JPH0533254Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shot circulation device for shot peening.

[Conventional technology]

Shot peening is performed, for example, by projecting shot particles in a predetermined particle size range onto a workpiece such as a carburized and quenched steel gear to harden the surface of the workpiece and improve its fatigue strength. It is something. Conventionally, in this shot peening apparatus, as shown in FIG. 7, shot particles 3, 3, .
The shot particles 3, 3, .

In the shot sorting section 1, the shot particles 3, 3... are sorted by particle size, the part with the largest particle size is sent to the impeller 4, the part with the next largest particle size is sent to the overflow passage 6, and the part with the smallest particle size, which contains dust etc., is discharged. are supplied to the respective passages 7 for use. In addition,
The outlet portion of the overflow passage 6 is connected to the middle of the shot circulation path 5.

[The problem that the idea aims to solve]

By the way, in the above device, in order to prevent the shot particles 3, 3... from clogging the shot circulation path 5, even when the impeller 4 is not projecting the shot particles 3, 3... The particles 3, 3, . . . are circulated between a shot circulation path 5, a shot sorting section 1, and an overflow path 6.

However, in this case, while a relatively small amount of shot particles 3, 3... in the shot circulation path 5 and overflow path 6 are repeatedly circulated through the above-mentioned path, a relatively small amount of these shot particles 3, 3... Those with smaller particle sizes are sequentially discharged into the discharge passage 7, and as a result, the average particle size of the shot particles 3, 3, .

By the way, next time when the impeller 4 projects the shot particles 3, 3, . , 3... will be sent to the impeller 4 first, but as mentioned above, the average particle size of these shot particles 3, 3... has become considerably large during circulation, so it will be difficult to start the next shot peening. At times, only the shot particles 3, 3, etc. having a large particle size are projected onto the workpiece, resulting in a problem that the desired effect of shot peening cannot be obtained.

[Means to solve the problem]

In order to solve the above-mentioned problems, the shot circulation device for shot peening according to the present invention includes a shot chamber having a projection means for projecting shot particles onto a workpiece housed therein, and a shot circulation device for distributing shot particles that have already been projected in the shot chamber. A shot circulation path that feeds the shot particles to the shot sorting section, a part with the largest particle size that is sorted by particle size into the above-mentioned projection means in the shot chamber, a part with the next largest particle size into the overflow passage, and a part with the smallest particle size. The shot circulation device for shot peening is equipped with a shot sorting section for supplying the shot to the discharge section, and the shot peening shot circulation device is characterized in that an outlet section of the overflow passage is connected to a shot chamber.

[Effect]

According to the above configuration, since the outlet of the overflow passage is connected to the shot chamber, when the shot particles are not projected by the projection means, the shot particles are transferred to the shot chamber, the shot circulation path, the shot sorting section, and the shot separation section. It becomes circulated between the overflow passages. In this case, not only the shot particles in the shot circulation path as in the past, but also the shot particles in the shot chamber are circulated through the above path, so the amount of shot particles circulated during the pause in projection is greater than in the past. . Therefore, the number of times that the shot particles are circulated through the above-mentioned path during a pause in projection is reduced, so that the degree to which the average particle size of the shot particles increases is also suppressed, and when the next projection is performed, the shot particles are supplied to the projection means. As a result, the particle size of the shot particles is no longer significantly larger than that of the previous shot, so that the desired effect can be obtained during the next shot peening.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

As shown in FIG. 4, the shot circulation device for shot peening according to the present invention includes a shot chamber 12 having an impeller 11 as a projection means, and a shot sorting section 15 for separating shot particles 13, 13, . . . in the shot chamber 12. shot circulation path 14 for feeding the
Then, the shot particles 13, 13... sent from the shot circulation path 14 are sorted by particle size and sent to the impeller 1.
1. A shot sorting section 15 is provided which supplies either an overflow passage 16 or a discharge passage 17 serving as a discharge section. Note that the shot circulation path 14 includes a shot particle storage section 18 as necessary.
Unused shot particles 13, 13, . . . are supplied from there.

As shown in Figures 1 and 2, the shot chamber 1
2 has six projection spaces 12 arranged on the same circumference and divided at predetermined angular intervals.
a, 12a... Each of the projection spaces 12a is configured to accommodate a workpiece (not shown) therein, and at least a portion of the outer periphery of each projection space 12a is used to take in and take out the workpiece and to project the shot particles 13, 13... is open.

Impellers 11 are arranged at radially outer positions corresponding to the three adjacent projection spaces 12a, 12a... in the shot chamber 12, and as each impeller 11 rotates, the three projection spaces 12a, . . .
Shot particle 1 for the workpieces a, 12a...
3, 13, . . . are projected.
Each impeller 11 is driven by a motor 22 via a pair of pulleys 19, 20 and a belt 21.

Further, one projection space 12a in the shot chamber 12 is located at the workpiece loading/unloading section 23. The upper part of the shot chamber 12 having each of the projection spaces 12a, 12a, .
2a are sequentially located at the portion facing each impeller 11 and at the loading/unloading section 23.

The lower part of the shot chamber 12 forms a space for accommodating shot particles 13, 13, . . . that have already been projected. The lower part of this shot chamber 12 is connected to a first horizontal conveyance section 14a in a shot circulation path 14. The shot particles 13, 13... housed in the lower part of the shot chamber 12 are transferred to the screw conveyor 2.
4 to be transported in the A direction via the first horizontal transport section 14a.

The end in the A direction of the first horizontal conveyance section 14a is connected to the lower end of the vertical conveyance section 14b in the shot circulation path 14, and in the vertical conveyance section 14b, the shot particles 13, 13... are transported upward by a bucket conveyor 25. It is now being transported.

Further, the upper end of the vertical conveyance section 14b is connected to a second horizontal conveyance section 14c in the shot circulation path 14, and in the second horizontal conveyance section 14c, the shot particles 13, 13... are transported in the direction B by a screw conveyor 26. It is now being transported. The end of the second horizontal conveyance section 14c in the B direction is connected to the shot sorting section 15.

As shown in FIG. 3, in the shot sorting section 15, the shot particles 13, 13, . It is designed to fall through the horizontal part 15b of 15a.

A blower 27 is attached to the window 15c provided in the shot sorting section 15, and the blower 27 blows air in the D direction. As a result, shot particles 13, 13 falling from the horizontal part 15b
... was subjected to air sorting and shot particles 13, 13...
The portion with the largest particle size falls as it is into the projection supply section 28 directly below, as shown by arrow E.

Three projection supply passages 30, 30... (see Fig. 1) branch from this projection supply section 28, and shot particles 13, 13... are supplied from the lower end of each projection supply passage 30 to each impeller 11. Ru. In addition, the opening/closing shutter section 3 in each projection supply passage 30
0a is configured to turn on and off the supply of shot particles 13, 13, . . . to the impeller 11 using a built-in shutter (not shown).

In addition, shot particles 1 falling from the horizontal part 15b
Among particles 3, 13, . . . , the part with the next largest particle size is slightly carried in the direction D by the wind pressure of the blower 27 and falls into the overflow passage 16 as shown by arrow F. The lower end of this overflow passage 16 is
As shown in FIG. 1, it is connected to the lower part of the shot chamber 12.

Furthermore, among the shot particles 13, 13... that have fallen from the horizontal section 15b, the part with the smallest particle size, including dust, etc., is carried in the direction D by the wind pressure of the blower 27, and is sent for discharge as shown by arrow G. It falls into the passage 17. A window 15d for dust collection is formed above the discharge passage 17, and dust is collected by a dust collector (not shown) through this window 15d.

In the above configuration, when performing shot peening, the opening/closing shutter section 30a in each projection supply passage 30 is opened, and shot particles 13, 13, . . . are supplied from the shot sorting section 15 to each impeller 11. Then, at predetermined time intervals, the projection space 1
2a, 12a... are rotated to sequentially carry out projected workpieces and carry in new workpieces at the loading/unloading section 23, while each impeller 11 sequentially applies shot particles 1 to the workpieces in each projection space 12a.
3, 13... are projected. Projected shot particle 1
3, 13... are sent to the shot sorting section 15 via the shot circulation path 14, and after being sorted here, those with larger particle sizes are sent to the impellers 11, 11 again.
...supplied to...

When the projection of the shot particles 13, 13... by the impellers 11, 11... is stopped, the opening/closing shutter portion 30a of the projection supply passage 30 is closed, and the shot particles 13, 13... to the impellers 11, 11... are stopped.
In this case, the supply of shot particles 1
The shot particles 13, 13... are circulated among the shot sorting section 15, the overflow passage 16, the shot chamber 12, and the shot circulation path 14. In this way, when the shot particles 13, 13... are not being projected, the shot particles 13, 13... in the shot chamber 12 also circulate along the above-mentioned path.
The number of times that 3, 13... cycles decreases,
The degree to which the average particle size of the shot particles 13, 13 ... increases is also suppressed. Therefore, the shot particles 13 projected onto the workpiece during the next shot peening are
The particle size of No. 3, 13, . . . will not be significantly larger than that of the previous shot peening.

Figure 5 shows shot particles 13, 13...
The particle size distribution of shot particles 13, 13... collected from the overflow passage 16 10 minutes after stopping the projection of the particles is shown. In FIG. 5, H is the particle size distribution in the present invention in which the outlet of the overflow passage 16 is connected to the shot chamber 12, and I is the particle size distribution in the conventional example in which the outlet of the overflow passage is connected to the shot circulation path. As is clear from Figure 5,
In the present invention, the degree to which the particle size increases while the projection of the shot particles 13, 13... is stopped is suppressed, and the particle size of the shot particles 13, 13... passing through the overflow passage 16 is smaller than in the conventional example.

Further, FIG. 6 shows the particle size distribution of the shot particles 13, 13... collected from the overflow passage 16 during the projection of the shot particles 13, 13... (30 seconds after the start of the projection). However, in FIG. 6, H is the particle size distribution in the present invention in which the outlet of the overflow passage 16 is connected to the shot chamber 12, and I is the particle size distribution in the conventional example in which the outlet of the overflow passage is connected to the shot circulation path. According to this, in the present invention, the particle size of shot particles 13, 13... that pass through the overflow passage 16 during projection is lower than that of the conventional example, and in particular, the proportion of shot particles 13, 13... whose particle size is larger than 32 mesh is extremely small. It is. This shows that the particle size of the shot particles 13, 13, . . . supplied to the impellers 11, 11, .

[Effect of idea]

As described above, the shot circulation device for shot peening according to the present invention includes a shot chamber that accommodates a workpiece and has a projection means for projecting shot particles onto the workpiece, and a shot chamber that stores shot particles that have already been projected in the shot chamber. A shot circulation path that feeds the shot particles to the shot sorting section, a part with the largest particle size that is sorted by particle size into the above-mentioned projection means in the shot chamber, a part with the next largest particle size into the overflow passage, and a part with the smallest particle size. In the shot circulation apparatus for shot peening, the outlet section of the overflow passage is connected to the shot chamber.

As a result, when the shot particles are not being projected by the projection means, the shot particles circulate between the shot chamber, the shot circulation path, the shot sorting section, and the overflow passage.
Since not only the shot particles in the shot circulation path as in the prior art but also the shot particles in the shot chamber are circulated through the above-mentioned path, the amount of shot particles that are circulated during a pause in projection is greater than in the prior art. Therefore, the number of times that the shot particles are circulated through the above-mentioned path during a pause in projection is reduced, so that the degree to which the average particle size of the shot particles increases is also suppressed, and when the next projection is performed, the shot particles are supplied to the projection means. Since the particle size of the shot particles does not become significantly larger than that of the previous shot, the desired effect can be obtained even during the next shot peening.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention, in which FIG. 1 is a schematic front view of the shot circulation device, FIG. 2 is a schematic plan view of the shot chamber, and FIG. 3 is a shot sorting section. 4 is an explanatory diagram showing the schematic configuration of the shot circulation device, and FIG. 5 is a graph showing the particle size distribution of shot particles collected from the overflow passage 10 minutes after stopping shot particle projection. , FIG. 6 is a graph showing the particle size distribution of shot particles collected from the overflow passage during shot particle projection, and FIG. 7 is an explanatory diagram showing the schematic configuration of a conventional shot circulation device. 11 is an impeller (projection means), 12 is a shot chamber, 13 is shot particles, 14 is a shot circulation path, and 15 is a shot sorting section.

Claims (1)

[Claims for Utility Model Registration] A shot chamber having a projection means for projecting shot particles onto a workpiece housed therein, a shot circulation path for feeding shot particles in the shot chamber to a shot sorting section, and a shot particle and a shot sorting section that sorts the particles according to particle size and supplies the part with the largest particle size to the above-mentioned projection means in the shot chamber, the part with the next largest particle size to the overflow passage, and the part with the smallest particle size to the discharge section. A shot circulation device for shot peening, characterized in that an outlet of the overflow passage is connected to a shot chamber.