CN115071067A

CN115071067A - Internal thread injection mold and injection molding method thereof

Info

Publication number: CN115071067A
Application number: CN202211002316.5A
Authority: CN
Inventors: 张二召
Original assignee: Suzhou Minyusu Electronic Technology Co ltd
Current assignee: Suzhou Minyusu Electronic Technology Co ltd
Priority date: 2022-08-22
Filing date: 2022-08-22
Publication date: 2022-09-20
Anticipated expiration: 2042-08-22
Also published as: CN115071067B

Abstract

The invention discloses an internal thread injection mold and an injection molding method thereof, and provides the following technical scheme aiming at the problem that the angles and shapes of a convex hull, an internal thread and an injection molding pattern are difficult to completely correspond by the existing injection molding method and mold; the convex hull mechanism is used for molding an inner convex hull of the injection molding part; the anti-slip tooth mechanism is used for preventing the injection molding part from rotating along with the screw tooth mechanism during demolding; an upper die parting surface covering the thread part of the thread mechanism; the lower die parting surface of the molding cavity is formed by parting combination with the upper die; and the demolding power mechanism is used for controlling the screw tooth mechanism to rotate and reset accurately. The mold provided by the invention is stable in operation, and can ensure that the angles and the shapes of the convex hull, the internal thread and the injection molding pattern are completely corresponding; the injection molding method provided by the invention is simple in steps and easy to operate.

Description

Internal thread injection mold and injection molding method thereof

Technical Field

The invention relates to the field of injection molds, in particular to an internal thread injection mold and an injection molding method thereof.

Background

The injection molding part is a product which is formed by heating, plasticizing and melting plastics by an injection molding machine, then injecting the melted plastics into a cavity of a forming mold for forming, cooling, demolding after the melt is solidified, and performing injection molding by the injection molding machine.

At present, there is an injection molding, see fig. 7, which includes a cover body 8, an internal thread 82 is provided on the inner side of the cover body 8, two sets of convex hulls 81 for preventing the injection molding from loosening during transportation are provided below the internal thread 82, each set of convex hulls 81 is 2, the convex hulls 81 are used for matching with the internal thread 82, when the internal thread 82 is completely screwed, the convex hulls 82 are clamped into a clamping groove preset by another matched assembly part, thereby prompting the internal thread 82 to be completely screwed in. In addition, the surface of the cover 8 is provided with a pattern according to the product requirements, which pattern is to correspond exactly to the surface pattern of another mating fitting after the internal thread 82 is screwed in completely, and no angular deviation can occur.

The initial positions of the threads formed by the existing injection molding method and the existing mold are generally random, and the complete correspondence of the angles and the shapes of the convex hull 81, the internal thread 82 and the patterns on the cover body 8 is difficult to meet, so that an injection mold is urgently needed at present to meet the production requirement and overcome the technical problem.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an internal thread injection mold and an injection molding method thereof, which have the advantages of ensuring that the threads, the convex hulls and the injection molding patterns of an injection molding part keep corresponding angles and consistent shapes.

In order to achieve the purpose, the invention provides the following technical scheme:

the present invention provides, in a first aspect, an internally threaded injection mold comprising:

the thread mechanism is used for forming the inner ring threads of the injection molding piece; the convex hull mechanism is sleeved on the screw tooth mechanism, is in sliding connection with the screw tooth mechanism and is used for molding an inner convex hull of the injection molding piece; the anti-slip tooth mechanism is sleeved on the convex hull mechanism and is used for preventing the injection molding part from rotating along with the screw tooth mechanism during demolding; the demolding power mechanism is in meshing transmission with the thread mechanism and is used for controlling the thread mechanism to rotate accurately and reset accurately; the parting surface of the upper die covers the thread mechanism; and the lower die parting surface is sleeved on the anti-slip tooth mechanism and combined with the upper die parting surface to form a forming cavity.

By adopting the technical scheme, the convex hull mechanism connected with the screw tooth mechanism in a sliding manner is adopted, so that the convex hull can be demolded in one step before the screw tooth demolding, the demolding cannot be hindered by the convex hull mechanism, the convex hull can be completely reserved, and the damage of the convex hull caused by the screw tooth demolding cannot be caused; by arranging the anti-slip tooth mechanism, the injection molding piece can be clamped by the anti-slip tooth mechanism during demolding, so that the injection molding piece body can be effectively prevented from rotating along with the screw tooth mechanism by the demolding screw teeth of the injection molding piece, the demolding of the injection molding piece can be more smooth and stable, and the mold can be prevented from being incapable of continuously producing due to the failure of demolding; the demolding power mechanism is arranged, so that the thread mechanism can accurately rotate, the starting position and the end position of the thread mechanism can be completely determined, the shape of the thread cannot be changed, the thread and the surface pattern of an injection molding part can be kept consistent, and the requirements of the invention are met; the mold is compact in structure and not easy to break down.

Further, the convex closure mechanism includes the convex closure body and sets up in convex closure body surface and be used for the fashioned convex closure chamber of convex closure, and the one end that the convex closure body is close to the shaping region is provided with and is used for promoting the convex closure body when the drawing of patterns and keeps away from the moving member that the shaping region removed, and the other end of convex closure body is connected with the spacing subassembly that the restriction convex closure body slided.

By adopting the technical scheme, through setting up the moving member for the convex hull body can move voluntarily, and easy operation, convenient to use through setting up spacing subassembly, can carry out the locking spacing when need not the motion of convex hull body, can prevent effectively that the convex hull body from sliding by mistake.

Further, the moving member is selected from one or a combination of a plurality of springs, air cylinders, oil cylinders and ball screw pairs.

Further, the moving member is a spring.

Adopt above-mentioned technical scheme, adopt the spring as the locating part, need not additional energy and supply energy, just can accomplish the regulation motion through self elastic deformation, help reducing the volume of mechanism, be convenient for further simplify the structure of mould, help improving the stability of mould operation, reduce the probability of breaking down.

Furthermore, spacing subassembly includes the spacing post that just can break away from the butt with convex closure body bottom butt.

By adopting the technical scheme, the limiting column is adopted as the limiting component, so that the limiting component is more stable and reliable in function, and the limiting component is prevented from being broken down in operation.

Furthermore, the demolding power mechanism comprises a driven gear connected with the thread mechanism, a first driving gear is arranged in a meshed driven gear, and the first driving gear is coaxially connected with a second driving gear driven to rotate by the power part.

By adopting the technical scheme, the accuracy of the movement of the screw tooth mechanism can be further ensured by adopting gear meshing transmission.

Furthermore, the power part comprises a rack in meshing transmission with the second driving gear, and the rack is driven by a hydraulic oil cylinder connected with the rack to move forwards and backwards.

By adopting the technical scheme, the rack is meshed with the transmission gear, the number of turns of the gear rotation can be controlled by controlling the length of the rack in the advancing and retreating process, the structure is simple, the equipment cost is low, the cost is far lower than that of a servo module, the operation is stable, and the problem of mechanism operation caused by temperature can be avoided.

Furthermore, the anti-skidding tooth mechanism comprises an anti-skidding tooth pipe body sleeved on the convex hull mechanism, and clamping teeth embedded into an injection molding piece during injection molding are arranged on the anti-skidding tooth pipe body.

By adopting the technical scheme, the injection molding part is fixed through the clamping teeth, the structure is simple, and the fixing and limiting effects are good.

Furthermore, a connecting rod is fixedly arranged on the inner side of the convex hull mechanism, and a waist-shaped groove for the connecting rod to slide is formed in one side, close to the connecting rod, of the screw tooth mechanism.

Adopt above-mentioned technical scheme, the length in waist type groove is the portable displacement distance of convex closure body, and waist type groove plays spacing and guide effect to the removal of convex closure body, helps making the operation of convex closure body more stable, and the convex closure body can keep synchronous motion with thread mechanism under the linking effect of connecting rod simultaneously to guarantee the real-time correspondence of thread shape and convex closure position, guarantee that the thread shape and the convex closure position of final injection molding product can accomplish the standard unified.

The invention provides an internal thread injection molding method in a second aspect, which applies the internal thread injection mold and comprises the following steps:

s1, injecting molten rubber into the die;

s2, cooling, forming and then opening the mold;

s3, the limit component relieves the limit on the convex hull mechanism, the convex hull mechanism automatically slides and separates from the convex hull, then the demoulding power mechanism drives the screw tooth mechanism to rotate quantitatively, the injection molding piece separates from the screw tooth mechanism under the limit of the anti-skid tooth mechanism, and the injection molding piece falls;

s4, the demolding power mechanism drives the screw tooth mechanism to rotate quantitatively, so that the screw tooth mechanism is reset accurately, and then the limiting assembly pushes the convex hull mechanism to reset accurately to mold;

s5, repeating the steps S1-S4.

By adopting the technical scheme, the convex hull is separated firstly and then the thread is demoulded, the process is advanced, the technical difficulty that the convex hull is difficult to protect perfectly in the prior art is overcome, the convex hull, the thread and the surface pattern of the injection molding part manufactured by the method can keep accurate correspondence of the convex hull, the thread and the surface pattern of the injection molding part, and the process parameter requirements of the injection molding part are met.

In conclusion, the invention has the following beneficial effects:

1. the convex hull, the screw teeth and the surface pattern of the injection molding piece can keep the accurate correspondence of the convex hull, the screw teeth and the surface pattern of the injection molding piece, thereby greatly improving the injection molding precision;

2. the injection mold provided by the invention has a compact structure, runs stably and is not easy to break down in running;

3. the injection molding method provided by the invention has fewer steps and is convenient to operate.

Drawings

FIG. 1 is a perspective view of an internal thread injection mold according to the present invention;

FIG. 2 is a schematic structural view of a demolding power mechanism according to the present invention;

FIG. 3 is a schematic view of the internal structure of an internal thread injection mold according to the present invention;

FIG. 4 is an exploded view of an internal thread injection mold according to the present invention;

FIG. 5 is an enlarged view of portion A of FIG. 4 according to the present invention;

FIG. 6 is an enlarged view of portion B of FIG. 4 according to the present invention;

FIG. 7 is a perspective view of a portion of a prior art injection molded part of the present invention.

In the figure: 1. parting surface of the upper die; 11. a lower template; 12. injection molding a runner; 2. parting surfaces of the lower die; 3. an anti-slip tooth mechanism; 31. the anti-skid tooth pipe body; 32. clamping teeth; 4. a convex hull mechanism; 41. a convex hull pipe body; 42. an annular outer rim; 43. a convex hull cavity; 44. blind holes; 45. a moving member; 46. a circular hole; 47. a connecting rod; 5. a thread mechanism; 51. a threaded cylinder; 52. a screw thread portion; 53. a waist-shaped groove; 6. a limiting component; 61. a limiting rod; 7. a demoulding power mechanism; 71. a hydraulic cylinder; 72. a rack; 73. a second driving gear; 74. a first drive gear; 75. a transmission rod; 76. a driven gear; 77. a lower fixing sleeve; 78. fixing a sleeve; 8. a cover body; 81. a convex hull; 82. an internal thread.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

An internal thread injection mold, see fig. 1 and 2, comprises a thread mechanism 5 for forming an inner ring thread of an injection molded part; a convex hull mechanism 4 for molding an inner convex hull of the injection molding piece; the anti-slip tooth mechanism 3 is used for preventing the injection molding part from rotating along with the screw tooth mechanism 5 during demolding; an upper mold parting surface 1 covering the thread part 52 of the thread mechanism 5; a lower die parting surface 2 of a forming cavity is formed by combining the upper die parting surface 1 and the lower die parting surface; and the demoulding power mechanism 7 is used for controlling the screw tooth mechanism 5 to rotate accurately and reset accurately.

Specifically, referring to fig. 3 and 4, the upper mold parting surface 1 is a cylindrical cover body, and the inner cavity of the upper mold parting surface is formed according to the shape 1 of an injection molding piece: 1, the lower die parting surface 2 is also a cylindrical cylinder, which is fixedly embedded in the lower die plate 11. The upper die parting surface 1 and the lower die parting surface 2 are both made of S136 steel with the hardness of 60, and have excellent wear resistance and smoothness and long service life. And the lower template 11 is made of a common steel plate with the hardness of 40, so that unnecessary cost investment can be reduced. And the upper die parting surface 1 and the lower die parting surface 2 are butted up and down to form a cylindrical sealing area for molding the injection molding part, namely a cavity.

Referring to fig. 2 to 4, the thread mechanism 5 is a cylindrical member, and includes a cylindrical thread cylinder 51, a disc-shaped thread portion 52 is fixedly disposed on the top of the thread cylinder 51, the edge of the thread portion 52 fits the shape of the thread of the molding member, the length of the radius of the thread portion 52 is greater than that of the thread cylinder 51, and the thread portion 52 and the thread cylinder 51 are coaxially disposed.

Referring to fig. 2 to 5, the convex hull mechanism 4 includes a cylindrical convex hull tube 41, convex hull cavities 43 for convex hull forming are formed in the side wall surface of the convex hull tube 41 at preset convex hull positions, the convex hull cavities 43 are semi-cylindrical, the number of the convex hull cavities 43 is four, two of the convex hull cavities are one, and the included angle between two groups of convex hull cavities 43 is 180 °. The screw cylinder 51 is inserted into the convex hull tube 41, and the top end of the convex hull tube 41 is fitted to the lower end surface of the screw portion 52 when the mold is closed. The top end face of the convex hull body 41 is provided with four cylindrical blind holes 44 downwards along the vertical direction, and the interval angles among the four blind holes 44 are 90 degrees. All fixedly provided with both ends respectively in every blind hole 44 with blind hole 44 bottom and thread portion 52 lower terminal surface fixed connection's moving member 45, moving member 45 is used for promoting convex hull body 41 and keeps away from thread portion 52 along thread cylinder 51 and moves, and moving member 45 adopts the spring in this embodiment, and when the compound die state, the spring is compressed in blind hole 44. The side wall of the convex hull pipe body 41 is provided with a round hole 46, a connecting rod 47 with the same aperture as the round hole 46 is fixedly connected in the round hole 46, the other end of the connecting rod 47 is inserted into the surface of a thread cylinder 51, the thread cylinder 51 is provided with a waist-shaped groove 53 for the connecting rod 47 to slide at the inserted position of the connecting rod 47, the length of the waist-shaped groove 53 is the movable moving distance of the convex hull pipe body 41, namely, the waist-shaped groove 53 plays the role of limiting and guiding the movement of the convex hull pipe body 41. When the main screw tooth cylinder rotates, the convex hull pipe body 41 can keep synchronous motion with the screw tooth cylinder 51 under the connecting action of the connecting rod 47, so that the real-time correspondence between the screw tooth shape and the convex hull position is ensured, and the standard unification between the screw tooth shape and the convex hull position of a final injection molding product is ensured. The lower end of the convex hull pipe body 41 is provided with an annular outer edge, and a limiting component 6 used for limiting the movement of the convex hull pipe body 41 is arranged close to the annular outer edge. The limiting assembly 6 comprises four limiting columns which are arranged on the outer edge of the pressing ring, and included angles among the four limiting columns are 90 degrees. Spacing post adopts hydraulic drive in this embodiment, when spacing post promotes towards thread portion 52, the convex hull body 41 removes near thread portion 52 gradually under the pushing action of spacing post, finally make the terminal surface of the top of convex hull body 41 and the laminating of the lower terminal surface of thread portion 52, the extreme motion position of convex hull body 41 when being the compound die this moment, when the drawing of patterns, spacing post loosens the thrust to convex hull body 41, make convex hull body 41 keep away from thread portion 52 and remove under the effect of spring, thereby make convex hull chamber 43 and the convex hull separation of injection molding.

Referring to fig. 4 and 6, the sliding gear mechanism includes an anti-sliding gear tube 31 sleeved on the convex hull tube 41, the upper end surface of the anti-sliding gear tube 31 is provided with a latch 32 embedded in the injection molding piece during injection molding, and the anti-sliding gear tube 31 is fixedly connected with the parting surface of the lower template 11, so that the injection molding piece cannot rotate along with the thread part 52 during demolding. The latch 32 is a triangular tooth-shaped structure and is uniformly arranged around the upper end face of the anti-slip tooth tube 31.

Referring to fig. 3 to 6, when the mold is assembled, the screw cylinder 51 is located at the innermost side, the convex hull tube body 41, the anti-slip tooth tube body 31 and the lower mold parting surface 2 are sequentially sleeved on the screw cylinder 51, and the upper mold parting surface 1 and the lower mold parting surface 2 are butted to form a cavity. The thread part 52 of the thread mechanism 5, the latch 32 of the anti-slip mechanism 3, the convex hull cavity 43 of the convex hull mechanism 4 and the inner cavity surfaces of the upper and lower die parting surfaces 2 are combined to form a molding area of the injection molding piece. An injection runner 12 extending into the molding area is arranged on the lower template 11.

Referring to fig. 1 to 4, the demolding power mechanism 7 includes an upper fixing sleeve 78 and a lower fixing sleeve 77 fixedly sleeved on the screw cylinder 51, the upper fixing sleeve 78 plays a role in limiting and fixing, and the lower fixing sleeve 77 is fixedly provided with a driven gear 76 coaxial with the screw cylinder 51. In the present embodiment, there are four threaded cylinders 51, that is, there are four driven gears 76, a first driving gear 74 engaged with the four driven gears 76 is disposed at a central position surrounded by the four gears, a lower end surface of the first driving gear 74 is fixedly connected to a transmission rod 75 coaxial with the first driving gear 74, one end of the transmission rod 75 far away from the first driving gear 74 is fixedly connected to a second driving gear 73 coaxial with the first driving gear 74, and the second driving gear 73 is driven by a power unit to rotate. The power part comprises a rack 72 meshed with the second driving gear 73, and one end of the rack 72 far away from the second driving gear 73 is fixedly connected with a hydraulic oil cylinder 71 used for driving the rack 72 to advance and retreat.

An internal thread injection molding method applies the internal thread injection mold and comprises the following specific steps:

and S1, injecting the molten rubber material into the mold.

And S2, waiting for cooling, and after the mold is cooled to the set temperature, separating the upper mold parting surface 1 from the lower mold parting surface 2 to open the mold.

S3, when the mold is opened, the limit function of the limit post on the annular outer edge is cancelled synchronously, the convex hull pipe body 41 slides away from the thread part 52 under the extension action of the spring, so that the convex hull is separated from the convex hull cavity 43. After the convex hull is demolded, the hydraulic cylinder 71 is driven to advance the rack 72, so as to drive the second driving gear 73 and the first driving gear 74 to rotate, and the driven gear 76 is rotated through meshing transmission, so as to finally drive the thread cylinder 51 to rotate. The injection molding is under the restriction of latch 32 on the antiskid tooth body 31, vertical removal, with the separation of thread mechanism 5, the injection molding drops at last.

S4, after the injection molding falls, the hydraulic oil cylinder 71 is driven, the rack 72 is reversed, the second driving gear 73 and the first driving gear 74 are driven to rotate reversely, the driven gear 76 rotates reversely through meshing transmission, the thread cylinder 51 is finally driven to rotate reversely, the thread part 52 is reset, the limiting column pushes the convex hull body 41, the upper end of the convex hull body 41 is abutted to the lower end face of the thread part 52, and accurate resetting of the convex hull cavity 43 is achieved. And finally, butting the upper die parting surface 1 and the lower die parting surface 2 again to complete die assembly.

And S5, repeating the steps of S1-S4 until the production is finished.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. An internal thread injection mold, comprising:

the thread mechanism (5) is used for molding the inner ring thread of the injection molding piece;

the convex hull mechanism (4) is sleeved on the screw tooth mechanism (5), is connected with the screw tooth mechanism (5) in a sliding manner, and is used for molding an inner convex hull of the injection molding piece;

the anti-slip tooth mechanism (3) is sleeved on the convex hull mechanism (4) and is used for preventing the injection molding piece from rotating along with the screw tooth mechanism (5) during demolding;

the demolding power mechanism (7) is in meshed transmission with the screw tooth mechanism (5) and is used for controlling the screw tooth mechanism (5) to rotate accurately and reset accurately;

the upper die parting surface (1) is covered on the screw tooth mechanism (5);

and the lower die parting surface (2) is sleeved on the anti-slip tooth mechanism (3) and is combined with the upper die parting surface (1) to form a forming cavity.

2. An internally threaded injection mold as defined in claim 1, wherein: convex closure mechanism (4) are including convex closure body (41) and set up in convex closure body (41) surface and be used for convex closure fashioned convex closure chamber (43), convex closure body (41) are close to the regional one end of shaping and are provided with and are used for promoting convex closure body (41) when the drawing of patterns and keep away from moving member (45) that the shaping region removed, the other end of convex closure body (41) is connected with spacing subassembly (6) that restriction convex closure body (41) slided.

3. An internally threaded injection mold as set forth in claim 2 wherein: the moving member (45) is selected from one or a combination of a plurality of springs, air cylinders, oil cylinders and ball screw pairs.

4. An internally threaded injection mold as set forth in claim 3 wherein: the moving member (45) is a spring.

5. An internally threaded injection mold as set forth in claim 2 wherein: the limiting component (6) comprises a limiting column which is abutted against the bottom of the convex hull pipe body (41) and can be separated from the convex hull pipe body.

6. An internally threaded injection mold as defined in claim 1, wherein: the demolding power mechanism (7) comprises a driven gear (76) connected with the thread mechanism (5), a first driving gear (74) is meshed with the driven gear (76), and the first driving gear (74) is coaxially connected with a second driving gear (73) driven to rotate by a power part.

7. An internally threaded injection mold as set forth in claim 6 wherein: the power part comprises a rack (72) in meshing transmission with the second driving gear (73), and the rack (72) is driven by a hydraulic oil cylinder (71) connected with the rack to move forwards and backwards.

8. An internally threaded injection mold as defined in claim 1, wherein: the anti-skidding tooth mechanism (3) comprises an anti-skidding tooth pipe body (31) sleeved on the convex hull mechanism (4), and the anti-skidding tooth pipe body (31) is provided with a latch (32) embedded into an injection molding piece during injection molding.

9. An internally threaded injection mold as defined in claim 1, wherein: the inner side of the convex hull mechanism (4) is fixedly provided with a connecting rod (47), and one side of the thread mechanism (5) close to the connecting rod (47) is provided with a waist-shaped groove (53) for the connecting rod (47) to slide.

10. An internal thread injection molding method using the internal thread injection mold according to any one of claims 2 to 9, comprising the steps of:

s1, injecting molten rubber into the die;

s2, cooling, forming and then opening the mold;

s3, the limit component (6) relieves the limit on the convex hull mechanism (4), the convex hull mechanism (4) automatically slides and is separated from the convex hull, then the demoulding power mechanism (7) drives the screw tooth mechanism (5) to rotate quantitatively, the injection molding piece is separated from the screw tooth mechanism (5) under the limit rotation of the anti-slip tooth mechanism (3), and the injection molding piece falls;

s4, the demolding power mechanism (7) drives the screw tooth mechanism (5) to rotate quantitatively, so that the screw tooth mechanism (5) is reset accurately, and then the limiting component (6) pushes the convex hull mechanism (4) to reset accurately to mold;

s5, repeating the steps S1-S4.