CN114102970A - Insert molding device and molding method - Google Patents

Abstract

The invention discloses an insert molding device and a corresponding molding method. The insert-molding apparatus includes a first mold and a second mold forming a mold cavity, wherein the first mold includes a mold body and at least one insert disposed in the mold body, the insert having a mating surface adapted to mate with the insert, wherein the insert-molding apparatus further includes a resilient member arranged to apply a force to the insert, the force applied by the resilient member holding the insert in a first position when the first mold is open relative to the second mold, the insert being movable out of the first position against the force of the resilient member when the first mold and the second mold are mated together and the insert is disposed on the mating surface of the insert. The insert molding device according to the present invention is suitable for using inserts within a certain manufacturing tolerance range without performing an additional mold repair process.

Description

Insert molding device and molding method

Technical Field

The present invention relates to the field of injection molding technology, and more particularly, to a molding apparatus and a molding method for insert molding.

Background

Insert injection molding is a common process in the injection molding art. Generally, a heterogeneous insert prepared in advance is loaded into a mold, and then, a molten material such as a resin is injected into a cavity of the mold to form an integrated product with the insert.

For the molding of the pipe sleeve type inserts, the sizes of inserts of different batches cannot be ensured to be completely consistent, particularly, when the heights of the inserts are different, the inserts of different batches have problems during molding, and under the condition, the molds need to be continuously repaired according to the sizes of the inserts of different batches, so that the production and manufacturing efficiency is extremely low, and the cost is high. In addition, the new die usually leaves iron for matching the die to complete die testing, but when the size of the pipe sleeve is smaller in subsequent volume production, a gap is generated between the insert and the insert, the maximum size can reach 0.15mm, the product is rich in glue, and the appearance and the function of the insert are affected.

Therefore, the conventional insert molding process cannot overcome the quality problem caused by the height difference of the pipe-sleeve type inserts, and still needs to solve the problem of accommodating the height deviation of the inserts, particularly the pipe-sleeve type inserts in different batches in the injection molding process.

Disclosure of Invention

To overcome the deficiencies of the prior art, the present invention provides an insert-molding apparatus configured for making an injection molded part having an insert, the insert-molding apparatus comprising a first mold and a second mold forming a mold cavity, wherein the first mold comprises a mold body and at least one insert disposed in the mold body, the insert having a mating surface adapted to mate with the insert, wherein the insert-molding apparatus further comprises a resilient member arranged to apply a force to the insert, and allowing the insert to move within a predetermined range of motion relative to the mold body, the force exerted by the resilient member holding the insert in a first position relative to the mold body when the first mold is opened relative to the second mold, when the first and second molds are closed to form a mold cavity, the insert is movable out of the first position against the force of the resilient member when subjected to the force exerted by the second mold.

According to one aspect of the invention, the insert has a first end at which the mating surface is disposed and a second end opposite the first end at which the resilient member is mounted.

According to another aspect of the invention, the second end of the insert has a receiving cavity for receiving a resilient member, the receiving cavity being recessed inwardly from an end surface of the second end, the resilient member being disposed in the receiving cavity and abutting a bottom of the receiving cavity.

According to another aspect of the invention, the receiving cavity is formed in a cylindrical shape and the mating surface of the first end is formed in a circular ring shape, wherein the cylindrical receiving cavity is arranged in a center with the circular ring-shaped mating surface.

According to a further aspect of the invention, the insert is provided with a stop defining a first position, the stop abutting against the die body when the first die is opened relative to the second die to thereby define the insert in the first position.

According to a further aspect of the present invention, the stop of the insert is a step surface formed on an outer surface of the insert, the step surface being formed on a surface substantially perpendicular to an axis of movement of the insert, and the insert holes in the die body on which the insert is arranged form respective stop surfaces which, when engaged with the step surface, define the insert in the first position.

According to yet another aspect of the invention, the first end has a boss portion that projects relative to the mating surface and extends into the mold cavity to allow the insert to be seated on the boss portion.

According to a further aspect of the invention, the insert is movable against the resilient force to a second position when the first and second mould parts are brought together, the distance of movement between the first and second positions being about 0.5 mm.

In addition, the present invention provides a molding method using the insert-molding apparatus as described above, in which the insert is located at the first position by the force of the elastic member when the first mold and the second mold are hit against each other; placing an insert on a first end of the insert; closing the first and second molds, the insert moving away from the mold cavity against the force of the resilient member during the closing.

Thus, for the molding device according to the invention, the dimensional requirements for the insert are less critical. If the sizes of different batches of inserts are different, no special mould repairing treatment is needed to be carried out on the inserts in the device.

The insert part produced by the insert molding device avoids the problem of excessive glue and has high yield. In addition, the insert molding device itself has a simple structure without increasing excessive mold cost.

Drawings

For a more complete understanding of the present invention, reference is made to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, in which:

fig. 1 shows a schematic sectional view of a part of an insert molding apparatus according to a preferred embodiment of the present invention, in which a product with an insert is included in the molding apparatus.

List of reference numerals

10 insert

20 moulding device

30 first mold

40 mould body

41 insert hole

50 insert

51 first end

52 second end

53 mating surfaces

511 boss part

55 step surface

56 accommodating cavity

60 elastic member

Detailed Description

The present invention is further described in the following description with reference to specific embodiments and the accompanying drawings, wherein the details are set forth in order to provide a thorough understanding of the present invention, but it is apparent that the present invention can be embodied in many other forms different from those described herein, and it will be readily appreciated by those skilled in the art that the present invention can be implemented in many different forms without departing from the spirit and scope of the invention.

FIG. 1 shows a schematic view of a portion of a molding apparatus 20 according to a preferred embodiment of the present invention. The molding device 20 is suitable for producing injection-molded parts with an insert 10. In the preferred embodiment, the insert 10 is a tube-in-tube insert, i.e., the insert 10 has a central bore extending along its height. The insert 10 in the injection molded part is pre-formed. The insert 10 is of two different materials than the injection molded material, for example the insert 10 may be metal. In the manufacturing process, a pre-formed insert is placed in a molding apparatus, and then a molding material such as resin is injected so that the insert 10 is embedded in the molding material, thereby forming the insert 10 with the molding material as an integral part.

Conventionally, the insert molding apparatus 20 includes two molds capable of forming a cavity corresponding to the shape of a molded part, one of which is a movable mold and the other of which is a stationary mold. The movable mold can move between an opening position and a closing position relative to the fixed mold under the action of the driving mechanism.

Specifically, a first mold 30 of the insert molding apparatus 20 is shown in fig. 1, typically the first mold 30 is a stationary mold. The insert 10 is stably held in the first mold 30 before the molding material is injected, and specifically, the insert 10 is in contact with a cavity surface of the first mold 30 forming a part of the cavity. For simplicity of illustration, the second mold of the insert molding apparatus 20 as the movable mold and the driving apparatus of the movable mold are omitted.

According to the present invention, the first mold 30 of the insert-molding apparatus 20 includes a mold body 40 and an insert 50, the insert 50 being movable with respect to the mold body 40. An insert bore 41 is formed in the die body 40, an insert 50 is movably disposed in the insert bore 41 formed in the die body 40, and the preformed insert 10 is supported above the insert 50.

In a preferred embodiment, the insert 50 is formed as an elongated member, such as a rod or cylinder, and correspondingly, a corresponding insert hole 41 is formed in the die body 40, and the rod-shaped insert 50 is inserted into the insert hole 41 of a matching shape, so that the insert 50 can be linearly reciprocated relative to the die body 40. It should be understood that in other alternative embodiments, the insert 50 may be provided in other shapes, such as a block, with the particular shape depending on the arrangement of the mold, the configuration of the injection molded part, and the configuration of the insert.

As shown in fig. 1, two substantially identical inserts 50 are positioned side-by-side in the first mold 30 for holding the insert 10. It should be understood that the number of inserts 50 is not limited thereto and that the same number of inserts 50 may be provided depending on the actual number of inserts 10 in the injection molded article. In other alternative embodiments, the number of inserts 50 may be less than the number of inserts 10, in which case one insert may hold multiple inserts simultaneously.

Further, the insert-molding apparatus 20 further comprises a resilient member 60, the resilient member 60 being arranged to apply a force to the insert 50, allowing movement of the insert 50 relative to the mold body in a predetermined range of motion, the force being directed towards the mold cavity. The provision of the resilient member 60 enables the molding device 20 to accommodate a range of height sizes of the insert 10.

When the two molds are open, the force exerted by the resilient member 60 on the insert 50 will hold the insert 50 in the first position. When the movable mold is actuated to close relative to the stationary mold, at which time the insert 10 has been retained on the insert 50, the force exerted by the movable mold is transferred to the insert 50 by way of the insert 10, so that the insert 50 can move out of the aforementioned first position in a direction away from the mold cavity against the force of the resilient member 60. The furthest movable position of the insert 50 relative to the mold cavity is defined as the second position. In other words, the provision of the resilient member 60 enables the insert 50 to define a linear range of motion relative to the die body 40 of the first die 30 that accommodates the allowable manufacturing tolerances of the associated insert 10. Generally, for small-sized inserts 10, the movable range may be set in the range of 0.3mm to 1mm, preferably about 0.5 mm. In the preferred embodiment shown in fig. 1, the distance of movement of each insert 50 between the first and second positions defines a range of movement that is set depending on the manufacturing tolerances typically allowed for the insert 10, and in particular the allowable manufacturing tolerances of the tube-in-tube insert 10 in its height direction.

In the preferred embodiment, rod-shaped insert 50 has opposing first and second ends 51, 52. The first end 51 is the end that holds the insert 10 and the second end 52 is the end that mounts the resilient member 60. A first end 51 of the insert 50 extends into the mold cavity, while a second end 52 of the insert 50 is generally located at an open end of a mold-holding base or substrate (not shown) in the mold body 40 that forms the corresponding insert bore 41.

Corresponding to the pipe-in-pipe insert 10, the insert 10 is generally received over a boss portion 511 of the first end 51. Specifically, one annular end surface of the insert 10 in the height direction is adapted to contact an annular mating surface 53 at the first end 51 of the insert 50, while the inner surface of the central opening of the insert 10 engages the outer periphery of the boss portion 511. By providing the resilient member 60, the insert 10 and the mating surface 53 of the insert 50 remain in contact at all times during the molding process when the insert 10 is within an allowable tolerance.

According to a preferred embodiment, the second end 52 of the insert 50 is provided with a receiving cavity 56 for receiving a resilient member 60, the receiving cavity 56 being recessed inwardly from the end surface of the second end 52. The elastic member 60 is entirely buried in the accommodation chamber 56 from an opening of the accommodation chamber 56 on the end face, so that one end of the elastic member 60 abuts against the bottom of the accommodation chamber 56, and the other end of the elastic member 60 may abut against a fixed base or a base plate of a mold, for example.

For the tube-in-tube insert 10, the mating surface 53 of the first end 51 to which it is mated is formed in a circular ring shape, while the receiving cavity 56 at the second end 52 of the insert 50 is formed in a cylindrical shape, preferably with the cylindrical receiving cavity 56 being substantially centered with the circular ring-shaped mating surface 53, i.e., with the central axes of the two being substantially aligned.

On the other hand, according to a preferred embodiment of the invention, the first position of the insert 50 is defined at the stop cooperation of the outer surface of the insert 50 with the die body 40, i.e. the insert 50 is defined in the first position by the abutment of the respective stops with the die body 40 when the first die 30 is opened with respect to the second die.

Preferably, the stop of the insert 50 is an annular step surface 55 formed on the outer surface of the insert 50, the step surface 55 being formed on a surface substantially perpendicular to the axis of movement of the insert 50, and the diameter of the bore 41 of the die body 40 near the second end of the insert 50 is enlarged, forming a counterbore portion, whereby a corresponding stop surface is formed in the insert bore 41, which stop surface, when engaged with the step surface 55, the insert 50 is defined in the first position.

The second position of movement of the insert 50 is generally defined by abutment between an end surface of the second end 52 of the insert 50 and a base or baseplate located below the first mold 30, or by a stop action of the insert 50 and the mold body in a direction away from the mold cavity.

In the preferred embodiment, the resilient member 60 is a coil spring, but it should be understood that other embodiments of resilient members capable of applying force to the insert 50 to effect movement between the first and second positions are within the scope of the present disclosure.

In the preferred embodiment shown in fig. 1, two inserts 50 are provided in the first mold 30 of the insert-molding apparatus 20, the two inserts 50 correspond to the two inserts 10, respectively, and each insert 50 is provided with a separate resilient member 60. That is, the manufacturing tolerances allowed for each insert 10 are determined by the individual inserts 50 and the resilient member 60.

The use of the insert-molding apparatus 20 according to the present invention allows the insert 10 molding to be performed with a range of dimensional tolerances in the height direction of the insert 10. First, the two molds of the molding apparatus 20 are actuated to an open state in which the force exerted by the resilient member 60 on the insert 50 is capable of moving or holding the insert 50 in a first position in which the insert 50 is in a position most protruding into the mold cavity relative to the mold body 40. Next, the insert 10 is fitted over the boss portion 511 of the first end 51 of the insert 50 such that the lower surface of the insert 10 is in direct contact with the mating surface 53 of the first end 51. After all the inserts 10 have been placed, the two molds are moved relative to each other into the closed position. During closure of the two molds, the second mold above the first mold 30 will abut the upper surface of the insert 10. If the insert 10 used at this point has a height dimension greater than the lower limit of the manufacturing tolerance allowed for the insert, the mold exerts a force on the insert 10 as the mold moves relative to the mold in the closing direction, which force is transmitted to the insert 50, thereby moving the insert 50 away from the mold cavity until the two molds are fully closed.

For example, the tolerance range allowed for the pipe-in-pipe insert 10 shown in fig. 1 is 0.5mm, i.e., the difference between the maximum height dimension and the minimum height dimension allowed in the height direction of the pipe-in-pipe insert 10 is 0.5 mm. When the insert 50 in the mold body 40 is in the first position, this position is just suitable for fitting the minimum allowable height dimension of the insert 10. When the insert 10 having the minimum allowable height dimension is placed on the insert 50, the insert 50 remains substantially in the first position when the two molds are closed, with the insert 10 properly positioned in the mold cavity with the mating surface 53 of the insert 50 in contact with the lower surface of the insert 10. If the height dimension of the insert 10 for molding is greater than the minimum allowable height dimension, for example by 0.15mm, in this case, when the two molds are closed, the force acting on the insert 10 is transmitted to the insert 50, moving the insert 50 downward as viewed in fig. 1 along the insert bore 41 by 0.15mm, while the mating surface 53 of the insert 50 remains in contact with the lower surface of the insert 10 under the action of the resilient member 41.

Thus, the molding apparatus 20 according to the present invention is less critical to the dimensional requirements of the insert 10, thereby reducing the difficulty of producing the insert 10. No special mold trimming of the inserts 50 in the molding apparatus 20 is required if different batches of inserts 10 are sized differently.

In addition, the product produced by the insert molding device 20 does not generate much glue on the appearance, and the yield is high.

On the other hand, the insert molding apparatus 20 itself is simple in structure and does not increase the cost of the mold excessively.

The insert 10 is shown in fig. 1 as being a tube-in-tube type insert 10 by way of example, but it should be understood that the molding apparatus 20 according to the present invention can be adapted to other shapes of inserts 10 within the scope of the present disclosure.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the invention, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims (10)

1. An insert-molding apparatus configured for making an injection molded part having an insert, the insert-molding apparatus comprising a first mold and a second mold forming a mold cavity, wherein the first mold comprises a mold body and at least one insert disposed in the mold body, the insert having a mating surface adapted to mate with the insert,

it is characterized in that the preparation method is characterized in that,

the insert-molding apparatus further comprising a resilient member arranged to apply a force to the insert and to allow movement of the insert relative to the mold body within a predetermined range of motion,

the force exerted by the resilient member causes the insert to remain in a first position relative to the mold body when the first mold is opened relative to the second mold,

when the first and second molds are closed to form the mold cavity, the insert is movable out of the first position against the force of the resilient member when subjected to the force exerted by the second mold.

2. The insert-molding apparatus according to claim 1, wherein said insert has a first end and a second end opposite said first end, said mating surface being disposed at the first end, said resilient member being mounted at said second end.

3. The insert-molding apparatus according to claim 2, wherein the second end of the insert has a receiving cavity for receiving the resilient member, the receiving cavity being recessed inwardly from an end surface of the second end, the resilient member being disposed in the receiving cavity and abutting a bottom of the receiving cavity.

4. The insert-molding apparatus according to claim 3, wherein said receiving cavity is formed in a cylindrical shape, a fitting surface of said first end is formed in a circular ring shape,

wherein the cylindrical receiving cavity is arranged in alignment with the circular fitting surface.

5. The insert-molding apparatus according to claim 1, wherein said insert is provided with a stop defining said first position, said stop abutting said mold body when said first mold is opened relative to said second mold, thereby defining said insert in said first position.

6. The insert-molding apparatus according to claim 5, wherein the stopper of the insert is a stepped surface formed on an outer surface of the insert, the stepped surface being formed on a surface substantially perpendicular to a moving axis of the insert,

and, an insert bore in the die body in which the insert is disposed forms a respective stop face which, when engaged with the step face, the insert is defined in a first position.

7. The insert-molding apparatus according to claim 2, wherein said first end has a boss portion that projects from said mating surface and extends into said mold cavity.

8. The insert-molding apparatus according to claim 1, wherein said insert is furthest moved against said resilient force to a second position when said first mold and said second mold are closed, said first position and said second position defining said predetermined range of mobility of said insert.

9. The insert-molding apparatus according to claim 8, wherein said predetermined movable range is about 0.5 mm.

10. A molding method employing the insert molding apparatus according to any one of claims 1 to 9, the method comprising:

the insert is located in the first position under the force of the resilient member when the first and second molds are open relative to each other;

placing an insert on a first end of the insert;

closing the first and second molds, the insert capable of transferring a force from the second mold to the insert to move the insert away from the cavity against the force of the resilient member.

Images