Hydraulic control valve system and loader

Abstract

The present application relates to the technical fields of hydraulic control system, and particularly relates to a hydraulic control valve system and a loader, which comprises a variable piston pump body, a constant displacement pump body and a valve body device, the variable piston pump body and the constant displacement pump body are communicated with the valve body device respectively, the valve body device is communicated with an oil tank, the valve body device comprises a control valve assembly, an overflow valve assembly, a working valve assembly and a connecting pipeline assembly, the connecting pipeline assembly has a first inlet and a second inlet, the first inlet is communicated with the variable piston pump body, the second inlet is communicated with the constant displacement pump body, the control valve assembly, the overflow valve assembly and the working valve assembly are communicated through the connecting pipeline assembly, in the above structure, the control valve assembly, the overflow valve assembly and the working valve assembly are integrated on a valve body, realizing double-pump confluence of the constant variable system, and the required installation space is small and the cost is lower.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control system, in particular to a hydraulic control valve system and a loader. BACKGROUND

[0002] The excavator is the most important earth-moving machine in engineering construction, and the micro-excavator is mainly used for land leveling, soil digging or loading, and is suitable for urban construction, farmland water conservancy, landscaping and other working conditions.

[0003] The current middle-end loader hydraulic system equipment is a double-pump system of a variable plunger pump and a constant displacement gear pump, but due to the design method of the double pump, it will lead to too many oil lines and control valves to coordinate the working mode of the double pump, thereby the hydraulic system occupies a large space, which is not conducive to miniaturization design. SUMMARY

[0004] The hydraulic control valve system and the loader disclosed by the embodiments of the present application are used to simplify the hydraulic system of the loader and reduce the use volume of the hydraulic system.

[0005] In order to achieve the above purpose, the embodiments of the present application provide the following technical solutions:

[0006] In a first aspect, the present application provides a hydraulic control valve system, comprising: a variable plunger pump body, a constant displacement pump body and a valve body device;

[0007] The variable plunger pump body and the constant displacement pump body are respectively communicated with the valve body device, and the valve body device is communicated with an oil tank;

[0008] The valve body device comprises a control valve assembly, an overflow valve assembly, a working valve assembly and a connecting pipeline assembly;

[0009] The connecting pipeline assembly has a first inlet and a second inlet, wherein the first inlet is communicated with the variable plunger pump body, the second inlet is communicated with the constant displacement pump body, the control valve assembly, the overflow valve assembly and the working valve assembly are communicated through the connecting pipeline assembly, and when the flow of the plunger pump body meets the demand of the connecting pipeline assembly, the plunger pump body is conducted through the connecting pipeline assembly and the working valve assembly; when the flow of the plunger pump body cannot meet the demand of the connecting pipeline assembly, the constant displacement pump body is communicated with the control valve assembly through the connecting pipeline assembly, and is conducted with the working valve assembly through the control valve assembly, so as to supplement the flow demand in the connecting pipeline assembly.

[0010] The application adds a valve body device, wherein the valve body device comprises a control valve assembly, an overflow valve assembly, a working valve assembly, and is provided with a connecting pipeline assembly, and the control valve assembly, the overflow valve assembly, and the working valve assembly are communicated through the connecting pipeline assembly. In addition, the variable plunger pump body and the constant pump body are also respectively communicated with the valve body device. When the hydraulic system of the application is in standby or small power operation, the flow rate supplied by the variable plunger pump body to the valve body device can meet the demand of the hydraulic system. However, when there is a large power working condition, the demand of the connecting pipeline assembly is greater than the flow rate supplied by the variable plunger pump body to the valve body device, and at this time, the constant pump body needs to start to operate, and the constant pump supplements the remaining flow rate through the control valve assembly, so as to ensure the stable operation of the whole system. In the above structure, the control valve assembly, the overflow valve assembly, and the working valve assembly are integrated on one valve body, the double pump of the constant variable system is combined, the required installation space is small, and the cost is lower.

[0011] In some embodiments, the valve body device further comprises an oil return pipeline, which is respectively communicated with the control valve assembly, the overflow valve assembly, and the working valve assembly, and the oil return pipeline is communicated with an oil tank.

[0012] In some embodiments, the connecting pipeline assembly comprises a first oil path, a second oil path, and a connecting oil channel. The first inlet is arranged on the first oil path, and the second inlet is arranged on the second oil path. The first oil path is communicated with the control valve assembly, the overflow valve assembly, and the working valve assembly. The second oil path is communicated with the control valve assembly. The connecting oil channel is used for communicating the control valve assembly, the overflow valve assembly, and the working valve assembly.

[0013] In some embodiments, the control valve assembly comprises a combination valve, one end of which is communicated with the variable plunger pump body through the first oil path, the other end is communicated with the constant pump body through the second oil path, and the combination valve is communicated with the overflow valve assembly.

[0014] In some embodiments, the connecting pipeline assembly further comprises an oil discharge pipeline, which is communicated with the overflow valve assembly and the oil return pipeline.

[0015] In some embodiments, the overflow valve assembly comprises a main overflow valve, a safety valve, and a port overflow valve.

[0016] The oil discharge pipeline is respectively communicated with the main overflow valve, the safety valve, and the port overflow valve. The safety valve is communicated with the combination valve. The port overflow valve is communicated with the working valve assembly. The main overflow valve is arranged on the connecting oil channel, one end of which is respectively communicated with the combination valve and the working valve assembly, and the other end is communicated with the oil tank through the oil return pipeline.

[0017] The safety valve, the port overflow valve and the main overflow valve are used for detecting the flow pressure in the connecting oil passage, and when the flow pressure in the connecting oil passage is abnormal, the oil discharge pipeline and the oil return pipeline are turned on to reduce the flow pressure in the connecting oil passage.

[0018] In some embodiments, the working valve assembly comprises a bucket three-position six-way spool valve and a boom four-position six-way spool valve, the bucket three-position six-way spool valve is communicated with the port overflow valve, the bucket three-position six-way spool valve is communicated with the boom four-position six-way spool valve through the connecting oil passage, and the bucket three-position six-way spool valve and the boom four-position six-way spool valve are communicated with the oil discharge pipeline and the oil return pipeline respectively.

[0019] In some embodiments, the valve body device further comprises a pressure compensator, which is arranged in the connecting oil passage and is used for controlling the opening and closing of the bucket three-position six-way spool valve and the boom four-position six-way spool valve.

[0020] In some embodiments, the valve body device further comprises a back pressure valve, which is arranged in the connecting oil passage and is communicated with the oil return pipeline.

[0021] In the second aspect, the application further provides a loader, comprising a loader body and a hydraulic control valve system as described in any one of the above, the hydraulic control valve system is arranged inside the loader body. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The hydraulic control valve system provided by the embodiment of the application is shown in the whole structure schematic view;

[0023] Figure 2 The hydraulic control valve system provided by the embodiment of the application is shown in the whole structure schematic view;

[0024] In the figure: 1-merging valve, 2-safety valve, 3-back pressure valve, 4-port overflow valve, 5-pressure compensator, 6-main overflow valve, 7-bucket three-position six-way spool valve, 8-boom four-position six-way spool valve, 9-variable plunger pump body, 10-constant displacement pump body, 11-oil tank, 12-first oil passage, 13-second oil passage, 14-oil return pipeline. DETAILED DESCRIPTION

[0025] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " represents the meaning of or, for example, A / B can represent A or B; the "and / or" in the text only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0026] Hereinafter, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" is two or more than two.

[0027] The embodiments of the present application disclose a hydraulic control valve system and a loader for simplifying the hydraulic system of the loader and reducing the use volume of the hydraulic system.

[0028] To achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions:

[0029] Please refer to Figure 1 、 Figure 2 In a first aspect, the present application provides a hydraulic control valve system, comprising: a variable piston pump body 9, a constant pump body 10 and a valve device;

[0030] The variable piston pump body 9 and the constant pump body 10 are respectively communicated with the valve device, and the valve device is communicated with an oil tank 11;

[0031] The valve device comprises a control valve assembly, an overflow valve assembly, a working valve assembly and a connecting pipeline assembly;

[0032] The connecting pipeline assembly has a first inlet and a second inlet, wherein the first inlet is communicated with the variable plunger pump body 9, and the second inlet is communicated with the fixed displacement pump body 10; the control valve assembly, the overflow valve assembly and the working valve assembly are communicated through the connecting pipeline assembly, and when the plunger pump body flow meets the demand of the connecting pipeline assembly, the plunger pump body is communicated with the working valve assembly through the connecting pipeline assembly; when the plunger pump body flow cannot meet the demand of the connecting pipeline assembly, the fixed displacement pump body 10 is communicated with the control valve assembly through the connecting pipeline assembly, and is communicated with the working valve assembly through the control valve assembly to supplement the flow demand in the connecting pipeline assembly.

[0033] The application is additionally provided with a valve body device, wherein the valve body device comprises a control valve assembly, an overflow valve assembly, a working valve assembly, and is additionally provided with a connecting pipeline assembly, and the control valve assembly, the overflow valve assembly and the working valve assembly are communicated through the connecting pipeline assembly; in addition, the variable plunger pump body 9 and the fixed displacement pump body 10 are also respectively communicated with the valve body device; when the hydraulic system of the application is in standby or small power operation, the flow supplied by the variable plunger pump body 9 to the valve body device can meet the demand of the hydraulic system; when there is high power operation, the demand of the connecting pipeline assembly is greater than the flow supplied by the variable plunger pump body 9 to the valve body device, at this time, the fixed displacement pump body 10 starts to operate, and the fixed displacement pump supplements the remaining flow through the control valve assembly to ensure the stable operation of the whole system; in the above structure, the control valve assembly, the overflow valve assembly and the working valve assembly are integrated on one valve body, realizing the combination of the variable displacement system and the fixed displacement system, and the required installation space is small and the cost is lower.

[0034] Further, please refer to Figure 1 , Figure 2 The valve body device further comprises an oil return pipeline 14, which is communicated with the control valve assembly, the overflow valve assembly and the working valve assembly, and is communicated with the oil tank 11; as shown in the figure, the oil return pipeline 14 is the pipeline with the reference number T, which is mainly used to connect with the oil tank 11 to return the excess oil in the connecting pipeline assembly to the inside of the oil tank 11 in use; in addition, the oil return pipeline 14 in the application is communicated with the control valve assembly, the overflow valve assembly and the working valve assembly, that is, the overall structure of the valve body device of the application returns the excess oil to the inside of the oil tank 11 through the oil return pipeline 14 to reduce the cost.

[0035] Further, please refer to Figure 1 , Figure 2The connecting pipeline assembly includes a first oil path 12, a second oil path 13 and a connecting oil passage, the first inlet is arranged on the first oil path 12, and the second inlet is arranged on the second oil path 13; the first oil path 12 is communicated with the control valve assembly, the overflow valve assembly and the working valve assembly; the second oil path 13 is communicated with the control valve assembly; and the connecting oil passage is used for communicating the control valve assembly, the overflow valve assembly and the working valve assembly. As shown in the figure, the variable plunger pump body 9 is connected with the PV port, and the fixed displacement pump body 10 is connected with the Pf port, that is, the first inlet is the PV port in the figure, and the second inlet is the Pf port in the figure. When the whole machine is in the standby state, the swing angle of the variable plunger pump body 9 is the smallest at this time, and the fixed displacement pump body 10 hardly provides flow. The fixed displacement pump body 10 is unloaded through the merging valve 1 in the middle position. When the whole machine works, the variable plunger pump body 9 preferentially provides flow through the first oil path 12. When the required flow of the system is greater than the flow provided by the variable plunger pump body 9, the fixed displacement pump body 10 supplements the remaining flow through the merging valve 1 along the second oil path 13 at this time. The above process is the merging system of variable and fixed displacement, and the connecting oil passage in the application has a plurality of connecting oil passages, which are mainly used for connecting the control valve assembly, the overflow valve assembly and the working valve assembly, so that the logic valve, the shuttle valve and the working valve in the application are integrated on a valve body, and the installation space of the whole system of the application is further reduced.

[0036] Further, please refer to Figure 1 The control valve assembly includes the merging valve 1, one end of the merging valve 1 is communicated with the variable plunger pump body 9 through the first oil path 12, the other end of the merging valve 1 is communicated with the fixed displacement pump body 10 through the second oil path 13, and the merging valve 1 is communicated with the overflow valve assembly. The merging valve 1 is mainly used for connecting the first oil path 12 and the second oil path 13, and the flow in the first oil path 12 and the second oil path 13 can be combined to provide the necessary demand for the working valve assembly.

[0037] Further, please refer to Figure 1 The connecting pipeline assembly further includes an oil drain pipeline, the oil drain pipeline is communicated with the overflow valve assembly and the oil return pipeline 14. In the above structure, the oil drain pipeline in the application is mainly used for returning the excess oil to the oil tank 11. Specifically, when the system pressure abnormally rises, that is, the state is that the oil input into the whole system is too much, resulting in excess, and when the overflow pressure of the safety valve 2 is reached, the safety valve 2 overflows to the oil drain pipeline. At this time, the pressure difference on both sides of the merging valve 1 becomes large, so that the swing angle of the variable plunger pump body is small, and the flow is reduced. The fixed displacement pump body 10 unloads oil to the oil tank 11 through the merging valve 1, so as to achieve the purpose of energy saving.

[0038] Further, please refer to Figure 1 The overflow valve assembly includes a main overflow valve 6, a safety valve 2 and a port overflow valve 4.

[0039] The oil leakage pipeline is communicated with the main overflow valve 6, the safety valve 2 and the port overflow valve 4 respectively, the safety valve 2 is communicated with the merging valve 1, the port overflow valve 4 is communicated with the working valve assembly, and the main overflow valve 6 is arranged in the connecting oil passage and communicated with the merging valve 1 and the working valve assembly at one end and communicated with the oil tank 11 through the oil return pipeline at the other end;

[0040] The safety valve 2 and the port overflow valve 4 are used for detecting the flow pressure in the connecting oil passage, and when the flow pressure in the connecting oil passage is abnormal, the oil leakage pipeline and the oil return pipeline 14 are turned on to reduce the flow pressure in the connecting oil passage.

[0041] Further, please refer to Figure 1 The working valve assembly comprises a bucket three-position six-way valve core 7 and a boom four-position six-way valve core 8, the bucket three-position six-way valve core 7 is communicated with the port overflow valve 4, the bucket three-position six-way valve core 7 is communicated with the boom four-position six-way valve core 8 through the connecting oil passage, and the bucket three-position six-way valve core 7 and the boom four-position six-way valve core 8 are communicated with the oil leakage pipeline and the oil return pipeline 14 respectively.

[0042] Further, please refer to Figure 2 The valve body device further comprises a pressure compensator 5 arranged in the connecting oil passage and used for controlling the opening and closing of the bucket three-position six-way valve core 7 and the boom four-position six-way valve core 8.

[0043] It is worth noting that the boom four-position six-way valve core 8 in the application also has a floating position function, so that the bucket can freely float with the ground and its own weight, thereby realizing the automatic leveling function of the bucket on uneven ground.

[0044] Further, please refer to Figure 2The valve body device further comprises a back pressure valve 3 arranged in the connecting oil path and communicated with the oil return pipeline 14. In the above structure, the back pressure valve 3 is arranged in the connecting oil path, and when the whole machine operates and returns oil, the back pressure valve 3 is used to improve the oil supplement efficiency and achieve the energy saving effect.

[0045] Further, in a second aspect, the application also provides a loader, comprising a loader body and the hydraulic control valve system according to any one of the above, the hydraulic control valve system is arranged in the loader body. The loader body in the application can be one of excavators and the like. The hydraulic control valve system in the application is arranged in the loader body, thereby completing the arrangement of the hydraulic system of the loader body.

[0046] Obviously, various modifications and changes can be made to the application by those skilled in the art without departing from the spirit and scope of the application. Thus, it is intended that the application cover modifications and changes as long as they come within the scope of the claims and their equivalents.

Claims

1. A hydraulic control valve system characterized by, The variable piston pump body, the constant displacement pump body and the valve body device are communicated respectively, and the valve body device is communicated with an oil tank. The valve body device comprises a control valve assembly, an overflow valve assembly, a working valve assembly and a connecting pipeline assembly. The connecting pipeline assembly has a first inlet and a second inlet, wherein the first inlet is communicated with the variable piston pump body, the second inlet is communicated with the constant displacement pump body, the control valve assembly, the overflow valve assembly and the working valve assembly are communicated through the connecting pipeline assembly, and when the flow of the piston pump body meets the demand of the connecting pipeline assembly, the piston pump body is conducted through the connecting pipeline assembly and the working valve assembly; when the flow of the piston pump body cannot meet the demand of the connecting pipeline assembly, the constant displacement pump body is communicated with the control valve assembly through the connecting pipeline assembly, and is conducted with the working valve assembly through the control valve assembly, so as to supplement the flow demand in the connecting pipeline assembly. The control valve assembly comprises a combined flow valve, the combined flow valve comprises a one-way valve and a control valve, the oil outlet of the one-way valve is communicated with the variable piston pump body through a first oil path, the oil inlet of the one-way valve is communicated with the constant displacement pump body through a second oil path, the oil inlet of the control valve is communicated with the oil inlet of the one-way valve, the oil outlet of the control valve is communicated with a return oil pipeline, and the oil outlet of the one-way valve is connected with the control cavity of the control valve through a throttle valve and can open the control valve. The feedback oil path (LS) in the valve body device is connected with the spring cavity of the control valve through a throttle valve and can close the control valve. The valve body device further comprises a return oil pipeline, which is communicated with the control valve assembly, the overflow valve assembly and the working valve assembly respectively, and is communicated with the oil tank. The connecting pipeline assembly comprises a first oil path, a second oil path and a connecting oil channel, the first inlet is arranged on the first oil path, the second inlet is arranged on the second oil path, the first oil path is communicated with the control valve assembly, the overflow valve assembly and the working valve assembly, the second oil path is communicated with the control valve assembly, and the connecting oil channel is used for communicating the control valve assembly, the overflow valve assembly and the working valve assembly.

2. The hydraulic control valve system of claim 1, wherein, The spring cavity of the combined flow valve is communicated with the overflow valve assembly through a throttle valve.

3. The hydraulic control valve system of claim 2, wherein, The connecting pipeline assembly further comprises a drain pipeline, which is communicated with the overflow valve assembly and the return oil pipeline.

4. The hydraulic control valve system of claim 3, wherein, The overflow valve assembly comprises a main overflow valve, a safety valve and a port overflow valve.

5. The hydraulic control valve system of claim 4, wherein, The drain pipeline is communicated with the main overflow valve, the safety valve and the port overflow valve respectively, the safety valve is communicated with the combined flow valve, the port overflow valve is communicated with the working valve assembly, the main overflow valve is arranged on the connecting oil channel, one end of which is communicated with the combined flow valve and the working valve assembly respectively, and the other end is communicated with the oil tank through the return oil pipeline.

6. The hydraulic control valve system of claim 5, wherein, ​ ​ The safety valve, the port overflow valve and the main overflow valve are used for detecting the flow pressure in the connecting oil passage, and when the flow pressure in the connecting oil passage is abnormal, the oil drain pipeline and the oil return pipeline are turned on to reduce the flow pressure in the connecting oil passage.

7. The hydraulic control valve system of claim 6, wherein, The working valve assembly includes a bucket three-position six-way spool and a boom four-position six-way spool, the bucket three-position six-way spool is communicated with the port overflow valve, the bucket three-position six-way spool is communicated with the boom four-position six-way spool through the connecting oil passage, and the bucket three-position six-way spool and the boom four-position six-way spool are communicated with the oil drain pipeline and the oil return pipeline respectively.

8. The hydraulic control valve system of claim 7, wherein, The valve body device further includes a pressure compensator, which is arranged in the connecting oil passage and is used for controlling the opening and closing of the bucket three-position six-way spool and the boom four-position six-way spool.

9. The hydraulic control valve system of claim 3, wherein, The valve body device further includes a back pressure valve, which is arranged in the connecting oil passage and is communicated with the oil return pipeline.

10. A loader characterized by The loader body and the hydraulic control valve system as claimed in any one of claims 1-9 are provided inside the loader body.

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