JP2002061628A - Shaft body and manufacturing method for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rational and functional shaft body and a manufacturing method for it capable of reducing the product cost without impairing the function by improving the constitution. SOLUTION: In a metal band plate with a required width, flat parts are formed at both end parts 4, 4, and a part outside both end parts is spirally 3 twisted in the axial direction to constitute the shaft part 1. A metal band plate with required dimensions is used as raw material, and cut to a required length. In the thus formed metal band plate, both end parts are fixed and held in designated positions, and with the holding space kept constant, rotating force is applied to one end part to twist the raw material, thereby forming the part outside both end held parts spirally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft formed by processing a metal plate, and more particularly, to a shaft formed by twisting a band-shaped metal plate to increase the sectional strength and rigidity, and manufacturing the same. It is about the method.

[0002]

2. Description of the Related Art Conventionally, as a supporting shaft or a rotating shaft used for a structure portion having a relatively small load or a mechanism portion rotating with a small applied rotating force or a very low rotating speed, for example, A solid body having a circular cross section with a small diameter or a solid body having a square cross section is used depending on the application.

[0003] Such a small-diameter shaft is often used as a support shaft involving rotation of a movable part or a simple support shaft in household electric appliances or small industrial equipment, for example. As an example, as shown in FIG. 6, the support shaft 100 having the mounting surface formed by cutting the end portion 101 has a limited rotation angle like a support shaft of a tape cassette loading frame in a VCR. It is used as a rotating support shaft.

[0004] In addition, a solid shaft having a circular cross section is used as a static member such as a support shaft or a connection shaft used for supporting a component on one axis without performing a rotary motion. .

[0005]

As such a shaft, there is usually used a shaft having a required size formed by processing a so-called polished round bar having a smooth surface. Therefore, when used for parts produced in large quantities, there is a problem that an increase in material price and processing cost affects the production cost. Therefore, in order to use it as a part to be mass-produced, lowering the unit price is a reasonable way to reduce the production cost of the finished product,
As an important means, there is a strong demand for the site where parts are manufactured and supplied.

[0006] However, in order to reduce the production cost as a part and to exert the desired function, it is necessary to reduce not only the raw material cost but also the processing cost. However, when the cost of raw materials is reduced, it is difficult to find favorable results, for example, by lowering the mechanical strength of materials and the like. In addition, in order to reduce the processing cost, it is necessary to manufacture a product that does not involve processing as much as possible, which causes a problem in processing accuracy. For this reason, it is difficult to obtain a product that does not impair the original function even if the product cost is reduced, because there are many very difficult elements.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by modifying the structure, the product cost can be reduced without impairing the function, and a shaft body having a rational and functional function can be provided. And a method for producing the same.

[0008]

In order to achieve the above-mentioned object, a shaft body according to the first invention is formed by forming flat portions at both ends with a metal strip having a required width. Is formed in a spirally twisted structure in the axial direction.

According to the present invention, the entire structure is twisted in the axial direction except for the flat portions at both ends in a spiral manner. The coefficient can be increased, and a rigid and lightweight shaft body can be configured. The flat portions at both ends are used to fit into rectangular holes provided in a molded part such as a synthetic resin, thereby facilitating connection with the part and fixing without special processing. be able to. Also, if a drawn material such as a flat steel wire is used as a material, it can be made into a product simply by twisting it, and cutting work is not required, so mass productivity can be easily increased and provided at low cost. It has the effect of being able to do it. The shaft body should be used as a rotating power transmission shaft with a torque smaller than the twisting force applied during the twisting process, or as a static support shaft for parts produced in large quantities, such as equipment, to reduce costs. Can be. of course,
It goes without saying that it is also effective as a small amount of production parts.

Next, in a method of manufacturing a spiral shaft according to the second invention, a metal strip having a required size is used as a raw material, and both ends of the metal strip cut to a required length are fixedly held at predetermined positions. It is characterized in that the material is twisted by applying a rotational force to one end while keeping the holding interval constant, and portions other than both ends to be held are formed in a spiral shape.

In the present invention, a metal strip having a required outer diameter (plate thickness, strip width, length) as a basic dimension of a shaft to be obtained is prepared as a material, and the material is prepared. Both ends are fixedly held at a length dimension suitable for processing, and a rotational force is applied to one end while keeping the distance between the holding positions constant. In this way, the belt-shaped material, the other end of which is fixed and held, is gradually twisted from one side to which a rotational force is applied, and is formed in a spiral shape. At this time, since the dimension between both end portions of the material is kept constant, a portion (intermediate portion) other than the holding portion is spirally plastically deformed by a rotational force while applying tension. Therefore, the spiral lead formed between both ends is substantially constant according to the number of rotations on the side to which the rotational force is applied. In other words, the higher the number of rotations applied to the material, the shorter the spiral leads are formed. When performing the twisting process, the number of rotations applied to the material is kept within a range exceeding the yield point of the material. In addition, the metal strip in the present invention includes a cut material and a drawn material (linear material).

According to the present invention, the shaft is formed in a helical shape by applying a rotational force by fixing and holding the band-shaped material having the required dimensions at both ends, so that the shaft is constantly tensioned in the axial direction. Since the twisting process is performed while applying the force, the strip is plastically deformed and, at the same time, its axis is kept constant. As a result, it is possible to easily manufacture a helical shaft body having flat portions at both ends and automatically correcting the axis line to be straight. Therefore, if the dimensions of the material are set and prepared in advance, the helical shaft can be manufactured by rotating the required number of times by holding both ends of the material in the holding section of the processing machine, and in the first invention, It is possible to produce a large number of shafts having an effect, and to provide the shaft at a low cost.

As means for fixing and holding both ends of the material, mounting holes are provided at both ends of the material at right angles to the plane thereof,
It is preferable that a pin that fits into the mounting hole is provided in the holding portion on the spiral processing machine side, and that the pin and the mounting hole of the material are engaged and held. By doing so, it is only necessary to fit the mounting hole at the end of the material to the pin on the processing machine to mount and hold the material on the processing machine side, so workability is good, and stress in the axial direction acts at the time of torsion processing Thus, there is an advantage that the holding force is automatically increased, and the processing can be performed without difficulty. Further, there is an effect that the mounting hole provided for holding can be used as it is as a mounting hole for a device and the like as a fixing means even after it is made into a product.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of a shaft body and a method of manufacturing the same according to the present invention will be described with reference to the drawings.

FIG. 1 is an overall perspective view of one embodiment of a shaft according to the present invention. FIG. 2 shows an enlarged cross-sectional view thereof.

The shaft body 1 of this embodiment is obtained by cutting a steel strip cut to a required length into flat portions of a required length at both ends thereof.
Both ends 4, 4 are arranged in a fixed direction (in the specific example, both ends are on the same plane), and the other shaft 2 is formed in a spiral shape 3 by twisting with a required lead. .
At both ends 4, 4, mounting holes 5 are provided as necessary.

Such a shaft body 1 is obtained by a manufacturing method described later. Since the shaft line is kept straight, there is no distortion such as bending, and the shaft body 1 is provided with rigidity as a whole by working. As long as no external force is applied, it is straight and rigid as a whole. Therefore, for example, as shown in FIG. 3A, in order to use a part of a device or the like as a shaft for rotatably supporting the part, the helical shape is formed on bearings 21 and 21 provided on the pair of frames 20 and 20. Parts 24 and 25 having mounting holes 22 in which flat portions at the ends of the shaft body 1 are previously inserted into both end portions 4 and 4 while supporting the shaft portion 2 of the shaft 3 in the same manner as a conventional solid shaft, It is fitted and mounted in the mounting hole 22. In this case, the shaft 1
The required parts 24 and 25 are attached to the
It is supported at 21 and can be assembled rotatably.
In the bearing 21, the outer shape of the shaft 2 is a spiral 3
Therefore, the peripheral portion can be held and rotated around the inner periphery of the bearing portion 21 without any trouble.

When used as a stationary shaft,
As shown in FIG. 3B, for example, the flat portions of the end portions 4 are inserted into the insertion holes 26a, 27 in the boss portions 26, 27 on the mounting side.
a, and fixed to the frame 20A or the like with a set screw 28, or a hole is provided in advance on the mounting side where a flat shape portion of the shaft end fits, and the end 4 of the shaft body 1 is inserted into this. You may make it hold | maintain. Further, depending on the case, a holding means (not shown) which can be engaged and fixed by a pin or the like by using the mounting hole 5 provided in the end portion 4 can be adopted. When used as such a stationary shaft or a rotating shaft at a required rotation angle, a component 15
Can be attached and supported (see FIG. 3B). In such a use, if the push screw 16 is used to fix the helical portion to the three helical portions, it can be securely fixed by pressing the end of the push screw against the surface of the helical portion.

Next, the characteristics of the shaft body 1 of the present invention will be more clarified by the method of manufacturing the shaft body of the present embodiment described below.

FIGS. 4 (a) to 4 (d) are views for explaining a specific example of a method of manufacturing the shaft body of this embodiment.

First, as shown in FIG. 4 (a), a steel strip having an outer dimension required to have a required outer diameter of a target shaft body is prepared as a raw material. The steel strip 10 used is, for example, one obtained by cutting a steel sheet having a required thickness. Outer diameter d of shaft body 1 to be obtained here (see FIG. 2)
Is approximately the width B of the strip. The total length of the shaft 1 is basically the total length L of the steel strip 10 to be prepared. The plate thickness can be set arbitrarily according to the purpose of use. That is, to increase the strength by reducing the outer diameter, a material having a large thickness may be used. However, it is preferable to reduce the thickness of the sheet as much as possible in consideration of economy because of good workability.

The prepared steel strip 10 (hereinafter referred to as material 10)
), Mounting holes 5 are formed at both ends. Next, the material is mounted on a separately prepared processing device. As the torsion processing device 30 used here, one having a configuration as shown in FIG. 5 is used.

The processing apparatus 30 includes a rotation holding means 32 rotatably supported by a bearing fixedly installed at one end on a base 31, and a fixed movable opposite to the rotation holding means 32 and movable in an axial direction. It comprises a holding means 36 and a holding interval setting means 40. The rotation holding means 32 is rotatably held at a fixed position in the axial direction by a bearing portion 33a of a holding block 33 to be fixed, projects the holding portion 34a in the axial direction from the bearing portion 33a, and has another end. A rotating holder 34 is provided, to which a rotating handle 35 is attached so as to protrude outward in the opposite direction. Holder 3 of the rotary holder 34
4a has an attachment holding surface 34b formed along the rotation axis,
The holding pin 34 crosses the mounting holding surface 34b on the axis.
c is planted. The fixed holding means 36 includes a fixed block 38 slidably supported on a guide rail 37a formed along a guide block 37 provided on the base 31 in the longitudinal direction and movably in the axial direction. And a fixed holder 39 whose axis is aligned with the rotary holder 34 at the center of the fixed holder 3.
A holding pin 39b is implanted on the mounting surface 39a formed along the axis of No. 9 so as to intersect the axis similarly to the rotary holder 34. The fixed holder 39 of the fixed holding means 36 is rotatable with the tip of a screw shaft 42 which is screwed into a female screw portion of an end plate 41 attached to the other end of the base 31 (the end opposite to the holding block 33). By rotating the other end of the screw shaft 42, the fixed block 38 is attached to the guide block 3 provided with the base 31.
The holding interval setting means 40 which can advance and retreat along the 7 guide rails 37a is connected.

As shown in FIG. 4 (b), the steel strip blank 10 previously prepared is provided with mounting holes 5 and 5 provided at both ends thereof as a fixed holder 39 and a rotating holder 34, respectively. Pin 39 on each of the holding surfaces 39a and 34a
b, 34c. At this time, FIG.
The fixed block 38 of the fixed holding means 36 shown in FIG.
Is moved by rotating the screw shaft 42 of the holding interval setting means 40 with the attached handle 43, and the fixed holder 39 is moved.
And the holding pin 39b, 34c of the rotary holder 34
Position setting is performed so that the mounting holes 5 and 5 of 0 match. When the both ends of the material 10 are held on the holding surfaces of the fixed and rotating holders 38 and 34, the material 10 is positioned so as not to easily come off.

Next, the handle 35 of the rotation holding means 32
When the rotating operation is performed, the rotating holder 34 is rotated to rotate one of the materials 10 held thereby to apply a torsional force. Then, the other end of the material 10 is engaged and held by the holding pin 39 b and the mounting hole 5 on the holding surface of the fixed holder 39, and when the one end is rotated by the rotary holder 34, the tension at the fixed end is increased. The intermediate portion of the material 10 is twisted while being kept fixed only by applying a force (FIG. 4C).
reference).

In this state, the rotation holder 34 is rotated a required number of times.
Is rotated, the intermediate portion is formed in a spiral shape 3 by the torsional force applied to the material 10. In this processing state, the distance between the holding pins 39b and 34c of the fixed holder 39 and the rotary holder 34 is always constant.
0 is plastically deformed into a spiral shape 3 while being elongated in the axial direction as it is twisted. Therefore, the torsionally applied material 10 is always helically formed by a lead which is substantially equal to the number of times of torsion, because the tensile stress always acts in the axial direction during the processing, and the material 10 is tensioned. To form a torsion shaft portion (FIG. 4).
(D)). As a result, the obtained shaft body 1 automatically becomes straight and spiral. When the processing is completed, the fixed block 38 is moved to the rotation block 33 by rotating the screw shaft 42, and the product can be easily removed if the tension is removed. In order to facilitate the operation of removing the product from the processing device, the operation is completed with both ends aligned on the same plane. Further, assuming a springback amount accompanying the twisting process, the work is performed by setting an amount of twisting so that both ends are aligned on the same surface after product removal.

The shaft body 1 is formed into a helical shape 3 so that appropriate work hardening is caused, and the work hardening and the torsion structure make it possible to finish the shaft body as a whole with high rigidity. Since the shaft 1 is formed in this manner, the apparent diameter of the spiral shaft 2 increases when the width of the strip is increased according to the purpose of use. Further, when the lead of the spiral is made smaller, the work hardening proceeds and the overall rigidity is increased.
However, it is not preferable to excessively increase the amount of twist because the strength is reduced because the load approaches the maximum load beyond the yield point of the material. In addition, when the thickness of the strip is increased, the strength is increased as a whole, but the workability is poor, and reduction in production cost cannot be expected much. Therefore, twisting using a strip having an appropriate thickness is the most preferable measure because the workability can be improved and the material cost can be reduced.

Further, if a flat strip having a required cross section is used as a drawn material instead of using a strip cut from a steel sheet, the process of cutting the steel sheet into a strip can be omitted. it can. Moreover, there is an advantage that no loss occurs when cutting to the required size. In addition, in the case of a material obtained by cutting a steel plate, burrs and the like are likely to be generated on the cut end surface, and it may be necessary to remove it. It is effective. Further, in the case of using a drawn material, there is an advantage that if a material drawn in a modified cross section is used as well as a simple flat material as necessary, the cross-sectional strength can be increased.

In addition, when the raw material is twisted by the processing device 30, mounting holes 5 and 5 are provided at the ends of the raw material 10 as means for holding both ends of the raw material. The description has been made of a method that employs a method in which the holding pins 34c and 39b provided on the rotating holder 34 and the fixed holder 39 are engaged. Instead of this method, the fixed holder and the rotating holder are provided with clamps, and these clamps are used to remove material. Both ends can be held. In this case, if the both ends of the material are fixed so as to be positioned in the clamp, the above-described processing can be performed without any problem. In addition, this method has an effect that the number of steps for providing a mounting hole at the end of the material can be reduced, and in particular, the processing of the mounting hole is effective when dealing with a wasteful material. That is, it is effective when the thickness of the plate is large, when the width of the band is narrow, and it is difficult to provide the mounting holes for the holding pins.

As described above, according to the present embodiment, the processing can be performed very easily. By automating the processing, the material cost can be reduced and the processing cost can be significantly reduced.
Compared with a conventional solid shaft, there is an effect that the cost can be reduced by at least a fraction.

The shaft body having a helical shaft portion according to the present invention can be used as a rod without twisting in addition to a support shaft as in the above-described embodiment, and is required to be a device requiring light weight. It can be said that it can be used as many rod-shaped parts. In addition, with such a spiral shaft part, if marking is performed using the flat part of the torsion part, it is difficult to directly attach the identification code etc. to the product with the conventional round shaft. And a secondary effect that can be used to improve productivity by facilitating component identification in a workplace where similar components are used in large quantities. is there.

The shaft according to the present invention can be applied not only to the above-mentioned articles such as the mechanical parts but also to articles in other fields, and utilizes the flat part formed at the end. Facilitating attachment (connection) to other parts is an element that can effectively utilize the whole.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of one embodiment of a shaft according to the present invention.

FIG. 2 is an enlarged cross-sectional view of FIG.

FIGS. 3A and 3B show an example of use of the shaft according to the present invention, wherein FIG. 3A shows a case where the shaft is used as a rotating shaft, and FIG. It is.

4 (a) to 4 (d) are views for explaining a processing procedure of the shaft body of the present embodiment.

FIGS. 5A and 5B are views of an embodiment of a shaft processing apparatus according to the present invention, in which FIG. 5A is an overall perspective view, and FIG.

FIG. 6 is a diagram illustrating an example of a conventionally used shaft body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft 2 Shaft 3 Spiral 4 End 5 Mounting hole 10 Material 30 Processing device 32 Rotation holding means 33 Holding block 34 Rotating holder 34c, 39b Holding pin 35 Handle 36 Fixed holding means 38 Fixed block 39 Fixed holder 40 Holding interval Setting means

Claims (4)

[Claims] 1. A shaft body wherein flat portions are formed at both ends with a metal strip having a required width, and the other portions are spirally twisted in an axial direction. 2. A metal strip having required dimensions is used as a material,
Both ends of the metal strip cut to a required length are fixedly held at predetermined positions, the material is twisted by applying a rotational force to one end while keeping the holding interval constant, and portions other than both ends to be held are twisted. A method for manufacturing a shaft, wherein the shaft is formed in a spiral shape. 3. As means for fixing and holding both ends of the material, mounting holes are provided at both ends of the material at right angles to a plane of the material, and pins which fit into the mounting holes are provided at a holding portion on the spiral processing machine side. 3. The method for manufacturing a shaft according to claim 2, wherein the pin and the mounting hole of the material are engaged and held. (4)