JPH03268865A - Exhaust structure of soldering part in automatic soldering device - Google Patents

Abstract

PURPOSE:To form a vortex extending over the whole of the upper space and to completely exhaust soldering fumes by providing vertically compressed air injection pipes so as to come into contact with the side face, placing them coaxially and at an equal interval so as to surround the central vertical axis, and making the directions of injection holes uniform. CONSTITUTION:Four pieces of compressed air injection pipes 4 are provided vertically coaxially and at an equal interval in the periphery of the central vertical axis of the upper space 3 so as to come into contact with a side face 31 of the upper space 3 from the solder face of a solder tank 21 of a soldering part 2. Each compressed air injection pipe 4 is an iron pipe and injection holes 41 are provided at a prescribed interval, blow air is obtained roughly like a plane, and by surrounding the central vertical axis by these four pices of plane blow air and making the directions uniform, a vortex is formed. To the compressed air injection pipe 4, the air adjusted to prescribed pressure is supplied equally so as to generate a sufficient vortex for collecting soldering fumes and exhausting them completely. In such a way, the soldering fumes are exhausted completely, and an efficient automatic soldering device is obtained.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to provide an efficient and low-cost exhaust structure that completely exhausts soldering fumes with respect to the exhaust structure of the soldering section in an automatic soldering device. An exhaust structure for a soldering part in an immersion or jet type automatic soldering device for temporary soldering, wherein the soldering part is in contact with the side surface of the upper space from the solder surface of the solder bath of the soldering part, and the central vertical axis of the upper space is A plurality of pressurized air injection pipes each having injection holes lined up at a predetermined interval so as to obtain fumes in a substantially planar manner coaxially and equally spaced around a The structure is such that an exhaust duct is installed in the ceiling of the upper space.

[Industrial application field]

The present invention relates to an exhaust structure for a soldering section in an automatic soldering device.

Soldering fumes generated during soldering contain harmful gases and have an unpleasant odor, so it is important to ensure that the smoke is exhausted to prevent workers from inhaling it.

[Conventional technology]

FIG. 3 shows a sectional view of the structure of an example of a conventional automatic soldering device.

A conventional example of an immersion or jet type automatic soldering device used for manufacturing printed wiring boards is as shown in FIG. An application section 7 and a cleaning section 8 are arranged on the exit side, and a belt conveyor 16 runs from the entrance to the exit. Each part has a different atmosphere, and is isolated from the outside world in a tunnel shape so as not to affect each other, and is separated by an appropriate partition wall. This is provided.

The printed wiring board 9 is conveyed at a constant speed with both side edges supported by a belt conveyor 16, is coated with flux and preheated in a flux application section 7, and then soldered by dipping or jet soldering in the next soldering section 2. Finally, in the cleaning section 8, dissolution cleaning using a cleaning solution for removing flux is performed to complete the process.

An exhaust duct 5 is provided on the ceiling of the upper space 35 of the solder tank 21 to exhaust soldering fumes generated when the printed wiring board 9 is soldered.

Furthermore, a banner 1 made of strips of rubber plates hung closely together so as not to be discharged from the inlet and outlet of the automatic soldering device 15.
7 blocks the entrance and exit, printed wiring! 7i29
The strip rubber plate is bent effortlessly when passing through, and after passing, it automatically returns to its original shape and closes.

[Problem to be solved by the invention]

However, (1) Smoke leaks out from the banner 17 through which the printed wiring board 9 is passing and other gaps, and is not completely exhausted to the exhaust duct 5.

(2) The rubber plate banner 17 is an insulator and is charged when it rubs against the printed wiring board 9. If the charging is not prevented, the parts may be destroyed, which is a problem.

(2) Completely filling and sealing the gap in the device requires expensive equipment to allow the printed wiring board 9 to pass through, and it is also difficult to operate and maintain.

There are other problems.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide an efficient and low-cost exhaust structure that completely exhausts soldering fumes.

[Means to solve the problem]

The above object, as shown in the principle diagram of FIG. In contact with the side surface 31 of the upper space 3 from the surface, the upper space 3
A plurality of pressurized air injection pipes 4 each having injection holes 41 arranged at predetermined intervals coaxially and equally spaced around the central vertical axis of the jet are arranged so that the injection holes 41 are arranged in parallel at predetermined intervals so as to obtain jets of jet in a substantially planar manner. This is achieved by the exhaust structure of the soldering section in the automatic soldering apparatus of the present invention, in which the exhaust ducts 41 are vertically arranged in the same direction and the exhaust duct 5 is provided in the ceiling section 32 of the upper space 3.

[Effect] In other words, the vortex flow whose center part is connected to the exhaust air has no outward diffusion action, but only aggregation action towards the center.

Therefore, in the soldering part 2, a vortex is formed around the central vertical axis of the upper space 3, and is exhausted from the exhaust duct 5 in the ceiling part 32, so the soldering smoke generated by soldering is also caught up in the vortex, and The air is collected in the air and is completely exhausted through the exhaust duct 32.

In order to form a vortex flow throughout the interior of the upper space 3, pressurized air injection pipes 4 are erected in contact with the side surface 31, placed coaxially at equal intervals around the central vertical axis, and the directions of the injection holes 41 are aligned. , a vortex flow that easily covers the entire upper space 3 is formed.

Although the figure shows four pressurized air injection pipes 4 erected, three or more may be used.

The compressed air of the lowest pressure that causes a vortex flow in the upper space 3 may be evenly supplied to each pressurized air injection pipe 4 .

In this way, the soldering fumes can be completely exhausted, and even for the conventional example described above, it is easier to modify the conventional example by installing the pressurized air injection pipe 4 upright than by closing the gap. There is no need for rubber plate banners, and static electricity is eliminated, making it possible to provide an efficient and low-cost exhaust structure.

〔Example〕

The present invention will be specifically described below with reference to embodiments shown in the drawings. The same reference numerals indicate the same objects throughout the figures. FIG. 2 shows a sectional view of the structure of an embodiment of the present invention.

The automatic soldering device 1 of this embodiment is a modified version of the conventional example described above, and as shown in FIG. A belt conveyor 16 runs from the inlet to the outlet, and each part has a different atmosphere so that they do not affect each other. To increase efficiency, a partition wall 12 is provided at the boundary to provide heat insulation and to prevent the cleaning liquid from scattering. It is also covered with an outer wall 11 in the form of a tunnel that isolates it from the outside world.

The printed wiring board 9 is conveyed at a constant speed with both edges supported by a belt conveyor 16, and flux is applied to the soldering surface in a flux application section 7, and the entire printed wiring board 9 is coated in a predetermined manner to improve solderability in the next step. Preheating is performed to a surface temperature of .

The soldering section 2 is equipped with a jet-type solder bath 21, and performs soldering by applying a solder jet to the moving printed wiring board 9.

(Continued) In the cleaning section 8, a rotating brush immersed in a solvent solution is pressed against the soldering surface of the printed wiring board 9 to dissolve and peel off flux and residue.

Here, the soldering section 2 is provided with an exhaust structure in order to exhaust harmful gases and unpleasant odors emitted during soldering.

This exhaust structure forms a vortex around the central vertical axis in the entire area of the space 3 above the solder surface of the solder bath 21, and
2 is exhausted through an exhaust duct 5 provided concentrically with the central vertical axis position.

The vortex flows from the side surface 31 of the space 3 (100 x 100 x height 80 CI 11) above the soldering surface of the solder bath 21 of the soldering part 2.
(inner surface of the outer wall 11), coaxially and equidistantly around the central vertical axis of the upper space 3 (i.e., at the four corners of the upper space 3)
, four pressurized air injection pipes 4 are installed upright, and each pressurized air injection pipe 4 is an iron pipe (over a length of about 80 cm) with injection holes 41 at predetermined intervals.
are arranged in parallel, and the fumes are obtained in a substantially planar shape, so a vortex is formed by aligning the directions of these four planar fumes surrounding the central vertical axis.

The pressure air injection pipe 4 is supplied with low-pressure air from the factory piping at a maximum of 7 atmospheres through a pressure regulator to a predetermined pressure so as to generate a vortex sufficient to collect the soldering fumes and completely expel them. Adjustable and evenly distributed.

The above embodiment shows an example 2 and is a jet type soldering tank, but
Of course, it can also be applied to an immersion solder bath.

Further, the dimensions and shape of the upper space 3, the number and arrangement of the pressurized air injection pipes 4, the type of air supplied, and the pressure are not limited to those described above, and the presence or absence of the partition wall 12 does not matter.

[Effects of the Invention] As described above, the present invention provides an efficient automatic soldering device that completely exhausts soldering fumes, and has a low-cost exhaust structure that can be modified to the same type of device. This eliminates the need for rubber plate banners installed at entrances and exits due to insufficient ventilation, and prevents static electricity build-up, which has a remarkable practical effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a cross-sectional view of an embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional automatic soldering apparatus. In the figure, ①, I5 is an automatic soldering device, 2 is a soldering part, 3.35 is an upper space, 4 is a pressurized air injection pipe, 5 is an exhaust duct,
7 is a flux application section, 8 is a cleaning section,
9 is a printed wiring board, 11 is an outer wall, 12
is the bulkhead, 16 is the belt conveyor, 17 is the banner, 21
is the solder tank, 31 is the side, 32 is the ceiling,
41 is an injection hole. Tadashi

Claims (1)

[Scope of Claims] An exhaust structure for a soldering part in an immersion or jet type automatic soldering device for soldering a printed wiring board, the soldering part (
From the soldering surface of the solder tank (21) in 2), in contact with the side surface (31) of the upper space (3), fumes are emitted coaxially and at equal intervals around the central vertical axis of the upper space (3) in a substantially planar shape. A plurality of pressurized air injection pipes (4) each having injection holes (41) arranged in parallel at predetermined intervals to obtain
1) are erected in the same direction, and an exhaust duct (5) is installed on the ceiling (32) of the upper space (3).
An exhaust structure for a soldering section in an automatic soldering device, characterized in that it is provided with: