End cover for magnetic core tube assembly, magnetic core tube assembly and hydraulic valve

Abstract

The utility model relates to an end cover (30) for a magnetic core tube assembly, the magnetic core tube assembly and a hydraulic valve. The end cover is configured to be installed on a sleeve of a magnetic core tube assembly and comprises an inner end face (31) and a through hole (35) used for receiving an ejector pin (40) of the magnetic core tube assembly, the end cover (30) is provided with a sealing groove (50) on the inner circumferential face defining the through hole (35), the sealing groove (50) is defined by first and second opposite side faces and a bottom face, the first side face (52) is closer to the inner end face (31) than the second side face (54), and the sealing groove (50) is located on the inner circumferential face defining the through hole (35). A first included angle (A) formed by the first side face and the second side face is larger than a self-locking angle between a material forming the end cover (30) and the same material, and a second included angle formed by the second side face and the bottom face ranges from 90 degrees to 95 degrees.

Description

Technical Field

[0001] This application belongs to the field of electromagnetic valve technology, specifically relating to end caps for magnetic core tube assemblies, magnetic core tube assemblies including end caps, and hydraulic valves including magnetic core tube assemblies. Background Technology

[0002] A solenoid valve is an automated actuator that uses electromagnetic technology to control the flow (e.g., flow direction) of fluid through it. A solenoid valve includes a core tube assembly. The core tube assembly mainly includes a sleeve and a push rod, armature, and ejector pin movably disposed within the sleeve, with the push rod and ejector pin positioned on opposite sides of the armature. Specifically, the ejector pin (or "manual push rod") extends through an end cap sealed to the sleeve into the armature cavity containing the armature, and is axially movable relative to the end cap and sleeve within a through-hole in the end cap. A seal is provided between the end cap and the ejector pin to prevent fluid leakage from the armature cavity. The seal can be installed in a sealing groove formed on the end cap. However, poor sealing problems still occur during the use of solenoid valves. Utility Model Content

[0003] The purpose of this application is to improve the sealing structure and enhance the sealing effect.

[0004] This application provides an end cap for a magnetic core tube assembly, the magnetic core tube assembly including a sleeve defining an armature cavity configured to receive an armature of the magnetic core tube assembly and open through an opening. The end cap is configured to be mounted to one end of the sleeve in such a manner that it extends through the opening into the armature cavity, and includes an inner end face facing the armature when mounted to the sleeve and a through hole extending in the axial direction and configured to receive a pin of the magnetic core tube assembly. The end cap has a sealing groove formed on the inner circumferential surface defining the through hole, extending in a circumferential direction about the axial direction and configured to receive a seal. The sealing groove is defined by opposing first and second side faces and a bottom surface connecting the first and second side faces. The first side face is closer to the inner end face than the second side face. The angle formed by the first and second side faces is greater than the self-locking angle between the material forming the end cap and the same material, and the angle formed by the second side face and the bottom surface is in the range of 90° to 95°.

[0005] In one embodiment, the self-locking angle is calculated based on the coefficient of friction between the material forming the end cap and the same material.

[0006] In one embodiment, the end cap is made of steel, and the included angle is in the range of 11.3° to 30° and / or the included angle formed by the first side surface and the bottom surface is in the range of 100° to 110°.

[0007] In one embodiment, the included angle is in the range of 17° to 20°.

[0008] In one embodiment, in the axial direction, the end cap includes an inner portion having a first outer diameter corresponding to the inner diameter of the armature cavity of the sleeve, a neck portion having an inner diameter corresponding to the opening of the sleeve and a second outer diameter smaller than the first outer diameter, and an outer portion having a third outer diameter larger than the first and second outer diameters.

[0009] In one embodiment, the sealing groove is located on the inner portion.

[0010] This application also provides a magnetic core tube assembly, including: the end cap for the magnetic core tube assembly described above; and the sleeve, wherein the end cap is mounted on one end of the sleeve.

[0011] In one embodiment, the core tube assembly further includes: a pin slidably disposed in the through-hole in an axial direction, the pin including a rod portion received in the through-hole and a head extending into the armature cavity with an outer diameter greater than the inner diameter of the through-hole; and a seal disposed in the sealing groove to provide a seal between the inner surface of the end cap and the outer peripheral surface of the rod portion.

[0012] In one embodiment, the sleeve defines an inner cavity including a first section serving as the armature cavity, a second section communicating with the first section and having an inner diameter smaller than that of the first section, and a third section communicating with the second section and opening to an end opposite to the first end. The core tube assembly also includes an armature received within the armature cavity and slidably movable, and a push rod arranged through the second section and slidably movable.

[0013] This application also provides a hydraulic valve comprising the above-described magnetic core tube assembly.

[0014] The end cap for a magnetic core tube assembly of this application has a sealing groove near its inner end face designed such that the angle between the side of the sealing groove for mounting the seal and a plane perpendicular to the axial direction is greater than the self-locking angle calculated based on the coefficient of friction between the material forming the end cap and the same material. This angle, greater than the self-locking angle, prevents milling debris from the end cap during the machining of the sealing groove from being self-locked (or "stuck") within the formed sealing groove, allowing it to easily leave the groove. No metal debris remains in the sealing groove. During the operation of the solenoid valve, the pin installed in the end cap reciprocates axially within the through-hole of the end cap, and the seal (typically an O-ring) installed in the sealing groove moves slightly within the sealing groove under the action of fluid from the armature cavity. The absence of metal debris in the sealing groove avoids scratching the seal, thus preventing leakage problems caused by scratched or even failed seals. Therefore, this application improves the sealing effect by redesigning the sealing groove. Attached Figure Description

[0015] This application will be more fully understood by referring to the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0016] Figure 1 A partial longitudinal cross-sectional view of the magnetic core tube assembly of a solenoid valve constructed according to the principles of this application is shown.

[0017] Figure 2 The sealing area between the ejector pin and the end cap is simplified and illustrated using a magnified view. Detailed Implementation

[0018] The principles of this application will now be described in detail with reference to the accompanying drawings.

[0019] Figure 1 A partial longitudinal section of a magnetic core tube assembly according to one embodiment of this application is shown. It should be noted that the accompanying drawings illustrate only one example of a magnetic core tube assembly constructed according to the principles of this application, and the drawings are only used to illustrate parts related to the structural improvements of this application, and do not represent all structural details of the magnetic core tube assembly. That is, the magnetic core tube assembly of this application is not limited to the illustrated example; structures or details not shown in the drawings may be included in some embodiments of the magnetic core tube assembly, while structures or details shown in the drawings are not necessarily included in all embodiments of the magnetic core tube assembly.

[0020] As shown in the figure, the magnetic core tube assembly includes a cylindrical sleeve 10 having a central axis X extending in an axial direction and a first end 10a and a second end 10b opposite in the axial direction. The sleeve 10 defines an inner cavity 15 extending through in the axial direction X. The inner cavity 15 includes a first section 12 opening to the first end 10a through an opening 11 and having a first inner diameter, a second section 14 communicating with the first section 12 and having a second inner diameter smaller than the first inner diameter, and a third section 16 communicating with the second section 14 and opening to the second end 10b. The first section 12 and the second section 14 define a stepped surface 13 facing the first section 12. The magnetic core tube assembly also includes an armature 22 slidably disposed in the first section 12 in the axial direction, and a pusher 24 slidably disposed through the second section 14 in the axial direction. Thus, the first section 12 and the second section 14 of the inner cavity 15 can also be referred to as the armature cavity and the pusher cavity, respectively. Figure 1 The image also shows the eccentric oil passage 26 inside the armature 22.

[0021] The core tube assembly also includes an end cap 30, which is mounted to a first end 10a of the sleeve 10 to seal an opening 11 of its inner cavity 15 (specifically, the first segment 12). The end cap 30 defines a through-hole 35. The core tube assembly also includes a push pin 40 (sometimes referred to as a "manual push rod") disposed axially through the through-hole 35, the push pin 40 and the push rod 24 pushing against the armature 22 from opposite sides. The push pin 40 can extend through the through-hole 35 into the first segment 12 of the sleeve 10.

[0022] Specifically, in the illustrated embodiment, the end cap 30 may include an inner portion 32, a neck portion 34, and an outer portion 36. The inner portion 32 has a first outer diameter corresponding to the inner diameter of the first segment 12 of the sleeve 10 and is located within the first segment 12 of the sleeve 10. The neck portion 34 has a second outer diameter corresponding to the inner diameter of the opening 11 of the sleeve 10 and smaller than the first outer diameter, thus being configured to engage the opening 11 of the sleeve 10. The outer portion 36 has a third outer diameter larger than the first and second outer diameters, thus the outer portion 36 of the end cap 30 is located outside the sleeve 10 and abuts against the first end 10a in the axial direction.

[0023] The inner portion 32 of the end cap 30 has an inner end face 31. When the end cap 30 is installed on the first end 10a of the sleeve 10, the end cap 30 seals the inner cavity 15 of the sleeve 10, and the inner end face 31 defines an axial movement space 28 for the armature 22 between it and the stepped surface 13. The armature 22 slides axially within the axial movement space 28, having a first extreme position closest to the end cap 30 (as shown) and a second extreme position furthest from the end cap 30.

[0024] In the illustrated embodiment, the ejector pin 40 may include a rod 42 received within a through-hole 35 and a head 44 extending from the through-hole 35 and thus located within the first section 12 or the axial movement space 28. The outer diameter of the head 44 is larger than the inner diameter of the through-hole 35 of the end cap 30, thereby preventing the head 44 of the ejector pin 40 from moving out in the axial direction. Figure 1 The armature 22 reaches its first limit position when it comes into contact with the head 44 of the ejector pin 40.

[0025] The end cap 30 has a sealing groove 50 extending circumferentially around the axial direction formed on its inner surface 33 defining the through hole 35. A seal 60, such as an O-ring (especially a rubber seal), is installed in the sealing groove 50 to achieve a fluid seal between the stationary end cap 30 and the axially movable ejector pin 40, preventing fluid in the inner cavity 15, specifically the armature cavity or axial movement space 28, from leaking between the inner surface of the end cap 30 and the outer peripheral surface of the ejector pin 40. In particular, the sealing groove 50, and therefore the seal 60, is located on the inner portion 32. The figure also shows a seal provided between the inner portion 32 of the end cap 30 and the corresponding inner surface of the sleeve 10, which is installed in a sealing groove formed on the outer peripheral surface of the end cap 30.

[0026] Figure 2 A partially enlarged schematic diagram is shown, illustrating the sealing area between the inner circumferential surface of the end cap 30 and the outer circumferential surface of the rod 42 of the ejector pin 40. Please note that... Figure 2 It is not drawn to scale and is only used to illustrate the principles of this application. Specifically, Figure 2 A pin 40 including a rod 42 and a head 44 is shown, as are a sealing groove 50 of an end cap 30 and a seal 60 installed therein.

[0027] The sealing groove 50 is defined by opposing first and second side surfaces 52 and 54 and a bottom surface 56 connecting the first and second side surfaces 52 and 54, wherein the first side surface 52 is the side closer to the inner end face 31 and the second side surface 54 is the side farther from the inner end face 31. The bottom surface 56 may extend along or substantially along the axial direction.

[0028] Figure 2An enlarged schematic diagram is shown. Although the second side 54 is shown as approximately perpendicular to the axial direction, in practice, the second side 54 formed when machining the sealing groove 50 using processes such as milling is not strictly perpendicular to the axial direction. For example, the second side 54 may form an angle between 0° and 5° relative to a (virtual) plane perpendicular to the axial direction, or an angle C between 90° and 95° between the second side 54 and the bottom surface 56. This can be achieved, for example, by milling the sealing groove 50. According to the principles of this application, the angle A between the first side 52 and the second side 54 of the sealing groove 50 is designed to be greater than the self-locking angle between the material forming the end cap 30 and the same material. Utilizing the principle that the tangent of the self-locking angle is approximately equal to the coefficient of friction, the self-locking angle can be calculated based on the coefficient of friction between the same materials. The coefficient of friction in various cases is known and can be obtained from practical experience or by consulting reference tables in the art.

[0029] End cap 30 is typically made of metal, such as 45# steel or copper. As an example, end cap 30 can be made of 45# steel. Cutting fluid, such as a water-based cutting fluid, is usually used during machining of the end cap 30, for example, milling the sealing groove 50. In this case, the coefficient of friction between the steel materials can be 0.2-0.3. For conservative and safety reasons, taking 0.3 as an example, a self-locking angle of 16.70° can be obtained. Therefore, for the case where the end cap 30 is made of 45# steel, this application can design angle A to be greater than 17°, which can effectively prevent self-locking between two parts made of the same steel material. At this time, the debris of the (same) material generated during the processing of the sealing groove 50 will not self-lock (or "adhere") between the first side 52 and the second side 54, ensuring that the debris leaves the sealing groove 50. The debris is removed during the processing of the sealing groove, effectively preventing the phenomenon that the debris "stuck" in the sealing groove 50 will cut the sealing element 60 during use after the sealing element 60 is installed. On the other hand, angle A can be less than a specific angle, such as 30°, to ensure that the sealing element 60 is reliably and stably retained in the sealing groove 50 during the axial reciprocating movement of the ejector pin 40, so as to ensure the sealing effect. Thus, in some embodiments, angle A can be designed in the range of 15° to 30°, preferably in the range of 17° to 30°, and more preferably in the range of 17° to 20°. In other embodiments, angle A can be designed to be 17° ± 2°.

[0030] As mentioned above, since angle A is greater than the self-locking angle, the structure of this application can achieve the technical effect of preventing machining debris from getting "stuck" in the sealing groove 50. Under this premise, as mentioned above, the second side 54, which is achieved by common processing technology, is slightly inclined so that the angle between it and the plane perpendicular to the axial direction is between 0° and 5°. Then, the first side 52 of the sealing groove 50 is characterized in that the included angle B (unit: °) between it and the bottom surface 56 satisfies the equation: B = A - (0~5) + 90, that is, B = A + (85~90). For example, as mentioned above, when angle A is in the range of 15°~30°, the corresponding angle B can be in the range of 100°~120°, preferably in the range of 100°~110°.

[0031] Depending on the actual machining conditions of the sealing groove 50, such as whether cutting fluid is not used or a different type of cutting fluid is used (i.e., different lubrication environments during machining), angle A will change based on the coefficient of friction corresponding to that actual machining condition. For example, if the coefficient of friction is 0.2 due to different lubrication conditions, angle A can be in the range of 11.3° to 30°. Similarly, if the material forming the end cap 30 is different, angle A can also change accordingly.

[0032] The above description, with reference to the accompanying drawings, illustrates a magnetic core tube assembly conforming to the principles of this application. The angle between the two sides of the sealing groove on the end cap is designed to be greater than the self-locking angle derived from the coefficient of friction between the materials forming the end cap. This effectively prevents the retention and jamming of machining debris within the sealing groove, reducing the possibility of damage to the sealing ring installed within the sealing groove during the operation of the magnetic core tube assembly. This application also relates to a solenoid valve including the aforementioned magnetic core tube assembly. In addition to including the magnetic core tube assembly, the solenoid valve may further include an electromagnetic coil arranged around a sleeve surrounding the magnetic core tube assembly and a valve body on which the magnetic core tube assembly is mounted. Under the action of the electromagnetic coil, the magnetic core tube assembly controls the movement of the valve body, thereby controlling the fluid flowing through the solenoid valve.

[0033] Those skilled in the art should understand that the figures and descriptions above are for illustrative purposes only and do not constitute any limitation on this application. Various modifications and variations of the structural details can be made by those skilled in the art without departing from the principles of this application. For example, the head 44 of the ejector pin 40 installed in the through hole 35 of the end cap 30 is not limited to the details shown in the figures; the inner end face of the head 44 may not be the plane shown, for example, it may be a concave conical surface. As another example, the sleeve 10 of the magnetic core tube assembly may be a single piece as shown in the figures, or it may be formed by connecting (e.g., welding) multiple parts. Such technical solutions also fall within the scope of this application and are protected within its protection.

Claims

1. An end cap (30) for a magnetic core tube assembly comprising a sleeve (10) defining an armature cavity configured for receiving an armature (22) of the magnetic core tube assembly and open through an opening (11), the end cap being configured for mounting to one end of the sleeve (10) in a manner extending through the opening into the armature cavity and comprising an inner end face (31) facing the armature when mounted to the sleeve (10) and a through hole (35) extending in an axial direction and configured for receiving a plunger (40) of the magnetic core tube assembly, the end cap (30) being formed with a sealing groove (50) on an inner peripheral face defining the through hole (35), the sealing groove (50) being defined by opposite first and second side faces (52, 54) and a bottom face (56) connecting the first and second side faces, the first side face (52) being closer to the inner end face (31) than the second side face (54), characterized in that, A first included angle (A) formed by the first side surface and the second side surface is greater than a self-locking angle between the material forming the end cap (30) and the same material, and a second included angle (C) formed by the second side surface (54) and the bottom surface (56) is in a range of 90° to 95°.

2. An end cap (30) for a magnetic core tube assembly according to claim 1, characterized in that The self-locking angle is calculated based on a coefficient of friction between the material forming the end cap (30) and the same material.

3. An end cap (30) for a magnetic core tube assembly according to claim 1, characterized in that The end cap (30) is a piece of steel material, the first included angle (A) is in a range of 11.3° to 30°, and / or a third included angle (B) formed by the first side surface and the bottom surface is in a range of 100° to 110°.

4. An end cap (30) for a magnetic core tube assembly according to claim 3, characterized in that The first included angle (A) is in a range of 17° to 20°.

5. An end cap (30) for a magnetic core tube assembly according to any one of claims 1-4, characterized in that, In an axial direction, the end cap (30) includes an inner portion (32) having a first outer diameter corresponding to an inner diameter of an armature cavity of the sleeve (10), a neck portion (34) having a second outer diameter corresponding to the inner diameter of the opening (11) of the sleeve and being smaller than the first outer diameter, and an outer portion (36) having a third outer diameter greater than the first outer diameter and the second outer diameter.

6. An end cap (30) for a magnetic core tube assembly according to claim 5, characterized in that The sealing groove (50) is located on the inner portion (32).

7. A magnetic core tube assembly, characterized by Comprising: An end cap (30) for a magnetic core tube assembly according to any one of claims 1-6; and the sleeve (10), the end cap being mounted to one end of the sleeve (10).

8. The magnetic core tube assembly of claim 7, wherein Further comprising: The plunger (40) is slidably disposed in the through hole (35) in an axial direction, the plunger (40) includes a rod portion (42) received in the through hole (35) and a head portion (44) extending into the armature cavity and having an outer diameter greater than an inner diameter of the through hole (35); and A seal (60) disposed in the sealing groove (50) to provide a seal between an inner surface of the end cap (30) and an outer peripheral surface of the rod portion (42).

9. The magnetic core tube assembly of claim 7, wherein, The sleeve (10) defines an inner cavity (15) including a first section (12) as the armature cavity, a second section (14) in communication with the first section (12) and having an inner diameter smaller than an inner diameter of the first section (12), and a third section (16) in communication with the second section (14) and open to an end opposite the one end, the magnetic core tube assembly further comprising an armature (22) received in the armature cavity and slidably movable, and a push rod (24) disposed through the second section (14) and slidably movable.

10. A hydraulic valve characterized by, Comprising the magnetic core tube assembly according to any one of claims 7-9. Comprising the magnetic core tube assembly according to any one of claims 7-9.

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