Gearbox hydraulic system and oil control method

Abstract

The application relates to the technical field of gearbox hydraulic control, and discloses a gearbox hydraulic system and an oil control method. The gearbox hydraulic system comprises an oil storage tank, a cooling lubricating oil path, a first oil path, a second oil path and a control oil path. The first oil path comprises an electronic pump and a first check valve. The first oil inlet of the electronic pump is communicated with the oil storage tank. The first oil outlet of the electronic pump is communicated with the cooling lubricating oil path in one direction through the first check valve. The second oil path comprises a mechanical pump, a first pressure regulating valve and a second check valve. The second oil inlet of the mechanical pump is communicated with the oil storage tank. The second oil outlet of the mechanical pump is communicated with the third oil inlet and a pilot oil inlet of the first pressure regulating valve. The pilot oil inlet is suitable for providing pilot oil into the first pressure regulating valve to make the third oil inlet communicated with the third oil outlet of the first pressure regulating valve. The third oil outlet is communicated with the cooling lubricating oil path in one direction through the second check valve. The cooling lubricating demand of the motor, the shaft tooth and the clutch is met, and the cooling lubricating efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transmission hydraulic control, and in particular to a transmission hydraulic system and an oil control method. BACKGROUND

[0002] The currently mass-produced transmission hydraulic system usually adopts a mechanical pump as an execution pump to establish oil pressure through the mechanical pump to control the combination and separation of the clutch, but the current transmission hydraulic system is difficult to meet the cooling and lubrication requirements of the motor, shaft tooth and clutch, and the cooling and lubrication efficiency is low. SUMMARY

[0003] The present application provides a transmission hydraulic system and an oil control method, which can use an electronic pump to provide oil to the cooling and lubrication oil circuit alone, can use a mechanical pump to provide oil to the cooling and lubrication oil circuit alone, and can use the electronic pump and the mechanical pump to provide oil to the cooling and lubrication oil circuit simultaneously, so as to not only meet the cooling and lubrication requirements of the motor, shaft tooth and clutch under various working conditions, but also improve the cooling and lubrication efficiency by providing oil through the electronic pump and the mechanical pump simultaneously.

[0004] In order to achieve the above-mentioned purpose, the main technical scheme adopted by the present application includes:

[0005] In a first aspect, the present application provides a transmission hydraulic system, comprising:

[0006] an oil storage tank;

[0007] a cooling and lubrication oil circuit for providing oil to the motor, shaft tooth and clutch;

[0008] a first oil circuit comprising an electronic pump and a first check valve, a first oil inlet of the electronic pump being in communication with the oil storage tank, and a first oil outlet of the electronic pump being in one-way communication with the cooling and lubrication oil circuit through the first check valve;

[0009] a second oil circuit comprising a mechanical pump, a first pressure regulating valve and a second check valve, a second oil inlet of the mechanical pump being in communication with the oil storage tank, a second oil outlet of the mechanical pump being in communication with a third oil inlet and a pilot oil inlet of the first pressure regulating valve, the pilot oil inlet being adapted to provide pilot oil to the first pressure regulating valve to make the third oil inlet and a third oil outlet of the first pressure regulating valve in communication, and the third oil outlet being in one-way communication with the cooling and lubrication oil circuit through the second check valve.

[0010] The gearbox hydraulic system provided by the first aspect of the present application can use the electronic pump to provide oil to the cooling and lubricating oil circuit alone, can use the mechanical pump to provide oil to the cooling and lubricating oil circuit alone, and can use the electronic pump and the mechanical pump to provide oil to the cooling and lubricating oil circuit simultaneously. Therefore, the cooling and lubricating requirements of the motor, the shaft gear, and the clutch under various working conditions are met, and the cooling and lubricating efficiency is improved by using the electronic pump and the mechanical pump to provide oil simultaneously.

[0011] Optionally, the gearbox hydraulic system further comprises a control oil circuit, the control oil circuit comprising a first control valve and a pressure reducing valve, the pressure reducing valve having a fourth oil inlet and a fourth oil outlet in communication, the fourth oil inlet being in communication with the second oil outlet, the first control valve being in communication with the fourth oil outlet and the first pressure regulating valve, and the first control valve being configured to selectively provide pressure oil to the first pressure regulating valve.

[0012] In this way, the oil pressure of the control oil circuit is reduced by the pressure reducing valve, so that the oil pressure of the control oil circuit is less than the oil pressure of the second oil circuit, thereby reducing the loss of the main oil pressure of the second oil circuit. Meanwhile, the first control valve is controlled to provide pressure oil to the first pressure regulating valve, so that the oil inlet pressure of the first pressure regulating valve is reduced, thereby reducing the pressure damage and improving the efficiency of the gearbox.

[0013] Optionally, the gearbox hydraulic system further comprises:

[0014] The third oil circuit comprises a second pressure regulating valve, a fifth oil inlet of the second pressure regulating valve being in communication with the second oil outlet, and a fifth oil outlet of the second pressure regulating valve being in communication with a first execution oil circuit, the first execution oil circuit being configured to deliver oil to the first clutch.

[0015] The fourth oil circuit comprises a third pressure regulating valve, a sixth oil inlet of the third pressure regulating valve being in communication with the second oil outlet, and a sixth oil outlet of the third pressure regulating valve being in communication with a second execution oil circuit, the second execution oil circuit being configured to deliver oil to the second clutch.

[0016] The control oil circuit further comprises a second control valve and a third control valve, the second control valve being in communication with the second oil outlet and the second pressure regulating valve, and the second control valve being configured to selectively provide pilot oil to the second pressure regulating valve to make the fifth oil inlet and the fifth oil outlet conductive or disconnected.

[0017] The third control valve is in communication with the second oil outlet and the third pressure regulating valve, and the third control valve is configured to selectively provide pilot oil to the third pressure regulating valve to make the sixth oil inlet and the sixth oil outlet conductive or disconnected.

[0018] In this way, the mechanical valve can also provide a gear shifting flow, realizing the two-gear gear shifting function of the gearbox, and can also provide oil to the cooling and lubricating oil circuit through the second oil circuit to provide cooling and lubricating oil to the motor, the shaft gear, and the clutch.

[0019] Optionally, the cooling lubricating oil circuit further comprises an oil cooler, the oil cooler having a seventh oil inlet and a seventh oil outlet in communication, the first oil outlet being unidirectionally communicated with the seventh oil inlet through a first check valve, the second oil outlet being unidirectionally communicated with the seventh oil inlet through a second check valve, and the seventh oil outlet being configured to provide oil to the motor, the shaft gear and the clutch.

[0020] In this way, the oil cooler further reduces the temperature of the oil delivered to the motor, the shaft gear and the clutch, and is conducive to further improving the cooling effect of the motor, the shaft gear and the clutch.

[0021] Optionally, a filter is arranged between the mechanical pump and the oil tank.

[0022] In this way, impurities in the oil can be filtered, and the normal operation of the gearbox hydraulic system can be ensured.

[0023] Optionally, the first actuating oil circuit is provided with a first pressure sensor configured to test the pressure of the first actuating oil circuit.

[0024] The second actuating oil circuit is provided with a second pressure sensor configured to test the pressure of the second actuating oil circuit.

[0025] In this way, the stability and reliability of the operation of the first clutch and the second clutch can be ensured, and the wear and failure of the first clutch and the second clutch can be reduced.

[0026] In a second aspect, the embodiments of the present application provide an oil control method, and the gearbox hydraulic system in the first aspect adopts the oil control method. The oil control method comprises the following steps:

[0027] determining the working mode of the gearbox;

[0028] if the gearbox is in the pure electric mode, controlling the electronic pump to operate;

[0029] if the gearbox is in the non-pure electric mode, controlling the mechanical pump to operate, obtaining the temperature of the motor, and if the temperature of the motor is greater than a preset temperature, controlling the electronic pump to operate.

[0030] The oil control method provided by the second aspect of the present application can provide oil to the cooling lubricating oil circuit through the electronic pump when the gearbox is in the pure electric mode, can provide oil to the cooling lubricating oil circuit through the mechanical pump when the gearbox is in the non-pure electric mode, and can provide oil to the cooling lubricating oil circuit through the electronic pump and the mechanical pump when the temperature of the motor is greater than the preset temperature. Therefore, the cooling and lubricating requirements of the motor, the shaft gear and the clutch under various working conditions can be met, and the cooling and lubricating efficiency can be improved by providing oil through the electronic pump and the mechanical pump at the same time.

[0031] Optionally, if the gearbox is in the pure electric mode, the method further comprises the following steps:

[0032] acquire a motor temperature;

[0033] if the motor temperature is greater than a preset temperature, increase the electronic pump rotating speed.

[0034] In this way, when the motor temperature is greater than the preset temperature or the temperature rising speed is relatively high, the oil supply to the cooling lubricating oil circuit can be increased by increasing the electronic pump rotating speed, so that the cooling effect on the motor is improved, and the motor is prevented from being damaged due to overheating.

[0035] Optionally, if the gearbox is in the non-pure electric mode, the method further includes:

[0036] if the gearbox is in the series mode, controlling the first control valve to provide pressure oil to the first pressure regulating valve.

[0037] In this way, the oil inlet pressure of the first pressure regulating valve can be reduced, so that the pressure damage is reduced, and the gearbox efficiency is improved.

[0038] Optionally, if the gearbox is in the non-pure electric mode, the method further includes:

[0039] if the gearbox is in the direct drive mode or the parallel mode, controlling the first control valve to stop providing pressure oil to the first pressure regulating valve, and acquiring a vehicle speed or an accelerator pedal angle;

[0040] controlling the second control valve to provide pilot oil to the second pressure regulating valve and controlling the third control valve to stop providing pilot oil to the third pressure regulating valve, or controlling the second control valve to stop providing pilot oil to the second pressure regulating valve and controlling the third control valve to provide pilot oil to the third pressure regulating valve, according to the vehicle speed or the accelerator pedal angle.

[0041] In this way, the mechanical valve can also provide a gear shifting flow, realizing the two-gear gear shifting function of the gearbox, and the second oil circuit can also provide oil to the cooling lubricating oil circuit to provide cooling lubricating oil to the motor, the gear shaft and the clutch. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0043] Figure 1 a schematic diagram of a gearbox hydraulic system provided by an embodiment of the present application;

[0044] Figure 2 a flowchart of an oil control method provided by an embodiment of the present application;

[0045] Figure 3 Flowchart of the oil control method according to another embodiment of the present application;

[0046] Figure 4 Flowchart of the oil control method according to yet another embodiment of the present application.

[0047] [BRIEF DESCRIPTION OF DRAWINGS]

[0048] Gearbox hydraulic system 100;

[0049] Oil reservoir 1;

[0050] Cooling lubricant passage 2; oil cooler 21; seventh oil inlet port 211; seventh oil outlet port 212; first safety overflow valve 22;

[0051] First oil passage 3; electronic pump 31; first oil inlet port 311; first oil outlet port 312; first check valve 32;

[0052] Second oil passage 4; mechanical pump 41; second oil inlet port 411; second oil outlet port 412; first pressure regulating valve 42; third oil inlet port 421; third oil outlet port 422; pilot oil inlet port 423; second check valve 43; second safety overflow valve 44;

[0053] Control oil passage 5; first control valve 51; pressure reducing valve 52; fourth oil inlet port 521; fourth oil outlet port 522; second control valve 53; third control valve 54;

[0054] Third oil passage 6; second pressure regulating valve 61; fifth oil inlet port 611; fifth oil outlet port 612;

[0055] Fourth oil passage 7; third pressure regulating valve 71; sixth oil inlet port 711; sixth oil outlet port 712;

[0056] First actuating oil passage 8; first pressure sensor 81;

[0057] First clutch 9;

[0058] Second actuating oil passage 10; second pressure sensor 101;

[0059] Second clutch 11;

[0060] Filter 12. DETAILED DESCRIPTION

[0061] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0063] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor are they necessarily mutually exclusive or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0064] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0066] "Multiple" appearing in the present application means two or more (including two), and similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces).

[0067] Currently, mass-produced transmission hydraulic systems typically use mechanical pumps as actuators to establish oil pressure and control clutch engagement and disengagement. However, current transmission hydraulic systems struggle to meet the cooling and lubrication requirements of the motor, shaft gears, and clutch, resulting in low cooling and lubrication efficiency.

[0068] Based on this, this application proposes a gearbox hydraulic system 100, which can supply oil to the cooling and lubrication circuit 2 by means of an electronic pump 31 alone, or by means of a mechanical pump 41 alone, or by means of both electronic pump 31 and mechanical pump 41 simultaneously. Thus, it not only meets the cooling and lubrication requirements of the motor, shaft gears and clutch under various operating conditions, but also improves the cooling and lubrication efficiency by supplying oil by means of both electronic pump 31 and mechanical pump 41 simultaneously.

[0069] The transmission hydraulic system 100 and the oil control method proposed in this application are described below with reference to the accompanying drawings.

[0070] like Figures 1-4 As shown, the gearbox hydraulic system 100 according to the first aspect embodiment of this application includes: an oil reservoir 1, a cooling and lubricating oil circuit 2, a first oil circuit 3, a second oil circuit 4, and a control oil circuit 5.

[0071] The cooling and lubrication circuit 2 is used to supply oil to the motor, shaft gears, and clutch. The first oil circuit 3 includes an electronic pump 31 and a first check valve 32. The first oil inlet 311 of the electronic pump 31 is connected to the oil reservoir 1. The first oil outlet 312 of the electronic pump 31 is unidirectionally connected to the cooling and lubrication circuit 2 through the first check valve 32. The second oil circuit 4 includes a mechanical pump 41, a first pressure regulating valve 42, and a second check valve 43. The second oil inlet 411 of the mechanical pump 41 is connected to the oil reservoir 1. The second oil outlet 412 of the mechanical pump 41 is connected to the third oil inlet 421 and the pilot oil inlet 423 of the first pressure regulating valve 42. The pilot oil inlet 423 is adapted to provide pilot oil to the first pressure regulating valve 42 so that the third oil inlet 421 is connected to the third oil outlet 422 of the first pressure regulating valve 42. The third oil outlet 422 is unidirectionally connected to the cooling and lubrication circuit 2 through the second check valve 43.

[0072] It should be noted that shafts, gears, motors (such as P1 motors and P3 motors), and clutches are typically used in hybrid vehicles to transmit power and change speeds. Therefore, they will generate friction and wear during operation, as well as a lot of heat. Thus, it is necessary to cool and lubricate the shafts, gears, clutches, and motors.

[0073] Based on this, the cooling lubricating oil circuit 2 in the present application is used to provide cooling lubricating oil to the motor, shaft tooth and clutch. In this way, the shaft tooth is lubricated by the oil, which not only reduces the direct contact between the shaft tooth surfaces, but also prevents the shaft tooth from sticking and jamming, ensuring smooth engagement and operation of the shaft tooth. The oil can also carry away the heat generated during high-speed operation of the shaft tooth, which helps to reduce the wear and metal fatigue of the shaft tooth, thereby improving the mechanical performance and service life.

[0074] At the same time, the motor is cooled by the oil, which helps to reduce the temperature of the motor and ensure its operation at a safe and efficient working temperature, avoiding damage to the motor due to overheating. Compared with water cooling, the specific heat capacity of oil is larger, so it can absorb more heat. In addition, the vaporization temperature of oil is usually higher than that of water, so oil cooling is more stable and durable in high-temperature environments. At the same time, the bearings and other moving parts in the motor need to be properly lubricated with oil to reduce friction and wear, making the motor run more smoothly and efficiently, reducing the noise and vibration of the motor, and improving the ride comfort and driving experience.

[0075] Similarly, the clutch is lubricated by the oil, which helps to reduce the friction and wear of the clutch, preventing overheating of the clutch and affecting its performance, thereby improving the service life of the clutch and reducing the frequency of maintenance and replacement of parts.

[0076] Further, in some embodiments of the present application, the first oil circuit 3 and the second oil circuit 4 of the gearbox hydraulic system 100 can be selectively connected between the oil tank 1 and the cooling lubricating oil circuit 2, so as to provide oil to the cooling lubricating oil circuit 2 through the first oil circuit 3 alone, or through the second oil circuit 4 alone, or through the first oil circuit 3 and the second oil circuit 4 simultaneously.

[0077] Specifically, the mechanical pump 41 of the second oil circuit 4 is driven by the engine. When the hybrid vehicle operates in pure electric mode, the electronic pump 31 in the first oil circuit 3 operates. The electronic pump 31 extracts oil from the oil tank 1. The oil flows into the electronic pump 31 from the first oil inlet 311 and flows out from the first oil outlet 312. In this way, the first one-way valve 32 unidirectionally guides the first oil outlet 312 and the cooling lubricating oil circuit 2 under the push of the oil, so that the oil in the oil tank 1 enters the cooling lubricating oil circuit 2, realizing that the first oil circuit 3 supplies oil to the cooling lubricating oil circuit 2 alone.

[0078] It should be noted that when the electronic pump 31 operates, the operating temperature of the motor can be obtained in real time by the temperature sensor. When the operating temperature of the motor is high or the temperature rising speed is fast, the oil supply to the cooling lubricating oil circuit 2 can be increased by increasing the rotating speed of the electronic pump 31, so as to improve the cooling effect of the motor and prevent the motor from being damaged due to overheating.

[0079] When the hybrid vehicle operates in the non-pure electric mode, such as the hybrid vehicle operates in the parallel, direct drive or series mode, the engine works, the engine drives the mechanical pump 41 in the second oil circuit 4 to operate, the mechanical pump 41 extracts oil from the oil tank 1, and the oil flows out of the second oil outlet 412 of the mechanical pump 41, wherein a part of the oil flowing out of the second oil outlet 412 flows into the pilot inlet 423 of the first pressure regulating valve 42, for example, as shown in the figure, the pilot inlet 423 can provide a pilot pressure to the spool in the first pressure regulating valve 42 to drive it to move, so that the third inlet 421 of the first pressure regulating valve 42 is in communication with the third outlet 422, and further, another part of the oil flowing out of the second oil outlet 412 flows into the first pressure regulating valve 42 from the third inlet 421 and flows out of the third outlet 422, so that the second check valve 43 unidirectionally communicates the third outlet 422 and the cooling and lubricating oil circuit 2 under the push of the oil, so that the oil in the oil tank 1 enters the cooling and lubricating oil circuit 2, and the second oil circuit 4 alone supplies oil to the cooling and lubricating oil circuit 2. Figure 1

[0080] It should be noted that since the mechanical pump 41 is connected with the engine input shaft, the speed of the mechanical pump 41 is controlled by the engine speed, so the oil supply amount cannot be controlled alone, when the temperature sensor detects that the motor operating temperature is relatively high or the temperature rising speed is relatively fast, the first oil circuit 3 and the second oil circuit 4 can be simultaneously supplied with oil to the cooling and lubricating oil circuit 2 by starting the electronic pump 31, which improves the cooling efficiency, and the speed of the electronic pump 31 can be flexibly adjusted according to the motor operating temperature, which can meet the lubrication requirements of the motor, shaft tooth and clutch under different working conditions.

[0081] In summary, the gearbox hydraulic system 100 provided by the first aspect of the present application can use the electronic pump 31 to alone provide oil to the cooling and lubricating oil circuit 2, can use the mechanical pump 41 to alone provide oil to the cooling and lubricating oil circuit 2, and can use the electronic pump 31 and the mechanical pump 41 to simultaneously provide oil to the cooling and lubricating oil circuit 2, thereby not only meeting the cooling and lubrication requirements of the motor, shaft tooth and clutch under various working conditions, but also improving the cooling and lubrication efficiency by simultaneously providing oil through the electronic pump 31 and the mechanical pump 41.

[0082] In some embodiments of the present application, as shown in the figure, the gearbox hydraulic system 100 further comprises a control oil circuit 5, the control oil circuit 5 comprises a first control valve 51 and a pressure reducing valve 52, the pressure reducing valve 52 has a fourth inlet 521 and a fourth outlet 522 in communication, the fourth inlet 521 is in communication with the second outlet 412, the first control valve 51 is in communication with the fourth outlet 522 and the first pressure regulating valve 42, and the first control valve 51 selectively provides pressure oil to the first pressure regulating valve 42. Figure 1 ​​

[0083] Specifically, part of the oil flowing out from the second oil outlet 412 flows into the pressure reducing valve 52 through the fourth oil inlet 521, and then flows into the first control valve 51 from the fourth oil outlet 522 of the pressure reducing valve 52, and the first control valve 51 selectively provides pressure oil to the first pressure regulating valve 42. It should be noted that the oil pressure of the control oil circuit 5 can be reduced by the pressure reducing valve 52, so that the oil pressure of the control oil circuit 5 is less than the oil pressure of the second oil circuit 4, thereby reducing the loss of the main oil pressure of the second oil circuit 4.

[0084] When the hybrid vehicle operates in series mode, the engine does not directly drive the vehicle, so there is no need to establish the clutch oil pressure, and the first control valve 51 is controlled to provide pressure oil to the first pressure regulating valve 42. At this time, the oil inlet pressure of the first pressure regulating valve 42 can be reduced, thereby facilitating the reduction of pressure loss and improving the efficiency of the gearbox.

[0085] In some embodiments of the present application, the first control valve 51 can be configured as a normally high solenoid valve, and the first pressure regulating valve 42 can be configured as a pilot proportional relief valve. When the first control valve 51 is not powered, the first control valve 51 provides pressure oil to the first pressure regulating valve 42.

[0086] In some embodiments of the present application, as shown in Figure 1 The gearbox hydraulic system 100 further includes a third oil circuit 6 and a fourth oil circuit 7.

[0087] The third oil circuit 6 includes a second pressure regulating valve 61, the fifth oil inlet 611 of the second pressure regulating valve 61 is in communication with the second oil outlet 412, and the fifth oil outlet 612 of the second pressure regulating valve 61 is in communication with the first actuating oil circuit 8, which is used to deliver oil to the first clutch 9. The fourth oil circuit 7 includes a third pressure regulating valve 71, the sixth oil inlet 711 of the third pressure regulating valve 71 is in communication with the second oil outlet 412, and the sixth oil outlet 712 of the third pressure regulating valve 71 is in communication with the second actuating oil circuit 10, which is used to deliver oil to the second clutch 11. The control oil circuit 5 further includes a second control valve 53 and a third control valve 54. The second control valve 53 is in communication with the second oil outlet 412 and the second pressure regulating valve 61, and the second control valve 53 is used to selectively provide pilot oil to the second pressure regulating valve 61 to make the fifth oil inlet 611 and the fifth oil outlet 612 conductive or disconnected. The third control valve 54 is in communication with the second oil outlet 412 and the third pressure regulating valve 71, and the third control valve 54 is used to selectively provide pilot oil to the third pressure regulating valve 71 to make the sixth oil inlet 711 and the sixth oil outlet 712 conductive or disconnected.

[0088] Specifically, the gearbox hydraulic system 100 can further control the engagement of the first clutch 9 through the third oil path 6 and the engagement of the second clutch 11 through the fourth oil path 7, when the hybrid vehicle is running in parallel or direct drive mode, the engine is working and used to drive the vehicle, so it is necessary to establish the main oil pressure in the second oil path 2, that is, to control the first control valve 51 to stop providing pressure oil to the first pressure regulating valve 42, and the second pressure regulating valve 61 and the third pressure regulating valve 71 can output pressure. For example, the first control valve 51 can be configured as a normally high solenoid valve, and the first pressure regulating valve 42 can be configured as a pilot proportional relief valve. When the first control valve 51 is powered, the first control valve 51 stops providing pressure oil to the first pressure regulating valve 42, the second oil path 4 establishes the main oil pressure, and then the clutch oil pressure can be established.

[0089] Further, when the mechanical pump 41 is running, the mechanical pump 41 draws oil from the oil tank 1 and delivers the oil to the second oil outlet 412, part of the oil flowing out of the second oil outlet 412 flows into the control oil path 5, when the second control valve 53 in the control oil path 5 provides pilot oil to the second pressure regulating valve 61, the fifth inlet 611 of the second pressure regulating valve 61 is in communication with the fifth outlet 612, and thus part of the oil flowing out of the second oil outlet 412 can flow into the first execution oil path 8 through the third oil path 6, and the first execution oil path 8 can supply oil to the first clutch 9 to drive the engagement of the first clutch 9 in the gearbox. When the second control valve 53 in the control oil path 5 stops providing pilot oil to the second pressure regulating valve 61, the fifth inlet 611 of the second pressure regulating valve 61 is disconnected from the fifth outlet 612, and thus the first execution oil path 8 stops supplying oil to the first clutch 9, so that the first clutch 9 is opened; Similarly, when the third control valve 54 in the control oil path 5 provides pilot oil to the third pressure regulating valve 71, the sixth inlet 711 of the third pressure regulating valve 71 is in communication with the sixth outlet 712, and thus part of the oil flowing out of the second oil outlet 412 can flow into the second execution oil path 10 through the fourth oil path 7, and the second execution oil path 10 can supply oil to the second clutch 11 to drive the engagement of the second clutch 11 in the gearbox. When the third control valve 54 in the control oil path 5 stops providing pilot oil to the third pressure regulating valve 71, the sixth inlet 711 of the third pressure regulating valve 71 is disconnected from the sixth outlet 712, and thus the second execution oil path 10 stops supplying oil to the second clutch 11, so that the second clutch 11 is opened.

[0090] Further, in order to better understand the present scheme by those skilled in the art, the second control valve 53 and the third control valve 54 in the present application are both configured as normally low solenoid valves, and the second pressure regulating valve 61 and the third pressure regulating valve 71 are both configured as pilot proportional pressure reducing valves 52. When the second control valve 53 is powered on, the second control valve 53 provides pilot oil to the second pressure regulating valve 61. When the second control valve 53 is powered off, the second control valve 53 stops providing pilot oil to the second pressure regulating valve 61. Similarly, when the third control valve 54 is powered on, the third control valve 54 provides pilot oil to the third pressure regulating valve 71. When the third control valve 54 is powered off, the third control valve 54 stops providing pilot oil to the third pressure regulating valve 71. Assuming that the second clutch 11 corresponds to a higher vehicle speed relative to the first clutch 9, when the hybrid vehicle is operating in parallel or direct drive mode, the engine is operating, the engine drives the mechanical pump 41 to operate, the first control valve 51 (normally high solenoid valve) is powered on, the first pressure regulating valve 42 establishes main oil pressure in the second oil line 4, and the second oil line 4 provides oil to the cooling and lubricating oil line 2.

[0091] Meanwhile, the vehicle controller controls the second control valve 53 to provide pilot oil to the second pressure regulating valve 61 and controls the third control valve 54 to stop providing pilot oil to the third pressure regulating valve 71, or controls the second control valve 53 to stop providing pilot oil to the second pressure regulating valve 61 and controls the third control valve 54 to provide pilot oil to the third pressure regulating valve 71 according to the vehicle speed or the accelerator pedal angle, for example, when the vehicle speed or the accelerator pedal angle is small, the second control valve 53 is powered on and the third control valve 54 is powered off, the second control valve 53 provides pilot oil to the second pressure regulating valve 61 and the third control valve 54 stops providing pilot oil to the third pressure regulating valve 71, that is, the first execution oil path 8 supplies oil to the first clutch 9 to drive the first clutch 9 to engage in the gearbox, and the second execution oil path 10 stops supplying oil to the second clutch 11, so that the second clutch 11 is opened, that is, the vehicle is driven by the first clutch 9 to run, so that the vehicle runs in a low gear, when the vehicle speed or the accelerator pedal angle is large, the second control valve 53 is powered off and the third control valve 54 is powered on, the second control valve 53 stops providing pilot oil to the second pressure regulating valve 61 and the third control valve 54 provides pilot oil to the third pressure regulating valve 71, that is, the second execution oil path 10 supplies oil to the second clutch 11 to drive the second clutch 11 to engage in the gearbox, and the first execution oil path 8 stops supplying oil to the first clutch 9, so that the first clutch 9 is opened, that is, the vehicle is driven by the second clutch 11 to run, so that the vehicle runs in a high gear, in this way, the mechanical valve can also provide a gear shifting flow, realizing the two-gear gear shifting function of the gearbox, and the second oil path 4 can also supply oil to the cooling and lubricating oil path 2 to provide cooling and lubricating oil for the motor, the pinion shaft, the first clutch 9 and the second clutch 11. It should be noted that when the temperature sensor detects that the motor operating temperature is relatively high or the temperature rising speed is relatively fast, the first oil path 3 and the second oil path 4 can supply oil to the cooling and lubricating oil path 2 by starting the electronic pump 31, which improves the cooling efficiency, and the speed of the electronic pump 31 can be flexibly adjusted according to the motor operating temperature, which can meet the lubrication requirements of the motor, the shaft gear, the first clutch 9 and the second clutch 11 under different working conditions.

[0092] In some embodiments of the present application, as Figure 1As shown, the cooling and lubricating oil circuit 2 further comprises an oil cooler 21, the oil cooler 21 is provided with a seventh oil inlet 211 and a seventh oil outlet 212 in communication, the first oil outlet 312 is unidirectionally communicated with the seventh oil inlet 211 through the first one-way valve 32, the second oil outlet 412 is unidirectionally communicated with the seventh oil inlet 211 through the second one-way valve 43, and the seventh oil outlet 212 is used to supply oil to the motor, shaft tooth and clutch. That is, the oil supplied by the first oil circuit 3 and the second oil circuit 4 is cooled by the oil cooler 21 before being delivered to the motor, shaft tooth and clutch for cooling and lubrication. In this way, the oil cooler 21 further reduces the temperature of the oil delivered to the motor, shaft tooth and clutch, which is conducive to further improving the cooling effect of the motor, shaft tooth and clutch.

[0093] In some embodiments of the present application, as shown in Figure 1 As shown, the cooling and lubricating oil circuit 2 is further provided with a first safety overflow valve 22, and the second oil circuit 4 is further provided with a second safety overflow valve 44. In this way, the first safety overflow valve 22 can provide protection when the oil pressure of the cooling and lubricating oil circuit 2 is too high, and the second safety overflow valve 44 can provide protection when the oil pressure of the second oil circuit 4 is too high.

[0094] In some embodiments of the present application, as shown in Figure 1 As shown, the mechanical pump 41 and the electronic pump 31 are provided with a filter 12 between the mechanical pump 41 and the electronic pump 31 and the oil tank 1. That is, when the mechanical pump 41 and the electronic pump 31 are running, the oil extracted from the oil tank 1 by the mechanical pump 41 and the electronic pump 31 needs to be filtered through the filter 12, so as to filter the impurities in the oil and ensure the normal operation of the gearbox hydraulic system 100.

[0095] In some embodiments of the present application, as shown in Figure 1 As shown, the first execution oil circuit 8 is provided with a first pressure sensor 81 for testing the pressure of the first execution oil circuit 8, and the second execution oil circuit 10 is provided with a second pressure sensor 101 for testing the pressure of the second execution oil circuit 10.

[0096] Specifically, the first pressure sensor 81 can monitor the real-time pressure of the first execution oil circuit 8 and feed back the real-time pressure to the vehicle controller, so as to accurately control the first clutch 9 by adjusting the pilot oil pressure of the second pressure valve through the second control valve 53, ensure the stability and reliability of the operation of the first clutch 9, and reduce the wear and failure of the first clutch 9; similarly, the second pressure sensor 101 can monitor the real-time pressure of the second execution oil circuit 10 and feed back the real-time pressure to the vehicle controller, so as to accurately control the second clutch 11 by adjusting the pilot oil pressure of the third pressure valve through the third control valve 54, ensure the stability and reliability of the operation of the second clutch 11, and reduce the wear and failure of the second clutch 11.

[0097] To further improve the oil control level of the gearbox hydraulic system 100, the present application also provides an oil control method based on the gearbox hydraulic system 100, wherein the gearbox hydraulic system 100 is the gearbox hydraulic system 100 in the first embodiment of the first aspect.

[0098] The oil control method proposed by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0099] Figure 2 The flowchart of the oil control method according to the first embodiment of the present application. As shown in the figure, the oil control method includes: Figure 2

[0100] Step S101, determine the working mode of the gearbox.

[0101] Specifically, determine the working mode of the gearbox according to the working mode of the hybrid vehicle, wherein the hybrid vehicle has a pure electric mode and a non-pure electric mode (parallel, direct drive, series).

[0102] Step S102, if the gearbox is in pure electric mode, control the electronic pump to run.

[0103] When the hybrid vehicle is running in pure electric mode, the gearbox is in pure electric mode, and the vehicle controller controls the electronic pump 31 in the first oil circuit 3 to run, the electronic pump 31 draws oil from the oil tank 1, the oil flows into the electronic pump 31 from the first oil inlet 311 and flows out from the first oil outlet 312, so that the first one-way valve 32 is one-way conducted between the first oil outlet 312 and the cooling and lubricating oil circuit 2 under the push of the oil, so that the oil in the oil tank 1 enters the cooling and lubricating oil circuit 2, realizing that the first oil circuit 3 supplies oil to the cooling and lubricating oil circuit 2 alone.

[0104] Step S103, if the gearbox is in non-pure electric mode, control the mechanical pump to run, and obtain the motor temperature, if the motor temperature is greater than the preset temperature, control the electronic pump to run.

[0105] When the hybrid vehicle is running in non-pure electric mode, the gearbox is in non-pure electric mode, such as running in parallel, direct drive or series mode, the engine is working, the engine drives the mechanical pump 41 in the second oil circuit 4 to run, the mechanical pump 41 draws oil from the oil tank 1, the oil flows out from the second oil outlet 412 of the mechanical pump 41, wherein a part of the oil flowing out from the second oil outlet 412 flows into the pilot oil inlet 423 of the first pressure regulating valve 42, for example, Figure 1 ​As shown, the pilot oil inlet 423 can provide a pilot pressure to the spool in the first pressure regulating valve 42 to drive it to move, so that the third oil inlet 421 of the first pressure regulating valve 42 is communicated with the third oil outlet 422, and further, another part of the oil flowing out of the second oil outlet 412 flows into the first pressure regulating valve 42 from the third oil inlet 421 and flows out of the third oil outlet 422, so that the second one-way valve 43 is one-way communicated with the third oil outlet 422 and the cooling lubricating oil circuit 2 under the pushing of the oil, so that the oil in the oil tank 1 enters the cooling lubricating oil circuit 2, and the second oil circuit 4 is realized to supply oil to the cooling lubricating oil circuit 2 alone.

[0106] It should be noted that the motor temperature can be detected in real time by the temperature sensor, and when the motor temperature is greater than the preset temperature or the temperature rising speed is relatively fast, the first oil circuit 3 and the second oil circuit 4 can be simultaneously supplied with oil to the cooling lubricating oil circuit 2 by starting the electronic pump 31, so that the cooling efficiency is improved, and the speed of the electronic pump 31 can be flexibly adjusted according to the motor operating temperature, so as to meet the lubrication requirements of the motor, shaft tooth and clutch under different working conditions.

[0107] The oil control method provided by the second aspect of the present application can supply oil to the cooling lubricating oil circuit 2 by the electronic pump 31 alone when the gearbox is in the pure electric mode, can supply oil to the cooling lubricating oil circuit 2 by the mechanical pump 41 alone when the gearbox is in the non-pure electric mode, and can supply oil to the cooling lubricating oil circuit 2 by the electronic pump 31 and the mechanical pump 41 simultaneously when the motor temperature is greater than the preset temperature, so that not only the cooling and lubrication requirements of the motor, shaft tooth and clutch under various working conditions are met, but also the cooling and lubrication efficiency is improved by supplying oil by the electronic pump 31 and the mechanical pump 41 simultaneously.

[0108] In some embodiments of the present application, if the gearbox is in the pure electric mode, the method further includes: Figure 3 As shown, the method further includes:

[0109] Step S201: Obtain the motor temperature.

[0110] Step S202: If the motor temperature is greater than the preset temperature, increase the speed of the electronic pump.

[0111] Specifically, when the gearbox is in the pure electric mode, the motor temperature is detected in real time by the temperature sensor, and when the motor temperature is greater than the preset temperature or the temperature rising speed is relatively fast, the oil supply to the cooling lubricating oil circuit 2 can be increased by increasing the speed of the electronic pump 31, so as to improve the cooling effect of the motor and prevent the motor from being damaged due to overheating.

[0112] In some embodiments of the present application, if the gearbox is in the non-pure electric mode, the method further includes: if the gearbox is in the series mode, controlling the first control valve to provide pressure oil to the first pressure regulating valve.

[0113] Specifically, the first control valve 51 selectively provides pressure oil to the first pressure regulating valve 42, when the hybrid vehicle operates in series mode, the engine does not directly drive the vehicle, thus there is no need to establish clutch oil pressure, the first control valve 51 is controlled to provide pressure oil to the first pressure regulating valve 42, at this time, the oil inlet pressure of the first pressure regulating valve 42 can be reduced, thereby facilitating the reduction of pressure loss, and further improving the efficiency of the gearbox.

[0114] In some embodiments of the present application, the first control valve 51 can be configured as a normally high solenoid valve, and the first pressure regulating valve 42 can be configured as a pilot proportional relief valve, when the first control valve 51 is not powered, the first control valve 51 provides pressure oil to the first pressure regulating valve 42.

[0115] In some embodiments of the present application, if the gearbox is in non-pure electric mode, such as Figure 4 As shown in the method further comprises:

[0116] Step S301, if the gearbox is in direct drive mode or parallel mode, the first control valve is controlled to stop providing pressure oil to the first pressure regulating valve, and the vehicle speed or the accelerator pedal angle is obtained.

[0117] Step S302, according to the vehicle speed or the accelerator pedal angle, the second control valve is controlled to provide pilot oil to the second pressure regulating valve and the third control valve is controlled to stop providing pilot oil to the third pressure regulating valve, or the second control valve is controlled to stop providing pilot oil to the second pressure regulating valve and the third control valve is controlled to provide pilot oil to the third pressure regulating valve.

[0118] Specifically, when the hybrid vehicle operates in parallel or direct drive mode, the engine is working and is used to drive the vehicle, thus it is necessary to establish main oil pressure in the second oil circuit 2, that is, the first control valve 51 is controlled to stop providing pressure oil to the first pressure regulating valve 42, only then can the second pressure regulating valve 61 and the third pressure regulating valve 71 output pressure, for example, the first control valve 51 can be configured as a normally high solenoid valve, and the first pressure regulating valve 42 can be configured as a pilot proportional relief valve, when the first control valve 51 is powered, the first control valve 51 stops providing pressure oil to the first pressure regulating valve 42, the second oil circuit 4 establishes main oil pressure, the second oil circuit 4 provides oil to the cooling and lubricating oil circuit 2, and then the clutch oil pressure can be established.

[0119] Further, it is assumed that the second control valve 53 and the third control valve 54 in the present application are both configured as normally low solenoid valves, and the second pressure regulating valve 61 and the third pressure regulating valve 71 are both configured as pilot proportional pressure reducing valves 52. When the second control valve 53 is energized, the second control valve 53 provides pilot oil to the second pressure regulating valve 61. When the second control valve 53 is de-energized, the second control valve 53 stops providing pilot oil to the second pressure regulating valve 61. Similarly, when the third control valve 54 is energized, the third control valve 54 provides pilot oil to the third pressure regulating valve 71. When the third control valve 54 is de-energized, the third control valve 54 stops providing pilot oil to the third pressure regulating valve 71. It is assumed that the second clutch 11 corresponds to a higher vehicle speed relative to the first clutch 9.

[0120] Further, the vehicle controller controls the second control valve 53 to provide pilot oil to the second pressure regulating valve 61 and controls the third control valve 54 to stop providing pilot oil to the third pressure regulating valve 71, or controls the second control valve 53 to stop providing pilot oil to the second pressure regulating valve 61 and controls the third control valve 54 to provide pilot oil to the third pressure regulating valve 71, according to the vehicle speed or the accelerator pedal angle. For example, when the vehicle speed or the accelerator pedal angle is small, the second control valve 53 is energized, the third control valve 54 is de-energized, the second control valve 53 provides pilot oil to the second pressure regulating valve 61, and the third control valve 54 stops providing pilot oil to the third pressure regulating valve 71, that is, the first execution oil circuit 8 supplies oil to the first clutch 9 to drive the first clutch 9 to engage in the transmission, and the second execution oil circuit 10 stops supplying oil to the second clutch 11, so that the second clutch 11 is opened, that is, the vehicle is driven by the first clutch 9, so that the vehicle runs in a low gear. When the vehicle speed or the accelerator pedal angle is large, the second control valve 53 is de-energized, the third control valve 54 is energized, the second control valve 53 stops providing pilot oil to the second pressure regulating valve 61, and the third control valve 54 provides pilot oil to the third pressure regulating valve 71, that is, the second execution oil circuit 10 supplies oil to the second clutch 11 to drive the second clutch 11 to engage in the transmission, and the first execution oil circuit 8 stops supplying oil to the first clutch 9, so that the first clutch 9 is opened, that is, the vehicle is driven by the second clutch 11, so that the vehicle runs in a high gear.

[0121] In this way, the mechanical valve can also provide a gear shifting flow, realizing the two-gear gear shifting function of the transmission, and the second oil circuit 4 can also supply oil to the cooling and lubricating oil circuit 2 to provide cooling and lubricating oil for the motor, the gear shaft, the first clutch 9, and the second clutch 11. It should be noted that when the temperature sensor detects that the operating temperature of the motor is relatively high or the temperature rising speed is relatively fast, the first oil circuit 3 and the second oil circuit 4 can supply oil to the cooling and lubricating oil circuit 2 by starting the electronic pump 31, which improves the cooling efficiency, and the speed of the electronic pump 31 can be flexibly adjusted according to the operating temperature of the motor, so as to meet the lubrication requirements of the motor, the gear shaft, the first clutch 9, and the second clutch 11 under different working conditions.

[0122] It should also be noted that the terms "comprising," "including," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a... " does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0123] Various embodiments in the present specification are described in progressive manner, and the same or similar parts between various embodiments can be mutually referred to, and each embodiment focuses on the difference from other embodiments. In particular, for system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0124] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

[0125] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A hydraulic system for a gearbox, characterized in that, include: Oil storage tank; A cooling and lubrication oil circuit is used to supply oil to the motor, shaft gears, and clutch. The first oil circuit includes an electronic pump and a first check valve. The first oil inlet of the electronic pump is connected to the oil reservoir, and the first oil outlet of the electronic pump is unidirectionally connected to the cooling and lubricating oil circuit through the first check valve. The second oil circuit includes a mechanical pump, a first pressure regulating valve, and a second check valve. The second oil inlet of the mechanical pump is connected to the oil reservoir, and the second oil outlet of the mechanical pump is connected to the third oil inlet and the pilot oil inlet of the first pressure regulating valve. The pilot oil inlet is adapted to provide pilot oil to the first pressure regulating valve so that the third oil inlet is connected to the third oil outlet of the first pressure regulating valve. The third oil outlet is connected to the cooling and lubrication oil circuit unidirectionally through the second check valve. The control oil circuit includes a first control valve and a pressure reducing valve. The pressure reducing valve has a fourth oil inlet and a fourth oil outlet connected together. The fourth oil inlet is connected to a second oil outlet. The first control valve is connected to the fourth oil outlet and the first pressure regulating valve. The first control valve selectively supplies pressurized oil to the first pressure regulating valve. The third oil circuit includes a second pressure regulating valve, the fifth oil inlet of the second pressure regulating valve is connected to the second oil outlet, and the fifth oil outlet of the second pressure regulating valve is connected to the first execution oil circuit, which is used to deliver oil to the first clutch. The fourth oil circuit includes a third pressure regulating valve, the sixth oil inlet of the third pressure regulating valve is connected to the second oil outlet, and the sixth oil outlet of the third pressure regulating valve is connected to the second execution oil circuit, which is used to deliver oil to the second clutch. The control oil circuit also includes a second control valve and a third control valve. The second control valve is connected to both the second oil outlet and the second pressure regulating valve. The second control valve is used to selectively provide pilot oil to the second pressure regulating valve so that the fifth oil inlet and the fifth oil outlet are connected or disconnected. The third control valve is connected to both the second oil outlet and the third pressure regulating valve. The third control valve is used to selectively provide pilot oil to the third pressure regulating valve so that the sixth oil inlet and the sixth oil outlet are connected or disconnected.

2. The gearbox hydraulic system according to claim 1, characterized in that, The cooling and lubrication circuit also includes an oil cooler, which has a seventh oil inlet and a seventh oil outlet connected together. The first oil outlet is unidirectionally connected to the seventh oil inlet through the first check valve, and the second oil outlet is unidirectionally connected to the seventh oil inlet through the second check valve. The seventh oil outlet is used to supply oil to the motor, shaft gears, and clutch.

3. The gearbox hydraulic system according to claim 1, characterized in that, A filter is provided between the mechanical pump, the electronic pump and the oil tank.

4. The gearbox hydraulic system according to claim 1, characterized in that, The first actuation oil circuit is equipped with a first pressure sensor, which is used to test the pressure of the first actuation oil circuit; The second actuation oil circuit is equipped with a second pressure sensor, which is used to test the pressure of the second actuation oil circuit.

5. A method for controlling oil flow, characterized in that, The transmission hydraulic system according to any one of claims 1-4 employs the oil control method described above, the oil control method comprising: Determine the operating mode of the transmission; If the transmission is in pure electric mode, control the electronic pump to operate; If the gearbox is in non-pure electric mode, the mechanical pump is controlled to run and the motor temperature is obtained. If the motor temperature is greater than the preset temperature, the electronic pump is controlled to run.

6. The oil control method according to claim 5, characterized in that, If the transmission is in pure electric mode, the method further includes: Obtain the motor temperature; If the motor temperature is higher than the preset temperature, then the speed of the electronic pump is increased.

7. The oil control method according to claim 5, characterized in that, If the transmission is in non-pure electric mode, the method further includes: If the gearbox is in series mode, the first control valve is controlled to supply pressurized oil to the first pressure regulating valve.

8. The oil control method according to claim 5, characterized in that, If the transmission is in non-pure electric mode, the method further includes: If the transmission is in direct drive mode or parallel mode, control the first control valve to stop supplying pressurized oil to the first pressure regulating valve, and obtain the vehicle speed or accelerator pedal angle; Based on the vehicle speed or the accelerator pedal angle, control the second control valve to provide pilot oil to the second pressure regulating valve and control the third control valve to stop providing pilot oil to the third pressure regulating valve, or control the second control valve to stop providing pilot oil to the second pressure regulating valve and control the third control valve to provide pilot oil to the third pressure regulating valve.

Images