Die casting deep hole finishing device

Abstract

The utility model relates to deep hole machining device technical field discloses die casting deep hole finish machining device, including female die, male die, work piece deep hole positioning cavity, extrusion pin mechanism, drive mechanism and deep hole cooling mechanism. Adopt this structure, can move through drive mechanism and push extrusion pin mechanism, force push the metal liquid that has not solidified fills the contraction space, breaks the problem of outer layer solidification hindering make up, and the pressure makes the metal structure of work piece more dense, reduces the blowhole, loose of deep hole setting place, improves air tightness, and simultaneously is provided with deep hole cooling mechanism, and extrusion pin mechanism can quickly absorb the heat of die casting work piece deep hole wall thickness place, accelerates the solidification speed from surface layer to core, shortens the solidification time of die casting work piece deep hole position, and improves cooling uniformity, effectively avoids the problem that the shrinkage cavity leads to the problem that the rejection rate is too high.

Description

Technical Field

[0001] This utility model relates to the technical field of deep hole machining devices, specifically a deep hole precision machining device for die-cast parts. Background Technology

[0002] Shrinkage cavities are a critical quality defect and a major cause of scrap in aluminum alloy die castings. Their formation mechanism stems from the shrinkage characteristics of the molten alloy during solidification. Due to uneven wall thickness, thinner sections solidify preferentially, hindering the flow of the molten alloy and pressure transmission. In particular, some workpieces have pre-cast deep holes during the die casting process, typically located in areas of thick wall thickness. These deep holes create thermal hotspots and uneven wall thickness, resulting in slower cooling rates in these thicker areas. This uneven thermal shrinkage easily leads to shrinkage cavities, causing a decrease in the density of the finished workpiece and a high failure rate in airtightness tests. Utility Model Content

[0003] This utility model mainly provides a deep hole precision machining device for die castings, which solves the problem that the deep hole of the workpiece is located in the thick wall area. Due to the heat points and uneven wall thickness around the deep hole, the local cooling rate of the thick area is slow, which easily leads to shrinkage cavities due to uneven thermal shrinkage, resulting in decreased tightness and high airtightness leakage rate.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A deep hole finishing device for die castings includes a concave mold and a convex mold that form a cavity after mold closing. The convex mold has multiple deep hole positioning cavities for the workpiece. Each deep hole positioning cavity has a slidingly mounted extrusion pin mechanism, and a drive mechanism located outside the convex mold to move the extrusion pin mechanism. The extrusion end of the extrusion pin mechanism extends into the cavity, and a deep hole cooling mechanism is provided on the extrusion pin mechanism. The drive mechanism can be any existing type, as long as it can drive the extrusion pin mechanism to slide within the deep hole positioning cavity. Specifically, it is located at the rear end of the convex mold, can be hydraulically driven, and has a stroke control component to extrude the deep hole within its travel stroke. In use, after the die and punch close to form a cavity, the extrusion pin mechanism is in an immobile position. Subsequently, molten aluminum enters the cavity through the gating system on the die or punch, filling the entire workpiece. At this time, the original forming position of the deep hole in the workpiece is filled with molten aluminum before the extrusion pin mechanism enters. When the molten aluminum begins to solidify and form a "hard shell", but the center is still in a semi-molten state, the drive mechanism moves the extrusion pin mechanism and inserts it into the forming cavity of the workpiece, applying pressure to the semi-solidified metal in the deep hole. The pressure causes the molten metal to flow to the solidified and contracted area around the deep hole, filling the shrinkage cavities and porosity that may occur around the deep hole due to wall thickness and heat spots. After the extrusion pin mechanism forms to the preset deep hole forming depth, it does not retract and continues until the die-cast workpiece is completely solidified. After the extrusion pin mechanism has traveled its stroke, the deep hole cooling mechanism can drive the heat out of the thick wall area of ​​the workpiece, accelerating the cooling and forming of that area. This structure allows the extrusion pin mechanism to be moved by the drive mechanism, forcibly pushing the undiluted molten metal to fill the shrinkage space, breaking the problem of the outer layer solidifying and hindering the feeding process. The pressure also makes the metal structure of the workpiece denser, reducing porosity and looseness at the deep hole location and improving airtightness. At the same time, a deep hole cooling mechanism is provided, which allows the extrusion pin mechanism to quickly absorb the heat from the wall thickness of the deep hole in the die-cast workpiece, accelerating the solidification speed from the surface to the core, shortening the solidification time of the deep hole part of the die-cast workpiece, and improving the cooling uniformity, effectively avoiding the problem of excessive scrap rate caused by shrinkage.

[0006] Furthermore, a guide sleeve is provided inside the deep hole positioning cavity of the workpiece; an annular groove is formed at one end of the deep hole positioning cavity near the mold cavity, and an annular conical surface is provided on the deep hole positioning cavity of the workpiece corresponding to the rear side of the annular groove; the extrusion pin mechanism includes a sliding body slidably connected to the guide sleeve, a connecting seat provided on the rear side of the sliding body, and an extrusion body provided at the front end of the sliding body, and a mating conical surface that matches the annular conical surface is provided at the connection between the extrusion body and the sliding body; an O-ring seal that matches the extrusion body is provided inside the annular groove; the connecting seat is fixedly connected to the drive mechanism. Specifically, an exhaust hole communicating with the outside of the mold is provided at the bottom of the deep hole positioning cavity of the workpiece to prevent air in the fitting gap from being compressed and forming high pressure during extrusion. The O-ring seal can be made of fluororubber material, with a temperature resistance of over 200℃. Specifically, the guide sleeve is installed inside the deep hole positioning cavity of the workpiece, and the sliding body is slidably connected to the inner wall of the guide sleeve, with a precise fit. The outer surface of the sliding body can be ion nitrided, and the inner wall of the guide sleeve is TD coated. The combination of the two can significantly reduce the coefficient of friction. In use, the extrusion body remains in its original position before insertion, with the O-ring contacting the end sidewall of the extrusion body to form a seal. The drive mechanism connects to the connecting seat, which drives the sliding body to move within the guide sleeve. After the sliding and extrusion bodies move, the extrusion body inserts into the cavity. The mating conical surface at the connection between the extrusion body and the sliding body contacts the annular conical surface of the deep hole positioning cavity of the workpiece, forming a second seal. Simultaneously, the guide sleeve guides the sliding body. This structure guides the movement of the sliding body through the guide sleeve. An annular groove is created at the end of the deep hole positioning cavity near the cavity, and an O-ring that mates with the extrusion body is placed within the groove, forming a primary seal. Furthermore, the annular conical surface, in conjunction with the moving mating conical surface, further blocks molten aluminum after contact and closure, preventing its entry and forming a secondary seal.

[0007] Furthermore, the sliding body penetrates the connecting seat, and a first through hole is formed within both the sliding body and the pressurizing body; the deep-hole cooling mechanism includes a liquid distributor head disposed at the rear end of the sliding body, the liquid distributor head having a liquid distributor hole, the liquid distributor hole having a liquid distributor plug, and the liquid distributor plug having a partition plate for dividing the liquid distributor hole into a second through hole and a third through hole, and the partition plate being insertable into the first through hole; the liquid distributor head having an inlet hole communicating with the second through hole and an outlet hole communicating with the third through hole, and the liquid distributor plug having a connecting hole for connecting the second through hole and the inlet hole; the inlet hole and the outlet hole are connected to the coolant circulation assembly. Specifically, after the partition plate is inserted into the first through hole, it forms a flow passage with the inner wall of the pressurizing body at the end of the first through hole. Specifically, the coolant circulation assembly can utilize existing technology, as long as its technical principle can be achieved. This includes coolant storage components and pipes, forming a coolant flow loop with inlet and outlet ports and corresponding components. It also includes a circulation pump to drive coolant circulation and a heat dissipation component to cool the coolant. In use, the coolant circulation assembly drives the coolant from the inlet port and connecting hole into the second through hole, then from the second through hole into one side of the first through hole separated by a partition plate. The partition plate and the extrusion body at the end of the first through hole form a flow passage. The coolant flows from the flow passage to the other side of the first through hole separated by the partition plate, finally flowing into the third through hole and exiting through the outlet port, returning to the coolant circulation assembly. Using this structure, a cooling channel is formed within the sliding body and extrusion body through a deep-hole cooling mechanism, connecting to the coolant circulation mechanism. Active cooling enhances and accelerates the solidification efficiency of the deep-hole wall thickness of the die-cast workpiece. Utilizing the pressure-feeding method of extrusion and forced cooling, the metal solidification speed is accelerated, further reducing shrinkage and improving production efficiency.

[0008] Furthermore, the connecting seat includes a first seat body disposed on the sliding body, a plurality of connecting rods disposed on the first seat body, and a second seat body disposed at the outer end of the connecting rods. The second seat body is detachably connected to the output end of the drive mechanism. With this structure, the piping to the coolant circulation assembly can pass through the gaps between the connecting rods.

[0009] Furthermore, the rear end of the sliding body is threadedly connected to the liquid distribution plug. This structure facilitates a detachable connection between the sliding body and the liquid distribution plug.

[0010] Beneficial effects: The extrusion pin mechanism can be driven by the drive mechanism to move, forcibly pushing the undiluted molten metal to fill the shrinkage space, breaking the problem of the outer solidification hindering the feeding, and the pressure makes the metal structure of the workpiece more compact, reducing porosity and looseness at the deep hole setting, and improving airtightness; at the same time, a deep hole cooling mechanism is set, and the extrusion pin mechanism can quickly absorb the heat of the wall thickness of the deep hole of the die-cast workpiece, accelerate the solidification speed from the surface to the core, shorten the solidification time of the deep hole part of the die-cast workpiece, and improve the cooling uniformity, effectively avoiding the problem of excessive scrap rate caused by shrinkage. Attached Figure Description

[0011] Figure 1 This is a slanted view of the extrusion pin mechanism in this embodiment;

[0012] Figure 2 This is a cross-sectional schematic diagram of the extrusion pin mechanism in this embodiment;

[0013] Figure 3 This is a schematic diagram of the extrusion pin mechanism installed on the punch in this embodiment.

[0014] Reference numerals: 1. Punch; 2. Workpiece deep hole positioning cavity; 3. Extrusion pin mechanism; 3. Sliding body; 301. Extrusion body; 302. Mating conical surface; 303. First through hole; 304. First seat; 305. Connecting support rod; 306. Second seat; 307. Drive mechanism; 4. Guide sleeve; 5. Annular conical surface; 6. O-ring seal; 7. Liquid distributor; 8. Liquid distributor hole; 801. Liquid distributor plug; 802. Second through hole; 803. Third through hole; 804. Divider plate; 805. Liquid inlet hole; 806. Liquid outlet hole; 807. Connecting hole; 808. Detailed Implementation

[0015] The technical solution of the deep hole precision machining device for die castings involved in this utility model will be further described in detail below with reference to the embodiments.

[0016] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0017] like Figure 1 , Figure 2 , Figure 3As shown, the die casting deep hole finishing device of this embodiment includes a concave mold and a convex mold 1 that form a cavity after mold closing. The convex mold 1 has multiple workpiece deep hole positioning cavities 2. Each workpiece deep hole positioning cavity 2 is slidably provided with an extrusion pin mechanism 3, and a driving mechanism 4 is provided outside the convex mold 1 to drive the extrusion pin mechanism 3 to move. The extrusion end of the extrusion pin mechanism 3 extends into the cavity, and a deep hole cooling mechanism is provided on the extrusion pin mechanism 3. A guide sleeve 5 is provided inside the deep hole positioning cavity 2 of the workpiece; an annular groove is provided at one end of the deep hole positioning cavity 2 near the cavity, and an annular conical surface 6 is provided on the rear side of the deep hole positioning cavity 2 corresponding to the annular groove; the extrusion pin mechanism 3 includes a sliding body 301 slidably connected to the guide sleeve 5, a connecting seat provided on the rear side of the sliding body 301, and an extrusion body 302 provided at the front end of the sliding body 301, and a mating conical surface 303 that mates with the annular conical surface 6 is provided at the connection between the extrusion body 302 and the sliding body 301; an O-ring 7 that mates with the extrusion body 302 is provided in the annular groove; the connecting seat is fixedly connected to the drive mechanism 4. The sliding body 301 penetrates the connecting seat, and a first through hole 304 is provided in both the sliding body 301 and the extrusion body 302; the deep hole cooling mechanism includes a liquid distribution head 8 disposed at the rear end of the sliding body 301, a liquid distribution hole 801 disposed in the liquid distribution head 8, a liquid distribution plug 802 disposed in the liquid distribution hole 801, a partition plate 805 disposed on the liquid distribution plug 802 for dividing the liquid distribution hole 801 into a second through hole 803 and a third through hole 804, and the partition plate 805 can be inserted into the first through hole 304; the liquid distribution head 8 is provided with an inlet hole 806 communicating with the second through hole 803 and an outlet hole 807 communicating with the third through hole 804, and the liquid distribution plug 802 is provided with a connecting hole 808 for communicating with the second through hole 803 and the inlet hole 806; the inlet hole 806 and the outlet hole 807 are connected to the coolant circulation assembly. Specifically, after the separator plate 805 is inserted into the first through hole 304, it forms a flow hole with the inner wall of the extrusion body 302 at the end of the first through hole 304. The connecting seat includes a first seat 305 disposed on the sliding body 301, a plurality of connecting rods 306 disposed on the first seat 305, and a second seat 307 disposed at the outer end of the connecting rods 306. The second seat 307 is detachably connected to the output end of the drive mechanism 4. The rear end of the sliding body 301 is threadedly connected to the liquid distribution plug 802.

[0018] In use, after the die and punch 1 close to form a cavity, the extrusion pin mechanism 3 is in an immobile position. Then, the molten aluminum enters the cavity through the gating system on the die or punch 1, filling the entire workpiece. At this time, the original forming position of the deep hole of the workpiece is filled with molten aluminum before the extrusion pin mechanism 3 enters. When the molten aluminum begins to solidify and form a "hard shell", but the center is still in a semi-molten state, the drive mechanism 4 drives the extrusion pin mechanism 3 to move and insert into the forming cavity of the workpiece, applying pressure to the semi-solidified metal in the deep hole. The pressure causes the molten metal to flow to the solidified and contracted area around the deep hole, filling the shrinkage cavities and porosity that may be caused by the wall thickness and heat spots around the deep hole. After the extrusion pin mechanism 3 forms to the preset deep hole forming depth, it does not retract and continues until the die-cast workpiece is completely solidified. After the stroke of the extrusion pin mechanism 3, the deep hole cooling mechanism set on it can drive the heat from the thick wall of the workpiece to flow out, accelerating the cooling and forming of that area. This structure allows the extrusion pin mechanism 3 to be moved by the drive mechanism 4, forcibly pushing the undiluted molten metal to fill the shrinkage space, breaking the problem of the outer layer solidifying and hindering the feeding process. The pressure also makes the metal structure of the workpiece denser, reducing porosity and looseness at the deep hole location and improving airtightness. At the same time, a deep hole cooling mechanism is provided. The extrusion pin mechanism 3 can quickly absorb the heat from the wall thickness of the deep hole of the die-cast workpiece, accelerate the solidification speed from the surface to the core, shorten the solidification time of the deep hole part of the die-cast workpiece, and improve the cooling uniformity, effectively avoiding the problem of excessive scrap rate caused by shrinkage.

[0019] The control method of this utility model is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge or conventional technology in the field. Therefore, this utility model will not explain the control method and circuit connection in detail.

[0020] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A deep hole finishing device for die castings, comprising a die and a punch that form a cavity after mold closing, characterized in that: The punch has multiple deep hole positioning cavities for workpieces. Each deep hole positioning cavity for workpieces is slidably equipped with a pressing pin mechanism and a driving mechanism located outside the punch for moving the pressing pin mechanism. The pressing end of the pressing pin mechanism extends into the cavity, and a deep hole cooling mechanism is provided on the pressing pin mechanism.

2. The deep hole finishing device for die-cast parts according to claim 1, characterized in that: A guide sleeve is provided inside the deep hole positioning cavity of the workpiece; an annular groove is provided at one end of the deep hole positioning cavity near the cavity, and an annular conical surface is provided on the rear side of the deep hole positioning cavity corresponding to the annular groove; the extrusion pin mechanism includes a sliding body slidably connected to the guide sleeve, a connecting seat provided on the rear side of the sliding body, and an extrusion body provided at the front end of the sliding body, and a mating conical surface that matches the annular conical surface is provided at the connection between the extrusion body and the sliding body; an O-ring seal that matches the extrusion body is provided inside the annular groove; the connecting seat is fixedly connected to the drive mechanism.

3. The deep hole finishing device for die-cast parts according to claim 2, characterized in that: The sliding body penetrates the connecting seat, and a first through hole is formed in both the sliding body and the pressurizing body; the deep-hole cooling mechanism includes a liquid distributor head disposed at the rear end of the sliding body, a liquid distributor hole disposed in the liquid distributor head, a liquid distributor plug disposed in the liquid distributor hole, a partition plate disposed on the liquid distributor plug for dividing the liquid distributor hole into a second through hole and a third through hole, and the partition plate can be inserted into the first through hole; the liquid distributor head has an inlet hole communicating with the second through hole and an outlet hole communicating with the third through hole, and the liquid distributor plug has a connecting hole for communicating with the second through hole and the inlet hole; the inlet hole and the outlet hole are connected to the coolant circulation assembly.

4. The deep hole finishing device for die-cast parts according to claim 3, characterized in that: The connecting seat includes a first seat body disposed on the sliding body, a plurality of connecting rods disposed on the first seat body, and a second seat body disposed on the outer end of the connecting rods. The second seat body is detachably connected to the output end of the driving mechanism.

5. The deep hole finishing device for die-cast parts according to claim 3, characterized in that: The rear end of the sliding body is threadedly connected to the liquid distribution plug.

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