Aluminum alloy caliper sand core mold and forming method

Abstract

The invention relates to an aluminum alloy caliper sand core and a forming method thereof, and belongs to the technical field of casting. According to the method, through innovative mold design and technological processes, the precision, strength and consistency of the caliper sand core are remarkably improved, and a powerful guarantee is provided for high-quality casting of the aluminum alloy calipers. The mold comprises a sand shooting assembly, an upper sand ejection assembly, an upper mold assembly, a lower mold assembly and a lower sand ejection assembly, and precise molding and smooth demolding of a sand core are achieved through the synergistic effect of all the assemblies. The forming method comprises the steps of mold preheating, release agent spraying, mold closing, sand shooting, curing, demolding, aftertreatment and the like, all parameters are strictly controlled, and the quality of the sand core is ensured. The method has the advantages of improving the precision and strength of the sand core, enhancing the consistency of the sand core, facilitating demolding, being high in adaptability and the like, can be widely applied to production and manufacturing of aluminum alloy brake calipers, and has important economic and social benefits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of casting, and particularly relates to a sand core mold for an aluminum alloy brake caliper and a molding method thereof. The core purpose of the present application is to significantly improve the precision, strength and consistency of the sand core through innovative mold design and process design, thereby providing strong protection for the high-quality casting of the aluminum alloy brake caliper. BACKGROUND

[0002] Aluminum alloy calipers are widely used in modern automobile brake systems due to their light weight, high strength, corrosion resistance and other characteristics. However, the structure of the aluminum alloy caliper is complex, especially the internal oil channel and heat dissipation channel, which have very high requirements for the precision and strength of the surrounding dendritic structure of the sand core. The surface precision of the sand core prepared by the traditional sand core forming method is difficult to meet the requirements, and the small dendritic structure has poor filling property and is accompanied by pores, which is difficult to meet the use requirements of the caliper sand core, resulting in many casting defects and low yield. Therefore, it is particularly important to develop a mold and molding method suitable for the sand core of the aluminum alloy brake caliper.

[0003] In view of the deficiencies of the prior art, the present application provides an aluminum alloy caliper sand core and a molding method thereof, which improves the precision, strength and consistency of the caliper sand core by designing the sand core mold structure and molding process, thereby improving the casting quality of the aluminum alloy brake caliper. SUMMARY

[0004] The mold for preparing the caliper sand core provided by the present application comprises a sand injection assembly, an upper sand ejection assembly, an upper mold assembly, a lower mold assembly and a lower sand ejection assembly. The sand injection assembly injects sand into the upper mold assembly and the lower mold assembly. After solidification and shaping, the sand core is ejected from the cavity of the upper mold assembly and the lower mold assembly by the upper sand ejection assembly and the lower sand ejection assembly, and the manufacturing of the caliper sand core is completed.

[0005] The sand injection assembly comprises a sand blocking plate, a sand injection plate and a sand injection nozzle. The sand blocking plate is located above the sand injection plate and has a hole in the middle for connecting the sand injection equipment. The sand blocking plate is connected to the sand injection plate by bolts and pads, and the distance z1 between the sand blocking plate and the sand injection plate is adjusted by different pad heights to control the flow rate and flow range of the sand. The sand injection nozzle is located below the sand injection plate and has threads on the outside and a through hole in the inside. The sand injection plate has a threaded through hole arranged below the sand blocking plate, and the sand injection nozzle is connected to the sand blocking plate by threads. The positions of the sand injection nozzle and the sand blocking plate are determined by the structure of the sand core.

[0006] The upper sand ejecting assembly comprises an upper ejector plate, an upper ejector rod, and an upper ejector guide pin. The upper ejector plate has stepped holes at its four corners. The upper ejector guide pin is located below the upper ejector plate and is installed into the stepped holes of the upper ejector plate to limit the position of the upper sand ejecting assembly in the vertical direction during sand ejecting. The upper ejector plate has a plurality of through holes in its middle part for installing the lower upper ejector rod. The installation position of the upper ejector rod is determined by the sand core structure.

[0007] The upper mold assembly comprises an upper mold, an upper mold insert, a nozzle bushing, an exhaust plug, an upper mold exhaust pin, and an upper mold heating rod. The upper mold not only has the cavity structure of the sand core, but also serves as the installation carrier of the upper mold insert, the nozzle bushing, the exhaust plug, the upper mold exhaust pin, and the upper mold heating rod. According to the sand core structure, a plurality of through holes are arranged in the middle part of the upper mold sand core cavity for fixing the nozzle bushing. The sand material reaches the middle part of the cavity through the nozzle bushing and then spreads to the surrounding area. A plurality of through holes are vertically arranged at the middle part of both ends of the sand core cavity for installing the upper mold exhaust pin. Adjacent through holes are cut with a gap of width y1 for exhaust during the injection and solidification of the sand core material to avoid defects such as incomplete filling of the caliper sand core. Through holes are vertically arranged at the position of the dendritic structure of the caliper sand core cavity for installing the upper mold insert. The insert has a plurality of gaps of length y2 and depth z2 for exhaust during the injection and solidification of the sand core material to avoid defects such as incomplete filling of the caliper sand core. A plurality of through holes are arranged in the middle area of the upper mold sand core cavity. The upper and lower parts of the through holes are respectively installed with the upper mold exhaust plug for exhaust during the injection and solidification of the sand core, which is beneficial to the diffusion of the sand core material. The relief cavity and a plurality of holes for installing the upper mold insert, the nozzle bushing, the exhaust plug, and the upper mold exhaust pin are arranged with a plurality of through holes in the middle part of the height direction of the upper mold along the depth direction for installing the upper mold heating rod to adjust the temperature during the molding of the sand core.

[0008] The lower mold assembly comprises a lower mold body, a mold foot, a guide column, an upper ejector plate limiting column, and a lower mold heating rod. Holes are symmetrically arranged in the middle part of the left and right sides of the lower mold body for installing the guide column. The guide column plays an auxiliary positioning role when the upper mold assembly and the lower mold assembly are combined to ensure that the upper mold cavity and the lower mold body cavity are tightly sealed and that the appearance of the caliper sand core is good. Holes are symmetrically arranged on the left and right sides of the lower mold body, avoiding the guide column holes, for installing the upper ejector plate limiting column to limit the lower position of the upper ejector rod and avoid damaging the caliper sand core during demolding. Through holes are arranged in the middle part and the dendritic structure around the lower mold body cavity for demolding after the molding of the caliper sand core. A plurality of holes for installing the guide column and the upper ejector plate limiting column are avoided. A plurality of through holes are arranged in the middle part of the height direction of the lower mold body along the depth direction for installing the lower mold heating rod to adjust the temperature during the molding of the caliper sand core.

[0009] The lower ejection assembly comprises a lower ejector plate, a lower ejector push plate, a lower ejector plate reset rod, and a lower mold ejector rod. The lower ejector plate is provided with a plurality of through holes. The lower mold ejector rod is installed on the lower ejector plate and is used to separate the caliper sand core from the lower mold body cavity after the caliper sand core is formed. The lower ejector push plate is located below the lower ejector plate. Both the lower ejector plate and the lower ejector push plate are provided with reset through holes around the periphery. The lower ejector plate reset rod is inserted through the reset through holes of the lower ejector plate and the lower ejector push plate, and the upper end of the lower ejector plate reset rod is installed into the through holes in the four corners of the lower mold body. The lower end of the lower ejector plate reset rod is provided with a nut for limiting the lower ejector push plate. In this way, the lower ejector plate reset rod connects the lower ejector plate, the lower ejector push plate, and the lower mold body. When demolding, the lower ejector push plate is pushed by external force, and the lower ejector plate and the lower mold ejector rod move vertically upward. After the caliper sand core is ejected from the lower mold body cavity, the lower ejector plate and the lower ejector push plate return to the original position under the action of gravity.

[0010] The movement sequence and process of each component in the caliper sand core manufacturing process are as follows: Step 1: Preheat the mold. The upper mold and the lower mold body are preheated to a set temperature, usually 200-260°C, through the upper mold heating rod and the lower mold heating rod, respectively, to ensure that the sand core material has good fluidity and curing effect during injection and curing.

[0011] Step 2: Spray demolding agent. Spray demolding agent evenly on the surface of the upper mold cavity and the lower mold body cavity to reduce the adhesion between the sand core and the cavity, facilitating the subsequent demolding of the sand core.

[0012] Step 3: Close the mold. Move the preheated upper mold assembly downward, and the lower mold assembly remains stationary. The upper plate limiting column on the lower mold body first enters the corresponding through hole in the upper mold, and then the guide column enters the hole in the upper mold, ensuring that the upper mold cavity and the lower mold body cavity form a closed space. When the lower surface of the upper mold contacts the upper surface of the lower mold body, the upper mold stops moving, which ensures the sealing of the mold and prevents leakage of the sand core material.

[0013] Step 4: Shoot sand. Move the sand shooting assembly vertically downward until the sand shooting nozzle connects with the sand shooting nozzle bushing in the upper mold. Inject the sand core material into the closed space formed by the upper mold cavity and the lower mold body cavity through the sand shooting nozzle. During the sand shooting process, the sand shooting pressure should be controlled at 0.2-0.8 MPa, and the sand shooting time should be controlled at 10-20 seconds to ensure uniform filling of the sand core material.

[0014] Step 5: Curing. After the sand core material is filled, maintain the mold temperature constant to cure the sand core material. The curing time is 360-480 seconds. At this time, remove the sand shooting assembly, move the upper ejection assembly above the upper mold assembly, and then move the upper ejection assembly vertically downward until the upper plate guide pin passes through the corresponding through hole in the upper mold and contacts the upper surface of the upper plate limiting column, and then keep it stationary.

[0015] Step 6: Demolding, after the curing is completed, move the upper mold assembly up by a distance z2, at this time the sand core is separated from the upper mold cavity under the action of the upper ejector rod, at this time the sand core remains in the lower mold assembly cavity; then move the lower ejector pin push plate up, so that the lower mold ejector rod contacts the sand core and pushes the sand core out of the lower mold body cavity by a certain height, then take out the sand core from the lower mold body, this process ensures that the lower ejector pin pushing speed is slow and uniform, avoiding causing the caliper sand core damage.

[0016] Step 7: Post-processing, clean and inspect the caliper sand core, remove the defects such as flash and burr on the surface of the sand core. Advantages

[0017] Improve the precision and strength of the caliper sand core: through the design of the sand shooting assembly, the flow rate and flow range of the sand core material can be accurately controlled, ensuring uniform filling of the mold cavity, thereby significantly improving the precision and strength of the sand core. In addition, the exhaust system arranged in the mold effectively avoids the problems of incomplete filling of the dendritic sand core structure and internal defects, further improving the quality of the caliper sand core.

[0018] Enhance the consistency of the caliper sand core: through precise mold design and strict manufacturing process control, the invention can ensure high consistency in shape, size and performance of each caliper sand core, which is crucial for improving the casting quality and overall performance of aluminum alloy brake calipers.

[0019] Easy demolding: the mold design takes into account factors that facilitate demolding, such as the use of demolding agents and reasonable ejection mechanisms, so that the caliper sand core can be easily removed from the mold and the integrity of the caliper sand core is guaranteed.

[0020] Strong adaptability: the mold and molding method of the invention can be flexibly adjusted according to the structure of different aluminum alloy brake caliper sand cores, by replacing different mold inserts, sand shooting nozzles and ejector rods, it can meet the manufacturing needs of various specifications and models of caliper sand cores, with strong adaptability and versatility. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Schematic diagram of aluminum alloy brake caliper sand core.

[0022] Figure 2 Schematic diagram of sand core mold.

[0023] Figure 3 Cross-sectional view of sand shooting assembly.

[0024] Figure 4 Cross-sectional view of upper sand ejecting assembly.

[0025] Figure 5 Axial side view of upper mold assembly.

[0026] Figure 6Top view of the upper die assembly.

[0027] Figure 7 Axial view of the lower die assembly.

[0028] Figure 8 Top view of the lower die assembly.

[0029] Figure 9 Axial view of the lower knockout assembly.

[0030] Figure 10 Sectional view of the lower knockout assembly.

[0031] Wherein: 1-caliper sand core, 2-mold, 3-sand injection assembly, 4-upper knockout assembly, 5-upper die assembly, 6-lower die assembly, 7-lower knockout assembly, 31-sand blocking plate, 32-sand injection plate, 33-sand injection nozzle, 34-pad, 41-upper ejector plate, 42-upper ejector guide pin, 43-upper ejector rod, 51-upper die, 52-upper die cavity, 53-upper die heating rod, 54-upper die insert, 55-nozzle bushing, 56-exhaust plug, 57-upper die exhaust pin, 61-lower die body, 62-die foot, 63-guide column, 64-upper ejector limit column, 65-lower die heating rod, 66-lower die body cavity, 661-lower die body cavity dendritic structure, 71-lower ejector plate, 72-lower ejector push plate, 73-lower ejector plate reset rod, 74-lower die ejector rod. Embodiments

[0032] The application will be further described in conjunction with the drawings and specific embodiments. Embodiments

[0033] In this embodiment, the application provides a mold 2 for preparing a caliper sand core, which comprises a sand injection assembly 3, an upper knockout assembly 4, an upper die assembly 5, a lower die assembly 6, and a lower knockout assembly 7. The sand injection assembly 3 injects sand into the upper die assembly 5 and the lower die assembly 6, and after solidification and shaping, the caliper sand core 1 is ejected from the cavities of the upper die assembly 5 and the lower die assembly 6 by the upper knockout assembly 4 and the lower knockout assembly 7, thus completing the manufacture of the caliper sand core 1.

[0034] Sand shooting assembly 3 includes sand shooting plate 31, sand shooting plate 32, sand shooting nozzle 33, sand shooting plate 31 is located above sand shooting plate 32, with a hole in the middle, used to connect sand shooting equipment, sand shooting plate 31 is connected with sand shooting plate 32 through bolt 35 and pad 34, the height of pad 34 adjusts the distance z1=6mm between sand shooting plate 31 and sand shooting plate 32, reasonably controls the flow rate and flow range of sand, which will not overflow everywhere, nor will it be blocked; sand shooting nozzle 33 is below sand shooting plate 32, sand shooting nozzle 33 has threads on the outside and a through hole in the inside, sand shooting plate 32 has threaded through holes, the threaded through holes are arranged below sand shooting plate 31, sand shooting nozzle 33 is connected with sand shooting plate 31 through threads. The position of sand shooting nozzle 33 and sand shooting plate 31 is determined by the structure of sand core.

[0035] Upper sand ejecting assembly 4 includes upper ejector plate 41, upper ejector rod 43, upper ejector guide pin 42, the four corners of upper ejector plate 41 are provided with stepped holes, upper ejector guide pin 42 is located below upper ejector plate 41 and is installed into the stepped hole of upper ejector plate 41, used to limit the vertical position of upper sand ejecting assembly 4 during sand ejecting; a plurality of through holes are arranged in the middle of upper ejector plate 41, used to install lower upper ejector rod 43. The installation position of upper ejector rod 43 is determined by the structure of sand core 1.

[0036] Upper mold assembly 5 includes upper mold 51, upper mold insert 54, nozzle bushing 55, exhaust plug 56, upper mold exhaust pin 57, upper mold heating rod 53, the upper mold not only has upper mold cavity 52 structure, but also serves as the installation carrier of upper mold insert 54, nozzle bushing 55, exhaust plug 56, upper mold exhaust pin 57 and heating rod 53. According to the structure of sand core 1, a plurality of through holes are arranged in the middle of upper mold sand core cavity 52 for fixing nozzle bushing 55, sand material reaches the middle of upper mold sand core cavity 52 through nozzle bushing 55 and then spreads to all directions; a plurality of through holes are vertically arranged in the middle of both ends of upper mold sand core cavity 52 for installing upper mold exhaust pin 57, a gap with a width y1=0.2mm is cut between adjacent through holes for exhaust during sand core injection and solidification, avoiding defects such as incomplete filling of caliper sand core 1; a through hole is vertically arranged at the position of branch structure 111 of caliper sand core cavity for installing upper mold insert 54, upper mold insert 54 has a plurality of through gaps with a width y2=0.2mm and a depth z2=7.5, used for exhaust during sand core injection and solidification, avoiding defects such as incomplete filling of sand core; a plurality of through holes are arranged in the middle area of upper mold sand core cavity 52, upper mold exhaust plug 56 is installed above and below the through holes respectively, used for exhaust during injection and solidification of caliper sand core 1, which is beneficial to the diffusion of sand material; a plurality of holes for installing upper mold insert 54, nozzle bushing 55, exhaust plug 56 and upper mold exhaust pin 57 are arranged in the middle of the height direction of upper mold 51 along the depth direction, used for installing heating rod 53 to adjust the temperature during the forming process of caliper sand core 1.

[0037] The lower mold assembly 6 includes a lower mold body 61, a mold foot 62, a guide column 63, and an upper platen limiting column 64. Holes are symmetrically arranged in the middle of the left and right sides of the lower mold body 61 for installing the guide column 63. The guide column 63 plays an auxiliary positioning role when the upper mold assembly 5 and the lower mold assembly 6 are closed, ensuring that the upper mold cavity 52 and the lower mold body cavity 66 are tightly sealed, and ensuring that the appearance of the caliper sand core 1 is good. On the left and right sides of the lower mold body 61, avoiding the guide column 63 hole, holes are symmetrically arranged for installing the upper platen limiting column 64, which is used to limit the lower limit of the upper ejector rod 43 and avoid damaging the caliper sand core 1 before demolding. Through holes are arranged in the middle and around the branch structure 661 of the lower mold body cavity 66 for demolding after the caliper sand core 1 is formed. Avoiding the lower mold body cavity 66 and the several holes for installing the guide column 63 and the upper platen limiting column 64, several through holes are arranged in the middle of the height direction of the lower mold body 61 along the depth direction for installing the lower mold heating rod 65 to adjust the temperature during the forming process of the caliper sand core 1.

[0038] The lower ejection assembly 7 includes a lower ejector rod plate 71, a lower ejector rod push plate 72, a lower ejector rod plate reset rod 73, and a lower ejector rod. A plurality of through holes are arranged on the lower ejector rod plate, and the lower ejector rod is installed on the lower ejector rod plate for the caliper sand core 1 to be formed and separated from the lower mold body cavity 66. The lower ejector rod push plate 72 is located below the lower ejector rod plate 71, and both are uniformly arranged with reset through holes. The lower ejector rod plate reset rod 73 penetrates through the reset through holes on the ejector rod plate 71 and the lower ejector rod push plate 72, and the upper end of the lower ejector rod plate reset rod 73 is installed into the through holes in the four corners of the lower mold body 61. The lower end of the lower ejector rod plate reset rod 73 is provided with a nut for limiting the lower ejector rod push plate 72. In this way, the lower ejector rod plate 71, the lower ejector rod push plate 72, and the lower mold body 61 are connected through the lower ejector rod plate reset rod 73. When demolding, the lower ejector rod push plate 72 is pushed by the lower ejector rod plate 71 together with the lower ejector rod 74 vertically upward under the action of external force, the caliper sand core 1 is ejected from the lower mold body cavity 66, and then the lower ejector rod plate 71 and the lower ejector rod push plate 72 return to the original position under the action of gravity.

[0039] The movement sequence and process of each component in the manufacturing process of the caliper sand core 1 are as follows: Step 1: Preheat the mold. The upper mold 51 and the lower mold body 61 are preheated to a set temperature, usually 220-230°C, through the upper mold heating rod 53 and the lower mold heating rod 65, respectively, to ensure that the sand core material has good fluidity and solidification effect during injection and solidification.

[0040] Step 2: Spray demolding agent. The upper mold cavity 52 and the lower mold body cavity 65 are uniformly sprayed with demolding agent to reduce the adhesion between the caliper sand core 1 and the upper mold cavity 52 and the lower mold body cavity 65, facilitating the subsequent demolding of the caliper sand core 1.

[0041] Step 3: clamping, the preheated upper die assembly 5 is moved downward, and the lower die assembly 6 is fixed. The upper top plate limiting column 64 on the lower die body 61 first enters the corresponding through hole of the upper die 51, and then the guide column 63 enters the hole of the upper die 51, ensuring that the upper die cavity 52 and the lower die body cavity 65 form a closed space. When the lower surface of the upper die 51 contacts the upper surface of the lower die body 61, the upper die assembly 5 stops moving, which ensures the sealing of the mold 2 and prevents sand leakage.

[0042] Step 4: sand injection, the sand injection assembly 3 is moved vertically downward until the sand injection nozzle 33 is connected with the sand injection nozzle bushing 55 in the upper die 51, and the sand core material is injected into the mold cavity through the sand injection nozzle 33. During the sand injection process, the sand injection pressure is controlled at 0.5 MPa, and the sand injection time is 15 s, so that the sand core material uniformly fills the closed space formed by the upper die cavity 52 and the lower die body cavity 65.

[0043] Step 5: solidification, after the sand core material is filled, the mold 2 temperature is kept constant, and the sand core material is solidified. The solidification time is 420 s. At this time, the sand injection assembly 3 is removed, and the upper knockout assembly 4 is moved above the upper die assembly 5. The upper knockout assembly 4 is moved vertically downward until the upper knockout guide pin 42 passes through the corresponding through hole in the upper die 51 and contacts the upper surface of the upper knockout limiting column 64 and remains fixed.

[0044] Step 6: demolding, after solidification, the upper die assembly 5 is moved upward by 10 mm, at this time, under the action of the upper ejector rod 43, the caliper sand core 1 is separated from the upper die cavity 52, at this time the caliper sand core 1 remains in the lower die body cavity 66; then the lower ejector push plate 72 is moved upward, so that the lower die ejector rod 74 contacts the caliper sand core 1 and ejects the caliper sand core 1 from the lower die body cavity 66 by 100 mm height, then the caliper sand core 1 is taken out of the lower die body 61, this process ensures that the lower ejector 74 pushes at a speed of 5 mm / s and at a uniform speed, avoiding causing damage to the sand core.

[0045] Step 7: post-processing, the caliper sand core 1 is cleaned and inspected to remove defects such as flash and burrs on the surface of the caliper sand core.

Claims

1. A mold for making an aluminum alloy brake caliper core, characterized by, The mold is composed of a sand shooting assembly, an upper sand ejecting assembly, an upper mold assembly, a lower mold assembly and a lower sand ejecting assembly; the sand shooting assembly comprises a sand blocking plate, a sand shooting plate and a sand shooting nozzle, the sand blocking plate is located above the sand shooting plate, a hole is arranged in the middle of the sand blocking plate to connect the sand shooting equipment, the sand blocking plate is connected with the sand shooting plate, the distance z1 between the sand blocking plate and the sand shooting plate is adjustable to control the flow rate and flow range of the sand material; the upper sand ejecting assembly comprises an upper ejector pin plate, an upper ejector rod and an upper ejector plate guide pin, the four corners of the upper ejector pin plate are provided with stepped holes, the upper ejector plate guide pin is installed in the stepped holes, and a through hole is arranged in the middle of the upper ejector pin plate to install the upper ejector rod; the upper mold assembly comprises an upper mold, an upper mold insert, a nozzle bushing, an exhaust plug, an upper mold exhaust needle and an upper mold heating rod, the upper mold serves as a mounting carrier of various components, a through hole is arranged in the middle of a sand core cavity of the upper mold to fix the nozzle bushing, through holes are vertically arranged in the middle of both ends of the cavity to install the upper mold exhaust needle, a gap is arranged between adjacent through holes to realize exhaust, a through hole is arranged at a branch structure position of the cavity to install the upper mold insert, a gap is arranged on the insert to realize exhaust, the exhaust plug is installed above and below the through hole in the middle area of the cavity, and a through hole is further arranged in the middle of the upper mold to install the upper mold heating rod; the lower mold assembly comprises a lower mold body, a mold foot, a guide column and an upper ejector plate limiting column, holes are symmetrically arranged in the middle of both sides of the lower mold body to install the guide column, holes are symmetrically arranged at positions avoiding the guide column holes on both sides to install the upper ejector plate limiting column, through holes are arranged in the middle and around the branch structure of the cavity for demolding, and a through hole is arranged in the middle of the lower mold body to install the lower mold heating rod; the lower sand ejecting assembly comprises a lower ejector pin plate, a lower ejector pin push plate, a lower ejector pin plate reset rod and a lower mold ejector rod, a through hole is arranged on the lower ejector pin plate, the lower mold ejector rod is installed on the lower ejector pin plate, the lower ejector pin push plate is located on the lower side of the lower ejector pin plate, reset through holes are arranged around the two, the lower ejector pin plate reset rod passes through the reset through holes, the upper end of the lower ejector pin plate reset rod is installed in the through hole in the four corners of the lower mold body, and the lower end of the lower ejector pin plate reset rod is provided with a nut to limit the lower ejector pin push plate.

2. The mold for preparing a clamp core according to claim 1, wherein The positions of the sand shooting nozzle and the sand blocking plate are determined by the sand core structure, and the installation position of the upper ejector rod is determined by the sand core structure.

3. A method of manufacturing a caliper core using the mold of claim 1, characterized by, The method comprises the following steps: Mold preheating: the upper mold and the lower mold body are respectively preheated to 200-260 DEG C through the heating rods; Spraying demolding agent: uniformly spraying demolding agent on the surfaces of the upper mold cavity and the lower mold body cavity; Mold closing: the preheated upper mold assembly moves downward to close with the fixed lower mold assembly, the upper ejector plate limiting column and the guide column on the lower mold body enter the corresponding through holes of the upper mold in sequence, to ensure that the upper mold cavity and the lower mold body cavity form a closed space; Sand shooting: the sand shooting assembly moves vertically downward, the sand shooting nozzle is connected with the sand shooting nozzle bushing in the upper mold, the sand core material is injected into the mold cavity, the sand shooting pressure is controlled to be 0.2-0.8 MPa, and the sand shooting time is controlled to be 10-20 s; Solidification: after the sand filling is completed, the mold temperature is kept constant, and the solidification time is 360-480 s, during the solidification, the sand shooting assembly is removed, the lower sand ejecting assembly is moved above the upper mold assembly and vertically downward to a specific position; Demolding: After the solidification is completed, the upper mold assembly is moved upward to separate the sand core from the upper mold cavity, and the lower ejector push plate is moved upward to push the sand core from the lower mold body cavity to a certain height by the lower mold ejector rod, and then the sand core is taken out, ensuring that the speed of the lower ejector push is slow and uniform; Post-processing: cleaning and inspecting the sand core, removing surface flash and burrs and other defects.

4. The method of manufacturing a caliper core according to claim 3, wherein, In the demolding process, the upper mold assembly moves upward by 10 mm, the lower ejector push plate moves upward to make the lower mold ejector rod push the sand core from the lower mold body cavity to a height of 100 mm, and the speed of the lower ejector push is 5 mm / s.

5. The method of manufacturing a caliper core according to claim 3, wherein, In the mold preheating step, the preheating temperature of the upper mold and the lower mold body is 220℃ - 230℃.

6. The method of manufacturing a caliper core of claim 3, wherein, In the sand shooting step, the sand shooting pressure is controlled to be 0.5MPa, and the sand shooting time is 15s.

7. The method of manufacturing a caliper core according to claim 3, wherein, In the solidification step, the solidification time is 420s.

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