JPH084251Y2 - Cutting prevention device for wire saw - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting prevention device for a wire saw used for cutting stone materials and reinforced concrete structures.

[0002]

2. Description of the Related Art The wire saw method is a method of cutting a reinforced concrete structure or a stone material by using a wire saw in which beads having electrodeposited or sintered granular diamond are attached to a wire. 53426
It is disclosed in Japanese Patent Publication No. 1-53427 and Japanese Patent Publication No. 53427/1989, and has the advantage that high efficiency cutting is possible and there is little influence on the surrounding environment.

By the way, in this type of construction method, a wire saw is wound around an object to be cut, such as reinforced concrete, and the wire saw is frictionally traveled by a drive pulley. An accident in which the wire saw is cut occurs due to caulking at the joint portion of the wire saw.
Of these causes of wire saw cutting, defective crimping of the joint can be solved by strict checking before work, etc., but when foreign matter etc. cuts into the cutting part and cutting resistance increases, cutting Is in a very difficult situation to predict.

The cutting of the wire saw due to the non-uniformity of cutting resistance usually occurs on the tension side of the wire saw.
If excessive tension is applied to the wire saw, it will be cut from the part with a large cutting resistance, but if the wire saw is cut in such a state, the wire saw will fly like a whip and fly to the drive pulley side, Harm to.

To address this problem, for example, Japanese Patent Publication No. 10955/1992 discloses a construction method in which a tunnel-shaped or tubular protection fence is provided on the outer circumference of a wire saw to be circulated. According to the construction method disclosed in this publication, the safety of workers and the like is secured, but there are technical problems described below.

[0006]

[Problems to be Solved by the Invention] That is, in the construction method disclosed in the above publication, a tunnel-shaped or tubular protective fence is installed on the outer periphery of the wire saw. However, in the actual construction, as the cutting progresses, the guide pulley is rescaled, and the cutting direction is not only horizontal but also vertical, and every time such reshaping or cutting direction changes, There is a problem that disassembling and assembling the protective fence is very troublesome and the cutting of the wire saw cannot be prevented.

Also, depending on the installation condition of the wire saw,
In some cases, it is impossible to install a protective fence, and when the wire saw is cut, it takes a considerable amount of time to connect the wires, resulting in a significant increase in work time.
The present invention has been made in view of such conventional problems, and the purpose thereof is to reduce the tension of the wire saw when excessive tension is applied to the wire saw, thereby cutting the wire saw. An object of the present invention is to provide a wire saw cutting prevention device.

[0008]

In order to achieve the above object, the present invention provides an endless winding between an object to be cut and a drive pulley, which is circulated and run under a predetermined tension. In a wire saw cutting prevention device for cutting an object, an idler sheave that applies a predetermined tension to the wire saw, an arm that supports this idler sheave on one end side, and the other end side of the arm with a set torque value. And a torque limiter that swingably supports and releases the support when a torque equal to or greater than the set torque value acts on the arm.

The wire saw cutting prevention device may be provided with an elastic connecting member between the arm and the torque limiter. In addition, the torque limiter detects that the support of the arm has been opened, and
Provide a sensor with a pin protruding from the
The drive pulley through a proximity switch that is activated by
Can be stopped.

[0010]

According to the above-described wire saw cutting prevention device,
The arm that supports the idler sheave that applies a predetermined tension to the wire saw is swingably supported at the torque value set by the torque limiter at the other end, and a torque equal to or greater than the set torque value is supported. When the wire saw is applied, its support is released, so if an excessive tension acts on the wire saw, this tension is applied in the direction that moves the arm in the traveling direction of the wire saw, and the force rotates the other end of the arm. It acts as a torque force. When the torque force that rotates this arm becomes larger than the set value of the torque limiter, the support of the arm is released, which eliminates the tension applied to the wire saw by the idler sheave, and as a result, the excessive tension of the wire saw is eliminated. To be done.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of a wire saw cutting prevention device according to the present invention. The cutting prevention device 10 shown in FIG. 1 includes an idler sheave 12 on which a wire saw, which will be described later, is slidably contacted, and an arm 1 having one end side rotatably pivotably attached to the idler sheave 12.
4, an elastic connecting member 16 that swingably supports the other end of the arm 14, and a torque limiter 18 that is connected to the arm 14 via the connecting member 16.

The idler sheave 12 is provided with a concave groove 12a on the outer peripheral surface thereof with which the wire saw slides.
As shown in detail in FIG. 3, the elastic connecting member 16 has a hollow rectangular inner cylindrical portion 16 to which the upper end of the arm 14 is fixedly mounted.
a and a hollow rectangular outer cylindrical portion 16b arranged by being displaced in the circumferential direction at an angle of 45 ° with respect to the rectangular inner cylindrical portion 16a.
And four cylindrical rubber rods 16c interposed between the cylindrical portions 16a and 16b.

The elastic connecting member 16 is a rubber rod 16
The rectangular inner cylindrical portion 16a can be swung up to the elastic limit of c, and the arm 14 is swingably supported within this range to absorb the tension fluctuation of the wire saw slidingly contacting the idler sheave 12. When the elastic limit of the rubber rod 16c is exceeded, the arm 14 is rigidly connected to the rectangular outer cylindrical portion 16b.

The torque limiter 18, as shown in detail in FIGS. 4 and 5, has a rectangular outer cylindrical portion 1 of the elastic connecting member 16.
6b is a hollow cylindrical outer cylinder portion 18a fixedly mounted via a coupling 20, a fixed shaft portion 18b provided at the center of the outer cylinder portion 18a, and the outer cylinder portion 18a and the fixed shaft portion 18b. It has a pair of torque springs 18c provided therebetween.

An arcuate slide piece 18d is coupled to one end of each torque spring 18c, and the fixed shaft portion 1 is attached to the other end of the torque spring 18c.
A spring receiver 18e fixed to the 8b side is installed. Between the pair of slide pieces 18d, a drive key 18g that can be fitted into a groove portion 18f provided in the outer cylinder portion 18a.
And the drive key 18g is rotatably supported by a pin 18h.

The torque limiter 1 thus constructed
8, when a torque smaller than the set torque value (elastic force of the spring) of the torque spring 18c acts on the outer cylinder portion 18a, as shown in FIG. 18h, fixed shaft part 18
Although the outer cylindrical portion 18a is supported by b, when a rotational force larger than the set torque value of the torque spring 18c is applied to the outer cylindrical portion 18a, the drive key 18g resists the urging force of the spring 18c and slides the slide piece 18d. As it is pushed out, it is disengaged from the groove portion 18h, and the support of the outer cylindrical portion 18a is released.

A sensor 18i for detecting the support of the outer cylinder portion 18b when the support is opened is provided at another cross section of the torque limiter 18. As shown in detail in FIG. 5, the sensor 18i is urged toward the center by a spring 18j, and a pin 18l inserted into a through hole 18k formed in the outer cylindrical portion 18a and a fixed shaft portion 18b. Notch portion 18 provided in the large-diameter portion 18m to be connected
n.

In the sensor 18i, the pin 18l is in contact with the notch 18n by the urging force of the spring 18j when the outer cylinder 18a is supported by the fixed shaft 18b, but the outer cylinder 18a is fixed. Out of the support of the shaft portion 18b,
When rotated relatively, the pin 18l is pushed by the peripheral surface of the large-diameter portion 18m against the urging force of the spring 18j, and the outer cylinder portion 18a.
Project outwards. For example, when the proximity switch 22 receives the protrusion of the pin 18l, the operation of the proximity switch 22 can stop the rotation of the drive pulley described later.

The member 24 shown in FIGS. 1 and 2 is a mounting plate to which the fixed shaft portion 18b is fixed, and the member 26 is the torque limiter 18 as will be described later.
When the support of the arm 14 by the armature is released and the excessive tension of the wire saw is released, the arm 1 is moved by the reaction force of the wire saw.
Reference numeral 4 is a rotation preventing stopper for preventing the wire saw from rotating in the direction opposite to the traveling direction and applying tension to the wire saw again.

A cutting prevention device 10 constructed as described above
Is used in the state as shown in FIG. In the drawing, a through hole B is bored in a wall-shaped concrete structure A, a wire saw C is inserted into the through hole B, and when the structure A is vertically cut, a cutting prevention device of the present invention I am using 10. The wire saw C includes the drive pulley E of the drive device D installed on the front surface of the structure A to be cut and the structure A.
It is wound endlessly between and, and the drive pulley E is rotatably driven by a motor or an engine to circulate.

At this time, the guide sheave F is installed at an appropriate position of the structure A, and the cutting prevention device 10 of the present invention is installed on the tension side of the wire saw C. The cutting prevention device 10 is installed by applying a predetermined tension to the wire saw C while the wire saw C is pressed downward by the idler sheave 12. In the cutting prevention device 10, since the end portion of the arm 14 is coupled to the rectangular inner cylindrical portion 16a of the elastic connecting member 16, the rectangular inner cylindrical portion 16a can be rotated up to the elastic limit of the rubber rod 16c. Therefore, when the arm 14 is rotatably supported within this range to absorb the tension variation of the wire saw slidingly contacting the idler sheave 12, and when the tension exceeding the elastic limit of the rubber rod 16c acts, the arm 14 becomes It is in a rigidly coupled state with the mold outer cylinder portion 16b.

Then, in such a state, the arm 14 is connected to the torque limiter 1 via the elastic connecting member 16.
Since the wire saw C is swingably supported, an excessively large tension acts on the wire saw C due to the non-uniform cutting resistance, and the torque spring 1 is applied to the outer cylinder portion 18a of the torque limiter 18.
When a rotational force larger than the set torque value of 8c is applied, the drive key 18g resists the urging force of the spring 18c and pushes the slide piece 18d to widen the groove portion 18g.
After being removed from h, the support of the outer tubular portion 18a is released.

As a result, the swing support of the arm 14 is released, so that the arm 14 can freely rotate, and in such a state, the arm 14 moves in the traveling direction due to the reaction force of the wire saw C. Reversely rotates, and the tension applied by the idler sheave 12 disappears, so that the excessive tension of the wire saw C is eliminated, and as a result, the cutting of the wire saw C can be prevented.

In the above embodiment, the arm 14 is not directly swingably supported by the torque limiter 18 and the elastic connecting member 16 is provided between them, but the embodiment of the present invention has this configuration. It is not limited to the arm 1
4 may be directly supported by the torque limiter 18.

[0025]

[Effects of the Invention] As described above in detail in the embodiments,
In the wire saw cutting prevention device according to the present invention,
When excessive tension is applied to the wire saw, the tension is reduced and the driving force due to the friction of the wire saw is reduced, so that cutting of the wire saw can be prevented.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a cutting prevention device for a wire saw according to the present invention.

FIG. 2 is a front view of FIG.

3 is a cross-sectional view taken along the line AA of FIG.

4 is a cross-sectional view taken along line BB of FIG.

5 is a cross-sectional explanatory view taken along line CC of FIG.

FIG. 6 is an explanatory diagram of a usage example of the cutting prevention device of FIG. 1.

[Explanation of symbols]

 10 Cutting Prevention Device 12 Idler Sheave 14 Arm 16 Elastic Connection Member 18 Torque Limiter

Claims (3)

[Scope of utility model registration request] 1. A wire saw cutting prevention device for cutting an object to be cut by endlessly winding between the object to be cut and a drive pulley and circulatingly traveling under a predetermined tension condition, the wire saw having a predetermined size. Of the idler sheave that gives the tension of, the arm that supports the idler sheave at one end side, and the other end side of the arm that is swingably supported at a set torque value, and that is greater than or equal to the set torque value. A wire saw cutting prevention device comprising: a torque limiter that releases support when torque acts on the arm. 2. The wire saw cutting prevention device according to claim 1, further comprising an elastic connecting member provided between the arm and the torque limiter. 3. The torque limiter detects a release of the support of the arm and detects a pin protruding to the outside.
It has a sensor equipped with it and is activated by the protrusion of the pin.
The cutting prevention device for a wire saw according to claim 1 or 2, wherein the drive pulley is stopped via a proximity switch .