JPS6146268B2 - - Google Patents

Description

[Detailed description of the invention]

The purpose of this invention is to rotate a barrel tank loaded with a workpiece and media in an eccentric and inclined state to generate a tornado-like flow circulation in multiple layers in the mass, thereby achieving a precision polishing finish on the workpiece. Regarding the tornado flow finishing method. The dry media used in this finishing method is, for example, corn cobs, walnut shells, wood chips, or these coated with a finely powdered abrasive such as chromium oxide, aluminum oxide, or cerium oxide using carnauba wax or oil as a medium. In the case of inorganic abrasives, it can also be used wet. Barrel finishing methods are roughly divided into three types: rotating barrel finishing method, vibrating barrel finishing method, and centrifugal barrel finishing method.
Although the rotating barrel finishing method provides extremely good surface roughness of polished workpieces, it has the disadvantage that it requires a large amount of polishing time. In addition, although the vibrating barrel finishing method is easy to automate and has several times the polishing power compared to the rotating barrel finishing method, it has the disadvantage of requiring a large amount of polishing time when dry polishing small parts, just like the rotating barrel finishing method. . The polishing efficiency of the centrifugal barrel finishing method is several tens of times higher than that of the rotating barrel finishing method, but there are problems such as it takes a lot of time and effort to attach and remove the lid, automation is extremely difficult, and heavy work is required. There was a risk that dents would occur when polishing objects. However, as shown in FIG. 1, this invention makes the barrel tank 1 eccentric in distance with respect to the vertical main axis Y and tilts it by θ degrees so that the upper side faces inward, and each point of the barrel tank is always in the same direction. while maintaining
In other words, since it rotates at high speed on the same self-trajectory centering on the vertical main axis Y without rotating in space, the contents in the barrel tank (a mixture of workpieces and media - hereinafter collectively referred to as mass) ), as shown by reference numeral 2 in Figure 2, forms multiple layers horizontally and causes a tornado-like flow circulation, and even when multiple types of workpieces are charged at the same time, they are separated vertically depending on their specific gravity and mass. Since the fluid circulates and flows, there will be no collision between the workpieces and there is no risk of creating dents or impressions. In addition, the polishing efficiency is so huge that it surpasses the centrifugal barrel finishing method.
Furthermore, since the barrel tank is always tilted inward and rotated, the mass does not fly out to the outside, wear on the inner wall of the barrel is minimized, and there is no need to attach or remove the lid in the centrifugal barrel finishing method, which saves a lot of time. This method has succeeded in creating a completely new barrel finishing method that solves all the drawbacks of the conventional barrel finishing method, such as reducing labor and labor. An example of an apparatus for carrying out this invention will now be described with reference to FIG. That is, the rotating body 6 is placed on the base 8.
is installed horizontally so as to be rotatable, and the rotating body 6
is rotated via an electric motor 3, a pulley 4, and a belt 5. An adjustment disc 7 for adjusting the eccentric distance and the angle of inclination θ degrees is screwed onto the rotating body 6, and a barrel case 9 to which the barrel tank 1 is attached is rotatably supported on the adjustment disc 7. There is. The barrel tank 1 can be adjusted to an appropriate eccentric distance and inclination angle by rotating the adjustment disc 7 about its axis inside the rotating body 6. That is, the shaft of the barrel case 9 (barrel tank) and the rotating body 6
When the axes coincide, the eccentricity distance is 0 and there is no inclination angle. Furthermore, the structure is such that as the eccentric distance increases, the inclination angle also increases. The barrel tank 1 (a barrel case may also be used) is connected to the other end of a spring 11, one end of which is attached to a support 10 installed on the base 8, so that even when the rotating body 6 is rotated, the spring does not move. Due to the tension of 11, the shaft of the barrel case 9 idles within the bearing of the adjustment disc 7. Therefore, the barrel tank 1 does not rotate with respect to space. In addition to the cylindrical shape shown in FIG. 3, the shape of the barrel tank 1 may be an inverted tapered truncated cone shape as shown in FIG. 4. The diameter of this shaped barrel tank increases as it goes upwards, so
During polishing, the mass inside the barrel tank becomes more stable and can be prevented from flying out to the outside. Next, as an example of this invention, the eccentric distance is 2.5 mm ~
35mm, eccentricity/r (%) 7.1~100, inclination angle 1
The results shown in Table 1 were obtained by conducting an experiment under various conditions at a rotation speed of 1800 rpm to 800 rpm.

【table】

[Table] This example uses the device shown in Figure 3 and a small diameter of 70 mm.
A dry media SMC manufactured by Shikishima Chippton Co., Ltd. was installed using an inverted truncated conical barrel shown in Fig. 4 with a large diameter of 113 mm, a height of 130 mm, and an internal capacity of 0.86.
Made of brass using 30 (walnut shell) 28ψ×8mm, 41.8
Performance tests were conducted on the amount of polishing and surface roughness using the test piece No.g and varying the eccentricity distance (eccentricity ratio [eccentricity distance/barrel tank bottom radius]), inclination angle, and rotation speed. In addition, as a comparative example, using the same test piece and the same media, a vibrating barrel finishing machine CQ-20 manufactured by Shikishima Chippton Co., Ltd. (inner capacity 20
, media 100% charging) and centrifugal barrel finishing machine
HS-1-4V (content 1, media 50% charged)
The results of the tests conducted are also listed. As is clear from Table 1, the barrel finishing method of the present invention had much better polishing efficiency and improved surface roughness than the vibrating barrel finishing method. In addition, even compared to the centrifugal barrel finishing method, which was conventionally considered to have the best polishing efficiency, when a certain eccentricity distance (eccentricity ratio) is exceeded, the polishing amount exceeds that of the centrifugal barrel finishing method.
The finished surface roughness showed the best surface roughness as well as the finished surface of the rotating barrel. (See Table 1) Especially when the eccentricity is
40% to 60%, tilt angle 8 degrees to 10 degrees, rotation speed
It became clear that the polishing ability was increased and improved compared to the centrifugal barrel finishing method in the case of 1000rpm to 1300rpm. Such achievements could not be confirmed with any barrel polishing method and equipment in the world, but only if the eccentricity was 85% and the rotation speed was
If the speed exceeds 1700 rpm, a bubbling (resonance) state occurs and polishing becomes impossible, so this limit must be taken into consideration. In addition, the eccentricity is less than 15% and the rotation speed is
If the speed is less than 800 rpm, the amount of polishing will be extremely reduced and it cannot be used for practical work. The inclination angle is the eccentricity distance (eccentricity)
It may be selected as appropriate depending on the number of rotations, but it is desirable to select 1 degree to 15 degrees, most preferably 8 degrees to 10 degrees. Table 2 and FIG. 5 are examples of applications of this invention. As is clear from FIG. 5, the fluidization position (height within the fluidized bed) of the workpiece has a nearly linear relationship with the weight per unit surface area (g/cm ² ) of the workpiece. In other words, multiple types of workpieces can be efficiently polished simultaneously without any dents.

[Table] As mentioned above, this invention makes the barrel tank loaded with workpieces and media eccentric and tilts inward, allowing it to rotate at high speed without rotating relative to the space, thereby achieving centrifugal barrel finishing. We were able to obtain polishing ability and surface roughness that exceeded the standard.
In addition, even if multiple types of workpieces are input, the flow position differs depending on the weight per unit surface area, so multiple types of workpieces can be efficiently polished at the same time without dents. be. still,
Furthermore, in addition to dry media, the finishing method of this invention can also use dry or wet porcelain media, organic media, fused aluminum oxide media, magnetic chips, etc., and is within the technical scope of this invention. It goes without saying that it belongs.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram showing the state of the barrel tank used in the barrel finishing method of this invention, Fig. 2 is a diagram showing the flow state of the mass in the barrel tank, and Fig. 3 is a front view of the apparatus for carrying out this invention. , FIG. 4 is a perspective view of an inverted truncated conical barrel tank, and FIG. 5 is a graph showing the flow position of the workpiece. 1... Barrel tank, 2... Mass, 3... Electric motor, 4... Pulley, 5... Belt, 6... Rotating body, 7... Adjustment disc, 8... Base, 9... Barrel case, 10... Support column,
11...Spring.

Claims (1)

[Scope of Claims] 1. A cylindrical barrel tank is eccentric with respect to the vertical main axis by 15% to 85% of the bottom radius of the barrel, and is inclined inward by 1° to 15°, and a predetermined amount of water is provided inside the barrel tank. A workpiece and an appropriate amount of media are charged, and the barrel is rotated at 800 rpm to 1700 rpm around the vertical main axis without rotating relative to the space so that each point of the barrel tank is always maintained in the same direction. Tornado flow finishing method, which is characterized by polishing. 2. The tornado flow finishing method according to claim 1, wherein the barrel tank is cylindrical or inverted truncated conical. 3. Set the eccentricity to 40% to 60% of the barrel bottom radius, set the inward inclination to 8 degrees to 10 degrees, and set the number of rotations to 1000 rpm.
~1300rpm The tornado flow finishing method according to claim 1. 4. The tornado fluid finishing method according to claim 1, in which one or more types of workpieces are used.