JPS6325913B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polishing machines, particularly pneumatic polishing machines.

There are two types of polishing machines known in the past: a double-cushion sander in which the polishing pad moves in double rotation, and an orbital sander in which the polishing pad moves in an orbital motion. The reality is that these two types of polishing machines are used together to compensate for their shortcomings in order to achieve a polished finish. Therefore,
In practice, these two types of polishing machines must be prepared, and polishing with only one type of polishing machine requires a high level of skill.

In view of the above points, it is an object of the present invention to provide a polishing machine that can perform the functions of a double action sander and an orbital sander by a simple switching operation.

This purpose is to provide an abrasive material mounting pad that is rotatably supported by an eccentric drive unit that is rotated by a motor built into the main body of the polisher, and the rotation of the eccentric drive unit moves the pad into a double rotational motion. The polishing machine is configured to have an annular operating member that is arranged to be movable up and down with respect to the polishing machine body around an eccentric drive part, and an annular operating member that is fixed to the lower surface of the annular operating member and whose upper and lower ends are relatively movable. at least one pair of displaceable struts; and an annular restraining member affixed to the lower ends of the struts and frictionally engaging an upper surface of the pad when the annular actuating member is brought to a lower limit position. The invention is solved by a polishing machine characterized in that the pad can be moved in an orbital manner by moving the annular actuating member to the lower limit position.

The present invention will be described below with reference to an embodiment shown in the drawings. 1 incorporates an air motor 2 of a known structure, rotatably supports its rotating shaft 2a at two upper and lower positions, and supplies air to the air motor 2. It includes an air supply passage 1a for introducing air, an air valve 1b that opens and closes the air supply passage 1a by operating a lever 1b', and an exhaust passage 1c that surrounds the air supply passage 1a and also serves as a grip part. The main body of the polishing machine, 3 is a cover fixed to the lower side of the main body 1, 4 is an eccentric drive unit of a known structure attached to the lower end of the rotating shaft 2a of the air motor 2, and the lower side is used for polishing with an eccentric amount e. The pad 5 is attached by rotatably bearing a boss portion 5a protruding from the pad 5 for attaching the material. The above structure is the same as that of a conventionally known double action sander in which the polishing pad performs double rotational motion, and the operation is also similar. 6 is cover 3
The air piston is an annular air piston that is airtightly fitted into an air cylinder 3a in the form of an annular groove provided downward on the inner surface of the air cylinder 3a so as to be able to move up and down.
Its lower limit position is regulated by a stroke adjustment rod 7 screwed onto the bottom surface of the rod, and a spring 7a imparts an upward movement and prevents rotation in the circumferential direction. As shown in Fig. 2, 8 is made of at least one (three in the figure) an elastic material such as rubber arranged at equal angular intervals on the lower surface of the air piston 6, and the axially central part thereof is slightly recessed. Cylindrical columns (see FIG. 3), 9 are at least one inelastic column disposed on the lower surface of the air cylinder 6, each facing the column 8, as shown in FIG. This is an annular restraining member that is fixed to the lower side of the pillars 8 and 9 and that presses against and frictionally engages the upper surface of the pad 5 when the air piston 6 is brought to the lowering limit position.
Note that the support column 9 includes a disk portion 9a having a relatively large diameter fixed to the air piston 6, a steel ball tray portion 9b supported by a restraining member 10 fixed to the support column 8, and the disk portion 9a. and a steel ball 9c held between a steel ball receiving tray 9b and a steel ball 9c, which prevents friction from the orbital movement of the pad 5 due to the rotation of the air motor 2 when the restraining member 10 is pressed against the upper surface of the pad 5. Even when the restraining member 10 cannot be effectively pressed against the pad 5 due to deformation of the elastic strut 8, the steel ball 9c rolls on the disk portion 9a and the steel ball receiving tray portion 9b contacts the disk portion 9a. On the other hand, the restraining member 10 is displaced in the lateral direction so that the restraining member 10 continues to be pressed against the pad 5 evenly and reliably. Reference numeral 11 denotes a spool valve for introducing air into the air cylinder 3a, and when ON, the passage 12 branched from the air supply passage 1a is communicated with the passage 13 leading into the air cylinder 3a (Fig. 4B). (see FIG. 4A), and when OFF, it closes the passage 12 and connects the passage 13 to the exhaust passage 1c (see FIG. 4A).

Since the embodiment of the present invention is constructed as described above, when the spool valve 11 is turned OFF, no air is introduced into the air cylinder 3a, and therefore the air piston 6 is at the upper limit position as shown in FIG. 3A. Since the restraining member 10 is separate from the pad 5, the pad 5 is given a double rotary movement by the rotation of the air motor 2, and thus the sanding machine functions as a double action sander. When the spool valve 12 is turned ON from this state, the passage 12 is made to communicate with the passage 13 as shown in FIG. The restraining member 10 is brought to its lower limit position against the elastic force of the restraining member 7a.
is brought into pressure contact with the upper surface of the pad 5 to prevent double rotational movement of the pad 5, thus causing the pad 5 to move in an orbital manner, and the present polishing machine functions as an orbital sander. In order to make the pad 5 double rotation again, turn the spool valve 11.
This allows the passage 13 to communicate with the exhaust passage 1c, and the air in the air cylinder 3a is discharged by the negative pressure in the exhaust passage 1c, so that the air piston 6 returns to its upper limit position. I am forced to do it. In the above embodiments, an air motor is used as the drive source, but it goes without saying that an electric motor can also be used. However, when using an electric motor, it is necessary to prepare a dedicated compressed air source for driving the air piston, or to create and supply compressed air using the electric motor.

FIG. 5 shows another embodiment of the present invention, in which an annular actuating member 22 is fitted into a cover 21 fixed to the polishing machine body, and is fixed to the outer periphery thereof and provided on the side wall of the cover 21. By moving the lever 22a along the slot 21a by a lever 22a that engages with a diagonal slot 21a, it can be moved up and down. The restraining member 10 can be brought into pressure contact with the upper surface of the pad 5 via the constructed inelastic strut 24, but the operation of the polishing machine in its upper and lower limit positions is the same as in the previous embodiment. In this case, since the annular actuating member is manually driven, it can be easily used in an electric polishing machine or the like.

As described above, according to the present invention, a conventional double-action sander is equipped with an annular actuating member, a column whose upper and lower ends are movable relative to each other, and an annular restraining member to prevent the rotational movement of the pad. By changing the spool valve or lever, these parts can be moved up and down to switch between double-action sander and orbital sander functions, making it possible to use a single sanding machine efficiently without requiring advanced skills. Not only can the desired polishing finish be achieved, but when the polishing machine is used as an orbital sander, the restraining member and the top surface of the pad engage uniformly and frictionally over a relatively wide area, so the orbital movement of the pad can be prevented. It has the advantage of being carried out effortlessly and smoothly.

It goes without saying that in the first embodiment, a support 8 may be provided instead of the support 9, and the restraining member 10 may be supported only by the support 8.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the polishing machine according to the present invention, FIG. 2 is a bottom view of the air piston, and FIG. 3 is a sectional view of the polishing machine in FIG. 1 corresponding to the line direction of FIG. 2. A is a diagram showing the upper limit position of the air piston, B is a diagram showing the lower limit position, Figure 4 is a cross-sectional view taken along the line of Figure 1, and A is a diagram showing the spool valve when it is OFF, B is a diagram when it is ON, and Figure 5 is a diagram showing the spool valve when it is ON. A is a horizontal cross-sectional view, and B is a partially cutaway side view showing the main parts of another embodiment according to the present invention. 1... Main body, 2... Air motor, 3, 21... Cover, 4... Eccentric drive unit, 5... Pad, 6... Air piston, 7... Stroke adjustment rod, 8, 9... Support column, 10... Suppression member, 11... Spool valve, 1
2, 13... passage, 22... annular actuating member.

Claims (1)

[Claims] 1 A pad for attaching an abrasive material is rotatably supported by an eccentric drive part rotated by a motor built into the polishing machine body, and the pad is made to undergo double rotational movement by rotation of the eccentric drive part. The polishing machine includes: an annular actuating member disposed to be movable up and down with respect to the polishing machine body around an eccentric drive part; and an annular actuating member fixed to the lower surface of the annular actuating member so that upper and lower ends thereof can be relatively displaced. at least one pair of struts; and an annular restraining member secured to a lower end of the struts and frictionally engaging an upper surface of the pad when the annular actuating member is brought to a lower limit position; A polishing machine characterized in that the pad is caused to orbitally move by moving the annular actuating member to a lower limit position.