JP2011031742A - Oil pressure controller for drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil pressure controller for drive unit that reduces frequency of high pressure operation of a motor-driven oil pump, and reduces electric power consumption. <P>SOLUTION: The oil pressure controller for drive unit includes: a regulator valve 73 provided between hydraulic brakes 60A, 60B and the motor-driven oil pump 70, and having a switching mechanism 73f for switching set oil pressure between low-pressure oil pressure PL and high-pressure oil pressure PH; a brake control valve 74 for connecting/disconnecting a pump oil passage 72 with/from a brake oil passage 75, and a switching control valve 77 for switching the set oil pressure of the regulator valve 73 and for controlling the connection of the brake control valve 74. The oil pressure controller also includes a control means for opening the brake control valve 74 to connect the pump oil passage 72 with the brake oil passage 75, when engaging the hydraulic brakes 60A, 60B for transmitting motive power in a direction of opening one clutch, and for closing the brake control valve 74 to disconnect the pump oil passage 72 from the brake oil passage 75, when releasing the hydraulic brakes 60A, 60B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydraulic control device that controls the hydraulic pressure of a drive device of a vehicle.

  As shown in FIG. 25, the vehicle described in Patent Document 1 has a front wheel driven by a main drive source (not shown) such as an engine, and the rear wheel 102 of the vehicle 100 is auxiliary driven. It is driven via a power transmission mechanism 104 by an electric motor (motor) 103 as a source.

  The power transmission mechanism 104 includes a speed reduction mechanism 105 that inputs power from the electric motor 103 and a differential gear 106 that distributes power output from the speed reduction mechanism 105 to the left and right rear wheels 102 and 102. The reduction mechanism 105 includes a first gear 105 a fixed to the output shaft of the electric motor 103, a second gear 105 b that meshes with the first gear 105 a, and a third gear 105 c that meshes with the input gear 106 a of the differential gear 106. It consists of a reduction gear train. A hydraulic clutch 107 is provided between the second gear 105b and the third gear 105c. When the hydraulic clutch 107 is engaged, the second gear 105b and the third gear 105c are connected to transmit power. The power of the electric motor 103 can be transmitted to the rear wheel 102 via the mechanism 104, and when the hydraulic clutch 107 is released, the second gear 105b and the third gear 105c are disconnected, Transmission to the wheel 102 is interrupted.

  As shown in FIG. 26, the hydraulic control device 120 of the drive device includes a one-way valve 123 that permits the flow of hydraulic oil from the electric oil pump 121 to the hydraulic clutch 107 and prevents the flow in the opposite direction; An accumulator 126 connected to an oil supply passage 125 connecting the one-way valve 123 and the hydraulic clutch 107 and capable of accumulating the oil pressure necessary for the operation of the hydraulic clutch 107, a hydraulic sensor 131 for detecting the oil pressure in the oil supply passage 125, and a vehicle speed sensor 134. And a controller 110 that sets a first predetermined pressure based on the vehicle speed detected by (see FIG. 25), the hydraulic clutch 107 is engaged, and the hydraulic pressure detected by the hydraulic sensor 131 is lower than the predetermined pressure. When this happens, the electric oil pump 121 is operated in the high pressure mode to supply hydraulic pressure from the electric oil pump 121 to the oil supply passage 125. It has been disclosed. The controller 110 considers the output characteristics of the electric motor 103 and changes the predetermined pressure according to the vehicle speed, thereby reducing the operating frequency of the oil pump 121 in the high pressure mode and reducing the power consumption of the electric oil pump 121. I am trying.

JP 2006-258279 A

  However, in the control device 120 described in Patent Document 1, all power transmission between the second gear 105b and the third gear 105c is controlled by the hydraulic clutch 107, so there is room for improvement in reducing power consumption. Further, since the control device 120 selects the operation mode of the oil pump 121 between the low pressure mode and the high pressure mode according to the oil pressure of the oil supply passage 125 and the vehicle speed, the control tends to be complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic control device for a drive device that can reduce the frequency of high-pressure operation of an electric oil pump and reduce power consumption.

In order to achieve the above object, the invention described in claim 1
An electric motor that outputs a driving force (for example, electric motors 2A, 2B, and 2C in embodiments described later);
A drive shaft (for example, an axle of an embodiment described later) connected to an output shaft (for example, a cylindrical shaft 16A, 16B of an embodiment described later) and a wheel (for example, rear wheels LWr, RWr of an embodiment described later) of the electric motor. 10A, 10B) and a reduction gear (for example, planetary gear type reduction gears 12A, 12B, 12C of the embodiment described later),
A speed reducer case (for example, a speed reducer case 11 in an embodiment described later) that houses the electric motor and the speed reducer;
One-way power transmission means (for example, a one-way clutch 50 in an embodiment described later) that is disposed on a transmission path from the motor to the drive shaft and that transmits rotational power in one direction of the motor to the drive shaft. When,
A part of the reduction gear (for example, ring gears 24A and 24B in the embodiments described later) and the reduction gear case are connected and disconnected, and the bidirectional rotational power of the electric motor is connected to the drive shaft in the connected state. A hydraulic brake that can be transmitted (for example, hydraulic brakes 60A and 60B in the embodiments described later);
A hydraulic control device of a drive device (for example, a drive device 1 of an embodiment described later) including an electric oil pump (for example, an oil pump 70 of an embodiment described later) that supplies oil of a predetermined pressure to the hydraulic brake. There,
Provided between the hydraulic brake and the electric oil pump, the set hydraulic pressure of the oil is a first hydraulic pressure (for example, a low pressure hydraulic pressure PL in an embodiment described later) and a second hydraulic pressure higher than the first hydraulic pressure (for example, described later). A regulator valve (for example, a regulator valve 73 according to an embodiment described later) having a switching mechanism (for example, a switching mechanism 73f, spool 73a according to an embodiment described later) that can be switched to the high pressure hydraulic pressure PH of the embodiment;
Brake control for communicating / blocking a pump oil passage (for example, a pump oil passage 72 in an embodiment to be described later) connected to the regulator valve and a brake oil passage (for example, a brake oil passage 75 in an embodiment to be described later) connected to the regulator valve. A valve (for example, a brake control valve 74 in an embodiment described later);
A switching control valve (for example, a switching control valve 77 in an embodiment described later) for switching the set hydraulic pressure of the regulator valve and controlling the communication / blocking of the brake control valve;
When the hydraulic brake is engaged to transmit the power in the opening direction of the one-way power transmission means, the brake control is interlocked with switching the set hydraulic pressure of the regulator valve from the first hydraulic pressure to the second hydraulic pressure. When the valve is opened to connect the pump oil passage and the brake oil passage to release the hydraulic brake, the brake control is interlocked with switching the set hydraulic pressure of the regulator valve from the second hydraulic pressure to the first hydraulic pressure. Control means (for example, ECU 45 and hydraulic pressure control means 48 in an embodiment described later) for closing the valve and shutting off the pump oil path and the brake oil path is provided.

Moreover, in addition to the structure of Claim 1, the invention of Claim 2 is
The one-way power transmission means is set so as to be engaged when the vehicle is traveling forward and when the electric power is driven, and disengaged when regenerating.
The control means sets the set hydraulic pressure to the first hydraulic pressure when the unidirectional power transmission means is engaged, shuts off the pump oil passage and the brake oil passage, and opens the hydraulic brake.

Moreover, in addition to the structure of Claim 2, the invention of Claim 3 is
The control means sets the set hydraulic pressure to the second hydraulic pressure when the vehicle is traveling forward and the motor is regenerating, or when the motor is traveling backward and the power is driven. A road and the brake oil path are communicated, and the hydraulic brake is engaged.

Moreover, in addition to the structure in any one of Claims 1-3, the invention of Claim 4 is
The control means corresponds to a failure time when the set hydraulic pressure is set to the first hydraulic pressure, the pump oil passage and the brake oil passage are shut off, and the hydraulic brake is released when the electric motor or a control unit controlling the electric motor fails. Means (for example, means for dealing with failure 49 in embodiments described later) is provided.

Moreover, in addition to the structure in any one of Claims 1-4, the invention of Claim 5 is
The electric motor is composed of first and second electric motors (for example, electric motors 2A and 2B in embodiments described later) arranged on the left and right in the vehicle width direction,
The speed reducer is composed of first and second planetary gear type speed reducers (for example, planetary gear type speed reducers 12A and 12B of the embodiments described later) arranged on the left and right in the vehicle width direction,
The power of the first electric motor is transmitted to the left wheel drive shaft (for example, an axle 10A in an embodiment described later) via the first planetary gear type reduction gear,
The power of the second electric motor is transmitted to a right wheel drive shaft (for example, an axle 10B in an embodiment described later) via the second planetary gear speed reducer.

Moreover, in addition to the structure of Claim 5, the invention of Claim 6 is
The hydraulic brake includes a first hydraulic brake (for example, a hydraulic brake 60A according to an embodiment described later) connected to a ring gear (for example, a ring gear 24A according to an embodiment described later) of the first planetary gear reducer, A second hydraulic brake (for example, a hydraulic brake 60B according to an embodiment described later) connected to a ring gear (for example, a ring gear 24B according to an embodiment described later) of the second planetary gear type reduction gear,
The brake fluid passage communicates with the first hydraulic brake and the second hydraulic brake.

  According to the first aspect of the present invention, only when the hydraulic brake is engaged, the electric oil pump may be operated in the high pressure mode by switching the oil setting oil pressure from the low pressure first oil pressure to the high pressure second oil pressure. The frequency of operation of the electric oil pump in the high pressure mode can be reduced, and the power consumption of the electric oil pump can be reduced. In addition, when the hydraulic brake is engaged, the control means opens the brake control valve in conjunction with switching the set hydraulic pressure of the regulator valve from the low-pressure first hydraulic pressure to the high-pressure second hydraulic pressure. When the road is connected and the hydraulic brake is released, the brake control valve is closed and the pump oil path and the brake oil path are closed in conjunction with switching the set hydraulic pressure of the regulator valve from the high pressure second oil pressure to the low pressure first oil pressure. Since they are shut off, the hydraulic brake can be engaged and released without requiring complicated control.

  According to the second aspect of the present invention, the one-way power transmission means is set so as to be engaged when the vehicle is traveling forward and when the electric motor is driven by power running, and to be disengaged when regenerating. Therefore, when the oil temperature is low, such as when the vehicle is starting, the one-way power transmission means is engaged and it is not necessary to engage the hydraulic brake. Therefore, the response at the time of starting is improved and the oil temperature is low. It is possible to avoid operating the electric oil pump in the high pressure mode.

  According to the third aspect of the present invention, when necessary, since the pressure is adjusted by the set hydraulic pressure of the high second hydraulic pressure, the hydraulic brake can be reliably engaged, and the one-way power transmission means is provided. Even if it is not engaged, power can be transmitted between the electric motor and the drive shaft.

  According to the fourth aspect of the present invention, it is possible to prevent the electric motor from being forcedly engaged due to the engagement of the hydraulic brake when the electric motor or the controller that controls the electric motor fails.

  According to the fifth aspect of the present invention, since the speed reducer and the electric motor are disposed on the left and right wheels, respectively, the left and right wheels can be controlled independently to improve the steering stability (turning). In addition, compared with the case where turning performance is improved with one electric motor and two friction materials, loss due to heat generation due to slip control of the friction material can be suppressed. For example, the optimum specification when mounted on a hybrid vehicle can do.

1 is a block diagram illustrating a schematic configuration of a hybrid vehicle that is an embodiment of a vehicle on which a hydraulic control device according to the present invention can be mounted. It is a block diagram of ECU. It is a longitudinal cross-sectional view of the drive device controlled by the hydraulic control device according to the present invention. FIG. 4 is a partially enlarged view of the drive device shown in FIG. 3. It is a perspective view which shows the state with which the drive device was mounted in the flame | frame. It is a hydraulic circuit diagram of the hydraulic control device in a state where the hydraulic brake is released. It is a hydraulic circuit diagram of the hydraulic control device in a state where the hydraulic brake is engaged. It is a graph which shows the load characteristic of an electric oil pump. It is an alignment chart of the drive device when the vehicle is stopped. It is a collinear diagram of the drive device when the drive device is on the drive side and travels forward. FIG. 6 is a collinear diagram of the drive device when the drive device travels forward on the coast side and the motor stops. FIG. 6 is a collinear diagram of the drive device when the drive device travels forward on the coast side and is regenerated by an electric motor. It is an alignment chart of the drive device when the drive device is on the drive side and travels backward. It is a collinear diagram of the drive device when the drive device is traveling on the coast side and traveling backward. The engagement control assisting from the state where the left and right motors are stopped is shown. (A) is a nomographic chart during high-speed cruise by the internal combustion engine, (b) is a nomographic chart at the time of rotation matching, and (c) is an assist. It is an alignment chart of time. FIG. 4 shows engagement control that regenerates when the left and right motors are stopped, (a) is an alignment chart during high-speed cruise by the internal combustion engine, (b) is an alignment chart at the time of rotation adjustment, and (c) is hydraulic pressure. The alignment chart at the time of brake engagement, (d) is the alignment chart at the time of regeneration. It is the figure which showed the state of the electric motor in the driving | running | working state of a vehicle, the state of a separation mechanism, and the line pressure. It is a timing chart at the time of forward travel of vehicles. It is a timing chart at the time of reverse running of vehicles. The engagement control that assists and regenerates from a state where there is a difference in rotation between the left and right electric motors by turning the vehicle is shown, (a) is a nomographic chart during turning, (b) is a nomographic chart at the time of rotation matching, (c) Is a collinear diagram during assist and regeneration. The engagement control that assists and regenerates from a state where there is a difference in rotation between the left and right electric motors by turning the vehicle is shown, (a) is a nomographic chart during turning, (b) is a nomographic chart at the time of rotation matching, (c) Is an alignment chart when the hydraulic brake is engaged, and (d) is an alignment chart when assisting and regenerating. It is a flowchart of the control flow of the hydraulic control apparatus which concerns on this invention. It is a driving force characteristic figure of the electric motor of a drive device. It is a block diagram which shows schematic structure of the hybrid vehicle which is other embodiment of the vehicle which can mount the hydraulic control apparatus which concerns on this invention. 10 is a block diagram of a drive device described in Patent Document 1. FIG. 2 is a hydraulic circuit diagram described in Patent Document 1. FIG.

First, an embodiment of a vehicle drive device to which a hydraulic control device according to the present invention can be applied will be described with reference to FIGS.
The drive device 1 uses the electric motors 2A and 2B as drive sources for driving the axle, and is used for the vehicle 3 of the drive system as shown in FIG. 1, for example.
A vehicle 3 shown in FIG. 1 is a hybrid vehicle having a drive unit 6 in which an internal combustion engine 4 and an electric motor 5 are connected in series at the front part of the vehicle, and the power of the drive unit 6 is transmitted to a front wheel Wf via a transmission 7. On the other hand, the power of the drive device 1 provided at the rear of the vehicle separately from the drive unit 6 is transmitted to the rear wheels Wr (RWr, LWr). The electric motor 5 of the driving unit 6 and the electric motors 2A and 2B of the driving device 1 on the rear wheel Wr side are connected to the battery 9 via the PDU 8 (power drive unit), and supply of power from the battery 9 and energy regeneration to the battery 9 are performed. Is performed via the PDU 8. The PDU 8 is connected to an ECU 45 described later.

  FIG. 3 is a longitudinal sectional view of the entire drive device 1. In FIG. 3, 10A and 10B are left and right axles on the rear wheel Wr side of the vehicle, and are arranged coaxially in the vehicle width direction. ing. The reduction gear case 11 of the drive device 1 is formed in a substantially cylindrical shape as a whole, and includes an axle driving motor 2A, 2B, and a planetary gear type reduction gear 12A for reducing the drive rotation of the motor 2A, 2B. , 12B are arranged coaxially with the axles 10A, 10B. The electric motor 2A and the planetary gear type reduction gear 12A control the left rear wheel LWr, and the electric motor 2B and the planetary gear type reduction gear 12B control the right rear wheel RWr, and the electric motor 2A, the planetary gear type reduction gear 12A, the electric motor 2B, The planetary gear type speed reducer 12B is disposed symmetrically in the vehicle width direction within the speed reducer case 11. As shown in FIG. 5, the speed reducer case 11 is supported by the support portions 13 a and 13 b of the frame member 13 that is a part of the frame that is the skeleton of the vehicle 3 and the frame of the drive device 1 (not shown). Yes. The support portions 13a and 13b are provided on the left and right with respect to the center of the frame member 13 in the vehicle width direction. In addition, the arrow in FIG. 5 has shown the positional relationship in the state in which the drive device 1 was mounted in the vehicle.

  The stators 14A and 14B of the electric motors 2A and 2B are respectively fixed inside the left and right ends of the speed reducer case 11, and annular rotors 15A and 15B are rotatably arranged on the inner peripheral sides of the stators 14A and 14B. . Cylindrical shafts 16A and 16B surrounding the outer periphery of the axles 10A and 10B are coupled to the inner peripheral portions of the rotors 15A and 15B, and the cylindrical shafts 16A and 16B are decelerated so as to be coaxially rotatable with the axles 10A and 10B. The machine case 11 is supported by end walls 17A and 17B and intermediate walls 18A and 18B via bearings 19A and 19B. In addition, the rotational position information of the rotors 15A and 15B is transmitted to the end walls 17A and 17B of the reduction gear case 11 on the outer periphery on one end side of the cylindrical shafts 16A and 16B, and the control controllers (not shown) of the motors 2A and 2B. Resolvers 20A and 20B are provided for feedback.

  The planetary gear speed reducers 12A and 12B include sun gears 21A and 21B, a plurality of planetary gears 22A and 22B meshed with the sun gear 21, planetary carriers 23A and 23B that support the planetary gears 22A and 22B, and planetary gears. Ring gears 24A and 24B meshed with the outer peripheral sides of 22A and 22B, and the driving forces of the electric motors 2A and 2B are input from the sun gears 21A and 21B, and the reduced driving force is output through the planetary carriers 23A and 23B. It is like that.

  The sun gears 21A and 21B are formed integrally with the cylindrical shafts 16A and 16B. Further, as shown in FIG. 4, for example, the planetary gears 22A and 22B include large-diameter first pinions 26A and 26B that are directly meshed with the sun gears 21A and 21B, and second pinions that are smaller in diameter than the first pinions 26A and 26B. The first and second pinions 26A and 26B and the second pinions 27A and 27B are integrally formed in a state of being coaxially and offset in the axial direction. The planetary gears 22A and 22B are supported by the planetary carriers 23A and 23B, and the planetary carriers 23A and 23B are supported so as to be integrally rotatable with the axially inner ends extending inward in the radial direction and being spline-fitted to the axles 10A and 10B. Along with the bearings 33A and 33B, the intermediate walls 18A and 18B are supported.

  The intermediate walls 18A and 18B separate the motor housing space for housing the motors 2A and 2B and the speed reducer space for housing the planetary gear type speed reducers 12A and 12B, and the axial distance from the outer diameter side to the inner diameter side. It is configured to bend so as to spread. Bearings 33A and 33B for supporting the planetary carriers 23A and 23B are arranged on the inner diameter side of the intermediate walls 18A and 18B and on the planetary gear type speed reducers 12A and 12B, and the outer diameter side of the intermediate walls 18A and 18B. In addition, bus rings 41A and 41B for the stators 14A and 14B are disposed on the motors 2A and 2B side (see FIG. 3).

  The ring gears 24A and 24B are disposed opposite to each other at gears 28A and 28B whose inner peripheral surfaces are meshed with the second pinions 27A and 27B having a small diameter, and smaller in diameter than the gear parts 28A and 28B, at an intermediate position of the speed reducer case 11. Small-diameter portions 29A and 29B, and connecting portions 30A and 30B that connect the axially inner ends of the gear portions 28A and 28B and the axially outer ends of the small-diameter portions 29A and 29B in the radial direction. . In the case of this embodiment, the maximum radii of the ring gears 24A and 24B are set to be smaller than the maximum distance from the center of the axles 10A and 10B of the first pinions 26A and 26B. The small diameter portions 29A and 29B are spline-fitted to an inner race 51 of a one-way clutch 50, which will be described later, and the ring gears 24A and 24B are configured to rotate integrally with the inner race 51 of the one-way clutch 50.

  By the way, a cylindrical space is secured between the speed reducer case 11 and the ring gears 24A and 24B, and hydraulic brakes 60A and 60B that constitute braking means for the ring gears 24A and 24B are provided in the space portions in the first pinion 26A, It wraps in the radial direction with 26B and wraps in the axial direction with the second pinions 27A and 27B. The hydraulic brakes 60A and 60B include a plurality of fixed plates 35A and 35B that are spline-fitted to the inner peripheral surface of a cylindrical outer diameter side support portion 34 that extends in the axial direction on the inner diameter side of the speed reducer case 11, a ring gear 24A, A plurality of rotating plates 36A, 36B that are spline-fitted to the outer peripheral surface of 24B are alternately arranged in the axial direction, and these plates 35A, 35B, 36A, 36B are engaged and released by the annular pistons 37A, 37B. It has become so. The pistons 37 </ b> A and 37 </ b> B are formed between a left and right dividing wall 39 extending from the intermediate position of the housing 11 toward the inner diameter side, and an outer diameter side support portion 34 and an inner diameter side support portion 40 connected by the left and right division walls 39. The pistons 37A and 38B are accommodated in the annular cylinder chambers 38A and 38B so as to freely advance and retract. The pistons 37A and 37B are advanced by introducing high-pressure oil into the cylinder chambers 38A and 38B, and the oil is discharged from the cylinder chambers 38A and 38B. , 37B is retracted. The hydraulic brakes 60A and 60B are connected to an oil pump 70 disposed between the support portions 13a and 13b of the frame member 13 described above, as shown in FIG.

More specifically, the pistons 37A and 37B have first piston walls 63A and 63B and second piston walls 64A and 64B in the axial direction, and the piston walls 63A, 63B, 64A and 64B are cylindrical. Are connected by inner peripheral walls 65A and 65B. Therefore, an annular space that opens radially outward is formed between the first piston walls 63A and 63B and the second piston walls 64A and 64B. This annular space is formed on the inner periphery of the outer wall of the cylinder chambers 38A and 38B. It is partitioned forward and backward in the axial direction by partition members 66A and 66B fixed to the surface. A space between the left and right dividing walls 39 of the reduction gear case 11 and the second piston walls 64A and 64B is a first working chamber into which high-pressure oil is directly introduced, and between the partition members 66A and 66B and the first piston walls 63A and 63B. The second working chamber is electrically connected to the first working chamber through a through hole formed in the inner peripheral walls 65A and 65B. The second piston walls 64A and 64B and the partition members 66A and 66B are electrically connected to the atmospheric pressure.
In the hydraulic brakes 60A and 60B, high pressure oil is introduced into the first working chamber and the second working chamber, and the fixing plate 35A and the fixing plate 35A and the second piston walls 64A and 64B are pressurized by the oil pressure acting on the first piston walls 63A and 63B and the second piston walls 64A and 64B. 35B and the rotating plates 36A and 36B can be pressed against each other. Therefore, since the large pressure receiving area can be gained by the first and second piston walls 63A, 63B, 64A, 64B in the front and rear in the axial direction, the fixed plates 35A, 35B A large pressing force against the rotating plates 36A and 36B can be obtained.

  In the case of the hydraulic brakes 60A and 60B, the fixed plates 35A and 35B are supported by the outer diameter side support portion 34 extending from the reduction gear case 11, while the rotation plates 36A and 36B are supported by the ring gears 24A and 24B. When the plates 35A, 35B, 36A, and 36B are pressed by the pistons 37A and 37B, the frictional engagement between the plates 35A, 35B, 36A, and 36B causes a braking force to act on the ring gears 24A and 24B, and the state is fixed. When the engagement by the pistons 37A and 37B is released, the ring gears 24A and 24B are allowed to freely rotate.

  Also, a space is secured between the coupling portions 30A and 30B of the ring gears 24A and 24B facing each other in the axial direction, and only power in one direction is transmitted to the ring gears 24A and 24B in the space to transmit power in the other direction. A one-way clutch 50 is arranged to be shut off. The one-way clutch 50 has a large number of sprags 53 interposed between an inner race 51 and an outer race 52. The inner race 51 is connected to the small diameter portions 29A, 29B of the ring gears 24A, 24B by spline fitting. It is configured to rotate integrally. The outer race 52 is positioned by the inner diameter side support portion 40 and is prevented from rotating. The one-way clutch 50 is configured to engage and lock the rotation of the ring gears 24A and 24B when the vehicle moves forward. More specifically, the one-way clutch 50 is configured to lock or disconnect the ring gears 24A and 24B depending on the direction of the torque acting on the ring gears 24A and 24B, and the rotation of the sun gears 21A and 21B when the vehicle moves forward. When the direction is the forward rotation direction, the rotation of the ring gears 24A and 24B is locked when the torque in the reverse rotation direction acts on the ring gears 24A and 24B.

Next, a hydraulic circuit constituting the hydraulic control apparatus according to the present invention will be described with reference to FIGS.
The hydraulic circuit 71 is configured such that hydraulic oil discharged from the electric oil pump 70 can be supplied to the first working chambers of the hydraulic brakes 60A and 60B via the regulator valve 73 and the brake control valve 74. The electric oil pump 70 The motor 80 composed of a position sensorless brushless DC motor is operated in two modes, a high pressure mode and a low pressure mode.

  The brake control valve 74 is connected to a pump oil passage 72 connecting the electric oil pump 70 and the brake control valve 74 and a brake oil passage 75 connected to the hydraulic brakes 60A and 60B, and the pump oil passage 72 and the brake oil passage 75 are communicated and cut off. Is configured to do. In a state where the pump oil passage 72 and the brake oil passage 75 communicate with each other, the hydraulic oil in the pump oil passage 72 is supplied to the hydraulic brakes 60 </ b> A and 60 </ b> B and engaged with each other, and the pump oil passage 72 and the brake oil passage 75 are shut off. In this state, the brake oil passage 75 is connected to the drain port 74b, and oil is discharged from the hydraulic brakes 60A and 60B to release the hydraulic brakes 60A and 60B.

  The regulator valve 73 is connected to the pump oil passage 72, and includes a spool 73a that communicates and blocks the pump oil passage 72 and the supply port 73b as a switching mechanism 73f. The spool 73a is urged by a spring 73c in a direction that shuts off the pump oil passage 72 and the supply port 73b (left side in FIG. 6, hereinafter referred to as a non-supply direction), and is placed in the oil chamber 73d at the left end in the drawing. The oil pressure of the pump oil passage 72 that is input pushes the pump oil passage 72 and the supply port 73b in a direction (rightward in FIG. 6, hereinafter referred to as a supply direction), and further, the oil chamber at the right end in the drawing. It is pressed in the non-supply direction by the hydraulic pressure input to 73e.

  The oil chamber 73 e at the right end of the regulator valve 73 can be connected to the pump oil passage 72 via a pilot oil passage 76 and a switching control valve 77. The switching control valve 77 is constituted by an electromagnetic three-way valve controlled by the ECU 45 (hydraulic control means 48). When the ECU 45 energizes the solenoid 77a of the switching control valve 77, the pump oil path 72 is connected to the pilot oil path 76. Then, the hydraulic pressure of the pump oil passage 72 is input to the oil chamber 73e. The switching control valve 77 disconnects the connection between the pump oil passage 72 and the pilot oil passage 76 when the ECU 45 stops energizing the solenoid 77a, connects the pilot oil passage 76 to the drain port 77b, and opens the oil chamber 73e to the atmosphere. To do.

  The pilot oil passage 76 is connected to the brake control valve 74 together with the oil chamber 73e, and the switching control valve 77 connects the pump oil passage 72 to the pilot oil passage when the ECU 45 energizes the solenoid 77a of the switching control valve 77. 76, the brake control valve 74 is opened, and the pump oil passage 72 and the brake oil passage 75 are communicated with each other. In addition, the switching control valve 77 disconnects the connection between the pump oil passage 72 and the pilot oil passage 76 when the ECU 45 stops energizing the solenoid 77a, and closes the brake control valve 74 so that the pump oil passage 72 and the brake oil passage are closed. And 75.

  A low pressure passage 78 is connected to the supply port 73 b of the regulator valve 73. The oil flowing through the low-pressure passage 78 is supplied to each part of the drive device 1, for example, the electric motors 2A and 2B, the planetary gear type speed reducers 12A and 12B, and the bearings through a plurality of branch passages (not shown). Used as a lubricating oil.

  The pump oil passage 72 is connected to a relief valve 79b for releasing the hydraulic pressure when the line pressure becomes abnormally high.

  Here, the ECU 45 is a control device for performing various controls of the entire vehicle. As shown in FIG. 2, the ECU 45 estimates the traveling state of the vehicle from the vehicle speed, the steering angle, the accelerator pedal opening AP, and the like. 46, torque calculating means 47 for calculating the torque of the two electric motors 2A and 2B, hydraulic control means 48 for controlling the hydraulic brakes 60A and 60B from the running state of the vehicle estimated by the running state estimating means 46, the electric motor 2A, At the time of failure to release the hydraulic brakes 60A and 60B by setting the set hydraulic pressure of the regulator valve 73 to the low pressure hydraulic pressure PL when a high voltage system control unit (inverter, booster, etc., not shown) that controls the motor 2A or 2B or 2B fails. Corresponding means 49 is provided, and the vehicle speed, steering angle, accelerator pedal opening AP, shift position, SOC, etc. are input to the ECU 45. From the ECU 45, a signal for controlling the engine 6, a signal for controlling the electric motors 2 </ b> A and 2 </ b> B, a signal indicating the power generation state / charge state / discharge state of the battery 9, the solenoid 74 a of the brake control valve 74 and the solenoid of the switching control valve 77. A control signal to 77a is output.

Next, the operation of the hydraulic circuit 71 of the drive device 1 will be described.
FIG. 6 shows a state of the hydraulic circuit 71 in a state where the hydraulic brakes 60A and 60B are released. At this time, the electric oil pump 70 is operated in the low pressure mode, and the ECU 45 deenergizes the solenoid 77a of the switching control valve 77, disconnects the connection between the pump oil passage 72 and the pilot oil passage 76, and the pilot oil passage 76. Is connected to the drain port 77b. At this time, the pump oil passage 72 and the supply port 73b communicate with each other, the brake oil passage 75 is connected to the drain port 74b, and the pump oil passage 72 and the brake oil passage 75 are shut off.
The balance formula between the hydraulic pressure and the spring load force in the regulator valve 73 in this state is
PL × A1 = K × δ (1)
From this equation, the pressure of the hydraulic circuit when the hydraulic brakes 60A and 60B are released is
PL = (K × δ) / A1 (2)
Thus, the line pressure of the pump oil passage 72 is maintained at the low pressure oil pressure PL (first oil pressure).
In the above equations (1) and (2),
A1: Pressure receiving area (mm ² ) of the spool 73a in the oil chamber 73d,
PL: Line pressure (N / mm ² ) when the hydraulic brakes 60A and 60B are released,
K: Spring constant of the spring 73c (N / mm),
δ: Deflection allowance of spring 73c (stroke allowance of spool 73a) (mm).

  When engaging the hydraulic brakes 60 </ b> A and 60 </ b> B from the state of FIG. 6, the electric oil pump 70 is operated while being switched to the high pressure mode, and the ECU 45 energizes the solenoid 77 a of the switching control valve 77. To the pilot oil passage 76. As a result, the hydraulic oil of the pump oil passage 72 is input to the oil chamber 73e, and the pump oil passage 72 and the brake oil passage 75 communicate with each other. At this time, the spool 73a of the regulator valve 73 is pressed in the non-supply direction to temporarily shut off the pump oil passage 72 and the supply port 73b.

FIG. 7 shows a state of the hydraulic circuit 71 in a state where the hydraulic brakes 60A and 60B are engaged. When the ECU 45 energizes the solenoid 77a of the switching control valve 77, the pump oil passage 72 and the brake oil passage 75 communicate with each other, and the hydraulic oil is accumulated in the first working chambers of the brake oil passage 75 and the hydraulic brakes 60A and 60B. The spool 73a of the regulator valve 73 pressed in the non-supply direction moves from a state where the pump oil passage 72 and the supply port 73b are temporarily blocked to a state where the pump oil passage 72 and the supply port 73b are communicated with each other. .
The balance formula between the hydraulic pressure and the spring load force in the regulator valve 73 in this state is
PH × A1 = K × δ + PH × A2 (3)
From this equation, the pressure of the hydraulic circuit when the hydraulic brakes 60A and 60B are released is
PH = (K × δ) / (A1−A2) (4)
Thus, the line pressure of the pump oil passage 72 is maintained at the high pressure hydraulic pressure PH (second hydraulic pressure).
As is clear from the equations (2) and (4), the high pressure hydraulic pressure PH is higher than the low pressure hydraulic pressure PL.
In the above equations (3) and (4),
A1: Pressure receiving area (mm ² ) of the spool 73a in the oil chamber 73d,
A2: pressure receiving area (mm ² ) of the spool 73a in the oil chamber 73e,
PH: Line pressure (N / mm ² ) when the hydraulic brakes 60A and 60B are engaged,
K: Spring constant of the spring 73c (N / mm),
δ: Deflection allowance of spring 73c (stroke allowance of spool 73a) (mm).

  In the state where the hydraulic brakes 60A and 60B are engaged, the hydraulic oil decompressed by the relief valve 79a is supplied to the low-pressure passage 78, and each part of the drive device 1 is provided via a plurality of branch passages (not shown). For example, the electric motors 2A and 2B, the planetary gear type speed reducers 12A and 12B, are supplied to the respective bearings and used as cooling oil or lubricating oil.

As described above, in the hydraulic control device of the present embodiment, the ECU 45 connects the pump oil passage 72 to the pilot oil passage 76 by energizing the solenoid 77a when the hydraulic brakes 60A and 60B are engaged. Along with this, the set hydraulic pressure of the regulator valve 73 is switched from the low pressure hydraulic pressure PL to the high pressure hydraulic pressure PH (see the above formulas (2) and (4)). Further, since the pilot oil passage 76 is connected to the brake control valve 74 together with the oil chamber 73e, the brake control valve 74 is opened and the pump oil passage 72 and the brake oil passage 75 are communicated. That is, when the hydraulic brakes 60A and 60B are engaged, the ECU 45 opens the brake control valve 74 in conjunction with switching the set hydraulic pressure of the regulator valve 73 from the low pressure hydraulic pressure PL to the high pressure hydraulic pressure PH, and the pump oil passage 72 and the brake. The oil passage 75 is communicated.
On the other hand, when releasing the hydraulic brakes 60A and 60B, the ECU 45 deenergizes the solenoid 77a, thereby connecting the pilot oil passage 76 to the drain port 77b and opening the oil chamber 73e to the atmosphere. Along with this, the set oil pressure of the regulator valve 73 is switched from the high pressure oil pressure PH to the low pressure oil pressure PL (see the above formulas (2) and (4)). Further, since the pilot oil passage 76 is connected to the brake control valve 74 together with the oil chamber 73e, the brake control valve 74 is closed and the pump oil passage 72 and the brake oil passage 75 are shut off. That is, when the hydraulic brakes 60A and 60B are released, the ECU 45 closes the brake control valve 74 in conjunction with switching the set hydraulic pressure of the regulator valve 73 from the high pressure hydraulic pressure PH to the low pressure hydraulic pressure PL, and the pump oil passage 72 and the brake oil. The path 75 is blocked.
The electric oil pump 70 is operated in a low pressure mode in which the line pressure is the low pressure oil pressure PL when the hydraulic brakes 60A and 60B are open, and the line is operated when the hydraulic brakes 60A and 60B are engaged. The electric oil pump 70 is operated in a high pressure mode in which the pressure becomes the high pressure oil pressure PH.

FIG. 8 is a graph showing load characteristics of the electric oil pump 70.
As shown in FIG. 8, compared with the high pressure mode, the low pressure mode can reduce the power of the electric oil pump 70 to about ¼ to ５ while maintaining the supply flow rate of the hydraulic oil. That is, the load of the electric oil pump 70 is small in the low pressure mode, and the power consumption of the electric motor 80 that drives the electric oil pump 70 can be reduced compared to the high pressure mode.

  Next, the operation of the drive device 1 will be described. 9 to 14 are collinear diagrams in each state, and S and C on the left side are a sun gear 21A of a planetary gear type reduction gear 12A connected to the electric motor 2A, and a planetary carrier 23A connected to the axle 10A, respectively. S and C on the right side are the sun gear 21B of the planetary gear type reduction gear 12B connected to the electric motor 2B, the planetary carrier 23B connected to the axle 10B, R is the ring gears 24A and 24B, BRK is the hydraulic brakes 60A, 60B, and OWC are A one-way clutch 50 is represented. In the following description, the rotation direction of the sun gears 21A and 21B during forward movement is defined as the forward rotation direction. Further, in the figure, from the stationary state, the upper direction is the rotation in the forward direction, the lower direction is the rotation in the reverse direction, and the arrow indicates the torque in the normal direction, and the lower side indicates the torque in the reverse direction.

  FIG. 9 is an alignment chart when the vehicle is stopped. At this time, since the electric motors 2A and 2B are stopped and the axles 10A and 10B are stopped, no torque acts on any of the elements.

  FIG. 10 is a collinear diagram when the vehicle travels forward by the motor torques of the electric motors 2A and 2B of the drive device 1, that is, when the drive device 1 becomes the drive side and the vehicle moves forward. When the electric motors 2A and 2B are driven, torque in the forward rotation direction is applied to the sun gears 21A and 21B. At this time, as described above, the ring gears 24A and 24B are locked by the one-way clutch 50, and a lock torque in the forward direction is applied to the ring gears 24A and 24B that are about to rotate in the reverse direction. As a result, the planetary carriers 23A, 23B rotate in the forward rotation direction and travel forward. Note that the running resistance from the axles 10A and 10B acts in the reverse direction on the planetary carriers 23A and 23B. Thus, when the vehicle is running, the ignition is turned on and the torque of the electric motors 2A and 2B is increased, so that the one-way clutch 50 is mechanically engaged and the ring gears 24A and 24B are locked. The vehicle can be started without engaging 60B. Thereby, the responsiveness at the time of vehicle start can be improved.

  FIG. 11 shows a case where the electric motors 2A and 2B are stopped in a state where the vehicle is traveling forward by the drive unit 6 or pulled in the forward direction by another vehicle or the like, that is, the driving device 1 is on the coast side and the electric motor It is an alignment chart in case 2A and 2B stop. When the electric motors 2A and 2B are stopped from the state shown in FIG. 10, the forward rotation torque from the axles 10A and 10B is applied to the planetary carriers 23A and 23B, so the reverse rotation direction is applied to the ring gears 24A and 24B. The one-way clutch 50 is released by the action of the torque. Accordingly, the ring gears 24A and 24B idle at a higher speed than the planetary carriers 23A and 23B. As a result, when it is not necessary to regenerate with the electric motors 2A and 2B, if the ring gears 24A and 24B are not fixed by the hydraulic brakes 60A and 60B, the electric motors 2A and 2B are stopped and the rotation of the electric motors 2A and 2B is prevented. be able to. At this time, the cogging torque in the forward direction acts on the electric motors 2A and 2B, and the total torque that balances the cogging torque and the friction of the ring gears 24A and 24B becomes the axle loss of the axles 10A and 10B.

  FIG. 12 shows a case where the vehicle is traveling forward by the drive unit 6 and is regenerated by the electric motors 2A and 2B in a natural deceleration state with the accelerator off and a braking deceleration by the brake. It is a collinear diagram in case the motors 2A and 2B are regenerated on the side. When the electric motors 2A and 2B are regenerated from the state of FIG. 10, the forward rotation torque that tries to continue traveling forward from the axles 10A and 10B is applied to the planetary carriers 23A and 23B, and therefore the reverse rotation direction is applied to the ring gears 24A and 24B. The one-way clutch 50 is released by the action of the torque. At this time, by engaging the hydraulic brakes 60A and 60B and applying a reverse rotation lock torque to the ring gears 24A and 24B, the ring gears 24A and 24B are fixed and the electric motors 2A and 2B have a regenerative braking torque in the reverse rotation direction. Works. Thereby, regenerative charging can be performed by the electric motors 2A and 2B.

  FIG. 13 is a collinear diagram when the vehicle travels backward by the motor torque of the electric motors 2A and 2B of the drive device 1, that is, when the drive device 1 moves backward on the drive side. When the motors 2A, 2B are driven in the reverse direction, torque in the reverse direction is applied to the sun gears 21A, 21B. At this time, forward torque acts on the ring gears 24A and 24B, and the one-way clutch 50 is released. At this time, by engaging the hydraulic brakes 60A and 60B and applying a reverse locking torque to the ring gears 24A and 24B, the ring gears 24A and 24B are fixed and the planetary carriers 23A and 23B rotate in the reverse direction and move backward. Driving is done. Note that running resistance from the axles 10A and 10B acts in the forward direction on the planetary carriers 23A and 23B.

  FIG. 14 is a collinear diagram of the drive device 1 on the coast side when the vehicle is traveling backward by the drive unit 6 or being pulled by another vehicle or the like in the backward direction, that is, in backward traveling. At this time, torque in the reverse direction to continue the reverse travel from the axles 10A and 10B acts on the planetary carriers 23A and 23B. Therefore, the ring gears 24A and 24B are locked by the one-way clutch 50 to rotate in the reverse direction. The forward rotation direction lock torque is applied to the ring gears 24A and 24B, and the motors 2A and 2B generate back electromotive force in the forward rotation direction.

Next, specific engagement control of the one-way clutch 50 and the hydraulic brakes 60A and 60B during vehicle travel will be described with reference to FIGS.
FIG. 15A is a collinear diagram of the drive device 1 during high-speed cruise by the drive unit 6 (state of FIG. 11). In this state, as described above, neither the one-way clutch 50 nor the hydraulic brakes 60A and 60B are engaged. When assisting with the electric motors 2A and 2B from this state, the target rotational speeds of the electric motors 2A and 2B are determined according to the rotational speeds of the planetary carriers 23A and 23B, and the rotations of the electric motors 2A and 2B as shown in FIG. The one-way clutch 50 can be engaged and assisted as shown in FIG. 15C by outputting the assist drive torque (power running torque) by the electric motors 2A and 2B in accordance with the target rotational speed (see FIG. 15C). The state of FIG.

  On the other hand, when charging with the electric motors 2A and 2B during high-speed cruise by the drive unit 6 (FIG. 16A), first, the target rotational speeds of the electric motors 2A and 2B are determined according to the rotational speeds of the planetary carriers 23A and 23B. When the rotational speeds of the electric motors 2A and 2B are adjusted to the target rotational speed as shown in FIG. 16 (b) and the rotational speeds become substantially equal as shown in FIG. 16 (c), the hydraulic brakes 60A and 60B are engaged. In addition, by outputting the regenerative braking torque (regenerative torque) with the electric motors 2A and 2B, charging can be performed with the electric motors 2A and 2B as shown in FIG. 16D (state of FIG. 12).

  FIG. 17 shows the state of the electric motors 2A and 2B and the separation mechanism (the one-way clutch 50 and the hydraulic brakes 60A and 60B may be collectively referred to as the separation mechanism hereinafter) and the hydraulic circuit 71 in the traveling state of the vehicle. It is the figure which showed the line pressure. Note that the front means the drive unit 6 that drives the front wheel Wf, the rear means the drive device 1 that drives the rear wheel Wr, ○ means activation (including drive and regeneration), and x means non-operation (stop). Further, the MOT state means the state of the electric motors 2A and 2B of the driving device 1. Furthermore, OWC means the one-way clutch 50, and the brake means the hydraulic brakes 60A and 60B.

  While the vehicle is stopped, the motors 2A and 2B of the drive device 1 are stopped, and the drive unit 6 on the front wheel Wf side and the drive device 1 on the rear wheel Wr side are both stopped, and are separated as described with reference to FIG. The mechanism is also inactive. At this time, the line pressure is regulated by the low pressure oil pressure PL (see FIG. 6).

  Then, after the ignition is turned on, the electric motors 2A and 2B of the driving device 1 for the rear wheel Wr are driven when the EV starts. At this time, as described with reference to FIG. 10, the separation mechanism is locked by the one-way clutch 50, and the power of the electric motors 2A, 2B is transmitted to the axles 10A, 10B. At this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  Subsequently, during acceleration, the four-wheel drive of the drive unit 6 on the front wheel Wf side and the drive device 1 on the rear wheel Wr side is performed, and at this time as well, the separation mechanism is locked by the one-way clutch 50, as described in FIG. The power of the electric motors 2A and 2B is transmitted to the axles 10A and 10B. Also at this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  In the EV cruise in the low / medium speed range, since the motor efficiency is good, the driving unit 6 on the front wheel Wf side is inactive and the driving device 1 on the rear wheel Wr side performs rear wheel driving. Also at this time, as described with reference to FIG. 10, the separation mechanism is locked by the one-way clutch 50, and the power of the electric motors 2A, 2B is transmitted to the axles 10A, 10B. Also at this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  On the other hand, in high-speed cruise in the high speed region, the engine efficiency is good, so that the front wheel drive is performed by the drive unit 6 on the front wheel Wf side. At this time, as described with reference to FIG. 11, the one-way clutch 50 of the separation mechanism is disconnected (OWC free) and the hydraulic brakes 60A and 60B are not operated, so that the electric motors 2A and 2B are stopped. Also at this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  In the case of natural deceleration, as described with reference to FIG. 11, the one-way clutch 50 of the disengagement mechanism is disengaged (OWC free) and the hydraulic brakes 60A and 60B are not operated, so the motors 2A and 2B are stopped. Also at this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  On the other hand, when decelerating and regenerating, for example, when driving by the driving force of the driving unit 6 on the front wheel Wf side, as described with reference to FIG. 12, the one-way clutch 50 of the separation mechanism is disengaged (OWC free). By engaging the brakes 60A and 60B, regenerative charging is performed by the electric motors 2A and 2B. At this time, the line pressure is regulated by the high pressure hydraulic pressure PH (see FIG. 7).

  In normal driving, the motor 2A, 2B regenerates and recovers the traveling energy in cooperation with the vehicle brake braking control. However, when emergency braking is required (ABS operation), the regeneration of the motors 2A, 2B is prohibited and the vehicle brake is disabled. Prioritize. In this case, the one-way clutch 50 is disengaged (OWC free), and the electric motors 2A and 2B are stopped by not operating the hydraulic brakes 60A and 60B. At this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  In the case of reverse travel, the driving unit 6 on the front wheel Wf side stops and the driving device 1 on the rear wheel Wr side is driven to perform rear wheel driving, or the driving unit 6 on the front wheel Wf side and driving on the rear wheel Wr side are driven. The four-wheel drive of the device 1 is performed. At this time, as described with reference to FIG. 13, the electric motors 2A and 2B rotate in the reverse direction, and the one-way clutch 50 of the disengagement mechanism is disengaged (OWC free), but the hydraulic brakes 60A and 60B are engaged. The power of the electric motors 2A and 2B is transmitted to the axles 10A and 10B. At this time, the line pressure is regulated by the high pressure hydraulic pressure PH.

  Further, when towing in the forward direction side (FWD towed), as described with reference to FIG. 11, the one-way clutch 50 of the separation mechanism is disengaged (OWC free) and the hydraulic brakes 60A and 60B are not operated. The electric motors 2A and 2B are stopped. In the case of FWD towing, when regenerating the motors 2A and 2B, the hydraulic brakes 60A and 60B are connected in the same manner as during deceleration regeneration. At this time, the line pressure is regulated by the low pressure hydraulic pressure PL.

  When the motors 2A and 2B cannot be driven due to a high voltage system failure such as a PDU failure, the failure response means 49 deenergizes the solenoid 74a of the brake control valve 74 and the solenoid of the switching control valve 77. The motors 2A and 2B are opened by de-energizing 77a. Then, the front-wheel drive is performed by the drive unit 6 on the front wheel Wf side, so that the one-way clutch 50 is disconnected (OWC-free) as described with reference to FIG. At this time, since the hydraulic brakes 60A and 60B are also opened, the electric motors 2A and 2B are stopped, and the line pressure is regulated by the low pressure hydraulic pressure PL.

FIG. 18 is a timing chart of the drive device 1 and the hydraulic circuit 71 when the vehicle goes straight in the forward direction.
First, by turning on the ignition, the electric motors 2A and 2B are driven, and the electric oil pump 70 (EOP) is activated. At this time, the one-way clutch 50 and the hydraulic brakes 60A and 60B are opened, and the line pressure is set to the low pressure oil pressure PL (state shown in FIG. 9). From this state, when the driver depresses the accelerator with the shift range set to drive (D), the one-way clutch 50 is engaged with the hydraulic brakes 60A and 60B open, and the motor torque is transmitted to the axles 10A and 10B to start EV. Acceleration is performed (state shown in FIG. 10). When the vehicle reaches the high speed range, high speed cruise is performed by the drive unit 6. During this time, the motors 2A and 2B are stopped, the one-way clutch 50 is released together with the hydraulic brakes 60A and 60B, and the line pressure is set to the low pressure oil pressure PL as before (the state of FIG. 11). Subsequently, when the driver steps on the brake and stops while traveling on a high-speed cruise, as shown in FIGS. 16B and 16C, the rotation adjustment control of the electric motors 2A and 2B is performed, and the hydraulic brakes 60A and 60B are Engage. At this time, the line pressure is set to the high pressure oil pressure PH (state shown in FIG. 12). When the vehicle stops, the hydraulic brakes 60A and 60B are released, the line pressure is switched to the low pressure hydraulic pressure PL, and the electric motors 2A and 2B are stopped by turning off the ignition.

FIG. 19 is a timing chart of the drive device 1 and the hydraulic circuit 71 when the vehicle goes straight in the reverse direction.
First, by turning on the ignition, the electric motors 2A and 2B are driven, and the electric oil pump 70 (EOP) is activated. At this time, the one-way clutch 50 and the hydraulic brakes 60A and 60B are opened, and the line pressure is set to the low pressure oil pressure PL (state shown in FIG. 9). When the driver shifts the shift range to reverse (R) from this state, the hydraulic brakes 60A and 60B are engaged. When the driver depresses the accelerator, the motor torque is transmitted to the axles 10A and 10B, and the vehicle starts moving backward and accelerates (state shown in FIG. 13). At this time, the line pressure is set to the high pressure hydraulic pressure PH. When the driver steps on the brake and stops while traveling on a high-speed cruise, the one-way clutch 50 is engaged together with the hydraulic brakes 60A and 60B. At this time, since the hydraulic brakes 60A and 60B are also engaged, the line pressure is set to the high hydraulic pressure PH as before (the state of FIG. 14). When the vehicle is stopped and the shift range is set to parking (P), the hydraulic brakes 60A and 60B are released, the line pressure is switched to the low pressure oil pressure PL, and the electric motors 2A and 2B are stopped by turning off the ignition.

  The case where the vehicle travels straight ahead, that is, the case where there is no rotational difference between the left and right electric motors 2A, 2B has been described so far. Next, with reference to FIGS. 20 and 21, when the vehicle turns, that is, the left and right electric motors 2A A specific engagement control between the one-way clutch 50 and the hydraulic brakes 60A and 60B while the vehicle is traveling when there is a rotational difference between 2B will be described.

  FIG. 20A is a collinear diagram of the drive device 1 when the vehicle turns left during high-speed cruise by the drive unit 6. In this state, the electric motor 2A that drives the left rear wheel LWr rotates in the reverse direction, and the electric motor 2B that drives the right rear wheel RWr rotates in the forward direction. A case will be described in which the rotation difference between the left and right rear wheels LWr, RWr is used to regenerate (charge) with the electric motor 2A that drives the left rear wheel LWr and to perform power driving (assist) with the right rear wheel RWr. At this time, as shown in FIG. 20 (b), the rotational speeds of the electric motors 2A and 2B are determined according to the rotational speeds of the planetary carriers 23A and 23B, respectively, and the target rotational speeds of the electric motors 2A and 2B are determined. As shown, the rotational speeds of the electric motors 2A and 2B are adjusted to the target rotational speed. At this time, the regenerative braking torque (regenerative torque) and the assist driving torque (power running torque) of the electric motors 2A and 2B are calculated. If the regenerative braking torque is large, the hydraulic brakes 60A and 60B are engaged, and if the assist driving torque is large. The one-way clutch 50 is engaged. In FIG. 20C, the one-way clutch 50 is engaged because the assist drive torque of the electric motor 2B that drives the right rear wheel RWr is larger than the regenerative braking torque of the electric motor 2A that drives the left rear wheel LWr. .

  On the other hand, in the state of FIG. 21D, the regenerative braking torque of the electric motor 2A that drives the left rear wheel LWr is larger than the assist driving torque of the electric motor 2B that drives the right rear wheel RWr. The target rotational speeds of the electric motors 2A and 2B are determined according to the rotational speeds of the planetary carriers 23A and 23B, respectively, and the rotational speed is substantially equal to the target rotational speed as shown in FIG. When equal, the hydraulic brakes 60A and 60B are engaged and the regenerative braking torque is output by the electric motors 2A and 2B, so that the electric motor 2A can be charged and the electric motor 2B can assist as shown in FIG. it can.

A control flow of the hydraulic control device of the drive device 1 will be described with reference to FIG.
First, in step S01 shown in FIG. 22, the state of the vehicle (vehicle speed, steering angle, accelerator pedal opening AP) is detected. Next, in step S02, it is determined from the state of the vehicle whether the driving of the electric motors 2A, 2B of the driving device 1 is necessary by the traveling state estimating means 46.

  As a result, if there is no drive request, the series of processing ends (step S03). If there is a drive request in step S03, then in step S04, it is detected whether the vehicle is turning. As a result, if the vehicle is turning, the required torques Tlmr and Trmr of the left and right electric motors 2A and 2B are calculated from the running state by the torque calculating means 47 in step S05. Subsequently, in step S06, the required torques Tlmr and Trmr are set to the instruction torques Tlm and Trm. At this time, the assist driving torque has a positive value, and the regenerative braking torque has a negative value. In step S07, the sum of the command torques Tlm and Trm of the left and right motors 2A and 2B is calculated. When the sum of the command torques Tlm and Trm is positive, that is, when the assist drive torque is greater than the regenerative braking torque, Since the direction clutch 50 is automatically engaged, a series of processing is terminated. On the other hand, when the sum of the command torques Tlm and Trm is negative in step S07, that is, when the regenerative braking torque is greater than the assist drive torque, the hydraulic brakes 60A and 60B are used to connect the left and right motors 2A and 2B to the axles 10A and 10B. Are engaged (step S08).

  Further, when the vehicle is not turning at step S04, that is, when the vehicle is traveling straight ahead, the required torque Tmr of the left and right electric motors 2A, 2B is calculated from the traveling state at step S09. During straight traveling, the required torque values of the left and right motors 2A, 2B have the same value as described above. Subsequently, in step S10, it is detected whether or not the assist drive is performed. If it is assist driving, the one-way clutch 50 is automatically engaged. On the other hand, if it is not assist driving in step S10, that is, if regenerative braking is used, the left and right motors 2A, 2B and the axles 10A, 10B are connected. Therefore, the hydraulic brakes 60A and 60B are engaged (step S11). In step S12, the required torque Tmr is set to the instruction torque Tm.

FIG. 23 is a driving force characteristic diagram during forward travel (FWD drive), forward travel regeneration (FWD regeneration), and reverse travel (RVS drive) by the electric motors 2A and 2B of the drive device 1. In the figure, the upper right represents the axle torque during forward travel (FWD drive), the lower right represents the axle torque during forward travel regeneration (FRD regeneration), and the upper left represents the axle torque during reverse travel (RVS drive).
As shown in FIG. 23, the axle torque at the time of FWD regeneration and RVS driving in the drive device 1 is set lower than the axle torque at the time of FWD driving. As a result, during FWD regeneration and RVS driving, braking is performed by the hydraulic brakes 60A and 60B as described with reference to FIGS. 12 and 13. However, since the regenerative braking torque and reverse torque are set low, the brake capacity is reduced. Since it is low, the fixed plates 35A and 35B and the rotating plates 36A and 36B can be reduced, and the pump loss can be reduced by setting the low hydraulic pressure.

  As described above, according to the control device of the drive device 1 according to the present embodiment described above, when the hydraulic brakes 60A and 60B are engaged to transmit the power in the direction in which the one-way clutch 50 is released, the ECU 45 Since the brake control valve 74 is opened and the pump oil passage 72 and the brake oil passage 75 are communicated with each other when the set oil pressure is switched from the low pressure oil pressure PL to the high pressure oil pressure PH, the motor is electrically driven only when the hydraulic brakes 60A and 60B are engaged. Since the oil pump 70 only needs to be operated in the high pressure mode, the frequency of operation of the electric oil pump 70 in the high pressure mode can be reduced and the power consumption of the electric oil pump 70 can be reduced compared to the case where the oil pump 70 is always operated in the high pressure mode. it can. In addition, the hydraulic brake can be engaged and released without requiring complicated control.

  The one-way clutch 50 is set so as to be engaged when the motors 2A and 2B are driven by power while the vehicle is traveling forward, and to be disengaged when the motor is regenerated. When 50 is engaged, the set oil pressure is set to the low pressure oil pressure PL, the pump oil passage 72 and the brake oil passage 75 are shut off, and the hydraulic brakes 60A and 60B are opened. The clutch 50 is engaged, and there is no need to engage the hydraulic brakes 60A and 60B. Thereby, the responsiveness at the time of start can be improved and the electric oil pump 70 can be avoided from operating in the high pressure mode in a state where the oil temperature is low.

  Here, the one-way clutch 50 is set so as to be engaged when the motors 2A and 2B are driven to assist during forward traveling of the vehicle and to be disengaged when regenerative braking is performed. The frequency with which 60A and 60B are engaged can be lowered. Therefore, in most of the normal running of the vehicle, the line pressure is regulated by the low pressure oil pressure PL, and thereby the power consumption of the electric oil pump 70 can be significantly reduced. In the case where the electric oil pump 70 is an electric motor with a brush, brush wear can be reduced and the life can be extended.

  Further, the EUC 45 is configured to set the set hydraulic pressure to the high pressure hydraulic pressure PH when the vehicle is traveling forward and the motors 2A and 2B are regenerating, or when the vehicle is traveling backward and the motors 2A and 2B are assisted. 72 and the brake oil passage 75 are communicated and the hydraulic brakes 60A and 60B are engaged, so that the hydraulic brakes 60A and 60B can be reliably engaged when necessary, and the one-way clutch 50 is not engaged. Even if it exists, the motive power transmission between electric motor 2A, 2B and axle 10A, 10B can be performed reliably.

  Further, the ECU 45 sets the oil pressure to the low pressure oil pressure PL and the pump oil passage 72 and the brake oil passage 75 when a control unit (inverter, booster, etc., not shown) that controls the electric motors 2A, 2B or the electric motors 2A, 2B fails. Since the failure response means 49 that shuts off and opens the hydraulic brakes 60A and 60B is provided, it is possible to prevent the hydraulic brakes 60A and 60B from being engaged and the electric motors 2A and 2B being forcibly brought in at the time of failure. .

  The electric motor is composed of electric motors 2A and 2B arranged on the left and right in the vehicle width direction, the reduction gear is composed of planetary gear type reduction gears 12A and 12B arranged on the left and right in the vehicle width direction, and the power of the electric motor 2A is The left and right wheels RWr, LWr are transmitted to the left wheel drive shaft 10A via the planetary gear speed reducer 12A and the power of the electric motor 2B is transmitted to the right wheel drive shaft 10B via the planetary gear speed reducer 12B. Can be controlled independently to improve steering stability (turning). In addition, compared with the case where turning performance is improved with one electric motor and two friction materials, loss due to heat generation due to slip control of the friction material can be suppressed. For example, the optimum specification when mounted on a hybrid vehicle can do.

  The hydraulic brake includes a hydraulic brake 60A connected to the ring gear 24A of the planetary gear speed reducer 12A and a hydraulic brake 60B connected to the ring gear 24B of the planetary gear speed reducer 12B. Since the hydraulic brakes 60A and 60B communicate with each other, the ring gears 24A and 24B can be reliably locked by engaging the hydraulic brakes 60A and 60B.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
The drive device 1 of the present embodiment is configured such that the two electric motors 2A and 2B are respectively provided with planetary gear speed reducers 12A and 12B, and control the left rear wheel LWr and the right rear wheel RWr. The present invention is not limited to this, and as shown in FIG. 24, one electric motor 2C and one speed reducer 12C may be connected to a differential device (not shown). In FIG. 24, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

DESCRIPTION OF SYMBOLS 1 Drive device 2A Electric motor (1st electric motor)
2B electric motor (second electric motor)
10A axle (left wheel drive shaft, drive shaft)
10B Axle (right wheel drive shaft, drive shaft)
11 Reduction gear case 12A Planetary gear type reduction gear (first planetary gear type reduction gear, reduction gear)
12B planetary gear reducer (second planetary gear reducer, reducer)
16A cylindrical shaft (output shaft)
16B cylindrical shaft (output shaft)
24A ring gear 24B ring gear 45 ECU (control means)
46 Traveling state estimating means 47 Torque calculating means 48 Hydraulic control means (control means)
49 Failing response means 50 One-way clutch (one-way power transmission means)
60A hydraulic brake (first brake)
60B Hydraulic brake (second brake)
70 Electric oil pump 72 Pump oil passage 73 Regulator valve 73f Switching mechanism 74 Brake control valve 75 Brake oil passage 77 Switching control valve Wf Front wheel LWr Left rear wheel RWr Right rear wheel PL Low pressure hydraulic pressure (first hydraulic pressure)
PH High pressure oil pressure (2nd oil pressure)

Claims (6)

An electric motor that outputs driving force;
A speed reducer disposed between an output shaft of the electric motor and a drive shaft connected to a wheel;
A speed reducer case that houses the electric motor and the speed reducer;
Unidirectional power transmission means disposed on a transmission path from the electric motor to the drive shaft, and transmitting unidirectional rotational power of the electric motor to the drive shaft;
A hydraulic brake capable of connecting and disconnecting between a part of the reduction gear and the reduction gear case, and capable of transmitting bidirectional rotational power of the electric motor to the drive shaft in a connected state;
An electric oil pump that supplies oil of a predetermined pressure to the hydraulic brake;
A regulator valve provided between the hydraulic brake and the electric oil pump and having a switching mechanism capable of switching a set oil pressure to a first oil pressure and a second oil pressure higher than the first oil pressure;
A brake control valve for communicating / blocking a pump oil passage connected to the regulator valve and a brake oil passage connected to the hydraulic brake;
A switching control valve for switching the set hydraulic pressure of the regulator valve and controlling communication / cutoff of the brake control valve;
When the hydraulic brake is engaged to transmit the power in the opening direction of the one-way power transmission means, the brake is interlocked with switching the set hydraulic pressure of the regulator valve from the first hydraulic pressure to the second hydraulic pressure. When the control valve is opened to connect the pump oil passage and the brake oil passage and the hydraulic brake is released, the set hydraulic pressure of the regulator valve is interlocked with switching from the second hydraulic pressure to the first hydraulic pressure. Control means for closing the brake control valve to shut off the pump oil passage and the brake oil passage;
A hydraulic control device for a drive device comprising: The one-way power transmission means is set so as to be engaged when the vehicle is traveling forward and when the electric power is driven, and disengaged when regenerating.
The control means sets a set oil pressure to the first oil pressure when the unidirectional power transmission means is engaged, shuts off the pump oil passage and the brake oil passage, and opens the hydraulic brake. Item 2. A hydraulic control device for a drive device according to Item 1.   The control means sets the set hydraulic pressure to the second hydraulic pressure when the vehicle is traveling forward and the motor is regenerating, or when the motor is traveling backward and the power is driven. The hydraulic control device for a drive device according to claim 2, wherein the hydraulic brake is engaged by communicating a road and the brake oil passage.   The control means corresponds to a failure time when the set hydraulic pressure is set to the first hydraulic pressure, the pump oil passage and the brake oil passage are shut off, and the hydraulic brake is released when the electric motor or a control unit controlling the electric motor fails. The hydraulic control device for a drive device according to any one of claims 1 to 3, further comprising means. The electric motor is composed of first and second electric motors arranged on the left and right in the vehicle width direction,
The speed reducer is composed of first and second planetary gear speed reducers arranged on the left and right in the vehicle width direction,
The power of the first electric motor is transmitted to the left wheel drive shaft through the first planetary gear reducer,
The power of the second electric motor is transmitted to the right wheel drive shaft through the second planetary gear type reduction gear.
The hydraulic control device for a drive device according to any one of claims 1 to 4, wherein the hydraulic control device is a drive device. The hydraulic brake includes: a first hydraulic brake connected to a ring gear of the first planetary gear reducer; and a second hydraulic brake connected to a ring gear of the second planetary gear reducer. Configured,
6. The hydraulic control device for a drive device according to claim 5, wherein the brake fluid passage communicates with the first hydraulic brake and the second hydraulic brake.

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