JPS636520Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field The invention consists of a stepped pulley, a driving flat belt stretched between both pulleys, and a pair of belts facing each other on both sides of the belt for switching the gear ratio. The present invention relates to a transmission device equipped with a guide roller.

Conventional technology Conventionally, in a method for changing speeds of a drive device using a flat belt, the mechanism is simple and the transmission efficiency due to speed change is reduced by combining a stage pulley having two or more stages and a belt moving device. Many transmission devices are used.

An example of such a device will be explained based on FIGS. 1 and 2. The device that moves the flat belt 3 stretched between the driving side pulley 1 and the driven side pulley 2 is a motor capable of forward and reverse rotation. A T-shaped lever 4 rotated by the motor M, and a pair of guide rollers 5A and 5B provided on the lever 4 so as to face each other on both sides of the belt 3. Note that a guard roller 7 is rotatably supported by a bracket 6 fixed to the lever 4.
This is to prevent excessive twisting of the belt 3 during movement.

Now, in the state shown in FIG. 1, the flat belt 3 is at the shift position (hereinafter referred to as
However, when the motor M is rotated in the normal direction based on a normal rotation operation command from a control device (not shown), the lever 4 is rotated in the direction of the arrow shown in the figure, and the flat belt 3 is rotated in the direction of the arrow shown in the figure. It is pressed and moved by the guide roller 5B and moves to a shift position (hereinafter referred to as a high speed shift position) where the driven side pulley 2 is rotated at high speed. And lever 4 is the limit switch
When it comes into contact with LS1, normal rotation of the motor M is stopped.

Conversely, when the flat belt 3 is at the high-speed shifting position, when a reverse operation command is sent from the control device to the motor M, the flat belt 3 is pressed and moved to the low-speed shifting position by the guide roller 5A. Then, when lever 4 comes into contact with limit switch LS2,
The reverse rotation of the motor M is stopped.

By the way, conventionally, the pair of guide rollers 5A and 5B are provided parallel to each other,
Both rollers 5A and 5B are designed to always apply a pressing force to the flat belt 3 in the perpendicular direction. However, if an attempt is made to move the flat belt 3 in such a state, for example, when the flat belt 3 is moved from the high-speed side shifting position to the low-speed side shifting position as shown in FIG. In the initial stage, the edge in contact with the guide roller 5A is curved so as to be pressed against the stepped pulleys 1 and 2 (second
(indicated by a solid line in the figure, hereinafter referred to as an inward folded state), or curved to the opposite side (hereinafter referred to as an outward folded state) as indicated by a chain line in the same figure. If such a phenomenon is repeated, cracks may occur in the flat belt 3 in its longitudinal direction, and the side edges of the flat belt 3 will be subject to strong pressing force from the right angle direction by the guide rollers 5A and 5B, resulting in early damage. This may result in the flat belt 3 being cut.

In addition, with the recent aim of improving transmission efficiency in flat belt drive devices, belts with a thinner thickness and higher elongation have been developed. Problems have arisen in which defects have become more noticeable or the flat belt has become impossible to move.

Purpose The present invention has been made in consideration of the above facts, and its purpose is to provide a flat belt type power transmission mechanism that can prevent damage to the flat belt and that can smoothly move the flat belt on the stepped pulleys. Our objective is to provide a transmission system for this purpose.

Configuration In order to achieve the above object, in the present invention, respective generatrix lines of a pair of guide rollers that can come into contact with the flat belt are spaced apart from each other as they move toward the inside of the flat belt, and in a direction perpendicular to the running direction of the flat belt. The guide rollers are arranged opposite to each other on both sides of the flat belt so as to be inclined almost symmetrically.

Embodiment Hereinafter, an embodiment in which the present invention is embodied in a ring spinning machine will be described based on FIG. 3 while referring to FIG. 1.

In a ring spinning machine, at the beginning of winding and near the full tube, the tension of the yarn changes drastically due to the height from the snell wire to the ring and ballooning, so the flat belt 3 is moved to the low speed shift position to operate at low speed. When the change in the tension of the intermediate yarn is small, the flat belt 3 is moved to the high-speed side shifting position to perform high-speed operation in order to improve productivity. When the tube is almost full, the motor M is reversed based on a reverse rotation operation command from a control device (not shown). Along with this, the guide rollers 5A and 5B are moved in the direction of the arrow in FIG. 3, and the flat belt 3 is pressed and moved by the guide roller 5A. In this embodiment, both guide rollers 5
Both ends of the T-shaped lever 4 supporting the guide rollers 5A and 5B are bent slightly toward the outside of the flat belt 3 (lower side in FIG. 3), and the flat belt is placed on the circumferential surface of both guide rollers 5A and 5B. 3, the two generating lines l that can come into contact with the flat belt 3 are spaced apart from each other as they move toward the inside (upper side in FIG. 3) of the flat belt 3, and are symmetrically inclined in a direction perpendicular to the running direction of the flat belt 3. Guide rollers 5A and 5B are provided. That is, both straight guide rollers 5A,
The rotation axes of 5B, and thus both generatrix lines, are inclined in opposite directions at an angle θ, as shown in FIG. Therefore, when the guide roller 5A presses the flat belt 3, the pressing force applied to the flat belt 3 is applied not only in the moving direction of the flat belt 3 but also in the direction of movement of the flat belt 3.
It also occurs in the direction of pressing the stepped pulleys 1 and 2. As a result, the flat belt 3 tries to move while being pushed toward the corrugated pulleys 1 and 2 with its side surface on the guide roller 5A side, so that the flat belt 3 always moves in an inwardly folded state, as shown in FIG.

At the beginning of winding, where the tension of the yarn changes rapidly, the flat belt 3, which is in the low speed shift position, is moved in the direction opposite to the arrow in FIG. Even if
The flat belt 3 is pressed and moved by the guide roller 5B, and is bent inward as shown by the chain line in the figure.

In this embodiment, when the flat belt 3 changes its shifting position from the high speed side to the low speed side or from the low speed side to the high speed side, the belt 3 always moves in an inwardly folded state. Therefore, in the transmission device of this embodiment, the guard roller 7 prevents the flat belt 3 from being pushed toward the stepped pulleys 1 and 2, and from being twisted greatly.
Since the flat belt moves while being prevented from moving, it is possible to prevent the drawback that tends to occur in the conventional transmission device, that is, longitudinal cracks in the flat belt due to repeated bending inward and outward bending. Furthermore, when the side edges of the flat belt 3 come into contact with the guide rollers 5A, 5B, they are smoothly guided into an inward folded state, so there is an advantage that they are less likely to be damaged.

Furthermore, when the flat belt is folded outward, the belt does not move smoothly, but in this embodiment, the flat belt 3 always moves in an inward folded state, so smooth movement is achieved. .

As mentioned above, flat belts with thinner thickness and higher elongation have recently been developed in the pursuit of improving transmission efficiency in flat belt moving devices. This is a sufficient measure to prevent damage to the belt, prevent shortening of its life, or prevent poor movement of the belt.

In the embodiment described above, both ends of the T-shaped lever 4 are bent in order to tilt the guide rollers 5A, 5B, but instead of bending the lever 4, the support shafts of the guide rollers 5A, 5B (Fig. 3) are bent. 10 to
) may be bent.

Furthermore, although guide rollers having straight circumferential surfaces are used as guide rollers in the above embodiments, guide rollers 8A and 8B having tapered circumferential surfaces may also be used as shown in FIG. In this case, although the rotational axes of both guide rollers 8A and 8B are parallel, the flat belt 3 always moves in an inwardly folded state as in the previous embodiment.

In addition, in the present invention, if the inclination angle θ becomes too large, the balance between the pressing force in the moving direction of the flat belt 3 and the pressing force in the direction of the stepped pulleys 1 and 2 will be lost, and the flat belt 3 will become a guide. Roller 5A, 5
There is a risk that it will deviate from B, 8A, and 8B.
The present inventor believes that under the conditions that the width of the flat belt 3 is 60 to 110 mm and the thickness is 2 to 4 mm, it is appropriate to set the inclination angle θ to 4 to 12 degrees, so that the flat belt 3 can move smoothly. The result is that it moves.

Since the flat belt 3 moves smoothly, the gear ratio of the step pulleys 1 and 2 can be made larger than before. Further, in the embodiment described above, a guard roller 7 is provided to prevent the flat belt 3 from excessively twisting when the flat belt 3 is moved. When the width is narrow or the elongation is small, it is not necessary to provide the guard roller 7.

In the above embodiment, a system in which the guide rollers are moved rotationally is used, but it is of course possible to embody the present invention in a transmission device in which the guide rollers are moved linearly using a rack and a pinion.

Effects As detailed above, the transmission of the present invention can prevent damage to the flat belt and shorten its service life, and the belt can move smoothly and the gear ratio of the step pulley can be adjusted better than before. It has the excellent effect of being able to be made larger.

[Brief description of the drawings]

Fig. 1 is a perspective view showing an example of a transmission of a flat belt device, Fig. 2 is a plan view of main parts showing a conventional example, and Figs. 3 and 4 are plan views of main parts showing embodiments embodying the present invention. It is a diagram. Step pulleys...1, 2, flat belts...3, guide rollers...5A, 5B, 8A, 8B, busbars...
l, inclination angle...θ.

Claims (1)

[Claims for Utility Model Registration] 1. A pair of stepped pulleys, a driving flat belt stretched between both pulleys, and a pair of moving belts placed opposite each other on both sides of the same belt for changing the gear ratio. In the transmission device equipped with a guide roller, generatrix lines on the circumferential surfaces of both guide rollers that are capable of contacting the flat belt are spaced apart from each other as they move toward the inside of the flat belt, and are substantially parallel to the running direction of the flat belt. A transmission with a flat belt type power transmission mechanism characterized by symmetrical inclination in orthogonal directions. 2. A utility model registration claim in which the pair of guide rollers have straight circumferential surfaces, and their rotational axes are spaced apart toward the inner side of the flat belt and inclined in the running direction of the belt. A transmission of a flat belt type power transmission mechanism according to item 1. 3. A transmission for a flat belt power transmission mechanism according to claim 1, wherein the pair of guide rollers have a tapered peripheral surface.