JP2766688B2 - Tenter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tenter clip travel path, and more particularly to a tenter such as a plastic film transverse stretching machine and a cloth tentering machine, which is characterized by a tenter frame shape at a turning portion of the clip.

(Prior art) A tenter clip sandwiches both ends of a film or a fabric flowing from a previous process between a clip lever and a clip table while a main body of the tenter clip runs along a guide rail provided endlessly. Then, the sheet is expanded in the width direction, and the pinching is released when a predetermined width is reached. The tenter clip, which has been released, goes around the turning portion along the guide rail, returns to the tenter entrance portion, and thereafter repeats the above operation.

This will be described with reference to the drawings taking a cloth tentering machine as an example. FIG. 2 schematically shows one clip chain passage of the tentering machine. The chain passage is endless and includes a forward traveling section and a return traveling section. It is assembled from a number of interconnected parts. The two thus joined parts are indicated at 16 and 16 '. These parts which are joined to each other can be swung with each other at various angular positions around the swing midpoint 19 as required. The guide rail 14 for the running rollers of the clip has a path shown by dashed lines and extends through the chain passage sections 16, 16 'and passes over the pivoting midpoint 19.

The chain sprocket 32 drives the chain and engages the chain roller of the clip. The guide rail 14 guides the forward traveling portion and the returning traveling portion to a position immediately adjacent to the chain sprocket 32. In the other turning section of the endless chain path, in contrast, no turning chain sprocket is provided, where the guide rails for the running rollers of the clips are provided.
14 is formed as an arc from one running side to the other.

FIG. 3 is a plan view of the clip turning portion with the help of the chain sprocket 32. FIG. The teeth on the chain sprocket are indicated at 33. The seamless guide rail 14 is sandwiched between fixed parts, for example, angle rails 15. A running locus 28 of the running roller 10 that supports the weight of the clip is shown in the horizontal portion of the angle rail 15. On the chain itself, several clips 1 are shown with their chain rollers 11 and a connection 13 connecting the clips 1 to one another. As can be seen, the teeth 33 of the chain sprocket 32 mesh with the chain roller 11 of the clip. Here, too, the clamping weight is supported by the running rollers 10 in the region of the turning chain sprocket 32, which rolls on the running path 28. Here, the rollers for undertaking the horizontal tension of the clip, ie the rollers 8 and 9, are completely free and can rotate further without any hindrance after leaving the linear part of the guide rail 14. These rollers do not have any shock stoppage and do not have any redirection. Also, the chain roller 11 is not braked or stopped by the chain sprocket 32. This is because it does not change the rotation during transport of the chain, such as by the passage section 16, and is therefore gripped and transported by the teeth 33 of the chain sprocket 32 without any disadvantage.

The lower part of FIG. 3 shows the turning part on the other side of the chain path, from which a continuous seamless guiding device can be seen immediately. The end of the linear portion of the guide rail 14 is a curved portion 34
Connected to. On the straight part, the guide rails 14 are similarly sandwiched between the angle rails 15. This clamping method also continues at the curved portion 34 as an annular portion.

Although the above prior art relates to a cloth tentering machine, even in a plastic film lateral stretching machine, the turning part of the tenter entrance is configured such that the straight part of the guide rail is continuously formed as a tangent to the arc part of the turning part. In general, the clip body is configured to run on a rail.

(Problems to be Solved by the Invention) As described above, the tenter clip device is configured such that the turning portion of the tenter entrance changes from a straight line to a curved line along the guide rail.
Alternatively, the traveling path is switched from a curve to a straight line, but the conventional clip traveling path forms a clip traveling turning section by connecting the arc end and its tangent as described above, and forms an endless circulation path. When the transition from the straight part to the turning part or from the turning part to the straight part on the guide rail,
That is, at the switching point of the clip traveling path indicated by A and D in FIG. As a result, the force acting on the clip changes abruptly, and as a result, noise is generated, the contact portion between the support roller and the guide rail is easily worn, and the life of the support roller and the guide rail is shortened. Problem has occurred.

The present invention has been made in order to solve such a point, and a transition from a straight portion to a turning portion or from a turning portion to a straight portion is made without giving a sudden change in external force to the clip even at the switching point. An object of the present invention is to provide a tenter having a traveling route that can be smoothly performed.

(Means for Solving the Problems) Therefore, the present invention relates to a tenter including a clip body which grips a side end of a film or the like with a stretching portion and circulates a straight portion and a turning portion along a guide rail. The path shape of the portion is formed as a clothoid curve, which is used as a means for solving the problem.

(Operation) The clip traveling on the linear guide rail first shifts from the linear guide rail to a curved guide rail applying a clothoid curve, and then to an arc-shaped guide rail located on the outer periphery of the chain sprocket. As a result, the centrifugal force acting on the clip gradually increases. Further, when shifting from the curved guide rail to the straight guide rail, the centrifugal force acting on the clip gradually decreases.
Therefore, it is possible to avoid a sudden change in centrifugal force that occurs when entering the arc-shaped guide rail on the outer periphery of the chain sprocket directly from the conventional linear guide rail or directly exiting the guide rail from the guide rail part. The smooth movement path of the clip leads to a reduction in noise, abnormal wear of the guide rail, and a longer life of the clip supporting roller.

(Example) Hereinafter, an example of the present invention will be described with reference to schematic diagrams thereof.

FIG. 1 shows the shape of a clip guide rail of a film transverse stretching machine according to one embodiment of the present invention. Clip body (not shown) running while holding a film (for example, Japanese Patent Application No. 59-247544)
Is supported by rollers (not shown) provided opposite to the upper part and the side part of the linear guide rail 100, travels on the linear guide rail 100, and turns at the tenter frame entrance. The present invention is characterized by the shape of the guide rail (that is, the movement locus of the clip body), particularly the shape of the guide rail in the turning portion where the clip body changes direction.

In the present embodiment, the above-mentioned guide rail shape is adopted on the entrance side of the turning portion following the going straight portion, or a clothoid curve whose centrifugal force gradually increases or an approximate curve thereof is adopted, and thereafter, through the arc portion around the chain sprocket. Then, a clothoid curve in which the centrifugal force gradually decreases in a certain section is adopted, and a straight line portion is formed returning from the turning portion outlet. That is, in FIG. 1, the linear guide rail 100 going in the direction of the arrow is connected in the order of a (clothoid) curved guide rail 102 → an arc guide rail 103 → a (clothoid) curved guide rail 105 → a return linear guide rail 100. I have. In the figure, reference numeral 104 denotes a chain sprocket. The definition of the clothoid curve is "a curve in which the curvature (the reciprocal of the radius of curvature) increases uniformly in proportion to the length of the curve."
Is a curve that satisfies the relationship of 1 / R = CL when L is a curve radius and L is a curve length. Here, C is a constant.

On the guide rail having such a shape, the clip body travels on a straight guide rail 100 on a straight path. At the point A, which is a switching point from the straight part to the turning part in the figure, the straight guide rail 100 is connected to a curved guide rail 102 having a clothoid curve, where the clip body shifts from a straight locus to a clothoid locus. The vehicle travels on a locus, and the direction of the clip body changes at a constant angle per unit time from the linear direction. The centrifugal force acting on the clip body at this time Gradually increases and the direction of the clip changes to the chain sprocket.
The angle of contact with the arc guide rail 103 on the outer circumference of 104 becomes almost close, and the centrifugal force at that point B also acts on the clip body on the arc guide rail. Almost approach. Then the clip body is an arc guide rail 10
The vehicle travels along an arc locus on 3 and moves to a curved guide rail 105 having a clothoid curve opposite to the entrance side at point C.

Curved guide rail 105 is straight guide rail 100 at point D
Connect to At this point D, the centrifugal force acting on the clip body is close to zero, and the clip body passes through the point D and continues traveling on the returning linear guide rail to the other turning portion.

The curve guide rail formed by clothoid curve,
In addition to partially using a clothoid curve such as a clothoid arc clothoid as in the present embodiment, the same curve may be used for the entire turning portion of the clip body, for example, and an intermediate arc guide rail in the present embodiment. Alternatively, a linear guide rail may be used.

(Effects of the Invention) As described above in detail, the present invention enters the arc guide rail on the outer periphery of the straight chain sprocket from the conventional straight guide rail by setting a part or the whole of the guide rail of the direction changing portion of the clip body as a clothoid curve. This prevents sudden changes in centrifugal force caused by such a configuration, and also makes the movement trajectories of the clips at the entrance and exit of the chain sprocket smooth, reducing noise and abnormalities in the guide rails. The wear and the life of the clip supporting roller can be extended. In other words, when shifting from the turning part track to the straight part track, or vice versa, the centrifugal force and inertia force of the traveling parts are gradually relaxed, and the linear part is not subjected to a large load due to centrifugal force and inertia force. From the turning part,
Alternatively, it is possible to smoothly travel from the turning part to the straight part. Therefore, damage to the track, abrasion, and generation of noise are suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a running locus and a centrifugal force of a tenter clip according to a typical embodiment of the present invention. FIG. 2 is a plan view showing the entire tenter frame in a conventional cloth spreading machine. Is a detailed configuration diagram of a turning portion of the frame,
FIG. 4 is an explanatory diagram showing a running locus and a centrifugal force of the clip in the same width output machine. Description of main parts in the figure 100 Linear guide rails 102, 105 (Crosoid) Curved guide rail 103 Arc guide rail 104 Chain sprocket

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Minoru Tsukiki 1 Nagoya Equipment Works, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Equipment Works (72) Inventor Toshiro Miki Machiji Takamichi 1 Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (56) References Utaro Majima, Chain Conveyor, pp. 182-183, 17.6 Chain Direction Change / Description and Figures 17, 19, Engineering Books Issued June 20, 1967 (58) Fields investigated (Int.Cl. ⁶ , DB name) B65H 20 / 16,20 / 20 B41J 11/26 G03G 15/00

Claims (1)

(57) [Claims] 1. A tenter provided with a clip body which grips a side end of a film or the like with a stretching portion and circulates a straight portion and a turning portion along a guide rail, wherein a path shape of the turning portion is a clothoid curve. The tenter characterized by.