JP6666766B2 - Pump system - Google Patents

Description

  The present invention relates to a pump system mounted on a vehicle.

  Conventionally, a mechanical oil pump mounted on a vehicle is driven by an engine and supplies oil to a transmission and the like. However, when only one oil pump is provided, if the oil pump capacity is set so as to satisfy a required discharge amount at a high hydraulic load, an excessive amount of oil is discharged at a low hydraulic load. There is a problem that the loss due to the pump increases.

  Therefore, a main pump driven by an engine and an assist pump driven by an electric motor are provided, and a check valve is arranged on a discharge flow path of the assist pump. A pump system in which discharge passages of a pump join has been proposed (for example, Patent Document 1).

  In this pump system, the main pump is driven to supply oil, and when the oil discharge amount (flow rate) of the main pump is insufficient, the assist pump is driven to compensate for the shortage of the main pump. The capacity of the pump can be reduced.

Japanese Patent No. 4484316

  However, in the above pump system, when pressure pulsation occurs in the main pump and the assist pump, depending on the relationship between the pressure pulsations generated by the two pumps, the oil is supplied from the assist pump to the junction position via the check valve. There was a problem that the oil could not be supplied sufficiently and the oil supply could not be increased as a whole.

  The present invention has been made in view of the above circumstances, and has as its object to provide a pump system capable of increasing an oil supply amount.

In order to solve the above problems, a pump system of the present invention is driven by an engine, a main pump that supplies oil to a transmission, and an assist pump that is driven by an electric motor and has a smaller discharge amount than the main pump. An accumulator connected to a discharge flow path of the assist pump, for accumulating and releasing oil discharged from the assist pump; and an accumulator connected to a discharge flow path of the main pump and provided in the discharge flow path of the assist pump. A high-pressure release valve that supplies oil to the transmission from the high-pressure discharge passage of the hydraulic pressure of the discharge passage of the main pump, and the hydraulic pressure of the discharge passage of the assist pump, wherein the high-pressure relief valve is the hydraulic pressure of the discharge flow path of the main pump, the a lowered by hydraulic pressure pulsation If it becomes lower than the hydraulic pressure of the discharge flow path of Sutoponpu, supplying oil to the transmission from a discharge flow path of said assist pump.

  According to the present invention, the oil supply amount can be increased.

It is a figure showing composition of a car. It is a figure showing composition of a pump system. FIG. 3 is a diagram showing a configuration of a main pump. FIG. 3 is a diagram illustrating a hydraulic pressure of a discharge flow path of a main pump and a hydraulic pressure of a discharge flow path of an assist pump.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values and the like shown in the embodiments are merely examples for facilitating the understanding of the present invention, and do not limit the present invention unless otherwise specified. In the specification and the drawings, elements having substantially the same function and configuration will be denoted by the same reference numerals, and redundant description will be omitted. Elements not directly related to the present invention will be omitted. I do.

  FIG. 1 is a diagram illustrating a configuration of the automobile 1. As shown in FIG. 1, the vehicle 1 is a so-called hybrid vehicle having an engine 10, a first motor generator 12, and a second motor generator 14.

As the engine 10, a gasoline engine or a diesel engine is applied, power is obtained by burning fuel (gasoline, light oil, or the like) supplied from a fuel tank (not shown), and the obtained power is connected to a crankshaft 10a. Output to the damper 16.

  The first motor generator 12 mainly functions as a power generator, and charges the battery by supplying power obtained by generating power to the battery. The first motor generator 12 may also function as a motor, and in this case, is driven by electric power supplied from a battery.

  The second motor generator 14 mainly functions as a motor, and is driven by electric power supplied from a battery (not shown). The second motor generator 14 may also function as a power generator. In this case, the battery is charged by supplying power obtained by power generation to the battery.

  The damper 16 transmits the power transmitted from the engine 10 to the input shaft 16a while suppressing vibration. The input shaft 16a is connected to the carrier 18d of the power split device 18 and rotates integrally with the carrier 18d.

  The power split mechanism 18 is a planetary gear including a sun gear 18a, a planetary gear 18b, a ring gear 18c, and a carrier 18d. The ring gear 18c is arranged coaxially with the sun gear 18a, and is arranged radially outside the sun gear 18a. The plurality of planetary gears 18b are arranged between the sun gear 18a and the ring gear 18c, and mesh with the sun gear 18a and the ring gear 18c, respectively. The carrier 18d is rotatably supported coaxially with the sun gear 18a, and rotatably supports the planetary gear 18b. Therefore, the planetary gear 18b can rotate around the central axis of the planetary gear 18b and revolve around the central axis of the carrier 18d.

  The sun gear 18a is connected to the rotation shaft 12a of the first motor generator 12, and rotates integrally with the rotation shaft 12a. Ring gear 18c is connected to rotation shaft 14a of second motor generator 14, and rotates integrally with rotation shaft 14a.

  A drive gear 20 is integrally rotatably fitted to the rotation shaft 14a, and the drive gear 20 rotates integrally with a drive shaft 22 arranged in parallel with the rotation shaft 14a. It is meshed with the driven gear 24 fitted as possible. The drive shaft 22 has wheels 26 connected to both ends, and rotates integrally with the wheels 26.

  In the vehicle 1, the power output from the engine 10 is transmitted to the carrier 18 d of the power split device 18 via the damper 16. When the first motor generator 12 functions as a generator and the second motor generator 14 functions as a motor, the power split mechanism 18 rotates the sun gear 18a by rotating the planetary gear 18b that revolves as the carrier 18d rotates. The ring gear 18c rotates at an independent rotation speed while transmitting power. Thereby, power split mechanism 18 splits the power transmitted from engine 10 and transmits the split power to first motor generator 12 via sun gear 18a, and also transmits the power to rotation shaft 14a of second motor generator 14 via ring gear 18c. introduce. The rotating shaft 14 a transfers the power output from the second motor generator 14 and the power from the engine 10 split by the power split mechanism 18 to the wheels 26 via the drive gear 20, the driven gear 24, and the drive shaft 22. To communicate. The first motor generator 12 generates electric power by motive power transmitted via the sun gear 18a.

  When the first motor generator 12 functions as a motor and the second motor generator 14 functions as a generator, the power output from the engine 10 is input to the carrier 18 d of the power split mechanism 18 via the damper 16. At the same time, the power output from first motor generator 12 is input to sun gear 18 a of power split device 18. Then, in power split device 18, ring gear 18c is rotated by rotation of sun gear 18a and planetary gear 18b. Thereby, power split device 18 transfers the power input from engine 10 and the power input from first motor generator 12 via ring gear 18c, rotation shaft 14a, drive gear 20, driven gear 24, and drive shaft 22. To the wheels 26. Further, second motor generator 14 generates electric power by motive power transmitted via ring gear 18c.

  In addition, the automobile 1 is provided with a pump system 30 that supplies oil for cooling the first motor generator 12 and the second motor generator 14 to the first motor generator 12 and the second motor generator 14.

  FIG. 2 is a diagram illustrating the configuration of the pump system 30. As shown in FIG. 2, the pump system 30 includes a main pump 32, an assist pump 34, an electric motor 36, an accumulator 38, a high-pressure release valve 40, and a relief valve 42.

  The main pump 32 is a mechanical pump constantly driven by the engine 10, and is set so that a sufficient discharge amount can be secured when the engine 10 is idling. A high-pressure release valve 40 is connected to the discharge passage of the main pump 32.

  The assist pump 34 is a mechanical pump that is constantly driven by the electric motor 36, and is set to a discharge amount smaller than the discharge amount of the main pump 32. A high-pressure release valve 40 is connected to a discharge channel of the assist pump 34.

  The accumulator 38 is provided on a discharge channel of the assist pump 34, and temporarily accumulates (accumulates) oil when the oil pressure of the oil discharged from the assist pump 34 is higher than a preset pressure. Thereafter, when the oil pressure of the oil becomes lower than the preset pressure, the accumulated oil is released to the high pressure release valve 40 side, so that the hydraulic pressure applied to the high pressure release valve 40 is kept constant.

  The high-pressure release valve 40 is provided with two inflow ports and one discharge port. The main pump 32 is connected to one of the two inflow ports, and the assist pump 34 is connected to the other inflow port via an accumulator 38. The high-pressure release valve 40 connects the high-pressure inflow port of the two inflow ports with the discharge port, and shuts off the low-pressure inflow port from the discharge port.

  The relief valve 42 is provided on a bypass flow path that connects the discharge flow path and the suction flow path of the assist pump 34, and when the discharge flow path of the assist pump 34 has a pressure equal to or higher than a preset pressure, the relief pump 42 This is a one-way valve that returns oil from the discharge flow path to the suction flow path.

  FIG. 3 is a diagram illustrating the configuration of the main pump 32. Here, as shown in FIG. 3, the main pump 32 is, for example, an internal gear pump, and has an inner rotor 50 provided with a plurality of external teeth on an outer peripheral surface and a plurality of internal teeth provided on an inner peripheral surface. And the outer rotor 52. In the main pump 32, a plurality of gaps between the inner rotor 50 and the outer rotor 52 form a pump chamber 54.

  The inner rotor 50 has a shaft (not shown) that rotates by the power of the engine 10 inserted through the center, and rotates integrally with the shaft. The outer teeth of the inner rotor 50 have one less tooth than the inner teeth of the outer rotor 52, and the inner rotor 50 and the outer rotor 52 are eccentrically meshed with each other. When the inner rotor 50 rotates in the direction indicated by the solid arrow in FIG. 3, the outer rotor 52 also rotates integrally. At this time, the plurality of pump chambers 54 are repeatedly reduced and expanded sequentially.

  The housing 56 that houses the inner rotor 50 and the outer rotor 52 is provided with a suction port 56a and a discharge port 56b. The suction port 56a is opened in a range in which the volume of the pump chamber 54 increases with the rotation of the inner rotor 50 and the outer rotor 52 among the plurality of pump chambers 54. To the oil. On the other hand, the discharge port 56b is located rearward in the rotation direction from the suction port 56a, and is open in a range where the volume of the pump chamber 54 is reduced as the inner rotor 50 and the outer rotor 52 rotate. The oil in the pump chamber 54 compressed by the action is discharged.

  In the main pump 32 having such a configuration, the inner rotor 50 and the outer rotor 52 block part or all of the discharge port 56b with the rotation of the inner rotor 50 and the outer rotor 52. Changes. Accordingly, as the opening area of the discharge port 56b increases, the amount of oil discharged from the main pump 32 increases and the oil pressure also increases, and as the opening area of the discharge port 56b decreases. As the amount of oil discharged from the main pump 32 decreases, the oil pressure also decreases. Therefore, the main pump 32 generates a hydraulic pulsation in the discharge passage.

  On the other hand, the assist pump 34 is, for example, an internal gear pump similar to the main pump 32, and generates hydraulic pulsation in the discharge flow path. An accumulator 38 is provided in the discharge flow path of the assist pump 34. Therefore, the hydraulic pressure applied to the high-pressure release valve 40 is kept substantially constant.

  Therefore, when the hydraulic pressure of the discharge flow path of the main pump 32 is higher than the hydraulic pressure of the discharge flow path of the assist pump 34, the high pressure release valve 40 connects the inflow port and the discharge port of the main pump 32, The oil discharged from the pump 32 is supplied to the first motor generator 12 and the second motor generator 14.

  When the hydraulic pressure in the discharge flow path of the main pump 32 is lower than the hydraulic pressure in the discharge flow path of the assist pump 34, the high-pressure release valve 40 connects the inflow port and the discharge port on the discharge flow path side of the assist pump 34. Then, the oil discharged from the assist pump 34 is supplied to the first motor generator 12 and the second motor generator 14.

  FIG. 4 is a diagram illustrating the hydraulic pressure P1 of the discharge flow path of the main pump 32 and the hydraulic pressure P2 of the discharge flow path of the assist pump 34.

  As shown in FIG. 4, the hydraulic pressure P1 in the discharge passage of the main pump 32 pulsates with time. On the other hand, the hydraulic pressure P2 in the discharge passage of the assist pump 34 is substantially constant. The high-pressure release valve 40 supplies the oil having the higher oil pressure among the oil discharged from the main pump 32 and the oil discharged from the assist pump 34 to the first motor generator 12 and the second motor generator 14. I do.

  Therefore, when the hydraulic pressure P1 of the discharge flow path of the main pump 32 is lower than the hydraulic pressure P2 of the discharge flow path of the assist pump 34, oil corresponding to the area shown by hatching in FIG. And the second motor generator 14.

  Thus, in the pump system 30, the main pump 32 is directly connected to the high-pressure release valve 40, and the assist pump 34 is connected to the high-pressure release valve 40 via the accumulator 38. Accordingly, when the hydraulic pressure is reduced due to the pressure pulsation generated in main pump 32, pump system 30 supplies oil to first motor generator 12 and second motor generator 14 from assist pump 34 maintained at a constant hydraulic pressure. . On the other hand, the pump system 30 supplies oil from the main pump 32 to the first motor generator 12 and the second motor generator 14 when the oil pressure rises due to the pressure pulsation generated by the main pump 32.

  Therefore, the pump system 30 can increase the oil supply amount when the main pump 32 in which pressure pulsation occurs is used, as compared with the case where the main pump 32 supplies oil alone.

  In addition, pump system 30 can improve the cooling performance of first motor generator 12 and second motor generator 14 by increasing the oil supply amount.

  As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. However, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications within the scope described in the claims. Needless to say, modified examples also belong to the technical scope of the present invention.

  In the above-described embodiment, the first motor generator 12 and the second motor generator 14 have been described as examples of the target member for supplying oil. It may be used for cooling or lubrication of the target member.

  In the above-described embodiment, the main pump 32 is driven by the engine 10 and the assist pump 34 is driven by the electric motor 36. However, the drive source for driving the main pump 32 and the assist pump 34 is not limited to this. , Or another driving source.

  Further, in the above embodiment, the case where the internal gear pump is applied to the main pump 32 and the assist pump 34 has been described as an example. However, the main pump 32 and the assist pump 34 may be other mechanical pumps. Good.

  INDUSTRIAL APPLICATION This invention can be utilized for the pump system mounted in a vehicle.

30 pump system 32 main pump 34 assist pump 40 high pressure release valve

Claims (1)

A main pump driven by the engine and supplying oil to the transmission;
An assist pump driven by an electric motor and having a smaller discharge amount than the main pump;
An accumulator connected to a discharge flow path of the assist pump, for accumulating and releasing oil discharged from the assist pump;
The hydraulic pressure of the discharge flow path of the main pump and the hydraulic pressure of the discharge flow path of the assist pump are connected to the discharge flow path of the main pump and connected to the discharge flow path of the assist pump via the accumulator. A high-pressure release valve that supplies oil to the transmission from a discharge passage having a high pressure;
With
The high-pressure release valve removes oil from the discharge flow path of the assist pump when the hydraulic pressure of the discharge flow path of the main pump decreases due to hydraulic pulsation and becomes lower than the hydraulic pressure of the discharge flow path of the assist pump. A pump system for supplying to a transmission.

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