JPH032060B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot stamping apparatus, and particularly to a hot stamping apparatus suitable for performing thermal transfer on a three-dimensionally shaped surface.

Thermal transfer of a decorative film using a hot stamp is carried out on molded products that require decorative surfaces, such as decorative synthetic resin molded products for vehicles.
It has been difficult to hot stamp the surface of a dimensional shape.

FIG. 1 is a vertical sectional view showing a conventional hot stamping device. In the drawings, reference numeral 1 denotes a lower platen, which is fixedly provided, and a lower mold 2 is removably attached to the upper surface of the lower platen with bolts 3 or the like. The lower mold 2 includes a pedestal 2a having a three-dimensional receiving surface corresponding to the back surface of a workpiece (not shown), and a die plate 2b for attaching the pedestal 2a to the lower platen 1.

Upper platen 4 is opposite to the upper side of lower platen 1.
is provided to be movable up and down, and a heating element 5 is installed inside.
is provided, and an upper mold 6 is removably attached to the lower surface with bolts 7 or the like. The upper mold 6 includes a rubber-like elastic body 6a having a three-dimensional pressing surface corresponding to the surface of the workpiece, a metal body 6b in contact with the upper side of this rubber-like elastic body 6a, and this metal body 6b.
Temperature detector 6c provided inside, and metal body 6
Consists of b.

Reference numeral 8 denotes a transfer film, which is fed from a supply roll 9 via a guide roll 10 between the lower mold 2 and the upper mold 6, and is wound onto a take-up roll 11.

In the conventional hot stamping apparatus configured as described above, the workpiece is placed on the pedestal 2a of the lower mold 2, the transfer film 8 is supplied from the supply roll 9, and the upper platen 4 is lowered. , the transfer film 8 is pressed against the workpiece on the pedestal 2a by the rubber-like elastic body 6a. At this time, the transfer film 8 is thermally transferred to the workpiece by pressing the rubber-like elastic body 6a heated by heat transfer from the heating element 5, and a hot stamp can be applied.

However, in such a conventional hot stamping apparatus, since the heating element 5 is provided on the upper platen 4, the following problems arise.

Since the upper platen 4 and the rubber-like elastic body 6a are separated from each other, it takes a long time for heat transfer, resulting in wasted setup time and a large heat loss.

It is difficult to accurately control the temperature of the rubber-like elastic body 6a, resulting in variations in quality.

When the workpiece has a three-dimensional shape, hot stamping cannot be applied properly unless the horizontal position of the upper die 6 relative to the lower die 2 is positioned within approximately 0.1 mm, but conventional equipment cannot do so. This is difficult, requiring long hours of fine adjustment each time the upper and lower molds are replaced, and one of the die plates expands due to heating.
It was not possible to provide a positioning device.

Since one heating element 5 is fixedly provided, if the upper and lower dies are replaced depending on the workpiece, a constant amount of heat is given regardless of the size and shape of the workpiece, so the amount of heat can be reduced. There will be an excess or deficiency of
There were problems such as deterioration of quality.

This invention has been made by focusing on the above-mentioned conventional problems.In addition to providing a heat generating element and a thermally defective conductor for blocking heat in the upper mold, the present invention also provides a heat generating element and a thermal conductor for blocking heat in the upper mold. The object of the present invention is to solve the above-mentioned problems by providing a positioning member that prevents movement of the mold and by detachably attaching the upper and lower molds to the upper and lower platens.

The present invention provides a rubber-like elastic body having a pressing surface having a shape corresponding to the surface shape of a workpiece to be hot-stamped, a metal body in contact with the rubber-like elastic body, a heating element provided in the metal body, and the above-mentioned. It has a die plate connected to the metal body via a heat conductor, and has an upper die detachably attached to the upper platen, a pedestal and a die plate on which the workpiece is placed, and a lower die plate. A lower die removably attached to a platen is engaged between the die plates of the upper die and the lower die to allow movement only in the vertical direction and prevent movement in other directions. The hot stamping device is characterized in that it is equipped with a positioning member.

The present invention will be explained below based on the drawings. FIG. 2 is a vertical sectional view showing a hot stamping apparatus according to an embodiment of the present invention, and the same reference numerals as in FIG. 1 indicate the same or corresponding parts.

In Fig. 2, lower platen 1 and lower mold 2 are shown.
is structured almost the same as the one in Figure 1, but
The die plate 2b is provided with a plurality of hollow cylindrical guide posts 2c around the pedestal 2a as positioning members.

The upper platen 4 and the upper mold 6 are also constructed almost in the same way as those shown in FIG. Not yet. Further, the rubber-like elastic body 6a has a pressing surface consisting of a three-dimensional curved surface corresponding to the surface shape of the workpiece to be hot-stamped, as shown in FIG. It is fixed in contact with a surface close to the body 5. Between the metal body 6b and the die plate 6d, two thermally defective conductors 6e and 6f such as Bakelite and a second metal body 6g sandwiched between them are inserted, and the second metal body 6g is secured by a bolt 6h. The die plate 6d is fixed to the second metal body 6g via the thermally defective conductor 6f by bolts 6i. Further, the die plate 6d is provided with a guide pin 6j as a positioning member around the rubber-like elastic body 6a etc., which is inserted into and engaged with the guide post 2c.

The structures of the transfer film 8, supply roll 9, guide roll 10, and take-up roll 11 are the same as those shown in FIG.

In the hot stamping device configured as described above, hot stamping is performed in substantially the same manner as in the case shown in FIG. 1, but when the upper platen 4 is lowered, the guide pin 6j is inserted into the guide post 2c. The upper mold 6 is engaged with the lower mold 2 and horizontally positioned with respect to the lower mold 2. Further, the temperature of the heat generated by the heating element 5 is controlled by a temperature detector 6c such as a thermocouple, and while it directly heats the rubber-like elastic body 6a, it is blocked by the thermally poor conductors 6e and 6f, and the die plate is heated. 6d and the upper platen 4, thereby heating the rubber-like elastic body 6a in a short time and maintaining it at a constant temperature.

Therefore, thermal transfer of the transfer film 8 is always performed under constant conditions by the pressure of the rubber-like elastic body 6a.
The quality of hot stamps is stable. Also, the metal body 6
Since there is little heat leakage from b, die plate 6
d expansion is prevented, and the guide post 2c and guide pin 6j, which are positioning members, are not distorted in the horizontal direction due to thermal expansion, and accurate positioning can be performed.

The lower mold 2 and the upper mold 6 are stored in an integrated state with the guide pin 6j inserted into the guide post 2c, and a certain period of time before the start of use, the heating element 5 is energized to heat the metal body 6b and the rubber-like elastic body. Heat 6a.
Next, the combined lower mold 2 and upper mold 6 are placed on the lower platen 1, and the upper platen 4 is lowered until it almost touches the die plate 6d, and the die plates 2b and 6d are placed on the lower platen 1 and the upper platen 4. All you have to do is fix them with bolts 3 and 7, etc.
This positions the lower die 2 and the upper die 6, and almost no fine adjustment is required. Moreover, heating is completed during this time, and the setup time is shortened. Replacement of the lower mold 2 and upper mold 6 is performed in substantially the same manner.

In the above description, the guide pin 6j is configured to be separated from the guide post 2c, but the guide post 2c may be made longer as shown by the broken line 2d so that the guide pin 6j is always engaged. In addition, as a positioning member, the guide post 2
In addition to the guide pins 6j and 6j, those with similar structures may be used. Further, in the upper mold 6, the thermally defective conductors 6e and 6f are provided in two layers, but they may be provided in one layer or three or more layers.

As explained above, according to this invention,
The structure is such that a heating element and a heat conductor that blocks heat are provided in the upper mold, a positioning member is provided between the die plates of the upper and lower molds to prevent movement in directions other than the vertical direction, and the upper and lower molds are moved vertically. Since it is removably attached to the platen, the rubber-like elastic body can be heated in a short time to shorten setup time, and the temperature can be maintained at a constant level to improve the quality of hot stamps and to prevent expansion of the die plate. When replacing the mold, a mold with a heating element suitable for the size and shape of the workpiece can be installed in a short time with high positioning accuracy.
Effects such as almost no need for fine adjustment can be obtained. In addition, using guide pins and guide posts as positioning members makes positioning easier.
Moreover, if the two are always maintained in an engaged state, there is an effect that positioning accuracy can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional hot stamping apparatus, and FIG. 2 is a vertical sectional view showing a hot stamping apparatus according to an embodiment of the present invention. In each figure, the same symbols indicate the same or corresponding parts,
1 is the lower platen, 2 is the lower mold, 2a is the pedestal, 2b,
6d is a die plate, 2c is a guide post, 4 is an upper platen, 5 is a heating element, 6 is an upper mold, 6a is a rubber-like elastic body, 6b is a metal body, 6c is a temperature detector, 6
e, 6f are thermally poor conductors, 6g is the second metal body, 6j
8 is a guide pin, and 8 is a transfer film.

Claims (1)

[Claims] 1. A rubber-like elastic body having a pressing surface with a shape corresponding to the surface shape of the workpiece to be hot-stamped, a metal body in contact with the rubber-like elastic body, and a heating element provided in the metal body. , and has a die plate connected to the metal body via a thermally poor conductor, and has an upper mold detachably attached to the upper platen, a pedestal on which the workpiece is placed, and a die plate. , and a lower die removably attached to the lower platen engages between the die plates of the upper die and the lower die to allow movement only in the vertical direction and prevent movement in other directions. A hot stamping device comprising: a positioning member provided in the hot stamping device; 2. The hot stamping apparatus according to claim 1, wherein the metal body of the upper mold is connected to the die plate via a plurality of thermally defective conductors and another metal body provided in between. 3. The hot stamping device according to claim 1 or 2, wherein the positioning member is a guide pin provided on the upper mold and a guide post provided on the lower mold. 4. The hot stamping device according to claim 3, wherein the guide pin and the guide post are always maintained in an engaged state.