JPS6124982B2 - - Google Patents

Abstract

PURPOSE:To assure effective concurrent multispot deposition operation on thermoplastic material by heating until a heating portion is fitted and pressure-adhered to the heat-deposited portion of a thermplastic material, spurting a cooling fluid and suspending heating under a ''fit-together'' state. CONSTITUTION:A cylinder means 23 is stopped by the action of a change-over valve 25, and a protruded portion 33a is crushed into a flat form melt by the heating of a heating portion 4 and the deviation force of coil springs 18, 18'. The bottom surface 16a of a control lever 16 comes in contact with the upper surface 34a of an adhered member 34 of thermplastic material, so that the protruded portion 33b is no longer pressed by the heating portion 4 beyond the aforementioned limits. A nozzle portion 3a approaches the upper surface of the heating portion 4. Next, a power supply 29 is put in ''OFF'' position, turning off an electric current to the heating portion 4. At the same time, the change-over valve 25 is switched to connect a compressed air source 24 to a cooling fluid supply means 2, and a cooling fluid is spurted from the nozzle part 3a. Thus the heating portion 4 is quenched.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for thermally welding thermoplastic materials.

For example, when a transparent plate as a dial display window is fixed to the housing of a radio receiver, tape recorder, etc., which is molded from thermoplastic synthetic resin, the housing has a through-hole in a shape corresponding to the transparent plate for the window. a plurality of protrusions are integrally provided at predetermined intervals along the periphery of the through-hole, and holes into which these protrusions can be fitted are formed in the transparent plate. , when the window transparent plate is attached to the through hole, the projection fits into the small hole,
A method is used in which the fitted protrusions are pressed and fixed while being heated with a soldering iron.

However, in this method, the protrusions have to be crushed one by one, resulting in poor workability.Moreover, since the work is done manually, it is difficult to equalize the crushing force to each protrusion. It is difficult to do so, and therefore the degree of crushing is uneven, or because the work is done with a soldering iron, when the soldering iron is removed from the crushed part after crushing, so-called There have been various problems such as a stringing phenomenon, resulting in an uneven finish, or, in the worst case, the transparent plate being damaged by the pressing of the soldering iron.

In consideration of such problems, it has been proposed to use an ultrasonic welding device as a heating means. However, in such ultrasonic welding equipment, a so-called horn is used to concentrate the ultrasonic energy on the part to be welded, but it is virtually impossible to make such a horn smaller than a certain size. For this reason, it cannot be applied to narrow spaces, the equipment is bulky, and in addition, ultrasonic vibrations cause discomfort to workers, so special measures must be taken for this purpose. It was hot.

The present invention has been made in order to avoid all the various problems and difficulties of the prior art as described above, and embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, electrical heating means in an apparatus for thermally welding thermoplastic materials according to the invention are indicated generally at 1. This electric heating means 1 includes an electric heating member 2 and a tubular nozzle member 3 for jetting cooling fluid. The electric heating member 2, as also shown in FIG.
A heating portion 4 formed in a thin plate shape with a bottom surface 4a having a flat plane or a curved surface, and this heating portion 4
The rod-shaped portions 5, 5' are bent in a substantially right angle direction from both ends, forming a substantially U-shape, and the free ends of the rod-shaped portions 5, 5' have screw grooves 6, 6', respectively. It is provided. Further, in the rod-shaped portions 5, 5', near the heating portion 4 side, there are electrical connection portions 8, 8' which are bulged in the shape of a thin plate and have a small hole 7, 7' in the center. It is formed. Such an electric heating member 2 can be manufactured in one piece from, for example, a nichrome wire, and its electrical connection portions 8, 8'
When the heating portion 4 is energized through the thin plate-shaped heating portion 4, which has a smaller cross-sectional area than the rod-shaped portions 5, 5' and therefore has a higher electrical resistance, it generates heat mainly. is being done. Reference numeral 9 denotes a support member that carries the electric heat generating member 2 as described above, and is formed into, for example, a cylindrical shape with an upper surface 9a and a lower surface 9b that are flat, and has a through hole 10 provided parallel to its axis. Insulating cylinders 11, 11' and 12,1 having flanges 11a, 11a' and 12a, 12a' in 10', respectively.
2' are inserted from the upper surface 9a side and the lower surface 9b side of the support member 9, respectively, and this insulating intervening cylinder 1
The rod-shaped portions 5, 5' of the heat generating member 2 can be slidably inserted into the members 1, 11' and 12, 12'. Before being inserted into the support member 9, the rod-shaped portions 13 and the regulating rod support member 14 are inserted from the free end side having the thread grooves 6, 6', respectively, and the rod-shaped portions 13 are Since the electrical connection portion 8 of the rod-shaped portion 5 is bulged, it abuts and is locked to the electric connection portion 8. It is fixed at a position of the rod-shaped portion 5' that substantially corresponds to 13. A regulating rod 16 is vertically extended from the regulating rod support member 14 and extends substantially parallel to the rod-shaped portion 5'.
It is attached to the regulating rod support member 14 so as to be vertically adjustable by screws 17 so that its relative position with respect to the bottom surface 4a in the horizontal direction can be displaced. This regulation rod 16
is for regulating the press-fitting engagement of the heating portion 4 with the member to be heated 32, which will be described later. The rod-shaped portions 5, 5' have both ends between the flanges 12a, 12a' of the insulating cylinders 12, 12' on the lower surface 9b side of the support member 9 and the cylinders 13 and the regulating rod support member 14. The coil springs 18, 1 are in contact with each other.
8' are inserted, respectively, and the flanges 11 of the insulating cylinders 11 and 11' on the upper surface 9a side of the support member 9
Nuts 19 and 19' are screwed into the screw grooves 6 and 6' of the rod-shaped parts 5 and 5' that protrude from above a and 11a', respectively, so that the electric heating member 2 is electrically connected to the support member 9. The support member 9 is electrically insulated and slidably supported on the support member 9 in a downwardly spring-biased manner.

The cooling fluid injection tubular nozzle member 3 extends substantially parallel to the rod-shaped portions 5 and 5' and passes through the support member 9, and is fixed to the support member 9 with screws 20. This tubular nozzle member 3 has a nozzle portion 3a opened at its lower protruding end, and is positioned above the heating portion 4 of the electrical heating member 2 to inject cooling fluid to the heating portion 4. There is. The above-mentioned electrical heating member 2 is attached to the support member 9.
and tubular nozzle member 3 as well as electrical heating means 1
A screw rod 21 for attaching to the device extends upward and is fixed.

The above is the configuration of the electric heating means 1 in the apparatus for thermally welding thermoplastic materials according to the present invention.As shown in FIG. Multiple pieces on mounting plate 2
2 via screw rods 21 at predetermined intervals. The mounting plate 22 is connected to cylinder means 23, shown as a block;
By selectively supplying compressed air from a compressed air source 24 to this cylinder means 23 via a switching valve 25, a plurality of electric heating means 1 can be moved up and down simultaneously. Further, one end of a flexible hose 26 is connected to the upper end of each tubular nozzle member 3, and the other end is connected to a cooling fluid supply means 27, to which compressed air is supplied from a compressed air source 24. By being selectively supplied via the switching valve 25, the cooling fluid is ejected downward from the nozzle portion 3a of the tubular nozzle member 3. Compressed air is normally used as the cooling fluid, but compressed air may be mixed with a suitable refrigerant, such as alcohol, to improve cooling efficiency. The electrical connection portions 8, 8' of each electrical heating member 2 are wires 2
The heating portion 4, which is connected to a power source 29 by a power supply 8 and has a high electric resistance as described above, is mainly heated by being energized. power supply 2
9 and the switching valve 25 are controlled by the control means 30 to drive the cylinder means 23, energize the electric heating means 1, and supply cooling fluid from the nozzle portion 3a via the cooling fluid supply means 27. The injection is controlled at predetermined timing.

On the other hand, a heated member 32 made of thermoplastic synthetic resin is mounted on the base 31 . The heated member 32 is, for example, the housing of a radio receiver or tape recorder as described at the beginning, and is integrally provided with a protrusion 33 at a position corresponding to the heating portion 4 of the electric heating means 1. . Reference numeral 34 denotes a member to be fixed to the member to be heated 32, such as a transparent plate serving as a dial display window as described at the beginning. The fixed member 34 is provided with a hole 35 into which the protrusion 33 can fit, and the protrusion 33 is fitted into the hole 35 so that the upper end of the protrusion 33 is a predetermined length from the upper surface 34a of the fixed member 34. This protruding portion is designated by reference numeral 33a.
It is shown in

The apparatus for thermally welding thermoplastic materials according to the invention, in the configuration as described above, is operated according to the sequence described below.

() the switching valve 25 is operated to connect the compressed air source 24 and the cylinder means 23;
Compressed air is supplied to the cylinder means 23, causing the electric heating means 1 to move downwards. The power supply 29 is turned off.

() During the downward movement of the electric heating means 1, the power source 29 is turned on, and the electric heating member 2 is energized to heat its heating portion 4 to a desired temperature.

() The bottom surface 4a of the heating part 4 is the member to be heated 32
The electric heating means 1 is engaged with the upper end of the protrusion 33a of the protrusion 33 of the cylinder means 2.
3 further moves downwards by a predetermined distance, so that the electrical heating member 2 is compressed by the coil springs 18, 18' while supporting member 9
Helical springs 18, 18' are slid upwardly against
The biasing force causes the protrusion 33 to be pressed against the protrusion 33a of the protrusion 33. At the time when the bottom surface 4a of the heating portion 4' is engaged with the top end of the protrusion 33a, the bottom surface 16a of the regulating rod 16 has not reached the top surface 34a of the member to be fixed 34.

() The cylinder means 23 is stopped by the operation of the switching valve 25, and the protrusion 33a is melted and crushed by the heating by the heating portion 4 and the biasing force by the coil springs 18, 18'. As shown by reference numeral 33b in the figure, it has a flat shape that bulges laterally, and at this point the bottom surface 16a of the regulating rod 16 is attached to the member to be fixed 33.
The protruding portion 3 of the heating portion 4 is in contact with the upper surface 34a of the
No further pressure is applied to 3b. The nozzle portion 3 a of the tubular nozzle member 3 is close to the upper surface of the heating portion 4 .

() At the same time that the power supply 29 is turned off and the current supply to the heating part 4 is interrupted,
The switching valve 25 is switched to connect the compressed air source 24 and the cooling fluid supply means 27, and the cooling fluid is injected from the nozzle portion 3a, so that the heating portion 4 is rapidly cooled. Therefore, the molten protrusion 33b, which the heating part 4 has been engaged and press-bonded with, is rapidly cooled and solidified while being pressed by the heating part 4.

() The switching valve 25 is operated and the supply of compressed air from the compressed air source 24 to the cooling fluid supply means 27 is cut off, and the cylinder means 23
is moved upward and the operation of the device is completed.

The configuration and operation of the apparatus for thermally welding thermoplastic materials according to the present invention have been clarified above. According to such an apparatus, it is possible to (2) cylinder means 23 for vertically moving the electrical heating means 1; (3) electrical heating means 1; (4) a cylinder means 23, such as a switching valve 25;
and means for selectively supplying compressed air to the cooling means; (5) driving the cylinder means 23, energizing the electric heating means 1, and supplying cooling fluid from the cooling means; The timing with the injection is such that the heated part 4 is heated to a required temperature by the time the heated part 4 is engaged and crimped with the part to be thermally welded, and the crimped engagement is maintained when the cooling fluid is injected, and the energization is interrupted. By having the control means 30 configured to perform control in a controlled manner, simultaneous multi-point welding work on thermoplastic materials can be performed extremely reliably and efficiently, reducing processing time and improving work efficiency. can be realized. Further, the finished surface of the heated portion is smooth and beautiful, making it possible to make the product uniform, and there is no problem of damage to the adhered member 34. Furthermore, unlike conventional ultrasonic welding devices, the device can be used in small spaces and has various practical benefits, such as being compact and inexpensive.

[Brief explanation of the drawing]

FIG. 1A is a partially sectional front view showing an electric heating means in an apparatus for thermally welding thermoplastic materials according to the present invention, FIG. 1B is a side view thereof, and FIGS. 3 is a front view of an apparatus for thermally welding thermoplastic materials according to the present invention, and FIG. 4 is a front view showing a state in the middle of the thermal welding process. It is a diagram. In the figure, 1 is an electric heating means, 2 is an electric heating member, 3 is a tubular nozzle member for jetting cooling fluid, 4 is a heating part, 5 and 5' are rod-shaped parts, and 8 and 8' are electrical connections. 9 is a support member, 14 is a regulation rod support member,
16 is a regulating rod, 23 is a cylinder means, 24 is a compressed air source, 25 is a switching valve, 27 is a cooling fluid supply means, 29 is a power source, 30 is a control means, 32 is a member to be heated, 33 is a protrusion, and 34 is a Each member to be fixed is shown.

Claims (1)

[Scope of Claims] 1. A movable electric heating means having a heating portion that is adapted to engage and press the part of the thermoplastic material to be thermally welded, and a cylinder means for vertically moving the electric heating means. a cooling means configured to inject a cooling fluid into the heating portion of the electric heating means to cool the heating portion and the heat welding portion; and cooling means for the cylinder means and the cooling means. means for selectively supplying compressed air; heating a heating portion of the electric heating means to a required temperature; and engaging and press-bonding the heated portion to the portion to be welded. The heat welding part is thermally welded, and then, with the heating part engaged and press-bonded to the heat welding part, electricity to the electric heating means is interrupted, and the cooling fluid is injected to the heating part. After cooling the heated portion and cooling and solidifying the heat welded portion, the electric heating means is applied at a timing such that the supply of the cooling fluid is stopped and the heating means is separated from the heat welded portion. , control means for controlling said cylinder means, said means for cooling and said means for selectively supplying compressed air.