Washer

Abstract

To provide a washer which can suppress slackening upon fixing a stationary member with the washer.SOLUTION: A washer 50 is used for being tighten to a bolt 30 passing through a heat insulation material 20, and the gravity center position of the washer 50 is shifted downwards with respect to the position of a hole 51 through which the bolt 30 passes. A washer 50f is provided between the heat insulation material 20 and a nut 41 to be tighten to the bolt 30 passing through the heat insulation material 20 and has a recessed part 52 for storing the nut 41, and a gap with the nut 41 in the recessed part 52 may be buried with a filler member 53.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This disclosure relates to washers.

Background Art

[0002] Patent Document 1 discloses a heat insulation structure in which a heat insulating material is disposed in a vacuum carburizing furnace. Patent Documents 2 and 3 disclose washers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Fixing members such as heat insulating materials fasten bolts via washers, but during the use of a vacuum carburizing furnace, the washers and nuts may loosen and fall into the furnace.

[0005] An object of this disclosure is to solve such problems, and an object is to provide a washer capable of suppressing loosening when fixing a fixing member with a washer.

Means for Solving the Problems

[0006] A washer according to an aspect of this disclosure is a washer that is tightened to a bolt penetrating a fixing member, and a center of gravity position of the washer is shifted downward with respect to a position of a hole through which the bolt penetrates.

Effects of the Invention

[0007] According to this disclosure, it is possible to provide a washer that can suppress loosening when fixing a fixing member with a washer. [Brief explanation of the drawing]

[0008] [Figure 1] (a) and (b) are cross-sectional and front views illustrating washers according to comparative examples, with (a) showing the cross-section along line 1A-1A in (b). [Figure 2] This is a partial cross-sectional perspective view illustrating a configuration in which a bolt that penetrates the heat insulation material of a heat treatment furnace according to a comparative example is fastened at both ends with a nut and washer. [Figure 3] (a) and (b) are a cross-sectional view and a front view illustrating a washer according to Embodiment 1, where (a) shows the cross-section of line 3A-3A in (b). (c) and (d) are a cross-sectional view and a front view illustrating a teardrop-shaped washer according to Modification 1 of Embodiment 1, where (c) shows the cross-section of line 3C-3C in (d). (e) and (f) are a cross-sectional view and a front view illustrating an eccentric diamond-shaped washer according to Modification 2 of Embodiment 1, where (e) shows the cross-section of line 3E-3E in (f). [Figure 4] (a) and (b) are cross-sectional and front views illustrating a mixed-material washer according to modification 3 of Embodiment 1, where (a) shows the cross-section along line 4A-4A in (b). (c) and (d) are cross-sectional and front views illustrating a washer with an irregular surface shape according to modification 4 of Embodiment 1, where (c) shows the cross-section along line 4C-4C in (d). (e) and (f) are cross-sectional and front views illustrating a washer with an irregular thickness according to modification 5 of Embodiment 1, where (e) shows the cross-section along line 4E-4E in (f). [Figure 5] This figure illustrates the combinations of washer configurations according to Embodiment 1 and Modifications 1 to 5. [Figure 6] (a) and (b) are a cross-sectional view and a front view illustrating a washer according to Embodiment 2, where (a) shows the cross-section of line 6A-6A in (b). (c) and (d) are a cross-sectional view and a front view illustrating a washer according to Embodiment 3, where (c) shows the cross-section of line 6C-6C in (d). [Modes for carrying out the invention]

[0009] The specific configuration of this embodiment will be described below with reference to the drawings. The following description illustrates preferred embodiments of the disclosure, and the scope of the disclosure is not limited to the following embodiments. Furthermore, not all of the configurations described in this embodiment are necessarily essential as means to solve the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted as necessary.

[0010] Before describing the washer according to the embodiment, a comparative example washer and its problems will be described. Then, the washer according to the embodiment will be described in comparison with the comparative example washer. This will clarify the washer according to the embodiment. Note that the comparative example washer and its problems are also included within the scope of the technical concept of the embodiment.

[0011] (Comparative example) Figures 1(a) and 1(b) are cross-sectional and front views illustrating washers according to comparative examples, with (a) showing the cross-section along line 1A-1A in (b). Figure 2 is a partial cross-sectional perspective view illustrating a configuration in which both ends of a bolt that penetrates the heat insulation material of a heat treatment furnace according to comparative examples are fastened with nuts and washers. As shown in Figures 1 and 2, for example, in order to prevent the heat insulation material 20 inside the heat treatment furnace 10, such as a vacuum carburizing furnace, from falling, the heat insulation material 20 is fixed to the inside of the heat treatment furnace 10 using bolts 30, nuts 40 and washers 150. The internal temperature of the heat treatment furnace 10 is, for example, around 900°C to 1000°C, and it is necessary to suppress heat dissipation with the heat insulation material 20 for energy saving and safety. Note that the internal temperature of the heat treatment furnace 10 is not limited to 900°C to 1000°C, but may be lower than 900°C or higher than 1000°C.

[0012] The thermal insulation material 20 is, for example, placed on the inner wall surface of the furnace wall 11 of the heat treatment furnace 10. In this embodiment, the thermal insulation material 20 is described as an example of a fixing member that is fixed using bolts 30, nuts 40 and washers 150. The fixing member is not limited to thermal insulation material as long as it is fixed using bolts 30, nuts 40 and washers 150.

[0013] The insulation material 20 is secured by fastening both ends of a bolt 30, which penetrates both the furnace wall 11 and the insulation material 20, with nuts 40 and washers 150. The nut 40 fastens one end of the bolt 30 on the outer wall surface 12 of the furnace wall 11. The washer 150 fastens the other end of the bolt 30 on the insulation material 20, which is placed on the inner wall surface 13 of the furnace wall 11.

[0014] The bolt 30 penetrates through holes provided in the furnace wall 11 and the insulation material 20. One end of the bolt 30 is exposed on the outer wall surface 12 of the furnace wall 11. The other end of the bolt 30 is exposed on the insulation material 20 placed on the inner wall surface 13 of the furnace wall 11. Both ends of the bolt 30 have screw threads. Therefore, one end of the bolt 30 is fixed by a nut 40. The other end of the bolt 30 is fixed by a washer 150. Thus, the bolt 30 includes a type that has screw threads at both ends and is fastened with nuts 40 or the like at both ends.

[0015] The nut 40 has a hole with a screw thread formed on its inner circumference. The nut 40 is fixed to one end of the bolt 30.

[0016] The washer 150 is, for example, plate-shaped. The washer 150 may be circular or rectangular when viewed from the direction of the hole 151, that is, from the direction perpendicular to the plate surface. Figure 1 shows a washer 150 with a circular plate surface, and Figure 2 shows a washer 150 with a rectangular plate surface. The washer 150 has a hole 151. The hole 151 of the washer 150 extends in a direction perpendicular to the plate surface. The hole 151 may penetrate from one plate surface in contact with the insulation material 20 to the other plate surface on the inside of the heat treatment furnace 10. The hole 151 may extend from one plate surface and have a bottom inside the washer 150.

[0017] The hole 151 of the washer 150 is formed so as to pass through the center of gravity of the washer 150. Specifically, when the washer 150 is supported at a single point so that the plate surface of the washer 150 is horizontal, the hole 151 is formed at the balanced center of gravity. When the thickness of the plate-shaped washer 150 is uniform, the hole 151 is formed at the center of gravity of the plate surface of the washer 150 as viewed from the direction in which the hole 151 extends, that is, the direction perpendicular to the plate surface. For example, when the plate surface is circular, the hole 151 is formed at the center of the circular plate surface. For example, when the plate surface is square or rectangular, the hole 151 is formed at the intersection of the diagonals of the plate surface.

[0018] The hole 151 of the washer 150 is a hole 151 into which the bolt 30 fits. The bolt 30 may penetrate through the hole 151. The inner peripheral surface of the hole 151 of the washer 150 may have a thread groove. Therefore, the bolt 30 may be screwed into the hole 151. The washer 150 is tightened to the other end of the bolt 30 that penetrates the heat insulating material 20. After tightening the washer 150 to the other end of the bolt 30, the washer 150 and the bolt 30 may be fixed by welding so as not to loosen during use. In a heat treatment environment, the heat insulating material 20 may shrink due to heat. In this case, a clearance may occur between the washer 150 and the heat insulating material 20. However, if it is possible to prevent the heat insulating material 20 from falling into the furnace, the occurrence of a small amount of clearance can be tolerated.

[0019] When the washer 150 and the bolt 30 are not fixed by welding, due to the use of the heat treatment furnace 10 such as opening and closing the door of the heat treatment furnace 10, the washer 150 may rotate, and the washer 150 may gradually loosen and fall into the heat treatment furnace 10. Then, the fallen washer 150 or the like may hit the heat treatment object such as the product in the heat treatment furnace 10, resulting in appearance damage. In addition, an abnormality may occur when the product is conveyed out of the furnace. Therefore, in order to prevent such appearance damage and abnormalities in advance, it is essential to suppress the rotation of the washer 150.

[0020] However, when welding the washers 150 to the bolts 30, welding work is required for each washer 150. For example, welding work is required when manufacturing the heat treatment furnace 10 and when periodically replacing the insulation material 20. Fixing dozens of washers 150 requires an enormous amount of welding time.

[0021] Furthermore, although the purpose is to suppress the rotation of the washer 150, it is necessary to make the line layout of the heat treatment furnace 10 as compact as possible, so stacking multiple nuts 40 should be avoided. For these reasons, there was a need for a washer that could suppress loosening when fixing the fixing member with a washer, without requiring welding.

[0022] (Embodiment 1) Next, a washer according to Embodiment 1 will be described. Figures 3(a) and 3(b) are a cross-sectional view and a front view illustrating a washer 50 according to Embodiment 1, where (a) shows the cross-section along line 3A-3A in (b). As shown in Figure 3, in this embodiment, the hole 51 of the washer 50 is formed eccentrically at a position offset from the center of gravity of the washer 50. Specifically, the hole 51 is formed at a position offset from the center of gravity at which the washer 50 balances when its plate surface is supported at one point so that it is horizontal.

[0023] Therefore, when the ends of the bolt 30 that passes through the insulation material 20 are tightened with nuts 40 and washers 50, the center of gravity of the washer 50 is shifted downward relative to the position of the hole 51 through which the bolt 30 passes. In this way, the center of gravity of the washer 50 is lower than the center of rotation of the washer 50, so unless a continuous force is applied to rotate it counterclockwise by more than 180 degrees, the washer 50 will return to its original position, that is, the position where the center of gravity of the washer 50 is shifted downward from the hole 51, due to its own weight.

[0024] For example, the washer 20 of the comparative example was fixed to the door of an actual heat treatment furnace 10 using the washer 150 of the comparative example and the washer 50 of the embodiment 1, and a repeated operation verification test was performed approximately N=50 times. As a result, each time vibration was applied by opening and closing the door, the washer 150 of the comparative example (without welding) gradually rotated in the loosening direction. In contrast, the washer 50 of the embodiment 1 (without welding) did not move at all, and it was confirmed that loosening did not progress. From this, it can be seen that by setting the center of gravity of the washer 50 below the center of rotation, the effect of suppressing the rotation of the washer 50 can be achieved (hereinafter referred to as the eccentric effect). Thus, the washer 50 of this embodiment, by offsetting the hole 51 from the center of gravity, can suppress loosening when fixing the heat insulation material 20 with the washer 50, while eliminating the need for welding, compared to the comparative example.

[0025] (modified version) Next, a modified example of the washer 50 will be described. Figures 3(c) and (d) are a cross-sectional view and a front view illustrating a teardrop-shaped washer according to Modification 1 of Embodiment 1, where (c) shows the cross-section along the 3C-3C line in (d). As shown in Figures 3(c) and (d), the shape of the washer 50a when viewed from the direction of the hole 51a is teardrop-shaped. Specifically, the washer 50a has the cross-sectional shape of a water droplet. The center of gravity of the washer 50a is eccentrically shifted downward from the hole 51a. By adopting this shape, the center of gravity of the washer 50a can be set below the center of rotation, and the aforementioned eccentric effect that suppresses the rotation of the washer 50a can be obtained. Furthermore, by making the shape of the washer 50a teardrop-shaped, the range over which it can be eccentric can be increased compared to a circular shape. Therefore, it can be made more stable against vibration and external forces.

[0026] Figures 3(e) and (f) are a cross-sectional view and a front view illustrating an eccentric diamond-shaped washer according to a modification 2 of Embodiment 1, where (e) shows the cross-section along the 3E-3E line in (f). As shown in Figures 3(e) and (f), the shape of the washer 50b when viewed from the direction of the hole 51b includes an eccentric diamond shape. Specifically, the washer 50b is a quadrilateral formed by connecting one side of an equilateral triangle with the base of an isosceles triangle. The center of gravity of the washer 50b is eccentrically shifted downward from the hole 51b. By adopting this shape, the center of gravity of the washer 50b can be set below the center of rotation, and the aforementioned eccentric effect that suppresses the rotation of the washer 50b can be obtained. Furthermore, by making the shape of the washer 50b an eccentric diamond shape, the rotation space during installation can be reduced, and the limitations on installation space can be alleviated.

[0027] Figures 4(a) and (b) are a cross-sectional view and a front view illustrating a dissimilar material mixed washer according to modification 3 of Embodiment 1, where (a) shows the cross-section along line 4A-4A in (b). As shown in Figures 4(a) and (b), the washer 50c has a dissimilar material mixed shape. The washer 50c is divided into an upper and a lower part. The hole 51c is formed between the upper and lower parts. The specific gravity of the upper material is lower than that of the lower material. For example, the upper part contains stainless steel with a specific gravity of 7.93, and the lower part contains lead with a specific gravity of 11.35. By making the upper and lower materials of the washer 50c different in this way, the center of gravity of the washer 50c can be set below the center of rotation, and the aforementioned eccentric effect that suppresses the rotation of the washer 50c can be obtained. Furthermore, by making the washer 50 a dissimilar material mixed type, the hole 51c can be formed at the center position of the shape of the washer 50c as viewed from the direction of the hole 51c. Furthermore, since the shape of the washer 50c is not specified, the degree of freedom in the shape of the washer 50c can be increased.

[0028] Figures 4(c) and (d) are a cross-sectional view and a front view illustrating a washer with an irregular surface shape according to a modified example 4 of Embodiment 1, where (c) shows the cross-section along the 4C-4C line in (d). As shown in Figures 4(c) and (d), the washer 50d has a mixed material shape. The washer 50d is divided into an upper and lower part with a uniform thickness. The hole 51d is formed between the upper and lower parts. The area of ​​the upper part as viewed from the direction of the hole 51d is smaller than the area of ​​the lower part. By making the shape of the upper part and the lower part of the washer 50d different in this way, the center of gravity of the washer 50c can be set below the center of rotation, and the aforementioned eccentric effect that suppresses the rotation of the washer 50c can be obtained.

[0029] Figures 4(e) and (f) are a cross-sectional view and a front view illustrating a washer of varying thickness according to a modification 5 of Embodiment 1, where (e) shows the cross-section along the line 4E-4E in (f). As shown in Figures 4(e) and (f), the washer 50e has a shape of varying thickness. The washer 50e is divided into an upper and a lower part. The hole 51e is formed between the upper and lower parts. The thickness of the upper part is smaller than the thickness of the lower part. By making the thickness of the upper part and the thickness of the lower part of the washer 50e different in this way, the center of gravity of the washer 50e can be set below the center of rotation, and the aforementioned eccentric effect that suppresses the rotation of the washer 50e can be obtained.

[0030] Figure 5 illustrates the combinations of washer configurations according to Embodiment 1 and Modifications 1 to 5. As shown in Figure 5, the circular eccentric washer 50 of Embodiment 1 is designated as item 1, the teardrop-shaped washer 50a of Modification 1 as item 2, the eccentric diamond-shaped washer 50b of Modification 2 as item 3, the dissimilar material mixed washer 50c of Modification 3 as item 4, the irregularly shaped surface washer 50d of Modification 4 as item 5, and the irregularly shaped thickness washer 50e of Modification 5 as item 6. By combining each of the configurations from item 1 to item 6, considering the usage environment and cost-effectiveness, it is possible to expand to items 7 to 27.

[0031] (Embodiment 2) Next, a washer according to Embodiment 2 will be described. Figures 6(a) and (b) are a cross-sectional view and a front view illustrating a washer according to Embodiment 2, where (a) shows the cross-section along line 6A-6A in (b). As shown in Figures 6(a) and (b), the washer 50f of this embodiment is positioned between the heat insulating material 20 and the nut 41. The nut 41 is fastened to the other end of a bolt 30 that penetrates the heat insulating material 20. Thus, the bolt 30 penetrates the furnace wall 11, the heat insulating material 20, and the washer 50f. One end of the bolt 30 is fastened with the nut 40, and the other end of the bolt 30 is fastened with the nut 41.

[0032] The washer 50f has a recess 52 for accommodating the nut 41. The recess 52 is also called a counterbore. The recess 52 is formed on the furnace-side plate surface of the washer 50f. Preferably, the depth of the recess 52 is the same as the thickness of the nut 41. The gap between the nut 41 and the recess 52 is filled with a filler material 53. The filler material 53 is, for example, a refractory material. The center of gravity of the washer 50f is shifted downward relative to the position of the hole 51f through which the bolt 30 passes.

[0033] According to this embodiment, the other end of the bolt 30 is fixed with a washer 50f and a nut 41, so that loosening when fixing the heat insulating material 20 with the washer 50f can be suppressed. In addition, the nut 41 is embedded in the recess 52 by the filling member 53 and fixed with the washer 50f. Furthermore, the center of gravity of the washer 50f is shifted downward to make it difficult to rotate. This suppresses loosening when fixing with the washer 50f. Since the nut 41 is housed in the recess 52, interference with heat-treated objects such as products in the furnace can be suppressed. Other configurations and effects are described in Embodiment 1 and Modifications 1 to 5.

[0034] (Embodiment 3) Next, a washer according to Embodiment 3 will be described. Figures 6(c) and (d) are a cross-sectional view and a front view illustrating a washer according to Embodiment 3, where (c) shows the cross-section along line 6C-6C in (d). As shown in Figures 6(c) and (d), the washer 50g of this embodiment is placed between the heat insulating material 20 and the nut 42. The nut 42 is fastened to the other end of a bolt 30 that penetrates the heat insulating material 20. Thus, the bolt 30 penetrates the furnace wall 11, the heat insulating material 20, and the washer 50g. One end of the bolt 30 is fastened with the nut 40, and the other end of the bolt 30 is fastened with the nut 42. The inner circumferential surfaces of the holes 51f and 51g of the washers 50f and 50g of Embodiments 2 and 3 may or may not have screw grooves, similar to Embodiment 1. Thus, the washers 50f and 50g may or may not be fastened to the bolt 30.

[0035] The washer 50g has a recess 54 for accommodating the nut 42. The recess 54 is also called a counterbore. The recess 54 is formed on the inner plate surface of the washer 50g. Preferably, the depth of the recess 54 is the same as the thickness of the nut 42. The gap between the nut 42 and the recess 54 is not filled with a filler material 53. However, the gap between the nut 42 and the recess 54 may be filled with a filler material 53. The filler material 53 is, for example, a refractory material. The center of gravity of the washer 50g is shifted downward relative to the position of the hole 51g through which the bolt 30 passes. When viewed from the direction of the hole 51g, the nut 42 is rectangular. Therefore, when viewed from the direction of the hole 51g, the recess 54 for accommodating the nut 42 is also rectangular.

[0036] According to this embodiment, the washer 50g has a rectangular counterbore recess 54, and the nut 42 is a rectangular nut. Therefore, it is possible to suppress the independent rotation of the nut 42 within the recess 54 of the washer 50g. This eliminates the need to fill the gap between the nut 42 and the recess 54 with a filler member 53. Consequently, the cost and management of the filler member 53 can be reduced. Note that a filler member 53 may also be used, in which case the independent rotation of the nut 42 within the recess 54 of the washer 50g can be further suppressed. Other configurations and effects are described in Embodiments 1 to 2 and Modifications 1 to 5.

[0037] While embodiments of this disclosure have been described above, this disclosure includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the above embodiments. Furthermore, the configurations in Embodiments 1 to 3 and Modifications 1 to 5 may be combined as appropriate. In addition, the washers described below are also within the scope of the technical concept of the embodiments. (Note 1) A washer positioned between a fixing member and a nut that is fastened to a bolt passing through the fixing member, It has a recess for accommodating the nut, The center of gravity of the washer is shifted downward relative to the position of the hole through which the bolt passes. The shape of the nut and the recess, when viewed from the direction of the hole, is rectangular. Washer. [Explanation of Symbols]

[0038] 10 Heat treatment furnace 11 Furnace wall 12 Exterior wall surface 13 Interior wall surface 20 Insulation 30 volts 40, 41 nuts Washers 50, 50a, 50b, 50c, 50d, 50e, 50f 51, 51a, 51b, 51c, 51d, 51e, 51f holes 52 recess 53 Filling material 150 washers 151 holes

Claims

1. A plate-shaped washer that is fastened to a bolt that passes through a fixing member, One of the board surfaces is in contact with the fixing member, The center of gravity of the washer is shifted downward relative to the position of the hole through which the bolt passes. Displaced between the aforementioned fixing member and the nut that is fastened to the bolt that passes through the fixing member, It has a recess for accommodating the nut, The gap between the nut and the recess is filled with a filling material. Washer.

2. The shape of the washer, as viewed from the direction of the hole, includes any of the following: circular, rectangular, teardrop, and eccentric diamond shape. The washer according to claim 1.

3. The washer includes the upper and lower parts. The upper part and the lower part differ in at least one of the following: material, shape as viewed from the direction of the hole, and thickness in the direction of the hole. The washer according to claim 1 or 2.

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