A hydraulic control system for a two-speed transmission of a pure electric vehicle

Abstract

The application provides a hydraulic control system of a two-gear transmission of a pure electric vehicle, adopts a mechanical pump and an electronic pump double-pump working mode, the oil suction circuits of the mechanical pump and the electronic pump are independently separated, and the hydraulic control system can meet normal driving, parking and reversing functions of a new energy vehicle; a one-way valve is arranged in a bypass of the mechanical pump, highly integrated design is adopted, and the hydraulic control system occupies a small space; the hydraulic control system can regulate main oil pressure and flow; and a parking mechanism is controlled by using a hydraulic system, so that the cost is reduced and the safety is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vehicles, and particularly relates to a hydraulic control system of a two-gear transmission of a pure electric vehicle. BACKGROUND

[0002] With the large-scale application of electric vehicles, the reducers of electric vehicles begin to use two-gear transmissions, adopt hydraulic gear shifting control, and have the advantages of no power interruption during gear shifting, high transmission efficiency, etc. For example, Chinese Patent Application CN201822229504.7 provides a two-gear double-clutch transmission hydraulic system, which comprises a pump body assembly, a check valve, a hydraulic valve block, a lubrication system and a clutch gear shifting system. However, the hydraulic system provided by the patent has the following defects:

[0003] 1) Since the motor of the pure electric vehicle is reversed during reversing, the mechanical pump connected with the motor will also be reversed, which causes the oil suction port of the mechanical pump to become an oil outlet port, and the oil outlet port to become an oil suction port, thereby causing the mechanical pump to generate a vacuum and be damaged.

[0004] 2) The mechanical pump and the electronic pump share an oil suction port, and when the mechanical pump and the electronic pump work at the same time, the oil will be stolen, and the pump with smaller displacement may not be able to suck oil.

[0005] In addition, as an important actuating mechanism of electric vehicles, the hydraulic system is required to be simple in structure, light in weight and fast in response, which is a universal pursuit. Therefore, there is further improvement space for the hydraulic system. SUMMARY

[0006] Therefore, the present application provides the following technical solutions:

[0007] A hydraulic system suitable for electric vehicles, comprising:

[0008] a mechanical pump, an oil inlet of the mechanical pump being connected with an oil storage device, and the mechanical pump being capable of pumping oil in the oil storage device out;

[0009] an electronic pump, an oil inlet of the electronic pump being connected with the oil storage device, and the electronic pump being capable of pumping oil in the oil storage device out;

[0010] the mechanical pump and the electronic pump are arranged in parallel oil paths, so that the mechanical pump and the electronic pump can independently suck oil from the oil storage device.

[0011] In addition, in order to solve the problem that the mechanical pump in the prior art is prone to vacuum when the motor is reversed, the application provides a hydraulic system suitable for an electric vehicle, which comprises a mechanical pump, wherein the mechanical pump is connected with a motor, an oil inlet of the mechanical pump is connected with an oil storage device, the mechanical pump can pump oil in the oil storage device out, and a one-way valve is arranged at an oil outlet of the mechanical pump; and another one-way valve is arranged between the one-way valve and the oil storage device, and the another one-way valve is arranged in parallel with the mechanical pump.

[0012] As an improved aspect of the application, the pressure flow control system comprises a first electromagnetic valve, a main oil pressure regulating valve and a pressure reducing valve, and hydraulic oil pumped by the mechanical pump or the electronic pump is divided into multiple paths, one of which enters a piston side of the main oil pressure regulating valve, one of which passes through the pressure reducing valve and then enters the first electromagnetic valve, and the hydraulic oil enters a rod side of the main oil pressure regulating valve after pressure regulation by the first electromagnetic valve.

[0013] As an improved aspect of the application, the clutch shift control system comprises a shift control valve, an electromagnetic valve and a hydraulic operating cylinder.

[0014] As an improved aspect of the application, the oil liquid after pressure regulation by the main oil pressure regulating valve enters an oil inlet cavity of the shift control valve, the hydraulic oil passing through the pressure reducing valve enters the electromagnetic valve, and the hydraulic oil passing through the electromagnetic valve enters a valve core piston side of the shift control valve and then enters the hydraulic operating cylinder.

[0015] As an improved aspect of the application, in the clutch shift control system, the shift valve comprises a first shift valve and a second shift valve, the electromagnetic valve comprises a second electromagnetic valve and a third electromagnetic valve, and the hydraulic operating cylinder comprises a first hydraulic operating cylinder and a second hydraulic operating cylinder for controlling two shift clutches respectively.

[0016] As an improved aspect of the application, the parking control system comprises a switch electromagnetic valve, a parking control valve and a parking valve, the parking valve is connected with a parking mechanism of the vehicle, hydraulic oil passing through the pressure reducing valve enters the switch electromagnetic valve, the parking control valve is controlled to be on or off by the switch electromagnetic valve, when the parking control valve is opened, oil liquid after pressure regulation by the main oil pressure regulating valve enters the parking control valve and then enters the parking valve, so that the parking mechanism is in a non-parking gear.

[0017] As an improved aspect of the application, the parking control system comprises a switch electromagnetic valve, a parking control valve and a parking valve, the parking valve is connected with a parking mechanism of the vehicle, hydraulic oil passing through the pressure reducing valve enters the switch electromagnetic valve, the parking control valve is controlled to be on or off by the switch electromagnetic valve, when the parking control valve is opened, oil liquid after pressure regulation by the main oil pressure regulating valve enters the parking control valve and then enters the parking valve, so that the parking mechanism is in a non-parking gear.

[0018] As an improved aspect of the present application, the reset device of the parking lock mechanism is a wave spring.

[0019] As an improved aspect of the present application, the pressure flow control system further comprises a flow control valve, hydraulic oil from the lubrication port of the main oil pressure regulating valve enters the flow regulating valve and the tank lubricating oil circuit.

[0020] Therefore, the patent provides a kind of hydraulic control system of pure electric vehicle, adopts mechanical pump and electronic pump double pump working mode, mechanical pump and electronic pump oil suction circuit are independently separated, can satisfy new energy vehicle normal driving, parking, reversing function;Mechanical pump bypass sets a check valve, adopts highly integrated design, small space occupation;Can carry out main oil pressure and flow regulation;Parking mechanism adopts hydraulic system control, reduce cost, improve safety at the same time.

[0021] Other advantages of the present application will be more easily understood after reading the detailed description of the technical solutions of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A kind of hydraulic control system principle diagram of pure electric vehicle provided by the present application.

[0023] 1-mechanical pump suction filter;2-electronic pump suction filter;3-first check valve;4-mechanical pump;5-second check valve;6-electronic pump;7-third check valve;8-first gear shift control valve;9-second gear shift control valve;10-first electromagnetic valve;11-main oil pressure regulating valve;12-pressure reducing valve;13-flow regulating valve;14-tank lubricating oil circuit;15-switch electromagnetic valve;16-parking control valve;17-parking valve;18-wave spring;19-guide sleeve;20-proportional solenoid;21-second electromagnetic valve;22-third electromagnetic valve;23-parking mechanism;24-first hydraulic operating cylinder;25-second hydraulic operating cylinder DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, it should be understood that the following drawings only show some embodiments of the present application, therefore should not be regarded as a limitation on the scope, for ordinary skilled person in the art, without paying creative labor, other related embodiments can also be obtained according to these embodiments.

[0025] Reference Figure 1 The present application provides a kind of hydraulic control system of pure electric vehicle, mainly including pump body assembly, pressure flow control system, clutch gear shift control system, parking control system and cooling lubrication system several parts.The following will be described respectively each part.

[0026] The pump assembly includes a mechanical pump and an electronic pump and related auxiliary components. Specifically, the mechanical pump and its auxiliary components include a mechanical pump suction filter 1, a mechanical pump 4, a first one-way valve 3, and a second one-way valve 5, wherein the mechanical pump suction filter 1 is connected to an oil pan, the suction port of the mechanical pump 4 is connected to the mechanical pump suction filter 1 through a pipeline, the hydraulic oil filtered by the suction filter 1 enters the oil inlet of the mechanical pump 4, the oil outlet of the mechanical pump 4 is connected to the second one-way valve 5, the oil outlet and the oil inlet of the mechanical pump 4 are provided with a circulation loop, and the first one-way valve 3 is arranged in the circulation loop. Since the mechanical pump 4 and the electronic pump 6 are arranged in parallel oil paths, they can suck oil independently, avoiding oil stealing. In addition, the mechanical pump 4 is provided with a bypass first one-way valve 3, so that the mechanical pump 4 can be self-circulated through the first one-way valve 3 when it is reversed, avoiding the mechanical pump 4 from being reversed when the motor is reversed, causing vacuum and damage to the mechanical pump.

[0027] The electronic pump and its auxiliary components include an electronic pump suction filter 2, an electronic pump 6, and a third one-way valve 7. The suction port of the electronic pump 6 is connected to the electronic pump suction filter 2, the electronic pump suction filter 2 is connected to the oil pan, the oil outlet of the electronic pump 6 is connected to the third one-way valve 7, and the oil outlets of the second one-way valve 5 and the third one-way valve 7 are connected together through a pipeline to supply oil to the entire hydraulic system.

[0028] After the hydraulic oil is pumped out by the mechanical pump 4 and the electronic pump 6, it flows to the pressure flow control system and the clutch shifting system, the parking control system, and the cooling and lubrication system.

[0029] The pressure flow control system includes a first electromagnetic valve 10, a main oil pressure regulating valve 11, a pressure reducing valve 12, and a flow regulating valve 13. The hydraulic oil from the pump assembly is divided into multiple paths, one of which enters the piston side of the main oil pressure regulating valve 11, and one of which passes through the pressure reducing valve 12 and then enters the first electromagnetic valve 10. After pressure regulation by the first electromagnetic valve 10, it enters the rod side of the main oil pressure regulating valve 11. After the hydraulic oil is regulated by the pressure flow control system, it enters the clutch shifting control system, the parking control system, and the cooling and lubrication system, respectively.

[0030] The clutch shift control system includes: a first shift control valve 8, a second shift control valve 9, a second solenoid valve 21, a third solenoid valve 22, a first hydraulic operating cylinder 24, and a second hydraulic operating cylinder 25. Hydraulic oil, after being pressurized by the main oil pressure regulating valve 11, enters the inlet chambers of the first shift control valve 8 and the second shift control valve 9 respectively. Hydraulic oil, through the pressure reducing valve 12, enters the second solenoid valve 21 and the third solenoid valve 22 respectively. Hydraulic oil through the second solenoid valve 21 enters the piston side of the valve core of the first shift control valve 8, and then enters the first hydraulic operating cylinder 24. Hydraulic oil through the third solenoid valve 22 enters the piston side of the valve core of the second shift control valve 9, and then enters the second hydraulic operating cylinder 25. The first hydraulic operating cylinder 24 and the second hydraulic operating cylinder 25 are respectively used to control the engagement or disengagement of one clutch.

[0031] This invention also uses a hydraulic system to control the parking control system. Specifically, the parking control system includes: a solenoid valve 15, a parking control valve 16, a parking valve 17, a wave spring 18, a guide sleeve 19, and a proportional electromagnet 20. The parking control system controls the parking mechanism 23 to achieve the parking function of the vehicle. Hydraulic oil enters the solenoid valve 15 through the pressure reducing valve 12, and the solenoid valve 15 controls the opening and closing of the parking control valve 16 by being energized or de-energized. When the parking control valve 16 is open, the oil pressure regulated by the main oil pressure regulating valve 11 enters the parking control valve 16, and the oil entering the parking control valve 16 enters the piston side of the parking valve 17, pushing the parking valve 17 to extend, thereby pushing the parking mechanism 23 into a non-P position. The parking control valve 16 adopts a constant height design, so that even if the whole vehicle system loses power, the parking function will not be affected.

[0032] At the same time, the proportional electromagnet 20 is energized, the solenoid valve head extends, and pushes the guide sleeve 19 downward. The guide sleeve 19 compresses the wave spring 18, thereby causing the proportional electromagnet 20 to lock the parking valve 17 when energized. The parking locking mechanism composed of these three components is simple and reliable, and due to the use of wave springs, the installation space is smaller.

[0033] The cooling and lubrication system mainly includes the gearbox lubrication oil circuit 14. Hydraulic oil coming out of the lubrication port of the main oil pressure regulating valve 11 enters the flow regulating valve 13, and the lubricating oil coming out of the flow regulating valve 13 enters the gearbox lubrication oil circuit 14 to lubricate and cool the gearbox.

[0034] The structures of the various embodiments of the present invention have been described in detail above, and the working mode of the present invention has also been explained. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of the present invention without departing from the scope of the present invention are within the protection scope of this technical solution.

Claims

1. A hydraulic system suitable for an electric vehicle, the electric vehicle including a battery-powered pure electric vehicle, the hydraulic system comprising: A mechanical pump is connected to a motor. The inlet of the mechanical pump is connected to an oil storage device and can pump oil from the oil storage device. A one-way valve is provided after the outlet of the mechanical pump. An electronic pump, the oil inlet of which is connected to an oil storage device and is capable of pumping oil from the oil storage device. Its features are, The mechanical pump and the electronic pump are arranged in parallel oil circuits, allowing each pump to draw oil from the oil storage device independently. Between the check valve and the oil storage device, there is another check valve, which is connected in parallel with the mechanical pump. It also includes a pressure and flow control system, which comprises a first solenoid valve, a main oil pressure regulating valve, and a pressure reducing valve. Hydraulic oil pumped from a mechanical or electronic pump is divided into multiple paths. One path enters the piston side of the main oil pressure regulating valve, another path passes through the pressure reducing valve, and then through the first port of the first solenoid valve. After pressure regulation by the first solenoid valve, the oil enters the rod side of the main oil pressure regulating valve. It also includes a parking control system, which comprises a solenoid valve, a parking control valve, and a parking valve. The parking valve is connected to the vehicle's parking mechanism. Hydraulic oil from the pressure reducing valve enters the solenoid valve, and the solenoid valve is energized or de-energized to control the opening and closing of the parking control valve. When the parking control valve is open, hydraulic oil pressure-regulated by the main hydraulic pressure regulating valve enters the parking control valve and then the parking valve, thereby putting the parking mechanism in the non-parking position. It also includes a parking brake locking mechanism, which comprises a proportional electromagnet and a reset device. When the parking control valve is opened, the proportional electromagnet is energized, locking the parking valve. The pressure and flow control system also includes a flow regulating valve. Hydraulic oil exiting from the lubrication port of the main hydraulic pressure regulating valve enters the flow regulating valve and the lubrication oil circuit of the housing. The second port of the first solenoid valve is connected to the rod side of the main hydraulic pressure regulating valve on one side and the rod side of the flow regulating valve on the other side. It also includes a clutch shifting control system, which comprises: a shifting control valve, a solenoid valve, and a hydraulic operating cylinder. The shifting control valve includes a first shifting control valve and a second shifting control valve. The solenoid valve includes a second solenoid valve and a third solenoid valve. The hydraulic operating cylinder includes a first hydraulic operating cylinder and a second hydraulic operating cylinder, respectively used to control two shifting clutches. The outlets of the mechanical pump and the electronic pump are directly connected to the first and second shift control valves on one side, and directly to the main oil pressure regulating valve, the pressure reducing valve, and the parking control valve on the other. The hydraulic oil flowing from the pressure reducing valve is divided into three paths, respectively connected to the first solenoid valve, the second solenoid valve, the third solenoid valve, and the switching solenoid valve. The outlet of the switching solenoid valve is connected to the parking control valve, and the outlet of the parking control valve is connected to the parking valve. The first solenoid valve is also connected to the flow regulating valve. The hydraulic oil, after being regulated by the main hydraulic pressure regulating valve, enters the oil inlet chamber of the shift control valve. The hydraulic oil, through the pressure reducing valve, enters the solenoid valve, and then the hydraulic oil, through the solenoid valve, enters the valve core piston side of the shift control valve, and subsequently enters the hydraulic operating cylinder.

2. The hydraulic system for electric vehicles according to claim 1, characterized in that, The reset device of the parking lock mechanism is a wave spring.

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