JPS5943289B2 - A method for stretching a transmission belt and a belt stretching machine for carrying out the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for elongating a power transmission belt in order to reduce the elongation of a vulcanized belt that occurs when the belt is driven and to obtain a belt of uniform length, and a belt for carrying out the method. This relates to a stretching machine.

Conventionally, to manufacture a low-edge type V-belt, the outer circumferential surface of a cylindrical drum is normally coated with rubber-covered canvas, an adhesive rubber sheet, a tensile rope, a rubber sheet of a certain thickness, and a rubber-covered canvas in order. This is wrapped to form a wide end-flow belt sleeve, which is then flow-flowed with a drum, cut to a predetermined width and angle, and reversed to form multiple V-belts of the same size (
In order to obtain poly IJ V-belts and multi-rib belts, a method is used to obtain poly V-belts and multi-rib belts (cutting the flush belt sleeve of poly V-belts and multi-rib belts into a predetermined width), but this method causes large heat shrinkage in the tensile material. Because tensile ropes such as polyester and polyamide fibers are used, the heat during vulcanization and residual heat after removal causes thermal contraction of the tensile ropes, resulting in uneven alignment, which may occur during belt drive. The heat generated causes the belt to stretch and slip, which not only causes premature breakage, but also causes the belt length to become uneven.

Therefore, in order to solve this problem, we first established a
A vulcanized belt as described in Publication No. 5-34694 is wrapped around two extension pulleys, stretched again while being heated, and cooled in the stretched state for a predetermined period of time to form a vulcanized belt. A method of reducing belt elongation has been proposed, but this method requires a large amount of man-hours because the belt must be manually wound around one pulley and then removed.

The present invention focuses on the conventional problems such as sloping, and aims to reduce the elongation of the vulcanized belt, ensure a uniform belt length, and simplify and speed up the elongation process of the vulcanized belt. The first invention was invented for the purpose of: expanding and expanding a belt sleeve wrapped around the outer peripheral surface of an inner cylindrical drum via a flexible jacket using fluid pressure, and then cooling the belt sleeve; A second invention, in which the belt sleeve is wrapped around the drum and left to cool for a long time after being mudded, is expanded and expanded by fluid pressure, and then heated again and then cooled, and the first invention. The invention is constituted by each invention of the third invention, which is a simple belt stretching machine used in the stretching process of the second invention.

Hereinafter, the belt stretching method and belt stretching machine according to each of the above-mentioned inventions will be explained in detail based on the accompanying drawings, but for convenience of explanation of the belt stretching method, the belt stretching machine will be explained first.

FIG. 1 is a cross-sectional view showing an example of a belt stretching machine according to the third aspect of the present invention used in carrying out the method of the present invention. The drum 1 is equipped with a fluid flow port A in the center for supplying and discharging compressed fluid, which will be described later, and grooves 1/ and 1/ in the upper and lower outer peripheral surfaces, respectively. are carved along the circumference of the drum 1.

Reference numeral 2 denotes a cylindrical flexible jacket made of an elastic material such as rubber that is installed on the outer periphery of the drum 1 and can be expanded and contracted. are fitted into the concave grooves 1/, 1/ of the inner drum 1, and iron tightening rings 3.3 are inserted at the upper and lower parts of each, and furthermore, the tightening rings 3, The ports 4, 4 are passed through a plurality of locations to be tightened and fixed onto the inner drum 1.

Therefore, the flexible jacket 2 is fixed at the top and bottom, and the central flat part is in close contact with the inner drum 1 under normal conditions.

Next, 5 in the figure is a vulcanized sleeve of a poly V belt formed by reverse molding, which is attached to the flat part of the flexible jacket 2 on the outer periphery of the inner drum 1.
, polyester, polyamide, etc., and a compressed rubber R' are sequentially wound endlessly around the flat part, and the surface of the compressed rubber R' is shaped in the vulcanization process. The polygonal IJ V-belt is formed as a vulcanized sleeve with continuous triangular ribs.

Of course, this vulcanized belt sleeve is not limited to the illustrated polygon belt, but may be a multi-rib belt sleeve in which V-belts having a trapezoidal cross section are connected, or a low-edge type V-belt vulcanized sleeve.

On the other hand, on the outer periphery of the inner cylindrical drum 1, an outer cylindrical drum 6 having a predetermined size and having a hollow interior is disposed on a base 7 corresponding to the drum 1, with a certain gap between the vulcanized belt sleeve 5 and the vulcanized belt sleeve 5. This outer cylindrical drum 6
The internal hollow part is a cooling mechanism, for example, the lower population
A cooling mechanism is provided in which water flows in from the outer drum 6 and flows out from the upper outlet Y while filling and circulating the entire hollow part, and a steam pipe (not shown) is installed in the hollow part, and after draining the cooling water from the outer drum 6, This is a cooling/heating section equipped with a heating mechanism that heats the outer drum 6 by feeding high-temperature steam into a steam pipe.

That is, the outer drum 6 is configured to have cooling and heating functions.

Next, in the diagonal-up configuration, the expansion and contraction mechanism of the flexible jacket 2, which is a feature of the present invention, will be explained. The fluid communication port A provided near the center of the inner cylindrical drum 1 is connected to the joint J1.

1. On fluid inlet and outlet pipes or flexible hoses. It is connected to a switching pipe V through a joint J2, and is divided into two parts at this switching pipe V. One pipe is connected to a fluid compressor M such as an air compressor by 2, and a vacuum pump is connected to the other pipe by 3. It is connected to P.

Therefore, if the air compressor M is activated here and high-pressure compressed air is delivered to the inner surface of the flexible jacket 2, the jacket 2 can be expanded, and,
After a certain period of time has elapsed, the valve V is then switched to the vacuum pump P, and the vacuum pump P is operated to exhaust the air filled between the jacket 2 and the inner drum 1, and at the same time,
The suction action causes the expanded jacket 2 to contract, allowing the drum 1 to return to its original outer surface position.

The belt stretching machine of the present invention has the above-mentioned configuration, and the first belt stretching method and the second belt stretching method carried out using this belt stretching machine will be described below.

First, in the first belt stretching method, a flat wide unvulcanized belt sleeve is wrapped around the outer periphery of the cylindrical flexible jacket 2 that is wrapped around the inner cylindrical drum 1 in the forming process, and then This sleeve is placed in a vulcanizer (not shown) with the sleeve wrapped around the drum 1, and the outer surface of the unvulcanized belt sleeve is heated and cured using an outer mold having a plurality of V grooves in the circumferential direction of the inner surface. The belt is pressed and vulcanized while forming triangular ribs in the circumferential direction on the surface of the unvulcanized belt.

After vulcanization, the inner cylindrical drum 1 is taken out from the vulcanizer with the vulcanized belt sleeve 5 having a plurality of triangular ribs formed in the circumferential direction on the outer surface of the sleeve still attached, as shown in FIG. As shown in FIG. 2, the outer drum 6 is placed and fixed on a base 7 with a gap W formed at a predetermined position inside the outer drum 6.

In this case, since the inner drum 1 is moved from another vulcanizer, the fluid flow port A and the pipe 1 are separated, and after placing the inner drum 1 on the base 7, Connect flow port A to pipe 1 with joint J1.

Thus, after the above-mentioned work is completed, the stretching process which is a feature of the present invention is carried out, but since the belt stretching process needs to be carried out when the vulcanized belt sleeve 5 is in a hot state immediately after vulcanization, the inner drum After completing the installation in step 1, immediately operate the air compressor M to supply high-pressure air to the pipe. Valve ■, 1 on the pipe. It is fed into the flexible jacket 2 through the flow port A.

Here, the upper and lower parts of the flexible jacket 2 are tightly fixed on the inner drum 1 with tightening rings 3, 3 and bolts 4, 4, so that the inner surface of the flexible jacket 2 and the inner drum Air is filled between the outer surfaces of the flexible jacket 2 and the flexible jacket 2 gradually expands as shown in FIG. Then, it is brought into contact with an outer cylindrical drum 6 equipped with a cooling mechanism.

At this time, since the cooling water is circulating in the outer cylindrical drum 6 as described above, the vulcanized belt sleeve 5 in contact with it is cooled while being in an expanded state.

By bringing the stretched vulcanized belt sleeve 5 into contact with the outer cylindrical drum 6 and cooling it for a certain period of time, the tensile rope T embedded in the belt sleeve 5 is also stretched uniformly, resulting in less elongation. A vulcanized belt sleeve 5 of good quality is formed.

3. After the expansion is completed, switch the valve (■) to the vacuum pump P, operate the vacuum pump P, discharge the air filling the jacket 2, and then move the jacket 2 with the suction action as shown in Figure 1. Let it contract and return to its original position.

Next, the inner drum 1 is taken out, and finally the stretched vulcanized belt sleeve 5 is taken out.The taken out vulcanized belt sleeve 5 is then inserted into another drum and the sleeve 5
By cutting the surface to a predetermined width in the circumferential direction, a plurality of poly V-belts of uniform length with little elongation are formed, and then the finished product is made by inverting the belt so that the triangular ribs are on the inside. Become.

In this case, the vulcanized belt sleeve 5 is attached to the point IJ as described above.
For example, in the case of a multi-rib belt vulcanized sleeve in which V-belts with a trapezoidal cross section are connected, a plurality of multi-rib belts can be obtained by cutting to a predetermined width, and the rib portion is not limited to V-belts. Multiple V-belts can be obtained by cutting one piece of V-belt.

As described above, the belt stretching method according to the present invention is a method in which the entire wide vulcanized belt sleeve on the drum is expanded and stretched at once through the flexible jacket, so that the belt stretching method according to the present invention is a method in which the entire wide vulcanized belt sleeve on the drum is expanded and stretched at the same time. Belt, multi-rib belt, V
It is possible to obtain belts, etc., and since the operation is simple, the working time can be greatly shortened, which is an industrial advantage.

The above is a method of stretching a high-temperature vulcanized belt sleeve immediately after vulcanization, and is the method according to the first invention, but due to the work process, the vulcanized belt sleeve taken out from the vulcanizer is left to cool for a long time. It may then expand again.

This case is somewhat different from the first belt stretching method described above, and is not necessarily uniform.

Next, the second invention of the present invention stretches the cooled vulcanized belt sleeve.
The belt stretching method will be explained below.

As mentioned above, although not shown in the drawings, a steam pipe is installed inside the outer cylindrical drum 6, and is used as a heating and cooling mechanism.

The operation leading to vulcanization is the same as in the first invention, but when stretching a vulcanized belt sleeve that has been left to cool after vulcanization, first, the vulcanized belt sleeve that has been cooled is The inner cylindrical drum 1 to which the inner drum 1 is mounted is placed and fixed on a base 7 with a cavity W formed at a predetermined position inside the outer drum 6 as shown in FIG.

This is also no different from the first invention.

Then, the air compressor M is operated to inflate and expand the flexible jacket 2° mud belt sleeve 5 by an amount W in the circumferential direction using high-pressure compressed air, and the outer drum 6
make contact with.

That is, the process up to this point is the same as the first belt stretching method, and the common operations are performed, but from then on, high-temperature steam is fed into the steam pipe in the outer drum 6 to heat the drum 6, This is a process in which the mud adding belt sleeve 5, which has been cooled by the conductive heat and radiant heat, is heated for a predetermined period of time while being in an expanded state.

Therefore, the previous cooling water must be drained once.

After heating, the steam is exhausted, and then cooling water is circulated in the outer drum again in the same way as in the first belt stretching method to cool the muddy belt sleeve 5 again for a certain period of time. The poly V-belt in a predetermined shape is formed through the following steps: exhausting air by air, returning the jacket 2 to contraction by vacuum suction, taking out the inner cylindrical drum 6, taking out the stretched vulcanized belt sleeve 5, cutting it, and reversing it. A multi-rib belt, ■belt, can be obtained.

Although not shown here, it is also possible to further promote heating and cooling from the inside of the inner drum 1 by installing a cylindrical body equipped with a heating and cooling mechanism inside the inner drum 1. .

As described above, the present invention expands and expands a wide vulcanized belt sleeve attached to the outer circumferential surface of a cylindrical drum via a flexible jacket using fluid pressure, and furthermore, the high temperature vulcanized belt sleeve immediately after vulcanization, A novel belt stretching method that can be applied to any muddy belt sleeve that has been cooled after being left standing, and a belt stretching machine for carrying out the method. The resulting belt has improved thermal stability of the tensile rope and is uniform in length, with extremely little belt elongation even when heat is generated during driving, preventing early breakage due to belt slipping and increasing belt life as a whole. It also has many advantages over conventional methods, such as being extremely easy to operate and using a fluid-based expansion/contraction mechanism, which can significantly reduce the number of man-hours.

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[Brief explanation of the drawing]

Figure 1 shows one of the belt stretching machines used to carry out the method of the present invention.
FIG. 2 is a cross-sectional view showing an example of the belt stretching machine when the belt is stretched. 1...Inner cylindrical drum, 1'...Concave groove of inner drum, 2...Flexible jacket, 3.
...Tightening ring, 5...Vulcanized belt sleeve, 6...Outer cylindrical drum, A...
Fluid flow port.

Claims (1)

[Scope of Claims] 1. An endless vulcanized belt wrapped around the outer circumferential surface of an inner cylindrical drum via a flexible jacket, immediately after vulcanization, is heated by pressurized fluid while the heat from vulcanization still remains. is introduced between the outer periphery of the inner cylindrical drum and the inner surface of the flexible jacket to cause the vulcanized belt to expand and expand through the flexible jacket, and the vulcanized belt is cooled from the outer periphery of the belt for a predetermined period of time in the stretched state. A method for stretching a power transmission belt, characterized by obtaining a belt with low elongation and uniform length. 2. An endless vulcanizing belt, which is wrapped around the outer circumferential surface of the inner cylindrical drum through a flexible jacket and left to cool for a long time after vulcanization, is used to connect pressurized fluid between the outer circumferential surface of the inner cylindrical drum and the inner surface of the flexible jacket. The vulcanized belt is expanded and stretched through a flexible jacket, heated from the outer circumferential surface of the belt in the stretched state for a predetermined period of time, and then cooled again from the outer circumferential surface of the belt to reduce the elongation. A method for stretching a power transmission belt, characterized by obtaining a belt of uniform length. 3. An inner cylindrical drum consisting of a cylindrical flexible jacket that can be expanded and contracted on the outer circumferential surface of the cylindrical drum provided with a fluid flow port, fixed with tightening rings at the upper and lower parts thereof, and a cooling mechanism or A belt stretching machine comprising an external cylindrical drum equipped with a cooling mechanism and a heating mechanism.