CN213162937U - Sand casting and casting die for producing valves - Google Patents

Abstract

The utility model belongs to the technical field of the casting die, especially, relate to a foundry sand casting die utensil for production valve. The utility model discloses, mould and casting lower mould on including the casting, the casting go up the mould and be equipped with valve molding sand chamber and casting runner in, the casting lower mould in be equipped with down valve molding sand chamber, when the compound die, last valve molding sand chamber and be equipped with valve runner molding cavity down between the valve molding sand chamber. The utility model discloses a set up runner high pressure cutter and incision sliding plate, after the casting cooling, leave the cutting counterpoint space, can amputate unnecessary runner automatically, need not artifical excision, the excision is clean, degree of automation and cutting accuracy are higher, will cast through mechanical buckle spare and go up the mould and closely laminate with the casting lower mould, guarantee the compound die precision, the inside runner of shaping valve that can be convenient for of runner shaping section of thick bamboo spare need not secondary operation, saves the process, reduction in production cost.

Description

Sand casting and casting die for producing valves

Technical Field

The utility model belongs to the technical field of the casting die, a production foundry sand casting die utensil for valve is related to.

Background

At present, the mould is used for obtaining various moulds and tools of required products by injection molding, blow molding, extrusion, die casting or forging forming, smelting, stamping and other methods in industrial production. The pouring (casting) method is a method of melting gold, silver and other substances into liquid state, and adopting a master mould to pour and make into ware, and is one of the earliest gold and silver processing methods. The valve production generally adopts the casting mode to carry out the shaping, and current valve casting mould needs the manual work to excise unnecessary runner after the casting is accomplished, and excision precision and degree of automation are lower, and need secondary operation valve internal flow channel after the casting, and the process is more.

In order to overcome the defects of the prior art, various solutions are proposed through continuous exploration, for example, a chinese patent discloses a foundry molding machine capable of automatically filling sand [ application number: 201620949526.9], a first mounting seat and a second mounting seat are arranged on the side surface of the base at intervals; the moving plate is connected with a first driving device, and the first driving device can drive the moving plate to reciprocate relative to the base; the sand box is arranged on the movable plate; the sand feeding groove is arranged on the first mounting seat, and when the moving plate drives the sand box to move to the position below the sand feeding groove, the sand feeding groove fills sand into the sand box; and the pressing plate structure is fixedly connected to the second mounting seat and is positioned above the sand box, and the pressing plate structure can press the molding sand in the sand box moving below the pressing plate structure under the action of the second driving device. The utility model discloses can save the labour in a large number, the foundry moulding machine of casting operation and improvement product quality of being convenient for. However, after the casting is finished, the excess gates still need to be manually cut off, the cutting precision and the automation degree are low, and the internal flow channels of the valve need to be machined secondarily after the casting, so that the defect of more working procedures exists.

Disclosure of Invention

The utility model aims at the above-mentioned problem, a production foundry sand casting die utensil for valve is provided.

In order to achieve the above purpose, the utility model adopts the following technical proposal:

the utility model provides a production valve is with founding casting die utensil, includes mould and casting lower mould in the casting, the casting go up the mould and be equipped with valve molding sand chamber and casting runner, the casting lower mould in be equipped with down valve molding sand chamber, when the compound die, last valve molding sand chamber and down form valve runner molding cavity between the valve molding sand chamber, last valve molding sand chamber and be equipped with the runner shaping section of thick bamboo spare that can follow straight reciprocating motion down between the valve molding sand chamber, the corresponding and shape of position of runner shaping section of thick bamboo spare and valve runner shaping cavity match and adapt, the casting go up in the mould still be equipped with and follow the automatic eager subassembly that waters that is close to or keep away from casting runner one end and be straight reciprocating motion, the casting lower mould on be equipped with casting mould looks butt complex mechanical buckle spare.

Furthermore, the automatic cutting and pouring component comprises a pouring gate high-pressure cutter arranged in the upper casting mould, the pouring gate high-pressure cutter can linearly reciprocate along one end close to or far away from the casting runner, a notch sliding plate capable of linearly reciprocate along one end close to or far away from the casting runner is further arranged in the upper casting mould, and the notch sliding plate corresponds to the pouring gate high-pressure cutter in position.

Furthermore, the casting upper die is internally provided with a cutter deviation-preventing chute, the sprue high-pressure cutter is provided with a cutter limiting plate extending into the cutter deviation-preventing chute, and the cutter limiting plate is in sliding fit with the cutter deviation-preventing chute.

Furthermore, a first linear driver and a second linear driver are further arranged in the casting upper die, a power shaft of the first linear driver is connected with the sprue high-pressure cutter, and a power shaft of the second linear driver is connected with the notch sliding plate.

Furthermore, runner shaping barrel spare insert a section of thick bamboo including setting up the valve runner shaping in valve runner shaping intracavity, the valve runner shaping insert and be equipped with unable adjustment base on the section of thick bamboo, unable adjustment base keep away from valve runner shaping and insert a section of thick bamboo one end and be equipped with the pull handle.

Further, valve runner shaping chamber keep away from unable adjustment base one side and be equipped with the sealed chamber of leak protection, valve runner shaping insert a section of thick bamboo and keep away from unable adjustment base one end and be equipped with and extend and let in the sealed piece of leak protection to the sealed intracavity of leak protection, the sealed piece of leak protection match with the shape in the sealed chamber of leak protection and fit.

Further, the upper die and the lower die are respectively provided with a base aligning sliding groove, the fixed base is provided with two base deviation-preventing sliding blocks extending into the base aligning sliding grooves, and the base deviation-preventing sliding blocks are in sliding fit with the base aligning sliding grooves.

Furthermore, machinery buckle spare including set up two buckle bases on the casting lower mould, the casting go up the mould and be equipped with two and buckle base position corresponding buckle on the butt plate, the buckle base be equipped with can be followed and be close to or keep away from on the buckle butt plate one end and do straight reciprocating motion's pushing down fixed plate.

Further, the buckle on butt plate be parallel to each other with the buckle base, the fixed plate that pushes down in be equipped with the butt plate and pass through the groove, the fixed plate below that pushes down be equipped with and rotate the ware mount pad, the rotation ware mount pad in be equipped with the circumference rotation ware, the axis of rotation and the fixed plate that pushes down of circumference rotation ware link to each other.

Furthermore, a third linear driver is arranged in the buckle base, a power shaft of the third linear driver is connected with the rotator mounting seat, the casting lower die is provided with a plurality of die assembly alignment holes which are symmetrical along the central line of the casting lower die, and the casting upper die is provided with a plurality of die assembly alignment shafts which correspond to the die assembly alignment holes in position and are matched in shape.

Compared with the prior art, the utility model has the advantages of:

1. the utility model discloses a set up runner high pressure cutter and incision sliding plate, after the casting cooling, leave the cutting counterpoint space, can amputate unnecessary runner automatically, need not artifical excision, the excision is clean, degree of automation and cutting accuracy are higher, will cast through mechanical buckle spare and go up the mould and closely laminate with the casting lower mould, guarantee the compound die precision, the inside runner of shaping valve that can be convenient for of runner shaping section of thick bamboo spare need not secondary operation, saves the process, reduction in production cost.

2. The utility model discloses a set up the sealed piece of leak protection and the sealed chamber of leak protection, when inserting a section of thick bamboo with the shaping of valve runner and insert to the shaping intracavity of valve runner, insert the sealed piece of leak protection to the sealed intracavity of leak protection, through the sealed piece of leak protection and the sealed cooperation in the chamber of leak protection, can avoid the casting raw materials to insert a lateral part discovery at the shaping of valve runner and leak, the leakproofness is better.

3. The utility model discloses a set up the base and prevent inclined to one side slider and base spout of counterpointing, when a section of thick bamboo and unable adjustment base are inserted in the shaping of slide valve runner, prevent inclined to one side slider and base through the base and counterpoint the sliding fit between the spout, can avoid the shaping of valve runner to insert a section of thick bamboo and unable adjustment base to take place angle skew and rotation in the removal process.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is an enlarged schematic view at a in fig. 1.

Fig. 3 is a schematic structural view in another direction of the present invention.

Fig. 4 is a schematic structural view of the fixing base.

Fig. 5 is a schematic structural view of the hold-down plate.

In the figure: the casting mold comprises a casting upper mold 1, an upper valve type sand cavity 2, a casting runner 33, a lower valve type sand cavity 3, a valve runner forming cavity 4, a runner forming cylinder part 5, an automatic cutting and casting assembly 6, a mechanical clamping part 7, a pouring gate high-pressure cutter 8, a notch sliding plate 9, a cutter deviation-preventing sliding groove 10, a cutter limiting plate 11, a first linear driver 12, a second linear driver 13, a valve runner forming insertion cylinder 14, a fixed base 15, a drawing handle 16, a leakage-proof sealing cavity 17, a leakage-proof sealing block 18, a base alignment sliding groove 19, a base deviation-preventing sliding block 20, a clamping base 21, a clamping upper abutting plate 22, a pressing fixed plate 23, an abutting plate through groove 24, a rotator mounting seat 25, a circumferential rotator 26, a third linear driver 27 and a mold closing alignment hole 28.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1-5, a foundry casting mold for producing a valve comprises an upper casting mold 1 and a lower casting mold, an upper valve molding sand cavity 2 and a casting runner 33 are arranged in the upper casting die 1, a lower valve molding sand cavity 3 is arranged in the lower casting die, when the mould is closed, a valve runner molding cavity 4 is formed between the upper valve molding sand cavity 2 and the lower valve molding sand cavity 3, a runner molding cylinder part 5 which can reciprocate along a straight line is arranged between the upper valve type sand cavity 2 and the lower valve type sand cavity 3, the flow channel forming cylinder part 5 corresponds to the valve flow channel forming cavity 4 in position and is matched with the valve flow channel forming cavity in shape, the casting device is characterized in that an automatic cutting and casting assembly 6 capable of performing linear reciprocating motion along one end close to or far away from the casting runner 33 is further arranged in the upper casting die 1, and a mechanical fastener 7 which is in butt fit with the upper casting die 1 is arranged on the lower casting die.

In the embodiment, when the valve is cast and formed, firstly, molding sand is laid in an upper valve type sand cavity 2 and a lower valve type sand cavity 3, a valve model is placed between the upper valve type sand cavity 2 and the lower valve type sand cavity 3, a casting upper die 1 and a casting lower die are matched, the molding sand in the upper valve type sand cavity 2 and the molding sand in the lower valve type sand cavity 3 are compacted after the die is matched, the valve model is taken out after the die is opened, the die is matched again, a runner forming cylinder part 5 is inserted into a valve runner forming cavity 4 at the moment, the casting upper die 1 and the casting lower die are tightly jointed through a mechanical clamping part 7, the die matching precision is ensured, casting raw materials enter the die through a casting runner 33 to realize casting, after the casting is cooled, redundant gates can be automatically cut through an automatic cutting and casting component 6 without manual cutting, the automation degree and the cutting precision are high, the runner forming barrel part 5 can be used for conveniently forming the internal runner of the valve, secondary processing is not needed, the working procedures are saved, and the production cost is reduced.

Referring to fig. 1 and 2, the automatic gate cutting assembly 6 includes a gate high-pressure cutter 8 disposed in the upper casting mold 1, the gate high-pressure cutter 8 can linearly reciprocate along one end close to or far from the casting runner 33, a notch sliding plate 9 capable of linearly reciprocate along one end close to or far from the casting runner 33 is further disposed in the upper casting mold 1, and the notch sliding plate 9 corresponds to the gate high-pressure cutter 8.

Specifically, when the gate of the molded valve needs to be cut off, the gate sliding plate 9 is moved towards the end far away from the casting runner 33 to leave a cutting alignment space, at the moment, the gate high-pressure cutter 8 is moved towards the end close to the casting runner 33 to automatically cut off the redundant gate until the gate high-pressure cutter 8 enters the cutting alignment space left by the gate sliding plate 9, the gate material is completely cut off, the cutting is clean, the automation degree is high, and manual cutting is not needed.

Referring to fig. 1 and 2, a cutter deviation-preventing chute 10 is arranged in the upper die 1 for casting, a cutter limiting plate 11 extending into the cutter deviation-preventing chute 10 is arranged on the sprue high-pressure cutter 8, and the cutter limiting plate 11 is in sliding fit with the cutter deviation-preventing chute 10.

In this embodiment, in runner high pressure cutter 8 removal in-process, through the sliding fit between cutter limiting plate 11 and the inclined to one side spout 10 is prevented to the cutter, can ensure that runner high pressure cutter 8 can not take place the angular deflection at the removal in-process, has improved the accuracy of cutting.

The casting upper die 1 is also internally provided with a first linear driver 12 and a second linear driver 13, a power shaft of the first linear driver 12 is connected with the sprue high-pressure cutter 8, and a power shaft of the second linear driver 13 is connected with the notch sliding plate 9.

In this embodiment, when the gate high-pressure cutter 8 needs to be moved, the first linear driver 12 is started, the gate high-pressure cutter 8 is driven to move by the power shaft of the first linear driver 12, and when the notch sliding plate 9 needs to be moved, the second linear driver 13 is started, and the notch sliding plate 9 is driven to move by the power shaft of the second linear driver 13, it should be understood by those skilled in the art that the first linear driver 12 and the second linear driver 13 may be an air cylinder, an oil cylinder, or a linear motor.

Referring to fig. 1, the flow channel forming tube 5 includes a valve flow channel forming tube 14 disposed in the valve flow channel forming cavity 4, the valve flow channel forming tube 14 is provided with a fixing base 15, the fixing base 15 is far away from one end of the valve flow channel forming tube 14 and is provided with a drawing handle 16.

In this embodiment, before casting, the valve runner forming insert cylinder 14 is inserted into the valve runner forming cavity 4, the fixing base 15 is used for fixing the valve runner forming insert cylinder 14, the drawing handle 16 is convenient for a worker to draw the fixing base 15 and the valve runner forming insert cylinder 14, and the valve runner forming insert cylinder 14 is used for forming an internal runner of a valve.

Valve runner shaping chamber 4 keep away from unable adjustment base 15 one side and be equipped with the sealed chamber of leak protection 17, valve runner shaping insert a section of thick bamboo 14 and keep away from unable adjustment base 15 one end and be equipped with the leak protection sealed piece 18 that extends to let in to the sealed chamber of leak protection 17, the sealed piece of leak protection 18 match with the shape in the sealed chamber of leak protection 17 and fit.

In this embodiment, when inserting the valve runner molding cartridge 14 into the valve runner molding cavity 4, insert the leak protection sealing block 18 into the leak protection sealing cavity 17, through the cooperation between the leak protection sealing block 18 and the leak protection sealing cavity 17, can avoid the casting raw materials to find at the valve runner molding cartridge 14 lateral part and leak, the leakproofness is better.

Referring to fig. 1 and 4, the upper mold 1 and the lower mold are respectively provided with a base aligning chute 19, the fixing base 15 is provided with two base deviation-preventing sliding blocks 20 extending into the base aligning chute 19, and the base deviation-preventing sliding blocks 20 are in sliding fit with the base aligning chute 19.

In this embodiment, when the sliding valve runner forming insert cylinder 14 and the fixed base 15 are formed, the sliding fit between the base anti-deviation sliding block 20 and the base alignment sliding groove 19 can prevent the valve runner forming insert cylinder 14 and the fixed base 15 from generating angular deviation and circumferential rotation in the moving process.

As shown in fig. 3, the mechanical fastener 7 includes two fastener bases 21 disposed on the lower casting mold, the upper casting mold 1 is provided with two upper fastener abutment plates 22 corresponding to the positions of the fastener bases 21, and the fastener bases 21 are provided with lower pressing fixing plates 23 capable of performing linear reciprocating motion along ends close to or far from the upper fastener abutment plates 22.

In this embodiment, after the upper mold 1 and the lower mold are closed, the upper buckle abutting plate 22 is in abutting fit with the buckle base 21, and then the lower pressing fixing plate 23 is moved to a position close to one end of the upper buckle abutting plate 22 to compress and fix the upper buckle abutting plate 22, so that the upper buckle abutting plate 22 is tightly fitted with the buckle base 21, and the close fitting degree of the closed mold is ensured.

Referring to fig. 3 and 5, the upper buckle abutting plate 22 is parallel to the buckle base 21, an abutting plate passing groove 24 is formed in the lower pressing fixing plate 23, a rotator mounting seat 25 is arranged below the lower pressing fixing plate 23, a circumferential rotator 26 is arranged in the rotator mounting seat 25, and a rotating shaft of the circumferential rotator 26 is connected with the lower pressing fixing plate 23.

In this embodiment, rotator mount 25 is used for fixing circumferential direction rotator 26, before the compound die, circumferential direction rotator 26 is started earlier, rotation axis through circumferential direction rotator 26 drives holding down plate 23 and rotates, make butt plate pass through groove 24 and buckle on butt plate 22 position corresponding, butt plate 22 passes through butt plate and passes through groove 24 back and buckle base 21 butt on the buckle, will push down behind holding down plate 23 and rotate the back again, move down holding down plate 23, through holding down plate 23 and compressing tightly butt plate 22 on the buckle, make butt plate 22 and buckle base 21 hug closely the cooperation mutually on the buckle, ensure the hugging closely degree of compound die.

Referring to fig. 3, a third linear actuator 27 is arranged in the buckle base 21, a power shaft of the third linear actuator 27 is connected with the rotator mounting seat 25, the lower casting mold is provided with a plurality of mold closing alignment holes 28 which are symmetrical along the central line of the lower casting mold, and the upper casting mold 1 is provided with a plurality of mold closing alignment shafts 29 which correspond to the mold closing alignment holes 28 in position and are matched in shape.

In this embodiment, when the bottom plate 23 needs to be moved, the third linear actuator 27 is activated, the power shaft of the third linear actuator 27 drives the rotator mounting seat 25 and the bottom plate 23 to move, and when the mold is closed, the upper mold 1 and the lower mold are ensured not to rotate circumferentially during the mold closing process by the cooperation between the mold closing alignment shaft 29 and the mold closing alignment hole 28, and it should be understood by those skilled in the art that the third linear actuator 27 may be an air cylinder, an oil cylinder, or a linear motor.

The utility model discloses a theory of operation is:

when the valve is cast and formed, firstly, molding sand is laid in an upper valve molding sand cavity 2 and a lower valve molding sand cavity 3, a valve model is placed between the upper valve molding sand cavity 2 and the lower valve molding sand cavity 3, a casting upper die 1 and a casting lower die are closed, the molding sand in the upper valve molding sand cavity 2 and the molding sand in the lower valve molding sand cavity 3 are compacted after the closing of the dies, the valve model is taken out after the opening of the dies, the dies are closed again,

at the moment, the valve runner forming insert cylinder 14 is inserted into the valve runner forming cavity 4, the fixing base 15 is used for fixing the valve runner forming insert cylinder 14, the drawing handle 16 is convenient for workers to draw the fixing base 15 and the valve runner forming insert cylinder 14, the valve runner forming insert cylinder 14 is used for forming an internal runner of a valve, when the valve runner forming insert cylinder 14 is inserted into the valve runner forming cavity 4, the leakage-proof sealing block 18 is inserted into the leakage-proof sealing cavity 17, leakage of casting raw materials at the side part of the valve runner forming insert cylinder 14 can be avoided through the matching between the leakage-proof sealing block 18 and the leakage-proof sealing cavity 17, and the sealing performance is good;

when the sliding valve runner forming insert cylinder 14 and the fixed base 15 are in use, the sliding fit between the base deviation-preventing slide block 20 and the base alignment slide groove 19 can prevent the valve runner forming insert cylinder 14 and the fixed base 15 from angular deviation and circumferential rotation in the moving process.

The casting upper die 1 and the casting lower die are tightly attached through the mechanical clamping piece 7, die assembly precision is guaranteed, casting raw materials enter the die through the casting runner 33, casting is achieved, after casting cooling is conducted, redundant runners can be automatically cut off through the runner high-pressure cutter 8, manual cutting is not needed, the automation degree and the cutting precision are high, the runner forming barrel piece 5 can be used for conveniently forming the runner inside the valve, secondary processing is not needed, the process is saved, and the production cost is reduced.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein will be apparent to those skilled in the art without departing from the spirit of the invention.

Claims (10)

1. A founding and casting mold for producing a valve comprises an upper casting mold (1) and a lower casting mold, and is characterized in that an upper valve type sand cavity (2) and a casting runner (33) are arranged in the upper casting mold (1), a lower valve type sand cavity (3) is arranged in the lower casting mold, when mold closing is carried out, a valve runner forming cavity (4) is formed between the upper valve type sand cavity (2) and the lower valve type sand cavity (3), a runner forming cylinder (5) capable of linearly reciprocating is arranged between the upper valve type sand cavity (2) and the lower valve type sand cavity (3), the runner forming cylinder (5) corresponds to the valve runner forming cavity (4) in position and is matched in shape, an automatic cutting and casting assembly (6) capable of linearly reciprocating along one end close to or far away from the casting runner (33) is further arranged in the upper casting mold (1), and the casting lower die is provided with a mechanical fastener (7) which is in butt fit with the casting upper die (1).

2. The foundry casting mold for producing the valve according to claim 1, characterized in that the automatic casting component (6) comprises a gate high-pressure cutter (8) arranged in the upper casting mold (1), the gate high-pressure cutter (8) can linearly reciprocate along one end close to or far away from the casting runner (33), a notch sliding plate (9) capable of linearly reciprocate along one end close to or far away from the casting runner (33) is further arranged in the upper casting mold (1), and the notch sliding plate (9) corresponds to the gate high-pressure cutter (8).

3. The foundry casting mold for producing the valve according to claim 2, characterized in that a cutter deviation-preventing chute (10) is arranged in the upper casting mold (1), a cutter limiting plate (11) extending into the cutter deviation-preventing chute (10) is arranged on the gate high-pressure cutter (8), and the cutter limiting plate (11) is in sliding fit with the cutter deviation-preventing chute (10).

4. The foundry casting mold for producing valves according to claim 3, characterized in that a first linear actuator (12) and a second linear actuator (13) are further arranged in the upper casting mold (1), a power shaft of the first linear actuator (12) is connected with the gate high-pressure cutter (8), and a power shaft of the second linear actuator (13) is connected with the notch sliding plate (9).

5. The foundry casting mold for producing the valve according to claim 1, characterized in that the runner forming barrel (5) comprises a valve runner forming insert barrel (14) arranged in the valve runner forming cavity (4), the valve runner forming insert barrel (14) is provided with a fixing base (15), and one end of the fixing base (15) far away from the valve runner forming insert barrel (14) is provided with a drawing handle (16).

6. The foundry casting mold for producing the valve according to claim 5, characterized in that a leakage-proof sealing cavity (17) is arranged on one side of the valve runner molding cavity (4) far away from the fixing base (15), a leakage-proof sealing block (18) extending into the leakage-proof sealing cavity (17) is arranged on one end of the valve runner molding insert cylinder (14) far away from the fixing base (15), and the leakage-proof sealing block (18) is matched with the leakage-proof sealing cavity (17) in shape.

7. The foundry casting mold for producing the valve according to claim 5, characterized in that a base aligning chute (19) is respectively arranged in the upper casting mold (1) and the lower casting mold, two base deviation-preventing blocks (20) extending into the base aligning chute (19) are arranged on the fixed base (15), and the base deviation-preventing blocks (20) are in sliding fit with the base aligning chute (19).

8. The foundry casting mold for producing the valve according to claim 1, characterized in that the mechanical fastener (7) comprises two fastener bases (21) arranged on the lower casting mold, the upper casting mold (1) is provided with two upper fastener abutting plates (22) corresponding to the positions of the fastener bases (21), and the fastener bases (21) are provided with lower pressing fixing plates (23) capable of linearly reciprocating along one ends close to or far away from the upper fastener abutting plates (22).

9. The foundry casting mold for producing valves according to claim 8, characterized in that the upper butt plate (22) of the clip is parallel to the clip base (21), the lower fixing plate (23) is provided with a butt plate passing groove (24), the lower fixing plate (23) is provided with a rotator mounting seat (25), the rotator mounting seat (25) is provided with a circumferential rotator (26), and the rotation axis of the circumferential rotator (26) is connected with the lower fixing plate (23).

10. The foundry casting mold for producing the valves as claimed in claim 9, characterized in that a third linear actuator (27) is arranged in the buckle base (21), a power shaft of the third linear actuator (27) is connected with the rotator mounting seat (25), the lower casting mold is provided with a plurality of mold closing alignment holes (28) symmetrical along a center line of the lower casting mold, and the upper casting mold (1) is provided with a plurality of mold closing alignment shafts (29) corresponding to the mold closing alignment holes (28) in position and matching in shape.

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