An exhaust structure of a core pin of an upper tie plate product mold

Abstract

The utility model provides a kind of exhaust structure of upper link plate product mould core needle, including core needle, core needle is arranged with exhaust passage along its axial direction, the outer surface of the end of core needle is opened with recess along circumference direction, and the depth of recess is 0.03-0.1mm;Exhaust structure in the scheme is by in the end area of core needle most easily gas, process out the recess of depth less than the critical penetration depth of metal liquid, utilize the micro gap cooperation between the recess and its mounting hole, jointly form a narrow channel that only allows gas molecules to pass through and blocks metal liquid (or only allows to form very thin flash), this channel guides the high-pressure gas trapped near core needle to the main exhaust system of mould, finally, exhaust outside mould, to effectively reduce the blowhole defect of casting in this area, improve filling effect.

Description

Technical Field

[0001] This utility model relates to the field of product die casting technology, specifically to a venting structure for the core pin of an upper connecting plate product mold. Background Technology

[0002] Die casting molds are an indispensable key piece of equipment in the die casting process. They are specialized tools used to inject molten metal into the mold cavity under high pressure and high speed, and then rapidly cool and solidify it under pressure to form precision metal parts of the required shape and size. Among them, the venting structure of the core pin (ejector pin) in the die casting mold is crucial, as it directly affects the quality of the casting (porosity, incomplete filling, surface defects) and production efficiency. Furthermore, since the core pin is usually located deep in the casting or in complex areas, these locations are prone to air trapping.

[0003] In existing technologies, to improve the venting problem of the mandrel pin, a venting pin is usually specially set on one side of the mandrel pin. The venting pin and the corresponding ejector sleeve have a precisely controlled tiny gap, through which venting is performed. However, adding a separate venting pin requires extremely high manufacturing precision in the shape of the venting pin (gap control), is costly, and requires regular maintenance and cleaning of the channel to prevent blockage. Utility Model Content

[0004] In view of the deficiencies in the existing technology, the purpose of this utility model is to provide a simple and low-cost venting structure for the core pin of the mold of the upper connecting plate product.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] This application provides a venting structure for a mandrel pin of an upper plate product mold, including a mandrel pin, wherein the mandrel pin has a venting channel arranged along its axial direction, and the outer surface of the end of the mandrel pin has a groove along the circumferential direction, wherein the depth of the groove is 0.03-0.1mm.

[0007] Furthermore, the core needle includes a needle tip, a needle body, and a needle base. The needle tip is fixedly installed at the bottom end of the needle body, and the needle base is fixedly installed at the top end of the needle body. The needle tip is made of hard alloy material, and the needle body is made of hot work die steel.

[0008] Furthermore, the needle body has a threaded cooling channel along its axial direction inside, the needle seat has a liquid inlet at its outer end, the liquid inlet is connected to the upper end of the cooling channel, and the needle body has a liquid outlet at its bottom outer side, the liquid outlet is connected to the bottom end of the cooling channel.

[0009] Furthermore, the outer surface of the needle tip is provided with a plurality of evenly spaced concave recesses along the circumferential direction.

[0010] Furthermore, the tip of the needle has multiple evenly spaced spray holes on its end face near the casting, which are used to spray out a release agent to facilitate demolding.

[0011] Furthermore, the bottom end face of the needle holder is provided with spray holes evenly spaced along the circumferential direction, and the spray holes are used to spray cooling nitrogen gas onto the outer surface of the needle body.

[0012] Compared with the prior art, the beneficial technical effects of this solution are as follows: The venting structure in this solution processes a groove with a depth less than the critical penetration depth of the molten metal in the end region of the mandrel where it is most prone to trapping gas. The groove and the mounting hole are fitted with a micro-gap to form a narrow channel that allows only gas molecules to pass through while blocking the molten metal (or only allows the formation of extremely thin flash). This channel guides the high-pressure gas trapped near the mandrel to the main venting system of the mold and finally discharges it outside the mold, thereby effectively reducing the porosity defects of the casting in this area and improving the filling effect. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the venting structure of the core pin of the upper connecting plate product mold in the embodiments of this application.

[0014] Figure 2 This is a three-dimensional structural diagram of the venting structure of the mold core pin of the upper connecting plate product in this embodiment of the application, viewed from another angle.

[0015] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the diagram.

[0016] Figure 4 for Figure 2 A magnified schematic diagram of the structure at point B in the diagram.

[0017] In the picture:

[0018] 100-Exhaust structure;

[0019] 10-needle body;

[0020] 20 - Needle seat; 21 - Spray nozzle;

[0021] 30 - Needle tip; 31 - Groove; 32 - Exhaust channel; 33 - Injection hole; 34 - Recess;

[0022] 40 - Liquid inlet;

[0023] 50-liquid outlet. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] See Figure 1 , Figure 2 and Figure 4 As shown, this embodiment provides an exhaust structure 100 for a core pin of an upper connecting plate product mold, including a core pin. The core pin has an exhaust channel 32 arranged along its axial direction. The outer surface of the end of the core pin has a groove 31 along the circumferential direction, and the depth of the groove 31 is 0.03-0.1mm.

[0026] By machining a groove 31 with a depth less than the critical penetration depth of the molten metal in the end region of the mandrel where air is most easily trapped, and using the micro-gap fit between the groove 31 and its mounting hole, a narrow channel is formed that allows only gas molecules to pass through while blocking the molten metal (or only allows the formation of extremely thin flash). This channel guides the high-pressure gas trapped near the mandrel to the main exhaust system of the mold, and finally discharges it outside the mold, thereby effectively reducing the porosity defects in the casting in this region and improving the filling effect.

[0027] Reference Figure 1 and Figure 2 As shown, in this embodiment, the mandrel adopts a combined external structure, including a needle tip 30, a needle body 10, and a needle base 20. The needle tip 30 is fixedly installed at the bottom end of the needle body 10, and the needle base 20 is fixedly installed at the top end of the needle body 10. The connection between the needle tip 30, the needle base 20, and the needle body 10 can be fixed by threaded connection. Considering that the needle tip 30 is a vulnerable part, it is made of hard alloy material, giving it high strength. The needle body 10 is made of a material with good toughness, such as hot work die steel, thus achieving both good toughness and low production cost.

[0028] Continue to refer to Figure 1 and Figure 2As shown, in this embodiment, a spiral cooling channel is formed along its axial direction inside the needle body 10. A liquid inlet 40 is formed at the outer end of the needle seat 20, which is connected to the upper end of the cooling channel. A liquid outlet 50 is formed at the outer side of the bottom end of the needle body 10, which is connected to the bottom end of the cooling channel. The liquid inlet 40 and the liquid outlet 50 are also connected to an externally provided cooling source and a circulation pump, respectively. The liquid cooling source enters the spiral cooling channel inside the needle body 10 through the inlet 40 under the action of the circulation pump, flows along the cooling channel, and flows back to the cooling source from the liquid outlet 50. By providing a spiral cooling channel inside the needle body 10, the cooling channel can significantly improve cooling efficiency, extend service life, and improve the surface quality and dimensional stability of the casting.

[0029] Reference Figure 2 and Figure 3 As shown, spray holes 21 are evenly spaced along the circumferential direction on the bottom end face of the needle holder 20. The spray holes 21 are used to spray cooling nitrogen gas onto the outer surface of the needle body 10. After ejection and before mold closing, spraying cooling nitrogen gas onto the outer surface of the needle body 10 through the spray holes 21 can accelerate the cooling of the surface of the needle body 10 and reduce heat accumulation.

[0030] Reference Figure 2 and Figure 4 As shown, multiple evenly spaced injection holes 33 are provided on the end face of the needle tip 30 near the casting end along the circumferential direction. The injection holes 33 are used to spray out a release agent that facilitates demolding. In the instant before ejection, the release agent is precisely sprayed into the contact surface between the core needle and the casting through the injection holes 33, which can strongly promote separation and reduce adhesion and tearing.

[0031] Continue to refer to Figure 2 and Figure 4 As shown, the outer surface of the needle tip 30 is provided with a plurality of evenly spaced concave recesses 34 along the circumferential direction. The multiple concave recesses 34 are processed on the outer surface of the needle tip 30 by means of laser processing or etching. The setting of the recesses 34 can form tiny air holes, which can act like an "air cushion" to reduce the separation force.

[0032] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A venting structure for a core pin of an upper connecting plate product mold, characterized in that, The device includes a mandrel, which has an exhaust channel arranged along its axial direction, and the outer surface of the end of the mandrel has a groove along the circumferential direction, the depth of which is 0.03-0.1mm.

2. The venting structure of the upper connecting plate product mold core pin according to claim 1, characterized in that, The core needle includes a needle tip, a needle body, and a needle base. The needle tip is fixedly installed at the bottom end of the needle body, and the needle base is fixedly installed at the top end of the needle body. The needle tip is made of hard alloy material, and the needle body is made of hot work die steel.

3. The venting structure of the upper connecting plate product mold core pin according to claim 2, characterized in that, The needle body has a threaded cooling channel along its axial direction inside. The needle seat has a liquid inlet at its outer end, which is connected to the upper end of the cooling channel. The needle body has a liquid outlet at its bottom outer side, which is connected to the bottom end of the cooling channel.

4. The venting structure of the core pin of the upper connecting plate product mold according to claim 2 or 3, characterized in that, The outer surface of the needle tip is provided with a plurality of evenly spaced concave depressions along the circumferential direction.

5. The venting structure of the core pin of the upper connecting plate product mold according to claim 2 or 3, characterized in that, The needle tip has multiple evenly spaced spray holes on its end face near the casting, which are used to spray out a release agent to facilitate demolding.

6. The venting structure of the core pin of the upper connecting plate product mold according to claim 2 or 3, characterized in that, The bottom surface of the needle holder is provided with spray holes evenly spaced along the circumference, and the spray holes are used to spray cooling nitrogen gas onto the outer surface of the needle body.

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