Constant-power controller with pressure control for high-pressure plunger pump

Abstract

The utility model discloses a constant power controller with pressure control for a high-pressure plunger pump, which comprises a shell, a variable piston is arranged in the shell, a return spring connected with the shell is arranged at the small end of the variable piston, a shifting block rotationally connected with the shell is arranged on the radial side of the variable piston, and a power control valve is arranged on one side of the shifting block. A variable supporting column extending towards the shifting block is arranged on the variable piston in the radial direction, a guide hole is formed in the end face of the variable supporting column, the bottom face of the guide hole is communicated with the small end of the variable piston, a variable plunger is arranged in the guide hole and comprises a plunger body and a sliding shoe, the plunger body is in sliding connection with the variable supporting column, and one side of the sliding shoe is in spherical hinge joint with the plunger body. And the other side of the sliding shoe is in surface contact with the shifting block. The utility model has the advantages of longer service life and higher constant power control precision.

Description

Technical Field

[0001] The utility model belongs to the field of high-pressure plunger pumps, in particular to a constant power controller with pressure control used in the high-pressure plunger pump. Background Art

[0002] In the marine machinery hydraulic control system, constant power control is one of the most widely used variable modes for axial piston pumps. In particular, the constant power controller with pressure control can enable the main pump to automatically adjust the output flow according to the load pressure. When the system pressure continues to rise, the pump senses the pressure signal and adjusts the pump to a smaller displacement through the variable mechanism, so that the output power W = P 出 Q 出 It is basically constant. When the main engine performs multiple actions, the flow rate output by the main pump corresponds to the load pressure. It has high engine power utilization and high-pressure protection functions, so it is widely used in construction machinery such as lifting machinery and mining machinery.

[0003] In the existing constant power controller, the roller connected to the variable piston is used to contact the dial block to rotate. When the variable piston moves, the roller is driven to move. When the roller moves, the dial block is driven to rotate accordingly, so that the dial block applies force to the power control valve, and the output power of the pump is basically constant through the power control valve. Since there is a rigid line contact between the roller and the dial block, the contact pressure is strong and static pressure support cannot be established. When the constant power controller works for a long time at a pressure of more than 35MPa, the dial block and the roller will be damaged to varying degrees, resulting in a short service life of the constant power controller.

[0004] The ideal design is to hope that the roller and the shift block are in line contact during relative motion, but the cumulative tolerances between the parts and the differences in assembly make the roller and the shift block have point contact during the actual working process, which accelerates the wear and failure between the roller and the shift block, further reducing the service life of the constant power controller. Point contact will also cause the force on the shift block to be unstable, causing local drift in the constant power control curve, resulting in low constant power control accuracy.

[0005] Therefore, the existing constant power controller has the defects of short service life and low control accuracy. Utility Model Content

[0006] The purpose of the utility model is to provide a constant power controller with pressure control for a high-pressure plunger pump. The utility model has the advantages of long service life and high constant power control accuracy.

[0007] The technical solution of the utility model: a constant power controller with pressure control for a high-pressure plunger pump, comprising a shell, a variable piston arranged in the shell, a return spring connected to the shell at the small end of the variable piston, a shift block rotatably connected to the shell arranged on the radial side of the variable piston, a power control valve arranged on one side of the shift block, a variable support extending toward the shift block arranged in the radial direction of the variable piston, a guide hole arranged on the end face of the variable support, the bottom face of the guide hole being connected to the small end of the variable piston, a variable plunger arranged in the guide hole, the variable plunger comprising a plunger body and a sliding shoe, the plunger body being slidably connected to the variable support, one side of the sliding shoe being ball-hinged to the plunger body, and the other side of the sliding shoe being in surface contact with the shift block.

[0008] In the aforementioned constant power controller with pressure control for high-pressure plunger pump, the shift block is T-shaped, the junction of the three arms of the shift block is rotatably connected to the housing, one arm of the shift block contacts the sliding surface, and the other arm of the shift block is connected to the power control valve.

[0009] In the aforementioned constant power controller with pressure control for high-pressure plunger pump, the small end of the variable piston is connected to the large end of the variable piston through a power control valve, and a first throttling hole is provided between the power control valve and the large end of the variable piston.

[0010] In the aforementioned constant power controller with pressure control for high-pressure plunger pump, an oil groove connected to the guide hole is provided on the end surface of the sliding shoe facing the shifting block, so that a static pressure support surface J is formed between the sliding shoe and the shifting block.

[0011] In the aforementioned high-pressure plunger pump with constant power controller with pressure control, the plunger body is axially provided with a first oil channel connected to the oil groove, and the outer circumferential surface of the plunger body is provided with a plurality of annular grooves; a second oil channel is provided in the variable piston, and a third oil channel is provided in the variable support, one end of the second oil channel is located on the small end face of the variable piston, and the other end of the second oil channel is connected to the guide hole through the third oil channel.

[0012] Compared with the prior art, the utility model improves the roller that drives the shift block to rotate in the existing constant power controller into a variable plunger. The variable plunger and the shift block are in surface contact, the contact pressure is reduced, the parts are not easy to wear, and the service life is increased. In addition, by introducing oil between the variable plunger and the shift block, a static pressure support is established between the variable plunger and the shift block, and oil film lubrication is achieved between the variable plunger and the shift block, the parts are less prone to wear, and the service life is further increased. At the same time, the variable plunger is composed of a plunger body and a sliding shoe. The plunger body and the sliding shoe ball are hinged to ensure that the sliding shoe can be adaptively fitted on the shift block, so that the shift block is stably stressed, avoiding or reducing local drift of the constant power control curve, so that the constant power controller can accurately control the pump output flow and pressure, that is, the constant power control accuracy is high. Therefore, the utility model has the advantages of long service life and high constant power control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Figure 2 yes Figure 1 Enlarged view at A.

[0015] Figure 3 It is a structural diagram of the variable piston.

[0016] Figure 4 yes Figure 3 Top view of the .

[0017] Figure 5 It is a hydraulic principle diagram of the utility model.

[0018] The markings in the accompanying drawings are: 1-oil supply component, 2-return spring, 3-power control valve, 4-first throttle hole, 5-remote relief valve, 6-second throttle hole, 7-pressure control valve, 8-shift block, 9-variable plunger, 901-shoe, 902-plunger body, 903-oil groove, 904-first oil channel, 905-annular groove, 10-variable support, 101-guide hole, 102-third oil channel, 11-variable piston, 110-second oil channel. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0020] Example 1. A high pressure plunger pump with a constant power controller for pressure control, such as Figure 1 As shown, it includes a housing, a variable piston 11 is arranged in the housing, and the small end ( Figure 1 The W in the figure is provided with a return spring 2 connected to the housing, a shift block 8 rotatably connected to the housing is provided on the radial side of the variable piston 11, and a power control valve 3 is provided on one side of the shift block 8, and the features are as follows:

[0021] The variable piston 11 is radially provided with a variable support 10 extending toward the shift block 8. A guide hole 101 is provided on the end face of the variable support 10. A variable plunger 9 is provided in the guide hole 101. The variable plunger 9 includes a plunger body 902 and a sliding shoe 901. The plunger body 902 is slidably connected to the variable support 10. One side of the sliding shoe 901 is ball-jointed to the plunger body 902, and the other side of the sliding shoe 901 is in surface contact with the shift block 8.

[0022] The shift block 8 is T-shaped, and the junction of the three arms of the shift block 8 is rotatably connected to the housing. One arm of the shift block 8 is in surface contact with the sliding shoe 901 , and the other arm of the shift block 8 is connected to the power control valve 3 .

[0023] The small end of the variable piston 11 is connected to the large end of the variable piston 11 through the power control valve 3 ( Figure 1A first throttle hole 4 is provided between the power control valve 3 and the large end of the variable piston 11 (indicated by Q in the middle).

[0024] An oil groove 903 is disposed on the end surface of the sliding shoe 901 facing the shifting block 8 .

[0025] The plunger body 902 is axially provided with a first oil passage 904 connected to the oil groove 903, and the outer peripheral surface of the plunger body 902 is provided with a plurality of annular grooves 905; a second oil passage 110 is provided in the variable piston 11, and a third oil passage 102 is provided in the variable support 10, one end of the second oil passage 110 is located on the small end surface of the variable piston 11, and the other end of the second oil passage 110 is connected to the guide hole 101 through the third oil passage 102.

[0026] The constant power controller is connected to a hydraulic system for use. The oil supply component 1 of the hydraulic system is an axial piston pump. The outlet of the axial piston pump is connected to the small end of the variable piston 11 , and the swash plate of the axial piston pump is connected to the variable piston 11 .

[0027] Working principle of embodiment 1: Figure 1 As shown, the high-pressure oil at the outlet of the oil supply component 1 enters the small end W of the variable piston 11, driving the variable piston 11 to move leftward, the swash plate rotates, and the output flow of the pump changes. The high-pressure oil simultaneously enters the guide hole 101 through the second oil passage 110 and the third oil passage 102, pushing the variable plunger 9 upward, causing the shift block 8 to rotate. At the same time, the high-pressure oil also enters the oil groove 903 through the first oil passage 904, forming a static pressure support surface J between the sliding shoe 901 and the shift block 8 ( Figure 4 J in the middle) to prevent wear. Since the sliding shoe 901 and the plunger body 902 are ball-jointed, the sliding shoe 901 and the shift block 8 have a good adaptive fit. As the load pressure increases, the force at the bottom of the variable plunger 9 increases, and the pressure given to the power control valve 3 by the shift block 8 increases, forcing the power control valve 3 to open. A portion of the high-pressure oil at the outlet of the oil supply component 1 enters the large end Q of the variable piston 11 through the power control valve 3 and the first throttle hole 4 in turn, causing the variable piston 11 to move to the right. Since the cross-sectional area of ​​the large end Q of the variable piston is larger than the cross-sectional area of ​​the small end W of the variable piston, the variable piston 11 moves to the right, the variable force arm La decreases, and the force of the shift block 8 decreases accordingly. To overcome the internal spring force of the power control valve 3, the outlet pressure needs to be continuously increased to achieve balance. As the pressure increases, the swash plate swing angle decreases, and the outlet flow rate also decreases accordingly, making the output power W of the pump = Pout Qout basically constant.

[0028] When the load pressure drops, the force at the bottom of the variable piston 9 decreases, and the force on the shift block 8 also decreases. The power control valve 3 is in a closed state, and the oil at the large end Q of the variable piston is unloaded through the power control valve 3. The variable piston 11 moves to the right, the swash plate angle increases, and the outlet flow rate also increases, so that the output power W of the pump is equal to P 出 Q 出Basically constant. This is repeated, so that the output power of the variable pump is constant in the entire variable range.

[0029] Example 2. Based on Example 1, Figure 2 As shown, a pressure control valve 7 and a remote relief valve 5 are also provided in the shell. The inlet of the pressure control valve 7 is connected to the small end W of the variable piston, the outlet of the pressure control valve 7 is connected to the large end Q of the variable piston, and the control end of the pressure control valve 7 is connected to the remote relief valve 5.

[0030] Working principle of embodiment 2: Figure 2 As shown, when the oil supply component 1 is working, the high-pressure oil is introduced into the oil branches of the variable control mechanism into three paths a, b, and c. The control oil in path a enters the small end W of the variable piston. The hydraulic force formed and the return spring force push the swash plate to the maximum swing angle, and enters the bottom of the variable plunger 9 through the variable piston 11 and the variable support 10, forming a hydraulic thrust to push the shift block 8 to rotate. At the same time, the control oil enters the static pressure support surface J of the slipper 901 of the variable plunger 9; the variable plunger 9 is designed with a plunger body 902 and a slipper 901 as spherical contact, and can rotate freely within a certain angle, thereby realizing the adaptive adjustment of the slipper 901 of the variable plunger 9 and the shift block 8 surface.

[0031] As the load pressure increases, the force at the bottom of the variable plunger 9 increases, pushing the shift block 8 to rotate, compressing the power valve spring to force the power control valve 3 to open, and the oil in line b enters the large end Q of the variable piston through the first throttle hole 4, pushing the variable piston 11 to move to the left. Since the cross-sectional area of ​​the large end Q of the variable piston is larger than the cross-sectional area of ​​the small end W of the variable piston, the variable piston 11 moves to the left, the variable force arm La decreases, and the force of the shift block 8 decreases accordingly. To overcome the spring force of the power control valve 3, the outlet pressure needs to be continuously increased to achieve balance. As the pressure increases, the swash plate angle decreases, and the outlet flow rate also decreases accordingly, making the pump output power W = P 出 Q 出 Basically constant.

[0032] When the load pressure drops, the force at the bottom of the variable piston 9 decreases, and the force on the shift block also decreases. The power control valve 3 is in a closed state, and the oil at the large end Q of the variable piston is unloaded through the power control valve. The variable piston 11 moves to the right, the swash plate angle increases, and the outlet flow rate also increases, making the pump output power W = P 出 Q 出 Basically constant. This is repeated, so that the output power of the variable pump is constant in the entire variable range.

[0033] When the remote relief valve 5 is not working, no matter how the load pressure changes, the pressure control valve 7 is in a closed state. Only when the remote relief valve 5 is opened, the throttling pressure difference is formed by the throttling orifice 6 at the upper and lower ends of the valve core of the pressure control valve 7, and the pressure control valve 7 will open, and the oil in line C enters the large end Q of the variable piston through the pressure control valve 7, and the variable piston 11 moves to the left and the swash plate swings to zero angle, the output flow is zero, and the pressure is cut off. It should be emphasized that the pressure control valve 7 has priority. Once the pump load pressure reaches the set value of the pressure control valve 7, the pressure control valve 7 intervenes first, and the power control valve 3 exits its working function to achieve system overload protection.

[0034] In the description of the embodiments, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation.

Claims

1. A constant power controller with pressure control for a high-pressure plunger pump, comprising a housing, a variable piston (11) is arranged in the housing, a return spring (2) connected to the housing is arranged at the small end of the variable piston (11), a shift block (8) rotatably connected to the housing is arranged on the radial side of the variable piston (11), and a power control valve (3) is arranged on one side of the shift block (8), characterized in that: The variable piston (11) is radially provided with a variable support (10) extending toward the shift block (8); a guide hole (101) is provided on the end surface of the variable support (10); the bottom surface of the guide hole (101) is connected to the small end of the variable piston (11); a variable plunger (9) is provided in the guide hole (101); the variable plunger (9) comprises a plunger body (902) and a sliding shoe (901); the plunger body (902) is slidably connected to the variable support (10); one side of the sliding shoe (901) is ball-jointed to the plunger body (902); and the other side of the sliding shoe (901) is in surface contact with the shift block (8).

2. The constant power controller with pressure control for high-pressure plunger pump according to claim 1, characterized in that: The shift block (8) is T-shaped, and the junction of the three arms of the shift block (8) is rotatably connected to the housing, one arm of the shift block (8) is in surface contact with the sliding shoe (901), and the other arm of the shift block (8) is connected to the power control valve (3).

3. The constant power controller with pressure control for high pressure plunger pump according to claim 1, characterized in that: The small end of the variable piston (11) is connected to the large end of the variable piston (11) through a power control valve (3), and a first throttle hole (4) is provided between the power control valve (3) and the large end of the variable piston (11).

4. The constant power controller with pressure control for high pressure plunger pump according to claim 1, characterized in that: An oil groove (903) communicating with the guide hole (101) is provided on the end surface of the sliding shoe (901) facing the shifting block (8), so that a static pressure support surface J is formed between the sliding shoe (901) and the shifting block (8).

5. The constant power controller with pressure control for high pressure plunger pump according to claim 4, characterized in that: The plunger body (902) is axially provided with a first oil passage (904) connected to the oil groove (903), and the outer peripheral surface of the plunger body (902) is provided with a plurality of annular grooves (905); a second oil passage (110) is provided in the variable piston (11), and a third oil passage (102) is provided in the variable support (10); one end of the second oil passage (110) is located on the small end surface of the variable piston (11), and the other end of the second oil passage (110) is connected to the guide hole (101) through the third oil passage (102).

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