A die-casting mold ejector pin mounting structure

Abstract

This utility model discloses a die-casting mold ejector pin mounting structure, including a runner plate, a mold frame, and ejector pins. The runner plate has an ejector pin through-hole, within which is a 0.5mm thick 304 or 316 stainless steel nest, in which the ejector pin slides. The nest has a flared structure at the junction of the runner plate and the mold frame, with a cone angle of 30°-60°, located within a countersunk hole at the end of the through-hole, its end face flush with the runner plate, sealing the gap between the nest and the through-hole to prevent molten aluminum from seeping in. The single-sided gap between the outer wall of the nest and the inner wall of the through-hole is 0.05-0.1mm, and the inner wall roughness Ra≤1.6μm, reducing sliding friction. In the event of ejector pin breakage, the nest, along with the remaining fragments and spilled aluminum, can be quickly removed, reducing maintenance time from 1-3 days to several hours. This structure is simple, low-cost, and readily available with spare parts, significantly improving production efficiency, reducing maintenance costs, and meeting the needs for cost reduction and efficiency improvement.

Description

Technical Field

[0001] This utility model belongs to the field of die casting mold technology, specifically relating to a die casting mold ejector pin mounting structure, which is particularly suitable for solving the problem of molten aluminum seeping into the ejector pin through-hole after the die casting mold ejector pin breaks. Background Technology

[0002] Die casting molds are widely used forming equipment in modern manufacturing, especially in the automotive, aerospace, and electronics industries, for producing high-precision, high-strength metal parts. Taking a 3500T shock absorber tower die casting mold as an example, the ejector pin through-holes within the mold frame are typically long, straight holes machined using deep-hole drilling, with a maximum length approaching 500mm. The single-sided clearance between the ejector pin and the through-hole sidewall is generally 1-2mm. The ejector pin passes through the through-hole and mates with the mold core to push the molded part out of the mold. However, due to potential shrinkage defects within the casting mold frame, the machined ejector pin through-hole walls may expose an uneven surface, or residual machining marks may result in rough sidewalls. These defects can cause serious problems in actual production.

[0003] Ejector pin breakage is a common anomaly in die-casting production. When an ejector pin breaks, hot molten aluminum easily seeps into the gap between the ejector pin and the through-hole. After cooling, it forms an aluminum block encasing the ejector pin, causing it to become stuck inside the through-hole and difficult to remove. Traditional repair methods usually require a fitter to repeatedly hammer or cut with tools, and may even require disassembling the mold frame, typically taking 1-3 days. This not only leads to production interruptions but also increases labor and equipment downtime costs, severely impacting production efficiency. Given the increasing cost pressures in the manufacturing industry, extending mold repair time significantly compresses profit margins, making it difficult to meet the demands for cost reduction and efficiency improvement.

[0004] In existing technologies, there are few solutions to the problem of aluminum leakage after ejector pin breakage. Some methods attempt to reduce jamming by improving the ejector pin material or increasing through-hole lubrication, but these solutions are costly and have limited effectiveness. For example, while using high-strength alloy ejector pins can reduce the probability of breakage, it cannot completely prevent molten aluminum from seeping into the through-hole, and high-strength materials are expensive, increasing mold manufacturing costs. Other solutions reduce friction by coating the inner wall of the through-hole with a lubricating coating, but the coating is prone to wear and failure in the high-temperature and high-pressure die-casting environment, resulting in high maintenance costs. Furthermore, existing technologies lack a structural solution for quickly cleaning out leaked aluminum and replacing the ejector pin after breakage, making it difficult to meet the needs of efficient and low-cost maintenance.

[0005] To address the aforementioned issues, there is an urgent market need for a die-casting mold ejector pin mounting structure that is simple in structure, low in cost, and capable of quickly repairing aluminum leakage issues following ejector pin breakage. By optimizing the structural design of the ejector pin through-hole, it is possible to prevent aluminum molten material from seeping in and to quickly remove the broken ejector pin and removed aluminum leakage in the event of an anomaly, thus restoring production efficiency. Simultaneously, this structure needs to be easy to manufacture and have readily available spare parts to meet the practical needs of large-scale production. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a die-casting mold ejector pin mounting structure to solve the problems in the prior art where aluminum melt seeps into the ejector pin through-hole after the ejector pin breaks, causing jamming, long repair time, and high cost. This structure achieves the functions of sealing the aluminum melt and quick disassembly by setting a nested structure within the ejector pin through-hole and equipping it with a flared opening.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A die-casting mold ejector pin mounting structure includes a runner plate, a mold frame, and ejector pins. The runner plate has an ejector pin through hole, and a nest is provided in the ejector pin through hole. The ejector pin is slidably disposed in the nest. One end of the nest at the junction of the runner plate and the mold frame has a flared structure. The flared structure seals the gap between the nest and the end of the ejector pin through hole to prevent molten aluminum from entering the gap.

[0009] Furthermore, the end of the ejector pin through hole is provided with a countersunk hole, and the flared structure is located in the countersunk hole, so that the end face of the flared structure is flush with the end face of the flow channel plate.

[0010] Furthermore, the cone angle of the flared structure is 30° to 60°.

[0011] Furthermore, the nest is a stainless steel tube with a thickness of 0.5 mm, and the nest is fitted with the inner wall of the ejector pin through hole with a clearance fit.

[0012] Furthermore, the single-sided gap between the nested outer wall and the inner wall of the ejector pin through hole is 0.05mm to 0.1mm.

[0013] Furthermore, the nesting material is 304 stainless steel or 316 stainless steel.

[0014] Furthermore, the inner wall surface of the nested structure is smooth, with a surface roughness Ra value of no more than 1.6 μm, in order to reduce the frictional resistance when the ejector pin slides.

[0015] The beneficial effects of this utility model are as follows:

[0016] The ejector pin mounting structure of this invention significantly improves the maintenance efficiency and production stability of die-casting molds by setting a nest within the ejector pin through hole and equipping it with a flared structure. The specific beneficial effects are as follows:

[0017] 1. Prevents aluminum molten material from seeping in and improves sealing: The nested flared structure fits tightly with the countersunk hole at the end of the ejector pin through-hole, sealing the gap and effectively preventing high-temperature aluminum molten material from seeping into the gap between the nest and the through-hole, thus avoiding the problem of the ejector pin getting stuck after the aluminum molten material cools down. The cone angle design (30°~60°) of the flared structure optimizes the sealing effect and ensures the stability of the nest during the ejector pin sliding process.

[0018] 2. Quick repair and reduced downtime: When the ejector pin breaks and aluminum leaks out, the nest can be easily removed along with the broken ejector pin fragment and the leaked aluminum. There is no need for a fitter to hammer or disassemble the mold frame for a long time. The repair time is reduced from the traditional 1-3 days to a few hours, which significantly reduces production interruption losses and improves equipment utilization.

[0019] 3. Low cost and readily available spare parts: The nesting is made of 0.5mm thick 304 or 316 stainless steel pipe. The material is universal and inexpensive. The flared structure can be machined on-site by a fitter without complicated manufacturing processes or special equipment. Spare parts can be obtained quickly, reducing procurement and inventory costs.

[0020] 4. Optimized sliding performance and extended service life: The surface roughness Ra value of the inner wall of the nest is no greater than 1.6μm, which reduces the frictional resistance during ejector pin sliding and reduces wear. The 304 or 316 stainless steel material has excellent corrosion resistance and high temperature resistance, adapting to the high temperature and high pressure environment of die-casting molds, thus extending the service life of the nest and ejector pin.

[0021] 5. Simple structure and convenient installation: The single-sided gap between the nest and the ejector pin through hole is 0.05-0.1mm, which ensures a tight fit and facilitates disassembly and assembly. The flared structure is located inside the countersunk hole, and the end face is flush with the runner plate, which does not affect the overall mold structure. Installation and maintenance are simple and suitable for large-scale production applications.

[0022] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0024] Figure 1 This is a schematic diagram of the ejector pin mounting structure of the die casting mold in this utility model.

[0025] Figure 2This is a schematic diagram of the nested structure in this utility model.

[0026] Figure 3 This is a schematic diagram of the nested horn-shaped structure in this utility model.

[0027] Reference numerals: 1-Ejector pin; 2-Nesting; 3-Ejector pin through hole; 4-Flow channel plate; 5-Flare mouth structure. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0031] Please see Figures 1-3 This is a die-casting mold ejector pin mounting structure, including a runner plate 4, a mold frame, and ejector pins 1. The runner plate 4 has ejector pin through holes 3, which are long, straight through holes machined using deep hole drilling, with a maximum length approaching 500mm. The single-sided clearance between the ejector pin 1 and the sidewall of the through hole is 1-2mm. Nesting devices 2 are provided within the ejector pin through hole 3, such as... Figure 2As shown, the nest 2 is a 0.5mm thick 304 or 316 stainless steel tube, and its outer wall is clearance-fitted with the inner wall of the ejector pin through hole 3, with a single-sided clearance of 0.05mm to 0.1mm, ensuring a tight fit while facilitating assembly and disassembly. The ejector pin 1 is slidably disposed within the nest 2, and the inner wall surface of the nest 2 is smooth with a surface roughness Ra value not exceeding 1.6μm to reduce the frictional resistance when the ejector pin 1 slides.

[0032] The nested part 2 has a flared structure 5 at one end where it connects to the runner plate 4 and the mold frame. The cone angle of the flared structure 5 is 30° to 60°, which optimizes the sealing effect. A countersunk hole is provided at the end of the ejector pin through-hole 3, and the flared structure 5 is located in the countersunk hole, with its end face flush with the end face of the runner plate 4, ensuring the flatness of the overall mold structure. The flared structure 5 seals the gap between the nested part 2 and the end of the ejector pin through-hole 3 by tightly fitting the countersunk hole, preventing high-temperature molten aluminum from seeping into the gap.

[0033] When ejector pin 1 breaks and aluminum leaks out, the nest 2 can be removed from the ejector pin through hole 3 along with the broken ejector pin fragment and the leaked aluminum. The nest 2 is made of ordinary stainless steel tubing, and the flared structure 5 is machined on-site by a fitter, resulting in low manufacturing costs and readily available spare parts. After removing the nest 2, a new nest and ejector pin can be quickly replaced, and production can be resumed. Figure 2 and Figure 3 The overall structure of the nested structure 2 and the details of the flared structure 5 are further shown to facilitate understanding of their relationship with the ejector pin through hole 3 and ejector pin 1.

[0034] The structural design of this embodiment is simple. The clearance fit between the nest 2 and the ejector pin through hole 3, as well as the countersunk hole installation method of the flared structure 5, ensures convenient installation and reliable sealing. The 304 or 316 stainless steel material gives the nest 2 excellent corrosion resistance and high temperature resistance, making it suitable for the high temperature and high pressure environment of die-casting molds and extending its service life.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A die-casting mold ejector pin mounting structure, comprising a runner plate, a mold frame, and ejector pins, characterized in that: The flow channel plate is provided with ejector pin through holes, and a nest is provided in the ejector pin through holes. The ejector pin is slidably disposed in the nest. One end of the nest at the junction of the flow channel plate and the mold frame is provided with a flared structure. The flared structure seals the gap between the nest and the end of the ejector pin through hole to prevent molten aluminum from entering the gap.

2. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The end of the ejector pin through hole is provided with a countersunk hole, and the flared structure is located in the countersunk hole, so that the end face of the flared structure is flush with the end face of the flow channel plate.

3. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The cone angle of the flared structure is 30° to 60°.

4. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The nest is a stainless steel tube with a thickness of 0.5 mm, and the nest is fitted with the inner wall of the ejector pin through hole with a clearance fit.

5. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The single-sided gap between the nested outer wall and the inner wall of the ejector pin through hole is 0.05mm to 0.1mm.

6. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The nesting material is 304 stainless steel or 316 stainless steel.

7. The die-casting mold ejector pin mounting structure according to claim 1, characterized in that: The inner wall of the nested structure has a smooth surface with a surface roughness Ra value of no more than 1.6 μm to reduce the frictional resistance when the ejector pin slides.

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