Injection mold

Abstract

The injection mold comprises a rear mold body and a sliding block, the sliding block moves to complete core pulling or mold closing, a product forming cavity is formed in the end of the sliding block in the sliding direction, the product forming cavity is provided with a product ejector pin which is used in cooperation with the product forming cavity and vertically ascends and descends, and the injection mold further comprises a protection mechanism which comprises a safety ejector pin and a limiting assembly. The safety ejector pin is parallel to the product ejector pin and ascends and descends along with the product ejector pin, a through hole for the upper portion of the safety ejector pin to penetrate through is formed in the sliding block, and when the product ejector pin completely retreats, the safety ejector pin synchronously and completely retreats from the through hole. The limiting assembly comprises a telescopic pin arranged in the rear mold in a telescopic mode, a limiting hole matched with the telescopic pin in an inserted mode is formed in the sliding block, the sliding block moves in a core pulling mode to drive the limiting hole to move to the position opposite to the telescopic pin, and the telescopic pin stretches out to be inserted into the limiting hole. The safety ejector pin can be prevented from being damaged by movement of the sliding block, so that long-time stable use of the safety ejector pin is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic part production, and particularly to an injection mold. Background Art

[0002] As Figure 9 shown, it is a common injection molded part, mainly used in electronic products. The structure of this type of part is relatively complex, so in the design of the mold structure, product ejector pins are usually designed under the rear mold slider. After the product is molded, the slider is first withdrawn a certain distance to complete the core pulling action, and then the molded product can be ejected through the product ejector pins. After the product is ejected, the product ejector pins need to return to their original positions, and the rear mold slider returns to the closed mold state under the action of the ejector rod and the closing force of the front and rear molds.

[0003] However, during the production process, the product ejector pins may not be able to fully return to their original positions. If the front and rear molds are closed at this time, the slider and the ejector pins will collide, resulting in damage to the slider or the ejector pins, and ultimately affecting the service life of the mold. For this reason, in the prior art, a safety ejector pin is used to limit the position of the slider. The safety ejector pin moves up and down synchronously with the product ejector pins. When the product ejector pins do not move down to the proper position, the safety ejector pins do not move down to the proper position either. The safety ejector pins cooperate with the slider. If the safety ejector pins do not move down to the proper position, the slider will be inserted into the safety ejector pins and the slider will not be able to move, so the product ejector pins will not be damaged by the movement of the slider when the product ejector pins do not descend to the proper position.

[0004] To enable the safety ejector pins and the slider to cooperate, the size of the safety ejector pins is appropriately smaller than the insertion holes of the slider, so that there can be a certain error in the sliding distance of the slider, and it can be ensured that the safety ejector pins can pass through the slider smoothly. In this structure, during the sliding process of the slider, the upper part of the safety ejector pins is easily damaged. In severe cases, the insertion of the safety ejector pins into the insertion holes of the slider will fail, and there is also the problem of frequent replacement of the safety ejector pins. To avoid damage to the safety ejector pins, the gap between the safety ejector pins and the insertion holes can be appropriately reduced, that is, the width dimension of the safety ejector pins is increased to increase the anti-deformation ability of the safety ejector pins. However, this method requires ensuring that the moving distance of the slider is the same each time, so that the insertion holes are just opposite to the safety ejector pins, and the sliding of the slider needs to be positioned. Therefore, there is a need for an injection mold that can ensure the limited sliding of the slider. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the present invention provides an injection mold, which solves the problems that the cooperation between the slider and the safety ejector pins in the prior art is likely to damage the safety ejector pins or is not convenient to cooperate with the safety ejector pins.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An injection mold includes a rear mold, on which a slidable slider is provided. The slider moves to complete core pulling or mold closing. At the end of the sliding direction of the slider, a product forming cavity is provided. The product forming cavity is provided with a product ejector pin that cooperates and vertically lifts and lowers. It further includes a protection mechanism, which includes a safety ejector pin and a limiting component. The safety ejector pin is parallel to the product ejector pin and rises and falls with the product ejector pin. A through hole for the upper part of the safety ejector pin to pass through is provided on the slider. When the product ejector pin is completely retracted, the safety ejector pin synchronously completely exits the through hole. The limiting component includes a telescopic pin telescopically arranged in the rear mold. A limiting hole that is inserted and cooperates with the telescopic pin is provided on the slider. When the slider moves for core pulling, it drives the limiting hole to move to the relative position of the telescopic pin, and the telescopic pin extends out and is inserted into the limiting hole.

[0007] Compared with the prior art, the present invention has the following beneficial effects: On the basis of the existing safety ejector pin for protecting the product ejector pin in the present application, a limiting component is also provided to limit the movement of the slider, ensuring that the safety ejector pin can be smoothly inserted into the through hole. Among them, the telescopic pin can adopt a spring plunger in the prior art. The telescopic pin can be used to position the moving distance of the slider so that the safety ejector pin can smoothly pass through the through hole. At this time, appropriately increasing the size of the safety ejector pin can increase the anti-deformation ability of the safety ejector pin, and further avoid the damage of the safety ejector pin caused by the movement of the slider, thereby ensuring the long-term stable use of the safety ejector pin.

[0008] Further, the telescopic pin is telescopically arranged in the installation hole on the rear mold. The upper part of the telescopic pin is in a wedge-shaped structure. When the slider moves for core pulling, it drives the telescopic pin to contract in the installation hole opened on the rear mold. The movement of the slider drives the limiting hole to move. When the limiting hole moves above the telescopic pin, the telescopic pin extends out of the installation hole and is inserted into the limiting hole.

[0009] Further, the limiting component further includes a limiting member for limiting the telescopic distance of the telescopic pin; The limiting member is used in cooperation with the safety ejector pin. When the safety ejector pin is not completely withdrawn from the through hole, the limiting member limits the moving distance of the telescopic pin, so that at least part of the telescopic pin is inserted into the limiting hole to limit the sliding distance between the slider and the rear mold.

[0010] Further, the limiting member includes a limiting post. One horizontal end of the limiting post contacts the safety ejector pin, and the other end is connected to the installation hole. When the safety ejector pin rises, it forces the limiting post to move, so that part of the limiting post contacts the telescopic pin to limit the moving distance of the telescopic pin.

[0011] Furthermore, one end of the limit post in contact with the safety ejector pin is provided with a guiding inclined surface. The safety ejector pin has a special-shaped rod structure with a smaller upper part and a larger lower part, and a transition inclined surface for cooperating with the guiding inclined surface is provided on the side of the safety ejector pin in contact with the limit post. When the safety ejector pin moves, the end of the limit post contacts the upper part or the middle-lower part of the safety ejector pin.

[0012] Furthermore, a return spring is provided at the bottom of the telescopic pin, and the return spring is fixed in the mounting hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a positional relationship diagram of the slider, the rear mold, and the injection molded part in the mold closing state in the present invention; Figure 2 is Figure 1 the enlarged view of part A in Figure 3 It is a positional relationship diagram of the slider, the rear mold, and the injection molded part in the core pulling state in the present invention; Figure 4 is Figure 3 the enlarged view of part B in Figure 5 It is a schematic structural diagram of the slider cooperating with the rear mold in the mold closing state in the present invention; Figure 6 is Figure 5 the enlarged view of part C in Figure 7 It is a schematic structural diagram of the slider cooperating with the rear mold in the core pulling state in the present invention; Figure 8 is Figure 7 the enlarged view of part D in Figure 9 It is a schematic structural diagram of the injection molded part produced by the present invention.

[0014] In the figure: rear mold 100, product forming cavity 110, chute 120, mounting hole 130, connection hole 140, injection molded part 200, slider 300, guiding hole 310, through hole 320, insert 330, limit hole 340, main product ejector pin 420, by-product ejector pin 410, safety ejector pin 500, transition inclined surface 510, telescopic pin 600, insertion part 610, sliding part 620, return spring 630, limit post 800, acting spring 810, guiding inclined surface 820. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0016] Such as Figure 1 、 3, as shown in Figures 5 and 7, the present application provides an injection mold, which is used to produce the injection molded part 200 product shown in the figure. The overall structure of the mold is equivalent to that of the existing mold, including a front mold, a rear mold 100, a mold core, a cooling system, etc. The present application mainly improves the structure of the rear mold 100 to avoid the problem that the product ejector pin is damaged by the slider 300 during mold closing when it is not fully retracted.

[0017] For this reason, the injection mold in the present application mainly includes a rear mold 100, on which a slidable slider 300 is provided. The slider 300 slides in the chute 120 on the rear mold 100. There are various ways for the slider 300 to slide, such as Figure 1 , 2 , as shown in Figures 3, 4, 5, and 7, in the present application, by using the inclined guide posts (not shown) and the inclined guide holes 310 on the slider 300, during the movement of the rear mold 100, under the action of the guide posts, the guide holes 310 can make the slider 300 move along the chute 120. An insert 330 is provided at the end of the slider 300. The movement of the slider 300 drives the insert 330 to move to complete the core pulling or mold closing operation. The slider 300 slides in the horizontal direction. A product forming cavity 110 is provided at the end of the sliding direction of the slider 300. The product forming cavity 110 is a chamber in the lower half. The product formed in the product forming cavity 110 needs to be demolded. For this reason, a product ejector pin that cooperates and moves vertically is provided in the product forming cavity 110. The number of product ejector pins can be set according to the structural characteristics of the product to ensure that the product ejector pin can smoothly eject the product. In this embodiment, the number of product ejector pins is five, one main product ejector pin 420 and four secondary product ejector pins 410. The four secondary product ejector pins 410 are grouped in pairs and are respectively located on both sides behind the main product ejector pin 420. The main product ejector pin 420 is used in cooperation with the slider 300. For this reason, the limit mechanism provided in the present application is actually used to protect the main product ejector pin 420. The present application mainly elaborates on the positional relationship and cooperation relationship between the main product ejector pin 420 and other components.

[0018] To avoid damage to the main product ejector pin 420 during use, the present application also provides a protection mechanism, which includes a safety ejector pin 500 and a limit component. As Figure 5 , 7 shown, the safety ejector pin 500 is the same as the safety ejector pin 500 in the prior art, mainly used to limit the slider 300. When the slider 300 performs core pulling movement, the through hole 320 opened on the slider 300 is located above the safety ejector pin 500. The safety ejector pin 500 is parallel to the product ejector pin and is slidably arranged in the rear mold 100. The safety ejector pin 500 and the product ejector pin lift and lower synchronously. When the product ejector pin is fully retracted, the safety ejector pin 500 completely exits the through hole 320 synchronously; when the product ejector pin is not fully retracted, the safety ejector pin 500 does not completely exit the through hole 320 synchronously, thereby protecting the product ejector pin.

[0019] To enable the safety ejector pin 500 to have better anti-deformation ability, under the condition of the through hole 320 with specific dimensions, the closer the dimensions of the safety ejector pin 500 are to those of the through hole 320, the better the anti-deformation ability. However, at this time, the smoothness of the insertion between the safety ejector pin 500 and the through hole 320 is worse. To enable the slider 300 and the safety ejector pin 500 to be smoothly inserted, the present application further provides a limiting component. The limiting component includes a telescopic pin 600 telescopically arranged in the rear mold 100. A limiting hole 340 for insertion and cooperation with the telescopic pin 600 is provided on the slider 300. When the slider 300 performs core-pulling movement, it drives the limiting hole 340 to move to the relative position of the telescopic pin 600, and the telescopic pin 600 extends out and is inserted into the limiting hole 340.

[0020] Based on the existing safety ejector pin 500 for protecting the product ejector pin, the present application also provides a limiting component to limit the movement of the slider 300, ensuring that the safety ejector pin 500 can be smoothly inserted into the through hole 320. Among them, the telescopic pin 600 can adopt a spring plunger in the prior art. The telescopic pin 600 can be used to position the moving distance of the slider 300, so that the safety ejector pin 500 can smoothly pass through the through hole 320. At this time, appropriately increasing the size of the safety ejector pin 500 can increase the anti-deformation ability of the safety ejector pin 500, thereby avoiding damage to the safety ejector pin 500 caused by the movement of the slider 300, and ensuring the long-term stable use of the safety ejector pin 500.

[0021] In the present application, since the slider 300 reciprocates horizontally and does not expand and contract in other directions, the telescopic pin 600 is telescopically arranged in the mounting hole 130 on the rear mold 100. Therefore, as shown in Figure 5 、 6 、7, and 8, in this embodiment, the slider 300 is horizontally slidably arranged on the rear mold 100. The telescopic pin 600 is vertically arranged below the slider 300. A vertically arranged mounting hole 130 is opened on the rear mold 100, and at least a part of the telescopic pin 600 is located in the mounting hole 130. An elastic member, such as a spring, is provided between the telescopic pin 600 and the mounting hole 130, which can realize the telescopic setting of the telescopic pin 600 under the action of an external force and the elastic member. To enable the insertion and cooperation between the telescopic pin 600 and the limiting hole 340, as shown in the figure, the upper part of the telescopic pin 600 is in a wedge-shaped structure. The limiting hole 340 is opened at the bottom of the slider 300, and the limiting hole 340 is a wedge-shaped structure matching the shape of the telescopic pin 600. Then, when the slider performs core-pulling movement, it drives the telescopic pin 600 to contract in the mounting hole 130 opened on the rear mold 100. The movement of the slider 300 drives the limiting hole 340 to move. When the limiting hole 340 moves above the telescopic pin 600, the telescopic pin 600 extends out of the mounting hole 130 and is inserted into the limiting hole 340 to realize the positioning connection between the telescopic pin 600 and the slider 300.

[0022] In some cases, when the size of the safety ejector pin 500 is smaller than the size of the through hole 320 (equivalent to the hole diameter) and the difference between the two is large, even with the positioning of the telescopic pin 600, the safety ejector pin 500 cannot be protected. Considering that when the safety ejector pin 500 is of a smaller size, the telescopic pin 600 can provide a protective effect on the movement of the safety ejector pin 500, the limiting component of the present application further includes a limiting member, which is used in cooperation with the safety ejector pin 500. When the safety ejector pin 500 has not completely withdrawn from the through hole 320, the limiting member limits the movement distance of the telescopic pin 600, so that at least part of the telescopic pin 600 is inserted into the limiting hole 340, and the sliding distance between the slider 300 and the rear mold 100 is limited. The present application uses the limiting member to limit the telescopic distance of the telescopic pin 600. Especially when the safety ejector pin 500 and the product ejector pin have not completely retracted, at this time, the limiting member can prevent the telescopic pin 600 from completely contracting. At least part of the telescopic pin 600 is inserted into the limiting hole 340, and the movement distance of the slider 300 along the rear mold 100 is limited. By the telescopic pin 600, the impact force of the slider 300 on the safety ejector pin 500 is offset, so as to have a certain protective effect on the safety ejector pin 500.

[0023] In the present application, in combination with the structure of the telescopic pin 600, to realize the limitation of the movement distance of the telescopic pin 600 by the limiting member, the positional relationship between the limiting member and the telescopic pin 600 is as Figure 5 、 6 、7, 8 show that the mounting hole 130 is a stepped hole with a larger upper part and a smaller lower part. The telescopic pin 600 is located in the upper part of the mounting hole 130. A return spring 630 is intercepted at the stepped position of the mounting hole 130. The lower end of the return spring 630 can be fixed to the stepped position of the mounting hole 130, or the return spring 630 can be directly placed at the stepped position of the mounting hole 130. Of course, the return spring 630 can also use other fixing methods to limit its deformation direction. The upper part of the return spring 630 contacts the bottom of the telescopic pin 600. When the telescopic pin 600 is subjected to an external pressure, the telescopic pin 600 contracts in the upper part of the mounting hole 130, and the return spring 630 is compressed. When the slider 300 moves until the limiting hole 340 is located above the telescopic pin 600, the return spring 630 resumes deformation and can drive the upper part of the telescopic pin 600 to be inserted into the limiting hole 340. In this embodiment, the telescopic pin 600 includes a plugging part 610 in the upper part and a sliding part 620 in the lower part. The upper part of the plugging part 610 is a wedge-shaped structure, and the sliding part 620 is a rod-shaped structure. The sliding part 620 penetrates through the return spring 630 and extends into the lower part of the mounting hole 130. To limit the movement distance of the plugging part 610, the structure below the wedge-shaped structure of the plugging part 610 of the present application has a larger size, and the mounting hole 130 is provided with a necking structure at the top. The necking structure is adapted to the size of the wedge-shaped structure, so that under the action of the return spring 630, the wedge-shaped structure of the plugging part 610 extends out of the mounting hole 130, and the structure below the wedge-shaped structure of the plugging part 610 is located in the mounting hole 130.

[0024] Combined with the movement principle of the telescopic pin 600, when the slider 300 moves, the telescopic pin 600 can expand and contract within the mounting hole 130. When the safety ejector pin 500 is not fully retracted (equivalent to the product ejector pin not being fully retracted), the limiting member needs to limit the movement of the telescopic pin 600 to protect the safety ejector pin 500. Based on the structure of the telescopic pin 600 in this application, the limiting member includes a limiting post 800. One horizontal end of the limiting post 800 contacts the safety ejector pin 500, and the other end is connected to the mounting hole 130. When the safety ejector pin 500 rises, it forces the limiting post 800 to move, causing a part of the limiting post 800 to contact the telescopic pin 600 to limit the movement distance of the telescopic pin 600. As Figure 5 、 6 shown in Figures 7 and 8, a connection hole 140 is formed in the rear mold 100. One end of the connection hole 140 communicates with the movement hole where the safety ejector pin 500 is located, and the other end of the connection hole 140 communicates with the mounting hole 130. The limiting post 800 is horizontally slidably arranged within the connection hole 140. The position of the connection hole 140 needs to ensure that when the telescopic pin 600 is inserted into the limiting hole 340 and the limiting post 800 extends into the mounting hole 130, the limiting post 800 is exactly located below the insertion portion 610. By limiting the telescopic pin 600 with the limiting post 800, when the safety ejector pin 500 is not fully retracted, the telescopic pin 600 cannot expand and contract under the action of the movement of the slider 300. Conversely, if the telescopic pin 600 cannot expand and contract, then the telescopic pin 600 can be inserted into the limiting hole 340 to lock the rear mold 100 and the slider 300, protecting the safety ejector pin 500 and avoiding the problem of damage to the safety ejector pin 500.

[0025] To enable the safety ejector pin 500 to drive the limit post 800 to move horizontally while rising, as shown in the figure, in the present application, a guiding inclined surface 820 is provided at one end of the limit post 800 in contact with the safety ejector pin 500. The guiding inclined surface 820 is inclined downward. The safety ejector pin 500 has a special-shaped rod structure with a smaller upper part and a larger lower part. A transition inclined surface 510 for cooperating with the guiding inclined surface 820 is provided on the side of the safety ejector pin 500 in contact with the limit post 800. The transition inclined surface 510 connects the upper and lower parts of the safety ejector pin 500. When the safety ejector pin 500 moves upward, the limit post 800 moves toward the installation hole 130 under the action of the transition inclined surface 510 until the end of the limit post 800 contacts the position with a larger dimension at the lower part of the safety ejector pin 500. When the safety ejector pin 500 retracts, the limit post 800 abuts against the safety ejector pin 500 and contacts the upper part of the safety ejector pin 500 through the transition inclined surface 510. Just setting the contact position between the limit post 800 and the upper part of the safety ejector pin 500 at the position where the top of the safety ejector pin 500 exits the through hole 320 can achieve the movement of the limit post 800 driven by the lifting of the safety ejector pin 500. Of course, to enable the limit post 800 to have sufficient "tensile force" to abut against the side wall of the safety ejector pin 500, as Figure 5 , 7 shown, the connection hole 140 has a structure with a larger end and a smaller end. The larger end of the connection is adjacent to the safety ejector pin 500. The limit post 800 has a special-shaped structure with a larger end and a smaller end similar to a 7-shaped structure. The larger end of the limit post 800 cooperates with the safety ejector pin 500. A working spring 810 is provided between the larger end of the limit post 800 and the smaller end of the connection hole 140. The working spring 810 is a compression spring. The cooperation between the connection hole 140 with a specific structure and the limit post 800 can achieve the limited sliding of the limit post 800. At the same time, the working spring 810 can make the limit post 800 abut against the side wall of the safety ejector pin 500 to achieve the setting purpose of the present application.

[0026] The principle of the present application: After the injection molded part 200 is formed, the mold is opened. The slider 300 slides on the rear mold 100 to realize the sliding core-pulling operation. The sliding position is positioned by the telescopic pin 600. Then, the product ejector pin and the safety ejector pin 500 move synchronously. The product ejector pin ejects the injection molded part 200 out of the product molding cavity 110 (as Figure 3As shown, the injection molded part 200 is unloaded. After unloading, the mold needs to be closed. At this time, the product ejector pin and the safety ejector pin 500 are retracted synchronously. At this time, when the safety ejector pin 500 and the product ejector pin are not fully retracted, the cooperation between the safety ejector pin 500 and the limit post 800 can lock the limit post 800 to the telescopic pin 600, thereby realizing the locking of the rear mold 100 and the slider 300. At this time, if the safety ejector pin 500 and the product ejector pin are fully retracted, correspondingly, the limit post 800 is reset under the action of the acting spring 810, the limit pin extends into the connection hole 140, and the telescopic pin 600 can be telescoped under the action of sliding to complete the mold closing operation.

[0027] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0029] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. An injection mold, comprising a rear mold (100), a slider (300) slidably arranged on the rear mold (100), the slider (300) moves to complete core pulling or mold closing, a product molding cavity (110) is arranged at the end of the slider (300) in the sliding direction, and the product molding cavity (110) is provided with a product ejector pin used in conjunction with and vertically lifted, characterized in that: It also includes a protection mechanism, which includes a safety ejector pin (500) and a limit assembly. The safety ejector pin (500) is parallel to the product ejector pin and rises and falls with the product ejector pin. The slider (300) is provided with a through hole (320) for the upper part of the safety ejector pin (500) to pass through. When the product ejector pin is fully retracted, the safety ejector pin (500) is synchronously and fully retracted from the through hole (320). The limiting assembly comprises a telescopic pin (600) telescopically arranged in the rear mold (100); a limiting hole (340) is provided on the slider (300) and is plugged with the telescopic pin (600); the slider (300) moves by core pulling, driving the limiting hole (340) to move to a position relative to the telescopic pin (600); and the telescopic pin (600) extends out and is plugged with the limiting hole (340).

2. The injection mold according to claim 1, characterized in that: The telescopic pin (600) is telescopically arranged in the mounting hole (130) on the rear mold (100), and the upper part of the telescopic pin (600) is a wedge-shaped structure. The slider (300) moves by core pulling, driving the telescopic pin (600) to shrink in the mounting hole (130) provided on the rear mold (100). The movement of the slider (300) drives the limiting hole (340) to move, and the limiting hole (340) moves to the top of the telescopic pin (600), and the telescopic pin (600) extends out of the mounting hole (130) and is plugged into the limiting hole (340).

3. The injection mold according to claim 1 or 2, characterized in that: The limiting assembly also includes a limiting member, which is used to limit the telescopic distance of the telescopic pin (600); The limiting member is used in conjunction with the safety ejector pin (500); when the safety ejector pin (500) has not completely withdrawn from the through hole (320), the limiting member limits the moving distance of the telescopic pin (600), so that at least part of the telescopic pin (600) is plugged into the limiting hole (340), thereby limiting the sliding distance between the slider (300) and the rear mold (100).

4. The injection mold according to claim 3, characterized in that: The limiting member comprises a limiting column (800), one horizontal end of the limiting column (800) contacts the safety ejector pin (500), and the other end is connected to the mounting hole (130). The safety ejector pin (500) rises, forcing the limiting column (800) to move, so that part of the limiting column (800) contacts the telescopic pin (600), thereby limiting the moving distance of the telescopic pin (600).

5. The injection mold according to claim 4, characterized in that: A guiding inclined surface (820) is provided at one end of the limiting column (800) that contacts the safety ejector pin (500); the safety ejector pin (500) is a special-shaped rod-shaped structure with a small upper portion and a large lower portion; and a transition inclined surface (510) used in conjunction with the guiding inclined surface (820) is provided at the contact side of the safety ejector pin (500) and the limiting column (800); the safety ejector pin (500) moves so that the end of the limiting column (800) contacts the upper portion or the middle and lower portion of the safety ejector pin (500).

6. The injection mold according to claim 5, characterized in that: A return spring (630) is provided at the bottom of the telescopic pin (600), and the return spring (630) is fixed in the mounting hole (130).

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