Energy-saving system of excavator without pilot pump

Abstract

The utility model discloses a kind of energy-saving system of excavator without pilot pump, belong to hydraulic system technical field, solve the problem of existing super small excavator hydraulic system layout and inconvenient operation, high energy consumption.It includes hydraulic pump, hydraulic multiway valve, hydraulic pilot valve and energy accumulator, the oil source valve includes pressure retaining valve and pressure reducing valve, the output end of the hydraulic pump is communicated with the input end of pressure retaining valve, pressure reducing valve respectively, the output end of the pressure retaining valve is communicated with the input end of hydraulic multiway valve, the output end of the hydraulic multiway valve is communicated with the input end of oil cylinder, the output end of the pressure reducing valve is communicated with energy accumulator, the energy accumulator is communicated with the pressure feedback oil port of pressure retaining valve, the output end of the pressure reducing valve is also communicated with the input end of hydraulic pilot valve.The energy-saving system of the utility model, without providing pilot oil pump, effectively reduce energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic system technology, and more specifically, it relates to an energy-saving system for excavators without a pilot pump. Background Technology

[0002] In ultra-mini excavators weighing 1 ton or less, mechanical control is generally used (i.e., the handle directly pulls the valve core of the multi-way valve through a mechanical structure). A small number of models use a hybrid mechanical and hydraulic pilot control system, where the boom, bucket, stick, and swing are operated with high-frequency hydraulic pilot control to improve operating comfort. These ultra-mini excavators are very small, and can only accommodate a maximum of two working gear pumps, leaving no room for a pilot pump. Without a pilot pump, the pilot hydraulic circuit cannot obtain pilot pressure. To solve the problem of no pilot pressure, two solutions are generally used.

[0003] Option 1: Because of the mechanical control, after the machine starts, a mechanical operation is performed first to pressurize the accumulator with high-pressure oil. Once the accumulator is pressurized, pilot control actions can be performed. Simultaneously, high-pressure oil can pressurize the accumulator again. The disadvantage is that a mechanical operation must be performed every time the machine is started before hydraulic pilot control can be initiated. After the machine has been idle for a certain period, if the accumulator pressure is insufficient, a mechanical operation must also be performed before hydraulic pilot control can be initiated, making the operation very cumbersome and inconvenient.

[0004] Option 2: To address the issue of mechanical control actions required to start the machine as in Solution 1, the working pipeline is maintained at a pressure of 2-2.3 MPa through throttling and overflow methods. Even during operation, this pressure loss will increase. Since excavators of 1 ton or less typically use gear pumps, maintaining this constant pressure would result in relatively high energy consumption.

[0005] Therefore, there is an urgent need to develop and design an energy-saving system for excavators without a pilot pump to solve the above problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to address the above-mentioned shortcomings of the existing technology. The purpose of this utility model is to provide an excavator pilot pump-free energy-saving system that does not require a pilot oil pump. After the machine is started, pilot control actions can be performed directly without first performing mechanical control actions, making operation very convenient and effectively reducing energy consumption.

[0007] To achieve the above objectives, this utility model provides an excavator pilot-pump-less energy-saving system, including a hydraulic pump, a hydraulic multi-way valve, a hydraulic pilot valve, and an accumulator, and also includes an oil source valve for throttling. The oil source valve includes a pressure-holding valve and a pressure-reducing valve. The input end of the hydraulic pump is connected to an oil tank, and the output end of the hydraulic pump is connected to the input ends of the pressure-holding valve and the pressure-reducing valve, respectively. The output end of the pressure-holding valve is connected to the input end of the hydraulic multi-way valve, and the output end of the hydraulic multi-way valve is connected to the input end of the hydraulic cylinder. The output end of the pressure-reducing valve is connected to the accumulator, and the accumulator is connected to the pressure feedback port of the pressure-holding valve. The output end of the pressure-reducing valve is also connected to the input end of the hydraulic pilot valve, and the output end of the hydraulic pilot valve is connected to the pilot port of the hydraulic multi-way valve. The set pressure of the pressure-reducing valve is greater than the set pressure of the pressure-holding valve.

[0008] As a further improvement, an accumulator check valve is also provided between the pressure reducing valve and the accumulator.

[0009] Furthermore, a pilot safety solenoid valve is also provided between the accumulator check valve and the hydraulic pilot valve.

[0010] Furthermore, the pressure holding valve is set to a pressure of 2.3 MPa, and the pressure reducing valve is set to a pressure of 3.5 MPa.

[0011] Furthermore, the return ports of the pressure reducing valve, pilot safety solenoid valve, hydraulic multi-way valve, and hydraulic pilot valve are all connected to the oil tank through return oil pipelines.

[0012] Furthermore, the hydraulic pump is a double gear pump, the hydraulic multi-way valve and the hydraulic pilot valve are both double valves, there are two oil cylinders, the two oil outlets of the hydraulic pump are respectively connected to a pressure holding valve, and the two oil outlets of the hydraulic pump are connected to the oil inlet of the pressure reducing valve. The two pressure holding valves are respectively connected to the two oil inlets of the hydraulic multi-way valve, and the two oil cylinders are respectively connected to the two oil outlets of the hydraulic multi-way valve.

[0013] Furthermore, a one-way valve for oil supply is provided between each of the two oil outlets of the hydraulic pump and the oil inlet of the pressure reducing valve.

[0014] Beneficial effects Compared with the prior art, the advantages of this utility model are as follows: This utility model's excavator pilot pump-free energy-saving system automatically provides pilot pressure when the excavator has no pilot pump by adding an oil source valve to the control hydraulic system. As long as the pressure in the accumulator is greater than the set pressure of the pressure holding valve, the pressure holding valve is always in the fully open state. Once the machine performs an action, the pilot pressure no longer consumes additional energy and is always maintained. Moreover, there is no need to waste energy to achieve pilot control actions, and pilot control actions can be performed directly, which conforms to the working habits of most people and makes operation more convenient. Attached Figure Description

[0015] Figure 1 This is a hydraulic schematic diagram of the present invention; Figure 2 This is a hydraulic schematic diagram of the oil source valve in this utility model.

[0016] Among them: 1-hydraulic pump, 2-hydraulic multi-way valve, 3-hydraulic pilot valve, 4-accumulator, 5-oil source valve, 6-oil tank, 7-oil cylinder, 8-return oil line, 51-pressure holding valve, 52-pressure reducing valve, 53-accumulator check valve, 54-pilot safety solenoid valve, 55-oil supply check valve, a-pressure feedback oil port, b-pilot oil port. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0018] See Figure 1-2 This utility model discloses an energy-saving system for excavators without a pilot pump, comprising a hydraulic pump 1, a hydraulic multi-way valve 2, a hydraulic pilot valve 3, and an accumulator 4. It also includes an oil source valve 5 for throttling, which comprises a pressure-holding valve 51 and a pressure-reducing valve 52. The input end of the hydraulic pump 1 is connected to an oil tank 6, and the output end of the hydraulic pump 1 is connected to the input ends of the pressure-holding valve 51 and the pressure-reducing valve 52, respectively, enabling the diversion of hydraulic oil to the pressure-holding valve 51 and the pressure-reducing valve 52. The output end of the pressure-holding valve 51 is connected to the input end of the hydraulic multi-way valve 2, thus supplying oil to the hydraulic multi-way valve 2. The output end of the pressure reducing valve 2 is connected to the input end of the hydraulic cylinder 7, thus supplying oil to the hydraulic cylinder 7. The output end of the pressure reducing valve 52 is connected to the accumulator 4, thus supplying oil to the accumulator 4 and increasing its pressure. The accumulator 4 is connected to the pressure feedback port a of the pressure holding valve 51, providing pressure for the movement of the valve core of the pressure holding valve 51. The output end of the pressure reducing valve 52 is also connected to the input end of the hydraulic pilot valve 3, thus supplying oil to the hydraulic pilot valve 3. The output end of the hydraulic pilot valve 3 is connected to the pilot port b of the hydraulic multi-way valve 2, thus providing pilot oil to the hydraulic multi-way valve 2, thereby driving the valve core of the hydraulic multi-way valve 2 to move and switch directions. The pressure holding valve 51 has a pressure feedback port a, which can adjust the pressure holding pressure, i.e., set a specific pressure value. The pressure reducing valve 52 can also be set to a specific pressure value. The set pressure of the pressure reducing valve 52 is greater than the set pressure of the pressure holding valve 51, so as to ensure that after the excavator starts, the hydraulic oil is first supplied to the pressure holding valve 51, and then transmitted to the accumulator 4 and the hydraulic pilot valve 3 through the pressure reducing valve. In this embodiment, the pressure setting of the pressure holding valve 51 is 2.3 MPa and the pressure setting of the pressure reducing valve 52 is 3.5 MPa, as an example.

[0019] Preferably, an accumulator check valve 53 is also provided between the pressure reducing valve 52 and the accumulator 4 to reduce leakage of the accumulator 4 and make the accumulator 4 maintain pressure for a longer time.

[0020] Preferably, a pilot safety solenoid valve 54 is also provided between the accumulator check valve 53 and the hydraulic pilot valve 3, which not only provides safety for cutting off the pilot oil circuit, but also further extends the pressure holding time of the accumulator 4 in the event of power failure.

[0021] Preferably, the return ports of the pressure reducing valve 52, the pilot safety solenoid valve 54, the hydraulic multi-way valve 2, and the hydraulic pilot valve 3 are all connected to the oil tank 6 through the return oil pipeline 8 to realize the return oil of the hydraulic system.

[0022] Preferably, the pilot-less energy-saving system in this embodiment is applied to an excavator. Since the excavator has a two-hand operation function, the hydraulic pump 1 is a double gear pump. The hydraulic multi-way valve 2 and the hydraulic pilot valve 3 are both double valves. There are two cylinders 7. The two oil outlets of the hydraulic pump 1 are respectively connected to a pressure-holding valve 51, and the two oil outlets of the hydraulic pump 1 are connected to the inlet of the pressure-reducing valve 52. Figure 2 In the P1 / P2 oil circuit, the two pressure holding valves 51 are respectively connected to the two oil inlets of the hydraulic multi-way valve 2, that is, corresponding to Figure 2 In the P1 / P2 oil circuit, the two oil cylinders 7 are respectively connected to the two oil outlets of the hydraulic multi-way valve 2, so as to drive the two oil cylinders 7 to work simultaneously.

[0023] Preferably, a one-way valve 55 is provided between each of the two oil outlets of the hydraulic pump 1 and the oil inlet of the pressure reducing valve 52 to isolate the corresponding oil circuits of the two oil outlets of the hydraulic pump 1 (i.e., corresponding...). Figure 2 (P1 / P2 oil circuit in the middle).

[0024] In this embodiment, taking the set pressure of the pressure-holding valve 51 as 2.3 MPa and the set pressure of the pressure-reducing valve 52 as 3.5 MPa as an example, a control method for an excavator's pilot-operated pump-less energy-saving system is provided. This control method includes: Before the excavator is started, there is no pressure at the output end of hydraulic pump 1 (P1 / P2 port of hydraulic pump 1) and accumulator 4. After the excavator is started, hydraulic pump 1 works, and the hydraulic oil output by hydraulic pump 1 enters pressure holding valve 51. Since there is no pressure in accumulator 4, the valve core of pressure holding valve 51 moves to the right, throttling the hydraulic oil output by hydraulic pump 1, so that the hydraulic oil pressure output by hydraulic pump 1 (the P1 / P2 oil circuit pressure of hydraulic pump 1) rises to the set pressure of pressure holding valve 51 (i.e., 2.3 MPa). At the same time, the pressure in accumulator 4 also gradually rises to the set pressure of pressure holding valve 51 (i.e., 2.3 MPa). When the excavator is in operation, the hydraulic pump 1 continues to work, and the hydraulic oil pressure output by the hydraulic pump 1 continues to rise. Part of the hydraulic oil passes through the oil supply check valve 55, the pressure reducing valve 52, and the accumulator check valve 53 to reach the accumulator 4, causing the pressure in the accumulator 4 to rise to the set pressure of the pressure reducing valve 51 (i.e., 3.5 MPa). The other part of the hydraulic oil passes through the oil supply check valve 55, the pressure reducing valve 52, the accumulator check valve 53, and the pilot safety solenoid valve 54 to reach the hydraulic pilot valve 3. At this time, the accumulator 4 feeds back the pressure (i.e. 3.5 MPa) to the pressure feedback port a of the pressure holding valve 51. Since the pressure of the accumulator 4 (i.e. 3.5 MPa) is greater than the set pressure of the pressure holding valve 51 (i.e. 2.3 MPa), the valve core of the pressure holding valve 51 moves to the left, and the hydraulic oil output by the hydraulic pump 1 is not throttled. The hydraulic oil enters the hydraulic multi-way valve 2 through the pressure holding valve 51. When the hydraulic pilot valve 3 is activated, the hydraulic oil in the hydraulic pilot valve 3 pushes the valve core of the hydraulic multi-way valve 2 to move and switch directions, connecting the hydraulic oil in the hydraulic multi-way valve 2 with the cylinder 7, thereby pushing the cylinder 7 to activate. When the excavator stops operating, the pressure in accumulator 4 (3.5 MPa) remains higher than the set pressure of pressure holding valve 51 (2.3 MPa), keeping the valve core of pressure holding valve 51 fully open to the left. This ensures that the hydraulic oil output from hydraulic pump 1 is not throttled, preventing additional energy consumption while the excavator is running. Throughout the entire operation, pressure holding valve 51 does not cause any pressure loss in the oil circuit.

[0025] This utility model's excavator pilot pump-free energy-saving system automatically provides pilot pressure when the excavator has no pilot pump by adding an oil source valve 5 to the control hydraulic system. As long as the pressure in the accumulator 4 is greater than the set pressure of the pressure holding valve 51, the pressure holding valve 51 is always in the fully open state. Once the machine performs an action, the pilot pressure no longer consumes additional energy and is always maintained. As long as the pressure in the accumulator 4 is not released, no energy will be consumed by providing pilot pressure, and there is no need to waste energy to achieve pilot control actions. Pilot control actions can be performed directly, which conforms to the working habits of most people and makes operation more convenient.

[0026] The above are merely preferred embodiments of this utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model, and these will not affect the implementation effect of this utility model or the practicality of the patent.

Claims

1. A pilot-free energy-saving system for excavators, comprising a hydraulic pump (1), a hydraulic multi-way valve (2), a hydraulic pilot valve (3), and an accumulator (4), characterized in that, It also includes an oil source valve (5) for throttling, the oil source valve (5) includes a pressure holding valve (51) and a pressure reducing valve (52), the input end of the hydraulic pump (1) is connected to the oil tank (6), the output end of the hydraulic pump (1) is connected to the input end of the pressure holding valve (51) and the pressure reducing valve (52) respectively, the output end of the pressure holding valve (51) is connected to the input end of the hydraulic multi-way valve (2), the output end of the hydraulic multi-way valve (2) is connected to the input end of the oil cylinder (7), the output end of the pressure reducing valve (52) is connected to the accumulator (4), the accumulator (4) is connected to the pressure feedback oil port (a) of the pressure holding valve (51), the output end of the pressure reducing valve (52) is also connected to the input end of the hydraulic pilot valve (3), the output end of the hydraulic pilot valve (3) is connected to the pilot oil port (b) of the hydraulic multi-way valve (2), and the set pressure of the pressure reducing valve (52) is greater than the set pressure of the pressure holding valve (51).

2. The pilot-less energy-saving system for excavators according to claim 1, characterized in that, An accumulator check valve (53) is also provided between the pressure reducing valve (52) and the accumulator (4).

3. The pilot-less energy-saving system for excavators according to claim 2, characterized in that, A pilot safety solenoid valve (54) is also provided between the accumulator check valve (53) and the hydraulic pilot valve (3).

4. The pilot-less energy-saving system for excavators according to claim 2, characterized in that, The pressure holding valve (51) is set to a pressure of 2.3 MPa, and the pressure reducing valve (52) is set to a pressure of 3.5 MPa.

5. The pilot-less energy-saving system for excavators according to claim 3, characterized in that, The return ports of the pressure reducing valve (52), pilot safety solenoid valve (54), hydraulic multi-way valve (2), and hydraulic pilot valve (3) are all connected to the oil tank (6) through the return oil pipeline (8).

6. A pilot-less energy-saving system for excavators according to any one of claims 2-5, characterized in that, The hydraulic pump (1) is a double gear pump, the hydraulic multi-way valve (2) and the hydraulic pilot valve (3) are both double valves, there are two oil cylinders (7), the two oil outlets of the hydraulic pump (1) are respectively connected to a pressure holding valve (51), and the two oil outlets of the hydraulic pump (1) are connected to the oil inlet of the pressure reducing valve (52). The two pressure holding valves (51) are respectively connected to the two oil inlets of the hydraulic multi-way valve (2), and the two oil cylinders (7) are respectively connected to the two oil outlets of the hydraulic multi-way valve (2).

7. The pilot-less energy-saving system for excavators according to claim 6, characterized in that, The hydraulic pump (1) is equipped with a one-way valve (55) between its two outlet ports and the inlet port of the pressure reducing valve (52).

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