Part ejection structure of low-pressure casting mold

Abstract

The utility model provides a part ejection structure which is suitable for a metal low-pressure casting mold and comprises an ejection rod plate arranged above an upper mold and an ejection rod assembly connected to the bottom of the ejection rod plate, and the lower end of the ejection rod assembly extends into the upper mold and can be driven by a second vertical driving piece to vertically move relative to the upper mold. The automatic casting device is convenient and fast to use, can meet the requirement for automation of the casting process, and effectively reduces the difficulty of clamping the parts by a mechanical arm. According to the utility model, the ejector rod plate is connected with the ejector rod assembly through the sectional assembly type ejector structure, and the structural strength of the ejector rod is improved and the risk of breaking the ejector rod is reduced due to the arrangement of the pressing block and the connecting column.

Description

Technical Field

[0001] This utility model relates to low-pressure casting molds, specifically to a part ejection structure for a low-pressure casting mold. Background Technology

[0002] Low-pressure casting is a conventional process for manufacturing aluminum alloy and other alloy parts. Its principle involves setting up relatively movable upper and lower molds. After the upper and lower molds are closed, liquid alloy is injected from the bottom of the lower mold, and the pressure is controlled to allow the liquid alloy to solidify and form within the cavity under low pressure. After the injection is complete, the upper mold is controlled to separate with the formed part, and a robotic arm removes the part. In existing technologies, the formed part has a certain bonding force with the upper mold, which may cause the robotic arm to fail to grasp and release the part, disrupting the casting process cycle. Therefore, it is necessary to improve the existing low-pressure casting molds. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a part ejection structure for a low-pressure casting mold. The casting mold includes an upper mold and a lower mold arranged opposite to each other. The upper mold is driven by a first vertical drive member to close with the lower mold. The feature is that it further includes an ejector plate disposed above the upper mold and an ejector assembly connected to the bottom of the ejector plate. The other end of the ejector assembly passes through the surface of the upper mold and extends to the cavity after mold closing. The ejector plate is connected to the drive end of a second vertical drive member and is driven by the second vertical drive member to move vertically relative to the upper mold.

[0004] The push rod assembly includes a pressure block, a connecting post, and a push rod. The connecting post has a through mounting hole, and one end of the connecting post is connected to the bottom of the push rod plate. One end of the push rod is engaged in the mounting hole, and the other end extends into the cavity. Therefore, the pressure block presses against the upper surface of the push rod.

[0005] Furthermore, the lower end of the ejector pin assembly is flush with the bottom end face of the upper mold when the mold is closed.

[0006] Furthermore, the mounting through hole has a structure that is wider at the top and narrower at the bottom, and the upper end of the top rod is engaged with the upper part of the mounting through hole.

[0007] Furthermore, there is a radial horizontal gap between the upper end of the top rod and the upper part of the mounting through hole, the radial length of which is 1-3 mm.

[0008] Furthermore, the end of the push rod that connects to the cavity is provided with an exhaust groove.

[0009] Furthermore, the number of the exhaust slots is at least one set arranged in a ring on the top rod.

[0010] Furthermore, the exhaust groove has a length of 150-250 mm and a radial length of 0.10-0.15 mm.

[0011] Furthermore, the pressure block and the top of the connecting column are locked and fixed to the top rod plate.

[0012] Furthermore, the lower surface of the top rod plate is provided with return columns, and the upper surface of the lower mold plate is provided with support columns corresponding to the position of each return column. Each return column and support column are engaged and connected when the upper mold and the lower mold are closed.

[0013] This invention provides a part ejection structure suitable for low-pressure metal casting molds. It includes an ejector plate located above the upper mold and an ejector assembly connected to the bottom of the ejector plate. The lower end of the ejector assembly extends into the upper mold and can move vertically relative to the upper mold under the action of a second vertical drive component, ejecting the formed part from the upper mold quickly and easily. This facilitates automation of the casting process and effectively reduces the difficulty for robotic arms to handle parts. This invention uses a segmented, assembled ejection structure to connect the ejector plate and the ejector assembly. The inclusion of pressure blocks and connecting pillars increases the structural strength of the ejector and reduces the risk of breakage. Attached Figure Description

[0014] Figure 1 This is a structural schematic diagram of a low-pressure casting mold provided by this utility model;

[0015] Figure 2 Schematic diagram of a single-station low-pressure casting mold

[0016] Figure 3 This is a structural schematic diagram of a push rod assembly provided by this utility model;

[0017] Figure 4 This is a schematic diagram of a push rod structure provided by this utility model;

[0018] Reference numerals: 1. Ejector plate; 2. Ejector assembly; 21. Pressure block; 22. Connecting column; 23. Mounting through hole; 24. Ejector; 25. Venting groove; 3. Return column; 4. Support column; 5. Upper mold; 6. Upper template; 7. Lower mold; 8. Lower template; 9. Cavity. Detailed Implementation

[0019] like Figure 1 and Figure 2As shown, this embodiment provides a part ejection structure for a low-pressure casting mold. The structure of the low-pressure casting mold is existing technology. At least one set of casting molds is provided on the lower template 8, including an upper mold 5 and a lower mold 7 arranged opposite to each other. The upper mold 5 and the lower mold 7 are respectively connected to the upper template 6 and the lower template 8. The upper template 6 and the upper mold 5 are driven downward by a first vertical drive member until they close with the lower mold 7. The space between the upper mold 5 and the lower mold 7 is the forming cavity 9 of the part. The first vertical drive member is an externally located clamping cylinder or other lifting module. Since the first vertical drive member is existing technology, its specific structure is not shown in the figure.

[0020] The part ejection structure includes an ejector plate 1 and an ejector assembly 2. The ejector plate 1 is located above the upper mold plate 6. One end of the ejector assembly 2 extends from the bottom of the ejector plate 1, and the other end passes through the upper mold 5 and extends to the cavity 9 until the lower surface of the ejector assembly 2 is flush with the bottom end face of the upper mold 5. The ejector assembly 2 and the upper mold 5 jointly participate in the forming of the upper surface of the part. The ejector plate 1 is mounted on the driving end of a second vertical drive member, which can drive the ejector plate 1 and the ejector assembly 2 to move vertically relative to the upper mold plate 6 and the upper mold 5. After the part is formed, it is controlled by the first vertical drive member to detach from the lower mold 7. The second vertical drive member is activated, and the ejector 24 moves downward relative to the upper mold 5, applying a downward force to the part and ejecting the part from the upper mold 5.

[0021] Specifically, such as Figure 3 As shown, the push rod assembly 2 includes a pressure block 21, a connecting column 22, and a push rod 24. One end of the connecting column 22 is connected to the push rod plate 1, and the center of the connecting column 22 has a through-hole 23 extending vertically. The through-hole 23 has a slotted structure that is wider at the top and narrower at the bottom. The upper end of the push rod 24 is fitted into the upper part of the through-hole 23, and the lower end extends out from the lower part of the through-hole 23. The pressure block 21 is located at the upper part of the through-hole 23 and presses against the upper surface of the push rod 24. The above structure divides the push rod assembly 2 into three parts: the pressure block 21, the connecting column 22, and the push rod 24. This separate design reduces the strength requirements of the slender push rod 24 while increasing its structural strength, preventing it from breaking due to insufficient strength, and also reduces the difficulty of installation.

[0022] Furthermore, the end of the push rod 24 that connects to the cavity 9 is provided with, for example... Figure 4 As shown in the venting groove 25, during the low-pressure casting process, the gas present in the cavity 9 will be discharged along the venting groove 25 under low pressure, thereby reducing the gas discharge resistance, maintaining close contact between the ejector rod 24 and the part, and making the ejector rod 24's ejection action on the part more stable and reliable.

[0023] Furthermore, the number of exhaust grooves 25 can be set to an odd number based on the diameter of the push rod 24, such as 5, 7, or 9. The number of exhaust grooves 25 is positively correlated with the diameter of the push rod 24; the larger the diameter of the push rod 24, the more exhaust grooves 25 there are, and the smaller the diameter of the push rod 24, the fewer exhaust grooves 25 there are. The length of the exhaust grooves 25 is 150-250 mm, and the depth is 0.10-0.15 mm. During the ejection process, an odd number of exhaust grooves 25 helps to achieve better pressure balance, allowing gas to be discharged more evenly from each exhaust groove 25, and an odd number of exhaust grooves 25 can provide better structural stability in terms of layout. Meanwhile, the length of the venting groove 25 is increased from 75mm in the prior art. By increasing the length of the venting groove 25 of the ejector rod 24, the possibility of reusing the ejector rod 24 is reserved while providing a sufficiently long venting channel. When the end of the ejector rod 24 with the venting groove 25 is damaged, the damaged part can be cut off and the ejector rod 24 can be reused. The depth of the venting groove 25 is set at 0.12mm, which is a suitable size. This makes the venting groove 25 less likely to be blocked by impurities (such as metal chips, slag, etc.) generated during the casting process, and allows gas to pass through smoothly without affecting the mechanical properties of the ejector rod 24.

[0024] To better facilitate the operation of the ejector pin 24 during its working process, in one optional configuration, the upper end of the ejector pin 24 has a gap of 1-3 mm with the upper part of the mounting through hole 23. During equipment operation, temperature changes may cause thermal expansion of the ejector pin 24 and the pressure block 21. The 1-3 mm gap effectively reduces the contact area between the ejector pin 24 and the inner cavity wall, thereby reducing friction and wear. The added horizontal clearance at the mating point of the ejector pin 24 and the pressure block 21 also reduces the concentricity requirements of the mold assembly, preventing the ejector pin 24 from jamming during movement.

[0025] In existing technologies, the pressure block 21 is generally machined using cutting methods. However, due to the high hardness of the pressure block 21, cutting methods cause severe wear on the cutting tools. The electrical discharge machining (EDM) technology used in this design can precisely shape the pressure block according to design requirements, achieving micron-level machining accuracy and ensuring the dimensional accuracy and shape of the mounting through-hole 23. After the mounting through-hole 23 of the pressure block 21 is formed by EDM, a high-hardness nitriding layer is formed on the surface of the mounting through-hole 23 using an overall nitriding treatment technology. This improves the corrosion resistance of the pressure block 21, thereby effectively extending its service life.

[0026] In actual installation, the ejector pin 24 is first placed inside the cavity of the pressure block 21 and engaged within it. The other end of the ejector pin 24 extends out of the mounting through hole 23 of the pressure block 21 and contacts the part located in the mold cavity 9, thus participating in the shaping of the part. After the ejector pin 24 is installed, the connecting post 22 is placed inside the cavity of the pressure block 21. This split design reduces the length of the ejector pin 24 while increasing its strength, and also avoids the risk of breakage of the slender ejector pin 24 in existing designs. When assembling the ejector pin assembly 2 and the ejector pin plate 1, a slot is opened at the bottom of the ejector pin plate 1. The pressure block 21 is engaged within the slot. The slot design allows the pressure block 21 to quickly find the correct installation position when assembled with the ejector pin plate 1, achieving precise positioning. The installer only needs to align the pressure block 21 with the slot and insert it. This simple and intuitive installation method significantly reduces assembly time compared to other complex positioning methods. Meanwhile, when the equipment needs maintenance or replacement of the push rod assembly 2, the slot design makes it easy to remove the pressure block 21 from the push rod plate 1. Maintenance personnel can easily remove the pressure block 21 from the slot using tools, without requiring complex disassembly. Furthermore, the slot effectively prevents lateral displacement of the pressure block 21 within the push rod plate 1, ensuring reliable connection between the push rod assembly 2 and the push rod plate 1. Finally, the pressure block 21 and the connecting column 22 are locked together via the push rod plate 1, which can be achieved using bolts and nuts; there are no restrictions on this method. The push rod plate 1 comes into play when the pressure block 21 and the connecting column 22 need to be fixed together. After the push rod 24 is inserted into the inner cavity of the pressure block 21 and extends out of the mounting through hole 23, the push rod 1 can apply pressure to the pressure block 21 and the connecting column 22 by some means (such as tightening the nut, rotating the screw to extend the push rod 24, etc.). This pressure will make the pressure block 21 and the connecting column 22 fit tightly together, thereby achieving locking and fixing, so that they cannot easily move relative to each other, and finally completing the fixing of the push rod 1 and the push rod assembly 2.

[0027] Furthermore, to better maintain balance when the pressure block 21 is subjected to external forces, the number of mounting through holes 23 in the pressure block 21 can be set to two, and they can be evenly distributed on the left and right sides of the pressure block 21. By inserting and fixing the two connecting posts 22 into the inner cavities on the left and right sides of the pressure block 21 respectively, when the pressure block 21 is subjected to tension or pressure, the evenly distributed structure on both sides can make the force evenly distributed on the pressure block 21, ensuring that the force of the push rod 24 is uniform during the process of pushing the part out, and realizing the smooth ejection of the part.

[0028] Furthermore, the lower surface of the ejector plate 1 is provided with return columns 3, and the upper surface of the lower mold plate 8 is provided with support columns 4 corresponding to the position of each return column 3. When the upper mold 5 and the lower mold 7 are closed, each return column 3 and support column 4 are engaged and connected. The return columns 3 and support columns 4 can position the ejector plate 1 and the ejector assembly 2 during the casting process, preventing the ejector plate 1 from shifting position during the casting process, which could lead to molding defects in the parts.

[0029] The working process of the ejection structure of the part is described in conjunction with the production process of the low-pressure casting mold. First, the second vertical drive component controls the ejector plate 1 and ejector assembly 2 to move upward until the return column 3 on the ejector plate 1 aligns with the support column 4 on the lower mold plate 8. Then, driven by the first vertical drive component, the upper mold 5 of the mold begins to move downward relative to the lower mold 7. At this time, the upper mold 5 and the lower mold 7 are just closed, and the lower end of the ejector assembly 2 is located on the lower surface of the upper mold 5. Entering the low-pressure casting process, the molten metal is filled into the cavity 9 formed by the upper mold 5 and the lower mold 7 through the gating system. During the filling process, the molten metal gradually fills all corners of the cavity 9. After filling is completed, the molten metal waits to solidify in the cavity 9. As the temperature decreases, it gradually forms a part with a specific shape and properties.

[0030] After the part is formed, the first vertical drive unit drives the mold to open, separating the upper mold 5 and the lower mold 7. At this time, the robotic pallet moves to the bottom of the upper mold 5 to receive the ejected part. Subsequently, the second vertical drive unit drives the ejector plate 1 to press down relative to the upper mold plate 6. Under the push of the ejector plate 1, the ejector rod 24 ejects the part from the cavity 9. After the part leaves the mold, the robotic pallet steadily catches the part and moves it out of the mold range. At this point, the production cycle of a single low-pressure casting mold ends, and then the next production cycle begins. This process is repeated continuously to produce a batch of parts.

[0031] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A part ejection structure of a low pressure casting mold, the casting mold comprising an upper mold (5) and a lower mold (7) disposed opposite to each other, the upper mold (5) being closed with the lower mold (7) by a first vertical driving member, characterized in that: The ejection rod assembly (2) is connected to the bottom of the ejection rod plate (1), and the other end of the ejection rod assembly (2) penetrates the surface of the upper die (5) and extends to the cavity (9) after the mold is closed, the ejection rod plate (1) is connected to the driving end of the second vertical driving member and is driven by the second vertical driving member to vertically displace relative to the upper die (5); the ejection rod assembly (2) comprises a pressing block (21), a connecting column (22) and an ejection rod (24), the connecting column (22) has a mounting through hole (23) penetratingly arranged, and one end of the connecting column (22) is connected to the bottom of the ejection rod plate (1); one end of the ejection rod (24) is clamped in the mounting through hole (23), and the other end extends to the cavity (9); and therefore the pressing block (21) is pressed on the upper surface of the ejection rod (24).

2. A part ejection structure for a low pressure casting mold as set forth in claim 1, characterized in that: The lower end of the ejection rod assembly (2) is flush with the bottom end surface of the upper die (5) when the mold is closed.

3. A part ejection structure of a low pressure casting mold according to claim 1, characterized in that: The mounting through hole (23) has a structure of being wide at the top and narrow at the bottom, and the upper end of the ejection rod (24) is clamped in the upper part of the mounting through hole (23).

4. A part ejection structure for a low pressure casting mold as set forth in claim 3, characterized in that: There is a radial horizontal gap between the upper end of the ejection rod (24) and the upper part of the mounting through hole (23), and the radial length of the horizontal gap is 1-3 mm.

5. A part ejection structure for a low pressure casting mold as set forth in claim 1, characterized by: One end of the ejection rod (24) connected to the cavity (9) is provided with an exhaust groove (25).

6. A part ejection structure for a low pressure casting mold as set forth in claim 5, characterized in that: The number of the exhaust grooves (25) is at least one group arranged annularly on the ejection rod (24).

7. A part ejection structure for a low pressure casting mold as set forth in claim 5, characterized in that: The length of the exhaust groove (25) is 150-250 mm, and the radial length is 0.10-0.15 mm.

8. A part ejection structure of a low pressure casting mold according to claim 1, characterized in that: The top of the connecting column (22) and the pressing block (21) are locked and fixed with the ejection rod plate (1).

9. A part ejection structure of a low pressure casting mold according to claim 1, wherein The lower surface of the ejection rod plate (1) is provided with a return column (3), and the upper surface of the lower die plate (8) is provided with a support column (4) corresponding to the position of each return column (3), and each return column (3) and the support column (4) are in butt joint when the upper die (5) and the lower die (7) are closed.

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