JPH11141529A - Screw with spring washer - Google Patents

Abstract

(57) [Problem] To provide a screw with a spring washer so that even if the screw is tightened to a state where the spring washer is pressed and shrunk flat, the tightening force is not so large. SOLUTION: A non-hardened plate-shaped spring washer 16 is used. Unhardened disc-shaped spring washer 1
6 is flattened and contracted by a relatively small tightening force.
If the screwing of the screw 1 is stopped, the tightening torque of the screw body 11 at that time is not so large, and a temporary tightening state can be obtained. For this reason, in the case of temporarily tightening the tightening target 19 and correcting its position, the work can be efficiently performed.
Further, fine position correction can be easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw with a spring washer, wherein a disc-shaped spring washer is attached to a lower portion of a neck of a shaft portion having a thread.

[0002]

As shown in FIG. 6, a conventional screw 1 with a spring washer is provided on a screw body 4 comprising a shaft portion 2 and a head portion 3 at a portion below the neck of the shaft portion 2. A flat washer 5 and a spring washer 6 are attached. When the mounting object is tightened and fixed by such a screw 1 with a spring washer, the screw body 4 is further strongly tightened even after the spring washer 6 has been compressed and adhered to the head 3 and the flat washer 5. To complete tightening.

[0003] By the way, depending on the object to be tightened, the screw body 4 is loosely tightened, that is, the screw body 4 is temporarily tightened, and the mounting position of the object is corrected.
May be further tightened to a completely tightened and fixed state. In this case, the detection that the screw main body 4 is in the temporarily tightened state is performed while the screw main body 4 is tightened while the spring washer 6 originally having a spiral shape is flattened and shrunk to contact the head 3 and the flat washer 5. It is obtained by stopping the tightening at a point in time.

However, the conventional screw 1 with spring washer
In this case, the spring washer 6 is made of spring steel and quenched. Therefore, the spring washer 6 is hard and has a very large spring constant. For this reason, even if the screw body 4 is stopped tightening when the spring washer 6 is flattened and contracted as described above and comes into contact with the head 3 and the flat washer 5, the screw at this time is The tightening torque of the main body 4 is considerably large. Therefore, although it is said that it is temporary tightening, the object to be tightened is considerably strongly tightened, so even if you try to move the object by hand for position correction, it does not move easily, it takes time and effort to correct the position, and it is subtle. There were problems such as difficulty in correcting the position.

[0005] If such a problem occurs, there may be a question as to whether the tightening torque should be controlled and the tightening stopped before the spring washer 6 is flattened and contracted in obtaining the temporary tightening state. I don't know. However, since the spring constant of the spring washer 6 is very large, the tightening force fluctuates greatly with a slight rotation of the screw body 4, and it is very difficult to control the tightening torque. Before tightening, it is difficult to stop the tightening and obtain an appropriate temporary tightening state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is that even if the spring washer is tightened flat and compressed, the tightening force does not become so large. An object of the present invention is to provide a screw with a washer capable of efficiently performing the work and easily performing a fine position correction when the position is corrected in a temporarily tightened state.

[0007]

In order to achieve the above object, a screw with a spring washer according to the present invention is provided with a screw body having a head integrally formed at one end of a shaft having a thread. ,
A spring washer attached to a lower portion of the shaft portion of the screw main body, wherein the spring washer is made of a low-hardness disc-shaped spring washer that has not been hardened. According to this configuration, the disc-shaped spring washer is not quenched, is relatively soft and has a small spring constant, so even if the screw is tightened until the disc-shaped spring washer is flattened and compressed. The tightening torque is not so large. For this reason, since the fastening target can be moved with a small force, the work for correcting the mounting position of the target can be easily performed, and the delicate position correction can be easily performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG.
The screw body 11 of the screw with the spring washer is provided with a hexagonal head 14 as shown in FIG. A flat washer 15 and a disc-shaped spring washer 16 are attached to the lower part of the neck of the shaft portion 13 of the screw body 11. The disc-shaped spring washer 16 has an endless annular shape, but may have an end.

Here, the materials of the screw body 11, the flat washer 15, and the disc-shaped spring washer 16 will be described first.
The screw body 11 is made of, for example, a hardenable high carbon steel such as S45C, and the flat washer 15 and the disc-shaped spring washer 16 have no or little if any hardening effect such as SPCC. Manufactured from unobtainable low carbon steel.

The procedure for manufacturing such a screw with a spring washer will be described. First, a screw body 11 having a head 14 and a shaft 13 (without a thread 12) integrally manufactured by cold forging, and thereafter Then, the disc-shaped spring washer 16 and the flat washer 15 are inserted into the shaft portion 13. Then, in this state, the thread 12 is formed on the shaft portion 13 by rolling means, and finally, the whole is heated to a quenching temperature to perform quenching. At the time of this quenching, the shaft portion 13 and the head 14 are made of high carbon steel such as S45C, so that they are quenched. Since it does not enter or even if it is burned, it is still soft.

By the way, conventionally, the screw body 4 is S45
Since the spring washer 6 is made of high carbon steel such as C, the quenching conditions are different. First, the screw body 4 is forged, and then the screw body 4 and the spring washer 6 are separately quenched. Thereafter, the spring washer 6 and the flat washer 5 are inserted into the shaft portion 2 of the screw main body 4, and finally the thread is rolled into the shaft portion 2. Conventionally, since the thread is rolled on the shaft portion 2 that has been hardened and has a high hardness, the life of the rolling tool has been shortened. In contrast, in the present invention, as described above,
Before the hardening of the screw body 11, the thread 1
2, the rolling tool has a long life.

Now, the operation when the mounting object is tightened and fixed to the mounted object while the position of the mounted object is corrected using the screw with the spring washer configured as described above will be described. In FIG. 3, a nut 18 is fixed to the back surface side of the attachment 17. The through hole 2 is provided in the object 19 and the object 17.
0 and 21 are formed. The shaft 13 of the screw body 11 is passed through the through holes 20 and 21 and screwed into the nut 18.

When the head 14 is rotated by a tool and the screw body 11 is tightened to the nut 18, the disc-shaped spring washer 16 is gradually pressed and shrunk by the tightening force of the screw body 11, and finally becomes flat. As a result, the lower surface of the head 14 and the upper surface of the flat washer 15 come into flat contact with each other. The operator performs the screwing operation while visually observing the disc-shaped spring washer 16, and when the disc-shaped spring washer 16 is flattened and contracted as described above and comes into contact with the head 14 and the flat washer 15, The rotation operation of 14 is stopped, and the object 19 is temporarily tightened.

At this time, since the disc-shaped spring washer 16 is not hardened and has a relatively small spring constant, it is compressed flat by a small pressing force. For this reason, when the rotation operation of the head 14 is stopped, the object 19 is not fastened to the object 17 with such a large tightening force, and the object 19 can be moved with a small force. Therefore, when the object 19 is displaced from the proper mounting position, the position can be easily corrected, and fine position correction can be easily performed. After correcting the position of the object 19, the screw body 11 is turned again to be strongly tightened to the nut 18. As a result, the object 19 is strongly tightened to the object 17 to be completely fixed.

FIG. 4 shows the results of an experiment comparing the tightening torque of the screw body 11 with the conventional one when the object 19 is temporarily tightened. The provisionally tightened state indicates the screwing torque when only the shaft portion 13 is screwed into the nut 18 in the screwing rotation speed-screwing torque characteristic of FIG. 5, and B to C and B ′ to C ′ indicate Disc spring washer 1
6, the screwing torque when the spring washer 6 is pressed and shrunk, and C and C 'indicate the tightening torque in the temporary tightening state when the disc-shaped spring washer 16 is flattened and shrunk. D indicates the tightening torque at the time of permanent fixing.
As is clear from FIG. 5, in the conventional product, the tightening torque greatly changes with a small screwing rotation angle in B ′ to C ′, so that it is difficult to obtain an appropriate temporary tightening torque. The tightening torque in the temporarily tightened state is small, and as a result, the object 19 can be easily moved.
It is understood that fine adjustment can also be easily performed.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, the head 14 is not limited to a hexagon and may be constituted as a self-tapping screw. Various modifications can be made without departing from the scope of the present invention.

[0017]

As described above, according to the present invention, even if the screw is tightened until the spring washer is pressed and contracted, the tightening force is not so large. In such a case, the operation can be performed efficiently, and fine position correction can be easily performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a cross-sectional view showing a state where an object is tightened;

FIG. 4 is a diagram showing the result of a comparison experiment of the temporary tightening torque of the product of the present invention and the conventional product.

FIG. 5 is a diagram showing a relationship between a screwing rotation speed and a screwing torque.

FIG. 6 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

11 is a screw main body, 13 is a shaft portion, 14 is a head, 15 is a flat washer, 16 is a disc-shaped spring washer, 17 is a mounted object, 18 is a nut, and 19 is a tightening target.

Claims (1)

[Claims] 1. A screw body comprising: a screw body having a head integrally formed at one end of a shaft portion having a thread; and a spring washer attached to a lower portion of a neck portion of the shaft portion of the screw body. A screw with a spring washer, wherein the washer is made of a low-hardness disc-shaped spring washer that has not been hardened.