Metal structures for easy sealing and their sealing molds

Abstract

This utility model discloses a metal structure for easy sealing, including a ring-shaped skeleton. The upper end face of the skeleton is a first pressure-bearing surface, which is used to abut against an upper mold core for sealing. The inner sidewall of the skeleton is a second pressure-bearing surface, and the lower end of the second pressure-bearing surface abuts against a lower mold core for sealing through an interference fit. A filling area is formed between the inner side of the skeleton and the lower mold core. A sealing mold for processing the aforementioned metal structure includes an upper mold and a lower mold. The upper mold core and the lower mold core fit together to form a receiving cavity for placing the skeleton. The upper mold has an upper mold core, which has a downward pressing part on the upper side of the receiving cavity for abutting against the first pressure-bearing surface. The lower mold has a lower mold core, which has an upper and lower protruding locking part for abutting against the second pressure-bearing surface. By setting the first and second pressure-bearing surfaces, the control of two key dimensions is changed to control only one key dimension, avoiding glue overflow from the lower end of the skeleton during product molding and reducing production costs.

Description

Technical Field

[0001] This utility model relates to the field of oil seal skeleton technology, and in particular to a metal structure that is easy to seal and its sealing mold. Background Technology

[0002] As a typical example of oil seals, skeleton oil seals are mainly used for sealing rotating shafts to prevent lubricating oil leakage and the entry of external contaminants (such as dust and moisture) into mechanical equipment. Their background technology stems from the need to protect transmission components (such as bearings and shaft systems), especially to ensure long-term stable operation of equipment in high-speed rotation or harsh environments. The core background technology is analyzed below from three aspects: structure, principle, and application.

[0003] Structurally, the core structure of a skeleton oil seal consists of the seal body, a metal skeleton, and a self-tightening helical spring. The seal body includes the bottom, waist, cutting edge, and sealing lip, and is usually made of materials such as nitrile rubber. In its free state, the inner diameter is smaller than the shaft diameter (with a certain "interference fit") to ensure a tight fit to the shaft surface after installation. The metal skeleton, similar to the reinforcing bars in concrete, provides support and shape stability. According to its structure, it can be divided into internal skeleton, external skeleton, or assembled oil seal. The self-tightening helical spring is located at the rear of the sealing lip and continuously compensates for radial tension, preventing seal failure due to operational wear.

[0004] Its technical principle is based on fluid lubrication and surface tension; through oil film control, a thin oil film is formed between the sealing lip and the shaft, creating a "crescent" under the surface tension of the liquid, thus preventing media leakage; the oil film thickness needs to be moderate—too thick will lead to leakage, while too thin will cause dry friction and wear.

[0005] During installation, oil must be applied and the oil seal must be perpendicular to the shaft centerline; otherwise, the sealing lip will drain the lubricant, accelerating wear. Ideally, the lubricant will seep slightly during operation to maintain oil film balance.

[0006] Skeleton oil seals are widely used in scenarios where lubrication of components needs to be isolated, such as engine crankshafts, gearboxes, differentials, and industrial pumps.

[0007] Leakage and contamination prevention: Isolating lubrication components from output components prevents oil leakage and external impurities from entering, thereby reducing bearing wear and extending equipment life.

[0008] Performance and maintenance: In high-pressure environments (such as hydraulic pumps), the pressure-bearing capacity is limited (usually ≤1 MPa), and it needs to be used in conjunction with other sealing methods; its reliability directly affects the overall performance of the equipment, and reasonable selection needs to consider factors such as speed and temperature (such as silicone fluororubber for high-temperature environments).

[0009] Traditional metal skeleton sealing involves the metal skeleton extending to the base of the lip to form a sealing lip fixing end, used to prevent the rubber from deforming and failing under high pressure. The sealing method involves filling the glue from the sealing lip fixing end to the inside of the skeleton (wrapping the sealing lip fixing end), which is prone to glue overflow. For example, patent publication number CN 201856316U discloses a mold to prevent glue overflow from the exposed skeleton oil seal. By setting a protrusion in the upper mold to form an interference fit with the upper plane of the skeleton, and the lower mold to form an interference fit with the bottom of the skeleton, the gap is eliminated, thereby achieving the purpose of preventing rubber overflow.

[0010] However, after the rubber is sealed, it only covers the sealing lip and the fixed end of the skeleton. The sealing area between the rubber and the skeleton is small, and the connection strength between the rubber and the skeleton is weak. When the product is used in a high-speed rotating shaft, it will accelerate the separation of the rubber from the skeleton, shorten its service life, require frequent replacement, and increase the cost of use.

[0011] Traditional metal frame sealing methods involve sealing from the inner wall along the lower side of the sealing lip fixing end inwards, increasing the sealing area of ​​the frame to improve the strength and service life of the oil seal. To prevent glue overflow on the outer side of the product, the mold is designed for pressure sealing on the upper and lower surfaces of the frame. However, because the frame is machined by a metal stamping machine, the flatness of the lower surface after stamping is poor, and the height tolerance of the frame is difficult to guarantee, easily leading to glue overflow. Increased glue overflow at the frame edges can affect the outer diameter of the oil seal, causing excessive interference during press-fitting (>0.55mm), resulting in rubber tearing or frame deformation (eccentricity). To prevent glue overflow after sealing the frame with the mold, a height must be reserved for machining the lower surface to ensure the frame height and the flatness of the lower surface, thus preventing glue overflow after sealing. This process is complex, costly, and inefficient.

[0012] The above-mentioned shortcomings have become a pressing technical problem that needs to be solved. Utility Model Content

[0013] The purpose of this invention is to solve one of the above-mentioned defects and provide a metal structure and its sealing mold that are easy to seal.

[0014] The objective of this utility model is achieved through the following means:

[0015] A metal structure for easy sealing includes an annular skeleton, the upper end face of which is a first pressure-bearing surface for sealing with an upper mold core, the inner sidewall of which is a second pressure-bearing surface, and the lower end of which is sealed with a lower mold core through an interference fit. A filling area is formed between the inner side of the skeleton and the lower mold core.

[0016] As a preferred embodiment, the tolerance of the inner diameter of the skeleton is 0 to 0.05 mm.

[0017] As a preferred embodiment, the cross-section of the skeleton is inverted L-shaped.

[0018] A sealing mold for processing the aforementioned metal structure includes an upper mold and a lower mold. The upper mold core and the lower mold core are joined to form a receiving cavity for placing the skeleton. The upper mold has an upper mold core, and the upper mold core has a downward pressing part formed on the upper side of the receiving cavity for abutting against a first pressure surface. The lower mold has a lower mold core, and the lower mold core has an upper and lower protruding locking part for abutting against a second pressure surface.

[0019] As a preferred embodiment, there is a gap between the sidewall of the receiving groove and the outer sidewall of the skeleton.

[0020] As a preferred embodiment, the outer side of the engaging portion is steeply sloped, and the engaging portion engages with the second pressure surface through the steep outer slope.

[0021] As a preferred embodiment, the upper end of the mold core is provided with a glue inlet, the upper end of the lower mold core is shaped like a kettle knob, the glue inlet is continuously bent from the inside out and downward to form a glue inlet channel with the upper end of the lower mold core, the sealing lip of the skeleton is spaced apart from the lower mold core, the glue inlet channel is connected to the receiving cavity, and the pressing part is located on the side of the glue inlet channel away from the upper end of the lower mold core.

[0022] As a preferred embodiment, the sealing lip fixing end is flush with the glue inlet channel outlet.

[0023] As a preferred embodiment, the upper mold includes an upper plate, and the lower mold includes a middle plate and a lower plate. The upper plate, middle plate, and lower plate are arranged sequentially from top to bottom. The upper mold core is disposed on the upper plate, and the lower mold core is disposed on the lower plate. The middle plate is provided with a clearance groove for the lower mold core to extend upward.

[0024] As a preferred embodiment, the upper mold core is detachably mounted on the upper mold, and the lower mold core is detachably mounted on the lower mold.

[0025] The beneficial effects of this invention are as follows: By setting a first pressure surface and a second pressure surface, the control of two key dimensions is reduced to controlling only one key dimension, preventing glue overflow from the lower end of the skeleton during product molding. Simultaneously, while reducing the number of controlled dimensions, the production precision of the skeleton can be lowered, thereby reducing the manufacturing cost of the stamping die, extending the service life of the product, and preventing glue overflow after the skeleton is sealed. Furthermore, this technical solution can increase the contact area between the rubber and the skeleton, thereby strengthening their adhesion, resulting in more stable product quality and extended service life. Finally, it reduces the number of personnel required to handle glue overflow, lowering manufacturing and production costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the skeleton structure of an embodiment.

[0027] Figure 2 This is a schematic diagram of the product structure in an embodiment.

[0028] Figure 3 This is a schematic diagram of the skeleton in the mold for an embodiment.

[0029] Figure 4 for Figure 3 Enlarged view of position A in the middle

[0030] Explanation of reference numerals in the attached diagram:

[0031] 10-Skeleton; 11-First pressure-bearing surface; 12-Second pressure-bearing surface; 13-Sealing lip fixing end; 20-Mold; 21-Upper mold core; 211-Pressure fitting part; 212-Inlet; 22-Lower mold core; 221-Clamping part; 23-Upper plate; 24-Middle plate; 241-Relief groove; 25-Lower plate; 26-Accommodation cavity; 27-Inlet channel; 271-Inlet channel outlet; 28-Inlet filling area; 30-Rubber; D-Inner diameter of skeleton. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] To facilitate understanding, the present invention will now be described in further detail with reference to specific implementation examples, but this is not intended to limit the present invention.

[0034] Example 1, as Figure 1-4 As shown, a metal structure for easy sealing is disclosed, including an annular skeleton 10. The upper end surface of the skeleton 10 is a first pressure-bearing surface 11, which is used to abut against the upper mold core 21 for sealing. The inner sidewall of the skeleton 10 is a second pressure-bearing surface 12, and the lower end of the second pressure-bearing surface 12 abuts against the lower mold core 22 for sealing through an interference fit. A filling area 28 is formed between the inner side of the skeleton 10 and the lower mold core 22. By setting the first pressure-bearing surface 11 and the second pressure-bearing surface 12, the control of two key dimensions is changed to control only one key dimension, avoiding glue overflow from the lower end of the skeleton 10 during product molding. This reduces the production cost of the skeleton 10, makes the mold for producing the skeleton 10 easier to manufacture, and extends the wear life of the mold. Only the accuracy of one dimension needs to be guaranteed, without having to pay attention to the accuracy of two dimensions simultaneously.

[0035] In this embodiment, the cross-section of the skeleton 10 is an inverted L-shape (see reference). Figure 1 , Figure 2 The product requires filling the inner side of the skeleton with 30% rubber through an injection molding sealant and vulcanizing it.

[0036] To avoid deformation during pressure sealing due to an excessively small inner diameter of the skeleton 10, or to prevent the skeleton 10 from being unable to withstand pressure sealing due to an excessively large inner diameter, the tolerance of the inner diameter D of the skeleton 10 is 0 to 0.05 mm.

[0037] like Figure 3-4 As shown, a sealing mold 20 for processing the above-mentioned metal structure includes an upper mold and a lower mold. The upper mold core 21 and the lower mold core 22 are combined to form a receiving cavity 26 for placing the skeleton 10. The upper mold is provided with an upper mold core 21, and the upper mold core 21 has a downward pressing part 211 formed on the upper side of the receiving cavity 26 for abutting against the first pressure surface 11. The lower mold is provided with a lower mold core 22, and the lower mold core 22 has an upper and lower protruding locking part 221 for abutting against the second pressure surface 12.

[0038] When the engaging part 221 and the second pressure surface 12 are engaged through an interference fit, the frame 10 receives a radial force from the inside to the outside, and the outer diameter increases slightly. There is a gap between the side wall of the receiving groove and the outer wall of the frame 10, which serves to avoid the slight increase in the size of the frame 10.

[0039] In order to facilitate the engagement of the skeleton 10 and avoid damage to the skeleton 10, the outer side of the engagement part 221 is steeply sloped. The engagement part 221 engages with the second pressure surface 12 through the interference fit of the steep outer side, thereby achieving pressure sealing.

[0040] The upper end of the mold core is provided with a glue inlet 212. The upper end of the lower mold core 22 is shaped like a kettle knob. The glue inlet 212 is continuously bent from the inside out and downward to form a glue inlet channel 27 with the upper end of the lower mold core 22. The sealing lip fixing end 13 of the skeleton 10 is spaced apart from the lower mold core 22. The glue inlet channel 27 is connected to the accommodating cavity 26. The pressing part 211 is located on the side of the glue inlet channel 27 away from the upper end of the lower mold core 22.

[0041] To facilitate the handling of the sprue, the sealing lip fixed end 13 is flush with the outlet of the glue inlet channel.

[0042] In this embodiment, the upper mold includes an upper plate 23, and the lower mold includes a middle plate 24 and a lower plate 25. The upper plate 23, middle plate 24, and lower plate 25 are arranged sequentially from top to bottom. The upper mold core 21 is disposed on the upper plate 23, and the lower mold core 22 is disposed on the lower plate 25. The middle plate 24 is provided with a clearance groove 241 for the lower mold core 22 to extend upward. The upper mold core 21 is detachably mounted on the upper mold, and the lower mold core 22 is detachably mounted on the lower mold, allowing for modification according to different vulcanization models of products.

[0043] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A metal structure facilitating encapsulation comprising a ring-shaped skeleton, characterized in that, The upper surface of the skeleton is the first pressure surface, which is used to abut against the upper mold core for sealing. The inner wall of the skeleton is the second pressure surface, and the lower end of the second pressure surface abuts against the lower mold core for sealing through an interference fit. A filling area is formed between the inner side of the skeleton and the lower mold core.

2. The metal structure of claim 1, wherein, The tolerance of the inner diameter of the skeleton is 0 to 0.05 mm.

3. The metal structure of claim 1, wherein, The cross-section of the skeleton is inverted L-shaped.

4. An encapsulation mold for processing the metal structure of claim 1 or 2, characterized by, It includes an upper mold and a lower mold. The upper mold core and the lower mold core are joined to form a receiving cavity for placing the skeleton. The upper mold is provided with an upper mold core, and the upper mold core has a downward pressing part formed on the upper side of the receiving cavity for abutting against the first pressure surface. The lower mold is provided with a lower mold core, and the lower mold core has an upper and lower protruding locking part for abutting against the second pressure surface.

5. The encapsulation mold according to claim 4, wherein There is a gap between the sidewall of the accommodating cavity and the outer sidewall of the skeleton.

6. The encapsulation mold according to claim 4, wherein The outer side of the engaging part is steeply sloped, and the engaging part abuts against the second pressure surface through the steep outer slope.

7. The encapsulation mold according to claim 4, wherein The upper end of the mold core is provided with a glue inlet, and the upper end of the lower mold core is shaped like a kettle knob. The glue inlet is continuously bent from the inside out and downward to form a glue inlet channel with the upper end of the lower mold core. The sealing lip of the skeleton is spaced apart from the lower mold core. The glue inlet channel is connected to the accommodating cavity. The pressing part is located on the side of the glue inlet channel outlet away from the upper end of the lower mold core.

8. The encapsulation mold according to claim 7, wherein The sealing lip is flush with the outlet of the glue inlet channel.

9. The encapsulation mold according to claim 4, wherein The upper mold includes an upper plate, and the lower mold includes a middle plate and a lower plate. The upper plate, middle plate, and lower plate are arranged sequentially from top to bottom. The upper mold core is arranged on the upper plate, and the lower mold core is arranged on the lower plate. The middle plate is provided with a clearance groove for the lower mold core to extend upward.

10. The sealing mold according to claim 4, characterized in that, The upper mold core is detachably mounted on the upper mold, and the lower mold core is detachably mounted on the lower mold.

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