Shot processing device

Abstract

To provide a shot treatment device which can efficiently perform shot treatment to a processed object smaller than a projection range of a shot medium.SOLUTION: A shot treatment device projects a shot medium T onto a processed object W and causes the shot medium T to collide with the processed object W to perform surface treatment of the processed object. The shot treatment device includes: a shot mechanism 3 which projects the shot medium T to the processed object W; and a reflector plate 5 which is provided at the downstream side of flow of the shot medium T across the processed object W and reflects the shot medium T projected from the shot mechanism 3 onto the processed object W. The reflector plate 5 has a reflection surface 5b which is a concave surface in which a curvature continuously increases to the downstream of the shot medium T.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a shot processing apparatus.

Background Art

[0002] For surface treatments such as shot blasting for scale removal, deburring, and surface roughening of workpieces, and shot peening for improving fatigue strength, etc., a shot processing apparatus that projects or sprays shot materials onto the surface of the workpiece to process the workpiece is used. (For example, refer to Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When shot media are projected onto an object to be processed by a projector to perform shot processing, the shot processing area of the object to be processed located within the projection range of the shot media, that is, the range where the shot media collide with the object to be processed, may be smaller than the projection range of the shot media. At this time, the shot media projected onto the area where the object to be processed exists collide with the object to be processed and the shot processing is effectively performed. However, the shot media projected onto the range where the shot media do not collide with the object to be processed do not contribute to the shot processing and are redundant projections. In addition, since these shot media that did not contribute to the shot processing collide with the inside of the shot processing apparatus housing, it may cause wear inside the shot processing apparatus housing. Furthermore, the kinetic energy of the shot media that collided inside the housing is converted into heat, which may cause the temperature inside the apparatus to rise and the apparatus to become hot.

[0005] The present invention has been made in consideration of the above-mentioned situation, and the problem that the present invention aims to solve is to provide a shot processing device that can efficiently shot process objects that are smaller than the projection range of the shot medium. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means. That is, one aspect of the present invention is a shot processing apparatus that projects a shot medium onto a workpiece and causes it to collide with the workpiece, thereby performing surface processing on the workpiece. This shot processing apparatus includes a shot mechanism and a reflector. The shot mechanism projects the shot medium toward the workpiece. The reflector, which is provided downstream of the flow of the shot medium across the workpiece, reflects the shot medium projected from the shot mechanism onto the workpiece. The reflector has a concavely curved reflecting surface whose curvature continuously increases downstream of the shot medium. According to the present invention, a reflector having a reflective surface whose curvature continuously increases toward the downstream side of the shot medium is provided, so that the shot medium that passes through without colliding with the workpiece can be reflected back onto the workpiece, thereby enabling efficient shot processing.

[0007] In one aspect of the present invention, the reflector has an opening on the opposite side of the shot mechanism across the object to be processed. In this embodiment, the openings are provided in the reflecting plate, so that the shot medium can be prevented from remaining on the reflecting plate.

[0008] In one aspect of the present invention, a passage restriction member is provided downstream of the flow of the shot medium, at a position past the opening of the reflector as viewed from the shot mechanism, to restrict the passage of the shot medium flowing out from the opening. In this aspect, the passage restriction member restricts the passage of the shot medium flowing out from the opening, thereby preventing the shot medium from damaging the inside of the housing of the shot processing device.

[0009] In one aspect of the present invention, the longitudinal sectional shape of the reflecting surface of the reflector is a parabola y = ax 2 -b approximated with the line from the center of the object to be processed towards the shot mechanism as the positive y-axis direction, the center of the object to be processed being the origin, and a and b being positive. In this aspect, the longitudinal sectional shape of the reflecting surface of the reflector is approximated by the parabola y = ax 2 -b, and since the center of the object to be processed is positioned at the origin of the approximation formula, an optimal curved reflecting plate for reflecting the shot medium in an appropriate direction can be formed.

[0010] In one aspect of the present invention, for the parabola y = ax 2 -b, a is in the range of 0.001 to 0.009, b is in the range of 10 to 20, and b / a is in the range of 1111 to 20000. In this aspect, the cross-sectional shape of the reflecting surface of the reflector is made to match the parabola, and an optimal curved reflecting plate for reflecting the shot medium in an appropriate direction can be formed.

[0011] In one aspect of the present invention, for the parabola y = ax 2 -b, a is in the range of 0.003 to 0.007, b is in the range of 13 to 17, and b / a is in the range of 1857 to 5667. In this aspect, the cross-sectional shape of the reflecting surface of the reflector is made to match the parabola, and an optimal curved reflecting plate for reflecting the shot medium in an appropriate direction can be formed.

[0012] In one aspect of the present invention, the object to be processed is a wire. In this aspect, since the wire is sufficiently smaller than the projection range of the shot medium and has a circular cross-sectional shape, the shot medium reflected by the reflector efficiently collides with the wire.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a shot processing apparatus capable of efficiently shot-processing an object to be processed that is smaller than the projection range of the shot medium.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0015] (Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the object to be processed W is a metal wire having a linear shape and a circular cross-sectional shape, and this case will be described as an example. FIG. 1 is a schematic diagram showing the configuration of a shot processing apparatus 1 according to an embodiment of the present invention, as viewed from the side. FIG. 2 is a plan view of the shot processing apparatus 1 of FIG. 1.

[0016] Note that the "projection" in this specification includes any mode, such as when the shot medium T is projected by the centrifugal force of a impeller type shot mechanism 3 as in the case of using an impeller type shot mechanism 3, or when the shot medium T is ejected by compressed air or wind force as in the case of using an air type shot mechanism 3.

[0017] Shot media is a material that collides with an object to be processed and performs shot peening on the object. Shot peening is a surface treatment for the object to be processed. This surface treatment includes processes similar to polishing to remove burrs, rust, and scale on the surface of the object to be processed, surface finishing of the object to be processed, or shot peening to achieve work hardening by plastic deformation and impart compressive residual stress to the surface of the object to be processed. The material of the shot media T is selected from various materials such as metals (e.g., iron, zinc, stainless steel), ceramics (e.g., alumina, silicon carbide, zircon), glass, resins (e.g., nylon resin, melamine resin, urea resin), and plant-derived materials (e.g., walnut, peach). The shape of the shot media T is selected from various shapes such as spherical, polygonal, and cylindrical. For example, in the case of metal particles, spherical particles called shots, polygonal particles with sharp corners called grids, and cylindrical particles or particles with rounded corners of a cylindrical shape called cut wires can be selected. They can be appropriately selected and adopted based on the desired conditions of shot peening from various materials and shapes.

[0018] As shown in FIGS. 1 and 2, the shot peening apparatus 1 includes a shot mechanism 3 that projects shot media T toward an object to be processed W in a projection chamber 15, and a reflector 5 that is provided on the downstream side of the flow of the shot media T with the object to be processed W interposed therebetween and reflects the shot media T projected from the shot mechanism 3 onto the object to be processed W. That is, they are arranged in the order of the shot mechanism 3, the object to be processed W, and the reflector 5. A blow-off chamber 17 is provided adjacent to the projection chamber 15. The object to be processed W is carried into the projection chamber 15 by a carry-in roller 11, carried out from the blow-off chamber by a carry-out roller 13, and advances along a straight path in one direction. The shot mechanism 3 according to the present embodiment is an impeller, and the impeller is rotated by a drive motor 9 via a belt (not shown) to project the shot media onto the object to be processed W.

[0019] FIG. 3 is a schematic diagram of the main part of the shot processing apparatus according to the present embodiment. FIG. 3 schematically shows a state where the shot medium T is projected onto the object to be processed W by the shot mechanism 3. FIG. 4 is an enlarged view seen from the direction of arrow A in FIG. 3. As shown in FIG. 4, the reflector 5 according to the present embodiment has a reflecting surface 5b whose curvature continuously increases toward the downstream of the shot medium T.

[0020] FIG. 5 is a plan view of the reflector 5. As shown in FIGS. 4 and 5, the reflector 5 has an opening 5a on the opposite side of the object to be processed W with the shot mechanism 3 interposed therebetween. Here, the width of the opening 5a in the short side direction may be 200% to 50% (however, ≧ 5 mm) of the diameter of the object to be processed W. Further, as shown in FIGS. 3 and 4, in front of the reflector 5 as seen from the shot mechanism 3, a passage restricting member 7 for restricting the passage of the shot medium T flowing out from the opening 5a is provided. The passage restricting member 7 is arranged with an inclination with respect to the direction from the shot mechanism 3 toward the opening 5a. In FIGS. 1 and 2, the passage restricting member 7 is omitted due to the magnification relationship.

[0021] As shown in FIG. 4, the curved surface of the reflecting surface 5b of the reflector 5 has a parabola y = ax 2 -b approximated with the line from the center o of the object to be processed W toward the shot mechanism 3 as the y-axis, the center of the object to be processed W being the origin o, and a and b being positive. Here, a is suitably in the range of 0.001 to 0.009, more preferably 0.003 to 0.007. b is suitably in the range of 10 to 20, more preferably 13 to 17. Further, b / a is suitably in the range of 1111 to 20000, more preferably 1857 to 5667. The present inventor obtained this suitable numerical range from various experiments.

[0022] Next, with reference to FIGS. 1 and 2, the operation of the shot processing apparatus 1 will be described. The object W to be processed is continuously conveyed through the inside of the projection chamber 15 toward the ejection chamber 17 from the loading roller 11 to the unloading roller 13 so as to be carried into the projection chamber 15 and carried out through the ejection chamber 17. In the projection chamber 15, impellers 3a, 3a for projecting the shot medium T onto the object W to be processed from the horizontal left and right directions and impellers 3b, 3b for projecting the shot medium T onto the object W to be processed from the vertical directions are provided.

[0023] As shown in FIG. 2, the object W to be processed carried into the projection chamber 15 by the loading roller 11 is shot-processed by having the shot medium T projected onto it from the right by the impeller 3a. The object W that has been shot-processed from the right is further conveyed to the back (left side in the drawing) of the projection chamber 15 and is shot-processed by having the shot medium T projected onto it from the left by the impeller 3a. The object W that has been shot-processed in the left and right directions is then conveyed to the left side in the drawing of FIG. 1 as shown in FIG. 1 and is shot-processed by having the shot medium T projected onto it from above by the impeller 3b. The object W that has been shot-processed from above is further conveyed to the back (left side in the drawing) of the projection chamber 15 and is shot-processed by having the shot medium T projected onto it from below by the impeller 3b.

[0024] The object W that has been shot-processed in the four directions of up, down, left, and right is conveyed to the ejection chamber 17, and dust and the shot medium are separated by a brush, a scraper (not shown), blowing of compressed air, etc., so that it becomes clean and is conveyed outside the shot processing apparatus 1 by the unloading roller 13. Note that the mechanism related to the circulation device of the shot medium and the dust collector using a screw conveyor, a bucket elevator, etc. is the same as the conventional one (for example, see Patent Document 1), so the description thereof is omitted here.

[0025] FIG. 6 is a schematic diagram for explaining the action of the reflector 5, where the shot medium T is projected from above the paper surface downward toward the workpiece W. As shown in FIG. 6, the particle p of the shot medium T having an orbit a that directly collides with the workpiece W collides with the workpiece W and bounces back (orbit b). At this time, shot peening is performed on the workpiece W. The particle q of the shot medium T having an orbit c that does not collide with the workpiece W passes through beside the workpiece W without colliding with the workpiece W. A reflector 5 is provided downstream of the shot medium T of the workpiece W. The reflecting surface 5b of the reflector 5 is a concave curved surface. The reflecting surface 5b is formed such that its curvature continuously increases toward the downstream of the flow of the shot medium T. The longitudinal sectional shape of the reflecting surface 5b (i.e., the cross section horizontal in the direction from the shot mechanism toward the workpiece W) is preferably y = ax 2 -b approximated with respect to the origin at the center of the cross section of the workpiece W. Therefore, the reflecting surface 5b is formed such that when the particle q collides with the reflecting surface 5b, the particle q is reflected toward the workpiece W (orbit d). The reflecting surface 5b is formed such that its curvature changes continuously. Therefore, it becomes possible to adjust the reflection orbit so as to reflect the shot medium T that has passed through the region where it does not collide with the workpiece W toward the center o of the workpiece W for each orbit.

[0026] Also, an opening 5a is formed in the reflector 5b on the opposite side of the workpiece W with respect to the shot mechanism 3 across the workpiece W. The particle q that collides with the workpiece W and heads downward in the figure flows out further downward from the opening 5a (orbit e). In front of the opening 5a, a passage restricting member 7 is disposed with an inclination in a direction perpendicular to the opening 5a. The particle q that heads downward from the opening 5a collides with the passage restricting member 7 and is reflected in its orbit f.

[0027] As described above, in the present embodiment, a reflector 5 that reflects the shot medium T projected from the shot mechanism 3 to the workpiece W is provided. The reflector 5 has a reflecting surface 5b whose curvature continuously increases toward the downstream of the shot medium T, and preferably y = ax with the center of the workpiece W as the origin 2It is approximated by -b. With this approximation formula, the reflecting plate 5 with the optimal curved surface for reflecting the shot medium in an appropriate direction can be formed. Therefore, when shot - treating the workpiece W smaller than the projection range of the shot medium T, the shot medium T that does not directly collide with the workpiece W can be efficiently reflected by the reflecting plate 5 to the workpiece W for shot - treatment. Further, in this approximation formula, when a is in the range of 0.001 to 0.009, b is in the range of 10 to 20, and b / a is in the range of 1111 to 20000, the shot medium T can be efficiently reflected toward the workpiece W, so the time for shot - treatment can be shortened.

[0028] In this embodiment, a metal wire is shot - treated as the workpiece W. Since the wire is extremely thin compared to the projection range of the shot medium, in a conventional device, there are many shot media that do not collide with the wire but collide with the inside of the housing of the shot - treatment device. Due to the collision of this shot medium with the housing, the energy that was not imparted to the wire is imparted to the device housing, and this energy causes an increase in the device temperature. Also, generally, a device for shot - treating a wire is formed in a small size, so compared to a large - sized device, the surface area is small and the heat dissipation is low. Therefore, the heat generated by the high - energy collision of the shot medium inside the housing accumulates inside, resulting in an even higher temperature. In a device with a high temperature, various measures are required, such as installing a cover using a heat - insulating material on the outer surface of the device for the protection of the operator from burns, or controlling the air flow inside the device so that the mechanisms inside the device are not damaged by heat.

[0029] From the above viewpoints, the shot processing apparatus 1 in the present embodiment can be suitably used when shot processing a wire as the workpiece W. That is, in the present embodiment, by using the reflector 5, the shot medium T that would not collide with the wire in the conventional case is reflected by the reflector 5 and made to collide with the wire, preventing the loss of energy given to the shot medium T, and enabling efficient shot processing of the wire. Further, since the collision of the shot medium T with the housing can be prevented, the energy that collided with and was consumed by other than the wire in the prior art is reduced, so that the temperature rise of the shot processing apparatus 1 can be prevented. Furthermore, by optimizing the shape of the reflector 5 as described above, the time required for shot processing can be shortened, so that the temperature rise due to heat accumulation can be suppressed.

[0030] Since the reflector 5 is provided with an opening 5a on the opposite side of the workpiece W with respect to the shot mechanism 3, it is possible to prevent the shot medium T from staying on the reflector 5. Since the passage restricting member 7 is provided in front of the opening 5a, it is possible to restrict the passage of the shot medium T flowing out from the opening 5a and prevent the inner wall of the housing of the shot processing apparatus 1 and the apparatus itself from being worn out. In the present embodiment, the passage restricting member 7 is a plate-like body arranged at a certain angle with respect to the opening direction of the opening 5a, but it is not limited to this. As long as it can prevent the shot medium T passing through the opening 5a from colliding with the housing, its shape does not matter. For example, a metal block having a convex shape or a concave shape may be adopted as the passage restricting member 7.

[0031] In the above-described embodiment, a wire is selected as the workpiece W, but it is not limited to this, and it is effective when the shot medium T passes downstream without colliding with the workpiece W. For example, in a workpiece W having a rod-shaped long shape or a workpiece W smaller than the projection range, the present invention can be effectively utilized.

[0032] Further, in order to process an object to be processed having a general shape (e.g., a shape approximated by a cube) without being limited to a long shape, as the reflector 5, for example, a mortar-shaped one having a cross-sectional shape approximable by a parabola may be adopted.

[0033] Also, in the embodiment, the impeller is adopted as the shot mechanism 3 for description, but it is not limited thereto. For example, even when a nozzle that injects the shot medium T toward the object to be processed W together with compressed air or a blower that blows the shot medium T by wind force is adopted as the shot mechanism 3, the present invention is effective. Also, in the present embodiment, the case where the cross-sectional shape of the reflecting surface 5b of the reflector 5 is a parabola has been described. However, the cross-sectional shape of this reflecting surface 5b may be other than a parabola, and it may be a concave reflecting surface whose curvature continuously increases toward the downstream of the shot medium T.

[0034] Note that the present invention is not limited to the above-described embodiment, and includes various modified examples in which components are added, deleted, or converted with respect to the above-described configuration. The present invention also includes various modifications in which components are added, deleted, or converted with respect to the above-described configuration.

Example

[0035] Hereinafter, with reference to FIGS. 7 to 10, examples and comparative examples of the present invention will be described. FIGS. 7 to 10 are diagrams showing the hitting condition of shots on a wire rod depending on the presence or absence of a reflector and the shape of the reflector. The projection conditions are all as follows. <Projection conditions>: Shot medium: Steel shot, particle size: φ0.2, projection speed: 73 m / s, projection amount 2.8 kg / min

[0036] Figure 7 shows an example using a reflector with a concave surface approximated by a parabola according to an embodiment of the present invention. As shown in Figure 7, the shot media visible in the region indicated by the broken line R are the shot media that have collided with and are reflected from the upper surface of the wire. In this way, the upper surface portion of the wire is effectively shot-treated. The portion indicated by the broken line S represents the region where the shot media that did not directly collide with the wire are reflected by the reflecting surface of the reflector and collide toward the lower surface of the wire. The reflector according to the present invention can reflect the shot media that do not originally contribute to the shot treatment with the reflector and contribute to the shot treatment of the lower surface of the wire. As can be seen from the figure, since the reflector is symmetrically curved, it can be seen that not only the region S on the left side in the figure but also the shot media in the region on the right side are reflected by the reflector and contribute to the shot treatment of the wire.

[0037] Figure 8 is a view when a reflector having a flat reflecting surface according to a comparative example of the present invention is horizontally arranged. The portion of the region R is equivalent to that in Figure 7, and the shot media that have contributed to the shot treatment collide with and are reflected from the upper surface of the wire. The portion of the region S is where the shot media that did not directly collide with the wire are reflected by the flat surface of the reflector. Since the reflection direction is vertical, it can be seen that no shot media collide with the lower surface of the wire. From this, it can be understood that the effects of the present invention cannot be obtained simply by horizontally arranging a mere flat reflector.

[0038] Figure 9 is a view when a reflector having a flat reflecting surface according to a comparative example of the present invention is arranged at an inclination with respect to the projection direction of the shot media. The portion of the region R is equivalent to that in Figure 7, and the shot media that have contributed to the shot treatment collide with and are reflected from the upper surface of the wire. The portion of the region S is where the shot media that did not directly collide with the wire are reflected by the flat surface of the reflector. Since the reflector in this comparative example is arranged at an inclination with respect to the projection direction of the shot media, the shot media are reflected by the reflector and fly obliquely upward, but these shot media do not contribute to the shot treatment of the wire. From this, it can be understood that the effects of the present invention cannot be obtained even by arranging a mere flat reflector with an inclination.

[0039] FIG. 10 is a view when the reflector according to the comparative example of the present invention is not arranged. The portion of region R is equivalent to that in FIG. 7, and the shot medium that contributed to the shot treatment collides with the upper surface of the wire and is reflected. In the portion of region S, the shot medium that did not directly collide with the wire passes directly downward, and these shot media do not contribute to the shot treatment of the wire. From the above examples and comparative examples, it has become clear that the reflector having a concave surface approximated by a parabola according to the present invention can utilize shot media that did not contribute to the conventional shot treatment for shot treatment.

Explanation of reference numerals

[0040] 1 Shot treatment apparatus 3, 3a, 3b Shot mechanism (impeller) 5 Reflector 5a Opening 5b Reflecting surface 7 Passage restricting member T Shot medium W Object to be treated (wire)

Claims

1. A shot blasting apparatus that projects a shot medium onto an object to be processed and causes it to collide to perform surface treatment of the object to be processed, comprising: a shot mechanism that projects the shot medium toward the object to be processed; a reflector that is provided on the downstream side of the flow of the shot medium with the object to be processed sandwiched therebetween and reflects the shot medium projected from the shot mechanism onto the object to be processed; the reflector has a reflecting surface that is a concave surface with a continuously increasing curvature toward the downstream of the shot medium; the reflector has an opening on the opposite side of the object to be processed as viewed from the shot mechanism; A shot blasting apparatus, comprising a passage restricting member that restricts the passage of the shot medium flowing out of the opening at a position downstream of the flow of the shot medium and passing through the opening as viewed from the shot mechanism.

2. A shot blasting apparatus that projects a shot medium onto an object to be processed and causes it to collide to perform surface treatment of the object to be processed, comprising: a shot mechanism that projects the shot medium toward the object to be processed; a reflector that is provided on the downstream side of the flow of the shot medium with the object to be processed sandwiched therebetween and reflects the shot medium projected from the shot mechanism onto the object to be processed; the reflector has a reflecting surface that is a concave surface with a continuously increasing curvature toward the downstream of the shot medium; The longitudinal cross-sectional shape of the reflecting surface of the reflector is approximated by a parabola y = ax 2 - b, where the line from the center of the object to be processed toward the shot mechanism is the positive y-axis direction, the center of the object to be processed is the origin, and a and b are positive; In the parabola y = ax ２ - b, a ranges from 0.001 to 0.009, b ranges from 10 to 20, and b / a ranges from 1111 to 20000, the shot processing device.

3. In the parabola y = ax ２ - b, a ranges from 0.003 to 0.007, b ranges from 13 to 17, and b / a ranges from 1857 to 5667. The shot processing device according to claim 2.

4. The reflector has an opening on the opposite side of the object to be processed as viewed from the shot mechanism; The shot blasting apparatus according to claim 2, further comprising a passage restricting member that restricts the passage of the shot medium flowing out of the opening at a position downstream of the flow of the shot medium and passing through the opening as viewed from the shot mechanism.

5. The shot blasting apparatus according to any one of claims 1 to 4, wherein the object to be processed is a wire.

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