Improved structure of valve sleeve and direct-acting proportional pressure reducing valve

Abstract

The utility model belongs to the technical field of proportional valve structures, and discloses a valve sleeve improved structure and a direct-acting proportional pressure reducing valve. A first pilot hole is formed in the valve sleeve and located on the side, away from the control oil port, of the oil inlet, and the first pilot hole is used for enabling oil to flow into the first groove before the oil inlet in the process that the valve element is switched to the first position from the second position. According to the improved structure of the valve sleeve, the first pilot hole is additionally formed in the valve sleeve, so that when the electromagnet is started, a part of oil liquid enters the valve element through the first pilot hole, the valve element has higher response speed when the electromagnet is started, the linearity of a current-force characteristic curve is improved, the flow adjusting precision is higher, and the service life of the valve element is prolonged. And the proportional performance of the direct-acting proportional pressure reducing valve is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of proportional valve structures, and in particular to an improved structure of a valve sleeve and a direct-acting proportional pressure reducing valve. Background Technique

[0002] A pressure reducing valve is a valve that reduces the inlet pressure to a required outlet pressure through adjustment and relies on the energy of the medium itself to automatically maintain the outlet pressure stable. From the perspective of fluid mechanics, a pressure reducing valve is a throttling element with variable local resistance, that is, by changing the throttling area, the flow velocity and the kinetic energy of the fluid are changed, resulting in different pressure losses, so as to achieve the purpose of pressure reduction. Then, relying on the adjustment of the control and regulation system, the fluctuation of the pressure behind the valve is balanced with the spring force, so that the pressure behind the valve remains constant within a certain error range.

[0003] A direct-acting proportional pressure reducing valve is directly driven by a proportional electromagnet. It converts the input electrical signal into a pressure output signal in proportion, drives the spool to move left and right, and connects the oil inlet, working oil chamber and oil outlet on the valve sleeve through a throttling orifice to form a progressive flow characteristic. The existing direct-acting proportional pressure reducing valve uses a proportional electromagnet to drive the spool to make a small displacement, has high stability, and is suitable for occasions with high reliability requirements. However, there is inevitably a control dead zone in the valve sleeve. When starting up with power on, the response speed of the spool has a certain delay, resulting in poor linearity of the current-force characteristic curve and relatively low flow regulation accuracy, which affects the use of the pressure reducing valve. Content of the Utility Model

[0004] Based on the above problems, the purpose of the utility model is to provide an improved structure of a valve sleeve and a direct-acting proportional pressure reducing valve, so that the spool has a faster response speed when the electromagnet starts, thereby improving the linearity of the current-force characteristic curve and ensuring the performance of the direct-acting proportional pressure reducing valve.

[0005] To achieve the above object, on the one hand, the utility model adopts the following technical solutions:

[0006] An improved structure of a valve sleeve. A valve core capable of axial movement is arranged in the valve sleeve. An oil inlet, a control oil port and an oil return port are sequentially arranged at intervals along the axial direction of the valve sleeve. A first groove, a second groove and a third groove are sequentially arranged on the surface of the valve core along its axial direction. A first shoulder is arranged between the first groove and the second groove, and a second shoulder is arranged between the second groove and the third groove. A flow passage communicating the first groove and the second groove is opened inside the valve core. When the valve core is in the first position, the second shoulder cuts off the control oil port and the oil return port, and the oil inlet is communicated with the control oil port through the first groove, the flow passage and the second groove in sequence; when the valve core is in the second position, the first shoulder blocks the oil inlet, the blocking function of the second shoulder fails, and the control oil port is communicated with the oil return port through the third groove. Wherein, a first pilot hole is arranged on the valve sleeve and on the side of the oil inlet away from the control oil port, and the first pilot hole is used for enabling the oil to flow into the first groove prior to the oil inlet during the process of the valve core switching from the second position to the first position.

[0007] As an alternative solution, a plurality of oil inlets are arranged. The plurality of oil inlets penetrate through the valve sleeve and are circumferentially evenly distributed. A first pilot hole is arranged between two adjacent oil inlets, and the edge of the first pilot hole extends beyond the edge of the oil inlet away from the control oil port.

[0008] As an alternative solution, the aperture of the first pilot hole is 0.8 mm to 1.2 mm.

[0009] As an alternative solution, a second pilot hole is arranged on the valve sleeve and on the side of the control oil port close to the oil return port, and the second pilot hole is used for enabling the oil to flow into the third groove prior to the control oil port during the process of the valve core switching from the first position to the second position.

[0010] As an alternative solution, a plurality of control oil ports are arranged. The plurality of control oil ports penetrate through the valve sleeve and are circumferentially evenly distributed. The second pilot hole is arranged between any two adjacent control oil ports, and the edge of the second pilot hole extends beyond the edge of the control oil port close to the oil return port.

[0011] As an alternative solution, the aperture of the second pilot hole is 1.2 mm to 1.6 mm.

[0012] On the other hand, the present utility model adopts the following technical solution:

[0013] A direct-acting proportional pressure reducing valve, which comprises a housing. An electromagnet is arranged inside the housing. One end of the electromagnet is provided with a valve sleeve. A valve core is arranged in the valve sleeve. A return spring is arranged at one end of the valve core away from the electromagnet. The valve sleeve adopts the above-mentioned improved structure of the valve sleeve. A guide sleeve is arranged inside the electromagnet. An armature is arranged inside the guide sleeve. A push rod is arranged between the armature and the valve core. When the electromagnet is energized, the valve core reaches the first position under the thrust of the push rod; when the electromagnet is de-energized, the valve core reaches the second position under the elastic force of the return spring.

[0014] As an alternative, one end of the push rod abuts against the armature, and the other end of the push rod is connected to the valve core through a pin.

[0015] Advantages of the present utility model: The improved structure of the valve sleeve enables a part of the oil to enter through the first pilot hole on the valve sleeve when the electromagnet is activated, so that the valve core has a faster response speed when the electromagnet is activated, thereby improving the linearity of the current-force characteristic curve, having higher flow regulation accuracy, and enhancing the proportional performance of the direct-acting proportional pressure reducing valve. Description of the Drawings

[0016] Figure 1 is a schematic diagram of the improved structure of the valve sleeve provided by the embodiment of the present utility model;

[0017] Figure 2 is a schematic diagram of the valve core in the first position in the embodiment of the present utility model;

[0018] Figure 3 is a schematic diagram of the valve core in the second position in the embodiment of the present utility model.

[0019] In the drawings:

[0020] 1. Valve sleeve; 11. Oil inlet; 12. Control oil port; 13. Oil return port; 14. First pilot hole; 15. Second pilot hole;

[0021] 2. Valve core; 21. First groove; 22. Second groove; 23. Third groove; 24. First shoulder; 25. Second shoulder;

[0022] 3. Outer shell; 4. Electromagnet; 5. Return spring; 6. Guide sleeve; 7. Armature; 8. Push rod; 9. Pin. Detailed Embodiments

[0023] The present utility model will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present utility model and not for limiting the present utility model. Additionally, it should be noted that for the sake of description, only parts related to the present utility model are shown in the drawings rather than all the structures.

[0024] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0025] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0026] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left", and "right" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0027] Please refer to Figures 1 to 3 As shown, this preferred embodiment provides an improved structure of a valve sleeve. A valve core 2 capable of axial movement is arranged in the valve sleeve 1. Along its axial direction, an oil inlet 11 (P port), a control oil port 12 (C port), and an oil return port 13 (T port) are sequentially arranged at intervals on the valve sleeve 1. Along its axial direction, a first groove 21, a second groove 22, and a third groove 23 are sequentially arranged on the surface of the valve core 2. A first shoulder 24 is arranged between the first groove 21 and the second groove 22, and a second shoulder 25 is arranged between the second groove 22 and the third groove 23. A flow passage communicating the first groove 21 and the second groove 22 is opened inside the valve core 2. When the valve core 2 is in the first position, the second shoulder 25 cuts off the control oil port 12 and the oil return port 13, and the oil inlet 11 is sequentially communicated with the control oil port 12 through the first groove 21, the flow passage, and the second groove 22; when the valve core 2 is in the second position, the first shoulder 24 blocks the oil inlet 11, the blocking function of the second shoulder 25 fails, and the control oil port 12 is communicated with the oil return port 13 through the third groove 23.

[0028] Specifically, a first pilot hole 14 is provided on the valve sleeve 1 and on the side of the oil inlet 11 away from the control oil port 12. The first pilot hole 14 is used to allow the hydraulic fluid to flow into the first groove 21 prior to the oil inlet 11 during the process of the spool 2 switching from the second position to the first position.

[0029] Therefore, by adding the first pilot hole 14 on the valve sleeve 1, during the process of the spool 2 moving from the second position to the first position, a part of the hydraulic fluid will first enter through the first pilot hole 14, so that the spool 2 has a higher throttling area resolution during movement, a faster response speed, thereby improving the linearity of the current-force characteristic curve and the flow regulation accuracy.

[0030] Specifically, a plurality of oil inlets 11 are provided. The plurality of oil inlets 11 penetrate the valve sleeve 1 and are circumferentially evenly distributed. A first pilot hole 14 is provided between any two adjacent oil inlets 11. The edge of the first pilot hole 14 extends beyond the edge of the oil inlet 11 away from the control oil port 12, so as to enable the hydraulic fluid to preferentially enter the first groove 21 from the first pilot hole 14.

[0031] Preferably, the aperture of the first pilot hole 14 is 0.8 mm to 1.2 mm. The plurality of first pilot holes 14 with such an aperture can meet the flow requirements of the pressure hydraulic fluid, so that at the moment when the oil inlet 11 supplies oil to the first groove 21, the first groove 21 can be just filled, realizing the rapid output of the hydraulic fluid from the oil inlet 11 to the control oil port 12.

[0032] Furthermore, a second pilot hole 15 is provided on the valve sleeve 1 and on the side of the control oil port 12 close to the oil return port 13. The second pilot hole 15 is used to allow the hydraulic fluid to flow into the third groove 23 prior to the control oil port 12 during the process of the spool 2 switching from the first position to the second position. The existence of the second pilot hole 15 enables the hydraulic fluid to enter the third groove 23 through the second pilot hole 15 prior to the control oil port 12 during the process of the spool 2 moving from the first position to the second position, so that the spool 2 has a faster response speed during movement.

[0033] Specifically, a plurality of control oil ports 12 are provided. The plurality of control oil ports 12 penetrate the valve sleeve 1 and are circumferentially evenly distributed. The second pilot hole 15 is provided between any two adjacent control oil ports 12. The edge of the second pilot hole 15 extends beyond the edge of the control oil port 12 close to the oil return port 13, so as to enable the hydraulic fluid to preferentially enter the third groove 23 from the second pilot hole 15.

[0034] Preferably, the aperture of the second pilot hole 15 is 1.2 mm to 1.6 mm. Since the purpose is to relieve pressure and return oil through the control oil port 12 when the electromagnet 4 is powered off, the oil pressure is relatively small at this time. One second pilot hole 15 with such an aperture can meet the oil return requirement, so that when the oil returns from the control oil port 12 to the third groove 23 instantaneously, the third groove 23 can be just filled, realizing the rapid output of the oil from the control oil port 12 to the oil return port 13.

[0035] On this basis, this embodiment further provides a direct-acting proportional pressure reducing valve, which includes a housing 3. An electromagnet 4 is arranged inside the housing 3. A valve sleeve 1 is arranged at one end of the electromagnet 4. A valve core 2 is arranged in the valve sleeve 1. A return spring 5 is arranged at the end of the valve core 2 away from the electromagnet 4. The valve sleeve 1 adopts the improved structure of the valve sleeve described above. A guide sleeve 6 is arranged inside the electromagnet 4. An armature 7 is arranged inside the guide sleeve 6. A push rod 8 is arranged between the armature 7 and the valve core 2. When the electromagnet 4 is powered on, the valve core 2 reaches the first position under the thrust of the push rod 8; when the electromagnet 4 is powered off, the valve core 2 reaches the second position under the elastic force of the return spring 5.

[0036] Specifically, one end of the push rod 8 abuts against the armature 7, and the other end of the push rod 8 is connected to the valve core 2 through a pin 9.

[0037] Thus, when the electromagnet 4 is powered on, a part of the oil will first enter through the first pilot hole 14, so that when the oil is delivered to the oil inlet 11, the valve core 2 has a faster response speed; similarly, when the electromagnet 4 is powered off, a part of the oil will first enter through the second pilot hole 15, so that when the oil is delivered to the control oil port 12, the valve core 2 has a faster response speed, thereby improving the linearity of the current-force characteristic curve of the direct-acting proportional pressure reducing valve, improving the flow regulation accuracy, and improving the proportional performance of the direct-acting proportional pressure reducing valve.

[0038] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Improved structure of valve sleeve. A valve core (2) capable of axial movement is arranged in the valve sleeve (1). An oil inlet (11), a control oil port (12) and an oil return port (13) are sequentially arranged at intervals along the axial direction of the valve sleeve (1). First grooves (21), second grooves (22) and third grooves (23) are sequentially arranged on the surface of the valve core (2) along its axial direction. A first shoulder (24) is arranged between the first groove (21) and the second groove (22), and a second shoulder (25) is arranged between the second groove (22) and the third groove (23). A flow passage communicating the first groove (21) with the second groove (22) is opened inside the valve core (2). When the valve core (2) is in the first position, the second shoulder (25) cuts off the control oil port (12) from the oil return port (13), and the oil inlet (11) is communicated with the control oil port (12) through the first groove (21), the flow passage and the second groove (22) in sequence; when the valve core (2) is in the second position, the first shoulder (24) blocks the oil inlet (11), the blocking function of the second shoulder (25) fails, and the control oil port (12) is communicated with the oil return port (13) through the third groove (23). It is characterized in that A first pilot hole (14) is arranged on the valve sleeve (1) and on the side of the oil inlet (11) away from the control oil port (12). The first pilot hole (14) is used to make the oil flow into the first groove (21) prior to the oil inlet (11) during the process of the valve core (2) switching from the second position to the first position.

2. The improved valve sleeve structure according to claim 1, wherein A plurality of oil inlets (11) are provided. The plurality of oil inlets (11) penetrate through the valve sleeve (1) and are circumferentially evenly distributed. A first pilot hole (14) is arranged between any two adjacent oil inlets (11), and the edge of the first pilot hole (14) extends beyond the edge of the oil inlet (11) away from the control oil port (12).

3. The improved valve sleeve structure according to claim 1, characterized in that, The aperture of the first pilot hole (14) is 0.8 mm to 1.2 mm.

4. The improved valve sleeve structure according to claim 1, characterized in that, A second pilot hole (15) is arranged on the valve sleeve (1) and on the side of the control oil port (12) close to the oil return port (13). The second pilot hole (15) is used to make the oil flow into the third groove (23) prior to the control oil port (12) during the process of the valve core (2) switching from the first position to the second position.

5. The improved valve sleeve structure according to claim 4, characterized in that, A plurality of control oil ports (12) are provided. The plurality of control oil ports (12) penetrate through the valve sleeve (1) and are circumferentially evenly distributed. The second pilot hole (15) is arranged between any two adjacent control oil ports (12), and the edge of the second pilot hole (15) extends beyond the edge of the control oil port (12) close to the oil return port (13).

6. The improved valve sleeve structure according to claim 4, characterized in that, The aperture of the second pilot hole (15) is 1.2 mm to 1.6 mm.

7. Direct-acting proportional pressure reducing valve, characterized in that, It includes a housing (3), an electromagnet (4) is arranged inside the housing (3), a valve sleeve (1) is arranged at one end of the electromagnet (4), a valve core (2) is arranged in the valve sleeve (1), a return spring (5) is arranged at one end of the valve core (2) away from the electromagnet (4), the valve sleeve (1) adopts the improved structure of the valve sleeve according to any one of claims 1 to 6, a guide sleeve (6) is arranged inside the electromagnet (4), an armature (7) is arranged inside the guide sleeve (6), a push rod (8) is arranged between the armature (7) and the valve core (2), when the electromagnet (4) is energized, the valve core (2) reaches the first position under the thrust of the push rod (8); when the electromagnet (4) is de-energized, the valve core (2) reaches the second position under the elastic force of the return spring (5).

8. The direct-acting proportional pressure reducing valve according to claim 7, characterized in that, One end of the push rod (8) abuts against the armature (7), and the other end of the push rod (8) is connected to the valve core (2) through a pin (9).

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