JPS6361105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing burrs from a core used in casting.

Various methods have been researched to automatically remove burrs that occur on the core along the mating surface of the mold during core manufacturing, but there are few highly effective practical methods. I couldn't find anything that was versatile.

Therefore, the present inventor conducted research to find a method that is particularly suitable for high-mix, low-volume production, and found that the method of projecting particles onto a core and removing burrs from the core is highly versatile, and therefore developed a method using various particles. Through experiments, rice was found to be a suitable particle for removing burrs from the core, and was published in Japanese Patent Application No. 119060/1983 (Japanese Unexamined Patent Publication No. 119060/1983).
44448), but due to subsequent implementation, when the rice is thrown into the core, it will be crushed, so the running cost required to replenish it will be high, and the work environment will be bad as the rice will be crushed and dust will be generated, and the rice will not be crushed. The problem was that the particles adhered to the surface of the core, making cleaning work in the next process complicated.

Therefore, the present inventor further conducted experiments using various particles, and found polypropylene as a particle that can replace rice and improve the above-mentioned drawbacks.

That is, the present invention provides a deburring device for cores made of shell sand, with a particle size of 1.0 mm to 7.0 mm and a thickness of 2 mm to 3 mm.
mm, specific gravity 0.7~1.5, Rockwell hardness 90~110,
A core characterized in that cylindrical resin particles having a heat resistance of 80°C or higher are projected toward a foundry core at a speed of 1 m/sec to 15 m/sec to remove burrs from the core. This is a method for removing burrs, and by using the method of the present invention, burrs can be removed without roughening the surface of the core.Since particles are projected, the method does not affect the shape of the core. Not only can burrs be removed, but it can also prevent increases in running costs, deterioration of the working environment, and complication of cleaning work due to crushing like rice.

Hereinafter, one embodiment of the present invention will be specifically described.

FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention, in which a conveyor 1 conveys cores 2, and a projection chamber 3 is provided on the upper surface of the conveyor 1. In this projection chamber 3, a large number of plastic strips are hung in the form of blinds at the bottom of the left and right walls, and cores 2 transported by a conveyor 1 are carried into the projection chamber 3.
It allows it to be carried out. Two rotors (impellers) 4 are provided in the projection chamber 3 in the conveying direction of the conveyor 1, and a receiving port of the rotor 4 is connected to a reservoir 5 provided at the upper part of the projection chamber 3. The guide 6 is connected to the projection port of the rotor 4 and is formed to ensure that the projectile from the rotor 4 hits the core 2.
Incidentally, polypropylene particles 7 are stored in the reservoir 5. The pedestal 8 is provided below the projection chamber 3 and below the conveyor 1 on the left side of the projection chamber. The transport pipe 9 has one end connected to the lower end of the pedestal 8 and is connected to the upper end of the separator 11 via a pump 10. The separator 11 consists of a first sieve 12, a second sieve 13, and a sand reservoir 14, and the meshes of the first sieve 12 contain polypropylene particles 7 and casting sand (shell sand).
The openings of the second sieve 13 are large enough to not allow the polypropylene particles 7 to pass through, but to allow casting sand to pass through. A pipe 15 connected to the reservoir 5 is opened at the left end of the upper surface of the second sieve 13, and a sand reservoir 14 is located on the lower surface of the second sieve 13.

In the above configuration, the core 2 formed from shell sand (foundry sand) in a mold and fired has a temperature of approximately 300°C, and is transported by a transport means (not shown) and placed on the right end of the conveyor 1. place Then, the conveyor 1 moves the core 2 to the left and carries it into the projection chamber 3. Then, since the polypropylene particles 7 supplied from the reservoir 5 are projected from the rotor 4 toward the conveying surface of the conveyor 1, the polypropylene particles 7 collide with the core 2, causing burrs to protrude around the core 2. removed. Then, when the core 2 is carried out from the projection chamber 3 and reaches the left end of the conveyor 1, it is carried out from the conveyor 1 by another conveyance device. Further, the flash and polypropylene particles 7 removed from the core 2 fall onto a pedestal 8, and from the lower end of this pedestal 8, they are passed through a transport pipe 9 by a pump 10 to the upper end of a separator 11, and are passed through a first sieve 12. fall on top. Then, the polypropylene particles 7 are filtered through the first sieve 12.
Larger diameter debris and sand clumps are removed,
The casting sand and polypropylene particles 7 fall onto the second sieve 13. Then, the casting sand passes through the second sieve 13 having a fine diameter and falls into the sand basin 14. Furthermore, since the second sieve 13 is tilted to the left, the polypropylene particles 7 move on the second sieve 13 toward the left end, enter the pipe 15 opened at the left end, and slide inside the pipe 15. It falls and is stored in reservoir 5.

In addition, the above polypropylene particles (specific gravity 0.9, Rockwell hardness around 100, particle size 5 mmφ, thickness 2~
3 mm) is projected at a speed of 4 to 5 m/sec, and the projection time is 3 to 5 seconds per burr.

When the polypropylene particles 7 were projected onto the burrs of the core 2, the burrs were completely removed and the skin of the core was in good condition without becoming rough. In the above embodiment, the polypropylene particles were projected by the rotor 4, but they may also be blown away by air pressure.

The particle size was set to 1.0 to 7.0 mm, but if it is less than 1.0 mm, the particles are too small and burrs cannot be removed sufficiently.
If it exceeds 7.0 mm, the grains are too large and will roughen the skin of the core, and small burrs cannot be removed. Preferably, the particles are cylindrical with a diameter of 5 mm and a thickness of 2 to 3 mm, and the corners of the particles are preferably rounded so as not to roughen the skin of the core.

The specific gravity was set to 0.7 to 1.5, but if it was less than 0.7, sufficient impact could not be applied to the burrs and the burrs could not be removed.
Also, if it exceeds 1.5, it is too heavy and may irritate the skin of the core.

The hardness was set to Rockwell hardness 90 to 110, but 90
If it is less than 110, it will be too soft to remove burrs, and if it exceeds 110, it will be too hard and will irritate the skin of the core. The core is fired at a maximum temperature of approximately 300℃.
℃, but since the time that the particles are in contact with the core is only a few seconds, the heat resistance temperature of the particles is set at 80℃ or higher, since it can withstand temperatures as high as 80℃.

Further, in the above embodiment, the projection speed of the polypropylene particles 7 was set to 4 to 5 m/sec, but in the case of the method of the present invention, this speed can be variously selected depending on the specific gravity and hardness of the particles, and the hardness of the core. But 1
m/sec to 15 m/sec is preferred.

As described above, compared to the conventional rice projection, the present invention has the following advantages:
It has many merits.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a schematic diagram of particles of the present invention. 1: conveyor, 2: core, 3: projection chamber, 4: rotor, 7: polypropylene particles, 8: pedestal, 1
1: Separation.

Claims (1)

[Claims] 1 In a deburring device for shell sand cores, particle size is 1.0 mm to 7.0 mm, thickness is 2 mm to 3 mm, specific gravity is 0.7 to 1.5,
Projecting cylindrical resin particles with a Rockwell hardness of 90 to 110 and heat resistance of 80°C or higher toward a foundry core at a speed of 1 m/sec to 15 m/sec to remove burrs from the core. A method for removing burrs from cores.