JPH022581Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a clamp jacket for a continuous vacuum forming apparatus.

(Prior art and its problems) Continuous vacuum forming machines are mainly used for mass production of lightweight containers, and as shown in FIG.
Automatic intermittent transport of the sheet 14 through the sheet 13 to trimming or shearing (not shown) is provided. The heating method for the heating zone 12 is mainly a radiation heating method, and while the sheet 14 has finished moving and the heating/forming work is in progress, both sides are heated to prevent this radiant heat from directly transmitting to the molding zone 13. During steps 12 and 13, a pair of upper and lower heat shielding structures called "clamp jackets" 15 as shown in FIG. is provided between the seat 14 and movable up and down. If the temperature of the clamp jacket is too low, the surrounding sheet will absorb heat from the clamp jacket, and sufficient heating will not occur on the heating zone side, and the heat retention of the sheet will decrease on the forming zone side, resulting in poor molding. It does not elongate well over time and becomes thicker than other parts. On the other hand, if the temperature of the clamp jacket is too high, excess heat will be applied to the sheet, which will reduce the tensile modulus of elasticity in the part near the clamp jacket, making it thinner than other parts. In addition, the sheet shrinks differently depending on the temperature, so if the temperature is low, the molded product will warp in a concave shape, and if it is high, it will tend to warp in a convex shape. As described above, in vacuum forming, the clamp jacket plays an important role in preventing the occurrence of defective products. In order to make full use of its function, conventional clamp jackets have a width l in the sheet feeding direction (hereinafter referred to as the "sheet feeding width") due to their structure.
It was required to take at least 20mm. but,
While the heating and forming operations are progressing in continuous vacuum forming, the sheet portion corresponding to the sheet feed width that is narrowed by the clamp jacket is not involved in any of the operations, resulting in loss and reducing the product yield. decrease. This means that the length of the forming zone is
In a 900mm vacuum forming machine, it accounted for 2.2% of the total sheet, a value that could not be ignored in terms of process control.

(Means for solving the problem) This invention has a high heat shielding function, and as a result, it is possible to narrow the feed width of the sheet than before, and the continuous vacuum forming can improve the product yield. This is intended to provide a clamp jacket for the device, and the gist is that the sheet contact surface thereof is provided with sawtooth-like irregularities.

To explain this, the inventor of the present invention explains why the shielding effect does not occur unless the contact area is increased in conventional clamp jackets.If the cooling surface of the clamp jacket is brought into direct contact with the sheet surface, We believe that this is because heat is transmitted horizontally through the sheet, and we have arrived at this idea after various studies on ways to stop this flow. The clamp jacket of the present invention, which has serrated irregularities on the contact surface with the sheet, has an excellent heat shielding function because when the sheet is gripped by the clamp jacket, these serrations touch the sheet surface from above and below. This is thought to be due to the fact that the jacket's cold and heat acts effectively on the sheet through the serrations, preventing heat transfer from the sheet.

Next, the present invention will be explained in more detail based on the embodiment shown in FIGS. 1 to 3.

(Example) In the figure, reference numeral 1 denotes a clamp jacket according to the present invention, in which a cooling means 2 is built into the lower part of the clamp jacket, and side edges 3 which extend upwardly along the side walls in the front and rear direction of the flow of sheets are provided in the upper part of the clamp jacket. It is equipped with 4. In the recess 5 between the side edges 3 and 4, a plurality of flat plates 7 with sawtooth edges 6 on one side are planted in a superposed manner, and the upper end surface of these polymers 8, that is, the sheet The surface of contact with the main body has sawtooth-like unevenness 9 as a whole. As shown in Fig. 2, the shape of the edge 6 of the flat plate 7 includes a relatively serrated shape (a), a rough right-angled shape (b), a pointed and oblique shape (c), and a loose shape. Various shapes can be used, such as a round wave shape (d) or a shape that is an appropriate combination of these shapes (not shown), as long as the sheet is not seriously damaged when the clamp jacket grips the sheet. Furthermore, when these flat plates 7 are superposed, flat plates 7 having edges of the same or different shapes can be appropriately combined. Furthermore, in this combination, a slight gap may be created between each flat plate, as when commercially available hacksaws are combined.

On the other hand, in place of the polymer 8, as shown in FIG.
0, or, as shown in FIG. 2B, it is also possible to have a structure in which the portion 10a having this shape is provided in the upper part and the cooling part 2a is provided in the lower part, and is formed integrally.

The method of planting the polymer 8 or the columnar body 10 into the recess 5 includes drilling into the recess 5, welding, fixing with screws from one side wall, or drilling into both side lines 3, 4 and each flat plate 7... Various means such as fastening with bolts, nuts, etc. can be applied.

Next, the operation of the above configuration will be explained.

The above clamp jacket 1 is installed in the continuous vacuum forming apparatus shown in FIG. 4 in place of the conventional one 15. Sheet 1 by a pair of clamp jackets 1 between intermittent transfers of sheet 14
When gripping the jacket 4, since sawtooth-like irregularities 8 are formed on the contact surfaces of both jackets with the sheet, their tips dig into the sheet surface, ensuring that the cold heat of the jacket is transferred to the sheet, and the heat of the sheet is also removed. Prevents escape in the horizontal direction and improves heat shielding function. In addition, when this clamp jacket 1 has a structure in which a plurality of flat plates 7 each having a sawtooth edge 6 on one side are superposed on top of each other and a sawtooth unevenness 8 is formed on the upper end surface of the clamp jacket 1, It has the advantage of transmitting the cold air of the jacket in the vertical direction along each flat plate, and furthermore, when the overlapping flat plates 7 are made with a small gap between the flat plates like the polymer of a hacksaw,
This creates the effect of guiding cold air through the gap,
By adding a function to reliably transmit the cold and heat of the jacket to the sheet, the heat shielding function is further improved.

As mentioned above, the clamp jacket according to the present invention can significantly improve the heat shielding function compared to the conventional one, so the sheet feed width can be reduced to 40% (8 mm) of the conventional one using Polymer 8. and 60% for the configuration shown in Figure 3.
(12mm), resulting in a molding zone length of 800~
In the case of a 1000mm device, we were able to keep the sheet feed width loss to less than 1.0% and 1.2%, respectively.

(Effects of the invention) As described above, according to the invention, the sawtooth-like unevenness is formed on the contact surface with the sheet, which improves the heat shielding function.
As a result, it is possible to reduce the sheet feed width, which has the effect of improving product yield.

[Brief explanation of drawings]

Figures 1 to 3 relate to embodiments of the present invention, in which Figure 1a is a perspective view of the clamp jacket, Figure 2b is a side view thereof, and Figures 2a to d show main parts of different embodiments. FIG. 3 is a front view, FIGS. 3A and 3B are perspective views of main parts and the whole of different embodiments, FIG. 4 is a schematic explanatory view of a continuous vacuum forming apparatus, and FIG. 5 is a perspective view of a conventional example. 1... Clamp jacket, 8... Unevenness.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A clamp jacket for continuous vacuum forming equipment, which has serrated irregularities on the sheet contact surface. 2. The serrated unevenness is formed on the upper end surface of a plurality of polymerized flat plates having serrated edges on one side, which are implanted in the upper part of the jacket. Clamp jacket for continuous vacuum forming equipment.