controlled by the electronic control unit 40.

  The generator 5 (generator) is an AC motor generator (motor generator) having a function as a starter for starting the engine 6, and generates electric power with engine power when the engine 6 is operated. The generator 5 also has a function of charging a driving battery device that is a power supply source of the motor 4 and a function of directly supplying power to the motor 4. The outer shape of the generator 5 is formed, for example, in a cylindrical shape having a rotating shaft as a cylinder shaft, and is fixed to the left side surface of the transaxle 1 with the bottom surface facing the transaxle 1 side, like the motor 4. The operating state of the generator 5 is controlled by the electronic control unit 40.

  The transaxle 1 is a power transmission device in which a final drive (final reduction gear) including a differential gear (differential device) and a transmission (speed reduction gear) are integrally formed, and power between a drive source and a driven device. Incorporates multiple mechanisms responsible for transmission. Three power transmission paths are mainly formed inside the transaxle 1 of the present embodiment.

[2. Power transmission path]
A power transmission path formed inside the transaxle 1 is schematically shown in FIG. The transaxle 1 includes a first path 31 related to power transmission from the engine 6 to the drive wheels 8, a second path 32 related to power transmission from the motor 4 to the drive wheels 8, and power from the engine 6 to the generator 5. A third path 33 for transmission is provided. An engine 6 and a motor 4 are connected to the drive wheel 8 in parallel via the transaxle 1. A generator 5 and drive wheels 8 are connected to the engine 6 in parallel via the transaxle 1.

  The first path 31 (first mechanism) is a power transmission path that connects between the crankshaft 6 a of the engine 6 and the drive shaft 9, and is responsible for transmission of power during operation of the engine 6. In the middle of the first path 31, a clutch 3 that connects and disconnects the power transmission is interposed. The clutch 3 of this embodiment is built in the transaxle 1. A transmission (not shown) may be interposed on the first path 31.

  The clutch 3 is a connecting shaft that controls the power connection / disconnection state of the engine 6, and is, for example, a multi-plate clutch. Inside the clutch 3, there are provided a driving-side engaging element 3 a to which driving force from the engine 6 is input and a driven-side engaging element 3 b that outputs driving force to the driving wheel 8 side. These engagement elements 3a and 3b are driven in a direction of separating and approaching (that is, cutting and engaging) from each other in accordance with the hydraulic pressure applied from the pump 2.

  The pump 2 is a hydraulic pressure generator that pumps hydraulic oil to a hydraulic circuit using the driving force on the drive wheel 8 side, and is, for example, a gear pump, a vane pump, a piston pump, or the like. The pump 2 is disposed on the left side surface of the transaxle 1 at a position coaxial with the clutch 3 (may be adjacent). The hydraulic pressure generated by the pump 2 acts so as to drive the engagement elements 3a and 3b of the clutch 3 in a direction approaching each other. That is, the clutch 3 is connected when the hydraulic pressure generated by the pump 2 rises sufficiently to engage the engagement elements 3a and 3b.

  The pump 2 of the present embodiment is a bidirectional pump that rotates in the forward or reverse direction in conjunction with the drive wheels 8 of the vehicle 10. For example, the pump 2 rotates in the forward direction when the vehicle 10 moves forward, and the pump 2 rotates in the reverse direction when the vehicle 10 moves backward. When rotating in the reverse direction, hydraulic oil is discharged in the direction opposite to that when rotating in the forward direction. Further, the capacity of the pump 2 and the engagement characteristics of the engagement elements 3a and 3b are such that the clutch 3 is connected with the hydraulic pressure generated by the pump 2 only when the traveling speed of the vehicle 10 is equal to or higher than the predetermined vehicle speed. Is set.

  The engine 6 is driven when the clutch 3 is engaged, and the driving force is transmitted to the drive wheels 8 via the first path 31 to switch to the parallel hybrid mode. On the other hand, when the traveling speed of the vehicle 10 is less than the predetermined vehicle speed, the power train 7 is controlled so that the clutch 3 is disengaged and the engine 6 is stopped, or generator power generation by engine power is performed. That is, the connection / disconnection state of the clutch 3 is controlled according to the traveling state of the vehicle 10. Thus, the drive source of the pump 2 that generates the hydraulic pressure of the clutch 3 is not the engine 6 but the drive wheels 8.

  The second path 32 (second mechanism) is a power transmission path that connects the rotating shaft 4 a of the motor 4 and the drive shaft 9, and bears power transmission of the motor 4. The motor 4 has both a function of assisting the driving force of the engine 6 and a pure electric power traveling function, and its operating state is controlled regardless of whether the clutch 3 is connected or disconnected. For example, when the vehicle 10 starts or when the clutch 3 is disengaged, the vehicle 10 travels only with the driving force of the motor 4. When the traveling speed of the vehicle 10 becomes equal to or higher than the predetermined vehicle speed, the driving force of the motor 4 is added to the driving force of the engine 6 according to the traveling state, or the motor 4 is controlled to be in a non-driving state. Further, regenerative power generation is performed when the vehicle 10 decelerates or travels downhill.

  The third path 33 (third mechanism) is a power transmission path that connects the crankshaft 6a of the engine 6 and the rotating shaft 5a of the generator 5, and transmits power when the engine starts and power transmission when the engine 6 generates power. Is responsible for. The driving force input from the driving wheel 8 side to the generator 5 through the third path 33 is converted into electric power, and is charged in the driving battery device or the low voltage battery.

[3. Control configuration]
The hybrid vehicle 10 is provided with an electronic control device 40. The electronic control unit 40 is configured as, for example, an LSI device or an embedded electronic device in which a microprocessor, ROM, RAM, and the like are integrated, and is connected to a communication line of an in-vehicle network provided in the vehicle 10. On the in-vehicle network, various known electronic control devices such as a brake control device, a transmission control device, a vehicle stability control device, an air conditioning control device, and an electrical component control device are connected so as to communicate with each other. The electronic control device 40 is an electronic control device that comprehensively controls a wide range of systems related to the clutch 3, the motor 4, the generator 5, and the engine 6. For example, the connection / disconnection state of the clutch 3, the driving force of the motor 4, the generator The power generation amount at 5 and the driving force of the engine 6 are controlled.

  The vehicle 10 is set with three types of travel modes: EV mode, series hybrid mode, and parallel hybrid mode. The EV mode is a mode in which the vehicle travels with the driving force of only the motor 4. On the other hand, the series hybrid mode is a mode in which the engine 6 is used as a power supply source (generator) of the motor 4 while using the motor 4 as a drive source. In this mode, the generator 5 is driven by the power of the engine 6, and the electric power generated by the generator 5 is supplied to the motor 4.

  The parallel hybrid mode is a mode that travels using both the engine 6 and the motor 4 as drive sources. In the EV mode and the series hybrid mode, the clutch 3 is controlled to be disconnected, whereas in the parallel hybrid mode, the clutch 3 is controlled to be engaged.

  As shown in FIG. 2, the electronic control unit 40 includes an engine control unit 41, a motor control unit 42, a clutch control unit 43 (clutch control means), and a switching control unit 44 (switching means). The engine control unit 41 controls the operation of the engine 6, and the motor control unit 42 controls the operation of the motor 4. The clutch control unit 43 controls the connection / disconnection state of the clutch 3.

  The switching control unit 44 controls the engine control unit 41, the motor control unit 42, and the clutch control unit 43 in an integrated manner based on various conditions relating to the driving state of the vehicle 10. Here, the engine 6, the motor 4 and the clutch 3 are controlled based on the traveling mode of the vehicle 10 set according to the traveling speed of the vehicle 10, the state of charge of the driving battery, and the like. Table 1 below shows an example of setting the driving mode according to the driving state of the vehicle 10.

  The EV mode is selected when the vehicle speed is less than a predetermined vehicle speed, the charging rate of the driving battery is equal to or higher than the predetermined charging rate, and the output required for the vehicle 10 is relatively small. On the other hand, even if the vehicle speed is less than the predetermined vehicle speed, the series hybrid mode is selected when the charging rate of the driving battery is less than the predetermined charging rate or when the output required for the vehicle 10 is relatively large. . For example, when the vehicle 10 is accelerated (when the accelerator opening is fully open acceleration) or when continuously climbing up, it corresponds to a case where the required output is relatively large. Further, when the vehicle speed is equal to or higher than the predetermined vehicle speed, the parallel hybrid mode is selected.

Therefore, the stopped vehicle 10 starts with the driving force of the motor 4 and drives the engine 6 when the traveling speed increases to some extent. After the engine 6 is started, hybrid traveling using both the driving force of the engine 6 and the motor 4 according to the traveling state of the vehicle 10 is realized.
In addition, the relationship of the driving mode with respect to the output (driving force) required for the vehicle 10 and the vehicle speed can also be expressed as shown in FIG. When the vehicle speed of the vehicle 10 is less than the predetermined vehicle speed, the EV mode or the series hybrid mode is selected. On the other hand, when the vehicle speed is equal to or higher than the predetermined vehicle speed, the parallel hybrid mode is selected. Therefore, when the vehicle speed decreases or increases over the predetermined vehicle speed, the clutch 3 is controlled so as to change the connection / disconnection state. Here, the conditions regarding the drive battery are excluded.

[4. Transaxle]
The external appearance of the transaxle 1 incorporating the above three power transmission paths is illustrated in FIG. FIG. 4 is a perspective view of the transaxle 1 with the pump 2 connected thereto. The casing 18 of the transaxle 1 is formed in a shape in which flat hollow cylinders are continuously provided in the radial direction so as to correspond to the shapes of a large number of rotating shafts and gears built in the transaxle 1. Further, on one side surface (the left side surface in FIG. 4) of the casing 18, opening holes 13a, 14a and 16a for connecting the rotating shaft 4a of the motor 4, the rotating shaft 5a of the generator 5 and the pump 2 are formed. Is done. An opening hole 11a for connecting the crankshaft 6a of the engine 6 is formed on the other side surface of the casing 18. The opening hole 12a for connecting the drive shaft 9 is formed on both side surfaces of the casing 18.

  Hereinafter, the rotating shaft in the transaxle 1 connected to the crankshaft 6a is referred to as an input shaft 11. Similarly, the drive shaft 9, the rotation shaft 4a of the motor 4 and the rotation shaft 5a of the generator 5 are connected to the output shaft 12, the motor shaft 13 (electric motor shaft), and the generator shaft 14 (generator shaft). Call. The rotation center axis of the clutch 3 built in the transaxle 1 is called a clutch shaft 15, the rotation center axis of the pump 2 is called a pump shaft 16, and the counter shaft with respect to the output shaft 12 is a counter shaft 17. Call.

  The arrangement of the rotation shaft in the transaxle 1 is shown in FIG. Here, the clutch shaft 15 and the pump shaft 16 are arranged coaxially. Further, the input shaft 11, the output shaft 12, the motor shaft 13, the generator shaft 14, the clutch shaft 15, and the counter shaft 17 are all arranged in parallel to each other. A power transmission path from the input shaft 11 to the output shaft 12 corresponds to the first path 31. The second path 32 corresponds to a power transmission path from the motor shaft 13 to the output shaft 12, and the third path 33 corresponds to a power transmission path from the input shaft 11 to the generator shaft 14.

  The path from the generator shaft 14 to the motor shaft 13 is accommodated in the transaxle 1 so as to form a single polygonal line as shown by a two-dot chain line in FIG. The motor 4 and the generator are connected to both ends of this path, and the engine 6 and the drive shaft 9 of the drive wheel 8 are connected to the middle of the path. When the output shaft 12 connected to the drive shaft 9 is used as a reference, the generator shaft 14 is disposed in front of the vehicle with respect to the output shaft 12 with an interval in the horizontal direction. On the other hand, the motor shaft 13 is disposed vertically above the output shaft 12 with an interval in the vertical direction. Therefore, the entire power transmission path has an L shape bent at the position of the output shaft 12.

On the power transmission path from the output shaft 12 to the generator shaft 14, the input shaft 11 and the clutch shaft 15 are arranged. As shown in FIG. 5, the input shaft 11 is disposed above a straight line L ₁ corresponding to a plane connecting the generator shaft 14 and the output shaft 12. On the other hand, the clutch shaft 15 is disposed below a straight line L ₂ corresponding to a plane connecting the input shaft 11 and the output shaft 12. The position of the clutch shaft 15 is set at a position where it does not overlap with the motor 4 and the generator 5. For example, when the external shape of the pump 2 is a cylindrical shape centered on the pump shaft 16 coaxial with the clutch shaft 15, the cylindrical surface is positioned so as not to interfere with the motor 4 and the generator 5.

Thereby, the path shape from the output shaft 12 to the generator shaft 14 becomes a lightning bolt shape that vibrates up and down, and the dimension in the vehicle front-rear direction is shortened. Similarly, the generator shaft 14 is disposed below a straight line L ₃ corresponding to a horizontal plane passing through the input shaft 11. If the distance between the generator shaft 14 and the input shaft 11 is constant, when the generator shaft 14 is moved downward, the forward protrusion amount of the generator 5 in the vehicle top view is reduced.

A counter shaft 17 is disposed on the power transmission path from the output shaft 12 to the motor shaft 13. The counter shaft 17 is disposed behind the straight line L ₄ corresponding to the plane connecting the output shaft 12 and the motor shaft 13. Thereby, the path shape from the output shaft 12 to the motor shaft 13 becomes a “<” shape protruding toward the rear, and the vertical dimension is shortened.

[5. Skeleton diagram]
FIG. 6 is a skeleton diagram of the transaxle 1 in which mechanical elements related to gear shifting are omitted.
The input shaft 11 is provided with two gears 11b and 11c. One gear 11 b meshes with a gear 14 b fixed to the generator shaft 14 and transmits power to the generator shaft 14. The generator shaft 14 is connected coaxially with the rotating shaft 5a coupled to the rotor 5b of the generator 5 (so as to be located on the same straight line). The stator 5c of the generator 5 is fixed to the casing of the generator 5.

  The other gear 11 c fixed to the input shaft 11 meshes with a gear 15 b connected to the engagement element 3 a on the driving side of the clutch 3. The driven engagement element 3 b disposed to face the engagement element 3 a is fixed to the clutch shaft 15. The clutch shaft 15 is also provided with a gear 15c for transmitting power to the output shaft 12 side. The gear 15 c is meshed with a differential gear 12 b fixed to the output shaft 12.

  One end of the clutch shaft 15 is coaxially connected to the pump shaft 16 of the rotating body 2 a built in the pump 2. The rotating body 2a corresponds to, for example, a rotor when the pump 2 is a vane pump, and corresponds to a piston when the pump 2 is a piston pump. The rotating body 2a (bidirectional pump) receives the rotational driving force transmitted from the clutch shaft 15 side, generates hydraulic pressure, and pumps hydraulic oil to the hydraulic circuit 2b. The hydraulic pressure generated here is transmitted to the clutch 3 and used as a driving pressure for the engagement elements 3a and 3b.

  The motor shaft 13 is provided with a gear 13b, and the counter shaft 17 is provided with two gears 17b and 17c. The gear 13 b of the motor shaft 13 meshes with the gear 17 b of the counter shaft 17, and the other gear 17 c of the counter shaft 17 is engaged with a differential gear 12 b fixed to the output shaft 12. The motor shaft 13 is coaxially connected to the rotating shaft 4 a coupled to the rotor 4 b of the motor 4. The stator 4c of the motor 4 is fixed to the casing of the motor 4.

  As described above, the input shaft 11 of the transaxle 1 is a shaft that supplies the power of the engine 6 to the two systems of the driving wheel 8 side and the generator 5 side, and includes a power transmission mechanism for power generation and a power transmission for driving. It is sandwiched between the mechanism. In other words, the input shaft 11 is located at a branch point between the first path 31 and the third path 33.

  On the other hand, the output shaft 12 is a shaft that individually receives two systems of power from the engine 6 side and the motor 4 side and transmits them to the drive wheel 8 side, and transmits a power transmission path for driving the engine and a power transmission for driving the motor. It is provided between the route. In other words, the output shaft 12 is located at the junction of the first path 31 and the second path 32.

[6. Hydraulic circuit diagram]
FIG. 7 schematically shows the circuit configuration of the hydraulic circuit 2 b of the pump 2. A pump shaft 16 that is the rotation center of the rotating body 2 a of the pump 2 is connected coaxially with the clutch shaft 15. As a result, the rotational motion of the drive wheel 8 is transmitted to the pump shaft 16 regardless of whether the clutch 3 is connected or disconnected.

  The rotating body 2 a is provided so as to be able to rotate in both the forward and reverse directions in conjunction with the drive wheels 8 of the vehicle 10. The two hydraulic oil ports formed in the rotating body 2a both function as an inlet and an outlet. When the vehicle 10 moves forward, the rotating body 2a rotates in the forward rotation direction, sucks hydraulic oil from the second port 2d side and discharges it to the first port 2c side. Further, when the vehicle 10 moves backward, the rotating body 2a rotates in the reverse direction, sucks the hydraulic oil from the first port 2c side and discharges it to the second port 2d side.

  The hydraulic circuit 2 b is provided with a first passage 21, a second passage 22, and a third passage 23 as hydraulic oil passages connecting the clutch 3 and the hydraulic oil tank 29. The first passage 21 is a passage for transmitting hydraulic pressure to the clutch 3 when the rotating body 2a is rotating forward, and the second passage 22 circulates hydraulic oil between the first passage 21 and the rotating body 2a when the rotating body 2a is reversely rotated. It is a passage for making it. The third passage 23 is a passage for circulating the excess hydraulic oil introduced into the clutch 3 to the hydraulic oil tank 29 side.

  As shown in FIG. 7, the filter 28, the rotating body 2 a of the pump 2, the pressure regulating valve 25, and the electromagnetic valve 26 are interposed in this order on the first passage 21 starting from the hydraulic oil tank 29. The filter 28 is a filtration device for removing contaminants contained in the hydraulic oil in the hydraulic circuit 2b.

  The pressure regulating valve 25 is a mechanical pressure control valve for making the pressure of hydraulic fluid transmitted to the clutch 3 side substantially constant. Here, the opening degree of the valve body is controlled so that a pressure difference does not occur upstream and downstream of the pressure regulating valve 25. A drain line 50 is provided between the pressure regulating valve 25 and the third passage 23. The drain line 50 functions as a pressure relief passage for relieving the hydraulic oil to the third passage 23 side when the upstream pressure of the pressure regulating valve 25 increases. Thereby, the pressure on the upstream side and the downstream side of the pressure regulating valve 25 is maintained constant.

  The electromagnetic valve 26 is a switching valve for clutch switching that receives or transmits the hydraulic pressure to the clutch 3 in response to a control signal transmitted from the clutch control unit 43. Here, when the ON signal from the clutch control unit 43 is not input to the electromagnetic valve 26 (when no control signal is input), the spool of the electromagnetic valve 26 moves to the right in FIG. Thus, the first passage 21 is closed. On the other hand, when an ON signal is input from the clutch control unit 43, the spool of the electromagnetic valve 26 moves in the opposite direction, and the first passage 21 is opened.

  The second passage 22 is a passage connecting the upstream side of the second port 2d of the rotating body 2a and the downstream side of the first port 2c. The second passage 22 is branched from the filter 28 and the rotating body 2 a in the first passage 21, and the tip is connected between the pressure regulating valve 25 and the electromagnetic valve 26. A check valve 24 is provided on the second passage 22. The check valve 24 has a function of allowing the operating oil to flow to the clutch 3 side on the second passage 22 and blocking the operating oil from the clutch 3 side.

  Therefore, during the normal rotation of the rotating body 2a, the check valve 24 is closed, and the hydraulic oil does not flow through the second passage 22. On the other hand, when the rotating body 2a rotates in the reverse direction, the hydraulic oil discharged from the second port 2d passes through the check valve 24 and flows to the electromagnetic valve 26 side. At this time, if the electromagnetic valve 26 is closed, the hydraulic oil passes through the first passage 21 via the pressure regulating valve 25 and is sucked from the first port 2c side of the rotating body 2a. As a result, when the rotating body 2a is reversely rotated, the hydraulic oil circulates in the annular hydraulic oil circuit composed of the first passage 21 and the second passage 22.

  The third passage 23 is a passage formed by branching from between the filter 28 and the rotating body 2 a in the first passage 21, and the tip thereof is connected to the electromagnetic valve 26. Therefore, the excess hydraulic fluid when the ON signal is not input to the solenoid valve 26 (when OFF) is circulated again to the first passage 21 via the third passage 23, and the second port of the rotating body 2a. Suctioned from the 2d side. When the clutch 3 is engaged, hydraulic oil is supplied to the first passage 21, and the surplus portion flows from the pressure regulating valve 25 to the third path 23 side via the drain line 50.

  A relief passage 30 is provided between the first passage 21 and the third passage 23. The relief passage 30 is branched from the rotary body 2 a and the pressure regulating valve 25 in the first passage 21, and the tip of the relief passage 30 is connected to the third passage 23. A relief valve 27 that regulates the upper limit pressure of the first passage 21 is interposed on the relief passage 30. For example, when the hydraulic pressure in the first passage 21 becomes equal to or higher than a predetermined upper limit pressure, the relief valve 27 is opened and the pressure is relieved. As a result, the hydraulic fluid circulates in the annular hydraulic fluid circuit composed of the first passage 21 and the relief passage 30 at the time of abnormality (for example, when the pressure regulating valve 25 fails).

[7. Action, effect]
[7-1. Related to hydraulic circuit]
(1) In the hydraulic circuit 2 b built in the transaxle 1 of the power train 7, a check valve 24 is interposed in the second passage 22. Thereby, for example, the hydraulic oil discharged from the first port 2c of the rotating body 2a when the vehicle 10 moves forward does not flow back to the second passage 22 side. Therefore, when the ON signal is transmitted from the clutch control unit 43, the hydraulic pressure can be immediately transmitted to the clutch 3 side to operate the clutch 3.

  On the other hand, when the vehicle 10 moves backward, the rotation direction of the rotating body 2a is reversed. At this time, the hydraulic oil discharged from the second port 2d of the rotating body 2a passes through the second passage 22 and flows to the electromagnetic valve 26 side via the check valve 24. That is, the hydraulic oil circulates in the first passage 21 and the second passage 22. Therefore, excessive hydraulic pressure does not act on various devices in the rotating body 2a, the filter 28, and the hydraulic circuit 2b, and the protection and reliability of the entire hydraulic circuit 2b can be improved.

  (2) Further, in the hydraulic circuit 2 b described above, the pressure regulating valve 25 is interposed in the first passage 21. Therefore, regardless of the rotational speed of the rotating body 2a, it is possible to adjust the magnitude of the hydraulic pressure transmitted to the clutch 3 side and apply a substantially constant pressure. For example, the hydraulic pressure input to the solenoid valve 26 when the traveling speed of the vehicle 10 is 50 [km / h] is substantially the same as the hydraulic pressure input to the solenoid valve 26 when the travel speed is 100 [km / h]. Can be. Therefore, regardless of the traveling state of the vehicle 10, the clutch 3 can be controlled with a uniform control pressure, and the connection / disconnection state of the clutch 3 can be accurately controlled.

  (3) In the hydraulic circuit 2b described above, when the electromagnetic valve 26 is interposed downstream from the junction of the first passage 21 and the second passage 22 and an ON signal is input to the electromagnetic valve 26. Only when the hydraulic pressure is transmitted to the clutch 3 side. Therefore, the operation of the electromagnetic valve 26 can be controlled independently of the hydraulic pressure actually generated by the rotating body 2a.

  For example, even when the traveling speed of the vehicle 10 is equal to or higher than a predetermined speed and sufficient hydraulic pressure is generated, the electromagnetic valve 26 can be closed when the clutch 3 does not need to be connected. Thus, the timing and timing at which the hydraulic oil is transmitted to the clutch 3 can be freely controlled, and the traveling performance of the vehicle 10 can be improved.

  (4) Regarding the control of the electromagnetic valve 26, in the power train 7, the operating states of the clutch 3, the motor 4, and the engine 6 are controlled by the electronic control unit 40 according to the traveling speed of the vehicle 10. For example, when the traveling speed is less than a predetermined speed, control is performed such that only the driving force of the motor 4 is transmitted to the drive wheels 8 while the clutch 3 is disengaged and the engine 6 is stopped. In general, since the electric motor 4 can output a large torque that is stable in a low speed range as compared with the engine 6, the startability of the vehicle 10 can be improved by executing the motor running at the start.

  Further, when the traveling speed of the vehicle 10 is equal to or higher than a predetermined speed, the engine 6 can be operated to travel with the driving force of the engine 6 alone, or the assist traveling using the engine 6 and the motor 4 together. Can be implemented. In addition, since the output torque of the engine 6 increases while the output torque of the motor 4 decreases in the middle and high speed range, the motion performance of the vehicle 10 can be improved by using these together.

  The clutch 3 is connected by the power train 7 at least when the traveling speed is equal to or higher than a predetermined speed, and the rotating body 2a of the pump 2 is rotating at a high speed. Thereby, a hydraulic pressure large enough to connect the clutch 3 can be ensured. Therefore, by outputting an ON signal from the clutch control unit 43 to the electromagnetic valve 26, the clutch 3 can be immediately connected, and the driving force of the engine 6 can be reliably transmitted to the drive wheel 8 side.

  (5) Furthermore, in the hydraulic circuit 2b described above, no hydraulic pressure is generated when the vehicle is stopped and at a low speed. In other words, even if a fail-safe circuit is not set for the solenoid valve or the like in consideration of the failure of the hydraulic system, if the rotational speed (vehicle speed) is limited, the hydraulic pressure does not occur above a predetermined level, and the engine and drive wheels Since the separated state is maintained, EV traveling or series traveling is possible. That is, there is no need to add a complicated fail-sail circuit, the control is simplified, and the cost is advantageous.

[7-2. Concerning arrangement configuration]
Further, in the power train 7 described above, since one power transmission path branched from the input shaft 11 in the transaxle 1 is joined by the output shaft 12, the motor is connected from the generator shaft 14 via the input shaft 11 and the output shaft 12. A series of paths (paths that can connect the start point and the end point with a single stroke) to the axis 13 are formed. Therefore, as shown in FIG. 5, it becomes easy to bend the path in an arbitrary direction with each axis as a bending point without affecting the power transmission performance, and the pump 2 and the motor 4 fixed to the transaxle 1. It is possible to design the arrangement of various devices such as the generator 5 and the engine 6 relatively freely.

  (1) After adopting such a power transmission structure with a high degree of freedom, in the transaxle 1 described above, the motor 4 and the generator 5 are spaced apart in the vertical and horizontal directions around the output shaft 12. Provided. Thereby, it becomes easy to arrange the motor 4 and the generator 5 in the horizontal direction, and the entire transaxle 1 can be downsized. Therefore, space efficiency and vehicle mountability can be improved.

  Further, as shown in FIG. 5, the mounting height of the motor 4 in a side view is different from the mounting height of the generator 5, in other words, the motor 4 is disposed at an oblique position with respect to the generator 5. . Therefore, for example, an empty space can be secured below the motor 4, and the pump 2 and the output shaft 12 can be arranged in the empty space. That is, the pump 2, the motor 4 and the generator 5 can be arranged without waste on the side surface of the transaxle 1 so as not to interfere with the drive shaft 9, and space efficiency can be improved. Thereby, the whole powertrain 7 can be reduced in size.

  For example, even if the mounting method described in Patent Document 1 is used and the pump 2 is provided at a position where it overlaps with the motor 4 and the generator 5 in a side view, the dimension in the vehicle width direction increases. On the other hand, in the transaxle 1 described above, the projecting amount of the pump 2 in the vehicle width direction from the left side surface of the transaxle 1 can be reduced, and both the vehicle longitudinal dimension and the vehicle width dimension are downsized. Can be

  Furthermore, since the pump 2, the motor 4 and the generator 5 do not overlap each other in a side view of the transaxle 1, accessibility can be improved. Further, since the motor 4, the generator 5 and the pump 2 can be removed without disassembling the transaxle 1, the maintainability can be improved.

(2) Further, in the transaxle 1, as shown in FIG. 5, the clutch shaft 15 serving as the rotation center of the clutch 3 is disposed below the straight line L ₂ , so that the input shaft 11, the output shaft 12, The distance in the horizontal front-rear direction can be shortened. As a result, the transaxle 1 can be further compacted to a size in the front-rear direction.

Incidentally, if only to shorten the length horizontal longitudinal between the input shaft 11 and the output shaft 12, (which in a convex polygonal line above) is arranged above the straight line L ₂ and the clutch shaft 15 is also Conceivable. However, in this case, since the size of the engine 6 connected to the input shaft 11 is larger than the clutch 3 fixed to the clutch shaft 15, the projecting amount of the transaxle 1 to the vehicle lower surface side may increase. . In contrast, if disposed below the straight line L ₂ smaller clutch 3 relatively sizes, can be substantially flat lower surface of the transaxle 1, it is possible to improve the vehicle mountability.

(3) Further, in the transaxle 1 described above, the generator shaft 14 serving as the rotation center of the generator 5 is disposed below the straight line L ₃ , so that the distance between the generator 5 and the crankshaft 6 a of the engine 6 when viewed from above. Can be shortened. As a result, the transaxle 1 can be further compacted in the horizontal direction.
Similarly, in the transaxle 1, the input shaft 11 is disposed above the straight line L _1, it is possible to shorten the distance between the generator 5 and the drive shaft 9 in top view. Therefore, the transaxle 1 can be further compacted in the horizontal direction.

  (4) Moreover, as shown in FIG. 1, only the engine 6 is arrange | positioned at the right side surface of said transaxle 1, and the pump 2, the motor 4, and the generator 5 are arrange | positioned at the left side surface. That is, it becomes possible to select the dimension and capacity of the engine 6 independently of the restrictions on the layout, dimensions, and the like of the pump 2, the motor 4, and the generator 5. That is, the degree of freedom related to the size setting of the engine 6 employed in the power train 7 can be increased, and the thermal influence on the pump 2, the motor 4, and the generator 5 can be suppressed.

  Further, since the pump 2, the motor 4, and the generator 5 are arranged in the left side surface direction of the vehicle 10 so as not to overlap each other, the accessibility from the outside of the vehicle 10 can be enhanced. Further, since the motor 4, the generator 5, and the pump 2 can be removed without disassembling the transaxle 1, the maintainability can be improved.

  (5) Further, as shown in FIG. 5, in the power train 7 described above, the transaxle 1 itself is made compact by devising the arrangement of the shafts built in the transaxle 1. Therefore, it is reasonable as a technique for improving the space efficiency of the power train 7, and downsizing of the entire apparatus is possible while realizing an unreasonable power transmission.

[8. Modified example]
In the above-described embodiment, as illustrated in FIG. 5, the generator shaft 14 is disposed in the horizontal front direction with respect to the output shaft 12 and the motor shaft 13 is disposed vertically above the output shaft 12. The relative positions of the shaft 14 and the motor shaft 13 with respect to the output shaft are not limited to this. Note that the size of the drive shaft 9 that can be arranged in the vertical direction is limited, and in the case of a strong hybrid type hybrid vehicle, the motor 4 is preferably arranged in the vicinity of the drive shaft 9. It is preferable to arrange the motor 4 at a position spaced apart in the vertical direction.

  Therefore, the generator 5 is preferably arranged at a position spaced apart from the output shaft 12 in the horizontal direction. By making the horizontal position and the vertical position of the motor 4 and the generator 5 different from each other at least, an empty space can be secured either above or below the motor 4, and the drive shaft 9 can be secured using the empty space. A pump 2 can be arranged.

  In the above embodiment, the input shaft 11, the output shaft 12, the motor shaft 13, the generator shaft 14, the clutch shaft 15, and the counter shaft 17 built in the transaxle 1 are all illustrated in parallel. These axes do not necessarily have to be parallel. Therefore, a universal joint for changing the rotation axis direction may be interposed on the power transmission path, or the extension direction of the shaft may be inclined using a bevel gear, a staggered shaft gear, or the like.

Moreover, the specific shape of the power transmission path in the transaxle 1 is not limited to that shown by the two-dot chain line in FIG. For example, the generator shaft 14 may be moved from the straight line L ₃ upward, the input shaft 11 may be moved from the straight line L ₁ downward. The transaxle 1 can be made compact without impairing the traveling performance of the vehicle 10 by making at least a part of the shape of the power transmission path a lightning bolt shape.

1 Transaxle 2 Pump 2a Rotating body (bidirectional pump)
2b Hydraulic circuit 2c 1st port 2d 2nd port 3 Clutch 4 Motor (electric motor)
5 Generator
6 Engine 7 Powertrain 8 Drive Wheel 9 Drive Shaft 10 Vehicle 21 First Passage 22 Second Passage 23 Third Passage 24 Check Valve 25 Pressure Control Valve 26 Solenoid Valve 41 Engine Control Unit 42 Motor Control Unit 43 Clutch Control Unit (Clutch Control) means)
44 switching control unit (switching means)

Claims (4)

A hydraulic control device for connection / disconnection of a clutch mounted on a vehicle,
A bidirectional pump that rotates in the forward or reverse direction in conjunction with the drive wheels of the vehicle and generates hydraulic pressure;
A first passage through which the bidirectional pump is interposed to transmit the hydraulic pressure to the clutch;
A second passage connecting the upstream side and the downstream side of the bidirectional pump interposed in the first passage;
A check valve interposed in the second passage and allowing a flow of hydraulic oil to the clutch side and blocking a flow of hydraulic oil from the clutch side. Hydraulic control device. 2. The clutch hydraulic control device according to claim 1, further comprising a pressure regulating valve that is disposed on the first passage and regulates the pressure of hydraulic oil transmitted to the clutch. The clutch hydraulic control device according to claim 1 or 2, further comprising an electromagnetic valve interposed on the first passage and allowing or blocking the flow of the hydraulic oil. The vehicle has switching means for switching between EV mode or series hybrid mode and parallel hybrid mode,
4. The clutch hydraulic control device according to claim 3, further comprising clutch control means for controlling an opening degree of the electromagnetic valve in an opening direction when the switching means is in a parallel hybrid mode.

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