JPH0442284Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an auxiliary drive device for nip rolls used in, for example, a plastic film take-off device of a plastic film manufacturing apparatus.

[Conventional technology]

BACKGROUND ART Nip rolls such as pinch rolls are used to grip and convey films in longitudinal stretching devices, forming devices, etc. of film manufacturing equipment.

As shown in FIGS. 3 and 4, the film forming apparatus in which the above-mentioned Nippro roll is used is such that the sheet 2 extruded from the die 1 as a molten continuous flow is transferred to cooling rolls A, B, and and an air knife 4 that assists in adhering the sheet to the roll surface.
It is cooled and solidified, taken up by take-up rolls D and pinch rolls E, and wound up by a winder 5.

The cooling roll A is driven by a chain 7 from a variable speed motor 6, and its speed is set by changing the rotational speed of the motor 6. Also, the cooling roll B that the sheet 2 contacts is driven by the drive system of the cooling roll A via a gear 8 and a chain 7, and its speed is set to be the same as that of the cooling roll A. It is considered that the speed difference between the cooling roll A and the cooling roll A can be set in stages.

On the other hand, the cooling roll C is driven via a continuously variable transmission 10, and the speed of the cooling roll A can be increased or decreased. Further, the driving of the take-up roll D can be adjusted in the same manner as the cooling roll C via the continuously variable transmission 11, and the sheet is taken off by pressing the pinch roll E into contact with this roll.

In the above, the structure and operation of a sheet take-up device including a conventional nip roll auxiliary drive device will be described in detail.

The sheet take-up device includes a take-up roll D, a pinch roll E, an arm 12, an air cylinder 13, a motor 14, a belt 15, a pulley 16, and a cam clutch 17.

The pinch roll E is rotatably supported by the arm 12 and moves in an arc around the fulcrum 18 of the arm 12 under the action of the air cylinder 13 to press against or retreat from the take-up roll D. When pressing the pinch roll E against the take-up roll D, the pinch roll E is moved by the motor 14 in order to prevent the running sheet 2 from being broken by the friction shock caused by pressing against the stationary pinch roll E. , belt 1
5, a pulley 16, and a cam clutch 17, and when the rotation is increased to a speed slightly lower than the speed of the sheet, the sheet is brought into pressure contact with the take-up roll D. The cam clutch 17 is rotated by the take-up roll after the pinch roll E is pressed against the cam clutch 17, so that the cam clutch 17 functions to separate the drive device from the pinch roll E.

[Problem that the invention attempts to solve]

Conventional pinch roll drive devices have many components such as motors, belts, pulleys, cam clutches, etc. and are expensive. Furthermore, the motor 14 is rotated for a certain period of time using a timer to accelerate the pinch roll E to a speed close to the sheet speed, but when the sheet speed is changed, it is necessary to change the timer setting time, making the operation complicated. .

The present invention attempts to solve the above problems.

[Means for solving problems]

The present invention provides a take-up device that grips and conveys a sheet or the like between a drive roll and a pinch roll that is provided in pressure contact with the drive roll by a forward/backward drive means, in which a sheet is fixed to a movable part of another forward/backward drive means. A bracket and two rolls rotatably supported by the bracket are provided such that their circumferential surfaces contact the drive roll and the pinch roll, and their circumferential surfaces contact each other.

[Effect]

In the above, when the pinch roll is brought into pressure contact with the drive roll, first the movable part of the other advance/retreat drive means is driven to bring the two rolls into contact with the pinch roll and the drive roll, respectively. Due to the contact between the two rolls, the rotation of the drive roll is gradually transmitted to the pinch roll, and when the circumferential speed of the pinch roll becomes approximately equal to the circumferential speed of the drive roll, the two rolls are retracted and the pinch roll is transferred to the drive roll. Pressure contact.

As a result of the above, it has been possible to realize a device with a small number of parts that can press the pinch roll against the drive roll with a simple operation without giving a shock to the running sheet or the like and causing the sheet to break.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 and 2.

The present embodiment shown in FIGS. 1 and 2 includes a take-up roll D driven by a motor 26, and a pinch roll E that is pressed against or retracted from the take-up roll D by an air cylinder 27 via an arm 25. In the take-up device, a bracket 30 is fixed to a piston rod of another air cylinder 29, and a bracket 30 is rotatably supported by the bracket 30, and the circumferential surfaces thereof are in contact with a take-up roll D and a pinch roll E, respectively. It includes rubber rolls 28, 28a whose circumferential surfaces are in contact with each other.

In the above, the pinch roll E is replaced by the take-up roll D.
The film 22 is pressed between the two rolls.
When trying to grip the rubber roll 2, first extend the piston rod of another air cylinder 29 and
8 and 28a are brought into contact with the take-up roll D and the pinch roll E, respectively, at the positions shown by solid lines in the figure. The rubber roll 28 in contact with the take-up roll D rotates due to frictional force, the rubber roll 28 rotates the rubber roll 28a, and the rubber roll 28a further rotates the pinch roll E. The above rubber roll 28a
When rotating the pinch roll E, the pinch roll E has a larger circumference and a larger inertia than the rubber roll 28a, so it slips and rotates slowly at the initial stage, but gradually accelerates and eventually reaches the same circumferential speed as the take-up roll D. is accelerated to.

After the circumferential speed of the pinch roll E becomes approximately equal to the circumferential speed of the take-up roll D, another air cylinder 29
Shrink the piston rod of the rubber rolls 28, 28a.
is retracted to the position shown by the two-dot chain line in the figure, and then the air cylinder 27 is driven to lower the pinch roll E to the position shown by the two-dot chain line in the figure.
is held between take-up roll D and pinch roll E.

As a result of the above, when the pinch roll is brought into pressure contact with the take-up roll, the rotation of the pinch roll is gradually increased via the rubber roll, and then the running sheet is shocked and the sheet is not broken, and the pressure contact can be made with a simple operation. This was achieved using a device with a small number of parts.

The rubber rolls 28, 28a may have their ends chamfered and moved forward and backward in the axial direction of the pinch roll and take-up roll.

[Effect of idea]

The present invention includes a bracket fixed to the movable part of the forward/backward drive means, and two rolls supported by the bracket that contact the drive roll and the pinch roll, and further rotate while in contact with each other. A device that can press a pinch roll against a drive roll with a simple operation without giving a shock to the sheet or the like and causing it to break was realized with a small number of parts.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is a view taken in the - direction of Fig. 1, Fig. 3 is an explanatory diagram of a conventional device, and Fig. 4 is a - direction view of Fig. 3. It is. 1... Die, 2, 22... Sheet, 3... Cooler, 4... Air knife, 5... Winder, 6... Variable speed motor, 7... Chain, 8... Gear, 9...
...Chain wheel, 10,11...Continuously variable transmission, 12,25
...Arm, 14...Motor, 15...Belt,
16...Pulley, 17...Cam clutch, 18...
...Fully point, 26...Motor, 27, 29...Air cylinder, 28, 28a...Rubber roller, 30...
Bracket, A, B, C...Cooling roll, D...
Takeover roll, E...pinch roll.

Claims (1)

[Scope of utility model registration request] In a take-up device that grips and conveys a sheet or the like between a drive roll and a pinch roll that is provided in pressure contact with the drive roll by an advance/retreat drive means,
A bracket fixed to the movable part of the other advance/retreat drive means, and a bracket rotatably supported by the bracket so that the respective circumferential surfaces contact the drive roll and the pinch roll, and further, the respective circumferential surfaces contact each other. An auxiliary drive device for a nip roll, characterized in that it is equipped with two rolls provided in the .