Balance valve for hydraulic travel motor

Abstract

The balance valve comprises a valve body and a valve element, a transversely-penetrating valve cavity is formed in the valve body, the valve element is in sliding connection with the valve cavity in a matched mode, the valve body is provided with a port A1, a port A2, a port B1 and a port B2 respectively, the left end and the right end of the valve cavity are connected with cylinders in a screwed mode respectively, springs are arranged between the bottoms of inner cavities of the cylinders and the valve element, and the springs are connected with the ports A1, A2, B1 and B2 respectively. A spring cavity is formed in the barrel, an annular groove a and an annular groove b are formed in the two sections, symmetrical left and right, of the valve element respectively, a communicated throttling groove is formed in the position, on the outer side of the valve element, between the annular groove a and the annular groove b, and the port A1 and the port A2 are correspondingly communicated with the annular groove a respectively. When the valve element is located at the left position or the right position, the annular groove a is communicated with the annular groove b, and the spring cavity is communicated to the annular groove a through a pilot hole axially extending inwards from the end of the valve element. A split one-way valve element and main valve element structure is adopted, the function of a balance valve is achieved, the structures of the main valve element and the valve cavity are simple, machining and manufacturing are convenient, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic valves, in particular to a balance valve for a hydraulic travel motor. Background Technique

[0002] The existing balance valves for travel motors generally include a valve body, a spool and a return spring arranged in the valve body. When the oil circuit is connected, the oil pressure can push the spool to axially move and compress the return spring to realize the rotation of the motor; when the motor needs to stop working, the return spring can provide a spring force to drive the spool to return to the middle position. For example, the Chinese invention patent with the publication number CN114483697B discloses a balance valve structure, a hydraulic motor and a construction machinery. Using the above structure, the hydraulic motor can be braked, and the impact force generated by braking can be reduced, solving the defect that the balance valve used in the existing travel motor is prone to generate a large impact force during braking. However, the above solution also has the following disadvantages: the structural shapes of the spool and the valve cavity are complex, the processing difficulty is large, and the manufacturing cost is relatively high. Content of the Utility Model

[0003] The purpose of the utility model is to provide a balance valve for a hydraulic travel motor to solve the problems put forward in the above background technique.

[0004] To achieve the above purpose, the utility model provides the following technical solution: A balance valve for a hydraulic travel motor includes a valve body and a spool. A horizontally penetrating valve cavity is provided in the valve body. The spool is slidably connected to the valve cavity in a matching manner. The valve body is respectively provided with A1 port, A2 port, B1 port and B2 port. The spool is a stepped shaft structure that is symmetric about the left and right. Cylinders are respectively screwed at the left and right ends of the valve cavity. A spring is arranged between the bottom of the inner cavity of the cylinder and the spool. A spring cavity is formed inside the cylinder. The spring applies an axial thrust to the end of the spool. Annular grooves a and b are respectively provided on the two symmetrically left and right segments of the spool. A communicating throttle groove is provided on the outer side of the spool between the annular groove a and the annular groove b. The A1 port and the A2 port are respectively correspondingly communicated with the annular groove a; the B1 port and the B2 port are respectively correspondingly communicated with the annular groove b. When the spool is in the left position or the right position, the annular groove a and the annular groove b are communicated. The spring cavity is connected to the annular groove a through a pilot hole extending axially inward from the end of the spool. Check valves are respectively screwed on the left and right sides of the valve body 1. The input ends of the two check valves 6 are correspondingly communicated with the A1 port and the A2 port one by one. The output end of the check valve is communicated with the annular groove b through an oil passage in the valve body.

[0005] Preferably, a plunger portion for isolating the left and right sides is provided in the middle of the spool.

[0006] Compared with the prior art, the beneficial effects of the present utility model are as follows: The present utility model adopts a split-type one-way valve spool and main spool structure to achieve the function of a balance valve. The structures of the main spool and the valve cavity are simple and convenient for processing and manufacturing, which is conducive to reducing the manufacturing cost and can reduce the pressure loss of oil flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic cross-sectional structure view of the present utility model;

[0008] Figure 2 is a schematic diagram of the oil flow when the spool is in the left position;

[0009] Figure 3 is a schematic diagram of the oil flow when the spool is in the right position.

[0010] In the figure: 1, valve body; 2, spool; 3, spring; 4, pilot hole; 5, throttle groove; 6, one-way valve; 7, annular groove a; 8, annular groove b. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0012] Please refer to Figures 1-3 , the present utility model provides a technical solution: A balance valve for a hydraulic walking motor, including a valve body 1 and a spool 2 (i.e., the main spool). A horizontally penetrating valve cavity is provided in the valve body 1. The spool 2 is slidably connected to the valve cavity in a matching manner. The valve body 1 is respectively provided with an A1 port, an A2 port, a B1 port, and a B2 port. The spool 2 is a stepped shaft structure that is symmetric about the left and right. A plunger portion that isolates the left and right sides is provided in the middle of the spool 2. Cylinders are respectively screwed at the left and right ends of the valve cavity. A spring 3 is provided between the inner cavity bottom of the cylinder and the spool 2. A spring cavity is formed inside the cylinder. The spring 3 applies an axial thrust to the end of the spool 2. The spring 3 is used to achieve the centered reset of the spool 2.

[0013] The two symmetrically arranged sections on the left and right of the spool 2 are respectively provided with an annular groove a7 and an annular groove b8. In the valve cavity, transition grooves with an enlarged diameter are provided at the positions where the annular groove a7 and the annular groove b8 are located. The transition grooves are used to circulate the hydraulic oil when the spool 2 moves left or right. A communicating throttle groove 5 is provided on the outside of the spool 2 between the annular groove a7 and the annular groove b8. When the spool 2 is in the middle position, the hydraulic oil between the annular groove a7 and the annular groove b8 is only conducted through the throttle groove 5. The A1 port and the A2 port are respectively correspondingly communicated with the annular groove a7; the B1 port and the B2 port are respectively correspondingly communicated with the annular groove b8. When the spool 2 is in the left position or the right position, the annular groove a7 and the annular groove b8 are conducted. The spring cavity is connected to the annular groove a7 through a pilot hole 4 extending axially inward from the end of the spool 2. One-way valves 6 (using cartridge one-way valve spools) are respectively screwed on the left and right sides of the valve body 1. The input ends of the two one-way valves 6 are correspondingly communicated with the A1 port and the A2 port one by one, and the output ends of the one-way valves 6 are communicated with the annular groove b8 through the oil passages in the valve body 1.

[0014] Working principle: Figure 2 As shown, when the A1 port is supplied with oil, the one-way valve 6 on one side of it opens, and the hydraulic oil enters the right spring cavity through the right pilot hole 4. The hydraulic oil pushes the spool 2 to move left, and the flow direction of the hydraulic oil is A1→B1→motor→B2→A2. Figure 3 As shown, when the A2 port is supplied with oil, the one-way valve 6 on one side of it opens, and the hydraulic oil enters the left spring cavity through the left pilot hole 4. The hydraulic oil pushes the spool 2 to move right, and the flow direction of the hydraulic oil is A2→B2→motor→B1→A1.

[0015] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A balancing valve for a hydraulic travel motor, comprising a valve body (1) and a valve core (2), wherein the valve body (1) is provided with a transversely penetrating valve cavity, the valve core (2) is adapted to be slidably connected to the valve cavity, the valve body (1) is provided with an A1 port, an A2 port, a B1 port, and a B2 port, and the characteristics are: The valve core (2) is a bilaterally symmetrical stepped shaft structure. The left and right ends of the valve cavity are respectively screwed with a cylinder. A spring (3) is arranged between the bottom of the inner cavity of the cylinder and the valve core (2). A spring cavity is formed inside the cylinder. The spring (3) applies an axial thrust to the end of the valve core (2). The two symmetrical sections of the valve core (2) are respectively provided with an annular groove a (7) and an annular groove b (8). A communicating throttling groove (5) is arranged between the annular groove a (7) and the annular groove b (8) on the outer side of the valve core (2). The A1 port and the A2 port are respectively connected to the annular groove a (7); the B1 port and the B2 port are respectively connected to the annular groove b (8). When the valve core (2) is in the left position or the right position, the annular groove a (7) and the annular groove b (8) are connected. The spring cavity is connected to the annular groove a (7) through a pilot hole (4) extending axially inward from the end of the valve core (2). One-way valves (6) are respectively screwed on the left and right sides of the valve body (1). The input ends of the two one-way valves (6) are connected to the A1 port and the A2 port in a one-to-one correspondence. The output ends of the one-way valves (6) are connected to the annular groove b (8) through the oil passage in the valve body (1).

2. The balancing valve for a hydraulic travel motor according to claim 1, characterized in that: The middle part of the valve core (2) is provided with a plunger part for isolating the left and right sides.

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