Pilot hydraulic system of bulldozer

Abstract

The utility model discloses a bulldozer pilot hydraulic system, and belongs to the technical field of bulldozer hydraulic pressure, the bulldozer pilot hydraulic system comprises a hydraulic oil tank, a pilot pump, an overflow valve group, an energy accumulator, a ball valve, a pilot handle and a main valve, a liquid inlet of the pilot pump is connected with the hydraulic oil tank through a pipeline, and a liquid outlet of the pilot pump is connected with the overflow valve group through a pipeline; the overflow valve bank conveys residual hydraulic oil in the pipeline into the hydraulic oil tank again, an energy accumulator is further arranged on the overflow valve bank, the end, away from the pilot pump, of the overflow valve bank is connected with the ball valve through a pipeline, and the end, away from the overflow valve bank, of the ball valve is connected with the pilot handle through a pipeline. And the pilot handle is connected with the main valve through a pipeline. The energy accumulator is arranged on the overflow valve set, when the bulldozer flames out, pressure in the energy accumulator is released, hydraulic oil in the pipeline is conveyed into the pilot handle through the pressure of the energy accumulator, the main valve is controlled through the pilot handle, and the scraper knife is restored to the initial state.

Description

Technical Field

[0001] The present application relates to the technical field of bulldozer hydraulics, and in particular to a bulldozer pilot hydraulic system. Background Art

[0002] The statements in this section merely provide background technical information related to the present application and do not necessarily constitute prior art.

[0003] Patent authorization announcement number CN210317955U discloses a bulldozer pilot control hydraulic system. For safety reasons, a safety lock is added between the pilot pump and the pilot handle. After the bulldozer is turned off, the pilot pump is turned off and the safety lock will also be closed. This can prevent the hydraulic oil in the pipeline from impacting the pilot handle, so that the safety lock plays a protective role.

[0004] However, in the actual working process, due to the operating habits of different operators, some operators will not retract the bulldozer's blade to its initial state and directly turn off the bulldozer. This will cause the blade to not be in the initial position when the bulldozer is started next time, affecting the accuracy of the blade. Therefore, it is necessary to design a pilot hydraulic system that can recycle the blade after turning off the engine. Utility Model Content

[0005] In order to solve the above problems, the present application proposes a bulldozer pilot hydraulic system.

[0006] The purpose of the present application is to provide a bulldozer pilot hydraulic system. By arranging an accumulator on the relief valve group, the pressure in the accumulator can be released when the bulldozer is turned off, and the hydraulic oil in the pipeline is transported to the pilot handle by the pressure of the accumulator. The main valve is then controlled by the pilot handle to restore the blade to its initial state.

[0007] In order to achieve the above purpose, this application adopts the following technical solutions:

[0008] A bulldozer pilot hydraulic system comprises: a hydraulic oil tank, a pilot pump, a relief valve group, an accumulator, a ball valve, a pilot handle and a main valve, wherein the liquid inlet of the pilot pump is connected to the hydraulic oil tank through a pipeline, and the liquid outlet of the pilot pump is connected to the relief valve group through a pipeline, and the relief valve group re-transports the hydraulic oil remaining in the pipeline to the hydraulic oil tank, and the relief valve group is also provided with an accumulator, and the end of the relief valve group away from the pilot pump is connected to the ball valve through a pipeline, and the end of the ball valve away from the relief valve group is connected to the pilot handle through a pipeline, and the pilot handle is connected to the main valve through a pipeline, and the main valve controls the operation of the bulldozer cylinder, the blade lifting cylinder and the blade tilting cylinder.

[0009] As a further preferred embodiment, the overflow valve group includes: a deceleration valve, a first one-way valve, and an accumulator. One end of the first one-way valve is connected to the pilot pump through a pipeline, the deceleration valve is connected in parallel to the pipeline of the first one-way valve and the pilot pump, and one end of the deceleration valve away from the pilot pump is connected to the hydraulic oil tank. The opening and closing of the deceleration valve is used to control the hydraulic oil from the pilot pump to the first one-way valve to return to the hydraulic oil tank.

[0010] As a further preference, a second one-way valve is also provided on the pipeline between the deceleration valve and the hydraulic oil tank.

[0011] As further preferred, the accumulator is located on the pipeline from the first one-way valve to the ball valve.

[0012] As a further preference, the pilot handle includes a four-position pilot handle and a two-position pilot handle, the two-position pilot handle controls the operation of the bulldozer cylinder through a main valve, and the four-position pilot handle controls the operation of the blade lifting cylinder and the blade tilting cylinder through the main valve.

[0013] As a further preference, the pilot handle is provided with an overflow port, and the overflow port is connected to the hydraulic oil tank through a pipeline.

[0014] Compared with the prior art, the beneficial effects of this application are:

[0015] The present application sets an accumulator on the relief valve group, so that when the bulldozer is turned off, the pressure in the accumulator can be released, and the hydraulic oil in the pipeline is transported to the pilot handle by the pressure of the accumulator. The pilot handle is then used to control the main valve to restore the shovel to its initial state. In this way, the hydraulic oil remaining in the pipeline can be used to realize the function of lowering the shovel to its initial state, thereby preventing the shovel from being unable to return to the initial state and affecting the next operation of the shovel.

[0016] The present application uses a relief valve group and a ball valve to prevent the normal operation of the bulldozer main hydraulic system from being affected when the pilot pump is suddenly turned on, thereby ensuring the safety of the pilot hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the hydraulic working principle diagram of this application;

[0018] Among them: 1. Hydraulic oil tank, 2. Pilot pump, 3. Overflow valve group, 4. Ball valve, 5. Four-position pilot handle, 6. Two-position pilot handle, 7. Main valve, 8. Bulldozer cylinder, 9. Blade lifting cylinder, 10. Blade tilting cylinder, 11. Working pump, 12. Accumulator, 13. First check valve, 14. Speed ​​reduction valve, 15. Second check valve. DETAILED DESCRIPTION

[0019] The present application is further described below in conjunction with the accompanying drawings and embodiments. Example 1

[0020] A bulldozer pilot hydraulic system, such as Figure 1 As shown, it includes: a hydraulic oil tank 1, a pilot pump 2, a relief valve group 3, an accumulator 12, a ball valve 4, a pilot handle and a main valve 7. The liquid inlet of the pilot pump 2 is connected to the hydraulic oil tank 1 through a pipeline, and the liquid outlet of the pilot pump 2 is connected to the relief valve group 3 through a pipeline. The relief valve group 3 re-transports the hydraulic oil remaining in the pipeline to the hydraulic oil tank 1. The relief valve group 3 is also provided with an accumulator 12. The end of the relief valve group 3 away from the pilot pump 2 is connected to the ball valve 4 through a pipeline, and the end of the ball valve 4 away from the relief valve group 3 is connected to the pilot handle through a pipeline. The pilot handle is connected to the main valve 7 through a pipeline. The main valve 7 controls the operation of the bulldozer cylinder 8, the blade lifting cylinder 9 and the blade tilting cylinder 10. By arranging the accumulator 12 on the overflow valve group 3, when the bulldozer is turned off, the pilot pump 2 is closed and the pressure in the accumulator 12 is released. The hydraulic oil in the pipeline is transported to the pilot handle by the pressure of the accumulator 12, and the main valve 7 is controlled by the pilot handle to restore the blade to its initial state. In this way, the hydraulic oil remaining in the pipeline can be used to realize the function of lowering the blade to its initial state, thereby preventing the blade from being unable to return to its initial state and affecting the next operation of the blade.

[0021] The pilot hydraulic system assists the bulldozer's main hydraulic system in its work. The pilot hydraulic system is supplied with oil by a separate pilot pump 2, which ensures the cleanliness of the hydraulic oil and reduces faults caused by hydraulic oil cleanliness. The pilot hydraulic system and the working pipeline are two independent hydraulic systems, which is conducive to fault analysis and troubleshooting.

[0022] like Figure 1 As shown, the main hydraulic system includes: a working pump 11, a main valve 7, a bulldozer cylinder 8, a blade lifting cylinder 9 and a blade tilting cylinder 10. The working pump 11 is connected to the hydraulic oil tank 1 through a pipeline, and one end of the working pump 11 away from the hydraulic oil tank 1 is connected to the main valve 7 to control the operation of the bulldozer cylinder 8, the blade lifting cylinder 9 and the blade tilting cylinder 10. When the main hydraulic system is working, the working pump 11 delivers hydraulic oil to the main valve 7, and after the main valve 7 is opened, it can control the opening or closing of the bulldozer cylinder 8, the blade lifting cylinder 9 and the blade tilting cylinder 10.

[0023] like Figure 1As shown, the overflow valve group 3 includes: a deceleration valve 14, a first one-way valve 13, and an accumulator 12. One end of the first one-way valve 13 is connected to the pilot pump 2 through a pipeline. The deceleration valve 14 is connected in parallel to the pipeline of the first one-way valve 13 and the pilot pump 2. The end of the deceleration valve 14 away from the pilot pump 2 is connected to the hydraulic oil tank 1. The opening and closing of the deceleration valve 14 controls the hydraulic oil from the pilot pump 2 to the first one-way valve 13 to return to the hydraulic oil tank 1.

[0024] like Figure 1 As shown, a second one-way valve 15 is further provided on the pipeline between the deceleration valve 14 and the hydraulic oil tank 1 , and the second one-way valve 15 prevents the hydraulic oil in the hydraulic oil tank 1 from flowing back to the deceleration valve 14 .

[0025] like Figure 1 As shown, the accumulator 12 is located on the pipeline from the first one-way valve 13 to the ball valve 4. After the pilot pump 2 is closed, the pressure of the accumulator 12 is used to transport all the hydraulic oil between the first one-way valve 13 and the ball valve 4 to the pilot handle, and the hydraulic oil pushes the valve core of the main valve 7, so that the shovel lifting cylinder 9 can be controlled to descend, causing the shovel to descend and return to the initial position. In this way, no hydraulic oil will remain in the pipeline to affect the next work.

[0026] like Figure 1 As shown, the pilot handle includes a four-position pilot handle 5 and a two-position pilot handle 6. The two-position pilot handle 6 controls the operation of the bulldozer cylinder 8 through the main valve 7, and the four-position pilot handle 5 controls the operation of the blade lifting cylinder 9 and the blade tilting cylinder 10 through the main valve 7.

[0027] The pilot handle is provided with an overflow port, and the overflow port is connected to the hydraulic oil tank 1 through a pipeline, so that residual hydraulic oil can be prevented in the pipeline from the ball valve 4 to the pilot handle, which will affect the normal operation of the pilot handle next time.

[0028] like Figure 1 As shown, the oil outlet of the pilot pump 2 enters the ball valve 4 through the relief valve group 3, and the outlet of the ball valve 4 is connected to the oil inlet of the pilot handle. The ball valve 4 is closed, and the hydraulic oil supplied by the pilot pump 2 returns to the hydraulic oil tank 1 through the relief valve group 3. At this time, no hydraulic oil passes through the pilot handle, and the working devices do not move. Because the relief valve group 3 has a certain opening pressure, the accumulator 12 installed on the relief valve group 3 will accumulate a certain amount of energy before opening; when the ball valve 4 is opened, the hydraulic oil of the pilot pump 2 enters the ball valve 4 through the relief valve group 3, and the outlet of the ball valve 4 is connected to the oil inlet of the pilot handle. The working devices are in motion. At this time, the pressure of the accumulator 12 is the same as that of the pilot pump 2, so that enough pressure can be accumulated in the accumulator 12, and the ball valve 4 plays a role in safety.

[0029] When the vehicle is turned off, the pilot pump 2 will no longer provide hydraulic oil, so pushing the pilot handle cannot control the main valve 7, and the main valve 7 cannot control the blade lifting cylinder 9.

[0030] Therefore, by adding an accumulator 12 to the overflow valve group 3, when the vehicle is turned off, the pilot pump 2 will no longer provide power hydraulic oil, but when the four-position pilot handle 5 is pushed, the accumulator 12 will release the hydraulic oil, and the hydraulic oil pushes the valve core of the main valve 7, and the function of lowering the shovel is achieved by the self-weight of the shovel. In this way, all the hydraulic oil remaining in the pipeline can be fully utilized, and the hydraulic oil will not be blocked in the pipeline to affect the next pilot work.

Claims

1. A bulldozer pilot hydraulic system, characterized in that: include: A hydraulic oil tank, a pilot pump, an overflow valve group, an accumulator, a ball valve, a pilot handle and a main valve. The liquid inlet of the pilot pump is connected to the hydraulic oil tank through a pipeline, and the liquid outlet of the pilot pump is connected to the overflow valve group through a pipeline. The overflow valve group re-transports the hydraulic oil remaining in the pipeline to the hydraulic oil tank. An accumulator is also provided on the overflow valve group. The end of the overflow valve group away from the pilot pump is connected to the ball valve through a pipeline, and the end of the ball valve away from the overflow valve group is connected to the pilot handle through a pipeline. The pilot handle is connected to the main valve through a pipeline. The main valve controls the operation of the bulldozer cylinder, the blade lifting cylinder and the blade tilting cylinder.

2. A bulldozer pilot hydraulic system as claimed in claim 1, characterized in that: The overflow valve group includes: a deceleration valve, a first one-way valve, and an accumulator. One end of the first one-way valve is connected to the pilot pump through a pipeline. The deceleration valve is connected in parallel to the pipeline of the first one-way valve and the pilot pump. The end of the deceleration valve away from the pilot pump is connected to the hydraulic oil tank. The opening and closing of the deceleration valve is used to control the hydraulic oil from the pilot pump to the first one-way valve to return to the hydraulic oil tank.

3. A bulldozer pilot hydraulic system as claimed in claim 2, characterized in that: A second one-way valve is also provided on the pipeline between the deceleration valve and the hydraulic oil tank.

4. A bulldozer pilot hydraulic system as claimed in claim 2, characterized in that: The accumulator is located on the pipeline from the first one-way valve to the ball valve.

5. A bulldozer pilot hydraulic system as claimed in claim 1, characterized in that: The pilot handle includes a four-position pilot handle and a two-position pilot handle. The two-position pilot handle controls the operation of the bulldozer cylinder through a main valve, and the four-position pilot handle controls the operation of the blade lifting cylinder and the blade tilting cylinder through the main valve.

6. A bulldozer pilot hydraulic system as claimed in claim 1, characterized in that: The pilot handle is provided with an overflow port, and the overflow port is connected to the hydraulic oil tank through a pipeline.

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