JP7122130B2 - Web tension adjustment device and web take-up device - Google Patents

Description

The present invention relates to a device for adjusting tension during winding of a web.

For example, continuous paper fed from a paper feed roll to a printing device is wound up on a take-up roll of a winding device after printing by the printing device. In this case, it is difficult to synchronize the speed of winding the continuous paper by the winding device with the speed of conveying the continuous paper in the printing device. Therefore, in the winding device, the continuous paper needs to be given slack in order to absorb tension fluctuations caused by the speed difference between the transport speed and the winding speed of the continuous paper.

However, if slack remains in the continuous paper wound on the take-up roll, the continuous paper may wrinkle, tear, or have uneven winding. Therefore, the winding device is provided with a tension adjusting mechanism that adjusts the tension of the continuous paper so as to wind the continuous paper around the winding roll without slack.

The tension adjustment mechanism is provided upstream of the winding roll of the winding device. The dancer roller mechanism has upstream and downstream guide rollers and a dancer roller resting on the continuous paper moving between the guide rollers.

The dancer roller is configured to move up and down along the guide. The dancer roller pushes down the continuous paper moving between the upstream and downstream guide rollers by its own weight. Then, the slack amount of the pressed continuous paper is adjusted by the balance between the dead weight of the dancer roller and the tension of the continuous paper (for example, Patent Document 1).

JP 2016-147740 A

By the way, when replacing the paper feed roll that feeds the continuous paper to the printing device, the above-described dancer roller mechanism carries out the work of passing the leading end portion of the continuous paper sent out from the printing device between the two guide rollers and the dancer roller.

During this operation, the dancer roller, which is lowered to the lower end of the guide by its own weight, is moved to the height of the guide roller. Then, the continuous paper is inserted into the gap between the two guide rollers and wound around the lower half of the dancer roller.

Therefore, both the upstream and downstream guide rollers are each arranged at a certain horizontal distance from the dancer roller moved to the height of the guide rollers. This arrangement prevents the dancer roller moved to the height of the guide rollers from interfering with both guide rollers. In addition, a gap necessary for winding the continuous paper around the dancer roller that has moved to the height of the guide roller can be secured between the dancer roller and the guide roller.

Instead, it is necessary to reserve horizontal space inside the take-up device that houses the dancer roller mechanism to accommodate both the upstream and downstream guide rollers. This space leads to an increase in the size of the winding device in the horizontal direction. If the horizontal distance between the upstream and downstream guide rollers is reduced in order to avoid an increase in the size of the take-up device, the workability of the continuous paper feeding operation at the time of replacing the paper feed roll will be sacrificed. put away.

This type of problem occurs not only when the continuous paper used for printing in the printing apparatus is wound, but also when a long web is wound on a winding roll.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a web tension adjusting device suitable for ensuring workability when a web is stretched over dancer rollers and suppressing an increase in the size of the device. and to provide a web take-up device.

To achieve the above object, the web tensioning device according to the first aspect of the present invention comprises:
a pair of guide rollers spaced apart at least in the gravitational direction to guide conveyance of the web;
move within a movement range along a guide extending in a direction intersecting the direction between the rotation axes of the pair of guide rollers at an acute angle, and roll on the web conveyed between the pair of guide rollers, a dancer roller that applies tension to the web according to the amount of movement along the guide from between the pair of guide rollers;
Prepare.

Advantageous Effects of Invention According to the present invention, it is possible to ensure workability when the web is stretched over the dancer rollers and to suppress an increase in the size of the apparatus.

1 is an explanatory diagram showing a schematic configuration of a printing system according to one embodiment of the present invention; FIG. FIG. 2 is an explanatory diagram showing a detailed configuration of the winding machine of FIG. 1; 3 is an explanatory view showing in detail the arrangement of a dancer roller and a pair of guide rollers of the tension adjusting device of FIG. 2; FIG. FIG. 10 is an explanatory diagram showing in detail the arrangement of a dancer roller and a pair of guide rollers of a tension adjusting device according to another embodiment of the present invention; FIG. 4 is an explanatory diagram showing in detail the arrangement of a dancer roller and a pair of guide rollers of a tension adjusting device according to a reference example ;

An embodiment of a printing apparatus according to the present invention will be described below with reference to the drawings. The same or equivalent reference numerals are given to the same or equivalent parts and components throughout each drawing. However, it should be noted that the drawings are schematic and differ from reality. In addition, it is a matter of course that there are portions with different dimensional relationships and ratios between the drawings.

Further, the embodiments shown below are examples of apparatuses and the like for embodying the technical idea of the present invention. Not specific. The technical idea of this invention can be modified in various ways within the scope of claims.

FIG. 1 is an explanatory diagram showing a schematic configuration of a printing system according to one embodiment of the present invention. The printing system shown in FIG. 1 includes a line-type inkjet recording device (hereinafter abbreviated as “inkjet recording device”) 1 and a winder 8 .

The inkjet recording apparatus 1 includes a delivery section 2 , a head-below conveying section 3 and a printer section 4 .

The delivery section 2 has a paper feed roller 2a and a tension adjusting device 2b. Among them, the paper feed roller 2 a feeds the continuous paper 7 drawn out from the paper feed roll 6 of the roll paper storage section 5 to the under-head transport section 3 .

The tension adjusting device 2b is provided between the paper feed roll 6 and the paper feed roller 2a, and has a pair of guide rollers 2c and 2d and a dancer roller 2e.

A pair of guide rollers 2c and 2d are horizontally spaced apart. The distance between the guide rollers 2c, 2d has a dimension greater than the diameter of the dancer roller 2e. The guide rollers 2c and 2d guide the continuous paper 7 conveyed from the paper feed roll 6 to the paper feed roller 2a.

The dancer roller 2e adjusts the tension of the continuous paper 7 by pushing down the continuous paper 7 between the guide rollers 2c and 2d by its own weight. By this tension adjustment, the dancer roller 2e eliminates slack in the continuous paper 7 fed out from the paper feed roll 6. As shown in FIG.

The delivery unit 2 may be separated from the inkjet recording apparatus 1 and configured as an independent feeding device for the continuous paper 7 .

The under-head transport section 3 transports the continuous paper 7 delivered from the delivery section 2 to the downstream side of the printer section 4 with the drive roller 3a.

The printer unit 4 includes four head units 21, 22, 23, and 24 of C color (cyan), K color (black), M color (magenta), and Y color (yellow) held in a head holder 25, and a line. and a sensor 26 .

Each head unit 21 , 22 , 23 , 24 is arranged to face the lower head transport section 3 . Each of the head units 21, 22, 23, and 24 is a line head having a width equal to or greater than the width of the recording area of the continuous paper 7 in the main scanning direction (front and back directions of the paper surface in FIG. 1) perpendicular to the conveying direction of the continuous paper 7. .

Each of the head units 21, 22, 23, and 24 ejects ink in a pattern corresponding to an image onto the continuous paper 7 conveyed by the under-head conveying unit 3 from the nozzles on the surface facing the under-head conveying unit 3. , images are continuously printed on the continuous paper 7 page by page.

The line sensor 26 reads an image printed on the continuous paper 7 by ink of each color CKMY ejected from nozzles (not shown) of the head units 21 , 22 , 23 , and 24 . It is arranged on the transport path of the paper 7 .

The winder 8 receives the continuous paper 7 printed with an image by the printer unit 4 and sent out from the paper discharge port 1a of the inkjet recording apparatus 1 from a receiving port 8c formed on the side surface 8b of the housing 8a. Take up on take-up roll 9 .

Here, for the continuous paper 7 before being wound on the winding roll 9, the speed of conveying the continuous paper 7 by the under-head conveying section 3 of the inkjet recording apparatus 1 and the winding speed of the winding roll 9 should be synchronized. is difficult, it is necessary to have slack to absorb tension fluctuations caused by the speed difference between the two.

However, if the continuous paper 7 wound on the winding roll 9 remains slack, the continuous paper 7 may be wrinkled or torn, and the winding of the continuous paper 7 on the winding roll 9 may be uneven. Therefore, the winder 8 is provided with a structure for winding the continuous paper 7 around the wind-up roll 9 without slack. One of them is the tension adjusting device 10 (corresponding to the tension adjusting device in the claims).

The tension adjusting device 10 is arranged in the vicinity of the receiving port 8c in the housing 8a of the winder 8. As shown in FIG. The tension adjusting device 10 has a pair of guide rollers 11 and 12 (corresponding to the guide rollers in the claims) and a dancer roller 13 (corresponding to the dancer rollers in the claims).

A pair of guide rollers 11 and 12 guide the continuous paper 7 conveyed to the take-up roll 9 from the inlet 8c. The dancer roller 13 pushes down the continuous paper 7 between the guide rollers 11 and 12 by its own weight in the direction of gravity, and applies tension to the continuous paper 7 in the return direction to the receiving port 8c.

The tension adjusting device 10 configured as described above applies a constant tension to the continuous paper 7 in the return direction to the receiving port 8c regardless of whether the speed of conveying the continuous paper 7 and the speed of winding the continuous paper 7 are synchronized. Always give.

Another component provided in the winding machine 8 for winding the continuous paper 7 around the winding roll 9 without slack is a brake unit 14 shown in the explanatory view of FIG.

The brake unit 14 is arranged at a location horizontally spaced from the downstream guide roller 12 . The brake roller 14c has a pair of guide rollers 14a and 14b and a brake roller 14c around which the continuous paper 7 is wound between the guide rollers 14a and 14b.

A pair of guide rollers 14 a and 14 b guide the continuous paper 7 that has passed through the tension adjusting device 10 . The brake roller 14 c brakes the continuous paper 7 conveyed from the tension adjusting device 10 to the take-up roll 9 . For the brake roller 14c, for example, a powder brake that generates a braking force by an electromagnetic clutch using magnetic iron powder can be used.

The brake unit 14 configured in this manner brakes the continuous paper 7 that has passed through the tension adjusting device 10 , and applies tension to the continuous paper 7 in the delivery direction to the take-up roll 9 .

The braking force of the brake unit 14 is determined by the winding speed of the continuous paper 7 by the winding roll 9 . That is, the tension applied to the continuous paper 7 by the braking force of the brake unit 14 has a magnitude corresponding to the winding speed of the continuous paper 7 by the winding roll 9 .

The tension adjuster 10 applies a constant tension to the continuous paper 7 in the return direction to the receiving port 8c, and the brake unit 14 has a magnitude corresponding to the winding speed of the continuous paper 7 by the winding roll 9. The continuous paper 7 whose slack has been eliminated is wound around the winding roll 9 by the tension in the feeding direction to the winding roll 9 applied to the continuous paper 7 at .

The winding roll 9 is rotated by the rotational force of the winding motor 15 reduced in speed by the deceleration mechanism 16 . The rotation speed of the winding motor 15 is adjusted (decelerated) according to the change (increase) in the winding diameter of the continuous paper 7 wound on the winding roll 9 . The rotational force that is decelerated by the deceleration mechanism 16 and applied from the winding motor 15 to the winding roll 9 is set higher than the braking force of the brake roller 14c.

By the way, conventional tension adjusting devices using dancer rollers, such as the tension adjusting device 2b of the feeding section 2 shown in FIG. 2e has a structure to be pushed down by its own weight. Therefore, the dancer roller 2e is configured to move up and down along the direction of gravity so that the dancer roller 2e efficiently pushes down the continuous paper 7 by its own weight.

Therefore, when the continuous paper 7 is passed over the tension adjusting device 2b due to the replacement of the paper feed roll 6, etc., the dancer roller 2e is placed between the two guide rollers 2c and 2d so that the continuous paper 7 can reach between the two guide rollers 2c and 2d. It is moved to the height of the rollers 2c and 2d. Then, the continuous paper 7 inserted through the gaps between the dancer roller 2e and the guide rollers 2c and 2d is wound around the lower half of the dancer roller 2e.

In order to wind the continuous paper 7 inserted through the gaps between the guide rollers 2c and 2d around the dancer roller 2e, it is necessary to secure a gap necessary for the work. Therefore, in the conventional tension adjusting device 2b, the two guide rollers 2c and 2d must be horizontally separated to some extent in order to secure a gap from the dancer roller 2e. However, if the two guide rollers 2c and 2d are horizontally spaced apart, the size of the apparatus in the horizontal direction is unavoidably increased.

Therefore, in the winder 8 of the present embodiment, the configuration of the tension adjusting device 10 is made different from that of the conventional tension adjusting device 2b. The configuration of the tension adjusting device 10 will be described below with reference to the explanatory diagram of FIG. 3 showing the detailed configuration of the tension adjusting device 10. As shown in FIG.

As shown in FIG. 3, the tension adjusting device 10 of the present embodiment is arranged inside the housing 8a of the winding machine 8, near the receiving opening 8c formed in the side surface 8b. Unlike the conventional tension adjusting device 2b, the tension adjusting device 10 has a pair of guide rollers 11 and 12 spaced apart not in the horizontal direction but in the direction of gravity. Therefore, the straight line C connecting the rotation shafts of the pair of guide rollers 11 and 12 extends in the direction of gravity.

It should be noted that the upstream guide roller 11 (corresponding to the upstream guide roller in the claims) in the conveying direction of the continuous paper 7 moves in the gravity direction of the downstream guide roller 12 (corresponding to the downstream guide roller in the claims). is located below the

Further, the dancer roller 13 is rotatably supported by a carriage 13a that moves on the guide shaft G. As shown in FIG. The guide shaft G extends in a direction inclined by an angle θ with respect to the direction of gravity (the direction of the straight line C). The movement distance in the direction of gravity can be shortened, and the space occupied by the tension adjusting device 10 can be reduced in the direction of gravity.

In the tension adjusting device 10 of the present embodiment, the distance L between the rotation axes of the guide rollers 11 and 12 on the upstream and downstream sides is
L=(r1+r2+d3+a)/sin θ
is set to a distance that satisfies the relational expression

In the above relational expression, r1 is the radius of the upstream guide roller 11, r2 is the radius of the downstream guide roller 12, and d3 is the diameter of the dancer roller 13. Further, a is the minimum clearance between the pair of guide rollers 11 and 12 when the dancer roller 13 comes closest to the upstream guide roller 11 arranged below in the direction of gravity.

Furthermore, θ is the angle between the direction between the rotation axes of the guide rollers 11 and 12 on the upstream and downstream sides and the extending direction of the guide shaft G (=the direction of gravity). The reason why the distance L between the rotation axes of the guide rollers 11 and 12 on the upstream and downstream sides is set to a distance that satisfies the above relational expression will be described below.

In the tension adjusting device 10 of the present embodiment, when the dancer roller 13 moves toward the upper limit position within the movement range along the guide shaft G, the dancer roller 13 moves toward the upstream guide roller 11 arranged below in the direction of gravity. Pass the sides from bottom to top.

Therefore, a clearance is required between the upstream guide roller 11 and the dancer roller 13 when the dancer roller 13 passes by the upstream guide roller 11 and the rollers 11 and 13 come closest to each other.

Without this clearance, when the dancer roller 13 passes by the guide roller 11 on the upstream side, the dancer roller 13 contacts the continuous paper 7 wound around the guide roller 11 on the upstream side. When the dancer roller 13 comes into contact with the continuous paper 7 on the upstream guide roller 11 , the continuous paper 7 is wrinkled or torn, and the winding roll 9 of the continuous paper 7 is unevenly wound. Therefore, it is essential to provide a clearance between the upstream guide roller 11 and the dancer roller 13 .

However, if a clearance is provided between the guide roller 11 on the upstream side and the dancer roller 13, the magnitude of the tension generated in the continuous paper 7 from the dancer roller 13 to the guide roller 11 on the upstream side changes depending on the movement position of the dancer roller 13. do. Therefore, in order to minimize the degree of change in tension occurring in the continuous paper 7, it is preferable to minimize the clearance provided between the guide roller 11 and the dancer roller 13 on the upstream side.

Further, in the tension adjusting device 10 of the present embodiment, the dancer roller 13 is brought into contact with the continuous paper 7 in order to adjust the tension generated in the continuous paper 7 between the guide rollers 11 and 12 on the upstream and downstream sides. need to keep

Here, the upstream and downstream guide rollers 11 and 12 are spaced apart in the direction of gravity. Therefore, the dancer roller 13 that contacts the continuous paper 7 between the guide rollers 11 and 12 should be positioned above the guide roller 12 on the downstream side of the guide rollers 11 and 12, which is positioned above in the direction of gravity. no.

Therefore, when the dancer roller 13 moves toward the upper limit position within the movement range, the dancer roller 13 does not pass by the guide roller 12 on the downstream side while being in contact with the continuous paper 7 . Therefore, in order to avoid contact between the guide roller 12 and the dancer roller 13 on the downstream side, it is not necessary to provide a clearance between the rollers 12 and 13 .

Therefore, in the tension adjusting device 10 of the present embodiment,
L=(r1+r2+d3+a)/sin θ
The distance L between the rotation shafts between the upstream guide roller 11 and the downstream guide roller 12 is set so that the relational expression of is satisfied.

This prevents the dancer roller 13 from coming into contact with the upstream guide roller 11 while it is moving, and minimizes the extent to which the tension generated in the continuous paper 7 changes depending on the movement position of the dancer roller 13 .

In addition, in the tension adjusting device 10 of the present embodiment, the upstream and downstream guide rollers 11 and 12 are arranged horizontally without a gap therebetween. For this reason, it is possible to maximize the suppression of the increase in size of the winder 8 in the horizontal direction.

Further, in the tension adjusting device 10 of the present embodiment, the angle θ is 20° or more. In addition, in the tension adjusting device 10 of the present embodiment, the direction of gravity (=the direction between the rotation axes of the guide rollers 11 and 12 on the upstream and downstream sides (the direction of the straight line C)) and the extending direction of the guide shaft G The angle θ1 (=angle θ) is set to 30° or less.

If the angle θ formed by the direction between the rotation axes of the upstream and downstream guide rollers 11 and 12 (the direction of the straight line C) and the extending direction of the guide shaft G is less than 20°, the moving dancer roller 13 may interfere with the guide roller 11 on the upstream side. This is because the horizontal movement distance of the dancer roller 13 relative to the movement distance of the dancer roller 13 along the guide shaft G becomes too small.

Therefore, in order to prevent the moving dancer roller 13 from interfering with the upstream guide roller 11, it is effective to separate the rotational axes of the upstream and downstream guide rollers 11 and 12 in the direction of gravity. If the upstream and downstream guide rollers 11 and 12 are largely separated in the direction of gravity, the moving dancer roller 13 passes by the upstream guide roller 11 by a distance that does not interfere with the upstream guide roller 11 . The dancer roller 13 can be moved horizontally.

However, if the upstream and downstream guide rollers 11 and 12 are separated greatly in the direction of gravity, the space for arranging the pair of guide rollers 11 and 12 must be expanded in the direction of gravity. can no longer be suppressed.

Further, the angle θ1 (=angle θ) formed by the direction of gravity (=the direction between the rotation axes of the guide rollers 11 and 12 on the upstream and downstream sides (the direction of the straight line C)) and the extending direction of the guide shaft G is 30°. , the tension of the continuous paper 7 cannot be sufficiently adjusted by the dancer roller 13 . This is because the sliding resistance between the dancer roller 13 and the guide shaft G increases the mechanical loss (the lubrication of the dancer roller 13 and the magnitude of the load applied from the dancer roller 13 to the continuous paper 7).

Moreover, in addition to the movement space of the dancer roller 13 in the direction of gravity necessary to push down the continuous paper 7 by the weight of the dancer roller 13, the dancer roller 13 in the horizontal direction necessary to move the dancer roller 13 along the guide shaft G is provided. more space to move.

Therefore, it is necessary to ensure a wide horizontal movement space for the dancer roller 13 in the housing 8a of the winding machine 8, and it becomes impossible to sufficiently suppress the increase in the size of the winding machine 8. Moreover, if it becomes necessary to avoid interference with the existing peripheral parts in the housing 8a, it becomes more difficult to avoid an increase in the size of the winder 8.

Therefore, the angle θ formed by the direction between the rotation axes of the pair of guide rollers 11 and 12 (the direction of the straight line C) and the extending direction of the guide shaft G is set to 20° or more, and the direction of gravity (=the direction of the straight line C). and the extending direction of the guide shaft G (=angle .theta.) is in the range of 30 degrees or less. As a result, it is possible to ensure workability when the continuous paper 7 is wound around the dancer roller 13 and to suppress an increase in the size of the winder 8 without impairing the tension adjusting function of the continuous paper 7 by the dancer roller 13. .

In the tension adjusting device 10 of this embodiment configured as described above, the continuous paper 7 received from the receiving port 8c is guided by the guide roller 11 on the upstream side and sent to the lower side of the housing 8a. It is folded back above 8a. The folded continuous paper 7 is guided by the guide roller 12 on the downstream side and conveyed to the brake unit 14 adjacent to the guide roller 12 on the downstream side in the horizontal direction.

Then, the dancer roller 13 pushes down the continuous paper 7 between the upstream and downstream guide rollers 11 and 12 by its own weight in the direction of gravity. At this time, the dancer roller 13 pushes down the continuous paper 7 to a position where the load applied to the continuous paper 7 by its own weight and the tension of the continuous paper 7 are balanced, and adjusts the tension applied to the continuous paper 7 to a constant magnitude.

The dancer roller 13, which pushes down the continuous paper 7 by its own weight, is positioned below the guide roller 11 on the upstream side, within the region described as "tension adjustment control range" in FIG. to move.

Further, when a new continuous paper 7 is conveyed from the ink jet recording apparatus 1 to the winder 8 through the receiving port 8c, the dancer roller 13 is driven by a power source (not shown) to move within the "dancer roller movement range" described in FIG. (corresponding to the working position in the claims), the carriage 13a is moved together.

In this embodiment, the rotation axis of the dancer roller 13 is positioned on the straight line C connecting the rotation axes of the upstream and downstream guide rollers 11 and 12 at the upper limit of the "dancer roller movement range." However, the position of the rotation axis of the dancer roller 13 at the upper limit of the "dancer roller movement range" may be on the inside of the housing 8a (right side in FIG. 3) from the line C, or on the outside of the housing 8a (in FIG. 3). to the left of).

That is, the position of the dancer roller 13 at the upper limit of the "dancer roller movement range" is upstream and downstream of the position of the dancer roller 13 that pushes down the continuous paper 7 by its own weight (the "tension adjustment control range" region in FIG. 3). Any position close to the guide rollers 11 and 12 is sufficient. At the upper limit position of the "dancer roller movement range", the leading end of the new continuous paper 7 can be wound around the lower half of the dancer roller 13 more easily than at the position within the tension adjustment control range.

Here, in the tension adjusting device 10 of the present embodiment, the distance between the upstream guide roller 11 and the downstream guide roller 12 is greater than that of a conventional tension adjusting device in which a pair of guide rollers are horizontally spaced apart. It is secured as a distance L between the rotation shafts.

Therefore, even when the dancer roller 13 is moved to the upper limit position between the pair of guide rollers 11 and 12, the pair of guide rollers are horizontally spaced between the dancer roller 13 and the guide rollers 11 and 12. It is possible to secure a gap greater than that of the conventional tension adjusting device placed in the space.

Therefore, when the new continuous paper 7 is conveyed to the winder 8, the new continuous paper 7 is pushed through the gap in the direction of gravity between the dancer roller 13 at the upper limit position and the guide rollers 11 and 12 on the upstream and downstream sides. The work of winding the continuous paper 7 around the lower half of the dancer roller 13 by inserting the leading end of the roller 13 can be easily performed.

Further, in the tension adjusting device 10 of the present embodiment, the direction between the rotation axes (the direction of the straight line C) of the upstream and downstream guide rollers 11 and 12 is made to coincide with the direction of gravity. Therefore, the distance L between the rotating shafts of the upstream and downstream guide rollers 11 and 12 is zero in the horizontal direction. Therefore, the space for arranging the pair of guide rollers 11 and 12 is smaller in the horizontal direction than in the conventional tension adjusting device in which the pair of guide rollers are arranged with an interval in the horizontal direction.

Therefore, by widening the gap between the dancer roller 13 and the guide rollers 11 and 12 to improve workability when winding the leading edge of the new continuous paper 7 around the dancer roller 13, the housing 8a of the winder 8 can be moved horizontally. It is suppressed that it becomes large in size.

In addition, the direction in which the dancer roller 13 moves along the guide shaft G includes a component in the direction of gravity. The contact between the carriage 13a and the guide shaft G does not interfere.

Therefore, even if the dancer roller 13 is moved in a direction inclined with respect to the direction of gravity, the dancer roller 13 rolls on the continuous paper 7 between the pair of guide rollers 11 and 12, and moves the continuous paper 7 in the direction of gravity due to its own weight. The configuration of pressing down to apply tension to the continuous paper 7 according to the amount of movement along the guide shaft G is ensured without impairing.

According to the tension adjusting device 10 of the present embodiment described above, it is possible to ensure workability when winding the continuous paper 7 around the lower half of the dancer roller 13 and to suppress an increase in the size of the winder 8. can be done.

In addition, in the tension adjusting device 10 of the embodiment described above, the direction between the rotation axes (the direction of the straight line C) of the upstream and downstream guide rollers 11 and 12 is made to coincide with the direction of gravity. However, the direction between the rotation axes of the upstream and downstream guide rollers 11 and 12 (the direction of straight line C) may be inclined with respect to the direction of gravity (the direction of straight line V).

In the tension adjusting device 10 according to another embodiment of the present invention shown in the explanatory diagram of FIG. 4, the direction between the rotation axes of the guide rollers 11 and 12 (the direction of the straight line C) is , in the direction opposite to the direction in which the guide shaft G of the dancer roller 13 extends.

Also in this case, the angle .theta. between the rotation axes of the upstream and downstream guide rollers 11 and 12 (the direction of the straight line C) and the extending direction of the guide shaft G of the dancer roller 13 is set to 20.degree. or more. Also, the angle θ1 between the direction of gravity (the direction of the straight line V) and the direction in which the guide shaft G extends is set to 30° or less.

Furthermore, in the tension adjusting device 10 of each embodiment described above, the extending direction of the guide shaft G is inclined with respect to the direction of gravity (the direction of the straight line V). However, like the tension adjusting device 10 of the reference example shown in the explanatory diagram of FIG. 5, the extending direction of the guide shaft G may be aligned with the direction of gravity (the direction of the straight line V).

In this case, the angle θ formed by the direction between the rotation axes of the upstream and downstream guide rollers 11 and 12 (the direction of the straight line C) and the extending direction of the guide shaft G of the dancer roller 13 is set to 20° or more. Since the direction in which the guide shaft G extends coincides with the direction of gravity (the direction of the straight line V), the limited range of the angle formed by the direction of gravity (the direction of the straight line V) and the direction in which the guide shaft G extends is do not have.

Further, in the tension adjusting device 10 according to each embodiment described above, the distance L between the rotation shafts between the upstream guide roller 11 and the downstream guide roller 12 is
L=(r1+r2+d3+a)/sin θ
However, the distance L between the rotating shafts may be set to a value that does not satisfy the above relational expression.

Further, in the above-described embodiment, the case where the present invention is applied to the tension adjusting device 10 of the winder 8 that winds the continuous paper 7 on which the image is printed by the inkjet recording apparatus 1 has been described. However, the present invention provides a winding device that winds a long web on a winding roll, and a web that rolls on a web conveyed between a pair of guide rollers and rolls along the guide from between the pair of guide rollers. It can be widely applied to a tension adjusting device that applies tension to the web according to the amount of movement.

The embodiments described above disclose the following aspects of the invention.

First, as an invention according to the first aspect,
a pair of guide rollers spaced apart at least in the gravitational direction to guide conveyance of the web;
move within a movement range along a guide extending in a direction intersecting the direction between the rotation axes of the pair of guide rollers at an acute angle, and roll on the web conveyed between the pair of guide rollers, a dancer roller that applies tension to the web according to the amount of movement along the guide from between the pair of guide rollers;
A web tensioning device is disclosed comprising:

According to the web tension adjusting device of the first aspect of the invention, the pair of guide rollers respectively arranged on the upstream side and the downstream side of the dancer roller in the web conveying direction are spaced apart at least in the gravitational direction. be.

Therefore, even if a pair of guide rollers are arranged with a gap in the horizontal direction, even if the same gap is secured between the rotating shafts of both guide rollers, both guide rollers in the horizontal direction can be displaced by the gap in the direction of gravity. Less roller spacing is required.

Therefore, even when the dancer roller moves along the guide to the position between the pair of guide rollers, the same gap as in the conventional art can be secured between the dancer roller and each guide roller.

Moreover, the space for arranging the pair of guide rollers can be made smaller in the horizontal direction than in the conventional art in which the pair of guide rollers are arranged at intervals in the horizontal direction. .

Further, the direction of movement of the dancer roller along the guide, which intersects at an acute angle with the direction between the rotation axes of the pair of guide rollers spaced at least in the direction of gravity, contains a component in the direction of gravity. Therefore, the dancer roller is not prevented from moving downward in the gravitational direction by its own weight within the movement range due to contact between the dancer roller and the guide.

Therefore, the dancer roller that moves within the movement range rolls on the web between the pair of guide rollers, pushes the web down in the direction of gravity by its own weight, and applies tension to the web according to the amount of movement along the guide. is secured intact.

As described above, it is possible to ensure workability when the web is stretched over the dancer rollers and to suppress an increase in the size of the apparatus.

Next, as an invention according to a second aspect,
The dancer roller imparts tension to the web in a control region below the pair of guide rollers in the gravitational direction within the movement range, and moves upward within the movement range when the web is stretched over the pair of guide rollers. A web tensioning device is disclosed that moves to a working position between the guide rollers of the.

According to the web tension adjusting device of the second aspect of the invention, the dancer roller in the control area below the pair of guide rollers in the gravitational direction is moved to the working position between the pair of guide rollers during the web stretching operation. By moving it, it is possible to facilitate the operation of passing the web through the gap between the guide roller and the dancer roller.

Subsequently, as an invention according to a third aspect,
The pair of guide rollers are arranged with the direction between the rotation axes aligned with the direction of gravity, and the direction in which the guide extends is inclined in the range of 20° or more and 30° or less with respect to the direction of gravity. A web tensioning device is disclosed that is:

In the web tension adjusting device according to the first or second aspect of the invention, if the inclination of the extension direction of the guide of the dancer roller with respect to the direction between the rotation axes of the pair of guide rollers is less than 20°, the movement of the dancer roller along the guide The horizontal movement distance of the dancer roller relative to the distance becomes too small, and the moving dancer roller may interfere with the guide roller.

Therefore, in order to prevent the moving dancer rollers from interfering with the guide rollers, it is effective to greatly separate the rotating shafts of the pair of guide rollers in the direction of gravity. If the pair of guide rollers are separated greatly in the direction of gravity, the dancer roller can be horizontally moved by a distance that does not interfere with the guide rollers before the dancer rollers pass by the guide rollers.

However, if the rotation shafts of the pair of guide rollers are greatly separated in the direction of gravity, the space for arranging the pair of guide rollers must be expanded in the direction of gravity. put away.

If the angle formed by the direction of gravity and the direction in which the dancer roller guide extends exceeds 30°, the mechanical loss due to the sliding resistance between the dancer roller and the guide (such as the lubrication of the dancer roller and the load applied to the web from the dancer roller) will occur. size) increases. As a result, the tension of the web cannot be sufficiently adjusted by the dancer roller.

Moreover, in addition to the moving space of the dancer roller in the direction of gravity required to push down the web by the weight of the dancer roller itself, the moving space of the dancer roller in the horizontal direction required to move the dancer roller along the guide increases.

Therefore, it is necessary to secure a wide moving space for the dancer rollers in the horizontal direction in the apparatus, and it becomes impossible to sufficiently suppress the enlargement of the apparatus. Moreover, if it becomes necessary to avoid interference with existing peripheral parts in the apparatus, it becomes more difficult to avoid an increase in the size of the apparatus.

Therefore, in the web tension adjusting device according to the third aspect of the invention, the angle formed by the direction between the rotation axes of the pair of guide rollers and the direction in which the guides of the dancer rollers extend is set to 20° or more, and the direction of gravity and the guides of the dancer rollers The angle formed with the extending direction of is set to 30° or less. As a result, it is possible to ensure workability when the web is stretched over the dancer rollers and to suppress an increase in the size of the device, without impairing the web tension adjustment function of the dancer rollers.

Next, as an invention according to a fourth aspect,
A web tension adjusting device is disclosed in which the pair of guide rollers and the dancer roller are arranged on a conveying path of the web wound on a winding roll.

According to the web tension adjusting device of the invention according to the fourth aspect, in adjusting the tension of the web on the conveying path of the web wound on the take-up roll, the workability when passing the web over the dancer rollers is improved. It is possible to achieve both securing and suppression of an increase in the size of the device.

Subsequently, as the invention according to the fifth aspect,
Of the pair of guide rollers, the radius of the upstream guide roller arranged upstream of the dancer roller in the web conveying direction is r1, the radius of the downstream guide roller arranged downstream of the dancer roller is r2, and d3 is the diameter of the dancer roller, a is the minimum clearance between the dancer roller and the guide roller which is arranged below in the direction of gravity among the upstream guide roller and the downstream guide roller, and the extension of the guide and the direction between the rotation axes is When the angle formed with the direction is θ, the distance L between the rotation axes of the pair of guide rollers is
L=(r1+r2+d3+a)/sin θ
A web tensioning device is disclosed that satisfies the relationship:

In the web tension adjusting device of the invention according to the first, second, third or fourth aspect, when the dancer roller moves toward the upper limit position within the movement range passing between the upstream guide roller and the downstream guide roller, the dancer roller passes from the bottom to the top by the side of the guide roller which is arranged downward in the direction of gravity among the two guide rollers.

Therefore, a clearance is required between the dancer roller and the lower guide roller when the dancer roller passes by the lower guide roller and the rollers are closest to each other. Without this clearance, the dancer roller would contact the web wrapped around the lower guide roller as it passed by the lower guide roller.

However, if a clearance is provided between the lower guide roller and the dancer roller, the magnitude of tension generated on the web on the side of the lower guide roller from the dancer roller changes depending on the moving position of the dancer roller. Therefore, it is preferable to minimize the clearance provided between the two rollers in order to minimize the degree of change in tension occurring in the web.

In the web tension adjusting device of the invention according to the first, second, third or fourth aspect, in order to adjust the tension generated in the web between the upstream guide roller and the downstream guide roller by the dancer roller, the dancer roller is Must be in contact with the web.

Here, the upstream guide roller and the downstream guide roller are spaced apart at least in the gravitational direction. Therefore, the dancer roller in contact with the web is never located above the guide roller which is arranged above the two guide rollers in the gravitational direction.

Therefore, when the dancer roller moves toward the upper limit position within the movement range passing between the upstream guide roller and the downstream guide roller, the dancer roller moves upward in the gravitational direction of both guide rollers while keeping contact with the web. It does not pass by the arranged guide rollers.

Therefore, there is no need to provide a clearance between the dancer roller and the upper guide roller to avoid contact between them.

Therefore, by setting the distance between the rotation shafts of the upstream guide roller and the downstream guide roller so as to satisfy the relational expression of the web tension adjusting device of the invention according to the fifth aspect, both guide rollers can be moved while the dancer roller is moving. It is possible to avoid contacting the guide rollers arranged below one of the rollers in the direction of gravity, and to minimize the degree to which the tension produced in the web varies with the movement position of the dancer rollers.

As a modified example of the invention according to the first, second, third, fourth or fifth aspect,
A web tension adjusting device is disclosed in which the extending direction of the guide can be inclined with respect to the direction of gravity.

Further, as a modified example of the invention according to the first, second, third, fourth or fifth aspect,
A web tension adjusting device is disclosed in which the pair of guide rollers are arranged such that the direction between the rotation axes is aligned with the direction of gravity.

According to this web tension adjusting device, in the web tension adjusting device according to the first, second, third, fourth or fifth aspect of the present invention, the pair of guide rollers are horizontally arranged without being spaced apart. be done. For this reason, it is possible to maximize suppression of an increase in the size of the apparatus in the horizontal direction.

Next, as the invention according to the sixth aspect,
a winding machine for winding the web;
a tension adjustment mechanism that adjusts the tension of the web wound on the winding machine;
A web winding device using the web tension adjusting device according to the first, second, third, fourth or fifth aspect of the present invention as the tension adjusting mechanism is disclosed.

According to the web winding device of the invention according to the sixth aspect, the web tension adjusting device of the invention according to the first, second, third, fourth or fifth aspect is applied to the web to be wound by the winding machine. Therefore, the effects obtained by the web tension adjusting device of the invention according to the first, second, third, fourth or fifth aspects can be obtained.

In addition, as a modification of the invention according to the sixth aspect,
The web tension adjusting device is provided inside the casing, and a pair of guide rollers of the web tension adjusting device are arranged along the side surfaces of the casing. A web take-up device is disclosed.

REFERENCE SIGNS LIST 1 inkjet recording device 1a discharge port 2 delivery unit 2a paper feed roller 2b tension adjustment device 2c, 2d guide roller 2e dancer roller 3 head lower transport unit 3a drive roller 4 printer unit 5 roll paper storage unit 6 paper feed roll 7 continuous paper 8 Winding machine 8a Case 8b Side 8c Receiving port 9 Winding roll 10 Tension adjusting device (tension adjusting device in the claims)
11 upstream guide roller (upstream guide roller)
12 downstream guide roller (downstream guide roller)
13 Dancer rollers (dancer rollers in claims)
13a Carriage 14 Brake Unit 14a, 14b Guide Roller 14c Brake Roller 15 Winding Motor 16 Reduction Mechanism 21-24 Head Unit 25 Head Holder 26 Line Sensor C Straight Line Connecting Rotational Axes of a Pair of Guide Rollers G Guide Shaft L Pair of Guides Distance between roller rotation axes θ Angle between the rotation axes of a pair of guide rollers and the extension direction of the guide shaft θ1 Angle between the direction of gravity and the extension direction of the guide shaft

Claims (6)

a pair of guide rollers spaced apart at least in the gravitational direction and arranged so as to overlap at least partially in the horizontal direction for guiding the conveyance of the web received from the inlet and wound on the take-up roll ;
move within a movement range along a guide extending in a direction intersecting the direction between the rotation axes of the pair of guide rollers at an acute angle, and roll on the web conveyed between the pair of guide rollers, a dancer roller that applies tension to the web according to the amount of movement along the guide from between the pair of guide rollers,
Of the pair of guide rollers, an upstream guide roller on the upstream side in the web conveying direction is arranged lower in the direction of gravity than the downstream roller on the downstream side in the conveying direction.
Web tension adjuster. The dancer roller applies tension to the web in a control region below the pair of guide rollers in the gravitational direction within the range of movement, and moves upward in the range of movement when the web is stretched. 2. A web tensioning device according to claim 1, wherein said web tensioner moves to a working position between said guide rollers. 3. A web tension adjusting device according to claim 1, wherein the extending direction of said guide is inclined in the range of 20[deg.] or more with respect to said inter-axis direction and 30[deg.] or less with respect to the direction of gravity. 4. A web tension adjusting device according to claim 1, wherein said pair of guide rollers and said dancer roller are arranged on a conveying path of said web wound on a winding roll. Of the pair of guide rollers, the radius of the upstream guide roller arranged upstream of the dancer roller in the web conveying direction is r1, the radius of the downstream guide roller arranged downstream of the dancer roller is r2, and d3 is the diameter of the dancer roller, a is the minimum clearance between the dancer roller and the guide roller which is arranged below in the direction of gravity among the upstream guide roller and the downstream guide roller, and the extension of the guide and the direction between the rotation axes is When the angle formed with the direction is θ, the distance L between the rotation axes of the pair of guide rollers is
L=(r1+r2+d3+a)/sin θ
satisfies the relation of
A web tensioning device according to claim 1, 2, 3 or 4. a winding machine for winding the web;
a tension adjustment mechanism that adjusts the tension of the web wound on the winding machine;
Using the web tension adjustment device according to claim 1, 2, 3, 4 or 5 as the tension adjustment mechanism,
Web take-up device.

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