Blasting device

Abstract

Provided is a blasting device that improves the yield of the blasting device, particularly enables shortening of the blasting processing time and reduction of the defective product generation rate. 【Solution means】The blasting device includes a rotating device and a projection unit, and the rotating device includes a hollow barrel 2 that houses a workpiece. The barrel 2 has a substantially spindle shape including vertical surface portions 13 on both left and right sides in the axial direction of rotation, a large-diameter parallel surface portion 11 that forms a polyhedron at the center, and inclined surface portions 12 on both left and right sides disposed therebetween. The ratio of the horizontal length of the barrel 2 (the length between the left and right vertical surface portions 13 on the rotation axis) to the vertical length (the vertical length from the rotation axis to the parallel surface portion 11) is 7 to 9 to 10, and the inclination angle between the parallel surface portion 11 and the inclined surface portion 12 is more than 50 and 60 degrees or less. As the barrel 2 rotates, the workpiece subjected to centrifugal force rises along the parallel surface portion 11, and when the gravity exceeds the centrifugal force, the workpiece is divided left and right and moves downward along the inclined surface portion 12.

Description

Technical Field

[0001] The present invention relates to a blasting device.

Background Art

[0002] The applicant of the present application has proposed a blasting device including a cylindrical barrel that stores and rotates a large number of workpieces, and a projection unit that projects a processing medium onto the workpieces in the barrel. For a cross-section perpendicular to the axial direction of the rotation, the inner wall surface of the barrel forms a polyhedron with a polygonal shape, and due to the inner surface shape with corners of the polyhedron, as the barrel rotates, the workpieces are configured to move upward in the rotation direction and fall while reversing. The applicant has developed such a blasting device and proposed Patent Document 1. The inventor of the present application has attempted to improve this blasting device, particularly to shorten the blasting processing time and reduce the occurrence rate of defective products.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to improve the yield of a blasting device, particularly to shorten the blasting processing time and reduce the occurrence rate of defective products.

Means for Solving the Problems

[0005] The present invention relates to an improvement of a blasting device including a cylindrical barrel that stores and rotates a large number of workpieces, and a projection unit that projects a processing medium onto the workpieces in the barrel.

[0006] The barrel has a substantially spindle shape including vertical surface portions on both the left and right sides in the axial direction of the rotation, large-diameter parallel surface portions forming a polyhedron at the center in the axial direction of the rotation, and inclined surface portions on both the left and right sides disposed between the vertical surface portions and the parallel surface portions. The inner diameter of the inclined surface portions gradually decreases toward both the left and right ends.

[0007] The ratio of the horizontal length (the length between the left and right vertical surface portions on the rotation axis) to the vertical length (the vertical length from the rotation axis to the parallel surface portion) of the barrel is 7 to 9 to 10, and the inclination angle between the parallel surface portion and the inclined surface portion exceeds 50 and is 60 degrees or less. With the rotation of the barrel, the workpiece subjected to centrifugal force rises along the parallel surface portion, and when gravity exceeds the centrifugal force, the workpiece is divided into left and right and repeats the movement of moving downward along the inclined surface portion.

Advantages of the Invention

[0008] The present invention can provide a blasting device that can improve the yield of the blasting device, particularly shorten the blasting processing time and dramatically reduce the occurrence rate of defective products.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Outline of the Main Part of the Blasting Device) This blasting device projects media as projectiles onto a plurality of small objects such as precision parts as workpieces to perform blasting, and its basic structure is the same as that of Patent Document 1. It will be described and illustrated centering on the barrel 2.

[0011] This blasting device includes a rotating device and a projecting unit. As shown in the figure, the rotating device includes a hollow barrel 2 that houses the workpiece. The inner surface of the barrel 2 in a cross-section orthogonal to the rotation axis has a substantially octagonal shape. In this example, the barrel 2 has a substantially spindle shape including vertical surface portions 13 on both left and right sides in the axial direction of rotation (the left-right direction in the figure), large-diameter parallel surface portions 11 that form a polyhedron at the center in the axial direction of rotation, and inclined surface portions 12 on both left and right sides disposed between the vertical surface portions 13 and the parallel surface portions 11. In other words, this barrel 2 includes a parallel surface portion 11 at the center in the left-right direction (i.e., the axial direction of rotation), inclined surface portions 12 on both left and right sides, and vertical surface portions 13 at both left and right ends. The parallel surface portion 11 is formed by annularly arranging a plurality of flat surface portions 11b that form each side of the octagon. The flat surface portions 11b adjacent to each other in the rotation direction form a valley, i.e., a substantially V-shape when viewed from the side, toward the inside of the barrel 2. The inner surface of the barrel 2 has the largest diameter of the parallel surface portion 11 formed by annularly arranging the flat surface portions 11b, and the inner diameter of the barrel 2 gradually decreases as the inclined surface portions 12 extend toward both left and right ends, and vertical surface portions 13 orthogonal to the rotation axis are provided on both sides thereof. The barrel 2 can rotate with its rotation axis extending substantially horizontally in the left-right lateral direction. The rotating device promotes the media to gather at the central parallel surface portion 11 by rotating the barrel 2, and due to the fact that the flat surface portions 11b are arranged at an angle with respect to each other, the workpiece is lifted from below to above while suppressing slippage and is dropped after being inverted and rolled. By projecting the media onto the workpieces that gather at the center in the axial direction while rolling in this way, efficient blasting with suppressed unevenness is realized.

[0012] (Details of the Blasting Device) The rotating device includes a base frame 1, a barrel 2, and a rotation driving unit that rotates the barrel 2. The base frame 1 supports the barrel 2, and the barrel 2 is mounted on the base frame 1. The outer surface of the barrel 2, together with the inner surface of the barrel 2, presents a substantially regular octagon (convex octagon) in side view as shown in the partial side view of the main part in Fig. 1(B). A drive shaft 21 is fixed to the left end of this barrel 2. This drive shaft 21 is supported by a bearing 22 on the base frame 1. In this example, the rotation drive part is constituted by the drive shaft 21, the bearing 22, the sprockets 23, 26, the belt 25, and the geared motor 24.

[0013] An opening that is circular in side view is formed at the right end of the barrel 2. The tip of the suction duct 3 fixed on the base frame 1 is inserted into this opening. By inserting the suction duct 3 into the opening, the right end of the barrel 2 is rotatably supported by the suction duct 3, and it receives the rotation of the drive shaft 21 at the left end and rotates at a low speed. At the base end of the suction duct 3, a suction port 32 of a duct hose 31 connected to the dust collecting device 5 is provided.

[0014] As described above, the barrel 2 has a substantially spindle shape in front view. Each of the flat portions 11b is arranged parallel to the rotation axis of the barrel 2 to constitute a parallel surface portion 11. And a lid body 14 is pivotally attached to one surface of the parallel surface portion 11 so as to be openable and closable, and a punching metal sieve member 13 made of rubber lining is stretched over the other seven surfaces. The mesh of this sieve member 13 is smaller than the workpiece. The inclined surface portion 12 for discharging the media is also constituted by a metal plate (rubber lining). The entire above-described rotating device is covered by a cover 4, and a slide-type lid 5 is provided on the upper part of this cover 4.

[0015] Also, the projection part includes a nozzle for projecting media, that is, a blast nozzle 36. The blast nozzle 36 is located at the same position as the flat portion 11b in the left-right direction of the barrel 2 and is arranged substantially at the center of the rotation of the barrel 2, and projects media toward the parallel surface portion 11. Specifically, a connecting pipe 33 is attached to the peripheral wall of the suction duct 3. Compressed air (air) necessary for the injection of the medium is supplied to the connecting pipe 33 from an air pipe connected to the blast hose B or the like. The air pipe 35 extends substantially horizontally from the connecting pipe 33 and extends to the center inside the barrel 2. The blast nozzle 36 is attached to the air pipe 35. The blast nozzle 36 directs its jet outlet downward, and projects the medium from this jet outlet onto the workpiece inside the barrel 2.

[0016] Further, a sorting machine 6 is disposed below the barrel 2. In the sorting machine 6, a sorting machine body 42 with a screening mesh 41 stretched is supported by a support spring 43. The sorting machine 6 sorts the workpiece and the medium by the vibration caused by a vibration motor provided on the lower surface of the sorting machine body 42. The medium passes through the screening mesh 41, is discharged from the medium discharge port 44, and is returned to the sorting machine body 42. The workpiece is sorted from the medium by being transferred on the screening mesh 41 to the workpiece discharge port 45.

[0017] (Usage method of the blasting device) Next, the usage method of this blasting device will be described. First, open the lid 5 of the cover 4 and put in the workpiece. After the above input, close the lid 14 and the lid 5, start the geared motor 24, and rotate the barrel 2. At the same time, operate the projection unit and the dust collector S. The medium is injected from the blast nozzle 36 onto the workpiece inside the barrel 2, and the blasting process of the workpiece is performed.

[0018] During processing, the fine powder generated from the media and workpieces that have danced up is collected by the dust collector S from the suction duct 3. Further, the medium is discharged from the screening member 13 of the barrel 2 and recovered into a medium tank (not shown).

[0019] (Conventional example and embodiment of the present invention) In Patent Document 1, it was widely described that "the inclination angle between the parallel surface portion 11 and the inclined surface portion 12 can be implemented as 30 to 60 degrees, preferably 40 to 50 degrees." Furthermore, in the drawings, one of about 42 degrees was shown and implemented. In this case, the ratio of the width (the length between the left and right vertical surface portions 13 on the rotation axis) to the length (the vertical length from the rotation axis to the parallel surface portion 11) of the barrel 2 was 10 to 10. In such a conventional example, while suppressing the workpiece from slipping off, it is lifted from below to above, inverted, and dropped so as to roll. By projecting the media onto the workpiece that gathers at the center in the axial direction while rolling in this way, efficient blasting with suppressed unevenness was realized.

[0020] On the other hand, in the barrel 2 of the embodiment of the present invention, the ratio of the horizontal length X (the length between the left and right vertical surface portions 13 on the rotation axis) to the vertical length Y (the vertical length from the rotation axis to the parallel surface portion 11) of the barrel 2 is 7 to 9 to 10, preferably 8 to 10. The inclination angle α between the parallel surface portion 11 and the inclined surface portion 12 can be implemented as exceeding 50 and being 60 degrees or less. When the aspect ratio was changed in this way, the movement of the workpiece changed to a movement that could not be predicted conventionally. Specifically, as shown in FIG. 2, as the barrel 2 rotates, the workpiece subjected to centrifugal force rises along the parallel surface portion 11. This movement was almost the same as in the conventional example, but at the stage where gravity exceeded the centrifugal force (hereinafter referred to as the upper limit of ascent), the workpiece was divided into left and right and repeatedly moved downward along the inclined surface portion 12. In the conventional example, at the upper limit of ascent where gravity exceeded the centrifugal force, the workpiece moved downward as a whole so as to collapse and collided with the rising workpiece. However, in the barrel 2 of the embodiment of the present invention, since the climbed workpiece is divided into left and right and moves downward, the collision with the rising workpiece is suppressed and it moves smoothly.

[0021] More specifically, when the ratio of the horizontal length (the length between the left and right vertical surface portions 13 on the rotation axis) to the vertical length (the vertical length from the rotation axis to the parallel surface portion 11) of the barrel 2 was set to 800 mm to 1000 mm, the following surprising results were obtained. Upper limit of workpiece rise in the conventional example: Approximately 250 mm from the rotation axis Upper limit of workpiece rise in the embodiment: Approximately 500 mm from the rotation axis As a result, there have also been dramatic improvements in the processing time and occurrence of scratches on the product. Processing time in the conventional example: Approximately 30 minutes Processing time in the embodiment: Approximately 21 minutes (a reduction of approximately 30%) Scratches visually confirmed in the conventional example: Overall, there are scratches. Scratches visually confirmed in the embodiment: Zero.

[0022] Figure 3 shows a blasting device in a form where the barrels of Figures 1 and 2 are mounted and its automation is advanced. In this device, automation after the workpiece is loaded into the bucket loader and automation of discharging after processing is completed (when the button is pressed, the door automatically opens, and after automatically discharging the workpiece, the door automatically closes) are being advanced. However, the behavior of the workpiece in barrel 2 during processing is the same as that of the barrels in Figures 1 and 2.

Explanation of reference numerals

[0023] 1... Base frame 2... Barrel (octagonal barrel) 3... Suction duct 4... Cover 5... Lid 6... Sorter 11... Parallel surface part 11b... Flat surface part 12... Inclined surface part 13... Vertical surface part 14... Lid body 15... Sieve member 21... Drive shaft 22... Bearing 23... Sprocket (sprocket on the drive shaft side) 24... Geared motor 25... Belt 26... Sprocket (sprocket on the motor side) 31... Duct hose 32... Suction port 33... Connecting pipe 34... Air pipe 35... Air pipe 36…Nozzle 41…Sieve 42…(Separator) Main Body 44…Media Outlet 45…Work Outlet B…Blast Hose S…Dust Collector

Claims

Claim 1 A blasting apparatus comprising a cylindrical barrel for storing and rotating a plurality of workpieces, and a projection unit for projecting a processing medium onto the workpieces in the barrel, the barrel has a substantially spindle shape including vertical surface portions on both left and right sides in the axial direction of rotation, large-diameter parallel surface portions forming a polyhedron at the center in the axial direction of rotation, and left and right inclined surface portions disposed between the vertical surface portions and the parallel surface portions, the inclined surface portions gradually decrease in inner diameter toward both left and right ends, the ratio of the horizontal length (the length between the left and right vertical surface portions on the rotation axis) to the vertical length (the vertical length from the rotation axis to the parallel surface portion) of the barrel is 7 to 9 to 10, and the inclination angle between the parallel surface portion and the inclined surface portion exceeds 50 and is 60 degrees or less, characterized in that as the barrel rotates, the workpieces subjected to centrifugal force rise along the parallel surface portion, and when gravity exceeds the centrifugal force, the workpieces are divided left and right and repeat the movement of moving downward along the inclined surface portions.

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