JP3182736U - Nut with axial force indication washer - Google Patents

Abstract

To provide a nut with an axial force indicating washer that allows tightening at a predetermined axial force to be visually confirmed, and that a large change point appears in a relational curve of axial force and rotational angle during tightening with a designed axial force. .
A nut main body 2 and an axial force indicating washer 3 that are rotatably and integrally engaged with the nut main body are provided. The axial force display washer 3 is composed of a disc-shaped seat portion 30 having a caulking through-hole 31 and an inner surface tapered deforming projection portion 33 that projects integrally with the seat portion 30. It is formed to have a hardness equal to or higher than the design axial force based on strength and diameter. The deformation protrusion 33 is formed to be plastically deformed so that the tip end portion protrudes from the outer peripheral end when tightening up to the designed axial force, and the inclination of the relationship curve of axial force and rotation angle during tightening is reduced. In addition, when the axial force satisfying the design axial force is applied, the plastic deformation is completed and the change point where the inclination of the relationship curve of the axial force and the rotation angle at the time of fastening becomes large is made to appear.
[Selection] Figure 1

Description

  The present invention relates to a nut with an axial force indicating washer used for fastening a fastened body together with a bolt.

  Conventionally, as a nut with a washer, for example, an annular flat washer or an annular washer is integrally attached to a lower portion of a seat surface of a nut body by caulking so as to be freely rotatable.

  And when fastening a to-be-fastened body with this washer-attached nut and bolt, for example, by tightening the nut body with the plain washer or washer pressed against the to-be-fastened body against a bolt inserted through the to-be-fastened body, Then, a flat washer or washer is pressed against the body to be fastened, and the loosening is prevented by the tightening resistance by the pressing force.

  However, in the case of the structure for preventing loosening by simply pressing the nut onto the body to be fastened via a plain washer or washer, such as the nut with washer described above, tightening is performed using a torque wrench or an ordinary tightening jig. When the work is performed, there is a variation in the axial force due to the tightening of the nut due to a torque coefficient or the like, and a stable tightening axial force cannot always be obtained. Therefore, if the tightening with the nut is weak, there is a serious problem that loosening occurs when vibration or some external force is applied. In addition, when the nut is temporarily fixed and the forgotten tightening is forgotten, there is a problem that it is difficult to visually confirm this.

  Therefore, the present invention can easily and visually confirm whether or not the tightening has been performed with a predetermined axial force, and the axial force at the time of tightening with the designed axial force based on the bolt strength and bolt diameter to be used. -It is an object to provide a nut with an axial force indicating washer so that a large change point appears in a relational curve of a rotation angle.

  In order to solve the above-described problem, a device according to claim 1 of the present application is a nut main body having a screw hole, and an axial force indicating washer which is rotatably and integrally attached to a lower portion of a seating surface of the nut main body by caulking. A nut with an axial force indicating washer provided with an axial force indicating washer integrally protruding in the thickness direction on a disc-shaped seat portion having a caulking through-hole at the center portion and an outer peripheral portion of the bottom surface of the seat portion. The seat part is formed to have a hardness greater than the designed axial force based on the bolt strength and bolt diameter of the bolt to be used, and the seat part is caulking through. While the caulking projection of the nut body is not caulked in the hole without protruding downward from the bottom surface of the seat, the deforming projection has a tip portion that is tightened up to the designed axial force. Plastically deformed so that it protrudes from the outer edge of the seat When the axial force satisfying the above-mentioned designed axial force is applied, the deforming projection part completes the plastic deformation and is tightened. It is characterized in that it is formed so that a change point where the inclination of the relationship curve of the axial force-rotation angle at the time of attachment becomes large appears.

  In the invention according to claim 2 of the present application, the deforming projection portion in the axial force display washer is formed in a cylindrical shape on the outer peripheral portion of the one end surface of the seat portion, and the deforming projection portion is formed on the inner side portion of the deforming projection portion in the seat portion. An annular groove is formed continuously on the tapered inner peripheral surface, and the seat portion has an intermediate diameter A, a hole diameter B, and a thickness C so as to have a hardness equal to or higher than the designed axial force based on the bolt strength and bolt diameter of the bolt to be used. On the other hand, the deformation protrusion is plastically deformed so that the tip portion protrudes from the outer peripheral end of the seat when tightening up to the designed axial force, and the axial force-rotation angle at the time of tightening is The height D of the deforming protrusion, the width E of the annular groove portion, and the outer diameter F of the deforming protrusion are formed so that the inclination of the relationship curve becomes small, and an axial force that satisfies the design axial force is applied. At this point, the deforming protrusion has completed the plastic deformation and the axial force during tightening Wherein the slope of the relationship curve of the rotation angle is formed so that the change point out largely.

  According to the nut with an axial force indicating washer according to claim 1 of the present application, at the time of fastening, the inner surface tapered deformed protrusion is formed by the design axial force based on the bolt strength and bolt diameter of the bolt to be used. From the degree of protrusion, it can be easily and visually confirmed whether or not the tightening has been performed with a predetermined axial force. In addition, the inner surface tapered deformation protrusion is plastically deformed so that the tip portion protrudes from the outer peripheral end of the seat when tightening up to the designed axial force, and the axial force-rotation angle at the time of tightening is When the axial force satisfying the design axial force is applied and the deformation projection part completes the plastic deformation and the axial force-rotation angle at the time of tightening is formed so that the inclination of the relationship curve is small Since the change point where the slope of the relationship curve increases is formed, when tightening with an electric wrench, the electric wrench is automatically stopped when an axial force that satisfies the design axial force is applied. be able to. In other words, when the plastic deformation of the deforming protrusion is completed and the inclination of the curve of the axial force-rotation angle changes greatly, the motor current of the electric wrench changes greatly. Tightening can be automatically stopped. As a result, according to the fastening means that catches this change point and automatically stops, it is possible to obtain a stable fastening axial force regardless of the torque coefficient, and to determine whether or not fastening has been performed with a predetermined axial force. Even when the force is checked at a later date, the visual check of the deformed protrusion and the check using the electric wrench can be easily and quickly performed.

  Further, as in the invention of claim 2 of the present application, the deforming protrusion is formed in a cylindrical shape on the outer peripheral portion of the one end surface of the seat, and the taper of the deforming protrusion is formed on the inner portion of the deforming protrusion in the seat. An annular groove is formed on the inner peripheral surface of the shape, and the seat has a middle diameter A, a hole diameter B, and a thickness C so as to have a hardness equal to or higher than the designed axial force based on the bolt strength and bolt diameter of the bolt to be used. On the other hand, the deformation protrusion is plastically deformed so that the tip portion protrudes from the outer peripheral end of the seat when tightening up to the designed axial force, and the relationship between axial force and rotation angle during tightening The height D of the deforming protrusion, the width E of the annular groove portion, and the outer diameter F of the deforming protrusion are formed so as to reduce the inclination of the curve, and an axial force that satisfies the design axial force is applied. At this point, the deforming protrusion has completed the plastic deformation, and the axial force at the time of tightening−the rotation angle If the configuration is such that the change point at which the slope of the curve curve increases, the axial force that satisfies the design axial force in accordance with the design axial force based on the material of the washer and the bolt strength and bolt diameter. This is preferable because it can be easily set so that a change point where the inclination of the relationship curve of axial force and rotation angle at the time of tightening becomes large is applied.

It is a longitudinal cross-sectional view of the nut with an axial force display washer according to the present invention. It is a longitudinal cross-sectional view of a coaxial force display washer. It is a bottom view of a coaxial force display washer. It is a relational curve figure of axial force at the time of fastening-rotation angle. It is a partial longitudinal cross-sectional view which shows the state before fastening. It is a partial longitudinal cross-sectional view which shows the state after fastening. It is a front view of another axial force display washer. It is a bottom view of a coaxial force display washer. It is a longitudinal cross-sectional view of a coaxial force display washer. It is explanatory drawing of the incorrect attachment state of a coaxial force display washer.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 show a nut 1 with an axial force indicating washer according to the present invention. The nut 1 is rotated by caulking at a nut body 2 having a screw hole 21 at the center and a lower seating surface of the nut body 2. An axial force display washer 3 that is freely and integrally engaged is provided.

  The nut body 2 has a polygonal shape (in the figure, a hexagonal shape), and a caulking cylindrical protrusion 22 is integrally provided around the screw hole 21 at the lower portion of the seat surface. The axial force indicator washer 3 includes a disc-shaped seat 30 having a caulking through-hole 31 in the center, an annular groove 32 formed near the outer periphery of the bottom surface of the seat 30, and an annular groove 32. It is composed of an inner tapered portion 33 and a cylindrical projecting projection portion 33 that are integrally projected on the lower peripheral side of the seat portion 30 in the thickness direction. The seat 30 has a hardness equal to or higher than the design axial force based on the bolt diameter (for example, M12 M16 M20) and the bolt strength (8.8 10.9 12.9, etc.) of the bolt to be used. A material is appropriately selected, and an intermediate diameter A, a hole diameter B, and a thickness C are formed. Further, the caulking cylindrical protrusion 22 of the nut body 2 is fastened to the caulking through hole 31 of the seat portion 30 without protruding downward from the bottom surface of the seat portion 30.

  On the other hand, the deformation protrusion 33 is plastically deformed so that the tip portion protrudes from the outer periphery of the seat portion 30 at the time of tightening up to the designed axial force, and the axial force at the time of tightening as shown in FIG. -The height D of the deforming protrusion, the width E of the annular groove portion, and the outer diameter F of the deforming protrusion 33 are formed so as to reduce the inclination of the relationship curve of the rotation angle. When the axial force that satisfies the above-mentioned designed axial force is applied, the deforming projection 33 completes the plastic deformation that protrudes outward from the outer peripheral end of the seat 30 and is tightened as shown in FIG. A change point G at which the inclination of the relationship curve of the axial force-rotation angle during attachment increases is formed. Further, it is preferable that the tip end portion of the cylindrical deformation projection portion 33 is sharpened at an acute angle as shown in FIG. 1 so as to facilitate initial plastic deformation and not to be crushed on the inner surface side.

  In use, for example, as shown in FIG. 5, the nut 1 with an axial force indicating washer 1 is screwed into a bolt 5 inserted into the body to be fastened 4 with the deformation projection 33 of the axial force indicating washer 3 facing downward. And then tighten and tighten with an electric wrench (not shown). At the time of the tightening, the deformation projection 33 of the axial force display washer 3 is deformed while expanding its diameter so as to protrude outward from the outer peripheral end of the seat 30 as shown in FIG. At this time, the deformation projection 33 is a relationship curve of the axial force-rotation angle at the time of tightening as shown by a in FIG. 4 when tightening up to the designed axial force based on the bolt strength and bolt diameter of the bolt 5 to be used. The tip portion is plastically deformed so as to protrude from the outer periphery of the seat portion 30 so that the inclination of the head portion becomes smaller. When the axial force that satisfies the above-mentioned designed axial force is applied, the deforming projection portion completes the plastic deformation that protrudes outward from the outer peripheral end of the seat portion 30, and as shown in FIG. A change point G at which the inclination of the relational curve of axial force-rotation angle becomes large appears. When the detector incorporated in the electric wrench senses this change point, the electric wrench is automatically stopped to complete the fastening. That is, since the motor current of the electric wrench changes greatly at the change point G where the plastic deformation of the deformation protrusion 33 is completed and the inclination of the curve of the axial force-rotation angle has changed greatly, the change point G can be detected. Thus, the tightening by the electric wrench can be automatically stopped.

  In this way, when tightening using an electric wrench, the electric wrench can be automatically stopped when the axial force that satisfies the above-mentioned designed axial force is applied, and the manual tightening can be completed, which is related to the torque coefficient. And a tightening axial force within a certain elastic range can be obtained. Further, even if the maximum load is applied beyond the change point G, it is within the elastic range of the bolt and the axial force is not lost. In addition, the fastening axial force of the nut main body 2 to the fastened body 4 can be easily confirmed by visual observation from the degree of protrusion of the deformed protrusion 33 to the outer peripheral end of the seat portion 30, that is, the outer peripheral end of the nut main body 2. be able to. Further, when checking the fastening axial force at a later date, it is possible to easily and quickly check using a visual check or an electric wrench.

  Further, the shape of the deforming protrusion 33 of the axial force display washer 3 is not limited to the tapered tubular deforming protrusion 33 as shown in FIGS. 1 to 3, for example, as shown in FIGS. 7 to 9. Alternatively, a plurality (six in the figure) of deforming protrusions 33a... 33a may be provided intermittently in the circumferential direction. In the embodiment shown in the figure, annular grooves 32a... 32a are formed around the deformed protrusions 33a. The plurality of deforming protrusions 33a... 33a are also plastic so that the deforming protrusions 33a... 33a are protruded from the outer peripheral end of the seat 30 when tightening up to the design axial force. The deformation projections 33a to 33a are formed at the time when the deformation is formed so that the inclination of the relationship curve of the axial force-rotation angle at the time of tightening is small and an axial force that satisfies the design axial force is applied. It is formed so that a change point at which the plastic deformation is completed and the inclination of the relational curve of the axial force and the rotation angle at the time of tightening is increased.

  In the case of the nut 1 with an axial force display washer having the axial force display washer 3 formed in this way, as in the case of the nut 1 with an axial force display washer, the deformed protrusion 33a. 33a is deformed so that the deforming projections 33a... 33a greatly protrude outward in the radial direction from the outer peripheral end of the seat portion 30 when tightening up to the designed axial force. Thereby, the fastening axial force by the bolts and nuts can be visually confirmed by the degree of deformation of the plurality of deformation projections 33a... 33a, and the inclination of the relationship curve between the axial force and the rotation angle at the time of tightening is small. It has become. When the axial force that satisfies the design axial force is applied, the deforming protrusions 33a... 33a complete the plastic deformation, and accordingly, the inclination of the relationship curve between the axial force and the rotation angle at the time of tightening is increased. Since it becomes larger, the tightening by the electric wrench can be automatically stopped by detecting this changing point G.

  In the above-described embodiment, the annular groove 32 or the annular groove 32a... 32a is formed around the deformed protrusion 33 or the deformed protrusion 33a... 33a, respectively. May be omitted.

  Further, according to the nut with an axial force indicating washer of the present invention, when the axial force indicating washer is incorporated into the nut body, or when it is erroneously incorporated as shown in FIG. Therefore, it is automatically selected at the time of manufacture or use. Thereby, even if it is a beginner, it can prevent using it accidentally.

DESCRIPTION OF SYMBOLS 1 Nut with an axial force display washer 2 Nut main body 22 Cylindrical protrusion 3 Axial force display washer 3a Axial force display washer 30 Seat 30a Seat 31 Through hole 31a Through hole 32 Annular groove 32a Annular groove 33 Deformed protrusion 33a Deformed protrusion Part

Claims (2)

  A nut with an axial force indicator washer comprising a nut body having a screw hole and an axial force indicator washer that is rotatably and integrally engaged with a lower portion of the seat surface of the nut body. Consists of a disc-shaped seat having a caulking through-hole in the center, and an inner tapered tapered protrusion projecting integrally in the thickness direction on the outer periphery of the bottom surface of the seat, It is formed to have a hardness that is higher than the design axial force based on the bolt strength and bolt diameter of the bolt to be used, and the caulking through hole for the seat portion has the caulking projection portion of the nut body downward from the bottom surface of the seat portion. On the other hand, the deformation protrusion is plastically deformed so that its tip protrudes from the outer peripheral edge of the seat when tightening up to the above-mentioned designed axial force, without being projected. Shape to reduce the slope of the force-rotation angle relationship curve In addition, when an axial force that satisfies the design axial force is applied, the deforming projection portion completes the plastic deformation and a change point at which the inclination of the relational curve of the axial force and the rotation angle at the time of tightening increases. A nut with an axial force indicating washer, characterized in that it is formed so as to be exposed.   An annular groove formed in the outer peripheral portion of one end surface of the seat portion with a deforming projection portion in the axial force indicating washer and continuous with the tapered inner peripheral surface of the deforming projection portion in the inner portion of the deforming projection portion in the seat portion The seat is formed with an intermediate diameter A, a hole diameter B, and a thickness C so as to have a hardness equal to or higher than the design axial force based on the bolt strength and bolt diameter of the bolt to be used. At the time of tightening up to the designed axial force, the tip part is plastically deformed so that it protrudes from the outer peripheral end of the seat, and the axial force-rotation angle relationship curve during tightening is reduced. When the height D of the protrusion, the width E of the annular groove, and the outer diameter F of the deformation protrusion are formed, and the axial force that satisfies the design axial force is applied, the deformation protrusion is plastically deformed. The inclination of the relationship curve between axial force and rotation angle during tightening is large. Axial force display washer nut according to claim 1, wherein the Kunar change point is formed as out.

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