A hydraulic system and a hydraulic control method

Abstract

The present application provides a hydraulic system and a hydraulic control method. The hydraulic system includes: an oil tank, a power source, a valve, a pressure reduction module, a first hydraulic pump, a second hydraulic pump, a booster pump, and a controller. The output end of the booster pump is connected to the input end of the valve. The first output end of the valve is connected to the output end of the first hydraulic pump. The second output end of the valve is connected to the output end of the second hydraulic pump. The controller is used to control the switching states of the first output end and the second output end of the valve, and to boost the first hydraulic pump and the second hydraulic pump by controlling the valve under different working conditions. The hydraulic control method includes: obtaining the input rotational speed and the hydraulic oil temperature, using the input rotational speed and the hydraulic oil temperature as judgment conditions to judge the working conditions corresponding to the hydraulic system, and boosting the first hydraulic pump and the second hydraulic pump by controlling the valve under different working conditions through the controller to improve the performance of the controlled device.

Description

Technical Field

[0001] This application relates to the field of hydraulic control, and particularly to a hydraulic system and a hydraulic control method. Background Art

[0002] With the continuous development of technology, in actual production and use, people have higher and higher requirements for the performance of the transmission. The transmission is a component in mechanical equipment and is a device for changing the speed ratio and the direction of motion. The transmission is used in automobiles, tractors, ships, machine tools and various machines to change the torque, speed and direction of motion transmitted from the driving shaft to the driven shaft under different working conditions. The transmission can be controlled by a hydraulic control method, and a hydraulic control system is integrated in the transmission controlled by this method.

[0003] The existing technology uses a transmission internally integrated with two hydraulic pumps, namely a working pump and a lubricating pump. The working pump provides working oil for the transmission, and the lubricating pump provides lubricating oil for the transmission. The existing hydraulic control method controls the amount of working oil and lubricating oil by using the working pump and the lubricating pump to control the transmission.

[0004] However, the transmission using the hydraulic system and the hydraulic control method provided by the existing technology often has poor overall performance. Therefore, how to provide a hydraulic system and a hydraulic control method to improve the performance of the transmission has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] Based on the above problems, this application provides a hydraulic system and a hydraulic control method.

[0006] This application discloses a hydraulic system, which includes components such as an oil tank, a power source, a valve, a first hydraulic pump, a second hydraulic pump, a booster pump and a controller;

[0007] The power source is coaxially connected to the first hydraulic pump, the second hydraulic pump and the booster pump;

[0008] The output end of the booster pump is connected to the input end of the valve;

[0009] The first output end of the valve is connected to the output end of the first hydraulic pump;

[0010] The second output end of the valve is connected to the output end of the second hydraulic pump;

[0011] The controller is used to control the on-off states of the first output end and the second output end of the valve;

[0012] The output end of the pressure reducing module is connected to the input end of the oil tank, and the pressure reducing module is used to reduce the pressure of the hydraulic oil in the system;

[0013] The output end of the fuel tank is connected to the input ends of the first hydraulic pump, the second hydraulic pump and the booster pump.

[0014] Optionally, the hydraulic system further includes a first check valve and a second check valve:

[0015] The first check valve is connected between the connection oil path of the first output end of the valve and the output end of the first hydraulic pump.

[0016] Optionally, the step of closing the first output end of the valve and the second output end of the valve when the condition is not met includes:

[0017] A third check valve and a fourth check valve, and the third check valve and the fourth check valve face in opposite directions.

[0018] The present application also provides a hydraulic control method based on the above hydraulic control system, and the hydraulic control method includes:

[0019] Obtain the rotational speed input by the power source;

[0020] Judge whether the rotational speed is less than a first rotational speed threshold;

[0021] If so, open the first output end of the valve so that the booster pump boosts the first hydraulic pump;

[0022] If not, close the first output end of the valve and the second output end of the valve.

[0023] Optionally, the step of closing the first output end of the valve and the second output end of the valve when the condition is not met includes:

[0024] Judge whether the input rotational speed of the power source is not less than the first rotational speed threshold and less than a second rotational speed threshold, and the second rotational speed threshold is not less than the first rotational speed threshold;

[0025] If so, close the first output end of the valve and the second output end of the valve;

[0026] If not, open the second output end of the valve so that the booster pump boosts the second hydraulic pump.

[0027] Optionally, the step of opening the second output end of the valve so that the booster pump boosts the second hydraulic pump when the condition is not met includes:

[0028] Obtain the temperature of the hydraulic oil in the hydraulic system;

[0029] Judge whether the temperature is greater than a first temperature threshold;

[0030] If so, open the second output end of the valve so that the booster pump pressurizes the second hydraulic pump until the temperature is less than a second temperature threshold, where the second temperature threshold is less than the first temperature threshold;

[0031] If not, close the first output end and the second output end of the valve.

[0032] Optionally, the rotational speed includes: the average rotational speed input by the power source within a first period of time.

[0033] Optionally, the temperature includes: the average temperature of the hydraulic oil in the hydraulic system within a second period of time.

[0034] This application also discloses a gearbox, which includes the above hydraulic system and is controlled based on the above hydraulic control method.

[0035] Compared with the prior art, this application has the following beneficial effects:

[0036] The hydraulic system disclosed in this application includes a booster pump in addition to the first hydraulic pump and the second hydraulic pump. The output end of the booster pump is connected to the input end of the valve, and the two output ends of the valve are respectively connected to the output ends of the first hydraulic pump and the second hydraulic pump. The switching states of the two output ends of the valve are determined by the controller. Through such a connection method, a method for the booster pump to pressurize the two hydraulic pumps under different working conditions is realized, so as to improve the performance of the device controlled by the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of a hydraulic control system provided by this application;

[0039] Figure 2 It is a flowchart of a hydraulic control method provided by this application. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular forms "a", "an", "the", "above-mentioned", "said", and "this" are also intended to include, for example, the expression "one or more", unless there is a clear indication to the contrary in the context. It should also be understood that in the embodiments of the present application, "one or more" means one, two, or more than two; "and / or" describes the association relationship of associated objects and means that three relationships can exist; for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship.

[0041] The reference to "one embodiment" or "some embodiments" etc. described in this specification means that a specific feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0042] The "multiple" involved in the embodiments of the present application means greater than or equal to two. It should be noted that in the description of the embodiments of the present application, words such as "first" and "second" are only used for the purpose of distinguishing descriptions and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0043] As described above, currently, two hydraulic pumps are integrated inside the gearbox controlled by hydraulic technology, namely the working pump and the lubricating pump. The working pump provides working oil for the gearbox, and the lubricating pump provides lubricating oil for the gearbox. The hydraulic control method of the prior art uses the working pump and the lubricating pump to control the amounts of the working oil and the lubricating oil to control the gearbox.

[0044] Through research, it is found that the prior art controls the transmission through two hydraulic pumps, namely the working pump and the lubricating pump. In the prior art, when the rotational speed of the transmission is low, the oil supply of the working oil is small, and the small oil supply of the system oil will lead to limited performance of the working components in the transmission, ultimately resulting in insufficient torque transmission capacity; when the rotational speed of the transmission is high, the flow rate of the lubricating pump will be restricted. In order to meet the heat dissipation requirements of the transmission, a radiator with a larger size will be selected, which will cause the overall volume of the transmission to be too large. If a large-displacement working pump is selected to solve the problem of insufficient oil supply of the working oil when the rotational speed of the transmission is low, this high-power working pump will increase the overall power loss of the transmission when the rotational speed of the transmission is high. If a large-displacement lubricating pump is selected to solve the problem of restricted flow rate of the lubricating pump when the rotational speed of the transmission is high, this large-displacement lubricating pump will cause the pressure of the lubricating oil to be too high, and the too high pressure of the lubricating oil will lead to abnormal lubrication of the friction pair. In addition, using a large-displacement lubricating pump may also cause the problem of too low overall temperature of the hydraulic oil in the system when the ambient temperature is low. In order not to change the displacement of the existing working pump and lubricating pump and be able to adapt to various working conditions, this application discloses a hydraulic system and a hydraulic control method.

[0045] In order to enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this application.

[0046] Figure 1 The following is a schematic diagram of a hydraulic control system provided by this application. Specifically, the hydraulic control system includes:

[0047] Fuel tank 100: The fuel tank is a special container for storing hydraulic oil in the hydraulic system. The input end of the fuel tank is the oil inlet, and the output end of the fuel tank supplies oil to the lubricating pump, working pump, and booster pump shown in the figure.

[0048] Filter 200: A filter is a device on the pipeline for transporting the medium. In the hydraulic system provided by this application, on the oil pipeline, the input end of the filter 200 is connected to the output end of the fuel tank 100. When the fuel tank outputs hydraulic oil, the output hydraulic oil is filtered to remove some impurities.

[0049] Valve 300: In the hydraulic system provided in this application, it can specifically be a three-position four-way valve. The three-position four-way reversing valve has three working positions, namely the a position, the middle position, and the b position. It has four oil ports, two inlets and two outlets, which are respectively represented by P, T, A, and B. P and T are the input ends, where P is the oil inlet and T is the oil return port. A and B are the two output ends, that is, the oil outlets. A is connected to the output end of the working pump, and B is connected to the output end of the lubricating pump. The three-position four-way valve has a stationary position, that is, the middle position. When the three-position four-way valve is in the middle position, the hydraulic oil output by the booster pump flows from P to T and does not flow to A and B, that is, the booster pump does not supply oil to the lubricating pump and the working pump. When the three-position four-way valve is in the a position, the P port is connected to the A port. The hydraulic oil output by the booster pump first enters the three-position four-way valve and then flows out through the A port of the three-position four-way valve. After flowing out, it merges with the hydraulic oil output by the working pump to boost the working pump. When the three-position four-way valve is in the b position, the P port is connected to the B port. The hydraulic oil output by the booster pump first enters the three-position four-way valve and then flows out through the B port of the three-position four-way valve. After flowing out, it merges with the hydraulic oil output by the lubricating pump to boost the lubricating pump. Valve 300 is controlled by a controller, which is not shown in the figure. The controller can specifically be a controller for controlling the valve state.

[0050] Pressure reduction module 400: The pressure reduction module can reduce the pressure in the hydraulic system by draining the hydraulic oil back to the fuel tank when the pressure in the hydraulic system is too high. The pressure reduction module can specifically include two one-way valves with springs. The oil path between the two one-way valves is connected to the input end of the fuel tank. The two one-way valves face in opposite directions. The side with the arrow of the one-way valve is the input port, and the side without the arrow is the output port. When the pressure in the hydraulic system is too high, the one-way valves open, and the hydraulic oil enters the oil path between the two one-way valves through the two one-way valves and is input into the fuel tank through the input end of the fuel tank to reduce the pressure in the hydraulic system. When the pressure in the hydraulic system decreases, the two one-way valves close under the action of the two springs, preventing the hydraulic oil in the hydraulic system from flowing into the oil path between the two one-way valves.

[0051] First one-way valve 500: The first one-way valve is located between the connection oil path of the first output end of valve 300 and the output end of the working pump. A one-way valve is a valve through which fluid can only flow in from the input port, and the medium at the output port cannot flow back. The side with the arrow of the first one-way valve 500 is the input port, and the side without the arrow is the output port. That is to say, the hydraulic oil flowing out from the A port of valve 300 can merge with the hydraulic oil flowing out from the output end of the working pump through the first one-way valve 500, while the hydraulic oil output from the output end of the working pump cannot flow back along the oil path to the A port of valve 300.

[0052] Second one-way valve 600: The second one-way valve is located between the connection oil path of the second output end of valve 300 and the output end of the lubricating pump.

[0053] Power source 700: The power source mainly inputs power to the hydraulic system. Specifically, it inputs rotational speed to the hydraulic system in the gearbox.

[0054] The lubricating pump and the working pump in the figure are hydraulic pumps. The first hydraulic pump described above is specifically the working pump shown in the figure, and the second hydraulic pump described above is specifically the lubricating pump described in the figure. The lubricating pump, the working pump, and the booster pump are coaxially connected. The figure also includes a lubricating oil output oil circuit and a working oil output oil circuit. The lubricating oil output oil circuit is a device controlled by the hydraulic system and can specifically provide lubricating oil for the gearbox; the working oil output oil circuit is a device controlled by the hydraulic system and can specifically provide working oil for the gearbox.

[0055] The hydraulic system provided by this application not only includes a lubricating pump and a working pump, but also a booster pump. The booster pump is controlled by a controller to boost the lubricating pump and the working pump under different working conditions to improve the performance of the controlled device. The decompression module provided by this application can protect the hydraulic system. When the liquid pressure inside the hydraulic system is too high, the system is decompressed through the decompression module to protect the hydraulic system and make the hydraulic system safer and more stable. A check valve is connected between the output port of the valve in the hydraulic system provided by this application and the oil circuit connected to the working pump and the lubricating pump to prevent the hydraulic oil from flowing back and increase the stability of the system.

[0056] This application also provides a hydraulic control method. It can be understood that this method can be applied to a processing device, which is a processing device that can perform hydraulic control, such as a terminal device or a server that can perform hydraulic control. This method can be independently executed by the terminal device or the server, or can be applied to a network scenario where the terminal device and the server communicate and be executed in cooperation by the terminal device and the server. Among them, the terminal device can be a device such as a computer or a mobile phone. The server can be understood as an application server or a Web server. In actual deployment, the server can be an independent server or a cluster server. The hydraulic control method provided by this application can be specifically applied to the hydraulic system provided by this application.

[0057] This application also provides a Figure 2 flow chart of the hydraulic control method as shown, and the method includes the following steps:

[0058] S201: Obtain the rotational speed input by the power source.

[0059] The processing device obtains the rotational speed input by the power source, and the power source can specifically be the power source inside the gearbox. Here, n is used to represent the rotational speed input by the power source. The rotational speed input by the power source can be the average rotational speed output by the power source within a certain period of time.

[0060] S202: Determine whether the rotational speed is less than the first rotational speed threshold.

[0061] After the processing device obtains the rotational speed input from the power source, it determines whether the rotational speed is less than the first rotational speed threshold, which is represented by n1 here, that is, it determines whether n < n1 holds. The first rotational speed threshold can be any rotational speed value set artificially. If the processing device determines that the rotational speed input from the power source is less than the first rotational speed threshold n1, it executes S203; if the processing device determines that the rotational speed input from the power source is not less than the first rotational speed threshold n1, it executes S204.

[0062] S203: Open the first output end of the valve so that the booster pump pressurizes the first hydraulic pump.

[0063] The first booster pump can specifically be a working pump. The processing device controls the valve through a controller. Here, the valve can specifically be a three-position four-way valve. The processing device controls the three-position four-way valve to be in position a through the controller, that is, connects the P port of the valve to the A port, so that the hydraulic oil output by the booster pump and the hydraulic oil output by the working pump merge to pressurize the working pump.

[0064] S204: Determine whether the rotational speed is not less than the first rotational speed threshold and less than the second rotational speed threshold.

[0065] The processing device determines whether the rotational speed input from the power source is not less than the first rotational speed threshold and less than the second rotational speed threshold. Here, the second rotational speed threshold is represented by n2, that is, it determines whether n1 ≤ n < n2 holds. The second rotational speed threshold is not less than the first rotational speed threshold, that is, n2 ≥ n1. If the rotational speed input from the power source is not less than the first rotational speed threshold and less than the second rotational speed threshold, it executes S205; if the rotational speed input from the power source is not less than the second rotational speed threshold, it executes S206.

[0066] S205: Close the first output end and the second output end of the valve.

[0067] The processing device controls the valve through a controller. Here, the valve can specifically be a three-position four-way valve. The processing device controls the three-position four-way valve to be in the middle position through the controller, that is, the hydraulic oil output by the booster pump flows from the P port to the T port through the valve, that is, the booster pump does not pressurize the other hydraulic pumps.

[0068] S206: Obtain the temperature of the hydraulic oil in the hydraulic system.

[0069] The processing device obtains the temperature of the hydraulic oil in the hydraulic system. The temperature of the hydraulic oil in the hydraulic system can be the average temperature of the hydraulic oil in the hydraulic system over a period of time.

[0070] S207: Determine whether the temperature is greater than the first temperature threshold.

[0071] The processing device determines whether the temperature is greater than the first temperature threshold, and the first temperature threshold can be any preset temperature value. If the temperature is greater than the first temperature threshold, S208 is executed; if the temperature is not greater than the first temperature threshold, S209 is executed.

[0072] S208 opens the second output end of the valve so that the booster pump pressurizes the second hydraulic pump until the temperature is less than the second temperature threshold.

[0073] Here, the second hydraulic pump can specifically be a lubricating pump, and the second temperature threshold is less than the first temperature threshold.

[0074] The processing device controls the valve through the controller. Here, the valve can specifically be a three-position four-way valve. The processing device controls the three-position four-way valve to be in the b position through the controller, that is, the P port and the B port of the three-position four-way valve are connected, so that the hydraulic oil output by the booster pump is combined with the hydraulic oil output by the lubricating pump, thereby pressurizing the lubricating pump. When the processing device determines that the temperature is higher than the first temperature threshold, the processing device controls the lubricating oil to flow out continuously through the controller, and the lubricating oil plays a role in cooling. The booster pump continuously pressurizes the lubricating pump until the temperature is less than the second temperature threshold, and then the processing device makes the three-position four-way valve in the middle position through the controller to stop the booster pump from pressurizing the lubricating pump.

[0075] S209: Close the first output end and the second output end of the valve.

[0076] The processing device controls the valve through the controller. Here, the valve can specifically be a three-position four-way valve. The processing device controls the three-position four-way valve to be in the middle position through the controller. When the three-position four-way valve is in the middle position, the hydraulic oil output by the booster pump flows from the P port to the T port, and the booster pump does not pressurize the working pump and the lubricating pump.

[0077] This application controls different positions of the valve through the processing device, so that the booster pump can pressurize the lubricating pump and the working pump under different working conditions. When the working condition has a low rotational speed, the processing device can control the valve to pressurize the working pump through the controller, improving the torque transmission ability of the gearbox under the working condition with a low rotational speed. When the rotational speed is high and the temperature of the hydraulic oil is too high, the processing device controls the booster pump to pressurize the lubricating pump through the controller. In this working condition, even if the flow rate of the lubricating pump is limited, the booster pump can pressurize the lubricating pump to meet the heat dissipation requirements. Compared with the prior art, the method provided by this application can better adapt to different working conditions, and there are different pressurization methods corresponding to different working conditions, increasing the overall performance of the devices that can be controlled.

[0078] This application also provides a gearbox, which has the above hydraulic system and is controlled based on the above hydraulic control method.

[0079] It should be noted that the various embodiments in this specification are described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key points of each embodiment are the differences from other embodiments. In particular, for the apparatus embodiments, since they are basically similar to the method embodiments, they are described relatively simply. For the relevant parts, reference can be made to the descriptions in the method embodiments. The apparatus embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components referred to as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative efforts.

[0080] As described above, this is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A hydraulic system, characterized in that, Comprising: A fuel tank, a power source, a valve, a pressure reduction module, a first hydraulic pump, a second hydraulic pump, a booster pump, and a controller; The power source is coaxially connected to the first hydraulic pump, the second hydraulic pump, and the booster pump; The output end of the booster pump is connected to the input end of the valve; The first output end of the valve is connected to the output end of the first hydraulic pump; The second output end of the valve is connected to the output end of the second hydraulic pump; The controller is used to control the switching states of the first output end and the second output end of the valve; The output end of the pressure reduction module is connected to the input end of the fuel tank, and the pressure reduction module is used to reduce the pressure of the hydraulic oil in the system; The output end of the fuel tank is connected to the input ends of the first hydraulic pump, the second hydraulic pump, and the booster pump; The pressure reduction module includes: a third one-way valve and a fourth one-way valve. The orientations of the third one-way valve and the fourth one-way valve are opposite. The input port of the third one-way valve is connected to the output end of the working pump, and the input port of the fourth one-way valve is connected to the output end of the booster pump; the output port of the third one-way valve and the output port of the fourth one-way valve are connected to the oil path between the third one-way valve and the fourth one-way valve, and the oil path between the third one-way valve and the fourth one-way valve is connected to the input end of the fuel tank.

2. The system according to claim 1, wherein The system further includes a first one-way valve and a second one-way valve: A first one-way valve is connected between the connection oil path of the first output end of the valve and the output end of the first hydraulic pump; A second one-way valve is connected between the connection oil path of the second output end of the valve and the output end of the second hydraulic pump.

3. The system according to claim 1, wherein The system further includes a filter: The output end of the fuel tank is connected to the filter, and the filter is used to filter the hydraulic oil output from the fuel tank.

4. A hydraulic control method, applied to the system according to any one of claims 1-3, characterized in that, The method includes: Obtaining the rotational speed input by the power source; Judging whether the rotational speed is less than a first rotational speed threshold; If so, opening the first output end of the valve so that the booster pump boosts the first hydraulic pump; If not, closing the first output end and the second output end of the valve.

5. The method according to claim 4, characterized in that The "if not, closing the first output end and the second output end of the valve" includes: Judging whether the input rotational speed of the power source is not less than the first rotational speed threshold and less than a second rotational speed threshold, and the second rotational speed threshold is not less than the first rotational speed threshold; If so, closing the first output end and the second output end of the valve; If not, opening the second output end of the valve so that the booster pump boosts the second hydraulic pump.

6. The method according to claim 5, wherein The "if not, opening the second output end of the valve so that the booster pump boosts the second hydraulic pump" includes: Obtaining the temperature of the hydraulic oil in the hydraulic system; Judging whether the temperature is greater than a first temperature threshold; If so, opening the second output end of the valve so that the booster pump boosts the second hydraulic pump until the temperature is less than a second temperature threshold, and the second temperature threshold is less than the first temperature threshold; If not, closing the first output end and the second output end of the valve.

7. The method according to claim 4, characterized in that, The rotational speed includes: the average rotational speed input by the power source within a first period of time.

8. The method according to claim 6, wherein The temperature includes: the average temperature of the hydraulic oil in the hydraulic system within a second period of time.

9. A transmission, characterized in that, It includes the hydraulic system according to any one of claims 1-3 and is controlled based on the hydraulic control method according to any one of claims 4-8.

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