Counterweight part sand mold

Abstract

The utility model discloses a sand mold for a counterweight part, which is used for molding a sand mold of the counterweight part and comprises a lower mold and an upper mold, the key points of the utility model are as follows: the lower parting surface of the lower die is concavely arranged downwards to form a lower cavity, and the lower cavity is provided with a hot spot chamber corresponding to a hot spot of the counterweight piece; the upper parting surface of the upper die protrudes downwards to form an upper male die corresponding to the lower cavity, a hot spot male die is formed on the bottom surface of the upper male die, corresponds to the hot spot cavity, is used for forming a reverse feeding allowance cavity of a sand mold, can replace a traditional riser, and is small in size and small in occupied space of the sand mold. The reverse feeding allowance cavity is suitable for a sand mold with a small distance between a casting and the edge of the sand mold, and when the sand mold is used for casting and molding the casting, the reverse feeding metal liquid in the reverse feeding allowance cavity is used for feeding the hot spot part of the casting, so that shrinkage cavities and shrinkage porosity of the casting are prevented, and the yield of the casting is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile parts casting, in particular to a sand mold for a counterweight. Background Art

[0002] The counterweight is a component installed at the rear of the loader, which plays a balancing role during the operation and working process of the loader. The counterweight is generally cast by a sand mold formed by a sand mold, and the sand mold includes an upper sand mold and a lower sand mold. The existing counterweight sand mold includes a lower mold and an upper mold, the lower mold is used to form the lower sand mold, and the upper mold is used to form the upper sand mold. When the upper sand mold and the lower sand mold are combined, the casting process of the counterweight (i.e., the casting) can be carried out. However, when the sand mold formed by the above-mentioned counterweight sand mold is used for casting, shrinkage holes are very likely to appear in the casting, thereby affecting the quality of the casting. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a counterweight sand mold which compensates the shrinkage of the hot node of the casting by arranging a hot node punch corresponding to the hot node chamber on the bottom surface of the upper punch to prevent shrinkage cavities and shrinkage in the casting.

[0004] To achieve the above purpose, the embodiment of the utility model adopts the following technical solutions:

[0005] A counterweight sand mold, used for forming a sand mold for the counterweight, comprising a lower mold and an upper mold corresponding to the lower mold;

[0006] The lower mold has a lower parting surface, the lower parting surface is upwardly protruding with a sprue nest and a lower runner located on one side of the sprue nest, and is downwardly concave to form a lower cavity located on one side of the lower runner, and the lower cavity has a thermal node chamber corresponding to the thermal node of the counterweight;

[0007] The upper mold has an upper parting surface corresponding to the lower parting surface, the upper parting surface protrudes downward to form an upper sprue corresponding to the sprue socket, an upper punch located on one side of the upper sprue and corresponding to the lower cavity, and an upper cross runner located on one side of the upper punch and corresponding to the lower cross runner, a hot node punch is formed on the bottom surface of the upper punch, and the hot node punch corresponds to the hot node cavity.

[0008] Furthermore, the heat node punch extends along the length direction of the upper punch and is arc-shaped.

[0009] Furthermore, the radius of the hot node punch is R, and R is 120.2mm~123.5mm.

[0010] Furthermore, the distance between the bottom surface of the hot-spot punch and the bottom surface of the upper punch is D, and D≤20 mm.

[0011] Furthermore, one end of the bottom surface of the hot section punch close to the upper sprue protrudes downward to form an exhaust needle.

[0012] Furthermore, the bottom surface of the hot node chamber protrudes upward to form a cold iron protrusion, and the cold iron protrusion is used to form the cold iron cavity of the sand mold.

[0013] Further, the lower mold cavity includes two first mold cavities and one second mold cavity, the two first mold cavities are respectively located at the two ends of the lower mold cavity, the second mold cavity is located between the two first mold cavities, there are two hot node chambers, one of the hot node chambers is located in one of the first mold cavities, there are two cold iron protrusions, one of the cold iron protrusions is arranged on the bottom surface of one of the first mold cavities, and accordingly, there are two hot node convex molds, one of the hot node convex molds corresponds to one of the cold iron protrusions.

[0014] Furthermore, there are two lower cross runners, which are respectively located on opposite sides of the straight runner socket along the length direction of the lower cavity and connected to the straight runner socket. There are multiple upper cross runners, which are arranged along the length direction of the upper punch and connected to the upper punch. In the up and down directions, the projection of the upper straight runner coincides with the projection of the straight runner socket, and the projections of the multiple upper cross runners intersect with the projections of the corresponding lower cross runners.

[0015] The counterweight sand mold of the utility model is provided with a hot node convex mold corresponding to the hot node chamber on the bottom surface of the upper convex mold. The hot node convex mold is used for forming the reverse shrinkage margin cavity of the sand mold, which can replace the traditional riser and has a small volume and occupies a small space of the sand mold. It can be suitable for sand molds with a small distance between the casting and the edge of the sand mold. When the sand mold is poured to form the casting, the reverse shrinkage metal liquid in the reverse shrinkage margin cavity compensates the hot node of the casting, thereby preventing the casting from generating shrinkage cavities and shrinkage porosity, and improving the casting yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional schematic diagram of a sand mold of a counterweight according to an embodiment of the utility model;

[0017] Figure 2 for Figure 1 A three-dimensional schematic diagram of the upper mold from another perspective;

[0018] Figure 3 A top view of a casting according to an embodiment of the utility model;

[0019] Figure 4 for Figure 3 AA direction cross-sectional view;

[0020] Figure 5 for Figure 3 BB direction cross-sectional view. DETAILED DESCRIPTION

[0021] Below, in conjunction with the accompanying drawings and specific implementation methods, the utility model is further described:

[0022] like Figures 1 to 5 As shown, the embodiment of the utility model provides a counterweight sand mold, which is used for molding a sand mold 100, and the sand mold 100 is used for casting a counterweight (i.e., a casting 200) of a molding loader and includes a lower sand mold 103 and an upper sand mold 102 located above the lower sand mold 103, wherein the static pressure line sand box (i.e., sand mold) has a size of 2.5m long and 0.9m wide, an upper box height of 0.4m, and a lower box height of 0.35m, and the geometric size of the counterweight is 2.381mX0.474mX0.376m, and the weight is a large casting 200 of 970Kg. The counterweight sand mold includes a lower mold 1 and an upper mold 2 corresponding to the lower mold 1.

[0023] like Figure 1 As shown, the lower mold 1 is used to form the lower sand mold 103 and has a lower parting surface 11, the lower parting surface 11 has a sprue socket 12 and a lower runner 13 located on one side of the sprue socket 12 protruding upwards, and a lower cavity 14 located on one side of the lower runner 13 is formed downwards, and the lower cavity 14 has a thermal node chamber 1411 corresponding to the thermal node 201 of the counterweight. Specifically, there are two lower runners 13, which are respectively located on opposite sides of the sprue socket 12 along the length direction of the lower cavity 14 and connected to the sprue socket 12.

[0024] like Figure 1 , Figure 2 As shown, the upper mold 2 is used to form the upper sand mold 102 and has an upper parting surface 21 corresponding to the lower parting surface 11. The upper parting surface 21 protrudes downward to form an upper sprue 22 corresponding to the sprue cavity 12, an upper punch 23 located on one side of the upper sprue 22 and corresponding to the lower cavity 14, and an upper runner 24 located between the upper punch 23 and the upper sprue 22 and corresponding to the lower runner 13. When the upper sand mold 102 and the lower sand mold 103 are molded together (as shown in FIG. Figure 4 , Figure 5As shown in the figure, the upper punch 23 and the lower mold cavity 14 form a mold cavity of the sand mold 100, and the mold cavity is used to cast and mold the casting 200. The bottom surface of the upper punch 23 is formed with a hot spot punch 231, and the hot spot punch 231 corresponds to the hot spot chamber 1411, wherein the hot spot punch 231 is used to mold the reverse compensation shrinkage margin cavity of the sand mold 100, and its volume is small, and the space occupied by the sand mold 100 is small, and it can be applied to the sand mold 100 of the type with a small distance between the casting 200 and the edge of the sand mold 100 (i.e., the edge of the sand box). When the sand mold 100 is cast to mold the casting 200, the reverse compensation metal liquid in the reverse compensation shrinkage margin cavity will affect the hot spot 200 of the casting 200. 1 is used for shrinkage compensation, thereby preventing the casting 200 from generating shrinkage cavities and shrinkage porosity, and improving the yield of the casting 200; after the casting is cooled and solidified, the casting 200 is solidified and formed, and the reverse shrinkage compensation metal liquid in the reverse shrinkage compensation margin cavity is solidified and formed into a shrinkage compensation margin 25, which is connected to the casting 200 and is higher than the top of the casting 200; when the casting 200 is demoulded, the chill 3 will naturally fall off to be separated from the casting 200, and the shrinkage compensation margin 25 on the casting 200 is polished flat and smooth by a polishing machine.

[0025] like Figure 2 , Figure 3 As shown, specifically, there are multiple upper runners 24, and the multiple upper runners 24 are evenly arranged along the length direction of the upper punch 23 and connected to the upper punch 23. In the up and down directions, the projection of the upper sprue 22 coincides with the projection of the sprue pocket 12, and the projections of the multiple upper runners 24 intersect with the projections of the corresponding lower runners 13. When the upper sand mold 102 and the lower sand mold 103 are closed, the upper sprue 22, the upper runner 24, the sprue pocket 12 and the lower runner 13 form a runner system connected to the mold cavity.

[0026] like Figure 2 As shown, specifically, the bottom surface of the upper punch 23 is concavely formed upward to form a groove 230, and the heat section punch 231 is embedded in the groove 230 and protrudes from the bottom surface of the upper punch 23. The bottom surface of the heat section punch 231 near the upper sprue 22 also protrudes downward to form an exhaust needle 232. The exhaust needle 232 is used to form the air channel 26 of the upper sand mold 102. The air channel 26 is used to exhaust air to prevent the casting 200 from generating air holes. The heat section punch 231 extends along the length direction of the upper punch 23 and is arc-shaped to form a structure with a high middle and low sides. Experiments have shown that this upper punch 23 can further improve the shrinkage compensation effect. Figure 4 , Figure 5As shown, more specifically, the radius of the hot section punch 231 is R, R is 120.2mm~123.5mm, where the value of R can be flexibly selected within this numerical range according to actual conditions. In this embodiment, R is 123mm, at which time, the shrinkage compensation effect is the best. In order to facilitate the removal of the shrinkage excess material 25 while ensuring a good shrinkage compensation effect, the distance between the bottom surface of the hot section punch 231 and the bottom surface of the upper punch 23 is set to D, D≤20mm, in this embodiment, D=20mm, D This value not only ensures the shrinkage compensation effect, but also the shrinkage excess material 25 is relatively thin, which is easy to grind and remove.

[0027] like Figure 1 , Figure 4 As shown, in order to further prevent shrinkage cavities and shrinkage in the casting 200, a chill convex portion 1412 is formed on the bottom surface of the hot node chamber 1411 and protrudes upward. The chill convex portion 1412 is used to form a chill cavity of the sand mold 100. The chill cavity is used to place the chill 3, that is, the chill 3 is installed at the bottom of the hot node 201 of the counterweight (casting 200), and the size of the chill 3 is 227mmX98mmX45mm. In this embodiment, the lower mold cavity 14 includes two first mold cavities 141 and a second mold cavity 142, the two first mold cavities 141 are respectively located at the two ends of the lower mold cavity 14, the second mold cavity 142 is located between the two first mold cavities 141, there are two hot joint chambers 1411, one hot joint chamber 1411 is located in one first mold cavity 141, there are two chiller protrusions 1412, one chiller protrusion 1412 is arranged on the bottom surface of one first mold cavity 141, and accordingly, there are two hot joint convex molds 231, one hot joint convex mold 231 corresponds to one chiller protrusion 1412. By setting the chiller 3, a chilling effect can be played during the solidification and shrinkage process of the casting 200, so as to reduce the shrinkage of the casting 200 as much as possible and make the hot joint convex mold 231 as small as possible, which not only improves the quality of the casting 200, but also facilitates the removal of the shrinkage supplement surplus material 25 from the casting 200, so that the appearance of the casting 200 has no defects such as slag inclusion, sand inclusion, sand hole, air hole, etc.

[0028] The counterweight sand mold of the utility model is provided with a hot node convex mold corresponding to the hot node chamber on the bottom surface of the upper convex mold. The hot node convex mold is used for forming the reverse shrinkage margin cavity of the sand mold, which can replace the traditional riser and has a small volume and occupies a small space of the sand mold. It can be suitable for sand molds with a small distance between the casting and the edge of the sand mold. When the sand mold is poured to form the casting, the reverse shrinkage metal liquid in the reverse shrinkage margin cavity compensates the hot node of the casting, thereby preventing the casting from generating shrinkage cavities and shrinkage porosity, and improving the casting yield.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A sand mold for a counterweight, used for forming a sand mold for a counterweight, characterized in that: It includes a lower mold and an upper mold corresponding to the lower mold; The lower mold has a lower parting surface, the lower parting surface is upwardly protruding with a sprue nest and a lower runner located on one side of the sprue nest, and is downwardly concave to form a lower cavity located on one side of the lower runner, and the lower cavity has a thermal node chamber corresponding to the thermal node of the counterweight; The upper mold has an upper parting surface corresponding to the lower parting surface, the upper parting surface protrudes downward to form an upper sprue corresponding to the sprue socket, an upper punch located on one side of the upper sprue and corresponding to the lower cavity, and an upper cross runner located on one side of the upper punch and corresponding to the lower cross runner, a hot node punch is formed on the bottom surface of the upper punch, and the hot node punch corresponds to the hot node cavity.

2. The counterweight sand mold according to claim 1, characterized in that: The heat node punch extends along the length direction of the upper punch and is arc-shaped.

3. The counterweight sand mold according to claim 2, characterized in that: The radius of the hot section punch is R, and R is 120.2mm~123.5mm.

4. The counterweight sand mold according to claim 1, characterized in that: The distance between the bottom surface of the hot section punch and the bottom surface of the upper punch is D, and D≤20mm.

5. The counterweight sand mold according to claim 1, characterized in that: The bottom surface of the hot section punch mold protrudes downwards at one end close to the upper sprue to form an exhaust needle.

6. The counterweight sand mold according to claim 1, characterized in that: The bottom surface of the hot node chamber protrudes upward to form a cold iron convex portion, and the cold iron convex portion is used to form the cold iron cavity of the sand mold.

7. The counterweight sand mold according to claim 6, characterized in that: The lower mold cavity includes two first mold cavities and one second mold cavity, the two first mold cavities are respectively located at the two ends of the lower mold cavity, the second mold cavity is located between the two first mold cavities, there are two hot node chambers, one of the hot node chambers is located in one of the first mold cavities, there are two cold iron protrusions, one of the cold iron protrusions is arranged on the bottom surface of one of the first mold cavities, and accordingly, there are two hot node convex molds, one of the hot node convex molds corresponds to one of the cold iron protrusions.

8. The counterweight sand mold according to claim 1, characterized in that: There are two lower cross runners, which are respectively located on opposite sides of the straight runner socket along the length direction of the lower cavity and connected with the straight runner socket. There are multiple upper cross runners, which are arranged along the length direction of the upper punch and connected with the upper punch. In the up and down directions, the projection of the upper straight runner coincides with the projection of the straight runner socket, and the projections of the multiple upper cross runners intersect with the projections of the corresponding lower cross runners.

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