CN113478757A

CN113478757A - Arc core pulling device for plastic mold

Info

Publication number: CN113478757A
Application number: CN202110889273.6A
Authority: CN
Inventors: 杨立韫; 杨立勇
Original assignee: Shenzhen Borrell Industrial Co ltd
Current assignee: Shenzhen Borrell Industrial Co ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2021-10-08

Abstract

The invention discloses an arc core pulling device for a plastic mold, which relates to the technical field of plastic molds and comprises an upper mold plate with an upper cavity and a lower mold plate with a lower cavity, wherein a mold core unit is arranged between the upper cavity and the lower cavity after mold closing, the mold core unit is provided with a core pulling unit and an oil supply system, the mold core unit comprises an inner tube arranged between the upper cavity and the lower cavity, the upper circumference of the side wall of the inner tube is provided with a plurality of sliding grooves, a guide post is movably connected in the plurality of sliding grooves, one end of the guide post is fixedly connected with an elastic shell sleeved on the inner tube, and the arc core pulling device further comprises a distance monitoring unit and a pressure monitoring unit. The invention has reasonable structure, realizes the adjustment of the material thickness of the injection molding product during injection molding, reduces the shrinkage rate of the injection molding product after molding, improves the precision of the material thickness, avoids the adhesion with the inner wall of the molded injection molding product, is convenient for core pulling, and avoids the problems of clamping with the injection molding product and the like.

Description

Arc core pulling device for plastic mold

Technical Field

The invention relates to the technical field of plastic molds, in particular to an arc core pulling device for a plastic mold.

Background

With the continuous development of economy and the continuous progress of society, various material consumer goods are provided for the life of people so as to meet the individual pursuit of people, and a plastic product is one of the material consumer goods.

As is known, plastic products are formed by plastic molds. Because the plastic product formed by the plastic mold has the advantages of good quality, high efficiency, low cost and the like, the plastic mold is widely popularized and applied in various industries, and the plastic mold is more and more favored by the manufacturing industry.

At present, for plastic products with arc-shaped pipe fittings or arc-shaped cavities, arc-shaped loose cores are generally used to be deeply inserted into a mold cavity for injection molding; treat the completion of moulding plastics, cylinder pulling arc through outside slope is loosed core and is carried out curvilinear motion with the drawing of patterns, nevertheless when the arc structure of loosing core is complicated, difficult demolding, some arcs are loosed core and are adopted multistage loose core piece concatenation to form, do not produce the gap when just enabling multistage loose core piece concatenation through multiple connecting piece and direction setting element, this kind of method has increased the manufacturing degree of difficulty and manufacturing cost, and arc plastic product shaping back, the inner wall of product is loosed core the outer wall with the arc easily and is produced the adhesion, lead to the arc to loose core and can't take out, lead to the damage of plastic product even, and the thickness of arc plastic product can not change according to actual demand, the suitability of plastic mould has been reduced.

Therefore, the application provides an arc device of loosing core for plastic mould satisfies the demand.

Disclosure of Invention

The utility model provides a circular arc device of loosing core for plastic mould realizes that the material when adjusting injection moulding product and moulding plastics is thick to reduce the shrinkage behind the injection moulding product shaping, improved the thick precision of material, avoided with the adhesion of shaping injection moulding product inner wall, and loose core the convenience, avoid blocking the scheduling problem with injection moulding product.

In order to achieve the above purpose, the present application provides the following technical solutions: an arc core pulling device for a plastic mold comprises an upper mold plate with an upper cavity and a lower mold plate with a lower cavity, wherein a mold core unit is arranged between the upper cavity and the lower cavity after mold closing, a core pulling unit and an oil supply system are installed on the mold core unit, the mold core unit comprises an inner tube arranged between the upper cavity and the lower cavity, a plurality of sliding grooves are formed in the upper circumference of the side wall of the inner tube, guide posts are movably connected in the sliding grooves, and one end of each guide post is fixedly connected with an elastic shell sleeved on the inner tube;

the core pulling device further comprises a distance monitoring unit and a pressure monitoring unit, the oil supply system is used for supplying oil to the elastic shell and the cavity formed between the inner pipes, the distance monitoring unit is used for monitoring displacement of the elastic shell after the oil is supplied to the cavity, the pressure monitoring unit is used for pressure values in the cavity after the oil is supplied to the cavity, and the core pulling unit is used for mold core unit demolding and mold entering.

Preferably, the unit of loosing core includes a pair of slide rail, and is a pair of one side that the slide rail is close to each other all begins to have a shifting chute, and is a pair of sliding connection has same base on the shifting chute, the top fixedly connected with fixing base of base, one side fixedly connected with of fixing base keeps off the seat, inner tube fixed connection be in keep off one of seat serve, it is a pair of the same hydraulic telescoping rod of one end fixedly connected with of slide rail, first hydraulic telescoping rod's flexible fixed connection be in on one side of base, oil feeding system with first hydraulic telescoping rod is connected.

Preferably, a positioning identifier is fixedly connected to the top of one of the slide rails, a positioning emitter is fixedly connected to one side of the fixing seat, and the positioning emitter and the positioning identifier are matched to be used for positioning the inner pipe.

Preferably, oil feeding system include fixed connection in hydraulic pressure fuel feed pump on the first hydraulic telescoping rod top, the oil outlet end fixedly connected with fuel feeding hose of hydraulic pressure fuel feed pump, fuel feeding hose's one end fixedly connected with fuel feeding steel pipe, the fuel feeding steel pipe is located in the inner tube, and with the structure of inner tube is the same, a plurality of fuel feeding branch pipes of the lateral wall border fixedly connected with of fuel feeding steel pipe, it is a plurality of the equal fixed connection of fuel feeding branch pipe is in on the lateral wall of inner tube, and with the cavity is linked together, the inner tube with be provided with the sealed unit on the elastic housing.

Preferably, the sealing unit comprises a sealing plate, one side of the sealing plate is fixedly connected with a sealing ring, one side of the inner tube is provided with a first sealing groove, one side of the sealing ring is clamped in the first sealing groove, a second sealing groove is formed in the sealing ring, one side of the elastic shell is clamped in the second sealing groove, and one end of the elastic shell is fixedly connected to one side of the sealing plate.

Preferably, the distance monitoring unit including set up in distance sensor in the cavity, distance sensor is used for the monitoring after the cavity fuel feeding the displacement volume of elastic housing, the pressure monitoring unit including set up in pressure sensor in the cavity, pressure sensor is used for the monitoring unit to be used for after the cavity fuel feeding pressure value in the cavity still includes the display, be provided with the voice broadcast ware on the display, distance sensor with pressure sensor all with display signal connection, be provided with the hot plate in the cavity, the hot plate is used for right hydraulic oil heating in the cavity, be provided with temperature sensor in the cavity, temperature sensor is used for the monitoring the temperature of hydraulic oil in the cavity, temperature sensor with display signal connection.

Preferably, the die comprises a lower die base and an upper die base, the upper die plate is installed at the bottom of the upper die base, the lower die plate is installed at the top of the lower die base, a second hydraulic telescopic rod is fixedly connected to the top of the lower die base, a fixing block is fixedly connected to the output end of the second hydraulic telescopic rod, the fixing block is fixedly connected to one side of the upper die base, and the display is installed at the top of the upper die base.

Preferably, the lower die base, the lower die plate, the upper die base and the upper die plate are all provided with circulating water holes, and the circulating water holes are used for communicating cold water and cooling plastic during molding.

Preferably, the outer surface of the elastic shell is coated with teflon.

In conclusion, the technical effects and advantages of the invention are as follows:

1. the invention has reasonable structure, the cavity is filled with hydraulic oil at the beginning, and according to the thickness requirement generated by actual injection molding, the hydraulic oil supply pump realizes oil injection or oil discharge in the cavity through the oil supply hose, the oil supply steel pipe and the oil supply branch pipe to realize the expansion and contraction of the elastic shell, thereby adjusting the distance between the outer surface of the elastic shell and the inner walls of the upper cavity of the upper template and the lower cavity of the lower template and realizing the adjustment of the material thickness generated by injection molding; by arranging the pressure sensor, the pressure value inside the cavity after oil supply is monitored in real time, and by arranging the distance sensor, after oil is filled or oil is drained in the cavity, the elastic variation of the elastic shell is monitored in real time, the pressure sensor is matched with the distance sensor, and the numerical value is directly observed through the display and the voice broadcaster, so that the distance from the elastic shell to the inner wall is accurately adjusted, on one hand, the material thickness of an injection molding product is accurately adjusted, on the other hand, the elastic variation of the elastic shell is adjusted through monitoring, the compensation quantity of the material thickness is controlled in the injection molding process, the water shrinkage rate of the injection molding product after injection molding is reduced, and the precision of the material thickness is improved;

2. in the invention, after the injection molding product is molded, the elastic shell is contracted through the hydraulic oil supply pump, the diameter of the elastic shell in the upper cavity and the lower template is reduced, the hydraulic oil is heated through the heating plate, the temperature of the hydraulic oil heated by the heating plate in the cavity is observed in real time through the temperature sensor, so that the contraction of the elastic shell is facilitated, the contraction speed is accelerated, the elastic shell is conveniently separated from the inner wall of the molded injection molding product, the adhesion condition is avoided, the Teflon coating is coated on the elastic shell, the Teflon coating has better heat resistance, chemical inertness, excellent insulation stability and low friction, the inner wall performance of the elastic shell and the molded injection molding product is further improved, the telescopic end of the second hydraulic telescopic rod drives the upper die holder to move, the separation of the die is realized, when the telescopic end of the first hydraulic telescopic rod moves, the base is driven to move along the moving grooves on the pair of slide rails, so that the base drives the fixed seat, the baffle seat, the inner pipe and the elastic shell to move out of the molded injection product;

3. according to the invention, the sealing ring, the sealing plate, the first sealing groove and the second sealing groove are arranged, so that the sealing of the elastic shell and the inner pipe in the matching process is realized, the phenomenon that an injection molding product is scrapped due to leakage in the oil injection process is avoided, the contraction and expansion of the elastic shell are not influenced by the structure, and the sealing performance is good.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic perspective view of an arc core pulling device for a plastic mold;

FIG. 2 is a schematic view of an internal three-dimensional structure of an arc core pulling device for a plastic mold;

FIG. 3 is an enlarged schematic perspective view of the core pulling unit and the oil supply system;

FIG. 4 is an enlarged perspective view of a partially cut-away portion of the core pulling unit;

fig. 5 is a schematic cross-sectional front view of the sealing unit.

In the figure: 1. a lower die holder; 2. an upper die holder; 3. a display; 4. a first hydraulic telescopic rod; 5. a hydraulic feed pump; 6. a second hydraulic telescopic rod; 7. an elastic housing; 8. a fixed seat; 9. a base; 10. a slide rail; 11. an oil supply hose; 12. positioning the transmitter; 13. a positioning identifier; 14. a blocking seat; 15. an inner tube; 16. an oil supply steel pipe; 17. a guide post; 18. a sealing plate; 19. and (4) a sealing ring.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example (b): referring to fig. 1-5, an arc core pulling device for a plastic mold includes an upper mold plate having an upper cavity and a lower mold plate having a lower cavity, a mold core unit is disposed between the upper cavity and the lower cavity after mold closing, the mold core unit is provided with a core pulling unit and an oil supply system, the mold core unit includes an inner tube 15 disposed between the upper cavity and the lower cavity, a plurality of sliding grooves are disposed on an upper circumference of a side wall of the inner tube 15, guide posts 17 are movably connected in the plurality of sliding grooves, and one end of each guide post 17 is fixedly connected with an elastic shell 7 sleeved on the inner tube 15;

still include apart from monitoring unit and pressure monitoring unit, oil feeding system is used for supplying oil to the cavity that forms between elastic shell 7 and the inner tube 15, and apart from monitoring unit and be used for monitoring the displacement volume of elastic shell 7 after the cavity supplies oil, pressure value in the cavity behind the pressure monitoring unit is used for the cavity to supply oil, and the unit of loosing core is used for mold core unit demolding and advance the mould.

As an implementation manner in this embodiment, the core pulling unit includes a pair of slide rails 10, one side that a pair of slide rails 10 are close to each other all begins to have a shifting chute, sliding connection has same base 9 on a pair of shifting chute, top fixedly connected with fixing base 8 of base 9, one side fixedly connected with of fixing base 8 keeps off

seat

14, 15 fixed connection of inner tube is on keeping off one end of seat 14, the same first hydraulic telescoping rod 4 of one end fixedly connected with of a pair of slide rails 10, the flexible fixed connection of first hydraulic telescoping rod 4 is on one side of base 9, oil feeding system is connected with first hydraulic telescoping rod 4, when the flexible end of first hydraulic telescoping rod 4 removes, it moves about to drive base 9 along the shifting chute on a pair of slide rails 10, thereby base 9 drives fixing base 8, keep off seat 14, inner tube 15 removes.

In this embodiment, the top of one of the slide rails 10 is fixedly connected with a positioning identifier 13, one side of the fixing base 8 is fixedly connected with a positioning emitter 12, the positioning emitter 12 and the positioning identifier 13 are matched for positioning the inner pipe 15, and the positioning accuracy of the inner pipe 15 after moving is improved by arranging the positioning emitter 12 and the positioning identifier 13.

In this embodiment, oil feeding system includes hydraulic pressure fuel feed pump 5 on the top of fixed connection 4 first hydraulic telescoping rod, the oil outlet end fixedly connected with fuel feed hose 11 of hydraulic pressure fuel feed pump 5, the one end fixedly connected with fuel feed steel pipe 16 of fuel feed hose 11, fuel feed steel pipe 16 is located inner tube 15, and the same with the structure of inner tube 15, a plurality of fuel feed branch pipes of the lateral wall border fixedly connected with of fuel feed steel pipe 16, the equal fixed connection of a plurality of fuel feed branch pipes is on the lateral wall of inner tube 15, and be linked together with the cavity, be provided with sealed unit on inner tube 15 and the elastic housing 7, initial condition, fill hydraulic oil in the cavity, hydraulic pressure fuel feed pump 5 is through fuel feed hose 11, fuel feed steel pipe 16, fuel or oil extraction are realized carrying out in the cavity to fuel feed branch pipe, realize the expansion and the shrink of elastic housing 7.

In this embodiment, sealing unit includes closing plate 18, one side fixedly connected with sealing ring 19 of closing plate 18, first seal groove has been seted up to one side of inner tube 15, one side joint of sealing ring 19 is in first seal groove, the second seal groove has been seted up on the sealing ring 19, one side joint of elastic housing 7 is in the second seal groove, the one end fixed connection of elastic housing 7 is on one side of closing plate 18, through setting up sealing ring 19, closing plate 18, first seal groove, the second seal groove, realize the sealing when elastic housing 7 and inner tube 15 cooperate, when avoiding the oiling, the seepage takes place, lead to the injection moulding product to scrap, and this structure setting does not influence the shrink of elastic housing 7 and expansion, the leakproofness is good.

As an implementation manner in the embodiment, the distance monitoring unit comprises a distance sensor arranged in the cavity, the distance sensor is used for monitoring the displacement of the elastic shell 7 after the cavity is supplied with oil, the pressure monitoring unit comprises a pressure sensor arranged in the cavity, the pressure sensor is used for monitoring the pressure value in the cavity after the cavity is supplied with oil, the distance monitoring unit further comprises a display 3, a voice broadcaster is arranged on the display 3, the distance sensor and the pressure sensor are both in signal connection with the display 3, a heating plate is arranged in the cavity and used for heating the hydraulic oil in the cavity, a temperature sensor is arranged in the cavity and used for monitoring the temperature of the hydraulic oil in the cavity, the temperature sensor is in signal connection with the display 3, by arranging the pressure sensor, the pressure value in the interior of the cavity after the oil is supplied is monitored in real time, by arranging the distance sensor, after oiling or the oil extraction in the real-time supervision cavity, the temperature of the hydraulic oil after the heating of hot plate in the real-time observation cavity through setting up temperature sensor, the 7 elastic variable volume of elastic housing to through display 3 and voice broadcast ware direct observation numerical value.

In this embodiment, still include die holder 1 and upper die base 2, the cope match-plate pattern is installed on the bottom of upper die base 2, and the lower bolster is installed on the top of die holder 1, and the top fixedly connected with second hydraulic stretching rod 6 of die holder 1, the output fixedly connected with fixed block of second hydraulic stretching rod 6, fixed block fixed connection are on one side of upper die base 2, and display 3 is installed on the top of upper die base 2.

In this embodiment, all be provided with the circulation water hole on die holder 1, lower bolster and cope match-plate pattern 2, the cope match-plate pattern, the circulation water hole is used for the intercommunication cold water, cools off when shaping to the plastic.

As an embodiment in this embodiment, the outer surface of the elastic casing 7 is coated with teflon, and the teflon coating has good heat resistance, chemical inertness, and excellent insulation stability and low friction.

The working principle of the invention is as follows:

initially, hydraulic oil is filled in the cavity, according to the thickness requirement generated by actual injection molding, the hydraulic oil supply pump 5 is used for filling oil or discharging oil in the cavity through the oil supply hose 11, the oil supply steel pipe 16 and the oil supply branch pipe, so that the expansion and contraction of the elastic shell 7 are realized, the distance between the outer surface of the elastic shell 7 and the inner walls of the upper cavity of the upper template and the lower cavity of the lower template is adjusted, and the material thickness adjustment generated by injection molding is realized;

by arranging the pressure sensor, the pressure value inside the cavity after oil supply is monitored in real time, and by arranging the distance sensor, after oil is filled or oil is drained in the cavity, the elastic change quantity of the elastic shell 7 is monitored in real time, the pressure sensor is matched with the distance sensor, and the numerical value is directly observed through the display 3 and the voice broadcaster, so that the distance from the elastic shell 7 to the inner wall is accurately adjusted, on one hand, the material thickness of an injection molding product is accurately adjusted, on the other hand, the elastic change of the elastic shell 7 is adjusted through monitoring, the compensation quantity of the material thickness is controlled in the injection molding process, the shrinkage rate of the injection molding product after injection molding is reduced, and the precision of the material thickness is improved;

after the injection molding product is molded, the elastic shell 7 is contracted through the hydraulic oil supply pump 5, the diameter of the elastic shell 7 in the upper cavity and the lower template is reduced, the hydraulic oil is heated through the heating plate, the temperature of the hydraulic oil heated by the heating plate in the cavity is observed in real time through the temperature sensor, so that the contraction of the elastic shell 7 is facilitated, the contraction speed is accelerated, the elastic shell 7 is conveniently separated from the inner wall of the molded injection molding product, the adhesion condition is avoided, the Teflon coating is coated on the elastic shell 7, the Teflon coating has better heat resistance, chemical inertness, excellent insulation stability and low friction, the adhesion resistance between the elastic shell 7 and the inner wall of the molded injection molding product is further improved, the telescopic end of the second hydraulic telescopic rod 6 moves to drive the upper die base 2 to move, the separation of the die is realized, when the telescopic end of the first hydraulic telescopic rod 4 moves, the base 9 is driven to move along the moving grooves on the pair of sliding rails 10, so that the base 9 drives the fixed seat 8, the baffle seat 14, the inner tube 15 and the elastic shell 7 to move out of the molded injection product.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.

Claims

1. The utility model provides a circular arc device of loosing core for plastic mould, is equipped with mold core unit, its characterized in that including the cope match-plate pattern that has last die cavity and the lower bolster that has lower die cavity, last die cavity after the compound die and lower die cavity between: the mould core unit is provided with a core pulling unit and an oil supply system, the core pulling unit is used for mold stripping and mold feeding of the mould core unit, the oil supply system is used for supplying oil to a cavity formed between the elastic outer shell (7) and the inner tube (15), the mould core unit comprises the inner tube (15) arranged between an upper cavity and a lower cavity, a plurality of sliding grooves are formed in the upper circumference of the side wall of the inner tube (15), guide columns (17) are movably connected in the sliding grooves, and one ends of the guide columns (17) are fixedly connected with the elastic outer shell (7) sleeved on the inner tube (15); the core pulling device further comprises a distance monitoring unit and a pressure monitoring unit, the distance monitoring unit is used for monitoring the displacement of the elastic shell (7) after the cavity supplies oil, and the pressure monitoring unit is used for monitoring the pressure value in the cavity after the cavity supplies oil.

2. The circular arc core pulling device for the plastic mold according to claim 1, wherein: the core pulling unit comprises a pair of sliding rails (10) and is a pair of sliding grooves are formed in one side, close to each other, of each sliding rail (10) and are a pair of sliding grooves, one side of each sliding groove is connected with the same base (9) in a sliding mode, the top fixedly connected with fixing seats (8) of the bases (9), one side fixedly connected with blocking seats (14) of the fixing seats (8) is fixedly connected with inner pipes (15), one end of each blocking seat (14) is connected with one corresponding first hydraulic telescopic rod (4) of each sliding rail (10), the telescopic ends of the first hydraulic telescopic rods (4) are fixedly connected with one side of the base (9), and an oil supply system is connected with the first hydraulic telescopic rods (4).

3. The circular arc core pulling device for the plastic mold according to claim 2, wherein: one of them the top fixedly connected with location recognizer (13) of slide rail (10), one side fixedly connected with location transmitter (12) of fixing base (8), location transmitter (12) with location recognizer (13) cooperation is used for inner tube (15) location.

4. The circular arc core pulling device for the plastic mold according to claim 2, wherein: oil feeding system includes fixed connection in hydraulic pressure fuel feed pump (5) on first hydraulic telescoping rod (4) top, the oil outlet end fixedly connected with fuel feed hose (11) of hydraulic pressure fuel feed pump (5), the one end fixedly connected with fuel feed steel pipe (16) of fuel feed hose (11), fuel feed steel pipe (16) are located in inner tube (15), and with the structure of inner tube (15) is the same, a plurality of fuel feed branch pipes of the lateral wall border fixedly connected with of fuel feed steel pipe (16), it is a plurality of the equal fixed connection of fuel feed branch pipe is in on the lateral wall of inner tube (15), and with the cavity is linked together, inner tube (15) with be provided with sealed unit on elastic housing (7).

5. The circular arc core pulling device for the plastic mold according to claim 4, wherein: the sealing unit comprises a sealing plate (18), a sealing ring (19) is fixedly connected to one side of the sealing plate (18), a first sealing groove is formed in one side of the inner tube (15), one side of the sealing ring (19) is connected in a clamped mode in the first sealing groove, a second sealing groove is formed in the sealing ring (19), one side of the elastic shell (7) is connected in the second sealing groove in a clamped mode, and one end of the elastic shell (7) is fixedly connected to one side of the sealing plate (18).

6. The circular arc core pulling device for the plastic mold according to claim 1, wherein: the distance monitoring unit comprises a distance sensor arranged in the cavity, the distance sensor is used for monitoring the displacement of the elastic shell (7) after the oil is supplied to the cavity, the pressure monitoring unit comprises a pressure sensor arranged in the cavity, the pressure sensor is used for monitoring the pressure value in the cavity after the unit is used for supplying oil to the cavity, the pressure monitoring unit also comprises a display (3), a voice broadcaster is arranged on the display (3), the distance sensor and the pressure sensor are in signal connection with the display (3), a heating plate is arranged in the cavity and used for heating the hydraulic oil in the cavity, the hydraulic oil temperature control device is characterized in that a temperature sensor is arranged in the cavity and used for monitoring the temperature of hydraulic oil in the cavity, and the temperature sensor is in signal connection with the display (3).

7. The circular arc core pulling device for the plastic mold according to claim 6, wherein: still include die holder (1) and upper die base (2), the cope match-plate pattern is installed the bottom of upper die base (2), the lower bolster is installed the top of die holder (1), the top fixedly connected with second hydraulic stretching pole (6) of die holder (1), the output fixedly connected with fixed block of second hydraulic stretching pole (6), the fixed block fixed connection be in on one side of upper die base (2), install display (3) the top of upper die base (2).

8. The circular arc core pulling device for the plastic mold according to claim 7, wherein: and circulating water holes are formed in the lower die base (1), the lower die plate, the upper die base (2) and the upper die plate and are used for communicating cold water and cooling plastic during molding.

9. The circular arc core pulling device for the plastic mold according to claim 1, wherein: the outer surface of the elastic shell (7) is coated with Teflon.