Bushing partition sealing structure and engine

Abstract

The utility model relates to the technical field of engine sealing, in particular to a lining partition sealing structure and an engine. A first sealing area and a second sealing area are arranged on the outer circle of the lining, the first sealing area and the second sealing area are adjacently arranged in the axial direction of the lining, and the first sealing area is located at the inner end of the lining. The outer circle of the lining of the first sealing area is in interference fit with a bottom hole of the cylinder cover, the diameter of the outer circle of the lining of the second sealing area is smaller than that of the outer circle of the first sealing area, a protruding edge is arranged on the outer circle of the lining of the second sealing area, and the second sealing area is provided with a vulcanized rubber layer. And the excircle diameter of the vulcanized rubber layer in a normal state is greater than the excircle diameter of the bushing in the first sealing area. According to the utility model, the problem of sealing failure of the inner end of the spark plug bushing and the cylinder cover at high temperature in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of engine sealing, in particular to a bushing partition sealing structure and an engine. Background Art

[0002] In an engine of an automobile or other internal combustion engine, the sealing performance between a spark plug bushing and a cylinder head is crucial for the normal operation of the engine. The function of the spark plug bushing is to protect the spark plug, and at the same time ensure the seal between the cylinder head and the spark plug to prevent leakage of coolant, oil or gas.

[0003] In the existing technology, the small end (inner end) of the spark plug bushing and the cylinder head are usually connected by an interference fit, and then the seal is achieved through the interference fit. This design can ensure the sealing performance to a certain extent, but during the operation of the engine, due to the increase in temperature, the thermal expansion coefficients of the bushing and the cylinder head materials are different, resulting in the failure of the interference fit seal between the bushing and the cylinder head, and then causing faults such as water leakage, oil leakage or gas leakage. For the conventional O-ring sealing method, the O-ring is first installed in the sealing groove and then the bushing is assembled with the cylinder head. Since the O-ring can move in the sealing groove, during the assembly process, the O-ring is flipped, twisted or even squeezed and damaged in the groove due to the combined extrusion of the side wall of the bottom hole of the cylinder head and the bushing, resulting in seal failure. Therefore, the conventional O-ring seal cannot achieve a good sealing effect in this scenario. Summary of the Utility Model

[0004] Aiming at the deficiencies of the existing technology, the purpose of the embodiments of the present utility model is to provide a bushing partition sealing structure and an engine to solve the problem of seal failure between the inner end of the spark plug bushing and the cylinder head at high temperature in the existing technology.

[0005] In order to achieve the above purpose, the embodiments of the present utility model provide the following technical solutions:

[0006] A bushing partition sealing structure for sealing with a cylinder head, the outer circle of the bushing is provided with a first sealing area and a second sealing area, the first sealing area and the second sealing area are arranged adjacent to each other along the axial direction of the bushing, wherein the first sealing area is located at the inner end of the bushing; the outer circle of the bushing in the first sealing area is in interference fit with the bottom hole of the cylinder head, the outer circle diameter of the bushing in the second sealing area is smaller than the outer circle diameter of the first sealing area, a convex rib is provided on the outer circle of the bushing in the second sealing area, a vulcanized rubber layer is provided in the second sealing area, and the outer circle diameter of the vulcanized rubber layer in the normal state is larger than the outer circle diameter of the bushing in the first sealing area.

[0007] Optionally, the convex rib is arranged in a spiral shape on the outer circle of the bushing in the second sealing area, and the angle between the convex rib and the outer circle generatrix is 30 degrees to 60 degrees.

[0008] Optionally, the difference between the outer diameter of the vulcanized rubber layer under normal conditions and the outer diameter of the bushing in the first sealing area is 0.2 mm - 0.5 mm.

[0009] Optionally, the outer contour surface of the vulcanized rubber layer is a smooth cylindrical surface.

[0010] Optionally, the outer contour surface of the vulcanized rubber layer is a wavy contour surface composed of triangular protrusions.

[0011] Optionally, the outer contour surface of the vulcanized rubber layer is a serrated contour surface composed of triangular protrusions, and the triangular protrusions of the serrated contour surface are larger than those of the wavy contour surface.

[0012] Optionally, the outer contour surface of the vulcanized rubber layer is a concave contour surface, and both ends of the concave contour surface protrude along the axial direction while the middle is concave.

[0013] An embodiment of the present invention also provides an engine, which includes a cylinder head, a bushing, and a spark plug. The bushing is inserted into the cylinder head, and the spark plug is inserted into the bushing. Among them, the inner end of the outer circle of the bushing is provided with the bushing partition sealing structure as described above.

[0014] Optionally, the outer end of the outer circle of the bushing is in clearance fit with the cylinder head and is sealed with an O-ring.

[0015] Optionally, a sealing groove is provided on the bottom hole of the cylinder head, the O-ring is installed in the sealing groove, and the inner diameter of the O-ring is crimped on the outer circle of the bushing.

[0016] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0017] In this partition sealing structure, the first sealing area is an interference sealing area to ensure the sealing effect at normal temperature, and the second sealing area is a rubber sealing area to ensure the sealing effect when the engine temperature rises, even after permanent deformation of the bushing and the cylinder head. The interference sealing and rubber elastic sealing are combined through the first sealing area at the end and the adjacent second sealing area. Compared with the existing sealing methods, the partition sealing structure of the present invention can provide effective sealing under both normal temperature and high temperature conditions of the engine. Even when permanent deformation occurs to the bushing and the cylinder head, it can effectively prevent the failure of the full sealing section, thereby ensuring the sealing performance of the engine under various working conditions, avoiding faults such as water leakage, oil leakage, or air leakage, and improving the reliability and service life of the engine.

[0018] The advantages of the additional aspects of the present invention will be given in the following description, some of which will become obvious from the following description, or will be understood through the practice of the present invention. Description of the Drawings

[0019] The attached drawings of the specification, which form a part of the present utility model, are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In addition, the distances or dimensions between each part are exaggerated for showing the positions of each part, and the schematic drawings are only for illustration purposes.

[0020] Figure 1 is a schematic diagram of the existing bushing and cylinder head sealing structure;

[0021] Figure 2 is a schematic diagram of the bushing and cylinder head sealing structure provided by the embodiment of the present utility model;

[0022] Figure 3 is a schematic diagram of the partition sealing structure provided by the embodiment of the present utility model;

[0023] Figure 4 is a schematic diagram of the convex rib provided by the embodiment of the present utility model;

[0024] Figure 5 is a schematic diagram of the surface of the vulcanized rubber provided by the embodiment of the present utility model;

[0025] In the figure: 1. Cylinder head; 2. Bushing; 21. Convex rib; 3. O-ring; 4. Partition sealing structure; 41. First sealing area; 42. Second sealing area; Detailed implementation manners

[0026] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present utility model. Unless otherwise specified, all technical and scientific terms used in the present utility model have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] As introduced in the background art, in the existing technical solution, the spark plug bushing and the cylinder head are in interference fit and are rigidly connected. In general design, there are differences in the materials of the bushing and the cylinder head. During the operation of the engine, as the temperature rises, due to the different thermal expansion coefficients of the two, when the engine temperature exceeds the allowable temperature of the two, irreversible permanent deformation occurs, resulting in the interference failure between the spark plug bushing and the cylinder head, and leakage faults such as water leakage, oil leakage, and air leakage occur, seriously affecting the normal operation of the engine.

[0028] Such as Figure 1As shown, the small end (inner end, i.e., the bottom in the figure) of the bushing 2 and the cylinder head 1 are usually in interference fit. The diameter tolerance of the small end is larger than the bottom hole of the cylinder head 1. If the O-ring sealing method is adopted, the sealing groove is set on the bushing 2. The installation steps are that the O-ring is first installed into the sealing groove of the bushing 2, and then the bushing 2 and the O-ring are assembled with the cylinder head 1. During this process, due to the combined extrusion of the side wall of the bottom hole of the cylinder head 1 and the bushing 2, the O-ring is turned over, distorted or even extruded and damaged in the groove, resulting in failure during use.

[0029] Therefore, the main problems existing in the prior art are: the interference fit between the spark plug bushing 2 and the cylinder head 1 is prone to failure at high temperatures, resulting in a decrease in sealing performance, seriously affecting the normal operation of the engine, and may lead to more serious mechanical failures. And the conventional O-ring sealing method cannot achieve good sealing effects in this scenario.

[0030] In order to solve the above technical problems, the present utility model proposes a bushing partition sealing structure 4, which solves the problem of sealing failure between the spark plug bushing 2 and the cylinder head 1 at high temperatures through innovative design.

[0031] As Figure 2 、 Figure 3 As shown, the outer circle of the bushing 2 is provided with a first sealing area 41 and a second sealing area 42. The first sealing area 41 and the second sealing area 42 are arranged adjacent to each other along the axial direction of the bushing 2, wherein the first sealing area 41 is located at the inner end of the bushing 2; the outer circle of the bushing 2 in the first sealing area 41 is in interference fit with the bottom hole of the cylinder head 1. The outer circle diameter of the bushing 2 in the second sealing area 42 is smaller than the outer circle diameter of the first sealing area 41. A convex rib 21 is provided on the outer circle of the bushing 2 in the second sealing area 42. The second sealing area 42 is provided with a vulcanized rubber layer, and the vulcanized rubber layer is connected to the bushing 2 by vulcanization. The outer circle diameter of the vulcanized rubber layer in the normal state is larger than the outer circle diameter of the bushing 2 in the first sealing area 41.

[0032] This embodiment relates to a bushing partition sealing structure 4 for sealing with the cylinder head 1. Two adjacent sealing areas are arranged along the axial direction on the outer circle of the bushing 2: the first sealing area 41 and the second sealing area 42. The first sealing area 41 is located at the inner end of the bushing 2 and forms an interference fit with the inner wall of the bottom hole of the cylinder head 1. This interference fit is achieved by designing the outer circle diameter of the bushing 2 to be slightly larger (about 0.07 mm) than the diameter of the bottom hole of the cylinder head 1 to ensure efficient sealing at normal temperature. Due to the design of the interference fit, the first sealing area 41 can prevent air leakage, oil leakage, water leakage, etc. from occurring at normal temperature.

[0033] The second sealing area 42 is located on the axial side of the first sealing area 41, and its outer diameter is smaller than that of the first sealing area 41. To cope with the permanent deformation that may occur under the high-temperature conditions of the engine, a rib 21 structure is designed on the outer circle of the second sealing area 42, and a vulcanized rubber layer is coated. The outer diameter of the vulcanized rubber layer under normal conditions is larger than that of the first sealing area 41, which can effectively fill the gap between the cylinder head 1 and the bushing 2 caused by the high-temperature deformation of the engine, so as to continue to provide a sealing function. Vulcanized rubber has good elasticity and high-temperature resistance, and can continue to play a sealing role after the permanent deformation of the bushing 2 and the cylinder head 1, thus avoiding the occurrence of "three leakage failures".

[0034] Through the design of partition sealing, this structure can provide effective sealing under both normal and high-temperature conditions of the engine. Even when the bushing 2 and the cylinder head 1 undergo permanent deformation, it can effectively prevent the failure of the fully sealed section, thus ensuring the sealing performance of the engine under various working conditions, avoiding failures such as water leakage, oil leakage or air leakage, and improving the reliability and service life of the engine.

[0035] The overall sealing area height of the bushing 2 is H, and the heights of the rubber sealing area (the second sealing area 42) and the interference sealing area (the first sealing area 41) are H1 and H2 respectively. The ratio of H1 to H2 can be adjusted according to the interference requirements of the bushing 2.

[0036] As Figure 4 shown, in this embodiment, the ribs 21 of the second sealing area 42 are arranged in a spiral shape, and the angle range between the spiral ribs 21 and the outer circle generatrix of the bushing 2 is 30 degrees to 60 degrees. The spiral arrangement of the ribs 21 strengthens the vulcanization strength of the rubber, thus ensuring the sealing performance of the rubber sealing area.

[0037] The difference between the outer diameter of the vulcanized rubber layer under normal conditions and the outer diameter of the bushing 2 of the first sealing area 41 is 0.2 mm - 0.5 mm. This design ensures that during the operation of the engine, when the temperature rises and causes thermal expansion and deformation of the cylinder head 1 and the bushing 2, the vulcanized rubber layer can use its elasticity to fill the gap generated by the deformation, ensuring that there are no failures such as water leakage, oil leakage or air leakage. At the same time, this diameter difference range avoids damage due to excessive extrusion during the reassembly process and the use process, and extends the service life of the sealing structure while ensuring sealing.

[0038] The outer contour surface structure of the vulcanized rubber layer can be designed with various structures, such as Figure 5 shown, from right to left are smooth shape, wavy shape, serrated shape and concave shape respectively.

[0039] The outer contour surface of the vulcanized rubber layer is a smooth cylindrical surface. This structural design is simple and the manufacturing process is relatively convenient. It is suitable for use under working conditions with relatively small temperature changes or mild deformations. The design of the smooth cylindrical surface enables the vulcanized rubber layer to better contact the inner wall of the cylinder head 1, thereby providing a uniform sealing effect. This structure can provide sufficient sealing pressure at room temperature and performs stably during the normal operation of the engine. It is suitable for application scenarios that do not require a large deformation absorption capacity.

[0040] The outer contour surface of the vulcanized rubber layer is a wavy contour surface composed of triangular protrusions. The design of the wavy contour surface increases the contact area between the vulcanized rubber layer and the inner wall of the cylinder head 1, enhancing its sealing ability under high temperature and high pressure.

[0041] The outer contour surface of the vulcanized rubber layer is a serrated contour surface composed of triangular protrusions, and the triangular protrusions of the serrated shape are larger than those of the wavy shape. The serrated contour surface further enhances the compression resistance of the vulcanized rubber and is suitable for scenarios with relatively high temperatures and pressures inside the engine. When the temperature changes drastically or the interference fit fails, the larger triangular protrusions of the serrated contour surface can withstand greater deformations, ensuring an effective sealing effect under extreme working conditions.

[0042] The outer contour surface of the vulcanized rubber layer is a concave contour surface. The two ends of the concave contour surface protrude along the axial direction, and the middle is concave. The design of the concave contour surface can provide additional volume change space. The concave design enables the rubber layer to undergo a certain degree of controllable deformation under pressure, and its concave structure can absorb and relieve the extrusion effect of the external pressure on the rubber layer, effectively avoiding excessive deformation and failure of the rubber layer, and ensuring the stability and reliability of the sealing performance.

[0043] In this embodiment, 4 types of rubber surface structures are proposed. Different structures are applied according to different temperatures inside the engine cylinder. The serrated, wavy, concave, and smooth structures are used in sequence from high to low engine temperatures. At high engine temperatures, after the cylinder head 1 deforms, the bottom hole of the bushing 2 deforms. The larger the irregularity of the rubber surface structure, the better the deformation resistance and the better the sealing effect.

[0044] Based on the above partitioned sealing structure 4, this embodiment also provides an engine. The engine includes a cylinder head 1, a bushing 2, and a spark plug. The bushing 2 is inserted into the cylinder head 1, and the spark plug is inserted into the bushing 2. Among them, the above-mentioned bushing partitioned sealing structure 4 is provided at the inner end of the outer circle of the bushing 2.

[0045] The outer end of the outer circle of the bushing 2 is in clearance fit with the cylinder head 1 and is sealed with an O-ring 3. The clearance fit makes it easier to install and remove the bushing 2, while the O-ring 3 is responsible for providing further sealing effect after installation. The O-ring 3 can form a sealing barrier between the bushing 2 and the cylinder head 1 to prevent external contaminants from entering the engine. By using the O-ring 3, not only the installation process of the bushing 2 is simplified, but also the sealing performance of the entire engine is improved.

[0046] In this embodiment, a sealing groove is designed on the bottom hole of the cylinder head 1 to accommodate the O-ring 3. The inner diameter of the O-ring 3 is pressed on the outer circle of the bushing 2 to ensure the sealing effect between the bushing 2 and the cylinder head 1, ensuring the normal operation of the engine for a long time.

[0047] Although the above describes the specific implementation methods of the utility model in conjunction with the accompanying drawings, it is not intended to limit the protection scope of the utility model. Technical personnel in the relevant field should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the protection scope of the utility model.

Claims

1. A bushing partition sealing structure, used for sealing with a cylinder head, characterized in that: The outer circle of the bushing is provided with a first sealing area and a second sealing area, the first sealing area and the second sealing area are arranged adjacent to each other along the axial direction of the bushing, wherein the first sealing area is located at the inner end of the bushing; The outer circle of the bushing in the first sealing area is interference fit with the bottom hole of the cylinder head, the outer circle diameter of the bushing in the second sealing area is smaller than the outer circle diameter of the first sealing area, a convex ridge is arranged on the outer circle of the bushing in the second sealing area, the second sealing area is provided with a vulcanized rubber layer, and the outer circle diameter of the vulcanized rubber layer under normal conditions is larger than the outer circle diameter of the bushing in the first sealing area.

2. The bushing partition sealing structure according to claim 1, characterized in that: The convex ridge is spirally arranged on the outer circle of the bushing in the second sealing area, and the angle between the convex ridge and the generatrix of the outer circle is 30 degrees to 60 degrees.

3. The bushing partition sealing structure according to claim 1, characterized in that: The difference between the outer diameter of the vulcanized rubber layer under normal conditions and the outer diameter of the bushing in the first sealing area is 0.2 mm to 0.5 mm.

4. The bushing partition sealing structure according to claim 1, characterized in that: The outer contour surface of the vulcanized rubber layer is a smooth cylindrical surface.

5. The bushing partition sealing structure according to claim 1, characterized in that: The outer contour surface of the vulcanized rubber layer is a wavy contour surface composed of triangular protrusions.

6. The bushing partition sealing structure according to claim 5, characterized in that: The outer contour surface of the vulcanized rubber layer is a sawtooth contour surface composed of triangular protrusions, and the triangular protrusions of the sawtooth contour surface are larger than the triangular protrusions of the wavy contour surface.

7. The bushing partition sealing structure according to claim 1, characterized in that: The outer contour surface of the vulcanized rubber layer is an inner concave contour surface, and the inner concave contour surface is convex at both ends along the axial direction and concave in the middle.

8. An engine, characterized in that: The engine comprises a cylinder head, a bushing and a spark plug, wherein the bushing is inserted in the cylinder head, and the spark plug is inserted in the bushing, wherein the outer circle inner end of the bushing is provided with a bushing partition sealing structure as described in any one of claims 1-7.

9. The engine according to claim 8, characterized in that The outer end of the outer circle of the bushing is matched with the cylinder head in a clearance and is sealed by an O-ring.

10. The engine according to claim 9, characterized in that A sealing groove is arranged on the bottom hole of the cylinder cover, the O-ring is installed in the sealing groove, and the inner diameter of the O-ring is pressed onto the outer circle of the bushing.

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