JPS6029376Y2 - Tension adjustment device with overtension prevention device for endless running belt - Google Patents

Description

[Detailed description of the invention] The present invention is a tension system in which an endless running band is placed on a tension roll, and the axis of the roll is moved by rotation of a tension adjustment screw shaft to adjust the degree of tension on the endless running band. In the adjustment device, the tension adjustment of the endless running band with an overstrain prevention device is configured to make the adjusting screw shaft unrotatable immediately before the endless running band becomes overstressed due to overrotation of the tension adjusting screw shaft. The object of the present invention is to provide a tension adjustment device that effectively prevents breakage accidents due to excessive tension of an endless running belt.

An embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a pipe cutting machine 1 according to the present invention, in which a movable frame 4 is swingably supported by a shaft 3 of a mounting base 2.
A positive rotation roll 6 driven by a motor 5 is pivotally supported on one side of the frame 4, and a tension roll 7 of the present invention is installed on the other side to form an endless hacksaw band 8, which is a type of endless running band. The exposed running portion 9 connects the pipe a.
cut.

The tension roll 7 is a metal fitting 1 attached to the frame 4.
A shaft body 1 that partially slides freely through a long hole 11 formed at 0
A thrust bearing 17 is also interposed between the side surface of the central portion of the roll 7 and the step of the large diameter portion of the shaft 13.

A square part 14 that moves in contact with the edge of the elongated hole 11 is provided on the outside of the shaft body 12, and a screw hole 15 parallel to the longitudinal direction of the elongated hole 11 is formed therethrough.

A lock fitting 18 that is perpendicular to the longitudinal direction of the elongated hole 11 is integrally attached to a part of the frame 4, and the through hole 19
Then, the tension adjusting screw shaft 20 is loosely inserted almost tightly from the outside of the frame 4, and the adjusting screw 21 at the inner end is screwed into and passed through the screw hole 15 of the square part 14.

An integral structure of an enlarged diameter portion 22, a flange 23, and a handle 24 is fitted onto the tension adjustment screw shaft 20 on the outside of the lock fitting 18, and is fixed. Spring 25 loosely wound around portion 22
Interpose.

Further, the lock fitting 18 is provided with a stop engager 27 that protrudes outward due to the elasticity of the second spring 26, and the stop engager 27 is attached to the inner end surface of the enlarged diameter portion 22 of the tension adjusting screw shaft 20 as the spring 25 is compressed. Engagement large part 2 that fits into
8 will be provided.

As shown in FIG. 6, guide slopes 27' and 2B' are provided on either or both of the stop engager 27 and the large engagement portion 28 to allow the tension adjusting screw shaft 20 to rotate freely in the direction of decreasing tension. establish.

To explain the operation of this embodiment, the bundle 24 is rotated, for example, clockwise, and the shaft body 12 is moved in the direction of the arrow in FIG. .

While the adjustment tension of the endless hacksaw band 8 is appropriate, the spring 2
The tension adjusting screw shaft 20, the shaft body 12, and the tension roll 7 are pulled by the elasticity of the part 5, and the large engaging portion 28 of the enlarged diameter portion 22 is not fitted into the stop engaging element 27 as shown in the figure, and the rotation is prevented. Be free.

When the tension roll 7 is pulled to the maximum tension pressure by the tension adjustment screw shaft 20, a slight overtension is generated in the endless hacksaw band 8, and the tension roll 7 and the shaft body 12 are
It becomes impossible to move in the direction of the arrow in the figure.

In this state, remove the tension adjustment screw shaft 20! 24
As the adjustment screw shaft 20 continues to turn, the adjustment screw shaft 20 moves in the direction opposite to the arrow in the screw hole 15 of the square part 14 while compressing the jig 25, and the stop engager 27 is moved to the second position at the end face of the enlarged diameter part 22.
Pushing against the spring 26, the large engaging portion 28 finally searches and fits the engaging element 27, making it impossible for the bundle 24 and the tension adjusting screw shaft 20 to rotate in the tension increasing adjusting direction.

The device of the present invention has an enlarged diameter portion 22 of a tension adjusting screw shaft 20.
A configuration in which the tension of an endless traveling band 8 such as an endless hacksaw band is adjusted by a tension roll 7 by freely rotating the tension adjusting screw shaft 20 within a range where the end face of the frame 4 does not contact the stop engaging element 27 projected from the frame 4. When the screw shaft 20 is rotated excessively in the tension increasing direction, the spring 25 is compressed, and the stop engager 27 ejected from the frame 4 side and the end surface of the enlarged diameter portion 22 of the tension adjusting screw shaft The engagement of the large engaging portions provided in the screw shaft 20 makes it impossible to rotate the screw shaft 20, effectively preventing excessive tension that would cause the endless running band 8 to break, and at the same time increasing the tension of the adjusting screw shaft 20. This has the effect of warning that the endless running belt 8 is becoming overstrained due to the fact that rotation in the direction is no longer possible.

[Brief explanation of the drawing]

The attached drawings show one embodiment of the present invention, with Fig. 1 being a schematic side view, Fig. 2 being an enlarged front view of the main parts, and Fig. 3 being Fig. 2 A-A.
Figure 4 is a cross-sectional view taken along the line B-B in Figure 3.
The figure is a front view of the enlarged diameter portion 22, etc., and FIG. 6 is a partial perspective view. 4...Frame, 6...Positive rotation roll, 7...Tension roll, 8...
Endless running band (endless hacksaw band), 11...long hole,
12...Shaft body, 15...Screw hole, 16
...Bearing, 18...Tatsuku metal fittings,
19...Through hole, 20...Tension adjustment screw shaft, 21...Adjustment screw, 22...
- Expanded diameter part, 23... collar, 25... spring, 26... second spring, 27... stop engager, 28... ... Part of the engagement.

Claims (1)

[Scope of utility model registration request] A shaft body 12 that allows the long hole 11 to move freely in the longitudinal direction is passed through a long hole 11 provided in the frame 4, and the tension roll 7 is fitted into the tension roll 7 that is rotatably supported by the shaft body 12. At the same time as hanging the endless running belt 8,
A tension adjustment screw shaft 20 that is freely slidably inserted into the frame from the outside is screwed orthogonally to the shaft body 12, and a flange 2 is provided on the outside of the frame 4 of the adjustment screw shaft 20.
A spring 25 wound around the adjustment screw shaft 20 is interposed between the adjustment screw shaft 20 and the frame 4, and a second spring 25 is installed in the frame.
A stop engager 27 is provided which protrudes outward with the elastic force of 6.
An enlarged diameter portion 22 corresponding to the outer surface of the frame of the screw shaft 20
A tension adjusting device with an overtension prevention device for an endless running band, characterized in that an engaging top portion 28 is provided which fits into the stop engaging element 27 when the spring 25 is compressed.