JPS6348375Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a curved surface polishing device in which the grinding wheel is rotated about two axes.

For example, finishing of free-form surfaces such as mold cavities for plastic molding has been performed using ball end mills with spherical tips or grindstones with a shaft.
In this case, the grinding speed varies depending on the inclination angle of the finished surface, and in particular, at a position where the inclination angle is 0°, the speed becomes 0, which has the disadvantage that uniform finishing cannot be achieved. To overcome such drawbacks, a so-called two-axis rotation type polishing device uses a grinding wheel whose grinding surface has a partially spherical shape and rotates the grinding wheel around two axes, a horizontal axis and a vertical axis. has been developed, but in order to polish a curved surface with a large curvature, the diameter of the grinding wheel must be made small, so the diameter of the grinding wheel is limited. Furthermore, it is necessary to increase the width of the grinding wheel in order to improve the finish of the inclined surface, enable heavy grinding, and extend the life of the grinding wheel. However, in order to enable curved surface polishing with a wide range of curved angles, it is desirable to fit the area around the bearing of the grinding wheel within a spherical surface whose diameter is the diameter of the grinding wheel.Since the allowable space around the bearing is limited, the width of the grinding wheel must be made sufficiently large. In this case, the belt width of the timing belt as a transmission member cannot be set sufficiently, and belt damage becomes the biggest problem.

Therefore, with the prior art, only a light grinding finish can be performed, and the peripheral portion of the bearing, particularly the belt, is damaged much earlier than the life of the grinding wheel, which shortens its life.

The purpose of the present invention is to solve the above-mentioned problems of the conventional technology. Therefore, the purpose of the present invention is to improve durability by preventing the bearing peripheral area, especially the transmission belt, from being easily damaged, and to withstand medium or heavy grinding. It is an object of the present invention to provide a two-axis rotary curved surface polishing device having a structure that provides the following advantages.

In order to achieve the above object, the characteristics of the polishing device according to the present invention are that the support shaft of the grinding wheel is supported at both ends by bearings, and the transmission device for rotating the grinding wheel via the support shaft is installed on both sides of the grinding wheel. It consists of a pair of symmetrical transmission belts, and each bearing is placed outside the transmission to increase the total belt width and improve balance.

Next, embodiments of the present invention will be described with reference to the drawings. Fig. 1 shows a two-axis rotating curved surface polishing device to which the present invention relates, and this type of device shows a main shaft 1 rotated by a suitable drive device such as a motor, and a main shaft 1 that is rotatable with respect to the main shaft 1. a support 2 that is installed on the shaft and rotatably supports the main shaft 1; a first bevel gear 3 that is fixed to the support 2 and serves as a sun gear; A freely provided horizontal shaft 4, a pair of second bevel gears 5 which mesh with the bevel gear 3 and which are provided on the horizontal shaft 4 and serve as planetary gears, rotate perpendicularly to the main shaft at the tip of the main shaft 1. A grinding wheel 7 attached to a freely provided support shaft 6 and a support shaft 6
and a transverse shaft 4 . One of the second bevel gears 5 is fixed to one end of the horizontal shaft 4, and the other bevel gear 5 is rotatably attached to the other end of the horizontal shaft 4 for balance. The grinding surface of this grinding wheel 7 has a partially spherical shape.

In such a curved surface polishing device, as the main shaft 1 rotates, the horizontal shaft 4 also rotates, and the bevel gears 5 at both ends also revolve along the bevel gear 3 and rotate at the same time, so the horizontal shaft 4 also rotates. This rotation of the horizontal shaft 4 is transmitted to the support shaft 6 via a transmission device, and the grinding wheel 7 is rotated around the support shaft 6. The grinding wheel 7 is also rotated about the main shaft 1 at the same time. Therefore,
Since the grinding wheel undergoes a synthetic motion, the change in grinding speed due to the angular position of the grinding wheel is small, and since the grinding wheel alternately grinds in opposite directions every half rotation of the main shaft 1, an excellent finished surface is obtained.

The present invention is characterized by a support structure for the grinding wheel 7 and a transmission system therefor, and as shown in FIG. 2, the support shaft 6 is supported at both ends by a pair of bearings 9 and 10. The horizontal shaft 4 also has a pair of bearings 1.
1 and 12, it is rotatably provided on the main shaft 1.
In order to increase the width of the grinding wheel and the total belt width, it is preferable to fix support pieces 13 of the same shape on both sides of the main shaft 1, in which case each bearing is attached to a corresponding support piece 13. Note that in some cases, this support piece 13 is provided only on one side of the main shaft. Each support piece 13 is fixed to the main shaft 1 by a mounting bolt 14 provided on the side surface. The grinding wheel 7 is located at the center of the support shaft 6 between the bearings 9 and 10 and is installed to coincide with the center line of the main shaft 1.

The transmission device that transmits the rotation of the horizontal shaft 4 to the support shaft 6 is composed of a belt transmission device, and each transmission device is preferably composed of timing belts 15 and 16 as shown. These timing belts 15, 16 are arranged inside the bearings of the support shaft 6, that is, between the bearings, in order to increase the bearing spacing. Therefore, the pair of toothed wheels 17 and 18 on which the timing belt 15 is hung are located closer to the main shaft 1 than the bearing 11 of the horizontal shaft 4 and the bearing 9 of the support shaft 6, respectively.
The toothed wheels 19 and 20 on which the bearings are hung are also installed closer to the main shaft 1 than the bearings 10 and 12, respectively.

During operation, the horizontal shaft 4 is rotated by the rotation of the main shaft 1 as described above, and the rotation of the horizontal shaft is transmitted to the support shaft 6 by the pair of timing belts 15 and 16, and the grinding wheel 7 is rotated.
rotates around the support shaft 6 and also rotates around the main shaft 1. In one example, the grinding wheel 7 is centered around the main shaft 1.
It rotates at a high speed of 800 rpm and about 2000 rpm around the support shaft 6 to perform polishing work. In this device, the timing belts 15 and 16 are installed symmetrically and between the grinding wheel and the bearing 9 or 10, respectively, so the balance is good and the total belt width can be increased without increasing the space around the bearings. . Therefore, together with the large bearing spacing, there is little lateral runout and the behavior during grinding is stable. Furthermore, since a pair of timing belts are used, the load applied to the bearings 11 and 12 of the horizontal shaft 4 is well balanced and stably distributed evenly. Note that a normal belt may be used as the transmission device instead of the timing belt, and in these cases, the transmission device is similarly arranged inside the bearing.

Therefore, according to the present invention, the bearings of the support shaft of the grinding wheel that intersects with the main shaft in a two-axis rotary curved surface polishing device are installed with large bearing intervals, and the total belt width can be increased, so that the width of the grinding wheel can be increased. It allows the use of large grinding wheels, is favorable in terms of grinding performance, and can maintain a long service life.

Therefore, even if a grinding wheel with excellent wear resistance such as a CBN grinding wheel is used, a situation where the belt is damaged first can be avoided, and such a grinding wheel can be suitably used.

Therefore, it becomes possible to perform not only light grinding as in the conventional method, but also medium grinding or heavy grinding. In addition, since the transmission device is placed inside the bearing for supporting the grinding wheel, there is a tip of the main shaft or a support piece on the outside. It is also easily possible to fit the part within an imaginary spherical surface whose diameter is the diameter of the grinding wheel, and in this way it is possible to polish any curved surface from horizontal to vertical. On top of that,
Since both sides are driven, the width of the belts on both sides can be reduced depending on the case, and the bearing on the horizontal shaft can be made relatively large if desired.

[Brief explanation of the drawing]

FIG. 1 is a schematic elevational view of a conventional two-axis rotary curved surface polishing apparatus, FIG. 2 is a vertical cross-sectional view of the main part of a preferred embodiment of the present invention, and FIG. 3 is a side view of the main part. In the figure, 1...Main shaft, 2...Support, 3...First
bevel gear, 4...horizontal shaft, 5...second bevel gear, 6...support shaft, 7...grinding wheel, 9, 10...
Support shaft bearings, 11, 12...Horizontal shaft bearings, 1
5,16...Transmission device.

Claims (1)

[Claims for Utility Model Registration] (1) A rotationally driven main shaft, and a first shaft rotatably installed on the main shaft and fixed to a support of the main shaft.
a bevel gear, a horizontal shaft passing through the main shaft and rotatably installed by a pair of bearings, each meshing with the first bevel gear, one of which is fixed to the horizontal shaft, and the other is fixed to the horizontal shaft. a pair of second bevel gears that are rotatably provided; a grinding wheel that is rotatably provided at the tip of the main shaft and has a grinding surface partially shaped as a spherical surface; In a polishing device including a transmission device installed between orthogonal support shafts and the horizontal shaft to transmit power therebetween, the support shaft of the grinding wheel is supported at both ends by bearings, and the transmission device is connected to both sides of the grinding wheel. 1. A curved surface polishing device comprising a belt provided on the support shaft, and each of the pair of bearings of the support shaft being provided on the outside of the transmission device. (2) The curved surface polishing apparatus according to claim 1, wherein the transmission device is a timing belt.