JPH0737284B2 - Belt tension adjustment device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt driving device, and in a belt driving device, a belt tension adjusting device that automatically adjusts the tension of the belt according to the load and the elongation of the belt.

[Conventional technology]

Endless belts are stretched along the rails that form a circulation path and run, and the hanger unit suspended on the rails is conveyed by friction with the belts. There is.

FIG. 7 shows a case where this type of belt conveying device is used as a conveying means for conveying a sewn product to each sewing station in a sewing factory. A rail 101 having a U-shaped cross section has a plurality of columns 102.
The hanger unit 103 is held horizontally at a high position by the rail 101 and is suspended from the rail 101.The hanger unit 103 has a hanger 104 on which a sewing product is hung at the lower end thereof. A sewing station is provided.

An endless round belt (hereinafter referred to as “belt”) 105 is endlessly stretched inside the rail 101 as shown in FIG. 8, and is driven in the direction of arrow A by a drive motor 108 via pulleys 106 and 107. It This belt 105 encloses a stranded wire such as steel wire or glass fiber in the center,
The outer peripheral portion is covered with a rubber material such as chloroprene rubber or a synthetic resin material such as urethane and molded into a circular cross section.

Further, on the upper part of the hanger unit 103, a traveling carriage 109 that is frictionally engaged with the belt 105 and moves by being guided by the rail 101 is integrally provided.

Conventionally, in such a belt conveying device, in order to set the belt tension to a predetermined value, the belt 105 between the pulleys 106 and 107 is set.
It was common to adjust the belt tension by pressing the tension pulley 110 under pressure.

[Problems to be Solved by the Invention]

However, in such a conventional belt tension adjusting device, the belt set to the required tension at the time of setting is stretched over time and the tension gradually decreases, causing the belt and pulley to slip and cause abnormal noise. May occur or the hanger unit may not be conveyed normally.

In addition, if the clothes are hung on each hanger unit at the same time, if the hanger units are stopped at the same time, or if part of the belt is locked for some reason, excessive tension may be applied to cut the belt. .

The present invention has been made in view of the above points, and an object of the present invention is to provide a belt tension adjusting device that can automatically adjust the tension of a belt in response to load and elongation.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention introduces a part of an endless belt circulating on a track in a track by a belt guide member to form a loop part, and the loop part is driven by a belt driving member. After that, the belt tension adjusting device in the belt driving device is configured to move the belt in a predetermined direction by returning the belt to the track by the belt guiding member again, and the movable device is movable while holding the belt driving member. Means, urging means for urging the movable means in a direction away from the belt guide member, and adjusting means for adjusting the urging force of the urging means are provided.

The belt guide member is composed of two-stage belt pulleys that are coaxially and independently mounted to be rotatable.

Further, the movable means may be composed of a fixed slider guide and a slider slidable via the slider guide.

The biasing means is composed of a coil spring, but a spiral spring can also be used.

Further, it is preferable that the adjusting means comprises an adjusting bolt connected to the base end portion of the coil spring via a swivel, and a fixing nut for screwing the adjusting bolt along the track center line.

[Action]

With the above configuration, the belt driving member can set the belt tension to a predetermined value by adjusting the urging force of the urging means by the adjusting means.

If the load on the belt increases and the belt tension increases while the belt is circulating in this state, the belt drive member moves toward the belt guide member, and the belt drive is performed with the belt tension and the biasing force of the biasing means balanced. The movement of the member is stopped and the belt is prevented from being overloaded.

Also, when the belt stretches and the tension becomes weaker due to changes in diameter, etc., and it is likely that the belt will come off or slip on the driven body, the belt drive member will move away from the belt guide member due to the biasing force of the biasing means. The belt tension is automatically adjusted by moving it away.

In the belt tension adjusting device having such a configuration,
If the belt guide member is composed of two-stage belt pulleys that can rotate independently of each other, there is no risk that the belt introduced into the loop portion and the belt led out from the loop portion interfere with each other, and You can run smoothly.

If the movable means is composed of a slider guide and a slider that slide, the belt driving member can be moved with an extremely light force, and a slight change in belt tension can be immediately dealt with. .

Further, if the biasing means is composed of a coil spring, the intended purpose can be achieved with a simple structure, and if the biasing means is composed of a spiral spring, the biasing force can be always constant. Therefore, the adjustment accuracy can be improved.

Further, in the urging means using the coil spring, if the coil spring is connected to the adjusting bolt via the swivel, the coil spring will not move even if the urging force of the coil spring is adjusted by rotating the adjusting bolt. It is convenient that the biasing force can be adjusted stably without twisting.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 of the accompanying drawings.

FIG. 1 is a plan view showing an embodiment in which the present invention is applied to the belt conveying device shown in FIG. 7, and FIG. 2 is a front view thereof.

A rail bracket 1 forming a circulation path of the belt conveying device is composed of straight line portions having a U-shaped cross section and parallel to each other, and semi-arcuate folded portions formed on both sides of these straight line portions in the longitudinal direction. It is formed into an oval shape and is horizontally held at a high place by a plurality of columns 102 as shown in FIG.

Inside the rail bracket 1, an endless belt 2 is provided along the rail bracket 1 and a plurality of guide rollers 3 and a fall prevention piece 4 (fourth
As shown in FIG. 5 and FIG. 5), it is mounted so that it can travel on an elliptical track, and a pipe-shaped round rail 5 parallel to it is fixed below the belt 2 to form an oval track.

On one end side of the rail bracket 1 in the longitudinal direction, bridges 6,7,8,9 are fixed at right angles to the center line C of the track.
The shaft 10 is provided on the underside of the track on the center line C of the track, and the belt guide pulley 11 including the pulleys 11A and 11B having the same diameter, which can be independently rotated, is rotatably attached to the shaft 10. ,
The adjustment board 12 is fixedly mounted on the center line C of the orbit 8 and 9. A slider guide 13 having a U-shaped cross section is fixedly mounted on the adjustment board 12 with its axis aligned with the center line C of the track.
A slider 14 is slidably mounted on the shaft 13 through a circulating ball (not shown) in the axial direction to form a known moving means.

A drive motor 16 having a built-in reduction mechanism is fixedly mounted on the slider 14 via a motor base 15, and the reduced rotation shaft 16a is positioned on the center line C of the track. A belt drive pulley 17 having a diameter substantially the same as that of the pulley 11 is fixed and constitutes a belt drive member together with the drive motor 16.

Further, the bracket 18 is fixed to the bridge 9, the bush 19 having a shaft hole is fixed on the track center line C of the bracket 18, and the nut 20 is fixed to the side wall of the bridge 9 concentrically with the bush 19. Then, screw the adjusting bolt 21 to the nut 20 and insert it into the shaft hole of the bush 19, and provide a square shaft portion 21a at one end of the adjusting bolt 21 and mount an appropriate jig 22 to rotate it. , So that the adjusting bolt 21 can move in the axial direction.

One end of a tension spring 25 is attached to the other end of the adjusting bolt 21 via an S-shaped hook 23 and a freely swivel swivel 24, and the other end is fixed to the motor base 15 in a U-shape. Attach to the hook 26 of the
The movable means, that is, the urging means for the belt driving member, is configured so as to urge to the drawing).

Then, a part of the endless belt 2 is passed through the belt guide pulley 11
Belt drive pulley 1
After being wound around 7, the belt 2 is returned to the track again via the pulley 11B, and the tension spring 25 pulls the belt driving pulley 17 to the left via the motor base 15 to give tension to the belt 2. . This tension can be freely adjusted by rotating the adjustment belt 21 in the forward and reverse directions.

Next, the structure of the hanger unit 29 conveyed on the round rail 5 by the belt 2 will be described with reference to the plan view shown in FIG. 3, the front view shown in FIG. 4 and the side view shown in FIG. .

The hanger unit 29 has a traveling carriage 30 on the upper part thereof, and the traveling carriage 30 is provided with a frame 31 bent at a right angle, and on a horizontal plane thereof, as shown in FIG.
The two ends are pivotally attached by a common shaft 33, and the springs 34, 34 respectively
Is urged toward the belt 2. At the free ends of the pressing plates 32, 32, the middle parts of the swing arms 36, 36 are pivotally mounted by shafts 35, 35, respectively, and the friction rollers 37 are respectively rotatable at both ends of the swing arms 36, 36. The friction rollers 37 are pressed against the belt 2 by a uniform force by the urging force of the springs 34, 34.

The vertical surface of the frame 31 has a pair of shafts 3 at a slight interval.
8, 38 are planted, hourglass-shaped rollers 39, 39 are rotatably mounted on these shafts 38, 38, and the rollers 39, 39 are rotatably supported on the upper part of the round rail 5.

Further, both ends of the frame 31 on the horizontal plane are projected forward, and the rollers 40, 40 are rotatably mounted, so that the traveling carriage 30 moves to the sixth position.
As shown in the figure, when the rail bracket 1 is folded back at both ends, the rollers 40, 40 face the inner surface of the cover 27 (see FIG. 5) fixed to the outer side of the rail bracket 1 with a slight gap therebetween. Set its position to.

Arc-shaped bumpers 41, 41 centered on the substantially central portion of the horizontal plane are integrally formed on the outermost portion of the frame 31, and the length between the bumpers is connected to the frame 31 via a pole 42. Make it approximately equal to the maximum width of the hanger 43 with fingers such as triples, doubles and singles.

In addition, place the angle 44 at the specified position on the rail bracket 1.
The stopper unit 50 is fixed through the stopper, and the rod of the air cylinder 51 provided inside is fixed to the stopper pin 52, and when the traveling carriage 30 reaches the sewing position, the stopper pin 50 is stopped.
52 is held in a protruding state by air pressure, and the pole 42 is locked so that the traveling carriage can be stopped.

Then, the foot switch 53 arranged at each sewing place is stepped on to switch the air introduction path so that the stopper pin 52 is retracted from the pole 42.

In addition, reference numeral 31a in FIG. 5 is a runout preventing piece of the hanger unit 29 provided on the frame 31 in a protruding manner.

Next, the operation of this embodiment having the above structure will be described.

When the adjusting bolt 21 is rotated in either forward or reverse direction using the jig 22, the tension spring 25 expands and contracts, and the tension of the belt 2 changes. Here, the belt 2 has a predetermined tension (for example,
When the drive motor 16 is started after adjusting so as to apply 20 Kgf), the belt 2 is frictionally driven by the belt drive pulley 17 and runs clockwise while maintaining a predetermined tension.

In this state, for example, when a plurality of hanger units 29 are simultaneously locked by the stopper pins 52, the friction roller 37 of the traveling carriage 30 idles, the load applied to the belt 2 increases rapidly, and the tension of the belt 2 increases.

As a result, the belt driving pulley 17 moves to the belt guide pulley 11 side due to the tension of the belt 2, and the belt 2 travels while keeping the tension and the urging force of the tension spring 25 balanced to prevent the overload. To do.

On the contrary, when multiple hanger units 29 are running,
The load is reduced and the tension of the belt 2 is weakened. In this case, the belt drive pulley is driven by the biasing force of the tension spring 25.
17 moves in a direction away from the belt guide pulley 11 and becomes in a state of being balanced with the tension of the belt 2, and the belt 2 is automatically adjusted so that an appropriate tension is always maintained without sagging.

Further, even if the belt 2 is gradually expanded due to aging and the belt tension is reduced and slipping may occur, the belt driving pulley 17 moves in a direction away from the belt guide pulley 11 and the tension of the belt 2 increases. Can be kept at an appropriate value.

Further, in the unlikely event that a part of the belt 2 is disengaged from the belt guide roller 3 and held by the fixed portion and locked, and the tension of the belt 2 becomes abnormally high, the belt drive pulley 17 is directed toward the belt guide pulley 11. The belt drive pulley 17 slips between the belt 2 and the belt 2 and prevents the belt 2 from being cut. In this case, the drive motor
As 16 loads increase and overcurrent flows, it is desirable to use a safety device that detects this and automatically activates the breaker to turn off the power.

When one traveling carriage 30a is stopped as shown in FIG. 6 while a plurality of traveling carriages 30 are traveling on the belt conveying device equipped with the belt tension adjusting device as described above, the following traveling carriage 3
0b, 30c …… will collide with the preceding traveling vehicle 30a and stop. At this time, the bumpers 41 of the traveling carriages 30a, 30b, 30c, etc. collide with each other, but the distance between the bumpers of the traveling carriage 30 is almost equal to the maximum width of the hanger 43, so they are too close to each other. The pole 42 does not tilt and the roller 39 does not slip off the round rail 5.

Further, since each bumper 41 is formed in an arc shape centering around the center of the bogie, each traveling bogie 30a, 30b, 30c.
As shown in the figure, even when the rail bracket 1 is stopped at both ends of the rail bracket 1, the impact does not cause a large component force and the traveling carriage does not come off the round rail 5 and jump out.

Further, even if an unexpected external force such as a human power is applied to the pole 42 or the hanger 43, the pair of rollers 40, 40 provided on the trolley portion rolls and moves on the inner surface of the cover 27. There is no fear of

Further, since two rollers 39 rolling on the round rail 5 are provided in the front and rear as a drum shape, the tilt of the pole 42 is prevented, the traveling carriage 30 can be stably run, and the wheels between the rollers are provided. By shortening the base, the radius of the folded portion of the round rail 5 can be reduced to, for example, about 200 mm, and the installation area of the belt conveying device can be reduced.

In the above embodiment, the coil spring is used as the tension spring 25 which gives the tension to the belt 2, but the present invention is not limited to this, and the fixed side is a spiral spring of a constant tension that is spirally wound in the barrel. You can also In this case, the belt tension is set by rotating the winding shaft of the mainspring in both the forward and reverse directions.

Further, the present invention is not limited to the belt conveying device and can be applied to any belt transmission device without any trouble.

〔The invention's effect〕

As described above, according to the present invention, when the load applied to the running belt increases or decreases and the belt tension fluctuates, the belt driving member moves correspondingly and the tension is automatically adjusted to an appropriate value. .

As a result, the tension of the belt becomes too high and there is no risk of cutting, and the tension becomes too low and abnormal noise is generated, or the belt driving member and the belt slip and the conveyance state of the conveyed object deteriorates. Is also prevented.

In addition, the belt driving member, the biasing means, and the means for adjusting the biasing force can be compactly installed in the upper space of the belt conveying device, which is convenient even in a small space in the factory.

Further, in the apparatus of the second aspect, the interference between the belt introduced into the loop portion and the belt led out is completely prevented, and the smooth running of the belt becomes possible.

Further, in the apparatus according to the third aspect, the belt driving member can be moved with an extremely weak force, and a minute change in the belt tension can be immediately dealt with.

Further, in the apparatus of the fourth aspect, the belt tension can be adjusted by a simple spring mechanism, and in the apparatus of the fifth aspect, the accurate biasing force can be set regardless of the position of the belt driving member.

Furthermore, in the apparatus of claim 6, since the coil spring is not twisted by the adjustment of the biasing force, it is possible to stably adjust the biasing force.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is a plan view showing a traveling carriage of a belt conveying device embodying the present invention, and FIG. Fig. 5, Fig. 5 is a side view thereof, Fig. 6 is a partial plan view of a belt conveyor when a plurality of traveling carriages are stopped, Fig. 7 is a perspective view illustrating a conventional belt conveyor, and Fig. 8 is the same. It is a perspective view which expands and shows a part. 1 ... Rail bracket, 2 ... Round belt 5 ... Round rail, 11 ... Belt guide pulley 12 ... Adjustment board, 13 ... Slider guide 14 ... Slider, 16 ... Drive motor 17 ... Belt drive pulley, 20 ... Nut 21 ... Adjustment belt, 24 ... Swivel 25 ... Tension spring, 27 ... Cover 29 ... Hunger unit, 30 ... Traveling carriage 37 ... Friction roller, 39 ... Hourglass roller 40 ... Roller (prevention of fall), 41 ... Bumper 43 ... Hanger 50 ... Stopper unit, 51 ... Air Cylinder 52 ... Stopper pin, 53 ... Foot switch

Claims (6)

[Claims] 1. A part of an endless belt circulating on a track is introduced into a track by a belt guide member to form a loop portion, and the loop portion is driven by a belt driving member, and then the belt guide member is again formed. A belt tension adjusting device in a belt driving device configured to move the belt in a predetermined direction by returning to the track by a movable means that holds the belt driving member and is movable.
A belt tension adjusting device comprising: an urging means for urging the movable means in a direction away from the belt guide member; and an adjusting means for adjusting an urging force of the urging means. 2. The belt tension adjusting device according to claim 1, wherein the belt guide member comprises a two-stage belt pulley which is coaxially and rotatably mounted independently of each other. 3. The belt tension adjusting device according to claim 1, wherein the movable means comprises a fixed slider guide and a slider slidable via the slider guide. 4. The urging means comprises a coil spring.
Alternatively, the belt tension adjusting device according to item 3. 5. A spring according to claim 1, wherein the biasing means is a spring.
The belt tension adjusting device according to 2 or 3. 6. The adjusting means comprises an adjusting bolt connected to a base end portion of a coil spring through a swivel, and a fixing nut for screwing the adjusting bolt along the track center line. Belt tension adjusting device.