JPS632738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing circular cross-section bodies such as endless round packing and round belts.

Conventionally, various methods for manufacturing endless round packings, etc. are known, but one involves rotating a square cross-section annular material in a figure-eight shape and applying a grindstone to the twisted material to grind the cross-section into a circular shape. However, because the material does not rotate sufficiently or the twist angle tends to change at a constant cycle along the length of the material, the cross-sectional shape after grinding becomes asymmetrical along the length. It may happen. This tendency has a large effect when the material is an annular body having a bent portion such as a rectangular shape, and there remain portions that are not sufficiently ground, such as inside the bent portion. In an attempt to improve such drawbacks, the shaft on which the annular material is suspended is reciprocated in the axial direction,
A method of rocking has been proposed, but the device becomes complicated and is difficult to obtain economically.

In view of such circumstances, the present invention provides a guide groove that meanders in the rotational direction on the shaft that suspends the annular material, without reciprocating or swinging the shaft that suspends the annular material, and allows the grinding wheel to be removed from the guide groove. This method changes the progress of the material over time and changes the cycle of twisting of the material so that it can be ground uniformly into a round cross section.

This will be explained below along with examples.

In the figure, a main shaft 2 and a tension shaft 3 on which an annular material 1 is suspended have guide grooves 4 and 5, respectively.
The guide groove is formed directly on the main shaft, and the pulley 6 is provided on the tension shaft, and the guide groove is formed on the pulley. However, it is not possible to form either guide groove directly on the shaft or on the pulley. Can be done.
The grindstone 7 is provided close to the main shaft 2, and rotates in the opposite direction to the main shaft so as to grind the annular material 1 having a square cross section into a round cross section using a semicircular groove 8 formed around the main shaft. In addition, in the figure, the main shaft is driven, but the tension shaft may be driven.
The guide groove 5 of the tension shaft meanders in the rotational direction so that the position of the annular material toward and away from the guide groove of the tension shaft toward the guide groove of the main shaft changes over time in the axial direction of the tension shaft. The guide groove 5 is formed into a substantially V-shape with two inclined surfaces, and the length, angle, etc. of each inclined surface are adjusted so that the bottom part moves from one side of the groove width center to the other side as the groove rotates. It's a good idea to change it. 3 to 6 show changes in the state in which the annular material 1 is suspended in the guide groove of the tension shaft. In the state shown in FIG. As the tension shaft rotates, it moves away from the central position toward the main shaft in the state shown in Figure 4.
When it rotates to the position shown in FIG. 5, it leaves the position on the left side in the figure and heads toward the guide groove of the main shaft, and then again heads toward the main shaft from the approximately central position in the state shown in FIG. Thereafter, the changes shown in FIGS. 3 to 6 are repeated with rotation. When the guide groove shown in the figure is developed, the bottom of the groove is formed so that it reciprocates once in one rotation as shown in Figure 7. However, when the diameter of the tension shaft or pulley is large,
As shown in the figure, two or more reciprocations may be made. The amplitude of the reciprocation, that is, the amount of displacement in the axial direction, is preferably large, but can be determined as appropriate within a range that does not allow the material to come off the guide grooves of the main shaft and tension shaft. Further, the inclined surface needs to have a certain degree of inclination, and it is preferable to decide this in consideration of the relationship with the amount of displacement.

Therefore, if an annular material with a square cross section is suspended in the guide grooves 4 and 5 of the main shaft and the tension shaft in a substantially figure-eight shape and rotated, the material moving from the tension shaft to the main shaft will flow through the guide grooves of the main shaft. Twisting occurs when the angle with respect to the center line changes over time, and torsion also occurs when the tension shaft rolls on the inclined surface of the guide groove 5, and the twisting of the material in the guide groove of the main shaft is complicated. Therefore, the above-mentioned material is ground into a uniform round cross section by the grindstone 7.

The present invention is constructed as described above, and has a simple construction and can economically produce round cross-section annular bodies such as endless round packings and round belts.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a front view of the material suspended, Fig. 2 is a plan view, and Figs. 3 to 6 show the tension shaft suspended in the guide groove and each axis and cross section. FIGS. 7 and 8 are explanatory diagrams showing changes in the suspension state as the annular material rotates, and each is a developed view of the bottom of the guide groove of the tension shaft. 1... Annular material, 2... Main shaft, 3... Tension shaft,
4, 5...Guide groove.

Claims (1)

[Claims] 1. A guide groove is provided on the main shaft and the tension shaft, a square cross-section annular material is suspended between the guide grooves in a substantially figure-eight shape, and the twisted material is ground with a grindstone adjacent to the main shaft to produce a round cross-section annular body. The method is characterized in that the guide groove of the tension shaft is meandered in the rotational direction so that the position of the annular material toward and away from the guide groove of the tension shaft toward and away from the guide groove of the main shaft changes over time in the axial direction. A method for manufacturing a circular cross-section annular body.