Gasket manufacturing method

Abstract

To provide a production method of a packing which can produce packings having various sizes or / and various shapes.SOLUTION: A production method of a packing according to the disclosure produces an annular packing having a core material, and a first cover body which covers the core material and is made of rubber or resin. In the production method of the packing, the core material is covered with the first cover body to form an elongated member. Predetermined lengths of the core material protrude at both ends of the elongated member, and both protruding ends of the core material are joined to form a connection part. The connection part is covered with a second cover body formed of rubber or resin.SELECTED DRAWING: Figure 10

Description

Technical Field

[0004] , , , , , , , , ,

[0005] ,

[0001] The present disclosure relates to packings used for automotive parts, packings used for various mechanical parts, packings used for building materials such as window frames, and packings used for home appliances and others.

Background Art

[0002] Conventionally, packings using a core material are described in Patent Document 1 and Patent Document 2. The packing disclosed in Patent Document 1 is arranged at the joint of a pipe. The packing described in Patent Document 1 has a first core material and a second core material, and both are covered with rubber. Both the first core material and the second core material incorporated in the packing of Patent Document 1 are formed in an annular shape so as to conform to the end face shape of the pipe as the object. That is, the core material used in the packing disclosed in Patent Document 1 is pre-formed in an annular shape and has no joints.

[0003] The packing disclosed in Patent Document 2 is formed by extruding a long rubber having a wire in the center, cutting the long rubber to size, and joining both ends with an adhesive or the like to form an annular shape. In the packing disclosed in Patent Document 2, the rubber portions at both ends of the cut long rubber are adhered with an adhesive, but the core materials are not connected to each other. <0,000017>

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0006] The packing disclosed in Patent Document 2 has a problem in that only the rubber portion is joined with adhesive, and the core material portion is not joined, resulting in low strength at the joint. For example, when manufacturing packings with shapes that include rectangular or irregularly shaped sections, or three-dimensional packings, excessive force may be applied to the joint, potentially causing the connection to tear and the packing to break. Furthermore, there is a problem that if the packing is subjected to vibration after being installed in equipment, the connection to tear and the packing to break. [Means for solving the problem]

[0007] A method for manufacturing a packing according to one aspect of the present disclosure is a method for manufacturing an annular packing having a core material and a first covering made of rubber or resin that covers the core material, wherein a long member is formed in which the first covering is covered on the core material, the core material of a predetermined length is made to protrude from both ends of the long member, the core material at both protruding ends is joined to form a connection, and the connection is covered with a second covering made of rubber or resin.

[0008] A method for manufacturing a packing according to another aspect of the present disclosure is a method for manufacturing an annular packing having at least two first core materials and second core materials and a first covering made of rubber or resin that covers the first core material and the second core material, wherein a first elongated member and a second elongated member are formed on the first core material and the second core material, respectively, with the first covering covered on each of the first and second elongated members, a predetermined length of the first core material and the second core material is made to protrude from each of the ends of the first elongated member and the second elongated member, a connection is formed by joining one end of the protruding first core material and the one end of the protruding second core material, and the second covering made of rubber or resin is covered on the connection. [Effects of the Invention]

[0009] According to a method for manufacturing a packing according to one aspect of this disclosure, packings of various sizes and / or shapes can be provided. Furthermore, even when processed into packings of various complex shapes such as two-dimensional and three-dimensional, the connection portion will not tear, and packings with improved strength can be manufactured and provided. In addition, even when the packing is subjected to vibration after being installed in equipment, etc., the connection portion will not tear, and packings with improved strength can be manufactured and provided. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view of the electronic control unit to which the packing of Embodiment 1 is installed. [Figure 2] Figure 1 is a schematic exploded perspective view of the electronic control unit. [Figure 3] This is a schematic plan view of the inside of the main body of the electronic control unit shown in Figure 1, with the cover removed. [Figure 4] This figure shows the schematic structure of the packing in Embodiment 1, where (a) is a schematic plan view of the packing, and (b) is a cross-sectional view of (a) AA, which is a cross-sectional view of the elliptical region in Figure 4. (c) is a cross-sectional view of (a) BB. [Figure 5] (a) to (g) are perspective views listing the structure of the packing connection part in Embodiment 1. [Figure 6] (a) to (s) are cross-sectional views listing examples of the cross-sectional shapes of the packing in Embodiment 1. [Figure 7] This is a schematic diagram of the main part of a component to which a packing is attached, according to Embodiment 2. [Figure 8] Figure 7 is a plan view of the entire packing. [Figure 9] This is a packing according to Embodiment 3, where (a) is a plan view thereof, (b) is a cross-sectional view AA of (a), (c) is a partially enlarged view of (a), and (d) is a cross-sectional view BB of (c). [Figure 10] This is a schematic diagram showing the steps of the manufacturing method for the packing according to Embodiments 1 to 3. [Figure 11] It is a schematic diagram showing the steps following FIG. 10 of the method for manufacturing the packing according to Embodiments 1 to 3. [Figure 12] (a) and (b) are schematic diagrams showing the molding process of the method for manufacturing the packing according to Embodiments 1 to 3. [Figure 13] It is a schematic diagram showing the process of attaching the second covering body in the method for manufacturing the packing according to Embodiments 1 to 3.

Mode for Carrying Out the Invention

[0011] Hereinafter, more specific embodiments of the present disclosure will be described. However, detailed descriptions that are more than necessary may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. The inventors provide the accompanying drawings and the following description so that those skilled in the art can fully understand the present disclosure, and do not intend to limit the subject matter described in the claims thereby. In the following description, the same or similar components are denoted by the same reference numerals.

[0012] The packing showing one aspect of the present disclosure is a packing used for automotive parts, a packing used for various mechanical parts, a packing used for building materials such as window frames, and a packing used for home appliances and others. Here, the packing is a general term for being arranged between a plurality of members to prevent or suppress the passage of fluids such as gas, liquid, and powder. For example, the internal space and the external space are partitioned by two partition walls, and it is arranged between the partition walls to seal the gap between the two, and prevent or suppress the movement of fluids such as gas, liquid, and powder from the internal space to the external space or from the external space to the internal space. The packing may be stationary or may move. The packing may be called a gasket.

[0013] (Embodiment 1) Hereinafter, as one aspect of the present disclosure, a packing used for an electronic control unit (ECU) that controls an automobile, which is a part for an automobile, will be described with reference to the drawings. Prior to the description of the structure of the packing, the electronic control unit (ECU) to which the packing is attached will be described.

[0014] (Overall Configuration of Electronic Control Unit) FIG. 1 is a schematic perspective view of an electronic control unit 10 to which a packing 1 of Embodiment 1 is attached. As shown in FIG. 1, the electronic control unit 10 includes a lid portion 2, a main body portion 3, and a connector portion 7. The main body portion 3 is covered with a bottom surface and a side wall 8, is box-shaped with one surface open, and has various electronic components inside. A lid portion 2 is attached to the opening of the main body portion 3. FIG. 2 is a schematic exploded perspective view of the electronic control unit 10.

[0015] FIG. 3 is a schematic plan view of the inside of the main body portion 3 with the lid portion 2 of the electronic control unit 10 removed. As shown in FIG. 3, electronic components such as a CPU, various LSIs, a memory, a resistor, and a capacitor are housed in a region covered by the bottom surface and the side wall 8 of the main body portion 3. A lid portion 2 is attached to the opening of the main body portion 3. The lid portion 2 is fixed to the main body portion 3 by screws 5. That is, the screws 5 are inserted through holes provided in the lid portion 2 and screw holes 6 provided in the main body portion 3 and tightened, and the lid portion 2 is fixed to the main body portion 3. In the present embodiment, a packing 1 is interposed between the main body portion 3 and the lid portion 2 of the electronic control unit 10. That is, as shown in FIG. 2, in the electronic control unit 10, a packing 1 is disposed between the lid portion 2 and the main body portion 3. The packing 1 is disposed on the surface of the upper surface of the side wall 8 so as to fit within the width of the upper surface of the side wall 8. Further, the packing 1 is disposed so as to pass inside the screw hole 6 so as to avoid the screw hole 6.

[0016] (Packing) Next, the packing 1 will be described. Figure 4 shows the general structure of packing 1. Figure 4(a) is a general plan view of packing 1, Figure 4(b) is a general cross-sectional view of the dashed line portion of packing 1 in the longitudinal direction, and Figure 4(c) is a general cross-sectional view of packing 1 perpendicular to the longitudinal direction. As shown in Figure 4(a), the packing 1 is molded to conform to the planar shape of the opening of the main body 3, and is based on a rectangular shape. On the left side of Figure 4, there is a U-shaped recess 23 that is recessed on the inside to avoid the connector portion 7. Furthermore, the four corners of packing 1 have inwardly recessed rounded portions (R). Thus, the packing 1 can have complex shapes, not just simple circles or rectangles. The planar shape of the packing 1 is not limited and may be a simple square or circle, etc. As shown in Figure 4(c), the overall structure of the packing 1, excluding the dashed line portion in Figure 4(a), consists of a single core material 20 placed inside the packing 1 and a first covering body 21 that covers the single core material 20. Figure 4(b) is a schematic cross-sectional view of the dashed line portion in Figure 4(a). The core material 20 is formed by connecting one first core material end 20a and the other second core material end 20b of a single wire, thereby forming an annular shape. That is, as shown in Figure 4(b), a single wire has one first core material end 20a and the other second core material end 20b. The packing 1 has a connection portion 12 where the wire is joined by connecting the first core material end 20a and the other second core material end 20b at an arbitrary position.

[0017] At the connection portion 12, the packing 1 is covered by the second covering 22 over a certain length of area centered on the connection portion 12. The packing 1 is covered by the first covering 21 in all other areas except for the second covering 22.

[0018] The core material 20 can be made of metals such as stainless steel, galvanized iron, brass, copper, or alloys thereof. The first covering 21 is made of rubber or resin. As rubber materials, one or more types of rubber can be appropriately blended from ethylene propylene rubber (EPDM), chloroprene rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), acrylic rubber (ACM), ethylene-acrylic rubber (AEM), fluororubber (FKM, FPM), silicone rubber (VQM), liquid NBR, natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), etc. The material of the second coating 22 is a rubber material or a resin material, and the same material as the first coating 21 is used. The material of the second coating 22 may be different from that of the first coating 21. As the resin materials for the first coating 21 and the second coating 22, general-purpose resin materials that exhibit elastic deformation are used.

[0019] Figure 5 lists examples of the configuration of the connection part 12 of the packing 1. The method of connecting the wires is not limited to this; in addition to welding and brazing, a physical fitting structure or a method involving the interposition of other connecting members can be considered. Figure 5(a) shows a connection 12 fabricated by welding. For example, flash butt welding is used to bring the end of the first core material end 20a and the end of the second core material end 20b into contact and apply an electric current to melt and weld the ends of the first core material end 20a and the second core material end 20b together, thereby creating the connection 12. The diameters of the first core material end 20a and the second core material end 20b in the connection 12 are approximately the same thickness. The connection 12 in Figure 5(a) is firmly joined by welding. Figure 5(b) shows the joint 12 fabricated by brazing with brazing material 13. Figure 5(c) shows a connection part 12 made by forming a U-shaped hook at the end 20a of the first core material and an arc-shaped hook at the end 20b of the second core material. Figure 5(d) shows a connection section 12 made by forming a U-shaped hook at the end 20a of the first core material and a U-shaped hook at the end 20b of the second core material. Figure 5(e) shows a connection part 12 made by forming a circular hook at the end 20a of the first core material and a circular hook at the end 20b of the second core material. Figure 5(f) shows the connection part 12 created by twisting the end 20a of the first core material and the end 20b of the second core material. Figure 5(g) shows the connection part 12 created by inserting the first core material end 20a and the second core material end 20b into the pipe 25 and crimping the pipe 25. If the first core material end 20a and the second core material end 20b cannot be pulled out from the pipe 25, crimping is not necessary.

[0020] Figure 6 is a schematic diagram of the cross-section of packing 1. As shown in Figure 6, the packing 1 has a core material 20 near its center, which is covered by a first covering 21. As shown in Figures 6(a) to (s), the cross-sectional shape of the first covering 21 is a polygon such as a square, rectangle, triangle, rhombus, or hexagon, or a cross-sectional shape such as a star shape, ellipse shape, arc shape, or convex shape. The cross-sectional shape of the second coating 22 is the same as that of the cross-sectional shape of the first coating 21. In this case, the cross-sectional shape of the core material 20 is circular. If the core material 20 is linear in shape, the cross-sectional shape of the core material 20 may be not only circular, but also elliptical, rectangular, triangular, polygonal, star-shaped, or other shapes.

[0021] The size of packing 1 is not limited; its circumference may be a few centimeters or extend to several meters.

[0022] As described above, the packing 1 deforms so that the first covering 21 and the second covering 22 fit into the irregularities on the surface of the lower surface of the lid 2 and the irregularities on the surface of the upper surface of the side wall 8 of the main body 3, thereby sealing the inside of the main body 3 from the outside of the main body 3 (see Figure 2). Since automobiles are used in various external environments such as temperature, humidity, dust, and vibration, the packing 1 can prevent or suppress the movement of external fluids such as gases, liquids, and powders into the main body 3 in order to protect the electronic components inside the main body 3.

[0023] Thus, according to one aspect of the present disclosure, packings 1 of various sizes and / or various shapes can be provided. Furthermore, even when processed into various complex shapes such as two-dimensional and three-dimensional packings 1, the connection part will not tear, and a packing 1 with improved strength can be provided. Furthermore, even when vibration is applied to the packing 1 after it has been installed in a device, the connection part will not tear, and a packing 1 with improved strength can be provided. In addition, since the packing 1 is simply installed between the lid part 2 and the main body part 3 and is not fixed with adhesive or the like, it can be easily removed and the old packing 1 can be replaced with a new one.

[0024] (Embodiment 2) Embodiment 2, as shown in Figure 7, relates to a gasket, and more specifically to a packing 51 interposed between, for example, the housing 52 of an electric vehicle motor and the casing 53 of a PCU (power control unit) to maintain a seal between them.

[0025] Embodiment 2 will now be described. In Figures 7 and 8, the packing 51 is formed in a generally rectangular frame shape. This packing 51 is interposed between the motor housing 52 and the PCU (power control unit) casing 53 to maintain a seal between them. Both the motor and the PCU are mounted in an electric vehicle. The motor housing 52 has a cubic shape overall, while the PCU casing 53 is a box shape with the entire bottom surface open. In Figure 7, the right side of the casing 53 is the exterior, and the left side is the interior.

[0026] The motor housing 52 is made of die-cast aluminum, and its upper surface 52A is a rough surface with numerous minute irregularities because it is left in its cast state. The outer circumference of the upper surface 52A of the housing 52 forms a frame-shaped sealing surface 52B. On the other hand, the PCU casing 53 is also made of die-cast aluminum, and its lower surface, which forms the outline of its opening, is a frame-shaped sealing surface 53A. The packing 51 is installed between the sealing surface 52B of the lower housing 52 and the sealing surface 53A of the upper casing 53, and is generally in the shape of a rectangular frame.

[0027] The packing 51 of Embodiment 2 is composed of a core material 56 which is an endlessly continuous base material made of iron or stainless steel, and a rubber seal 57 which covers the entire circumference and the entire longitudinal area of ​​the core material 56 with a predetermined thickness. The cross-sectional shape of the core material 56 is circular, and its diameter is set to approximately 0.5 to 2 mm. On the other hand, the rubber seal 57 covering the core material 56 also has a circular cross-section, and its diameter (outer diameter) is set to approximately 3 to 6 mm. The thickness of this rubber seal 57 is set to 0.8 mm or more. As the material for the rubber seal 57, ordinary rubber including NBR and EPDM, foamed rubber, and elastomer are used.

[0028] In the packing 51 of this embodiment, the core material 56 is integrally joined by welding or the like in the area indicated by the arrow in Figure 8. Specifically, the area indicated by the arrow in Figure 8 is the connection portion 12, where the core material 56 is surrounded by the second covering 22. In other areas, the core material 56 is surrounded by the first covering 21.

[0029] In Embodiment 2, since an iron or stainless steel wire is used as the core material 56 that serves as the base material, the packing 51 as a whole has rigidity, and the frame-like shape shown in Figure 8 is maintained at all times.

[0030] When assembling the packing 51 configured as described above between the sealing surfaces 52B and 53A, as shown in Figure 8, the frame-shaped packing 51 is first installed on the sealing surface 52B of the housing 52, which is on the lower side. At this time, since the packing 51 as a whole is rigid and maintained in a frame shape, the entire area of ​​the packing 51 can be easily installed over the entire area of ​​the sealing surface 52B.

[0031] Subsequently, after the sealing surface 53A of the casing 53 is placed on the packing 51, the housing 52 and the casing 53 are connected at the required points using fastening bolts and nuts. As a result, the lower side of the rubber seal 57 of the packing 51 elastically deforms and adheres tightly to the sealing surface 52B of the housing 52, while the upper side of the rubber seal 57 is also pressed and adheres tightly to the sealing surface 53A of the casing 53.

[0032] In this way, when assembly is complete, the entire packing 51 is sandwiched between the two sealing surfaces 52B and 53A, causing the rubber seal 57 to elastically deform and adhere tightly to the two sealing surfaces 52B and 53A, thereby ensuring that the seal between them is reliably maintained. In Embodiment 2, when assembling the packing 51 between the sealing surfaces 52B and 53A, the packing 51 itself is rigid and maintains a shape that conforms to the contours of both sealing surfaces 52B and 53A, so the worker can easily install the packing 51. Furthermore, even if the sealing surface 52B of the housing 52 is a rough surface as it is after aluminum die casting, the rubber seal 57 can elastically deform and adhere tightly to the unevenness of the sealing surface 52B. Therefore, the motor housing 52 does not require polishing of the upper surface 52A and the sealing surface 52B after casting. In other words, by using the packing 51 of this embodiment, it is possible to omit the surface finishing work of the housing 52 after casting, which was conventionally required. This reduces the manufacturing cost of the motor housing 52 accordingly.

[0033] Furthermore, when replacing the packing 51 after some time has passed since assembly, since no sealant is applied to the sealing surfaces 52B and 53A, the old packing 51 can be easily removed, and the new packing 51 can then be easily installed as described above. Therefore, according to Embodiment 2, it is possible to provide a packing 51 that is easy to attach and detach and has good sealing performance compared to the conventional method.

[0034] (Embodiment 3) Figure 9 shows a packing 551 of yet another embodiment of the present invention. In the embodiments shown in Figures 7 and 8, the packing 51 was composed of a core material 56 with a circular cross-section as a base material and a rubber seal 57 covering it. However, in the packing 551 of the embodiment shown in Figure 9, it is composed of a thin, narrow core material 511 with a shape corresponding to the contours of the sealing surfaces 52B and 53A described above, and first covering rubber seals 517A and 517B that are endlessly fixed in the longitudinal direction to the upper surface 511A and the lower surface 511B opposite to the upper surface 511A. As shown in Figure 9(a), in this embodiment, in order to improve the yield of the SUS plate that is the material for the core material 511, the core material 511 is divided into multiple divided members 511a (for example, the first core material), 511b (for example, the second core material), and 511f, and by welding the boundary portions 511X (connecting portions) of adjacent divided members, the core material 511 (also called the frame) as a whole is formed in the shape of a stepped frame. In the packing 551 of this embodiment, the boundary portion 511X of each divided member is the connecting portion 12, and at least a part of the boundary portion 511X around the core material 511 is covered by the second covering 517'. For other areas, the core material 511 is covered by the first coverings 517A and 517B.

[0035] As shown in Figure 9(d), in the packing 551, one divided member 511d and the other divided member 511c are connected at the boundary portion 511X (connection portion). That is, one end 560a of the core material of one divided member 600 and one end 511d of the core material of the other divided member 511c are welded together to form a single unit. In this embodiment, a frame-shaped core material 511 is constructed by welding one end 560a and the other end 560b of the core material at the boundary portion 511X of adjacent dividing members 511d and 511c. Furthermore, the joint and the surrounding area are covered with the second covering 517'. In other words, there are welding points (boundary portions 511X) at multiple locations on the core material 511 in a direction perpendicular to its longitudinal direction (see Figure 9). As shown in Figures 9(b) and (c), at least a portion of the boundary portions 511X (connections) is covered by the second covering body 517' on the upper surface 511A and the lower surface 511B so as to cover the boundary portions 511X (connections).

[0036] The materials for the rubber seals 517A and 517B can be the same materials as those shown in the above embodiment, or CIPG can be used. The core material 511 is expected to have a width of 4 to 10 mm and a thickness of 0.15 to 0.4 mm. Furthermore, when using CIPG as the rubber seal, the thickness is set to 0.8 mm or more, and the width is set to 50% to 150% of the thickness. As described above, since the upper surface 511A and lower surface 511B of the core material 511 have an endless rubber seal 517A, 517B that is continuous in the longitudinal direction fixed to the center in the width direction, when the packing 551 is assembled between the two sealing surfaces 52B, 53A, the rubber seals 517A, 517B and the second covering 517' will be in close contact with the sealing surfaces 52B, 53A. Furthermore, since the core material 511 is made of SUS (stainless steel) and therefore has rigidity, the overall frame shape is maintained.

[0037] Therefore, even with the packing 551 of the embodiment shown in Figure 9, the same functions and effects as those of the embodiments shown in Figures 7 to 8 can be obtained. Moreover, in this embodiment, the SUS plate to be used as material can be prepared as multiple linear divided members 511a to 511f to constitute the core material 511, so that the expensive SUS material can be used efficiently and with good yield. Furthermore, although the boundary portion 511X of adjacent divided members is welded, it can be covered with rubber seals 517A and 517B and fixed to the upper surface 511A and lower surface 511B without surface treatment of that portion. In other words, deburring work on the welded area of ​​the boundary portion 511X is unnecessary. As a result, the SUS plate material can be utilized with good yield, and the packing 551 can be manufactured at a relatively low cost. In the embodiments described above, iron or stainless steel core materials were used, but a resin or rubber harder than the rubber seal may be used instead.

[0038] (Embodiment 4) As Embodiment 4, a method for manufacturing the packing 1 of this disclosure will be described with reference to Figures 10 to 13. Figures 10 and 11 are schematic diagrams showing the steps of the manufacturing method for packing 1, and the manufacturing process for packing 1 consists of steps (a) to (i). Embodiment 4 describes the process of covering a single core material 20 with a first covering 21 and a second covering 22. The first covering 21 and the second covering 22 are described as being made of rubber. Step (a) in Figure 10 shows the extrusion molding process, in which the core material 20 is covered with a first rubber covering 21 by the extrusion molding machine 30. The extrusion molding machine 30 includes a screw 31, a heater 32, and a head section 33. As shown in Figure 10(a), the raw rubber 26 before vulcanization is inserted into the extrusion molding machine 30 by the screw 31, and the raw rubber 26 is then inserted into the head section 33.

[0039] The head portion 33 has an entry passage 34, a merging chamber 35, an insertion hole 36, and a discharge hole 37. The raw rubber flows through the inlet passage 34 and into the confluence chamber 35. Meanwhile, the core material 20 is inserted into the insertion hole 36 and reaches the confluence chamber 35. In the confluence chamber 35, the raw rubber 26 coats the core material 20. The core material 20, now covered with the raw rubber 26, is discharged from the discharge hole 37.

[0040] Figure 10(b) shows the heating process, in which the discharged raw rubber 26 is heated to a temperature of approximately 200°C by the heating device 40 to vulcanize the raw rubber 26 and produce a first rubber coating 21.

[0041] Figure 10(c) shows the cooling process, in which water is sprayed from the spraying device 42 of the cooling device 50 to cool the first rubber coating 21.

[0042] Figure 10(d) shows the thickness adjustment process, in which the two belt rollers 61 of the thickness adjustment machine 60 are pressed against the first rubber covering 21 with the core material 20 from above and below to adjust the thickness of the first rubber covering 21 with the core material 20. Through these processes, a long member 15 is formed in which the periphery of the core material 20 is covered with the first covering 21.

[0043] Figure 10(e) shows the cutting process for cutting the long member 15. In process (e), the cutter 71 of the cutting machine 70 cuts the long member 15 to a predetermined length. That is, the long member 15, in which the core material 20 is covered with vulcanized rubber, is cut to a predetermined length.

[0044] Figure 11(f) shows the first rubber covering 21 (long member 15) with core material 20 attached, which has been cut from the cutting machine 70. At both ends of the long member 15, the cut surfaces of the core material 20 at both ends and the cut surfaces of the first covering 21 are on the same plane.

[0045] Figure 11(g) shows the first covering 21 being peeled off at both ends of the long member 15, leaving the first core material end 20a and the second core material end 20b protruding. In other words, the rubber layer near both ends of the long member 15 is peeled off.

[0046] In Figure 11(g), a rubber layer of a predetermined length (first coating 21) is cut with wire cutters, causing the first core material end 20a and the second core material end 20b to protrude from the first coating 21. If the first rubber covering 21 with the core material 20 is removed immediately after the cutting process (e), and a predetermined time has elapsed, the first core material end 20a and the second core material end 20b may protrude from the first covering 21 by a predetermined length. In that case, it is not necessary to cut the first covering 21 to a predetermined length with wire cutters to make the first core material end 20a and the second core material end 20b protrude from the first covering 21.

[0047] Figure 11(h) shows the connection between the end 20a of the first core material and the end 20b of the second core material. In Figure 11(h), for example, using the flash butt welding method described in Figure 5(a), the end of the first core material end 20a and the end of the second core material end 20b are brought into contact, and an electric current is passed through them to melt and weld the ends of the first core material end 20a and the second core material end 20b together, thereby creating the joint 12.

[0048] By joining the core materials 20 at both ends of the long member 15, the long member 15 is connected in a ring shape. Next, the core material 20 of the long member 15 is plastically deformed to form a shape that matches the shape of an object, such as the main body 3 in Figure 3. For example, a mold 605 having grooves 603 that match the shape to be formed is prepared, as shown in Figure 12(a), and the long member 15 is fitted into the grooves 603 of the mold 605 to form the shape, as shown in Figure 12(b). Mold 605 can be a simple one, such as a wooden or resin mold.

[0049] As shown in Figure 13, the exposed core material 20 is then placed into the mold 610. The mold 610 is designed to hold only a portion of the annularly connected elongated member 15. The mold 610 in this embodiment is a simple mold consisting of a lower mold 611 and an upper mold 612, with a gate portion 615 provided on the upper mold 612. Furthermore, groove-shaped molding cavities 620 and 621 are formed in the lower mold 611 and the upper mold 612, respectively.

[0050] Next, rubber or resin is injected from the gate portion 615, and the second covering 22 is attached around the exposed core material 20. Since the lower mold 611 only contains the area of ​​the exposed core material 20, it can be used as a mold for manufacturing packings 1, 51, and 551 of any shape.

[0051] Figure 11(i) is a perspective view showing the connection portion 12 covered with the second covering 22. In Figure 11(i), for example, a connecting portion 12 is installed in upper and lower molds having grooves with the same diameter as the first coating 21, and raw rubber is poured in so that a second coating 22 of a predetermined length covers the center of the connecting portion 12, and the rubber second coating 22 is formed by vulcanization with heat. As described above, the packing 1 can be manufactured by the steps (a) to (i) shown in Figures 10 to 11.

[0052] (Embodiment 5) In Embodiment 5, the manufacturing method for the packing 551 shown in Figure 9 will be described. This embodiment is basically the same as Embodiment 4. The difference is that in Embodiment 4, a single core material 20 is bent and joined, whereas in Embodiment 5, at least two divided members 511a and 511b are used as the core material. One end 560a of the divided member 511a and one end 560b of the divided member 511b are joined together to create a connection portion 511X. Then, a second covering 517' is formed on the connection portion 511X. Otherwise, it is the same as in Embodiment 4. In Embodiment 5, since multiple core materials can be joined together, packings of various sizes and / or shapes can be provided.

[0053] Furthermore, the inventions described in Embodiments 1 to 5 can be substituted or combined, as long as no contradictions arise.

[0054] As described above, this disclosure includes a method for manufacturing a packing as described in the following items.

[0055] [Item 1] A method for manufacturing an annular packing having a core material and a first covering made of rubber or resin that covers the core material, A long member is formed in which the core material is covered with the first covering, At both ends of the long member, the core material of a predetermined length is made to protrude, The core material at both ends that protrude is joined together to form a connection part. A method for manufacturing a packing, wherein the connecting portion is covered with a second covering made of rubber or resin. According to the above embodiment, packings of various sizes and / or shapes can be manufactured and provided. Furthermore, even when processed into packings of various complex shapes such as two-dimensional and three-dimensional, the connection part will not tear, and packings with improved strength can be manufactured and provided. In addition, even when the packing is subjected to vibration after being installed in equipment, etc., the connection part will not tear, and packings with improved strength can be manufactured and provided.

[0056] [Item 2] A method for manufacturing a packing as described in item 1, wherein the first and second coatings are made of the same material. According to the above embodiment, since the first coating and the second coating deform in the same way, a packing with excellent sealing properties can be manufactured and provided.

[0057] [Item 3] A method for manufacturing a packing according to item 1 or 2, wherein both ends of the core material are in contact at the connection portion. According to the above embodiment, even when processed into packings of various complex shapes such as two-dimensional and three-dimensional, the connection part will not tear, and packings with improved strength can be manufactured and provided. Furthermore, even when the packing is subjected to vibration after being installed in equipment, etc., the connection part will not tear, and packings with improved strength can be manufactured and provided.

[0058] [Item 4] The method for manufacturing a packing according to any one of items 1 to 3, wherein the core material is in the shape of a line. According to the above embodiment, packings of various complex shapes, such as two-dimensional and three-dimensional, can be manufactured and provided.

[0059] [Item 5] A method for manufacturing an annular packing having at least two first core materials and second core materials, and a first covering made of rubber or resin that covers the first core material and the second core material, wherein a first elongated member and a second elongated member are formed on the first core material and the second core material, respectively, with the first covering covered on each of them, and the first core material and the second core material core material of a predetermined length are made to protrude from each of the ends of the first elongated member and the second elongated member, and a connecting portion is formed by joining one end of the protruding first core material and one end of the protruding second core material. A method for manufacturing a packing, wherein the connecting portion is covered with a second covering made of rubber or resin. According to the above embodiment, packings of various complex shapes, such as two-dimensional and three-dimensional, can be manufactured and provided.

[0060] [Item 6] A method for manufacturing a packing as described in item 5, wherein the first and second coatings are made of the same material. According to the above embodiment, since the first coating and the second coating deform in the same way, a packing with excellent sealing properties can be manufactured and provided.

[0061] [Item 7] The core material is a packing as described in item 5 or 6, which is linear in shape. According to the above embodiment, packings of various complex shapes, such as two-dimensional and three-dimensional, can be manufactured and provided. [Explanation of symbols]

[0062] 1. Packing 12 Connection part 15 Long members 20 Core material 20a 1st core material end 20b 2nd core material end 21 First covering 22 Second covering

Claims

1. A method for manufacturing an annular packing having at least two plate-shaped first core material and plate-shaped second core material, and a first covering made of rubber or resin that covers the first core material and the second core material, The packing is formed by connecting the first core material and the second core material to form a connecting portion, and the connecting portion is covered with a second covering made of rubber or resin. The width of the first core material and the width of the second core material are the same. The width of the first coating and the width of the second coating are the same. The widths of the first covering and the second covering are smaller than the widths of the first core material and the second core material. The first covering and the second covering are positioned in the center of the first core material and the second core material in the width direction, The first covering and the second covering protrude from the upper and lower sides of the first core material, and from the upper and lower sides of the second core material. A first elongated member is formed on the first core material, with the first covering covering the central part of the first core material in the width direction. A second elongated member is formed on the second core material, with the first covering covering the central part in the width direction of the second core material. At each end of the first long member and the second long member, the first covering is peeled off to expose the first core material and the second core material of a predetermined length. A connection is formed by joining one end of the protruding first core material and one end of the protruding second core material. A method for manufacturing a packing, wherein the second covering made of rubber or resin covers the connecting portion.

2. The method for manufacturing a packing according to Claim 1, wherein the thickness of the first covering and the second covering is greater than the thickness of the first core material and the second core material.

3. The method for manufacturing a packing according to claim 2, wherein the first coating and the second coating are made of the same material.

Images