Method of casting a loader counterweight

Abstract

The application discloses a casting method of a loader weight, which comprises the following steps: S1, making a foam model; S2, making a sand box; making an upper sand mold box and a lower sand mold box according to the foam model; and S3, casting. In the process of making the foam model, the weight model is divided into a plurality of block units in a three-dimensional model, a foam block is selected for each block unit, the foam block is cut into a preliminary blank, a mother material is formed after each column preliminary blank is bonded and fixed, the mother material is cut into a rough blank, and the plurality of rough blanks are sequentially arranged along an X direction and bonded together to form the foam model. The foam block is cut along an arc track in two perpendicular directions respectively, so that the curved surface modeling of the front surface of the bonded foam model is consistent with the weight model. The application can quickly complete model making, improves the casting efficiency of the loader weight, reduces the cost, and improves the machining precision of the loader weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, in particular to a casting method of a loading machine counterweight. BACKGROUND

[0002] The loading machine usually needs to be configured with a counterweight at its tail, which plays a balancing role for the loading machine. In order to ensure better counterweight effect, the counterweight is integrally casted. Since the outer part of the counterweight is the appearance surface of the loading machine, it is necessary to ensure that the appearance surface of the counterweight is consistent with the overall modeling of the loading machine during casting. The traditional counterweight casting method is to select wood raw materials of appropriate size, process the wood raw materials into a wooden model completely consistent with the modeling of the counterweight by cutting, milling, and finishing, then use the wooden model to make the sand mold upper box and the sand mold lower box, combine the sand mold upper box and the sand mold lower box, pour molten iron, and complete the casting of the counterweight. Since the appearance surface of the counterweight usually has LOGO, ribs, and recessed structures, the modeling of the appearance surface is extremely complex. This traditional casting method uses manual operation to modify the wood raw materials when processing the wooden model, which consumes high labor cost and has a long wooden model manufacturing cycle. Manual operation results in a large error between the curved surface parameters of the processed wooden model and the curved surface parameters of the counterweight, so the size precision of the castings is low.

[0003] Currently, in the casting process of the counterweight, some use CNC machining centers to make iron models, and use the iron models to manufacture sand mold upper boxes and sand mold lower boxes. This operation method can make the curved surface parameters of the iron model highly consistent with the curved surface parameters of the counterweight, but the cost of developing a set of iron models by CNC machining center is extremely high, which increases the processing cost of the counterweight. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a casting method of a loading machine counterweight, which improves the casting efficiency of the loading machine counterweight while reducing the processing cost of the loading machine counterweight.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The casting method of the loading machine counterweight comprises the following steps:

[0007] S1, making a foam model;

[0008] S11, establish a cuboid closed member in the three-dimensional model, place the counterweight model diagram completely in the closed member, make the top surface of the counterweight model diagram flush with the top end surface of the closed member, make the bottom surface of the counterweight model diagram flush with the bottom end surface of the closed member, the length, width and height of the closed member are consistent with the X-axis, Y-axis and Z-axis respectively, and the length, height and width of the counterweight model diagram are consistent with the X-axis, Y-axis and Z-axis respectively;

[0009] S12, establish a plurality of horizontal sections parallel to the XY plane and a plurality of vertical sections parallel to the YZ plane in the three-dimensional model, the plurality of horizontal sections and the plurality of vertical sections divide the closed member into a plurality of regions, and the counterweight model diagram is divided into a plurality of block units one-to-one corresponding to the plurality of regions; the top surface edge of the block unit forms a first contour, the bottom surface edge of the block unit forms a second contour, and the two side surface edges of the combination of the plurality of block units in each column form a third contour and a fourth contour respectively;

[0010] S13, according to the size of the plurality of regions in the three-dimensional model, select a plurality of foam blocks corresponding one-to-one to the size of the plurality of regions;

[0011] S14, according to the first contour, make a top mold plate, according to the second contour, make a bottom mold plate, and according to the third contour and the fourth contour, make side mold plates; the front side edge of the top mold plate forms a first curved edge, and the front side edge of the bottom mold plate forms a second curved edge; the front side edge of one of the side mold plates forms a third curved edge, and the front side edge of the other side mold plate forms a fourth curved edge;

[0012] S15, place the top mold plate on the top surface of the foam block, place the bottom mold plate on the bottom surface of the foam block, pull a flexible cutting member along the Z direction and make the two ends of the flexible cutting member abut against the first curved edge and the second curved edge respectively, make the foam block and the flexible cutting member move relative to each other along the X direction, and the plurality of foam blocks are cut into a plurality of preliminary blanks respectively;

[0013] S16, sequentially bond the plurality of preliminary blanks in each column to form a mother material, place the two side mold plates on the two sides of the mother material respectively, pull a flexible cutting member along the X direction and make the two ends of the flexible cutting member abut against the third curved edge and the fourth curved edge respectively, make the mother material and the flexible cutting member move relative to each other along the Z direction, and the mother material is cut into a rough blank;

[0014] S17, sequentially bond the plurality of rough blanks to make a foam model;

[0015] S2, make a sand box; make a sand mold upper box and a sand mold lower box according to the foam model;

[0016] S3, casting; close the mold by the sand mold upper box and the sand mold lower box to form a mold cavity, inject iron liquid into the mold cavity from the gate, demold after cooling, and cut and polish the casting to make a loader counterweight.

[0017] Preferably, after completing step S15 and before proceeding to step S16, the following steps also need to be performed:

[0018] S151. Select a piece of foam board with the same length and width as the closed component. The foam board is engraved with a pattern that matches the front shape of the counterweight model drawing. Cut the foam board into several small pieces.

[0019] S152. Adhere the multiple patches corresponding to each preform to the front side of the preform, fill the gaps between adjacent patches with foam material, and use the foam material to smooth the joint between adjacent patches into a smooth transition.

[0020] Preferably, the flexible cutting element is a resistance wire heated to above 120°C.

[0021] Preferably, in step S14, the rear edge of one side template forms a fifth curved edge protruding forward in the middle, and the rear edge of the other side template forms a sixth curved edge protruding forward in the middle; in step S16, the flexible cutting component is also tightened along the X direction, so that the two ends of the flexible cutting component abut against the fifth and sixth curved edges on the two side templates respectively, and the two ends of the flexible cutting component move along the fifth and sixth curved edges respectively to cut the base material.

[0022] Preferably, in step S14, a back template is made according to the back shape of the counterweight model drawing, and the inner edge of the back template forms a seventh curved edge; in step S16, the flexible cutting component cuts the outermost base material into a first base material unit located in front of the fifth and sixth curved edges, and a transition block located behind the fifth and sixth curved edges; the back template is attached to the back of the transition block, the flexible cutting component is stretched along the Y direction, the flexible cutting component cuts along the seventh curved edge of the back template, the transition block is cut into a second base material unit, and the second base material unit is bonded to the first base material unit to form a rough blank.

[0023] Preferably, in step S2, after the upper and lower sand mold boxes are made, a layer of graphite powder coating is applied to the inner surfaces of the upper and lower sand mold boxes.

[0024] Preferably, in step S2, the parting surfaces of the upper and lower sand mold boxes on the back of the foam model are used.

[0025] The beneficial effects of this invention are as follows:

[0026] The loader counterweight casting method of the present invention uses a method of combining multiple smaller foam blocks to make a foam model. Each smaller foam block can be quickly constructed with its front curved shape by cutting. After the shape of each foam block is completed, multiple foam blocks are glued together, which can quickly complete the model making, improve the casting efficiency of loader counterweights, reduce costs, and improve the processing accuracy of loader counterweights. Attached Figure Description

[0027] Figure 1 This is a schematic diagram showing the segmentation of the counterweight model in the three-dimensional model of this invention;

[0028] Figure 2 This is a diagram showing the correspondence between foam blocks and model block units;

[0029] Figure 3a and Figure 3b This is a schematic diagram of the top template, bottom template, and side templates;

[0030] Figures 4a-4c This is a schematic diagram illustrating the process of processing foam blocks into rough blanks;

[0031] Figures 5a-5e This is a schematic diagram of the process of processing foam blocks into rough blanks with edges. Implementation

[0032] The present invention will now be further described with reference to the accompanying drawings and specific embodiments: Example

[0033] The casting method for loader counterweights includes the following steps:

[0034] S1. Make a foam model;

[0035] S11, see also Figure 1 As shown, a rectangular closed component 200 is created in the 3D model containing the counterweight model 100, so that the counterweight model 100 is completely placed within the closed component 200, meaning that no part of the counterweight model 100 exceeds the outer contour surface of the closed component 200. The front of the counterweight model 100 is an irregular curved surface, while the top, bottom, and back surfaces are all flat. Specifically, the top surface of the counterweight model 100 is flush with the top surface 201 of the closed component 200, the bottom surface of the counterweight model 100 is flush with the bottom surface 202 of the closed component 200, and the back surface of the counterweight model 100 is flush with the rear side surface of the closed component 200. The length, width, and height of the closed component 200 are aligned with the X-axis, Y-axis, and Z-axis, respectively, and the length, width, and height of the counterweight model 100 are aligned with the X-axis, Y-axis, and Z-axis, respectively.

[0036] S12. In the 3D model, establish two horizontal cut surfaces 203 and four vertical cut surfaces 204. The two horizontal cut surfaces 203 are parallel to the XY plane, and the four vertical cut surfaces 204 are parallel to the YZ plane. Thus, through the two horizontal cut surfaces 203, the top surface 201 of the closed component 200, the bottom surface 202 of the closed component 200, the four vertical cut surfaces 204, and the two end surfaces 205 of the closed component 200, the closed component 200 is divided into fifteen regions. The counterweight model diagram 100 is divided into fifteen block units corresponding to these regions. These fifteen block units are specifically block unit 2101, block unit 2102, block unit 2103, block unit 2104, block unit 2105, and block unit 2106. 105, block unit 2106, block unit 2107, block unit 2108, block unit 2108, block unit 2110, block unit 2111, block unit 2112, block unit 2113, block unit 2114, block unit 2115; taking block unit 2101 as an example, a first contour is formed at the top edge of its top surface, and a second contour is formed at the top edge of its top surface. The other block units also contain the first contour and the second contour; the two sides of the vertical combination formed by block units 2101, 2102, and 2103 in the same column respectively form a third contour and a fourth contour; wherein, the front edge of the first contour, the second contour, the third contour, and the fourth contour is a curved edge;

[0037] S13, Participation Figure 2 As shown, based on the dimensions of the fifteen regions divided by the closed component 200 in the three-dimensional model, fifteen foam blocks corresponding one-to-one with the dimensions of the fifteen regions are selected; or a large foam block with the same dimensions as the closed component 200 and in the shape of a cuboid is selected, and based on the positions of the two horizontal cut surfaces 203 and the four vertical cut surfaces 204 in the closed component 200, the large foam block is cut into fifteen foam blocks with dimensions corresponding one-to-one with the fifteen regions. For example, the foam block 2101a corresponds to the block unit 2101.

[0038] S14, see also Figure 3a , 3b As shown, a top template 31 is made according to the first contour, a bottom template 32 is made according to the second contour, a side template 33 is made according to the third contour, and another side template 34 is made according to the fourth contour. The front edge of the top template 31 forms a first curved edge 311, the front edge of the bottom template 32 forms a second curved edge 321, the front edge of the side template 33 forms a third curved edge 331, and the front edge of the side template 34 forms a fourth curved edge 341.

[0039] S15, see also Figure 4aAs shown, multiple foam blocks are cut. Taking the foam block 2101a corresponding to block unit 2101 as an example, the top template 31 is placed on the top surface of the foam block 2101a, and the bottom template 32 is placed on the bottom surface of the foam block 2101a. A resistance wire 40 is heated to above 120°C. Using the resistance wire 40 as a flexible cutting element, the resistance wire 40 is pulled taut along the Z direction, so that the top end of the resistance wire 40 abuts against the first curved edge 311 of the top template 31 and the bottom end of the resistance wire 40 abuts against the second curved edge 321 of the bottom template 32. The foam block 2101a is fixed on the tooling fixture, so that the length, width, and height of the foam block 2101a correspond to the X, Y, and Z directions, respectively. The resistance wire 40 is moved along the X direction, and the foam block 2101a is cut from one side to form a preliminary blank 2101b. Repeatedly, multiple foam blocks are cut into preliminary blanks in the above manner.

[0040] S16, see also Figure 4b , 4c As shown, multiple preforms in each column are sequentially bonded together along the Z-direction to form a base material 5010. Taking preforms 2101b, 2102b, and 2103b as an example, they are bonded together along the height direction in the order of preforms 2103b, 2101b, and 2102b to form a base material. Side templates 33 and 34 are placed on both sides of the base material. The resistance wire is heated to above 120°C and pulled taut along the X-direction so that the two ends of the resistance wire abut against the third curved edge 331 of the side template 33 and the fourth curved edge 341 of the side template 34, respectively. The resistance wire is moved downward along the Z-direction from the top of the base material to cut the base material composed of the preforms 2103b, 2101b, and 2102b into a rough blank 501. Repeatedly, the base material composed of multiple preforms in each column is cut into a rough blank in the above manner.

[0041] S17. Glue multiple rough blanks together in the X-direction arrangement to make a foam model.

[0042] S2. Making the sand mold box: Based on the foam model, using the back of the foam model as the parting surface for the upper and lower sand mold boxes, make the upper and lower sand mold boxes. This includes the following steps:

[0043] S21. Place the foam model face up on a horizontal platform. Cover the horizontal platform with a mixture of casting quartz sand, resin and curing agent, so that the mixture covers the front and perimeter of the foam model. Let it stand for 30 minutes until the mixture has solidified and formed into a sand mold. The ratio of casting quartz sand, resin and curing agent in the mixture is existing technology and will not be described in detail here.

[0044] S22. Flip the upper sand mold box and the foam model 180 degrees and place them on a horizontal platform. Cover the back of the upper sand mold box and the foam model with a mixture of casting quartz sand, resin and curing agent. Let it stand for 30 minutes until the mixture has solidified and formed to make the lower sand mold box. Separate the upper and lower sand mold boxes and separate the foam model from the upper and lower sand mold boxes.

[0045] S3. Casting: The prepared upper and lower sand mold boxes are assembled. The assembled upper and lower sand mold boxes form a cavity. Molten iron is poured into the cavity through the pre-set gate on the lower sand mold box. After cooling, the upper and lower sand mold boxes are separated to demold the casting. The casting is then cut and polished at the gate, riser and other parts to make the loader counterweight. Example

[0046] The casting method described in Embodiment 1 above is for casting loader counterweights with a curved front surface and flat top, bottom, sides, and back. However, some loader counterweights do not have a regularly curved front surface. Their front surface not only has a curved shape but also features raised and / or recessed structures to enhance the loader's aesthetics and provide product identification. For example, some loader counterweights typically use recessed structures to form the product logo. For casting such loader counterweights, the technical solution of Embodiment 2 of this invention can be used, specifically:

[0047] The casting method for loader counterweights includes the following steps:

[0048] S11, see also Figure 1 As shown, a rectangular closed component 200 is created in the 3D model containing the counterweight model 100, so that the counterweight model 100 is completely placed within the closed component 200, meaning that no part of the counterweight model 100 exceeds the outer contour surface of the closed component 200. The front of the counterweight model 100 is an irregular curved surface, while the top, bottom, and back surfaces are all flat. Specifically, the top surface of the counterweight model 100 is flush with the top surface 201 of the closed component 200, the bottom surface of the counterweight model 100 is flush with the bottom surface 202 of the closed component 200, and the back surface of the counterweight model 100 is flush with the rear side surface of the closed component 200. The length, width, and height of the closed component 200 are aligned with the X-axis, Y-axis, and Z-axis, respectively, and the length, width, and height of the counterweight model 100 are aligned with the X-axis, Y-axis, and Z-axis, respectively.

[0049] S12. In the 3D model, establish two horizontal cut surfaces 203 and four vertical cut surfaces 204. The two horizontal cut surfaces 203 are parallel to the XY plane, and the four vertical cut surfaces 204 are parallel to the YZ plane. Thus, through the two horizontal cut surfaces 203, the top surface 201 of the closed component 200, the bottom surface 202 of the closed component 200, the four vertical cut surfaces 204, and the two end surfaces 205 of the closed component 200, the closed component 200 is divided into fifteen regions. The counterweight model diagram 100 is divided into fifteen block units corresponding to these regions. These fifteen block units are specifically block unit 2101, block unit 2102, block unit 2103, block unit 2104, block unit 2105, and block unit 2106. 105, block unit 2106, block unit 2107, block unit 2108, block unit 2108, block unit 2110, block unit 2111, block unit 2112, block unit 2113, block unit 2114, block unit 2115; taking block unit 2101 as an example, a first contour is formed at the top edge of its top surface, and a second contour is formed at the top edge of its top surface. The other block units also contain the first contour and the second contour; the two sides of the vertical combination formed by block units 2101, 2102, and 2103 in the same column respectively form a third contour and a fourth contour; wherein, the front edge of the first contour, the second contour, the third contour, and the fourth contour is a curved edge;

[0050] S13, Participation Figure 2 As shown, based on the dimensions of the fifteen regions divided by the closed component 200 in the three-dimensional model, fifteen foam blocks corresponding one-to-one with the dimensions of the fifteen regions are selected; or a large foam block with the same dimensions as the closed component 200 and in the shape of a cuboid is selected, and based on the positions of the two horizontal cut surfaces 203 and the four vertical cut surfaces 204 in the closed component 200, the large foam block is cut into fifteen foam blocks with dimensions corresponding one-to-one with the fifteen regions. For example, the foam block 2101a corresponds to the block unit 2101.

[0051] S14, see also Figure 3a , 3b As shown, a top template 31 is made according to the first contour, a bottom template 32 is made according to the second contour, a side template 33 is made according to the third contour, and another side template 34 is made according to the fourth contour. The front edge of the top template 31 forms a first curved edge 311, the front edge of the bottom template 32 forms a second curved edge 321, the front edge of the side template 33 forms a third curved edge 331, and the front edge of the side template 34 forms a fourth curved edge 341.

[0052] S15, see also Figure 4aAs shown, multiple foam blocks are cut. Taking the foam block 2101a corresponding to block unit 2101 as an example, the top template 31 is placed on the top surface of the foam block 2101a, and the bottom template 32 is placed on the bottom surface of the foam block 2101a. A resistance wire 40 is heated to above 120°C. Using the resistance wire 40 as a flexible cutting element, the resistance wire 40 is pulled taut along the Z direction, so that the top end of the resistance wire 40 abuts against the first curved edge 311 of the top template 31 and the bottom end of the resistance wire 40 abuts against the second curved edge 321 of the bottom template 32. The foam block 2101a is fixed on the tooling fixture, so that the length, width, and height of the foam block 2101a correspond to the X, Y, and Z directions, respectively. The resistance wire 40 is moved along the X direction, and the foam block 2101a is cut from one side to form a preliminary blank 2101b. Repeatedly, multiple foam blocks are cut into preliminary blanks in the above manner.

[0053] S151. Select a foam board with the same length and width as the closed component. Engrave a pattern on the foam board that matches the front shape of the counterweight model in Figure 100. Cut the foam board into several small pieces 29. Specifically, the foam board thickness can be 5mm-8mm. Cut several slits along the X and Z directions into pieces 29 with a length of 40mm-50mm and a width of 20mm-30mm. Each block unit has multiple pieces 29 on its front side. Then, establish a correspondence between these multiple pieces 29 on the front side of each block unit and each initial blank.

[0054] S152. A number of patches corresponding to the preform are sequentially glued to the front side of the preform. For example, multiple patches 29 corresponding to each preform 2101b, 2102b, and 2103b are glued to the front side of the preform respectively. After the patches 29 are glued, if there are gaps between adjacent patches 29, they are filled with foam material. The foam material is used to correct the joint of adjacent patches 29 to a smooth transition.

[0055] S16, see also Figure 4b , 4cAs shown, multiple preforms in each column are sequentially bonded together to form a base material 5010. Taking preforms 2101b, 2102b, and 2103b as an example, they are bonded together along the height direction in the order of preforms 2103b, 2101b, and 2102b to form a base material. Side templates 33 and 34 are placed on both sides of the base material. The resistance wire is heated to above 120°C and pulled taut along the X direction so that the two ends of the resistance wire abut against the third curved edge 331 of the side template 33 and the fourth curved edge 341 of the side template 34, respectively. The resistance wire moves downward along the Z direction from the top of the material to cut the mother material composed of the above-mentioned initial blanks 2103b, 2101b, and 2102b into a rough blank 501. During the cutting process, the resistance wire is used to cut multiple patches 29. From the YZ plane, after the outer side of the patch 29 is cut, the structure formed by the projection of the outer surface of the multiple patches 29 on the YZ plane is consistent with the front shape of the corresponding part in the counterweight model diagram 100. Repeatedly, the mother material composed of multiple initial blanks in each column is cut into a rough blank 501 in the above manner.

[0056] S17. Glue multiple rough blanks together in the X-direction arrangement to make a foam model.

[0057] S2. Making the sand mold box: Based on the foam model, using the back of the foam model as the parting surface for the upper and lower sand mold boxes, make the upper and lower sand mold boxes. This includes the following steps:

[0058] S21. Place the foam model face up on a horizontal platform. Cover the horizontal platform with a mixture of casting quartz sand, resin and curing agent, so that the mixture covers the front and perimeter of the foam model. Let it stand for 30 minutes until the mixture has solidified and formed into a sand mold. The ratio of casting quartz sand, resin and curing agent in the mixture is existing technology and will not be described in detail here.

[0059] S22. Flip the upper sand mold box and the foam model 180 degrees and place them on a horizontal platform. Cover the back of the upper sand mold box and the foam model with a mixture of casting quartz sand, resin and curing agent. Let it stand for 30 minutes until the mixture has solidified and formed to make the lower sand mold box. Separate the upper and lower sand mold boxes and separate the foam model from the upper and lower sand mold boxes.

[0060] S3. Casting: The prepared upper and lower sand mold boxes are assembled. The assembled upper and lower sand mold boxes form a cavity. Molten iron is poured into the cavity through the pre-set gate on the lower sand mold box. After cooling, the upper and lower sand mold boxes are separated to demold the casting. The casting is then cut and polished at the gate, riser and other parts to make the loader counterweight. Example

[0061] To achieve a larger overall size while ensuring the total weight meets the vehicle's requirements, some loader counterweights require hollowing out the back side. This creates a recessed structure on the back of the counterweight. For example, in the counterweight model diagram 100, the shape formed by the vertical sections 204 is roughly C-shaped. Therefore, when making the foam model, the corresponding position on the back of the foam model needs to be hollowed out to make its shape consistent with the counterweight model diagram 100.

[0062] This requires, based on the above embodiments one and two, such as Figure 3b As shown, in step S14, a fifth curved edge 332 protruding forward in the middle is formed on the rear edge of the side template 33, making the side template 33 roughly C-shaped. Similarly, a sixth curved edge 342 protruding forward in the middle is formed on the rear edge of the side template 34, making the side template 34 roughly C-shaped. Meanwhile, in step S16, see... Figure 4b , 4c As shown, the resistance wire needs to be tightened along the X direction so that the two ends of the resistance wire 40 abut against the fifth curve edge 332 and the sixth curve edge 342 respectively, so that the two ends of the resistance wire 40 move along the fifth curve edge 332 and the sixth curve edge 342 respectively, and the base material is cut so that the rough blank 501 becomes the final assembled foam model shape; this method is suitable for the case where the shape of the loader counterweight is approximately C-shaped on any YZ section.

[0063] The other steps in this third embodiment are the same as those in the first and second embodiments described above, and will not be repeated here. Example

[0064] In reality, most loader counterweights are not approximately C-shaped in any YZ section. For example, in the X direction, the two sides of the loader counterweight have blind ends. Therefore, when making the foam model, the aforementioned blind end structure needs to be considered; specifically,

[0065] When creating the foam model corresponding to the two blind ends, such as Figure 5a , 5b As shown in 5c, 5d, and 5e, the parent material 5020 composed of the edge preforms 2115b, 2113b, and 2114b is taken as an example;

[0066] In step S14, a back template 35 needs to be made according to the back shape of the counterweight model drawing 100, and the inner edge of the back template 35 forms a seventh curved edge 351.

[0067] In step S16, the initial blanks 2115b, 2113b, and 2114b are bonded together in a top-to-bottom sequence to form the base material 5020. Side templates 34 and 33 are placed on both sides of the base material 5020. A patch is cut from the front of the base material 5020 using a resistance wire to form the front shape of the base material 5020. Then, a cut is made from the back of the base material 5020 using a resistance wire to cut the base material 5020 into the first base material unit 5021 located in front of the fifth and sixth curved edges. The cut-off portion is located in... The transition block 5022 behind the fifth and sixth curved edges is used to attach the back template 35 to the back of the transition block 5022 (i.e., the XZ surface). The resistance wire is pulled taut along the Y direction, so that the resistance wire cuts the transition block 5022 along the seventh curved edge 351. The part located outside the seventh curved edge 351 forms the second base material unit 5023. The second base material unit 5023 is aligned and bonded with the first base material unit 5021 to form the rough blank 502. The rough blank 502 at this edge is bonded to the other rough blanks in sequence to finally make the foam model.

[0068] The other steps in this embodiment four are the same as those in embodiments one and two above, and will not be described again here.

[0069] In the loader counterweights described in embodiments three and four above, reinforcing ribs are also required to be installed in the hollowed-out portion on the back to ensure that the strength of the entire loader counterweight meets the requirements. Therefore, when making the foam model, it is also necessary to configure a structure on the foam model that corresponds to the reinforcing ribs on the loader counterweight. Specifically, after gluing multiple rough blanks together in sequence, select a foam board of appropriate size, place the foam board in the corresponding position on the back of the rough blank, and use glue to glue the foam board to the rough blank.

[0070] It should be emphasized that when cutting foam blocks, the present invention uses resistance wire as a flexible cutting element. In fact, the flexible cutting element is not limited to resistance wire; it can also be other flexible components capable of cutting foam materials.

[0071] The loader counterweight casting method of the present invention uses a method of combining multiple smaller foam blocks to make a foam model. Each smaller foam block can be quickly constructed with its front curved shape by cutting. After the shape of each foam block is completed, multiple foam blocks are glued together, which can quickly complete the model making, improve the casting efficiency of loader counterweights, reduce costs, and improve the processing accuracy of loader counterweights.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A casting method for loader counterweights, characterized in that, Includes the following steps: S1. Make a foam model; S11. Create a closed cuboid component in the 3D model. Place the counterweight model completely inside the closed component, making the top surface of the counterweight model flush with the top surface of the closed component and the bottom surface of the counterweight model flush with the bottom surface of the closed component. The length, width, and height of the closed component are aligned with the X-axis, Y-axis, and Z-axis, respectively. The length, height, and width of the counterweight model are aligned with the X-axis, Y-axis, and Z-axis, respectively. S12. In the 3D model, establish several horizontal cut surfaces parallel to the XY plane and several vertical cut surfaces parallel to the YZ plane. The horizontal and vertical cut surfaces divide the closed component into multiple regions. The counterweight model diagram is divided into multiple block units corresponding to the multiple regions. The top edge of the block unit forms the first contour, the bottom edge of the block unit forms the second contour, and the two side edges of the combination formed by multiple block units in each column form the third contour and the fourth contour, respectively. S13. Based on the dimensions of multiple regions in the 3D model, select multiple foam blocks that correspond one-to-one with the dimensions of these multiple regions; S14. Create a top template based on the first contour, a bottom template based on the second contour, and side templates based on the third and fourth contours; the front edge of the top template forms a first curved edge, and the front edge of the bottom template forms a second curved edge; the front edge of one side template forms a third curved edge, and the front edge of the other side template forms a fourth curved edge. S15. Place the top template on the top surface of the foam block and the bottom template on the bottom surface of the foam block. Pull a flexible cutting piece along the Z direction and make the two ends of the flexible cutting piece abut against the first curved edge and the second curved edge respectively, so that the foam block and the flexible cutting piece move relative to each other along the X direction, and the multiple foam blocks are cut into multiple initial blanks respectively. S16. Sequentially bond together multiple blanks in each column to form a base material. Place the templates on both sides of the base material. Pull a flexible cutting piece along the X direction and make the two ends of the flexible cutting piece abut against the third and fourth curved edges respectively. Move the base material and the flexible cutting piece relative to each other along the Z direction. The base material is cut into a rough blank. S17. Glue multiple rough blanks together in sequence to make a foam model; S2. Making sand boxes; making the upper and lower sand mold boxes based on the foam model; S3. Casting: The prepared sand mold upper box and sand mold lower box are closed to form a cavity. Molten iron is poured into the cavity through the gate. After cooling, the mold is removed, and the casting is cut and polished to make the loader counterweight. After completing step S15 and before proceeding to step S16, the following steps are also required: S151. Select a piece of foam board with the same length and width as the closed component. The foam board is engraved with a pattern that matches the front shape of the counterweight model drawing. Cut the foam board into several small pieces. S152. Adhere the multiple patches corresponding to each preform to the front side of the preform, fill the gaps between adjacent patches with foam material, and use the foam material to smooth the joint between adjacent patches into a smooth transition.

2. The casting method for the loader counterweight as described in claim 1, characterized in that, The flexible cutting component is a resistance wire that has been heated to over 120°C.

3. The casting method for the loader counterweight as described in claim 1, characterized in that, In step S14, a fifth curved edge protruding forward in the middle is formed on the rear edge of one side template, and a sixth curved edge protruding forward in the middle is formed on the rear edge of the other side template. In step S16, the flexible cutting component needs to be tightened along the X direction so that the two ends of the flexible cutting component abut against the fifth and sixth curved edges on the two side templates respectively, and the two ends of the flexible cutting component move along the fifth and sixth curved edges respectively to cut the base material.

4. The casting method for the loader counterweight as described in claim 3, characterized in that, In step S14, a back template is made according to the back shape of the counterweight model drawing, and the inner edge of the back template forms a seventh curved edge. In step S16, the flexible cutting element cuts the outermost parent material into a first parent material unit located in front of the fifth and sixth curved edges, and a transition block located behind the fifth and sixth curved edges. The back template is attached to the back of the transition block, the flexible cutting part is pulled taut along the Y direction, the flexible cutting part is cut along the seventh curve edge of the back template, the transition block is cut into the second parent material unit, and the second parent material unit is bonded to the first parent material unit to form a rough blank.

5. The casting method for the loader counterweight as described in claim 1, characterized in that, In step S2, after the upper and lower sand mold boxes are made, a layer of graphite powder coating is applied to the inner surfaces of the upper and lower sand mold boxes.

6. The casting method for the loader counterweight as described in claim 1, characterized in that, In step S2, the parting surfaces of the upper and lower sand mold boxes on the back of the foam model are used.

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