A split cast and drawn pin

Abstract

The utility model belongs to cast and pull out pin technical field discloses a kind of split cast and pull out pin, including pin body and detachable pin sleeve, pin body has protrusion, the inside of pin sleeve is provided with the anti-rotation key groove corresponding and matching with protrusion position, pin sleeve is set in the end of pin body by interference fit;The wear position of pin sleeve extends to the product part of pin body lower area, and forms stress buffer section, the outer surface of pin sleeve is covered with nanometer ceramic coating, and the thickness of nanometer ceramic coating is 0.05-0.1mm, friction coefficient≤0.15, the proportion of effective working length L of pin sleeve and diameter D satisfies 1.2≤L / D≤1.8.The utility model is designed by pin body and pin sleeve split type, allow when pin sleeve damage only replace pin sleeve, avoid the waste that traditional integrated pin needs overall replacement, while the wear-resistant design of pin sleeve to prolong its service life, the combination of both can significantly reduce accessory replacement frequency and material consumption, and shorten equipment downtime maintenance time and improve production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of casting and drawing pin technology, and in particular to a decomposable casting and drawing pin. Background Technology

[0002] Cast-out pins are a type of pin in the field of die casting technology. In the mold casting process, metal pins used to position castings or assist in demolding usually need to be pulled out from the solidified casting.

[0003] In the casting process, cast pins are subjected to mechanical and thermal stresses for a long time. The right-angle design at the root of the pin is prone to stress concentration, which leads to frequent breakage. Traditional one-piece cast pins have the following problems: 1) High maintenance cost: the entire pin needs to be replaced when the pin is partially damaged, resulting in serious material waste; 2) Low production efficiency: frequent shutdowns to replace parts affect the continuity of the production line; 3) Structural limitations: due to the shape of the part, the stress concentration problem cannot be solved by simple reinforcement. Therefore, we propose a decomposed cast pin. Utility Model Content

[0004] In view of the problems of high maintenance costs, low production efficiency and structural limitations of the existing one-piece cast-drawn pins, this utility model is proposed.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A decomposable cast-drawn pin includes a pin body and a detachable pin sleeve. The pin body has an integrally formed protrusion, and the pin sleeve has an anti-rotation keyway inside that corresponds to and matches the position of the protrusion. The pin sleeve is fitted onto the end of the pin body by an interference fit. The breakage location of the pin sleeve extends to the area below the workpiece portion of the pin body, forming a stress buffer section.

[0006] As a technical solution for the decomposition casting and drawing pin described in this utility model, the outer surface of the pin sleeve is covered with a nano-ceramic coating, and the thickness of the nano-ceramic coating is 0.05-0.1mm, and the coefficient of friction is ≤0.15.

[0007] As a technical solution for the decomposition casting and drawing pin described in this utility model, the ratio of the effective working length L of the pin sleeve to its diameter D satisfies 1.2≤L / D≤1.8.

[0008] As a technical solution for the decomposition casting and drawing pin described in this utility model, the pin sleeve is made of high-strength alloy steel, and the hardness of the pin sleeve is 3-5 degrees higher than that of the pin body.

[0009] As a technical solution for the decomposition casting and drawing pin described in this utility model, wherein: the stress buffer section and the pin body are provided with a transition chamfer with R≥2mm.

[0010] As a technical solution of the present invention, the decomposable casting and pulling pin is applicable to the ejection mechanism of aluminum alloy die casting mold.

[0011] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This utility model, through the separate design of the pin body and the pin sleeve, allows only the pin sleeve to be replaced when it is damaged, avoiding the waste of replacing the entire pin as required by the traditional one-piece pin. At the same time, the wear-resistant design of the pin sleeve extends its service life. The combination of the two can significantly reduce the frequency of parts replacement and material consumption, and shorten equipment downtime for maintenance and improve production efficiency.

[0012] 2. This utility model effectively disperses and alleviates the serious stress concentration problem caused by the traditional right-angle root design by setting a stress buffer section and using a large-radius transition chamfer at the connection between it and the main body. Combined with the optimized L / D ratio of the pin sleeve, it can improve the overall stress distribution and greatly improve the ability of the cast and drawn pin to resist cyclic loads and thermal stress, thereby significantly extending its service life and reducing failures caused by fracture.

[0013] 3. This utility model provides an extremely low coefficient of friction through an ultra-thin nano-ceramic coating on the outer surface of the pin sleeve, which can effectively reduce demolding resistance and reduce casting adhesion and pin sleeve wear. At the same time, the pin sleeve is made of high-strength alloy steel with a hardness higher than that of the pin body, which ensures that the pin sleeve has excellent wear resistance, deformation resistance and working stability in the harsh aluminum alloy die casting environment, while ensuring a smooth and reliable ejection process. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them: Figure 1 This is a schematic diagram of the main structure of this utility model.

[0015] Figure 2 This is a half-sectional structural diagram of the present invention.

[0016] Figure 3 This is a schematic diagram of the exploded main view structure of this utility model.

[0017] Figure 4This is a side view diagram of the exploded structure of this utility model.

[0018] Explanation of reference numerals in the attached figures: In the figure: 11, pin body; 111, protrusion; 12, pin sleeve; 121, anti-rotation keyway; 122, stress buffer section. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0021] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0022] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0023] Reference Figures 1-4 A disassembled cast-drawn pin is provided, which includes a pin body 11 and a detachable pin sleeve 12. The pin body 11 has an integrally formed protrusion 111. The pin sleeve 12 has an anti-rotation keyway 121 that corresponds to and matches the position of the protrusion 111. The pin sleeve 12 is fitted onto the end of the pin body 11 by interference fit. The breakage point of the pin sleeve 12 extends to the area below the workpiece part of the pin body 11, forming a stress buffer section 122. In application, when the pin sleeve 12 is damaged due to stress concentration or wear, only the pin sleeve 12 needs to be replaced, eliminating the need for integral casting and drawing of the pin. This directly solves the problems of high maintenance costs (requiring replacement of the entire pin for partial damage) and low production efficiency (frequent downtime for replacement) in traditional integral casting and drawing pins. At the same time, the cooperation between the protrusion 111 and the anti-rotation keyway 121 ensures that there is no relative rotation between the pin sleeve 12 and the pin body 11, guaranteeing that both function as... The overall ejection force is transmitted to maintain structural rigidity and function. At the same time, the interference fit ensures the firmness and tightness of the connection between the pin sleeve 12 and the pin body 11, preventing loosening or falling off during ejection. Furthermore, by designing the stress buffer section 122, the breakage location of the pin sleeve 12 is specifically designed in the area below the product part. By changing the geometry of this area, the stress peak at the right angle at the root can be effectively dispersed or alleviated. This can solve the problems of structural limitations (stress concentration cannot be solved by simple reinforcement) and frequent breakage, and can also significantly extend the fatigue life of the pin sleeve 12.

[0024] Reference Figure 1 , Figure 3 as well as Figure 4 The outer surface of the pin sleeve 12 is covered with a nano-ceramic coating with a thickness of 0.05-0.1mm and a friction coefficient of ≤0.15. In application, covering the outer surface of the pin sleeve 12 with an ultra-thin (0.05-0.1mm) nano-ceramic coating significantly reduces the friction coefficient (≤0.15), ensuring that the pin sleeve 12 has the characteristics of reducing demolding resistance, improving wear resistance and preventing aluminum adhesion, and extending its service life.

[0025] Reference Figures 1-4 The ratio of the effective working length L to the diameter D of the pin sleeve 12 satisfies 1.2≤L / D≤1.8. In application, the L / D ratio limit (1.2≤L / D≤1.8) design optimizes the ratio of the effective working length L to the diameter D of the pin sleeve 12, which can ensure sufficient stability.

[0026] Reference Figure 1 , Figure 3 as well as Figure 4 The pin sleeve 12 is made of high-strength alloy steel, and the hardness of the pin sleeve 12 is 3-5 degrees higher than that of the pin body 11. In application, the pin sleeve 12 uses a higher strength material, and its hardness (such as Rockwell hardness) is 3-5 degrees higher than that of the pin body 11 (such as HRC3-5), thereby enhancing its wear resistance and making it easier to replace.

[0027] Reference Figure 3 and Figure 4The stress buffer section 122 is provided with a transition chamfer with R≥2mm at the connection between it and the pin body 11. In application, providing a sufficiently large rounded transition (chamfer radius≥2mm) at the connection between the stress buffer section 122 and the pin body 11 can significantly reduce the stress concentration factor and improve fatigue strength.

[0028] Reference Figures 1-4 The decomposed casting-pull pin is suitable for the ejection mechanism of aluminum alloy die casting molds. In application, its specific application scenario should be clearly defined. Aluminum alloy die casting is characterized by high temperature, high pressure and rapid circulation, which places extremely high requirements on the heat resistance, wear resistance and thermal fatigue resistance of the ejection mechanism (especially the casting-pull pin). It provides an effective solution to the problems of stress concentration, wear and frequent maintenance.

[0029] The working principle of this utility model is as follows: Installation stage: Align the protrusion 111 of the pin body 11 with the anti-rotation keyway 121 on the pin sleeve 12, and then fix it with a special clamp and press it in until the interference fit is in place. Disassembly stage: When the surface coating of the pin sleeve 12 is worn by more than 30% or cracks are visible to the naked eye, the pin sleeve 12 can be heated to 200-250℃ (thermal expansion method) and removed while hot with a pin puller. Avoid violent disassembly that may damage the pin body 11.

[0030] 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 the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A decomposable casting-drawn pin, characterized in that: It includes a pin body (11) and a detachable pin sleeve (12). The pin body (11) has an integrally formed protrusion (111). The pin sleeve (12) has an anti-rotation keyway (121) inside that corresponds to and matches the position of the protrusion (111). The pin sleeve (12) is fitted onto the end of the pin body (11) by interference fit. The broken part of the pin sleeve (12) extends to the area below the workpiece part of the pin body (11) and forms a stress buffer section (122).

2. The decomposable casting and drawing pin according to claim 1, characterized in that: The outer surface of the pin sleeve (12) is covered with a nano-ceramic coating, and the thickness of the nano-ceramic coating is 0.05-0.1mm, and the coefficient of friction is ≤0.

15.

3. The decomposable casting and drawing pin according to claim 1, characterized in that: The ratio of the effective working length L to the diameter D of the pin sleeve (12) satisfies 1.2≤L / D≤1.

8.

4. The decomposable casting and drawing pin according to claim 1, characterized in that: The pin sleeve (12) is made of high-strength alloy steel, and the hardness of the pin sleeve (12) is 3-5 degrees higher than that of the pin body (11).

5. The decomposable casting and drawing pin according to claim 1, characterized in that: The stress buffer section (122) and the pin body (11) are connected by a transition chamfer with R≥2mm.

6. The decomposable cast-drawn pin according to any one of claims 1-5, characterized in that: The decomposable casting and pulling pin is suitable for the ejection mechanism of aluminum alloy die-casting molds.

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