JPS6020156B2 - Method of forming grooves in foamed plastic sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming grooves in a foamed plastic sheet for heat insulating pipes used for central heating, cooling, etc.

Conventionally, as a method for forming grooves on the surface of a foamed plastic sheet, as shown in FIG. Another method is to cut the groove 7 by rotating a router 6 having a propeller-shaped rotary blade 5 at the tip of the drive shaft 4 at high speed.

In this method, the grooves 7 are directly cut into the surface of the foamed plastic sheet 3 by a propeller-shaped rotary blade 5 that rotates at high speed, so the rotary blade 5 is subjected to a large resistance force due to cutting.

Therefore, in the groove forming method using the router 6, the machining speed is extremely slow and the workability is poor. In addition, the shape of the groove 7 to be formed changes even with slight movements of the router 6, making it difficult to cut the groove 7 regularly and stably, resulting in poor processing accuracy and high processing costs for trenching. There are drawbacks. In addition, as a groove forming method different from the above-mentioned forming method, as shown in FIG. Jig 1 with section 10
1 to form grooves 7 on the surface of the foamed plastic sheet 3.
There is a way to form.

In this method, both sides 2, 2 along the longitudinal direction of a strip-shaped foamed plastic sheet 3 are fed out while being sandwiched by the guide roll 1, and the peeling part 10 is heated by the heater 8 of the jig 11. The heat action melts the surface of the foamed plastic sheet 3 and cuts the grooves 7.

However, in this method, a large tension is generated when the molten foamed plastic sheet 3 is peeled off.
There is a drawback that the groove portion 7 is easily deformed and it is impossible to form the groove portion 7 with desired dimensions. In view of the above, as a result of various studies, the present invention has been developed by forming at least two slit-like grooves parallel to each other along the longitudinal direction on the surface of a continuously running foamed plastic sheet. A method of grooving a foamed plastic sheet, which is fast in processing speed, has excellent workability, and has excellent processing accuracy, by peeling off a band-shaped part formed by slit-like grooves with a heated jig to form a groove part. This is what I saw and published.

Hereinafter, the method of the present invention will be explained in detail with reference to the drawings.

FIG. 3 shows a method for forming grooves in a foamed plastic sheet according to the present invention. A plastic sheet 3 is supplied and grooves 7, 7 are formed on its surface.

The groove cutting part 12 includes a guide roll 1 that holds the both side edges 2, 2 along the longitudinal direction of the strip-shaped foamed plastic sheet 3, and a slit-like cut groove 15 on the surface of the foamed plastic sheet 3 along the longitudinal direction. Four disc-shaped rotary blades 16 are provided.

These four rotary blades 16 are attached to a rotary shaft 17 (the drive mechanism is not shown) provided between the guide rolls 1, 1, so as to be perpendicular to the longitudinal direction of the foamed plastic sheet 3. A foamed plastic sheet 3 is placed in the grooved portion 13.
a presser roll 18 that presses the material from both sides,
18 and four slit-shaped grooves 15 formed on the upper surface of the foamed plastic sheet 3 by the rotary blade 16.
A jig 20 is provided for peeling off two strips 19, 19 on both sides of the three strips 19 formed by the above steps to form the groove 7.

This jig 20 consists of a heater 20b and two L-shaped forks 20c, 20c connected to the bottom of the heater 20b.
The distal ends of the exfoliating parts 20a, 20a are bent slightly upward so as to quickly remove the exfoliated foamed plastic.

Further, the shape of the peeling portions 20a, 20a may be any other shape such as a V-shaped cross section or a flat plate shape as shown in FIGS. 4A and 4B, in addition to the pentagonal cross section shown in the figure. In the above apparatus, the foamed plastic sheet 3 supplied to the thin slicing section 12 is held by the guide roll 1 with the green parts 2, 2 on both sides along the longitudinal direction thereof being held between the foamed plastic sheet 3 and the rotary blade 16 which cuts four slits on the surface of the foamed plastic sheet 3. A groove 15 is formed.

In this case, the foamed plastic sheet 3 is cut by the rotary blade 16 attached to the drive shaft IT while its both sides are restrained by the guide rolls 1, so that the surface of the foamed plastic sheet 3 has a uniform depth. Thus, regular slit-like grooves 15 are formed in the longitudinal direction. Next, the foamed plastic sheet 3 on which the slit-shaped grooves 15 have been formed, which has been led to the groove processing section 13, is held between both sides by presser rolls 18, 18, and heated to about 25,000 yen by the heater 20b of the pick-up tool 20. heated fork 20c
, 20c are used to sequentially peel off the belt-like parts 19, 19 on both sides while melting them to form the twill parts 7, 7.

At this time, the strip portion 19 of the foamed plastic sheet 3,
19, the pressing action of the presser roll 18, the peeling part 20a,
It is quickly peeled off due to the bent shape of the end portion 20a and the heating action of the peeling portions 20a, 20a. The reason why the slit-like grooves 15 are formed in advance on the surface of the foamed plastic sheet 3 in the method of the present invention is as follows. heated jig 2
This is to reduce the burden on the driver and improve the speed of groove formation.

That is, in order to form a predetermined groove using only the heated jig 20, it is necessary to melt the foam of the entire outline of the groove, and the heat capacity of the blade at the tip of the pick-up tool 20 must be increased accordingly. To do this, it is necessary to raise the temperature of the blade to a higher temperature. If this happens, the grooves of the flexible foam will be thermally degraded and the shape will shift, making it impossible to get a good cut surface. Therefore, by reducing the portion of the blade that directly melts the foam, the temperature of the blade of the jig 20 can be kept as low as possible, allowing the groove to melt efficiently and at high speed without the above-mentioned drawbacks. Ru. The purpose of forming the slit-like grooves 15 in advance in this way is to remove the heated pick-up tool 2.
The slit 15 is formed in a range where the slit can be easily cut from the surface of the foam sheet 3 because the purpose is to minimize the portion of the foam that is directly melted by the blade.

As mentioned above, for example, in order to form a groove with a V-shaped cross section as shown in FIG. You can make it diagonal. Further, in order to form a groove having a U-shaped cross section as shown in FIG. 4B, it is sufficient to cut slits 16 only in both vertical portions of the U-shape with the rotary blade 16. in this way,
In the method of forming grooves in a foamed plastic sheet 3 according to the method of the present invention, after forming the slit-like grooves 15, the grooves 7, 7 are cut using the two pick-up tools. Compared to a method of directly forming grooves or a method of forming grooves directly by heat action without forming slit-like grooves 15, grooves 7 can be quickly formed in the longitudinal direction with a uniform depth, Moreover, the processing cost is low and it is highly economical.

The foamed plastic sheet 3 in which the grooves 7 are formed as described above is used as a material for a heat insulating pipe used for central heating, cooling, and the like.

Next, a method of manufacturing a heat insulating pipe using the foamed plastic sheet 3 in which the grooves 7 are formed by the method of the present invention as described above will be described.

As shown in FIG. 5A, the foamed plastic sheet 3 with the grooves 7 formed as described above and the foamed plastic sheet 3 without the band-shaped grooves 7 are overlapped, and a heating shell 21 is placed on the joint surface. When inserted and heat fused, a rectangular heat insulating pipe 22 having a pentagonal hollow part is obtained. Alternatively, as shown in FIG. 5B, a heat insulating pipe 22 can be obtained in the same manner using two foamed plastic sheets 3, 3 in which grooves 7 are formed. Furthermore, as shown in FIG.
, 25, and place a foamed plastic sheet 3 on which the grooves 7 are not formed so as to close the grooves 7, 7.
overlap. Next, the outer sides of the delicate metal tubes 25, 25 are covered with two foamed plastic sheets 3, 3, and both sides of the flexible metal tubes 25, 25 are sandwiched between press rolls 18, 18 and brought into close contact.
Next, in the same manner as in the production of the heat insulating pipe 22, the heating part 21a of the similar jig 21 is inserted into the joint surfaces of the two foamed plastic sheets 3, 3 to heat-seal them, and then the two pieces are taken out. It is fed between the belts 24, 24 and taken off by its rotational force. In this way, as shown in FIG. 7, a composite heat insulating pipe 23 is obtained in which the outside of the soft metal tubes 25, 25 are covered with foamed plastic sheets 3, 3. As explained above, according to the method for forming grooves in a foamed plastic sheet according to the method of the present invention, regular grooves of uniform depth can be continuously formed on the surface of a foamed plastic sheet at low processing costs. Furthermore, the present invention has remarkable effects such as the ability to easily manufacture pipes suitable for uses such as central heating and cooling using the foamed plastic sheet in which grooves are formed using the method of the present invention. .

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing how grooves are formed on the surface of a foamed plastic sheet using a router using a conventional method, and Figure 2 shows grooves formed on the surface of a foamed plastic sheet using heat action. FIG. 3 is a perspective view of an apparatus for forming grooves on the surface of a foamed plastic sheet according to the method of the present invention, and FIG. 4A is a cross-sectional view of V.
FIG. 5B is a perspective view showing a jig for forming a groove with a semicircular cross section; FIG. A perspective view showing a state in which an insulating pipe is manufactured using a foamed plastic sheet with a sheet and a groove formed therein;
FIG. 6 is a perspective view showing a state in which an insulated pipe is manufactured using two foamed plastic sheets with grooves formed therein, and a composite insulated pipe in which a sensitive metal pipe is covered with a foamed plastic sheet is manufactured. 7 is a sectional view showing a cross section of the skin in FIG. 6. 1... Guide roll, 3... Foamed plastic sheet 5... ...Rotary blade, 6...
Router, 7..., groove section, 10... peeling section,
12...Thin slice part, 13...Groove processing part, 14...Groove forming device, 15...Slit-shaped groove, 16...・Rotary blade, 18...
・Presser roll, 20... Feeding tool, 22...
・Insulated pipe, 24... Taking belt, 25...
...Soft metal tube. Fig. 1 Fig. O 2 Fig. O 3 Fig. Om Fig. 5 Fig. 6 Fig. 2' 7 Fig.

Claims (1)

[Claims] 1. After forming at least two slit-shaped grooves parallel to each other along the longitudinal direction on the surface of a continuously running foamed plastic sheet, a band-shaped part formed by the adjacent slit-shaped grooves is A method for digging grooves in a foamed plastic sheet, characterized by forming grooves by peeling with a heated jig.