JP2007177983A - Drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly recover a drive force from a slippage if the slippage occurs on a wheel. <P>SOLUTION: This first drive device 10 is mounted on a vehicle and drives it. The first drive device 10 comprises: a main pump 15 discharging a hydraulic oil; a first hydraulic motor 14L and a second hydraulic motor 14R driven by the hydraulic oil f1 discharged from the main pump 15; and a first hydraulic oil passage 18A and a second hydraulic oil passage 18B allowing the main pump 15 to communicate with the first and second hydraulic motors 14L, 14R. A first relief valve 19A is installed in the first hydraulic oil passage 18A, and a second relief valve 19B is installed in the second hydraulic oil passage 18B. If the slippage occurs on the wheel of the vehicle, the difference between the pressures at the inlet and outlet of each of the first hydraulic motor 14L and the second hydraulic motor 14R is reduced, or the pressures at the inlet and outlet of each of the first hydraulic motor 14L and the second hydraulic motor 14R are inverted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive device that transmits a driving force by a power transmission fluid and that can distribute the driving force to a plurality of driving wheels.

  2. Description of the Related Art A hydraulic drive device that drives a hydraulic motor by a hydraulic pump and thereby drives a vehicle wheel is known. For example, Patent Literature 1 discloses a hydraulic auxiliary drive device including an auxiliary hydraulic pump driven by an electric motor in order to ensure the hydraulic pressure of a hydraulic circuit of a main hydraulic pump.

Japanese Patent Laid-Open No. 9-315170

  However, the mechanism disclosed in Patent Document 1 does not mention the case where the behavior of the vehicle is disturbed due to wheel slip, and there is room for improvement in the control of the driving device in such a case.

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a driving device capable of quickly recovering the driving force from the slip when the wheel slips.

  In order to achieve the above-described object, the present invention is a drive device that is mounted on a vehicle and drives the vehicle, and includes a power transmission fluid supply unit that sucks and discharges a power transmission fluid, and the power transmission fluid supply A power conversion means that takes in the power transmission fluid discharged from the means and converts the energy of the power transmission fluid into a driving force of the driving device; and a power transmission fluid that connects the power transmission fluid supply means and the power conversion means Pressure adjustment that is provided in the passage and makes the differential pressure between the inlet side and the outlet side of the power transmission fluid in the power conversion means smaller than before the slip occurs when slip occurs in the wheel of the vehicle Means.

  The drive device according to the present invention reverses the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid in the power conversion means with respect to before the occurrence of the slip when the slip occurs on the wheel. As a result, when a slip occurs on the wheel, the driving force can be quickly recovered from the slip.

  The following present invention is a drive device that is mounted on a vehicle and drives the vehicle, wherein the power transmission fluid supply means sucks and discharges the power transmission fluid, and is discharged from the power transmission fluid supply means. Provided in a power transmission fluid passage that connects the power transmission fluid supply means and the power conversion means; and a power conversion means that takes in the power transmission fluid and converts the energy of the power transmission fluid into a driving force of the driving device; Pressure adjustment means for reversing the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid with respect to before the occurrence of the slip when slip occurs on the wheels of the vehicle. And

  In the drive device according to the present invention, when slip occurs in the wheel, the differential pressure between the inlet side and the outlet side of the power transmission fluid in the power conversion means is made smaller than before the slip occurs. Thereby, when a slip occurs in the wheel, the driving force can be recovered from the slip more quickly.

  The following present invention is a drive device that is mounted on a vehicle and drives the vehicle, wherein the power transmission fluid supply means sucks and discharges the power transmission fluid, and is discharged from the power transmission fluid supply means. Provided in a power transmission fluid passage that connects the power transmission fluid supply means and the power conversion means; and a power conversion means that takes in the power transmission fluid and converts the energy of the power transmission fluid into a driving force of the driving device; When slip occurs on the wheel of the vehicle, the pressure difference between the inlet side and the outlet side of the power transmission fluid in the power conversion means is set to be larger than that before the slip occurs according to the size of the slip. Pressure adjusting means for performing either one of reducing or reversing the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid with respect to before the occurrence of slip; Characterized in that it contains.

  In the drive device according to the present invention, when slip occurs in the wheel, the differential pressure between the inlet side and the outlet side of the power transmission fluid in the power conversion means is changed according to the size of the slip before the slip occurs. Or the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid in the power conversion means are reversed with respect to before the occurrence of the slip. As a result, when a slip occurs on the wheel, the driving force can be quickly recovered from the slip.

  The following present invention is characterized in that, in the present invention, the differential pressure changes according to the magnitude of slip of the wheel.

  Further, the present invention includes a hydraulic circuit pressurizing unit that pressurizes a power transmission fluid in a hydraulic circuit configured to include the power transmission fluid supply unit and the power conversion unit in the present invention, When the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid are reversed, the pressure by which the hydraulic circuit pressurizing means pressurizes the power transmission fluid is made larger than before the occurrence of slip. .

  Further, in the present invention described above, in the present invention, when the pressure adjustment means acts from the power transmission fluid when the pressure exceeding the set pressure is applied, the power transmission fluid is placed outside the power transmission fluid passage. By discharging, the pressure of the power transmission fluid is adjusted to a set value.

  Further, the following present invention provides the power split mechanism for dividing the output of the power generating means into the first output and the second output, a part of the first output, and one of the second outputs. The first power combining means for combining the first power combining means and outputting the driving power as a driving force, the remaining output of the first output combined by the first power combining means, and the first power combining means combined by the first power combining means. Second power combining means for combining the remaining outputs of the two outputs and outputting as a driving force, and the power conversion means is a first power conversion means driven by a part of the second output. And second power conversion means driven by the remaining second output that has driven the first power conversion means, wherein the first power combining means comprises a part of the first output and the first power Combining with a part of the second output outputted through the conversion means, The second power synthesizing means is synthesized by the first power synthesizing means that is output via the second power conversion means and the remaining output of the first output synthesized by the first power synthesizing means. The remaining output of the second output is synthesized.

  The following present invention is the first planetary gear device including a sun gear, a carrier, and a ring gear as constituent elements in the present invention, and the second power synthesizing unit. Is a second planetary gear device comprising a sun gear, a carrier, and a ring gear as components, wherein the power split mechanism sends the first output to one of the carrier, the sun gear, or the ring gear. Transmitting the second output to one of the remaining components, and the first output and the second output of the sun gear, the carrier, or the ring gear included in the first planetary gear device. A first drive shaft that is attached to a part other than the one that is transmitted, and the sun gear, the carrier, or the ring gear included in the second planetary gear device, First output and the second output is characterized in that it is configured to include a second drive shaft which is mounted in addition to what is transmitted.

  The drive device according to the present invention can quickly recover the driving force from the slip when the wheel slips.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  The present invention can be applied to a drive device using an internal combustion engine as power generation means, a so-called hybrid drive device combining an electric motor and a heat engine, or a so-called drive device using an electric motor as power generation means. Further, in the following description, the case where the present invention is applied to a passenger car, a truck, a bus, and other vehicles is taken as an example, but the application target of the present invention is not limited to such a vehicle.

(Embodiment 1)
In this embodiment, when slip occurs in the wheel, the pressure difference between the inlet side and the outlet side of the power transmission fluid in the power conversion means is made smaller than that before the slip occurs, or in the power conversion means. It is characterized in that either the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid are reversed with respect to before the slip occurs. Next, the drive device according to this embodiment will be described in detail.

  FIG. 1 is an explanatory diagram illustrating a configuration of a vehicle on which the drive device according to the first embodiment is mounted. FIG. 2 is an explanatory diagram showing a configuration of a drive device provided in the vehicle of FIG. A vehicle 1 shown in FIG. 1 includes an internal combustion engine 5 that is an output generating means, a first drive device 10 (see FIG. 2 for details), and a second drive device 30. In the vehicle 1, the first front wheel (left front wheel) 3 </ b> L and the second front wheel (right front wheel) 3 </ b> R are driven by the second drive device 30.

  The output shaft 35 of the second drive device 30 and the input shaft 21 of the first drive device 10 are connected by the propeller shaft 20, and the output of the internal combustion engine 5 is transmitted to the first drive means 10 as necessary. The Accordingly, the first driving device 10 drives the first rear wheel (left rear wheel) 2L and the second rear wheel (right rear wheel) 2R as necessary.

  As described above, in this embodiment, the output of the internal combustion engine 5 is transmitted through at least one of the first drive device 10 and the second drive device 30 to the left rear wheel 2L and the right rear wheel 2R that are wheels of the vehicle 1. , Transmitted to the left front wheel 3L and the right front wheel 3R. Even if the left front wheel 3L and the right rear wheel 3R of the vehicle 1 are driven via the first drive device 10 and the left rear wheel 2L and the right rear wheel 2L of the vehicle 1 are driven via the second drive device 30. Good.

  Here, the left and right concepts are determined based on the traveling direction of the vehicle 1 (the direction of arrow A in FIG. 1). That is, “left” or “left side” refers to the left side with respect to the traveling direction of the vehicle 1 (the direction of arrow A in FIG. 1), and “right” or “right side” refers to the traveling direction of the vehicle 1. Right side (the same shall apply hereinafter).

  The first drive device 10 and the second drive device 30 are controlled by an ECU (Electronic Control Unit) 50. In this embodiment, the outputs of the first drive device 10 and the second drive device 30 are controlled by the accelerator 40p. The opening degree of the accelerator 40p is detected by the accelerator opening degree sensor 40 and is taken into the ECU 50. The output of the internal combustion engine 5 is controlled by a signal from the accelerator opening sensor 40.

  The left rear wheel 2L, the right rear wheel 2R, the left front wheel 3L, and the right front wheel 3R of the vehicle 1 are respectively connected to the left rear wheel speed sensor 45L, the right rear wheel speed sensor 45R, the left front wheel speed sensor 46L, and the right front wheel speed sensor 46R. The rotational speed of the wheel is detected. The rotational speeds of the wheels detected by these sensors are taken into the ECU 50 and used for detecting wheel slip.

  The first drive device 10 and the second drive device 30 are mounted on a vehicle (for example, a passenger car or a bus) 1. The vehicle 1 travels while the second driving device 30 drives the front wheels 3L and 3R during normal traveling. For example, when idling or skidding occurs on the first and second front wheels 3L and 3R, The first driving device 10 drives the first and second rear wheels 2L, 2R. As described above, the vehicle 1 is based on the front wheel drive, and the first and second rear wheels 2L and 2R are driven as necessary to drive all four wheels included in the vehicle 1. Only the first driving device 10 may be used to drive only the rear wheels 2L, 2R of the vehicle 1 or only the front wheels 3L, 3R of the vehicle 1 may be driven. Next, the configuration of the first drive device 10 will be described.

  The first drive device 10 includes a power split mechanism 16 that splits the output of the internal combustion engine 5 that is input to the input shaft 21 via the propeller shaft 20 into a first output Fe1 and a second output Fe2, and a planetary gear train. The first planetary gear unit (first power combining unit) 11L and the second planetary gear unit (first power combining unit) 11R are provided. The first drive device 10 transmits the first output Fe1 of the internal combustion engine 5 divided by the power split mechanism 16 to the first and second rear wheels 2L and 2R to transmit the first and second rear wheels 2L and 2R. And the driving force transmitted to the first and second rear wheels 2L, 2R is changed by adjusting the size of the second output Fe2.

  The output Fe of the internal combustion engine 5 that is the power generation means, which is input via the input shaft 21 of the first drive device 10, is first input to the power split mechanism 16 and is output to the first output Fe1 and the second output Fe2. Divided. The power split mechanism 16 includes a first output split gear 16GO attached to the input shaft 21, and a second output split gear 16GI attached to the main pump 15 and driving it. With such a configuration, the power split mechanism 16 splits the output Fe of the internal combustion engine 5 into the first output Fe1 and the second output Fe2, and the bevel gear device 22 attached to the input shaft 21 with the split first output Fe1. Output to. The divided second output Fe2 is input to the main pump 15 to drive it.

  The bevel gear device 22 includes a first bevel gear 22O attached to the input shaft 21 and a second bevel gear 22I that meshes with the first bevel gear 22O and transmits the first output Fe1 in a direction orthogonal to the input shaft 21. It is comprised including. The second bevel gear 22I is attached to the axle 23. Here, the axle 23 connects the ring gear 11Lr of the first planetary gear unit 11L and the ring gear 11Rr of the second planetary gear unit 11R. With such a configuration, the first output Fe1 of the power generation means divided by the power split mechanism 16 is transmitted to the left and right rear wheels 2L, 2R, and drives the left and right rear wheels 2L, 2R.

  The power split mechanism 16 may be configured with a chain and a sprocket, or a belt and a pulley. Further, the power split mechanism 16 may be configured to change the power split ratio, for example, by changing the gear ratio. In this way, when the rotational speed of the input shaft 21 is low, it can be accelerated and transmitted to the main pump 15. Therefore, even when the rotational speed of the input shaft 21 is low, the flow rate of the main pump 15 is ensured. be able to.

  With such a configuration, the power split mechanism 16 divides the output Fe of the internal combustion engine 5 into a first output Fe1 and a second output F2. Then, the divided first output Fe1 is output to the first and second planetary gear devices 11L and 11R, and the second output Fe2 is output to the main pump 15 to drive it. The hydraulic oil is discharged from the main pump 15, and the second output Fe2 is converted into the energy of the hydraulic oil. The hydraulic oil discharged from the main pump 15 is supplied to the first hydraulic motor 14L that is the first power conversion means and the second hydraulic motor 14R that is the second power conversion means. As a result, the second output Fe2 is converted into the outputs of the first hydraulic motor 14L and the second hydraulic motor 14R, and the first planetary gear device (first power combining means) 11L and the second planetary gear device (first power combining). (Means) 11R is combined with the first output and becomes the driving force of the first driving device 10.

  The first and second hydraulic motors 14L and 14R are supplied with hydraulic oil as a power transmission fluid from the main pump 15 and generate torque. The first hydraulic motor 14L and the second hydraulic motor 14R are arranged in parallel with the flow of the hydraulic oil fl, and the hydraulic oil fl discharged from the main pump 15 is the first and second hydraulic motors 14L and 14R. To be supplied. The hydraulic oil fl that has passed through the first hydraulic motor 14L and the hydraulic oil fl that has passed through the second hydraulic motor 14R merge and then return to the main pump 15. Thus, in the 1st drive device 10 concerning this embodiment, the main pump 15 and the 1st and 2nd hydraulic motors 14L and 14R constitute the closed hydraulic circuit. The hydraulic oil fl circulates in a closed hydraulic circuit composed of the main pump 15 and the first and second hydraulic motors 14L and 14R.

  In this embodiment, in the hydraulic circuit, the power transmission medium is not limited to oil, and the power of the internal combustion engine 5 or the like as power generation means can be transmitted to the first and second hydraulic motors 14L and 14R as power conversion means. Can be used as a power transmission fluid. The power transmission fluid flowing through the hydraulic circuit is not necessarily hydraulic fluid. That is, although it is a hydraulic circuit, the power transmission fluid which flows through a hydraulic circuit does not necessarily need to be hydraulic fluid. As the power transmission fluid, for example, an incompressible fluid such as oil or water is preferable.

  The hydraulic oil fl may be supplied to the first and second hydraulic motors 14L and 14R by a main pump corresponding to each of the first hydraulic motor 14L and the second hydraulic motor 14R. In this case, the first hydraulic motor 14L and one main pump constitute a closed hydraulic circuit, and the second hydraulic motor 14R and the other main pump constitute a closed hydraulic circuit.

  The axle 23 of the first drive device 10 connects the ring gear 11Lr of the first planetary gear device 11L and the ring gear 11Rr of the second planetary gear device 11R. With such a configuration, the first output Fe1 of the power generation means divided by the power split mechanism 16 is transmitted to the ring gear 11Lr of the first planetary gear device 11L and the ring gear 11Rr of the second planetary gear device 11R via the axle 23. The

  The first drive shaft 12L of the first drive device 10 is attached to the carrier 11Lc of the first planetary gear device 11L. The left rear wheel 2L is attached to the first drive shaft 12L. The second drive shaft 12R of the first drive device 10 is attached to the carrier 11Rc of the second planetary gear device 11R. The right rear wheel 2R is attached to the second drive shaft 12R.

  A first gear 13L is attached to the sun gear 11Ls of the first planetary gear unit 11L. The first gear 13L meshes with a first motor gear 14GL attached to an output shaft (first motor output shaft) 14SL of a first hydraulic motor 14L serving as first driving force adjusting means. As a result, the second output Fm2 of the electric motor 4 is converted into the output of the first hydraulic motor 14L and then transmitted to the sun gear 11Ls of the first planetary gear unit 11L via the first gear 13L and the first motor gear 14GL. .

  A second gear 13R is attached to the sun gear 11Rs of the second planetary gear unit 11R. The second gear 13R meshes with the second motor gear 14GR attached to the output shaft (second motor output shaft) 14SR of the second hydraulic motor 14R serving as the second driving force adjusting means. As a result, the second output Fm2 of the electric motor 4 is converted into the output of the second hydraulic motor 14R, and then transmitted to the sun gear 11Rs of the second planetary gear unit 11R via the second gear 13R and the second motor gear 14GR. .

  With the above configuration, in the first drive device 10 according to this embodiment, the first hydraulic motor 14L, which is the first drive force adjusting means, is part of the second output Fe2 of the internal combustion engine 5 divided by the power split mechanism 16. The second hydraulic motor 14R, which is the second driving force adjusting means, is driven by the remaining second output that is driven and drives the first hydraulic motor 14L. Then, the output of the first hydraulic motor 14L and the part of the first output Fe1 of the internal combustion engine 5 divided by the power split mechanism 16 are combined by the first planetary gear unit 11L which is the first power combining means, The second planetary gear unit 11R synthesizes the output of the second hydraulic motor 14R and the remaining output of the first output synthesized by the first planetary gear unit 11L.

  That is, the first drive device 10 according to this embodiment combines a part of the first output Fe1 and a part of the second output Fe2 by the first planetary gear device 11L and outputs it as a driving force. Further, the first drive device 10 according to this embodiment includes the remaining output of the first output Fe1 synthesized by the first planetary gear device 11L and the remaining output of the second output Fe2 synthesized by the first planetary gear device 11L. Are combined by the second planetary gear unit 11R and output as a driving force. Accordingly, the first and second planetary gear devices 11L and 11R are attached to the first and second planetary gear devices 11L and 11R by adjusting the size of the divided second output Fe1 via the first and second hydraulic motors 14L and 14R. The driving force of the second drive shafts 12L and 12R can be controlled.

  Here, in the above example, the first output Fe1 of the internal combustion engine 5 is transmitted to the ring gear of the planetary gear device, the second output Fe2 is transmitted to the sun gear of the planetary gear device, and the first and second drive shafts 12L , 12R are attached to the carrier of the planetary gear set. However, the transmission targets of the first output Fe1 and the second output Fe2 and the mounting targets of the first and second drive shafts 12L and 12R are not limited to the above example. That is, the first output Fe1 is transmitted to any one of the carrier, the sun gear, or the ring gear of the planetary gear device, the second output Fe2 is transmitted to the other one, and the driving shaft transmits the driving force to the wheels. May be attached to a carrier, a sun gear, or a ring gear other than the one that transmits the first output Fe1 and the second output Fe2.

  In the first drive device 10 according to this embodiment, when the output of the internal combustion engine 5 is input via the input shaft 21, the first hydraulic motor 14L and the second hydraulic pressure are generated using the divided second output Fm2. An output is generated in the motor 14R. In this way, the reaction force of the driving force generated by the first output Fe1 of the internal combustion engine 5 can be received by the first hydraulic motor 14L and the second hydraulic motor 14R. As a result, the first drive device 10 generates drive force on the first drive shaft 12L and the second drive shaft 12R, and drives the left rear wheel 2L and the right rear wheel 2R.

  Further, by changing the output (torque) of the first hydraulic motor 14L and the second hydraulic motor 14R, the driving force of the first drive shaft 12L and the second drive shaft 12R is changed, and the left rear wheel 2L and the right rear wheel are changed. The driving force of 2R can be changed. When the output (torque) generated by the first hydraulic motor 14L and the second hydraulic motor 14R is 0, no driving force is generated on the left rear wheel 2L and the right rear wheel 2R. As described above, the first hydraulic motor 14L and the second hydraulic motor 14R function as driving force adjusting means for adjusting the driving force generated in the first driving shaft 12L and the second driving shaft 12R of the first driving device 10. Have

  The first and second hydraulic motors 14L and 14R included in the first drive device 10 according to this embodiment are piston-type hydraulic motors, and control the torque by changing the angle of the swash plate. It is a hydraulic motor. As shown in FIG. 2, each of the first hydraulic motor 14L and the second hydraulic motor 14R includes a first swash plate 14PL and a second swash plate 14PR. The first swash plate 14PL serves as output changing means (first output changing means) of the first hydraulic motor 14L serving as first driving force adjusting means, and the second swash plate 14PR serves as second driving force adjusting means. It becomes an output changing means (second output changing means) of the hydraulic motor 14R. The first swash plate 14PL and the second swash plate 14PR change the torques of the first hydraulic motor 14L and the second hydraulic motor 14R, respectively.

  The first and 14L second hydraulic motor 14R is not limited to a swash plate type, and a so-called oblique axis type hydraulic motor may be used. Further, the first and 14L second hydraulic motor 14R is not limited to these types, and may be any one that can change the shaft torque of the hydraulic motor. For example, a radial piston type hydraulic motor may be used as the first and 14L second hydraulic motor 14R.

  The main pump 15 is a variable displacement pump, and in this embodiment, a swash plate type axial piston pump is used. The main pump 15 includes a main pump swash plate 15P, and the flow rate of hydraulic oil discharged from the main pump 15 can be changed by adjusting the angle of the main pump swash plate 15P. Thus, the main pump swash plate 15P functions as a flow rate changing means for the main pump 15. The main pump 15 may be of a variable displacement type, and is not limited to a swash plate type axial piston pump. For example, a radial piston type pump can be used for the main pump 15.

  The first swash plate 14PL and the second swash plate 14PR of the first and second hydraulic motors 14L and 14R and the main pump swash plate 15P of the main pump 15 are respectively a first swash plate drive actuator 14AL and a second swash plate drive. The actuator 14AR for driving and the actuator 15A for driving the main pump swash plate are driven. The first swash plate driving actuator 14AL, the second swash plate driving actuator 14AR, and the main pump swash plate driving actuator 15A are controlled by the ECU 50.

  The first drive device 10 according to this embodiment includes a boost pump 17 that is a hydraulic circuit pressurizing unit. The boost pump 17 is a variable displacement pump, similar to the main pump 15, and may be, for example, a swash plate type axial piston pump. The boost pump 17 sucks the hydraulic oil fl from the reservoir tank 17RT, and discharges the sucked hydraulic oil fl to the hydraulic circuit composed of the main pump 15 and the first and second hydraulic motors 14L and 14R, Pressurize supplementarily. As a result, the amount of hydraulic fluid fl in the hydraulic circuit can be kept constant even when the hydraulic fluid fl leaks from the seal portions of the main pump 15 and the first and second hydraulic motors 14L and 14R. The air bubbles are prevented from being mixed into the hydraulic oil fl in the hydraulic circuit. Here, the boost pump 17 is driven by a boost pump driving electric motor 25. The boost pump drive motor 25 is controlled by a slip suppression control device 60 in the ECU 50 (see FIG. 1).

  In this embodiment, the main pump 15 and the first and second hydraulic motors 14L and 14R are a first hydraulic fluid passage 18A that is a first output transmission fluid passage and a second hydraulic fluid that is a second output transmission fluid passage. It is connected with the passage 18B. The first hydraulic oil passage 18A is provided with a first relief valve 19A as first pressure adjusting means used for adjusting the pressure of the hydraulic oil in the first hydraulic oil passage 18A. Further, the second hydraulic oil passage 18B is provided with a second relief valve 19B as second pressure adjusting means used for adjusting the pressure of the hydraulic oil in the second hydraulic oil passage 18B. The hydraulic oil ejected from the first and second relief valves 19A and 19B is returned to the reservoir tank 17RT through the first and second return passages 26A and 26B. The hydraulic fluid returned to the reservoir tank 17RT is returned again into the hydraulic circuit by the boost pump 17. Here, the first and second relief valves 19A and 19B, which are pressure adjusting means, cause the hydraulic oil to flow out of the hydraulic circuit when the pressure exceeding the set pressure is applied from the hydraulic oil as the power transmission fluid. discharge. Thus, the pressure in the hydraulic circuit is adjusted to a set value.

  The first and second relief valves 19A and 19B can arbitrarily change the set pressure, that is, the set value (relief pressure set value) of the hydraulic oil discharge pressure (relief pressure). By changing the relief pressure of the first and second relief valves 19A and 19B, the pressure difference (differential pressure) between the inlet side and the outlet side of the hydraulic oil in the first and second hydraulic motors 14L and 14R is changed. Can do.

  The torques of the first and second hydraulic motors 14L and 14R are determined by the differential pressure and the angles of the first swash plate 14PL and the second swash plate 14PR. Therefore, the torque of the first and second hydraulic motors 14L and 14R can be adjusted by changing the pressure difference of the first and second relief valves 19A and 19B to change the differential pressure. Here, the relief pressures of the first and second relief valves 19A and 19B are set by the ECU 50.

  The first hydraulic oil passage 18A is provided with a first pressure sensor 43A as first pressure detection means used for detecting the pressure of the hydraulic oil in the first hydraulic oil passage 18A. The second hydraulic oil passage 18B is provided with a second pressure sensor 43B as second pressure detection means used for detecting the pressure of the hydraulic oil in the second hydraulic oil passage 18B. The detection signals of the first and second pressure sensors 43A and 43B are acquired by the ECU 50 and used for slip suppression control according to this embodiment. Further, in each of the first hydraulic oil passage 18A and the second hydraulic oil passage 18B, the first oil temperature sensor 47A and the second oil used for detecting the temperature (oil temperature) of the hydraulic oil in each hydraulic oil passage. A temperature sensor 47B is attached.

  Thus, the first drive device 10 according to this embodiment uses the power split mechanism 16 that divides the output of the power generation means to output the output of the internal combustion engine 5 as the power generation means to the first output Fe1 and the second output Fe2. And split. The first output Fe1 is output to the first and second drive shafts 12L and 12R via the first and second planetary gear units 11L and 11R, and the driving reaction force by the first output Fe1 is generated by the second output Fe2. receive. Accordingly, the driving force of the first and second drive shafts 12L and 12R can be controlled, and the distribution ratio between the driving force of the first drive shaft 12L and the driving force of the second drive shaft 12R can be changed. Can do. Further, the main pump 15 is driven by the second output Fe2 of the internal combustion engine 5 to generate torque in the first and second hydraulic motors 14L, 14R, and the driving force of the first drive shaft 12L and the drive of the second drive shaft 12R. Since the force is changed, the distribution ratio between the driving force of the first driving shaft 12L and the driving force of the second driving shaft 12R can be changed in a wide range.

  The driving reaction force by the first output Fe1 of the internal combustion engine 5 divided by the power split mechanism 16 drives the main pump 15 by the second output Fe2 of the internal combustion engine 5 split by the power split mechanism 16, and the first And receiving the torque by generating torque in the second hydraulic motors 14L and 14R. Thereby, the power transmission efficiency is improved as compared with the case where the first and second drive shafts 12L and 12R are directly driven by the first and second hydraulic motors 14L and 14R.

  Moreover, the 1st drive device 10 which concerns on this embodiment drives the boost pump 17 with the electric motor 25 for a boost pump drive. Thus, the hydraulic circuit of the first drive device 10 can be pressurized even when the vehicle 1 is stopped. As a result, when it is necessary to generate driving force on the first and second drive shafts 12L and 12R from the start of the vehicle 1, the driving force of the first and second drive shafts 12L and 12R quickly rises. , Improve responsiveness.

  FIG. 3 is a conceptual diagram illustrating a configuration of the slip suppression control device according to the first embodiment. As shown in FIG. 3, the slip suppression control device 60 according to this embodiment is configured to be incorporated in the ECU 50. The ECU 50 includes a CPU (Central Processing Unit) 50p, a storage unit 50m, input and output ports 55 and 56, and input and output interfaces 57 and 58.

  A slip suppression control device 60 according to this embodiment may be prepared separately from the ECU 50 and connected to the ECU 50. In realizing the slip suppression control of the hydraulic circuit according to this embodiment, the slip suppression control device 60 can use the control function for the first drive device 10 and the second drive device 30 provided in the ECU 50. It may be configured.

  The slip suppression control device 60 includes an operating condition determination unit 61, a control parameter setting unit 62, and a hydraulic pressure control unit 63. These are the parts that execute the slip suppression control according to this embodiment. In this embodiment, the slip suppression control device 60 is configured as a part of the CPU 50p configuring the ECU 50.

The CPU 50p and the storage unit 50m are connected via an input port 55 and an output port 56 via buses 54 _{1 to} 54 ₃ . As a result, the operating condition determination unit 61, the control parameter setting unit 62, and the hydraulic pressure control unit 63 constituting the slip suppression control device 60 are configured to exchange control data with each other or to issue commands to one side. The Further, the slip suppression control device 60 can acquire operation control data of the first drive device 10 and the second drive device 30 included in the ECU 50 and use them. Further, the slip suppression control device 60 can interrupt the slip suppression control according to this embodiment into an operation control routine provided in advance in the ECU 50.

  An input interface 57 is connected to the input port 55. The input interface 57 includes a left rear wheel speed sensor 45L, a right rear wheel speed sensor 45R, a left front wheel speed sensor 46L, a right front wheel speed sensor 46R, a vehicle speed sensor 44, a first pressure sensor 43A, a second pressure sensor 43B, Sensors that acquire information necessary for operation control of the first drive device 10 are connected, such as the oil temperature sensor 47A, the second oil temperature sensor 47B, and the like. Signals output from these sensors are converted into signals that can be used by the CPU 50 p by the A / D converter 57 a and the digital input buffer 57 d in the input interface 57 and sent to the input port 55. Thereby, CPU50p can acquire the information required for the driving control of the 1st drive device 10, and the slip suppression control concerning this embodiment.

An output interface 58 is connected to the output port 56. The output interface 58 includes a boost pump driving motor 25, a main pump swash plate driving actuator 15A, a first relief valve 19A, a second relief valve 19B, a first swash plate driving actuator 14AL, and a second swash plate driving actuator. 14AR and other control objects necessary for slip suppression control are connected. The output interface 58 includes control circuits 58 ₁ , 58 _{2 and the} like, and operates the control target based on a control signal calculated by the CPU 50p. With such a configuration, the CPU 50p of the ECU 50 can control the internal combustion engine 4 based on the output signals from the sensors.

  The storage unit 50m stores a computer program including a slip suppression control processing procedure according to this embodiment, a control map, or a control data map used for the slip suppression control according to this embodiment. Here, the storage unit 50m can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a flash memory, or a combination thereof.

  The computer program may be capable of realizing the processing procedure of the slip suppression control according to this embodiment in combination with the computer program already recorded in the CPU 50p. Further, the slip suppression control device 60 may realize the functions of the operating condition determination unit 61, the control parameter setting unit 62, and the hydraulic control unit 63 using dedicated hardware instead of the computer program. Good. Next, the slip suppression control according to this embodiment will be described. In the following description, please refer to FIGS. Note that the slip suppression control according to this embodiment can be realized by the slip suppression control device.

  FIG. 4 is a flowchart illustrating a procedure of first slip suppression control according to the first embodiment. FIG. 5A is a conceptual diagram illustrating a pressure change in the hydraulic circuit when the slip suppression control according to the first embodiment is not used. FIG. 5-2 is a conceptual diagram illustrating a pressure change in the hydraulic circuit when the slip suppression control according to the first embodiment is used. In the slip suppression control, when slip occurs on the wheels (left rear wheel 2L and right rear wheel 2R) driven by the first drive device 10, the first and second hydraulic motors 14L included in the first drive device 10 are provided. The pressure on the side (inlet side) where the hydraulic oil flows into 14R and the pressure on the side (outlet side) where the hydraulic oil flows out are reversed. When the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R are reversed, the hydraulic circuit is pressurized by the boost pump 17 that is a hydraulic circuit pressurizing unit. Thereby, the pressure in the hydraulic circuit at the time of pressure reversal can be changed rapidly.

  Here, the side (inlet side) into which the hydraulic oil flows into the first and second hydraulic motors 14L and 14R is the high pressure side of the hydraulic circuit, and the side from which the main pump 15 discharges the hydraulic oil (discharge side). is there. Further, the side (exit side) from which the hydraulic oil flows out from the first and second hydraulic motors 14L and 14R is the low pressure side of the hydraulic circuit, and is also the side (intake side) from which the main pump 15 sucks the hydraulic oil. . That is, the pressure on the side (inlet side) where the hydraulic oil flows into the first and second hydraulic motors 14L and 14R included in the first drive device 10 and the pressure on the side (outlet side) where the hydraulic oil flows out are reversed. This means that the high pressure side and the low pressure side of the hydraulic circuit included in the first drive device 10 are reversed.

  In the first slip suppression control according to this embodiment, first, it is detected whether or not the operating condition determination unit 61 included in the slip suppression control device 60 is slipping on the wheel of the first drive device 10 (step S101). ). In this embodiment, since the first driving device 10 drives the left rear wheel 2L and the right rear wheel 2R, at least one of the left rear wheel 2L and the right rear wheel 2R driven by the first driving device 10 slips. In this case, the driving condition determination unit 61 determines that slip has occurred in the wheel driven by the first drive device 10. For the wheel slip, for example, the minimum value of the rotational speed of the left front wheel 3L, the right front wheel 3R, the left rear wheel 2L, and the right rear wheel 2R of the vehicle 1 is obtained, and at least one of the left rear wheel 2L and the right rear wheel 2R is obtained. When the deviation between the minimum value and the actual rotational speed exceeds a predetermined allowable value, it is determined that the wheel is slipping.

  When the wheel of the vehicle 1 is not slipping (step S101: No), the differential pressure between the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 is reduced. The method is shifted to a method (a method related to the second slip suppression control) (step S111). The second slip suppression control will be described later. Then, returning to START, the driving condition determination unit 61 continues to monitor the slip of the wheels (here, the left rear wheel 2L and the right rear wheel 2R) provided in the vehicle 1. When the wheels of the vehicle 1 are slipping (step S101: Yes), the operating condition determination unit 60 compares the slip ratio S of the wheels that are slipping with a predetermined first reference slip ratio α ( Step S102). Here, the slip rate S represents the size of the wheel slip, and when the slip rate S is large, the wheel slip increases.

  A method of reversing the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first driving device 10 to recover from the slip (that is, a method related to the first slip suppression control) is as follows. Since the force for recovering from slip (stopping slip) is large, it is possible to recover from slip rapidly. However, a sudden change in driving force may cause a large shock to the vehicle 1 on which the first driving device 10 is mounted, which may cause discomfort to the passenger. Therefore, in this embodiment, when the slip ratio S exceeds a certain reference value (first reference slip ratio α), the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R are calculated. Invert to recover from slip. When slip occurs on the wheel and the slip ratio S is equal to or less than the reference value, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are provided. A method of reducing the differential pressure from the pressure is used.

  When S ≦ α (step S102: No), the wheel has slipped, but the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first driving device 10 Can be determined not to recover from the reverse slip. In this case, a technique for reducing the differential pressure between the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 (a technique related to the second slip suppression control) is used. Used (step S111). The second slip suppression control will be described later.

  If S> α (step S102: Yes), the wheel is slipping and the slip ratio S is large. In such a case, unless the wheel slip is quickly converged and recovered, there is a high possibility that the vehicle 1 falls into a spin, and it can be determined that the urgency of recovering from the slip is high. In such a case, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are reversed to recover from the slip.

  In reversing the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L, 14R included in the first drive device 10 to recover from the slip, the control parameter setting unit 62 of the slip suppression control device 60 is The relief pressure set value is calculated so that the suction side pressure and the discharge side pressure of the main pump 15 are switched (step S103). In the example shown in FIG. 2, before the slip occurs in the left rear wheel 2L or the right rear wheel 2R, the relief pressure of the first relief valve 19A (pressure on the inlet side of the hydraulic motor) is higher than that of the second relief valve 19B. It is set higher than the relief pressure (pressure on the outlet side of the hydraulic motor). In the slip suppression control according to this embodiment, when the wheel slips, the relief pressure of the second relief valve 19B (pressure on the outlet side of the hydraulic motor) is changed to the relief pressure of the first relief valve 19A (inlet of the hydraulic motor). Set higher than (pressure on the side). That is, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first driving device 10 are reversed.

  Thus, the first and second hydraulic motors 14L and 14R are driven by slipping wheels and function as pumps. Then, after reversing the pressure in the hydraulic circuit, hydraulic oil is ejected from the relief valve (particularly the second relief valve 19B set to a high pressure), thereby converting the rotational energy of the slipping wheel into thermal energy. By these actions, the driving torque of the slipping wheel can be quickly reduced, so that the wheel slip can be quickly stopped. Further, since only the relief pressures of the first and second relief valves 19A and 19B are changed, the time from the command of the slip suppression control device 60 until the wheel slip is suppressed is extremely short.

  In reversing the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 when the wheel slips, in this embodiment, for example, the first relief valve 19A is used. Is set to the lowest pressure (approximately 0), and the relief pressure set value of the second relief valve 19B is set to the highest settable pressure. In this way, the high pressure side (the second relief valve 19B side) after the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are reversed. And the low pressure side (the first relief valve 19A side) can be increased, so that the wheel slip can be stopped more quickly.

The relief pressure so that the suction side pressure and the discharge side pressure of the main pump 15 are switched, that is, the inlet side pressure and the outlet side pressure of the first and second hydraulic motors 14L, 14R are reversed. When the set value is calculated (step S103), the hydraulic pressure control unit 63 included in the slip suppression control device 60 sets the discharge pressure of the boost pump 17 that is the hydraulic circuit pressurizing means from the discharge pressure before the slip suppression control is executed. (Step S104). 5A and 5B, the alternate long and short dash line indicates the change in the pressure of the hydraulic oil in the first hydraulic oil passage 18A, and the dotted line indicates the change in the pressure of the hydraulic oil in the second hydraulic oil passage 18B. Before the reversal of pressure, the first hydraulic oil passage 18A is on the high pressure (Ph) side, and the second hydraulic oil passage 18B is on the low pressure (Pl) side. As shown in FIG. 5A, when the discharge pressure of the boost pump 17 is not increased when reversing the pressure in the hydraulic circuit, the inlets of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are used. The time from the start of the reversal of the pressure on the outlet side to the pressure on the outlet side until the reversal ends requires te ₁ -ts.

However, when the discharge pressure of the boost pump 17 is increased from Pl to Pb when the pressure in the hydraulic circuit is reversed as in the slip suppression control according to this embodiment, as shown in FIG. The time from the start of the reversal of the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L, 14R included in the one driving device 10 to the end of the reversal is shortened to te ₂ -ts. The This improves the responsiveness when reversing the pressure in the hydraulic circuit, so that the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 can be quickly increased. As a result, the wheel slip can be quickly converged and recovered.

  In this embodiment, when the discharge pressure of the boost pump 17 is increased, as shown in FIG. However, the discharge pressure of the boost pump 17 is not limited to such a method, and the discharge pressure may gradually change after the discharge pressure of the boost pump 17 reaches the maximum value. Further, the discharge pressure of the boost pump 17 may be gradually increased.

  Next, the operating condition determination unit 61 determines whether or not the oil temperature in the hydraulic circuit included in the first drive device 10 is equal to or higher than a predetermined value (step S105). Here, the higher one of the temperature detected by the first oil temperature sensor 47A or the temperature detected by the second oil temperature sensor 47B is used as the oil temperature. In this way, it is possible to more reliably determine the risk that the oil temperature in the hydraulic circuit will rise excessively. When the oil temperature is lower than the predetermined value (step S105: No), the hydraulic pressure control unit 65 commands the relief pressure set value set in step S103 to the first and second relief valves 19A and 19B. As a result, the required differential pressure is generated in the hydraulic circuit, and the pressure on the inlet side and the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are compared with those before the wheel slips. The pressure is reversed (step S106).

  Next, the hydraulic control unit 65 commands the main pump swash plate driving actuator 15A so that the angle of the main pump swash plate 15P of the main pump 15 is close to 0 (step S107). Thereby, it is possible to suppress the main pump 15 from generating a driving force by the hydraulic oil pumped up from the first and second hydraulic motors 14L and 14R functioning as pumps. As a result, the change in driving force of the wheels can be suppressed, so that the shock caused by the change in driving force can be suppressed.

  When the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R are reversed, the slip of the wheel is suppressed even when hydraulic oil is ejected from the relief valve (particularly the second relief valve 19B). Is done. Here, when the oil temperature in the hydraulic circuit included in the first drive device 10 is high, when the hydraulic oil is easily ejected from the relief valve, the temperature rise of the hydraulic oil is promoted, and the hydraulic circuit included in the first drive device 10 This may affect the durability of the components. For this reason, in this embodiment, when the said oil temperature is more than predetermined value, the quantity of the hydraulic fluid which ejects from a relief valve is suppressed.

  When the oil temperature is equal to or higher than the predetermined value (step S105: Yes), the control parameter setting unit 62 sets the main pump 15 so that the flow rate balance between the main pump 15 and the first and second hydraulic motors 14L and 14R is established. A required swash plate angle θp_S of 15 is calculated (step S108). In this case, the main pump 15 functions as a motor, and the flow rate balance between the main pump 15 and the first and second hydraulic motors 14L and 14R functioning as pumps is excessive from the relief valve (particularly the second relief valve 19B). Set so that no hydraulic oil is ejected. As a result, the amount of hydraulic fluid ejected from the relief valve (particularly the second relief valve 19B) can be suppressed while stopping the slipping of the wheel, so that the temperature rise of the hydraulic oil can be suppressed.

  Next, the hydraulic control unit 65 commands the relief pressure set value set in step S103 to the first and second relief valves 19A and 19B. Then, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are reversed before the wheel slips (step S109).

  Next, the hydraulic control unit 65 commands the required swash plate angle θp_S of the main pump 15 calculated in step S108 to the main pump swash plate driving actuator 15A (step S110). Thus, the swash plate angle of the main pump swash plate 15P is set to the necessary swash plate angle θp_S set in step S108. By such a procedure, the slip of the wheel is stopped, and the amount of hydraulic oil ejected from the first and second relief valves 19A and 19B is suppressed, thereby suppressing the temperature rise of the hydraulic oil. Next, in the second slip suppression control according to this embodiment, that is, in step S111, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 A method for reducing the differential pressure will be described.

  FIG. 6 is a flowchart illustrating a procedure of slip suppression control including second slip suppression control according to the first embodiment. In the following description, a procedure for determining the first slip control and the second slip control will be described. First, the operating condition determination unit 61 included in the slip suppression control device 60 detects whether or not the wheel of the first drive device 10 is slipping (step S201).

  When the wheel of the vehicle 1 is not slipping (step S201: No), it returns to START, and the driving condition determination part 61 monitors the slip of the wheel (here left rear wheel 2L and right rear wheel 2R) with which the vehicle 1 is provided. Continue. When the wheel of the vehicle 1 is slipping (step S201: Yes), the driving condition determination unit 61 compares the slip ratio S of the wheel that is slipping with a predetermined first reference slip ratio α (predetermined) ( Step S202).

  When S> α (step S202: Yes), the wheel is slipping and the slip ratio S is large. In such a case, as described above, since the urgency to recover from the slip is high, the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 are set. The control shifts to the reverse control (first slip suppression control) (step S205).

  When S ≦ α (step S202: No), the driving condition determination unit 61 compares the slip ratio S of the slipping wheel with a predetermined second reference slip ratio β (step S203). Here, α> β, and the second reference slip rate β is set to a slip rate that allows wheel slip. In addition, when detecting a slip of the wheel, if a slip rate smaller than the slip rate β is detected, it may be determined that no slip has occurred on the wheel.

  When S <β (step S203: No), a slip has occurred in the wheel of the vehicle 1, but since this is an allowable range, the slip suppression control is not executed. As a result, energy consumption by the slip suppression control is eliminated, so that fuel consumption can be suppressed and a change in driving force due to the slip suppression control can be avoided.

  If β ≦ S ≦ α (step S203: Yes), the wheel has slipped, but the high pressure side and the opposite side of the hydraulic circuit included in the first drive device 10 are reversed to recover from the slip. It can be determined that it is not about. In this case, by reducing the differential pressure between the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first driving device 10, the driving torque of the wheel on which the slip occurs is reduced. Is decreased (step S204). This allows the wheel to recover from slip. In addition, since the driving force changes more slowly than the method of reversing the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first driving device 10, the vehicle 1 The shock given to can be suppressed. Thereby, the behavior change of the vehicle 1 can be suppressed.

  In this embodiment, in the hydraulic circuit provided in the first drive device 10, the first relief valve 19A is provided on the high pressure side (the discharge side of the main pump 15, the first and second hydraulic motors 14L, 14R The inlet side) and the second relief valve 19B are provided on the low pressure side (the suction side of the main pump 15 and the outlet sides of the first and second hydraulic motors 14L and 14R). In this case, in order to reduce the pressure difference ΔP (= Ph−Pl) between the high pressure side and the low pressure side of the hydraulic circuit included in the first drive device 10, the relief pressure set value Pl_S of the second relief valve 19B is set constant. The relief pressure set value Ph_S of the first relief valve 19A is made lower than before the shift to the slip suppression control. Then, the hydraulic pressure control unit 63 commands the relief pressure set value set in this way to the first and second relief valves 19A and 19B. As a result, the pressure difference ΔP between the pressure on the inlet side and the pressure on the outlet side of the first and second hydraulic motors 14L and 14R included in the first drive device 10 can be reduced.

  Here, the response of the first and second relief valves 19A, 19B is faster than the operation of the first and second swash plates 14PL, 14PR of the first and second hydraulic motors 14L, 14R. Therefore, in order to reduce the driving torque of the wheels, the first and second relief valves 19A, rather than operating the first and second swash plates 14PL and 14PR of the first and second hydraulic motors 14L and 14R, The wheel can be quickly recovered from the slip by changing the relief pressure setting value of 19B.

  Further, the pressure difference ΔP (= Ph−Pl) between the high pressure side and the low pressure side of the hydraulic circuit provided in the first drive device 10 may be set based on the detected wheel slip ratio S. In this case, the relationship between the slip ratio S and the differential pressure ΔP is obtained in advance, and the differential pressure ΔP can be determined based on the result. Further, the differential pressure ΔP may be feedback controlled using the slip ratio S.

  As described above, in the first embodiment, when slip occurs in the wheel, the differential pressure between the inlet side and the outlet side of the power transmission fluid in the power conversion means is made smaller than before the slip occurs. As a result, when a slip occurs on the wheel, the driving force can be quickly recovered from the slip. Further, since the change in the driving force is relatively gradual, it is possible to suppress the change in the behavior of the vehicle when the slip is suppressed. In addition, since the hydraulic circuit provided in the first drive device according to this embodiment maintains the hydraulic oil at a high pressure at all times in order to transmit the drive force, the response of the drive force change is high. Therefore, in the drive device according to this embodiment and the slip suppression control according to this embodiment, the slip suppression control is compared with the case where the output of the power generation means such as the braking device or the internal combustion engine is reduced to suppress the slip. Responsiveness becomes extremely high (the same applies hereinafter).

  In the first embodiment, when slip occurs in the wheel, the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid in the power conversion means are reversed with respect to before the slip occurs. As a result, when a slip occurs on the wheel, the driving force can be quickly recovered from the slip. Further, since the driving force change is large, even when the slip ratio is large (the slip ratio is high), the slip can be quickly suppressed.

  Further, in the first embodiment, when a slip occurs in the wheel, the pressure difference between the inlet side and the outlet side of the power transmission fluid in the power conversion means is changed from before the slip occurs according to the size of the slip. Or the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid in the power conversion means are reversed with respect to before the slip occurs. As a result, when a slip occurs on the wheel, the driving force can be quickly recovered from the slip. In addition, since a suitable one of a plurality of slip suppression controls is selected and executed in accordance with the size of the slip, when the wheel slip is relatively small, a change in vehicle behavior due to excessive slip suppression is suppressed. Can do. In addition, what is equipped with the structure of this embodiment and its modification has the effect | action and effect similar to this embodiment. Further, the configuration of this embodiment and its modification examples can be applied as appropriate in the following embodiments.

(Embodiment 2)
FIG. 7 is an explanatory diagram illustrating a configuration of the first drive device according to the second embodiment. In the second embodiment, another example of a drive device to which the pressurization control of the hydraulic circuit described in the first embodiment can be applied will be described. The first drive device according to the second embodiment includes an electric motor 4 as power generation means, and an output Fm of the electric motor 4 is divided into a first output Fm1 and a second output Fm2 by a power dividing mechanism 16, and The first and second planetary gear units 11L and 11R, which are second power combining means, are combined.

  The first drive device 10a according to the second embodiment includes a power split mechanism 16 that divides the output of the electric motor 4 into a first output Fm1 and a second output Fm2, and a first planetary gear device (first gear) that includes a planetary gear train. (Power combining means) 11L and a second planetary gear unit (first power combining means) 11R. Then, the first drive device 10a transmits the first output Fm1 of the electric motor 4 divided by the power split mechanism 16 to the first and second rear wheels 2L and 2R to transmit the first and second rear wheels 2L and 2R. While driving, the driving force transmitted to the first and second rear wheels 2L, 2R is changed by adjusting the magnitude of the second output Fm2.

  The output Fm of the electric motor 4 is divided into a first output Fm1 and a second output Fm2 by a power dividing mechanism 16 attached to the first electric motor output shaft 4SL of the electric motor 4. The power split mechanism 16 included in the first drive device according to this embodiment includes a first output split gear 16GO and a second output split gear 16GI that meshes with the first output split gear 16GO. The first output split gear 16GO is attached to the first motor output shaft 4SL (may be the second motor output shaft SR) of the motor 4, and the second output split gear 16GI is a power transmission fluid supply means of the main pump 15. Mounted on the input shaft.

  With such a configuration, the power split mechanism 16 divides the output Fm of the electric motor 4 into a first output Fm1 and a second output Fm2. The first output Fm1 of the electric motor 4 divided by the power dividing mechanism 16 is taken out from the first electric motor output shaft 4SL and the second electric motor output shaft 4SR. The first motor output shaft 4SL is connected to the ring gear 11Lr of the first planetary gear device 11L, and the second motor output shaft 4SR is connected to the ring gear 11Rr of the second planetary gear device 11R. Thus, the first output Fm1 of the electric motor 4 is transmitted to the ring gear 11Lr of the first planetary gear device 11L and the ring gear 11Rr of the second planetary gear device 11R via the first and second electric motor output shafts 4SL, 4SR. Further, the second output Fm2 is output to the main pump 15 to drive it. The hydraulic oil is discharged from the main pump 15 and supplied to the first hydraulic motor 14L as the first driving force adjusting means and the second hydraulic motor 14R as the second driving force adjusting means. As a result, the second output Fm2 is converted into the outputs of the first hydraulic motor 14L and the second hydraulic motor 14R.

  With the above configuration, in the first drive device 10a according to this embodiment, the first hydraulic motor 14L, which is the first drive force adjusting means, is driven by a part of the second output Fm2 of the electric motor 4 divided by the power split mechanism 16. Then, the second hydraulic motor 14R as the second driving force adjusting means is driven by the remaining second output that has driven the first hydraulic motor 14L. Then, the output of the first hydraulic motor 14L and the part of the first output Fm1 of the electric motor 4 divided by the power split mechanism 16 are combined by the first planetary gear unit 11L which is the first power combining means, The output of the second hydraulic motor 14R and the remaining output of the first output synthesized by the first planetary gear device 11L are synthesized by the second planetary gear device 11R.

  That is, the first drive device 10a according to this embodiment combines a part of the first output Fm1 and a part of the second output Fm2 by the first planetary gear device 11L and outputs it as a driving force. Further, the first drive device 10a according to this embodiment includes the remaining output of the first output Fm1 synthesized by the first planetary gear device 11L and the remaining output of the second output Fm2 synthesized by the first planetary gear device 11L. Are combined by the second planetary gear unit 11R and output as a driving force. Accordingly, the first and second planetary gear devices 11L and 11R are attached to the first and second planetary gear devices 11L and 11R by adjusting the magnitude of the divided second output Fm1 via the first and second hydraulic motors 14L and 14R. The driving force of the second drive shafts 12L and 12R can be controlled.

  The first drive device 10a according to this embodiment includes a boost pump 17 that is a hydraulic circuit pressurizing unit. The boost pump 17 is provided with a boost pump input gear 17GI that meshes with a boost pump drive gear 17GO attached to the second motor output shaft 4SR (or the first motor output shaft 4SL) of the motor 4. The boost pump 17 is driven by a part of the output of the electric motor 4. That is, the electric motor 4 serves as boost pump driving means.

  The first drive device 10a according to this embodiment sets the main pump swash plate 15P to 0 or the first swash plate 14PL and the second swash plate 14L of the first hydraulic motor 14L when the vehicle on which the vehicle is mounted is stopped. By setting the second swash plate 14PR of the hydraulic motor 14R to 0, the driving force of the first and second drive shafts 12L and 12R can be set to 0. Alternatively, by setting the differential pressure between the high pressure side (the discharge side of the main pump 15) and the low pressure side (the suction side of the main pump 15) of the first hydraulic circuit to 0, the first and second drive shafts 12L, 12R The driving force can be reduced to zero. In order to make the differential pressure between the high pressure side and the low pressure side of the first hydraulic circuit zero, the relief pressure set value of the first relief valve 19A and the relief pressure set value of the second relief valve 19B are made equal.

  If the electric motor 4 is driven in a state where the driving forces of the first and second drive shafts 12L and 12R are set to 0, the boost pump 17 can be driven while the vehicle is stopped. Thereby, even when the vehicle on which the first drive device 10a according to this embodiment is mounted is stopped, the booster pump 17 can be used to pressurize the hydraulic circuit included in the first drive device 10a.

  As described above, since the drive device 10a according to the second embodiment includes the electric motor 4 as power generation means, it can be applied to an electric vehicle or a so-called hybrid vehicle in which an internal combustion engine and an electric motor / generator are combined. Further, even when the slip suppression control described in the first embodiment is applied to the first drive device 10a according to the second embodiment, the same as the case of the first drive device 10 (see FIG. 2) according to the first embodiment. Actions and effects can be obtained.

(Embodiment 3)
8 and 9 are explanatory views showing the first drive device according to the third embodiment. The first driving devices 10c and 10d according to FIGS. 8 and 9 have substantially the same configuration as the first driving device 10 according to the first embodiment (see FIG. 2), but are first driving force adjusting means. The difference is that the first hydraulic motor 14L and the second hydraulic motor 14R as the second driving force adjusting means directly drive the left rear wheel 2L and the right rear wheel 2R. Other configurations are the same as those of the first drive device 10 according to the first embodiment.

  The first drive device 10c shown in FIG. 8 transmits the output of the first hydraulic motor 14L to the left rear wheel 2L via the first drive shaft 12L, and the second hydraulic pressure via the second drive shaft 12R. The output of the motor 14R is transmitted to the right rear wheel 2R. On the other hand, the first drive device 10d shown in FIG. 9 includes a hydraulic motor inside the wheel. The output of the first in-wheel hydraulic motor 14I_L is directly transmitted to the left rear wheel 2L, and the output of the second in-wheel hydraulic motor 14I_R is directly transmitted to the right rear wheel 2R.

  The input shaft 21 is connected with power generation means such as an internal combustion engine or an electric motor. The output of the power generation means is input to the main pump 15 via the input shaft 21 and the power transmission mechanisms 16c and 16d. Drive. The main pump 15 discharges hydraulic oil and drives the first and second hydraulic motors 14L and 14R, or the first and second in-wheel hydraulic motors 14I_L and 14I_R. Further, the boost pump 17 sends hydraulic oil into the hydraulic circuit included in the first driving devices 10c and 10d, and avoids air bubbles from being mixed into the hydraulic oil. When controlling the operation of the first drive devices 10c and 10d according to this embodiment, the slip suppression control according to the above embodiment can be applied.

  As described above, in Embodiment 3, the left rear wheel 2L and the right rear wheel 2R are directly connected by the first hydraulic motor 14L as the first driving force adjusting means and the second hydraulic motor 14R as the second driving force adjusting means. To drive. Thereby, the configuration of the first drive device can be simplified. Moreover, even if the pressurization control of the hydraulic circuit described in the first embodiment is applied to the first driving devices 10c and 10d according to the third embodiment, the first driving device 10 according to the first embodiment (see FIG. 2). The same operation and effect as in the case of can be obtained.

  As described above, the drive device according to the present invention is useful for a drive device including a hydraulic circuit, and is particularly suitable for quickly recovering the drive force from the slip when a slip occurs on the wheel.

It is explanatory drawing which shows the structure of the vehicle carrying the drive device which concerns on Embodiment 1. FIG. It is explanatory drawing which shows the structure of the drive device with which the vehicle of FIG. 1 is provided. It is a conceptual diagram which shows the structure of the slip suppression control apparatus which concerns on Embodiment 1. FIG. 3 is a flowchart illustrating a procedure of first slip suppression control according to the first embodiment. It is a conceptual diagram which shows the pressure change in a hydraulic circuit when not using the slip suppression control which concerns on Embodiment 1. FIG. It is a conceptual diagram which shows the pressure change in a hydraulic circuit at the time of using the slip suppression control which concerns on Embodiment 1. FIG. 5 is a flowchart illustrating a procedure of slip suppression control including second slip suppression control according to the first embodiment. FIG. 6 is an explanatory diagram illustrating a configuration of a first drive device according to a second embodiment. FIG. 10 is an explanatory diagram illustrating a first drive device according to a third embodiment. FIG. 10 is an explanatory diagram illustrating a first drive device according to a third embodiment.

Explanation of symbols

1 vehicle 2L left rear wheel (first rear wheel)
2R right rear wheel (second rear wheel)
3L right front wheel (first front wheel)
3R right front wheel (second front wheel)
5 Internal combustion engine 10, 10c, 10d First drive unit 11L First planetary gear unit 11R Second planetary gear unit 11Lc, 11Rc Carrier 11Ls, 11Rs Sun gear 11Lr, 11Rr Ring gear 12L First drive shaft 12R Second drive shaft 14L First hydraulic pressure Motor 14R Second hydraulic motor 14AL First swash plate drive actuator 14AR Second swash plate drive actuator 14PL First swash plate 14PR Second swash plate 15 Main pump 15A Main pump swash plate drive actuator 15P Main pump swash plate 16 Power Dividing mechanism 17 Boost pump 18A 1st hydraulic fluid passage 18B 2nd hydraulic fluid passage 19A 1st relief valve 19B 2nd relief valve 20 Propeller shaft 21 Input shaft 22 Bevel gear device 23 Axle 25 Boost pump drive motor 35 Out Axis 40 Accelerator opening sensor 43A First pressure sensor 43B Second pressure sensor 45R Right rear wheel speed sensor 45L Left rear wheel speed sensor 46R Right front wheel speed sensor 46L Left front wheel speed sensor 47A First oil temperature sensor 47B Second oil temperature sensor 60 Slip Suppression Control Device 61 Operating Condition Determination Unit 62 Control Parameter Setting Unit 63 Hydraulic Control Unit

Claims (8)

A drive device that is mounted on a vehicle and drives the vehicle,
Power transmission fluid supply means for sucking and discharging the power transmission fluid;
Power conversion means for taking in the power transmission fluid discharged from the power transmission fluid supply means and converting the energy of the power transmission fluid into driving force of the driving device;
Provided in a power transmission fluid passage connecting the power transmission fluid supply means and the power conversion means, and when slip occurs in the wheels of the vehicle, the power transmission fluid inlet side and outlet of the power conversion means Pressure adjusting means for making the differential pressure with the side smaller than before the occurrence of slip;
A drive device comprising: A drive device that is mounted on a vehicle and drives the vehicle,
Power transmission fluid supply means for sucking and discharging the power transmission fluid;
Power conversion means for taking in the power transmission fluid discharged from the power transmission fluid supply means and converting the energy of the power transmission fluid into driving force of the driving device;
Provided in a power transmission fluid passage connecting the power transmission fluid supply means and the power conversion means, and when slip occurs in the wheel of the vehicle, the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid And pressure adjusting means for reversing the state before slip occurs,
A drive device comprising: A drive device that is mounted on a vehicle and drives the vehicle,
Power transmission fluid supply means for sucking and discharging the power transmission fluid;
Power conversion means for taking in the power transmission fluid discharged from the power transmission fluid supply means and converting the energy of the power transmission fluid into driving force of the driving device;
Provided in a power transmission fluid passage connecting the power transmission fluid supply means and the power conversion means, and when a slip occurs in the wheel of the vehicle, in the power conversion means according to the size of the slip The pressure difference between the inlet side and the outlet side of the power transmission fluid is made smaller than before the occurrence of slip, or the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid is reduced before the slip occurs. Pressure adjusting means for performing any one of reversing with respect to
A drive device comprising:   The drive device according to claim 1 or 3, wherein the differential pressure changes according to the magnitude of slip of the wheel. A hydraulic circuit pressurizing unit that pressurizes a power transmission fluid in a hydraulic circuit including the power transmission fluid supply unit and the power conversion unit;
When the pressure on the inlet side and the pressure on the outlet side of the power transmission fluid are reversed, the pressure by which the hydraulic circuit pressurizing means pressurizes the power transmission fluid is made larger than before the occurrence of slip. The drive device according to claim 2 or 3.   The pressure adjusting means sets the pressure of the power transmission fluid by releasing the power transmission fluid out of the power transmission fluid passage when a pressure exceeding a set pressure is applied from the power transmission fluid. The driving device according to claim 1, wherein the driving device is adjusted to the adjusted value. A power split mechanism that splits the output of the power generating means into a first output and a second output;
First power combining means for combining a part of the first output and a part of the second output and outputting as a driving force;
The second output of the first output combined by the first power combining unit and the remaining output of the second output combined by the first power combining unit are combined and output as a driving force. A power combining means, and
The power conversion means includes first power conversion means driven by a part of the second output, and second power conversion means driven by the remaining second output that has driven the first power conversion means. And
The first power synthesizing unit synthesizes a part of the first output and a part of the second output output via the first power conversion unit, and the second power synthesizing unit includes: The remaining output of the first output synthesized by the first power synthesis means and the remaining output of the second output synthesized by the first power synthesis means outputted via the second power conversion means. The drive device according to any one of claims 1 to 6, wherein the output is synthesized. The first power combining means is a first planetary gear device including a sun gear, a carrier, and a ring gear as constituent elements, and the second power combining means is a constituent element of a sun gear, a carrier, and a ring gear. A second planetary gear device comprising:
The power split mechanism transmits the first output to one of the carrier, the sun gear, or the ring gear, and transmits the second output to one of the remaining components,
A first drive shaft attached to the sun gear, the carrier, or the ring gear included in the first planetary gear device other than the one that transmits the first output and the second output;
A second drive shaft attached to the sun gear or the carrier or the ring gear included in the second planetary gear device other than the one to which the first output and the second output are transmitted;
The drive device according to claim 7, comprising:

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