CN104033437B - A kind of active proportional relief valve - Google Patents

Abstract

The invention discloses an active proportional pressure relief valve, which comprises a valve body, a proportional overflow valve and a reversing valve, and a first oil passage, a second oil passage, a third oil passage and a fourth oil passage are opened in the valve body; One end of the first oil passage communicates with the oil outlet of the proportional relief valve, and the other end of the first oil passage communicates with the external oil tank; one end of the second oil passage communicates with the oil inlet of the proportional relief valve, and the second oil passage communicates with the oil inlet of the proportional relief valve. The other end of the flow control valve is installed with a flow control valve, and the inlet of the flow control valve is connected with an external control oil source; one end of the third oil passage is connected with the second oil passage, and the other end of the third oil passage is connected with one of the reversing valves. The oil port is connected; one end of the fourth oil passage is connected with the other oil port of the reversing valve, and the other end of the fourth oil passage is the pressure relief oil port of the active proportional pressure relief valve. The invention has the advantages of simple structure, convenient processing, good performance consistency, reliable working performance and the like.

Description

An Active Proportional Pressure Relief Valve

technical field

The invention relates to a hydraulic valve, in particular to a pressure relief valve used in a hydraulic system to realize the pressure relief function.

Background technique

At the end of the pressure holding process of the hydraulic system, it is usually necessary to use a pressure relief circuit to slowly release the huge energy accumulated due to the elastic deformation of the frame, hydraulic cylinders and pipelines and the compressibility of the oil, so as to prevent the hydraulic pressure caused by the sudden release of energy. Shock, vibration, and even rupture of pipelines and valves, the pressure relief circuit is an important safety circuit for large equipment such as hydraulic presses, and the pressure relief valve is the main hydraulic component of the pressure relief circuit. The high-pressure proportional pressure relief valve described in Chinese invention patent CN201110288908.3 consists of a proportional pressure reducing valve, a valve housing, a main valve core, a small valve core, a first spring, a second spring, a third spring, a first oil port, The second oil port, valve seat, steel ball, control piston and other components. When maintaining the pressure of the first oil port, the main valve core is pressed against the valve seat under the force of the first spring, and at the same time, the steel ball is pressed against the stepped hole of the main valve core under the force of the second spring On the small hole part of the first oil port, the pressure oil in the first oil port enters the spring chamber through the first gap between the main valve core and the cartridge valve body, and acts on the steel ball and the main valve core at the same time, so at this time, the steel ball The small hole of the stepped hole of the ball and the main valve core makes the conical surface of the cone valve core contact with the perforated inlet of the valve seat. They are both line-sealed without leakage and can keep the pressure at an ultra-high pressure state, that is, Block between the first oil port and the pressure relief port. When the pressure relief work is required, the second oil port is connected to the pressure oil, and the proportional pressure reducing valve adjusts the output pressure of the pressure oil in the transition channel according to the size of the control current, and the pressure oil in the transition channel directly acts on the control piston. . When the oil pressure in the transition channel is enough to overcome the elastic force of the third spring, the control piston moves to the left; when the oil pressure is greater than the force generated by the first spring and the second spring and the ultra-high pressure acting on the steel ball, the push control is small The spool pushes the steel ball back, at this time, the pressure oil in the first oil port passes through the first gap, the spring cavity, the connecting channel on the first spring seat, and the third gap and finally flows into the pressure relief port, and the pressure oil in the first oil port decline slowly. Because the first gap and the third gap are very small, about 0.01mm, the pressure release speed is very gentle at this time, and the phenomenon of fast pressure release speed under ultra-high pressure will not occur. In the process of use, the above-mentioned invention patent has the following disadvantages: First, the above-mentioned proportional pressure relief valve has a complex structure, many parts, high processing costs, and poor performance consistency; secondly, the gap between the pressure relief ports of the above-mentioned proportional pressure relief valve is small (0.01mm) is prone to failures such as spool stuck. Finally, the above-mentioned proportional pressure relief valve only achieves pressure relief by letting go of the hydraulic oil at the first oil port. The recovery adjustment of the pressure at the first pressure relief port cannot be realized, and the proportional pressure relief of multiple proportional pressure relief valves cannot be realized synchronously.

Contents of the invention

The object of the present invention is to provide an active proportional pressure relief valve with simple structure and reliable operation.

In order to achieve the above object, the technical solution adopted by the present invention is: the active proportional pressure relief valve of the present invention includes a valve body, and also includes a proportional overflow valve and a reversing valve, and a first oil passage, The second oil passage, the third oil passage and the fourth oil passage; one end of the first oil passage communicates with the oil outlet of the proportional relief valve, and the other end of the first oil passage communicates with the external oil tank; one end of the second oil passage It communicates with the oil inlet of the proportional relief valve, and the other end of the second oil passage is installed with a flow control valve, and the inlet of the flow control valve communicates with the external control oil source; one end of the third oil passage communicates with the second oil passage , the other end of the third oil passage communicates with one of the oil ports of the reversing valve; one end of the fourth oil passage communicates with the other oil port of the reversing valve, and the other end of the fourth oil passage is for pressure relief oil port.

Further, the pressure relief oil port communicates with an external pressure relief control chamber.

Further, the proportional overflow valve of the present invention is replaced by a servo valve or a proportional throttle valve.

Further, the reversing valve of the present invention is an electromagnetic ball valve.

Further, the flow control valve of the present invention is a damper or a throttle valve.

Compared with the existing proportional pressure relief valve, the beneficial effect of the present invention is that the active proportional pressure relief valve of the present invention only includes main components such as a valve body, a proportional overflow valve, an electromagnetic ball valve, and a damper, and the valve body only needs to be drilled , tapping thread and other simplest mechanical processing techniques, and the proportional overflow valve and electromagnetic ball valve used in the present invention can be directly purchased from mature products in the market, so the active proportional pressure relief valve of the present invention has simple structure, easy processing, high performance Good consistency, reliable performance and so on.

Description of drawings

Fig. 1 is the structural representation of active proportional relief valve of the present invention;

Fig. 2 is a schematic diagram of the active proportional pressure relief valve of the present invention;

Fig. 3 is a structural schematic diagram of a proportional synchronous pressure relief hydraulic system composed of an active proportional pressure relief valve of the present invention in engineering practice;

In the figure 1. Pressure relief oil port, 2. Input oil port, 3. Output oil port, 4. Damper, 5. First oil passage, 6. Second oil passage, 7. Proportional relief valve, 8, 8.1 , 8.2 Active proportional pressure relief valve, 9. Valve body, 10. Third oil passage, 11. Solenoid ball valve, 12. Fourth oil passage, 13. Relief valve, 14. Hydraulic pump, 15. Pressure sensor, 16 . Hydraulic cylinder, 17. Pressure sensor, 18. Hydraulic cylinder.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the active proportional pressure relief valve 8 of the present invention includes a valve body 9, a proportional relief valve 7 and a reversing valve 11, and a first oil passage 5, a second oil passage 6, The third oil passage 10 and the fourth oil passage 12. Wherein, one end of the first oil passage 5 communicates with the oil outlet of the proportional relief valve 7, the other end of the first oil passage 5 is the output oil port 3 of the active proportional relief valve 8, and the output oil port 3 is connected to the external oil tank. connected. One end of the second oil passage 6 communicates with the oil inlet of the proportional relief valve 7, and the other end of the second oil passage 6 is installed with a flow control valve 4, and the inlet of the flow control valve 4 is the active proportional relief valve 8. Input oil port 2, which is connected with external control oil source. One end of the third oil passage 10 communicates with the second oil passage 6, and the other end of the third oil passage 10 communicates with one of the oil ports of the reversing valve 11; one end of the fourth oil passage 12 communicates with the other end of the reversing valve 11 The oil ports are connected, and the other end of the fourth oil passage 12 is the pressure relief oil port 1 of the active proportional pressure relief valve 8, and the pressure relief oil port 1 communicates with the external pressure relief control chamber.

The proportional relief valve in the present invention can be replaced by a servo valve or a proportional throttle valve.

Preferably, the reversing valve of the present invention is an electromagnetic ball valve.

Preferably, the flow control valve can be a damper 4 as shown in FIG. 1 . The thread of the damper 4 is inserted in the third oil passage 10 at a position close to the oil input port 2 .

The flow control valve in the present invention may also be a throttle valve.

The working principle and process of the active proportional pressure relief valve of the present invention are as follows:

When the electromagnetic ball valve 11 cuts off the oil passage between the third oil passage 10 and the fourth oil passage 12 of the valve body, the active proportional pressure relief valve 8 of the present invention is in the pressure maintaining condition, and the pressure relief of the active proportional pressure relief valve The hydraulic oil at port 1 is reliably sealed, and the pressure at port 1 of the active proportional pressure relief valve remains constant. When the electromagnetic ball valve 11 conducts the oil passage between the third oil passage 10 of the valve body and the fourth oil passage 12 of the valve body, the active proportional pressure relief valve 8 of the present invention is in the pressure relief working condition, and the active proportional pressure relief valve The input oil port 2, the damper 4, the proportional relief valve 7 and the valve body output oil port 3 together form a B-type hydraulic half bridge. Among them, the damper 4 is the input hydraulic resistance of the B-type hydraulic half-bridge, the proportional overflow valve 7 is the equivalent output variable hydraulic resistance of the B-type hydraulic half-bridge, and the outlet of the damper 4 is between the inlet of the proportional overflow valve 7 The intermediate oil passage chamber is the output control pressure chamber of the B-type hydraulic half-bridge, and the output control pressure chamber of the B-type hydraulic half-bridge passes through the third oil passage 10 of the valve body, the fourth oil passage 12 of the valve body, the guide The open electromagnetic ball valve 11 communicates with the relief oil port 1 of the valve body. According to the working principle of the B-type hydraulic half-bridge, changing the control current of the proportional relief valve 7 can control the equivalent opening of the proportional relief valve 7 (that is, the size of the output liquid resistance of the B-type hydraulic half-bridge) Therefore, the output pressure of the B-type hydraulic half bridge can follow the change of the input current of the proportional relief valve 7 .

The working principle of the active proportional pressure relief valve 8 of the present invention will be described in more detail below in conjunction with FIG. 2 . In Fig. 2, pressure relief oil port 1 communicates with one oil port of electromagnetic ball valve 11, the other oil port of electromagnetic ball valve 11 communicates with the oil inlet of proportional relief valve 7 and the outlet of damper 4, and the inlet of damper 4 The oil port communicates with the input oil port 2 of the active proportional pressure relief valve, and the oil outlet of the proportional relief valve 7 communicates with the output oil port 3 of the active proportional pressure relief valve. As shown in Figure 2, the external control oil source is introduced through the input oil port 2 of the active proportional pressure relief valve, and the external control oil source, damper 4, and proportional relief valve 7 form a B-type active hydraulic half bridge. The damper 4 and the proportional relief valve 7 are respectively the input liquid resistance and the equivalent output liquid resistance of the B-type hydraulic half-bridge. By changing the input current of the input proportional relief valve 7, the active proportional The proportional pressure relief of the hydraulic oil pressure at the pressure relief oil port 1 of the pressure relief valve, and when the hydraulic oil pressure at the pressure relief oil port 1 is lower than the expected pressure, the pressure relief oil port 1 can also be adjusted by adjusting the proportional relief valve 7. The desired pressure at which the hydraulic oil pressure rises. It can be seen that the present invention constitutes an active proportional pressure relief valve by introducing a constant pressure control oil source from the input oil port 2 of the valve body 9, which can overcome the fact that the proportional relief valve cannot be directly used to form proportional pressure relief due to the minimum flow limit. loop defect.

Fig. 3 is a structural schematic diagram of a proportional synchronous pressure relief hydraulic system composed of an active proportional pressure relief valve of the present invention in engineering practice. As shown in Figure 3, the oil inlet port of the relief valve 13 and the oil outlet port of the hydraulic pump 14 are respectively connected with the input oil port of each active proportional pressure relief valve at the same time, and the oil outlet port of the relief valve 13 is connected with the external oil tank . Each active proportional pressure relief valve is configured with a hydraulic cylinder and a pressure transducer. Specifically, as shown in Figure 3, the pressure relief oil port of the active proportional pressure relief valve 8.1 communicates with the rodless chamber of the hydraulic cylinder 18 and the pressure sensor 17 at the same time, and the input oil port of the active proportional pressure relief valve 8.1 simultaneously It communicates with the oil inlet of the relief valve 13 and the oil outlet of the hydraulic pump 14 . The pressure relief oil port of the active proportional pressure relief valve 8.2 communicates with the rodless cavity of the hydraulic cylinder 16 and the pressure sensor 15 at the same time, and the input oil port of the active proportional pressure relief valve 8.2 is connected with the oil inlet port of the relief valve 13 at the same time. And the oil outlet of the hydraulic pump 14 is communicated. The output oil ports of the active proportional pressure relief valve 8.1 and the active proportional pressure relief valve 8.2 are all communicated with the oil tank; the rod chambers of the hydraulic cylinder 18 and the hydraulic cylinder 16 are all communicated with the oil tank. During the working process of the hydraulic system, the hydraulic pump 14 and the relief valve 13 form a constant pressure control oil source, which provides constant control pressure to the input oil ports of the active proportional pressure relief valves 8.1 and 8.2. Hydraulic cylinder 17 and hydraulic cylinder 15 jointly drive a large load (for example, the ship-bearing compartment of a large ship lift), and before the hydraulic cylinder moves downward, the state of holding pressure is completed and the state of pressure relief is entered. The pressure relief of the high-pressure hydraulic oil in the rodless cavity requires that the pressure of the hydraulic oil in the rodless cavity of the hydraulic cylinder 18 and the hydraulic cylinder 16 be released synchronously according to the specified curve (for example, linear synchronous pressure relief), and during the pressure relief process Ensure that the pressure deviation of the rodless cavity of the hydraulic cylinder 18 and the hydraulic cylinder 16 does not exceed 3%. Using the active proportional pressure relief valve 8 of the present invention can realize a cost-effective synchronous pressure relief scheme: using the active proportional pressure relief valve 8.1, the active proportional pressure relief valve 8.2, the pressure sensor 17 and the pressure sensor 15 can respectively constitute a hydraulic cylinder 18 and the closed-loop control system of the rodless cavity pressure of the hydraulic cylinder 16. When releasing pressure, since the active proportional pressure relief valve has its own electromagnetic ball valve, the pressure relief oil port of the active proportional pressure relief valve is connected with the inlet of the proportional relief valve that comes with the active proportional pressure relief valve. The given signal of the built-in proportional relief valve of the pressure relief valve can proportionally adjust the pressure of the hydraulic oil at the pressure relief port of the active proportional pressure relief valve. Practice has proved that using the proportional synchronous pressure relief scheme of the active proportional pressure relief valve 8 of the present invention can ensure that the hydraulic cylinder 18 and the rodless chamber pressure of the hydraulic cylinder 16 are simultaneously relieved according to the specified curve during the pressure relief process, and during the proportional pressure relief process The synchronization deviation does not exceed 3%.

The main advantages of the present invention are: (1) The active proportional pressure relief valve of the present invention only includes main components such as a valve body 8, a proportional relief valve 7, an electromagnetic ball valve 11, and a damper 4, and the valve body 9 only needs to be drilled, Therefore, compared with the existing proportional pressure relief valve, the active proportional pressure relief valve of the present invention has greatly simplified structure and relatively simple manufacturing process. (2) During the working process, the valve openings of the proportional overflow valve 7, the electromagnetic ball valve 11 and the damper 4 are all much larger than 0.01mm, which greatly reduces the possibility of the valve core being blocked and has higher reliability. (3) The present invention realizes the active proportional pressure relief at the pressure relief port 1 by introducing a control oil source at the input oil port 2 of the valve body 9. When the pressure at the pressure relief port 1 is lower than the expected pressure, the proportional pressure can be adjusted The relief valve 7 raises the pressure of the hydraulic oil at the pressure relief oil port 1 to the desired pressure, which can realize the proportional and synchronous pressure relief of multiple hydraulic chambers. (4) Both the proportional overflow valve 7 and the electromagnetic ball valve 11 used in the present invention can be directly purchased from the market as mature products, which can ensure that the active proportional pressure relief valve of the present invention has better performance consistency. Therefore, in industrial applications, the active proportional pressure relief valve 8 proposed by the present invention has more advantages in terms of cost, reliability, proportional synchronous pressure relief, etc., and has a good application prospect.

Claims (5)

1. An active proportional pressure relief valve, including a valve body (9), characterized in that it also includes a proportional relief valve (7) and a reversing valve (11), and there is a valve in the valve body (9). The first oil passage (5), the second oil passage (6), the third oil passage (10) and the fourth oil passage (12); one end of the first oil passage (5) and the proportional relief valve (7) The oil outlet is connected, and the other end of the first oil passage (5) is connected with the external oil tank; one end of the second oil passage (6) is connected with the oil inlet of the proportional relief valve, and the other end of the second oil passage (6) A flow control valve (4) is installed, and the inlet of the flow control valve (4) communicates with an external control oil source; one end of the third oil passage (10) communicates with the second oil passage (6), and the third oil passage (10) The other end of the reversing valve (11) communicates with one of the oil ports; one end of the fourth oil passage (10) communicates with the other oil port of the reversing valve (11), and the fourth oil passage (10 ) is the pressure relief oil port (1). 2. The active proportional pressure relief valve according to claim 1, characterized in that: the pressure relief oil port (1) communicates with an external pressure relief control cavity. 3. The active proportional pressure relief valve according to claim 1 or 2, characterized in that: the proportional relief valve is replaced by a servo valve or a proportional throttle valve. 4. The active proportional pressure relief valve according to claim 1 or 2, characterized in that: the reversing valve is an electromagnetic ball valve. 5. The active proportional pressure relief valve according to claim 1 or 2, characterized in that: the flow control valve is a damper or a throttle valve.