Gasket and sealing device

Abstract

This sealing device is configured by joining two members which are like a case and cover, with a metal divided gasket sandwiched therebetween. The divided gasket is divided into a plurality of pieces that each have, at front and back surfaces thereof, a flat seal surface which is covered with an elastic body. The individual pieces are connected with hinges so as to form an annular shape when assembled. The hinges each bridge across seal surfaces of two adjacent pieces and rotate about an axis orthogonal to the lengthwise direction of the two adjacent pieces, thereby connecting the two pieces in a foldable manner. At least one of the two members is provided with a recess that accommodates a hinge protruding from the seal surface. The recess is filled with a liquid gasket that covers a portion where the two adjacent pieces are connected.

Description

Gaskets and sealing devices

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to gaskets and sealing devices.

[0002] A gasket is placed between two components to be joined, such as a case and a cover, to seal the two components. Gaskets are used to seal between the oil pan (case) used in internal combustion engines and the cylinder block (cover) that covers the opening of the oil pan, or to seal the joints of various pipes. Gaskets have an annular shape in order to seal two components.

[0003] When sealing components with a relatively large surface area, such as oil pans, the gaskets tend to be large, making them difficult to handle from manufacturing to assembly. Furthermore, since gaskets are manufactured by stamping a single sheet of metal, the annular inner part of the gasket becomes waste material, making the larger the gasket, the more undesirable it becomes from both a cost and environmental standpoint.

[0004] Therefore, a divided gasket has been devised in which the gasket is divided into a plurality of pieces that are annular in shape as a whole.

[0005] Japanese Patent Laid-Open Publication No. 2007-155043 (hereinafter referred to as "Patent Document 1") discloses an example of a gasket used as an oil pan gasket for an automobile engine (see paragraph 0014 and Figure 1). This gasket is divided into two pieces (components 5a and 5b), which are joined by laser spot welding (see paragraph 0015 and Figures 2-3). After joining, the two pieces are pressure-treated and smoothed (see paragraph 0016, Figures 3, and 7(a) and (b)). After that, an elastic body (rubber compound sheet 30) is adhesively fixed to the pieces (see paragraph 0017, Figures 3, and 6), forming a gasket (oil pan gasket 1).

[0006] Japanese Patent Laid-Open No. 2020-076467 (hereinafter referred to as "Patent Document 2") also divides a gasket into two pieces, a first segment (100A) and a second segment (100B), and joins the pieces to form a gasket (gasket 100) (see paragraphs 0020-0021 and Figures 1-2). The gasket described in Patent Document 2 differs from that described in Patent Document 1 in the method of joining the pieces and the method of fixing the elastic body to each piece.

[0007] In Patent Document 2, the two pieces that make up the gasket, i.e., the first split piece (100A) and the second split piece (100B), are fixed to each other by a liquid gasket (FIPG) (see paragraph 0020), and are not joined by laser spot welding as in Patent Document 1.

[0008] The first divided piece (100A) and the second divided piece (100B) are made by punching rubber-coated metal (RCM), which is a metal plate with a rubber film on both sides (see paragraph 0022). Therefore, the elastic body is not fixed to the two pieces after joining, but is formed as a film on the two pieces in advance.

[0009] JP 2007-155043 A JP 2020-076467 A

[0010] In both of the gaskets described in Patent Documents 1 and 2, pieces are joined together to produce an annular gasket, which is then placed between two components that are joined together. Therefore, when viewed as a sealing device in which a gasket is interposed between two components, a process of connecting the two pieces to produce the gasket is required prior to the process of joining the two components with the gasket in between, making the manufacturing process complicated. Improvements are needed.

[0011] An object of the present disclosure is to obtain a sealing device that can reduce the number of manufacturing steps and simplify manufacturing.

[0012] One aspect of the gasket comprises a metal split gasket that is divided into multiple pieces having flat sealing surfaces coated with an elastic material on the front and back sides and that forms an annular shape when assembled, and a hinge that is fixed across the sealing surfaces of two adjacent pieces in a straight line and rotates around an axis perpendicular to the longitudinal direction of the two pieces, connecting the two pieces in a foldable manner.

[0013] Another aspect of the gasket comprises a metal segmented gasket that is divided into multiple pieces having flat sealing surfaces coated with an elastic material on the front and back sides and that form an annular shape when assembled, and a connecting device that connects the ends of two adjacent pieces so that they can rotate around an axis perpendicular to the sealing surfaces.

[0014] One aspect of the sealing device comprises a metal split gasket divided into multiple pieces having flat sealing surfaces coated with an elastic material on the front and back sides, which form an annular shape when assembled; a hinge that is fixed across the sealing surfaces of two adjacent pieces in a straight line and rotates around an axis perpendicular to the longitudinal direction of the two pieces to foldably connect the two pieces; two members that are joined to each other across the sealing surfaces of the split gasket; a recess provided in at least one of the two members to accommodate the hinge that protrudes from the sealing surfaces; and a liquid gasket that is filled in the recess and covers the connecting portion of the two pieces.

[0015] Another aspect of the sealing device comprises a metal split gasket divided into multiple pieces having flat sealing surfaces coated with an elastomer on the front and back sides, which form an annular shape when assembled, a connector that rotatably connects the ends of two adjacent pieces around an axis perpendicular to the sealing surfaces, two members that are joined to each other across the sealing surfaces of the split gasket, and a liquid gasket filled in the gap between the facing ends of the two pieces.

[0016] According to the present disclosure, the number of steps required to manufacture a sealing device can be reduced, and manufacturing can be simplified.

[0017] 10 is an exploded perspective view showing a split gasket and a case; FIG. 11 is a plan view showing an example of a split gasket according to the first embodiment; FIG. 12 is a plan view showing another example of a split gasket; FIG. 13 is a plan view showing an enlarged view of the state in which the ends of adjacent pieces of a split gasket are connected by hinges; FIG. 14 is a front view showing an enlarged view of the state in which the ends of adjacent pieces of a split gasket are connected by hinges; FIG. 15 is a left side view showing an enlarged view of the state in which the pieces of a split gasket are folded by hinges; FIG. 16 is a front view showing an enlarged view of the sealing device being assembled at the hinge position, with a gasket interposed between a cover having a groove-shaped recess and a case; FIG. 17 is a front view showing an enlarged view of the sealing device being assembled at the hinge position, with a gasket interposed between a cover having a hole-shaped recess and a case; FIG. 18 is a cross-sectional view taken along line A-A in FIGS. 8 and 9; FIG. 19 is a longitudinal sectional front view showing an enlarged view of the sealing device before assembly, with the hinge position; FIG. 19 is a longitudinal sectional front view showing an enlarged view of the sealing device after assembly, with the hinge position. 14 is a plan view showing an example of a split gasket according to a second embodiment; FIG. 15 is an enlarged plan view showing the state in which the ends of adjacent pieces of the split gasket are connected by a connector; FIG. 16 is a cross-sectional view taken along line B-B in FIG. 14; FIG. 17 is an enlarged plan view showing the assembled sealing device at the position of the connector; and FIG. 18 is a cross-sectional view taken along line C-C in FIG.

[0018] An embodiment of the sealing device will be described. The items to be described are as follows. [Overview] [First embodiment] 1. Configuration (1) Gasket (1-1) Split gasket (A) Example of split gasket (B) Another example of split gasket (1-2) Hinge (2) Sealing device (2-1) Recess (2-2) Liquid gasket 2. Assembly of sealing device 3. Function and effect 4. Modification [Second embodiment] 1. Configuration (1) Gasket (1-1) Split gasket (1-2) Connector (2) Sealing device 2. Assembly of sealing device 3. Function and effect 4. Modification

[0019] 1, 12, and 17, a sealing device 11 of this embodiment is configured by interposing the gasket 12 between two members 101 (101A, 101B) that are joined together. The two members 101 are, for example, a case 101A and a cover 101B.

[0020] The gasket 12 has a structure in which the individual pieces P are connected in advance, with the individual pieces P being mainly composed of split gaskets 21 and 31 that are split into a plurality of pieces P. The individual pieces P are connected by hinges 41 (first embodiment) or connectors 51 (second embodiment).

[0021] As an example, the sealing device 11 is used to seal between an oil pan and a cylinder block used in an internal combustion engine. In this case, the oil pan serves as the case 101A, and the cylinder block serves as the cover 101B. The case 101A is one of two members 101, and is provided with an oil reservoir 102 for storing oil (not shown) inside, and has an opening 103 on the top surface. The cover 101B is the other of the two members 101, and covers the opening 103 provided in the case 101A.

[0022] Fig. 1 shows an example of the gasket 12 shown in Fig. 2, among the gaskets 12 of the first embodiment. The hinges 41 and connectors 51 are not directly shown, but are represented schematically by circles. Another example of a split gasket 21 shown in Fig. 3 and a split gasket 31 of the second embodiment have different shapes from the split gasket 21 shown in Fig. 1, and the positions of the hinges 41 and connectors 51 are also different. See the explanation below.

[0023] First Embodiment A first embodiment will be described with reference to FIGS. 1 to 12. FIG.

[0024] 1. Configuration (1) Gasket

[0025] (1-1) Segmented Gasket Two embodiments are introduced. (A) Example of a Segmented Gasket As shown in Figure 2, the first gasket 12 has a segmented gasket 21 that is segmented into eight pieces P1 to P8, each having a flat sealing surface 23 covered with an elastic body 22 on its front and back surfaces. The segmented gasket 21 has an annular shape that becomes a rectangle when assembled. The eight pieces P1 to P8 are provided four on the long and short sides and four at the corners. Pieces P1, P3, P5, and P7 are bent at right angles to form the four corners CR of the rectangle.

[0026] Each of the pieces P1 to P8 of the split gasket 21 has adjacent end portions E at both ends. The adjacent end portions E of the eight pieces P1 to P8 that make up the split gasket 21 are paired. Specifically, the following eight types of end portions E are paired: (a) end portion E11 of piece P1 and end portion E22 of piece P2; (b) end portion E21 of piece P2 and end portion E32 of piece P3; (c) end portion E31 of piece P3 and end portion E42 of piece P4; (d) end portion E41 of piece P4 and end portion E52 of piece P5; (e) end portion E51 of piece P5 and end portion E62 of piece P6; (f) end portion E61 of piece P6 and end portion E72 of piece P7; (g) end portion E71 of piece P7 and end portion E82 of piece P8; and (h) end portion E81 of piece P8 and end portion E12 of piece P1.

[0027] The individual pieces P1 to P8 of the split gasket 21 are made of a metal material such as stainless steel, cold-rolled steel, galvanized steel, or aluminum alloy, and are coated in advance with the elastic body 22, for example.

[0028] The elastic body 22 is a rubber compound containing rubber as a main component. For example, at least one type of synthetic rubber selected from nitrile rubber, styrene butadiene rubber, fluororubber, acrylic rubber, and silicone rubber can be used as the material for the elastic body 22. The rubber compound using these materials may be foamed rubber.

[0029] (B) Another Example of a Split Gasket As shown in Figure 3, the second gasket 12 includes a split gasket 21 that is split into two pieces P1 and P2, each having a flat sealing surface 23 coated with an elastic body 22 on its front and back sides. The split gasket 21 has an annular shape that becomes a rectangle when assembled. Each of the two pieces P1 and P2 has a U-shape with two corners CR. The two corners CR bend each of the individual pieces P1 and P2 at a right angle.

[0030] Each of the pieces P1 and P2 of the split gasket 21 has adjacent end portions E at both ends. The adjacent end portions E of the two pieces P1 and P2 that make up the split gasket 21 form a pair. In more detail, two types of end portions E form a pair: (i) end portion E11 of the piece P1 and end portion E21 of the piece P2, and (j) end portion E12 of the piece P1 and end portion E22 of the piece P2.

[0031] The individual pieces P1 and P2 of the split gasket 21 are made of a metal material such as stainless steel, cold-rolled steel, galvanized steel, or aluminum alloy, and are coated in advance with an elastic body 22, for example.

[0032] The elastic body 22 is a rubber compound containing rubber as a main component. For example, at least one type of synthetic rubber selected from nitrile rubber, styrene butadiene rubber, fluororubber, acrylic rubber, and silicone rubber can be used as the material for the elastic body 22. The rubber compound using these materials may be foamed rubber.

[0033] 4 to 7, the individual pieces P that make up the split gasket 21 are connected by hinges 41. The hinge 41 is fixed across the sealing surfaces 23 of two linearly adjacent pieces P, and rotates around an axis perpendicular to the longitudinal direction of the two adjacent pieces P, connecting the two pieces P in a foldable manner.

[0034] In the split gasket 21 shown in FIG. 2, the hinge 41 is bridged across two adjacent pieces P at the pair of end portions E of (a) to (h).

[0035] In the split gasket 21 shown in FIG. 3, the hinge 41 is bridged across two adjacent pieces P at the pair of end portions E of (i) and (j).

[0036] As shown in Fig. 5, the hinge 41 rotatably connects a pair of arms 42 with a pin 43. The pair of arms 42 are respectively fixed to the seal surfaces 23 on one side of two adjacent pieces P. Therefore, as shown in Fig. 6, the two pieces P connected by the hinge 41 rotate around an axis whose axis is the pin 43.

[0037] Each side of the split gasket 21 shown in Fig. 2 is divided into three. In Fig. 2, the top and bottom sides are divided into three: a set of pieces P1 and P7, a set of pieces P2 and P6, and a set of pieces P3 and P5. The left and right sides are divided into three: a set of pieces P1 and P3, a set of pieces P8 and P4, and a set of pieces P7 and P5. In this embodiment, hinges 41 are provided so that the three sets of pieces on the top and bottom sides and the three sets of pieces on the left and right sides can be folded alternately.

[0038] Figure 7 is a left side view illustrating the folded state of the set of pieces P1 and P3, the set of pieces P8 and P4, and the set of pieces P7 and P5. Because Figure 2 is viewed from the left side, only pieces P1, P8, and P7 appear, and pieces P3, P4, and P5 do not appear. As shown in Figure 7, adjacent hinges 41 are located on one side and the opposite side of the seal surface 23, respectively. That is, the hinge 41 connecting pieces P7 and P8 is fixed to the seal surface 23 on the upper side in Figure 7, and the hinge 41 connecting pieces P1 and P8 is fixed to the seal surface 23 on the lower side in Figure 7. This allows the set of pieces P1 and P3, the set of pieces P8 and P4, and the set of pieces P7 and P5 to be folded alternately.

[0039] (2) Sealing Device (2-1) Recess As shown in FIGS. 8 to 10, the two members 101 are provided with recesses 104 for accommodating the hinges 41 in the areas where the two pieces P of the split gasket 21 are adjacent to each other.

[0040] 2, eight hinges 41 are provided and appropriately arranged on both sealing surfaces 23. Therefore, a total of eight recesses 104 are provided on both the case 101A and the cover 101B.

[0041] 3, two hinges 41 are fixed only to the upper sealing surface 23 facing the cover 101B. Therefore, two recesses 104 are provided only in the cover 101B.

[0042] The recess 104 has a groove shape as an example (see FIG. 8 ), and a hole shape as another example (see FIG. 9 ). Regardless of the shape, the recess 104 is provided with a size that can completely cover the hinge 41 protruding from the sealing surface 23. In the case of the groove shape shown in FIG. 8 , the size of the recess 104 is determined by the groove width and groove depth. In the case of the hole-shaped recess 104 shown in FIG. 9 , the size of the recess 104 is determined by the diameter of the hole.

[0043] (2-2) Liquid Gasket As shown in Figures 11 and 12, the sealing device 11 fills the recess 104 with a liquid gasket 61. One example of the liquid gasket 61 is a gasket made of one-component, room-temperature curing silicone called a FIPG (Formed-In-Place Gasket). The liquid gasket 61 is initially fluid and can be applied to various parts. When it reacts with moisture in the air, the liquid gasket 61 hardens.

[0044] The liquid gasket 61 filled in the recess 104 penetrates between the ends E of the adjacent pieces P, and also flows between the sealing surface 23 of the split gasket 21 and the case 101A, and between the sealing surface 23 and the cover 101B. The liquid gasket 61 that has penetrated and flowed into each part reacts with moisture in the air and hardens.

[0045] 2. Assembly of the Sealing Device To join the two members 101 (101A, 101B) via the split gasket 21 and assemble the sealing device 11, the liquid gasket 61 is applied to the recess 104. If necessary, the liquid gasket 61 is also applied to the case 101A or the cover 101B at a position facing the recess 104.

[0046] Before or after the application of the liquid gasket 61, the folded split gasket 21 is opened and restored to the shape of the gasket 12.

[0047] Thereafter, gasket 12 is placed in a predetermined position on case 101A. Case 101A and cover 101B are aligned so as to cover opening 103 of case 101A, and the two are joined together with split gasket 21, which has been restored to the shape of gasket 12, sandwiched between them. This operation is carried out at a stage before liquid gasket 61 hardens and maintains its fluidity.

[0048] Once the liquid gasket 61 has hardened, the sealing device 11 is completed.

[0049] 3. Effects The sealing device 11 exerts a sealing effect by the elastic body 22 of the gasket 12 sandwiched between the joined case 101A and cover 101B. The hardened liquid gasket 61 also fills the space within the recess 104 that houses the hinge 41 and the gaps that occur between the ends E of the pieces P of adjacent split gaskets 21. Because the hardened liquid gasket 61 retains a certain degree of elasticity even after hardening, it also exerts a sealing effect on these spaces and gaps.

[0050] Therefore, according to this embodiment, the case 101A and the cover 101B that are joined together can be sealed.

[0051] According to this embodiment, the pieces P of the split gasket 21 are connected in advance by the hinges 41. Therefore, when assembling the seal device 11, it is not necessary to manufacture the gasket 12 by connecting multiple pieces P. The assembly of the seal device 11 can be completed in a single process by simply joining the two members 101 with the gasket 12 sandwiched between them.

[0052] Therefore, according to this embodiment, the number of steps required to manufacture the sealing device 11 can be reduced, and manufacturing can be simplified.

[0053] According to this embodiment, the split gasket 21 can be folded, which allows the gasket 12 to be made smaller before use, thereby reducing the space required for storage and transportation.

[0054] According to this embodiment, since the elastic body 22 is coated on the seal surface 23, the seal surface 23 coated with the elastic body 22 can be easily obtained, and the manufacturing process can be simplified.

[0055] 4. Modifications Various modifications and changes are possible in the implementation.

[0056] For example, the folding manner of the split gasket 21 is not limited to the examples shown in Figures 2 and 3, and any manner can be adopted. The hinge 41 only needs to be provided on at least one pair of opposite sides of the rectangular shape.

[0057] A base treatment layer may be provided between the sealing surface 23 of each piece P of the split gasket 21 and the liquid gasket 61 .

[0058] In the process of assembling the sealing device 11, in this embodiment, the operation of aligning the case 101A and the cover 101B and joining them with the split gasket 21 sandwiched therebetween is illustrated as being performed at a stage before the liquid gasket 61 hardens. This timing between the hardening of the liquid gasket 61 and the above operation is merely an example, and in practice, the above operation may be performed at a stage after the liquid gasket 61 hardens.

[0059] The liquid gasket 61 is not limited to a formed-in-place gasket (FIPG), but may also be liquid rubber (rubber glue) or a cured-in-place gasket (CIPG). Unvulcanized rubber in a paste form is used as the liquid rubber. CIPG is an ultraviolet-curing silicone, and while FIPG cures by absorbing moisture in the air, CIPG cures in place when exposed to ultraviolet light or light.

[0060] To assemble the sealing device 11 using liquid rubber as the liquid gasket 61, the liquid rubber is applied to the recess 104. If necessary, the liquid rubber is also applied to a position of the case 101A or the cover 101B facing the recess 104.

[0061] The folded split gasket 21 is opened before or after the liquid rubber application operation and restored to the shape of the gasket 12.

[0062] The gasket 12, which has been restored to its original shape, is placed in a predetermined position on the case 101A. Then, the case 101A and the cover 101B are aligned so as to cover the opening 103 of the case 101A, and the two are joined together with the split gasket 21, which has been restored to the shape of the gasket 12, sandwiched therebetween.

[0063] The liquid rubber paste hardens by drying or vulcanization (heating). When the liquid gasket 61, which is liquid rubber, is hardened by drying, the operation of sandwiching the split gasket 21 between the case 101A and the cover 101B and joining them may be performed before the liquid rubber hardens or after it has hardened. When the liquid gasket 61 is hardened by vulcanization (heating), the above operation is performed while the liquid rubber is hardening or after it has hardened.

[0064] To assemble the sealing device 11 using CIPG as the liquid gasket 61, CIPG is applied to the recess 104. If necessary, CIPG is also applied to a position facing the recess 104 in the case 101A or the cover 101B.

[0065] Thereafter, the CIPG is cured by irradiating it with ultraviolet light or light.

[0066] The folded split gasket 21 is opened before or after the CIPG application operation and restored to the shape of the gasket 12.

[0067] The gasket 12, which has been restored to its original shape, is placed in a predetermined position on the case 101A. Then, the case 101A and the cover 101B are aligned so as to cover the opening 103 of the case 101A, and the two are joined together with the split gasket 21, which has been restored to the shape of the gasket 12, sandwiched between them. The joining operation is performed while the CIPG, which is the liquid gasket 61, is hardening or after it has hardened.

[0068] Any other variations or modifications are possible.

[0069] Second Embodiment

[0070] The second embodiment will be described with reference to Figures 13 to 17. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted where appropriate.

[0071] 1. Structure (1) Gasket (1-1) Split Gasket As shown in Figure 13, the gasket 12 of this embodiment includes a split gasket 31 that is split into four pieces P1 to P4, each having a flat sealing surface 23 coated with an elastic body 22 on its front and back surfaces. The split gasket 31 has an annular shape that becomes a rectangle when assembled. The four pieces P1 to P4 are a pair of pieces P1 and P3 that form the long sides of the rectangle, and a pair of pieces P2 and P4 that form the short sides. These four pieces P1 to P4 are combined to form the split gasket 31 into a rectangular shape.

[0072] The four pieces P1 to P4 of the split gasket 31 have adjacent end portions E at both ends. The adjacent end portions E of the four pieces P1 to P4 that make up the split gasket 31 are paired. In more detail, the following four types of end portions E are paired: (k) end portion E11 of piece P1 and end portion E22 of piece P2; (l) end portion E21 of piece P2 and end portion E32 of piece P3; (m) end portion E31 of piece P3 and end portion E42 of piece P4; and (n) end portion E41 of piece P4 and end portion E12 of piece P1.

[0073] The individual pieces P1 to P4 of the split gasket 31 are made of a metal material such as stainless steel, cold-rolled steel, galvanized steel, or aluminum alloy, and are coated in advance with the elastic body 22, for example.

[0074] The elastic body 22 is a rubber compound containing rubber as a main component. For example, at least one type of synthetic rubber selected from nitrile rubber, styrene butadiene rubber, fluororubber, acrylic rubber, and silicone rubber can be used as the material for the elastic body 22. The rubber compound using these materials may be foamed rubber.

[0075] (1-2) Connectors The four pieces P1 to P4 of the split gasket 31 are connected by connectors 51 at the four corners CR of the rectangular shape. The four corners CR are located at four locations: between pieces P1 and P2, between pieces P2 and P3, between pieces P3 and P4, and between pieces P4 and P1.

[0076] 14, the end faces E of the pieces P that are adjacent to each other at the four corners CR face each other. The end faces ES are not perpendicular to the longitudinal direction of the piece P, but are angled at 45 degrees.

[0077] 14 shows a state in which end E11 of piece P1 and end E22 of piece P2 face each other with end faces ES that form a 45-degree angle, forming a right angle CR. The end faces ES do not contact each other, leaving a gap G. This arrangement of adjacent pieces P is not limited to pieces P1 and P2, but is also the same for pieces P2 and P3, pieces P3 and P4, and pieces P4 and P1.

[0078] 13 to 15, the four pieces P1 to P4 of the split gasket 31 are provided with circular connecting pieces 52 with connecting holes 52a at both end parts E that form corners CR of the rectangular shape. The connecting pieces 52 are provided at positions that are further outward from the rectangular shape than the end faces ES.

[0079] 14 and 15, adjacent pieces P1 and P2 have their connecting pieces 52 overlapping each other, and a connecting device 51 passes through the connecting hole 52a. The connecting device 51 is, for example, a rivet, and passes through the connecting holes 52a provided in the two connecting pieces 52 and is prevented from coming off by the large diameter portions 51a at both ends. This connects the pieces P1 and P2 to be rotatable around an axis perpendicular to the seal surface 23.

[0080] When the connector 51 is a rivet, one of the large-diameter portions 51a is a head portion provided in advance, and the other is a portion whose diameter has been enlarged by being crushed. This type of connection structure between adjacent pieces P is not only between pieces P1 and P2, but also between pieces P2 and P3, pieces P3 and P4, and pieces P4 and P1.

[0081] The sealing surfaces 23 on both sides of each piece P of the split gasket 31 must be positioned in the same plane due to the structure that constitutes the gasket 12. In contrast, the connecting piece 52 overlaps two adjacent pieces P in the axial direction of the connector 51. Therefore, in this embodiment, the connecting piece 52 is thinned to half its original thickness so that the thickness of each piece P matches the thickness of the two overlapping connecting pieces 52.

[0082] Please refer to Figure 15, which is a cross-sectional view taken along line B-B in Figure 14. In Figure 15, the thinned connecting piece 52 of piece P1 is shown at the top, and the thinned connecting piece 52 of piece P2 is shown at the bottom.

[0083] The individual pieces P1 to P4 of the split gasket 31 are made of a metal material such as stainless steel, cold-rolled steel, galvanized steel, or aluminum alloy, and are coated in advance with the elastic body 22, for example.

[0084] The elastic body 22 is a rubber compound containing rubber as a main component. For example, at least one type of synthetic rubber selected from nitrile rubber, styrene butadiene rubber, fluororubber, acrylic rubber, and silicone rubber can be used as the material for the elastic body 22. The rubber compound using these materials may be foamed rubber.

[0085] When two adjacent pieces P are connected with a connector 51, these pieces P are connected so as to be able to rotate freely around the axis of the connector 51, but the amount of rotation is small because the non-thinned portions of the pieces collide with each other. The four pieces P1 to P4 are in a state where they are loosely connected, so that gaps G are formed between the mutually facing end faces ES provided on each end E.

[0086] (2) Sealing Device As shown in FIGS. 16 and 17 , the sealing device 11 sandwiches a gasket 12 between two members 101 (101A, 101B). The gasket 12 fills a gap G between the ends E of two adjacent pieces P with a liquid gasket 61. As an example, the liquid gasket 61 is a gasket made of one-component, room-temperature curing silicone called a FIPG (Formed-In-Place Gasket). The liquid gasket 61 is initially fluid and can be applied to various parts. When it reacts with moisture in the air, the liquid gasket 61 hardens.

[0087] 2. Assembly of the Sealing Device To join two components 101 (101A, 101B) via the split gasket 31 and assemble the sealing device 11, the gasket 12 is placed in a predetermined position on the case 101A. Then, the liquid gasket 61 is filled into the gap G between the end faces ES of two adjacent pieces P. After that, the case 101A and the cover 101B are aligned so as to cover the opening 103 of the case 101A, and the two are joined together with the split gasket 31 in between. This operation is performed before the liquid gasket 61 hardens and maintains its fluidity.

[0088] Once the liquid gasket 61 has hardened, the sealing device 11 is completed.

[0089] 3. Effects The sealing device 11 exerts a sealing effect by the elastic body 22 of the gasket 12 sandwiched between the joined case 101A and cover 101B. The hardened liquid gasket 61 also fills the gap G between the end faces ES of two adjacent pieces P. Since the hardened liquid gasket 61 retains a certain degree of elasticity even after hardening, it also exerts a sealing effect on the gap G.

[0090] Therefore, according to this embodiment, the case 101A and the cover 101B that are joined together can be sealed.

[0091] According to this embodiment, the pieces P of the split gasket 31 are connected in advance by the connectors 51. Therefore, when assembling the seal device 11, it is not necessary to manufacture the gasket 12 by connecting multiple pieces P. The assembly of the seal device 11 can be completed in a single process by simply joining the two members 101 with the gasket 12 sandwiched between them.

[0092] Therefore, according to this embodiment, the number of steps required to manufacture the sealing device 11 can be reduced, and manufacturing can be simplified.

[0093] According to this embodiment, since the elastic body 22 is coated on the seal surface 23, the seal surface 23 coated with the elastic body 22 can be easily obtained, and the manufacturing process can be simplified.

[0094] 4. Modifications Various modifications and changes are possible in the implementation.

[0095] For example, the connector 51 is not limited to a rivet, and any other rotary connection structure may be used, such as a pin or a recessed / protruding engagement structure that rotatably connects two members.

[0096] The connecting positions of the individual pieces P of the split gasket 31 by the connecting members 51 are not limited to the corners CR, but may also be positions where two pieces P are adjacent to each other on a straight line.

[0097] A base treatment layer may be provided between the sealing surface 23 of each piece P of the split gasket 31 and the liquid gasket 61 .

[0098] In the process of assembling the sealing device 11, in this embodiment, the operation of aligning the case 101A and the cover 101B and joining them with the split gasket 31 sandwiched therebetween is illustrated as being performed at a stage before the hardening of the liquid gasket 61. This timing between the hardening of the liquid gasket 61 and the above operation is merely an example, and in practice, the above operation may be performed at a stage after the hardening of the liquid gasket 61.

[0099] The liquid gasket 61 is not limited to a formed-in-place gasket (FIPG), but may also be liquid rubber (rubber glue) or a cured-in-place gasket (CIPG). Unvulcanized rubber in a paste form is used as the liquid rubber. CIPG is an ultraviolet-curing silicone, and while FIPG cures by absorbing moisture in the air, CIPG cures in place when exposed to ultraviolet light or light.

[0100] To assemble the sealing device 11 using liquid rubber as the liquid gasket 61, the gasket 12 is placed in a predetermined position on the case 101A.

[0101] Next, the gap G between the end faces ES of the two adjacent pieces P is filled with liquid rubber.

[0102] Thereafter, the case 101A and the cover 101B are aligned so as to cover the opening 103 of the case 101A, and the two are joined together with the split gasket 31 sandwiched therebetween.

[0103] The liquid rubber paste hardens by drying or vulcanization (heating). When the liquid gasket 61, which is liquid rubber, is hardened by drying, the operation of sandwiching the split gasket 31 between the case 101A and the cover 101B and joining them may be performed before the liquid rubber hardens or after it has hardened. When the liquid gasket 61 is hardened by vulcanization (heating), the above operation is performed while the liquid rubber is hardening or after it has hardened.

[0104] To assemble the sealing device 11 using CIPG as the liquid gasket 61, the gasket 12 is placed in a predetermined position on the case 101A.

[0105] Next, CIPG is filled into the gap G between the end faces ES of two adjacent pieces P, and the CIPG is cured by irradiating it with ultraviolet light or light.

[0106] Thereafter, the case 101A and the cover 101B are aligned so as to cover the opening 103 of the case 101A, and the two are joined together with the split gasket 31 in between. The joining operation is carried out while the CIPG, which is the liquid gasket 61, is hardening or after it has hardened.

[0107] Any other variations or modifications are possible.

[0108] 11 Sealing device 12 Gasket 21 Split gasket 22 Elastic body 23 Sealing surface 31 Split gasket 41 Hinge 42 Arm 43 Pin 51 Connecting tool 51a Large diameter portion 52 Connecting piece 52a Connecting hole 61 Liquid gasket 101 Two members 101A Case 101B Cover 102 Oil reservoir 103 Opening 104 Recess CR Corner E (E11, E12, E21, E22, ..., E81, E82) End E (E11, E12, E21, E22) End E (E11, E12, E21, E22, ..., E41, E42) End ES End face G Gap P (P1 to P8) Piece P (P1, P2) Piece P (P1 to P4) Piece

Claims

1. A gasket comprising: a metal split gasket divided into a number of pieces having flat sealing surfaces covered with an elastomer on both front and back sides, which form an annular shape when assembled; and a hinge that is fixed to each other across the sealing surfaces of two adjacent pieces on a straight line, and that rotates around an axis perpendicular to the longitudinal direction of the two pieces to foldably connect the two pieces.

2. The gasket according to claim 1, wherein the split gaskets when combined have a rectangular shape, and the hinge is provided on at least one pair of opposing sides forming the rectangular shape.

3. The gasket according to claim 2, wherein adjacent hinges are disposed on one side of the sealing surface and on the opposite side thereof, respectively.

4. A gasket as claimed in any one of claims 1 to 3, wherein the elastic body is coated on the sealing surface.

5. A gasket comprising: a metal split gasket divided into a plurality of pieces having flat sealing surfaces covered with an elastomer on both front and back sides, which form an annular shape when assembled; and a connector that connects the ends of two adjacent pieces together rotatably around an axis perpendicular to the sealing surfaces.

6. The gasket according to claim 5, wherein the combined split gaskets have a rectangular shape, and the connectors are provided at the four corners of the rectangular shape.

7. The gasket according to claim 5 or 6, wherein the elastic body is coated on the sealing surface.

8. A sealing device comprising: a metal split gasket divided into a plurality of pieces having flat sealing surfaces covered with an elastomer on both front and back surfaces, and which forms an annular shape when assembled; a hinge that is fixed across the sealing surfaces of two adjacent pieces in a straight line and rotates about an axis perpendicular to the longitudinal direction of the two pieces to foldably connect the two pieces; two members that are joined to each other with the sealing surfaces of the split gasket in between; a recess that is provided in at least one of the two members and that houses the hinge protruding from the sealing surfaces; and a liquid gasket that is filled in the recess and covers the connecting portion of the two pieces.

9. The seal device according to claim 8, wherein the sealed surfaces of the two members and the split gasket are rectangular in shape, and the hinge is provided on at least one pair of opposing sides of the rectangular shape.

10. The seal device according to claim 8, wherein adjacent hinges are disposed on one side of the seal surface and on the opposite side of the seal surface, respectively.

11. The sealing device according to claim 8, wherein the recess has the shape of a groove.

12. The sealing device according to claim 8, wherein the recess has the shape of a hole.

13. The seal device according to claim 8, wherein the elastic body is coated on the seal surface.

14. A sealing device according to any one of claims 8 to 13, wherein one of the two members is a case, and the other of the two members is a cover that covers an opening of the case.

15. A sealing device comprising: a metal split gasket divided into a plurality of pieces having flat sealing surfaces covered with an elastomer on both front and back sides, which form an annular shape when assembled; a connector that connects the ends of two adjacent pieces so that they can rotate around an axis perpendicular to the sealing surfaces; two members that are joined to each other with the sealing surfaces of the split gasket in between; and a liquid gasket filled in the gap between the opposing ends of the two pieces.

16. The sealing device according to claim 15, wherein the sealed surfaces of the two members and the split gasket have a rectangular shape, and the connectors are provided at the four corners of the rectangular shape.

17. The seal device according to claim 15, wherein the elastic body is coated on the seal surface.

18. A sealing device according to any one of claims 15 to 17, wherein one of the two members is a case, and the other of the two members is a cover that covers an opening of the case.

Images