JP2016200226A - Fastening bolt and fastening method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastening bolt capable of tightly fastening the fastening bolt itself and a fastening plate, and a fastening method thereof.SOLUTION: A fastening bolt (1) includes a head part (2), a screw part (3), and a cylindrical part (4) formed between the head part (2) and the screw part (3) and having a diameter larger than that of the screw part. The head part (2) has an upper surface (5), a conical surface-shaped bearing surface (6), and a plurality of projections (7) having a cross section formed into a substantially triangular shape and projecting from the bearing surface (6). On the bottom part of the projection (7), an inclined surface (8) is formed so that a portion closer to an axial core (9) is get closer to the upper surface (5).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing bolt that is fixed to a fixing plate in advance and tightened with a nut through the fixing plate and a fixing method thereof.

  2. Description of the Related Art Conventionally, in assembling a structure using a fixing plate such as a metal material, an assembling method has been adopted in which a bolt is fixed to a fixing plate in advance, and the bolt (fixing bolt) is tightened with a nut through the fixing plate.

  FIG. 10 shows a conventional fixing bolt 21. The fixing bolt 21 includes a head portion 22, a screw portion 23, and a cylindrical portion 24 formed between the head portion 22 and the screw portion 23. The head 22 has a conical surface 25 and a plurality of convex portions 26 that have a triangular cross section and project from the seat 25.

  In the conventional fixing bolt 21, the bottom 27 of the convex portion 26 is formed as a plane parallel to the upper surface of the fixing plate 29, that is, as a plane orthogonal to the axis 28 of the fixing bolt 21.

  FIG. 11 is a diagram showing a process of fixing the conventional fixing bolt 21 to the fixing plate 29. A fixing hole 30 having a diameter larger than the diameter of the cylindrical portion 24 and smaller than the maximum diameter of the seating surface 25 is formed in the fixing plate 29, and the fixing bolt 21 is inserted into the fixing hole 30.

  Then, as shown in FIG. 11A, the upper press mold 31 that contacts the upper surface of the head 22 and the lower press mold 32 that contacts the lower periphery of the fixing hole 30 are set. As shown in FIG. 11B, as a result of pressing in the vertical direction using the upper press die 31 and the lower press die 32, the seating surface 25 is pressed and embedded with the fixing plate 29. Deforms into a wedge shape. As shown in FIG. 11 (c), pressing is performed in the vertical direction using an upper press mold 31 and a lower press mold 32 until the upper surface of the head 22 and the upper surface of the fixing plate 29 are flush with each other, and fixing bolts are used. 21 and the fixing plate 29 are fixed.

JP 2000-205227 A Utility Model Registration No. 3171082

  FIG. 12 is an enlarged view of the part shown in FIG. 11 (b) or (c). In the conventional fixing bolt 21, pressing is performed in the vertical direction using an upper press mold 31 and a lower press mold 32, and a gap between the fixing hole 30 and the cylindrical portion 24 is formed by a fixing plate material member that is a fixing counterpart. When filling, the material member of the fixing plate that has been plastically deformed cannot be sufficiently moved into the gap, and the gap 34 remains, and the fixing bolt 21 and the fixing plate 29 cannot be firmly fixed. was there.

  This inventor considers this problem as follows. That is, in the conventional fixing bolt 21, as described above, since the bottom portion 27 of the convex portion 26 is formed in parallel to the upper surface of the fixing plate 29, as shown by the arrow in FIG. The material member that is plastically deformed of the fixing plate 29 that is pressed and moved by the horizontal bottom portion 27 of the horizontal plate 27 tends to be distributed symmetrically with respect to the bottom portion 27, and the gap between the fixing hole 30 and the cylindrical portion 24. It is considered that the material member of the fixing plate 29 that is plastically deformed does not spread sufficiently, and as a result, the gap 34 remains.

  Thus, the conventional fixing bolt 21 has a problem that the fixing bolt 21 and the fixing plate 29 cannot be firmly fixed because the gap 34 remains.

  Therefore, the present invention solves the above-mentioned problems of the prior art and provides a fixing bolt capable of strongly fixing the fixing bolt and the fixing plate and a fixing method thereof.

  In order to solve the above problems, a fixing bolt according to the present invention includes a head, a screw portion, and a cylindrical portion formed between the head and the screw portion and having a larger diameter than the screw portion. The head includes a top surface, a conical bearing surface, and a plurality of projections having a substantially triangular cross section and projecting from the seating surface, and a bottom of the projection. Is characterized in that the inclined surface is formed so that a portion closer to the axis is closer to the upper surface.

  The outer lower end of the convex portion is fixed when inserted into a fixing hole formed in a fixing plate, which is a fixing partner, having a diameter larger than the diameter of the cylindrical portion and smaller than the maximum diameter of the seating surface. Contacting the plate surface of the plate, the inner upper end of the fixing hole contacting at the contact position of the seating surface, and contacting the fixing plate at two sites of the outer lower end and the contact position of the seating surface It is characterized by.

  Further, the diameter of the fixing hole having a diameter larger than the diameter of the cylindrical portion formed on the fixing plate as a fixing partner and smaller than the maximum diameter of the seating surface is defined as D, the diameter of the cylindrical portion is defined as D1, and the convex portion When the diameter up to the intersection of the inclined surface and the seat surface is D2, the D is larger than the D1 and smaller than the D2.

  In addition, an angle α formed by the inclined surface with respect to a horizontal plane perpendicular to the axis is in the range of 5 degrees to 25 degrees.

  Further, the inclined surface is formed in a flat shape.

  Further, the inclined surface is formed in a kamaboko shape.

  In addition, when the vertical length of the seating surface is L1 and the vertical length of the cylindrical portion is L2, L1 + L2 is set so that L1 + L2 becomes smaller as the plate thickness t of the fixing plate which is a fixing partner is smaller. It is characterized by changing the size.

  Further, the smaller the plate thickness t is, the smaller the angle β formed by the upper surface and the seating surface is.

  The fixing bolt fixing method according to the present invention is a fixing method for fixing a fixing bolt to a fixing plate, wherein the fixing bolt is formed between a head, a screw portion, and the head and the screw portion. A cylindrical portion having a diameter larger than that of the screw portion, and the head has a top surface, a conical seat surface, and a plurality of convex portions that are substantially triangular in cross section and project from the seat surface. In addition, an inclined surface is formed at a bottom portion of the convex portion in a direction in which a portion closer to the axis is closer to the upper surface, and the fixing plate is larger than the diameter of the cylindrical portion and smaller than the maximum diameter of the seating surface. Press using a press upper die that contacts the upper surface of the head with the fixing bolt inserted into the fixing hole and a lower press die that contacts the lower periphery of the fixing hole. And forming a wedge-shaped wedge-shaped portion in the lower peripheral portion and the fixing hole Characterized in that to fill the gap between the serial cylindrical portion of a material member of the fixing plate.

  The head is press-fitted into the fixing plate until the upper surface of the head and the upper surface of the fixing plate are flush with each other.

  According to the configuration of the present invention, since the inclined surface is formed at the bottom of the convex portion so that the portion closer to the axial center is closer to the upper surface, the inclined portion is inclined when the convex portion is pressed against the fixing plate. The material member of the fixing plate that is plastically deformed by the surface can be moved in the direction of the axis, and the gap between the fixing plate and the fixing hole can be filled with the material member of the fixing plate. Combined with the wedge-shaped part formed in the lower part, the fixing bolt and the fixing plate can be strongly fixed.

  In addition, the outer lower end of the convex part contacts the plate surface of the fixing plate, the inner upper end of the fixing hole contacts at the contact position of the seat surface, and is fixed at two parts of the outer lower end portion and the contact position of the seat surface. Since it contacts the plate, the fixing bolt can be easily positioned coaxially with respect to the fixing hole.

  Further, since the hole diameter D is larger than the diameter D1 of the cylindrical portion and smaller than the diameter D2 up to the intersection of the inclined surface and the seating surface, the fixing bolt can be reliably brought into contact with the fixing plate at the two portions.

  In addition, when the vertical length of the seating surface is L1 and the vertical length of the cylindrical portion is L2, the size of L1 + L2 is such that L1 + L2 becomes smaller as the plate thickness t of the fixing plate that is the fixing partner is smaller. Therefore, the height Δ of the wedge-shaped portion in the vertical direction can be set to a desired size.

  In addition, an inclined surface is formed on the bottom of the convex portion in a direction in which the portion closer to the axis is closer to the above, and with the fixing bolt inserted into the fixing hole, the top surface of the head and the lower peripheral portion of the fixing hole Is pressed using a press upper die and a press lower die, and a wedge-shaped wedge-shaped portion is formed in the lower part of the periphery and the gap between the fixing hole and the cylindrical portion is filled with the material member of the fixing plate. It becomes possible to firmly fix the plate.

The top view which shows the fixation bolt which concerns on embodiment of this invention. The partial cross section figure (a) which shows the head of a fixation bolt, and the figure (b) which expands and shows the site | part of A in (a). It is a figure explaining the process of adhering the fixing bolt to the fixing plate, and (a) shows a state in which the upper press die is set in contact with the upper surface of the head and the lower press die is set in contact with the lower peripheral portion of the fixing hole. (B) shows a state where pressing starts from the state shown in (a), (c) shows a state where pressing is further performed from the state shown in (b), and (d) shows in (c) The state where it was pressed until the upper surface of the head 2 and the upper surface of the fixing plate are flush with each other is shown. The figure explaining the effect | action of the inclined surface formed in the bottom part of a convex part. The figure which shows that a head contacts the upper surface of an adhering board at two points. It is a figure explaining the relationship between the magnitude | size of the head of a fixation bolt, and the thickness of a fixation board, (a) shows the case where thickness t is large, (b) shows the case where thickness t is large. The table | surface which shows the example of the specific dimension of a fixation bolt, and the thickness of a fixation board. The perspective view which shows the fixation bolt which concerns on other embodiment. The figure which shows the example in which the inclined surface of a convex part is not planar. The figure which shows the conventional fixation bolt. The figure which shows the process of adhering the conventional fixation bolt to the fixation board. The figure explaining a space | gap part remaining in the clearance gap between a fixation hole and a cylindrical part in the case of the conventional fixation bolt.

Embodiments of a fixing bolt according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a fixing bolt 1 according to the present embodiment. The fixing bolt 1 includes a head portion 2, a screw portion 3, and a cylindrical portion 4 formed between the head portion 2 and the screw portion 3 and having a larger diameter than the screw portion 3. The head 2 has an upper surface 5, a conical seat surface 6, and a plurality of convex portions 7 having a substantially triangular cross section and projecting from the seat surface 6.

  Here, in FIG. 1, which is a plan view of the fixing bolt 1, five convex portions 7 are displayed. However, the cross section is substantially triangular as shown in the convex portions 7 at the left and right ends of FIG. The section has a substantially triangular shape. The substantially triangular shape is composed of a side where the convex portion 7 is connected to the seat surface 6, a vertical side substantially parallel to the axis 9, and a bottom side. Yes. Note that the longitudinal side substantially parallel to the axis 9 does not have to be strictly parallel to the axis 9. Further, the term “substantially triangular” means that it is substantially triangular and is not limited to a strict triangular shape.

  An inclined surface 8 is formed at the bottom of the convex portion 7. The inclined surface 8 is formed so as to be inclined in a direction in which a portion closer to the axis 9 is closer to the upper surface 5 of the head 2, as shown by the convex portions 7 at the left and right ends of FIG. 1.

  FIG. 2A is a view showing an upper portion of the fixing bolt 1, and FIG. 2B is an enlarged view showing a portion A in FIG. 2A. As shown in FIG. 2A, the inclined surface 8 is formed in a flat shape inclined with respect to a horizontal plane orthogonal to the axis 9 in a direction approaching the axis 9 by an angle α. The angle α is, for example, an angle in the range of 5 degrees to 25 degrees. Here, when the angle α is smaller than 5 degrees, when the press upper die 15 and the lower press die 16 are pressed as will be described later, the plastically deformed material member of the fixing plate 11 moves in the direction in which the gap 13 exists. Can't turn enough to move. When the angle α is larger than 25 degrees, the outer lower end of the bottom of the convex portion 7 is too sharp and may not be strong enough to be deformed.

  In addition, the inclined surface 8 is not limited to being formed in a planar shape, and may be formed to be bound inward in a kamaboko shape, for example, as shown in FIG. FIG. 9A shows a case where the seat surface 6 is formed in the circumferential direction, and FIG. 9B shows a case where the seat surface 6 is formed in the inclined direction. When the inclined surface 8 is formed in a kamaboko shape inwardly, as will be apparent from the description to be described later, when the fixing bolt 1 and the fixing plate 11 are pressed, the plastically deformed material member of the fixing plate 11 becomes the axis. It is possible to move to the gap 13 between the fixing hole 12 and the cylindrical portion 4 more intensively without being dispersedly moved by being pushed and moved by the inclined surface 8 in the direction 9. In addition, in the case where the inclined surface 8 is formed to be bounded in a kamaboko shape, the definition of the angle α may be an angle formed by the surface on which the contour line of the inclined surface 8 is formed and the horizontal plane. .

Next, with reference to FIG. 3, the process of fixing the fixing bolt 1 to the fixing plate 11 will be described.
The fixing plate 11 which is the fixing partner of the fixing bolt 1 is made of, for example, an aluminum material having a hardness lower than that of the steel material forming the fixing bolt 1. A fixing hole 12 having a smaller diameter D is formed.

  The fixing plate 11 is not limited to an aluminum material, but may be a steel plate as long as it has a lower hardness than the fixing bolt 1. For example, the fixing bolt 1 is made of a steel material having a high hardness by heat treatment, and the fixing plate 11 is subjected to heat treatment. It may be made of a steel material having a low hardness.

  The diameter of the convex portion 7 up to the intersecting position of the inclined surface 8 and the seat surface 6 is defined as D2. As shown in FIG. 5, the diameter D of the fixing hole 12 is set larger than the diameter D1 and smaller than the diameter D2.

  An upper press mold 15 and a lower press mold 16 are prepared. The press upper die 15 and the press lower die 16 are made of a material having higher hardness than the steel material forming the fixing bolt 1.

  As shown in FIG. 3 (a), the fixing bolt 1 is inserted into the fixing hole 12, the press upper die 15 is set so as to contact the upper surface 5 of the head 2, and the press lower die 16 is around the fixing hole 12. It is set so that it can contact the lower part. A gap 13 is formed between the fixing hole 12 and the cylindrical portion 4.

  FIG. 3B shows a state where the press upper die 15 and the press lower die 16 are pressed from the state shown in FIG. 3A, and the lower portion of the head 2 is embedded in the upper portion of the fixing plate 11. The state which started the press contact | abutted to the peripheral lower part of the fixation hole 12 is shown.

  In FIG. 3C, pressing is further performed by the upper press die 15 and the lower press die 16 from the state shown in FIG. 3B, and the head 2 is further embedded in the upper portion of the fixing hole 12, and the gap 13 is reduced. This shows a state in which the lower peripheral portion of the fixing hole 12 is pressed and the wedge-shaped portion 18 is being formed.

  FIG. 3 (d) shows a state in which the upper surface 5 of the head 2 and the upper surface of the fixing plate 11 are pressed from the state shown in FIG. It is completely filled with the material member, the wedge-shaped portion 18 is completed, and the fixing bolt 21 and the fixing plate 29 are fixed by the material member of the fixing plate 11 sandwiched between the convex portion 7 and the wedge-shaped portion 18. . In FIG. 3D, a wedge-shaped portion 18 having a vertical height of Δ is finally formed.

  As described above, as shown in FIGS. 3A, 3 </ b> B, 3 </ b> C, and 3 </ b> D, by pressing with the upper press mold 15 and the lower press mold 16, the wedge-shaped portion is formed at the lower periphery of the fixing hole 12. 18 is formed and the gap 13 is filled with a plastically deformed material member of the fixing plate 11, and the fixing bolt 21 and the fixing plate 29 are fixed.

  FIG. 4 is a diagram corresponding to FIG. 3C, and is a diagram for explaining the action of the inclined surface 8 formed on the bottom of the convex portion 7. Since the inclined surface 8 is formed so as to be inclined so that the portion closer to the axis 9 is closer to the upper surface 5 of the head 2, the convex portion 7 is pressed against the fixing plate 11 as indicated by an arrow. Sometimes, the material member of the fixing plate 11 receives a force so as to move in the direction of the axis 9 by the action of the inclined surface 8. As a result, as shown in FIG. 3D, the wedge-shaped portion 18 is more completely formed, and the gap 13 can be completely filled with the material member of the fixing plate 11.

Next, referring to FIG. 5, contact points between the upper surface of the fixing plate 11 and the convex portions 7 and the seat surface 6 will be described.
As described above, the diameter D of the fixing hole 12 is set to be larger than the diameter D1 of the cylindrical portion 4 and smaller than the diameter D2 to the intersection position of the inclined surface 8 of the convex portion 7 and the seat surface 6. By setting the diameter D of the fixing hole 12 in this way, the following effects can be obtained.

  That is, in FIG. 5, when the contact position of the inner upper end portion of the fixing hole 12 with the seat surface 6 is P1, and the position of the outer upper end portion of the inclined surface 8 of the convex portion 7 is P2, the upper surface of the fixing plate 11 Is in contact with the fixing bolt 11 at two positions, the contact position P1 and the position P2. As a result, the axis 9 of the fixing bolt 11 and the axis of the fixing hole 12 can be easily matched, and the fixing bolt 1 can be easily positioned coaxially with respect to the fixing hole 12. On the other hand, in the conventional fixing bolt 21 shown in FIG. 10, the bottom of the convex portion 27 is formed horizontally in the direction perpendicular to the axis 28, and the bottom surface of the convex portion 27 and the top surface of the fixing plate 11. Therefore, the fixing position of the fixing bolt 21 with respect to the fixing hole 30 could not be easily determined coaxially. . In this respect, according to the present embodiment, the fixing bolt 1 can be easily positioned coaxially with respect to the fixing hole 12.

Next, the relationship between the size of the head 2 of the fixing bolt 1 and the thickness t of the fixing plate 11 will be described with reference to FIG.
6, the length of the seating surface 6 of the head 2 is L1, the length of the cylindrical portion 4 is L2, the angle between the upper surface 5 and the seating surface 6 is β, the diameter of the upper surface 5 of the head 2 is D3, Let the thickness of the fixing plate 11 be t. Further, as shown in FIG. 3D, the height in the vertical direction of the wedge-shaped portion 18 finally formed is assumed to be Δ.

  The height Δ of the wedge-shaped portion 18 in the vertical direction is obtained as height Δ = L1 + L2-t. The height Δ is roughly determined in consideration of the fixing strength required when the fixing bolt 1 and the fixing hole 12 are fixed. Therefore, when the thickness t is small in order to ensure the height Δ, it is necessary to reduce the value of L1 + L2, and for this reason, each of the length L1 and the length L2 is reduced. Here, consider reducing the length L1 as the thickness t decreases. When the thickness t is small, the diameter D3 of the upper surface 5 is reduced if the thickness t is the same as when the thickness t is larger without changing the size of the angle β. On the other hand, there is a viewpoint that the size of the diameter D3 of the upper surface 5 is preferably substantially constant regardless of the thickness t. Therefore, in the present embodiment, the diameter D3 is prevented from becoming extremely small by decreasing the angle β as the thickness t decreases. In order to secure the strength of the seating surface 6 of the head 2, the angle β is set in a range of about 50 degrees to about 40 degrees. For this reason, since there is a limit to reducing the angle β, in order to reduce the value of L1 + L2, in addition to reducing the angle β, the length L2 is reduced.

  FIG. 7 shows a specific example of the fixing bolt 1 with two screw sizes having a diameter of 6 mm (M6) and a diameter of 4 mm (M4) as examples. The angle α of the inclined surface 8 of the convex portion 7 with respect to the horizontal plane is set to 10 degrees. Here, as shown in FIG. 6, the diameter D <b> 3 indicates the diameter of the upper surface 5 of the head 2, and the diameter D <b> 4 indicates the outermost diameter of the convex portion 7.

  The height Δ of the wedge-shaped portion 18 in the vertical direction is determined by the height Δ = L1 + L2-t, and is 0.4 mm for M6 and 0.2 mm for M4. Further, it is recognized that the diameter D of the fixing hole 12 is larger than the diameter D1 and smaller than the diameter D2 so that the fixing bolt 1 can be easily positioned coaxially with respect to the fixing hole 12.

  Compared to the case where t = 1.0 mm and the case where t = 1.2 mm and t = 2.0 mm with respect to the thickness t of the fixing plate 11, the length L1 is shorter when t = 1.0 mm. In addition, the angle β is reduced to 40 degrees, so that the value of the diameter D3 of the upper surface 5 is 7.9 mm in the case of M6, and t = 1.2 mm and t = 2.0 mm. It is recognized that there is no great difference in the value of 0.0 mm, and the same is also observed in the case of M4.

  Further, when the case of t = 1.2 mm and the case of t = 2.0 mm are compared with respect to the thickness t of the fixing plate 11, the length L 1 and the angle β are different although the thickness t is different between the two. Are set to the same value, but the length L2 is set to a different value in order to reduce the value of L1 + L2 as the thickness t decreases.

  As described above, according to the present embodiment, the inclined surface 8 is formed so as to be inclined in a direction in which the portion closer to the axis 9 is closer to the upper surface 5 of the head 2, so that the convex portion 7 is relative to the fixing plate 11. When pressed, the material member of the fixing plate 11 receives a force so as to move in the direction of the axis 9 by the inclined surface 8, and the gap 13 can be fully or completely filled with the material member of the fixing plate 11. Become. The gap 13 can be completely filled with the material member of the fixing plate 11. As a result, the material member of the fixing plate 11 that is plastically deformed is sandwiched and held between the formed wedge-shaped portion 18 and the convex portion 7, and the fixing bolt 1 and the fixing plate 11 can be strongly fixed. Become.

  Further, by forming the inclined surface 8 so as to be bound inwardly in a kamaboko shape, the inclined member 8 can move the material member of the fixing plate 11 more reliably in the direction of the axis 9.

  Further, the outer lower end portion P2 of the convex portion 7 contacts the plate surface of the fixing plate 11, the inner upper end portion of the fixing hole 12 contacts at the contact position P1 of the seat surface 6, and the fixing bolt 1 is the outer lower end portion) 2. Since the contact with the fixing plate 11 is made at two locations with the contact position P 1 of the seat surface 6, the fixing bolt 1 can be easily positioned coaxially with respect to the fixing hole 12.

  Further, since the diameter D of the fixing hole 12 is larger than the diameter D1 of the cylindrical portion 4 and smaller than the diameter D2 up to the crossing position of the inclined surface 8 and the seating surface 6, the fixing bolt 1 is securely attached at the two portions of the fixing plate 11. Can be contacted.

  Further, since the length L1 + L2 which is the sum of the length L1 of the seat surface 6 and the length L2 of the cylindrical portion 4 is changed according to the thickness t of the fixing plate 11, the longitudinal direction of the wedge-shaped portion 18 is changed. The height Δ can be set to a desired size.

  Further, the angle L1 + L2 which is the sum of the length L1 of the seat surface 6 and the length L2 of the cylindrical portion 4 is changed according to the thickness t of the fixing plate 11, and the angle formed between the upper surface 5 and the seat surface 6 is changed. Since β is changed, the size of the diameter D3 of the upper surface 5 can be prevented from changing greatly when the screw size is determined.

Next, another embodiment will be described with reference to FIG.
The fixing bolt shown in FIG. 8 is provided with a thin cylindrical flat head 20 having a diameter larger than that of the upper surface 5 on the upper surface 5 of the head 2 of the fixing bolt 1 shown in FIG. The press upper die 15 is brought into contact with the upper surface of the flat head 20. 8 is used by pressing until the lower surface 20a of the flat head 20 contacts the upper surface of the fixing plate 11, that is, until the upper surface 5 of the head 2 is flush with the upper surface of the fixing plate 11. Is done.

  According to the present embodiment, since the flat head 20 is provided on the upper surface 5 of the head 2, when the fixing bolt with the flat head is tightened with the nut, the back surface of the flat head 20 abuts against the plate surface of the fixing plate 11, and the nut is attached. Can be pulled. The fixing bolt with a flat head is particularly useful when tightening strongly. If the flat head 20 is not provided, the seat surface 8 may be deformed when tightened strongly.

DESCRIPTION OF SYMBOLS 1 Fixing bolt 2 Head 3 Screw part 4 Cylindrical part 5 Upper surface 6 Seat surface 7 Convex part 8 Inclined surface 9 Axis 11 Fixing plate 12 Fixing hole 13 Gap 15 Press upper die 16 Press lower die 18 Wedge-like part 20 Flat head

Claims (10)

A fixing bolt including a head, a screw portion, and a cylindrical portion formed between the head and the screw portion and having a larger diameter than the screw portion,
The head includes an upper surface, a conical seat surface, and a plurality of convex portions having a substantially triangular cross section and projecting from the seat surface,
The fixing bolt according to claim 1, wherein an inclined surface is formed at a bottom portion of the convex portion so that a portion closer to the axial center is closer to the upper surface. When inserted into a fixing hole formed in a fixing plate, which is a fixing partner, having a diameter larger than the diameter of the cylindrical portion and smaller than the maximum diameter of the seating surface, the outer lower end portion of the convex portion of the fixing plate Contacting the plate surface, the inner upper end of the fixing hole contacts at the contact position of the seating surface, and contacts the fixing plate at two parts of the outer lower end portion and the contact position of the seating surface. The fixing bolt according to claim 1. The diameter of the fixing hole having a diameter larger than the diameter of the cylindrical portion formed on the fixing plate which is the fixing partner and smaller than the maximum diameter of the seating surface is set as D, the diameter of the cylindrical portion is set as D1, and the convex portion 2. The fixing bolt according to claim 1, wherein D is larger than D <b> 1 and smaller than D <b> 2 when D <b> 2 is a diameter to an intersection position between the inclined surface and the seating surface. 2. The fixing bolt according to claim 1, wherein an angle α formed by the inclined surface with respect to a horizontal plane perpendicular to the axis is in a range of 5 degrees to 25 degrees. The fixing bolt according to claim 1, wherein the inclined surface is formed in a flat shape. The fixing bolt according to claim 1, wherein the inclined surface is formed in a kamaboko shape. When the vertical length of the seating surface is L1 and the vertical length of the cylindrical portion is L2, the size of L1 + L2 is such that L1 + L2 is smaller as the thickness t of the fixing plate that is the fixing partner is smaller. The fixing bolt according to claim 1, wherein the fixing bolt is changed. The fixing bolt according to claim 7, wherein an angle β formed by the upper surface and the seat surface is decreased as the plate thickness t is decreased. A fixing method for fixing a fixing bolt to a fixing plate,
The fixing bolt includes a head portion, a screw portion, and a cylindrical portion formed between the head portion and the screw portion and having a larger diameter than the screw portion, and the head portion has an upper surface and a conical surface shape. And a plurality of protrusions that are substantially triangular in cross section and protrude from the seat surface, and the bottom surface of the protrusion is inclined in a direction in which a portion closer to the axis is closer to the upper surface Is formed,
Forming a fixing hole having a diameter larger than the diameter of the cylindrical portion and smaller than the maximum diameter of the seat surface in the fixing plate;
With the fixing bolt inserted into the fixing hole, pressing is performed using a press upper die that comes into contact with the upper surface of the head and a press lower die that comes into contact with the lower periphery of the fixing hole. A fixing method for fixing bolts, characterized in that a wedge-shaped part is formed and a gap between the fixing hole and the cylindrical part is filled with a material member of the fixing plate. The fixing method for fixing bolts according to claim 9, wherein the head is press-fitted into the fixing plate until the upper surface of the head and the upper surface of the fixing plate are flush with each other.

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