JP2004138167A - Press fitted and fixed type fastener - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the effect of preventing slipping off and rotation by preventing the force to make a fastener float in the direction of a head section from working when the fastener is press-fitted and fixed to a plate-like member in a press-fitted and fixed type fastener. <P>SOLUTION: In the press-fitted and fixed type fastener comprising a head section 11 and a shaft section 12, a recessed section 13 is formed. The shape of the recessed section 13 is not complete round having a shaft center in the boundary section between the head section and the shaft section 12 and/or is not the same shape in the cross section of the shaft center in all directions. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-fitting fixed type fastener in which the upper surface of a head is pressurized by a press machine or the like and the head is press-fitted and fixed to a plate-shaped member, so that a retaining effect and a rotation preventing effect can be enhanced.
[0002]
[Prior art]
Conventionally, in a press-fit fixed fastener, the rotation of the fastener is prevented by subjecting the outer periphery of the head to unevenness and press-fitting the head into a mating member. One example is JP-A-2002-79338.
[0003]
According to Japanese Patent Application Laid-Open No. 2002-79338, as shown in FIGS. 10 and 11, the spacer (30) has a shank (33) and one end of the shank (33). An annular groove (34) is formed on the outer surface of the shaft (33) adjacent to the flange (31). Further, it is described that the annular groove (34) is formed by rotating a product material on which the shaft portion (33) and the flange portion (31) are formed and pressing a tool.
[0004]
[Problems to be solved by the invention]
However, the conventional technology described above has the following problems.
[0005]
According to JP-A-2002-79338, irregularities (32) having an anti-rotation function are formed on the outer periphery of the flange portion (31) by plastic working that can be pushed into a mold. Therefore, the corners of the flange portion (31) including the irregularities (32) are slightly rounded. When the spacer (30) manufactured in such a processing step is pressed into the panel plate (35) and the spacer (30) is rotated around the axis (CL), the flange (31) However, the force to float up from the panel plate (35) worked, and it was easy to come off in the direction of the flange portion (31). In particular, when the spacer (30) was insufficiently press-fitted into the panel plate (35), the spacer (30) was easily removed in the direction of the flange portion (31). Such insufficient press-fitting tends to occur when a large number of the spacers (30) are press-fitted and fixed simultaneously by one press machine or the like.
[0006]
The present invention, in consideration of the above facts, press-fits and fixes a fastener into a plate-like member and, when rotated around an axis, prevents the fastener from lifting in the direction of the head. It is an object of the present invention to obtain a press-fitting fixed type fastener which can enhance the effect of preventing the rotation and preventing rotation.
[0007]
[Means for Solving the Problems]
The present invention according to claim 1 comprises a head portion and a shaft portion extending from one end of the head portion and having a smaller diameter than the head portion, and a through hole slightly larger than the shaft portion is provided in advance. After inserting the shaft portion into the through-hole with respect to the plate-like member, subsequently, in a press-fit fixed fastener for press-fitting and fixing the head portion, the center of the shaft center is located at the boundary between the head portion and the shaft portion. A concave shape that is not the same shape is formed in the shape that is not a perfect circle and / or in the axial cross section in any direction.
[0008]
Therefore, when the press-fit fixed fastener is press-fitted and fixed to the plate-shaped member, the head of the fastener is displaced, and the material of the plate-shaped member that has been plastically deformed is located at the boundary between the head and the shaft. When the formed concave portion is filled and the fastener is rotated around the axis, the fastener is prevented from being lifted in the direction of the head so that the force does not work. Can be enhanced.
[0009]
According to a second aspect of the present invention, there is provided the press-fit fixed fastener according to the first aspect, wherein the head has a substantially columnar shape with no unevenness in the periphery and a low height.
[0010]
Therefore, in the press-fit fixed fastener, the head does not have a rotation preventing function, so that the head does not need to be high, and can be easily formed and the cost can be reduced. Furthermore, even if the fastener is slightly press-fitted into the plate-like member, when the fastener is rotated around the axis, the force for lifting the head from the plate-like member acts. Absent. In addition, since the head has a low height and a substantially columnar shape, a relatively weak force may be used when the head is pressed into the plate-shaped member.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[0012]
As shown in FIG. 1, the press-fit fixed fastener (10) of the present embodiment extends from a head (11) and one end of the head (11) and has a smaller diameter than the head (11). 12), and the cross-sectional shape of the head (11) at the axis (H) is substantially cylindrical, and further, at the boundary between the head (11) and the shaft (12). A recess (13) is formed. Further, a penetrating female screw (12a) is machined at the center of the shaft portion (12).
[0013]
As shown in FIG. 2, the shape of the cross section perpendicular to the axis (H) of the recess (13) is composed of four sides (13a) having a gentle curve, And the intersection (13b) of the four sides (13a) has a certain length and is continuous with the surface of the shaft (12).
Although not described in detail, it is apparent to those skilled in the art that the press-fit fixed fastener according to the present embodiment can be easily manufactured without producing chips by a known forging method. is there. For reference, in the method of processing the concave portion (13), four nails concavely processed into a gentle curved surface are simultaneously driven into the boundary between the head (11) and the shaft (12). It is formed with.
[0014]
Next, the operation of the present embodiment will be described.
[0015]
In the present embodiment, as shown in FIG. 3, the shaft portion of the press-fit fixed fastener (10) is previously inserted into a plate-like member (15) provided with a through hole (14) slightly larger than the shaft portion (12). (12) is inserted, and the back surface (15c) of the plate-like member (15) is placed on the upper surface (16b) of the receiving base (16) provided with a hole (16a) slightly larger than the shaft portion (12). Abut.
[0016]
In this state, the top surface (11a) of the fastener (10) is pressed by a press machine (17), and the top surface (11a) of the fastener is the same as the surface (15a) of the plate-like member (15). Press in until it is flat. At this time, since the height (11b) of the head (11) is low and the shape of the head (11) is cylindrical without irregularities in the periphery, it can be press-fitted with a relatively weak force.
As a result, as shown in FIG. 4, when the head (11) is press-fitted into the plate-like member (15), the head (11) of the fastener (10) is pushed away, and the plastically deformed plate is displaced. The material (15b) of the shaped member (15) is filled in a concave portion (13) formed at a boundary portion between the head portion (11) and the shaft portion (12).
Therefore, when the fastener (10) is rotated around the axis (H), the material (15b) filled in the concave portion (13) becomes a resistance, so that the plate of the fastener (10) becomes The effect of preventing rotation of the shaped member (15) can be enhanced, and at the same time, the effect of preventing removal can be enhanced. Further, when the fastener (10) is rotated around the axis (H), the recess (13) may be disengaged in the head direction (S) or the shaft direction (T). It has a neutral shape so that the force does not work.
[0017]
In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are possible within the scope of the present invention. That will be apparent to those skilled in the art.
[0018]
For example, FIG. 5 shows a cross section of the concave portion (13c) of the second embodiment of the present invention, which is perpendicular to the axis (H), as viewed in the direction of the shaft portion (12). In the method for processing the concave portion (13) described in the above, four nails concavely processed into a gentle curved surface are further strongly driven into the boundary portion between the head and the shaft portion, thereby forming the shaft portion (12). The concave portion (13c) deep from the surface can be formed. The amount of the material (15b) of the plate-like member (15) filled in the concave portion (13c) is increased, and a convex portion (13d) that is convex when viewed from the concave portion (13c) is formed. Thereby, a higher retaining effect and a higher rotation preventing effect can be obtained. The outer diameter of the projection (13d) may be slightly larger than that of the shaft (12), but there is no problem in use and function as the press-fitting fixed type fastener of the present invention.
[0019]
FIG. 6 shows a cross section perpendicular to the axis (H) of the concave portion (13e) according to the third embodiment of the present invention, as viewed in the direction of the shaft portion (12). The shape is substantially triangular, and an extremely large anti-rotation effect can be obtained.
[0020]
FIG. 7 shows a cross section perpendicular to the axis (H) of the concave portion (13f) according to the fourth embodiment of the present invention, as viewed in the direction of the shaft portion (12). The shape is substantially gear-shaped.
[0021]
FIG. 8 is a side view of a press-fit fixed fastener (10) according to a fifth embodiment of the present invention. Regarding the shape of the concave portion (13g), the side of the shaft portion (12) is substantially wavy. After the fastener (10) is press-fitted and fixed to the plate-like part (15), when the fastener (10) is rotated around the axis (H), the fastener (10) tends to come off toward the shaft (12). Although a force is applied, the head (11) does not come off because the diameter of the head (11) is larger than the shaft (12).
[0022]
Further, regarding the shape of the shaft portion, as shown in FIG. 9, the size of the shaft portion (12b) adjacent to the concave portion (13) is determined by the size of the through hole (14) provided in advance in the plate member (15). The shape of the shaft portion (12) does not matter as long as it is slightly smaller than the above) and can be inserted into the hole (14).
This figure shows an example of a press-fit fixed fastener (10) applied as a bolt.
[0023]
【The invention's effect】
As described above, by using the press-fit fixed fastener according to the present invention, the head of the fastener is displaced, and the material of the plastically deformed plate-like member is applied to the boundary between the head and the shaft. By filling the formed recesses, when the fastener is rotated around the axis, the force for lifting the fastener in the direction of the head does not work, so that the fastener is prevented from slipping out and preventing rotation. Can be increased. Further, even if the fastener is slightly press-fitted into the plate-like member, no force is exerted on the fastener to float up toward the head.
Also, since the fastener does not have a rotation preventing function on the head, it has a columnar shape with no irregularities around the head, and can be reduced in height, so that it can be easily formed and cost can be reduced, The force at the time of press-fitting into the plate-shaped member may be a relatively weak force.
Further, the fact that the fastener is press-fitted into the plate-like member with a relatively weak force means that the fastener can be press-fitted and fixed using a relatively small press machine or the like. The head can be prevented from being deformed or scratched. For example, even if the fastener is subjected to surface treatment such as plating or painting, the appearance is not impaired.
Furthermore, the fixed press-fit type fastener of the present invention can be easily manufactured without producing chips by a known forging method, so that resource saving, energy saving, and manufacturing cost reduction can be achieved.
Further, the press-fit fixed fastener of the present invention is particularly useful as a press-fit fixed spacer nut attached to a plate-like member incorporated in an electronic device. The plate member and the spacer nut are both made of aluminum.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view showing a fixed press-fit type fastener according to a first embodiment of the present invention.
FIG. 2 is an AA cross-sectional view showing a groove of the press-fit fixed fastener according to the first embodiment of FIG. 1;
FIG. 3 is a side cross-sectional view showing a state when the press-fit fixed fastener according to the first embodiment of FIG. 1 is press-fitted into a plate-like member.
FIG. 4 is a side sectional view showing a state in which the press-fit fixed fastener according to the first embodiment of FIG. 1 is press-fitted and fixed to a plate-like member.
FIG. 5 is a cross-sectional view of a recess of a press-fit fixed fastener according to a second embodiment of the present invention as viewed in the axial direction, with a cross section perpendicular to the axis.
FIG. 6 is a cross-sectional view of a recess of a press-fit fixed fastener according to a third embodiment of the present invention as viewed in the axial direction, with a cross section perpendicular to the axis.
FIG. 7 is a cross-sectional view of a recess of a press-fitting fixed type fastener according to a fourth embodiment of the present invention as viewed in the axial direction, with a cross section perpendicular to the axis.
FIG. 8 is a side view showing a fixed press-fit type fastener according to a fifth embodiment of the present invention.
FIG. 9 is a side view showing a press-fit fixed fastener according to a sixth embodiment of the present invention.
FIG. 10 is an external perspective view showing a conventional spacer.
11 is a cross-sectional view showing a state where the conventional spacer of FIG. 10 is caulked to a panel plate.
[Explanation of symbols]
REFERENCE SIGNS LIST 10 Press-fit fixed fastener 11 Head 11b Head height 12 Shaft 13 Recess 13a Side 13b Intersection 14 Through hole 15 Plate-like member 15b Material 16 Cradle 17 Press machine 30 Spacer 31 Flange 32 Irregularity 33 Shaft 34 Annular Groove 35 Panel plate H Shaft center

Claims (2)

For a plate-shaped member that is formed from a head and a shaft part extending from one end of the head and having a smaller diameter than the head, and in which a through hole slightly larger than the shaft part is provided in advance, the shaft part is After being inserted into the through-hole, the press-fit fixed fastener for press-fitting and fixing the head subsequently has a shape that is not a perfect circle centered on the axis at the boundary between the head and the shaft. And / or a press-fitting fixed type fastener, wherein recesses that are not the same shape are formed in the axial center section in all directions. The press-fit fixed fastener according to claim 1, wherein the head has a substantially columnar shape with no irregularities around the periphery and a low height.

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