A device and method for reducing overshoot of plunger pressure of axial piston pump

Abstract

The present invention discloses a device and method for reducing the pressure overshoot of the plunger of an axial piston pump. It comprises a distribution plate and a cylinder body; a distribution plate recovery hole connected to an external oil tank is provided in the pressure-increasing transition zone of the distribution plate, and an electromagnetic control valve is provided between the distribution plate recovery hole and the oil tank; a plurality of distribution windows are provided at equal intervals circumferentially on the cylinder body, and a cylinder recovery hole is provided near each distribution window. When the plunger enters the pressure overshoot stage, the high-pressure oil inside the plunger can be drained to the oil tank through the cylinder recovery hole and the distribution plate recovery hole, thereby discharging the excess high-pressure oil that causes the internal pressure overshoot of the plunger from the plunger, thereby achieving the purpose of reducing the pressure overshoot.

Description

Technical Field

[0001] The invention relates to a method for reducing overshoot of plunger pressure of an axial piston pump, and in particular to a device and method for reducing overshoot of plunger pressure of a swash plate type axial piston pump. Background Art

[0002] The swash plate axial piston pump is a power element of the hydraulic system. It is widely used in engineering fields such as machine tool forging, metallurgy, engineering, mining, and shipbuilding due to its small size, simple structure, and high power density. Plunger pressure overshoot is a negative phenomenon that occurs in the flow distribution stage. It is equivalent to a pressure pulse, which not only causes vibration of surrounding components and increases mechanical noise, but also reflects a flow peak on the pump outlet flow curve, increasing the flow pulsation amplitude and increasing fluid noise. Vibration and noise are directly related to the quality of the pump's work. Therefore, vibration reduction and noise reduction are of great significance to improving the working performance and life cycle of the pump. Summary of the invention

[0003] In order to reduce the negative impact caused by pressure overshoot, the present invention provides a method for recovering plunger pressure overshoot, which can significantly reduce or even completely eliminate pressure overshoot, and has important engineering significance for reducing impact vibration and lowering working noise.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The present invention comprises a distribution plate, a cylinder body and an electromagnetic control valve. When the plunger enters the pressure overshoot stage, the excess high-pressure oil in the plunger can be discharged to the oil tank through the cylinder body recovery hole and the distribution plate recovery hole, thereby achieving the purpose of reducing the pressure overshoot amplitude.

[0006] The distribution plate is provided with a distribution plate recovery hole in the boost transition zone, and the distribution plate recovery hole is connected to the electromagnetic control valve. The starting position of the distribution plate recovery hole is the same as the starting position of the plunger cavity pressure overshoot under the design target working condition.

[0007] The cylinder body is provided with a cylinder body recovery hole, which is communicated with the plunger cavity, and the cylinder body recovery hole and the distribution plate recovery hole are on the same arc.

[0008] The solenoid control valve is a solenoid switch valve that controls the opening and closing of the valve by receiving an external signal.

[0009] In the present invention, a pressure recovery hole is opened on the distribution plate, and the recovery hole is located at the position where the plunger is about to enter the pressure overshoot. At the same time, a pressure recovery hole matched with the distribution plate recovery hole is set on the cylinder body. When the plunger is about to enter the pressure overshoot, the cylinder body recovery hole is connected with the distribution plate recovery hole, and the excess high-pressure oil inside the plunger is discharged into the oil tank. The opening and closing of the flow channel between the distribution plate recovery hole and the oil tank is determined by the electromagnetic control valve, and the opening and closing of the control valve is determined by the external signal. When the pressure overshoot reduction is required, the control valve receives the opening signal, and the control valve is in the closed state for other working conditions where the pressure overshoot reduction is not required.

[0010] The present invention has the following beneficial effects:

[0011] The present invention can reduce the overshoot amplitude of the internal pressure of the plunger during the pressure-increasing stage, and is of great significance for reducing the flow pulsation at the pump outlet, the overturning moment of the swash plate, and the impact vibration of the internal components of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a working principle diagram of an embodiment of the present invention.

[0013] Figure 2 It is a two-dimensional structural diagram of the distribution plate of the present invention.

[0014] Figure 3 This is a perspective view of the three-dimensional structure of the distribution plate of the present invention

[0015] Figure 4 This is the structural diagram of the traditional distribution plate.

[0016] Figure 5 It is a two-dimensional diagram of the cylinder body of the present invention.

[0017] Figure 6 It is a three-dimensional perspective view of the cylinder body of the present invention.

[0018] Figure 7 It is a partial cross-sectional view of the cylinder recovery hole of the present invention.

[0019] In the figure: 1. distribution plate, 2. cylinder body, 3. plunger chamber, 4. pressure-boosting transition zone, 5. distribution plate recovery hole, 6. electromagnetic control valve, 7. plunger chamber distribution window, 8. cylinder body recovery hole, 9. oil discharge waist groove, 10. pressure-relieving transition zone, 11. oil suction waist groove. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and examples.

[0021] like Figure 1As shown, the method of the present invention includes a distribution plate 1, an electromagnetic control valve 6 and a cylinder recovery hole 8. The distribution plate 1 is provided with a distribution plate recovery hole 5. An electromagnetic control valve 6 is arranged between the distribution plate recovery hole 5 and the oil tank. The electromagnetic control valve 6 is used to control the on-off of the pressure overshoot recovery channel, and the opening and closing of the valve is determined by an external signal.

[0022] like Figure 2 , Figure 3 As shown, the distribution plate of the present invention includes a pressure-increasing transition zone 4, a distribution plate recovery hole 5, an oil-discharging waist groove 9, a pressure-relieving transition zone 10, and an oil-absorbing waist groove 11.

[0023] like Figure 4 As shown, the conventional distribution plate includes a pressure-increasing transition zone 4, an oil-discharging waist groove 9, a pressure-relieving transition zone 10, and an oil-absorbing waist groove 11.

[0024] like Figure 3 As shown, a distribution plate recovery hole 5 is opened on the boost transition zone 4 of the distribution plate 1, and the distribution plate recovery hole 5 is connected to the oil tank; according to the designed target working condition, the starting position of the plunger cavity pressure overshoot is determined, and the distribution plate recovery hole 5 is located at the position where the plunger is about to enter the pressure overshoot; the method of the present invention exerts the best effect at the designed working condition point, and the pressure overshoot reduction is maximized.

[0025] like Figure 5 , Figure 6 , Figure 7 As shown, the present invention is provided with a cylinder recovery hole 8, a plunger cavity distribution window 7 and a plunger cavity 3, wherein when the cylinder 2 and the distribution plate 1 are coaxially installed, the center of the cylinder recovery hole 8 and the center of the distribution plate recovery hole 5 are on the same arc.

[0026] The working principle of the present invention to realize energy recovery and pressure compensation in the flow distribution and pressure relief stage is as follows:

[0027] When the plunger enters the pressure overshoot stage, the excess high-pressure oil inside the plunger flows into the oil tank through the cylinder recovery hole 8 and the distribution plate recovery hole 5, thereby achieving the purpose of reducing the pressure overshoot. In addition, an electromagnetic control valve 6 is arranged between the distribution plate recovery hole 5 and the oil tank to control the opening and closing of the recovery flow channel, and the opening and closing of the valve is determined by an external signal.

[0028] This embodiment is simulated and verified by simulating the traditional distribution plate and the pressure overshoot recovery distribution plate respectively, and comparing the internal pressure of the plunger in the oil suction stage under different working conditions. The results are shown in Table 1.

[0029] Table 1 is a comparison table of multiple working condition data of the embodiments of the present invention.

[0030]

Claims

1. A device for reducing the overshoot of the plunger pressure of an axial piston pump, comprising a valve plate (1), a cylinder body (2), and a plunger cavity (3), characterized in that: A distribution plate recovery hole (5) communicating with an external oil tank is provided in a pressure-increasing transition zone (4) of the distribution plate (1), and an electromagnetic control valve (6) is provided between the distribution plate recovery hole (5) and the oil tank; a plurality of plunger cavity distribution windows (7) are provided at equal intervals in the circumferential direction on the cylinder body (2), and a cylinder body recovery hole (8) is provided near each plunger cavity distribution window, and the cylinder body recovery hole (8) is communicated with the plunger cavity (3) via the plunger cavity distribution window (7); When the cylinder body (2) and the distribution plate (1) are coaxially mounted, the distribution plate recovery hole (5) is located on the circumference formed by connecting the cylinder body recovery holes (8); According to the target working condition, the starting position of the distribution plate recovery hole (5) is the same as the starting position of the pressure overshoot of the plunger chamber (3); During the rotation of the cylinder body (2), each cylinder body recovery hole (8) rotates to a position corresponding to the position of the distribution plate recovery hole (5), and the cylinder body recovery hole (8) overlaps with the distribution plate recovery hole (5); The electromagnetic control valve (6) is opened only when it is necessary to reduce the pressure overshoot.

2. The device for reducing overshoot of plunger pressure of an axial piston pump according to claim 1, characterized in that: The shape design of the distribution plate recovery hole (5) follows the principle of not damaging the smoothness of the pump outlet flow curve.

3. The device for reducing overshoot of plunger pressure of an axial piston pump according to claim 1, characterized in that: The distribution plate recovery hole (5) is connected to the oil tank through the pressure overshoot recovery channel, and the connection between the pressure overshoot recovery channel and the oil tank is controlled by the electromagnetic control valve (6), and the opening and closing of the electromagnetic control valve (6) is determined by an external signal.

4. A method for reducing overshoot of plunger pressure of an axial piston pump using the device according to any one of claims 1 to 3, characterized in that: When the plunger enters the pressure overshoot stage, the cylinder recovery hole (8) rotates to a position connected with the valve plate recovery hole (5), and the excess high-pressure oil inside the plunger flows into the oil tank through the cylinder recovery hole (8) and the valve plate recovery hole (5) in sequence, thereby achieving the purpose of reducing the pressure overshoot; The on-off of the pressure overshoot recovery flow channel is controlled by the electromagnetic control valve (6), and the electromagnetic control valve (6) is opened only when the pressure overshoot needs to be reduced.

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