JPS5914458Y2 - Device that weakens and compensates for the tensile force of strip material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device suitable for automatically weakening and compensating the tensile force acting on a strip material that is subjected to large accelerations during winding.

For example, when you begin to unwind a strip of material that has been wrapped around a stationary hoist, it is known that the tensile force exerted on the strip by the machine is opposed by a significant inertial force due to the mass of the hoist. It is being

At this time, the strip material is subjected to excessive tensile stress.

This stress easily exceeds the ultimate strength of the strip, causing tearing and failure.

In particular, when a strip of material that has been unrolled from the winding frame suddenly breaks, it is necessary to use an automatic splicing machine to join a second strip of material prepared separately to the cut previous strip of material. At times, these separately prepared spare strips are in a stopped state, so the above-mentioned inconvenience becomes a serious problem.

In these cases, the above-mentioned work had to be carried out by appropriately slowing down the advancing speed of the strip material, even if it meant lowering the overall production efficiency.

This is because if work is carried out under high-speed conditions without slowing down the progress of the strip material that is continuously supplied to the production line, it is extremely easy to generate tension or tensile stress that exceeds the breaking point of the supplied strip material. Therefore, the strip may be torn and the entire production line may be stopped.

Therefore, the purpose of the present invention is to weaken and compensate for the combined effect of the tensile force and resistance force applied to the strip material so that it is below a value that can withstand the tension generated in the strip material when it is accelerated considerably, that is, below the breaking point of the strip material. The objective is to provide equipment suitable for

The device according to the invention applies to the part of the web between the point at which it begins to be unwound, e.g. a reel being unwound from a reel holder, and the point at which a tensioning action is applied (e.g. by a suitable machine or drive roller). (a) a deflection device, such as an intermediate roller, which slides on a guide device to deflect the strip along a suitably determined direction;
and (b) a device for weakening the force applied to the strip material.

A device for attenuating this force is attached to the deflection device and is adjustable so as to always exert a force on the strip with a constant counter-force below that which would cause tearing of the strip;
The deflection device is therefore moved progressively rearward along its defined direction, in proportion to the force exerted by the strip with a large acceleration.

The range of movement of the deflection device is stable at a constant speed of the strip and corresponds to the normal slack in the flow of the strip, between one extreme position that affects the reservoir of the strip and the departure of the wound strip. and the other extreme position corresponding to the travel of the strip substantially close to the straight line segment from the point to the point where the tensile action is applied.

Such a function of gradually weakening the force has the effect of absorbing and compensating for the strong tensile force exerted on the deflection device by the strip when the strip is greatly accelerated and subjected to a sudden tensile force.

In fact, the deflection device discharges all or part of the pooled or stocked portion of the web when it moves backwards, so that the required change in velocity of the web at a position upstream of the web flow from the device is Over time, the strip will adapt and absorb excessive tensile stresses that would otherwise cause the strip to tear itself.

This device greatly reduces the possibility of strips with large accelerations being stranded, especially when such strips have to be spliced to other strips moving at high speeds.
Its functionality will be enhanced.

For example, such a splicing operation is carried out on a corrugated board production line between two strips of paper, one strip being unwound from a reel and the other strip stopped at the position to be spliced. A stationary strip of paper is subjected to a strong and rapid tensile stress the moment the reel around which it is wound begins to rotate.

In this case, by applying the device according to the present invention to the latter paper strip, the splicing operation can be carried out automatically without causing damage or cutting to the strip even when the strip is moving at full speed at high speed. I can do it.

This offers the possibility of significantly improving the performance of automatic seaming machines, so that effective and efficient seaming can be carried out, for example in the production of corrugated board.

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the invention and to show how it may be implemented in practice, a description of one embodiment thereof will be made with reference to the accompanying drawings.

The illustrated device according to an embodiment of the invention is applied to two strips 1 and 2, and a reel around which the strips are wound is carried by a reel holder 3.

When one of the two strips is unwound from its associated reel at a certain speed, the other one is stationary and in the splicing position.

In the figure, the device according to the invention is used to unwind strips 1 and 2 from each reel in two different ways. It may be a tin or aluminum film, plastic or other material.

The device according to the invention comprises a shoulder 6 slidably attached to a guiding device, also referred to as a guide or track, denoted by 7.
It has intermediate rollers 5, 5 provided adjacent to both ends of the strip material 1 or 2, and a damper device provided on each of the intermediate rollers 5.

This damper device is a resilient device such as a compression spring 8.
the spring 8 lies in front of a fixed pneumatic cylinder arrangement 9 with a sliding axle 9', one end of which rests against a support 8' fixed to the shoulder 6; The other ends of the springs 8 abut against each other, and these members are arranged continuously on a straight line.

The spring 8 and cylinder arrangement 9 associated with one roller 5 are mounted independently of the spring 8 and cylinder arrangement 9 associated with the other roller, thus preventing possible parallelism between the ends of the strip. Defects and differences in tension are compensated for.

In order to ensure as uniform a distribution of tensile force as possible on the strip material and to prevent concentration of tension, a damper device has the function of compensating for the movement of the intermediate roller 5 due to the small vibrations that the intermediate roller 5 receives when being pushed by the strip material while the strip material is moving. is provided.

The pneumatic cylinder 9 is calibrated to a value higher than the calibrated value of the spring 8 and has the function of reducing and compensating the force after almost completely compressing the spring 8, thus creating a It absorbs tensions that could break or tear the material whenever it is subjected to large accelerations, and performs its function particularly when the strip of relative reel starting is started from a standstill.

The inertia of the reel then causes a corresponding resistance force which counteracts the pulling force exerted by the drive roller 10 above the automatic seaming machine 4 through the corresponding guide roller 11.

The pneumatic cylinder counteracts the force exerted by the accelerated web 1 or 2 on the intermediate roller 5 and applies a fixed pressure to the web, adjusted by a calibration previously performed on the same roller 5. As the resulting counter-push force is constant, it is less than the force that would cause the strip to tear and break.

Once the direction of travel of the intermediate roller 5 has been suitably determined, for the strip 1 on the right side of the figure, the guide or track 7 is almost perpendicular to the normal direction of movement of the strip (represented by the dotted line 12). Since it is inclined, the intermediate roller 5 is
It slides along the inclination direction of the track and gradually retreats in proportion to the pushing force received from the strip material having a large acceleration.

The range of retraction ranges from one extreme position (approximate position indicated by arrow 13) to the reel, which corresponds to the deflection applied to the strip while the strip is moving at an almost constant speed or is at rest. to the final position 14, which corresponds to a travel of the web approximately equal to the linear travel between the position where the web begins to unravel and the position where the pulling force is applied.

The aforementioned deviations were given so that the strips were accumulated or fed (as clearly seen in the figure), so that
When the roller 5 makes a backward movement, it is possible for all or part of this accumulated web to adapt to the changes in speed required of the web located upstream of the device over a long period of time. do.

Such adaptation results in complete absorption of excessive tensile stresses that would cause the strip to tear and break.

In conclusion, by gradually weakening the force applied to the strip material using this device as described above, the force exerted by the strip material with large acceleration on the intermediate roller 5 is compensated and absorbed. This minimizes the possibility of the strip breaking and makes it possible to continue feeding the strip at a high rate, which provides significant benefits when applied to production lines, especially corrugated board production lines. .

Another feature of the device according to the invention is that it is counterbalanced, ie internally balanced.

That is, when the intermediate roller 5 is retracted to the final position 14, in the device the roller 5 is slowly moved to the position 13 of its normal function of accumulating the strip material, and the device applies a constant pressing force. maintaining and weakening it following possible changes in the tension acting on the strip.

Once started, the reel can overrun due to its inertia.

At this time, the roller 5 must automatically slide and move at an appropriate speed in a predetermined direction so as to maintain a constant tension on the strip.

The counterbalancing described above is usually performed by a valve arrangement as described below.

That is, if we consider, for example, the cylinder 9 on the left side of the drawing, the mandrel 9' can be moved within the cylinder 9 towards the right end of the cylinder, creating a vacuum in the chamber to the left of the piston of the cylinder 9. First, a constant and determined pressure is maintained therein (of course less than the constant pressure in the chamber to the right of the piston in the cylinder 9).

The force-reducing device according to the invention has a high operational adaptability and flexibility, since, as explained above, this device is adjusted and counterbalanced by a suitable calibration of the pneumatic cylinder 9 according to the mechanical properties of the strip. It has the advantage of gender.

In addition, this device can continuously and automatically correct the vibrations of the running strip, thereby eliminating the concentration of tension on the strip and improving the quality of the final product. This has the effect of reducing product waste.

The conclusion is that with the present invention, the possibility of the strip breaking during large speed changes of the strip, especially when starting from a standstill at very high speeds, is greatly reduced, resulting in consistently high productivity and higher work efficiency. The benefits include safety, better quality of the final product, less waste product and fewer production line stoppages.

The device for weakening the force of the device can have, in addition to the pneumatic cylinder 9, a hydraulic cylinder or a spring device or any other adjustable device suitable for adjusting and producing a gradual counter-push. .

Another modification is to provide a small pneumatic cylinder between the spring 8 (which has a fixed calibration value) and the head of the axle 9'.

The piston rod of the pneumatic cylinder cooperates with a spring, and the pneumatic cylinder has two chambers, a valve and a control device.

The pressure in the chamber can also be adjusted separately, allowing simple damping or stiffening of the spring to be obtained.

This device is therefore well adapted to different working conditions depending on the different stresses occurring in the strip.

The invention is not limited to the embodiments described, and numerous other modifications may be made without departing from the spirit of the invention.
It is clear that this can be done.

It is understood that all such modifications are within the scope of the present invention.

[Brief explanation of the drawing]

The drawing is a front view of a material supply device for a corrugated board production line incorporating the correction device of the present invention. 1.2...Band material, 3...Reel holder, 5...Intermediate roller, 8...Spring, 9...Empty Pressure cylinder, 11...Guidance roller.

Claims (3)

[Scope of utility model registration request] (1) A device that automatically weakens and compensates for the tensile force acting on the strip material that is subjected to high acceleration during winding, and is installed between the starting point of the rolled strip material and the point where the tensile force is applied. an automatic device comprising: a deflection device that deflects the strip by sliding on a guide device along a predetermined direction; and a deflection device provided on the deflection device and acted on by the strip. The biasing comprises an absorbing device for reducing the force, the biasing being determined by the calibration of the absorbing device, and the biasing is such that a constant drag opposing the force acts on the deflection device to reduce the stress experienced by the strip. The deflection device is configured such that the deflecting force is always lower than the ultimate strength of the strip material, and the deflection device is configured such that the push force received from the strip material along the predetermined direction is gradually retreated in proportion to the force. and the range of this retreat is from one extreme position at which the iron strip is deflected during normal advancement of the strip to the other extreme position at which said strip can advance in a straight line. There is a space between
A compensating device characterized in that the strip material is unwound excessively by this sliding movement of the deflecting device. (2) Utility Model Registration The device according to claim 1, wherein the deflection device has intermediate rollers mounted at opposite ends of each of two shoulders slidable on the guide device. and wherein the absorbent device is attached to each of the shoulders independently of each other. (3) Utility Model Registration The device according to claim 2, wherein the absorption device comprises a pneumatic cylinder that can be calibrated and that the pressing from the strip material counterbalances the force. and is configured such that the deflection device once retreats to the other extreme position and then slowly returns to the one extreme position under continuous constant pressure. Automatic equipment.