CN112477029B

CN112477029B - Pre-ejection demoulding mechanism of threaded connection cover mould

Info

Publication number: CN112477029B
Application number: CN202011237141.7A
Authority: CN
Inventors: 黄自强
Original assignee: Individual
Current assignee: Taizhou Yichuan Mould Co ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2022-09-02
Anticipated expiration: 2040-11-09
Also published as: CN112477029A

Abstract

The invention provides a pre-ejection demoulding mechanism of a threaded connection cover mould, and belongs to the technical field of mould manufacturing. The problem that the tail tooth of a plastic part is damaged due to the fact that the structure of an existing threaded connection cover die is complex is solved. This threaded connection lid mould push off demoulding mechanism in advance, including moving the module, be provided with the push pedal that can lead the displacement for moving the module parallel on moving the mould face of module, be provided with the perforating hole in this push pedal, move the screw that has the product that is used for the product spiral drawing of patterns on the module and move the pole, this screw moves back pole and moving module normal running fit, the screw move back the pole and stretch into corresponding perforating hole, this screw moves back the pole and forms the product die cavity with the push pedal, be provided with between push pedal and the moving module and can control the push pedal and for moving the twice reciprocating motion of module and can make the product fully break away from in the product die cavity drive arrangement. The invention has reasonable and simple structural design and reliable operation of the demoulding mechanism, can effectively avoid pulling the last half circle of the thread tail tooth of the product, and has more stable and reliable thread demoulding operation.

Description

Pre-ejection demoulding mechanism of threaded connection cover mould

Technical Field

The invention belongs to the technical field of die manufacturing, and relates to a pre-ejection demoulding mechanism of a threaded connection cover die.

Background

For many years, with the continuous development of the mold industry, the Chinese injection mold develops quite rapidly, and the proportion of the injection mold in the whole mold industry is higher and higher. Generally, when a plastic part with threads needs to be formed, the corresponding mold structure is relatively complex, the threads on the plastic part are divided into internal threads and external threads, and the internal threads are generally formed by a thread core and the external threads are formed by a thread type ring. According to the specific production requirements of different threads, the structural design of the die of the thread part is different, and the thread releasing mode is different. On the premise that the structure allows, the internal thread of the plastic part can be designed into a sectional internal thread, and the plastic part is molded by adopting an inclined push rod to internally loose a core. If a complete internal thread is required, the forming method mainly comprises the following three methods: the method can be adopted when the requirements on the aspects of product precision and the like are not high and the tooth height is not more than 1.5mm, and the demoulding mode needs to use plastic with better elasticity; secondly, the mold is manually demolded outside the mold, the threaded mold core is made into a movable insert, and the mold is manually taken out of the mold, so that the mold is simple in structure, low in demolding efficiency and high in labor intensity, and automation cannot be realized; and thirdly, the rotating mechanism automatically takes off the threads, and the die is high in production efficiency, small in labor intensity, easy to realize automation and suitable for batch production. In industrial production, most of plastic parts with threads have precision requirements, such as bottle caps of Russian beer storage tanks, air tightness is required after the bottle caps and the bottle bodies are matched, the requirements on the size and the thread precision of the bottle caps are provided, meanwhile, the products are generally produced in large quantities, and forced demolding and manual demolding outside the mold are not applicable to the products. For threaded plastic parts with required dimensions and structures, manufacturers typically use a rotating mechanism to perform the stripping.

At present, internal thread demoulding mechanisms are arranged in a plurality of injection moulds in the market, such as Chinese patent numbers: "201310648147.7, application publication date 2014 4, 9" of a plastic mold internal thread floating rotation-stopping demolding mechanism. The concrete structure of said patent includes upper and lower compound plates, under the upper compound plate a fixed die plate is mounted, on the lower compound plate a die pin is mounted, on the die pin a movable die bottom plate, a lower gear fixing plate, an upper gear fixing plate, a transition gear fixing plate and a movable die base plate are mounted, on the movable die base plate a movable die plate is mounted, between the movable die plate and fixed die plate a die cavity is set, in the die cavity a product is placed, and the inner wall of the product is equipped with an internal thread, and on the movable die base plate a screw core is set, and the head portion of the screw core is matched with the internal thread, and is driven by power by means of gear transmission component and rotated, and between the die pins an upper top plate, a lower top plate and a top pin are set, and the head portion of the top pin is contacted with injection-moulded material handle, and on the outer wall of the screw core a rotation-stopping insert is equipped with a rotation-stopping pin, and the rotation pin is embedded in the bottom portion of product wall body, and in the movable die base plate a floating spring is mounted, and in the movable die plate a spacing groove is equipped with a spacing screw, the limit screw penetrates through the floating spring to be connected with the movable die base plate.

The demolding mechanism of the application can conveniently demold, but the demolding mechanism is complex in structure and pushes a plastic part out of a mold by virtue of an ejector pin which is pushed against the plastic part, and the mold is high in thickness due to the ejector pin plate system, so that a larger injection molding machine is needed to be replaced for production due to the fact that the mold is ultrahigh in thickness, and the mold cost and the product production cost are increased; in addition, the demoulding mechanism only has a compression spring to eject the push plate, so that the ejection force cannot be adjusted, and the tail teeth of a plastic part are easily damaged during screw thread withdrawal and ejection, so that the product is scrapped; in addition, the demoulding mechanism has a major disadvantage that the centre of the thread core is provided with the thimble, and the thread core cannot be processed with a cooling water path, so that the product forming period is increased, and the product cost is obviously increased.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides the pre-ejection demoulding mechanism of the threaded connection cover mould, which has the advantages of simple structure, low manufacturing cost, reliable demoulding mechanism operation, high thread precision and more reliable work, and can effectively avoid pulling the thread tail teeth of products.

The purpose of the invention can be realized by the following technical scheme: the utility model provides a top demoulding mechanism in advance of threaded connection lid mould, is including moving the module, the die parting face of moving the module on be provided with the push pedal that can lead the displacement for moving the module parallel, be provided with the perforating hole on this push pedal, the module of moving on have the screw thread that is used for the product spiral drawing of patterns and move the pole, this screw thread moves back pole and moving module normal running fit, the screw thread move back the pole and stretch into corresponding perforating hole, this screw thread moves back the pole and forms the product die cavity with the push pedal, its characterized in that, push pedal and moving module between be provided with and control the push pedal and for moving the twice reciprocating displacement of module and can make the product fully break away from in the product die cavity.

This threaded connection covers ejection demoulding mechanism in advance of mould is mainly provided with drive arrangement between push pedal and movable mould piece, through drive arrangement control push pedal for the two reciprocating displacement of movable mould piece, make the product retreat the ejecting drawing of patterns of screw thread limit, stable in structure, demoulding mechanism operates reliably, can effectively avoid pulling product screw thread tail tooth.

In the pre-ejecting demoulding mechanism of the threaded connection cover mould, the driving device comprises an air cylinder, an electromagnetic valve, an air throttle and an air compressor, the air cylinder is connected with the air compressor sequentially through the air throttle, the electromagnetic valve and the air compressor, the air cylinder is arranged between the push plate and the movable mould block, an air cylinder rod of the air cylinder is fixed with the push plate, an air cylinder body of the air cylinder is fixed with the movable mould block, the air cylinder controls the push plate to reciprocate twice through the electromagnetic valve, and a compression spring pre-ejecting on the push plate is further arranged between the push plate and the movable mould block. Through the elastic acting force of the compression spring, the push plate always has the trend of outward parallel guiding displacement, when the screw thread withdrawing rod rotates and a product is demoulded when the screw thread withdrawing rod withdraws the die, the push plate is parallel and slowly guided to displace on the movable module under the combined action of the compression spring and the air cylinder, namely the push plate drives the product to displace outward on the screw thread withdrawing rod; when the push plate is slowly guided outwards in parallel for a certain distance, the compression spring is in a complete relaxation state, and the push plate loses the action of the elastic force of the compression spring; the cylinder continues to push the push plate to outwards parallelly and slowly guide and displace until the threads of the thread withdrawing rod and the threads of the product are completely disengaged; at the moment, the electromagnetic valve works in a reversing manner, the push plate moves inwards in parallel under the action of the cylinder, the product is separated from the push plate in an axial abutting manner with the screw thread withdrawing rod, the product is driven by the push plate to be separated from the screw thread withdrawing rod in an axial abutting manner, the inner port of the product and the screw thread withdrawing rod possibly have relative sleeves to be connected in an axial direction, the electromagnetic valve works in a reversing manner, the push plate moves outwards in parallel under the action of the cylinder, after one second, the electromagnetic valve works in a reversing manner again, the push plate rapidly moves inwards in parallel under the action of the cylinder, the product is rapidly bounced off by the push plate at the end part of the screw thread withdrawing rod, and the product is completely demoulded by ejecting the push plate twice, so that the structure is stable.

In the pre-ejection demoulding mechanism of the threaded connection cover mould, an inner end face of the push plate is provided with a first assembling groove, a parting surface of the movable module is provided with a second assembling groove, a cylinder rod of the cylinder penetrates through the first assembling groove of the push plate and is fixed by a bolt, a cylinder body of the cylinder is fixedly arranged in the second assembling groove of the movable module, when the cylinder rod and the cylinder body of the cylinder are relatively contracted, an inner end face of the push plate and the parting surface of the movable module are relatively abutted, the inner end face of the push plate is also provided with a first spring groove, the parting surface of the movable module is also provided with a second spring groove, and the compression spring is expanded or condensed and is always positioned between the first spring groove and the second spring groove. The purpose of setting up like this is to ensure the push pedal and move the abutting contact of module, ensures that compression spring is in spring groove one, spring groove two all the time, prevents effectively that compression spring from breaking away from in spring groove one, spring groove two.

In the above-mentioned pre-ejection demolding mechanism for the threaded connection cover mold, the movable mold block comprises a movable mold base and a movable mold front seat, the movable mold base and the movable mold front seat are distributed in parallel at intervals, a hydraulic motor is fixedly arranged on the movable mold base, the threaded withdrawing rod and a main shaft of the hydraulic motor are distributed in parallel, and a two-stage speed reduction transmission device is arranged between the threaded withdrawing rod and the main shaft of the hydraulic motor. The purpose that sets up like this is the rotational speed that can better control the screw thread and move back the pole, makes things convenient for the screw thread to move back the screw thread cooperation of moving back of pole and product.

In the pre-ejecting demoulding mechanism of the threaded connection cover mould, the two-stage speed reduction transmission device comprises a transmission shaft which is arranged in parallel and arranged between a threaded withdrawing rod and a main shaft of the hydraulic motor, a first chain wheel and a first transmission gear are fixedly arranged on the transmission shaft in the same axial direction and are distributed at intervals, a second chain wheel is fixedly arranged on the main shaft of the hydraulic motor, a chain is arranged between the second chain wheel and the first chain wheel of the main shaft of the hydraulic motor, the second chain wheel and the first chain wheel of the main shaft of the hydraulic motor form one-stage speed reduction transmission through chain transmission, a second transmission gear is fixedly arranged on the threaded withdrawing rod, and the second transmission gear and the first transmission gear form two-stage speed reduction transmission through meshing transmission. The mode that adopts chain drive and gear drive to combine carries out the screw thread demoulding that moves back of screw thread pole, and the transmission is more steady, and work is more reliable, and this two-stage speed reduction transmission's transmission distance is big simultaneously, compact structure, and it is small to occupy.

In the above-mentioned pre-ejection demolding mechanism for the threaded connection cover mold, one end of the transmission shaft is rotatably connected to the movable mold base through a bearing I, the other end of the transmission shaft is rotatably connected to the movable mold front seat through a bearing II, the chain, the second chain wheel on the main shaft of the hydraulic motor and the first chain wheel on the transmission shaft are all located at a gap between the movable mold base and the movable mold front seat, one end of the chain is hung on the second chain wheel, and the other end of the chain is hung on the first chain wheel. The purpose of setting up like this is the assembly of more reasonable utilization transmission space, compact structure, stable in structure.

In foretell top demoulding mechanism in advance of threaded connection lid mould, the screw thread move back the pole and include cooling axle core and screw thread axle sleeve, the rear end of cooling axle core wear to establish and fix on the movable mould base, the front end of this cooling axle core wears to establish in the movable mould front bezel, screw thread axle sleeve establish on the cooling axle core and rotatory the setting in the movable mould front bezel with the axial cover, this cooling axle core and screw thread axle sleeve normal running fit, two fixed cover of drive gear establish on screw thread axle sleeve. The purpose that sets up like this is that the screw thread axle sleeve is when rotatory function, and the concentricity is higher, and the screw thread axle sleeve is rotatory more steady, and the screw thread axle sleeve moves back helicitic texture more steady.

In the pre-ejection demolding mechanism of the threaded connection cover mold, the wear-resistant shaft sleeve is fixedly arranged at the orifice of the rear end of the through hole of the push plate, the outer diameter of the front end of the threaded shaft sleeve is matched with the inner diameter of the wear-resistant shaft sleeve, and the front end of the threaded shaft sleeve is in axial sliding fit with the wear-resistant shaft sleeve. The purpose of setting up wear-resisting axle sleeve can prevent effectively that the wearing and tearing of the perforating hole endwise slip adaptation of threaded shaft sleeve's front end and push pedal, and structural stability is high, long service life.

In the pre-ejecting demoulding mechanism of the threaded connection cover mould, a plurality of deep groove ball bearings are arranged between the threaded shaft sleeve and the front seat of the movable mould, and each deep groove ball bearing is distributed at intervals along the axial direction of the threaded shaft sleeve. The purpose of setting up like this is to enable the stable rotation of screw thread axle sleeve in the movable mould front seat, and structural stability is high.

In foretell threaded connection lid mould in ejection demoulding mechanism in advance, the movable mould base include movable mould bottom plate and axle core fixed plate, this movable mould bottom plate and the parallel stack of axle core fixed plate support and lean on fixedly, the movable mould front bezel include movable mould backup pad and movable mould fixed plate, this movable mould backup pad and the parallel stack of movable mould fixed plate support and lean on fixedly. The purpose of this arrangement is to facilitate screw back assembly.

Compared with the prior art, this spiral connection lid mould push up demoulding mechanism's advantage in advance does: the device is provided with a push plate, an air cylinder and a compression spring are arranged between the push plate and a movable module, and the ejection of a product while the thread is withdrawn is solved under the double acting force of the air cylinder and the compression spring; when the threaded shaft sleeve and a product are in the initial stage of thread withdrawal, the problem that the parallel displacement force of the push plate is insufficient at the beginning is solved under the dual acting force of the air cylinder and the compression spring, and in the later stage of thread withdrawal, the compression spring is in a completely relaxed state, the push plate loses the action of the elastic force of the compression spring, and the air cylinder continuously works to push the push plate to be outwards parallel and slowly displaced, so that the thread of the product is prevented from being pulled; during die testing, the air pressure input into the air cylinder can be adjusted through the air throttle valve, so that the ejection force of the air cylinder is changed, and the speed and the force of outward parallel guide displacement of the push plate are controlled; the compression spring is used for pre-pushing the push plate, the air cylinder is arranged for controlling the push plate to reciprocate twice to eject a product, the air cylinder is controlled by the electromagnetic valve, the electromagnetic valve controls the reciprocating action of the air cylinder once receiving a signal, the work of the push plate is realized twice by time control, and the product is ejected by adopting the outward reverse matching of the push plate and the product; the push plate is moved again, the product and the threaded shaft sleeve are pushed against and ejected out of the product in the relative axial direction through the relative movement of the push plate and the threaded shaft sleeve, the ejection is reliable, and the trace of the threaded shaft sleeve is left on the inner side of the product and does not damage the surface of the product; the invention has reasonable and simple structural design and reliable operation of the demoulding mechanism, can effectively avoid pulling the last half circle of the thread tail tooth of the product, and has more stable and reliable thread demoulding operation.

Drawings

Fig. 1 is a schematic sectional view showing the structure of the product in the non-thread-removed state in the pre-ejection demoulding mechanism of the screw connection cap mould.

Fig. 2 is a schematic sectional view showing the state of thread removal of a product in the pre-ejection demolding mechanism of the present threaded connection cap mold.

Fig. 3 is a schematic sectional structural view of a state in which a product is relatively axially ejected by a threaded shaft sleeve in the pre-ejection demolding mechanism of the threaded connection cap mold.

In the figure, 1, a push plate; 2. a cylinder; 3. an electromagnetic valve; 3a, a throttle valve; 4. an air compressor; 5. a compression spring; 6. a hydraulic motor; 7. a drive shaft; 8. a chain wheel I; 9. a first transmission gear; 10. a second chain wheel; 11. a chain; 12. a second transmission gear; 13. a first bearing; 14. a second bearing; 15. cooling the shaft core; 16. a threaded shaft sleeve; 17. a wear-resistant shaft sleeve; 18. a deep groove ball bearing; 19. a movable mold base plate; 20. a shaft core fixing plate; 21. a movable mold supporting plate; 22. and a movable mold fixing plate.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1, fig. 2 and fig. 3, the pre-ejecting demoulding mechanism of the threaded connection cover mould mainly comprises a movable mould block, a push plate 1 capable of being guided and displaced in parallel relative to the movable mould block is arranged on a mould parting surface of the movable mould block, a through hole is formed in the push plate 1, a thread withdrawing rod for spirally demoulding a product is arranged on the movable mould block, the thread withdrawing rod is in running fit with the movable mould block, the thread withdrawing rod extends into the corresponding through hole, the thread withdrawing rod and the push plate 1 form a product cavity, and a driving device capable of controlling the push plate 1 to perform reciprocating displacement twice relative to the movable mould block and enabling the product to be fully separated from the product cavity is arranged between the push plate 1 and the movable mould block.

In actual manufacturing, the specific implementation mode of the driving device is as follows: the device mainly comprises an air cylinder 2, an electromagnetic valve 3, an air throttle 3a and an air compressor 4, wherein the air cylinder 2 is connected with the air compressor 4 sequentially through the electromagnetic valve 3, the air throttle 3a, the air cylinder 2 is arranged between a push plate 1 and a movable mould block, a rod of the air cylinder 2 is fixed with the push plate 1, the air cylinder 2 body of the air cylinder 2 is fixed with the movable mould block, the air cylinder 2 controls the push plate 1 to reciprocate twice through the electromagnetic valve 3, and a compression spring 5 pre-pushed on the push plate 1 is also arranged between the push plate 1 and the movable mould block; specifically speaking: the inner end face of the push plate 1 is provided with a first assembling groove, the parting face of the movable module is provided with a second assembling groove, a cylinder 2 rod of a cylinder 2 penetrates through the first assembling groove of the push plate 1 and is fixed by a bolt, the cylinder 2 body of the cylinder 2 is fixedly arranged in the second assembling groove of the movable module, when the cylinder 2 rod and the cylinder 2 body of the cylinder 2 are relatively folded, the inner end face of the push plate 1 and the parting face of the movable module are relatively abutted, the inner end face of the push plate 1 is further provided with a first spring groove, the parting face of the movable module is further provided with a second spring groove, and a compression spring 5 is located between the first spring groove and the second spring groove all the time in a diastole or a condensation mode.

During actual manufacturing, the movable mould block mainly comprises a movable mould base and a movable mould front seat, the movable mould base and the movable mould front seat are distributed in parallel at intervals, a hydraulic motor 6 is fixedly arranged on the movable mould base, a thread withdrawing rod and a main shaft of the hydraulic motor 6 are distributed in parallel, and a two-stage speed reduction transmission device is arranged between the thread withdrawing rod and the main shaft of the hydraulic motor 6; in practical design, the two-stage reduction transmission device has the following specific implementation mode: a transmission shaft 7 arranged in parallel is arranged between the thread withdrawing rod and the main shaft of the hydraulic motor 6, a chain wheel I8 and a transmission gear I9 are fixedly arranged on the transmission shaft 7 in the same axial direction, the chain wheel I8 and the transmission gear I9 are distributed at intervals in the same axial direction, a chain wheel II 10 is fixedly arranged on the main shaft of the hydraulic motor 6, a chain 11 is arranged between the chain wheel II 10 and the chain wheel I8 of the main shaft of the hydraulic motor 6, the chain wheel II 10 and the chain wheel I8 of the main shaft of the hydraulic motor 6 are driven by the chain 11 to form primary speed reduction transmission, a transmission gear II 12 is fixedly arranged on the thread withdrawing rod, and the transmission gear II 12 and the transmission gear I9 are meshed for transmission to form secondary speed reduction transmission; specifically speaking: one end of the transmission shaft 7 is rotatably connected to the movable mould base through a first bearing 13, the other end of the transmission shaft 7 is rotatably connected to the movable mould front seat through a second bearing 14, the chain 11, the second chain wheel 10 on the main shaft of the hydraulic motor 6 and the first chain wheel 8 on the transmission shaft 7 are located at the interval between the movable mould base and the movable mould front seat, one end of the chain 11 is hung on the second chain wheel 10, and the other end of the chain 11 is hung on the first chain wheel 8.

During actual manufacturing, the threaded withdrawing rod mainly comprises a cooling shaft core 15 and a threaded shaft sleeve 16, the rear end of the cooling shaft core 15 is fixedly arranged on the movable die base in a penetrating mode, the front end of the cooling shaft core 15 is arranged in the movable die front seat in a penetrating mode, the threaded shaft sleeve 16 is coaxially sleeved on the cooling shaft core 15 and rotatably arranged in the movable die front seat, the cooling shaft core 15 is in rotating fit with the threaded shaft sleeve 16, and the transmission gear II 12 is fixedly sleeved on the threaded shaft sleeve 16.

In practical application, a wear-resistant shaft sleeve 17 is fixedly arranged at an orifice at the rear end of the through hole of the push plate 1, the outer diameter of the front end of the threaded shaft sleeve 16 is matched with the inner diameter of the wear-resistant shaft sleeve 17, and the front end of the threaded shaft sleeve 16 is in axial sliding fit with the wear-resistant shaft sleeve 17; a plurality of deep groove ball bearings 18 are arranged between the threaded shaft sleeve 16 and the front seat of the movable die, and each deep groove ball bearing 18 is distributed at intervals along the axial direction of the threaded shaft sleeve 16.

In actual manufacturing, the movable mold base mainly comprises a movable mold base plate 19 and an axle core fixing plate 20, the movable mold base plate 19 and the axle core fixing plate 20 are parallelly overlapped and abutted and fixed, the movable mold front seat mainly comprises a movable mold support plate 21 and a movable mold fixing plate 22, and the movable mold support plate 21 and the movable mold fixing plate 22 are parallelly overlapped and abutted and fixed.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments, or alternatives may be employed, by those skilled in the art, without departing from the spirit or ambit of the invention as defined in the appended claims.

Although push plates 1 are used more herein; a cylinder 2; an electromagnetic valve 3; a throttle valve 3 a; an air compressor 4; a compression spring 5; a hydraulic motor 6; a transmission shaft 7; a first chain wheel 8; a first transmission gear 9; a second sprocket 10; a chain 11; a second transmission gear 12; a first bearing 13; a second bearing 14; cooling the shaft core 15; a threaded bushing 16; a wear-resistant shaft sleeve 17; a deep groove ball bearing 18; a movable mold base plate 19; a shaft core fixing plate 20; a movable mold support plate 21; movable mold mounting plate 22, etc., without excluding the possibility of using other terminology. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to the spirit of the present invention.

Claims

1. A pre-ejection demoulding mechanism of a threaded connection cover mould comprises a movable mould block, wherein a mould parting surface of the movable mould block is provided with a push plate (1) which can be parallelly guided and displaced relative to the movable mould block, the push plate (1) is provided with a through hole, the movable mould block is provided with a thread withdrawing rod for spirally demoulding a product, the thread withdrawing rod is in running fit with the movable mould block, the thread withdrawing rod extends into the corresponding through hole, and the thread withdrawing rod and the push plate (1) form a product cavity; the driving device comprises an air cylinder (2), an electromagnetic valve (3), an air throttle (3a) and an air compressor (4), wherein the air cylinder (2) is sequentially connected with the air compressor (4) through the electromagnetic valve (3) and the air throttle (3a), the air cylinder (2) is arranged between a push plate (1) and a movable mould block, an air cylinder rod of the air cylinder (2) is fixed with the push plate (1), an air cylinder body of the air cylinder (2) is fixed with the movable mould block, the air cylinder (2) controls the push plate (1) to reciprocate twice through the electromagnetic valve (3), and a compression spring (5) pre-pushed on the push plate (1) is further arranged between the push plate (1) and the movable mould block; when the screw thread withdrawing rod rotates and a product is demoulded after the screw thread withdrawing, the push plate (1) drives the product to move outwards on the screw thread withdrawing rod until the screw threads of the screw thread withdrawing rod and the product are completely disengaged; the electromagnetic valve (3) works in a reversing way, the push plate (1) moves inwards in parallel under the action of the cylinder (2), a product is axially abutted against and separated from the thread withdrawing rod on the push plate (1), and the inner port of the product and the thread withdrawing rod are possibly in relative sleeved axial connection; the electromagnetic valve (3) works in a reversing way, and the push plate (1) moves outwards in parallel under the action of the cylinder (2); the electromagnetic valve (3) works in a reversing mode again, the push plate (1) rapidly moves inwards in parallel under the action of the cylinder (2), the product is rapidly bounced off by the push plate (1) at the end part of the thread retreating rod, and the product is completely demoulded by ejecting the push plate (1) twice.

2. The pre-ejection demolding mechanism of the threaded connection cap mold as claimed in claim 1, wherein a first assembling groove is formed in an inner end face of the push plate (1), a second assembling groove is formed in a parting surface of the movable module, a cylinder rod of the cylinder (2) penetrates through the first assembling groove of the push plate (1) and is fixed through bolts, a cylinder body of the cylinder (2) is fixedly arranged in the second assembling groove of the movable module, when the cylinder rod and the cylinder body of the cylinder (2) are relatively contracted, the inner end face of the push plate (1) and the parting surface of the movable module are relatively abutted, a first spring groove is further formed in the inner end face of the push plate (1), a second spring groove is further formed in the parting surface of the movable module, and the compression spring (5) is located between the first spring groove and the second spring groove in a relaxing or contracting manner.

3. The mechanism of claim 1 or 2, wherein the movable mold block comprises a movable mold base and a movable mold front seat, the movable mold base and the movable mold front seat are distributed in parallel at intervals, the movable mold base is fixedly provided with the hydraulic motor (6), the thread withdrawing rod and a main shaft of the hydraulic motor (6) are distributed in parallel, and a two-stage reduction transmission device is arranged between the thread withdrawing rod and the main shaft of the hydraulic motor (6).

4. The pre-ejecting demoulding mechanism of the threaded connection cover mould according to claim 3, wherein the two-stage speed reduction transmission device comprises a transmission shaft (7) which is arranged in parallel between a threaded withdrawing rod and a main shaft of the hydraulic motor (6), a first chain wheel (8) and a first transmission gear (9) are fixedly arranged on the transmission shaft (7) in the same axial direction, the first chain wheel (8) and the first transmission gear (9) are distributed at intervals in the same axial direction, a second chain wheel (10) is fixedly arranged on the main shaft of the hydraulic motor (6), a chain (11) is arranged between the second chain wheel (10) and the first chain wheel (8) of the main shaft of the hydraulic motor (6), the second chain wheel (10) and the first chain wheel (8) of the main shaft of the hydraulic motor (6) are driven by the chain (11) to form one-stage speed reduction transmission, a second transmission gear (12) is fixedly arranged on the threaded withdrawing rod, and the second transmission gear (12) and the first transmission gear (9) are meshed for transmission to form secondary speed reduction transmission.

5. The pre-ejection demolding mechanism for the threaded connection cover mold as claimed in claim 4, wherein one end of the transmission shaft (7) is rotatably connected to the movable mold base through a first bearing (13), the other end of the transmission shaft (7) is rotatably connected to the movable mold front seat through a second bearing (14), the chain (11), the second chain wheel (10) on the main shaft of the hydraulic motor (6) and the first chain wheel (8) on the transmission shaft (7) are located at a position between the movable mold base and the movable mold front seat, one end of the chain (11) is hung on the second chain wheel (10), and the other end of the chain (11) is hung on the first chain wheel (8).

6. The pre-ejection demolding mechanism of the threaded connection cap mold according to claim 5, wherein the threaded withdrawing rod comprises a cooling shaft core (15) and a threaded shaft sleeve (16), the rear end of the cooling shaft core (15) is fixedly arranged on the movable mold base in a penetrating manner, the front end of the cooling shaft core (15) is arranged in the movable mold front seat in a penetrating manner, the threaded shaft sleeve (16) is coaxially sleeved on the cooling shaft core (15) and rotatably arranged in the movable mold front seat, the cooling shaft core (15) is in rotating fit with the threaded shaft sleeve (16), and the second transmission gear (12) is fixedly sleeved on the threaded shaft sleeve (16).

7. The pre-ejection demolding mechanism of the threaded connection cap mold according to claim 6, wherein a wear-resistant shaft sleeve (17) is fixedly arranged at an opening of the rear end of the through hole of the pushing plate (1), the outer diameter of the front end of the threaded shaft sleeve (16) is matched with the inner diameter of the wear-resistant shaft sleeve (17), and the front end of the threaded shaft sleeve (16) is in axial sliding fit with the wear-resistant shaft sleeve (17).

8. The mechanism of claim 7, wherein a plurality of deep groove ball bearings (18) are arranged between the threaded shaft sleeve (16) and the front seat of the movable die, and each deep groove ball bearing (18) is distributed at intervals along the axial direction of the threaded shaft sleeve (16).

9. The mechanism of claim 3, wherein the movable die base comprises a movable die base plate (19) and a shaft core fixing plate (20), the movable die base plate (19) and the shaft core fixing plate (20) are parallelly overlapped, abutted and fixed, and the movable die front base comprises a movable die support plate (21) and a movable die fixing plate (22), and the movable die support plate (21) and the movable die fixing plate (22) are parallelly overlapped, abutted and fixed.