Injection mold with good sealing
By introducing an inner groove, inner parting ring, outer groove, outer parting ring, and sealing ring structure into the injection mold, the problems of gaps at the mold mating surfaces and ejector pin leakage are solved, achieving efficient sealing and stable demolding, thereby improving product quality and mold life.
Patent Information
- Application Number
- CN202522611086.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-12-09
AI Technical Summary
Existing injection molds are prone to gaps at the mating surfaces of the die holder and punch holder during high-pressure injection, leading to overflow. Furthermore, the lack of an effective sealing structure between the ejector pin and the mold mounting hole can cause problems such as glue leakage or jamming.
The structure employs an inner groove, an inner parting ring, an outer groove, an outer parting ring, and multiple sealing rings to form a stepped sealing surface. An inner sealing ring is set at the bottom of the ejector pin to cooperate with the outer sealing ring on the inner wall of the punch seat to ensure sealing performance.
It improves the sealing performance of injection molds, prevents leakage of molten raw materials, enhances product molding quality, extends mold life, and ensures stable operation.
Smart Images
Figure CN224928387U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of injection molding equipment technology, and in particular to an injection mold with good sealing performance. Background Technology
[0002] Injection molds are an indispensable and important process equipment in the molding and processing of plastic products. Injection molds mainly construct cavities to accommodate molten plastic by closing the cavity and the punch. During the injection molding process, the injection molding machine injects the high-temperature molten plastic liquid into the cavity at extremely high pressure, which places extremely high demands on the sealing performance of the injection mold.
[0003] However, existing injection molds use a simple planar contact sealing method at the mating surface of the die holder and the punch holder. When facing the high-pressure injection environment, the mold is prone to slight deformation under stress, resulting in gaps at the mating surface. Molten plastic liquid will overflow along the gaps and form flash or burrs on the product edges. This not only reduces the molding quality of the product, but also requires additional manpower and resources for subsequent trimming. At the same time, the ejector pins inside the existing injection molds need to maintain a clearance fit with the mold mounting holes in order to achieve the demolding action. In the absence of an effective sealing structure, this clearance can easily become a channel for leakage of molten material. After the material seeps into the gap and cools, it will increase the resistance of the ejector pin movement and even cause the ejector pin to jam, which seriously affects the service life and production efficiency of the injection mold.
[0004] Therefore, this utility model proposes an injection mold with good sealing performance to overcome the shortcomings of the prior art. Utility Model Content
[0005] In the existing technology, the simple planar contact sealing method used at the mold parting surface of the injection mold leads to gaps and overflow during high-pressure injection, and the lack of an effective sealing structure between the internal ejector pins and mounting holes can easily cause molten material to seep in, resulting in leakage or jamming. The present invention aims to provide an injection mold with improved structure that can effectively solve the above problems and has good sealing performance.
[0006] This utility model provides an injection mold with good sealing performance, including: a cavity mold base, multiple sets of guide pillars fixedly connected to the top of the cavity mold base, a guide sleeve slidably connected to the outer wall of the guide pillars, a punch mold base fixedly connected to the outer wall of the guide sleeve, and an inner parting ring, an inner groove, an outer parting ring, an outer groove, a positioning hole, a positioning pin, an electric push rod, a limiting ring, an ejector pin, an inner sealing ring, a limiting groove, and an outer sealing ring.
[0007] The die holder has an inner parting ring fixedly connected to the outer side of the concave surface at the top, an inner groove corresponding to the outer side of the convex surface at the bottom, an outer parting ring fixedly connected to the bottom of the punch at the outer side of the inner groove, a corresponding outer groove at the top, multiple sets of positioning holes at the top, multiple sets of positioning pins fixedly connected to the top, an electric push rod fixedly connected to the inner wall, a limit ring fixedly connected to the bottom end of the electric push rod, an ejector pin fixedly connected to the bottom of the limit ring, an inner sealing ring fixedly connected to the bottom end of the ejector pin, a limit groove at the inner wall, and an outer sealing ring fixedly connected to the bottom of the inner wall.
[0008] Furthermore, when the mold is closed, the inner groove is engaged with the inner wall of the inner parting ring, and when the mold is closed, the outer parting ring is engaged with the interior of the outer groove. The positioning pin can be engaged with the positioning hole. The limiting groove cooperates with the ejector pin to restrict the movement path of the inner sealing ring. The inner sealing ring cooperates with the outer sealing ring.
[0009] Preferably, the inner groove, the inner parting ring, the outer parting ring, and the outer groove together constitute a sealing mechanism. When the die seat and the punch seat are closed, the inner groove squeezes the inner wall of the inner parting ring and forms a line seal structure.
[0010] Preferably, the mating positions of the outer parting ring and the outer groove, and the mating positions of the inner groove and the inner parting ring, form a stepped parting surface, which increases the sealing contact area between the die seat and the punch seat.
[0011] Preferably, the engagement of the positioning pin and the positioning hole provides positioning for the punch seat and ensures that the inner parting ring and the inner groove, and the outer parting ring and the outer groove, can be smoothly engaged.
[0012] Preferably, the electric push rod, the limiting ring, the limiting groove, the ejector pin, the outer sealing ring, and the inner sealing ring together constitute a demolding mechanism. The electric push rod extends downward to drive the inner sealing ring to move downward and push the product to demold.
[0013] Preferably, the limiting groove is formed on the inner wall of the punch seat and located below the electric push rod. The inner diameter of the limiting groove is larger than the outer diameter of the ejector pin, so that the ejector pin can move within the guide range of the limiting groove.
[0014] Preferably, the inner sealing ring cooperates with the outer sealing ring to close the gap between the ejector pin and the punch seat, thereby enhancing the sealing effect during the injection molding process.
[0015] Preferably, the inner parting ring is fixedly connected to the edge of the concave surface at the top of the die holder, and the outer groove is formed on the plane at the top of the die holder, and the outer groove surrounds the periphery of the inner parting ring.
[0016] This utility model has the following beneficial effects: 1. This utility model solves the problems of poor planar sealing effect of existing injection molds and easy gaps during high-pressure injection molding that cause overflow in the product. It achieves the effects of increasing the sealing contact area, dispersing the mold clamping pressure, effectively preventing melt leakage by using multiple sealing structures, and improving the product molding quality.
[0017] 2. This utility model solves the problem that in traditional molds, the gap between the ejector pin and the mold through hole can easily cause molten material to seep in during injection, resulting in leakage or jamming. It achieves the effect of sealing the ejector pin gap with the sealing ring during injection to prevent leakage, and smoothly ejecting the product through the inner sealing ring during demolding, thereby ensuring the stability of mold operation and extending its service life. Attached Figure Description
[0018] Figure 1 This is a perspective view of the front side of an injection mold with good sealing performance proposed in this utility model; Figure 2 This is a partial structural exploded view of the cavity mold base of an injection mold with good sealing performance proposed in this utility model; Figure 3 This is a cross-sectional view of the cavity mold base of an injection mold with good sealing performance proposed in this utility model; Figure 4 This is a cross-sectional view of the punch holder of an injection mold with good sealing performance proposed in this utility model; Figure 5 This is a partial structural breakdown diagram of the ejector pin of an injection mold with good sealing performance proposed in this utility model.
[0019] Legend: 1. Die base; 2. Sealing mechanism; 201. Positioning hole; 202. Positioning pin; 203. Inner parting ring; 204. Outer groove; 205. Outer parting ring; 206. Inner groove; 3. Demolding mechanism; 301. Electric push rod; 302. Limiting ring; 303. Limiting groove; 304. Ejector pin; 305. Outer sealing ring; 306. Inner sealing ring; 4. Punch base; 5. Guide post; 6. Guide sleeve; 7. Product. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the protection scope of this utility model.
[0021] Example: Please refer to Figures 1 to 5 This utility model provides an injection mold with good sealing performance, which aims to solve the problems in the prior art where poor sealing effect of the parting surface during mold closing easily leads to overflow and leakage of glue easily occurs due to the gap between the traditional ejector pins.
[0022] Please refer to Figure 1 and Figure 2 A well-sealed injection mold includes a cavity mold base 1 and guide pillars 5 fixedly connected to the top of the cavity mold base 1. The cavity mold base 1 serves as the bottom mounting base of the overall device to bear the injection pressure and fix the lower mold part. Multiple sets of guide pillars 5 are distributed in a rectangular array at the four corners of the top of the cavity mold base 1 to provide vertical guiding reference. A guide sleeve 6 is slidably connected to the outer wall of the guide pillar 5. The inner wall of the guide sleeve 6 is precisely matched with the outer wall of the guide pillar 5 to achieve up-and-down reciprocating movement. A punch mold base 4 is fixedly connected to the outer wall of the guide sleeve 6. The punch mold base 4 is located above the cavity mold base 1 and serves as the upper mold part. The punch mold base 4 can drive the guide sleeve 6 to slide downward along the length direction of the guide pillar 5 through the drive of an external drive device, thereby realizing the mold closing action with the cavity mold base 1.
[0023] Please refer to Figure 3 , Figure 4 and Figure 5An inner parting ring 203 is fixedly connected to the outer side of the concave surface at the top of the die holder 1. The inner parting ring 203 is distributed in a ring-shaped protrusion along the edge of the concave surface of the die holder 1. An inner groove 206 is opened at the corresponding position on the outer side of the bottom convex surface of the punch holder 4. The shape and size of the inner groove 206 are adapted to the inner parting ring 203. When the die holder 1 and the punch holder 4 are closed, the inner parting ring 203 is embedded in the inner groove 206, and the inner wall of the inner groove 206 is in close contact with the outer wall of the inner parting ring 203, generating extrusion. At the same time, the bottom of the punch holder 4 is on the outer side of the inner groove 206. An outer parting ring 205 is fixedly connected. The outer parting ring 205 is an annular protrusion. An outer groove 204 is opened at the corresponding position on the top of the die holder 1. The outer groove 204 is an annular groove and surrounds the outer periphery of the inner parting ring 203. When the mold is closed, the outer parting ring 205 is embedded in the interior of the outer groove 204. The inner parting ring 203, together with the inner groove 206, and the outer parting ring 205, together with the outer groove 204, form a stepped parting surface. This stepped parting surface structure increases the sealing contact area between the die holder 1 and the punch holder 4 and disperses the clamping pressure.
[0024] Meanwhile, a demolding mechanism 3 is fixedly connected to the inner wall of the punch seat 4. The demolding mechanism 3 includes an electric push rod 301 fixedly connected to the top of the inner wall of the punch seat 4. The electric push rod 301 serves as a power source and is fixedly installed by bolts. A limit ring 302 is fixedly connected to the bottom output shaft of the electric push rod 301. An ejector pin 304 is fixedly connected to the bottom of the limit ring 302. The ejector pin 304 is vertically arranged along the central axis of the punch seat 4. An inner sealing ring 306 is fixedly connected to the bottom end of the ejector pin 304. Ring 306 directly contacts product 7. An outer sealing ring 305 is fixedly connected to the bottom of the inner wall of the punch seat 4. The outer sealing ring 305 is fixedly embedded in the through hole at the bottom of the punch seat 4. In the assembled state, the inner sealing ring 306 is slidably connected to the inner side of the outer sealing ring 305. An interference fit sealing contact surface is formed between the outer wall of the inner sealing ring 306 and the inner wall of the outer sealing ring 305. This fit structure ensures that the molten material cannot leak through the gap between the ejector pin 304 and the punch seat 4 during the injection molding process.
[0025] In a preferred embodiment, to ensure that the complex sealing structure can be precisely aligned without being damaged during mold closing, the top of the die holder 1 is provided with multiple sets of positioning holes 201, which are distributed on the outside of the outer groove 204. The top of the punch holder 4 is fixedly connected with multiple sets of positioning pins 202, and the positions of the positioning pins 202 correspond one-to-one with the positions of the positioning holes 201. During the mold closing process of the die holder 1 and the punch holder 4, the positioning pins 202 first contact the sealing mechanism 2 and are inserted into the positioning holes 201. The cooperation between the positioning pins 202 and the positioning holes 201 provides a precise positioning function for the punch holder 4, ensuring that the inner parting ring 203 is smoothly embedded into the inner groove 206 and the outer parting ring 205 is smoothly embedded into the outer groove 204.
[0026] In another preferred embodiment, in order to limit the demolding stroke and prevent the ejector pin 304 from shaking, a limiting groove 303 is provided on the inner wall of the punch seat 4. The limiting groove 303 is located below the output end of the electric push rod 301 and the length direction of the limiting groove 303 is parallel to the axial direction of the punch seat 4. The limiting ring 302 is slidably connected inside the limiting groove 303. The outer diameter of the limiting ring 302 is larger than the outer diameter of the ejector pin 304. The inner diameter of the limiting groove 303 is adapted to the outer diameter of the limiting ring 302. The limiting groove 303 limits the movement path of the inner sealing ring 306 by limiting the movement range of the limiting ring 302, and prevents the inner sealing ring 306 from falling out of the range of the outer sealing ring 305.
[0027] As another preferred embodiment, in order to further enhance the sealing performance and ensure the molding quality of product 7, the depth of the inner groove 206 is designed to be less than or equal to the height of the inner parting ring 203, so that the bottom or side wall of the inner groove 206 can generate sufficient clamping force on the inner parting ring 203 to form a line seal structure when the mold is closed. At the same time, the bottom surface of the inner sealing ring 306 remains flush with the bottom surface of the punch seat 4 in the injection molding state, avoiding the formation of uneven marks on the surface of product 7.
[0028] Working principle: When the mold is used to produce product 7, the external drive device drives the punch seat 4 to press down, and the guide sleeve 6 slides down along the guide post 5. Before the mold closes, the positioning pin 202 is first inserted into the positioning hole 201 for rough positioning. Then the punch seat 4 continues to press down, and the inner parting ring 203 enters the inner groove 206 and abuts tightly against the inner wall to generate extrusion and form a line seal. At the same time, the outer parting ring 205 enters the outer groove 204 to form a stepped seal. This multi-seal structure effectively prevents the molten material from overflowing from the parting surface. After injection molding is completed, the electric push rod 301 extends downward, causing the limiting ring 302 to slide downward in the limiting groove 303. The limiting ring 302 causes the ejector pin 304 and the inner sealing ring 306 at the bottom to move downward. The inner sealing ring 306 pushes the product 7 away from the punch seat 4. During this process, the inner sealing ring 306 always maintains a tight fit with the outer sealing ring 305, preventing the material from entering the gap of the ejector pin 304 during injection molding and demolding. Finally, the demolding work is achieved through the demolding mechanism 3, and the sealing effect during injection molding is improved.
Claims
1. An injection mold with good sealing performance, comprising: A die holder (1), multiple sets of guide posts (5) fixedly connected to the top of the die holder (1), a guide sleeve (6) slidably connected to the outer wall of the guide post (5), and a punch holder (4) fixedly connected to the outer wall of the guide sleeve (6). Its features are, An inner parting ring (203) is fixedly connected to the outer side of the concave surface at the top of the die holder (1). An inner groove (206) is opened at the corresponding position on the outer side of the convex surface at the bottom of the punch holder (4). When the mold is closed, the inner groove (206) is inserted into the inner wall of the inner parting ring (203). An outer parting ring (205) is fixedly connected to the outer side of the inner groove (206) at the bottom of the punch holder (4). A corresponding outer groove (204) is opened at the top of the die holder (1). When the mold is closed, the outer parting ring (205) is inserted into the interior of the outer groove (204). A number of positioning holes (201) are opened at the top of the die holder (1). A number of positioning pins (202) are fixedly connected to the top of the punch holder (4). The positioning pins (202) can be inserted into the positioning holes (201).
2. The injection mold with good sealing performance according to claim 1, characterized in that, The inner groove (206), the inner parting ring (203), the outer parting ring (205) and the outer groove (204) together constitute a sealing mechanism (2). When the die seat (1) and the punch seat (4) are closed, the inner groove (206) squeezes the inner wall of the inner parting ring (203) and forms a line sealing structure.
3. The injection mold with good sealing performance according to claim 1, characterized in that, The mating positions of the outer parting ring (205) and the outer groove (204), and the mating positions of the inner groove (206) and the inner parting ring (203) form a stepped parting surface, which increases the sealing contact area between the die seat (1) and the punch seat (4).
4. The injection mold with good sealing performance according to claim 1, characterized in that, The engagement of the positioning pin (202) and the positioning hole (201) provides positioning for the punch seat (4) and ensures that the inner parting ring (203) and the inner groove (206), and the outer parting ring (205) and the outer groove (204) are smoothly engaged.
5. The injection mold with good sealing performance according to claim 1, characterized in that, An electric push rod (301) is fixedly connected to the inner wall of the punch seat (4). A limit ring (302) is fixedly connected to the bottom end of the electric push rod (301). An ejector pin (304) is fixedly connected to the bottom of the limit ring (302). An inner sealing ring (306) is fixedly connected to the bottom end of the ejector pin (304). A limit groove (303) is formed on the inner wall of the punch seat (4). The limit groove (303) cooperates with the ejector pin (304) to restrict the movement path of the inner sealing ring (306). An outer sealing ring (305) is fixedly connected to the bottom of the inner wall of the punch seat (4). The inner sealing ring (306) cooperates with the outer sealing ring (305). The electric push rod (301), the limiting ring (302), the limiting groove (303), the ejector pin (304), the outer sealing ring (305), and the inner sealing ring (306) together constitute the demolding mechanism (3). The electric push rod (301) extends downward and can drive the inner sealing ring (306) to move down and push the product (7) to demold.
6. The injection mold with good sealing performance according to claim 5, characterized in that, The limiting groove (303) is opened on the inner wall of the punch seat (4) and located below the electric push rod (301). The inner diameter of the limiting groove (303) is larger than the outer diameter of the ejector pin (304) so that the ejector pin (304) can move within the guide range of the limiting groove (303).
7. The injection mold with good sealing performance according to claim 5, characterized in that, The inner sealing ring (306) cooperates with the outer sealing ring (305) to close the gap between the ejector pin (304) and the punch seat (4), thereby enhancing the sealing effect during the injection molding process.
8. The injection mold with good sealing performance according to claim 1, characterized in that, The inner parting ring (203) is fixedly connected to the edge of the concave surface at the top of the die holder (1), and the outer groove (204) is opened on the plane at the top of the die holder (1), and the outer groove (204) surrounds the outer periphery of the inner parting ring (203).