Gasket

Abstract

To provide a gasket 1 which can temporarily fix with efficiency without providing a complex mechanism.SOLUTION: In one embodiment of the present invention, the gasket 1 includes: a body 10 which has a plate part 12 outside of a through hole 11; a bead part 20 which is provided to surround an outer side of an edge 11a of the through hole 11 in the plate part 12; and a plurality of attachment holes 30 which are provided at a position outside of the beat part 20 in the plate part 12 and into which the attachment bolt 50 is inserted. When at least one of the plurality of attachment holes 30 is a first attachment hole 301, an edge 301a of the first attachment hole 301 has a plurality of projections 310. The maximum diameter r1 of an inner diameter of the first attachment hole 301 is larger than an outer diameter d of the attachment bolt 50, the minimum diameter r2 of the inner diameter of the first attachment hole 301 is smaller than the outer diameter d of the attachment bolt 50, and a thickness t of the plate part 12 is smaller than a width W of the attachment bolt 50 at a first position P1 of a screw groove 52.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a gasket that is sandwiched between two members when they are fastened together. [Background technology]

[0002] Patent Document 1 discloses a gasket in which mounting bolts can be easily inserted into bolt insertion holes, allowing for simple placement on a flange surface, and furthermore, which can be easily temporarily fastened to the mounting bolts, improving work efficiency during installation. This gasket is sandwiched between a first member having a plurality of mounting bolts protruding downward and a second member abutting the first member, and at least one of the bolt insertion holes through which the mounting bolts pass is formed as a bolt engagement hole having a diameter smaller than the other bolt insertion holes and larger than the outer diameter of the mounting bolts, but which is inclined relative to the first member when the mounting bolt is inserted toward the first member, and at least a portion of the peripheral portion of the insertion hole is formed as a bolt engagement hole with a diameter that engages with the threads of the mounting bolt to temporarily fasten the gasket.

[0003] Patent Document 2 discloses a gasket that can be temporarily fixed to prevent the bolt from falling off when fitted onto it. This gasket is an annular gasket used to seal between a bolt and its mounting member, and is characterized in that it comprises an annular metal retaining plate and an annular rubber plate with a U-shaped cross section that is attached to the surface of the retaining plate except for the outer periphery, and the annular rubber plate has imaginary small cylindrical holes that contact the tops of ridges provided at regular intervals in the thickness direction on its inner periphery, and imaginary large cylindrical holes that contact the bottoms of recessed grooves between the ridges, the diameter of the small cylindrical holes being slightly smaller than the diameter of the bolt, and the diameter of the large cylindrical hole being approximately the same as the diameter of the bolt.

[0004] Patent Document 3 discloses a metal gasket that holds a threaded fastener, such as a threaded bolt, that penetrates an exhaust manifold without damaging the threads of the threaded bolt. The gasket seals two metal surfaces that are fastened together by at least one threaded fastener having a major diameter and a root diameter of the threads, and includes a metal plate having a first minor diameter larger than the major diameter and having at least one hole for receiving the threaded fastener and a plurality of tabs extending radially inward that form a second minor diameter larger than the root diameter and smaller than the outer diameter, at least one of the tabs having a tip extending from the first minor diameter to the second minor diameter and having sides formed in part by adjacent scalloped portions, with a circumferential gap between at least two of the tabs large enough to allow the threaded fastener to be screwed into and out of the hole.

[0005] When fastening a gasket between two components, interference with surrounding components or the installation angle may prevent the use of stud bolts. In such cases, it is difficult to hold the gasket between the components and to grasp its position, which is hidden between the components. This makes aligning the gasket as well as the two components time-consuming. Therefore, incorporating a temporary fastening mechanism into the gasket can improve workability. Examples of temporary fastening mechanisms include bending a portion of the gasket or attaching a separate temporary fastening part. However, this leads to a more complex gasket structure, an increase in thickness, and an increase in manufacturing steps. Furthermore, when temporarily fastening a gasket due to the size relationship between the gasket's mounting hole and the mounting bolt, if it is difficult to insert the mounting bolt into the mounting hole, workability is compromised. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-051189 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-071025 [Patent Document 3] Japanese Patent Application Publication No. 8-061502 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a gasket that can be temporarily fastened with good workability without providing a complex mechanism, and can be clamped and fastened between members. [Means for solving the problem]

[0008] One aspect of the present invention is a gasket comprising: a main body having a through hole in the center and a plate-shaped portion outside the through hole; a bead portion arranged to surround the outside of the edge of the through hole on the plate-shaped portion; and a plurality of mounting holes arranged in the plate-shaped portion at positions outside the bead portion and into which mounting bolts are inserted, wherein at least one of the plurality of mounting holes is designated a first mounting hole, the edge of the first mounting hole has a plurality of protrusions that protrude toward the center of the first mounting hole, the maximum diameter of the first mounting hole is larger than the outer diameter of the mounting bolt and the minimum diameter of the first mounting hole is smaller than the outer diameter of the mounting bolt, the thickness of the plate-shaped portion is smaller than the width of the thread groove of the mounting bolt at a first position, and the first position is a position away from the tip of the thread of the mounting bolt toward the root of the thread by protrusion length L, where L is the protrusion length of the protrusions. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a gasket that can be temporarily fixed with good workability without providing a complex mechanism. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a plan view illustrating a configuration of a gasket according to an embodiment of the present invention. FIG. [Figure 2] 1(a) and 1(b) are cross-sectional views illustrating the configuration of a gasket according to the present embodiment. [Figure 3] FIG. 4 is an enlarged plan view of a first mounting hole. [Figure 4] FIG. 4 is a schematic cross-sectional view showing the relationship between a first mounting hole and a mounting bolt. [Figure 5] FIG. 10 is a partial perspective view showing an example of gasket installation. [Figure 6] FIG. 10 is a partial perspective view showing an example of gasket installation. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will now be described with reference to the drawings. The embodiments described below are preferred examples of the present invention, and therefore various technically preferable limitations are applied thereto, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is particularly limited. Furthermore, in each drawing, similar components are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0012] (Gasket configuration) FIG. 1 is a plan view illustrating the configuration of a gasket according to this embodiment. 2(a) and 2(b) are cross-sectional views illustrating the configuration of the gasket according to this embodiment, where Fig. 2(a) shows a cross-sectional view taken along line A-A' in Fig. 1, and Fig. 2(b) shows a cross-sectional view taken along line B-B' in Fig. 1. The gasket 1 is sandwiched between two components when they are fastened together, and is used to ensure airtightness between the components. The gasket 1 according to this embodiment is sandwiched between the cylinder block and manifold of an internal combustion engine, for example, and serves to prevent leakage of gas (intake air, exhaust air, etc.) from between the components.

[0013] The gasket 1 according to this embodiment includes a main body 10, a bead portion 20, and a plurality of mounting holes 30. The main body 10 has a through hole 11 provided in the center. The through hole 11 serves as a port (a hole for passing gas, liquid, etc.) that allows access between two components when the two components are fastened together with the gasket 1 sandwiched between them. The main body 10 has a plate-like portion 12 provided on the outside of the through hole 11.

[0014] The bead portion 20 is provided at a position on the plate-like portion 12 of the main body 10 outside the through-hole 11 so as to surround the edge 11a of the through-hole 11. As shown in Figure 2, the bead portion 20 is a bulging portion formed by bending a portion of the plate-like portion 12. When two components are fastened together with the gasket 1 sandwiched between them, the bead portion 20 acts as a bank, improving the sealing performance.

[0015] The multiple mounting holes 30 are provided in positions on the plate-like portion 12 outside the bead portion 20. The mounting holes 30 are holes into which mounting bolts 50 (see FIG. 5) are inserted when fastening two components with the gasket 1 sandwiched between them with the mounting bolts. In the example shown in FIG. 1, four mounting holes 30 (30A, 30B, 30C, and 30D) are provided in the plate-like portion 12, which is outside the bead portion 20. However, the number of mounting holes 30 is not limited to this.

[0016] The main body 10 is formed from a material that can ensure the functions (sealing properties, heat resistance, durability, etc.) of the gasket 1. For example, the main body 10 has a core member 10a and a covering member 10b that covers the front and back of the core member 10a. It is preferable that the covering member 10b be formed from a material with a lower elastic modulus than the core member 10a. For example, the core member 10a is formed from a material containing metal (e.g., steel), and the covering member 10b is formed from a material containing resin (e.g., nitrile rubber).

[0017] In the gasket 1 according to this embodiment, when at least one of the multiple mounting holes 30 is the first mounting hole 301, the edge 301a of the first mounting hole 301 has multiple protrusions 310 that protrude toward the center of the first mounting hole 301. In the example of the gasket 1 according to this embodiment, one of the four mounting holes 30 is the first mounting hole 301, and this first mounting hole 301 is provided with the protrusion 310. Note that two or more of the multiple mounting holes 30 may be the first mounting holes 301.

[0018] FIG. 3 is an enlarged plan view of the first mounting hole. FIG. 4 is a schematic cross-sectional view showing the relationship between the first mounting hole and the mounting bolt. Edge 301a of first mounting hole 301 has protrusions 310 that protrude from maximum circle R1 toward the center of first mounting hole 301, with maximum circle R1 being a circle whose diameter is the largest diameter (maximum diameter r1) among the inner diameters of first mounting hole 301. In the example shown in FIG. 3, six protrusions 310 are provided along the circumference of maximum circle R1. Note that the number of protrusions 310 is not limited to six. A circle that touches the tip of each of the multiple protrusions 310 is minimum circle R2, whose diameter is the smallest diameter (minimum diameter r2) among the inner diameters of first mounting hole 301.

[0019] In the gasket 1 according to this embodiment, the maximum diameter r1 of the inner diameters of the first mounting hole 301 is larger than the outer diameter d of the mounting bolt 50, and the minimum diameter r2 of the inner diameters of the first mounting hole 301 is smaller than the outer diameter d of the mounting bolt 50. Furthermore, the thickness t of the plate-like portion 12 of the main body 10 is smaller than the width W of the thread groove 52 of the mounting bolt 50 at a first position P1. Here, when the protruding length of the protruding portion 310 is L, the first position P1 is a position that is away from the tip 51p of the thread 51 of the mounting bolt 50 toward the root of the thread (in a direction perpendicular to the central axis of the bolt) by the protruding length L.

[0020] By providing such protrusion 310 on edge 301a of first mounting hole 301, when attempting to insert mounting bolt 50 perpendicularly into first mounting hole 301, threads 51 of mounting bolt 50 come into contact with protrusion 310 of first mounting hole 301. When mounting bolt 50 is pushed further in in this state, protrusion 310 deforms within the range of elastic deformation of protrusion 310 (including slight plastic deformation), expanding the inner diameter and allowing mounting bolt 50 to be inserted into first mounting hole 301.

[0021] Furthermore, when inserting the mounting bolt 50 into the first mounting hole 301, slightly rocking the mounting bolt 50 while the threads 51 of the mounting bolt 50 are in contact with the protrusion 310 changes the insertion position and angle of the mounting bolt 50 relative to the first mounting hole 301, making it easier for the threads 51 to pass over the position of the protrusion 310.

[0022] For example, if the insertion angle of the mounting bolt 50 is oblique to the direction perpendicular to the first mounting hole 301, the contact area between the thread 51 and the protrusion 310 will be smaller than when the mounting bolt 50 is inserted perpendicularly. Furthermore, by slanting the mounting bolt 50, one of the multiple protrusions 310 will be able to clear the thread 51 without hitting it. This reduces the insertion resistance of the mounting bolt 50, making it easier to insert. In this case, if the angle of the mounting bolt 50 is repeatedly tilted to one side and the other relative to the perpendicular while being inserted, the thread 51 on one side and the other of the mounting bolt 50 will sequentially clear the position of the protrusion 310, making it easier to insert.

[0023] Furthermore, in the first mounting hole 301 of the gasket 1 according to this embodiment, the thickness t of the plate-like portion 12 is smaller than the width W of the thread groove 52 of the mounting bolt 50 at the first position P1. Therefore, when the mounting bolt 50 is moved to one side in the inner diameter direction of the first mounting hole 301, the protrusion 310 located on one side of the mounting bolt 50 will enter the thread groove 52 deeper than the protrusion length L. As a result, the protrusion 310 located on the other side of the mounting bolt 50 will be positioned further outside the thread groove 52 (outside the tip 51p of the thread 51 in FIG. 4). Therefore, the insertion resistance caused by the mounting bolt 50 hitting the protrusion 310 is reduced, making it easier to insert.

[0024] On the other hand, because the minimum diameter r2 of the first mounting hole 301 is smaller than the outer diameter d of the mounting bolt 50, the thread 51 of the mounting bolt 50 climbs over the protruding portion 310, and the protruding portion 310 recovers from its elastic deformation, so that the protruding portion 310 becomes caught on the thread 51. This prevents the gasket 1 from falling off the mounting bolt 50.

[0025] In the gasket 1 according to this embodiment, multiple protrusions 310 are provided in the circumferential direction of the first mounting hole 301. If there were only one protrusion 310, when the mounting bolt 50 is inserted into the first mounting hole 301, if it becomes biased, the protrusion 310 would not be able to adequately catch on the thread 51, which would likely cause the gasket 1 to fall off. Therefore, by providing multiple protrusions 310, it is possible to effectively prevent the gasket 1 from falling off.

[0026] In the gasket 1 according to this embodiment, six protrusions 310 are provided at equal intervals around the circumferential direction of the first mounting hole 301. That is, the six protrusions 310 are provided at 60° intervals around the circumferential direction of the first mounting hole 301. This ensures that one of the protrusions 310 will catch on the threads 51 regardless of the direction in which the mounting bolt 50 is biased around the first mounting hole 301. Furthermore, when the mounting bolt 50 is inserted into the first mounting hole 301, the equally spaced protrusions 310 provide a stable and appropriate insertion resistance regardless of the direction of inclination of the mounting bolt 50. That is, when the mounting bolt 50 is inserted into the first mounting hole 301, an appropriate resistance is provided (for example, a force sufficient to easily elastically deform the protrusions 310 when the mounting bolt 50 is pushed in by hand), and after insertion, the protrusions 310 catch on the threads 51, preventing the gasket 1 from falling off.

[0027] Furthermore, in the gasket 1 according to this embodiment, the bead portions 20 are provided on the plate-like portion 12, and the bead portions 20 can increase the airtightness of the gasket 1. In other words, airtightness at the mounting hole 30 is not as important as at the bead portions 20. Furthermore, even if a protrusion 310 is provided on the edge 301a of the first mounting hole 301, the protrusion 310 protrudes toward the inside of the hole and does not affect the thickness of the gasket 1. Therefore, even if the protrusion 310 is provided on the first mounting hole 301, the gasket 1 can ensure sufficient airtightness.

[0028] In one example of a manufacturing method for gasket 1, the surface of a plate-shaped steel material that will become core member 10a is coated with nitrile rubber that will become covering member 10b, and then a mold is used to press through holes 11, mounting holes 30, and bead portions 20, along with the outer shape, to form them. When through holes 11 and mounting holes 30 are formed by pressing, no nitrile rubber covering member 10b is provided on edge 301a of first mounting hole 301, exposing core member 10a. Since covering member 10b is not provided on edge 301a, the maximum diameter r1 and minimum diameter r2 of first mounting hole 301 are accurately determined. Therefore, the resistance felt when inserting mounting bolt 50 into first mounting hole 301 can be stabilized.

[0029] It is also preferable that the tip of protrusion 310 of first attachment hole 301 has a curved shape. Furthermore, it is also preferable that the base end of protrusion 310 has a curved shape. By making the tip and base end of protrusion 310 have a curved shape, it is not necessary to use a special mold for press working, and the life of the mold can be extended.

[0030] Here, an example of the specific sizes of first mounting hole 301 and mounting bolt 50 will be shown. The mounting bolt 50 has a metric coarse thread with a nominal thread size of M6. The pitch p of the M6 ​​bolt is 1.0000 mm, the outer diameter d is 6.0000 mm, the effective diameter d2 is 5.3500 mm, the root diameter d1 is 4.9170 mm, and the lead angle φ is 3.4049 degrees. An example of the size of the first mounting hole 301 of the gasket 1 in this embodiment is as follows: maximum diameter r1 is 6.2000 mm, minimum diameter r2 is 5.6000 mm, thickness t is 0.3800 mm (thickness of core member 10a 0.25 mm, thickness of covering member 10b 0.065 mm), protrusion length L of protrusion 310 is 0.3 mm, and width W of thread groove 52 at first position P1 is 0.5225 mm.

[0031] (Example of gasket installation) 5 and 6 are partial perspective views showing examples of gasket attachment. Fig. 5 shows the state in which the mounting bolt 50 is aligned with the first mounting hole 301, and Fig. 6 shows the state in which the mounting bolt 50 has been inserted into the first mounting hole 301. For ease of explanation, Figs. 5 and 6 do not show the two components to be fastened with the gasket 1 between them.

[0032] The gasket 1 according to this embodiment is provided with four mounting holes 30 (30A, 30B, 30C, 30D) (see FIG. 1). One of the four mounting holes 30 (30A, 30B, 30C, 30D) is a first mounting hole 301. It is preferable that the first mounting hole 301 is one of the two mounting holes 30 among the plurality of mounting holes 30 that have the longest center-to-center distance.

[0033] In the example shown in FIG. 1 , the center-to-center distance between mounting hole 30A and mounting hole 30D is longer than the center-to-center distance between any two other mounting holes 30 (mounting hole 30A and mounting hole 30B, mounting hole 30A and mounting hole 30C, mounting hole 30B and mounting hole 30C, mounting hole 30B and mounting hole 30D, and mounting hole 30C and mounting hole 30D). Therefore, mounting hole 30D, which is one of mounting holes 30A and 30D, becomes first mounting hole 301. Note that mounting hole 30A may also be used as first mounting hole 301. The two mounting holes 30 with the longest center-to-center distance are the mounting holes 30 located farthest from the center of gravity of gasket 1, and therefore are among the parts that require the most support when attaching gasket 1. By setting the mounting holes 30 in this portion as first mounting holes 301, mounting bolts 50 can be inserted into the first mounting holes 301 to temporarily fasten and support the gasket 1.

[0034] When clamping the gasket 1 between two components and fastening them together, first, a mounting bolt 50 is passed through a bolt insertion hole in one of the components. Then, the mounting bolt 50 protruding from the bolt insertion hole is aligned with the first mounting hole 301 of the gasket 1 (see FIG. 5 ), and the mounting bolt 50 is inserted into the first mounting hole 301. When inserting the mounting bolt 50 into the first mounting hole 301, the mounting bolt 50 is slightly rocked, so that the mounting bolt 50 is inserted into the first mounting hole 301 with appropriate resistance. As a result, as shown in FIG. 6 , with the mounting bolt 50 inserted into the first mounting hole 301, the protrusion 310 catches on the thread 51 of the mounting bolt 50, temporarily securing the gasket 1. After insertion, the gasket 1 is temporarily secured to the extent that it will not slip off the mounting bolt 50 and fall off.

[0035] Next, one component to which the gasket 1 is temporarily attached is aligned with the other component, and the mounting bolt 50 inserted into the first mounting hole 301 is temporarily tightened into the threaded hole of the other component. Because the gasket 1 is temporarily attached to the mounting bolt 50, the one component can be aligned with the other component without worrying about the gasket 1 falling off. For example, when arranging one component to the mounting position, it may be necessary to access the component while avoiding interference with peripheral equipment. Even in such cases, the worker can concentrate on accessing and aligning the one component without worrying about the gasket 1 falling off. Then, while supporting the one component with one hand in the aligned state, the worker can tighten the mounting bolt 50 with a tool held in the other hand. After temporarily tightening one mounting bolt 50, another mounting bolt 50 is inserted into the other mounting hole 30 and temporarily tightened. Then, all mounting bolts 50 are fully tightened.

[0036] According to this embodiment, it is possible to provide a gasket 1 that can be temporarily fixed with good workability without providing a complex mechanism, and can be fastened by being sandwiched between members.

[0037] The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims. For example, the material and shape of the gasket 1, and the number and arrangement of the mounting holes 30 are not limited to these. Furthermore, the configurations of the above embodiment can be partially omitted or arbitrarily combined differently from those described above. [Explanation of symbols]

[0038] 1...gasket, 10...main body, 10a...core member, 10b...covering member, 11...through hole, 11a...edge, 12...plate-shaped portion, 20...bead portion, 30...mounting hole, 30A...mounting hole, 30B...mounting hole, 30C...mounting hole, 30D...mounting hole, 50...mounting bolt, 51...thread, 51p...tip, 52...thread groove, 301...first mounting hole, 301a...edge, 310...protrusion, P1...first position, R1...maximum circle, R2...minimum circle, d...outside diameter, d1...root diameter, d2...pitch diameter, p...pitch, r1...maximum diameter, r2...minimum diameter, t...thickness, φ...lead angle

Claims

1. a main body having a through hole at a center portion and a plate-like portion outside the through hole; a bead portion provided in the plate-like portion so as to surround the outside of the edge of the through hole; a plurality of mounting holes, each of which is provided at a position on the plate-shaped portion outside the bead portion, and into which a mounting bolt is inserted; A gasket comprising: At least one of the plurality of mounting holes is a first mounting hole, an edge of the first mounting hole has a plurality of protrusions that protrude toward the center of the first mounting hole; The maximum inner diameter of the first mounting hole is larger than the outer diameter of the mounting bolt, the smallest inner diameter of the first mounting hole is smaller than the outer diameter of the mounting bolt; a thickness of the plate-shaped portion is smaller than a width of the thread groove of the mounting bolt at a first position; a gasket characterized in that the first position is a position that is a protruding length L from the tip of the thread of the mounting bolt toward the root of the thread, where L is a protruding length of the protrusion.

2. The gasket according to claim 1 , wherein the first mounting hole is one of two mounting holes among the plurality of mounting holes that have the longest center-to-center distance between any two mounting holes.

3. The gasket according to claim 1 , wherein the plurality of protrusions are provided at equal intervals in a circumferential direction of the first mounting hole.

4. The gasket according to claim 3 , wherein six of the plurality of protrusions are provided in the circumferential direction of the first mounting hole.

5. The gasket according to claim 1 , wherein the main body portion includes a core member and a covering member that is made of a material having a lower elastic modulus than the core member and covers both sides of the core member.

6. The gasket according to claim 5 , wherein the core member includes a metal and the covering member includes a resin.

7. The gasket according to claim 5 , wherein the covering member is not provided on an edge of the first mounting hole, so that the core member is exposed.

8. The gasket according to claim 1 , wherein the tip of the protrusion has a curved shape.

9. The gasket according to claim 1 , wherein the base end of the protrusion has a curved shape.

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