Electric proportional displacement pump electric control valve capable of achieving large displacement in case of power failure

Abstract

The utility model discloses a power-off large-displacement electric control valve of an electric proportional displacement pump, which comprises an electric proportional electromagnetic valve, a valve sleeve is arranged on one side of the electric proportional electromagnetic valve, the valve sleeve is fixed with a shell of the electric proportional electromagnetic valve, a valve core is arranged in the valve sleeve, the valve core of the electric control valve is connected with an iron core of the electric proportional electromagnetic valve, and a spring is arranged between the valve core and the valve sleeve. In the extending direction of the iron core, a high-pressure oil port, a control oil port and an oil return port are sequentially formed in the peripheral face of the valve sleeve, a first oil way is arranged in the valve sleeve, a second oil way and a third oil way are arranged between the valve sleeve and the valve element, one end of the first oil way is used for being communicated with a variable cavity of the electric proportional displacement pump, and the other end of the first oil way is used for being communicated with a second oil way. The other end of the first oil way communicates with the oil return opening through the second oil way, one end of the third oil way communicates with the control oil opening, and the other end of the third oil way is close to the high-pressure oil opening. The utility model has the advantages that the maximum displacement output of the pump can be kept after power failure, and the operation risk of construction engineering machinery can be reduced.

Description

Technical Field

[0001] This utility model belongs to the field of electric proportional displacement pump control valves, and particularly relates to an electric proportional displacement pump control valve for large displacement when power is off. Background Technology

[0002] Electro-proportional displacement pumps are widely used in engineering machinery. These pumps feature a variable displacement mechanism, which includes a variable displacement cylinder containing a variable displacement chamber and a variable displacement piston. The variable displacement piston is connected to the pump's swashplate; changing the position of the piston alters the swashplate's tilt angle, thus changing the pump's displacement. A two-position, three-way electrically controlled valve is located on one side of the variable displacement cylinder. This valve has a high-pressure port, a control port, and a return port. The high-pressure port connects to the pump's outlet, the return port connects to the pump's return oil tank, and the control port connects to the variable displacement chamber. Under the control of the valve, the flow of fluid into and out of the variable displacement chamber changes the position of the variable displacement piston, thereby altering the pump's displacement.

[0003] Under the action of the electric control valve, when the electric proportional displacement pump is controlled by a current ≤150mA (power off), the pump's displacement will automatically return to the minimum displacement (0 displacement). Once the input control current fails due to non-human factors (i.e., current = 0), the pump's flow output will immediately become 0, posing a potential risk to the construction machinery under construction. Utility Model Content

[0004] The purpose of this invention is to provide an electrically controlled valve for a high-capacity electro-proportional displacement pump that operates without power. This invention has the advantage of retaining the pump's maximum displacement output after a power outage, thus reducing the operational risks for construction machinery.

[0005] The technical solution of this utility model is as follows: A power-off large-capacity electro-proportional displacement pump control valve includes an electro-proportional solenoid valve. A valve sleeve is provided on one side of the electro-proportional solenoid valve, and the valve sleeve is fixed to the outer shell of the electro-proportional solenoid valve. A valve core is provided inside the valve sleeve. The valve core of the control valve is connected to the iron core of the electro-proportional solenoid valve. A spring is provided between the valve core and the valve sleeve. In the direction of the iron core extension, a high-pressure oil port, a control oil port, and a return oil port are sequentially provided on the outer circumferential surface of the valve sleeve. A first oil passage is provided inside the valve sleeve. A second oil passage and a third oil passage are provided between the valve sleeve and the valve core. One end of the first oil passage is used to connect to the variable chamber of the electro-proportional displacement pump. The other end of the first oil passage is connected to the return oil port through the second oil passage. One end of the third oil passage is connected to the control oil port, and the other end of the third oil passage is close to the high-pressure oil port.

[0006] In the aforementioned large-displacement electro-proportional pump control valve for power failure, the valve sleeve has a countersunk hole on the end face facing the electro-proportional solenoid valve, the end of the valve core has a convex ring located in the countersunk hole, the spring is located between the convex ring and the bottom surface of the countersunk hole, and the first oil circuit is connected to the second oil circuit through the countersunk hole.

[0007] In the aforementioned large-displacement electro-proportional displacement pump control valve, the second oil circuit includes a first annular groove located on the outer circumferential surface of the valve core. The first annular groove is connected to the return oil port, and a through hole is provided on the bottom surface of the first annular groove.

[0008] In the aforementioned electrically controlled valve for a high-displacement electro-proportional pump that is designed to withstand power failure, the third oil passage is the second annular groove located on the outer circumferential surface of the valve core.

[0009] In the aforementioned electrically controlled valve for a high-displacement electro-proportional pump, the valve core has a blind hole with a through hole on its end face away from the electro-proportional solenoid valve.

[0010] In the aforementioned electro-proportional displacement pump control valve for high displacement pumps that are designed to withstand power failure, the first annular groove has a guide portion at one end near the electro-proportional solenoid valve that mates with the inner hole of the valve sleeve.

[0011] Compared with existing technologies, this invention adds one position to the existing electrically controlled valve, changing it from a two-position three-way valve to a three-position three-way valve. This new position ensures that the pump flow remains at maximum displacement after the electrically controlled valve is de-energized, reducing the operational risks for construction machinery. Furthermore, this invention retains the advantage of the original electrically controlled valve where the control current is directly proportional to and controllable from 0 to 100% of the displacement. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model.

[0013] Figure 2 This is a front view schematic diagram of the valve sleeve of this utility model.

[0014] Figure 3 This is a top view of the valve sleeve of this utility model.

[0015] Figure 4 A 3D view of the valve core.

[0016] Figure 5 This is a hydraulic schematic diagram of this utility model.

[0017] Figure 6 This is a control effect curve of a proportional displacement pump using the electronically controlled valve of this utility model.

[0018] Figure 7 This is a control effect curve of a proportional displacement pump using existing electronically controlled valves.

[0019] The labels in the attached diagram are as follows: 1-valve sleeve, 2-outer shell, 3-valve core, 4-iron core, 5-spring, 6-high pressure oil port, 7-control oil port, 8-return oil port, 9-first oil passage, 10-second oil passage, 11-third oil passage, 12-counterhead, 13-convex ring, 14-first annular groove, 15-through hole, 17-blind hole, 18-guide part, 19-variable piston. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0021] Example. An electrically controlled valve for a high-capacity electro-proportional displacement pump that is designed for use during power outages, such as... Figures 1 to 4 As shown, the device includes an electro-proportional solenoid valve. A valve sleeve 1 is provided on one side of the electro-proportional solenoid valve. The valve sleeve 1 is fixed to the outer shell 2 of the electro-proportional solenoid valve (the inner part of the outer shell 2 is a coil). A valve core 3 is provided inside the valve sleeve 1. The valve core 3 is connected to the iron core 4 of the electro-proportional solenoid valve. A spring 5 is provided between the valve core 3 and the valve sleeve 1. On the outer circumferential surface of the valve sleeve 1, a high-pressure oil port 6, a control oil port 7, and a return oil port 8 are sequentially provided in the direction of the iron core 4's extension. Its features are as follows:

[0022] The valve sleeve 1 is provided with a first oil passage 9. A second oil passage 10 and a third oil passage 11 are provided between the valve sleeve 1 and the valve core 3. One end of the first oil passage 9 is used to connect to the variable chamber of the electric proportional displacement pump. The other end of the first oil passage 9 is connected to the return oil port 8 through the second oil passage 10. One end of the third oil passage 11 is connected to the control oil port 7. The other end of the third oil passage 11 is close to the high pressure oil port 6.

[0023] The valve sleeve 1 has a countersunk hole 12 on the end face facing the electro-proportional solenoid valve, and the valve core 3 has a convex ring 13 located in the countersunk hole 12 at its end. The spring 5 is located between the convex ring 13 and the bottom surface of the countersunk hole 12. The first oil passage 9 is connected to the second oil passage 10 through the countersunk hole 12.

[0024] The second oil passage 10 includes a first annular groove 14 located on the outer peripheral surface of the valve core 3. The first annular groove 14 is connected to the return oil port 8, and a through hole 15 is provided on the bottom surface of the first annular groove 14.

[0025] The third oil passage 11 is a second annular groove located on the outer circumferential surface of the valve core 3.

[0026] The valve core 3 has a blind hole 17 on the end face away from the electro-proportional solenoid valve, which is connected to the through hole 15.

[0027] The first annular groove 14 has a guide portion 18 at one end near the electro-proportional solenoid valve, which mates with the inner hole of the valve sleeve 1. The guide portion 18 consists of four circumferentially distributed protrusions, and the outer side wall of the protrusions is an arc surface that mates with the inner hole of the valve sleeve 1.

[0028] Working principle: such as Figure 1 and 2As shown, in the first state, when the electro-proportional solenoid valve is de-energized or only a very small control current is applied, the valve core 3 is in the rightmost position under the preload of the spring 5. At this time, the oil in the variable displacement chamber is connected to the pump's return oil tank through the first oil passage 9, the countersunk hole 12, the first annular groove 14, the through hole 15, and the return port 8. The variable piston 19 is in its extreme position, and the pump is in its maximum displacement state. In the first state, the existing electro-hydraulic valve and this embodiment constitute a difference in technical effect.

[0029] In the second state, when the control current supplied to the electro-proportional solenoid valve reaches a certain value, the magnetic field on the iron core 4 overcomes the preload of the spring 5, pushing the valve core 3 to the left. This disconnects the countersunk hole 12 and the first annular groove 14, preventing the oil in the variable displacement chamber from connecting with the return port 8. Furthermore, the high-pressure port 6 connects with the third oil circuit 11. The high-pressure oil from the pump outlet passes through the high-pressure port 6, the third oil circuit 11, and the control port 7, entering the variable displacement chamber and pushing the variable piston 19 to move, thus changing the pump's displacement. The distance the variable piston 19 moves is proportional to the magnitude of the control current supplied to the electro-proportional solenoid valve, meaning the control current is proportional to the pump's displacement, facilitating control. In the second state, the existing electro-hydraulic valve operates on the same principle as this embodiment, connecting the high-pressure port 6 with the control port 7 and changing the pump's displacement by altering the connection area.

[0030] In the third state, the control current supplied to the electro-proportional solenoid valve continues to increase, causing the valve core 3 to continue moving until the control port 7 is disconnected from the third oil circuit 11. At this time, the control port 7 is connected to the first annular groove 14, and the oil in the variable chamber enters the pump's return oil tank through the control port 7, the first annular groove 14, the through hole 15, and the return oil port 8, and the pump is in the maximum displacement state. In the third state, the existing electro-hydraulic valve operates on the same principle as in this embodiment, also connecting the control port 7 to the return oil port 8 to maximize the pump's displacement.

[0031] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. A power-off large-capacity electro-proportional displacement pump control valve, comprising an electro-proportional solenoid valve, a valve sleeve (1) provided on one side of the electro-proportional solenoid valve, the valve sleeve (1) being fixed to the outer shell (2) of the electro-proportional solenoid valve, a valve core (3) provided inside the valve sleeve (1), the valve core (3) being connected to the iron core (4) of the electro-proportional solenoid valve, a spring (5) being provided between the valve core (3) and the valve sleeve (1), and a high-pressure oil port (6), a control oil port (7), and a return oil port (8) being sequentially provided on the outer circumferential surface of the valve sleeve (1) in the direction of the iron core (4) extending outward, characterized in that: The valve sleeve (1) is provided with a first oil passage (9), and a second oil passage (10) and a third oil passage (11) are provided between the valve sleeve (1) and the valve core (3). One end of the first oil passage (9) is used to connect to the variable chamber of the electric proportional displacement pump, and the other end of the first oil passage (9) is connected to the return oil port (8) through the second oil passage (10). One end of the third oil passage (11) is connected to the control oil port (7), and the other end of the third oil passage (11) is close to the high pressure oil port (6).

2. The electro-proportional displacement pump control valve for high-capacity discharge pumps under power failure as described in claim 1, characterized in that: The valve sleeve (1) has a countersunk hole (12) on the end face facing the electro-proportional solenoid valve. The end of the valve core (3) has a convex ring (13) located in the countersunk hole (12). The spring (5) is located between the convex ring (13) and the bottom surface of the countersunk hole (12). The first oil passage (9) is connected to the second oil passage (10) through the countersunk hole (12).

3. The electro-proportional displacement pump control valve for high-capacity discharge pumps under power failure as described in claim 2, characterized in that: The second oil passage (10) includes a first annular groove (14) located on the outer circumferential surface of the valve core (3), the first annular groove (14) is connected to the return oil port (8), and a through hole (15) is provided on the bottom surface of the first annular groove (14).

4. The electro-proportional displacement pump control valve for high-capacity discharge pumps under power failure as described in claim 3, characterized in that: The third oil passage (11) is the second annular groove located on the outer circumferential surface of the valve core (3).

5. The electro-proportional displacement pump control valve for high-capacity discharge pumps under power failure as described in claim 3, characterized in that: The valve core (3) has a blind hole (17) on the end face away from the electro-proportional solenoid valve, which is connected to the through hole (15).

6. The electro-proportional displacement pump control valve for high-capacity discharge pumps under power failure as described in claim 3, characterized in that: The first annular groove (14) has a guide part (18) that mates with the inner hole of the valve sleeve (1) at one end near the electro-proportional solenoid valve.

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