Multi-stage ejector pin automatic demolding structure of injection mold

Abstract

The utility model discloses a multistage ejector pin automatic demoulding structure of an injection mould, and relates to the technical field of injection moulds, the multistage ejector pin automatic demoulding structure comprises a front mould base and a rear mould base, one ends, close to each other, of the front mould base and the rear mould base are respectively provided with a forming groove, and the rear mould base is composed of a U-shaped block, a first ejector pin plate, a second ejector pin plate and a bottom plate. The bottom of the U-shaped block is fixedly connected with the upper end of the bottom plate, a first ejector plate and a second ejector plate are arranged between the U-shaped block and the bottom plate, the first ejector plate is located above the second ejector plate, and four guide columns are fixedly installed at the upper end of the second ejector plate. When a formed part adheres to the interior of the forming groove, the buffering spring in the second-stage ejector pin can achieve the buffering effect, the acting force of the first-stage ejector pin on the formed part is gradually increased, and therefore the phenomenon that the formed part is indented due to the fact that the acting force of the first-stage ejector pin on the formed part is suddenly increased is avoided.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, specifically to an automatic demolding structure for multi-stage ejector pins in injection molds. Background Technology

[0002] Injection molding, as an efficient plastic product manufacturing process, occupies an important position in the plastic processing industry. This technology involves injecting molten plastic into a closed mold, allowing it to cool and solidify before opening the mold and removing the product. Injection molding is widely used in many fields such as automobiles, electronics, and medical devices due to its high production speed, high degree of automation, and ability to produce products with complex shapes.

[0003] Existing injection molds rely on the electric telescopic rod of the injection molding machine to push the ejector plate, causing the ejector pins on the plate to detach from the molded part. However, if the molded part adheres strongly to the molding groove and the extension speed of the electric telescopic rod remains constant, the force exerted by the ejector pins on the molded part can suddenly increase, easily causing indentations and affecting the quality of the molded part. Therefore, a multi-stage automatic ejector pin structure for injection molds is proposed. Utility Model Content

[0004] The purpose of this invention is to provide an automatic demolding structure for multi-stage ejector pins in injection molds to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a multi-stage ejector pin automatic demolding structure for injection molds, comprising a front mold blank and a rear mold blank, wherein molding grooves are respectively opened at the ends of the front mold blank and the rear mold blank that are close to each other; the rear mold blank is composed of a U-shaped block, a first ejector pin plate, a second ejector pin plate, and a base plate; the bottom of the U-shaped block is fixedly connected to the upper end of the base plate; a first ejector pin plate and a second ejector pin plate are arranged between the U-shaped block and the base plate; the first ejector pin plate is located above the second ejector pin plate; four guide pillars are fixedly installed on the upper end of the second ejector pin plate; the upper ends of the guide pillars slide through the first ejector pin plate and the U-shaped block in sequence; multiple first-stage ejector pins are fixedly installed on the upper end of the first ejector pin plate; the upper ends of the first-stage ejector pins slide through the U-shaped block; multiple second-stage ejector pins are arranged between the first ejector pin plate and the second ejector pin plate; the second-stage ejector pins are composed of a movable rod, a fixed sleeve, a limiting plate, and a buffer spring.

[0006] As a further preferred embodiment of this technical solution, the end of the front mold blank away from the rear mold blank is provided with an injection port that communicates with the molding groove.

[0007] As a further preferred embodiment of this technical solution, a through hole is provided at the center of the base plate.

[0008] As a further preferred of the technical scheme, the fixed sleeve is fixedly connected to the upper end of the second ejector plate, the movable rod is fixedly connected to the bottom of the first ejector plate, the bottom of the movable rod is fixedly connected to the limiting plate, the limiting plate is slidingly installed in the interior of the fixed sleeve, and the buffer spring is fixedly connected between the bottom of the limiting plate and the bottom of the inner cavity of the fixed sleeve.

[0009] As a further preferred of the technical scheme, the four reset springs are fixedly installed between the second ejector plate and the U-shaped block, the through slot accommodating the reset spring is formed in the first ejector plate, the interior of the reset spring is provided with the fixed column, the bottom of the fixed column is fixedly connected to the upper end of the second ejector plate, and the upper end of the fixed column slidingly penetrates the U-shaped block.

[0010] As a further preferred of the technical scheme, the aperture of the through slot is greater than the outer diameter of the reset spring.

[0011] As a further preferred of the technical scheme, the bottom of the front mold base is fixedly installed with the four positioning rods, the upper end of the rear mold base is provided with the four positioning holes corresponding to the four positioning rods respectively, and the positioning hole and the positioning rod slidingly fit.

[0012] The utility model provides a kind of multi-stage ejector automatic demolding structure of injection mold, with following beneficial effects:

[0013] The utility model discloses a kind of multi-stage ejector automatic demolding structure of injection mold, with following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the schematic diagram of the overall structure of the utility model;

[0015] Figure 2 It is the split schematic diagram of rear mold base in the utility model;

[0016] Figure 3 It is the structural schematic diagram of first ejector plate and second ejector plate in the utility model;

[0017] Figure 4 It is the front view of rear mold base in the utility model;

[0018] Figure 5 It is the structural schematic diagram of the utility model Figure 4 A in the utility model;

[0019] In the figure: 1, front die blank; 2, rear die blank; 3, positioning rod; 4, positioning hole; 5, injection port; 6, U-shaped block; 7, No. 1 ejector plate; 8, No. 2 ejector plate; 9, bottom plate; 10, forming groove; 11, primary ejector pin; 12, guide column; 13, fixed column; 14, return spring; 15, through groove; 16, secondary ejector pin; 17, movable rod; 18, fixed sleeve; 19, limiting plate; 20, buffer spring; 21, through hole. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model.

[0021] The utility model provides technical schemes: as Figures 1 to 5 The utility model discloses a multi-stage ejector pin automatic demolding structure of injection mold, which comprises a front die blank 1 and a rear die blank 2, the end of the front die blank 1 and the rear die blank 2 close to each other is respectively provided with a forming groove 10, the end of the front die blank 1 away from the rear die blank 2 is provided with an injection port 5 communicated with the forming groove 10, the rear die blank 2 is composed of a U-shaped block 6, a No. 1 ejector plate 7, a No. 2 ejector plate 8 and a bottom plate 9, the bottom of the U-shaped block 6 is fixedly connected with the upper end of the bottom plate 9, the center position of the bottom plate 9 is provided with a through hole 21, the No. 1 ejector plate 7 and the No. 2 ejector plate 8 are arranged between the U-shaped block 6 and the bottom plate 9, the No. 1 ejector plate 7 is located above the No. 2 ejector plate 8, the upper end of the No. 2 ejector plate 8 is fixedly installed with four guide columns 12, the upper end of the guide column 12 is sequentially slid through the No. 1 ejector plate 7 and the U-shaped block 6, the upper end of the No. 1 ejector plate 7 is fixedly installed with a plurality of primary ejector pins 11, the upper end of the primary ejector pin 11 is slid through the U-shaped block 6, a plurality of secondary ejector pins 16 are arranged between the No. 1 ejector plate 7 and the No. 2 ejector plate 8, the secondary ejector pin 16 is composed of a movable rod 17, a fixed sleeve 18, a limiting plate 19 and a buffer spring 20.

[0022] The fixed sleeve 18 is fixedly connected with the upper end of the No. 2 ejector plate 8, the movable rod 17 is fixedly connected with the bottom of the No. 1 ejector plate 7, the bottom of the movable rod 17 is fixedly connected with the limiting plate 19, the limiting plate 19 is slidably installed in the fixed sleeve 18, and the buffer spring 20 is fixedly connected between the bottom of the limiting plate 19 and the bottom of the inner cavity of the fixed sleeve 18.

[0023] In use, the second ejector plate 8 is pushed by the electric telescopic rod on the injection molding machine through the through hole 21 on the bottom plate 9, so that the second ejector plate 8 moves towards the U-shaped block 6, and under the action of the secondary ejector pin 16, the primary ejector pin 11 on the first ejector plate 7 can generate an ejecting force on the molded part in the forming groove 10, if the molded part is adhered in the forming groove 10 and cannot be ejected in real time, with the movement of the second ejector plate 8 towards the U-shaped block 6, the buffer spring 20 in the secondary ejector pin 16 can be compressed, and the rebound force of the buffer spring 20 can gradually increase the force of the primary ejector pin 11 acting on the molded part, so that the sudden increase of the force of the primary ejector pin 11 acting on the molded part is avoided, and the indentation of the molded part is avoided.

[0024] Among them, four reset springs 14 are fixedly installed between the second ejector plate 8 and the U-shaped block 6, a through groove 15 for accommodating the reset spring 14 is formed in the first ejector plate 7, a fixed column 13 is arranged in the reset spring 14, and the bottom of the fixed column 13 is fixedly connected to the upper end of the second ejector plate 8.

[0025] In use, when the second ejector plate 8 moves towards the U-shaped block 6, the reset spring 14 between the second ejector plate 8 and the U-shaped block 6 is compressed, and when the molded part is demolded, the electric telescopic rod on the injection molding machine is reset, at this time, the second ejector plate 8 loses the extrusion of the electric telescopic rod on the injection molding machine, and under the rebound action of the reset spring 14, the second ejector plate 8 is extruded to the upper end of the bottom plate 9, at the same time, the secondary ejector pin 16 on the second ejector plate 8 pulls the first ejector plate 7 and the primary ejector pin 11 to the initial position, and the force of the buffer spring 20 in the secondary ejector pin 16 can support the first ejector plate 7 and the plurality of primary ejector pins 11, so that the upper surface of the primary ejector pin 11 is aligned with the inner wall of the forming groove 10.

[0026] Among them, the hole diameter of the through groove 15 is greater than the outer diameter of the reset spring 14.

[0027] In this way, it can be guaranteed that the reset spring 14 and the through groove 15 will not interfere with each other.

[0028] Among them, the bottom of the front mold 1 is fixedly installed with four positioning rods 3, the upper end of the rear mold 2 is provided with four positioning holes 4 corresponding to the four positioning rods 3 respectively, and the positioning hole 4 and the positioning rod 3 are in sliding fit.

[0029] The positioning rod 3 and the positioning hole 4 can ensure that the front mold 1 and the rear mold 2 can be aligned when the front mold 1 and the rear mold 2 are closed.

[0030] The utility model provides a kind of injection mold multistage ejector pin automatic demolding structure, specific working principle as follows:

[0031] In use, the front mold base 1 is installed at the injection end of the injection molding machine, and the rear mold base 2 is installed at the driving end of the injection molding machine, the closing of the rear mold base 2 and the front mold base 1 can be controlled through the driving end of the injection molding machine, when the molded part needs to be demolded after injection molding, the second ejector plate 8 is pushed through the through hole 21 on the bottom plate 9 by the electric telescopic rod on the injection molding machine, so that the second ejector plate 8 moves towards the U-shaped block 6, under the action of the secondary ejector pin 16, the primary ejector pin 11 on the first ejector plate 7 will generate an ejecting force on the molded part in the molding groove 10, if the molded part is adhered in the molding groove 10 and cannot be ejected in real time, with the movement of the second ejector plate 8 towards the U-shaped block 6, the buffer spring 20 in the secondary ejector pin 16 will be compressed, and the rebound force of the buffer spring 20 can gradually increase the force of the primary ejector pin 11 acting on the molded part, thereby avoiding that the force of the primary ejector pin 11 acting on the molded part is suddenly increased to cause indentation of the molded part.

[0032] When the second ejector plate 8 moves towards the U-shaped block 6, the reset spring 14 between the second ejector plate 8 and the U-shaped block 6 will be compressed, when the molded part is demolded, the electric telescopic rod on the injection molding machine will reset, at this time, the second ejector plate 8 loses the compression of the electric telescopic rod on the injection molding machine, under the rebound action of the reset spring 14, the second ejector plate 8 will be compressed to the upper end of the bottom plate 9, at the same time, the secondary ejector pin 16 on the second ejector plate 8 will pull the first ejector plate 7 and the primary ejector pin 11 to the initial position, and the force of the buffer spring 20 in the secondary ejector pin 16 can support the first ejector plate 7 and the plurality of primary ejector pins 11, so that the upper surface of the primary ejector pin 11 is aligned with the inner wall of the molding groove 10.

[0033] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and modifications can be made to the embodiments without departing from the principles and spirits of the present application, the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A multi-stage ejector pin automatic demolding structure of an injection mold, comprising a front mold base (1) and a rear mold base (2), characterized in that: The front die blank (1) and the rear die blank (2) are provided with a forming groove (10) at one end close to each other, the rear die blank (2) is composed of a U-shaped block (6), a first ejector plate (7), a second ejector plate (8) and a bottom plate (9), the bottom of the U-shaped block (6) is fixedly connected with the upper end of the bottom plate (9), the first ejector plate (7) and the second ejector plate (8) are arranged between the U-shaped block (6) and the bottom plate (9), the first ejector plate (7) is located above the second ejector plate (8), four guide columns (12) are fixedly installed at the upper end of the second ejector plate (8), the upper ends of the guide columns (12) sequentially slide through the first ejector plate (7) and the U-shaped block (6), a plurality of first ejector pins (11) are fixedly installed at the upper end of the first ejector plate (7), the upper ends of the first ejector pins (11) slide through the U-shaped block (6), a plurality of second ejector pins (16) are arranged between the first ejector plate (7) and the second ejector plate (8), the second ejector pin (16) is composed of a movable rod (17), a fixed sleeve (18), a limiting plate (19) and a buffer spring (20).

2. The multi-stage ejector pin automatic demolding structure of an injection mold according to claim 1, characterized in that: The front die blank (1) is provided with an injection port (5) at one end away from the rear die blank (2), which communicates with the forming groove (10).

3. The multi-stage ejector pin automatic demolding structure of an injection mold according to claim 1, characterized in that: A through hole (21) is formed at the center position of the bottom plate (9).

4. The multi-stage ejector pin automatic demolding structure of an injection mold according to claim 1, characterized in that: The fixed sleeve (18) is fixedly connected with the upper end of the second ejector plate (8), the movable rod (17) is fixedly connected with the bottom of the first ejector plate (7), the bottom of the movable rod (17) is fixedly connected with the limiting plate (19), the limiting plate (19) is slidingly installed in the fixed sleeve (18), and the buffer spring (20) is fixedly connected between the bottom of the limiting plate (19) and the bottom of the inner cavity of the fixed sleeve (18).

5. The multi-stage ejector pin automatic ejection structure of an injection mold according to claim 1, characterized in that: Four reset springs (14) are fixedly installed between the second ejector plate (8) and the U-shaped block (6), a through slot (15) is formed in the first ejector plate (7) for accommodating the reset spring (14), a fixed column (13) is arranged in the reset spring (14), the bottom of the fixed column (13) is fixedly connected with the upper end of the second ejector plate (8), and the upper end of the fixed column (13) slides through the U-shaped block (6).

6. The multi-stage ejector pin automatic demolding structure of an injection mold according to claim 5, characterized in that: The aperture of the through slot (15) is larger than the outer diameter of the reset spring (14).

7. The multi-stage ejector pin automatic ejection structure of an injection mold according to claim 1, characterized in that: Four positioning rods (3) are fixedly installed at the bottom of the front die blank (1), four positioning holes (4) are formed at the upper end of the rear die blank (2), and the positioning holes (4) and the positioning rods (3) are slidingly fitted.

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