JP2003275962A - Shot device and shot method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shot-peening ultrafine wire without curling it. <P>SOLUTION: A wire rod W drawn from a wire rod supply table 1 is entrained over one or more turns on a resting guide roller 3 before directed to a shot device body 4, and the wire rod W processed in the shot device body 4 is wound up on a winder 5. In the shot device body 4, a blaster 7 blasts blast media from each of vertical and lateral directions on the wire rod W running under given tension applied by the resting guide roller 3 and the winder 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a shot peening apparatus and a shot peening method, and more particularly to a technology for performing shot peening treatment on a wire rod such as a steel wire.

[0002]

2. Description of the Related Art Shot peening is used as a process for positively applying compressive residual stress to steel materials. FIG. 15 is a diagram showing a schematic configuration of a shot device that performs shot peening processing on a wire. As shown in the figure, a wire rod such as a steel wire to be treated is wound into a coil and is set on the material supply base 101, and the wire rod W drawn from the wire feeds through the outer peripheral surfaces of the rollers 102 and 103. Then, after traveling so as to penetrate the blasting device 104, it is sequentially wound up by the winding device 105. The blasting device 104 is provided with a projection device that projects the shot material (shot particles) onto the wire W at a high speed and a recovery device that circulates the shot material. The wire W passing through the chamber of the blasting device 104 has its working surface beat out by the collision of the shot material.

[0003]

The above-mentioned conventional apparatus is used for processing a wire having a relatively large diameter. With such a device, a very fine steel wire (for example, a wire diameter of 0.5 to 2.0 m)
When shot peening is performed on a steel wire (about m), the rigidity of the steel wire itself is low, so that the steel wire is easily curved and waviness occurs (a bending tendency occurs). Correcting the bending habit of the steel wire in the shot process in the subsequent process is troublesome, and the shot peening effect is lost during the correction.
For this reason, conventionally, it has been postponed to perform shot peening processing on ultrafine wires. However, in recent years, the mechanical characteristics (for example, fatigue strength) required for ultrafine wires have become stricter due to the demand for miniaturization of various devices, and there is also an increasing demand for imparting a shot peening effect to the ultrafine wires.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shot device and a shot method in which it is difficult for a wire to have a bending tendency.

[0005]

Means and Effects for Solving the Problems In order to solve the above problems, the present applicant has created the inventions described in the claims. In the invention according to claim 1, a wire rod supply unit for supplying the wire rod, a projection unit for projecting the projectile material onto the wire rod pulled out from the wire rod supply unit, and a wire rod on which the projection member is projected are wound. In a shot device having a take-up winding unit, a steady rest prevention unit is provided between the wire rod supply unit and the projection unit to prevent the wire rod from swinging. In this shot device, the runout preventing means provided between the wire rod supply unit and the projecting unit prevents the runout of the wire rod traveling in the projecting unit. Therefore, the running posture of the wire is stable, and the entire circumference of the wire can be uniformly processed. Therefore, it is possible to suppress the bending tendency of the wire rod after the projection. The term "wire" as used herein means a work to be processed, that is, a wire to be processed.

It is preferable that the steady rest prevention means is a steady rest guide roller for guiding the wire. With such a configuration, the posture of the wire rod during traveling can be stabilized with a simple configuration.

In the case of preventing the wire rod from swinging by the steady rest guide roller, it is preferable that the diameter of the steady rest guide roller is relatively large with respect to the diameter of the wire rod. By making the diameter of the steady rest guide roller large, the contact length between the wire rod and the steady rest guide roller becomes long, and the steady rest effect of the wire rod can be enhanced. For example, it is preferable to set the diameter D of the steady rest guide roller to 250 times or more the wire diameter d (D> 250d).

Further, it is also preferable to set a large contact angle (wrapping angle) between the steady rest guide roller and the wire rod to increase the contact length between the steady rest guide roller and the wire rod. For example, it is preferable to wind the wire rod around the steady rest guide roller one or more times. In this way, the contact length can be increased and the wire can be easily tensioned.

It is preferable that the steady rest guide roller is provided with an outer peripheral groove into which the wire is fitted. In such a configuration, the wire rod is positioned in the axial direction of the guide roller by fitting the wire rod into the outer peripheral groove of the steady rest guide roller. That is, it is possible to accurately guide the wire rod with a simple configuration, and it is possible to prevent the wire rod from swinging particularly in the axial direction of the guide roller.

In the shot apparatus according to the first aspect of the present invention, it is preferable that a tension applying means for applying a tension to the wire rod traveling in the projection unit is provided between the wire rod supply unit and the projection unit. By applying tension to the wire rod,
The compressive residual stress applied to the wire can be increased.

The projection unit is provided with a plurality of projection devices whose positions are different from each other in the traveling direction of the wire rod, and a guide member for guiding the wire rod is provided at the boundary of the projection areas formed by the adjacent projection devices. At the same time, it is preferable that an elastic material is arranged at a portion of the guide member that can come into contact with the wire. In such a configuration, the guide member provided at the boundary between the adjacent projection regions guides the wire rod, thereby restricting the traveling posture of the wire rod. In addition, since the elastic material arranged on the guide member can provide an appropriate vibration damping effect, the wire is less likely to vibrate. Therefore, the wire rod does not easily swing, and the posture during traveling is stable.

When a plurality of projection devices are provided in the projection unit, it is preferable that the projection direction of each projection device is set so as to face the wire rod from a plurality of different angular positions in the circumferential direction of the wire rod. In such a configuration, by adjusting the projection direction of each projection device, the striking direction of the projection material with respect to the wire can be prevented from being unbalanced (for example, the projection materials are arranged at 90 ° intervals at four positions in the vertical and horizontal directions). . This makes it possible to make hitting (projection) uniform.

It is preferable that the guide member is formed in a shape to be fitted onto the wire, and the elastic body is arranged on an inner wall surface of the guide member. In such a configuration, since the outer periphery of the wire rod is covered with the guide member, it is possible to prevent the shot material from colliding with the wire rod at the boundary portion of the projection area. As a result, the projection area (projection range of the wire rod) of each projection unit can be clearly defined, and the impact (projection) can be made uniform. Further, it becomes possible to support the wire rod in all directions so as not to largely bend in any direction.

The shot method according to claim 8 is a shot method in which a shot material is projected onto a running wire material that is drawn from a wire material supply part, and the wire material drawn out from the wire material supply part is applied to a steady rest guide roller. The projection material is projected onto the wire sent out from the steady rest guide roller by winding more than one turn. According to this method, the wire rod does not easily shake, the posture during traveling is stable, and it is possible to suppress the bending tendency of the wire rod after projection.

The shot method according to claim 10 is 50 N to 200 for a steel wire having a wire diameter of 0.5 mm to 2.0 mm.
The projection material is projected from a plurality of different angular positions in the circumferential direction of the steel wire in a state where the tension of N is applied. According to this method, a relatively large compressive residual stress can be easily applied to a steel wire having a small wire diameter.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a shot device that performs shot peening treatment on a wire material such as a steel wire. The shot device is roughly classified into a wire rod supply table 1 on which a coil body formed by winding a wire rod W which is an object to be processed is placed, and a wire rod W pulled out from the coil body on the wire rod supply table 1. Shot device main body provided with a guide roller 2 for guiding, a steady rest guide roller 3 for steadying a wire rod W traveling in the longitudinal direction, and a projection device for projecting projection material (shot particles) onto the wire rod W at high speed. 4 and a winding device 5 for winding the wire W.

A wire rod supply base 1 which is a wire rod supply portion is formed so as to be rotatable around a vertical axis line, and a guide roller 2 and a steady rest guide roller 3 (described in detail below) are formed so as to be rotatable around a horizontal axis line. Has been done. Then, the wire rod W has a guide roller 6a on the inlet side (wire rod supply side) and a guide roller 6b on the outlet side (opposite wire rod supply side) of the shot apparatus body 4.
With the height position determined, the vehicle travels straight in the horizontal direction and penetrates the chamber of the shot device body 4.
The winding device 5 is formed so that the wire W can be wound at a predetermined speed and a predetermined tension by a reel that is rotationally driven by a drive motor. The tension may be adjusted by either the winding device 5, the guide roller 2, or the steady rest guide roller 3.

As shown in FIGS. 2 and 3, the steady rest guide roller 3 has a substantially disc-shaped guide roller body 3e rotatably mounted on a mounting shaft 3b mounted on a leg 3a via a bearing 3c. It was supported. The guide roller main body 3e has an outer peripheral groove 3f into which the wire rod W is fitted, and the outer peripheral groove 3f is closed by three pressing rollers 3g so that the fitted wire rod W does not fall off. Pressing roller 3
The g is rotatably supported by a support shaft 3i attached to a mounting seat 3h extending from the leg 3a via a bearing 3j, and can rotate in a state of being in contact with the outer peripheral surface of the guide roller main body 3e. ing. The presser roller 3g is provided at two positions above and below the steady rest guide roller 3 and at one position on the rear side (the wire supply base 1 side). As a result, even when the wire rod W is wound one or more times around the steady rest guide roller 3, the wire rod W is prevented from falling off the outer peripheral groove 3f. The outer peripheral groove 3f is formed to have a predetermined groove width,
The wire W wrapped around this is the guide roller body 3e.
The axis of the wire W, that is, the horizontal direction of the wire W is positioned. In the shot device of this example, the wire diameter of the steel wire (wire material W) to be treated is 0.5 mm to
Compared to 2.0 mm, the diameter of the guide roller body 3e is 500 m
It is formed with a large diameter of m, and the wire W is wound about once around this to increase the winding angle. Therefore, since the contact length between the steady rest guide roller 3 and the wire W is made sufficiently long, it is easy to apply tension to the wire W between the steady rest guide roller 3 and the winding device 5. The reel diameter of the winding device 5 is 900 mm.

Next, the shot device body 4 will be described. As shown in FIGS. 4 and 5, the shot device body 4
Four projection devices 7 (71 to 74) for projecting a projection material (shot particles) at a high speed are installed in the chamber. The projection device 7 is a centrifugal type accelerator that projects the projection material at a high speed by a rotating impeller, and although not shown, the projection material is provided by a projection material discharge port of a casing accommodating the impeller and a window hole of the control cage. The direction to project is set. Specifically, as shown in FIGS. 4 to 6, the projection devices 71 to 74, which are arranged at predetermined intervals in the traveling direction of the wire W, project the projection material S onto the wire W from four directions of up, down, left and right. To project. In this example, the upward projection amount of the lower projection device 72 is set to 150 kg / min, and the projection amount of the other projection devices 71, 73, and 74 is set to be slightly larger than 125 kg / min. The shot force applied is equalized.

Then, guide pipes 8 (81 to 85) as guide devices for guiding the wire W are installed at the boundaries of the projection areas formed by the projection devices 7 (71 to 74), respectively, and adjacent guide pipes are installed. By making the interval of 8 constant (200 mm in this example), the projection range of each projection device 71 to 74 with respect to the wire W is made uniform. As shown in FIG. 7, these guide pipes 8 are formed by inserting a bush 8b made of an elastic material such as rubber or resin into a metal pipe 8a, and the bush inner diameter is formed slightly larger than the wire diameter of the wire W. ing. Therefore, when the wire W penetrating the bush 8b is largely bent, it comes into contact with it and acts as a vibration isolator. The guide pipe 8 is attached to the shot device body 4 by an arm 8c.

When the projection device 72 has a sufficient projection area for projecting the projection material S, the shots added from the projection device 72 to the wire W by widening the interval between the adjacent guide pipes 82 and 83. The power can be strengthened and the shot power can be equalized as a whole. This is simpler than the above-described method of setting a slightly larger amount of upward projection.

Further, in the shot device body 4, a supply device for supplying the projection material S to the projection device 7, a recovery device for circulating and reuse the projected projection material S, and a control device for controlling the drive device of each part. Etc. are provided. 9a in FIG.
Reference numeral 9b is a passage guide, and 9c is a screw conveyor constituting a recovery device.

Now, Experimental Examples 1 to 3 conducted to determine the specifications of the shot apparatus having the above-mentioned structure will be described. [Experimental Example 1] Deflection amount of only steady rest guide roller In the shot device having the above-described configuration, when the wire rod W is run from the wire rod supply base 1 to the winding device 5 with the projection device 7 stopped, Outer diameter D of the stop guide roller 3
Was changed to examine the amount of plastic deformation applied to the wire W, that is, the bending tendency amount a (mm). The bending tendency amount a is obtained by measuring the arc height a (mm) per 1000 mm of the chord length of the curved wire W as shown in FIG. The result is shown in the graph of FIG. In FIG. 9, d is the wire diameter of the wire W,
The horizontal axis of the graph represents a dimensionless amount obtained by dividing the guide roller diameter D by the wire diameter d. That is, the diameter D of the steady rest guide roller 3
Is set to be 250 times or more of the wire diameter d (D> 250d), the bending tendency amount a given to the wire W by the steady rest guide roller 3 is extremely small. The larger the steady rest guide roller 3 is, the larger the shot device is. Therefore, the diameter D of the steady rest guide roller 3 is 1000 times the wire diameter d or less (D ≦
1000d) is preferable.

[Experimental Example 2] Relationship between Tension and Compressive Residual Stress In the shot device having the above-described structure, the tension (tension) of the wire W traveling between the steady rest guide roller 3 and the winding device 5 and the projection device. The relationship between 7 and the compressive residual stress that could be added to the wire W was investigated. The result is shown in the graph of FIG. That is, the compressive residual stress is sufficiently increased at a tension of 50 N or more. It has been found that the compressive residual stress applied to the wire W becomes substantially constant when the tension is 100 N or more, and conversely, when the tension is 200 N or more, other mechanical properties of the wire W deteriorate.

[Experimental Example 3] Confirmation of effect of guide pipe in shot device Comparison between the case where the guide device 8 has the guide pipe in the above-described structure and the case where there is no guide pipe in the shot device having a similar structure is shown in a table. 11 shows. The respective conditions are as described in the figure. In this experimental example 3,
Since the structure of the steady rest guide roller is different, it is not possible to directly compare the amount of warpage (bending habit) of the experimental results, but if we comprehensively consider from the knowledge obtained from other experiments, the guide inside the shot machine (apparatus) The pipe seems to have the effect of suppressing the warp.

[Comparison Test Results] Next, the evaluation of the steel wire shot by the shot apparatus according to the present invention is shown in FIG.
Are shown together. In the figure, the No. 1 normal shot column shows the test results of the conventional shot device. Shot conditions and the like of this conventional example are as shown in FIG. The column of No. 2 guide roller addition relates to the present invention in which the guide roller 3 is added to the shot apparatus of No. 1 and a predetermined tension (50 N) is added to the steel wire. The No. 3 fixed projection range column relates to the invention of the present application, and in the shot apparatus having the No. 2 configuration, the guide pipes 8 are installed so that the intervals (that is, the projection range) are uniform. The column of No. 4 shot force equalization relates to the invention of the present application and is intended to make the shot amount of the shot apparatuses 71 to 74 uniform with respect to the steel wire in the shot apparatus having the No. 3 configuration. The table for setting the projection amount is shown in FIG. In the figure, the arrangement of the projection devices 71 to 74 corresponds to the above embodiment. The No. 4 shot conditions are as described in the shot apparatus according to the above-described embodiment.

As is apparent from FIG. 14, in the shot device according to the embodiment, the bending tendency is smaller and the compressive residual stress is larger than in the conventional example, and moreover,
The favorable result that the variation of the compressive residual stress was reduced was obtained.

Although some specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or the drawings exert technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technique illustrated in the present specification or the drawings achieves a plurality of purposes at the same time, and achieving the one purpose among them has technical utility.

[Brief description of drawings]

FIG. 1 is a front view showing a shot device according to an embodiment.

FIG. 2 is a front view of a steady rest guide roller.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a schematic cross-sectional view of a shot device main body for explaining the arrangement of a projection device and a guide pipe.

FIG. 5 is a schematic vertical cross-sectional view of the shot device main body for explaining the arrangement of the projection device and the guide pipe.

FIG. 6 is a perspective view illustrating an arrangement of a projection device and a guide pipe.

FIG. 7 is a perspective view illustrating a guide pipe.

FIG. 8 is a diagram illustrating measurement of a bending tendency amount of a wire.

FIG. 9 is a diagram showing the relationship between the diameter of the steady rest guide roller and the amount of bending tendency of the wire material.

FIG. 10 is a diagram showing a relationship between a tension amount of a wire and a compressive residual stress.

FIG. 11 is a table for explaining the effect of the guide pipe.

FIG. 12 is a table illustrating shot conditions.

FIG. 13 is a table for explaining the projection amount of the projection device.

FIG. 14 is a table illustrating test results.

FIG. 15 is a diagram showing a schematic configuration of a conventional shot device.

[Explanation of symbols]

1 Wire rod supply stand 4 shot device body 5 Winding device 7 (71-74) Projection device 8 (81-85) guide pipe S projectile W wire A bending amount d Wire diameter D Guide roller diameter

Continued front page    (72) Inventor Masami Wakita             68 Kamishiota, Narumi-cho, Midori-ku, Nagoya-shi, Aichi               Chuojo Co., Ltd. (72) Inventor Shigeru Yamamoto             28-12, Mei Station, Nakamura-ku, Nagoya, Aichi Prefecture               Within Shinto Kogyo Co., Ltd.

Claims (10)

[Claims] 1. A wire rod supply unit for supplying a wire rod, a projecting unit for projecting a projectile material onto a wire rod pulled out from the wire rod supply unit, and a winding unit for winding the wire rod projected by the projecting unit. A shot device having a section, wherein a steadying prevention means for preventing the wire rod from swinging is provided between the wire rod supply unit and the projection unit. 2. The shot device according to claim 1, wherein the steady rest prevention means is a steady rest guide roller for guiding the wire rod. 3. The shot device according to claim 2, wherein the steady rest guide roller is configured such that a wire can be wound one or more times. 4. The shot device according to claim 1, further comprising a tension applying unit that applies a tension to the wire rod traveling in the projection unit, between the wire rod supply unit and the projection unit. 5. The projection unit is provided with a plurality of projection devices whose positions are different from each other in a traveling direction of the wire rod, and a guide member for guiding the wire rod is provided at a boundary portion of the projection regions formed by the adjacent projection devices. The shot device according to claim 1, wherein an elastic material is provided at a portion of the guide member that can be provided and is in contact with the wire rod. 6. The shot device according to claim 5, wherein the projection direction of each projection device is set so as to face the wire rod from a plurality of different angular positions in the circumferential direction of the wire rod. 7. The shot device according to claim 6, wherein the guide member is formed in a shape to be fitted onto the wire rod, and the elastic body is arranged on an inner wall surface of the guide member. 8. A shot method of projecting a shot material onto a traveling wire drawn from a wire supplying section, wherein the wire drawn from the wire supplying section is wound around a steadying guide roller one or more times, and a steadying guide is provided. A shot method in which a shot material is projected onto a wire material sent from a roller. 9. The wire rod is a steel wire having a wire diameter of 0.5 to 2.0 mm, a tension of 50 to 200 N is applied to the wire rod fed from the touch-prevention guide roller, and the blast material is The shot method according to claim 8, wherein projection is performed from a plurality of different angular positions in the circumferential direction. 10. A shot method in which a projection material is projected from a plurality of different angular positions in the circumferential direction of a steel wire having a wire diameter of 0.5 mm to 2.0 mm and a tension of 50 N to 200 N applied thereto. .