Patent Application
20160059372
The present invention relates to centerless grinding technique in which a work is grinded without supporting the rotation axis, the work being rotationally supported on the peripheral surface thereof. More particularly, the present invention relates to an infeed centerless grinding apparatus with an improved work efficiency when a number of works are continuously grinded.
In a centerless grinding apparatus, a work is grinded by, in a state where the work is rotationally supported on the peripheral surface thereof between a fixed blade and a rotating regulating wheel instead of being supported on the rotation axis thereof, pushing a rotating grinding wheel against the peripheral surface of the rotating work. In an infeed centerless grinding apparatus, the rotating axis of the regulating wheel is disposed in parallel with the rotating axis of the grinding wheel.
In
Assuming the straight line connecting the axial center of the regulating wheel 23 and the axial center of the grinding wheel 22 on the space of
The regulating wheel slide 25 mounted with the regulating wheel 23 and the blade 24 is driven by the regulating wheel slide driving mechanism 25a to move forward and backward in the directions indicated by the f-r arrow. The regulating wheel slide 25 is moved forward (in the direction of the arrow f) to bring the work Wa into contact with the grinding wheel 22 and to be fed for cutting in the same direction. The move, contacting and feeding can be relatively operated and, for example, the grinding wheel 22 may be mounted on a slide and driven to move in the direction of the arrow r.
As shown in
As shown in
In the prior art centerless grinding apparatus, the grinding wheel 22 after being grinded in the operation in
The inventor sought for, as a solution to the above-described problem, an apparatus in which the time for loading and unloading the work is shortened. In the centerless grinding apparatus, however, it is required that the loader carries in a work from above the grinder in a position sufficiently distanced from the grinder because grinding area is positioned between the large-sized grinding wheel and regulating wheel. This requirement causes the loader to have high weight center and, thus, the loader becomes instable.
In addition to the above, as the diameter of the work becomes small, the chucking part for chucking the work mounted on the end of the loader is required to be made small such that it causes the rigidity of the loader to be reduced.
The two problems described in the above become prominent particularly in that the accuracy of positioning of the work in the grinding area is lowered due to the vibration inevitably amplified by speeding up the operation of the loader. Particularly when the work has a low weight and when the work has an unbalanced weight, positioning of the work tends to be inaccurate due to the interference of the work and the grinder caused by the effects of the coolant pressure and the wind pressure (negative pressure) generated by the grinding wheel rotating at a high speed. Every time the positioning fails, it is required to adjust the loader and in some cases even the grinder is damaged.
In consideration of the above problems, it is an object of the present invention to provide a centerless grinding apparatus in which the efficiency of the grinding operation is improved by 30%. In order to achieve this purpose, the present invention proposes a novel idea that the above problems can be solved by making the grinder to be moved instead of speeding up the operation of the loader.
In the centerless grinding apparatus, a grinding wheel Z-slide 13 is mounted on bed 1. On the grinding wheel Z-slide 13 is mounted a grinding wheel 2. In
The grinding wheel Z-slide 13 reciprocatively moves in the direction of the Z axis as indicated by the arrow L-R. On the bed 1 is also mounted a regulating wheel slide 5. On the regulating wheel slide 5 is mounted a first regulating wheel 9 and a second regulating wheel 10 arranged parallel in the Z direction and aligned axially with respect to each other.
A first blade 41 is disposed facing the first regulating wheel 9 at a distance. The first regulating wheel 9 and the first blade 41 forms a grinding area in which a work (not shown in the figure) is supported and the work is grinded by the grinding wheel 2. The area is hereinafter referred to as a first grinding area 11. The regulating wheel slide 5 is fed for infeed cutting in the direction of arrow f on the X axis.
Similarly, a second blade 42 is disposed facing the second regulating wheel 10 at a distance. The second regulating wheel 10 and the second blade 42 forms a grinding area in which a work (not shown in the figure) is supported and the work is grinded by the grinding wheel 2. The area is hereinafter referred to as a second grinding area 12. The regulating wheel slide 5 is fed for infeed cutting in the direction of arrow f on the X axis.
In
During this grinding operation, the grinding wheel 2 may be traversed in its axial direction (the L-R direction in the figure) while it grinds the work. This grinding operation, hereinafter referred to as oscillation grinding, results in improvement of the surface roughness of the work as the cross hatch grinding traces formed on the surface of the work provides non-oriented uniform surface finishing.
After the above grinding operation is finished, the grinding wheel Z-slide 13 is moved in the direction indicated by the arrow L to be brought into such position that the grinding wheel 2 faces the first grinding area 11. In this position, another work is carried into the first grinding area 11 and grinded.
Similar to the above, oscillation grinding is operated in the first grinding area 11 by traversing the grinding wheel 2 in its axial direction (the L-R direction in the figure) while it grinds the work. This oscillation grinding operation results in improvement of the surface roughness of the work as the cross hatch grinding traces formed on the surface of the work provides non-oriented uniform surface finishing.
A feature of the first embodiment of the centerless grinding apparatus that the single grinding wheel is reciprocatively moved between the first grinding area and the second grinding area so as to grind the works in two grinding areas alternately.
While the grinding wheel 2 grinds the second work Wb in the second grinding area 12, the unloader 6 carries out (in the direction of the arrow a) the first work Wa which has been grinded in the first process. Accordingly, the loader 7 carries a third work Wc into the first grinding area 11 from which the first work Wa is removed.
In the above-described second process, the first work Wa is already grinded and carried out and the second work Wb is being grinded in the second grinding area 12 while the third work Wc is carried into the first grinding area 11.
The unloader 6 and the loader 7 a may be made of independent members or may be made integrally.
By repeatedly performing the second process and the third process in the above-described way, number of works are continuously grinded.
In the instant embodiment, the grinding wheel 2 moves forward and backward along the Z axis in the direction indicated by the arrow L-R whereas the regulating wheel slide 5 mounted with the wide width regulating wheel 14 moves forward and backward along the X axis in the direction indicated by the arrow f-r so as to perform infeed cutting.
In the instant embodiment, the grinding wheel 2 is mounted on a grinding wheel infeed slide 16 which moves forward and backward in the f′-r′ direction along with the X axis so as to feed a work for cutting to perform infeed centerless grinding.
In the instant embodiment, the grinding wheel 2 performs oscillation grinding and moves forward and backward in the direction of the arrow L-R along the Z axis while the regulating wheel slide 5 mounted with the wide width regulating wheel 14 moves forward and backward in the direction of the arrow f-r along the X axis so as to feed a work for cutting.
Using the grinding apparatus of the instant embodiment, it is possible to grind a long work efficiently without necessitating it to use two or more grinding apparatus or to change the set up of the grinding operation.
In the instant embodiment, the grinding wheel 2 is mounted on a grinding wheel infeed slide 16 which moves forward and backward in the f′-r′ direction along with the X axis so as to feed a work for cutting to perform infeed centerless grinding.
The wide width regulating wheel 14 performs oscillation grinding and the regulating wheel slide 15 mounted with the wide width regulating wheel 14 moves forward and backward in the direction of the arrow L′-R′ along the Z axis while the grinding wheel 2 moves forward and backward in the direction of the arrow f′-r′ along the X axis so as to feed a work for cutting.
Using the grinding apparatus of the instant embodiment, it is possible to grind a long work efficiently without necessitating it to use two or more grinding apparatus or to change the set up of the grinding operation.
In the centerless grinding apparatus according to the present invention, a single grinding wheel moves reciprocatively among two grinding areas. While the grinding wheel grinds a work in one grinding area, works are replaced in preparation for the next grinding process on the other grinding area where the grinding wheel is not present. This operation improves the substantial efficiency of the grinding processes because the idle time during replacement of the works is reduced.
In the centerless grinding apparatus according to the present invention, it is possible to grind a long work efficiently without necessitating it to use two or more grinding apparatus or to change the set up of the grinding operation.
It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to one skilled in the art without departing from the scope of the present invention. For example, the driving mechanism of the grinding wheel slide may be flexibly designed as long as it does not impair the an element of the present invention that one or both of the regulating wheel slide and the grinding wheel slide is moved in the axial direction thereof such that the grinding wheel is reciprocatively moved relative to two grinding areas.
