JPH0433701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a nip mechanism in a sheet conveying device used in the manufacturing process of sheets such as synthetic resin films.

[Prior art]

For example, in an apparatus for producing a sheet-like material from a polymer, a conveying device is used to transport the sheet-like material between each process such as a sheet stretching process. With this device, in order to prevent fluctuations in the previous process from being transmitted to the winding and other subsequent processes, and conversely, to prevent fluctuations in the latter process from being transmitted to the previous process, the device further eliminates slippage between the roll and the sheet material. A nip mechanism is used to stabilize the conveyance of objects.

The nip mechanism commonly used in the past consists of one or two drive rolls in fixed positions and one free roll that is swingable by a swing mechanism.

If all the rolls are driven in such a conveyance process using a set of rolls, it is necessary to keep the circumferential speed of each roll very strictly the same. In other words, if there is even a slight difference in the circumferential speed of each roll, the sheet-like material will be scratched or wrinkled.
Further, if the difference in the circumferential speed of each roll is large, the sheet-like material may break.

In order to solve the above problem, in a nip mechanism consisting of two or three rolls, one of the rolls is a free roll. However, when one roll is a free roll as in such a conventional nip mechanism, the moment this free roll is pressed against the drive roll, the free roll changes from zero circumferential speed to a circumference equal to the circumferential speed of the drive roll. is rapidly accelerated to speed. As a result, slipping occurs between the drive roll and the free roll, which often causes the sheet material sandwiched between the two rolls to break, and the roll surface is also heavily worn. Furthermore, if the sheet-like material breaks, problems such as winding around the roll may occur.

The above-mentioned problems reduce the yield of sheet manufacturing, and when a broken sheet gets wrapped around a roll, the operation must be stopped and the wrapped sheet must be removed before operation can be resumed. Not only that, but the operation is stopped during that time, which lowers the operating rate.

In particular, today's sheet-like manufacturing equipment tends to be faster and wider, and the higher the speed, the wider the rolls, and the larger the rolls, the more the above problems occur. This is easy to do, and it takes a long time to process when it occurs.

[Problem that the invention seeks to solve]

Due to the above-mentioned circumstances, it is necessary to keep the circumferential speed of the drive roll and free roll almost constant during pressure contact, so that the sheet-like material does not wrinkle or break during transportation. .

[Means for solving problems]

In the present invention, when the free roll is separated from the drive roll, the drive means rotates the free roll at a circumferential speed close to the circumferential speed of the drive roll, and the free roll is separated from the drive means at least immediately before the free roll is pressed against the drive roll. By ensuring that
The circumferential speed of the free roll becomes equal to the circumferential speed of the drive roll in a short time after crimping, and the change in the circumferential speed at that time is made small.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention,
In this figure, 1 is a drive roll, 2 is a free roll configured to be crimped onto or separated from the drive roll 1 by the means described later, and 3 is fixed to the end of the shaft 4 of the free roll 2. The pulley 5 is a belt that is passed around the drive pulley 6 and the idler 7, and this belt 5 is the first belt.
As shown in Figure A, the free roll 2 is the driving roll 1.
When the free roll 2 is pressed against the drive roll 1, it is separated from the pulley 3, and when the free roll 2 is separated from the drive roll 1 as shown in FIG.

Since the structure is as described above, the first
In a state where the free roll 2 is separated from the drive roll 1 as shown in FIG. B, the pulley 3 of the free roll 2 is pressed against the belt 5 being moved by the drive pulley 6, so the free roll 2 is rotated. When this state is changed to the state in which the free roll 2 is pressed against the drive roll 1 as shown in FIG. 1A, the pulley 3 is separated from the belt 5 and the free roll 2 is rotated by the rotation of the drive roll 1. Since the free roll 2 is rotated in advance before being pressed onto the drive roll 1 in this way, the difference between the circumferential speed of the drive roll 1 and the circumferential speed of the free roll 2 is small. It becomes circumferential speed. In this case, it is desirable to set the moving speed of the belt 5 so that the circumferential speed of the free roll 2 is approximately equal to the circumferential speed of the drive roll.

As a means for press-bonding and cutting the free roll 2 to the drive roll 1, the means shown in FIG. 5 or 6 can be considered.

FIG. 5 shows a shaft 2 with a free roll 2 supported at one end.
It consists of an arm 21 that can rotate around 2, and a cylinder 23 with the tip of a rod 24 fixed to the other end of the arm 21.The arm 21 is rotated by the cylinder 23, and the free roll 2 is turned into a solid line. The state is changed from a state in which it is crimped to the drive roll 1, as shown by a dashed line, to a state in which it is separated from the drive roll 1, as shown in a chain line. Further, 30 is a sheet-like material.

In FIG. 6, by moving the free roll 2 in a straight line using the slide rail 25, the free roll 2 is converted between a state in which it is pressed against the drive roll 1 as shown by a solid line and a state that it is separated from the drive roll 1 as shown in a chain line. This is how it was done.

FIG. 2 is a diagram showing the configuration of a second embodiment of the present invention, similarly, A shows a state in which the free roll 2 is pressed against the drive roll 1, and B shows a state in which the free roll 2 is pressed against the drive roll 1.
is away from the drive roll 1.

In this second embodiment, an idler that movably holds the belt is made swingable, so that the tension on the belt is always approximately constant. In other words, in Fig. 2, 8 is another idler, 9 is an arm rotatably supported around a fulcrum shaft 10, the idler 8 is attached to its tip, and the other end is connected to the rod 12 of the cylinder 11. has been done. Note that 13 is an air supply path for pressure adjustment. Since the other configurations are substantially the same as those of the first embodiment shown in FIG. 1, the same parts are given the same reference numerals in the drawings, and the explanation of each part will be omitted.

Since this embodiment has the above configuration, the position of the swingable idler 8 is adjusted by adjusting the pressure of the air from the air supply path 13 that is supplied only to the rod side, and the belt 5 is The tension can be adjusted. Furthermore, the free roll 2 when changing between the state in which the free roll 2 is pressed against the drive roll 1 as shown in FIG. 2A and the state in which the free roll 2 is separated from the drive roll 1 as shown in FIG. 2B. Even if the path of the belt 5 by the pulley 3 provided in the belt changes and the idler 8 moves to follow this change, the belt 5 is always held at a constant tension. In this case, a spring may be used instead of the cylinder 11, but in the case of a spring, the tension of the belt changes depending on the displacement of the spring, so it is preferable to use the illustrated cylinder.
A similar effect can also be obtained by slidably holding the support member of the idler 8, attaching a rack to the support member, meshing the pinion with the rack, and applying a constant torque to the pinion.

In this embodiment, a system in which the idler swings using the arm 9 is adopted, but a system in which the idler slides on a straight line may also be used.

In addition, it is also possible to make the idler 7 swing in the first embodiment to provide the same effect as this embodiment.

In the first embodiment and the second embodiment, a belt 5, a drive pulley 6, and idlers 7, 8 are used, but instead of these, other transmission means such as a chain and sprocket or a rope and a rope wheel may be used. However, it is possible to construct a nip mechanism having the same functions and effects as those of both of the above embodiments. However, in the case of a transmission means consisting of a chain and a sprocket, care must be taken to ensure smooth connection between the sprocket provided at the shaft end of the free roll 2 and the chain.

FIG. 3 is a diagram showing a third embodiment of the present invention. This embodiment differs from the other embodiments in that the rotation of the drive pulley is not transmitted via a belt but directly to a pulley provided on the free roll. That is, as shown in FIGS. 3A and 3B, the free roll 2 is moved with respect to the drive pulley 6 fixedly arranged at a specific position, and the pulley 3 changes to the separated position and the crimping position, thereby causing the In the crimping position shown in FIG. 3B, the rotation of the drive pulley 6 is transmitted to the pulley 3 of the free roll 2 by frictional transmission.

In this case, in addition to the friction transmission using the pulley, the driving pulley 6 and the free roll pulley 3 may be replaced with gears, etc., and transmission may be performed by meshing teeth. However, in this case as well, care must be taken to ensure that the gears mesh smoothly.

FIG. 4 shows a fourth embodiment of the present invention, in which a clutch is used to connect and disconnect the drive source for pre-rotating the free roll. In the figure, reference numeral 21 denotes an arm, for example, as shown in FIG. 5, which moves to hold the free roll 2 and change the state between the state of contact with the drive roll 1 and the state of separation. Reference numeral 15 indicates brackets 16 and 17 attached to the arm 21 with a clutch.
It is maintained at 18 is a coupling that connects the clutch 15 to the shaft 4 of the free roll 2, which is rotatably supported by a bearing 19;
20 is a drive source for rotating the free roll 2.

In this embodiment, just before the free roll 2 is pressed against the drive roll 1, the clutch is disengaged by the action of a limit switch (located, for example, at the position indicated by reference numeral 26 in FIGS. 5 and 6). , the free roll 2 can now rotate freely. Conversely, when the free roll 2 separates from the drive roll 1, it is connected and rotated by the drive source 20.

In FIG. 4, the clutch 15 is attached to the arm by brackets 16, 17, but the coupling 1 between the free roll 2 and the clutch 15 is
It is also possible to attach it to a location other than the arm by making 9 an eccentric coupling, or by using a transmission mechanism using a belt, chain, etc.

Although a limit switch is shown in FIGS. 5 and 6, a limit switch is not particularly required in embodiments other than this fourth embodiment.

In addition to the above-mentioned embodiments, the free roll is connected to a drive source via a one-way clutch, and the rotation speed of the free roll by the drive source is made smaller than the rotation speed of the drive roll, thereby making the free roll free. When the roll is separated from the drive roll, it may be rotated at a slower circumferential speed than the drive roll, and when it is pressed against the drive roll, it may be slightly accelerated by the drive roll and then rotated at the same speed as the drive roll. During this pressure bonding, the circumferential speed of the drive source for rotating the free roll is smaller than the circumferential speed of the drive roll, so the free roll is in a free state due to the one-way clutch.

As a drive source for preliminary rotation of the free roll in each of the above embodiments, a drive motor exclusively for preliminary rotation may be provided. However, since the conveyance speed of the sheet material is changed as appropriate, the speed of the free roll 2 must also be changed in order to always keep the rotation of the drive roll and the preliminary rotation of the free roll 2 at almost the same speed. Providing a speed control mechanism like this increases costs and is not desirable. Therefore, it is desirable that the rotation by the drive motor used to rotate the drive roll 1 is transmitted by a transmission mechanism and used as a drive source. In this case, when the free roll 2 is pressed against the drive roll 1, there is no need to rotate the free roll, but only when the free roll is separated from the drive roll, the preliminary rotation is performed, and then immediately before the free roll is pressed against the drive roll. The speed should be approximately equal to the rotational speed of the drive roll. Therefore, in the first to third embodiments, the clutch is installed between the drive motor that rotates the drive roll 1 and the drive pulley, and in the fourth embodiment, the clutch is installed between the drive motor that rotates the drive roll 1 and the clutch. The clutch may be provided so that it can be driven only when necessary. The clutch used at this time must be a powder clutch or a friction clutch, since it is necessary to turn the clutch on and off while the drive motor is in operation.

〔Effect of the invention〕

As explained in detail above based on the examples,
The nip mechanism of the present invention is designed so that the circumferential speed of the free roll is always approximately equal to the circumferential speed of the drive roll before crimping the free roll to the drive roll, thereby eliminating sudden speed changes during crimping. There is no breakage or wrinkles, and there is no roll wear.

[Brief explanation of drawings]

Figures 1 to 4 show the first nip mechanism of the present invention.
Figures 5 and 6 showing the configuration of the fourth embodiment
In both figures, the free roll is crimped to the drive roll,
It is a figure which shows the mechanism when separating. 1... Drive roll, 2... Free roll, 3...
...Pulley, 4...Free roll shaft, 5...Belt, 6...Drive pulley, 7, 8...Idler, 9...Arm, 11...Cylinder, 15...
...Clutch, 20... Drive source, 30... Sheet-like material.

Claims (1)

[Scope of Claims] 1. A drive roll for conveying a sheet-like object, a free roll disposed so as to be able to press against and separate from the drive roll, and a peripheral speed of the free roll that is approximately the same as the circumferential speed of the drive roll. A nip mechanism in a sheet conveying apparatus, comprising a drive source for providing preliminary rotation at a speed, and a rotation transmission means configured to transmit the rotation by the drive source when separating the sheets, and cut off the rotation at least before pressing. 2. The rotation transmission means includes a pulley rotated by the drive source, at least one idler, and a belt hung around these pulleys and the idler, and the pulley provided on the shaft of the free roll rotates only when the free roll is separated. A nip mechanism in a sheet conveying device according to claim 1, which is configured to be crimped onto a belt. 3. Sheet material conveyance according to claim 2, wherein one of the idlers is connected and held to a tension adjusting means, whereby the tension of the belt is maintained at a desired value and substantially constant at all times. Nip mechanism in equipment. 4. A nip mechanism in a sheet conveying device according to claim 1, wherein a pulley provided on the shaft of the free roll is directly pressed against a pulley rotated by the drive source when the free roll is separated. 5. The shaft of the free roll is connected to the drive source via a clutch, and the clutch switches transmission or disconnection based on a signal from a position detecting means that detects a position of the free roll to separate or press it. Nip mechanism in the sheet material conveying device in range 1. 6. Claims 1, 2, 3, and 3, in which the drive motor for rotating the drive roll is transmitted via a clutch in order to be used as the drive source.
Nip mechanism in the sheet conveyance device of 4 or 5.