JPS5925768Y2 - belt automatic tension device - Google Patents

Description

[Detailed explanation of the idea] This invention is a tension device for belt devices.

In particular, the present invention relates to a tension device for applying a predetermined tension to flat belts, steel belts, etc. used in belt conveyor devices.

Various types of belt tension devices have been used in the past, but all of them have advantages and disadvantages.Belt conveyor devices, especially belts that use steel belts to convey parts, etc. in automatic assembly machines, etc. The following conditions are required in a conveyor device: (1) A predetermined belt tension load (and a fairly high load) must always be applied.

(2) Belt breakage or elongation exceeding a predetermined value can be accurately detected, and the belt will not be operated with a defective state.

(3) The belt can be easily replaced, and at this time, no tension load is applied to the belt.

(4) The tension load applied to the belt does not change when the belt is replaced.

(5) It should be possible to detect abnormal belt tension (belt stoppage due to jamming, etc.) if necessary.

It was not easy to find something that satisfied all of these requirements.

The present invention provides a belt tensioning device that satisfies all of these conditions.

The present invention will be explained below based on drawings showing embodiments thereof.

FIG. 1 is a plan view showing an embodiment of the belt tensioning device of the present invention, FIG. 2 is a front view, FIG. 3 is a front sectional view, and FIG.
The figure is a side sectional view.

In the figure, two guide shafts 3 are implanted in a fixed block 2 fixed to a main body (or stand) 1 of the apparatus.

The guide shafts 3 are guide members that support the movable block 5 so as to be movable in the belt tension direction (belt longitudinal direction), and are parallel to each other and also parallel to the belt tension direction.

A moving block 5 is attached to the guide shaft 3 via a slide ball bearing 4 so as to be easily slidable.

Support plates 6,6' are attached to both sides of the moving block 5, and the pulley shaft 7 is rotatably supported by bail bearings 8,8' through the support plates 6,6'.

A pulley 9 is provided at one end of the pulley shaft 7, and a conveyor belt 10 is wound around the pulley 9.

The other end of the conveyor belt 10 is wrapped around a pulley, not shown, by which the belt is driven in a known manner, and optionally has a support pulley in the middle of the known conveyor belt. It is similar to the device.

A rotatable screw shaft 14 is provided in the center of the fixed block 2 in parallel to the belt tension direction, and a first nut member 15 is screwed onto this screw shaft 14.

The first nut member 15 is fitted into a rotation prevention member 17 that engages with the rotation prevention shaft 16, and is rotatable and fixed to the rotation prevention member 17, thereby stopping the rotation of the screw shaft 14. By rotating the first nut member in this state, the spring load of the spring 18, which will be described later, can be adjusted.After adjustment, the spring load of the spring 18 can be adjusted by fixing it to the rotation stopper member 17, and by rotating the screw shaft 14, the spring load of the spring 18 can be adjusted. advance and retreat.

A bushing 19 is fitted into the moving block 5.
A screw shaft 14 is loosely fitted into the bush 19.

As mentioned above, the spring 18 is disposed between the bush 19 and the first nut member 15, and biases the movable block 5 in the direction of the tension of the belt 10 via the bush 19. can be adjusted by the first nut member 15.

A second nut member 20 is screwed onto the screw shaft 14 in the vicinity of the bush 19, and a limit switch 21, which is a detection device for detecting belt breakage, etc., is attached to the mounting plate. It is attached via 22.

Similar to the rotation prevention member 17, the mounting plate 22 is attached to the rotation prevention shaft 1.
6, the second nut member 20 is rotatably and fixedly fitted into the mounting plate 22, and by being rotated, the bush 19 and the second nut member 20 are engaged with each other when the bell 1 is set, which will be described later. By adjusting the clearance therebetween and then fixing it, the first nut member 15 moves forward and backward along the screw shaft 14 while maintaining a constant interval as the screw shaft 14 rotates.

The operating screw 23 of the limit switch is adjustable on the moving block 5 and is checked with a lock nut 24.

Although this embodiment is configured to detect only belt elongation or breakage, in order to detect abnormal tension in the belt, the detection devices (limit switch 21') are installed in an overlapping manner as shown by the imaginary line. This makes it possible.

Since the automatic belt tensioning device of the present invention is constructed as described above, the bell (10) wound between the pulley 9 and a pulley (not shown) is tensioned by the spring load of the spring 18. ing.

That is, a guide shaft 3, which is a guide member, is implanted in a fixed block 2 fixed to the device main body 1, and the pulley 9 is moved along the guide shaft 3 together with the movable block 5 via the pulley shaft 7 and the support plate 6. It can be slid.

On the other hand, a spring 18 that biases the movable block 5 in the belt tension direction is provided between the first nut member 15 screwed onto the screw shaft 14 provided on the fixed block 2 and the bush 19 provided on the movable block 5. is established, so
The spring load of the spring 18 is applied to the belt 10 as belt tension.

Here, it is necessary to leave a slight gap between the bush 19 and the second nut member 20.

When the belt extends beyond a predetermined length or when the belt breaks, the pulley 9 moves to the right (FIG. 3) together with the moving block 5 due to the spring load of the spring 18.

At this time, stretching or cutting of the belt 9 is detected by adjusting the operating screw 23 so that the limit switch 21 is activated.

When cutting the belt, the movable block 5 is further moved to the right (FIG. 3) by the load of the spring 18, and the bush 19 comes into contact with the second nut member 20 and stops.

When the belt is abnormally stretched, the pulley 9 is pulled to the left by the belt, and the moving block 5 is pulled to the left against the spring load of the spring 18.

(Figure 3). At this time, set the operating screw 23' so that the limit switch 21' shown by the imaginary line operates (opens the circuit).
Detection is possible by adjusting.

When replacing the belt, by rotating the screw shaft 14, the first nut member 15 and the second nut member 20 are moved to the left while maintaining the same interval, and the second nut member 20 is attached to the bush. After contacting 19, move block 5
(Pulley 9) also moves to the left.

When the pulley 9 has moved sufficiently to the left, a new belt is put on and the threaded shaft 14 is rotated in the opposite direction, thereby moving the moving block 5 to the right and tensioning the bell 1.

As is clear from the above explanation, when replacing the belt, no tension load is applied to the belt, and the belt can be easily replaced, and the gap between the bushing 19 and the second nut member 20 can be made the same. The tension load on the belt will be exactly the same, and the elongation of bells 1 to 1 will be the same until the next elongation is detected, and furthermore, even if there is a slight change in the length of the belt at the time of replacement, the moving block will change to the stop position. occurs, and no other adjustment is necessary.

In the embodiment described above, the guide members were two guide shafts 3, but this is exactly the same as a dovetail groove or square groove slide, and furthermore, if some variation in the belt position is allowed. It is also possible to use the cross-section device as a guide member.

As detailed above, the automatic belt tensioning device of the present invention has a relatively simple configuration and satisfies all of the above conditions.
Furthermore, it has the advantage of being able to handle changes in belt length when replacing belts, making it suitable for belt tension devices used in conveyor equipment, etc., and is especially suitable for steel belts that require high tension. This tension device is ideal for the conveyor device used.

[Brief explanation of the drawing]

1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view of FIG. 1, FIG. 3 is a sectional view of FIG. 2, and FIG. 4 is a side view of FIG. 1. 1... Device body, 2... Fixed block, 3... Guide shaft, 5... Moving block, 9... Pulley, 10 ······belt,
14... Screw shaft, 15... First nut member, 18... Spring, 19...
- Bush, 20...Second nut member, 21
...Detection device.

Claims (2)

[Scope of utility model registration request] (1) In an automatic tensioning device in which a belt is stretched between two or more pulleys, the device moves along a fixed block fixed to the main body of the device and a guide member provided parallel to the tensioning direction of the belt. a movable block, a rotatable pulley provided on the movable block, a screw shaft provided on the fixed block parallel to the belt tension direction, a first nut member screwed onto the screw shaft; a second nut member; provided on the moving block;
a bushing loosely fitted to the screw shaft between the first nut member and the second nut member; and a bushing provided between the first nut member and the bushing, with a predetermined belt tension load; a spring that biases the movable block in the direction of the belt tension; a detection device that detects a change in relative position between the second nut member and the movable block; 1. An automatic belt tensioning device comprising a rotation stopper for locking rotation of two nut members. (2) The automatic belt tensioning device according to claim 1, wherein the guide member is a plurality of guide shafts provided on the fixed block and all of which are parallel to the tension direction of the belt.