JP2005153043A - Blade for shot projection device and shot projection device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade for a shot projection device excellent in abrasion resistance and high in durability and the shot projection device using it. <P>SOLUTION: This blade for the shot projection device is set on a supporting member 2 to rotate around a rotation axis 21 as its center, has a groove part 31 to extend in the diametrically extending direction from the rotation axis 21 and projects shot grains by centrifugal force from the groove part 31. The groove part 31 is formed so that the groove width is gradually narrowed along the flowing direction of the shot grains, and a groove corner part 36 to be a boundary of a groove bottom surface 33 and groove side surfaces 34, 35 of the groove part 31 shows a chamfered shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shot projection device that projects shot grains by centrifugal force, and a blade used therefor.

  The shot projection device projects shot grains onto the steel material surface by centrifugal force to perform shot peening processing and shot blast processing. A shot projection apparatus usually includes a pair of rotating side plates having the same rotation axis, and a plurality of blades interposed between the pair of rotating side plates and arranged radially with respect to the rotation axis. The blade is formed with a groove portion extending in the diameter increasing direction from the rotating shaft. The shot grains are supplied from the vicinity of the rotation shaft to the groove portion of the blade. The supplied shot grain moves through the groove portion by the centrifugal force at the time of rotation, and is projected onto the steel material surface to be processed.

Conventionally, attempts have been made to improve the groove shape of the blade in order to increase the shot density on the projection surface to be processed and improve the projection efficiency. For example, Patent Document 1 discloses a blade in which a groove portion having a linear wide portion, a tapered portion, and a linear narrow portion is formed along the flow direction of shot grains. Patent Document 2 discloses a blade having a U-shaped groove section and a cemented carbide material adhered to the inner surface of the groove.
JP 54-164077 A JP 50-119382 A

  However, in the blade disclosed in Patent Document 1, the groove shape changes from a wide portion to a tapered portion and from a tapered portion to a narrow portion. For this reason, the flow of shot grains changes near the boundary of each part. For example, in the vicinity of the entrance from the tapered portion to the narrow width portion, the flow path that has gradually narrowed is switched to a straight flow path, so that the flow of shot grains is disturbed, and the distribution of shot grains is biased.

  Usually, the groove of the blade is worn by sliding contact with the shot grains. In addition, when the flow of shot grains is biased, wear is particularly severe at the biased portions. Due to local wear of the blade, the blade may be perforated or cracked. As a result, it is difficult to accurately project shot grains, and the quality of a product that is a projection target is deteriorated. In addition, due to local wear of the blade, the rotation center and the center of gravity of the rotating side plate on which the blade is installed may be shifted, and the rotating side plate may be decentered, resulting in a failure of the rotation drive unit or the like. Therefore, high durability is required for the blade for the shot projection device, and the durability is greatly related to the cost required for inspection and maintenance of the shot projection device.

  Further, in the blade shown in Patent Document 2, a groove portion having a U-shaped cross section is formed, and shot efficiency is improved by collecting shot grains in the central portion of the groove portion. However, the shot grains are concentrated in the central portion of the groove, and wear becomes intense at that portion. Therefore, the durability of the blade is low, causing the same problem as described above.

  The present invention has been made in view of such a situation, and it is an object of the present invention to provide a highly durable blade for a shot projection device and a shot projection device that suppress local wear of the blade.

  (1) A blade for a shot projection apparatus according to the present invention (hereinafter referred to as “the blade according to the present invention” as appropriate) is installed on a support member that rotates about a rotation shaft and extends from the rotation shaft in a diameter-enlarging direction. A blade for a shot projecting device that projects shot grains from the groove portion by centrifugal force, wherein the groove portion is formed so that a groove width is gradually narrowed along a flow direction of the shot particles. The groove corner portion that becomes the boundary between the bottom surface and the groove side surface has a chamfered shape (Claim 1).

  That is, in the groove portion of the blade according to the present invention, when attached to the shot grain flow direction, that is, the shot projection apparatus, the groove width is gradually narrowed from the rotation axis toward the diameter increasing direction. In the blade of the present invention, the groove width of the groove portion is continuously narrowed, and the flow path of the shot grain does not change suddenly. Therefore, the shot grains flow almost uniformly without being biased in the groove. Therefore, wear progresses almost uniformly in the groove. Thus, since local abrasion in a groove part is suppressed, the braid | blade of this invention has high durability.

  In addition, since the groove corner that becomes the boundary between the groove bottom surface and the groove side surface of the groove has a chamfered shape, the shot grain does not stagnate in the vicinity of the groove corner, and the shot grain flows smoothly. Thus, local wear at the groove corner is suppressed, and the durability of the blade is improved.

  Thus, in the blade of this invention, since local abrasion is suppressed, durability improves. Therefore, when used in a shot projection apparatus, the frequency of blade maintenance, replacement, etc. can be reduced, and maintenance costs can be reduced.

  (2) Further, it is desirable that the blade of the present invention is made of cemented carbide (Claim 2). By forming from cemented carbide, the hardness of the blade can be increased and the wear resistance can be improved. As a result, the durability of the blade of the present invention is higher.

  (3) A shot projection apparatus according to the present invention includes the blade according to the present invention. As described above, by using the highly durable blade of the present invention, the shot projection apparatus of the present invention can stably project shot grains for a long period of time. In addition, the frequency of inspection and maintenance of the shot projection device can be reduced, and the occurrence of failure can also be reduced. Therefore, in the shot projection apparatus of the present invention, maintenance costs are reduced.

  In the groove portion of the blade for a shot projection device of the present invention, the groove width is formed so as to gradually narrow along the flow direction of the shot grains, and the groove corner portion that becomes the boundary between the groove bottom surface and the groove side surface has a chamfered shape. Therefore, the flow of shot grains in the groove is almost uniform without being biased. As a result, local wear in the groove is suppressed, and the durability of the blade is increased. Moreover, in the shot projection apparatus of the present invention provided with the blade of the present invention, it is possible to project shot grains stably for a long period of time. In addition, the frequency of maintenance and replacement of blades is reduced, and maintenance costs are reduced.

  Hereinafter, embodiments of the blade for a shot projection device and the shot projection device of the present invention will be described in detail. First, the configuration of a blade and a shot projection device according to an embodiment of the present invention will be described. FIG. 1 is a perspective view showing a state of shot peening by a shot projection apparatus to which a blade according to an embodiment of the present invention is attached. FIG. 2 is a perspective view of the blade. Further, FIG. 3A shows a front view and a side view of both ends of the blade. FIG. 3B shows an enlarged view of a circle A portion in FIG.

  As shown in FIG. 1, the shot projection apparatus 1 includes a rotating side plate 2 and a blade 3. Two rotating side plates 2 are attached to one end of a rotating shaft 21 connected to a motor (not shown) at a predetermined interval. The rotating side plate 2 is made of SKD-11 and has a disk shape with a diameter of about 250 mm. The rotation side plate 2 corresponds to the support member in the present invention. In FIG. 1, one rotating side plate 2 is indicated by a one-dot chain line for convenience of explanation. Further, a mounting protrusion of the blade 3 described later is omitted.

  The blade 3 is made of cemented carbide (carbide GK20) and has a rectangular parallelepiped shape. The blade 3 is interposed between the two rotary side plates 2 and extends from the rotary shaft 21 in the diameter increasing direction. Eight blades 3 are arranged radially at an angle of 45 °. The length of the blade 3 is 112 mm, and the end portion in the diameter increasing direction protrudes outward from the outer peripheral edge of the rotating side plate 2. The blade 3 is arranged with a groove 31 side, which will be described later, facing in the rotational direction (the arrow direction in FIG. 1).

  As shown in FIGS. 2 and 3A, the blade 3 has a groove 31 and an attachment protrusion 32. The groove 31 is formed in a linear taper shape along the flow direction of the shot grains. The groove width D1 at the end on the rotating shaft side to which the shot grains are supplied is 27 mm, and the groove width D2 at the end in the diameter increasing direction from which the shot grains are discharged is 22 mm. The groove portion 31 includes a groove bottom surface 33 and groove side surfaces 34 and 35. The groove corner portion 36 which is the boundary between the groove bottom surface 33 and the groove side surfaces 34 and 35 has a smooth curved surface with a chamfered shape as shown in an enlarged view in FIG.

  The attachment protrusions 32 have a rectangular parallelepiped shape and protrude from both side surfaces of the blade 3. The blade 3 is fixed to the rotation side plate 2 by locking the attachment protrusion 32 to the rotation side plate 2.

  Next, the movement of the shot projection device will be described. The rotation side plate 2 is rotated at a rotation speed of 2460 to 3000 rpm around the rotation shaft 21 by driving of a motor. The shot grains are supplied from the vicinity of the center of one rotating side plate 2 to the rotating shaft side end of the blade 3 by a supply mechanism (not shown). The shot grains flow through the groove portion 31 by the centrifugal force generated by the rotation of the blade 3 and are projected from the end portion in the diameter increasing direction. The projected shot grain 4 projected from the blade 3 collides with the surface of the coil spring 5 as shown by dotted line hatching in FIG. 1, and the shot peening process of the coil spring 5 is performed.

  According to this embodiment, the following effects can be obtained. That is, since the groove portion 31 is formed in a linear taper shape, the flow of shot grains is hardly disturbed. Therefore, the shot grains flow almost uniformly in the groove 31 without being biased. As a result, local wear of the groove 31 is suppressed, and the durability of the blade 3 is improved. Further, the groove corner portion 36 that is the boundary between the groove bottom surface 33 and the groove side surfaces 34 and 35 has a smooth curved surface. As a result, the shot grain does not stagnate in the vicinity of the groove corner 36, and the flow of the shot grain becomes smooth. As a result, local wear at the groove corner 36 is suppressed, and the durability of the blade 3 is improved. Furthermore, since the blade 3 is made of a cemented carbide, it has excellent wear resistance. Therefore, the blade 3 is less likely to be worn and has excellent durability.

  The embodiment of the blade and the shot projection device of the present invention has been described above. However, the blade and the shot projection apparatus of the present invention are not limited to the above embodiment. The blade and the shot projection device of the present invention can be implemented in various forms that have been modified or improved by those skilled in the art without departing from the scope of the present invention.

  For example, in the above embodiment, the blade is made of cemented carbide. However, the material of the blade is not particularly limited as long as it has desired hardness and wear resistance. For example, highman steel, SKD-11, or the like can be used. Moreover, although the groove part was formed in the linear taper shape, the groove part should just be formed so that a groove width may become narrow gradually along the flow direction of a shot grain. For example, it may be a curved taper. Furthermore, in the said embodiment, although both the groove corners were made into the curved surface, it is good also considering only one of the groove corners as a curved surface. The groove corner is not limited to a curved surface, and may have a shape with a tapered cross section as long as it has a chamfered shape. In the above embodiment, the blade is attached to the rotating side plate by the attachment protrusion. However, the attachment protrusion is not necessarily required for the blade, and it may be attached by other attachment methods.

  In the above embodiment, the blades of the present invention are used for all eight blades. However, the blade of the present invention may be used only for a part of the blade used in the shot projection apparatus. Further, the number of blades of the shot projection device is not limited to eight, and a necessary number of blades can be used as appropriate. Further, although the blade is disposed between the two rotating side plates, the support member is not limited to these rotating side plates. In the above embodiment, the shot peening process is performed using the shot projection apparatus of the present invention. However, the shot projection apparatus of the present invention can also be used when performing shot blast processing.

It is the perspective view which showed the mode of shot peening by the shot projection apparatus which is one Embodiment of this invention. It is a perspective view of the braid | blade which is one Embodiment of this invention. (A) is the front view and both-ends side view of the braid | blade of this invention shown in FIG. (B) is an enlarged view of a circle A portion in (a).

Explanation of symbols

1: Shot projection device 2: Rotating side plate (supporting member) 21: Rotating shaft 3: Blade 31: Groove portion 32: Mounting projection 33: Groove bottom surface 34, 35: Groove side surface 36: Groove corner portion 4: Projection shot grain 5: Coil spring

Claims (3)

A blade for a shot projection device, which is installed on a support member that rotates around a rotation axis, has a groove portion extending in the diameter-expanding direction from the rotation shaft, and projects shot particles from the groove portion by centrifugal force,
The groove is formed such that the groove width gradually narrows along the flow direction of the shot grains,
The blade for a shot projection device, wherein a groove corner portion that becomes a boundary between a groove bottom surface and a groove side surface of the groove portion has a chamfered shape.   The blade for a shot projection device according to claim 1, wherein the blade is formed from a cemented carbide.   A shot projection apparatus comprising the blade for a shot projection apparatus according to claim 1.

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