A seal structure for use in a spray gun

Abstract

The utility model discloses a kind of sealing structure for spraying gun, including gun body, gun needle, gun needle is installed in gun body, the rear end of gun needle and gun body connection is respectively provided with positioning cone seat, sealing element, positioning cone seat, sealing element both abutting end portion is respectively provided with corresponding matching inner taper surface, outer taper surface, the rod hole for gun needle to pass through is provided in the sealing element, a plurality of containing grooves are provided in the rod hole, and the rear of the plurality of containing grooves is located on the sealing element rod hole upper axial taper surface extrusion sealing high pressure area.This utility model significantly reduces the friction between gun needle and sealing element, can effectively accommodate the leakage medium between gun needle and sealing element, prevent the phenomenon of abnormal increase and jamming of friction, and also can reduce trigger force, improve user experience.

Description

Technical Field

[0001] This utility model relates to the field of spray gun sealing technology, specifically to a sealing structure for use in spray guns. Background Technology

[0002] The gun needle, installed within the gun body, is a crucial component for controlling the operation of the spray gun. During use, the gun needle moves relative to the gun body, therefore a sealing structure is installed between the rear end of the gun needle and the gun body. Existing gun needle sealing structures have the following drawbacks: 1. Excessive frictional resistance during gun needle movement: Existing structures employ conical extrusion seals. The inner bore of the conical extrusion seal is typically a smooth cylindrical surface or a simple chamfer, forming a continuous and tight line or surface contact with the outer surface of the gun needle. Under high pressure, there is a large contact area and friction between the inner bore of the seal and the outer surface of the gun needle. This requires the operator to apply a large trigger force to open or close the spray gun, which can easily cause hand fatigue and reduce user experience over time. 2. Accumulation of leaking media leading to jamming failure: During long-term use of the spray gun, even with good sealing performance, trace amounts of high-pressure paint leakage or environmental contaminants can still enter the gap between the seal and the gun needle. The narrow gap between the inner hole of the seal and the nozzle lacks effective space for contamination and slag removal. These viscous coatings or contaminants continuously accumulate, solidify, and build up in the contact area between the reciprocating nozzle surface and the inner hole of the seal, significantly increasing the frictional resistance of the nozzle movement and even causing it to jam. This ultimately leads to nozzle seal failure and premature nozzle failure. The combined effect of these drawbacks makes operation laborious, and results in a high failure rate and shortened service life due to sealing problems. Therefore, it is essential to improve the existing structural design to address these defects. Summary of the Invention

[0003] The purpose of this invention is to solve the problems mentioned in the background art and provide a sealing structure for use in a spray gun.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows: a sealing structure for a spray gun, including a gun body and a gun needle, the gun needle being installed in the gun body, and a positioning cone seat and a sealing element being respectively provided at the rear end where the gun needle is connected to the gun body. The positioning cone seat and the sealing element are respectively provided with corresponding inner and outer conical surfaces at their abutting ends. The sealing element is provided with a rod hole for the gun needle to pass through, and multiple receiving grooves are provided in the rod hole. The multiple receiving grooves are located behind the high-pressure sealing area of ​​the axial conical surface on the rod hole of the sealing element.

[0005] In the aforementioned sealing structure for a spray gun, the midpoint M of the outer conical surface of the seal has a straight line L2 perpendicular to the central axis L1 of the rod hole and a straight line L3 parallel to the central axis L1 of the rod hole. The end point N of the seal has a straight line L4 perpendicular to the central axis L1 of the rod hole. The outer conical surface of the seal is divided into a high-pressure sealing zone, a medium-pressure sealing zone, and a low-pressure sealing zone by the intersection of L2, L3, and L4. One of the multiple receiving grooves is located in the medium-pressure sealing zone.

[0006] In the aforementioned sealing structure for a spray gun, the receiving groove within the sealing pressure zone is located in the middle position.

[0007] In the aforementioned sealing structure for a spray gun, the depth of the plurality of receiving grooves is less than the distance D between the straight line L3 and the inner wall of the rod hole.

[0008] In the sealing structure described above for use in a spray gun, the two side walls of the receiving groove are designed perpendicularly to the bottom of the groove.

[0009] In the aforementioned sealing structure for a spray gun, the receiving groove is rectangular or square in shape.

[0010] In the aforementioned sealing structure for a spray gun, the receiving groove is an annular groove design.

[0011] In the aforementioned sealing structure for a spray gun, the sealing element is provided with an auxiliary sealing groove, and a sealing ring is provided in the auxiliary sealing groove. The sealing ring and the receiving groove are respectively located on both sides of the straight line L3.

[0012] This utility model has the following beneficial effects: Significantly reduced friction: A receiving groove is designed in the non-sealing critical area of ​​the conical surface inside the rod hole of the seal (i.e. behind the high-pressure area of ​​the conical extrusion seal). The designed receiving groove directly interrupts the originally smooth inner wall of the rod hole of the seal, significantly reducing the actual contact length (area) between the rod hole of the seal and the outer cylindrical surface of the needle. The contact of the seal is limited to the conical sealing area at the front end of multiple receiving grooves and the very small part at the rear end of the grooves. The reduction in contact area directly leads to a reduction in sliding friction.

[0013] Effective containment of leaking media: Multiple containment grooves create cavities in the rod bore within the seal. Any trace amounts of paint or contaminants leaking from the front sealing cone area are carried in and temporarily contained within the containment grooves during the reciprocating motion of the needle. The presence of these grooves prevents the media from continuing to flow backward or remaining in the critical sealing contact area.

[0014] Preventing abnormal friction increase and jamming: Since the leaking medium is contained in the receiving groove, rather than accumulating in the narrow sliding gap between the sealing rod hole wall and the needle, abnormal increase in frictional resistance and needle jamming caused by medium accumulation and solidification are avoided.

[0015] Reduced trigger force and improved user experience: Reduced friction directly translates to a reduction in the trigger force required to open the spray gun needle. Operators can control the spray gun more easily, reducing hand fatigue and significantly improving the comfort and efficiency of spraying operations.

[0016] Improve spray gun reliability and lifespan: By preventing jamming caused by leaking media, the risk of sealing structure failure due to abnormally increased friction is greatly reduced, thereby improving the overall reliability and lifespan of the spray gun and reducing maintenance costs and downtime.

[0017] Simple structure and easy to implement: The machining of the receiving groove is a conventional machining process that can be easily implemented in the existing seal manufacturing process. It does not require complicated additional parts or assembly steps, and the cost increase is minimal, but it brings significant performance improvement. Attached Figure Description

[0018] Figure 1 This is a cross-sectional structural diagram of the present invention; Figure 2 yes Figure 1 Enlarged view of section A in the middle; Figure 3 This is a cross-sectional structural diagram of the sealing element in this utility model. Detailed Implementation

[0019] The present invention will be further described in conjunction with the accompanying drawings.

[0020] Please see Figures 1 to 3 This utility model provides a sealing structure for a spray gun, including a gun body 1 and a gun needle 2. The gun needle 2 is installed in the gun body 1. The rear end of the gun needle 2 connected to the gun body 1 is respectively provided with a positioning cone seat 3 and a sealing element 4. The abutting ends of the positioning cone seat 3 and the sealing element 4 are respectively provided with corresponding inner conical surfaces 5 and outer conical surfaces 6. The sealing element 4 is provided with a rod hole 7 for the gun needle 2 to pass through. The rod hole 7 is provided with a plurality of receiving grooves 8. The plurality of receiving grooves 8 are located behind the axial conical surface compression sealing high pressure area on the rod hole 7 of the sealing element 4.

[0021] Furthermore, the midpoint M of the outer conical surface 6 of the seal 4 has a straight line L2 perpendicular to the central axis L1 of the rod hole 7 and a straight line L3 parallel to the central axis L1 of the rod hole 7. The endpoint N of the seal 4 has a straight line L4 perpendicular to the central axis L1 of the rod hole 7. The outer conical surface 6 of the seal 4 is divided into a high-pressure sealing zone 9, a medium-pressure sealing zone 10, and a low-pressure sealing zone 11 by the intersection of L2, L3, and L4. One of the multiple receiving grooves 8 is located in the medium-pressure sealing zone 10. Preferably, the receiving groove 8 in the medium-pressure sealing zone 10 is located in the middle position. This design ensures that the receiving groove itself does not participate in the main sealing function.

[0022] Furthermore, the depth of the plurality of receiving grooves 8 is less than the distance D between the straight line L3 and the inner wall of the rod hole 7. The design of the receiving grooves ensures the structural strength of the seal.

[0023] Furthermore, the two side walls of the receiving groove 8 are designed perpendicularly to the bottom of the groove. Preferably, the receiving groove 8 is rectangular or square. The two side walls and the bottom of the receiving groove 8 can also be designed with slightly rounded corners, but the core is to form a clearly defined cavity rather than a guide slope.

[0024] Furthermore, the receiving groove 8 is an annular groove design. It can also be a partial groove, but the annular groove provides a more uniform and reliable effect.

[0025] Furthermore, in order to ensure the sealing effect of the sealing element installation, the sealing element 4 is provided with an auxiliary sealing groove 13, and a sealing ring 14 is provided in the auxiliary sealing groove. The sealing ring 14 and the receiving groove 8 are respectively located on both sides of the straight line L3.

[0026] When a small amount of high-pressure coating inevitably leaks through the conical sealing area at the front of the seal: the leaking coating is pushed backward with the reciprocating motion of the needle (especially the retraction motion). The receiving groove provides a low-resistance, relatively large space where the leaking coating is scraped or carried into the receiving groove. The presence of the receiving groove prevents these viscous media from continuing to diffuse backward along the narrow gap between the needle and the inner wall of the seal. Of the media contained in the receiving groove, some may be carried out of the receiving groove by the needle during subsequent needle movements (e.g., carried forward when moving towards the nozzle), while the rest is temporarily stored. Crucially, this prevents its continuous accumulation and solidification in the critical sliding contact area (the area between the front and rear ends of multiple receiving grooves).

[0027] Since the leakage medium is mainly contained within the receiving groove, and the gap between the receiving groove and the needle is relatively large (compared to the tight gap without a groove), even if a small amount of medium is stored in the receiving groove, the additional frictional resistance it causes to the movement of the needle is very limited, far lower than the "abrasive paste" effect formed by the medium solidifying in the narrow gap. This effectively prevents a sharp increase in frictional resistance and needle jamming caused by medium accumulation.

[0028] The above provides a detailed description of a sealing structure for a spray gun provided by the embodiments of this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the technical solution disclosed in this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A sealing structure for use in a spray gun, comprising a gun body (1) and a gun needle (2), the gun needle (2) being installed in the gun body (1), characterized in that: The rear end of the gun needle (2) connected to the gun body (1) is provided with a positioning cone seat (3) and a sealing element (4). The abutting ends of the positioning cone seat (3) and the sealing element (4) are respectively provided with corresponding inner cone surface (5) and outer cone surface (6). The sealing element (4) is provided with a rod hole (7) for the gun needle (2) to pass through. The rod hole (7) is provided with multiple receiving grooves (8). The multiple receiving grooves (8) are located behind the axial cone surface compression sealing high pressure area on the rod hole (7) of the sealing element (4).

2. A sealing structure for a spray gun according to claim 1, characterized in that: The outer conical surface (6) of the seal (4) has a straight line L2 perpendicular to the central axis L1 of the rod hole (7) and a straight line L3 parallel to the central axis L1 of the rod hole, respectively. The end point N of the seal (4) has a straight line L4 perpendicular to the central axis L1 of the rod hole (7). The outer conical surface (6) of the seal (4) is divided into a high-pressure sealing zone (9), a medium-pressure sealing zone (10), and a low-pressure sealing zone (11) by the intersection of L2, L3, and L4. One of the multiple receiving grooves (8) is located in the medium-pressure sealing zone (10).

3. A sealing structure for a spray gun according to claim 2, characterized in that: The receiving groove (8) in the sealed medium pressure zone (10) is located in the middle position.

4. A sealing structure for a spray gun according to claim 2, characterized in that: The depth of the plurality of receiving grooves (8) is less than the distance D between the straight line L3 and the inner wall of the rod hole (7).

5. A sealing structure for a spray gun according to any one of claims 1 to 4, characterized in that: The two sides of the receiving groove (8) are designed to be perpendicular to the bottom of the groove.

6. A sealing structure for a spray gun according to claim 5, characterized in that: The receiving groove (8) is rectangular or square in shape.

7. A sealing structure for a spray gun according to claim 5, characterized in that: The receiving groove (8) is an annular groove design.

8. A sealing structure for a spray gun according to claim 2, characterized in that: An auxiliary sealing groove (13) is provided on the sealing element (4), and a sealing ring (14) is provided in the auxiliary sealing groove. The sealing ring (14) and the receiving groove (8) are respectively located on both sides of the straight line L3.

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