Stamping bush structure for embedding injection molding and composite injection molding part
By designing through holes and fan grooves in the bushing structure of the injection molded parts, the problem of difficult to improve the concave and convex bite form between the bushing and the plastic parts is solved, and a strong circumferential loosening resistance and the effect of reducing production costs is achieved.
Patent Information
- Application Number
- CN202510320190.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-05-30
AI Technical Summary
In existing injection molded parts, the concave and convex biting form between the bushing and the plastic parts is difficult to effectively improve under the requirements of high structural strength and loosening resistance, and cracking problems are prone to occur.
A stamped bushing structure for infiltration molding is designed, including through holes and a sector groove. The inner wall of the sector groove includes the bottom surface of the groove, the side elevation of the groove and the curved surface of the groove, which allows molten plastic to enter and enhance the bite force between the bushing and the plastic part.
The design provides a strong circumferential resistance to loosening, reduces the possibility of cracking in the concave and convex bite parts of the bushing and plastic parts, is suitable for stamping, reduces production costs and improves efficiency.
Smart Images
Figure CN120062220A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of stamping bushings, and particularly to a stamping bushing structure and a composite injection molded part for insert injection molding. Background Art
[0002] Some injection molded parts need to be pre-embedded with bushings, generally metal bushings. The actual functions of the bushings are numerous. The metal bushings can be used as screw holes or wire harness installation holes. Since the bushing and the injection molded part body are made of two materials, the actual firmness between the two has always been one of the key concerns in this field, and it is necessary to ensure the anti-loosening ability of the bushing and the injection molded part body in all mechanical freedom directions.
[0003] As Figure 1 shown, it is a bushing obtained by means of a stamping process known to the inventor. Figure 1 The characteristic of the bushing in [[ ]] is that there are radially penetrating holes between its inner wall and outer wall. These holes can allow molten plastic to enter. After solidification, the bushing and the plastic part body can bite with each other, and have a certain structural firmness.
[0004] As Figure 2 shown, it is another bushing obtained by a machining process known to the inventor. Figure 2 The characteristic of the bushing in [[ ]] is that the outer wall has at least one circle of tooth-shaped structures, similar to a gear ring. The molten plastic and these teeth achieve concave-convex biting, and the structural firmness can also be improved after solidification, especially the anti-rotation loosening ability along the circumferential direction.
[0005] The above bushing structure designs can all improve the structural strength to a certain extent, but the situation where the concave-convex biting part of the plastic part and the bushing cracks often occurs. That is to say, in occasions with higher requirements for structural strength and anti-loosening ability, the concave-convex biting form of the bushing and the plastic part needs to be further improved. Summary of the Invention
[0006] The problem to be solved by the present invention is to provide a stamping bushing structure and a composite injection molded part for insert injection molding, in which the bushing part and the injection molded plastic part are concavo-convexly fitted, and can provide a strong circumferential anti-loosening ability. The bushing part is easy to be formed by stamping, and the concave-convex biting part of the bushing part and the plastic part is not easy to crack.
[0007] To solve the above problems, the present invention provides a stamping bushing structure and a composite injection molded part for insert injection molding. To achieve the above object, the technical solution adopted by the present invention to solve its technical problems is:
[0008] A stamping bushing structure for insert molding, comprising: a through hole axially penetrating both ends of the bushing; a sector groove recessed at the junction of the outer circumferential surface of the bushing and the shaft end face, and a plurality of sector grooves are annularly arrayed at each shaft end of the bushing; wherein, the inner wall of each sector groove includes a groove bottom surface, two groove side vertical surfaces, and a groove back curved surface, and the two groove side vertical surfaces are symmetrically arranged in the sector groove where they are located; the sector groove can allow molten plastic to enter.
[0009] As a further improvement of the present invention, the groove bottom surface is perpendicular to the axis of the bushing, the groove side vertical surface coincides with or is parallel to the axis of the bushing, the groove back curved surface is a convex curved surface, and the axis corresponding to the groove back curved surface coincides with the axis of the bushing.
[0010] As a further improvement of the present invention, the groove side vertical surface is parallel to the axis of the bushing, and there is an intersection in the extension of the two groove side vertical surfaces of the same sector groove, and the radial distance from the sector groove to the intersection is longer than the radial distance from the sector groove to the axis of the bushing.
[0011] As a further improvement of the present invention, the recessed depth of the sector groove in the radial direction is 0.3 to 0.5 of the wall thickness of the bushing.
[0012] As a further improvement of the present invention, from the axial perspective of the bushing, the sector angle range of a single sector groove is 35° to 45°.
[0013] As a further improvement of the present invention, the number of sector grooves at each shaft end of the bushing is four.
[0014] A composite injection molded part, comprising the stamping bushing structure for insert molding as described in any one of the above, including: a bushing; a plastic part in contact with the bushing except at the shaft end, and the plastic part has a convex block located in the sector groove, and the sector groove and the convex block are in concave-convex fit with each other.
[0015] As a further improvement of the present invention, one side of the plastic part has a raised circular rib, the circular rib surrounds the bushing, the top of the circular rib is flush with the adjacent shaft end of the bushing, and the side of the circular rib facing away from the bushing in the radial direction has a slope, and the slope makes the radial thickness of the circular rib gradually wider from the top to the root.
[0016] As a further improvement of the present invention, one end of the bushing protrudes from one side of the plastic part and forms a shaft convex part, and the protruding end of the bushing and the circular rib are respectively located on the front and back sides of the plastic part.
[0017] As a further improvement of the present invention, the bushing is a metal part with a structural strength greater than that of the plastic part.
[0018] The beneficial effects of the stamping bushing structure and the composite injection molded part for insert injection molding of the present application are as follows: The bushing component and the plastic part after injection molding are concavo-convexly fitted, and the fan-shaped grooves can bite the plastic part, providing a strong circumferential anti-loosening ability. At the same time, the position and shape of a single fan-shaped groove facilitate the direct stamping and processing of the bushing component during manufacturing. In addition, the volume of the plastic wrapped in the fan-shaped groove can be relatively large, and the concavo-convex engagement part between the bushing component and the plastic part is not easily cracked. Brief Description of the Drawings
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0020] Figure 1 is a perspective view of the first embodiment of the bushing;
[0021] Figure 2 is a perspective view of the second embodiment of the bushing;
[0022] Figure 3 is a front view of an embodiment of the stamping bushing structure for insert injection molding of the present invention;
[0023] Figure 4 is a top view of an embodiment of the stamping bushing structure for insert injection molding of the present invention;
[0024] Figure 5 is an A-A cross-sectional view of an embodiment of the stamping bushing structure for insert injection molding of the present invention;
[0025] Figure 6 is a B-B cross-sectional view of an embodiment of the stamping bushing structure for insert injection molding of the present invention;
[0026] Figure 7 is a schematic diagram of an embodiment of the composite injection molded part of the present invention;
[0027] Figure 8 is a schematic diagram of an embodiment of the composite injection molded part of the present invention;
[0028] Figure 9 is a cross-sectional view of an embodiment of the composite injection molded part of the present invention;
[0029] Figure 10 is an exploded view of an embodiment of the composite injection molded part of the present invention.
[0030] 1 - Through - hole; 2 - Outer wall circumferential surface; 3 - Upper sector - shaped groove; 31 - Groove bottom surface; 32 - Groove side vertical surface; 33 - Groove back curved surface; 4 - Lower sector - shaped groove; 5 - Chamfer; 6 - Hollowed - out hole; 7 - Upper convex block; 8 - Lower convex block; 9 - Circular rib; 10 - Lining kit; 11 - Shaft convex part; 20 - Plastic part. Detailed implementation manners
[0031] The following combines specific embodiments to further elaborate on the content of the present invention:
[0032] To achieve the purpose of the present invention, a stamping bushing structure for insert molding is as Figure 10 shown, including: a through - hole 1 axially penetrating both ends of the lining kit 10; sector - shaped grooves, at the junction of the outer wall circumferential surface 2 of the lining kit 10 and the shaft end face, sector - shaped grooves are stamped and recessed, and a number of sector - shaped grooves are annularly arrayed at each shaft end of the lining kit 10; wherein, the inner wall of each sector - shaped groove includes a groove bottom surface 31, two groove side vertical surfaces 32, and a groove back curved surface 33, and the two groove side vertical surfaces 32 are symmetrically arranged in the sector - shaped groove where they are located; the sector - shaped grooves can allow molten plastic to enter.
[0033] According to different positions, the sector - shaped grooves include upper sector - shaped grooves 3 and lower sector - shaped grooves 4, and each upper sector - shaped groove 3 axially coincides with a lower sector - shaped groove 4. The sum of the axial dimensions of a single upper sector - shaped groove 3 and a single lower sector - shaped groove 4 is 0.3 to 0.5 times the axial length of the lining kit 10.
[0034] The beneficial effect of adopting the above - mentioned technical solution is that the present lining kit 10 is mainly used for insert - molded parts to fasten products, and the main feature lies in the design of multiple sector - shaped groove structures.
[0035] After the lining kit 10 is injection - molded, the positions of the sector - shaped grooves will be wrapped by plastic. After the plastic solidifies, even if the lining kit 10 is rotated, due to the engagement between the plastic and the sector - shaped grooves, the lining kit 10 can maintain a good anti - torsion effect.
[0036] Traditional bushings of this type are generally formed by machining production processes, which are bound to be at a disadvantage in terms of cost and production capacity, so it is difficult to have an advantage and a market in the market. And the lining kit of the present application is located at the edge of the shaft end, different from Figure 1 the design that is located in the middle of the bushing and requires complete radial penetration, so the present application can meet the production by stamping process, improving both in terms of cost and efficiency. Figure 1 In the case of
[0037] In addition, compared with Figure 2 , on the premise that the overall outer diameter of the lining kit 10 remains the same, the single size of the sector - shaped groove must be larger than Figure 2The size of a single tooth in the middle gear ring, so the plastic in a single fan-shaped groove is not easily cracked, and the structure of the fan-shaped groove engaging with the plastic in a concave-convex manner provides a very large torsional resistance.
[0038] In some other embodiments of the present invention, the bottom surface 31 of the groove is perpendicular to the axis of the lining sleeve 10, the side vertical surface 32 of the groove coincides with or is parallel to the axis of the lining sleeve 10, the back curved surface 33 of the groove is a convex curved surface, and the axis corresponding to the back curved surface 33 coincides with the axis of the lining sleeve 10.
[0039] In addition, preferably, the contour of each back curved surface 33 of the groove is a square.
[0040] Make the roughness of the side vertical surface 32 of the groove equal to that of the side vertical surface 32 of the groove, and at the same time, the roughness of the side vertical surface 32 of the groove is greater than the roughness of the bottom surface 31 of the groove. This roughness setting facilitates the manufacture of minute concave-convex surfaces, namely micro-protrusions, micro-grooves or micro-textures, and can enhance the connection firmness between the molten plastic and the lining sleeve.
[0041] The side vertical surface 32 of the groove can be provided with barbs.
[0042] The beneficial effects of adopting the above technical solution are: The fan-shaped groove can be understood as being recessed radially or axially, so it can mainly enhance a powerful circumferential torsional resistance, and to a certain extent, it is also beneficial to the straight anti-loosening capabilities in the axial and radial directions.
[0043] In some other embodiments of the present invention, the side vertical surface 32 of the groove is parallel to the axis of the lining sleeve 10, there is an intersection in the extension of the two side vertical surfaces 32 of the same fan-shaped groove, and the radial distance from the fan-shaped groove to the intersection is longer than the radial distance from the fan-shaped groove to the axis of the lining sleeve 10.
[0044] The beneficial effects of adopting the above technical solution are: The meaning here is that along the radial direction, the fan-shaped groove is appropriately "small at the mouth and large at the bottom", achieving an effect similar to that of a dovetail groove, but actually from the perspective of dimensions, the fan-shaped groove is still "large at the mouth and small at the bottom". However, this design can appropriately enhance the radial anti-loosening ability.
[0045] In some other embodiments of the present invention, the depth range of the radial recess of the fan-shaped groove is 0.3 to 0.5 times the wall thickness of the lining sleeve 10.
[0046] In some other embodiments of the present invention, from the axial perspective of the lining sleeve, the fan-shaped angle range of a single fan-shaped groove is 35° to 45°.
[0047] The preferred fan-shaped angle is 40°.
[0048] In some other embodiments of the present invention, the number of fan-shaped grooves at each axial end of the lining sleeve 10 is four.
[0049] A composite injection molded part, including a stamping bushing structure for insert injection molding as described in any one of the above, comprising: a bushing part 10; a plastic part 20, the plastic part 20 having a hollowed-out hole 6 for accommodating the bushing part 10, and being in contact with the bushing part 10 at positions other than the shaft end. The plastic part 20 has bumps located in fan-shaped grooves, and the fan-shaped grooves and the bumps are in concave-convex fit with each other.
[0050] As Figure 10 shown, the bump includes an upper bump 7 and a lower bump 8 extending radially inward. The upper bump 7 is in concave-convex fit with the upper fan-shaped groove 3, and the lower bump 8 is in concave-convex fit with the lower fan-shaped groove 4.
[0051] The beneficial effects of adopting the above technical solution are: The upper bump 7 and the lower bump 8 are naturally formed according to the fan-shaped groove during die injection molding. The upper bump 7 and the lower bump 8 are the parts that play the role of concave-convex engagement.
[0052] As Figure 7 shown, in some other embodiments of the present invention, one side of the plastic part 10 has a raised circular rib 9. The circular rib 9 surrounds the bushing part 10. The top of the circular rib 9 is flush with the adjacent shaft end of the bushing part 20. The circular rib 9 has a slope on the side facing away from the bushing part 10 in the radial direction, and the slope makes the radial thickness of the circular rib 9 gradually wider from its top to its root.
[0053] The beneficial effects of adopting the above technical solution are: After the root of the circular rib 9, the structural strength in the radial direction is large and it is not easy to crack.
[0054] As Figure 8 shown, in some other embodiments of the present invention, one end of the bushing part 10 protrudes from one side of the plastic part 10 and forms a shaft protrusion 11. The protruding end of the bushing part 10 and the circular rib 9 are respectively located on the front and back sides of the plastic part 20.
[0055] The outer convex dimension of the shaft protrusion 11 is not greater than 2 mm.
[0056] The beneficial effects of adopting the above technical solution are: The existence of the shaft protrusion 11 is to fully expose one end of the bushing part 10 here, avoid the influence of the error of the plastic part 20, and avoid the plastic part 20 being too thick, so that the bushing part 10 is shrunk in the plastic part 20. When electrical connection is required, directly utilize the shaft protrusion 11 here to ensure that contact and electrical connection can be achieved here.
[0057] In some other embodiments of the present invention, the bushing part 10 is a metal part with a structural strength greater than that of the plastic part 20.
[0058] For example, the bushing part 10 is made of copper or aluminum, and the plastic part 20 is made of thermoplastic elastomer (TPE) or other polymer materials.
[0059] As Figure 6As shown, in other embodiments of the present invention, the through hole 1 transitions at the axial end of the bushing member 10 through a chamfer 5. The bushing member 10 is superior to the traditional stamping bushing, and the through hole 1 of this structure has better roundness and smaller tolerance, so the positioning is better during injection molding production, the position of the product is easier to ensure, and there will be no problems such as plastic overflow from the through hole 1.
[0060] In some other embodiments of the present invention, the inner wall of the through hole 1 is provided with an internal thread. The internal thread is preset, so that it is convenient to directly realize thread assembly with the outer wall screw.
[0061] in addition, Figure 7 and Figure 8 This is an oblique viewing angle from two different surfaces of the plastic part 20 . Figure 9 and Figure 5 The cutting position is the same.
[0062] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.
Claims
1. A stamping bushing structure for embedded injection molding, characterized in that: include: A through hole axially passes through both ends of the bushing; Sector-shaped grooves, where the junction between the outer circumferential surface of the bushing and the shaft end surface is sunken with sector-shaped grooves, and each shaft end of the bushing is provided with a plurality of sector-shaped grooves in an annular array; The inner wall of each fan-shaped groove includes a groove bottom surface, two groove side vertical surfaces, and a groove back curved surface, and the two groove side vertical surfaces are symmetrically arranged in the fan-shaped groove; the fan-shaped groove can allow molten plastic to enter.
2. The stamping bushing structure for embedded injection molding according to claim 1, characterized in that: The groove bottom surface is perpendicular to the axis of the liner, the groove side elevation surface coincides with or is parallel to the axis of the liner, the groove back curved surface is a convex curved surface, and the axis corresponding to the groove back curved surface coincides with the axis of the liner.
3. The stamping bushing structure for embedded injection molding according to claim 1, characterized in that: The groove side elevation is parallel to the axis of the liner, and the extensions of the two groove side elevations of the same sector groove intersect at a point, and the radial distance from the sector groove to the intersection is longer than the radial distance from the sector groove to the axis of the liner.
4. The stamping bushing structure for embedded injection molding according to claim 1, characterized in that: The recessed depth of the sector groove along the radial direction is 0.3 to 0.5 of the wall thickness of the liner.
5. The stamping bushing structure for embedded injection molding according to claim 1, characterized in that: From an axial perspective of the bushing, the sector angle of a single sector groove ranges from 35° to 45°.
6. The stamping bushing structure for embedded injection molding according to claim 1, characterized in that: The number of the fan-shaped grooves at each shaft end of the bushing is four.
7. A composite injection molded part, characterized in that: The stamping bushing structure for embedded injection molding according to any one of claims 1 to 6 comprises: Bushing kit; The plastic part contacts the bushing sleeve except the shaft end. The plastic part is provided with a convex block located in the fan-shaped groove. The fan-shaped groove and the convex block are matched with each other.
8. The composite injection molded part according to claim 7, characterized in that: One side of the plastic part has a raised annular rib, which surrounds the liner assembly. The top of the annular rib is flush with the axial end adjacent to the liner assembly. The side of the annular rib radially away from the liner assembly has a slope, which makes the radial thickness of the annular rib gradually widen from the top to the root.
9. The composite injection molded part according to claim 8, characterized in that: One end of the bushing member protrudes from one side of the plastic member to form a shaft protrusion, and the protruding end of the bushing member and the circular convex rib are respectively located on the front and back sides of the plastic member.
10. The composite injection molded part according to claim 7, characterized in that: The lining member is a metal member having a structural strength greater than that of the plastic member.