JPH02179785A - Method and device for thermal transfer to three dimensional curved surface - Google Patents

Abstract

PURPOSE:To enable a foil to be transferred to a three dimensional curved surface by a two dimensional movement by a method wherein a work mounting jig is linearly moved under a heated roll between positions corresponding to a flat surface part of a work and, thereafter, rotated about a rotating shaft between positions corresponding to a curved surface part. CONSTITUTION:In a work mounting jig 15 consisting of a curved surface part 15b having a curved surface, which is formed about a rotating shaft 17 in parallel to the rotating shaft 17, and a flat surface part 15a continuously formed from the curved surface 15b, a work loading surface is constructed so as to have a work fitting groove 15c for fitting a foil transfer surface formed on a work (a) in an approximately flush state. The jig 15 is rotated about the rotating shaft 17 (as shown by an arrow B) by a rotating drive cylinder 18 of a hydraulic cylinder disposed between the shaking end of the work mounting jig 15 and a sliding block 13. When a foil is thermally transferred to a three dimensional foil transfer curved surface (b), a work (a) is fitted into the work fitting groove 15c of the work mounting jig 15. By driving a device, a frame 12a is lowered to press a foil ribbon (c) so that a transfer foil comes into contact with the work (a) by foil guide bars 34, 35. Simultaneously, a thermal transfer roll 19 is lowered to press the transfer foil abutted on the foil transfer surface (b) of the work (a).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for applying foil transfer to a transfer surface having a three-dimensional curved surface by the Bot stamp method, and an apparatus for implementing the method.

[Conventional technology]

As shown in FIG. 9, a conventional thermal transfer device has been used in which a workpiece a is placed on a jig receiver 51 placed on a table 50, and a heated roll 52 is placed on the workpiece a through a transfer foil. A structure is known in which the foil is transferred onto the surface of the workpiece a by applying pressure vertically. However, with this type of thermal transfer device, it is difficult to perform foil transfer on the surface of workpiece a, which has a three-dimensional curved surface. The foil is thermally transferred using a hydraulic servo hot stamp machine, or the foil is thermally transferred using a hydraulic servo copying hot stamp machine, in which a work roll is moved relative to a copying plate placed in parallel with the work using a hydraulic servo.

[Problems to be Solved by the Invention] However, with the conventional device having the above configuration, double stamping as in the former case not only creates joints between the foils but also causes deterioration in quality such as large variations in stamping. In the latter case, the equipment including the hydraulic servo was expensive, and the drive part of the equipment had to be changed when the workpiece was changed, making it less useful as a general-purpose machine. .

The present invention was devised in view of the above problems, and enables hot stamping on three-dimensional curved surfaces.
The object of the present invention is to provide a thermal transfer device with a simple structure.

[Means to solve the problem]

Here, in the thermal transfer method and apparatus for a three-dimensional curved surface according to the present invention, the workpiece 1 having a three-dimensional curved surface to which foil is transferred is, as shown in FIG.
The workpiece curvature on the A side (arc Al-A2) and the curvature on the B side (arc B1-82) of the curved surface portion 1b around the rotation axis W continuous to
) are different from each other, and refer to those that constitute a three-dimensional curved surface that is twisted with each other.

That is, the principle of the present invention is to perform foil transfer only by horizontal relative movement of the roll 2, as shown in FIG. By selecting a rotation axis W'' that is inclined (arrow θ) so that the curvatures of the A side and B side approximately match, the work l can be regarded as an approximate two-dimensional curved surface.

[Effect]

Therefore, as shown in FIGS. 2(al to d), the workpiece mounting jig 3 is moved in a straight line (arrow A) L between the portions corresponding to the facing portion 1a of the workpiece a under the heated roll 2, and then the curved surface portion Rotate between parts corresponding to lb around rotation axis W' (arrow B)
By doing so, a three-dimensional curved surface can be transferred to the foil by two-dimensional movement, and the configuration of the apparatus can be simplified.

〔Example〕

The thermal transfer method for a three-dimensional curved surface according to the present invention is based on the above-mentioned principle, in which a workpiece 1 having a foil transfer surface curved in a three-dimensional direction is supported at an angle in the surface direction, and thereby the workpiece 1 is rotated around an axis W. Curved surface portion 1b having parallel curved surfaces and the curved surface portion 1
An approximate quadratic curved surface consisting of a continuous facing portion 1a is formed, and the facing portion 1a of the approximate quadratic curved surface is moved linearly, and the curved surface portion 1b is rotated in a two-dimensional direction with the axis W as the rotation axis. This method involves continuously transferring foil onto a foil transfer surface having a three-dimensional curved surface, and in this method, the foil transfer surface of the workpiece 1 curved in three-dimensional directions is fitted substantially flush with the foil transfer surface. This is realized by linearly moving and rotating a workpiece mounting jig 3 having a workpiece fitting groove in two-dimensional directions.

Next, an embodiment of a thermal transfer apparatus for carrying out the above thermal transfer method will be described with reference to FIGS. 3 to 6.

FIGS. 3 and 4 show the foil transfer state of the thermal transfer device. 1). 1) is a pair of guide rods horizontally installed on the upper surface of the machine base 12, and a sliding block 13 is installed slidably (arrow A) relative to both guide rods 1), 1).
A linear movement along the guide rod 1) is performed by a reciprocating cylinder 14 consisting of a hydraulic cylinder inserted between the machine bases 12.

Reference numeral 15 denotes a workpiece mounting jig whose one end is rotatably mounted between the upper bearing protrusions 1616 of the sliding block 13 via the rotation shaft 17.The workpiece mounting jig 15 is shown in FIG. As shown, approximately the rotation axis 17 is constructed around the rotation axis 17.
a curved surface portion 15b having a curved surface parallel to the curved surface portion 15b;
A workpiece fitting groove 15c is composed of a continuous face portion 15a, and the foil transfer surface formed on the workpiece a is fitted substantially flush with the workpiece fitting groove 15c.
It constitutes a workpiece mounting surface with a rotational axis 17 ( Arrow B). Also, 19
is the machine base 12 above the sliding part of the workpiece mounting jig 15.
A thermal transfer roll 1 made of silicone resin is pivotally mounted via a pressure regulating mechanism 20 to a machine frame 12a installed in the machine frame 12a so that it can be raised and lowered freely.
9, thrust bearings 30 and 30 protruding from both sides of the sliding frame 23 are inserted into the guide rods 22 and 22, which are configured perpendicularly to the suspension plate 21 fixed to the machine frame 12a. At the same time, a suspension block 25 having a thermal transfer roll 19 rotatably driven by a motor 24 mounted on its lower end and the sliding frame 23 are connected via a vertical low-friction cylinder 26. The thermal transfer roll 19 is axially installed so that the roll surface is parallel to the foil transfer surface of the workpiece a.

FIG. 6 shows a pressure regulating mechanism, and 27 is a balancer connected to one end of a chino 29 wound around a pulley 28 that is mounted on the machine frame 12a, and a sliding frame 23 is connected to the other end. At the same time, the low friction cylinder 26 is always connected at a predetermined pressure via a precision air regulator 31.

Further, 32 is a foil supply mechanism that supplies the foil ribbon C by stretching it along the lower surface of the thermal transfer roll 19, and the foil ribbon C is supplied by a bank tension motor (
The foil guide bar 34.3 is wound on a foil ribbon reel 33 with a foil ribbon reel 33 (not shown), and is fixed and suspended from the machine frame 12a.
5, the foil ribbon C is wound onto a take-up reel 37 configured to be rotated by a take-up motor 36 fixed to the other end of the machine frame 12a, and moved at a predetermined speed. Further, a foil stamping bar 39 is configured in a cylinder 38 located between the foil guide bar 34 and the thermal transfer roll 19 and extending and contracting in the vertical direction from the machine frame 12a side, and the foil ribbon C
It is pressed upward to follow the foil transfer surface of the workpiece a, resulting in a structure that corresponds to the rotation of the workpiece mounting jig 15 in two-dimensional directions.

The thermal transfer device having the above configuration is shown in FIGS. 7 and 8(a).

(This is used when thermally transferring foil to a foil transfer surface that is a three-dimensional curved surface shown by hatching, such as the inner lens of an automobile lamp as shown in bl. Workpiece fitting groove 1 of tool 15
5 Fits into c. When the device is driven, the machine frame 12a is lowered, and the foil guide bars 34 and 35 move the transfer foil onto the workpiece a.
At the same time, the thermal transfer roll 19 descends to press the transfer foil in contact with the foil transfer surface of the workpiece a. At this time, the foil guide bar is 34°35
Since the tip of the foil is located below the foil transfer surface, it improves the adhesion of the transfer foil.

The thermal transfer roll 19 is heated to a constant temperature necessary for transfer, and is applied to the foil ribbon C at a predetermined pressure set in advance by the action of a balancer 27 and a precision air regulator 31.
Press.

Simultaneously with the downward pressing of the thermal transfer roll 19, the reciprocating drive cylinder 14 is extended, and the workpiece mounting jig 15 is attached to the guide rod 1.
). 1) (rightward in Figures 3, 4 and 5). The transfer foil is transferred to the facing portion of the foil transfer surface of the workpiece a supported by the workpiece mounting jig 15 by the parallel sliding. When the thermal transfer roll 19 reaches the end of the face of the foil transfer surface, the reciprocating cylinder 14 stops, the foil stamping cylinder 38 extends, and the foil ribbon C is moved by the foil stamping bar 39 so that the transfer foil is on the workpiece a. The foil transfer surface is pressed down so as to be in contact with the curved surface direction, and at the same time, the rotary drive cylinder 18 is shortened and the workpiece mounting jig 15 is moved to the rotation axis 1.
7 as the central axis.

By this rotation, the thermal transfer roll 19 is pressed and transferred via the foil ribbon C to the curved surface of the foil transfer surface of the workpiece a supported by the workpiece mounting jig 15, and the curved surface is also transferred, completing the transfer. do.

During the above transfer, the foil ribbon C is fed and moved by the take-up motor 36 at the same speed as the foil transfer surface of the workpiece A, and the thermal transfer roll 19 is tilted at the same angle as the foil transfer surface. Therefore, the foil ribbon C moves in close contact with the foil transfer surface of the workpiece a.

〔Effect of the invention〕

As described above, according to the thermal transfer method and apparatus for a three-dimensional curved surface according to the present invention, the curved surface portion is approximated by holding the approximately facing portion of the workpiece having the three-dimensional foil transfer curved surface at an angle with respect to the workpiece mounting jig. Can be made into a quadratic surface,
It has extremely excellent effects, such as the ability to easily perform foil transfer by linking linear movement on the face part and rotational movement in two-dimensional directions on the curved part, and as a result, the structure of the thermal transfer device can be simplified. be.

[Brief explanation of the drawing]

Figure 1 (al and
) to (dl are explanatory diagrams showing the driving principle of the workpiece mounting jig for the thermal transfer roll; FIG. 3 is a schematic front view showing the state of foil transfer to the facing part of the workpiece regarding one embodiment of the thermal transfer device according to the present invention; FIG. 4 is a schematic front view showing the state of foil transfer to the curved surface of the workpiece, FIG. 5 is an enlarged front view showing the drive mechanism of the workpiece mounting jig, and FIG. 6 is a side view of the main parts showing the pressure regulating mechanism. Fig. 7 is an enlarged sectional view of the main part showing the state of pressure contact between the thermal transfer roll and the workpiece, Fig. 8 (al is a perspective view showing an example of the workpiece, (kll is a sectional view of the main part, and Fig. 9 is a conventional thermal transfer device) It is a schematic front view showing 1... Workpiece 2... Thermal transfer roll 3... Workpiece mounting jig w, w'... Rotating shaft 1
)...Guide rod 13...Sliding block 14...Reciprocating drive cylinder 15...Workpiece mounting jig 1 15b...Curved surface portion 18...Rotary drive cylinder 20...Pressure regulating mechanism 25 ...Low friction cylinder 31...Precision air regulator 32...Foil supply mechanism 34.35...Foil guide bar 37...Take-up reel a...Work C...Foil ribbon a...・Facing part 7...Rotating shaft 9...Thermal transfer roll 4...Motor 36...Take-up motor b...Thermal transfer surface Patent applicant Koito Seisakusho Co., Ltd. Agent Patent attorney 1) Kazuo No. Figure (b) 1 ・Work W゛ ...rotation axis 2 Figure 2 (b) :C) Figure (d) a...Work a Work b Thermal transfer surface C...Foil ribbon (CI) ) (b)

Claims (5)

[Claims] (1) By holding a workpiece having a three-dimensionally curved foil transfer surface at an angle in the surface direction, a curved surface portion having a curved surface parallel to the axis and a facing portion continuous to the curved surface portion are formed around the axis. Foil transfer that has a three-dimensional curved surface continuously by forming an approximate quadratic curved surface, moving the facing portion of the approximate quadratic curve linearly, and rotating the curved surface portion in a two-dimensional direction about the above-mentioned axis of rotation. A thermal transfer method for three-dimensional curved surfaces characterized by foil transfer onto the surface. (2) A claim characterized in that the workpiece is linearly moved and rotated in a two-dimensional direction by a workpiece mounting jig having a workpiece fitting groove that fits the workpiece having a foil transfer surface consisting of a three-dimensional curved surface substantially flush. The thermal transfer method for a three-dimensional curved surface according to item 1. (3) A workpiece mounting jig that supports a workpiece having a foil transfer surface consisting of a three-dimensional curved surface at an angle in the surface direction so as to form an approximate two-dimensional curved surface around the shaft circumference, and A workpiece reciprocating drive means that moves in parallel, a workpiece rotation drive means that rotationally displaces the shaft, and a workpiece rotation drive means that is located above the workpiece mounting jig so as to be able to rise and fall freely, and a pressure regulating mechanism is provided to the workpiece supported on the workpiece mounting jig. 1. A thermal transfer device comprising: a thermal transfer roll that presses down at a predetermined pressure and heats the work; and a foil supply mechanism that feeds and moves a foil ribbon stretched between the transfer roll and the workpiece at a predetermined speed. (4) The thermal transfer device according to claim 3, wherein the thermal transfer roll has an inclined axis parallel to the foil transfer surface of the workpiece. (5) Claim characterized in that the pressure regulating mechanism has a structure in which a low-friction cylinder is inserted between the thermal transfer roll and its suspension structure, and the air pressure supplied to the low-friction cylinder is controlled to be constant by an air regulator. 5. The thermal transfer device according to 3 or 4.