External control direct-acting overflow valve

Abstract

The utility model discloses an external control direct-acting overflow valve which comprises an overflow valve body, and the overflow valve body comprises a valve body, a main valve element, a valve sleeve, a spring seat, a main spring, a nut, an adjusting screw rod and a locking nut. One end of the valve sleeve is in threaded connection with the valve body, the other end of the valve sleeve is in threaded connection with the nut and the locking nut, the main valve element is arranged in the valve body, an oil inlet and an oil return opening are formed in the end portion and the side portion of the valve body, the adjusting screw rod is arranged in the nut and extends outwards, and a main spring cavity is formed between the valve body and the adjusting screw rod. One end of the main spring is pressed on the main valve core through the spring seat, and the other end is pressed on the adjusting screw rod; an external control opening is formed in the joint of the valve sleeve and the valve body and communicates the exterior of the overflow valve body with the main spring cavity. High-pressure oil enters an overflow valve spring cavity through an external control structure, high-pressure pressure acts on the main valve element to enable the overflow valve to be normally closed, meanwhile, the anti-pollution capacity of the overflow valve is improved through a single-stage main valve element structure, and the action requirement of an automobile crane supporting leg system is met.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering machinery, in particular to an externally controlled direct-acting overflow valve. Background Art

[0002] As a system pressure regulating and limiting element, the overflow valve is widely used in the hydraulic system of engineering machinery. In the outrigger control system of an automobile crane, the outrigger multi-way valve horizontal outrigger overflow valve not only limits the system pressure of the horizontal outrigger extension, but also requires external control pressure to act on the spring chamber to keep the overflow valve normally closed when the horizontal and vertical outriggers retract. At present, the horizontal outrigger overflow valve is a pilot-operated overflow valve with an external control port structure, but due to the multiple cone sealing structures and damping holes of the main and pilot stage structures, it has poor anti-pollution ability and is easy to get stuck, resulting in market problems such as weak horizontal outrigger movement and linkage of horizontal and vertical outriggers. Summary of the invention

[0003] Purpose of the utility model: In order to overcome the shortcomings of the background technology, the utility model discloses an externally controlled direct-acting overflow valve. When the outrigger retracts, high-pressure oil enters the overflow valve spring chamber through the external control structure, and the high-pressure pressure acts on the main valve core to make the overflow valve normally closed. At the same time, the single-stage main valve core structure improves the anti-pollution ability of the overflow valve to meet the action requirements of the outrigger system of the truck crane.

[0004] Technical solution: The externally controlled direct-acting relief valve disclosed in the utility model comprises a relief valve body, wherein the relief valve body comprises a valve body, a main valve core, a valve sleeve, a spring seat, a main spring, a nut, an adjusting screw and a locking nut;

[0005] One end of the valve sleeve is threadedly connected to the valve body, and the other end is threadedly connected to the nut and the locking nut. The main valve core is placed in the valve body, and an oil inlet and an oil return port are provided at the end and side of the valve body. The adjusting screw is placed inside the nut and extends outward. A main spring cavity is formed between the valve body and the adjusting screw. One end of the main spring is pressed on the main valve core through the spring seat, and the other end is pressed on the adjusting screw.

[0006] An external control port is provided at the connection between the valve sleeve and the valve body, connecting the outside of the overflow valve body with the main spring chamber.

[0007] Furthermore, a crescent-shaped groove extending axially is provided on the connection surface between the valve sleeve and the valve body, and a gap is formed between the crescent-shaped groove and the valve body and is connected with the main spring chamber to form an external control port.

[0008] Furthermore, the overflow valve body is placed on the valve block; the oil inlet, oil return port and external control port are respectively extended out of the valve block through oil circuits.

[0009] Furthermore, the outer wall of the valve sleeve is connected to the opening of the valve block, and a first sealing member is provided at the connection.

[0010] Furthermore, a first oil circuit seal and a second oil circuit seal are arranged at intervals on the outer wall of the valve body to form a seal with the valve block, and a third oil circuit seal is arranged between the main valve core and the valve body;

[0011] The first oil circuit seal is placed between the external control port and the oil return port, the second oil circuit seal is placed between the oil return port and the oil inlet, and the third oil circuit seal is placed between the main spring chamber and the oil return port.

[0012] Furthermore, the first oil circuit seal, the second oil circuit seal and the third oil circuit seal are all combinations of O-rings and retaining rings.

[0013] Beneficial effects: Compared with the prior art, the advantages of the utility model are: the external control pressure is applied to the main valve core through the crescent-shaped groove external control structure to realize the normally closed overflow valve; and the single-stage main valve core has a simple structure and strong anti-pollution ability, avoiding the problem of complex and easy jamming of the pilot overflow valve and reducing the risk of linkage between vertical and horizontal legs; the oil in the spring chamber is unloaded through the external control structure to realize the normal opening of the overflow valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the structure diagram of the overflow valve body of the utility model;

[0015] Figure 2 This is a structural diagram of the valve sleeve and valve body installation end of the utility model;

[0016] Figure 3 This is a structural diagram of the relief valve body of the utility model installed on the valve block;

[0017] Figure 4 This is the principle diagram of the overflow valve of the utility model in the hydraulic system. DETAILED DESCRIPTION

[0018] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0019] like Figure 1 The externally controlled direct-acting relief valve shown includes a relief valve body 1 , which includes a valve body 101 , a main valve core 102 , a valve sleeve 103 , a spring seat 104 , a main spring 105 , a nut 106 , an adjusting screw 107 and a locking nut 108 .

[0020] One end of the valve sleeve 103 is threadedly connected to the valve body 101, and the other end is threadedly connected to the nut 106 and the locking nut 108. The main valve core 102 is placed in the valve body 101, and an oil inlet 109 and an oil return port 110 are opened at the end and side of the valve body 101. The adjusting screw 107 is placed inside the nut 106 and extends outward. A main spring cavity is formed between the valve body 101 and the adjusting screw 107. One end of the main spring 105 is pressed against the main valve core 102 through the spring seat 104, and the other end is pressed against the adjusting screw 107.

[0021] like Figure 2 As shown, the connecting surface between the valve sleeve 103 and the valve body 101 is provided with an axially extending crescent groove 103-1, a gap is formed between the crescent groove 103-1 and the valve body 101, and the gap is connected with the main spring cavity to form an external control port 111. The external control port allows the external control oil to enter the main spring cavity and the main spring cavity oil to unload.

[0022] like Figure 3 As shown, the relief valve body 1 is placed on the valve block 2; the oil inlet 109, the oil return port 110 and the external control port 111 extend out of the valve block 2 through oil circuits respectively.

[0023] The outer wall of the valve sleeve 103 is connected to the opening of the valve block 2 , and a first sealing member 112 is provided at the connection.

[0024] The outer wall of the valve body 101 is provided with a first oil circuit seal 113 and a second oil circuit seal 114 to form a seal with the valve block 2, and a third oil circuit seal 115 is provided between the main valve core 102 and the valve body 101; the first oil circuit seal 113 is placed between the external control port 111 and the oil return port 110, the second oil circuit seal 114 is placed between the oil return port 110 and the oil inlet 109, and the third oil circuit seal 115 is placed between the main spring chamber and the oil return port 110. The first oil circuit seal 113, the second oil circuit seal 114 and the third oil circuit seal 115 are all combinations of O-rings and retaining rings.

[0025] like Figure 4 As shown, the above-mentioned relief valve is located in the hydraulic system. When the horizontal cylinder 3 is extended, the oil in the main spring chamber returns to the oil tank through the external control port 111 and the telescopic switching valve 4, the oil inlet 109 is connected to the rodless chamber of the horizontal cylinder 3, and the oil return port 110 is connected to the oil tank. The pressure of the rodless chamber acts on the main valve core 102, overcomes the spring force, and pushes the main valve core 102 to open and realize overflow. The setting value of the main spring 105 limits the maximum pressure of the horizontal leg action, realizing the pressure limiting function of the horizontal leg relief valve. When the vertical cylinder 5 retracts, the high-pressure oil enters the rod chamber of the vertical cylinder 5 and the horizontal cylinder 3, and at the same time, the high-pressure oil in the rod chamber enters the main spring chamber through the external control port 111. The high pressure acts on the main valve core 102, so that the relief valve body 1 is normally closed. It has a simple structure and strong anti-pollution ability, which effectively avoids the problem of vertical and horizontal leg linkage.

Claims

1. An externally controlled direct-acting relief valve, characterized in that: The overflow valve body (1) comprises a valve body (101), a main valve core (102), a valve sleeve (103), a spring seat (104), a main spring (105), a nut (106), an adjusting screw (107) and a locking nut (108); One end of the valve sleeve (103) is threadedly connected to the valve body (101), and the other end is threadedly connected to the nut (106) and the locking nut (108); the main valve core (102) is placed in the valve body (101), and an oil inlet (109) and an oil return port (110) are provided at the end and side of the valve body (101); the adjusting screw (107) is placed inside the nut (106) and extends outward; a main spring chamber is formed between the valve body (101) and the adjusting screw (107); one end of the main spring (105) is pressed against the main valve core (102) through the spring seat (104), and the other end is pressed against the adjusting screw (107); An external control port (111) is provided at the connection between the valve sleeve (103) and the valve body (101), connecting the outside of the relief valve body (1) with the main spring chamber.

2. The externally controlled direct-acting relief valve according to claim 1 is characterized in that: The connecting surface between the valve sleeve (103) and the valve body (101) is provided with an axially extending crescent-shaped groove (103-1), a gap is formed between the crescent-shaped groove (103-1) and the valve body (101), and is connected with the main spring chamber to form an external control port (111).

3. The externally controlled direct-acting relief valve according to claim 1 is characterized in that: The overflow valve body (1) is placed on the valve block (2); the oil inlet (109), the oil return port (110) and the external control port (111) respectively extend out of the valve block (2) through oil circuits.

4. The externally controlled direct-acting relief valve according to claim 3 is characterized in that: The outer wall of the valve sleeve (103) is connected to the opening of the valve block (2), and a first sealing member (112) is provided at the connection.

5. The externally controlled direct-acting relief valve according to claim 3 is characterized in that: A first oil circuit seal (113) and a second oil circuit seal (114) are arranged on the outer wall of the valve body (101) to form a seal with the valve block (2); and a third oil circuit seal (115) is arranged between the main valve core (102) and the valve body (101); The first oil circuit seal (113) is disposed between the external control port (111) and the oil return port (110), the second oil circuit seal (114) is disposed between the oil return port (110) and the oil inlet (109), and the third oil circuit seal (115) is disposed between the main spring chamber and the oil return port (110).

6. The externally controlled direct-acting relief valve according to claim 5 is characterized in that: The first oil circuit seal (113), the second oil circuit seal (114) and the third oil circuit seal (115) are all combinations of O-rings and retaining rings.

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