Low friction two position two way proportional directional valve

Abstract

The present application relates to a kind of low friction two-position two-way proportional valve, including electromagnet assembly, lever assembly, balance valve core, valve seat, valve body and eddy current sensor assembly.The lever assembly includes lever mechanism cover, lever, lever axle and lever shaft.The eddy current sensor assembly includes eddy current sensor, mounting plate, measured surface, joint and connecting rod;The proportional valve assembly is composed of valve body, balance valve core, push rod, valve seat, balance valve block, balance plug;The horizontal movement of valve core is converted into reciprocating linear motion by electromagnet assembly, lever assembly, and accurately opened to specified position.The present application has small size, light weight and high pressure resistance characteristics, can effectively reduce the friction resistance of sealing ring under high pressure working condition, so as to guarantee the response speed and control accuracy of output displacement.

Description

Technical Field

[0001] This invention relates to the field of proportional valve technology, specifically to the field of hydraulic components in the machinery industry, and more specifically, to a low-friction two-position two-way proportional directional valve. Background Technology

[0002] Existing emulsion pump electromagnetic unloading valves are all on / off valves, which have limitations such as large opening and closing pressure shocks and the inability to continuously control the flow rate in real time. They cannot respond in time to the large load fluctuations and high frequency of changes during coal mining in fully mechanized mining faces, and cannot meet the goals of intelligent fully mechanized mining faces to supply liquid on demand and achieve energy saving and high efficiency. As the core control element of the unloading valve, the proportional valve precisely controls the opening of the proportional pilot valve through electrical signals, thereby achieving precise control of the working pressure of the fully mechanized mining face.

[0003] In proportional control valves, the electromagnet and valve core are not on the same axis, but are connected by a lever mechanism. The lever arm of the electromagnet is greater than that of the valve core, and the electromagnetic force of the electromagnet is amplified, so a smaller electromagnet can be used to meet the driving requirements.

[0004] By adopting a hydraulic pressure-balanced structure, high pressure is directed to the other side of the valve core push rod. Through careful design, hydraulic pressure balance is achieved, minimizing the resistance to the pilot valve's opening and closing. Meanwhile, conventional valves use sealing rings for high-pressure sealing. While this method ensures sealing performance, under high pressure conditions, the frictional force generated by the dynamic sealing ring may exceed the electromagnetic thrust. Therefore, the dynamic sealing ring between the inlet and outlet of the pilot valve is eliminated, replaced by a gap seal. This almost completely eliminates the frictional force of the sealing ring. Furthermore, the leakage of the gap seal has been assessed and can be controlled within a very small range, without affecting the normal operation of the valve.

[0005] First, the linear relationship between the driving force of the electromagnet and the input current is fundamental to ensuring the accuracy of valve opening control. Nonlinear factors severely restrict the development of the linearity of proportional valves. Existing proportional valves, due to excessively high working pressures (up to 50 MPa), all use O-ring seals to isolate the high-pressure medium from the outside environment. This causes the valve core to be subjected to significant friction, resulting in sluggish valve core movement and affecting the dynamic adjustment and response speed of the valve core opening.

[0006] Secondly, because the proportional valve has a small opening and a small working range of the spring, it is more sensitive to nonlinear factors inside the electromagnet. For example, the nonlinearity inside the electromagnet, the hydraulic force on the valve core, and the signal amplification circuit will all affect the control accuracy and response speed of the proportional valve, and thus affect the overall performance of the unloading valve. Summary of the Invention

[0007] To address the shortcomings of existing proportional valves under high pressure and high flow conditions, such as slow response speed, low control accuracy, and excessive electromagnetic thrust requirements due to high friction of the sealing ring, a low-friction two-position two-way proportional directional valve is provided. It aims to achieve high-frequency response and high-precision proportional control under high pressure conditions through a balanced structure and lever force amplification mechanism.

[0008] To achieve the above objectives, the present invention proposes a low-friction two-position two-way proportional valve, characterized in that it comprises: an eddy current sensor assembly, a lever assembly, an electromagnet assembly, and a proportional valve assembly, wherein: The lever assembly includes a lever mechanism housing, a lever disposed inside the lever mechanism housing, and a lever slide shaft that supports the rotation of the lever. The lever slide shaft is installed outside the lever housing to fix the lever to the lever housing. An eddy current sensor assembly is connected to one end of the lever housing in the horizontal direction, and an electromagnet assembly and a proportional valve assembly are respectively connected to the top and bottom of the other end of the lever housing in the horizontal direction. The electromagnet assembly includes an electromagnet connecting block and an electromagnet connected in sequence to the lever cover. A first self-aligning ball is installed at the contact point between the electromagnet and the lever. The first self-aligning ball is built into the middle of the electromagnet connecting block. The electromagnet transmits the thrust to the lever assembly through the first self-aligning ball. The proportional valve assembly includes a valve body and a second self-aligning ball, a push rod, a valve seat, a sealing valve block, a spring seat, a spring, and a balance plug, which are arranged inside the valve body and connected to the lever cover in the horizontal direction. One end of the balance plug is connected to the inner wall of the valve body, and the other end is connected to the valve core in sequence through the spring and the spring seat. The valve core and the sealing valve block are connected by a gap seal, and one end of the valve core is connected to the valve seat. The valve core is provided with a pressure balance flow channel to balance the axial fluid pressure at both ends of the valve core. The second self-aligning ball is used to transmit the thrust of the lever assembly to the push rod, thereby driving the valve core to move.

[0009] Preferably, the rotation center of the lever assembly is located in the middle of the lever, and the lever arm from the rotation center of the lever assembly to the electromagnet is longer than the lever arm of the proportional valve assembly's force application point to amplify the electromagnet's thrust and reduce the valve core's thrust requirement.

[0010] Preferably, the lever slide shaft is installed in the U-shaped groove at the left end of the lever, the diameter of the lever slide shaft is the same as the diameter of the U-shaped groove, and the lever slide shaft can slide relative to the U-shaped groove along its length to compensate for radial displacement during the lever swing process.

[0011] Preferably, the eddy current sensor assembly includes an eddy current sensor, a sensor mounting plate, a sensor connector, a sensor measured surface, and a sensor connecting rod connected sequentially in the horizontal direction; the lever slide shaft is connected to the connector of the sensor measured surface through the sensor connecting rod and drives it to move synchronously; the diameter of the sensing surface of the connector of the sensor measured surface is larger than the diameter of the detection end of the eddy current sensor.

[0012] Preferably, the eddy current sensor is threaded onto the eddy current sensor mounting plate, and the eddy current sensor mounting plate is connected to the sensor connector by screws. The sensor connector is threaded to connect to the lever cover by screwing in. The sensor connector has an inner hole to facilitate the passage of the sensor connecting rod. The thread is used to adjust the screwing depth to control the distance between the eddy current sensor and the sensor measured surface.

[0013] Preferably, the balance plug has multiple through holes, which connect the outlet cavity of the valve body with the back pressure cavity of the valve core to counteract the static pressure acting on the valve core.

[0014] Preferably, the valve core is machined with a stepped shaft, and the stepped end face of the stepped shaft has space with the sealing valve block to improve the smoothness of the valve core movement. The end of the valve core away from the valve seat is connected to the spring seat by a thread.

[0015] Preferably, the minimum orifice diameter of the sealing valve block is the same as the valve port diameter of the valve core.

[0016] Preferably, the end of the second self-aligning ball near the push rod is pressed against the valve block sealing ring by a clamping nut to achieve the sealing between the proportional valve assembly and the lever assembly, and the material of the valve block sealing ring is fluororubber (FKM).

[0017] In summary, compared with the prior art, the technical solution conceived by this invention has the following main advantages: 1. The proportional directional valve of the present invention uses a lever mechanism to proportionally amplify the thrust of the electromagnet and transmit it to the proportional valve assembly, thereby reducing the dependence on the high-thrust electromagnet and effectively reducing the size and power consumption of the entire valve. Furthermore, the valve core in the proportional valve assembly of the present invention adopts a hydraulic pressure balance structure, which balances the pressure on the valve core at the valve core inlet, reducing the impact of high pressure on the valve core.

[0018] 2. The valve core of the present invention adopts a gap sealing method, and the valve stem is machined with a step so as to form a damping cavity with the sealing valve sleeve. The valve stem and the sealing valve block play the roles of sealing and stabilizing movement at the same time.

[0019] 3. In the proportional valve assembly of the present invention, since the high-pressure chamber is isolated from the outside world through the valve core outlet, the friction force generated by the valve block sealing ring is much smaller than the friction force generated under high pressure, thereby reducing the nonlinear factors of the proportional valve mechanism. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the proportional valve switching mechanism provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the components of the proportional valve assembly; In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Eddy current sensor 2-Sensor mounting plate 3-Sensor connector 4-Sensor measured surface 5-Sensor connecting rod 6-Lever sliding shaft 7-Lever 8-First self-aligning ball 9-Upper end cover 10-Electromagnet connecting block 11-Electromagnet 12-Valve body 13-Balance plug 14-Spring 15-Plug 16-Spring seat 17-Sealing valve block 18-Valve core 19-Valve seat 20-Push rod 21-Base 22-Pressure nut 23-Second self-aligning ball 24-Lever screw 25-Lever cover 26-Eddy current sensor assembly 27-Lever assembly 28-Electromagnet assembly 29-Proportional valve assembly. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figure 1 As shown, this embodiment of the invention provides a low-friction two-position two-way proportional reversing mechanism, including an electromagnet assembly 28, a lever assembly 27, an eddy current sensor assembly 26, and a proportional valve assembly 29. One end of the lever assembly 27 in the horizontal direction is connected to the eddy current sensor assembly 26, and the top and bottom of the other end of the lever assembly 27 in the horizontal direction are respectively connected to the electromagnet assembly 28 and the proportional valve assembly 29.

[0023] like Figure 2As shown, the electromagnet assembly 28 is mounted on the upper side of the lever cover 25 via the electromagnet connecting block 10; the valve body 12 of the proportional valve assembly 29 is fixed to the lower side of the lever cover 25 by bolts; and the eddy current sensor assembly 26 is mounted on the other side of the lever cover 25 via the sensor connector 3. The lever cover 25, the electromagnet connecting block 10, the sensor connector 3, and the valve body 12 together constitute the outer housing of the present invention.

[0024] Lever 7 is fixed between the electromagnet assembly 28 and the proportional valve assembly 29 via lever slide 6. Push rod 20 is installed in base 21, and valve block sealing ring is installed on base 21 via clamping nut 22 to prevent medium leakage to the outside through the gap between push rod 20 and base 21. Driven by the reciprocating swing of the electromagnet-driven lever, the first self-aligning ball 8, push rod 20, and valve core 18 are sequentially pushed to produce reciprocating linear motion. Through the cooperation of the above components, the problems of slow response and high thrust required by high-pressure proportional valves can be effectively solved, meeting the design requirements of low-frequency response of proportional valves. It has advantages such as small structural size, light weight, simple structure, low friction coefficient, good self-lubricating performance, and fast response.

[0025] like Figure 2 As shown, the electromagnet assembly 28 includes an electromagnet 11, an electromagnet connecting block 10, and a self-aligning ball 8. The electromagnet 11 is threadedly connected to the lever outer cover 25 through the electromagnet connecting block 10, and the electromagnet 11 transmits the thrust to the lever assembly 27 through the self-aligning ball 8. Through the spherical contact of the first self-aligning ball 8, the angular changes during the lever swing process can be automatically compensated, ensuring that the thrust is always transmitted axially and reducing friction caused by lateral forces.

[0026] like Figure 2 As shown, the lever assembly 27 includes a lever 7 and a lever slide shaft 6. The lever 7 is installed inside the lever cover 25 and can rotate freely around the lever slide shaft 6. One end (input end) of the lever 7 is connected to the self-aligning ball 8 via a lever screw 24; the other end (output end) is provided with a U-shaped groove, and the lever slide shaft 6 is installed in the U-shaped groove and can slide relative to it along the groove direction. This "U-shaped groove-slide shaft" structure can effectively absorb the radial component generated by the circumferential oscillation of the lever, prevent transmission jamming, and facilitate the eddy current sensor 1 to measure displacement via the sensor connecting rod 5. The upper end cover 9 is connected to the lever cover 25 by screws to prevent external impurities from entering.

[0027] like Figure 2As shown, the proportional valve assembly 29 includes a balance plug 13, a spring 14, a spring seat 16, a valve core 18, a sealing valve block 17, a valve seat 19, a push rod 20, and several valve blocks installed inside the valve body 12. The push rod 20 is installed in the hole of the base 21, and the sealing ring is installed on the base 21 through the clamping nut 22. The second self-aligning ball 23 transmits the thrust to the connected push rod 20, pushing the valve core 18 to move. The spring seat 16 is threadedly connected to the valve core 18, and the spring 14 provides a preload force to the valve core 18 through the spring seat 16, so that it is initially pressed tightly against the valve seat 19.

[0028] Specifically, the valve core 18 is shaped as a hemisphere at one end and a stepped shaft at the other. The hemisphere end contacts the valve seat 19, providing a good sealing effect. The valve core 18 has threads machined at the end to facilitate the installation of the spring seat 16. In addition, the diameter of the valve core 18 end is the same as the diameter of the valve seat 19 hole, so that the force-bearing area of ​​the valve core at the inlet and the valve core end is the same, so that the static pressure generated by the high pressure medium cancels each other at both ends of the valve core, achieving axial force balance.

[0029] like Figure 2 As shown, the eddy current sensor assembly 26 includes an eddy current sensor 1, a sensor mounting plate 2, a sensor measured surface 4, a sensor connector 3, and a sensor connecting rod 5. The eddy current sensor 1 is threaded onto the sensor mounting plate 2 and fixed to the sensor connector 3 with screws. The working principle of the proportional directional valve of the present invention will be briefly described below.

[0030] This invention uses an electromagnet as the power source for a proportional valve. When the electromagnet receives a control signal and generates a thrust, the thrust acts on the input end of the lever through the electromagnet's self-aligning ball, driving the lever to swing around its axis. After the lever amplifies the thrust according to the lever arm ratio, it pushes the proportional valve push rod through the proportional valve self-aligning ball, overcoming the return spring force and residual friction, causing the proportional valve core to produce a precise linear displacement, thus achieving proportional opening of the valve port.

[0031] The drive mechanism of this invention optimizes the working condition of the friction pair, reduces the friction force between the friction surfaces, and optimizes the motion of the high-pressure medium friction pair, which is beneficial to achieving low power consumption and high frequency response of the high-pressure medium proportional valve.

[0032] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-friction two-position two-way proportional valve, characterized in that, include: Eddy current sensor assembly (26), lever assembly (27), electromagnet assembly (28), and proportional valve assembly (29), wherein: The lever assembly (27) includes a lever mechanism cover (25), a lever disposed inside the lever mechanism cover, and a lever slide shaft (6) that supports the rotation of the lever. The lever slide shaft is installed outside the lever cover and fixes the lever (7) on the lever cover (25). An eddy current sensor assembly (26) is connected to one end of the lever cover (25) in the horizontal direction. An electromagnet assembly (28) and a proportional valve assembly (29) are respectively connected to the top and bottom of the other end of the lever cover (25) in the horizontal direction. The electromagnet assembly (28) includes an electromagnet connecting block (10) and an electromagnet (11) connected in sequence to the lever cover (25). A first self-aligning ball (8) is installed at the contact point between the electromagnet (11) and the lever (7). The first self-aligning ball (8) is built into the middle of the electromagnet connecting block (10). The electromagnet (11) transmits the thrust to the lever assembly (27) through the first self-aligning ball (8). The proportional valve assembly (29) includes a valve body (12) and a second self-aligning ball (23), a push rod (20), a valve seat (19), a sealing valve block (17), a spring seat (16), a spring (14), and a balance plug (13) arranged inside the valve body (12) and connected in the horizontal direction to the lever cover (25). One end of the balance plug (13) is connected to the inner wall of the valve body (12), and the other end is connected to the valve core (18) in sequence through the spring (14) and the spring seat (16). The valve core (18) is connected to the sealing valve block (17) through a gap seal, and one end of the valve core (18) is connected to the valve seat (19). The valve core (18) is provided with a pressure balance flow channel to balance the axial fluid pressure at both ends of the valve core (18). The second self-aligning ball (23) is used to transmit the thrust of the lever assembly (27) to the push rod (20) to drive the valve core (18) to move.

2. The low-friction two-position two-way proportional valve as described in claim 1, characterized in that, The rotation center of the lever assembly (27) is located in the middle of the lever (7), and the lever arm from the rotation center of the lever assembly (27) to the electromagnet (11) is longer than the lever arm of the proportional valve assembly (29) at the point of force application, so as to amplify the thrust of the electromagnet (11) and reduce the thrust requirement of the valve core (12).

3. A low-friction two-position two-way proportional valve as described in claim 1 or 2, characterized in that, The lever slide shaft (6) is installed in the U-shaped groove at the left end of the lever (7). The diameter of the lever slide shaft (6) is the same as the diameter of the U-shaped groove, and the lever slide shaft (6) can slide relative to the length of the U-shaped groove to compensate for the radial displacement of the lever (7) during the swing process.

4. A low-friction two-position two-way proportional valve as described in claim 3, characterized in that, The eddy current sensor assembly (26) includes an eddy current sensor (1), a sensor mounting plate (2), a sensor connector (3), a sensor measured surface (4), and a sensor connecting rod (5) connected in sequence in the horizontal direction; the lever slide shaft (6) is connected to the connector of the sensor measured surface (4) through the sensor connecting rod (5) and drives it to move synchronously; The diameter of the sensing surface of the connector of the sensor measured surface (4) is larger than the diameter of the detection end of the eddy current sensor (1).

5. A low-friction two-position two-way proportional valve as described in claim 4, characterized in that, The eddy current sensor (1) is mounted on the eddy current sensor mounting plate (2) by a thread. The eddy current sensor mounting plate (2) is connected to the sensor connector (3) by a screw. The sensor connector (3) has a thread for screwing in and connecting to the lever cover (25). The sensor connector (3) has an inner hole to facilitate the passage of the sensor connecting rod (5). The thread is used to adjust the screwing depth to control the distance between the eddy current sensor (1) and the sensor measured surface (4).

6. A low-friction two-position two-way proportional valve as described in claim 1, characterized in that, The balance plug (13) has multiple through holes, which connect the outlet of the valve body (12) with the back pressure chamber of the valve core to counteract the static pressure acting on the valve core.

7. A low-friction two-position two-way proportional valve as described in claim 1, characterized in that, The valve core (18) is machined with a stepped shaft. The stepped end face of the stepped shaft has space with the sealing valve block (17) to improve the smoothness of the valve core (18) movement. The end of the valve core (18) away from the valve seat (19) is connected to the spring seat (16) by a thread.

8. A low-friction two-position two-way proportional valve as described in claim 1 or 5, characterized in that, The minimum orifice diameter of the sealing valve block (17) is consistent with the valve port diameter of the valve core (18).

9. A low-friction two-position two-way proportional valve as described in claim 1, characterized in that, The second self-aligning ball (23) near the push rod (20) presses the valve block sealing ring with the pressure nut (22) to achieve the sealing between the proportional valve assembly (29) and the lever assembly (28). The valve block sealing ring is made of fluororubber.

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