A mold for miniature circuit breaker transformers

Abstract

This utility model belongs to the field of mold technology, specifically relating to a mold for a miniature circuit breaker transformer, including a punch assembly, a die, and an ejection assembly. The punch assembly and the die form a molding cavity. The punch assembly is connected to a movable plate via a punch base, and the die is connected to a fixed plate via a die base. Crucially, the die is provided with a set of fine sprues communicating with the molding cavity. These fine sprues are located at the top of the molding cavity and arranged in an array around the axis of the cavity. The inlet end of the fine sprues is located within a flow channel and connected to the gating port via the flow channel. This mold allows the molten liquid to fill the molding cavity evenly and demold smoothly, reducing the scrap rate and effectively improving the product quality and precision of the miniature circuit breaker transformer housing.

Description

Technical Field

[0001] This utility model belongs to the field of mold technology, specifically relating to a mold for a miniature circuit breaker transformer. Background Technology

[0002] Miniature circuit breaker transformers are small in size. Their housings are assembled from a thin-walled first housing and a second housing. The first housing has a wall thickness of 0.4 mm, and the second housing has a wall thickness of 0.35 mm. Both housings consist of an outer tube and an inner tube. The top of the outer tube is closed, and the inner tube is located inside the outer tube and passes through it. One side of the outer tube has a straight edge. During the production of the first and second housings, the molding cavity on the mold is small. Using a conventional gate for pouring can easily cause uneven filling of the molten plastic within the molding cavity, leading to defects such as shrinkage marks and deformation in the molded part. Furthermore, conventional demolding methods often involve direct separation of the die and punch with a single vertical ejection, resulting in uneven stress on the part, causing scratches, indentations, and even difficulty in demolding from the punch. It is difficult to produce a housing that meets the dimensions of a miniature circuit breaker transformer using ordinary gates and conventional demolding methods. Utility Model Content

[0003] To address the problems existing in the prior art, this utility model provides a mold for miniature circuit breaker transformers, which enables the molten liquid to fill the molding cavity evenly and demold smoothly, reducing the scrap rate and effectively improving the product quality and precision of the miniature circuit breaker transformer housing.

[0004] The specific technical solution adopted in this utility model is as follows:

[0005] A mold for a miniature circuit breaker transformer includes a punch assembly, a die, and an ejector assembly. The punch assembly and the die form a molding cavity. The punch assembly is connected to a movable plate via a punch base, and the die is connected to a fixed plate via a die base. Crucially, the die has a set of fine sprues communicating with the molding cavity. These fine sprues are located at the top of the molding cavity and arranged in an array around the axis of the molding cavity. The inlet end of each fine sprue is located within a flow channel and connected to the gating port via the flow channel.

[0006] The punch base is provided with an opening and closing device, the die is provided with a resistance hole that cooperates with the opening and closing device, and a tie rod is suspended on the die base. The die is fitted with the tie rod by means of a countersunk hole provided on it. The extended end of the tie rod cooperates with the countersunk hole to form a travel limit of the die on the die base.

[0007] The ejection assembly includes a top plate and a first ejector pin. The top plate is disposed between the movable plate and the punch base. The first ejector pin is disposed on the top plate and ejects the part from the molding cavity by means of the movement of the top plate.

[0008] The punch assembly includes a fixed punch and a movable punch. The fixed punch is fixedly connected to the punch base. The fixed punch is provided with a guide hole that matches the movable punch. The first ejector pin rises and drives the movable punch to eject the part from the forming cavity along the guide hole.

[0009] The movable punches are arranged in a circular array around the axis of the forming cavity.

[0010] The movable punch includes an inclined guide surface, which is set at an angle α with the mold opening direction. The movable punch forms an inclined ejector mechanism for the part by means of the guide surface and the guide hole, and the lifting of the first ejector pin. The included angle α ≤ 5°.

[0011] The molding cavity includes a first cavity and a second cavity, which are respectively located on both sides of the pouring gate and connected to the pouring gate via a fine nozzle and a diversion channel.

[0012] The beneficial effects of this utility model are:

[0013] This invention uses a narrow nozzle to pour molten plastic into the molding cavity, which allows the molten plastic to flow evenly into the molding cavity, improves the flow balance of the molten plastic, makes the filling of the molten plastic in the molding cavity more uniform, and ensures that thin-walled parts can be successfully molded.

[0014] The feed end of the narrow sprue is located inside the flow channel and is connected to the gating gate via the flow channel. The narrow sprue has a narrow cross-section, and the molten metal generates significant shear heat when passing through the narrow sprue after passing through the flow channel, ensuring that the molten metal has a fast flow rate and good fluidity when entering the molding cavity.

[0015] An opening and closing device is added between the punch base and the die. The frictional cooperation between the opening and closing device and the resistance hole ensures that the die and the punch base can move synchronously when the mold is opened, maintaining the integrity of the forming cavity and avoiding the problem of the die separating from the workpiece in advance, which causes the workpiece to be scratched or deformed. This improves the precision and quality of the workpiece and effectively reduces the scrap rate in the production of thin-walled workpieces.

[0016] The punch assembly includes a fixed punch and a movable punch. The movable punch and the fixed punch are guided and engaged by guide holes. The movable punch forms an inclined ejector mechanism by means of the first ejector pin. Not only does it use a large-area contact ejection method during the ejection process, but the movable punch and the workpiece are also horizontally displaced during the ejection process, so that the workpiece can be demolded smoothly and the thin-walled workpiece is prevented from deforming. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the mold opening state of this utility model;

[0018] Figure 2 This is a top view of the present invention;

[0019] Figure 3 for Figure 2 Sectional view along axis AA;

[0020] Figure 4 This is an assembly diagram of the die cavity, die cavity base, and fixing plate;

[0021] Figure 5 Assembly diagram of punch assembly, ejection assembly and moving plate;

[0022] Figure 6 This is a schematic diagram of the die structure;

[0023] Figure 7 This is a schematic diagram of the structure of the fixed punch;

[0024] Figure 8 This is a schematic diagram of the structure of the first shell and the second shell;

[0025] In the attached diagram, 1 is the die cavity, 2 is the punch base, 3 is the movable plate, 4 is the die cavity base, 5 is the fixed plate, 6 is the sprue, 7 is the molding cavity, 8 is the gating gate, 9 is the flow channel, 10 is the opener / closer, 11 is the resistance hole, 12 is the tie rod, 13 is the countersunk hole, 14 is the first ejector pin, 15 is the top plate, 16 is the fixed punch, 17 is the movable punch, 1701 is the guide surface, 18 is the guide hole, 19 is the first housing, and 20 is the second housing. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0027] Specific implementation examples Figure 1 As shown, this utility model relates to a mold for a miniature circuit breaker transformer, including a punch assembly, a die 1, and an ejection assembly. The punch assembly and the die 1 are matched to form a molding cavity 7. The punch assembly is connected to a movable plate 3 via a punch base 2, and the die 1 is connected to a fixed plate 5 via a die base 4. The key feature is that the die 1 is provided with a set of fine sprues 6 that communicate with the molding cavity 7. The fine sprues 6 are located at the top of the molding cavity 7 and are arranged in an array around the axis of the molding cavity 7. In this embodiment, each molding cavity 7 corresponds to 3 fine sprues 6, which can make the plastic melt flow into the molding cavity 7 evenly, improve the flow balance of the melt, make the filling of the melt in the molding cavity 7 more uniform, and ensure that the thin-walled parts can be successfully molded.

[0028] The feed end of the narrow sprue 6 is located inside the flow divider channel 9 and is connected to the gating port 8 via the flow divider channel 9. The narrow cross-section of the narrow sprue 6 causes the molten liquid to generate significant shear heat when passing through the flow divider channel 9 and then through the narrow sprue 6, ensuring that the molten liquid has a fast flow rate and good fluidity when entering the molding cavity 7.

[0029] The diversion channel 9 includes a main channel and a branch channel that are directly connected to the pouring port 8. The branch channel is located above the molding cavity 7 and is arranged in a cross shape with the main channel. Three fine nozzles 6 are respectively arranged to correspond to the main channel and the branch channels on both sides of the main channel, which further improves the filling stability of the molding cavity 7 and ensures that the molten liquid fills the molding cavity 7 evenly.

[0030] Preferably, the punch base 2 is provided with an opening and closing device 10, the die 1 is provided with a resistance hole 11 that cooperates with the opening and closing device 10, and a tie rod 12 is provided on the die base 4. The die 1 is fitted with the tie rod 12 by means of the countersunk hole 13 provided on it. The extended end of the tie rod 12 cooperates with the countersunk hole 13 to form a travel limit of the die 1 on the die base 4.

[0031] Due to the installation of the opening / closing device 10 and the resistance hole 11, the friction between the die 1 and the punch base 2 is increased. When the mold is opened, the movable plate 3 and the ejector assembly descend, driving the punch assembly and the die 1 to descend together. When the countersunk hole 13 on the die 1 contacts the overhanging end of the tie rod 12, the tie rod 12 acts as a limit to the die 1, causing the die 1 to separate from the continuing descending punch assembly, thus separating the die 1 from the workpiece. Subsequently, the ejector assembly rises, lifting the workpiece from the punch base 2, completing the demolding of the workpiece.

[0032] The frictional engagement between the opening / closing device 10 and the resistance hole 11 ensures that the die 1 and the punch base 2 can move synchronously when the mold is opened, maintaining the integrity of the forming cavity 7, avoiding the problem of the die 1 separating from the workpiece in advance, which causes the workpiece to be scratched or deformed, improving the precision and quality of the workpiece, and effectively reducing the scrap rate in the production of thin-walled workpieces.

[0033] Preferably, the ejection assembly includes a top plate 14 and a first ejector pin 15. The top plate 14 is disposed between the movable plate 3 and the punch base 2, and the first ejector pin 15 is disposed on the top plate 14 and ejects the part in the molding cavity 7 by means of the movement of the top plate 14.

[0034] Furthermore, the punch assembly includes a fixed punch 16 and a movable punch 17. The fixed punch 16 is fixedly connected to the punch base 2. The fixed punch 16 is provided with a guide hole 18 that matches the movable punch 17. The first ejector pin 15 rises and drives the movable punch 17 to eject the part from the molding cavity 7 along the guide hole 18. The ejection assembly also includes a second ejector pin and a third ejector pin, wherein the second ejector pin acts on the end of the inner tube of the part, and the third ejector pin acts on the end of the straight edge of the outer tube of the part. During demolding, the top plate 14 drives the first ejector pin 15 to rise. The first ejector pin 15 acts on the movable punch 17, causing the movable punch 17 to rise along the guide hole 18. The movable punch 17 achieves a large-area action on the part to lift the part and complete the demolding, which can effectively avoid deformation of the part.

[0035] The first ejector pin 15, together with the second and third ejector pins, ejects the workpiece in a large-area, dispersed ejection manner, so that the workpiece is subjected to force at multiple points, avoiding jamming between the workpiece and the punch assembly, and improving the uniformity of force on the workpiece, further preventing the workpiece from deforming.

[0036] The movable punches 17 are arranged in a circular array around the axis of the forming cavity 7. In this embodiment, the punch assembly of each part includes three movable punches 17, which further improves the uniformity of the force on the part.

[0037] The movable punch 17 includes an inclined guide surface 1701, which is set at an angle α with the mold opening direction. The movable punch 17, through the guiding engagement of the guide surface 1701 and the guide hole 18, and the rising of the first ejector pin 15, forms an inclined ejector mechanism for the part. The angle α ≤ 5°, preferably 1.5°. The first ejector pin 15 pushes the movable punch 17, and under the guiding engagement of the guide surface 1701 and the guide hole 18, the movable punch 17 tilts and rises, smoothly separating from the vertical wall of the part, further ensuring smooth demolding and improving the product quality.

[0038] The molding cavity 7 includes a first cavity and a second cavity. The first cavity and the second cavity are respectively located on both sides of the pouring gate 8 and are connected to the pouring gate 8 through the fine gate 6 and the diversion channel 9. The first cavity is used to produce the first shell 19, and the second cavity is used to produce the second shell 20. Since the wall thickness of the first shell 19 and the second shell 20 is similar, they can be produced synchronously with the same mold. The process parameters such as melt temperature, pressure, and mold opening speed during the production of the first shell 19 and the second shell 20 are the same, which can ensure that the two shells have consistent precision and improve the assembly precision of the two shells.

Claims

1. A mould for miniature circuit breaker transformers, comprising a male mould assembly, a female mould (1) and an ejection assembly, said male mould assembly, female mould (1) forming a moulding cavity (7) in combination, said male mould assembly being connected to a movable plate (3) by means of a male mould base (2), said female mould (1) being connected to a fixed plate (5) by means of a female mould base (4), characterised in that: The die (1) is provided with a set of fine sprues (6) that communicate with the molding cavity (7). The fine sprues (6) are located at the top of the molding cavity (7) and arranged in an array around the axis of the molding cavity (7). The feed end of the fine sprues (6) is located in the diversion channel (9) and is connected to the pouring port (8) through the diversion channel (9).

2. A mold for a miniature circuit breaker transformer according to claim 1, characterized in that: The punch base (2) is provided with an opening and closing device (10), the die (1) is provided with a resistance hole (11) that cooperates with the opening and closing device (10), and a pull rod (12) is suspended on the die base (4). The die (1) is fitted with the pull rod (12) by means of the countersunk hole (13) provided on it. The cantilever end of the pull rod (12) cooperates with the countersunk hole (13) to form a travel limit of the die (1) on the die base (4).

3. A mold for a miniature circuit breaker transformer according to claim 1, characterized in that: The ejection assembly includes a top plate (14) and a first ejector pin (15). The top plate (14) is disposed between the movable plate (3) and the punch base (2). The first ejector pin (15) is disposed on the top plate (14) and ejects the part in the molding cavity (7) by means of the movement of the top plate (14).

4. A mold for a miniature circuit breaker transformer according to claim 3, characterized in that: The punch assembly includes a fixed punch (16) and a movable punch (17). The fixed punch (16) is fixedly connected to the punch base (2). The fixed punch (16) is provided with a guide hole (18) that matches the movable punch (17). The first ejector pin (15) rises and drives the movable punch (17) to eject the part in the forming cavity (7) along the guide hole (18).

5. A mold for a miniature circuit breaker transformer according to claim 4, characterized in that: The movable punches (17) are arranged in a ring array around the axis of the forming cavity (7).

6. A mold for a miniature circuit breaker transformer according to claim 4, characterized in that: The movable punch (17) includes an inclined guide surface (1701), which is set at an angle α with the mold opening direction. The movable punch (17) forms a slanted ejector mechanism for the part by means of the guide surface (1701) and the guide hole (18) and the rise of the first ejector pin (15). The included angle α ≤ 5°.

7. A mold for a miniature circuit breaker transformer according to claim 1, characterized in that: The molding cavity (7) includes a first cavity and a second cavity. The first cavity and the second cavity are respectively located on both sides of the pouring port (8) and are connected to the pouring port (8) through the fine nozzle (6) and the diversion channel (9).

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