Die structure for casting auxiliary frame

Abstract

The utility model discloses a mold structure for casting an auxiliary frame, which comprises a lower mold, and an auxiliary frame casting lower molding cavity is formed on the top surface of the lower mold; the riser position of the central through hole of the front beam of the auxiliary frame, which needs to be cast and molded, is changed from the outside of the through hole to the inside of the through hole, that is, molten metal is discharged from the discharging through hole in the middle of the casting sand core for casting, so that the central temperature of the casting sand core is higher than the temperatures of the front end and the rear end of the central through hole after casting is completed; molten metal on the outer side wall where the casting sand core is located is gradually cooled and solidified from the front end and the rear end to the middle to form the inner side wall of the middle through hole of the front beam of the auxiliary frame, so that good sequential solidification is formed in the middle through hole during solidification forming, and the inner side wall of each position of the middle through hole can be supplemented with liquid in time. And therefore, the manufacturing quality is greatly improved, and the qualification rate is increased.

Description

Technical field:

[0001] The utility model relates to the technical field of metal machining equipment, and more specifically to a mold structure for casting a sub-frame. Background technology:

[0002] The existing automobile subframe is generally made of aluminum alloy and other materials by casting. The existing subframe has a central through hole formed in the middle of the front beam, and the gate is located at the front end of the central through hole for feeding (the front end surface of the inner wall of the central through hole of the front beam is connected to the riser, and the gate is located in front of the riser, that is, the riser is located between the central through hole of the front beam of the subframe and the gate, and the riser is used for the molten metal to smoothly flow into the casting cavity to ensure that the casting is fully filled and avoid the mixing of gas or other undesirable substances. In addition, the riser is provided to help the gas and other inclusions to be discharged from the molten metal, and reduce the formation of pores and shrinkage cavities on the surface and inside of the casting). Then, the casting is performed along the molding cavity at the side wall of the central through hole. Since the aluminum liquid is gradually formed into a product from high temperature to low temperature, if it fails to form a good sequential solidification due to factors such as the riser being far away, it is easy to cause the metal liquid to be unable to be replenished at a distance from the riser, resulting in shrinkage cavities and other problems;

[0003] At this time, since the riser is located at the front outer side of the front beam of the subframe, that is, the riser is located in front, its position is far away from the middle inner wall and the rear inner wall of the center through hole. At this time, the solidification of the center through hole fails to form a good sequential solidification, so that the liquid at the gate cannot be replenished into the inner wall of the center through hole in the area that needs to be replenished due to the failure to form a good sequential solidification. At this time, shrinkage holes will appear on the inner wall of the center through hole, which will affect the casting quality and cause a decrease in the overall qualified rate of the product.

[0004] At the same time, in order to ensure complete filling of the casting and its shrinkage compensation and thermal insulation effect, the cross-sectional area of ​​the riser diameter connected to the casting is large, and it needs to be cut with relevant cutting tools later, which increases the cutting steps and tool wear. Utility model content:

[0005] The utility model aims to overcome the deficiencies of the prior art and provide a sub-frame casting mold structure, which changes the riser position of the central through hole of the front beam of the sub-frame to be cast from being set outside the middle through hole to being set inside the hole, that is, the molten metal comes out from the discharge through hole in the middle of the casting sand core for casting, so that after the casting is completed, the central temperature of the casting sand core is greater than the temperature of the front and rear ends of the central through hole, so that the molten metal on the outer wall of the casting sand core is gradually cooled and solidified from the front and rear ends to the middle to form the inner wall of the middle through hole of the front beam of the sub-frame, so that the middle through hole forms a good sequential solidification during solidification, the inner wall of each position of the middle through hole can be replenished with liquid in time, and basically no shrinkage cavity is formed, which greatly improves the manufacturing quality and the qualified rate.

[0006] The solution of the utility model to solve the technical problem is:

[0007] A sub-frame casting mold structure comprises a lower mold, the top surface of the lower mold is formed with a sub-frame casting lower molding cavity, a rear support groove extending backward is formed on the middle rear wall surface of the front cross beam groove of the sub-frame casting lower molding cavity, a front support groove extending forward is formed in the middle of the front wall surface of the front cross beam groove, the top surfaces of the rear support groove and the front cross beam groove both extend out of the top surface of the lower mold, the rear of the casting sand core is inserted into the rear support groove, the front of the casting sand core is inserted into the front support groove of the casting sand core, the middle of the casting sand core is located in the middle of the front cross beam groove, and a molding spacing is provided between the bottom surface of the casting sand core and the middle bottom surface of the front cross beam groove;

[0008] A feed through hole extending backward is formed in the middle of the front wall surface of the casting sand core, and the feed through hole is connected to a middle transition cavity formed in the middle of the casting sand core. Discharge through holes extending horizontally to the left or right are formed on the left and right inner walls of the middle transition cavity, and the discharge through holes are connected to the front crossbeam groove.

[0009] The inner side wall of the middle transition cavity of the casting sand core is a conical wall surface, and the inner diameter of the front end is smaller than the inner diameter of the rear end.

[0010] The front part of the casting sand core is a small diameter cylindrical part, the rear end of the small diameter cylindrical part is formed with a main cylindrical part whose outer diameter is larger than that of the small diameter cylindrical part, and the rear end bottom surface of the main cylindrical part is formed with a limiting part extending downward;

[0011] A feed through hole is formed in the middle of the front wall surface of the small diameter cylindrical part and extends backward to the front of the main cylindrical part. The rear end of the feed through hole is connected to the middle transition cavity formed from the middle to the rear of the main cylindrical part, and the discharge through hole extends out of the outer wall of the main cylindrical part.

[0012] The front bottom surface of the rear support groove is formed with a rear support portion extending upward, the top surface of the rear support portion is an arc-shaped wall extending downward, the rear bottom surface of the main cylindrical portion is pressed against the arc-shaped wall, and the limiting portion formed on the rear end bottom surface of the main cylindrical portion is inserted into the rear part of the rear support groove.

[0013] A positioning recessed hole extending upward is formed in the middle of the bottom surface of the small-diameter cylindrical portion of the casting sand core, and a mounting groove extending downward is formed in the middle of the bottom surface of the corresponding front support groove. The bottom surface of the mounting groove is an arc-shaped wall surface, and a positioning protrusion column extending upward is formed in the middle of its bottom surface. The lower part of the small-diameter cylindrical portion is inserted into the mounting groove, and its bottom surface cooperates with and fits tightly against the bottom surface of the mounting groove, and the positioning protrusion column is inserted into the corresponding positioning recessed hole.

[0014] A laterally extending runner placement groove is formed on the top surface of the lower mold in front of the front crossbeam groove, the runner piece is inserted into the runner placement groove and matched with the runner placement groove, and the discharge port of the runner piece is connected to the front end of the feed through hole of the casting sand core.

[0015] The runner member is formed with two extensions extending backwards facing the front support groove, the two extensions are inserted into the left and right parts of the bottom surface of the front support groove, and the opposite wall surfaces of the two extensions are formed with side limiting protrusions with arc-shaped inner wall surfaces;

[0016] An upwardly extending arc-shaped groove is formed in the middle of the left and right sides of the small-diameter cylindrical portion, and the front end of the arc-shaped groove extends out of the front end of the small-diameter cylindrical portion. The left and right sides of the front end of the small-diameter cylindrical portion are inclined wall surfaces, and the two side limiting protrusions are inserted into the left and right parts of the arc-shaped groove and are tightly attached to the inner side walls of the arc-shaped groove. The front ends of the two side limiting protrusions are inclined wall surfaces, which are tightly attached to the inclined wall surfaces on the left and right sides of the front end of the small-diameter cylindrical portion.

[0017] The inner diameter of the discharge through hole is smaller than the minimum inner diameter of the middle transition cavity, and is smaller than one third of the minimum inner diameter of the middle transition cavity.

[0018] The outstanding effects of the utility model are:

[0019] It pours the molten metal from the discharge through hole in the middle of the casting sand core, so that after the casting is completed, the central temperature of the casting sand core is greater than the temperature of the front end, so that the molten metal on the outer wall of the casting sand core is gradually cooled and solidified from the front end and the rear end to the middle to form the inner wall of the middle through hole of the front beam of the sub-frame, so that the middle inner wall and the rear inner wall of the middle through hole can be replenished with liquid in time, and basically no shrinkage cavity is produced, which greatly improves the manufacturing quality and the qualified rate.

[0020] At the same time, the two discharge holes of the casting sand core are on both sides. At the same time, after the casting is completed, the molten metal at the two discharge holes of the casting sand core is formed together with the inner wall of the middle through hole of the front beam of the sub-frame formed by cooling and solidification (the discharge through hole of the casting sand core and the solidified part in its internal cavity are the riser, and the discharge through hole is the riser neck), and the inner diameter of the discharge through hole is small, that is, the cross-sectional area of ​​the connection between the inner side wall of the middle through hole of the front beam of the sub-frame formed by cooling and solidification is small, that is, the cross-sectional area of ​​the connection between it and the riser here (riser neck) is small, so that only the riser here needs to be knocked with an aluminum hammer before heat treatment to cause the riser neck here and the inner wall surface of the middle through hole to be partially broken, so that it is easy to remove, reduce the part that needs to be cut when cutting the riser, and reduce the wear on the cutting tool. Description of the drawings:

[0021] Figure 1 It is a partial structural schematic diagram of the auxiliary frame and other components of the utility model after casting;

[0022] Figure 2 yes Figure 1 Schematic diagram of the partial structure without the subframe;

[0023] Figure 3 yes Figure 2 Schematic diagram of the local structure without the casting sand core;

[0024] Figure 4 yes Figure 1 Schematic diagram of the local structure without the lower mold and other parts;

[0025] Figure 5 It is a partial cross-sectional view of the casting sand core and the subframe;

[0026] Figure 6 It is a schematic diagram of the structure of the casting sand core;

[0027] Figure 7 yes Figure 6 Schematic diagram of the angle-changing structure;

[0028] Figure 8 It is a schematic diagram of the local structure of the runner component;

[0029] Fig. 9 yes Figure 8 Schematic diagram of the angle-changing local structure;

[0030] Fig.10 It is a schematic diagram of the local structure between the lower mold and the fixed base plate. Specific implementation method:

[0031] For example, see Figures 1 to 10As shown, a sub-frame casting mold structure comprises a lower mold 10, the bottom surface of the lower mold 10 is fixed on the fixed bottom plate below, the top surface of the lower mold 10 is formed with a sub-frame casting lower molding cavity 11, a rear support groove 12 extending backward is formed on the middle rear wall surface of the front cross beam groove 111 of the sub-frame casting lower molding cavity 11, a front support groove 13 extending forward is formed in the middle of the front wall surface of the front cross beam groove 111, the top surfaces of the rear support groove 12 and the front cross beam groove 111 both extend out of the top surface of the lower mold 10, the rear part of the casting sand core 20 is inserted into the rear support groove 12, the front part of the casting sand core 20 is inserted into the front support groove 13 of the front cross beam groove 111, the middle part of the casting sand core 20 is located in the middle part of the front cross beam groove 111, and there is a molding spacing between its bottom surface and the middle bottom surface of the front cross beam groove 111;

[0032] A feed through hole 21 extending backward is formed in the middle of the front wall surface of the casting sand core 20, and the feed through hole 21 is connected to a middle transition cavity 22 formed in the middle of the casting sand core 20. Discharge through holes 23 extending horizontally to the left or right are formed on the left and right inner walls of the middle transition cavity 22, and the discharge through hole 23 is connected to the front crossbeam groove 111 (the area where the middle transition cavity 22 of the casting sand core 20 is cast is the riser, and the area where the feed through hole 21 and the discharge through hole 23 are cast is the riser neck).

[0033] In this embodiment, since the discharge through hole 23 is set on the middle outer wall of the casting sand core 20, when used in casting (during casting, it is necessary to cover the upper mold on the lower mold 10, and its structure is consistent with the existing one, which will not be described in detail), the metal liquid first enters the middle transition cavity 22 of the casting sand core 20, and then flows out from the two discharge through holes 23 and flows outward to the front and rear ends to the molding cavity composed of the upper mold and the lower mold 10. Since the discharge through hole 23 is in the middle of the casting sand core 20, after the subsequent casting is completed, during the cooling process, the temperature in the middle is higher than that at the two ends. Therefore, the side wall of the central through hole around the casting sand core 20 at the front beam of the subframe 100 formed by the casting is cooled and solidified from the front and rear ends to the middle. While solidifying, shrinkage is compensated by the metal liquid in the middle transition cavity 22. Since the distance from the middle to the front and rear ends is small, it is conducive to forming a good sequential solidification, so that each area of ​​the inner wall of the central through hole can be compensated in time.

[0034] This greatly improves the casting quality of the present embodiment, reduces the occurrence of shrinkage cavities, and improves the pass rate.

[0035] Furthermore, the inner side wall of the middle transition cavity 22 of the casting sand core 20 is a conical wall surface, and the inner diameter of the front end is smaller than the inner diameter of the rear end.

[0036] The front part of the casting sand core 20 is a small diameter cylindrical part 24, the rear end of the small diameter cylindrical part 24 is formed with a main cylindrical part 25 with an outer diameter larger than that of the small diameter cylindrical part 24, and the rear end bottom surface of the main cylindrical part 25 is formed with a limit part 26 extending downward;

[0037] A feed through hole 21 is formed in the middle of the front wall surface of the small diameter cylindrical portion 24 and extends backward to the front of the main cylindrical portion 25. The rear end of the feed through hole 21 is connected to a middle transition cavity 22 formed from the middle to the rear of the main cylindrical portion 25, and the discharge through hole 23 extends out of the outer wall of the main cylindrical portion 25.

[0038] The front bottom surface of the rear support groove 12 is formed with a rear support portion 121 extending upward, the top surface of the rear support portion 121 is an arc-shaped wall extending downward, the rear bottom surface of the main cylindrical portion is pressed against the arc-shaped wall, and the limiting portion 26 formed on the rear end bottom surface of the main cylindrical portion 25 is inserted into the rear part of the rear support groove 12.

[0039] The bottom surface of the limiting portion 26 is a plane, which is pressed against the bottom surface of the rear portion of the rear support groove 12 . The left and right side walls of the limiting portion 26 are vertical wall surfaces, which are close to the left or right side wall of the rear portion of the rear support groove 12 .

[0040] The rear portion of the casting sand core 20 is supported and fixed by the limiting portion 26 .

[0041] Furthermore, a positioning recessed hole 241 extending upward is formed in the middle of the bottom surface of the small-diameter cylindrical portion 24 of the casting sand core 20, and a mounting groove extending downward is formed in the middle of the bottom surface of the corresponding front support groove 13. The bottom surface of the mounting groove is an arc-shaped wall surface, and a positioning protrusion column 131 extending upward is formed in the middle of the bottom surface. The lower part of the small-diameter cylindrical portion 24 is inserted into the mounting groove, and its bottom surface cooperates with and fits tightly against the bottom surface of the mounting groove. The positioning protrusion column 131 is inserted into the corresponding positioning recessed hole 241.

[0042] The outer wall of the positioning protrusion column 131 is a conical wall surface, and its upper end diameter is smaller than the lower end diameter. The positioning recessed hole 241 cooperates with the positioning protrusion column 131, and the outer wall of the positioning protrusion column 131 is close to the inner wall of the positioning recessed hole 241. A downwardly extending protrusion is formed in the middle of the top surface of the positioning recessed hole 241, which is inserted into the through hole in the middle of the top surface of the positioning protrusion column 131.

[0043] The cooperation between the positioning protrusion column 131 and the positioning recessed hole 241 realizes the support and fixation of the front part of the casting sand core 20 .

[0044] Furthermore, a laterally extending runner placement groove 16 is formed on the top surface of the lower mold 10 in front of the front crossbeam groove 111, and a runner member 17 is inserted into and cooperates with the runner placement groove 16, and a discharge port of the runner member 17 is connected to the front end of the feed through hole 21 of the casting sand core 20.

[0045] The runner member 17 is formed with two extensions 171 extending backwards facing the front support groove 13. The two extensions 171 are inserted into the left and right parts of the bottom surface of the front support groove 13. The opposite wall surfaces of the two extensions 171 are formed with side limiting protrusions 172 with arc-shaped inner wall surfaces.

[0046] An upwardly extending arc groove 27 is formed in the middle of the left and right sides of the small diameter cylindrical portion 24, and the front end of the arc groove 27 extends out of the front end of the small diameter cylindrical portion 24. The left and right sides of the front end of the small diameter cylindrical portion 24 are inclined walls. The two side limiting protrusions 172 are inserted into the left and right parts of the arc groove 27 and are tightly attached to the inner side wall of the arc groove 27. The front ends of the two side limiting protrusions 172 are inclined walls, which are tightly attached to the inclined walls on the left and right sides of the front end of the small diameter cylindrical portion 24.

[0047] The two extension portions 171 of the runner member 17 can limit the upper portion of the front portion of the small-diameter cylindrical portion 24 to improve its positioning and fixing effect.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A sub-frame casting mold structure, comprising a lower mold (10), the top surface of the lower mold (10) is formed with a sub-frame casting lower molding cavity (11), characterized in that: A rear support groove (12) extending backward is formed on the middle rear wall surface of the front cross beam groove (111) of the subframe casting lower molding cavity (11), and a front support groove (13) extending forward is formed in the middle of the front wall surface of the front cross beam groove (111). The top surfaces of the rear support groove (12) and the front cross beam groove (111) both extend out of the top surface of the lower mold (10). The rear part of the casting sand core (20) is inserted into the rear support groove (12), and the front part of the casting sand core (20) is inserted into the front support groove (13) of the front cross beam groove (111). The middle part of the casting sand core (20) is located in the middle part of the front cross beam groove (111), and there is a molding distance between its bottom surface and the middle bottom surface of the front cross beam groove (111); A feed through hole (21) extending backward is formed in the middle of the front wall surface of the casting sand core (20), and the feed through hole (21) is communicated with a middle transition cavity (22) formed in the middle of the casting sand core (20), and a discharge through hole (23) extending horizontally to the left or right is formed on the left and right inner walls of the middle transition cavity (22), and the discharge through hole (23) is communicated with the front crossbeam groove (111).

2. The subframe casting mold structure according to claim 1, characterized in that: The inner side wall of the middle transition cavity (22) of the casting sand core (20) is a conical wall surface, and the inner diameter of the front end is smaller than the inner diameter of the rear end.

3. The subframe casting mold structure according to claim 1, characterized in that: The front part of the casting sand core (20) is a small diameter cylindrical part (24), the rear end of the small diameter cylindrical part (24) is formed with a main cylindrical part (25) whose outer diameter is larger than that of the small diameter cylindrical part (24), and the rear end bottom surface of the main cylindrical part (25) is formed with a limit part (26) extending downwards; A feed through hole (21) is formed in the middle of the front wall surface of the small diameter cylindrical portion (24) and extends rearward to the front of the main cylindrical portion (25). The rear end of the feed through hole (21) is connected to a middle transition cavity (22) formed from the middle to the rear of the main cylindrical portion (25). The discharge through hole (23) extends out of the outer wall of the main cylindrical portion (25).

4. The subframe casting mold structure according to claim 3, characterized in that: The front bottom surface of the rear support groove (12) is formed with a rear support portion (121) extending upward, the top surface of the rear support portion (121) is an arc-shaped wall surface extending downward, the rear bottom surface of the main cylindrical portion (25) is pressed against the arc-shaped wall surface, and the limiting portion (26) formed on the rear end bottom surface of the main cylindrical portion (25) is inserted into the rear part of the rear support groove (12).

5. The sub-frame casting mold structure according to claim 4, characterized in that: The bottom surface of the limiting portion (26) is a plane, which is pressed against the bottom surface of the rear part of the rear support groove (12), and the left and right side walls of the limiting portion (26) are vertical wall surfaces, which are closely attached to the left side wall or right side wall of the rear part of the rear support groove (12).

6. The subframe casting mold structure according to claim 1, characterized in that: The small diameter cylindrical part (24) of the casting sand core (20) is formed with a positioning recessed hole (241) extending upward in the middle of the bottom surface, and the corresponding front support groove (13) is formed with a mounting groove extending downward in the middle of the bottom surface. The bottom surface of the mounting groove is an arc-shaped wall surface, and the middle of the bottom surface is formed with a positioning protruding column (131) extending upward. The lower part of the small diameter cylindrical part (24) is inserted into the mounting groove, and its bottom surface matches and is tightly attached to the bottom surface of the mounting groove. The positioning protruding column (131) is inserted into the corresponding positioning recessed hole (241).

7. The sub-frame casting mold structure according to claim 6, characterized in that: The outer wall of the positioning protrusion column (131) is a conical wall surface, the diameter of the upper end of which is smaller than the diameter of the lower end. The positioning recessed hole (241) matches the positioning protrusion column (131), and the outer wall of the positioning protrusion column (131) is tightly attached to the inner wall of the positioning recessed hole (241).

8. The sub-frame casting mold structure according to claim 7, characterized in that: A runner placement groove (16) extending laterally is formed on the top surface of the lower mold (10) in front of the front cross beam groove (111), a runner piece (17) is inserted into the runner placement groove (16) and matched with the runner placement groove (16), and a discharge port of the runner piece (17) is communicated with a front end of a feed through hole (21) of a casting sand core (20).

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