Remote stepless voltage regulation control system of closed system

Abstract

The utility model discloses a remote stepless pressure regulation control system for a closed system, which relates to the technical field of hydraulic systems and comprises an oil tank, a main oil pump, a first control oil pipe, an adjustable overflow valve and a hydraulic control valve. The oil tank is used for storing hydraulic oil; the main oil pump is connected with a control assembly. The first control oil pipe is connected with the main oil pipe, and the first control oil pipe is connected with the second control oil pipe through the throttler; the adjustable overflow valve is arranged between the oil tank and the second control oil pipe, two control ports of the hydraulic control valve are connected with the first control oil pipe and the second control oil pipe respectively, an outlet of the hydraulic control valve is connected with the oil tank, an inlet of the hydraulic control valve is connected with the control assembly, and when the pressure difference of the two control ports reaches a preset value, the hydraulic control valve enables the control assembly to be communicated with the oil tank. The hydraulic oil pressure in the control assembly is reduced to reduce the hydraulic oil flow output by the main oil pump. According to the utility model, the cost of production equipment can be reduced, and overshoot is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic systems, and particularly relates to a closed-system remote stepless pressure regulating control system. Background Art

[0002] A closed hydraulic system is a hydraulic system in which the oil suction port of the main oil pump communicates with the oil discharge port of the oil cylinder or hydraulic motor, and only a small amount of oil needs to be replenished in the system. In the prior art, the remote pressure regulating control scheme of the closed hydraulic system is as follows: Control oil is taken from the outlet of the main oil pump, and after passing through a damping hole, it reaches an electro-hydraulic proportional relief valve. When the pressure reaches the set pressure of the electro-hydraulic proportional relief valve, this control oil passes through the electro-hydraulic proportional relief valve to the reverse working chamber of the variable control chamber of the main oil pump, pushing the swash plate of the main oil pump back to the middle position, reducing the displacement of the main oil pump to the minimum, and playing a role in pressure cut-off. The control system in the prior art has the disadvantages of complex structure and high cost. Moreover, the flow rate of the control oil directly determines the response speed of the pressure cut-off of the closed pump, so the control system in the prior art also has the disadvantage of a relatively large overshoot in pressure control. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a closed-system remote stepless pressure regulating control system, which can reduce the cost of production equipment.

[0004] A closed-system remote stepless pressure regulating control system according to an embodiment of the first aspect of the utility model includes: an oil tank, a main oil pump, a first control oil pipe, an adjustable relief valve, and a hydraulic control valve. The oil tank is used for storing hydraulic oil; the main oil pump is used for pressurizing and conveying the hydraulic oil in the return oil pipe to the main oil pipe, and the main oil pump is connected with a control assembly; the first control oil pipe is connected to the main oil pipe, and the first control oil pipe is connected to a second control oil pipe through a throttle; the adjustable relief valve is arranged between the oil tank and the second control oil pipe, and the adjustable relief valve opens when the pressure in the second control oil pipe reaches a preset value, so that the hydraulic oil in the second control oil pipe flows to the oil tank; two control ports of the hydraulic control valve are respectively connected to the first control oil pipe and the second control oil pipe, the outlet of the hydraulic control valve is connected to the oil tank, the inlet of the hydraulic control valve is connected to the control assembly, and when the pressure difference between the two control ports reaches a preset value, the hydraulic control valve connects the control assembly with the oil tank, and the pressure of the hydraulic oil in the control assembly is reduced, so that the flow rate of the hydraulic oil output by the main oil pump is reduced.

[0005] A closed - loop system remote stepless pressure - regulating control system according to an embodiment of the present utility model has at least the following beneficial effects: By cutting off the hydraulic oil supply of the control component and then using the automatic reset function of the control component to reduce the output of the main oil pump. The requirements for the pilot control element are low, which is beneficial to reducing equipment costs. Moreover, the adjustment reaction is sensitive, the pressure overshoot is small, and the pressure in the main oil pipe is more stable.

[0006] According to some embodiments of the present utility model, the adjustable overflow valve is an electromagnetic proportional overflow valve that can control the opening pressure.

[0007] According to some embodiments of the present utility model, the fuel tank is connected with a makeup oil pump, and the makeup oil pump is used to transport the hydraulic oil in the fuel tank to the return oil pipe and the main oil pipe.

[0008] According to some embodiments of the present utility model, the makeup oil pump is respectively connected to the return oil pipe and the main oil pipe through two buffer makeup oil overflow valves.

[0009] According to some embodiments of the present utility model, the makeup oil pump provides hydraulic oil to the control component through a control oil pipe.

[0010] According to some embodiments of the present utility model, the control oil pipe is communicated with the inlet of the hydraulic control valve.

[0011] According to some embodiments of the present utility model, the outlet of the makeup oil pump is connected with a makeup oil overflow valve, and the makeup oil overflow valve is used to limit the outlet pressure of the makeup oil pump.

[0012] According to some embodiments of the present utility model, the outlet of the makeup oil pump is connected with a filter.

[0013] According to some embodiments of the present utility model, the main oil pump and the makeup oil pump are driven by the same power device.

[0014] According to some embodiments of the present utility model, the first control oil pipe is communicated with the main oil pipe through a shuttle valve.

[0015] A closed - loop system remote stepless pressure - regulating control system according to an embodiment of the present utility model has at least the following beneficial effects:

[0016] (1) By cutting off the hydraulic oil supply of the control component and then using the automatic reset function of the control component to reduce the output of the main oil pump. The requirements for the pilot control element are low, which is beneficial to reducing equipment costs. Moreover, the adjustment reaction is sensitive, the pressure overshoot is small, and the pressure in the main oil pipe is more stable;

[0017] (2) By using the makeup oil pump to provide hydraulic oil for the control component for the control component to use, the stability of the control is improved;

[0018] (3) The first control oil pipe is connected to the main oil pipe through a shuttle valve, and the shuttle valve has the characteristics of simple structure, small fluid resistance, high pressure resistance, high reliability of rapid response, and convenient installation.

[0019] Additional aspects and advantages of the present utility model will be given in part in the following description, will become apparent in part from the following description, or will be learned through the practice of the present utility model. Brief Description of the Drawings

[0020] The following further describes the present utility model in conjunction with the drawings and embodiments, where:

[0021] Figure 1 is an overall schematic diagram of an embodiment of the present utility model.

[0022] Reference Numerals in the Drawings:

[0023] Oil tank 100;

[0024] Main oil pump 200, control assembly 210;

[0025] Return oil pipe 300;

[0026] Main oil pipe 400;

[0027] First control oil pipe 500, restrictor 501, shuttle valve 510;

[0028] Second control oil pipe 600;

[0029] Adjustable overflow valve 700;

[0030] Hydraulic control valve 800;

[0031] Make-up oil pump 900, buffer make-up oil overflow valve 910, control oil pipe 920, make-up oil overflow valve 930, filter 940. Detailed Embodiment

[0032] The following details the embodiments of the present utility model. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0033] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as up, down, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0034] In the description of the present utility model, "a plurality of" refers to more than two. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0035] In the description of the present utility model, unless otherwise clearly defined, terms such as "arrangement", "installation", and "connection" shall be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0036] Refer to Figure 1As shown in the figure, a closed - loop system remote stepless pressure regulating control system according to an embodiment of the present utility model includes: an oil tank 100, a main oil pump 200, a first control oil pipe 500, an adjustable relief valve 700, and a hydraulic control valve 800. The oil tank 100 is used for storing hydraulic oil; the main oil pump 200 is an inclined - plate variable piston pump. The flow rate of the inclined - plate variable piston pump is proportional to the driving speed and displacement, and can be adjusted steplessly. The hydraulic main oil pump 200 is used to pressurize and transport the hydraulic oil in the return oil pipe 300 to the main oil pipe 400. The main oil pump 200 is connected with a control assembly 210; the control assembly 210 is the variable control chamber of the inclined - plate variable piston pump. The specific structure of the variable control chamber of the inclined - plate variable piston pump is prior art, so it will not be described in detail. The control assembly 210 can also be a hydraulic cylinder. The control assembly 210 is used to control the angle of the swash plate of the inclined - plate variable piston pump to adjust the flow rate output by the inclined - plate variable piston pump. The first control oil pipe 500 is connected to the main oil pipe 400, and a part of the hydraulic oil in the main oil pipe 400 enters the first control oil pipe 500. The first control oil pipe 500 is connected to the second control oil pipe 600 through a throttle 501; the adjustable relief valve 700 is arranged between the oil tank 100 and the second control oil pipe 600. When the adjustable relief valve 700 is not opened, the pressures in the main oil pipe 400, the first control oil pipe 500, and the second control oil pipe 600 are equal. When the pressure in the second control oil pipe 600 reaches a preset value, the adjustable relief valve 700 opens, so that the hydraulic oil in the second control oil pipe 600 flows to the oil tank 100; due to the throttling effect of the throttle 501, a pressure difference will be generated between the first control oil pipe 500 and the second control oil pipe 600. The two control ports of the hydraulic control valve 800 are respectively connected to the first control oil pipe 500 and the second control oil pipe 600. The outlet of the hydraulic control valve 800 is connected to the oil tank 100, and the inlet of the hydraulic control valve 800 is connected to the control assembly 210. When the pressure difference between the two control ports reaches a preset value, that is, when the pressure difference between the first control oil pipe 500 and the second control oil pipe 600 reaches a preset value, the hydraulic control valve 800 opens. The hydraulic control valve 800 connects the control assembly 210 with the oil tank 100, and the hydraulic oil in the control assembly 210 directly flows to the oil tank 100. The pressure of the hydraulic oil in the control assembly 210 decreases, changing the swash - plate inclination angle, so that the flow rate of the hydraulic oil output by the main oil pump 200 decreases. Thus, the pressure of the hydraulic oil in the main oil pipe 400 is controlled to decrease. When the pressure of the hydraulic oil in the main oil pipe 400 drops below the preset pressure of the adjustable relief valve 700, the adjustable relief valve 700 closes. The pressures in the first control oil pipe 500 and the second control oil pipe 600 return to equality. The hydraulic control valve 800 closes. Since the make - up oil pump 900 inputs hydraulic oil into the control assembly 210, the pressure of the hydraulic oil in the control assembly 210 increases, changing the swash - plate inclination angle, so that the flow rate of the hydraulic oil output by the main oil pump 200 increases, thereby increasing the pressure in the main oil pipe 400.Compared with the prior art where high-pressure hydraulic oil is directly used to push the control component 210 to control the output of the main oil pump 200, in this solution, the hydraulic oil supply to the control component 210 is cut off, and then the automatic reset function of the control component 210 is utilized to reduce the output of the main oil pump 200. The requirements for the pilot control element are low, which is beneficial to reducing equipment costs. Moreover, the adjustment response is sensitive, the pressure overshoot is small, and the pressure in the main oil pipe 400 is more stable.

[0037] Referring to Figure 1 As shown, it can be understood that the adjustable relief valve 700 is an electromagnetic proportional relief valve with controllable opening pressure. By remotely controlling the adjustable relief valve 700 and changing its opening pressure, the pressure in the main oil pipe 400 can be remotely adjusted, thereby improving the degree of automation.

[0038] Referring to Figure 1 As shown, it can be understood that the oil tank 100 is connected with a makeup oil pump 900. The makeup oil pump 900 is a gear pump, and the makeup oil pump 900 is used to transport the hydraulic oil in the oil tank 100 to the return oil pipe 300 and the main oil pipe 400. Since hydraulic oil leakage is inevitable during the operation of the closed hydraulic system, in order to make up for the leaked hydraulic oil and keep the closed system working properly, the makeup oil pump 900 is set to continuously supply hydraulic oil to the return oil pipe 300 and the main oil pipe 400.

[0039] Referring to Figure 1 As shown, it can be understood that the makeup oil pump 900 is respectively connected to the return oil pipe 300 and the main oil pipe 400 through two buffer makeup oil relief valves 910. Since the makeup oil pump 900 needs to supply oil to both the return oil pipe 300 and the main oil pipe 400 simultaneously, and the pressure difference between the return oil pipe 300 and the main oil pipe 400 is relatively large, buffer makeup oil relief valves 910 need to be set for buffering to prevent the pressure in the return oil pipe 300 and the main oil pipe 400 from changing too quickly and ensure the normal operation of the hydraulic system.

[0040] Referring to Figure 1 As shown, it can be understood that the makeup oil pump 900 supplies hydraulic oil to the control component 210 through the control oil pipe 920. Since the control component 210 needs hydraulic oil to work properly, and the pressure in the main oil pipe 400 is variable, in order to ensure the stability of control, pressure oil cannot be led out from the main oil pipe 400 for the control component 210 to use. Therefore, the makeup oil pump 900 is used to supply hydraulic oil to the control component 210 for its use.

[0041] Referring to Figure 1As shown, it can be understood that the control oil pipe 920 is connected to the inlet of the hydraulic control valve 800. When the hydraulic control valve 800 is opened, most of the hydraulic oil in the control oil pipe 920 flows back to the oil tank 100 through the hydraulic control valve 800, so that the control oil pipe 920 cannot continue to supply hydraulic oil to the control component 210, causing the pressure of the hydraulic oil in the control component 210 to be lost. The spring in the control component 210 will push the control component 210 to reset, causing the swash plate tilt angle to move in the direction of reducing the displacement of the main oil pump 200, and reducing the hydraulic oil flow output by the main oil pump 200. Thereby, the hydraulic oil pressure in the main oil pipe 400 is controlled to decrease.

[0042] Refer to Figure 1 As shown, it can be understood that the outlet of the makeup oil pump 900 is connected with a makeup oil overflow valve 930, and the makeup oil overflow valve 930 is used to limit the outlet pressure of the makeup oil pump 900. Since the makeup oil pump 900 usually uses a gear pump, and the gear pump is a positive displacement pump, it is necessary to control its outlet pressure. The makeup oil overflow valve 930 mainly plays a role in safety control to prevent damage to the equipment due to excessive hydraulic oil pressure in the control oil pipe 920.

[0043] Refer to Figure 1 As shown, it can be understood that the outlet of the makeup oil pump 900 is connected with a filter 940. The function of the filter 940 is to filter impurities in the hydraulic oil. Due to various reasons in the hydraulic system, solid impurities and particles will be generated. The filter 940 filters out these impurities to protect the normal operation of the hydraulic components and extend the service life of the system.

[0044] Refer to Figure 1 As shown, it can be understood that the main oil pump 200 and the makeup oil pump 900 are driven by the same power device. The power device can use an electric motor, an internal combustion engine, etc. The displacement of the makeup oil pump 900 is very small relative to the main oil pump 200, and its additional power loss is usually only 1% to 2% of the power of the main oil pump 200, which can be ignored. Therefore, they can share the same power device for driving.

[0045] Refer to Figure 1 As shown, it can be understood that the first control oil pipe 500 is connected to the main oil pipe 400 through a shuttle valve 510. The shuttle valve 510 has the characteristics of simple structure, small fluid resistance, high pressure resistance, high reliability of fast response, and convenient installation.

[0046] Working principle: The main oil pump 200 pressurizes and conveys the hydraulic oil in the return oil pipe 300 to the main oil pipe 400. The make-up oil pump 900 supplies hydraulic oil to the control assembly 210 through the control oil pipe 920. A part of the hydraulic oil in the main oil pipe 400 enters the first control oil pipe 500, the throttle 501 and the second control oil pipe 600. When the pressure in the main oil pipe 400 is lower than the preset value, the adjustable overflow valve 700 closes, and the pressures in the main oil pipe 400, the first control oil pipe 500, and the second control oil pipe 600 are equal. The adjustable overflow valve 700 opens when the pressure in the second control oil pipe 600 reaches the preset value, causing the hydraulic oil in the second control oil pipe 600 to flow to the fuel tank 100; due to the throttling effect of the throttle 501, a pressure difference will be generated between the first control oil pipe 500 and the second control oil pipe 600. When the pressure difference between the two control ports of the hydraulic control valve 800 reaches the preset value, that is, when the pressure difference between the first control oil pipe 500 and the second control oil pipe 600 reaches the preset value, the hydraulic control valve 800 opens, and the hydraulic control valve 800 connects the control assembly 210 with the fuel tank 100, and the hydraulic oil in the control oil pipe 920 directly flows to the fuel tank 100, reducing the hydraulic oil pressure in the control assembly 210. The control assembly 210 changes the tilt angle of the swash plate, reducing the flow rate of the hydraulic oil output by the main oil pump 200. Thus, the pressure of the hydraulic oil in the main oil pipe 400 is controlled to decrease. When the pressure of the hydraulic oil in the main oil pipe 400 drops below the preset pressure of the adjustable overflow valve 700, the adjustable overflow valve 700 closes. The pressures in the first control oil pipe 500 and the second control oil pipe 600 return to equality. The hydraulic control valve 800 closes, the hydraulic oil pressure in the control assembly 210 increases, the tilt angle of the swash plate is changed, the flow rate of the hydraulic oil output by the main oil pump 200 is increased, and thus the pressure in the main oil pipe 400 is increased. By changing the opening pressure of the adjustable overflow valve 700, the pressure of the hydraulic oil in the main oil pipe 400 is controlled.

[0047] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art to which the present invention pertains, various changes can be made without departing from the gist of the present invention.

Claims

1. A closed-loop system remote stepless voltage regulation control system, characterized in that, Comprising: An oil tank (100) for storing hydraulic oil; A main oil pump (200) for pressurizing and delivering the hydraulic oil in the return oil pipe (300) to the main oil pipe (400), and the main oil pump (200) is connected with a control assembly (210); A first control oil pipe (500) connected to the main oil pipe (400), and the first control oil pipe (500) is connected to a second control oil pipe (600) through a throttle (501); An adjustable overflow valve (700) arranged between the oil tank (100) and the second control oil pipe (600), and the adjustable overflow valve (700) opens when the pressure in the second control oil pipe (600) reaches a preset value, so that the hydraulic oil in the second control oil pipe (600) flows to the oil tank (100); A hydraulic control valve (800), two control ports of the hydraulic control valve (800) are respectively connected to the first control oil pipe (500) and the second control oil pipe (600), the outlet of the hydraulic control valve (800) is connected to the oil tank (100), the inlet of the hydraulic control valve (800) is connected to the control assembly (210), when the pressure difference between the two control ports reaches a preset value, the hydraulic control valve (800) makes the control assembly (210) communicate with the oil tank (100), and the reduction of the hydraulic oil pressure in the control assembly (210) causes the reduction of the hydraulic oil flow output by the main oil pump (200).

2. The closed-loop system remote stepless voltage regulation control system according to claim 1, characterized in that: The adjustable overflow valve (700) is an electromagnetic proportional overflow valve with controllable opening pressure.

3. The closed-loop system remote stepless voltage regulation control system according to claim 1, characterized in that: The oil tank (100) is connected with a make-up oil pump (900), and the make-up oil pump (900) is used for delivering the hydraulic oil in the oil tank (100) to the return oil pipe (300) and the main oil pipe (400).

4. The closed-loop system remote stepless voltage regulation control system according to claim 3, characterized in that: The make-up oil pump (900) is respectively connected to the return oil pipe (300) and the main oil pipe (400) through two buffer make-up oil overflow valves (910).

5. The closed-loop system remote stepless voltage regulation control system according to claim 3, wherein: The make-up oil pump (900) supplies hydraulic oil to the control assembly (210) through a control oil pipe (920).

6. The closed-loop system remote stepless voltage regulation control system according to claim 5, characterized in that: The control oil pipe (920) is communicated with the inlet of the hydraulic control valve (800).

7. The closed-loop system remote stepless voltage regulation control system according to claim 3, wherein: The outlet of the make-up oil pump (900) is connected with a make-up oil overflow valve (930), and the make-up oil overflow valve (930) is used for limiting the outlet pressure of the make-up oil pump (900).

8. The closed-loop system remote stepless voltage regulation control system according to claim 3, characterized in that: The outlet of the make-up oil pump (900) is connected with a filter (940).

9. The closed-loop system remote stepless voltage regulation control system according to claim 3, wherein: The main oil pump (200) and the make-up oil pump (900) are driven by the same power device.

10. The closed-loop system remote stepless voltage regulation control system according to claim 1, characterized in that: The first control oil pipe (500) is communicated with the main oil pipe (400) through a shuttle valve (510).

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