JPH09201800A - Trimming blade - Google Patents

Abstract

(57) [Abstract] [Purpose] In a hot blade type trimming device, it is possible to quickly raise the temperature of a cutting edge to a predetermined temperature by using a heater with a small amount of heat generation and to keep the entire cutting edge uniform at a predetermined temperature. By providing a possible trimming blade, cost is reduced and defective cutting is eliminated to improve productivity. According to the trimming blade of the present invention, a heater 5 in which an electric heating body is covered with an insulator is brought close to the cutting edge of the trimming blade 2 and is positioned along the height of the cutting edge, and a plurality of heaters are provided along the heater 5. The strip-shaped metal plates 7, 7 are arranged at intervals, and the heater 5 is sandwiched between the trimming blade 2 and the plurality of strip-shaped metal plates 7, 7 and fastened and fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot blade type trimming device for cutting a sheet or plate made of a thermoplastic resin, a molded product, or a molded product in which a thermoplastic resin sheet is attached to a base material. More specifically, it relates to a trimming blade provided in the apparatus.

[0002]

2. Description of the Related Art Conventionally, a trimming device is generally used to cut a plate material or a molded product made of various materials into a predetermined shape to obtain a product. What is a trimming device?
A lower mold for placing a plate material to be cut or a work that is a molded product,
With an apparatus composed of an upper die equipped with a trimming blade, the upper die is lowered, the trimming blade is pressed against the trimming line of the work, and pressure is applied to cut. In addition, there is an apparatus of a type in which an upper die is provided with a cylinder and a trimming blade is moved up and down by driving the cylinder to cut, and an apparatus of a lower die having a cylinder and a trimming blade. Types of trimming blades provided in such a trimming device include a serrated blade having a serrated blade portion and a shear blade that is a straight blade. In particular, when cutting a work made of thermoplastic resin, a heater is attached to the trimming blade to raise the temperature of the cutting edge, and the heat softens or melts the part where the cutting edge of the work abuts to reduce the force required for cutting. A so-called hot-blade trimming method is also commonly used. A general example of a trimming blade equipped with a heater will be described with reference to FIGS. 3 and 4. Reference numeral 11 denotes a blade holder attached to an upper mold (not shown), and the material thereof is aluminum or iron. A trimming blade 12 is fixed to the blade mount 11. Further, a hole is provided in the blade mounting base 11 and a cylindrical heater 13 is fitted therein. When the heater 13 is energized to generate heat, the temperature of the blade mounting table 11 rises, and the heat is further transmitted to the trimming blade 12 so that the temperature of the blade tip is 80 to 80 ° C.
The temperature is raised to about 130 ° C.

[0003]

In the above-mentioned trimming cutting tool, the temperature of the cutting edge is raised by heat transfer from the cutting edge, so that the temperature of the cutting edge, which is a lump of aluminum or iron having a large heat capacity, is raised to a temperature higher than that of the cutting edge. There must be. Therefore, it is necessary to use a heater with a large amount of heat generation for the trimming blade, and accompanying that, it is necessary to use heat-resistant parts for the parts, which is high in cost. Further, the trimming blade has a distance from the heater to the blade tip, and it took time for the blade tip to reach a predetermined temperature due to heat transfer. Further, it is desirable to keep the entire cutting edge uniform at a predetermined temperature because the temperature rise of the cutting edge causes cutting failure if there is a temperature difference depending on the location. However, as shown in FIG.
Has a height difference in the cutting edge according to the change in the shape of the trimming line, and therefore the heater 13
Since the distance from the blade to the cutting edge is different, it was difficult to uniformly stabilize the temperature of the entire cutting edge. The present invention has been made to solve the above problems, in a trimming blade provided in a hot blade type trimming device, using a heater of a small amount of heat to quickly raise the blade edge to a predetermined temperature. An object of the present invention is to provide a trimming blade capable of uniformly maintaining the entire cutting edge at a predetermined temperature, reduce cost, eliminate defective cutting, and improve productivity.

[0004]

In order to achieve the above object, a trimming blade according to the present invention has a heater in which an electric heating body is covered with an insulating material, and a heater is provided in the vicinity of the cutting edge of the trimming blade and along the height of the cutting edge. It is characterized in that a plurality of strip-shaped metal plates are arranged at intervals along the heater, and the heater is sandwiched between the trimming blade and the strip-shaped metal plates and fastened and fixed. The heater is preferably housed in a flexible metal tube.
In addition, it is preferable that the trimming blade is provided with an elongated hole for vertically adjusting and fasteningly fixing the heater.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 denotes a blade mount provided on an upper die (not shown). A trimming blade 2 is attached to the blade mount 1 via a spacer 3 made of a heat insulating material. The trimming blade 2 is provided with a height difference according to a trimming line on a work (not shown) at the cutting edge, and a vertically elongated long hole 4 as a mounting hole penetrates at a proper interval in a portion near the cutting edge. Is provided. A heater 5 is a nichrome wire coated with magnesium oxide, which is an insulator. The heater 5 includes a flexible metal tube 6
It is stored in. The metal tube 6 accommodating the heater 5 is positioned along the height of the trimming blade 2 and is held between the plurality of strip-shaped metal plates 7, 7 and the trimming blade 2. A tap is provided at the center of each strip-shaped metal plate 7, and a bolt 8 is passed through the long hole 4 and screwed to the tap to firmly trim the metal tube 6 containing the heater 5. The blade 2 is brought into contact with and fastened and fixed. In this embodiment, the strip-shaped metal plate 7 is fixed by the single bolt 8. However, the temperature of the strip-shaped metal plate 7 becomes higher than that of the trimming blade 2 at the time of temperature rise, and the thermal expansion of both is increased. This is because the trimming blade 2 is bent when it is fixed at two or more places, and a deviation from the trimming line of the work occurs. If you do not require strict accuracy in the trimming line, you may fix it in two or more places. Further, although two heaters 5 are used in the present embodiment, it is possible to increase or decrease the number of heaters 5 to be used depending on the required amount of heat.

When actually cutting a work made of a thermoplastic resin by using the above-mentioned trimming blade 2, first the heater 5 is used.
To generate heat. Since the heater 5 is fixed to the blade tip proximity portion and the distance between them is short, the generated heat is immediately transferred to the blade tip, and the temperature is rapidly raised to a predetermined temperature. The heat of the heated trimming blade 2 is not blocked by the spacer 3 and is not taken by the blade mount 1. The cutting edge of the trimming blade 2 heated to about 130 ° C. is pressed against the trimming line of the work, and pressure is applied to perform cutting. If there is a difference in the temperature of the cutting edge depending on the location, the heater 5 at that location
Loosen the bolt 8 that fastens and fixes the heater 5 and the strip-shaped metal plate 7 together along the long hole 4 toward or away from the blade edge to adjust the fixing position to adjust the temperature of the blade edge at that location. Adjust so that the entire cutting edge is uniform at a given temperature. If the blade edge temperature does not require strict uniformity, the mounting hole provided in the trimming blade 2 need not be a long hole. In this embodiment, the temperature of the heater 5 is set to 200.
Since the temperature rises to above 0 ° C., the nichrome wire is coated with magnesium oxide having high heat resistance as an insulator, and this is housed in the metal tube 6 for use. However, when it is not necessary to raise the heater 5 to such a high temperature, for example, when the work is a thin film of thermoplastic resin, the heater 5 covers the nichrome wire with an insulator having low heat resistance such as silicon rubber. However, it is also possible to use it without storing it in the metal tube 6. Other trimming devices already mentioned,
That is, it is possible to use the same trimming blade as that of the above-mentioned embodiment even in a device of a type in which the trimming blade is moved up and down by driving a cylinder provided in the upper mold and a device of a type in which a lower mold has a cylinder and a trimming blade. . Further, although the shear blade is used as the trimming blade in the present embodiment, the same configuration is possible even when the already-described serrated blade is used.

[0007]

As is apparent from the above description, the trimming blade according to the present invention has the heater mounted in close proximity to the blade edge, so that the blade edge can be heated quickly. Further, since a heater having a small heat capacity and ordinary parts can be used, energy saving and cost reduction are realized. In addition, if the heater is housed in a metal tube and used, the blade edge temperature can be increased. Furthermore, by adjusting the mounting position of the heater so that the temperature of the cutting edge can be adjusted, it is possible to keep the entire cutting edge uniform at a predetermined temperature and eliminate cutting defects. Due to these advantages, the trimming blade of the present invention is very useful for improving productivity.

[Brief description of drawings]

FIG. 1 is a front view of a main part showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a front view of a main part showing a conventional technique.

FIG. 4 is a sectional view taken along line BB in FIG. 3;

[Explanation of symbols]

 2 Trimming blade 4 Long hole 5 Heater 6 Metal tube 7 Strip metal plate 8 Bolt

Claims (3)

[Claims] 1. A trimming blade provided in a hot blade type trimming device, wherein a heater 5 having an electric heating body coated with an insulator is brought close to the cutting edge of the trimming blade 2 and is positioned along the height of the cutting edge. A plurality of strip-shaped metal plates 7, 7 are arranged at intervals along the heater 5, and the heater 5 is sandwiched and fastened and fixed by the trimming blade 2 and the plurality of strip-shaped metal plates 7, 7. And trimming blade. 2. The trimming blade according to claim 1, wherein the heater 5 is housed in a flexible metal tube 6. 3. The trimming blade 2 is provided with the heater 5
The trimming blade according to claim 1 or 2, further comprising an elongated hole 4 for adjusting the vertical position and fastening and fixing the same.