JP2011131338A - Leaf spring device with spring eye, method for manufacturing the same, and shot peening device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leaf spring device for restraining a fatigue fracture and delayed fracture of a spring eye. <P>SOLUTION: The leaf spring device 10 is equipped with: a leaf spring 11 having the spring eyes 12 on the ends; and bushes 20 press-fitted in the spring eyes 12. A cutting process by a reamer or the like and shot peening are provided for the inner face 30 of the spring eye 12. For compression residual stress distribution of the spring eye inner face 30 by shot peening, the absolute value of the compression residual stress in a first range S1 including a winding start part 31 of the spring eye 12, and that of the compression residual stress in a second range S2 including a winding intermediate point 32 of the spring eye 12, are larger than that of the compression residual stress in the other range S3 of the spring eye inner face 30. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a leaf spring device having an eyeball portion used for a vehicle suspension mechanism or the like, a method for manufacturing the leaf spring device, and a shot peening device for the eyeball portion.

  A leaf spring device used for a suspension mechanism of a vehicle has a steel leaf spring having an eyeball at its end, a bush inserted into the eyeball of the leaf spring, and the like. It is attached to the vehicle body side member. Further, shot peening is performed in order to improve the durability of the leaf spring. Shot peening generates compressive residual stress on the surface of the leaf spring by hitting a large number of shots made of, for example, cut wires on the surface of the leaf spring at high speed. In addition, shot peening may be performed on the inner surface of the eyeball portion in order to improve the durability of the eyeball portion.

  For example, it is known to apply compressive residual stress to the inner surface of the eyeball using a shot peening apparatus described in Patent Document 1 below. In this known technique, a shot injection nozzle and a shot reflecting member are inserted inside the eyeball, and a shot is projected from the shot injection nozzle toward the shot reflecting member. The shot projected from the shot spray nozzle is reflected by the shot reflecting member and hits the inner surface of the eyeball. Further, this Patent Document 1 describes that by performing shot peening intensively at the lower part of the eyeball part, fatigue fracture and delayed fracture of the eyeball part are suppressed.

Japanese Patent Laid-Open No. 5-138535 (Japanese Patent Publication No. 7-36982)

  As disclosed in FIG. 1 and the like of Patent Document 1, if the shot peening is performed on the entire inner surface of the eyeball part, the durability of the eyeball part can be improved. However, if shots are evenly projected over the entire inner surface of the eyeball, a large amount of shots are projected even in areas where the effect of improving durability is small, which not only requires longer shot peening time, but also contradicts the demand for energy saving. .

  In addition, as disclosed in FIG. 9 of Patent Document 1, when shots are projected intensively on the lower part of the eyeball part, even if an effect is recognized in suppressing fatigue fracture, depending on the eyeball part. The effect of suppressing delayed fracture may be small. For example, in a high-strength leaf spring made of spring steel such as SUP11, when the outer diameter of the bush that is press-fitted into the eyeball part is 0.5 mm or more larger than the inner diameter of the eyeball part, shot peening is concentrated on the lower part of the eyeball part. It has also been found that simply performing it has little effect on suppressing delayed fracture after bush press-fitting.

  Accordingly, an object of the present invention is to provide a leaf spring device, a shot peening device, and a method for manufacturing the leaf spring device that can suppress fatigue fracture and delayed fracture of the eyeball portion into which the bush is press-fitted.

  The leaf spring device of the present invention is a leaf spring device comprising a leaf spring having an eyeball portion rounded around an end portion and a bush pressed into the eyeball portion, and is machined inside the eyeball portion. And an absolute value of the compressive residual stress of the first region including the winding start portion of the eyeball portion with respect to the distribution of compressive residual stress in the circumferential direction of the inner surface of the eyeball, and the center of the eyeball The absolute value of the compressive residual stress in the second region including the winding intermediate point on the vertical line passing through the region has a compressive residual stress distribution larger than the absolute value of the compressive residual stress in the other region of the inner surface of the eyeball .

  The manufacturing method of the leaf spring device of the present invention includes a step of forming the eyeball portion by winding the end portion of the leaf spring in a round shape, and finishing the inner surface of the eyeball into a circular shape by scraping the inner surface of the eyeball portion. A shaving step for removing the attached oxide film, an inner surface shot peening step performed after the shaving step is performed, and an outer diameter larger than the inner diameter of the eyeball portion at the eyeball portion after the inner surface shot peening step And press-fitting the bush. In the inner surface shot peening step, a compressive residual stress is imparted to the inner surface of the eyeball by projecting a shot onto the inner surface of the eyeball, and a winding start portion of the eyeball portion with respect to a distribution of compressive residual stress in the circumferential direction of the inner surface of the eyeball The absolute value of the compressive residual stress of the first region including the absolute value of the compressive residual stress of the second region including the winding intermediate point on the vertical line passing through the center of the eyeball is stored in the other region of the inner surface of the eyeball. It is larger than the absolute value of stress.

  A shot peening apparatus for performing shot peening on the inner surface of the eyeball includes a shot injection nozzle inserted inside the eyeball portion, and a shot projected from the shot injection nozzle having a reflective surface facing the shot injection nozzle. Is reflected by the reflecting surface and directed toward the inner surface of the eyeball, and the reflecting surface reflects the amount of shot reflected toward the first region and the second region in the other region. The shape is such that it is larger than the amount of shots reflected toward.

  In this shot peening apparatus, the angle formed by the reflecting surface with respect to the axis of the shot reflecting member is set such that the projection angle of the shot reflected by the reflecting surface is more than 0 ° and not more than 45 °. Good.

  According to the present invention, in a leaf spring device in which a bush is press-fitted into an eyeball part, it is possible to sufficiently apply compressive residual stress to an effective location for suppressing fatigue fracture and delayed fracture of the eyeball part. Reliability can be increased.

The front view of the leaf | plate spring apparatus which concerns on the 1st Embodiment of this invention. The front view which expands and shows the eyeball part of the leaf | plate spring apparatus shown by FIG. Sectional drawing shown in the state which isolate | separated the eyeball part and bush shown by FIG. The front view which shows only the eyeball part shown by FIG. FIG. 3 is a side view of a part of the eyeball portion shown in FIG. 2 and a tool for cutting. FIG. 3 is a side view of a part of the eyeball part shown in FIG. 2 and an apparatus for performing inner surface shot peening. The perspective view of the shot reflective member of the shot peening apparatus which concerns on the 2nd Embodiment of this invention. FIG. 8 is a side view of the shot reflecting member shown in FIG. 7. The perspective view of the shot reflective member of the shot peening apparatus which concerns on the 3rd Embodiment of this invention. FIG. 10 is a front view of the shot reflecting member shown in FIG. 9. The side view which shows the shot peening apparatus which concerns on the 4th Embodiment of this invention. The perspective view of the shot reflection member of the shot peening apparatus shown by FIG. FIG. 13 is a front view of the shot reflecting member shown in FIG. 12. The perspective view of the shot reflective member which concerns on the 5th Embodiment of this invention. The side view which shows the shot peening apparatus which concerns on the 6th Embodiment of this invention.

Hereinafter, a leaf spring device according to a first embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.
A leaf spring device 10 shown in FIG. 1 is used for a suspension mechanism of a vehicle such as an automobile, for example, and includes a steel leaf spring 11 having eyeballs 12 at both ends, and a bush 20 press-fitted into the eyeballs 12. And have.

  The leaf spring 11 is attached to a vehicle suspension mechanism (not shown) and elastically supports the load of the vehicle. For this reason, the sprung weight of the vehicle is loaded on the eyeball portion 12, and tensile stress repeatedly acts on the eyeball portion 12 when the vehicle is accelerated or decelerated. In general, a stacked leaf spring device is configured by overlapping a child plate (not shown) in the thickness direction of the leaf spring 11.

  An example of the material (spring steel) of the leaf spring 11 is SUP11. Examples of chemical components (mass%) are: C: 0.56-0.64, Si: 0.15-0.35, Mn: 0.70-1.00, P: 0.035 or less, S: 0.00. 035 or less, Cr: 0.70 to 1.00, B: 0.0005 or more, and the balance Fe. However, spring steels of other steel types may be used.

  As shown in FIGS. 2 and 3, an example of the bush 20 includes a metal outer cylinder 21, an inner cylinder 22, and an elastic member 23. The elastic member 23 is made of an elastic material such as rubber and is provided between the outer cylinder 21 and the inner cylinder 22. The leaf spring 11 is subjected to heat treatment such as quenching and tempering.

  A region between a pair of eyeball portions 12 provided at both ends of the leaf spring 11 is a strip-shaped leaf portion 11a. In other words, the eyeball portion 12 is formed at both ends of the leaf portion 11a. The eyeball part 12 of this embodiment is wound roundly upward from both ends of the leaf part 11a. That is, the eyeball portion 12 is an up-turned eye. A slight gap G is formed between the plate end 12a of the eyeball portion 12 and the upper surface of the leaf portion 11a.

  Shot peening is performed on the surface of the leaf spring 11 by a first shot peening device 25 (partially shown in FIG. 1). The first shot peening device 25 projects the shot 26 in the tangential direction of the impeller rotating at high speed while moving the leaf spring 11, and hits the shot 26 around the entire circumference of the leaf spring 11. Compressive residual stress is generated on the outer surface of the plate.

  As shown in FIG. 4, an inner surface 30 of the eyeball is formed on the inner side of the eyeball portion 12, which will be cut and shot peened, which will be described later. The eyeball inner surface 30 is a winding intermediate point on the vertical line V passing through the first region S1 (the portion indicated by the lower hatching in FIGS. 2 and 4) including the winding start portion 31 of the eyeball portion 12, and the eyeball center C1. 32 (a portion indicated by hatching on the upper side in FIG. 2 and FIG. 4). Moreover, the second region S2 includes a position P1 returned from the winding intermediate point 32 toward the winding start portion 31 by an angle θ (about 20 °). The second region S2 is located on the opposite side of the first region S1 across the center of the eyeball C1, that is, on the uppermost portion of the eyeball inner surface 30.

  As shown in FIG. 5, the eyeball inner surface 30 is finished in a circular shape by a cutting process using a cutting tool 40 such as a reamer. In this cutting process, the cutting tool 40 is inserted into the eyeball portion 12 while rotating. This rounding increases the roundness of the inner surface 30 of the eyeball, and the inner diameter D1 of the inner surface 30 of the eyeball is slightly smaller than the outer diameter D2 of the bush 20 (for example, the difference between D1 and D2 is 0.7 mm or less). Thus, the inner surface 30 of the centerpiece is finished.

  Further, a compressive residual stress is applied to the centerpiece inner surface 30 by an inner surface shot peening process performed after the shaving process. In the inner surface shot peening process, a second shot peening apparatus 50 shown in FIG. 6 is used. The second shot peening apparatus 50 includes a shot injection nozzle 51 inserted into the eyeball portion 12, a shot reflecting member 52, a drive mechanism 53, a compressed air supply source 54, a shot supply source 55, and a shot supply hose. 56 and the like. The shot reflecting member 52 is fixed to the shot spray nozzle 51 by a shaft 57. The reflection surface 58 of the shot reflecting member 52 is disposed at a position facing the injection port of the shot injection nozzle 51. The drive mechanism 53 has a function of moving the shot injection nozzle 51 and the shot reflecting member 52 in the axial direction of the eyeball portion 12 (the direction indicated by the arrow X1 in FIG. 6).

  Note that the shot spray nozzle 51 and the shot reflecting member 52 may be fixed, and the eyeball portion 12 may be relatively moved in the direction indicated by the arrow X2 in FIG. In short, the shot reflecting member 52 and the shot injection nozzle 51 can be moved relative to the inner surface 30 of the eyeball in the axial direction of the eyeball portion 12.

  An example of the shot reflecting member 52 has a triangular pyramid cone shape arranged concentrically with the shot injection nozzle 51. The shot 60 projected from the shot injection nozzle 51 is reflected by the reflecting surface of the shot reflecting member 52, and the shot is projected on the inner surface 30 of the eyeball by changing the direction in the radial direction of the shot reflecting member 52. For example, a round cut wire with a shot size (particle diameter) of φ1.3 mm or a cut wire with a shot size of φ1.0 mm is projected toward the eyeball inner surface 30 at a high speed (for example, a projection speed of 76.7 m / sec). An example of the projection pressure is 0.5 MPa, the projection amount is, for example, 200 g / second, and the projection time is 3 to 30 seconds.

  When the fatigue failure test of the leaf spring device 10 having the eyeball portion 12 is performed, it is known that the fatigue failure occurs mainly in the first region S1. However, as a result of diligent research by the present inventors, in the case of the eyeball portion 12 into which the bush 20 is press-fitted with a relatively large force, it has been found that shot peening in the second region S2 is particularly effective for delayed fracture. It was. In view of this, shot peening is performed mainly on the second region S2 in addition to the first region S1.

  For example, as shown in FIG. 6, in the first shot peening process, the center line C3 of the shot injection nozzle 51 and the shot reflecting member 52 is on the first region S1 side by an offset amount T with respect to the center line C2 of the eyeball portion 12. The shot injection nozzle 51 and the shot reflecting member 52 are moved in the axial direction X1 in a state where they are offset from each other. In the second shot peening process, the shot injection nozzle 51 and the shot reflecting member 52 are offset from the center line C2 of the eyeball portion 12 toward the second region S2 in the second shot peening process. 52 is moved in the axial direction X1.

  Therefore, by carrying out the first shot peening process and the second shot peening process, the compressive residual stress in the first and second regions S1, S2 is made larger than the compressive residual stress in the other region S3. Can do. Note that the shape of the shot reflecting member 52 may be changed so that shots are intensively projected on the first region S1 and the second region S2.

  For example, like the shot reflecting member 52 according to the second embodiment shown in FIG. 7 and FIG. 8, two reflecting surfaces 58 are formed, and the shot 60 is moved by the reflecting surfaces 58 to the first and second shots. You may enable it to project intensively toward area | region S1, S2.

  Alternatively, a pair of main reflecting surfaces 58 and a pair of sub-reflecting surfaces 59 are formed as in the shot reflecting member 52 of the third embodiment shown in FIGS. 60 may be projected intensively toward the first and second regions S1 and S2, and a small amount of shot 60 may be projected toward the other region S3 by the sub-reflection surface 59.

  11 to 13 show a shot peening apparatus 50 'according to the fourth embodiment. In the shot peening apparatus 50 ′, the shot injection nozzle 51 and the shot reflecting member 52 are configured separately. The shot reflecting member 52 has a pair of reflecting surfaces 58, and these reflecting surfaces 58 are opposed to the shot injection nozzle 51. When the eyeball portion 12 and the shot injection nozzle 51 are fixed, the shot reflecting member 52 moves in the direction of the axis X1. When the shot injection nozzle 51 and the shot reflecting member 52 are fixed, the eyeball portion 12 is configured to relatively move in the direction indicated by the arrow X2. Since other than that is the same as the shot peening apparatus 50 of 1st Embodiment shown in FIG. 6, description is abbreviate | omitted.

  The angle α formed by the reflecting surface 58 with respect to the axis C3 of the shot reflecting member 52 is set to be less than 45 ° (α <45 °) so that the shot projection angle β satisfies 0 <β ≦ 45 °. The projection angle β is an angle formed by the shot projection direction with respect to the normal Z of the projection surface (eyeball inner surface 30). When the projection angle β exceeds 45 °, the shot energy of the shot that collides with the projection surface (the inner surface 30 of the eyeball) is remarkably reduced, so that the shot peening effect is remarkably lowered.

  When the shot projection angle β is 0 °, the shot 60 facing the projection surface (eyeball inner surface 30) interferes with the shot 60a reflected by the projection surface (eyeball inner surface 30), and the shot projection energy cancels out. Therefore, the effect of shot peening is significantly reduced. Therefore, the projection angle β is preferably 0 ° or more. However, if the distance from the reflective surface 58 to the inner surface 30 of the eyeball is large and interference between the shot 60a reflected by the inner surface 30 of the eyeball and the shot 60 facing the inner surface 30 of the eyeball is not a problem, the projection angle β is set to 0 °. May be.

  In the case of this embodiment, as shown in FIG. 13, the shot reflecting member 52 may be reciprocally rotated around the axis (in the direction indicated by the arrow R) in the range of 0 to 45 °, for example. By doing so, it is possible to concentrate the shots in the first region S1 and the second region S2 and to project the shots in the other region S3.

  Alternatively, as in the shot reflecting member 52 of the fifth embodiment shown in FIG. 14, a pair of main reflecting surfaces 58 and a pair of sub reflecting surfaces 59 are formed, and a large number of shots 60 are first and While projecting intensively toward the second areas S1 and S2, a small amount of shot 60 may be projected toward the other area S3 by the sub-reflection surface 59.

  FIG. 15 shows a shot peening apparatus 50 ″ according to the sixth embodiment. The shot reflecting member 52 of this shot peening apparatus 50 ″ has a one-surface inclined type reflecting surface 58 formed thereon. The angle α of the reflection surface 58 (the angle α of the reflection surface 58 with respect to the axis C3) is 45 so that the shot projection angle β with respect to the normal Z of the projection surface (eyeball inner surface 30) satisfies 0 <β ≦ 45 °. It is set to less than °. The area of the reflection surface 58 is larger than the shot projection area of the shot injection nozzle 51. In this case, by rotating the shot reflecting member 52 about the axis C3, the deviation of the axis C3 with respect to the shot injection nozzle 51 can be absorbed to some extent. Further, the rotational speed is reduced to focus on shot peening at locations where the compressive residual stress is to be increased, such as the first and second areas S1 and S2, and the rotational speed is increased in the other area S3. Thus, a desired compressive residual stress distribution may be imparted in the circumferential direction of the inner surface 30 of the eyeball by performing short-time shot peening. Since other configurations and operations are the same as those of the shot peening apparatus 50 of FIG.

  Since the eyeball portion 12 of the leaf spring device 10 is heated at the time of molding, an oxide film called black skin is formed on the surface. When compressive residual stress was measured when shot peening was performed with the black skin remaining on the inner surface 30 of the eyeball, the compressive residual stress in the first region S1 was −408 MPa. On the other hand, when shot peening was performed in a state in which the inner surface 30 was cut and the black skin was removed, it was found to be −498 MPa, and an absolute value as high as 90 MPa was obtained. In addition, the compressive residual stress value is represented by minus as a convention in the industry. As described above, by performing the inner surface shot peening after performing the cutting process on the eyeball portion 12, it is possible to more effectively express the compressive residual stress in the first and second regions S1 and S2.

  The distribution of compressive residual stress in the circumferential direction of the inner surface 30 provided by the inner surface shot peening process includes the absolute value of the compressive residual stress in the first region S1 and the absolute value of the compressive residual stress in the second region S2. The absolute value of the compressive residual stress in the other region S3 in the circumferential direction is set to be, for example, 5 to 10% or more. For example, the compressive residual stress in the first and second regions S1, S2 is −498 MPa or more, and the compressive residual stress in the other region S3 is approximately −400 MPa. In addition, when the gradient of the compressive residual stress distribution becomes steep, a portion where the slope is steep may become a starting point of breakage.

  Thus, by increasing the compressive residual stress value in the second region S2, it was possible to improve the delayed fracture of the eyeball portion 12 with the bush 20 being press-fitted. In order to investigate the delayed fracture of the eyeball portion 12, a delayed fracture test was performed under the test condition of immersing the eyeball portion 12 into which the bush-corresponding metal fitting was press-fitted in a strongly acidic (pH 1.0) sulfuric acid solution. As a result, in the conventional eyeball part, delayed fracture occurred in a short time (10 minutes to 30 minutes), whereas the delayed fracture of the eyeball part 12 of this embodiment occurred in 5 hours or more, and the delayed fracture was significant. In addition, according to the inner surface shot peening process of the present embodiment, energy required for projection can be saved as compared to the case where shots are evenly projected on the entire circumference of the inner surface 30 of the eyeball. I was able to.

  After the inner surface shot peening process is finished, the bush 20 is press-fitted into the eyeball portion 12. The outer diameter D2 (shown in FIG. 2) of the bush 20 is slightly larger than the inner diameter D1 of the eyeball portion 12 in a free state before the bush 20 is inserted. The difference between D1 and D2 is, for example, about 0.5 to 0.7 mm. Therefore, the eyeball portion 12 is accommodated inside the eyeball portion 12 in a state in which the diameter of the bush 20 is slightly larger than that in the free state when the bush 20 is press-fitted.

  The eyeball inner surface 30 is subjected to the cutting step in advance before the bush 20 is press-fitted, so that the roundness and surface accuracy of the eyeball inner surface 30 are increased. Moreover, the inner diameter D1 of the eyeball portion 12 is finished to be slightly larger than the outer diameter D2 of the bush 20 by the cutting step. For this reason, the entire circumference of the bush 20 can be brought into close contact with the eyeball inner surface 30 with high accuracy.

As described above, the manufacturing method of the leaf spring device 10 of the present embodiment includes the following steps.
(1) The process of forming the eyeball part 12 by heating the end part of the leaf | plate spring 11 and winding round.
(2) A step of performing heat treatment such as quenching and tempering on the leaf spring 11.
(3) A step of performing shot peening on the outer surface of the leaf spring 11.
(4) A shaving process of machining the inner surface 30 of the centerpiece with a reamer or the like. Through this cutting process, the inner surface 30 of the eyeball is finished in a circular shape, and the oxide film on the inner surface 30 of the eyeball is removed.
(5) An inner surface shot peening process in which a shot is projected onto the eyeball inner surface 30 after the shaving process is performed. In this inner surface shot peening process, a compressive residual stress distribution is generated so that the absolute value of the compressive residual stress in the first and second regions S1, S2 is larger than the absolute value of the compressive residual stress in the other region S3.
(6) A step of press-fitting the bush 20 into the centerpiece 12 after the inner surface shot peening step.

  Needless to say, in carrying out the present invention, the shape of the leaf spring, the centerpiece, the bush, and the shape and structure of the leaf spring can be variously changed. Further, the eyeball portion is not limited to the up-turned eye as described in the above embodiment, but may be a down-turned eye.

DESCRIPTION OF SYMBOLS 10 ... Plate spring apparatus 11 ... Plate spring 12 ... Eyeball part 20 ... Bush 30 ... Eyeball inner surface 31 ... Winding start part 32 ... Winding intermediate point 50, 50 ', 50 "... Shot peening apparatus 51 ... Shot injection nozzle 52 ... Shot reflection Member 58 ... reflective surface

Claims (5)

A leaf spring having an eyeball rolled round at the end;
A leaf spring device comprising a bush press-fitted into the eyeball part,
The inside of the eyeball part has an eyeball inner surface that has been subjected to cutting and shot peening, and
Regarding the distribution of compressive residual stress in the circumferential direction of the inner surface of the eyeball, the second region including the absolute value of the compressive residual stress in the first region including the winding start portion of the eyeball portion and the winding intermediate point on the vertical line passing through the center of the eyeball The leaf spring device is characterized in that the absolute value of the compressive residual stress is greater than the absolute value of the compressive residual stress in the other region of the inner surface of the eyeball. Forming the eyeball portion by winding the end of the leaf spring roundly;
Sharpening the inner surface of the eyeball part by cutting the inner surface of the eyeball part and removing the oxide film adhering to the inner surface of the eyeball,
After the shaving step is performed, a compressive residual stress is applied to the inner surface of the eyeball by projecting a shot onto the inner surface of the eyeball, and the winding of the eyeball portion starts with respect to the distribution of the compressive residual stress in the circumferential direction of the inner surface of the eyeball The absolute value of the compressive residual stress of the first region including the portion and the absolute value of the compressive residual stress of the second region including the winding intermediate point on the vertical line passing through the center of the eyeball are determined for the other regions of the inner surface of the eyeball. An inner surface shot peening process for making the compressive residual stress larger than the absolute value;
A step of press-fitting a bush having an outer diameter larger than the inner diameter of the eyeball portion into the eyeball portion after the inner surface shot peening step;
A method for manufacturing a leaf spring device.   In the inner surface shot peening step, a shot injection nozzle is inserted inside the eyeball and a shot reflecting member is disposed at a position facing the shot injection nozzle, and a shot is made from the shot injection nozzle toward the shot reflecting member. A first shot peening step of projecting and projecting the shot with the shot reflecting member being reflected toward the inner surface of the eyeball and projecting the shot reflecting member close to the first region; 3. The method for manufacturing a leaf spring device according to claim 2, wherein a second shot peening step of projecting the shot in a state where the shot reflecting member is brought close to the second region is performed. A shot peening apparatus for performing the shot peening on the inner surface of the center of the leaf spring apparatus according to claim 1,
A shot spray nozzle inserted inside the centerpiece,
A shot reflecting member having a reflecting surface facing the shot spray nozzle and reflecting a shot projected from the shot spray nozzle on the reflecting surface and facing the inner surface of the eyeball;
The reflection surface is shaped so that the amount of shots reflected toward the first region and the second region is larger than the amount of shots reflected toward the other region. Shot peening equipment.   The angle formed by the reflection surface with respect to the axis of the shot reflection member is an angle at which a projection angle of a shot reflected by the reflection surface is greater than 0 ° and equal to or less than 45 °. Shot peening equipment.

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