JPH0680913U - Screw locking device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a screw locking device. As shown in FIG. 1, a screw locking device of the present invention has a spring projection washer C interposed between a head surface 10 of a screw or a nut seat surface 1 and a tightened surface 2, whereby a seat surface 1 is formed. And the tightened surface 2 are locked. That is, the spring protrusion washer C is provided with a vertical protrusion 5 on one surface, and the clamped surface 2 with which the protrusion 5 abuts
A notch 8 is formed in the and the projection 5 is fitted therein.
On the other surface, the tip 4c is provided on the concentric circle of the spring projection 4 having an angle smaller than 45 degrees in the tightening direction, and the sectional view is V-shaped on the concentric circle of the seat surface 1 with which the spring projection 4 abuts. The slope is 4
The depression 3 having an angle smaller than 5 degrees is formed. Upon completion of tightening, the spring protrusion 4 is fitted in the recess 3. When the nut B is loosened, the tip 4c of the spring projection 4 presses the tightening side slope 3a of the recess 3 and the screw is securely locked. When it is loosened using a tool, the spring protrusion 4 bends on the tightening side slope 3a and slides to the upper end, so that the seat surface 1 and the tightened surface 2 are separated in sequence.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention interposes a spring protrusion washer C having a spring protrusion on one surface and a protrusion on the other surface between the seating surface and the tightened surface of the screw head or nut, and is viewed in cross section on a concentric circle with which the spring protrusion abuts. Relates to a screw locking device having a V-shaped recess and a notch or a cylindrical hole formed on a concentric circle with which the protrusion abuts.

[0002]

[Prior art]

 Conventionally, to prevent screws from loosening, a method has been used in which cotter pins are inserted and fixed in the slivers and pin holes formed in the center lines of nuts and bolts. On the other hand, a system in which a washer is interposed between the screw head or the seat surface of the nut and the tightening surface was in the process of trial. In that example, there was a machine in which the seat surface and the tightened surface were machined, and protrusions were provided on both sides of the washer so that the protrusions were interposed (No. 49-20627). In addition, on the tightened surface of the soft material, a ring-shaped flange integrally formed on the outer periphery of the bearing surface of the nut is provided with a protrusion bent at a right angle so that it stands by above the flange. There is a type (Jitsuko Sho 56-53128) that is driven into the tightened surface of a softened material.

[0003]

[Problems to be solved by the device]

 Among the ones described in the prior art, the ones that use cotter pins have restrictions on use because of the wide variety of screw applications. In the screw loosening stopper (Japanese Utility Model Publication No. 49-20627), unequal-sided triangular recesses are sequentially provided on the inner circumference of the head seat surface of the bolt, and one end of the spring washer projects downward, Symmetrically, the portion of the upper seating surface that abuts the concave portion is provided with a triangle-shaped upward protrusion having substantially the same inclined surface on the steep slope of the concave portion, and the axial center is symmetrical on the tightening surface on the lower side of both protrusions. , An elliptical recess is provided. According to the present invention, the upward triangular protrusion engages with the concave portion, and when the screw is turned strongly, the triangular protrusion sinks downward and acts like a ratchet mechanism. However, the triangular protrusions are considered to have been formed by pressing at both positions with the shaft center of the washer on the same plate surface being symmetrical, and it is unavoidable that excessive strain hardening occurs due to this. The protrusions are triangular with no elasticity, and it is difficult to expect a locking effect like a ratchet because the bent part is prone to plastic deformation due to the sinking of the board.

In the flange nut with a claw of (Japanese Utility Model Publication No. 56-53128), the claw has an arc around the base and is driven into the tightened surface, but it requires considerable skill. The nails were easily bent and were not suitable for reuse. Also, the tightened surface was prone to damage.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to combine a recess and a spring projection washer formed on either of the tightening surfaces with each other. An object of the present invention is to provide a screw locking device that securely locks a screw and can be used repeatedly and does not damage the tightening surface of a soft tightening material.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, in the screw locking device of the present invention, a spring projection washer C is interposed between the seat surface 1 and the tightened surface 2. That is, a depression 3 having a V-shaped slope in cross-section is formed on the concentric circle of the seat surface 1, and the angle between the slope and the upper end surface (hereinafter referred to as the angle of the slope) is less than 45 degrees. Formed small. On the other hand, a notch 8 or a cylindrical hole 9 is formed in the center of the concentric circle of the tightening surface 2, and a vertical projection 5 is provided on the surface of the spring projection washer C on the concentric circle of the spring projection washer C that abuts it ( In the following description, the protrusion 5 is provided, which will be referred to as only), and the tip 4c is provided with a spring protrusion 4 having an angle smaller than 45 degrees in the tightening direction on a concentric circle with which the recess 3 abuts, on the seat surface 1 side. .

In the flat head screw F, it is preferable that the spring protrusion washer C is formed in a conical shape having the same shape as the seat surface 1, and the crown 22 is formed in the same shape as the upper end of the tightened surface 2.

In the seated head, a recess 3 is formed on the concentric circle of the tightened surface 2, a shaft hole 6 of the same shape as the square seat 11 is formed in the spring protrusion washer C, and the tip 4c is loosened on the tightened surface 2 side. Directional projections 4 are provided. The square seat 11 is formed slightly thinner than the spring protrusion washer C.

In the stud bolt G, it is preferable to maintain a gap between the female screw 14 and the outer peripheral edge of the stud spring washer H.

The pawl 18 of the pawl spring washer L is preferably short and wide in the central direction.

The depressurization groove 12 may have a depth slightly recessed from the tightening surface forming the depressurization groove 12. Further, when the pressure relief groove 12 is formed in the spring protrusion 4 in the opposite direction, it is preferable to use the tightening surface on the back side of the spring protrusion 4.

In the spring protrusion 4 in the opposite direction, it is preferable that the base portion 4d is projected at about 45 degrees and the tightening side slope 3a of the recess 3 is formed larger than 45 degrees.

The protrusion spring 21 projects toward the tightened surface (2) to enhance the locking function of the protrusion 20, and also has a cushioning function.

The fitting washer M placed on the tightened surface 2 is preferably provided with a through hole 20e on a concentric circle with which the protrusion 20 abuts.

[0015]

[Action]

 The washer having the spring protrusion 4 or the convex spring 21 has the protrusion 5 and the notch 8 or the cylindrical hole 9, the shaft hole 11 of the same type as the square seat 11, the reverse male screw 15 and the reverse female screw 16, and the pawl 18 and the soft tightening. Fix each with Attachment E and tighten the screws.

Along with this, the seat surface 1 and the tightened surface 2 come close to each other, and the spring protrusion 4 or the protruding spring 21 bends, the spring protrusion 4 fits into the recess 3, and the protrusion 20 fits into the recessed hole 20j or the through hole 20e. Inserting and locking is completed. When the screw is loosely operated, the tip 4c of the spring protrusion 4 presses the facing slope and holds the lock. In the protrusion spring 21, the protrusion 20 presses the facing surface or the facing line of the recess hole 20j or the through hole 20e to hold the lock.

When loosened using a tool, the spring protrusion 4 bends on the opposite slope and slides to the upper end. Similarly, the protrusion spring 21 bends and the protrusion 20 slides to the upper end on the opposing surface or on the opposing line, and the seat surface 1 and the tightened surface 2 are separated in sequence.

13 and 14, the spring protrusion 4 in the opposite direction, around the tightening, the tip 4c presses the sloping side slope 3b of the recess 3 according to the proximity of both tightening surfaces and slides to the upper end to complete tightening. In, the spring protrusion 4 is fitted in the recess 3. In the loosening, the upper end of the tightening side slope 3a of the recess 3 is locked to the base 4d. When the tool is loosened, the upper end of the slope 3a pushes in the direction of the tip 4c, and the spring projection 4 slides toward the tightening surface 2 side and slides to the upper end surface of the recess 3 and is tightened with the seat surface 1 Surface 2 is separated in sequence.

[0019]

【Example】

 Examples will be described with reference to the drawings. In FIG. 1 and FIG. 2, the concentric circles of the seat surface 1 are formed with V-shaped cross-sections on both slopes 3a and 3b each having an indentation 3 whose angle is smaller than 45 degrees. It is formed (hereinafter, referred to as forming the recess 3 only). The spring protrusion washers C are arranged as a pair on the concentric circle on the side where the recesses 3 contact, with the tip ends 4c of the spring protrusions 4 having an angle smaller than 45 degrees in the tightening direction at the same central angle as the recesses 3. However, the spring protrusion 4 and the tightening side slope 3a form an obtuse angle. On the concentric circle on the back side of the spring projection washer C, the projections 5 are provided with the central angles at equal angles, and the notches 8 are formed on the center line of the tightened surface 2 with which they abut.

3 and 4, the tightening surface 2 is formed by enlarging the seating surface 1 in a conical shape with the thickness of the spring projection washer C left over. The screw F is provided with a notch 8 in the axial direction of the seat surface 1, and the outer circumference of the crown 22 is enlarged and formed substantially to the thickness of the spring protrusion washer C. The spring protrusion washer C has the same conical shape as the bearing surface 1, and is provided with a protrusion 5 inward on a concentric circle with which the notch 8 abuts, and a spring protrusion 4 with a loosened tip 4c on an outer concentric circle. ing . Then, a conical recess 3 is formed on a concentric circle of the tightened surface 2 with which the spring protrusion 4 abuts.

In FIGS. 5 and 6, a square seat 11 is formed on the seat surface 1 and a recess 3 is formed on the concentric circle of the tightened surface 2, and the spring projection washer C on which the recess 3 is abutted is tightened on the concentric circle. A spring projection 4 whose tip 4c is loose is provided on the surface 2 side, and a shaft hole 6 of the same type as the square seat 11 is formed at the center. The square seat 11 is formed to be slightly thinner than the spring projection washer C.

In FIGS. 7 and 8, the recess 3 is formed on the center line of the tip 13g of the stud G, and the reverse female screw 16 having a small diameter is provided at the axial center of the bottom face of the female screw 14. In the stud spring washer H, the reverse female screw 16 is integrally formed with the upper end of a reverse male screw 15 having the same diameter, and the tip 4c is provided with the spring protrusion 4 in the tightening direction of the stud bolt G.

In FIG. 9 and FIG. 10, a thin ratchet 18 is provided on the tip end of the spring projection washer L with a pawl on the tightening surface 2 side, and is wide in the center direction. A conical depression 3 is formed on the concentric circle. The spring protrusion 4 is provided on the concentric circle of the spring protrusion washer L with a pawl on which the recess 3 abuts, with the tip 4c narrowed and with the tightening direction.

In FIG. 11 and FIG. 12, conical recesses 3 are formed on concentric circles of the seat surface 1 and the tightened surface 2, respectively, and the spring projection washer C on the seat surface 1 side is in contact therewith. Provide spring projections 4 in the direction of tightening the tip 4c and in the direction of loosening the tip 4c on the tightened surface 2 side. The height of the spring projection 4 on the seat surface 1 is concentric with the spring projection 4. A shallow depressurization groove 12 corresponding to approximately 1/5 of the above is formed.

13 and 14, the protrusion 5 is provided on a concentric circle on the tightened surface 2 side of the spring protrusion washer C, and the cylindrical hole 9 is formed in the tightened surface 2 with which the projection 5 abuts. The cylindrical hole 9 has substantially the same diameter as the length of the diagonal line of the cross section of the protrusion 5. On the other hand, a recess 3 is formed concentrically on the seat surface 1. The angle of the tightening side slope 3a of the recess 3 is formed to be larger than 45 degrees, and the base 4d is approximately 45 degrees on the concentric circle of the spring projection washer C with which it abuts, and a shallow inclination toward the tip 4c. The spring protrusion 4 is provided in the opposite direction.

In FIG. 15 and FIG. 16, an integral flange 19 is formed on the outer circumference of the seat surface 1, and a semi-spherical protrusion 20 having a slightly inferior arc cross section is formed on the concentric circled surface 2 side of the tip 4c. The protrusion spring 21 is provided with a tip 4c in a loosening direction and is projected, and a concave hole having a diameter corresponding to the concentric circle of the tightened surface 2 with which the protrusion 20 abuts is fitted. It forms 20j.

17 to 19, the connection of the pipes Q and Q is shown. That is, the joint body N has a shaft hole 6 through which the pipe Q is inserted in the shaft center, a male screw 13 that is screwed into the union P is provided on the outer periphery of the seating surface 1 side, and a cylindrical hole 9 is formed concentrically on the seating surface 1. Is provided. The raised spring washer K has a larger diameter than the seat surface 1 of the joint body, and an outer peripheral edge thereof is provided with a raised spring 21 with its tip 4c in the tightening direction. The projection 5 is provided on a concentric circle with which the cylindrical hole 9 abuts. The tightening surface 2 of the union P has the same shape as that of the joint body N, has a shaft hole 6 through which the pipe Q is inserted at the shaft center, and forms an inward flange 19k of the same diameter on the sleeve 23 at the lower end thereof. A female screw 14 is provided in the half portion, and a notch 8 is formed on the center line of the screwing port of the female screw 14. On the other hand, the mating washer M has the same diameter as that of the spring washer K with protrusions, and a concave hole 20j is formed on a concentric circle with which the protrusions 20 abut, and a corresponding recessed hole 20j is formed. The protrusion 5 is provided at a position where the notch 8 abuts.

In FIGS. 20 and 21, the outer circumference of the crown 22 of the screw F is enlarged and formed on the flange 19, and the protruding spring 21 is provided at the tip 4c in the tightening direction. Then, the conical surface 2 to be tightened is cut down so that the upper end edge thereof has the same diameter as the flange 19 of the seat surface 1 and the washer M is overlapped with the flange 19 and the cylindrical hole 9 is formed on the concentric circle. Is forming. The mating washer M has a through hole 20e having a diameter corresponding to that of the concentric circle with which the protrusion 20 abuts, and a protrusion 5 on a concentric circle with which the cylindrical hole 9 abuts. According to FIG. 3, the tightening surface 2 corresponding to the seat surface 1 corresponds to the conical portion in FIG. 20, but corresponds to the mating washer M, and has an annular shape cut down to the upper end. The portion is the tightening surface 2.

In each of the above-mentioned embodiments, the spring protrusions 4 are arranged in a pair at the same center angle as the recess 3. Therefore, by providing a plurality of pairs, the spring protrusions 4 can be formed in pairs. While being fitted in the recess 3, the other pair of spring projections 4 are located between the two clamping surfaces 1 and 2 to enhance the accuracy of proper clamping and also have a cushioning effect. When the number of spring protrusions 4 is limited to one or two, the recesses 3 are formed close to each other on the concentric circle of the tightening surface against which the spring protrusions 4 abut for proper tightening.

Because of the structure of the protrusion spring 21, it is preferable that the protrusion 20 be fitted into the recess hole 20j or the through hole 20e when the tightening is completed. It is appropriate to provide a plurality of pairs having the same number as 0.

In the present invention, in addition to the cushioning function of the spring protrusions 4, each spring protrusion washer and the flange 19 include a cushioning function by forming a spring-like shape.

[0032]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects.

In the screw locking device according to the first and second aspects, the process of the spring projection washer C having the spring projection 4 on one surface and the projection 5 on the other surface is simple. Further, the formation of the recess 3 and the notch 8 corresponding to the spring protrusion 4 and the protrusion 5 is simple, and this configuration enables the screw to be securely locked and the spring protrusion washer C to be repeatedly used.

In the screw locking device of the third aspect, the fixing force is increased by providing the spring projection washer C with the shaft hole 6 of the same type as the square seat 11. Especially suitable for machine screws.

In the stud bolt G according to the fourth aspect, since the stud spring washer H is screwed to the bottom surface of the female screw 14 with a reverse screw, a repulsive force acts between both screws and the fixing force is strong, so that the screw is repeatedly used. Can be used.

In the spring projection washer L with a pawl according to claim 5, since the pawl 18 is short and wide in the center direction and the tip is narrow, it is easy to fit the shaft hole 6 into the screw opening, while the fixing force is strong and detachable. Also, the tightened surface 2 is not damaged.

In the spring protrusion washer C of claim 6, the spring protrusions 4 and 4 are provided on both sides, and it is particularly suitable for the condition that the tightening operation uses the air spanner to keep the tightening. At that time, the spring protrusions 4 and 4 are not specified in the depressions 3 and 3, and it is assumed that the spring protrusions 4 and 4 are located between the clamping surfaces 1 and 2 and cause plastic deformation. Therefore, the depressurizing groove 12 in claim 8 is formed in the seat surface 1.

In the spring protrusion washer C in which the spring protrusion 4 of claim 7 is provided in the opposite direction, even if the spring protrusion 4 is rusted due to salt damage or the like, if the spring protrusion 4 is loosened with a tool, Since the tip 4c is pulled in the direction of the base 4d, it is easily separated.

The depressurizing groove 12 of claim 8 can be applied to any of the above-mentioned claims, and an effect can be expected. However, the depressurization groove 12 is not essential as long as the spring protrusion 4 has high flexibility and is bent gently.

In the projecting spring 21 according to claim 9, not only is the locking function excellent, but the projecting member 20 and the recessed hole 20j that locks it are both simple in construction and have a small occupied area. It is also highly applicable to.

In the connection of the pipes Q, Q according to claim 10, the fitting washer M of FIGS. 17 to 19 is a liner in which the seat surface 1 of the joint body N and the tightened surface 2 of the union P are narrow due to the use thereof. Under certain conditions, the protrusion spring spring washer K and the mating washer M are enlarged to enable reliable engagement by the protrusion spring 21.

As described above, the spring protrusion washers and the protruding spring washers are also fixed by the protrusions 5, the reverse male screw 15, and the pawl 18 even when the screw F is loose. On the other hand, the spring protrusion 4 presses the opposing sloped surface around the loosening, and the protrusion 20 presses the opposing surface of the recessed hole 20j or the opposing line of the through hole 20e while securely locking to securely lock. When loosened using a tool, the spring protrusion 4 and the protrusion 20 slide off the opposite slope, opposite face or line to the upper end. In other words, the screw locking device of the present invention is capable of reliably locking the screw and proper tightening, and is suitable for repeated use without loosening even if oil is applied.

As described above, the screw locking device of the present invention has various configurations and thus has a wide range of applications. Further, the degree of locking strength of the rib protrusion 4 can be easily adjusted and manufactured by selecting its bending strength, the angle between the opposite slopes, and the position and number on the center line of both.

[Brief description of drawings]

FIG. 1 is a partial front sectional view in which a spring washer C is interposed and locked.

FIG. 2 is an exploded partial view of FIG.

FIG. 3 is a front partial cross-sectional view in which a conical spring protrusion washer C is interposed and locked to a flat head screw.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a partial front sectional view of a spring washer C fitted and locked to a square seat 11.

6 is an exploded partial view of a bolt A and a spring protrusion washer C. FIG.

FIG. 7 is a front sectional view in which an implant spring washer H is fixed to the bottom surface of the female screw 14 and an implant bolt G is locked.

8 is an exploded partial view of FIG. 7. FIG.

FIG. 9 is a front partial sectional view in which a screw F is locked with a pawl spring protrusion washer L interposed.

10 is an exploded partial sectional view of a screw F and a pawl spring washer L. FIG.

FIG. 11 is a front partial cross-sectional view of a spring projection washer C having spring projections 4 and 4 provided on both surfaces thereof and a bolt A having a pressure relief groove 12 formed on the seat surface 1 which is engaged.

FIG. 12 is a bottom view of a bolt A, a spring projection washer C and a partial plan view of a material to be tightened D.

FIG. 13: Spring protrusion washer C having spring protrusion 4 provided in the opposite direction
FIG. 6 is a front cross-sectional view in which a bolt A is locked with the interposition of FIG.

14 is an exploded partial view of a bolt A and a spring protrusion washer C. FIG.

FIG. 15 is a screw F provided with a screw F provided with a convex spring 21;
FIG. 11 is a front partial cross-sectional view obtained by engaging with the concave hole 20j.

FIG. 16 is an exploded partial view of a main part of a locking mechanism using a convex spring 21.

FIG. 17 is a front partial cross-sectional view formed by connecting pipes Q, Q with a raised spring washer K and a mating washer M interposed between a joint body N and a union P.

FIG. 18 is a bottom view of the joint body N, and a partial plan view of the protrusion-provided spring washer K and the fitting washer M.

FIG. 19 is a front exploded partial sectional view of the pipe Q, Q connection mechanism of FIG. 17;

FIG. 20 is a front sectional view in which a convex spring 21 is provided on the flange 19 of the screw F, and a fitting washer M is interposed and locked.

FIG. 21 is an exploded partial view of a matching washer M and a tightening surface 2.

FIG. 22 is a partial front sectional view of a conventional screw locking device.

FIG. 23 is a partial cross-sectional view of a main part of a conventional nut with a claw.

[Explanation of symbols]

A bolt, B nut, C
Spring protrusion washer, D tightening material, E soft tightening material, F screw, G stud bolt, H
Implant spring protrusion washer, J foundation material, K convex spring washer, L pawl spring washer, M mating washer, N
Fitting body, P union, Q pipe, 1 seat surface, 2 tightening surface,
3 depressions, 3a tightening side slope, 3b loosening side slope, 4 spring protrusion, 4c tip,
4d base, 5 protrusions, 6 shaft holes,
7 Shaft, 8 Notch, 9
Cylindrical hole, 10 heads, 11
Square seat, 12 pressure relief groove, 13 male screw,
13g Male screw tip, 14 Female screw, 1
5 reverse male screw, 16 reverse female screw, 17 cross hole, 17h thread, 18th,
19 flanges, 19h inward flanges, 2
0 convex, 20j concave hole, 20e through hole,
21 convex spring, 22 crown, 2
3 sleeves

Claims (10)

[Scope of utility model registration request] 1. A slope (3) having a V-shaped cross-section on a concentric circle of a head (10) of a screw or a bearing surface (1) of a nut (B).
a, 3b) having a recess (3) formed on the concentric circle on the side of the spring projection washer (C) with which the recess (3) abuts, with the longitudinal tip (4c) in the tightening direction A spring protrusion (4) on the back side of the spring washer C, and a vertical protrusion (5) on the back side of the washer C, and a notch is formed in the center of the concentric circle of the tightened surface (2) with which it abuts. (8)
Alternatively, a screw locking device provided with a cylindrical hole (9). 2. A notch (8) or a cylindrical hole (9) is provided on the concentric circle of the seat surface (1), and a V-shaped recess (3) is formed on the concentric circle of the tightened surface (2). A protrusion (5) is provided on the bearing surface (1) side of the spring protrusion washer (C), and a tip (4) is provided on the tightened surface (2) side.
2. The screw locking device according to claim 1, wherein c) is provided with a spring projection (4) in a loosening direction. 3. A tightened surface (2) of a spring projection washer C having a square seat (11) in the center of the seat surface (1) and having a shaft hole (6) of the same type as the same square seat (11). Provide a spring protrusion (4) on the side,
The screw locking device according to any one of claims 1 and 2, wherein a recess (3) is formed on a concentric circle with which it abuts. 4. A V-shaped recess (3) is formed on the center line of the tip (13g) of the stud bolt G, and a small-diameter reverse female screw (16) is provided on the axial center of the female screw (14), and The screw locking device according to any one of claims 1 to 3, which comprises an implant spring protrusion washer (H) having a spring protrusion washer integrally or in combination fixedly attached to an upper end of an inverted male screw (15) having the same diameter. . 5. A soft clamped material (E) having a vertical pawl (1) on the clamped surface (2) side of a pawl spring projection washer (L).
8) is provided, The locking device of the screw of any one of Claims 1-4. 6. A spring projection (4) whose tip (4c) is in the tightening direction is provided on the bearing surface (1) side of the spring projection washer C.
The opposite spring protrusions (4) are provided on the tightened surface (2) side of the respective recesses, and the recesses are formed in the seat surface (1) and the tightened surface (2) with which both spring projections (4) and (4) come into contact. The screw locking device according to any one of claims 1 to 5, wherein (3, 3) is formed. 7. The angle of the tightening side slope (3a) with which the spring projection base (4d) comes into contact with the spring projection (4) in the opposite direction and in the loosening direction is larger than the angle of the base section (4d). The locking device for a screw according to any one of claims 1 to 6, which is formed. 8. A recess on the concentric circle of the seat surface (1) and the tightened surface (2) with which the spring projection (4) abuts, or on the concentric circle of either of the both surfaces (1, 2) of the concentric circle. Depressurization groove (1
2) The screw locking device according to any one of claims 1 to 7, which is formed. 9. A projection spring (21) having a hemispherical projection (20) is provided at the tip of a rectangular spring plate integrally formed with a flange (19) on the outer periphery of the seat surface (1), Same projection (2
The screw locking device according to any one of claims 1 to 8, wherein a concave hole (20j) of the same shape is formed on a concentric circle of the tightened surface (2) with which the (0) abuts. 10. A raised spring washer (K) having a raised spring (21) located outside the seat surface (1) and a concave hole (20j) or a transparent hole on a concentric circle with which the raised (20) abuts. The screw locking device according to any one of claims 1 to 9, comprising a mating washer (M) provided with a hole (20e).