Manufacturing method for operating parts

Abstract

To provide a method for manufacturing an operating component and an operating component that can satisfactorily manufacture a molded article in which a hard part is provided on a flexible silicon rubber.SOLUTION: A manufacturing method of an operating component includes a first molding step of molding a flexible elastic member that has a concave gap and can be elastically deformed by pressing force applied to a push button of an electronic device, and a second molding step of filling the gap for molding with a resin that is harder than the elastic material. The operating component includes a flexible elastic part that can be elastically deformed by pressing force applied to a push button of the electronic device, and a hard part that is harder than the elastic part and is molded by filling the elastic part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a method for manufacturing an operation component and an operation component. [Background Art]

[0002] Switches of various structures are used in electronic devices (see, for example, Patent Documents 1 to 3). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2012-028175 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2014-007027 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2014-135179 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] As a method for manufacturing an operation component used in an electronic device such as a mobile terminal, there is, for example, a method of molding silicone rubber after inserting an insert component into a mold in order to locally impart rigidity to flexible silicone rubber. However, according to this manufacturing method, the insertion of the insert component causes portions of the silicone rubber to have a thickness thinner than designed, and there is a risk that the silicone rubber may tear at these thin portions.

[0005] One aspect of the disclosed technology aims to provide a method for manufacturing an operation component and an operation component that enable favorable manufacturing of a molded product having rigid portions provided in flexible silicone rubber. [Means for Solving the Problems]

[0006] One aspect of the disclosed technology is exemplified by the following method for manufacturing an operation component. A first molding step involves forming a flexible elastic member that has a concave gap and is elastically deformable by the pressing force applied to a push button of an electronic device, The process includes a second molding step in which a resin with higher hardness than the elastic member is filled and molded into the gap. A method for manufacturing operating parts. [Effects of the Invention]

[0007] According to the disclosed technology, it is possible to successfully manufacture molded products in which a rigid portion is provided on a flexible silicone rubber. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 illustrates a method for manufacturing an operating component according to an embodiment. [Figure 2] Figure 2 is the first diagram showing the operating components as they are attached to an electronic device. [Figure 3] Figure 3 is a second diagram showing the operating components as they are attached to an electronic device. [Figure 4] Figure 4 is a schematic cross-sectional view of a part of an electronic device to which the operating components according to the comparative example are attached. [Figure 5] Figure 5 shows the operating parts related to the comparative example. [Figure 6] Figure 6 is a schematic cross-sectional view of a part of an electronic device with operating components related to another comparative example attached. [Figure 7] Figure 7 illustrates a method for manufacturing an operating component according to a modified example. [Figure 8] Figure 8 is a diagram that provides supplementary explanation of the functions of the operating components. [Modes for carrying out the invention]

[0009] <Embodiment> The configurations of the embodiments shown below are illustrative, and the disclosed technology is not limited to the configurations of the embodiments. Figure 1 is a diagram illustrating a method for manufacturing an operating part according to an embodiment. Below, the method for manufacturing the operating part 1 according to an embodiment will be described based on Figure 1. The operating part 1 shown in Figure 1(F) is a part manufactured by the said manufacturing method. Here, we will first describe the operating part 1. The operating part 1 is composed of a silicone rubber 11 (an example of an "elastic part" as referred to in this application) and a hard resin 12 (an example of a "hard part" as referred to in this application).

[0010] The silicone rubber 11 is flexible and can be elastically deformed by pressure, etc. The silicone rubber 11 is insulating and waterproof. On the other hand, the hard resin 12 is harder than the silicone rubber 11. The hard resin 12 is integrally molded with the silicone rubber 11, thereby providing rigidity to appropriate parts of the flexible silicone rubber 11. The hard resin 12 is conductive. The operating part 1 is used as a component in electronic equipment.

[0011] The following describes the manufacturing method of the operating part 1, which is molded using various molds, with reference to Figure 1. The various molds shown in Figure 1 can, of course, be separated into two or more parts at appropriate points, and the molded product inside the mold can be removed from the mold. Figure 1(A) shows the mold 2 for the silicone rubber 11 (an example of the "second mold" in this application) used to first mold the silicone rubber 11 (an example of the "elastic member" in this application).

[0012] The white area shown in Figure 1(A) represents the internal space of the mold 3, which is shaped to fit the silicone rubber 11 to be molded. The mold 3 has a first gap molding section 31 and a second gap molding section 32 that connects the two first gap molding sections 31. When molding the silicone rubber 11, a raw material such as a liquid monomer (e.g., liquid rubber) is poured into the mold 3, which is shaped to fit the silicone rubber 11 to be molded, and hardened by cooling or other means.

[0013] FIG. 1(B) shows a silicon rubber 11 in a state molded in the mold frame 3 of the mold 2. Such a molding method is referred to as injection molding, and a large amount of silicon rubber 11 can be molded in a short time. This molding step using the mold 2 is an example of the "first molding step" referred to in the present application.

[0014] FIG. 1(C) shows the molded silicon rubber 11 taken out from the mold 2. The molded silicon rubber 11 has leg portions 111 at both ends. Each leg portion 111 has a concave gap portion. Further, the molded silicon rubber 11 also has concave gap portions on both surfaces of a connection portion 112 located inside the leg portions 111 at both ends. In the silicon rubber 11 having such a shape, as shown in FIG. 1(A), the leg portions 111 are molded by curing the raw material poured into a first gap molding portion 31, and the connection portion 112 is molded by curing the raw material poured into a second gap molding portion 32.

[0015] FIG. 1(D) shows a state where the silicon rubber 11 is placed in the mold frame 30 of a mold 20 (which is an example of the "first mold" referred to in the present application). The mold frame 30 of the mold 20 has basically the same shape as the mold frame 3 of the mold 2, but differs from the mold frame 3 in that a first filling portion 301 and a second filling portion 302 are formed therein. That is, when the silicon rubber 11 molded using the mold 2 is set in the mold frame 30 of the mold 20, the first filling portion 301 and the second filling portion 302 are formed in the mold frame 30 as space portions generated in gaps between the silicon rubber 11 and the mold frame 30. formed. This step of setting the silicon rubber 11 in the mold frame 30 of the mold 20 is an example of the "arrangement step" referred to in the present application.

[0016] (E) of FIG. 1 shows a silicone rubber 11 in a state where a hard resin is filled and molded into a first filling portion 301 and a second filling portion 302 in a mold frame 30 of a mold 20. After setting the silicone rubber 11 in the mold frame 30 of the mold 20, the first filling portion 301 and the second filling portion 302 are filled with a liquid raw material of a resin that becomes harder than the silicone rubber 11 when cured. Then, the liquid raw material is solidified by allowing a predetermined time to elapse or by irradiating light. As a result, in the mold frame 30 of the mold 20, a molded product obtained by filling and molding the hard resin 12 in the concave portion of the silicone rubber 11 is formed. This molding step using the mold 20 is an example of the "second molding step" referred to in the present application.

[0017] (F) of FIG. 1 shows the operation component 1. By filling and molding the hard resin 12 in the concave portion of the silicone rubber 11 within the mold frame 30 of the mold 20, the molding of the operation component 1 in which the silicone rubber 11 and the hard resin 12 are integrated is completed. In the operation component 1, which is the final molded product, the hard resin 12 is filled and molded into the concave gap portions provided in the leg portions 111 and the connecting portion 112 of the silicone rubber 11.

[0018] By manufacturing the operation component 1 through the above series of manufacturing steps, it is easier to mold the silicone rubber 11 into the designed shape compared to the case where the silicone rubber 11 is molded so as to be in close contact with the hard resin 12 after the hard resin 12 is molded first. This is because molding the silicone rubber 11 using a mold 2 in advance makes it difficult for errors to occur in the dimensions related to the shape of the silicone rubber 11. If the thickness of the silicone rubber 11 is properly molded as designed, it is possible to prevent the silicone rubber 11 from breaking when a pressing force is applied to the operation component 1 in a state where the operation component 1 is used in an electronic device.

[0019] Figure 2 is a first diagram showing the operating component 1 attached to an electronic device. Figure 3 is a second diagram showing the operating component 1 attached to an electronic device. Examples of electronic devices in which the operating component 1 is used include mobile terminals and television remote controllers. Such electronic devices are equipped with various push buttons. The operating component 1 can be used as a component of such push buttons. That is, for example, as shown in the cross section X-X of Figure 2, the operating component 1 is arranged so that the hard resin 12 is in contact with the switch element 4 on the substrate 7. Although the silicone rubber 11 is flexible, the outer circumference portion, which is the leg portion 111, is filled and molded with hard resin 12, so the operating component 1 can be fitted into the mounting part of the electronic device.

[0020] When the operating component 1 is used for the push button of an electronic device, the hard resin 12, which has high hardness, comes into contact with the switch element 4, thereby improving the feel when pressing the push button. In addition, the elastic deformation and flexibility of the silicone rubber 11 prevent it from hindering the pressing force when operating the push button, and as mentioned above, the silicone rubber 11 is also resistant to tearing. Furthermore, since the silicone rubber 11 is waterproof, it can prevent water from entering the switch element 4, for example, if it gets wet or if the operating component 1 is touched with wet hands.

[0021] Figure 4 is a schematic cross-sectional view of a part of an electronic device to which the operating component 1a of the comparative example is attached. The electronic device of the comparative example is, for example, a smartphone, and in detail, Figure 4 is an enlarged view of the area around the mechanical switch of the smartphone. The operating component 1a is attached by fitting it into a mounting hole provided in the housing frame 41a of the electronic device. When the push button 5a exposed on the exterior surface of the electronic device is pressed, the operating component 1a transmits the pressing force to the switch element 4a mounted on the circuit board inside the electronic device.

[0022] Figure 5 shows an operating part 1a related to a comparative example. The operating part 1a related to the comparative example is manufactured by molding silicone rubber 11a with an insert part made of hard resin 12a set in a mold. In this comparative example, the insert part may be made of a material other than resin, and therefore the part molded integrally with the silicone rubber 11a is not limited to hard resin 12a. In this manufacturing method, the insert part may shift position within the mold, so the thickness of the silicone rubber 11a may be thinner than designed at locations such as the thickness T1 shown in Figure 5. Also, in order to hold the insert part within the mold, the insert part needs to have a certain thickness at locations such as the thickness T2 shown in Figure 5. When a pressing force is applied to the connecting part 112a, a load is applied to the part with thickness T1 due to the relative displacement between the leg part 111a, which is fitted into a hole in the housing frame 41a, and the connecting part 112a. Therefore, if the thickness T1 becomes thinner than designed, the part connecting the leg portion 111a and the connecting portion 112a becomes more prone to fracture.

[0023] Figure 6 is a schematic cross-sectional view of a part of an electronic device to which an operating component 1b relating to another comparative example is attached. The operating component 1b is attached near the housing frame 41b of the electronic device, and when the push button 5b exposed on the exterior surface of the electronic device is pressed, it transmits the pressing force to a switch element 4b mounted on a circuit board inside the electronic device. In Figure 6, a hard resin 12b is attached to the silicone rubber 11b to prevent the silicone rubber 11b from tearing when the push button 5b is pressed. However, in such a case, there is a risk that the position of the hard resin 12b attached to the silicone rubber 11b may be misaligned.

[0024] <Variation> The above embodiment may be modified as follows. Figure 7 is a diagram illustrating a method for manufacturing an operating part according to a modified example. In this modified example, in order to transmit the pressing force of the push button directly to the switch element via the hard resin, a through hole is formed in the part corresponding to the connection portion 112 of the silicone rubber 11 in the above embodiment. That is, the shape of the mold for the second gap molding portion 32 that was in the mold 3 in the embodiment is different, and as shown in Figure 7(A), the mold 2a is configured to form the connection portion 112a having a through hole. In this modified example, using such a mold 2a, liquid rubber is poured into a mold 3a that is shaped to the silicone rubber 11c to be molded, and the liquid rubber is hardened to mold the silicone rubber 11c. The silicone rubber 11c molded in this way has a through hole that penetrates both sides of the connection portion 112a for connection. Regarding the manufacturing process of the operating part 1c in this modified example, a detailed explanation is omitted as it is the same as in the above embodiment, except for the shape of the silicone rubber 11c, the shape of the operating part 1c manufactured by filling the gaps in the silicone rubber 11c with hard resin 12c, and the shape of the mold frame 3a of the mold 2a.

[0025] Figure 7(B) shows the state in which the silicone rubber 11c removed from mold 2a is placed within the frame of mold 20. The mold 20 in this modified example is the same as the mold 20 in the above embodiment, but is not limited to mold 20. When the silicone rubber 11c is set within the frame of mold 20, a first filling portion 301a and a second filling portion 302a are formed within the mold frame 30 as spaces created in the gap between the silicone rubber 11c and the mold frame 30. Figure 7(C) shows the silicone rubber 11c in the state in which the first filling portion 301a and the second filling portion 302a have been filled and molded with hard resin within the mold frame 30 of mold 20. After setting the silicone rubber 11c in the mold frame 30 of mold 20, the first filling portion 301 and the second filling portion 302 are filled with a liquid resin raw material that will become harder than the silicone rubber 11c when hardened. Then, the liquid raw materials are solidified by allowing a certain amount of time to pass or by irradiating them with light. As a result, a molded product is formed inside the mold frame 30 of the mold 20, in which the hard resin 12c is filled into the concave parts of the silicone rubber 11c. Figure 7(D) shows an operating part 1c according to a modified example. By filling the concave parts of the silicone rubber 11c with hard resin 12c inside the mold frame 30 of the mold 20, the silicone rubber 11c and the hard resin 12c are integrated. The molding of the modified operating part 1c is completed.

[0026] In this modified example, the operating part 1c has hard resin 12c filled into the through-hole of the silicone rubber 11c, so the pressing force of the push button is transmitted to the switch element via the hard resin without going through the silicone rubber. Therefore, the pressing feel can be improved compared to the operating part 1 of the embodiment.

[0027] <Other variations> The above embodiments and modifications may be modified as appropriate. Figure 8 is a diagram that further explains the function of the operating component. For example, as shown in the cross section X-X in Figure 8, a ground 6 is formed on the circuit board 6 of the electronic device in which the operating component 1 is used, and the operating component 1 may be attached to the electronic device so that the legs of the operating component 1 are in contact with the ground 6. This prevents the operating component 1 from becoming charged, and thus prevents electrical noise from being applied to the switch element 4.

[0028] In this case, it is preferable that the operating part 1 is formed from an electrically insulating material for the silicone rubber 11 and from an electrically conductive material for the hard resin 12. This makes it possible to suppress the charging of the operating part 1 as much as possible. This configuration can be realized not only in the operating part 1 of the embodiment but also in the operating part 1c of the modified example. [Explanation of Symbols]

[0029] 1, 1a, 1b, 1c... Operating parts 11, 11a, 11b, 11c... Silicone rubber 111,111a · Legs 112,112a ··Connection part 12,12a,12b,12c...Hard resin 2,20,2a ··Mold 3,30,3a ··formwork 31. First gap molding section 32. Second gap molding section 301, 301a ··First filling portion 302, 302a ··Second filling section 4, 4a, 4b... Switch elements 41a. Enclosure frame 5a, 5b... push buttons 6. Grand 7. Circuit board

Claims

1. A first molding step involves forming a flexible elastic member that has a concave gap and is elastically deformable by the pressing force applied to a push button of an electronic device, The process includes a second molding step in which a resin with higher hardness than the elastic member is filled and molded into the gap. In the second molding step described above, a first portion for pressing the switch element and a second portion formed circumferentially surrounding the first portion are formed. The resin has fluidity when it is used to fill the gap, and hardens after a certain period of time when exposed to light. A method for manufacturing operating parts.

2. The process further includes an arrangement step of placing the elastic member within the mold of the first mold, In the second molding step, the resin is filled and molded into the space between the elastic member inside the mold and the inside of the mold, which constitutes the gap portion. A method for manufacturing an operating component according to claim 1.

3. In the first molding step, the elastic member is molded using a second mold for the elastic member that is shaped to match the elastic member. A method for manufacturing an operating component according to claim 1 or 2.

4. In the arrangement step, the elastic member having a through hole that connects a predetermined gap portion and a gap portion located opposite the predetermined gap portion is placed within the mold frame of the first mold, In the second molding step, the resin is filled into the through hole by using the first mold. A method for manufacturing an operating component according to claim 2.

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