A bidirectional variable piston pump pressure regulating valve

Abstract

The invention discloses a bidirectional variable plunger pump pressure regulating valve, comprising a valve body (713), wherein a bushing (71), a valve sleeve (73) and a screw sleeve (79) are arranged in sequence from left to right in the valve body (713), wherein a shuttle valve core (72), a push rod (74), a valve core (75), a left spring seat (76), a spring (77) and a right spring seat (78) are arranged in sequence from left to right in the valve sleeve (73); wherein an A cavity, a B cavity, a T cavity and a P cavity are arranged in sequence on the valve body (713); wherein the A cavity and the B cavity are respectively located on both sides of the shuttle valve core (72). The invention not only has the characteristics of small size, compact structure, high integration and low cost, but also has the characteristics of adjustable set pressure and energy saving and environmental protection.

Description

Technical Field

[0001] The invention relates to a pressure regulating valve, in particular to a bidirectional variable plunger pump pressure regulating valve. Background Art

[0002] In construction machinery, the rotary system is usually driven by a variable piston pump. When the main engine rotates, the system pressure cannot be higher than the set pressure to ensure that the actuators will not be overloaded. Traditional variable piston pumps generally adjust the system pressure through a high-pressure relief valve, that is, when the system pressure is higher than the set pressure, the relief valve opens to achieve overflow. Although the system pressure can be maintained within the set range, a large amount of energy loss is generated during the overflow process, and the oil overflowing through the valve flows back to the oil tank, making the oil temperature too high, which is not energy-saving or environmentally friendly, and the main engine consumes a lot of energy and has high costs. Therefore, the existing technology has the problem of high energy consumption. Summary of the invention

[0003] The purpose of the present invention is to provide a bidirectional variable plunger pump pressure regulating valve, which has the characteristics of energy saving and environmental protection.

[0004] The technical solution of the present invention is: a bidirectional variable plunger pump pressure regulating valve, including a valve body, in which a bushing, a valve sleeve and a screw sleeve are arranged in sequence from left to right, and in which a shuttle valve core, a push rod, a valve core, a left spring seat, a spring and a right spring seat are arranged in sequence from left to right; the valve body is provided with an A cavity, a B cavity, a T cavity and a P cavity in sequence; the A cavity and the B cavity are respectively located on both sides of the shuttle valve core.

[0005] In the aforementioned bidirectional variable plunger pump pressure regulating valve, the P chamber corresponds to the position of the valve core.

[0006] In the aforementioned bidirectional variable plunger pump pressure regulating valve, the valve sleeve is provided with radial holes a and b corresponding to the A cavity and the B cavity respectively; the valve sleeve is also provided with radial holes d and e corresponding to the T cavity and the P cavity respectively.

[0007] In the aforementioned bidirectional variable plunger pump pressure regulating valve, an M cavity corresponding to the shuttle valve core is provided in the valve body, the bushing and the valve sleeve.

[0008] In the aforementioned bidirectional variable plunger pump pressure regulating valve, the valve sleeve is further provided with N cavities corresponding to the valve core.

[0009] In the aforementioned bidirectional variable plunger pump pressure regulating valve, a pressure regulating screw and a sealing locking nut are also provided on the threaded sleeve.

[0010] In the aforementioned bidirectional variable plunger pump pressure regulating valve, screw plugs are also provided at the lower parts of the A chamber and the B chamber.

[0011] Compared with the prior art, the present invention integrates a pressure regulating valve on the variable piston pump, sets the oil circuits of the two oil inlets and outlets on both sides of the shuttle valve core, so that when one of the oil inlets and outlets is connected to the pressure regulating valve, the other oil inlet and outlet is not connected to the pressure regulating valve; as the load increases, when the rotary system reaches the set pressure of the pressure regulating valve, the oil of the reversing valve is cut off to return the variable cylinder to the middle position, so that the pump is variable to a small displacement; at the same time, the output pressure of the variable piston pump is the set pressure of the pressure regulating valve, but there is no overflow loss, so the purpose of pressure regulation and energy saving is achieved. At the same time, the present invention integrates the pressure regulating valve on the variable piston pump, without changing the original design of the variable piston pump, and will not affect the installation of the main engine, and has the characteristics of small size, compact structure, high integration and low cost; according to the specific requirements of the customer, the preload force of the spring can be changed by adjusting the pressure regulating screw to adjust the regulating pressure. In summary, the present invention has the characteristics of energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] Figure 2 It is a working principle diagram of the present invention;

[0014] Figure 3 The A inlet and outlet oil ports are under high pressure, and the pressure regulating valve is in the open state.

[0015] Figure 4 The B inlet and outlet oil ports are under high pressure, and the pressure regulating valve is in the open state.

[0016] The markings in the accompanying drawings are: 1-variable plunger pump, 2-variable cylinder, 3-reversing valve, 4-first high-pressure relief valve, 5-second high-pressure relief valve, 6-throttle valve, 7-pressure regulating valve, 8-gear pump, 71-bushing, 72-shuttle valve core, 73-valve sleeve, 74-top rod, 75-valve core, 76-first spring seat, 77-spring, 78-second spring seat, 79-screw sleeve, 710-sealing locking nut, 711-pressure regulating screw, 712-screw plug, 713-valve body. DETAILED DESCRIPTION

[0017] 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.

[0018] Embodiment. A bidirectional variable piston pump pressure regulating valve, comprising: Figure 1As shown, it includes a valve body 713, in which a bushing 71, a valve sleeve 73 and a screw sleeve 79 are arranged from left to right in sequence, and in which a shuttle valve core 72, a push rod 74, a valve core 75, a left spring seat 76, a spring 77 and a right spring seat 78 are arranged from left to right in sequence; the valve body 713 is provided with an A cavity, a B cavity, a T cavity and a P cavity in sequence; the A cavity and the B cavity are respectively located on both sides of the shuttle valve core 72.

[0019] The P chamber corresponds to the position of the valve core 75 .

[0020] The valve sleeve 73 is provided with radial holes a and b corresponding to the A cavity and the B cavity respectively; the valve sleeve 73 is also provided with radial holes d and e corresponding to the T cavity and the P cavity respectively.

[0021] The valve body 713 , the bushing 71 and the valve sleeve 73 are provided with an M cavity corresponding to the shuttle valve core 72 .

[0022] The valve sleeve 73 is further provided with an N cavity corresponding to the valve core 75 .

[0023] The threaded sleeve 79 is also provided with a pressure regulating screw 711 and a sealing locking nut 710 .

[0024] The lower parts of the A and B cavities are also provided with screw plugs 712 .

[0025] Working principle: Figure 2 As shown, the pressure regulating valve 7 is connected to the variable piston pump 1, the A port and the B port of the variable piston pump 1 are respectively connected to the A chamber and the B chamber of the pressure regulating valve 7, the P chamber of the pressure regulating valve 7 is connected to the reversing valve 3, the reversing valve 3 is connected to the variable cylinder 2; the T chamber of the pressure regulating valve 7 is connected back to the oil tank.

[0026] The A oil inlet and outlet are connected to the second high-pressure relief valve 5, the B oil inlet and outlet are connected to the first high-pressure relief valve 4, the variable piston pump 1 is connected to the gear pump 8, the gear pump 8 is connected to the throttle valve 6 and then connected to the P chambers of the reversing valve 3 and the pressure regulating valve 7 respectively, and the gear pump 8 is connected to the first high-pressure relief valve 4 and the second high-pressure relief valve 5 respectively.

[0027] Assume that A inlet and outlet ( Figure 2 A in the figure indicates the oil outlet, then B oil inlet and outlet ( Figure 2 B in the figure indicates the oil inlet.

[0028] like Figure 1 , Figure 2 As shown, when the variable piston pump 1 is not working, the shuttle valve core 72 is in any position; when the A inlet and outlet oil ports of the variable piston pump 1 are the oil outlets and the B inlet and outlet oil ports are the oil inlets, the oil in the A inlet and outlet oil flows through the A cavity ( Figure 1 The valve body 73 is then passed through the radial hole a on the valve sleeve 73 and enters the M cavity ( Figure 1The shuttle valve core 72 moves to the left, and the left end conical surface of the shuttle valve core 72 forms a seal with the orifice of the bushing 71. At the same time, the clearance between the shuttle valve core 72 and the valve sleeve 73 forms an annular seal, so that the B cavity ( Figure 1 The oil pressure in the M chamber acts on the push rod 74. When the product of the oil pressure and the cylindrical area of ​​the push rod 74 is greater than the preload force of the spring 77, the push rod 74 is pushed, and then the valve core 75 is pushed to the right, so that the P chamber ( Figure 1 The oil passes through the radial holes ( Figure 1 The e in the figure) and the N cavity ( Figure 1 The oil in chamber N is connected to chamber T (as indicated by N in the figure) through the radial small hole d on the valve sleeve 73. Figure 1 The P chamber is connected to the T chamber, so the P chamber is connected to the T chamber, and the oil in the P chamber flows back to the oil tank, cutting off the oil in the reversing valve 3, so that the variable cylinder 2 returns to the middle position, and the pump returns to the zero position or the small displacement position. At this time, the pump is in a small displacement. When the pressure in the A chamber decreases, the pressure in the M chamber also decreases, and the valve core 75 moves to the left under the action of the spring 77, closing the e radial hole on the valve sleeve 73, so that the P chamber and the N chamber are not connected, and the oil enters the variable cylinder 2 through the reversing valve 3, and the pump changes to a large displacement.

[0029] Similarly, when the B inlet and outlet of the variable piston pump 1 is the outlet and the A inlet and outlet is the inlet, the oil from the B inlet and outlet passes through the B chamber and then through the b radial hole on the valve sleeve 73 to enter the M chamber, pushing the shuttle valve core 72 to move rightward, and the right end cone of the shuttle valve core 72 forms a seal with the orifice of the valve sleeve 73. At the same time, the clearance between the shuttle valve core 72 and the valve sleeve 73 forms an annular seal, so that the A chamber is not connected to the M chamber. At this time, the B chamber is connected to the M chamber, and the oil pressure in the M chamber is equal to the oil pressure in the B chamber. The oil in the M chamber acts on the push rod 74 through the small hole in the middle of the shuttle valve core 72, repeating the above pressure adjustment process, so that the variable cylinder 2 returns to the middle position, and the pump returns to the zero position or the small displacement position. At this time, the pump is in a small displacement. When the pressure in chamber B decreases, the pressure in chamber M also decreases, and the valve core 75 moves to the left under the action of spring 77, closing the radial hole e on the valve sleeve 73, so that chamber P and chamber N are not connected, and the oil enters the variable cylinder 2 through the reversing valve 3, and the pump changes to a large displacement.

[0030] When the customer has different requirements for the system pressure, the pressure regulating screw 711 can be adjusted to change the preload force of the spring 77, and then the sealing locking nut 710 can be used to lock it, so as to achieve the customer's cut-off requirements for different pressures.

Claims

1. A bidirectional variable plunger pump pressure regulating valve, characterized in that: The invention comprises a valve body (713), wherein a bushing (71), a valve sleeve (73) and a screw sleeve (79) are arranged in sequence from left to right in the valve body (713), and a shuttle valve core (72), a push rod (74), a valve core (75), a left spring seat (76), a spring (77) and a right spring seat (78) are arranged in sequence from left to right in the valve sleeve (73); an A cavity, a B cavity, a T cavity and a P cavity are arranged in sequence on the valve body (713); the A cavity and the B cavity are respectively located on two sides of the shuttle valve core (72); the P cavity corresponds to the position of the valve core (75); the valve sleeve ( A radial hole a and a radial hole b are respectively provided on the valve sleeve (73), which correspond to the A cavity and the B cavity respectively; a radial hole d and a radial hole e are respectively provided on the valve sleeve (73), which correspond to the T cavity and the P cavity respectively; an M cavity corresponding to the shuttle valve core (72) is provided in the valve body (713), the bushing (71) and the valve sleeve (73); an N cavity corresponding to the valve core (75) is also provided in the valve sleeve (73); a pressure regulating screw (711) and a sealing locking nut (710) are also provided on the screw sleeve (79); and screw plugs (712) are also provided at the lower parts of the A cavity and the B cavity.

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