Piston type injection mold without burr sealing surface

Abstract

The utility model belongs to the field of injection molds, and discloses a piston type injection mold with a burr-free sealing surface, which can be used for injection molding of piston type products with burr-free piston heads without using extra molds and matched machines, and comprises a rear mold rotation driving assembly used for driving a rear mold to rotate and forming two stopping positions, the plane where the rear mold rotates is perpendicular to the mold opening and closing direction, when the rear mold is located at the parking position, a semi-finished product mold cavity and a finished product mold cavity are formed between the front mold and the rear mold, and the finished product mold cavity forms different shapes on the two sides of a parting surface respectively, that is, when piston type products are subjected to injection molding, the semi-finished product mold cavity and the finished product mold cavity form different shapes. The piston rod part is mainly subjected to injection molding in the semi-finished product mold cavity, after the piston rod part is formed, the piston rod part is transferred into the finished product mold cavity through rotation of the rear mold, pouring of the piston head is carried out, and the piston head is completely formed in the front mold, so that the piston head avoids a parting surface, and no burr is generated on the piston head.

Description

Technical Field

[0001] This utility model belongs to the field of injection molds, specifically relating to piston-type injection molds with burr-free sealing surfaces. Background Technology

[0002] Piston-type products consist of a one-piece molded piston rod and piston head. The piston head enables the piston-type product to achieve a dynamic sealing function for predetermined channels and passages. The piston-type product is symmetrical about the extension axis of the piston rod. Therefore, during the injection molding of piston-type products, the extension axis of the piston rod is located in the plane of the parting surface.

[0003] However, in this injection molding method, the piston body is located in the rear mold and the front mold on both sides of the parting surface. As a result, during the injection molding process, the characteristics of the injection molding process will inevitably cause the piston body to overflow along the parting surface and form burrs. As a result, the surface of the piston product cannot completely fit the predetermined holes and channels, leading to the failure of the expected seal during implementation.

[0004] Currently, in order to address the aforementioned burr problem, manufacturers are using a dual-mold, two-color injection molding process to ensure that the piston head of injection-molded piston products is free of burrs, thereby meeting the sealing requirements.

[0005] However, while this implementation method is effective, it is clear that the additional mold and supporting machinery will significantly increase equipment costs. Utility Model Content

[0006] In view of the shortcomings of the existing technology, this utility model provides a piston injection mold with a burr-free sealing surface, which can injection mold piston products with burr-free piston heads without the need for additional molds and supporting machines.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A piston-type injection mold without a burr-free sealing surface has a front mold and a rear mold, and the front mold and the rear mold form a parting and closing direction based on the parting surface. The mold is characterized by including a rear mold drive assembly for driving the rear mold to rotate and forming two parking positions. The plane in which the rear mold rotates is perpendicular to the parting and closing direction. When the rear mold is in the parking position, a semi-finished product cavity and a finished product cavity are formed between the front mold and the rear mold, and the finished product cavity is formed with different shapes on both sides of the parting surface.

[0009] Preferably, the rear mold drive assembly includes a coupling gear ring and a drive cylinder. The coupling gear ring is disposed on the rear mold end face opposite to the parting surface, and the axis of the gear ring extends along the mold parting direction. The piston rod of the drive cylinder has a rack portion that meshes with the coupling gear ring. When the drive cylinder is activated, the rack portion drives the coupling gear ring to rotate, thereby causing the rear mold to rotate.

[0010] Furthermore, the present invention also includes a mold splitting and joining drive rod, which is fixedly connected to the front mold along the mold splitting and joining direction, and is used to drive the front mold to move linearly relative to the rear mold along the mold splitting and joining direction.

[0011] Furthermore, this utility model also includes a rear mold base, a coupling gear ring located inside the rear mold base, a drive cylinder located on the side of the rear mold base, and the piston rod of the drive cylinder inserted into the rear mold base and meshing with the coupling gear ring.

[0012] Furthermore, the coupling gear ring has a through hole extending along the mold splitting direction, through which the mold splitting drive rod passes.

[0013] Preferably, the amount of plastic injected into the semi-finished mold cavity and the finished mold cavity is different.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. Because the piston injection mold of this utility model with a burr-free sealing surface includes a rear mold drive assembly, which drives the rear mold to rotate and form two stopping positions. The plane in which the rear mold rotates is perpendicular to the parting and closing direction. When the rear mold is in the stopping position, a semi-finished product cavity and a finished product cavity are formed between the front mold and the rear mold. The finished product cavity is formed with different shapes on both sides of the parting surface. That is, when the piston product is being injection molded, the extension axis of the piston rod after the finished product is perpendicular to the parting surface. The piston rod is mainly injection molded in the semi-finished product cavity. After the piston rod is formed, the piston rod is transferred to the finished product cavity by the rotation of the rear mold for the casting of the piston head. The piston head is formed completely in the front mold, so the piston head avoids the parting surface. Therefore, after the product is finished, the piston head does not produce any burrs. Therefore, this utility model can injection mold piston products with burr-free piston heads without the need for additional molds and supporting machines.

[0016] 2. Because the piston-type rear mold drive assembly with no burr sealing surface of this utility model includes a coupling gear ring and a drive cylinder, the coupling gear ring is set on the rear mold end face opposite to the parting surface, and the axis of the gear ring extends along the mold parting direction. The piston rod of the drive cylinder forms a rack portion that meshes with the coupling gear ring. When the drive cylinder is activated, the rack portion drives the coupling gear ring to rotate and drives the rear mold to rotate. Therefore, this utility model realizes the drive rotation of the rear mold through a simple structure.

[0017] 3. Because the piston-type coupling gear ring with a burr-free sealing surface of this utility model has a through hole extending along the mold splitting direction, and the mold splitting drive rod passes through the through hole, the design of the coupling gear ring through which the mold splitting drive rod passes makes the structure of this utility model more compact. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a piston-type injection mold with a burr-free sealing surface, according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a piston-type product according to an embodiment of the present utility model;

[0020] Figure 3 for Figure 1 A sectional view;

[0021] Figure 4 for Figure 3 A magnified view of part A;

[0022] Figure 5 This is a schematic diagram illustrating the cooperation between the rear mold drive assembly and the rear mold in an embodiment of this utility model.

[0023] In the diagram: A, Piston-type product; A1, Piston rod; A2, Piston head; X, Extension shaft; 100, Injection mold for piston-type products with burr-free sealing surface; 10, Front mold; 20, Rear mold; 21, Drive rod channel; 22, Gear ring setting position; V1, Semi-finished product mold cavity; P1, First valve needle assembly; V2, Finished product mold cavity; P2, Second valve needle assembly; 30, Rear mold drive assembly; 31, Coupling gear ring; 32, Drive cylinder; 321, Rack section; 40, Mold opening and closing drive rod; 50, Rear mold base; D, Mold opening and closing direction. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the piston-type injection mold with a burr-free sealing surface of this utility model. It should be noted that the description of these embodiments is for the purpose of helping to understand this utility model, but does not constitute a limitation on this utility model.

[0025] like Figure 1 As shown, the piston-type injection mold 100 without burr sealing surface in this embodiment includes a front mold 10, a rear mold 20, a rear mold drive assembly 30, a mold opening and closing drive rod 40, and a rear mold base 50.

[0026] The front mold 10 and the rear mold 20 form a mold parting direction D based on the parting surface. The mold parting drive rod 40 is fixed to the front mold 10 along the mold parting direction D and is used to drive the front mold 10 to move linearly relative to the rear mold 20 along the mold parting direction D. Specifically, the front mold 10, the rear mold 20 and the rear mold base 50 are arranged sequentially along the mold parting direction D. The mold parting drive rod 40 passes through the rear mold base 50 and the rear mold 20 from the outside of the rear mold base 50. The mold parting drive rod 40 can be driven by an external cylinder.

[0027] Specifically, such as Figure 2 As shown, the piston-like product A, formed by injection molding through a piston-like injection mold 100 with a burr-free sealing surface, is formed by a piston rod portion A1 and a piston head A2 that are continuous along the extension axis X. During operation, the piston-like product A is sealed and fitted by the circumferential surface of the piston head A2 and the inner wall of the mating piston cavity, achieving the corresponding technical objective through dynamic friction. The piston rod portion A1 has an extension axis X. The extension length of the piston head A2 along the extension axis X is less than the extension length of the piston rod portion A1 along the extension axis X. The cross-sectional area of ​​the piston head A2 along the extension axis X is greater than the cross-sectional area of ​​the piston rod portion A1 along the extension axis X. Therefore, although any plane passing through the extension axis X forms a symmetrical plane of the piston-like product A, other planes cannot form a symmetrical plane of the piston-like product A. In this embodiment, the front mold 10, the rear mold 20, and the rear mold base 50 are all rectangular.

[0028] Specifically, after piston product A is formed in piston injection mold 100 without burr sealing surface, the extension axis X is perpendicular to the parting surface, so the parting surface does not pass through the extension axis X, that is, the parting surface is not the symmetrical surface of the formed piston product A.

[0029] Specifically, the rear mold 20 and the rear mold base 50 form an integral part having a drive rod channel 21 extending along the mold parting direction D. The drive rod channel 21 is used to drive the mold parting rod 40. The interior of the rear mold base 50 has a gear ring placement position 22 and a drive channel (not shown in the figure). The gear ring placement position 22 is a section of the drive rod channel 21. One end of the drive channel is connected to the gear ring placement position 22, and the other end is open to the outside through the circumference of the rear mold base 50. In this embodiment, the cross-sectional area of ​​the gear ring placement position 22 along the mold parting direction D is larger than the cross-sectional area of ​​the other drive rod channels 21 along the mold parting direction D. The extension direction of the drive channel is perpendicular to the mold parting direction D.

[0030] like Figures 3 to 5 As shown, the rear mold drive assembly 30 includes a coupling gear ring 31 and a drive cylinder 32.

[0031] The coupling gear ring 31 is disposed on the end face of the rear mold 20 opposite to the parting surface, and the axis of the coupling gear ring 31 extends along the mold parting direction D. Specifically, the coupling gear ring 31 is located in the gear ring setting position 22 inside the rear mold base 50 and is disposed on the end face of the rear mold 20.

[0032] The coupling gear ring 31 has a through hole (not shown in the figure) extending along the mold splitting direction D. The mold splitting drive rod 40 passes through the through hole and is driven to connect with the front mold 40.

[0033] The drive cylinder 32 is located on the side of the rear mold base 50. The piston rod of the drive cylinder 32 is inserted into the rear mold base 50 and meshes with the coupling gear ring 31. The piston rod of the drive cylinder 32 has a rack portion 321 that meshes with the coupling gear ring 31. When the drive cylinder 32 is activated, the rack portion 321 drives the coupling gear ring 31 to rotate, thereby rotating the rear mold 20. Specifically, the piston rod of the drive cylinder 32 enters the gear ring setting position 22 through the drive channel.

[0034] The rear mold drive assembly 30 is used to drive the rear mold 20 to rotate relative to the front mold 10 and form two stopping positions. The plane in which the rear mold 20 rotates is perpendicular to the mold parting direction D. When the rear mold 20 is in the stopping position, a semi-finished product cavity V1 and a finished product cavity V2 are formed between the front mold 10 and the rear mold 20. The finished product cavity V2 is formed with different shapes on both sides of the parting surface. Specifically, the piston-type injection mold 100 without a burr sealing surface uses the first valve needle assembly P1 to seal the semi-finished product cavity. The piston rod A1 is formed by injection molding in V1. After the rear mold rotates, the piston rod A1 is transferred to the finished mold cavity V2. The piston-type injection mold 100, which has no burr sealing surface, continues to inject the piston head A2 into the finished mold cavity V2 through the second valve needle group P2, thereby forming a complete piston-type product A. Therefore, the piston head A2 is formed entirely in the front mold 10, so the piston head A2 completely avoids the parting surface, and no burrs are generated on the circumferential surface of the piston head A2.

[0035] The injection volume of plastic in the semi-finished mold cavity V1 and the finished mold cavity V2 is different. Specifically, the volumes of the piston rod A1 and the piston head A2 are different.

[0036] The above embodiments are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Various modifications or variations that can be made by those skilled in the art without creative effort within the scope of the appended claims are still within the scope of protection of this patent.

Claims

1. A piston-type injection mold without a burr-free sealing surface, comprising a front mold and a rear mold, wherein the front mold and the rear mold form a parting direction based on a parting surface, characterized in that, include: The rear mold drive assembly is used to drive the rear mold to rotate and form two parking positions. The plane in which the rear mold rotates is perpendicular to the mold parting and closing direction. When the rear mold is in the parking position, a semi-finished product cavity and a finished product cavity are formed between the front mold and the rear mold, and the finished product cavity is formed with different shapes on both sides of the parting surface.

2. The injection mold for pistons with a burr-free sealing surface according to claim 1, characterized in that: in, The rear mold drive assembly includes a coupling gear ring and a drive cylinder. The coupling gear ring is disposed on the rear mold end face opposite to the parting surface, and the axis of the gear ring extends along the parting direction. The piston rod of the drive cylinder has a rack portion that meshes with the coupling gear ring. When the drive cylinder is activated, the rack portion drives the coupling gear ring to rotate, thereby causing the rear mold to rotate.

3. The injection mold for pistons with a burr-free sealing surface according to claim 2, characterized in that, Also includes: The splitting mold drive rod is fixedly connected to the front mold along the splitting mold direction and is used to drive the front mold to move linearly relative to the rear mold along the splitting mold direction.

4. The injection mold for pistons with a burr-free sealing surface according to claim 3, characterized in that, Also includes: The rear mold base has a coupling gear ring located inside it. The drive cylinder is located on the side of the rear mold base, and the piston rod of the drive cylinder is inserted into the rear mold base and meshes with the coupling gear ring.

5. The injection mold for pistons with a burr-free sealing surface according to claim 4, characterized in that: in, The coupling gear ring has a through hole extending along the direction of the mold splitting and joining, through which the mold splitting and joining drive rod passes.

6. The injection mold for pistons with a burr-free sealing surface according to claim 1, characterized in that: in, The amount of plastic injected into the semi-finished product mold cavity and the finished product mold cavity is different.

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