An automatic transmission hydraulic oil supply system and method

Abstract

The present invention provides an automatic transmission hydraulic oil supply system and method. By designing a first hydraulic part (12) and a second hydraulic part (13) with variable-diameter hollow cavities, the hydraulic oil entering the first hydraulic part (12) or the second hydraulic part (13) travels from the end with the largest diameter of the variable-diameter hollow cavity to the end with the smallest diameter, so that the oil pressure is increased, and the hydraulic oil with increased oil pressure in the first hydraulic part (12) and the second hydraulic part (13) alternately supplies oil to the main control oil circuit (20). The present invention can enable the electric oil pump (1) not to operate at high power for a long time, extend the service life of the electric oil pump (1), and has the beneficial effect of saving energy consumption.

Description

Technical Field

[0001] The present invention relates to a hydraulic oil supply system and method for an automatic transmission. Background Art

[0002] An automatic transmission requires a hydraulic oil supply system to supply oil to its clutch control end and shift control end, and the hydraulic oil pressure provided by the oil supply system needs to be greater than 40 bar. On this premise, the electronic oil pump that provides the hydraulic oil pressure for the oil supply system needs to have a relatively large power. Moreover, when there is an intermittent oil supply demand, the electronic oil pump needs to frequently and significantly change its own output power according to the intermittent change of the oil supply demand. The demand for a large output power increases the development cost of the electronic oil pump and also forces the volume of the electronic oil pump to be designed relatively large. Frequent and significant changes in the output power will shorten the service life of the electronic oil pump. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a hydraulic oil supply system and method for an automatic transmission.

[0004] The present invention provides a hydraulic oil supply system for an automatic transmission, including a high-pressure circuit at the control end. The high-pressure oil circuit at the control end includes:

[0005] A total control oil circuit;

[0006] A first hydraulic part, having a variable-diameter hollow cavity, including: a first oil supply cavity, a first accommodation cavity, a second accommodation cavity, and a first piston rod. The first piston rod can move in the first oil supply cavity, the first accommodation cavity, and the second accommodation cavity. The first oil supply cavity is located at the small-diameter end of the variable-diameter hollow cavity, and there is an outlet for hydraulic oil output thereon. The first accommodation cavity is located between the first oil supply cavity and the second accommodation cavity. The first accommodation cavity and the second accommodation cavity are respectively provided with outlets, and the flow direction of the hydraulic oil at the outlet of the second accommodation cavity is opposite to the flow direction of the hydraulic oil at the outlet of the first accommodation cavity;

[0007] A second hydraulic part, having a variable-diameter hollow cavity, including: a second oil supply cavity, a third accommodation cavity, a fourth accommodation cavity, and a second piston rod. The second piston rod can move in the second oil supply cavity, the third accommodation cavity, and the fourth accommodation cavity. The second oil supply cavity is located at the small-diameter end of the variable-diameter hollow cavity, and there is an outlet for hydraulic oil output thereon. The third accommodation cavity is located between the second oil supply cavity and the fourth accommodation cavity. The third accommodation cavity and the fourth accommodation cavity are respectively provided with outlets, and the flow direction of the hydraulic oil at the outlet of the third accommodation cavity is opposite to the flow direction of the hydraulic oil at the outlet of the fourth accommodation cavity;

[0008] The outlet for hydraulic oil output of the first oil supply cavity is communicated with the outlet for hydraulic oil output of the second oil supply cavity to the total control oil circuit.

[0009] Optionally, the high-pressure oil circuit at the control end further includes:

[0010] A first control valve, which communicates with the first accommodation cavity and the fourth accommodation cavity, and a second control valve, which communicates with the third accommodation cavity and the second accommodation cavity;

[0011] The hydraulic oil flows in opposite directions in the first control valve and the second control valve.

[0012] Optionally, the high-pressure oil circuit at the control end further includes:

[0013] A fourth control valve, the fourth control valve is a four-way reversing valve, one port of the fourth control valve communicates with the first accommodation cavity and the fourth accommodation cavity, and one port communicates with the second accommodation cavity and the third accommodation cavity.

[0014] Optionally, it further includes a first oil tank and a high-pressure pump, and the high-pressure oil circuit at the control end further includes: a main pressure valve, which connects the first control valve and the second control valve;

[0015] The high-pressure pump is used to extract hydraulic oil from the first oil tank and send it to the main pressure valve.

[0016] Optionally, it further includes a first oil tank, a low-pressure pump and a low-pressure oil circuit at the cooling end. The low-pressure oil circuit at the cooling end includes an oil-cooled pressure filter device. The low-pressure pump extracts hydraulic oil from a second oil tank and sends it to the oil-cooled pressure filter device. The first oil tank is communicated with the second oil tank. The oil-cooled pressure filter device is communicated with an oil return outlet, and the oil return outlet is communicated with the first oil tank.

[0017] Optionally, the high-pressure oil circuit at the control end is communicated with the low-pressure oil circuit at the cooling end through a branch.

[0018] Optionally, the branch that communicates the high-pressure oil circuit at the control end with the low-pressure oil circuit at the cooling end leads to the oil-cooled pressure filter device. A branch is in parallel with the oil-cooled pressure filter device, and a bypass valve is provided on this branch.

[0019] Optionally, a pressure limiting valve is further provided on the low-pressure oil circuit at the cooling end. One end of the pressure limiting valve is connected to the outlet of the oil-cooled pressure filter device, and the other end is connected to the channel between the second oil tank and the low-pressure pump.

[0020] The present invention also provides an automatic transmission hydraulic oil supply method, which uses the automatic transmission hydraulic oil supply system as described above, and includes the following steps:

[0021] Inject hydraulic oil into the first oil supply cavity, the second oil supply cavity, the second accommodation cavity and the third accommodation cavity;

[0022] Move the first piston rod in the direction of compressing the first oil supply chamber, and move the second piston rod in the direction of compressing the fourth accommodation chamber;

[0023] Introduce hydraulic oil into the first oil supply chamber, the second oil supply chamber, the first accommodation chamber, and the fourth accommodation chamber;

[0024] Move the second piston rod in the direction of compressing the second oil supply chamber, and move the first piston rod in the direction of compressing the second accommodation chamber.

[0025] Optionally, the step of introducing hydraulic oil into the first oil supply chamber, the second oil supply chamber, the second accommodation chamber, and the third accommodation chamber includes:

[0026] The hydraulic oil is introduced into the second accommodation chamber and the third accommodation chamber through one of the first control valve or the second control valve;

[0027] Or the step of introducing hydraulic oil into the first oil supply chamber, the second oil supply chamber, the first accommodation chamber, and the fourth accommodation chamber includes:

[0028] The hydraulic oil is introduced into the first accommodation chamber and the fourth accommodation chamber through one of the first control valve or the second control valve.

[0029] Optionally, the step of introducing hydraulic oil into the first oil supply chamber, the second oil supply chamber, the second accommodation chamber, and the third accommodation chamber includes:

[0030] The hydraulic oil is introduced into the second accommodation chamber and the third accommodation chamber through the fourth control valve;

[0031] The step of introducing hydraulic oil into the first oil supply chamber, the second oil supply chamber, the first accommodation chamber, and the fourth accommodation chamber includes:

[0032] The hydraulic oil is introduced into the first accommodation chamber and the fourth accommodation chamber through the fourth control valve.

[0033] Optionally, before the step of introducing the hydraulic oil into the first accommodation chamber and the fourth accommodation chamber through the fourth control valve, it includes:

[0034] Reverse the fourth control valve.

[0035] Optionally, the step of reversing the fourth control valve includes:

[0036] Make the third control valve provide the hydraulic oil pressure required for the movement of the spool inside the fourth control valve for the fourth control valve.

[0037] Optionally, after the step of moving the first piston rod in the direction of compressing the first oil supply chamber and moving the second piston rod in the direction of compressing the fourth accommodation chamber, it further includes:

[0038] Introduce the hydraulic oil flowing out of the first accommodation chamber and the fourth accommodation chamber into the low-pressure oil circuit at the cooling end; and / or

[0039] After the step of moving the second piston rod in the direction of compressing the second oil supply chamber and the first piston rod in the direction of compressing the second accommodation chamber, the following steps are further included:

[0040] Introduce the hydraulic oil flowing out of the second accommodation chamber and the third accommodation chamber into the low-pressure oil circuit at the cooling end.

[0041] In summary, the beneficial effects brought by the present invention are as follows:

[0042] 1. Enable the electric oil pump 1 not to operate at high power for a long time, extending the service life of the electric oil pump 1;

[0043] 2. Save energy consumption.

[0044] The above description is only an overview of the technical solution of the present invention. In order to be able to more clearly understand the technical means of the present invention, it can be implemented in accordance with the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically given and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the layout of the automatic transmission hydraulic oil supply system provided in the first embodiment of the present invention (first stage).

[0046] Figure 2 Schematic diagram of the layout of the main pressure valve ports in the first embodiment of the present invention.

[0047] Figure 3 Schematic diagram of the layout of the first control valve ports in the first embodiment of the present invention.

[0048] Figure 4 Schematic diagram of the layout of the second control valve ports in the first embodiment of the present invention.

[0049] Figure 5 Schematic diagram of the layout of the automatic transmission hydraulic oil supply system provided in the first embodiment of the present invention (second stage)

[0050] Figure 6 Schematic diagram of the layout of the automatic transmission hydraulic oil supply system provided in the second embodiment of the present invention (first stage).

[0051] Figure 7 Schematic diagram of the layout of the third control valve ports in the second embodiment of the present invention.

[0052] Figure 8 Schematic diagram of the layout of the fourth control valve ports in the second embodiment of the present invention.

[0053] Figure 9Schematic diagram of the layout of the automatic transmission hydraulic oil supply system provided in the second embodiment of the present invention (second stage).

[0054] Description of reference numerals

[0055] I - High - pressure oil circuit at the control end, II - Low - pressure oil circuit at the cooling end;

[0056] 1 - Electric oil pump, 101 - High - pressure pump, 102 - Low - pressure pump;

[0057] 2 - First oil tank, 3 - Second oil tank, 4 - Oil passage hole, 5 - Safety valve, 6 - First filter;

[0058] 7 - Main pressure valve, 71, 72, 73 - Ports of the main pressure valve;

[0059] 8 - First control valve, 81 - Port of the first control valve, 82 - Port of the second control valve, 83 - Port of the third control valve;

[0060] 9 - Second control valve, 91 - Port of the second control valve, 92 - Port of the second control valve, 93 - Port of the second control valve;

[0061] 10 - First check valve, 11 - Second check valve;

[0062] 12 - First hydraulic unit, 121 - First oil supply chamber, 122 - First piston rod, 123 - First accommodation chamber, 124 - Second accommodation chamber;

[0063] 13 - Second hydraulic unit, 131 - Second oil supply chamber, 132 - Second piston rod, 133 - Third accommodation chamber, 134 - Fourth accommodation chamber;

[0064] 14 - Third check valve, 15 - Fourth check valve, 16 - Accumulator, 17 - Pressure sensor, 18 - First control oil circuit, 19 - Second control oil circuit, 20 - Total control oil circuit;

[0065] a, b, c, d, e, f, g, h, i, j, k - Branch circuits, 21 - First branch circuit, 22 - Second branch circuit, 23 - Third branch circuit, 24 - Fourth branch circuit, 25 - Fifth branch circuit, 26 - Sixth branch circuit, 27 - Seventh branch circuit, 28 - Eighth branch circuit, 29 - Ninth branch circuit, 30 - Tenth branch circuit, 31 - Eleventh branch circuit, 32 - First shunt port, 33 - Second shunt port, 34 - Third shunt port, 35 - Fourth shunt port, 36 - Fifth shunt port, 37 - Sixth shunt port, 38 - Seventh shunt port, 39 - Eighth shunt port;

[0066] 40 - Bypass valve, 41 - Second filter, 42 - Oil cooler and pressure filter device, 43 - Fifth check valve, 44 - First outlet, 45 - Second outlet, 46 - Third outlet, 47 - Oil return outlet;

[0067] 48 - Third control valve, 481, 482, 483 - Ports of the third control valve;

[0068] 49 - Fourth control valve, 491, 492, 493, 494 - Ports of the fourth control valve;

[0069] 50 - Pressure limiting valve. Specific embodiments

[0070] The following will further describe in detail the specific embodiments of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0071] The terms "first", "second", etc. in the description and claims of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0072] Embodiment 1:

[0073] This embodiment provides an automatic transmission hydraulic oil supply system, including a control end high-pressure oil circuit I, a cooling end low-pressure oil circuit II, an electronic oil pump 1, a first oil tank 2, and a second oil tank 3. In this embodiment, the cooling end low-pressure oil circuit II of this system leads to the clutch shaft gear and bearing, the motor, and the third clutch respectively, and undertakes the function of cooling these components. As Figure 1 shown, the electronic oil pump 1 is a single-motor double-pump, including a high-pressure pump 101 and a low-pressure pump 102. The high-pressure pump 101 sucks hydraulic oil from the first oil tank 2 to provide an initial oil pressure for the control end high-pressure oil circuit I, and the low-pressure pump 102 sucks hydraulic oil from the second oil tank 3 to provide an initial oil pressure for the cooling end low-pressure oil circuit II. The first oil tank 2 and the second oil tank 3 are connected through an oil passing hole 4. In this embodiment, the first oil tank 2 includes an oil sump, and the second oil tank 3 includes the internal space of the transmission housing.

[0074] In this embodiment, the aforementioned control end high-pressure oil circuit I includes a safety valve 5, a first filter 6, a main pressure valve 7, a first control valve 8, a second control valve 9, a first check valve 10, a second check valve 11, a first hydraulic part 12, a second hydraulic part 13, a third check valve 14, a fourth check valve 15, an accumulator 16, and a pressure sensor 17.

[0075] Among them, the safety valve 5 is a ball valve that will open only when it has a certain pressure, and this ball valve can be replaced by a column valve or a slide valve that will open only when it has a certain pressure. Please further refer to Figure 2, the main pressure valve 7 is a three-position three-way pressure slide valve and is a hydraulic control valve, with oil pressure feedback ports provided at both ends. The main pressure valve 7 includes main pressure valve ports 71, 72, and 73. The main pressure valve ports 71 and 72 are opened on the same side of the main pressure valve 7, and the main pressure valve port 73 is located on the opposite side of them; the main pressure valve port 72 is directly connected to the first oil tank 2. When the oil pressure at the outlet of the first filter 6 is too high, part of the hydraulic oil can be guided back to the first oil tank 2 through the main pressure valve port 72.

[0076] Please further refer to Figure 3 and Figure 4 , the first control valve 8 and the second control valve 9 are pressure control type proportional solenoid valves. The first control valve 8 is a normally low pressure control valve, including first control valve ports 81, 82, and 83. The first control valve port 81 and the first control valve port 82 are opened on the same side of the first control valve 8, and the first control valve port 83 is located on the opposite side of them. The first control valve port 83 is communicated with the following first accommodation cavity 123 and the following fourth accommodation cavity 134. The second control valve 9 is a normally high pressure control valve, including second control valve ports 91, 92, and 93. The second control valve port 91 and the second control valve port 92 are opened on the same side of the second control valve 9, and the second control valve port 93 is located on the opposite side of them. The second control valve port 93 is communicated with the following second accommodation cavity 124 and the following third accommodation cavity 133.

[0077] Please refer to Figure 1 , the first hydraulic part 12 includes a first oil supply cavity 121, a first piston rod 122, a first accommodation cavity 123, and a second accommodation cavity 124. The first oil supply cavity 121, the first accommodation cavity 123, and the second accommodation cavity 124 form a T-shaped hollow cavity of the first hydraulic part 12. Among them, the first oil supply cavity 121 is the end with the smallest diameter in the T-shaped hollow cavity (hereinafter referred to as the small diameter end), and the first accommodation cavity 123 and the second accommodation cavity 124 are separated and formed at the end with the largest diameter in the T-shaped hollow cavity (hereinafter referred to as the large diameter end) via the following first piston rod 122, and the first accommodation cavity 123 is located between the second accommodation cavity 124 and the first oil supply cavity 121.

[0078] Continuing from the above, the first piston rod 122 is also T-shaped, having an end with the largest diameter (hereinafter referred to as the large end) and an end with the smallest diameter (hereinafter referred to as the small end). Its large end can reciprocate in the first accommodation cavity 123 and the second accommodation cavity 124, and its small end can reciprocate in the first oil supply cavity 121. An outlet is opened on the side wall of the first oil supply cavity 121 for hydraulic oil to be input, and an outlet is also opened at the end of the first oil supply cavity 121 far from the large end of the first piston rod 122 for hydraulic oil to be output.

[0079] As described above, the outlet of the first oil supply chamber 121 away from the large end of the first piston rod 122 communicates with the first control oil passage 18, and a third one-way valve 14 is provided on the first control oil passage 18; the second accommodation chamber 124 is located at one end of the first piston rod 122 away from the small end, and an outlet is provided on its side wall for communicating with the outside; an outlet is also provided on the side wall of the first accommodation chamber 123 for communicating with the outside.

[0080] Optionally, on the premise that the first oil supply chamber 121 is in the small-diameter end of the first hydraulic part 12, the hollow cavity can also adopt other variable-diameter forms.

[0081] In this embodiment, when the first oil supply chamber 121, the first accommodation chamber 123, and the second accommodation chamber 124 are all filled with hydraulic oil, since the first oil supply chamber 121 is the small-diameter end of the T-shaped hollow cavity, when the first piston rod 122 moves in the direction of compressing the first oil supply chamber 121, the hydraulic oil pressure flowing out from the outlet of the first oil supply chamber 121 will be several times the hydraulic oil pressure in the first accommodation chamber 123 and the second accommodation chamber 124. And, regardless of whether the first piston rod 122 moves in the direction of compressing the first oil supply chamber 121 or away from the first oil supply chamber 121, the flow direction of the hydraulic oil at the outlet of the second accommodation chamber 124 is always opposite to the flow direction of the hydraulic oil at the outlet of the first accommodation chamber 123.

[0082] The structure of the second hydraulic part 13 is similar to that of the first hydraulic part 12, including a second oil supply chamber 131, a second piston rod 132, a third accommodation chamber 133, and a fourth accommodation chamber 134, which will not be elaborated here. The outlet of the second oil supply chamber 131 away from the large end of the second piston rod 132 communicates with the second control oil passage 19, and a fourth one-way valve 15 is provided on the second control oil passage 19; the fourth accommodation chamber 134 is located at one end of the first piston rod 122 away from the small end, and an outlet is provided on its side wall for communicating with the outside; the third accommodation chamber 133 is located between the second oil supply chamber 131 and the fourth accommodation chamber 134, and an outlet is also provided on its side wall for communicating with the outside.

[0083] As described above, after the hydraulic oil entering the first control oil passage 18 passes through the third one-way valve 14, and the hydraulic oil entering the second control oil passage 19 passes through the fourth one-way valve 15, the hydraulic oil in the first control oil passage 18 and the hydraulic oil in the second control oil passage 19 will converge and flow into the total control oil passage 20 together. The total control oil passage 20 leads to the clutch control end and the shift control end of the transmission, and an accumulator 16 and a pressure sensor 17 are provided thereon to store hydraulic energy, reduce pressure fluctuations, and perform real-time pressure detection.

[0084] Specifically, the inlet of the high-pressure pump 101 communicates with the first oil tank 2, the outlet of the high-pressure pump 101 communicates with the first filter 6, the inlet of the safety valve 5 is located on the connection channel between the high-pressure pump 101 and the first filter 6, and the outlet communicates with the first oil tank 2. Thus, if the oil pressure in the connection channel between the high-pressure pump 101 and the first filter 6 is too high, the safety valve 5 will automatically open, enabling some hydraulic oil to be guided back to the first oil tank 2 through the safety valve 5 to complete pressure relief.

[0085] At the outlet of the first filter 6, the oil passage is divided into a first branch 21, branch a, and branch b. The first branch 21 includes the passage between the main pressure valve port 71 and the main pressure valve port 73. A first shunt port 32 is provided at the main pressure valve port 71. The first branch 21 is divided into branch d and a third branch 23 at the first shunt port 32. Branch d is then divided into a second branch 22 and branch g. Branch g communicates with the low-pressure oil path II at the cooling end. The second branch 22 is connected to the first control valve port 82 of the first control valve 8. When the first control valve port 82 is in communication with the first control valve port 83, the second branch 22 communicates with the fourth accommodation chamber 134 and the first accommodation chamber 123 respectively. The third branch 23 is connected to the second control valve port 92 of the second control valve 9. When the second control valve port 92 is in communication with the second control valve port 93, the third branch 23 communicates with the third accommodation chamber 133 and the second accommodation chamber 124 respectively.

[0086] On the other side, on branch a, branch a is divided into a fourth branch 24 and branch c. Branch b and branch c communicate with both ends of the main pressure valve 7 having an oil pressure feedback port respectively. On the fourth branch 24, a second shunt port 33, a third shunt port 34, and a fourth shunt port 35 are provided in sequence. The fourth branch 24 branches out a fifth branch 25 at the second shunt port 33. The fifth branch 25 is connected to the first control valve port 81 of the first control valve 8. When the first control valve port 81 is in communication with the first control valve port 83, the fifth branch 25 communicates with the fourth accommodation chamber 134 and the first accommodation chamber 123 respectively. At the third shunt port 34, the fourth branch 24 branches out a sixth branch 26. The sixth branch 26 is connected to the second control valve port 91 of the second control valve 9. When the second control valve port 91 is in communication with the second control valve port 93, the sixth branch 26 communicates with the third accommodation chamber 133 and the second accommodation chamber 124 respectively. At the fourth shunt port 35, the second branch 22 is divided into a seventh branch 27 and an eighth branch 28. A first one-way valve 10 is provided on the seventh branch 27 and leads to the side wall of the second oil supply chamber 131. A second one-way valve 11 is provided on the eighth branch 28 and leads to the side wall of the first oil supply chamber 121.

[0087] The above is the setting of the high-pressure oil circuit I at the control end. In this embodiment, the aforementioned low-pressure oil circuit II at the cooling end includes a bypass valve 40, a second filter 41, an oil-cooling pressure filter device 42, and a fifth one-way valve 43. Among them, the bypass valve 40 is a two-position two-way slide valve, with oil passages for feedback pressure provided at both ends; the fifth one-way valve 43 is arranged on the above-mentioned branch g, and its function is to only allow hydraulic oil to flow from the high-pressure oil circuit I at the control end into the low-pressure oil circuit II at the cooling end. The inlet of the second filter 41 is connected to the second oil tank 3, the outlet is connected to the inlet of the low-pressure pump 102, and the outlet of the low-pressure pump 102 is connected to the inlet of the oil-cooling pressure filter device 42.

[0088] Specifically, a fifth diversion port 36 is provided at the outlet of the fifth one-way valve 43. The branch g is divided into a branch e and a branch f at the fifth diversion port 36. The bypass valve 40 is arranged on the branch e, and the oil-cooling pressure filter device 42 is arranged on the branch f, and the bypass valve 40 is in parallel with the oil-cooling pressure filter device 42. In this way, when the oil-cooling pressure filter device 42 becomes blocked or fails, the pressure at both ends of the bypass valve 40 rises suddenly, causing the bypass valve 40 to open and undertake the diversion work, so that the low-pressure oil circuit II at the cooling end will not immediately stop working. At the outlet of the bypass valve 40, the branch f and the branch e merge into one oil passage, and this oil passage leads to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively.

[0089] Among them, the first outlet 44 leads to the clutch shaft teeth and bearings, the second outlet 45 leads to the motor, the third outlet 46 leads to the third clutch, and the oil return outlet 47 is connected to the first oil tank 2. In this way, the low-pressure oil circuit II at the cooling end can cool the clutch shaft teeth and bearings, the motor, and the third clutch, and the oil level height of the first oil tank 2 is always higher than that of the second oil tank 3. Of course, the number of outlets of the low-pressure oil circuit II at the cooling end and the destinations of each outlet can be flexibly adjusted by those skilled in the art according to needs.

[0090] Further, a pressure limiting valve 50 is also provided on the low-pressure oil circuit II at the cooling end. The pressure limiting valve 50 is a two-position two-way slide valve. One end of it is connected to the outlet of the oil-cooling pressure filter device 42 to feedback the outlet pressure of the oil-cooling pressure filter device 42, and the other end is connected to the passage between the second filter 41 and the low-pressure pump 102. In this way, when it is detected that the outlet pressure of the oil-cooling pressure filter device 42 is too high, the pressure limiting valve 50 will open and drain oil, and part of the hydraulic oil leaving the oil-cooling pressure filter device 42 returns to the inlet of the low-pressure pump 102 through the pressure limiting valve 50.

[0091] Based on the above high-pressure oil circuit I at the control end and low-pressure oil circuit II at the cooling end, the working steps of the system described in this embodiment are divided into two stages. For the convenience of description, the following is described on the premise that each chamber in the first hydraulic unit 12 and the second hydraulic unit 13 is filled with hydraulic oil.

[0092] In the first stage of the system operation, the electronic oil pump 1 is started, the first control valve 8 is closed, and the second control valve 9 is opened. At this time, the first control valve port 82 and the first control valve port 83 of the first control valve 8 are in a communicating state, and the second control valve port 92 and the second control valve port 93 of the second control valve 9 are in a communicating state.

[0093] In the low-pressure oil circuit II at the cooling end, the low-pressure pump 102 extracts hydraulic oil from the second oil tank 3. The hydraulic oil enters the oil cooler pressure filter device 42 through the second filter 41 and the low-pressure pump 102, and after leaving the oil cooler pressure filter device 42, it goes to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively.

[0094] In the high-pressure oil circuit I at the control end, the high-pressure pump 101 extracts hydraulic oil from the first oil tank 2. After the hydraulic oil passes through the high-pressure pump 101 and the first filter 6 in sequence, at the outlet of the first filter 6, a part of the hydraulic oil enters the first branch 21, enters the main pressure valve 7, and after leaving the main pressure valve port 71, part of it enters the branch d and part enters the third branch 23; another part of the hydraulic oil sequentially enters the fifth branch 25, the sixth branch 26, the seventh branch 27, and the eighth branch 28 along the branch a and the fourth branch 24. It should be noted that since the first control valve port 82 and the first control valve port 83 are in a communicating state, the first control valve port 81 is in a state of being closed by the valve core at this time, and the fifth branch 25 is also in a closed state. For the convenience of viewing, the channels in the closed state will not show the flow arrows in the shown drawings. Since the second control valve port 92 and the second control valve port 93 are in a communicating state, the second control valve port 91 is in a state of being closed by the valve core at this time, and the sixth branch 26 is also in a closed state.

[0095] Through the third branch 23, the hydraulic oil enters the third accommodation cavity 133 and the second accommodation cavity 124 respectively; through the seventh branch 27, the hydraulic oil enters the second oil supply cavity 131; through the eighth branch 28, the hydraulic oil enters the first oil supply cavity 121. At this time, the third accommodation cavity 133 and the second accommodation cavity 124 bear the first oil pressure, and the first oil supply cavity 121 and the second oil supply cavity 131 bear the second oil pressure.

[0096] By controlling the current applied to the second control valve 9 to make the first oil pressure greater than the second oil pressure, the first piston rod 122 can be made to move in the direction of compressing the first oil supply cavity 121 and the first accommodation cavity 123, and the second piston rod 132 can be made to move in the direction of compressing the fourth accommodation cavity 134. The hydraulic oil flows out from the outlet at the end of the first oil supply cavity 121 far from the large end of the first piston rod 122, the outlet on the side wall of the first accommodation cavity 123, and the outlet on the side wall of the fourth accommodation cavity 134.

[0097] Continuing from the above, the hydraulic oil flowing out of the first oil supply chamber 121 sequentially enters the first control oil circuit 18 and the main control oil circuit 20, and part of it enters the accumulator 16, and part of it flows to the clutch control end and the shift control end of the transmission. The hydraulic oil flowing out of the outlet on the side wall of the first accommodation chamber 123 and the hydraulic oil flowing out of the outlet on the side wall of the fourth accommodation chamber 134 converge and then enter the first control valve 8, flow from the first control valve port 83 to the first control valve port 82, and enter the second branch 22. The hydraulic oil entering the second branch 22 and the hydraulic oil flowing into branch d immediately converge and enter branch g, going to the low-pressure oil circuit II at the cooling end. After entering the low-pressure oil circuit II at the cooling end from branch g, it converges with the hydraulic oil from the low-pressure pump 102, enters the oil cooler and pressure filter device 42, and then leaves the oil cooler and pressure filter device 42 and goes to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively.

[0098] Please further refer to Figure 5 , in the second stage, the first control valve 8 is opened and the second control valve 9 is closed. At this time, the first control valve port 81 of the first control valve 8 is in a communicating state with the first control valve port 83, and the port 91 of the second control valve 9 is in a communicating state with the port 93. At this time, the flow direction of the hydraulic oil in the low-pressure oil circuit II at the cooling end is the same as that in the first stage, which will not be elaborated here. The flow direction of the hydraulic oil before the diversion at the outlet of the first filter 6 is the same as that in the first stage, which will not be elaborated here.

[0099] When the hydraulic oil is diverted at the outlet of the first filter 6, part of the hydraulic oil enters the first branch 21, enters the main pressure valve 7, and after leaving the main pressure valve port 71, enters branch d and the third branch 23, and branch d is immediately divided into branch g and the second branch 22; another part of the hydraulic oil sequentially enters the fifth branch 25, the sixth branch 26, the seventh branch 27, and the eighth branch 28 along branch a and the fourth branch 24. It should be noted that since the first control valve port 81 is in a communicating state with the first control valve port 83, the first control valve port 82 is in a state of being blocked by the valve core at this time, and the second branch 22 is also in a blocked state; after branch g enters the low-pressure oil circuit II at the cooling end, it converges with the hydraulic oil from the low-pressure pump 102, enters the oil cooler and pressure filter device 42, and then leaves the oil cooler and pressure filter device 42 and goes to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively; since the second control valve port 91 is in a communicating state with the second control valve port 93, the second control valve port 92 is in a state of being blocked by the valve core at this time, and the third branch 23 is also in a blocked state.

[0100] Through the fifth branch 25, the hydraulic oil enters the fourth accommodation chamber 134 and the first accommodation chamber 123 respectively; through the seventh branch 27, the hydraulic oil enters the second oil supply chamber 131; through the eighth branch 28, the hydraulic oil enters the first oil supply chamber 121. At this time, the fourth accommodation chamber 134 and the first accommodation chamber 123 bear the first oil pressure, and the first oil supply chamber 121 and the second oil supply chamber 131 bear the second oil pressure.

[0101] By controlling the current applied to the first control valve 8, making the first oil pressure greater than the second oil pressure, the first piston rod 122 can be moved in the direction of compressing the second accommodation chamber 124, and the second piston rod 132 can be moved in the direction of compressing the second oil supply chamber 131 and the third accommodation chamber 133. The hydraulic oil flows out from the outlet on the side wall of the second accommodation chamber 124, the outlet of the second oil supply chamber 131 away from the large end of the second piston rod 132, and the outlet on the side wall of the third accommodation chamber 133.

[0102] The hydraulic oil flowing out from the outlet of the second oil supply chamber 131 enters the second control oil circuit 19 and the total control oil circuit 20 in sequence, and part of it enters the accumulator 16, and part of it flows to the clutch control end and the shift control end of the transmission. The hydraulic oil flowing out from the outlet on the side wall of the second accommodation chamber 124 and the hydraulic oil flowing out from the outlet on the side wall of the third accommodation chamber 133 are collected and enter the second control valve 9, flow from the second control valve port 93 to the second control valve port 91, enter the sixth branch 26, and merge into the fourth branch 24.

[0103] It can be seen from the working steps of the above Embodiment 1 that when the first hydraulic part 12 and the second hydraulic part 13 are filled with hydraulic oil, one of the first control valve 8 and the second control valve 9 always guides the hydraulic oil into the first hydraulic part 12 and the second hydraulic part 13. At the same time, the first hydraulic part 12 and the second hydraulic part 13 always discharge part of the hydraulic oil at the same time. The discharged hydraulic oil enters the other one of the first control valve 8 and the second control valve 9, and flows to the low-pressure oil circuit II at the cooling end or re-enters the high-pressure oil circuit I at the control end for circulation. The flow directions of the hydraulic oil in the first control valve 8 and the second control valve 9 are always opposite.

[0104] On the premise that the flow directions of the hydraulic oil in the first control valve 8 and the second control valve 9 are always opposite, optionally, the first control valve 8 can also be connected to the third accommodation chamber 133 and the second accommodation chamber 124. At this time, the second control valve 9 is connected to the first accommodation chamber 123 and the fourth accommodation chamber 134.

[0105] Embodiment 2:

[0106] As Figure 6 shown, in Embodiment 2, on the basis of Embodiment 1, the first control valve 8 and the second control valve 9 are cancelled, and the third control valve 48 and the fourth control valve 49 are added.

[0107] Please further refer toFigure 7 and Figure 8 The third control valve 48 is a normally-closed pressure control valve, including third control valve ports 481, 482, and 483. The third control valve ports 481 and 482 are opened on the same side of the third control valve 48, and the third control valve port 483 is located on the opposite side of them. The fourth control valve 49 is a hydraulic directional control valve, including fourth control valve ports 491, 492, 493, and 494. The fourth control valve ports 491 and 492 are opened on the same side of the fourth control valve 49, and the fourth control valve ports 493 and 494 are located on the opposite side of them. The fourth control valve port 491 communicates with the first accommodation chamber 123 and the fourth accommodation chamber 134, and the fourth control valve port 492 communicates with the second accommodation chamber 124 and the third accommodation chamber 133.

[0108] In this embodiment, the function of the third control valve 48 is to provide the hydraulic oil pressure required for the spool movement of the fourth control valve 49, so as to control whether the fourth control valve 49 is reversed, and output the magnitude of the oil pressure to control the input-output ratio of each port of the fourth control valve 49.

[0109] In this embodiment, at the outlet of the first filter 6, the oil passage is divided into a first branch 21, a branch a, and a branch b. The first branch 21 includes the passage between the main pressure valve ports 71 and 73 of the main pressure valve 7. A sixth shunt port 37 is provided at the main pressure valve port 73. The first branch 21 is divided into a ninth branch 29 and a branch i at the sixth shunt port 37. The branch i is connected to the third control valve port 482 of the third control valve 48. When the third control valve port 482 is connected to the third control valve port 483, the branch i leads to the fourth control valve 49, and the hydraulic oil in the branch i can push the spool in the fourth control valve 49 to move, so that the fourth control valve 49 is reversed or the input-output ratio of its own ports is changed.

[0110] On the other side, on branch a, branch a is further divided into branch h and branch c. On branch h, a seventh diversion port 38, an eighth diversion port 39, and a fourth diversion port 35 are sequentially arranged. Branch h diverges into branch j at the seventh diversion port 38, and branch j is communicated with the third control valve port 481 of the third control valve 48; branch h diverges into the tenth branch 30 at the eighth diversion port 39, and the tenth branch 30 is communicated with the fourth control valve port 493 of the fourth control valve 49. When the fourth control valve port 493 is communicated with the fourth control valve port 491, the tenth branch 30 is respectively communicated with the fourth accommodation chamber 134 and the first accommodation chamber 123. When the fourth control valve port 493 is communicated with the fourth control valve port 492, the tenth branch 30 is respectively connected to the third accommodation chamber 133 and the second accommodation chamber 124; branch h is divided into the seventh branch 27 and the eighth branch 28 at the fourth diversion port 35. A first one-way valve 10 is provided on the seventh branch 27, leading to the second oil supply chamber 131, and a second one-way valve 11 is provided on the eighth branch 28, leading to the first oil supply chamber 121.

[0111] The working steps of the system described in this embodiment are divided into two stages. For the convenience of description, the following will be described on the premise that each chamber in the first hydraulic unit 12 and the second hydraulic unit 13 is filled with hydraulic oil.

[0112] In the first stage, start the electronic oil pump 1 and open the third control valve 48. At this time, the third control valve port 481 of the third control valve 48 is in a communicating state with the third control valve port 483. Apply a control current to the third control valve 48 so that the third control valve 48 can output the hydraulic oil required for the fourth control valve 49 to change its direction, making the fourth control valve port 493 of the fourth control valve 49 in a communicating state with the fourth control valve port 492, and the fourth control valve port 491 in a communicating state with the fourth control valve port 494.

[0113] In the low-pressure oil path II of the cooling end, the low-pressure pump 102 extracts hydraulic oil from the second oil tank 3. The hydraulic oil enters the oil-cooling pressure filter device 42 through the second filter 41 and the low-pressure pump 102, and after leaving the oil-cooling pressure filter device 42, it goes to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively.

[0114] In the high-pressure oil path I of the control end, the high-pressure pump 101 extracts hydraulic oil from the first oil tank 2. After the hydraulic oil passes through the high-pressure pump 101 and the first filter 6 in sequence, at the outlet of the first filter 6, a part of the hydraulic oil then sequentially enters branch j, the tenth branch 30, the seventh branch 27, and the eighth branch 28 along branch a and branch h, and another part of the hydraulic oil enters the first branch 21, enters the main pressure valve 7, and after leaving the main pressure valve port 71, it enters branch i and the ninth branch 29 respectively. It should be noted that since the third control valve port 481 is communicated with the third control valve port 483, at this time, the third control valve port 482 is blocked by the valve core, and branch i is in a closed state.

[0115] Through branch j, the hydraulic oil flows from the third control valve port 481 of the third control valve 48 to the third control valve port 483, and after flowing out of the third control valve port 483, it enters the fourth control valve 49 to provide moving power for the spool of the fourth control valve 49. Through the tenth branch 30, the hydraulic oil flows from the fourth control valve port 493 of the fourth control valve 49 to the fourth control valve port 492, and then enters the third accommodation chamber 133 and the second accommodation chamber 124 respectively; through the seventh branch 27, the hydraulic oil enters the second oil supply chamber 131; through the eighth branch 28, the hydraulic oil enters the first oil supply chamber 121.

[0116] At this time, the third accommodation chamber 133 and the second accommodation chamber 124 bear the first oil pressure, and the first oil supply chamber 121 and the second oil supply chamber 131 bear the second oil pressure. By controlling the current applied to the third control valve 48 to make the first oil pressure greater than the second oil pressure, the first piston rod 122 can be made to move in the direction of compressing the first oil supply chamber 121 and the first accommodation chamber 123, and the second piston rod 132 can be made to move in the direction of compressing the fourth accommodation chamber 134, and the hydraulic oil flows out from the outlet of the first oil supply chamber 121 away from the large end of the first piston rod 122, the outlet on the side wall of the first accommodation chamber 123, and the outlet on the side wall of the fourth accommodation chamber 134.

[0117] Specifically, the hydraulic oil flowing out from the first oil supply chamber 121 sequentially enters the first control oil circuit 18 and the total control oil circuit 20, and part of it enters the accumulator 16, and part of it flows to the clutch control end and the shift control end of the transmission. The hydraulic oil flowing out from the outlet on the side wall of the first accommodation chamber 123 and the hydraulic oil flowing out from the outlet on the side wall of the fourth accommodation chamber 134 are collected and then enter the fourth control valve 49, flow from the fourth control valve port 491 to the fourth control valve port 494, and enter the eleventh branch 31 communicated with the fourth control valve port 494. The hydraulic oil entering the eleventh branch 31 and the hydraulic oil flowing into the ninth branch 29 as described above are then collected and enter branch k, and branch k goes to the cooling end low-pressure oil circuit II. After branch k enters the cooling end low-pressure oil circuit II, it is collected with the hydraulic oil from the low-pressure pump 102, enters the oil cooler and filter press device 42, and then leaves the oil cooler and filter press device 42 and goes to the first outlet 44, the second outlet 45, the third outlet 46, and the oil return outlet 47 respectively.

[0118] In the second stage, the third control valve 48 is closed. At this time, the third control valve port 482 and the third control valve port 483 of the third control valve 48 are in a communicating state. The fourth control valve 49 loses the commutation power provided by the third control valve 48. The fourth control valve port 491 communicates with the fourth control valve port 493, and the fourth control valve port 492 communicates with the fourth control valve port 494. At this time, the flow direction of the hydraulic oil in the low-pressure oil circuit II at the cooling end is the same as that in the first stage, which will not be elaborated here. The flow direction of the hydraulic oil before the diversion at the outlet of the first filter 6 is the same as that in the first stage, which will not be elaborated here.

[0119] After the hydraulic oil is diverted at the outlet of the first filter 6, a part of the hydraulic oil sequentially enters the branch j, the tenth branch 30, the seventh branch 27, and the eighth branch 28 along the branch a and the branch h; another part of the hydraulic oil enters the first branch 21, enters the main pressure valve, and after leaving the main pressure valve port 71, part of it enters the branch i and part enters the ninth branch 29. It should be noted that at this time, the third control valve 48 is closed. The third control valve port 482 and the third control valve port 483 of the third control valve 48 are in a communicating state. The third control valve port 481 is blocked by the valve core, and the branch j is in a closed state. Although there is part of the hydraulic oil in the branch i, and this part of the hydraulic oil also flows from the third control valve port 482 to the third control valve port 483 and then into the fourth control valve 49, it is not sufficient to commutate the fourth control valve 49. Therefore, Figure 9 no symbol indicating the flow direction is marked on the branch i in the figure either.

[0120] Through the tenth branch 30, the hydraulic oil enters the fourth control valve 49, and after passing through the fourth control valve port 493 and the fourth control valve port 491, it enters the fourth accommodation chamber 134 and the first accommodation chamber 123 respectively; through the seventh branch 27, the hydraulic oil enters the second oil supply chamber 131; through the eighth branch 28, the hydraulic oil enters the first oil supply chamber 121. At this time, the fourth accommodation chamber 134 and the first accommodation chamber 123 bear the first oil pressure, and the first oil supply chamber 121 and the second oil supply chamber 131 bear the second oil pressure. And because the branch h first diverges at the eighth diversion port 39 and then diverges the seventh branch 27 and the eighth branch 28, the first oil pressure is greater than the second oil pressure. Therefore, the first piston rod 122 moves in the direction of compressing the second accommodation chamber 124, and the second piston rod 132 moves in the direction of compressing the second oil supply chamber 131 and the third accommodation chamber 133. The hydraulic oil flows out from the outlets on the side walls of the second accommodation chamber 124, the outlet of the second oil supply chamber 131, and the outlets on the side walls of the third accommodation chamber 133.

[0121] Continuing from the above, the hydraulic oil flowing out of the outlet of the second oil supply chamber 131 sequentially enters the second control oil circuit 19 and the main control oil circuit 20, and part of it enters the accumulator 16, and part flows to the clutch control end and the shift control end of the transmission. The hydraulic oil flowing out of the outlet on the side wall of the second accommodation chamber 124 and the hydraulic oil flowing out of the outlet on the side wall of the third accommodation chamber 133 converge and enter the fourth control valve 49, flow from the port 492 of the fourth control valve to the port 494 of the fourth control valve, and enter the eleventh branch 31. The hydraulic oil entering the eleventh branch 31 converges with the hydraulic oil from the ninth branch 29 and then flows into branch k and goes to the low-pressure oil circuit II at the cooling end. After branch k enters the low-pressure oil circuit II at the cooling end, it converges with the hydraulic oil from the low-pressure pump 102, enters the oil cooler and filter device 42, and then leaves the oil cooler and filter device 42 and goes to the first outlet 44, the second outlet 45, the third outlet 46 and the oil return outlet 47 respectively.

[0122] Continuing from the above, in the first embodiment, as long as the first control valve 8 and the second control valve 9 are alternately opened and closed, and the magnitude of the current applied to the first control valve 8 or the second control valve 9 is controlled, the first hydraulic part 12 and the second hydraulic part 13 can alternately supply oil to the main control oil circuit 20. In the second embodiment, as long as the third control valve 48 is alternately opened and closed, and the magnitude of the current applied to the third control valve 48 is controlled, the first hydraulic part 12 and the second hydraulic part 13 can alternately supply oil to the main control oil circuit 20.

[0123] In addition, the present invention also provides an automatic transmission hydraulic oil supply method, including:

[0124] Introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the second accommodation chamber 124 and the third accommodation chamber 133;

[0125] Moving the first piston rod 122 in the direction of compressing the first oil supply chamber 121, and moving the second piston rod 132 in the direction of compressing the fourth accommodation chamber 134;

[0126] Introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the first accommodation chamber 123 and the fourth accommodation chamber 124;

[0127] Moving the second piston rod 132 in the direction of compressing the second oil supply chamber 131, and moving the first piston rod 122 in the direction of compressing the second accommodation chamber 124.

[0128] Optionally, the step of introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the second accommodation chamber 124 and the third accommodation chamber 133 includes:

[0129] The hydraulic oil is introduced into the second accommodation chamber 124 and the third accommodation chamber 133 through one of the first control valve 8 or the second control valve 9;

[0130] The steps of introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the first accommodation chamber 123 and the fourth accommodation chamber 134 include:

[0131] The hydraulic oil is introduced into the first accommodation chamber 123 and the fourth accommodation chamber 134 through one of the first control valve 8 or the second control valve 9.

[0132] Optionally, the steps of introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the second accommodation chamber 124 and the third accommodation chamber 133 include:

[0133] The hydraulic oil is introduced into the second accommodation chamber 124 and the third accommodation chamber 133 through the fourth control valve 49;

[0134] The steps of introducing hydraulic oil into the first oil supply chamber 121, the second oil supply chamber 131, the first accommodation chamber 123 and the fourth accommodation chamber 134 include:

[0135] The hydraulic oil is introduced into the first accommodation chamber 123 and the fourth accommodation chamber 134 through the fourth control valve 49.

[0136] Optionally, before the step of introducing the hydraulic oil into the first accommodation chamber 123 and the fourth accommodation chamber 134 through the fourth control valve 49, it includes:

[0137] Reversing the fourth control valve 49.

[0138] Optionally, the step of reversing the fourth control valve 49 includes:

[0139] Making the third control valve 48 provide the hydraulic oil pressure required for the movement of the spool inside the fourth control valve 49 for the fourth control valve 49.

[0140] Optionally, after the step of moving the first piston rod 122 in the direction of compressing the first oil supply chamber 121 and the second piston rod 132 in the direction of compressing the fourth accommodation chamber 134, it further includes:

[0141] Introducing the hydraulic oil flowing out of the first accommodation chamber 123 and the fourth accommodation chamber 134 into the cooling end low-pressure oil circuit II; and / or

[0142] After the step of moving the second piston rod 132 in the direction of compressing the second oil supply chamber 131 and the first piston rod 122 in the direction of compressing the second accommodation chamber 124, it further includes:

[0143] Introducing the hydraulic oil flowing out of the second accommodation chamber 124 and the third accommodation chamber 133 into the cooling end low-pressure oil circuit II.

[0144] In summary, by designing the first hydraulic part 12 and the second hydraulic part 13 with a variable-diameter hollow cavity, the hydraulic oil entering the first hydraulic part 12 or the second hydraulic part 13 travels from the end with the largest diameter of the variable-diameter hollow cavity to the end with the smallest diameter, thereby increasing the oil pressure. The hydraulic oil with increased oil pressure in the first hydraulic part 12 and the second hydraulic part 13 is alternately supplied to the total control oil circuit 20, and the excess hydraulic oil in the high-pressure oil circuit I at the control end is sent into the low-pressure oil circuit II at the cooling end. The present invention has the following beneficial effects:

[0145] 1. The electronic oil pump 1 does not need to operate at high power for a long time, extending the service life of the electronic oil pump 1;

[0146] 2. Energy consumption is saved.

[0147] As described above, the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims described.

Claims

1. An automatic transmission hydraulic oil supply system, characterized in that, it includes a control end high-pressure oil circuit (I), and the control end high-pressure oil circuit (I) includes: a total control oil circuit (20); a first hydraulic part (12) with a variable-diameter hollow cavity, including: a first oil supply cavity (121), a first accommodation cavity (123), a second accommodation cavity (124) and a first piston rod (122). The first piston rod (122) can move in the first oil supply cavity (121), the first accommodation cavity (123) and the second accommodation cavity (124). The first oil supply cavity (121) is located at the small-diameter end of the variable-diameter hollow cavity, and there is an outlet for hydraulic oil output on it. The first accommodation cavity (123) is located between the first oil supply cavity (121) and the second accommodation cavity (124). There are outlets on the first accommodation cavity (123) and the second accommodation cavity (124) respectively. The flow direction of the hydraulic oil at the outlet of the second accommodation cavity (124) is opposite to the flow direction of the hydraulic oil at the outlet of the first accommodation cavity (123); a second hydraulic part (13) with a variable-diameter hollow cavity, including: a second oil supply cavity (131), a third accommodation cavity (133), a fourth accommodation cavity (134) and a second piston rod (132). The second piston rod (132) can move in the second oil supply cavity (131), the third accommodation cavity (133) and the fourth accommodation cavity (134). The second oil supply cavity (131) is located at the small-diameter end of the variable-diameter hollow cavity, and there is an outlet for hydraulic oil output on it. The third accommodation cavity (133) is located between the second oil supply cavity (131) and the fourth accommodation cavity (134). There are outlets on the third accommodation cavity (133) and the fourth accommodation cavity (134) respectively. The flow direction of the hydraulic oil at the outlet of the third accommodation cavity (133) is opposite to the flow direction of the hydraulic oil at the outlet of the fourth accommodation cavity (134); the outlet for hydraulic oil output of the first oil supply cavity (121) is communicated with the outlet for hydraulic oil output of the second oil supply cavity (131) to the total control oil circuit (20).

2. The automatic transmission hydraulic oil supply system according to claim 1, characterized in that, the control end high-pressure oil circuit (I) further includes: a first control valve (8) communicated with the first accommodation cavity (123) and the fourth accommodation cavity (134), and a second control valve (9) communicated with the third accommodation cavity (133) and the second accommodation cavity (124); the flow direction of the hydraulic oil in the first control valve (8) and the second control valve (9) is opposite.

3. The automatic transmission hydraulic oil supply system according to claim 1, characterized in that, the control end high-pressure oil circuit (I) further includes: a fourth control valve (49), the fourth control valve (49) is a four-way reversing valve, and one port of the fourth control valve (49) is communicated with the first accommodation cavity (123) and the fourth accommodation cavity (134), and one port is communicated with the second accommodation cavity (124) and the third accommodation cavity (133).

4. The automatic transmission hydraulic oil supply system according to claim 2, It is characterized in that it further includes a first oil sump (2) and a high-pressure pump (101), and the control-end high-pressure oil circuit (I) further includes: a main pressure valve (7) connecting the first control valve (8) and the second control valve (9); the high-pressure pump (101) is used to extract hydraulic oil from the first oil sump (2) and send it to the main pressure valve (7).

5. The automatic transmission hydraulic oil supply system according to claim 4, it is characterized in that it further includes a second oil sump (3), a low-pressure pump (102) and a cooling-end low-pressure oil circuit (II). The cooling-end low-pressure oil circuit (II) includes an oil cooler and pressure filter device (42). The low-pressure pump (102) extracts hydraulic oil from the second oil sump (3) and sends it to the oil cooler and pressure filter device. The first oil sump (2) is communicated with the second oil sump (3). The oil cooler and pressure filter device (42) is communicated with an oil return outlet (47), and the oil return outlet (47) is communicated with the first oil sump (2).

6. The automatic transmission hydraulic oil supply system according to claim 5, it is characterized in that the control-end high-pressure oil circuit (I) is communicated with the cooling-end low-pressure oil circuit (II) through a branch.

7. The automatic transmission hydraulic oil supply system according to claim 6, it is characterized in that the branch connecting the control-end high-pressure oil circuit (I) and the cooling-end low-pressure oil circuit (II) leads to the oil cooler and pressure filter device (42). A branch is in parallel with the oil cooler and pressure filter device (42), and a bypass valve (40) is provided on this branch.

8. The automatic transmission hydraulic oil supply system according to claim 6, it is characterized in that a pressure limiting valve (50) is further provided on the cooling-end low-pressure oil circuit (II). One end of the pressure limiting valve (50) is connected to the outlet of the oil cooler and pressure filter device (42), and the other end is connected to the channel between the second oil sump (3) and the low-pressure pump (102).

9. An automatic transmission hydraulic oil supply method, it is characterized in that using the automatic transmission hydraulic oil supply system according to claim 1, includes the following steps: Inject hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the second accommodation chamber (124) and the third accommodation chamber (133); Make the first piston rod (122) move in the direction of compressing the first oil supply chamber (121), and make the second piston rod (132) move in the direction of compressing the fourth accommodation chamber (134); Inject hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the first accommodation chamber (123) and the fourth accommodation chamber (134); Make the second piston rod (132) move in the direction of compressing the second oil supply chamber (131), and make the first piston rod (122) move in the direction of compressing the second accommodation chamber (124).

10. The automatic transmission hydraulic oil supply method according to claim 9, it is characterized in that the step of injecting hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the second accommodation chamber (124) and the third accommodation chamber (133) includes: The hydraulic oil is introduced into the second accommodation chamber (124) and the third accommodation chamber (133) through one of the first control valve (8) or the second control valve (9); or The steps of introducing hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the first accommodation chamber (123) and the fourth accommodation chamber (134) include: The hydraulic oil is introduced into the first accommodation chamber (123) and the fourth accommodation chamber (134) through one of the first control valve (8) or the second control valve (9).

11. The automatic transmission hydraulic oil supply method according to claim 9, characterized in that The steps of introducing hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the second accommodation chamber (124) and the third accommodation chamber (133) include: The hydraulic oil is introduced into the second accommodation chamber (124) and the third accommodation chamber (133) through the fourth control valve (49); The steps of introducing hydraulic oil into the first oil supply chamber (121), the second oil supply chamber (131), the first accommodation chamber (123) and the fourth accommodation chamber (134) include: The hydraulic oil is introduced into the first accommodation chamber (123) and the fourth accommodation chamber (134) through the fourth control valve (49).

12. The automatic transmission hydraulic oil supply method according to claim 11, characterized in that Before the step of introducing the hydraulic oil into the first accommodation chamber (123) and the fourth accommodation chamber (134) through the fourth control valve (49), it includes: Reversing the fourth control valve (49).

13. The automatic transmission hydraulic oil supply method according to claim 12, characterized in that The step of reversing the fourth control valve (49) includes: The third control valve (48) provides the hydraulic oil pressure required for the movement of the spool inside the fourth control valve (49) for the fourth control valve (49).

14. The automatic transmission hydraulic oil supply method according to claim 13, characterized in that After the step of moving the first piston rod (122) in the direction of compressing the first oil supply chamber (121) and the second piston rod (132) in the direction of compressing the fourth accommodation chamber (134), it further includes: Introducing the hydraulic oil flowing out of the first accommodation chamber (123) and the fourth accommodation chamber (134) into the cooling end low-pressure oil circuit (II); and / or After the step of moving the second piston rod (132) in the direction of compressing the second oil supply chamber (131) and the first piston rod (122) in the direction of compressing the second accommodation chamber (124), it further includes: Introducing the hydraulic oil flowing out of the second accommodation chamber (124) and the third accommodation chamber (133) into the cooling end low-pressure oil circuit (II).

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