WO2020082997A1

WO2020082997A1 - Mold for injection molding and injection molding method

Info

Publication number: WO2020082997A1
Application number: PCT/CN2019/108992
Authority: WO
Inventors: 伦英军; 梁贺; 王建新; 李振军
Original assignee: 歌尔股份有限公司
Priority date: 2018-10-25
Filing date: 2019-09-29
Publication date: 2020-04-30
Also published as: CN109571870A; CN109571870B

Abstract

A mold for injection molding and an injection molding method. The mold for injection molding comprises: a mold body (10) and at least one vibration apparatus (20), the vibration apparatus (20) being arranged inside the mold body (10). The mold body (10) is provided with a mold cavity, a placement position being formed inside the mold cavity, the placement position being used to bear an insert (40). The vibration apparatus (20) is provided with a head end, the head end being arranged so as to face the insert (40), and when the vibration apparatus (20) generates a vibration, the head end is arranged so as to be able to drive the insert (40) to vibrate. One technical effect of the present invention is to reduce cracks between the insert (40) and a surface of an injection-molded casing (50) caused by internal stress, thus improving product quality.

Description

Injection molding mold and injection method

Technical field

The present invention relates to the field of injection molding technology, and more specifically, to an injection molding mold and an injection molding method. Background technique

Plastic is a synthetic polymer compound, which is widely used in various industries such as electronics, automobiles, and medical treatment due to its excellent performance and easy processing. In order to make injection molded products have a good appearance, and at the same time have both practicality and structural strength, insert injection molding is usually used.

Insert injection molding utilizes the plastic's easy formability, heat resistance, and insert conductivity or mechanical properties to create an integrated product. Due to the advantages of low cost and unlimited types of insert materials, insert injection molding is widely used.

Generally, the injection molding process includes three stages of filling, holding pressure and cooling. The cooling process has an important impact on the production efficiency of injection molding molds and the quality of plastic parts. Existing injection molding molds In the injection molding process, insert the pre-prepared insert into the mold of the injection molding machine and inject resin, and the molten material joins and solidifies with the insert to make an integrated product. However, in the injection molding mold, due to the difference in shrinkage between the insert and the plastic product, it is easy to cause residual stress in the plastic product after hot melting, resulting in micro cracks between the solidified plastic and the insert, affecting the entire insert The sealing effect of the product.

Therefore, it is necessary to propose a new type of injection molding mold to overcome the above-mentioned defects. Summary of the invention

An object of the present invention is to provide a new technical solution for an injection molding mold and an injection molding method.

According to a first aspect of the present invention, there is provided an injection molding mold, the mold including: a mold body and at least one vibration device, the vibration device being disposed in the mold body;

The mold body has a cavity, and a placement position is formed in the cavity, the placement position is used for Bearing inserts;

The vibration device has a head end configured to face the insert, and when the vibration device generates vibration, the head end is configured to drive the insert to vibrate.

Optionally, the vibration device includes: a generator and a vibration rod, the vibration rod is located at a head end of the vibration device, and the generator is configured to drive the vibration rod to vibrate.

Optionally, the vibration device is provided with a cooling tube, and the cooling tube includes: an input cooling tube and an output cooling tube, and the input cooling tube and the output cooling tube are respectively connected to an external cooling device and constitute cooling Loop.

Optionally, an elastic member is provided at the tail end of the vibration device, and the elastic member is configured to adjust the position of the vibration device in the mold body.

Optionally, the mold body includes: an assembling plate, a first mounting plate, and a second mounting plate; the assembling plate is in contact with an elastic member at the tail end of the vibration device, and the first mounting plate and the second Mounting plates are connected in sequence below the mounting plate, and the vibration device is vertically arranged inside the first mounting plate and the second mounting plate;

A groove is provided on the connecting surface of the first mounting plate and the second mounting plate, and the cooling tube passes through the groove.

Optionally, the shape of the front end surface of the vibrating rod matches the shape of the surface of the insert.

Optionally, the generator is an ultrasonic transducer.

Optionally, the elastic member is a disc spring.

According to a second aspect of the present invention, there is provided an injection molding method, the method comprising: providing an injection molding mold;

Set up inserts in the injection mold;

Inject plastic into the cavity of the injection mold and apply vibration to the insert;

After the plastic cools and solidifies to form an injection molded part.

Optionally, a vibration device is provided in the injection molding mold, and the vibration device is configured to apply vibration to the insert.

Optionally, the frequency of applying vibration to the insert is 10KHZ-100KHZ.

Optionally, the vibration device is configured to adjust the position.

Optionally, the vibration device forms a contact point with the insert, and the area of the contact point accounts for 10% -50% of the surface area of the insert.

Optionally, the contact point is located at the center of the surface of the insert.

A technical effect of the present invention is that, by providing a vibration device in the injection molding mold, the vibration device is in contact with the insert, and under the action of high-frequency vibration, the shrinkage of the insert and the plastic material shell can be reduced due to the difference Internal stress to avoid micro-cracks between the injection molded shell and the insert, improving the quality of the entire insert product.

Other features and advantages of the present invention will become clear by the following detailed description of exemplary embodiments of the present invention with reference to the drawings. BRIEF DESCRIPTION

The drawings incorporated in and forming a part of the specification illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

1 is a cross-sectional view of an injection molding mold provided by a specific embodiment of the present invention;

Figure 2 is a partial enlarged view of Figure 1;

3 is a top view of an injection molding mold provided by a specific embodiment of the present invention;

Figure 4 is a partial enlarged view of Figure 3;

5 is a schematic structural diagram of a vibration device provided by a specific embodiment of the present invention;

6 is another schematic structural diagram of a vibration device provided by a specific embodiment of the present invention. detailed description

Various exemplary embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is actually merely illustrative, and is in no way intended to limit the present invention and its applications or uses.

Techniques, methods and equipment known to those of ordinary skill in the related art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the description.

In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiment may have different Value.

It should be noted that similar reference numerals and letters indicate similar items in the following figures, so once an item is defined in one figure, there is no need to discuss it further in subsequent figures.

1 shows a cross-sectional view of an injection molding mold provided by a specific embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, showing a schematic diagram of a vibration device and an injection insert cooperating in an injection molding mold, FIG. FIG. 4 is a partial enlarged view of FIG. 3, showing the positional relationship between the insert and the injection housing, and FIG. 5 shows the vibration provided by the specific embodiment of the present invention. A schematic structural diagram of the device. FIG. 6 shows another schematic structural diagram of a vibration device provided by a specific embodiment of the present invention. Taking FIGS. 1 to 6 as examples, the structure and principle of the injection molding mold of the present invention will be described in detail.

The present invention provides an injection molding mold, which includes a mold body 10 and at least one vibration device 20. Among them, the mold body is provided with a pouring system, a molding system, etc., which can realize the complete injection molding process such as filling, holding pressure, cooling, demoulding and so on. This injection mold is suitable for double-plate, three-plate and other structures. Since the number of cavities in the injection molding mold may be one or more, in the injection molding mold provided in this embodiment, the vibration device is provided in the body of the injection molding mold. According to the number of cavities, multiple vibration devices can be installed to improve production efficiency and reduce the cost of injection molding.

The mold body of the injection molding mold has a cavity, and a placement position is formed in the cavity, and the placement position is used to carry an insert. The insert is a part that is placed in the cavity before injection molding. The material of the insert is different from that of the injection molded plastic. It is usually a steel plate or a copper nut. In particular, the vibration device 20 has a head end configured to face the surface of the insert 40. When the vibration device generates vibration, the head end is configured to drive the insert to vibrate. It can be understood that the vibrating device makes a telescopic movement in the mold body, regularly contacts the surface of the insert, and transmits the vibration to the insert.

It should be particularly noted that in this embodiment, the "head end" and "tail end" refer to the vertical position of the mold body as a reference, where "head end" refers to the end of the vibration device near the cavity, " "Tail end" refers to the end of the vibration device near the top of the mold body.

The vibration device in the injection molding mold provided by this embodiment can be applied to the injection molding process Any stage or whole process. As shown in FIGS. 3 and 4, by providing a vibration device in the injection molding mold, the vibration device 20 is in contact with the insert 40. Under the action of high-frequency vibration, the shrinkage rate of the insert 40 and the injection housing 50 can be reduced due to the difference The internal stress is formed to improve the coupling effect of the insert 40 and the injection housing 50, to avoid the occurrence of micro cracks between the injection housing and the insert, and to improve the quality of the entire insert product.

Optionally, the vibration device 20 includes: a generator 21 and a vibration rod 22. The generator 21 is a device for converting the input electric power into mechanical power, and the vibrating rod 22 is connected to the sound generating device 20, and the sound generating device is used to drive the vibrating rod to vibrate. As shown in FIGS. 1 and 2, the vibrating rod 22 is located at the head end of the vibrating device 20, and the generator 21 can transmit mechanical power to the vibrating rod 22, and the vibrating rod performs vertical telescopic movement, that is, Energy can be gathered and released on the insert.

In this way, the technician can adjust the amplitude, frequency, etc. of the vibration device as needed. This embodiment does not require the type and type of the vibration device. For example, it may be an electromagnetic vibrator, a pneumatic vibrator, an ultrasonic focusing transducer, and so on. Correspondingly, for the types of generators and vibrating rods, different combinations can be selected according to needs.

In the injection molding mold provided by this embodiment, the vibration efficiency is improved by the cooperation of the generator and the vibrating rod. Extend the life and conversion efficiency of the generator. The vibrating rod can output mechanical vibration of different frequencies and different amplitudes under the configuration of the generator, and concentrate energy on the insert to cooperate with the injection molding mold to eliminate the internal stress of the insert during the injection process to improve the quality of the injection part .

In a possible implementation manner, the generator is an ultrasonic transducer. Ultrasonic transducer is a device that can convert high-frequency electrical energy into mechanical energy, which can be combined with a vibrating rod to form a vibrating device. Preferably, the vibrating rod is a horn. Usually, the cross section of the horn is small, that is, the area of contact with the surface of the insert is small, and the ability can be concentrated on a small area to realize the function of energy transmission and energy gathering.

The ultrasonic transducer can generate regular vibration under the excitation of the power supply, and the amplitude of the vibration input by the ultrasonic transducer can be changed after being transmitted through the horn. As shown in FIG. 2, the front end face of the horn faces the surface of the insert, and is in interference fit with the surface of the insert. In this way, under the action of the ultrasonic transducer, the horn transmits ultrasonic vibration to the insert within a certain amplitude to reduce the internal stress generated when the insert is combined with plastic. Compared with other vibration devices, there is a vibration device composed of an ultrasonic transducer and a horn, which improves the quality of injection molded parts better. On the one hand, the ultrasonic transducer provides more accurate amplitude and better energy gathering effect, which can achieve more precise control of the surface vibration of the insert; on the other hand, the ultrasonic transducer has high efficiency and low loss, and the horn can be It can effectively output from the ultrasonic transducer to the surface of the insert.

Further, the shape of the front end surface of the vibrating rod 22 matches the shape of the surface of the insert 40. It can be understood by those skilled in the art that there are many types of inserts, and the shape of the surface is not limited to a flat surface, but also has an arc surface or a cylindrical surface. Since the front end surface of the vibrating rod 22 faces the surface of the insert 40, and transmits vibration to the surface of the insert. Therefore, in the injection molding mold provided by the present application, the shape of the front end surface of the vibrating rod matches the shape of the surface of the insert. When the vibrating rod expands and contracts, the contact between the front end surface of the vibrating rod and the surface of the insert is more stable, which helps to release the energy collected on the vibrating rod to the surface of the insert evenly, so as to reduce defects such as vibration or uneven stress.

As shown in FIGS. 1 and 2, the vibrating rod 22 is located at the head end of the vibrating device 20, and the vibrating rod 22 faces the surface of the insert 40 and interferes with the surface of the insert. In this embodiment, the range of the interference pressure is 0.05mpa-0. 2mpa. In a vibration device composed of an acoustic wave transducer and a horn, the horn can change the amplitude within a certain range to adjust the intensity of vibration. Experiments have shown that the range of interference pressure is within 0.05mpa-0. 2mpa, which can achieve better results.

In particular, as shown in FIG. 2, the head end of the vibrating rod 22 faces the center of the surface of the insert 40. In this way, vibration can be evenly transmitted from the center of the surface of the insert to the surroundings, to avoid problems such as polarization and resonance, and to ensure that the insert does not deviate from a predetermined position or angle.

Correspondingly, an elastic member 30 is provided at the tail end of the vibration device 20, and the elastic member 30 is in contact with the mold body 20. Due to the retractable characteristics of the elastic member, it can be used to adjust or control the position of the vibration device in the mold body, that is, to adjust the assembly gap or pressure between the vibration device and the surface of the insert to achieve a better vibration effect.

Further, the mold body 10 includes an assembly board 12, a first mounting board 13, and a second mounting board 14. As shown in FIG. 1, the assembling plate 12 is located on the top of the mold body 10, and the elastic member 30 at the tail end of the vibration device 20 is in contact with the assembling plate 12. Below the assembling plate 12, a first mounting plate 13 and a second mounting plate 14 are also provided in this order. The first mounting plate and the second mounting plate can be connected by means commonly used in the art to facilitate disassembly and installation. On the first mounting plate and the second mounting plate Inside, a space for accommodating a vibration device is formed, and the vibration device is vertically provided inside the first mounting plate and the second mounting plate.

Optionally, the vibration device 20 is further provided with a cooling tube 23. As shown in FIGS. 5 and 6, the cooling pipe 23 includes: an input cooling pipe and an output cooling pipe. The cooling tube 23 is disposed in the vibrating device 20, and the generator 21 is close to an end of the vibrating rod 22. Wherein, a groove (not shown in the figure) is provided on the connecting surface of the first mounting plate 13 and the second mounting plate 14, and the cooling tube may pass through the groove. Obviously, the cooperation of the first mounting plate and the second mounting plate facilitates the assembly of the vibrating device, and at the same time, the groove provided on the connection surface of the first mounting plate and the second mounting plate provides a convenient accommodation space for the installed cooling pipe .

In addition, cooling liquid or cooling gas is injected into the input cooling pipe and the output cooling pipe. The cooling pipe is connected to an external cooling device and forms a cooling circuit. In this way, the temperature of the injection molding mold can be effectively reduced, the working unit is cooled, and the stable operation of the vibration device is ensured.

Optionally, the elastic member is a disc spring. As shown in FIGS. 5 and 6, a groove for accommodating the elastic member is formed at the tail end of the vibration device, in the injection molding mold, the elastic member is disposed in the groove, and the other end of the elastic member is connected to the mold body The assembly plate on the abutment can change the position of the vibration device in the mold body by adjusting the disc spring, and adjust the assembly gap or pressure between the vibration device and the surface of the insert to achieve a higher vibration effect.

In another aspect of this embodiment, an injection molding method is also provided. The method is applied to the above-mentioned injection molding mold. The method includes: providing an injection molding mold, setting an insert in the injection molding mold, and the insert is located at a specified position in a cavity of the injection molding mold. Next, plastic is injected into the cavity of the injection mold, and at the same time, vibration is applied to the insert. Or, first inject plastic into the cavity, and apply vibration to the insert at any stage of cooling or holding pressure. After the plastic cools and solidifies, an injection molded part is formed. The injection molding method provided in this embodiment can start the vibration device at any time during injection molding, and the injection molding method provided in this embodiment is not limited thereto.

Optionally, a vibration device is provided in the injection molding mold, and the vibration device may be an electromagnetic vibrator, a pneumatic vibrator, an ultrasonic energy-concentrating transducer, etc. In this embodiment, the type and type of the vibration device are not required. The vibration device is configured to apply vibration to the insert to reduce the internal stress caused by the difference in shrinkage between the insert and the injection molded housing.

Optionally, the frequency of applying vibration to the insert is 10KHZ-100KHZ. Due to the effect of vibration The result is related to the power and wavelength of vibration. Preferably, the frequency of vibration at 25KHZ can achieve high vibration efficiency and vibration effect, so as to avoid cracks at the connection between the injection housing 50 and the insert 40 during injection molding, thereby improving the quality of the injection product.

In addition, the vibration device is configured to be able to adjust the position. In this way, the gap between the vibration device and the surface of the insert or the pressure of the interference fit can be better adjusted to strengthen the combination of the insert and the injection-molded housing.

Further, the vibrating means and the insert member forming a contact point, the contact point area accounts for 10% -50% _o preferably the surface area of the insert member, the contact area of the point representing the surface area of the insert 20%, the effect of energy transmission and energy gathering is better.

In addition, the contact point is located in the center of the surface of the insert. For example, in an insert with a round surface, the center of the circle is the center of the surface of the insert. The head end of the vibrating device faces the center of the circle, and energy can be evenly transmitted around the insert to avoid problems such as polarization.

Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the invention is defined by the appended claims.

Claims

1. An injection molding mold, comprising: a mold body and at least one vibration device, the vibration device being disposed in the mold body;

The mold body has a cavity, and a placement position is formed in the cavity, and the placement position is used to carry an insert;

2. The mold according to claim 1, wherein the vibration device comprises: a generator and a vibration rod, the vibration rod is located at a head end of the vibration device, and the generator is configured to drive the The vibrating rod vibrates.

3. The mold according to claim 1, wherein the vibration device is provided with a cooling pipe, the cooling pipe comprising: an input cooling pipe and an output cooling pipe, the input cooling pipe and the output cooling pipe They are connected to external cooling devices and form a cooling circuit.

The mold according to claim 1, wherein an elastic member is provided at a tail end of the vibration device, and the elastic member is configured to adjust a position of the vibration device in the mold body.

5. The mold according to claim 4, wherein the mold body includes: an assembly plate, a first mounting plate, and a second mounting plate;

The mounting plate is in contact with the elastic member at the tail end of the vibration device, the first mounting plate and the second mounting plate are sequentially connected below the mounting plate, and the vibration device is vertically disposed Inside the first mounting plate and the second mounting plate;

6. The mold according to claim 2, wherein the shape of the front end surface of the vibrating rod matches the shape of the surface of the insert.

7. The mold according to claim 2, wherein the generator is an ultrasonic transducer.

8. The mold according to any one of claims 4-7, wherein the elastic member is a dish Yellow.

9. An injection molding method, characterized in that the method includes:

Provide injection moulds;

Set up inserts in the injection mold;

After the plastic cools and solidifies to form an injection molded part.

10. The method according to claim 9, wherein a vibration device is provided in the injection molding mold, and the vibration device is configured to apply vibration to the insert.

1 1. The method according to claim 9, characterized in that the frequency of applying vibration to the insert is 10KHZ-100KHZ.

12. The method of claim 10, wherein the vibration device is configured to be position adjustable.

13. The method according to claim 9, wherein said vibrating means is formed with a contact point of the insert, the contact area of the point of insert surface area accounted for 10% -50% _o

14. The method of claim 13, wherein the contact point is located at the center of the surface of the insert.