JP5592911B2 - Heat welding equipment - Google Patents

Description

  The present invention relates to a heat welding apparatus used when a small piece (hereinafter referred to as “chip material”) such as a resin sheet or a resin film is fixed to a thermoplastic resin component.

  In recent years, as the functionality of mobile phones and automotive electronic components has increased, these thermoplastic resin casings must be completely sealed, and at the same time, it is necessary to suppress changes in the casing internal pressure due to temperature and pressure fluctuations. Therefore, a ventilation hole is provided in a part of the casing, and a porous membrane filter called a vent filter is welded and fixed to the ventilation hole to achieve both waterproofness and ventilation.

  When a small piece (chip material) of the vent filter is welded and fixed to a thermoplastic resin housing, accurate positioning by hand is difficult and workability is poor, so the conveyance and positioning of the chip material to the welding position are automated. Is indispensable. In view of this, Japanese Patent Application Laid-Open No. 2004-148647 introduces a thermal welding apparatus in which a movable film and sheet adsorbing apparatus are integrated with a hot plate welding apparatus.

JP 2004-148647 A

  However, in the case of the above-mentioned Patent Document 1, since the adsorbing portion of the chip material is adjacent to the high temperature hot plate and is likely to become high temperature, it is necessary to provide heat insulation means so that the chip material is not affected by heat. .

  In addition, the structure is complicated, for example, because the chip material is separated from the hot plate so that it is not affected by the radiant heat from the hot plate during the transfer of the chip material. Therefore, it is inevitable to increase the size of the device.

  Further, in Patent Document 1, when the welded portion is solidified, the hot plate is removed and then cooled, but since the resin is in a molten state at the time of separation, the chip material is likely to float from the welded portion, resulting in poor welding. It's easy to do.

  In the case of the vent filter, since waterproofness, air permeability and weather resistance are required, a porous membrane made of PTFE (polytetrafluoroethylene) is generally used, but PTFE is an adhesive, double-sided tape, Since it is not suitable for adhesive fixing by hot melt or the like, a thermal welding method is adopted for this adhesive fixing.

  As one of the heat welding methods, there is an ultrasonic welding method. Since PTFE has a low friction coefficient, slip occurs between the pressing portion of the ultrasonic horn and the PTFE, and heat generation at the welding portion becomes unstable.

  In addition, when the ultrasonic horn is continuously operated, heat is easily accumulated in the horn itself and becomes high temperature, and there is a problem that the welded portion is not sufficiently solidified when the horn is detached, and the tip material is likely to rise from the molten portion.

An object of the present invention is to provide a simple and small-sized heat welding apparatus capable of carrying and positioning a chip material such as a vent filter to a welding position of a thermoplastic resin component, and continuously performing the subsequent welding. There is to do.

In order to achieve the above object, the invention according to claim 1 is an impulse heating type thermal welding apparatus for thermally welding a chip material to a plastic resin product, wherein the tip of the welding chip body of the thermal welding apparatus is provided. The part is formed with a contact surface comprising the chip-shaped welded contour, and a space is formed inside the contact surface , and the suction pipe is disposed downward from the center of the top surface of the space. A suction pad for adsorbing a chip material is attached to the tip of the suction pipe, and the lip surface of the suction pad is positioned in substantially the same plane as the contact surface .

  In addition, an exhaust hole is formed in the central portion of the top surface of the space portion, and the exhaust hole communicates with an exhaust slit formed in a body portion of the welding tip body, and a rear end portion of the suction pipe is The compressed air supply device and the air suction device are connected to the compressed air supply device and the air suction device, respectively. It is comprised so that it can inject.

In addition, the contact surface of the thermal welding apparatus is formed in a negative pressure in the suction pad after approaching or closely contacting the upper surface of the chip material as much as possible at the position where the chip material to be welded is disposed. The chip material is sucked, and by this action of suction, the chip material is held in close contact with the suction pad, and is moved as it is to a predetermined position on the thermoplastic resin product. After the pressure contact with the position, the negative pressure in the suction pad is released, a voltage is applied to the welded chip body to heat the contact surface , and the heat is used to weld the chip material to the product, and the compressed air is then applied to the compressed air. It is configured so that the welded portion of the tip material and the welded tip body can be rapidly cooled by spraying from the suction port.

  Furthermore, the thermal welding apparatus according to claim 2 is the thermal welding apparatus according to claim 1, wherein an air blow pipe is disposed outside the welding chip body, and the welding portion of the chip material and the welding chip body are disposed outside. It is characterized in that it can be rapidly cooled.

  Furthermore, the thermal welding apparatus according to claim 3 is the thermal welding apparatus according to claim 1 or 2, wherein a cooling air passage is formed outside the suction pipe, and the heating chip is passed through the cooling air passage. It is characterized in that the cooling air can be supplied to promote the cooling of the heating chip.

  By using the heat welding apparatus of the present invention, it is possible to continuously perform a series of steps from picking up and taking out chip materials, conveying, positioning, heat welding, and cooling and fixing with one heat welding apparatus. Further, the simple structure in which the adsorbing portion of the chip material and the welding heating portion are integrated allows the entire apparatus to be reduced in size, and allows easy maintenance and stable thermal welding.

The exploded view of a heat welding apparatus. The assembly drawing of a heat welding apparatus. Sectional drawing of a heat welding apparatus. Explanatory drawing which shows the state by which the heat welding apparatus and the chip | tip material are arrange | positioned on the mount. The heat welding process of Example 1 is shown, (a) is before heat welding, (b) is at the time of start of adsorption | suction of a chip material, (c) is a conveyance state of a chip material, (d) is moved to a heat welding position. (E) is a state where heat welding is started, (f) is a state where heat welding is completed, and (g) is an explanatory view showing a state during cooling. Explanatory drawing of the state in cooling in Example 2. FIG. Explanatory drawing of the state in cooling in Example 3. FIG.

  In the heat welding apparatus of the present invention, there is no limitation on the shape of the fixed object and the fixed object as long as the chip material is fixed to the thermoplastic resin product. Further, the chip material 12 is arranged on the sheet 13 as shown in FIG. 4 and is often supplied continuously by the sheet 13, but the shape of the chip material 12 is circular, rectangular, polygonal, or other arbitrary Even if it is the shape of this, if the adsorption | suction to a suction pad is possible, the shape will not ask | require.

  The material of the chip material 12 can be used as long as it has heat-weldability with the thermoplastic resin product. In addition to the thermoplastic resin, the chip material 12 is impregnated and fixed by the melt on the thermoplastic resin product side by heating. If it is the chip | tip material 12 formed with the cloth, nonwoven fabric, glass fiber, felt, etc. which can be formed, these can also be welded.

  The present Example 1 is the structure and welding process of the heat welding apparatus corresponding to the invention described in Claim 1, and the details thereof will be described with reference to FIGS.

  1 is an exploded view of the heat welding apparatus 1, FIG. 2 is an assembled state, and FIG. 3 is a cross-sectional view.

Second code is a welding tip body for heating, together with the the tip 3 forms an abutment surface 4 of the annular, the annular rib 5 is formed along the inner wall of said recessed from the abutting surface 4 position A vent hole 6 is formed at the center of the annular rib 5.

On both sides of the tip 3 of the welding tip body 2, windows 7 and 7 a are formed at symmetrical positions near the contact surface 4, and further slits upward from the windows 7 and 7 a. 8, 8a are formed, and the welding tip body 2 is divided into an anode and a cathode, and lead wires 9 and 9a for supplying power are connected to the anode and the cathode.

Wherein the welding chip upper portion of the main body 2 is fitted a ceramic insulator 11, the suction from the contact surface 4 of the welding tip body 2 by way of the center hole 11a of the insulator 11 to 0.2mm protruding position The suction pipe 10 is inserted with the suction pad 10a attached to the tip of the pipe 10 facing.

In order for the suction pad 10a to reliably suck the chip material 12, it is desirable that the tip (lip surface) of the suction pad 10a slightly protrudes from the contact surface 4 of the welded chip body 2. It sets suitably according to the material shape of the suction pad 10a in the range of -1.0 mm.

  The rear end of the suction pipe 10 is connected to a compressed air supply device (not shown) and an air suction device (not shown), respectively, and the compressed air supply device and the air suction device are connected to a controller (not shown). The suction pad 10a is configured to be negative pressure or compressed air can be injected into the suction pad 10a.

  FIG. 4 is an explanatory view of an arrangement state of the heat welding apparatus 1 and the chip material 12. The thermal welding apparatus 1 is attached to the tip of an actuator (not shown) that can be moved up and down, front and rear, and left and right installed on a gantry (not shown). As the actuator, a three-axis controlled air cylinder, an electric cylinder, a robot, or the like can be used.

  As shown in FIG. 4, the chip material 12 is regularly and continuously arranged on a sheet-like mount 13 and is supplied in conjunction with the operation of the thermal welding apparatus 1 by a supply device (not shown).

  Next, the welding process will be described with reference to [FIG. 5] (a) to (f).

  The chip material 12 in this embodiment is a porous membrane made of PTFE and has t = 0.3 mmφ9.0 mm.

The abutting surface 4 of the welding tip body 2 has an outer diameter of 8.0 mm, an inner diameter of 6.0 mm, the suction pipe 10 has an outer diameter of 3.0 mm, an inner diameter of 1.5 mm, and the suction pad 10a is commonly referred to as a flat pad. Diameter φ5.0mm

A vent hole 15 is provided in the thermoplastic resin product 14 to which the chip material 12 is welded, and concentric annular welding ribs 16 are formed on the welding surface 4 of the thermoplastic resin product 14 so as to surround the vent hole 15. .
The dimensions of the weld rib 16 are a semicircular ring shape with an outer diameter of 7.6 mm, an inner diameter of 6.4 mm, a protrusion of 0.3 mm, and an R of 0.3 mm.

  Initially, the adsorption | suction, conveyance, and positioning process of the chip | tip material 12 are demonstrated.

  [FIG. 5] (a) is a state in which the welding apparatus 1 stands by on the chip material 12 arranged on the mount 13. In this state, the supply of negative pressure and compressed air to the suction pipe 10 is stopped.

  [FIG. 5] (b) shows that the heat welding apparatus 1 descends to a preset position, and the suction surface 10 and the suction pad 10a attached to the tip of the suction pipe 10 come into contact with the chip material 12, and the controller In this state, negative pressure is applied to the suction pipe 10 from the air suction device by switching the electromagnetic valve, and the chip material 11 is adsorbed to the suction pad 10a.

  [FIG. 5] (c) is a state in which the chip material 12 adsorbed to the adsorbing pad 10a is peeled off from the mount 13 and is conveyed toward the thermoplastic resin product 12.

  Here, the negative pressure required for suction of the chip material 12 is -10 kpa to -50 kpa. When the negative pressure is weak, the suction of the chip material 11 to the suction pad 10a is weak and it is difficult to peel off the mount 13. In addition, if the negative pressure is too strong, the chip material 12 is deformed or scratched. Therefore, it is important to set an appropriate negative pressure. The negative pressure is balanced in relation to the material of the chip material 12. The

  In the case of the present embodiment, since the necessary negative pressure is −10 kpa to −50 kpa, large-scale equipment such as a pump and a vacuum generator is unnecessary.

  In this example, a device (Myokutaku Convum CCV-04HS) that generates negative pressure from compressed air of factory air was used, and the negative pressure was set to -20 kpa.

  In order to confirm that the chip material 12 has been adsorbed, it is also effective to incorporate a suction error check circuit by incorporating a negative pressure detection switch in the negative pressure circuit.

[FIG. 5] (d) shows that the heat welding apparatus 1 and the chip material 12 that have moved onto the welding position of the thermoplastic resin product 14 are positioned in the XY directions with respect to the center of the preset vent 15. Is done. Next, the thermal welding apparatus 1 descends and stops at a position where the chip material 12 contacts the welding rib 16, and the positioning of the chip material 12 is completed. This stop position is set in advance so that the gap between the thermoplastic resin product 14 and the contact surface 4 is the same as the thickness of the chip material 12. By switching the electromagnetic valve of the controller, the negative pressure to the suction pipe 10 is stopped, and the chip material 12 adsorbed on the suction pad 10a is released.

  Next, the welding process of the chip material 12 will be described.

[FIG. 5] (e) is a state in which the chip material 12 is sandwiched between the contact surface 4 of the welded chip body 2 and the welded rib 16 of the thermoplastic resin product 14 by the above process. Here, when a voltage is applied to the lead wires 9, 9a from a power supply device (not shown), the tip 3 of the welding chip body 2 generates heat due to electric resistance. At the same time, the tip 3 of the welding tip body 2 is pressed against the tip material 12 by applying an appropriate pressing force to the welding device 1 in the product direction.

  The generated heat of the tip 3 heats the chip material 12 and is also transmitted to the welding ribs 16 of the thermoplastic resin product 14 through the chip material 12, so that the welding ribs 16 soften and melt when reaching the melting temperature.

  [FIG. 5] (f) shows that the melted rib 16 is crushed together with the chip material 12 by the pressing force of the contact surface 4 and at the same time a part of the melted resin also impregnates the chip material 12 (porous membrane). The chip material 12 is in a state of being fixed integrally with the thermoplastic resin product 14.

  The lowering position of the heat welding apparatus 1 is set in advance, and the lowering position is selected so that the rib 16 melts and is impregnated and integrated into the chip material 12 so that a space where the welding portion of the chip material 12 is not damaged can be secured. In this example, a 0.2 mm space was set in the welded portion 17 with respect to the thickness of the chip material 12 of 0.3 mm.

After the set heating time has elapsed, the controller stops the application of voltage, and at the same time the controller electromagnetically supplies cooling air 18 from the suction pipe 10 provided in the welding tip body 2 as shown in FIG. 5 (g). Switch the valve. The lip portion of the suction pad 10a is elastically deformed by the blown air pressure, and a gap is formed between the suction pad 10a and the chip piece 12, and the cooling air 18 passes through the gap, and the tip 3 of the welded chip body 2 is passed from the inside. Cooling.

  The cooling air 18 is discharged to the outside through the windows 7 and 7 a and the slits 8 and 8 a via the gap between the suction pipe 10 and the vent hole 6.

By passing the cooling air 18 through the gap between the suction pipe 10 and the vent hole 6, the amount of the cooling air 18 released to the outside is controlled, and the cooling efficiency of the tip 3 of the welding tip body 2 is improved.

When the tip 3 and the contact surface 4 of the welding tip body 2 are cooled in a preset time and the resin of the welding portion 17 is solidified, the supply of the cooling air 18 is stopped by switching the electromagnetic valve of the controller, and the thermal welding apparatus 1 is raised. Let As a result, the chip material 12 is welded and fixed to the welding rib 16 of the vent hole 15 of the thermoplastic resin product 14.

  All the operations of the heat welding apparatus 1 described above are controlled by a controller.

In the second embodiment, in the thermal welding apparatus 1 of the first embodiment, the cooling air 18 is supplied from the suction pipe 10 as shown in FIG. 6, and at the same time, the air blow pipe 19 is disposed outside the welding tip body 2, The cooling air 18a is supplied from the air blow pipe 19 to cool the tip 3 and the welded portion 17 of the welding tip body 2 from the outside, thereby increasing the cooling efficiency and further shortening the cooling time.

In the third embodiment, in the heat welding apparatus 1 of the first embodiment, as shown in FIG. 7, a cooling circuit 22 is formed by a cooling flow path 20 outside the suction pipe 10, and the elbow 23 passes through the cooling circuit 22. the tip 3 of the welding tip body 2 and cooled, by discharging from the window 7, 7a, a structure to further facilitate cooling of the welding tip body 2.

DESCRIPTION OF SYMBOLS 1 Heat welding apparatus 2 Welding chip | tip main body 4 Contact surface 6 Ventilation hole 7,7a Window 10 Suction pipe 10a Adsorption pad 11 Insulator 12 Chip material 13 Mount 14 Thermoplastic resin product 15 Ventilation hole 16 Welding rib 17 Melting part 18 Cooling air 19 Air blow pipe 20 Cooling air flow path 21 Cover 22 Cooling circuit 23 Elbow

Claims (3)

a. An impulse heating type thermal welding apparatus for thermally welding a chip material formed of a material having thermal weldability to a thermoplastic resin product, the tip of the welding chip body of the thermal welding apparatus is disposed at the tip that a contact surface made of the outline of the welding shape of the timber, the interior surrounded by the abutting surface is formed a space portion,
b. A vent formed in the top surface central portion of the space portion, flared surface of the suction pad mounted to the distal end of the suction pipe provided with through suction pipe from the vent downwards are the same as the abutment surface It should be located protruding from the plane to 1.0 mm,
c. An exhaust port is formed in a part of the top surface of the space portion, and the exhaust port communicates with an exhaust slit formed in the body portion of the welding tip body,
d. The rear end portion of the suction pipe is connected to a compressed air supply device and an air suction device, respectively, and the compressed air supply device and the air suction device use the switching means to bring the suction port of the suction pipe to a negative pressure, Or it is configured to be able to inject compressed air from the suction port,
e. The abutting surface of the welding apparatus is close to or close to the top surface of the chip material at the position where the chip material to be welded is disposed, and then the suction pad is formed at a negative pressure to suck the chip material. Then, by this action of suction, the chip material is held in close contact with the suction pad and is moved as it is to a predetermined position on the thermoplastic resin product, where it is lowered to press the chip material to the predetermined position of the product. After that, the negative pressure of the suction pad is released, a voltage is applied to the welded chip body to heat the contact surface , the chip material is welded to the product by this heat, and then compressed air is jetted from the suction pad. A controller for controlling the rapid cooling of the welding portion of the tip material and the welding tip body,
f. A welding apparatus for thermally welding a chip material formed of a heat-weldable material to a thermoplastic resin product. Said air blow pipe disposed outside the welding tip body, even to quench the welded part and the welding tip body from the outside by spraying cooling air from the air blow pipe welded part and the welding tip body of the chip material The heat welding apparatus according to claim 1, wherein the heat welding apparatus is configured so that
Welding equipment. A cooling air flow path is formed outside the suction pipe, and cooling air is supplied into the welding chip main body via the cooling air flow path so as to promote cooling of the heating chip. The heat welding apparatus according to claim 1, comprising:

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