JPH0753347B2 - Rotor type shot peening machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a rotor type shot peening apparatus for performing surface treatment of, for example, a metallic material.

(Prior Art) Conventionally, a shot, which is a small metal ball, is projected on the surface of a portion such as a spring or gear used in a vehicle that receives stress concentration to increase the compressive stress and improve the fatigue strength. Shot peening equipment is known. According to this apparatus, a grain boundary oxide layer is formed on the surface of a work that has been carburized and quenched, and the fatigue strength is reduced. However, this layer can be removed by shot projection, and the peening effect is extremely large. .

Such a shot peening apparatus is a work handling apparatus for placing a work, a shot accelerating apparatus for projecting a shot onto a work, a shot circulating apparatus for circulating shots, a shot separating apparatus for separating shots having a small peening effect, and a new one. A shot supply device is provided for supplying shots. (For example, refer to JP-A-61-38869.) Of these, a conventional shot separation device is shown in FIG. 5, for example. In the figure, the shot separation device 101 is a mesh 103.
For example, the shot 105 has a ball diameter of 0.3 mm or more that does not pass through the mesh 103 and 0.3 mm that passes through the mesh 103.
Separated into less than.

Then, the shot 105 having a ball diameter of 0.3 mm or more is supplied to the drum 111 of the rotor 109 via the shot supply pipe 107.
The rotor 109 includes a plurality of blades 113 extending in the radial direction and having a predetermined length. The shot 105 in the drum 113 is supplied to the root of the blade 113 to be pre-accelerated and centrifugally accelerated along the blade 113 of the rotating rotor 109 to be projected on a work (not shown) to obtain a peening effect.

(Problems to be Solved by the Invention) By the way, while the lengths of the blades 113 are all substantially uniform, the ball diameter of the shot 105 separated by the shot separation device 101 and supplied to the rotor 109 side is worn. It varies depending on the situation. Therefore, the kinetic energy of each shot 105, which is uniformly centrifugally accelerated by the rotor 109, varies, the peening effect becomes non-uniform, and the quality of the work may become unstable.

The present invention has been made in view of the above problems, and an object thereof is to provide a rotor type shot peening apparatus capable of stabilizing the quality of a work by making the kinetic energy of shots having different spherical diameters substantially uniform. .

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of blades extending in a radial direction of a rotatable rotor and having a predetermined length. Provided is a rotor type shot peening apparatus for projecting a shot centrifugally accelerated from the outer peripheral portion of a rotor that rotates by supplying a shot to the rotor center side of this blade, setting a plurality of blade lengths, Supplying the shot to a blade having a length corresponding to the ball diameter so that the kinetic energy when projecting the shot selected by the selecting means and the selecting means for selecting the shot according to the ball diameter are substantially uniform And a supply means for

Further, the ball diameter of the shot is r _1, and when the length of the blade to which this shot is supplied is R ₁ , the ball diameter of other shots is r ₂ and the length of the blade to which this shot is supplied. Assuming that R ₂ is R ₂ , the supply means is r ₁ ³ R ₁ ² = r ₂ ³ R ₂ ²
The shot was supplied to a blade having a length corresponding to the spherical diameter so as to satisfy the formula.

Further, the selecting means has a mesh and selects a shot that passes through the mesh and a shot that does not pass through the mesh.

(Operation) In the above configuration, after the selecting means selects the shots according to the ball diameter, a blade having a length corresponding to the ball diameter is provided so that each kinetic energy when the supplying means projects the shots becomes substantially uniform. By supplying the shots, the kinetic energy of each shot becomes substantially uniform.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

1 to 4 show a rotor type shot peening apparatus for mass production according to an embodiment of the present invention.

First, the structure will be described. The shot peening apparatus 1 projects a shot 9 from a rotatable rotor 7 onto a plurality of works 5 placed between cabinets 3 made of normal steel, for example, as shown in FIG. It is composed.
Such shots 9 are sorted according to the ball diameter by a shot separating device 11 which is a sorting means.

The shot separating device 11 has a first frame 13, a second frame 15 and a third frame 17 from above as shown in FIG. First frame 13
A first mesh 19 that allows a shot 9 having a ball diameter of less than 0.7 mm to pass through is attached to the. The second frame 21 has a second mesh 21 that allows shots 9 of less than 0.5 mm to pass through.
Is affixed, and the third frame 17 is affixed with a third mesh 23 for passing shots 19 of less than 0.2 mm. Then, the shot 19 that has passed through the third mesh 23 is discarded through the waste pipe 24.

One ends of a first shot supply pipe 25, a second shot supply pipe 27, and a third shot supply pipe 29 are sequentially connected to the first frame 13, the second frame 15, and the third frame 17, respectively, as a supply means. . The other ends of the shot supply pipes 25, 27, 29 are connected to the rotor 7, respectively.

As shown in FIG. 1, the rotor 7 is provided with a plurality of flat blades 31 extending in the radial direction and having a predetermined length. In this embodiment, the length of the blade 31 is set in three types in the axial direction of the rotor 7. That is, a plurality of relatively short first blades 33, intermediate second blades 35 and relatively long third blades 37 extend in the radial direction of the rotor 7 (eight sets in this embodiment). .

The bases of the blades 33, 35, 37 are fixed to a pulley 39 that constitutes the shaft of the rotor 7. A belt 41 is wound around the pulley 39, and the pulley 41 is rotatable about a fixed shaft 43 via a bearing 45.

Drums 47 and 49 for supplying the shot 9 to the blade 31 are provided on the fixed side of the rotor 7. That is,
The rotor 7 has a first drum 47 for supplying the shot 9 to the first blade 33 and a second drum 49 for supplying the shot 9 to the second blade 35. Each drum 4
Subchambers 51 and 53 are formed in 7,49, respectively. Also,
A sub chamber 55 for supplying the shot 9 to the third blade 37 is formed in the middle of the fixed shaft 43, and the pulley 39 has this sub chamber 55.
A through hole 57 is formed at a position corresponding to 55 and at an appropriate position in the radial direction of the rotor 7.

The other end of the first shot supply pipe 25 is connected to the first drum 47, and the other end of the second shot supply pipe 27 is connected to the second drum 49. Further, the intermediate portion of the third shot supply pipe 29 penetrates between the fixed shafts 43 in the axial direction of the rotor 7, and the other end thereof is fixed shaft 43.
And the opening faces the sub chamber 55.

Therefore, a shot 9 of 0.7 mm or more is supplied to the first blade 33, a shot 9 of less than 0.7 mm and 0.5 mm or more is supplied to the second blade 35, and a shot 9 of less than 0.5 mm and 0.2 mm or more. Is supplied to the third blade 37 and pre-accelerated. A partition wall 59 is formed between the adjacent blades 33, 35 and 37 so that the shots 9 supplied to the blades 33, 35 and 37 are not mixed.

Next, the operation will be described.

In the above structure, the pulley 39 is rotated via the belt 41 by the operation of the driving mechanism (not shown), and the shot 9 is centrifugally accelerated along the blade 31 of the rotating rotor 7 and projected onto the work 5 from the outer peripheral portion of the rotor 8. It

Here, the lengths of the first to third blades 33, 35, 37 are set as follows. That is, the motion equation of the shot 9 projected as described above is Is. However, m ₁ is the mass of the shot 9, m ₂ is the mass of the other shots 9, and v ₁ and v ₂ are the initial velocities when each shot 9 is projected from the blade 31.

At this time, the initial velocity v can be expressed by v = ARω. However, A is a constant (1 experimentally or empirically.
2 to 1.3), R is the radial length of the blade 31, and ω is the angular velocity.

Therefore, the equation (1) becomes m ₁ R ₁ ² = m ₂ R ₂ ² (2). Here, R ₁ is the length of the blade 31 to which the shot 9 is supplied, and R ₂ is the length of the blade 31 to which the other shot 9 is supplied.

The mass m of shot 9 is Is. Here, r is the spherical diameter of the shot 9, and ρ is the specific gravity of the shot 9.

Therefore, the equation (2) becomes r ₁ ³ R ₁ ² = r ₂ ³ R ₂ ² (3). Here, r ₁ is the sphere diameter of the shot 9 and r ₂ is the sphere diameter of the other shot 9. The spherical diameters r ₁ and r ₂ are, for example, the average value of the normal distribution of each shot 9 selected by the shot separation device 11.

Then, the length of the blade 31 is set so as to satisfy the above formula (3) with respect to the spherical diameter of the shot 9 supplied to the blade 31. Therefore, the kinetic energy of each shot 9 accelerated by the blade 31 becomes substantially uniform.

Therefore, according to this embodiment, the shot 9 whose kinetic energy is substantially uniform is projected onto the work 5 to obtain a stable peening effect, and the quality of the work 5 can be stabilized. Further, since the shot 9 having a ball diameter of less than 0.2 mm due to wear or the like is discarded, it is possible to effectively prevent the shot 9 having a small peening effect from being supplied to the rotor 7 side as in the conventional case. .

The shots 9 after projection are collected in the lower shot sump 63 provided at the bottom of the cabinet 3. Bottom shot no use
One end of a shot recovery pipe 65 is connected to 63, and the other end of the shot recovery pipe 65 is connected to the bottom of a bucket conveyor 67. The bucket conveyor 67 has a plurality of buckets 69,
The bucket 69 is connected to a belt 75 wound around an upper roller 71 and a lower roller 73. A driving device (not shown) is connected to either the upper roller 71 or the lower roller 73, and the belt 75 is rotated counterclockwise in FIG. 4 by driving the driving device. A guide plate 77 is provided below the upper roller 71 above the bucket conveyor 67, and the tip end of the guide plate 77 faces the upper shot reservoir 79.

The shot 9 after projection collected in the lower shot sump 63 passes through the shot collecting pipe 65 and is collected at the bottom of the bucket conveyor 67, and the belt 75 is rotated by driving the driving device so that the shot 9 is scratched by the bucket 69. Taken and rise. After that, when the bucket 69 is reversed over the upper roller 71, the shot 9 in the bucket 69 falls on the guide plate 77 and is collected by the upper shot reservoir 79.

After that, the shot 9 is supplied to the shot separating device 11. The shot 9 worn in such a circulation process is discarded, but a new shot is replenished by a shot replenishing device (not shown). Conventionally, for example, the shot 9 having a ball diameter of less than 0.3 mm was discarded, but in this embodiment, the ball diameter is 0.3 m.
Even if it is less than m, if it is 0.2 mm or more, it will be accelerated by the relatively long third blade 37, and the other ball diameter will be 0.3 mm or more shot 9
The same kinetic energy as is obtained. Therefore, the number of shots 9 to be discarded can be reduced as a whole, management can be facilitated, and cost can be reduced.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and the same effect can be obtained even if it is applied to, for example, a rotor type shot peening apparatus which is not a mass production type.

[Effects of the Invention] As described above, according to the present invention, the kinetic energy of the shot that is shot by selecting the shots according to the ball diameter and supplying the shots to the blade having the length according to the ball diameter. Can be made substantially uniform, the peening effect can be stabilized, and the quality of the work can be stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an essential portion of a rotor type shot peening apparatus according to an embodiment of the present invention, and FIG. 2 is a II-II of FIG.
A sectional view, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, FIG. 4 is a schematic overall sectional view of FIG. 1, and FIG. 5 is a perspective view corresponding to FIG. 1 of a conventional example. 5 ... Work, 7 ... Rotor 9 ... Shot 11 ... Shot separation device (selection means) 25 ... First shot supply pipe (supply means) 27 ... Second 〃 〃 (supply means) 29… Third 〃 〃 (supply means) 31 ... Blade

Claims (3)

[Claims] 1. A rotatable rotor having a plurality of blades extending in a radial direction and having a predetermined length, and supplying a shot to the rotor center side of the blades to rotate the rotor from the outer peripheral portion. In a rotor type shot peening apparatus for projecting a centrifugally accelerated shot onto a work, a plurality of blade lengths are set, and a selecting means for selecting the shots according to the ball diameter, and the selecting means A rotor type shot peening apparatus comprising: a supply unit that supplies a shot to a blade having a length corresponding to a spherical diameter so that each kinetic energy when projecting the shot is substantially uniform. 2. When the ball diameter of the shot is r ₁ and the length of the blade to which this shot is supplied is R ₁ , the ball diameter of another shot is r ₂ and this shot is supplied. Assuming that the length of the blade is R ₂ , the supply means is r ₁ ³ R ₁ ² =
The shot is supplied to a blade having a length corresponding to a spherical diameter so as to satisfy the r ₂ ³ R ₂ ² formula.
The described rotor type shot peening apparatus. 3. The rotor type shot peening apparatus according to claim 1, wherein the selecting means has a mesh and selects a shot passing through the mesh and a shot not passing through the mesh. .