CN117464923A

CN117464923A - Injection mold

Info

Publication number: CN117464923A
Application number: CN202311327425.9A
Authority: CN
Inventors: 孙光纳
Original assignee: Terumo Medical Products Hangzhou Co Ltd
Current assignee: Terumo Medical Products Hangzhou Co Ltd
Priority date: 2023-10-13
Filing date: 2023-10-13
Publication date: 2024-01-30

Abstract

The present invention provides an injection mold comprising: a front mold assembly including a front mold plate having a front mold cavity; a rear mold assembly including a rear mold plate having a rear mold cavity; the mold cavity is formed by combining a front mold cavity and a rear mold cavity; and a mold core, the mold core being mated with the mold cavity to injection mold the product; the mold core is driven by a cylinder with electromagnetic induction signals, and the surface of the mold core is subjected to sand blasting treatment and coating treatment. The injection mold disclosed by the invention can greatly reduce the adhesive force between the product and the mold core, and realizes stable batch production of the product.

Description

Injection mold

Technical Field

The invention relates to the technical field of injection molding, in particular to an injection mold.

Background

The TPU soft long tube has a length of about 150mm to 170mm, an outer diameter of about 7mm to 9mm and a difference between inner diameters of both ends of about 0.1mm. For soft long tubes of length > 150mm, the industry has not heretofore solved the problem of mass production by injection molding. The reason is that the core pulling distance of the side of the mould is too long (about 160 mm), the drawing angle is small, the core pulling force is too large, and therefore the long core of the mould cannot be pulled out, and the product is damaged and deformed by pulling.

Disclosure of Invention

In order to solve the technical problems in the prior art, the embodiment of the invention provides an injection mold, which can reduce the adhesive force between a product and a mold core, avoid the product from being damaged by pulling, and is beneficial to realizing batch and stable production of the product.

According to an embodiment of the present invention, an injection mold includes: a front mold assembly including a front mold plate having a front mold cavity; a rear mold assembly including a rear mold plate having a rear mold cavity; the mold cavity is formed by combining a front mold cavity and a rear mold cavity; and a mold core, the mold core being mated with the mold cavity to injection mold the product; the mold core is driven by a cylinder with electromagnetic induction signals, and the surface of the mold core is subjected to sand blasting treatment and Teflon coating spraying.

Optionally, the surface roughness of the mold core is 0.6-1.0.

Optionally, the mold core is provided with cooling channels for air cooling.

Optionally, the front mold assembly further comprises a front mold fixing plate and a runner push plate, the front mold plate is fixed to the front mold fixing plate, and the runner push plate is arranged between the front mold fixing plate and the front mold plate; and the rear mold assembly further comprises a rear mold fixing plate and a thimble plate assembly, wherein the rear mold plate is fixed to the rear mold fixing plate, and the thimble plate assembly is fixed to the rear mold plate and is used for ejecting the molded product out of the rear mold cavity.

Optionally, the mould core comprises a first mould core part and a second mould core part, the first mould core part and the second mould core part being mated by a bevel.

Optionally, the injection mold further comprises a controller connected to the cylinder, the controller configured to: when the runner push plate is separated from the front template by a first preset distance, controlling the first mold core part to be pulled out of the product; and when the front mould fixing plate and the runner push plate are separated by a second preset distance, controlling the front mould plate and the rear mould plate to be separated, and driving the second mould core part to be pulled out of the product.

Optionally, the runner push plate is provided with an upper wedging block, the rear mould plate is provided with an upper slide block seat, and the first mould core part is locked and released by the cooperation of the upper wedging block and the upper slide block seat.

Optionally, the front mold plate is provided with a lower wedging block, the rear mold plate is provided with a lower slide block seat, and the second mold core part is locked and released by the cooperation of the lower wedging block and the lower slide block seat.

Optionally, the lower wedging block is provided with an inclined guide post, and the lower sliding block seat is provided with an inclined hole matched with the inclined guide post.

Optionally, the lower slide block seat is further provided with a limiting spring for limiting the lower slide block seat.

Optionally, a pull rod for limiting the separation distance between the runner push plate and the front template is arranged on the runner push plate.

Optionally, the runner push plate is provided with a limit bolt for limiting the separation distance between the front mold fixing plate and the runner push plate.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following advantages:

according to the injection mold disclosed by the invention, the mold core is driven by the cylinder with electromagnetic induction signals, and the mold core is subjected to sand blasting treatment and is sprayed with a Teflon coating.

Firstly, tiny convex-concave is formed on the mold core through sand blasting, so that gas residues exist in tiny grooves between the product and the mold core, the contact area between the product and the mold core is reduced, and the adhesive force between the product and the mold core is reduced.

Secondly, the surface of the mold core is sprayed with the Teflon coating after sand blasting, so that the adhesive force between the product and the mold core can be further reduced, the smoothness of the surface of the product is improved, the mold core is facilitated to be pulled out of the product, the products are prevented from being damaged and deformed by pulling, and the mass production of the products is facilitated.

Drawings

Other features and advantages of the present invention will be better understood from the following detailed description of alternative embodiments taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof, and wherein:

FIG. 1 shows a schematic cross-sectional view of an injection mold according to one embodiment of the invention;

FIG. 2 shows another cross-sectional schematic view of an injection mold according to one embodiment of the invention;

FIGS. 3A and 3B show schematic cross-sectional views of the injection mold of the embodiment shown in FIG. 1, with the parting plane between the runner push plate and the front mold plate of the injection mold open;

FIG. 4 shows a schematic cross-sectional view of the injection mold of the embodiment shown in FIG. 1, wherein a first core portion of the injection mold completes a core pulling action;

FIGS. 5A and 5B are schematic cross-sectional views showing an injection mold of the embodiment shown in FIG. 1, wherein a parting plane between a front mold plate and a rear mold plate of the injection mold is opened, and a core pulling action is completed by a second mold core portion;

FIG. 6 shows a schematic cross-sectional view of the injection mold of the embodiment shown in FIG. 1, wherein the injection mold completes the ejection action of the product;

FIG. 7 shows a schematic cross-sectional view of the core of the injection mold of the embodiment shown in FIG. 1;

fig. 8 shows a schematic cross-sectional view of a mold cavity of the injection mold of the embodiment shown in fig. 1.

Detailed Description

The making and using of the embodiments are discussed in detail below. It should be understood, however, that the detailed description and the specific examples, while indicating specific ways of making and using the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The structural position of the various components as described, such as the directions of up, down, top, bottom, etc., is not absolute, but rather relative. When the individual components are arranged as shown in the figures, these directional expressions are appropriate, but when the position of the individual components in the figures changes, these directional expressions also change accordingly.

Traditionally, injection molded products have been provided with draft angles. However, in order to meet the functional requirements of a long-sized radioactive particle storage device, on the one hand, the selectable size of the drawing angle of the inner cavity of the radioactive particle storage device combined with the nutrition line is very limited; on the other hand, the draft angle of the particle chamber of the radiation particle storage device is not applicable, thereby making injection molding difficult. To this end, the present inventors creatively propose a new injection mold and injection molding method.

According to an embodiment of the present invention, the injection mold includes: a front mold assembly including a front mold plate having a front mold cavity; a rear mold assembly including a rear mold plate having a rear mold cavity; the mold cavity is formed by combining a front mold cavity and a rear mold cavity; and a mold core, the mold core being mated with the mold cavity to injection mold the product; the mold core is driven by a cylinder with electromagnetic induction signals, and the surface of the mold core is subjected to sand blasting treatment and Teflon coating spraying.

The sand blasting process adopts compressed air as power to form high-speed spray beam, and sprays abrasive material to the surface of workpiece to be treated at high speed, so that the surface of workpiece can obtain certain cleanliness and different roughness due to the impact and cutting action of abrasive material on the surface of workpiece. When the sand blasting is mainly used for producing injection molding products with matte or frosted surfaces on an injection mold, the corresponding mold parts are subjected to sand blasting. Because the surface of the part is formed with projections and depressions after the sand blasting, the sand blasting process is avoided in order to improve the mold release property. The invention adopts sand blasting to counter the sand blasting, thereby increasing the roughness of the mould part. The micro convex-concave is formed on the mold core through sand blasting, so that gas residues exist in the micro grooves between the product and the mold core, the contact area is reduced, and the adhesive force between the product and the mold core is reduced. In addition, the mold core is sprayed with the Teflon coating after sand blasting, so that the adhesive force between a product and the mold core can be reduced, the smoothness of the surface of a workpiece is improved, and the mold core is conveniently pulled out of the product.

The structure and function of the injection mold 100 according to the embodiment of the present invention are described in detail below with reference to the accompanying drawings.

As shown in fig. 1 and 2, the injection mold 100 includes a front mold assembly 10, a rear mold assembly 20, a mold cavity 30, and a mold core 40. The front mold assembly 10 includes a front mold plate 11, the front mold plate 11 having a front mold cavity 111. The rear mold assembly 20 includes a rear mold plate 21, the rear mold plate 21 having a rear mold cavity 211. The mold cavity 30 is formed by combining the front mold cavity 111 and the rear mold cavity 211. The mold core 40 cooperates with the mold cavity 30 to injection mold the product. The mold core 40 is driven by a cylinder 50 with electromagnetic induction signals.

In some embodiments, the front mold assembly 10 further includes a front mold fixing plate 12 and a runner push plate 13, the front mold plate 11 is fixed to the front mold fixing plate 12, and the runner push plate 13 is disposed between the front mold fixing plate 12 and the front mold plate 11. Rear mold assembly 20 further includes a rear mold plate 22 and a thimble plate assembly 23, rear mold plate 21 being secured to rear mold plate 22, thimble plate assembly 23 being secured to rear mold plate 21 for ejecting the molded product out of rear mold cavity 211.

In some embodiments, the mold core 40 includes a first mold core portion 41 and a second mold core portion 42, the first mold core portion 41 and the second mold core portion 42 having a length that is greater than a length of the second mold core portion 42 by a beveled fit therebetween.

In some embodiments, injection mold 100 further comprises a controller coupled to cylinder 50, the controller configured to: controlling the extraction of the first core portion 41 from the product while the runner push plate 13 is separated from the front mold plate 11 by a first predetermined distance; when the front mold fixing plate 12 and the runner push plate 13 are separated by a second predetermined distance, the front mold plate 11 and the rear mold plate 12 are controlled to be separated, and the second mold core part 42 is driven to be pulled out of the product. The first predetermined distance and the second predetermined distance may be set according to a specific application.

The front mold cavity 111 may be formed of S-STAR steel with a quench hardness of HRC 50-54 for forming half of the outer surface of the product. The front mold cavity 111 is provided with a runner and a gate for feeding glue and filling plastic. The waterway processed on the front mold cavity 111 is communicated with the front mold plate 11 through a sealing ring 112 for controlling the temperature in the front mold cavity 111.

The front mold fixing plate 12 is fixed on a front mold panel of the injection molding machine, and a guide post 121, a positioning ring 122, a sprue bush 123 and a grabbing needle 124 are mounted on the front mold fixing plate 12. Typically, 4 guide posts 121 are provided, the guide posts 121 can be made of SUJ2 steel, and the quenching hardness is HRC 58-60. The front die plate 11 and the runner push plate 13 can slide along the guide post 121, and the guide post 121 is also used for guiding and positioning with the rear die plate 21. The retaining ring 122 and sprue bush 123 may be bolted to the front mold anchor plate 12. The positioning ring 122 can be made of S50C steel, and the positioning ring 122 is used for positioning when the die is installed on the injection molding machine. The sprue bush 123 can be made of SKD61 steel, has quenching hardness of HRC 48-52 and is used for matching with a nozzle of an injection molding machine. The grabbing needle 124 can be made of SKH51 steel, and the quenching hardness is HRC 58-60. When the front template 11 and the runner push plate 13 are separated, the stub bar remains on the grasping needle 124.

The front template 11 slides on the guide post 121 through the front template guide sleeve 114 arranged on the front template guide sleeve, the front template guide sleeve 114 can be made of SUJ2 steel, and the quenching hardness is HRC 58-60. The runner push plate 13 slides on the guide post 121 through the runner push plate guide sleeve 134 arranged on the runner push plate 13, and the stub bar on the grabbing needle 124 is removed. The runner push plate guide sleeve 134 is made of SUJ2 steel, and the quenching hardness is HRC 58-60. The runner push plate 13, the sprue bush 123 and the grabbing needle 124 are matched by conical surfaces, so that abrasion between the matching parts is reduced.

The water channel is designed on the rear template 21, and the water is introduced to control the temperature of the rear template 21. The rear mold cavity 211 may be formed of S-STAR steel with a quench hardness of HRC 50-54 for the other half of the outer surface of the molded product. The waterway holes on the rear mold cavity 211 are communicated with the waterway of the rear mold plate 21 through a sealing ring for controlling the temperature of the rear mold cavity 211. The rear template 21 is matched with the guide post 121 through the rear template guide sleeve 214 to realize the guiding and positioning between the front die and the rear die.

The runner push plate 13 is provided with an upper wedge block 131 and the rear mold plate 21 is provided with an upper slide seat 213, and the first mold core part 41 is locked and released by cooperation of the upper wedge block 131 and the upper slide seat 213. In some embodiments, the flow channel pushing plate 13 is provided with a tie rod 132 for limiting the separation distance between the flow channel pushing plate 13 and the front mold plate 11. In some embodiments, the runner push plate 13 is provided with a limit bolt 133 for limiting the separation distance between the front mold fixing plate 12 and the runner push plate 13.

The upper wedging block 131 can be made of SKD11 steel, and the quenching hardness is HRC 60-63. When the front mold plate 11 and the flow path push plate 13 are separated, the upper wedge 131 is separated from the upper slider seat 213 so that the upper slider seat 213 can be retracted. The runner push plate 13 is fixed with a pull rod 132 and 4 limit bolts 133, the pull rod 132 pulls the runner push plate 13 to be separated from the front mold fixing plate 12, the length of the pull rod 132 limits the separation distance between the runner push plate 13 and the front mold plate 11, and the length of the limit bolts 133 limits the separation distance between the runner push plate 13 and the front mold fixing plate 12. The pull rod 132 is sleeved with a runner push plate spring 135 to assist in ensuring that the runner push plate 13 and the front template 11 are separated first during die opening.

In some embodiments, the front mold plate 12 is provided with a lower wedge block 113 and the rear mold plate 21 is provided with a lower slide block seat 212, the second mold core portion 42 being locked and released by cooperation of the lower wedge block 113 and the lower slide block seat 212. The lower wedging block 113 can be made of SKD11 steel, the quenching hardness is HRC 60-63, and when the front template 11 and the rear template 21 are opened, the lower sliding block seat 212 is moved to drive the second mold core part 42 to perform core pulling action.

In some embodiments, lower wedge 113 is provided with a diagonal guide post 1131 and lower slider seat 212 is provided with a diagonal bore 2121 that mates with diagonal guide post 2121. In some embodiments, the lower slider seat 212 is further provided with a stop spring 2122 for limiting the lower slider seat 212.

One side of the upper slide block seat 213 is connected with a piston 51 of the air cylinder 50, the other side is connected with the first mold core part 41, the first mold core part 41 can be made of SKH51 steel, the quenching hardness is HRC 58-60, and the air cylinder 50 drives the first mold core part 41 to move, so that the core pulling action of the first mold core part 41 is realized. The inclined hole 2121 on the lower slide block seat 212 is matched with the inclined guide column 1131 on the lower wedging block 113, one side of the lower slide block seat 212 is connected with the second mold core part 41, the second mold core part 41 can be made of SKH51 steel, the quenching hardness is HRC 58-60, and the second mold core part 41 is driven to move forwards and backwards through the closing and opening of the front mold and the rear mold, so that the core pulling action of the second mold core part 41 is realized. The lower slider seat 212 is also designed with spring holes to mount limit springs 2122 to ensure that the lower slider seat 212 is retracted into position and held in place.

The thimble plate assembly 23 includes an upper thimble plate 231 and a lower thimble plate 232, both of which may be made of P20 steel. The upper and lower ejector plates 231 and 232 are mounted on the rear mold plate 21 by ejector plate guide posts 233. The thimble plate guide column 233 may be made of SUJ2 steel, and has a quenching hardness of HRC58, and supports the upper thimble plate 231 and the lower thimble plate 232 to slide thereon. The upper thimble plate 231 and the lower thimble plate 232 are positioned by a thimble plate guide sleeve 234 and are locked together by bolts, the thimble plate guide sleeve 234 can be made of SUJ2 steel, and the quenching hardness is HRC 58-60.

Upper thimble plate 231 is used to secure all the thimbles 2311 and return pins 2312. The thimble 2311 can be made of SKH51 steel, has quenching hardness of HRC 58-60 and surface hard chrome plating hardness of 900HV, and is used for ejecting out the product from the post-mold cavity 211. The return pin 2312 can be made of SUJ2 steel, the quenching hardness is HRC58, the ejector plate return spring 2313 is sleeved on the quenching hardness, and the ejector plate 231 is pushed to return automatically after the upper ejector plate 231 ejects a product and the bench ejector rod is retracted. The upper thimble plate 231 is further provided with an ejection limiting block 2314 for limiting the ejection distance of the upper thimble plate 231, and the ejection limiting block 2314 can be made of S50C steel. The rear mold cavity 211 is provided with a thimble hole for sliding along with a thimble 2311.

The lower ejector plate 232 bears ejection of the ejector pins of the injection molding machine and is designed with an ejection pad 2321. The ejecting pad 2321 may be made of S50C steel. The ejector rod of the forming machine contacts with the ejection cushion 2321 when being ejected, so that the ejection distance of the ejector rod of the injection machine is reduced, and meanwhile, the phenomenon that the machine table ejector rod directly acts on the lower ejector plate 232 to abrade the lower ejector plate 232 is avoided.

In some embodiments, the rear module 20 further includes a nylon shutter 24 and a stand-off 25. In some embodiments, a nylon shutter 24 is mounted on the rear template 21. The nylon shutter 24 pulls the front die plate 11 to move backward together during die opening, so that the front die plate 11 and the runner push plate 13 are opened first, and the material grabbing needle 124 pulls out the material head. The front template 11 drives the runner push plate 13 to move backwards through the pull rod 132, so that the front template fixing plate 12 and the runner push plate 13 are opened, the runner push plate 13 dials down the stub bars on the grabbing needle 124, and finally the parting surfaces between the front template 11 and the rear template 21 are opened, so that the die opening sequence is ensured.

In some embodiments, the stand 25 is used to separate the rear mold plate 21 and the rear mold fixing plate 22, leaving a certain space between them, and is used to place the upper thimble plate 231 and the lower thimble plate 232 with a space for ejecting out, and the stand 25 is fixed on the rear mold fixing plate 22 by bolts.

In some embodiments, the rear mold fixing plate 22 is further provided with a stopper pin 221 and a support column 222, and the rear mold fixing plate 22 is locked with the rear mold plate 21 by 6 long bolts to form a rear mold portion of the mold.

The stop pin 221 can be made of S45C steel, has quenching hardness of HRC 46-50, is used for supporting the ejector plate assembly 23, keeps balance of the ejector plate assembly 23, avoids unbalance of the ejector plate assembly 23 caused by foreign matters between the lower ejector plate 232 and the rear die fixing plate 22, and can conveniently adjust the position of the ejector plate assembly 23 by adjusting the height of the stop pin 221.

The support column 222 may be made of S50C steel for supporting the back mold plate 21, so as to prevent the back mold plate 21 from being deformed due to excessive pressure in the cavity when the mold is closed and filled with the resin material.

In some embodiments of the invention, other steels conventional in the art may also be used to make the corresponding components.

The production process of the soft long tube product comprises die assembly, material filling, pressure maintaining and cooling, and the product is ejected out by die opening, and the stub bar is clamped.

And (3) die assembly: the front mold assembly 10 and the rear mold assembly 20 are combined into an injection mold 100, and the injection mold 100 has a mold core 40 and a mold cavity 30.

Filling: filling material between the mold cavity 30 and the mold core 40.

Pressure maintaining and cooling: the process parameters such as time, temperature and pressure can be adjusted by those skilled in the art according to the specific production process.

Demolding: the mold core 40 is withdrawn from the molded product and the molded product is ejected out of the mold cavity 40.

The mold core 40 is driven by a cylinder with electromagnetic induction signals, and the surface of the mold core 40 is subjected to sand blasting and Teflon coating spraying.

Wherein, the die sinking mainly includes following steps:

as shown in fig. 3A and 3B, at the time of mold opening, the parting plane between the front mold plate 11 and the runner push plate 13 is opened by the force of the nylon shutter 24 and the runner push plate spring 135, the upper wedge 131 is separated from the upper slider seat 213, and the grasping needle 124 pulls the head to be pulled out from the master mold plate runner 125.

As shown in fig. 4, when the parting plane between the front mold plate 11 and the runner push plate 13 is opened by a first predetermined distance, the injection molding machine starts to supply compressed air to the front hole of the cylinder 50, and the piston 51 of the cylinder 50 retreats to drive the first mold core part 41 to retreat together, thereby completing long-distance core pulling. In this process, the parting plane between the front mold plate 11 and the rear mold plate 21 is in a closed state, and the product is wholly left in the mold cavity 30, so that the shape of the product is fixed, and the product is ensured not to be pulled and deformed by the first mold core part 41.

As shown in fig. 5A, 5B and 6, after the first mold core portion 41 is completely withdrawn, the injection molding machine receives a cylinder retraction signal, and continues to open the mold, the nylon shutter 24 drives the front mold plate 11, the front mold plate 11 drives the pull rod 132, the pull rod 132 drives the runner push plate 13, so that the parting surface between the runner push plate 13 and the front mold fixing plate 12 is opened, and the stub bar is separated from the material grabbing needle 124 and the sprue bush 123.

When the parting plane between the runner push plate 13 and the front mold fixing plate 12 is opened to a second predetermined distance, the parting plane between the front mold plate 11 and the rear mold plate 21 is opened. In the parting surface opening process between the front template 11 and the rear template 21, a product is remained in the rear model cavity 211 of the rear template 21, and the lower slider seat 212 finishes the short-distance back core pulling under the acting force of the inclined guide post 1131 and the limit spring 2122.

When the injection molding machine reaches the set distance of mold opening, the machine bench ejector rod pushes the top plate to advance with the ejector pin, the ejector pin 2311 ejects the product to drop, and meanwhile, the mechanical arm takes away the stub bar.

As shown in fig. 7, the mold core 40 is provided with cooling channels 60 for air cooling. The cooling channel 60 comprises an air inlet 61, an air outlet 62 and a cooling path 63 communicating the air inlet 61 with the air outlet 62, the air inlet 61 being provided on the second core part 42 and the air outlet 62 being provided on the first core part 41, the cooling air flowing through the cooling channel 60 for air cooling the core 40.

As shown in fig. 8, the front mold cavity 111 of the front mold plate 11 is provided with a front mold-forming undercut 1111, and the rear mold cavity 211 of the rear mold plate 21 is provided with a rear mold-forming undercut 2111. In order to ensure that the product remains in the rear mold cavity 211 of the rear mold plate 21 when the parting plane between the front mold plate 11 and the rear mold plate 21 is opened during the production process, the width B of the rear mold forming undercut 2111 is greater than the width a of the front mold forming undercut 1111.

Further, according to the present invention, the surface of the mold core 40 is creatively sandblasted and sprayed with a teflon coating.

The sand blasting process adopts compressed air as power to form high-speed spray beam, and sprays abrasive material to the surface of workpiece to be treated at high speed, so that the surface of workpiece can obtain certain cleanliness and different roughness due to the impact and cutting action of abrasive material on the surface of workpiece. Therefore, the sand blasting is mainly used for producing injection molding products with matte or frosted surfaces on the injection mold, and the sand blasting procedure is avoided in order to improve the mold release performance because the convex and concave parts are formed on the surface of the part after sand blasting, which is not beneficial to mold release. The invention adopts sand blasting to counter the sand blasting, thereby increasing the roughness of the mould part. The micro convex-concave is formed on the mold core through sand blasting, so that gas residues exist in the micro grooves between the product and the mold core, the contact area between the product and the mold core is reduced, and the adhesive force between the product and the mold core is reduced.

Furthermore, as can be seen from table 1, the surface treatment by grinding, although also increasing the roughness of the mold parts, does not satisfy the requirements of the present long-sized radioactive particle storage device and the nutrition line.

Table 1 experimental results of different treatments

In some embodiments, the surface of the mold core 40 is grit blasted to a surface roughness of 0.6-1.0. Preferably, the surface roughness is required to be Ra 0.8. Because the surface is smooth, the vacuum lamination between the mold core and the product is caused, and the product is pulled by pulling the mold core; too thick surface can cause too large friction force between the mold core and the product, and the product can be pulled by pulling the mold core.

However, the applicant found that the blasting treatment of the present invention, although being capable of accomplishing demolding, does not ensure stability in mass production, and therefore, the present invention makes a surface coating treatment after the surface of the mold core is blasted, reducing the adhesion between the product and the mold core. In some embodiments, teflon treatment is adopted, so that the smoothness of the surface of a workpiece is improved, the mold cores are easily pulled out of products, and stable demolding of each batch in the batch production process is ensured. As shown in table 1, the roughness of Ra 0.8 plus the teflon coating treatment to reduce surface friction achieves the most desirable effect according to the embodiments of the present invention.

In some embodiments, the mold core 40 is provided with cooling channels for air cooling.

According to the embodiment of the invention, the mold core is cooled by adopting an air cooling mode. The cooling of the mould is usually liquid cooling, such as water cooling and oil cooling, on the one hand, the temperature of the liquid can be effectively controlled through the mould temperature machine, and on the other hand, the mould has higher heat conductivity. When the mold parts are not able to pass through the liquid, they cool naturally, typically by conduction of heat from the parts to the air or other mold parts. Because of the limitation of the structure and the shape, the mold core cannot be cooled by processing the water channel, the common practice is to lengthen the cooling time to naturally cool the mold core, but the production period is lengthened, and the efficiency is sacrificed to be replaced by the quality. The invention uses a long mould core (a first mould core part) and a short mould core (a second mould core part) to be inserted together, and a through hole is formed in the middle to connect the long mould core and the short mould core to form a cooling passage. The compressed air is continuously used in a limited time, so that the rapidly circulated gas takes away heat, and the purpose of rapidly cooling the mold core is achieved.

While the foregoing has described the technical content and features of the present invention, it will be appreciated that those skilled in the art, upon attaining the teachings of the present invention, may make variations and improvements to the concepts disclosed herein, which fall within the scope of the present invention. The above description of embodiments is illustrative and not restrictive, and the scope of the invention is defined by the claims.

Claims

1. An injection mold, comprising:

a front mold assembly including a front mold plate having a front mold cavity;

a rear mold assembly including a rear mold plate having a rear mold cavity;

the mold cavity is formed by combining the front mold cavity and the rear mold cavity; and

a mold core that cooperates with the mold cavity to injection mold a product;

the mold core is driven by a cylinder with electromagnetic induction signals, and the surface of the mold core is subjected to sand blasting treatment and Teflon coating spraying.

2. The injection mold of claim 1, wherein the surface roughness of the mold core is 0.6-1.0.

3. Injection mold according to claim 2, characterized in that the mold core is provided with cooling channels for air cooling.

4. The injection mold of any one of claims 1 to 3 wherein the front mold assembly further comprises a front mold fixing plate to which the front mold plate is fixed and a runner push plate disposed between the front mold fixing plate and the front mold plate; and

the rear mold assembly further comprises a rear mold fixing plate and a thimble plate assembly, wherein the rear mold plate is fixed to the rear mold fixing plate, and the thimble plate assembly is fixed to the rear mold plate and used for ejecting a molded product out of the rear mold cavity.

5. The injection mold of claim 4 wherein the mold core comprises a first mold core portion and a second mold core portion, the first mold core portion and the second mold core portion being mated by a chamfer.

6. The injection mold of claim 5, further comprising a controller coupled to the cylinder, the controller configured to:

controlling the first core portion to be withdrawn from the product when the runner push plate is separated from the front mold plate by a first predetermined distance; and

when the front mold fixing plate and the runner pushing plate are separated by a second preset distance, the front mold plate and the rear mold plate are controlled to be separated, and the second mold core part is driven to be pulled out of the product.

7. The injection mold of claim 6 wherein said runner push plate is provided with an upper keying block and said rear mold plate is provided with an upper slide block seat, said first mold core portion being locked and released by the cooperation of said upper keying block and said upper slide block seat; and/or

The front template is provided with a lower wedging block, the rear template is provided with a lower sliding block seat, and the second mold core part is locked and released through the cooperation of the lower wedging block and the lower sliding block seat.

8. The injection mold of claim 7, wherein the lower keying block is provided with a beveled guide post and the lower slider seat is provided with a beveled aperture that mates with the beveled guide post.

9. The injection mold of claim 8, wherein the lower shoe is further provided with a limit spring for limiting the lower shoe.

10. The injection mold according to claim 4, wherein a tie rod for limiting a separation distance between the runner push plate and the front mold plate is provided on the runner push plate; and/or

And the runner push plate is provided with a limit bolt for limiting the separation distance between the front die fixing plate and the runner push plate.