JPH0417134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a continuous stretching device that stretches a strip-shaped material to be stretched in its width direction while continuously conveying it in its longitudinal direction.

"Prior Art" When manufacturing heat-shrinkable articles, such as heat-shrinkable sheets for protecting cable connections, a preformed product (material to be stretched) is formed into a predetermined shape using a mold. The work of stretching is carried out.

Conventionally, a stretching device used for such stretching operations includes, for example, a pair of gripping tools disposed opposite to each other, and a movement mechanism that relatively moves these gripping tools in the opposing directions, and a stretching device that has been heated in advance. Grasp both sides of the softened preform with gripping tools,
It is designed to be stretched by pulling it on both sides. In other words, in the case of heat-shrinkable sheets, short preforms of several heat-shrinkable sheets are stretched one by one.

"Problems to be Solved by the Invention" By the way, when manufacturing a heat-shrinkable article with a simple shape such as the above-mentioned heat-shrinkable sheet, a long preformed product (heat-shrinkable sheet) is produced by extrusion molding. It is desirable to improve productivity by continuously molding a large number of strip-shaped preforms. However, with the above-mentioned conventional stretching equipment, it is impossible to stretch a long preform in the width direction without cutting it into pieces, and therefore, all manufacturing processes after the stretching process are discontinuous. This type of stretching equipment is the bottleneck for efficiently manufacturing heat-shrinkable sheets.

The present invention was made in view of the above circumstances, and
The purpose is to provide a continuous stretching device that can stretch a strip-shaped material to be stretched in its width direction while continuously conveying it in its longitudinal direction.

"Means for Solving the Problem" In order to achieve the above object, the first invention of the present application uses a pair of endless tracks formed by connecting a large number of gripping tools in a loop shape, and the pair of endless tracks are are arranged so that a part of their circumferential path faces each other, and an extending portion is provided in the opposing portion of the circumferential path, and the opposing interval gradually widens in the circumferential direction of the endless track, and each gripping tool has a pair of chips. The tracking blocks are connected so as to be able to approach and separate and are biased in the approach direction, and furthermore, guide members for guiding the tracking blocks in the separation direction are arranged on the circumferential path before and after the extension part. It is a feature.

Further, the second invention of the present application is characterized in that, in addition to the structure of the first invention, the circumferential path is configured to be movable in the opposite direction, and an interval adjustment mechanism for moving the circumferential path is provided.

Furthermore, in addition to the configuration of the first invention, the third invention of the present application provides cooling for cooling between both circumferential paths between the extending part and the guide member in front of the extending part (in front of the extending part in the circumferential direction of the endless track). It is characterized by the arrangement of a mechanism.

"Function" According to the first to third inventions described above, when the endless track is rotated, each gripping tool is guided by the guide member before and after the extension part and performs opening and closing operations (separating both chucking blocks). and then bring them closer again). Therefore, by feeding the tip of the softened belt-shaped material to be stretched between the two endless tracks, each gripper of the two endless tracks sequentially chucks both side edges of the material to be stretched at the rear position of the stretching section. It is held between blocks and conveyed in the circumferential direction. When the gripper reaches the stretching section, the distance between the circumferential paths gradually widens, so the gripper conveys the material to be stretched and stretches it in the width direction. Release the grip and circulate again to the rear position of the stretching section.

Further, according to the second invention, by operating the distance adjustment mechanism, the distance between the opposing portions, that is, the extending portion and the circumferential paths before and after the extending portion is changed.

Furthermore, according to the third aspect of the invention, the cooling mechanism cools the material to be stretched immediately after it has been stretched, and which is still being held by the gripper.

"Example" Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 schematically shows the overall structure of an embodiment of the present invention, and reference numerals 1 and 1 in the figure represent a pair of endless tracks. These endless tracks 1, 1 are made to rotate in opposite directions to each other along respective circumferential paths (paths formed by the chain guide 2, sprocket wheel 3, etc.) laid in a loop in a substantially horizontal plane. Parts of both circumferential routes are arranged to face each other on the left and right. The opposing parts of both circular paths have an opposing interval W.
There is an extended portion 4 that gradually widens toward the front of the running direction of the endless track 1 (the circumferential direction of the opposing portion, that is, the direction of arrow A in FIG. A parallel portion 5 is formed. Further, guide members 6 and 7 for guiding a chucking block, which will be described later, are provided on the circular path at the rear of the extending section 4 and at the front of the parallel section 5, respectively. These guide members 6 and 7 are, for example, rails that are inclined so as to gradually increase in height toward the front, as shown in FIG. These guide members 6, 7 and the circumferential path (that is, the chain guide 2, sprocket wheel 3, etc.) are configured to be able to move in opposite directions (the direction of arrow B in FIG. 1).
An interval adjustment mechanism 8 for adjusting the facing interval W by moving these is connected to both the circumferential paths. Moreover, cooling mechanisms 9 (see FIG. 2) are disposed above and below the parallel portions 5 to spray a refrigerant (for example, cold air, cooling gas, etc.) into the space between the parallel portions 5.

On the other hand, the endless track 1 has a large number of gripping tools 10...
Each gripping tool 10 is provided with a pair of upper and lower chucking blocks 12 and 13 as shown in FIG. 3.
The lower tracking block 12 is the chain 11
The upper chuck block 13 is connected to the lower chuck block 12 via a rod 14 so as to be able to slide (approach and separate) in the vertical direction. Also, the upper tracking block 1
3 is provided with an engagement groove 15 along the extending direction of the endless track 1 on its lower surface, and is provided with a hook 16 on its upper portion that can be engaged with the guide members 6 and 7.

Next, a method of operating the apparatus and its operation when stretching a heat-shrinkable sheet preform (indicated by reference numeral A in the figure) using the connected stretching apparatus configured as described above will be described. However, preformed product A
is, for example, a continuously extruded band-shaped plastic molded product, and projecting ridges a, a projecting from one side of the product are formed on both sides of the product as shown by the chain lines in Figure 3. .

First, the interval adjustment mechanism 8 is operated to move the chain guide 2, sprocket wheel 3, etc. in the opposing direction, and the opposing interval W between the circumferential paths is set to a desired interval. In other words, the opposing distance W at the rear position of the stretching portion 4 is adjusted to the width dimension of the preform A, and the opposing distance W in the parallel portion 5 is adjusted to the width dimension after stretching (width dimension determined by the desired stretching ratio). match. Then, the cooling mechanism 9 is activated and the sprocket wheel 3 is driven to continuously rotate the endless tracks 1,1. At this time, since the upper chucking block 13 is urged downward (in the approach direction) by gravity, each gripping tool 10 is attached to both chucking blocks 12, 13
As shown in Figure 3, the vehicle attempts to travel along the circuit route while approaching the vehicle as shown in Figure 3. However, when the guide members 6, 7 reach the position, the guide members 6, 7 engage with the hook 16 and the upper chuck block 13
As a result, each gripping tool 10 separates both chucking blocks 12 and 13 (opening operation, see FIG. 2), and guides the guide member 6,
7, the upper chucking block 13 falls, and the opening/closing operation is performed by bringing both chucking blocks 12 and 13 closer together again (closing operation).

In such an operating state, when the preform A, which has been heated and softened in advance, is made almost horizontal and its tip is fed between the two endless tracks 1, 1 from the rear of the extending section 4, it first passes through the guide member 6. Immediately after the gripping tool 10 closes, both chucking blocks 1
Grip both side edges of the preform A between 2 and 13. At this time, the engaging groove 15 of the upper tracking block 13 engages with the protrusions a, a of the preform A as shown by the chain lines in FIG. And the first gripper 10
As the leading end of the preform A is conveyed in the running direction, the subsequent gripping tools 10... grasp the preform A one after another and convey it together. Next, the gripping tools 10 in the gripping state are attached to the extending portion 4.
When reaching the end, the distance W between the two orbiting paths gradually widens, so the gripping tools 10 of the two endless tracks 1 gradually widen the distance between them. While conveying it in the direction (direction A in FIG. 1), it is stretched in the width direction (direction B in FIG. 1). At this time, a reaction force is generated in the preform A against the tension during stretching, and this reaction force tries to remove both side edges from the gripping tool 10, but the engagement between the engagement groove 15 and the protrusion a prevents this. Subsequently, when the gripping tools 10 reach the parallel portion 5, the cooling mechanism 9 cools the preform A just after being stretched from above and below. Due to this cooling action, the preformed product A after stretching is hardened while its both side edges are gripped (in a state where it is taut due to tension), so that the waving phenomenon of the sheet that tends to occur after the grip is released is less likely to occur. After that, the gripping tools 10... reach the guide member 7 and hold both the chucking blocks 12, 13.
, and the stretched preform A is released and circulated to the rear position of the stretching section 4 again. Therefore, the released preform A is either continuously conveyed as is to the next process, or wound up on a bobbin or the like.

On the other hand, FIGS. 4 to 6 show other embodiments of the present invention. In these figures, the endless track 17,
17 are configured to be rotated in the same direction along respective circular paths that draw loops in a substantially vertical plane, and are arranged such that a portion of both circular paths are opposite to each other on the left and right. That is, in this case, the endless track 17 is formed by connecting a large number of gripping tools 10 by a so-called curved chain 18.
Since such a stretching device has the circular path of the endless track 17 in a vertical plane, it occupies a smaller area than the stretching device of the above embodiment, and is suitable for installation in a limited space.

In the above embodiment, the two circumferential paths are opposed to each other laterally, but they may be opposed to each other in any direction, such as vertically or diagonally. In addition, when the circumferential paths are arranged to face each other left and right, there is an advantage that the upper tracking block 13 can be biased downward by gravity.
2 and 13 may be arranged upside down, and the tracking block 13 may be biased upward by a spring or the like, and the tracking block 13 may be guided downward by a guide member. Furthermore, a belt may be used instead of the chain 11 or the curved chain 18, and instead of connecting the two connecting blocks 12 and 13 via the rod 14, they may be connected by a hinge.

"Effects of the Invention" As explained above, according to the first invention of the present application, a pair of endless tracks formed by connecting a large number of gripping tools in a loop shape is prepared, and a part of the orbiting path of these endless tracks is They are arranged so as to face each other, and extending portions are provided in opposing parts of the circumferential path so that the opposing interval gradually widens in the circumferential direction of the endless track, and each gripper connects a pair of chucking blocks so as to be able to move toward and away from each other. At the same time, guide members are disposed on the circumferential path before and after the extending portion to guide the tracking block in the separating direction, so that the following effects can be obtained.

When the endless track is rotated, each gripper is guided by a guide member before and after the extending portion to perform opening and closing operations. Therefore, when the tip of the strip-shaped material to be stretched is fed between the two endless tracks, the gripping tools of the two endless tracks sequentially grip both side edges of the material to be stretched at the rear position of the stretching section and convey it in the circumferential direction. When reaching the stretching section, the material to be stretched is conveyed and stretched in the width direction, and then, at the front position of the stretching section, the material to be stretched is released and circulated again to the rear position of the stretching section. That is, it is possible to automatically stretch the strip-shaped material to be stretched in the width direction while continuously conveying it in the longitudinal direction, and it is possible to significantly improve the productivity of heat-shrinkable articles.

Further, according to the second invention of the present application, in addition to the structure of the first invention, the circumferential path is configured to be movable in the opposite direction, and an interval adjustment mechanism for moving the circumferential path is provided, so that in addition to the above-mentioned effects, The following effects can be obtained.

By activating the spacing adjustment mechanism and moving the circumferential paths in opposing directions, the opposing spacing at the rear position of the extending section can be freely adjusted to match the width dimensions of various preforms, and the parallel A desired stretching ratio can be set by freely adjusting the opposing distance in the parts.

Furthermore, according to the third invention of the present application, in addition to the configuration of the first invention, a cooling mechanism is provided between the extension part and the guide member in front of the extension part to cool the space between both the circumferential paths. In addition to the effect of invention 1, the following effects can be obtained.

The cooling mechanism cools the material to be stretched, which has just been stretched and is still being held by the gripping tool. Therefore, since the preformed product after stretching is cured while remaining taut due to the tension during stretching, the waving phenomenon of the sheet that tends to occur after the grip is released is less likely to occur.
In other words, a heat-shrinkable article of excellent quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an embodiment of the present invention;
2 is a view taken along the - line in FIG. 1, FIG. 3 is a view taken along the - line in FIG. 1, FIG. 4 is a schematic plan view showing another embodiment of the present invention, and FIG. V-V in Figure 4
6 is a view taken along the - line in FIG. 5. 1, 17... endless track, 4... extension section, 5...
Parallel portion, 6, 7... Guide member, 8... Spacing adjustment mechanism, 9... Cooling mechanism, 10... Gripping tool, 11...
... Chain, 12, 13 ... Chucking block, 15 ... Engagement groove, 16 ... Hook, 18 ...
Curved chain, A... Preformed product, a... Projection, W... Opposing distance.

Claims (1)

[Scope of Claims] 1. A pair of endless tracks 1 are arranged so that parts of their circular paths are opposite to each other, and the opposing interval W gradually increases in the opposing portions of the circular paths in the circumferential direction of the endless tracks. An extension part 4 is provided, and the endless track is formed by connecting a large number of gripping tools 10 in a loop shape, and each gripping tool has a pair of chucking blocks 12,
13 are connected so as to be able to approach and separate, and are biased in the approaching direction, and furthermore, guide members 6 and 7 for guiding the chucking block in the separating direction are respectively disposed on the circumferential path before and after the extending portion. A continuous stretching device characterized by: 2. A pair of endless tracks 1 are arranged so that a part of their circumferential paths are opposite to each other, and extending portions 4 are provided in opposing parts of the circumferential paths, the opposing distance W gradually increasing in the circumferential direction of the endless tracks, Moreover, the circumferential path is configured to be movable in the opposite direction, and an interval adjustment mechanism 8 is provided for moving the circumferential path, and the endless track is formed by connecting a large number of gripping tools 10 in a loop shape, and each gripping tool has two A pair of tracking blocks 12 and 13 are connected so as to be able to approach and separate from each other and are biased in the approach direction, and furthermore, a guide is provided on the circumferential path before and after the extension portion to guide the tracking blocks in the separation direction. A continuous stretching device characterized in that members 6 and 7 are respectively provided. 3 A pair of endless tracks 1 are arranged so that a part of their circumferential paths are opposite to each other, and extending portions 4 are provided in opposing parts of the circumferential paths, the opposing distance W gradually increasing in the circumferential direction of the endless tracks, The endless track is formed by connecting a large number of gripping tools 10 in a loop shape, and each gripping tool has a pair of chucking blocks 12,
13 are connected so as to be able to move toward and away from each other and are biased in the approaching direction, and furthermore, guide members 6 and 7 for guiding the chucking blocks in the separating direction are respectively disposed on the circumferential path before and after the extending portion. ,Moreover,
A continuous stretching apparatus characterized in that a cooling mechanism 9 is provided between the stretching section and the guide member in front of the stretching section to cool the area between both circumferential paths.