Injection molding device and injection molding method

Abstract

To provide an injection molding device and an injection molding method capable of suppressing inclusion of foreign matter in molded products without necessarily using filter components.SOLUTION: An injection molding device comprises an injection unit, a molding unit, a connecting unit, and a measuring unit. The injection unit forms and injects a two-component liquid rubber mixture. The molding unit molds the injected two-component liquid rubber mixture within a mold cavity. The connecting unit connects the injection unit to the mold, allowing the two-component liquid rubber mixture injected from the injection unit to flow through its interior. The measuring unit transmits ultrasonic signals into the interior of the connecting unit and receives reflected signals generated by the ultrasonic signals.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an injection molding apparatus and an injection molding method. [Background technology]

[0002] Patent Document 1 discloses an injection molding apparatus. The injection molding apparatus includes an injector and a mold. The injector injects molten resin. The mold molds the injected molten resin in a cavity to produce a molded product. A filter member is provided in the resin path leading from the injector to the mold. The filter member removes foreign matter from the molten resin injected from the injector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-159446 Summary of the Invention [Problem to be solved by the invention]

[0004] If the filter member becomes clogged with foreign matter, it may be subjected to a large amount of pressure, causing it to tear. If the filter member tears, the foreign matter may get mixed into the molded product. In addition, replacing clogged or torn filter members is a time-consuming process.

[0005] In one aspect of the present disclosure, it is preferable to provide an injection molding apparatus and an injection molding method that can prevent foreign matter from being mixed into a molded product without necessarily using a filter member. [Means for solving the problem]

[0006] One aspect of the present disclosure is an injection molding apparatus including an injection unit configured to form a two-component mixed liquid rubber and inject the two-component mixed liquid rubber, a molding unit configured to mold the two-component mixed liquid rubber injected from the injection unit into a cavity of a mold, a connection unit connecting the injection unit and the mold and configured to allow the two-component mixed liquid rubber injected from the injection unit to flow therethrough, and a measurement unit provided outside the connection unit. The measurement unit is configured to transmit an ultrasonic signal into the connection unit and receive a reflected signal generated by the ultrasonic signal.

[0007] According to an injection molding apparatus that is one aspect of the present disclosure, it is possible to prevent foreign matter from being mixed into a molded product without necessarily using a filter member.

[0008] Another aspect of the present disclosure is an injection molding method that includes forming a two-component liquid rubber, injecting the two-component liquid rubber, and molding the injected two-component liquid rubber into a cavity of a mold. The injected two-component liquid rubber flows through a connecting portion and is introduced into the cavity. A measuring unit provided outside the connecting portion transmits an ultrasonic signal into the connecting portion and receives a reflected signal generated by the ultrasonic signal.

[0009] According to an injection molding method that is another aspect of the present disclosure, it is possible to prevent foreign matter from being mixed into a molded product without necessarily using a filter member. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram showing the configuration of an injection molding device. [Figure 2] FIG. 2 is an explanatory diagram illustrating the configuration and functions of a measurement unit. [Figure 3] Fig. 3A is an explanatory diagram showing a state in which the two-component mixed liquid rubber flowing inside the connection part does not contain foreign matter, and Fig. 3B is an explanatory diagram showing measurement data acquired by the measurement unit and transmitted to the determination unit in the state shown in Fig. 3A. [Figure 4]Fig. 4A is an explanatory diagram showing a state in which foreign matter is contained in the two-component mixed liquid rubber flowing inside the connection part, and Fig. 4B is an explanatory diagram showing measurement data acquired by the measurement part and transmitted to the determination part in the state shown in Fig. 4A. DETAILED DESCRIPTION OF THE INVENTION

[0011] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1. Configuration of injection molding device 1 The configuration of the injection molding apparatus 1 will be described with reference to Figures 1 and 2. As shown in Figure 1, the injection molding apparatus 1 includes an injection unit 3. The injection unit 3 is a member that forms and injects two-component mixed liquid rubber 5.

[0012] The injection unit 3 includes a main body 7, a screw 9, and an injection port 11. The main body 7 is a hollow cylindrical member. The screw 9 is housed inside the main body 7. The axial direction of the screw 9 coincides with the axial direction of the main body 7. The screw 9 is rotatable.

[0013] The inside and outside of the main body 7 are connected through the inlet 11. An A component 13A, which is the main component of the two-component mixed liquid rubber 5, and an B component 13B, which is a curing agent for the two-component mixed liquid rubber 5, can be added through the inlet 11. The added A component 13A and B component 13B enter the inside of the main body 7. The A component 13A and B component 13B are, for example, silicone polymers.

[0014] Inside the main body 7, the screw 9 rotates, causing the A component 13A and the B component 13B to mix, forming a two-component mixed liquid rubber 5. The two-component mixed liquid rubber 5 is, for example, liquid silicone rubber.

[0015] As the screw 9 rotates, the two-component mixed liquid rubber 5 flows inside the main body 7 in the flow direction F shown in Figure 1. The two-component mixed liquid rubber 5 is injected from an outlet 15 at one end of the main body 7.

[0016] The injection molding apparatus 1 includes a molding section 21. The molding section 21 includes a mold 23. The molding section 21 is a component that molds the two-component mixed liquid rubber 5 injected from the injection section 3 within the cavity of the mold 23. The component molded within the cavity of the mold 23 is primarily crosslinked. This component will be referred to below as the primarily crosslinked product. After being removed from the mold 23, the primarily crosslinked product is secondarily crosslinked to become a molded product.

[0017] An example of the molded article is an insulator described in JP 2017-60242 A. The insulator is a part of a polymer porcelain bushing. The polymer porcelain bushing is a part of a polymer joint for a power cable.

[0018] The injection molding apparatus 1 includes a connection part 31. The connection part 31 is a member that connects the injection part 3 and the mold 23. The connection part 31 is a hollow cylindrical member. The two-component mixed liquid rubber 5 injected from the injection part 3 flows inside the connection part 31 in a flow direction F and is introduced into the cavity of the mold 23. The connection part 31 is a flow path for the two-component mixed liquid rubber 5 from the injection part 3 to the mold 23.

[0019] The injection molding apparatus 1 includes a measurement unit 41. The measurement unit 41 is provided outside the connection portion 31. The measurement unit 41 is provided, for example, at a position facing the outer circumferential surface of the connection portion 31. As shown in FIG. 2, the measurement unit 41 transmits an ultrasonic signal 43 into the inside of the connection portion 31. The ultrasonic signal 43 enters the inside of the two-component mixed liquid rubber 5 flowing inside the connection portion 31.

[0020] The ultrasonic signal 43 is reflected by foreign matter 53 contained in the two-component mixed liquid rubber 5 or the inner surface of the connection portion 31, generating a reflected signal 45. In other words, the reflected signal 45 is a signal generated by the ultrasonic signal 43. The foreign matter 53 is, for example, an early reaction product generated from the component A 13A and the component B 13B. The foreign matter 53 is likely to be generated when the component A 13A and the component B 13B are poorly mixed in the injection portion 3. The foreign matter 53 has a higher viscosity than normal parts of the two-component mixed liquid rubber 5.

[0021] The measurement unit 41 receives the reflected signal 45. For example, when performing the injection molding method, the measurement unit 41 repeatedly transmits the ultrasonic signal 43 and receives the reflected signal 45 at predetermined time intervals. The transmission of the ultrasonic signal 43 and the reception of the reflected signal 45 will be referred to as measurement hereinafter. An example of the measurement unit 41 is an ultrasonic flow meter. An example of the ultrasonic flow meter is an ultrasonic Doppler flow meter.

[0022] The injection molding apparatus 1 includes a determination unit 51. The determination unit 51 includes a calculation device. The calculation device is, for example, a PC. The determination unit 51 can communicate with the measurement unit 41 via wired communication or wireless communication. The determination unit 51 acquires measurement data from the measurement unit 41. The measurement data includes the results of measurements performed by the measurement unit 41. The measurement data includes the reception results of the reflected signal 45.

[0023] The determination unit 51 stores the measurement data acquired from the measurement unit 41. Based on the measurement data, the determination unit 51 determines whether or not the two-component mixed liquid rubber 5 contains foreign matter 53. For example, the determination unit 51 notifies the determination result by image, sound, etc. The determination unit 51 also stores the determination result. The determination unit 51 also transmits the determination result to an external device, etc.

[0024] The method by which the determination unit 51 determines whether or not foreign matter 53 is contained in the two-component mixed liquid rubber 5 will be described with reference to Figures 3A, 3B, 4A, and 4B. Figure 3A shows a state in which the two-component mixed liquid rubber 5 flowing inside the connection unit 31 does not contain foreign matter 53. The ultrasonic signal 43 is reflected by the opposite surface 31A, which is on the inner surface of the connection unit 31 opposite the measurement unit 41, and generates a reflected signal 45A. The reflected signal 45A is generated when the ultrasonic signal 43 is reflected by the opposite surface 31A, out of the reflected signals 45.

[0025] Fig. 3B shows the measurement data acquired by measurement unit 41 and transmitted to determination unit 51 in the state shown in Fig. 3A. Reflected signal 45A appears in the measurement data. In the measurement data, the signal received earlier than reflected signal 45A is the signal received when ultrasonic signal 43 was transmitted. Reflected signal 45B, which will be described later, does not appear in the measurement data shown in Fig. 3A.

[0026] 4A shows a state in which a foreign object 53 is contained in the two-component mixed liquid rubber 5 flowing inside the connection part 31. A part of the ultrasonic signal 43 is reflected by the foreign object 53, generating a reflected signal 45B. The reflected signal 45B is generated when the ultrasonic signal 43 is reflected by the foreign object 53, among the reflected signals 45. In addition, a part of the ultrasonic signal 43 is reflected by the opposite surface 31A, generating a reflected signal 45A.

[0027] Fig. 4B shows the measurement data acquired by measurement unit 41 and transmitted to determination unit 51 in the state shown in Fig. 4A. Reflected signals 45A and 45B appear in the measurement data shown in Fig. 4B. Because foreign object 53 is closer to measurement unit 41 than to opposite side surface 31A, measurement unit 41 receives reflected signal 45B earlier than it receives reflected signal 45A.

[0028] The determination unit 51 determines whether or not the reflected signal 45B appears in the measurement data. For example, the determination unit 51 determines whether or not the reflected signal 45B appears in the measurement data by comparing the measurement data with a reference. The reference is, for example, measurement data when there is no foreign matter 53 in the two-component mixed liquid rubber 5, and is stored in advance by the determination unit 51. The reference has, for example, a waveform similar to the measurement data shown in FIG. 3B.

[0029] If it is determined that the reflected signal 45B appears in the measurement data, the determination unit 51 determines that the two-component mixed liquid rubber 5 contains a foreign matter 53. If it is determined that the reflected signal 45B does not appear in the measurement data, the determination unit 51 determines that the two-component mixed liquid rubber 5 does not contain a foreign matter 53.

[0030] 2. Injection molding method performed using injection molding apparatus 1 (2-1) Basic structure of injection molding method The basic configuration of the injection molding method is as follows: Part A 13A and part B 13B are charged into charging port 11. Inside main body 7, part A 13A and part B 13B are mixed by rotation of screw 9, and two-part mixed liquid rubber 5 is formed.

[0031] As the screw 9 rotates, the two-component mixed liquid rubber 5 flows in the flow direction F shown in FIG. 1 inside the main body 7. The two-component mixed liquid rubber 5 is injected from the outlet 15 of the main body 7.

[0032] The two-component mixed liquid rubber 5 injected from the outlet 15 flows inside the connecting portion 31 and is introduced into the cavity of the mold 23. In the cavity of the mold 23, the two-component mixed liquid rubber 5 is molded.

[0033] (2-2) Configuration for measuring and determining foreign matter 53 The injection molding method is configured as follows regarding the measurement and determination of foreign matter 53. When the injection molding method is performed, measurement is performed by measurement unit 41 to obtain measurement data. For example, the measurement is performed repeatedly at predetermined time intervals.

[0034] The measurement unit 41 transmits the measurement data to the determination unit 51. For example, the measurement unit 41 repeatedly transmits the measurement data at predetermined time intervals. The determination unit 51 determines whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 based on the measurement data acquired from the measurement unit 41.

[0035] For example, the determination unit 51 repeatedly determines whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 at predetermined time intervals. For example, the determination unit 51 determines whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 every time measurement data is acquired. For example, the determination unit 51 notifies the determination result by image, sound, etc. The determination unit 51 also stores the determination result. The determination unit 51 also transmits the determination result to an external device, etc.

[0036] When the determining unit 51 determines that the two-component mixed liquid rubber 5 contains foreign matter 53, for example, the following processes (a) to (d) can be performed. These processes may be performed automatically by a device or by an operator.

[0037] (a) Discontinue the practice of injection molding methods. (b) Emptying operation is performed. The emptying operation is performed to prevent the two-component mixed liquid rubber 5 injected by the injection unit 3 from being introduced into the cavity of the mold 23.

[0038] In the emptying operation, for example, the two-component mixed liquid rubber 5 flowing through the connection part 31 can be branched in a direction different from the mold 23. Also, in the emptying operation, for example, the connection part 31 can be separated from the mold 23.

[0039] (c) During the emptying operation, the two-component mixed liquid rubber 5 injected by the injection unit 3 is repeatedly measured by the measurement unit 41 and judged by the judgment unit 51 at predetermined intervals. If the judgment unit 51 judges that the two-component mixed liquid rubber 5 contains foreign matter 53, the emptying operation is continued. If it is judged that the two-component mixed liquid rubber 5 does not contain foreign matter 53, the emptying operation is terminated and the injection molding method is resumed.

[0040] (d) The molded product manufactured immediately after the injection molding process is restarted is inspected for the presence of foreign matter 53. As a reference, the molded product manufactured before the injection molding process was stopped is also inspected for the presence of foreign matter 53.

[0041] Although the foreign matter 53 after cross-linking is made of the same rubber as its surroundings, it has a different shrinkage rate than its surroundings. Therefore, by imaging the internal strain using terahertz light, it is possible to inspect whether or not the foreign matter 53 is present inside the molded product.

[0042] 3. Effects of the injection molding apparatus 1 and the injection molding method (1A) By using the injection molding apparatus 1 and the injection molding method, it is possible to detect the presence of foreign matter 53 in the two-component mixed liquid rubber 5 flowing inside the connection part 31. When it is detected that foreign matter 53 is present in the two-component mixed liquid rubber 5 flowing inside the connection part 31, it is possible to stop the injection molding method. As a result, it is possible to prevent foreign matter 53 from being mixed into the molded product even if a filter member is not necessarily provided in the connection part 31.

[0043] (1B) According to the injection molding apparatus 1 and the injection molding method, the determination unit 51 can be used to determine whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 based on the reflected signal 45 received by the measurement unit 41. This makes it possible to more accurately determine whether or not the two-component mixed liquid rubber 5 contains foreign matter 53. Furthermore, since the determination work does not have to be performed by an operator, the labor of the operator can be reduced.

[0044] (1C) The injection molding device 1 can learn data such as the temperature conditions in the injection molding device 1, the pressure conditions in the injection molding device 1, the flow rate of the two-component mixed liquid rubber 5, and the generation cycle of foreign matter 53, and feed it back into the molding conditions.

[0045] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0046] (1) The injection molding apparatus 1 does not need to include the determination unit 51. In this case, for example, an operator can determine whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 based on the measurement data of the measurement unit 41. Also, for example, a computing device external to the injection molding apparatus 1 can determine whether or not the two-component mixed liquid rubber 5 contains foreign matter 53 based on the measurement data of the measurement unit 41.

[0047] (2) The determination unit 51 and the method described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the determination unit 51 and the method described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the determination unit 51 and the method described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer. The method for implementing the functions of each unit included in the determination unit 51 does not necessarily need to include software; all of the functions may be implemented using one or more hardware devices.

[0048] (3) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0049] (4) In addition to the injection molding apparatus 1 described above, the present disclosure can also be realized in various forms, such as a system including the injection molding apparatus 1 as a component, a program for causing a computer to function as the judgment unit 51, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a method for detecting foreign matter. [Explanation of symbols]

[0050] 1... injection molding apparatus, 3... injection section, 5... two-component mixed liquid rubber, 7... main body section, 9... screw, 11... inlet, 13A... agent A, 13B... agent B, 15... outlet, 21... molding section, 23... mold, 31... connection section, 41... measurement section, 43... ultrasonic signal, 45... reflection signal, 51... judgment section, 53... foreign matter

Claims

1. an injection unit configured to form a two-component mixed liquid rubber and inject the two-component mixed liquid rubber; a molding section configured to mold the two-component mixed liquid rubber injected from the injection section into a cavity of a mold; a connecting portion configured to connect the injection portion and the mold and to allow the two-component mixed liquid rubber injected from the injection portion to flow therethrough; a measuring unit provided outside the connection unit; Equipped with The measurement unit is configured to transmit an ultrasonic signal to the inside of the connection portion and receive a reflected signal generated by the ultrasonic signal. Injection molding equipment.

2. 2. The injection molding apparatus according to claim 1, The measuring unit further includes a determining unit configured to determine whether or not the two-component mixed liquid rubber contains foreign matter based on the reflected signal received by the measuring unit. Injection molding equipment.

3. Form a two-component mixed liquid rubber, The two-component mixed liquid rubber is injected, The injected two-component mixed liquid rubber is molded in a cavity of a mold.

1. An injection molding method comprising: The injected two-component mixed liquid rubber flows through the inside of the connecting portion and is introduced into the cavity, a measuring unit provided outside the connection portion transmits an ultrasonic signal to the inside of the connection portion and receives a reflected signal generated by the ultrasonic signal; Injection molding method.

4. 4. The injection molding method according to claim 3, and determining whether or not the two-component mixed liquid rubber contains foreign matter based on the reflected signal received by the measuring unit. Injection molding method.

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