JP3177869U - Axial force indicator washer - Google Patents

Abstract

Provided is an axial force display washer in which tightening with a predetermined axial force can be easily confirmed visually, and a large change point appears in a relational curve of axial force-rotation angle during tightening with a designed axial force. To do.
A disc-shaped washer body 10 having a through-hole 11 in the center, and an inner taper-shaped deformation projection 13 integrally formed with the washer body 10 and projecting in the thickness direction at an outer peripheral portion of one end surface thereof. The washer body 10 is formed to have a hardness equal to or higher than the designed axial force based on the bolt strength and bolt diameter to be used. The deformation protrusion 13 is plastically deformed so that the tip portion protrudes from the outer peripheral end of the washer body 10 at the time of tightening up to the design axial force, and the inclination of the relationship curve of axial force-rotation angle at the time of tightening is increased. In addition to being formed to be small, it is formed so that the plastic deformation is completed when the design axial force is applied, and a change point where the inclination of the relationship curve of axial force-rotation angle at the time of tightening becomes large appears.
[Selection] Figure 1

Description

  The present invention relates to an axial force indicating washer interposed between a bolt or nut and a body to be fastened.

  Conventionally, as a washer interposed between a bolt or nut and a body to be fastened, for example, an engagement groove having a chrysanthemum pattern is formed on the lower surface of a disc-shaped washer main body having an insertion hole through which a shaft portion of the bolt is inserted. It has a formed configuration.

  Then, when the above washer is interposed between the bolt and the body to be fastened and properly tightened with a jig, it is pressed against the body to be fastened via the washer against the lower surface of the head of the headed bolt and tightened by its axial force. It is designed to prevent loosening with resistance.

  However, as in the case of the washer described above, in the structure for preventing loosening by simply pressing the bolt to the body to be fastened via the washer, when using a torque wrench or a normal tightening jig, The axial force due to tightening of the head bolt varies depending on the torque coefficient, etc., and a stable tightening axial force cannot always be obtained. Therefore, if the tightening with the head bolt is weak, there is a serious problem that loosening occurs when vibration or some external force is applied. Further, when the head bolt 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. An object of the present invention is to provide an axial force display washer in which a large change point appears in the relationship curve of the rotation angle.

  In order to solve the above-described problem, the device according to claim 1 of the present application is provided with a disc-shaped washer body having a through-hole in the center, and a protrusion in the thickness direction at the outer peripheral portion of one end surface of the washer body. The washer body is formed so as to have a hardness equal to or higher than the design axial force based on the bolt strength and bolt diameter to be used, while the deformation projection is the above-described design axis. At the time of tightening up to the force, the tip portion is plastically deformed so as to protrude from the outer peripheral end of the washer body, and the inclination of the relationship curve of axial force and rotation angle at the time of tightening is reduced. When an axial force that satisfies the above-mentioned designed axial force is applied, the deforming projection part is formed so that a change point can be formed at which the plastic deformation is completed and the inclination of the relationship curve of axial force and rotation angle at the time of tightening increases. It is characterized by being.

  In the invention according to 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 washer body, and the tapered inner peripheral surface of the deforming protrusion is formed on the inner side of the deforming protrusion in the washer body. An intermediate groove A is formed, and an intermediate diameter A, a hole diameter B, and a thickness C are formed so that the washer body has a hardness equal to or higher than a design axial force based on a bolt strength and a bolt diameter to be used. At the time of tightening up to the designed axial force, the deformation protrusion is plastically deformed so that the tip portion protrudes from the outer peripheral end of the washer body, and the inclination of the relationship curve between axial force and rotation angle during tightening becomes small. 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, and when the axial force that satisfies the design axial force is applied, the deforming protrusion is The relationship between the axial force and rotation angle at the time of tightening after completing the above plastic deformation Wherein the slope of the curve is formed such that the change point out largely.

  According to the axial force indicating washer according to claim 1 of the present application, at the time of fastening with a bolt or a nut, the inner side taper-shaped deformed protrusion is moved from the outer peripheral end of the washer body by the designed axial force based on the bolt strength and bolt diameter to be used. It can be deformed so as to protrude outward, and it can be easily and easily confirmed visually whether or not tightening has been performed with a predetermined axial force from the degree of protrusion. In addition, the inner surface tapered deformation projection is plastically deformed so that the tip portion protrudes from the outer peripheral end of the washer body at the time of 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, a stable fastening axial force can be obtained regardless of the torque coefficient. Furthermore, when checking the fastening axial force at a later date, a visual check or a check using an electric wrench can be easily and quickly performed.

  Further, as in claim 2 of the present application, the deforming projection is formed in a cylindrical shape on the outer peripheral portion of the one end surface of the washer body, and the taper of the deforming projection on the inner portion of the deforming projection in the washer body. An annular groove is formed on the inner circumferential surface of the shape, and the washer body is formed with an intermediate diameter A, a hole diameter B, and a thickness C so as to have a hardness greater than the designed axial force based on the bolt strength and bolt diameter to be used. On the other hand, the deforming protrusion is plastically deformed so that the tip portion protrudes from the outer peripheral end of the washer body at the time of tightening up to the designed axial force, and the relational curve of axial force-rotation angle at the time of tightening is obtained. When 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, and an axial force that satisfies the above-mentioned designed axial force is applied. , The deformation protrusions have completed the plastic deformation and the axial force during tightening- If the configuration is such that the change point at which the inclination of the relationship of the turning angle increases, the design axial force is satisfied 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 at which the inclination of the relationship curve of the axial force-rotation angle at the time of tightening increases when an axial force is applied.

It is a longitudinal cross-sectional view of the axial force display washer according to the present invention. It is a partial 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 partial longitudinal cross-sectional view which shows the state before the shaping | molding start of an axial force display washer. It is a partial longitudinal cross-sectional view which shows the shaping | molding state in a 1st process. It is a partial longitudinal cross-sectional view which shows the state before the drilling start in a 2nd process. It is a partial longitudinal cross-sectional view which shows the drilling state in a 2nd process. It is a front view of another axial force display washer. It is the bottom view. It is the longitudinal cross-sectional view.

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

  1 to 3 show an axial force display washer 1 according to the present invention. This washer 1 is formed on one end surface (hereinafter referred to as a bottom surface) of a disc-shaped washer body 10 having a through-hole 11 in the center. An annular groove 12 formed in an intermediate portion, and a cylindrical deformed protrusion 13 having an inner tapered surface that projects from the outer side of the annular groove 12 and is integrally formed with the washer body 10 to the lower side in the thickness direction. It will be. The washer body 10 has a hardness equal to or higher than the designed axial force based on the bolt diameter (for example, M12, M16, M20, etc.) and the bolt strength (8.8, 10.9, 12.9, etc.). The material is appropriately selected, and an intermediate diameter A, a hole diameter B, and a thickness C are formed. On the other hand, when the deformation projection 13 is tightened up to the designed axial force, the distal end portion of the washer body 10 is fixed. The height D of the deforming protrusion, the width E of the annular groove portion so that the inclination of the relationship between the axial force and the rotation angle during tightening is reduced as shown in FIG. When the outer diameter F of the deforming protrusion 13 is formed and an axial force that satisfies the design axial force is applied, the deforming protrusion 13 completes the plastic deformation that protrudes outward from the outer peripheral end of the washer body 10. And when tightening as shown in Figure 4 Axial force - are formed so that the change point G of the slope increases the relational curve of the rotation angle out. Further, it is preferable that the tip end portion of the cylindrical deformation projection portion 13 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, as shown in FIG. 5, the axial force indicating washer 1 is interposed between the headed bolt (or nut) 3 and the body to be fastened 4 with the deformation projection 13 on the lower side, and an electric wrench (FIG. Tighten and tighten with (not shown). At the time of tightening, the deformation projection 13 of the axial force display washer 1 is deformed while expanding its diameter so as to protrude outward from the outer peripheral end of the washer body 10 as shown in FIG. At this time, when the deformation projection 13 is tightened to the design axial force based on the bolt strength and bolt diameter of the bolt to be used, as shown in FIG. The tip portion is plastically deformed so as to protrude from the outer periphery of the washer body 10 so as to reduce the inclination. When the axial force that satisfies the design axial force is applied, the deforming projection portion completes the plastic deformation that protrudes outward from the outer peripheral end of the washer body 10 and is tightened as shown in FIG. A change point G at which the inclination of the relationship 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 13 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, it is possible to easily visually confirm the fastening axial force of the bolt 3 to the fastened body 4 from the degree of protrusion of the distal end portion of the deformed protrusion 13 with respect to the outer peripheral end of the washer body 10, that is, the outer peripheral end of the bolt 3. it can. 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.

Next, a method for manufacturing the above-described axial force display washer 1 will be described.
First, using a hot forging machine 20 equipped with a double punching header mechanism as shown in FIG. 7, in a consistent two steps from a long metal material S made of heat-treatable metal to scrapless. A washer molded body 1B shown in FIG. 8 in which the washer main body 10 and the deformed protrusion 13 are integrally formed is formed.

  Here, the hot forging machine 20 is a long metal material S heated to a temperature of 1000 ° C. or less by a grip die 21, a washer molding die 22, a high-frequency heat treatment machine (not shown), or the like. And a ram 27 having a movable punch plate 26 in which a washer forming punch 24 in the first step and a piercing punch 25 in the second step are arranged side by side. ing. The ram 27 is moved forward and backward toward the machine body 23, and the movable punch plate 26 is supported so as to be movable in the moving punch juxtaposition direction with respect to the ram via a moving means (not shown). Further, the metal material S is heated to a temperature of 1000 ° C. or less by an induction heat treatment machine or the like, and then transferred to the washer forming die 22 by a supply mechanism. Further, although not specifically described, for forming the washer molded body 1B shown in FIG. 8 that does not have the through-holes 11 on the opposing surfaces of the washer forming die 22 and the first step washer forming punch 24, respectively. Split mold forming portions 22a and 24a are respectively formed. The inner diameter of the insertion hole 22a of the washer forming die 22 and the outer diameter of the piercing punch 24 in the second step are the same.

  When forming the axial force indicating washer 1, first, in the first step, as shown in FIG. 7, the long metal material S heated to a temperature of 1000 ° C. or less by the supply mechanism with the grip die 21 opened as shown in FIG. 7. Is fed forward from the insertion hole 22a of the washer forming die 22 by a predetermined length, and then the grip die 21 is closed to grip the metal material S so that the ram 26 is advanced to the die side under the grip state. The leading end of the metal material S is formed by forging with the washer forming punch 24 and the washer forming die 22 in the first step. As a result, a disc-shaped washer body 10 having a through hole 11 at the center as shown in FIG. 8 at the tip of the metal material S, and an annular groove 12 on one side in the thickness direction of the washer body 10. The intermediate formed body A including the tapered cylindrical deformation protrusion 13 for confirming the fastening axial force that protrudes integrally from the outer periphery in the axial direction is integrally formed by forging. In this case, the deforming protrusion 13 is formed to have the same diameter as the outer diameter of the washer body 10.

Next, as the second step, the ram 27 is once retracted, and then the movable punch plate 26 is moved in the direction in which the punches are arranged side by side. As shown in FIG. Opposite the part. Then, the ram 27 is advanced under the condition that the grip die 21 is opened and the metal material S is allowed to move backward, and the center portion of the intermediate formed body 1A is punched by the piercing punch 25 in the second step as shown in FIG. . As a result, the washer molded body 1 </ b> B having the through-hole 11 in the center is molded without scrap, and the separated metal material S is pushed back to the start position in the die 21.
Here, the inner diameter of the insertion hole 22b of the washer forming die 22 and the outer diameter of the piercing punch 24 in the second step are the same. The moving direction of the moving punch plate 25 with respect to the ram 26 may be the left-right direction (horizontal direction) or the vertical direction.

  Thereafter, the ram 27 is moved backward, and then the movable punch plate 26 is moved in the direction in which the punches are juxtaposed. As shown in FIG. 7, the washer forming punch 24 of the first step is inserted into the insertion hole of the forming die 22. Return to the start position opposite 22a. In addition, the washer molded body 1B is taken out from the washer molding die 22 during this movement, and thereafter the above-described operation is repeated to continuously mold the washer molded body 1B without generating scrap.

  Then, the washer molded body 1B taken out from the washer molding die 22 is heat-treated at 800 ° C. or lower by a high-frequency heat treatment machine (not shown) or the like, and at the time of fastening, a tapered cylindrical shape is matched to a predetermined fastening axial force to be obtained. The deformation projection 13 is formed on the axial force display washer 1 having elasticity that deforms so as to protrude outward from the outer peripheral end of the washer body 10.

  As described above, the washer body 10 can be scraplessly processed in two consistent steps from a long metal material S made of a heat-treatable metal using the hot forging machine 20 having a double punching header mechanism. And forming the washer molded body 1B in which the deformed protrusion 13 is integrally molded, and then applying heat treatment to the washer molded body 1B at a temperature of 800 ° C. or less by a high-frequency heat treatment machine (not shown) or the like. An axial force display washer 1 having elasticity that deforms so that the tapered cylindrical deformation protrusion 13 protrudes outward from the outer peripheral end of the washer body 10 in accordance with a predetermined fastening axial force to be obtained can be obtained. According to the above-described manufacturing method of the present invention, the axial force display washer 1 that is accurately set so as to be deformed when tightening is performed with a predetermined axial force required by the deformation projection 13 by using heat treatment is simplified. It can be manufactured easily, and moreover, there is no waste of materials and the cost can be reduced.

  In the forging machine 20 described above, the moving direction of the movable punch plate 25 relative to the ram 26 may be the vertical direction as well as the horizontal direction as in the above-described embodiment.

  Further, the shape of the deforming protrusion 13 of the axial force display washer 1 is not limited to the tapered tubular deforming protrusion 13 as shown in FIGS. 1 to 3, and for example, as shown in FIGS. 9 to 11. Alternatively, a plurality (six in the figure) of deforming projections 13a... 13a may be provided intermittently in the circumferential direction. In the embodiment shown in the figure, annular grooves 12a... 12a are formed around the deformed protrusions 13a. The plurality of deforming protrusions 13a... 13a are also fastened with bolts, nuts, etc., and the deforming protrusions 13a. When the axial force satisfying the above-mentioned designed axial force is applied, the deformed protrusion is deformed so that it is plastically deformed so as to be smaller and the inclination of the relationship curve of axial force and rotation angle during tightening is reduced. 13a... 13a is formed so that a change point is obtained at which the plastic deformation is completed and the inclination of the relational curve of axial force-rotation angle at the time of tightening increases.

  Also in the case of the axial force display washer 1 formed in this way, as in the case of the axial force display washer 1, the deforming projections 13a. The deforming projections 13a... 13a are deformed so as to largely protrude radially outward from the outer peripheral end of the washer body 10. Thereby, the fastening axial force by the bolt and nut can be visually confirmed by the degree of deformation of the plurality of deforming protrusions 13a... 13a, and the inclination of the relationship curve of axial force-rotation angle at the time of tightening is small. It has become. When the axial force satisfying the design axial force is applied, the deformation projections 13a... 13a complete the plastic deformation and the inclination of the axial force-rotation angle relationship curve during tightening increases. By sensing this change point G, the tightening by the electric wrench can be automatically stopped.

  In the above-described embodiment, the annular groove 12 or the annular groove 12a... 12a is formed around the deformed protrusion 13 or the deformed protrusion 13a... 13a, respectively. It may be omitted.

DESCRIPTION OF SYMBOLS 1 Axial force display washer 10 Washer main body 11 Through-hole 12 Annular groove 12a Annular groove 13 Deformed protrusion 13a Deformed protrusion

Claims (2)

  It consists of a disc-shaped washer body with a through-hole in the center, and an inner taper-shaped deformed projection that is integral with the washer body and protrudes in the thickness direction at the outer periphery of one end of the washer body. On the other hand, the deformed protrusion is formed with a hardness equal to or higher than the designed axial force based on the bolt strength and bolt diameter. When the axial force satisfying the above-mentioned designed axial force is applied, the deformed protrusion is deformed so that it is plastically deformed so as to be smaller and the inclination of the relationship curve of axial force and rotation angle during tightening is reduced. Is an axial force indicating washer which is formed so as to have a changing point which completes the plastic deformation and increases the inclination of the relationship curve of axial force and rotation angle at the time of tightening.   The deforming protrusion is formed in a cylindrical shape on the outer peripheral portion of the one end surface of the washer body, and an annular groove is formed in the inner portion of the deforming protrusion portion of the washer body on the tapered inner peripheral surface of the deforming protrusion. The washer body 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 to be used. The height D of the deforming projection portion so that the tip portion of the deformed portion is plastically deformed so as to protrude from the outer peripheral end of the washer body, and the inclination of the relationship curve of the axial force-rotation angle during tightening is reduced. At the time when the width E of the annular groove portion and the outer diameter F of the deformed protrusion are formed and an axial force that satisfies the design axial force is applied, the deformed protrusion completes the plastic deformation and is tightened. Change that increases the slope of the relationship curve Axial force display washer according to claim 1, characterized in that it is formed such that out.

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