JPH05192766A - Jet type soldering device - Google Patents

Abstract

PURPOSE:To provide the jet type soldering device capable of stably forming an inert atmosphere in a chamber having simple structure to incline upward. CONSTITUTION:The jet type soldering device is provided with the chamber 31 to form the inert atmosphere by filling inert gas (nitrogen gas) along a conveyor 24 to carry a work with a gradient upward. An inert gas filling pipe 32 is inserted into the upper part of this chamber 31. A spray fluxer 41, a preheater 42 and a jet type solder vessel 45 are provided in order on the bottom of the conveyor 24. A balance port 61 is opened in the vicinity of a work carrying-in port 35 provided on the lower side end of the chamber 31 and a blower 63 is connected to this balance port 61 via a suction pipe 62. The flow of the inert gas discharged forciblly from the balance port 61 on the work carrying-in port side of the chamber 31 by suction of the blower 63 is formed in the chamber 31 for the flow of the inert gas discharged naturally from a work carrying-out port 36 of the chamber 31 by a chimney effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet soldering device.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS.
A conveyor 11 that conveys a work (printed wiring board P) while inclining upward, and a work carry-in port and a work carry-out port that are provided along both ends of the conveyer 11 to form an inert atmosphere by injecting an inert gas. A chamber 12 having an opening, and a jet-type solder bath 13 for soldering a work with molten solder jetted from a nozzle in the chamber 12.
There is a jet type soldering device having a.

Since both ends of the chamber 12 are opened and the chamber 12 is inclined upward, a so-called "chimney effect" occurs in which the heating atmosphere inside moves vigorously to the upper side. Therefore, the inert atmosphere in the chamber flows out from the work carrying-out port, and the outside air flows in from the work carrying-in port, so that the oxygen concentration in the chamber easily rises.

In order to prevent this chimney effect and maintain an inert atmosphere in the chamber, the jet type soldering apparatus shown in FIGS. 3 and 4 has shutters at the work inlet and the work outlet of the chamber 12. 14 is provided. In particular, the soldering apparatus of FIG. 4 has an atmosphere replacement chamber 15 by adopting a double shutter structure on each of the work carry-in side and the work carry-out side, and when the inner shutter is opened, the interior of this chamber 15 is kept in an inert atmosphere. I am trying to meet.

Further, in the jet type soldering apparatus shown in FIG. 5, a conveyor 16 which inclines downward is provided separately at the tip of the conveyor 11 which inclines upward, and a downward inclination at the tip of the ascending inclination chamber 12. By providing the chamber 17 integrally, the chimney effect is suppressed.

[0006]

In the shutter system shown in FIGS. 3 and 4, the shutter 14 cannot cope with discontinuous work input and the sensor may malfunction to cause an accident. Further, the structure is complicated and maintenance is difficult. Further, the oxygen concentration in the chamber is likely to change with the opening / closing of the shutter 14, and the stability of the oxygen concentration is not good.

Further, the atmosphere displacement chamber system shown in FIG. 4 and the descending tilt chamber system shown in FIG. 5 have a drawback that the total length of the apparatus becomes large.

Further, the chimney effect becomes more prominent as the work transfer angle with respect to the horizontal plane is set larger, but the conventional apparatus structures cannot easily cope with the adjustment of the work transfer angle.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a jet type soldering apparatus capable of stably forming an inert atmosphere in a chamber having a simple structure which inclines upward. To do.

[0010]

DISCLOSURE OF THE INVENTION The present invention is directed to a conveyor for transporting a work by inclining upward and a work-carrying-in at both ends provided along the conveyor for forming an inert atmosphere by injecting an inert gas. In a jet-type soldering device having a chamber with an opening for opening a workpiece and a work outlet, and a jet-type solder bath for soldering a work with molten solder jetted from a nozzle in the chamber, a descending side end of the chamber A jet-type soldering apparatus is provided with a chamber air suction port opened in the vicinity of a workpiece loading port located therein, and a suction device connected to the chamber air suction port and sucking the chamber air to the outside.

[0011]

According to the present invention, the flow of the inert gas which is naturally exhausted from the work carrying-out port of the chamber due to the chimney effect is forced to be exhausted from the inside air suction port on the work carrying-in side of the chamber by the suction device. A flow of active gas is formed in the chamber so that the inert gas injected into the chamber is distributed in a balanced manner to both ends of the chamber.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in FIGS.

FIG. 1 shows a jet type soldering apparatus according to the present invention, in which a conveyor 24 for supporting a work by inclining upward is supported by a support member 22 and a support member 23 on a base 21. The workpiece loading side of the conveyor frame is rotatably attached to the support member 22 by a fulcrum shaft 25, and the workpiece unloading side of the conveyor frame is rotatably attached to a vertically adjustable support member 23 by a fulcrum shaft 26. There is.
The tilt angle of the conveyor 24 is adjusted by vertically adjusting the support member 23. 27 is a device cover.

Along the conveyor 24, a chamber 31 is provided for forming an inert atmosphere by injecting an inert gas (nitrogen gas or the like). An inert gas injection pipe 32 is inserted in the upper part of the chamber 31, and the chamber 31
The throat portions 33, 34 are formed at both ends of the throat so as to suppress the outflow of the inert gas to the outside, and the work carry-in port 35 and the work carry-out port 36 are provided at the end faces of the throat parts 33, 34. It is open.

Below the conveyor 24, a spray fluxer 41 for spraying and applying flux to the work.
And a preheater 42 for preheating the work in the chamber 31, and a primary nozzle 43 and a secondary nozzle in the chamber 31.
A jet-type solder bath 45 for soldering a work with molten solder jetted from 44 is sequentially arranged.

A dust collecting duct 51 is disposed at the opposite portion of the spray fluxer 41, and the duct 51 is connected to a dust collector 54 such as a cyclone through an inertia filter 52 and a pipe 53, and an excess flux not applied to the work. Is configured to be efficiently collected by these dust collecting mechanisms.

As also shown in FIG. 2, the chamber 31
An in-chamber air suction port (hereinafter referred to as a balance port) 61 is opened in the vicinity of the work carry-in port 35 provided in the descending-side end throat portion 33 of the chamber. A blower 63 as a suction device for sucking into is connected. Balance port 61
Is formed in a slender shape over the entire width of the throat portion 33, the connection portion 64 of the suction pipe 62 is also formed in a shape that matches the balance port 61, and the throat portion is formed by the flange portion 65.
Combined with 33.

The balance port 61 may be provided on both upper and lower surfaces of the throat portion 33 as shown in FIG. 1, or may be provided only on the lower surface.

The balance port 61 on the work loading side
By sucking the air in the chamber from the chamber, the tendency that only the work carrying-out side has a low pressure due to the chimney effect is eliminated, and the pressure difference at both ends of the chamber 31 is made substantially equal. As a result, the inert gas forcibly exhausted from the balance port 61 on the workpiece inlet side of the chamber 31 by the blower 63 against the flow of the inert gas that is naturally exhausted from the workpiece outlet 36 of the chamber 31 due to the chimney effect. A gas flow is formed in the chamber 31 so that the inert gas injected into the chamber 31
It is distributed to both ends of 31 in a well-balanced manner, and is exhausted from both ends at almost the same speed.

The blower 63 for sucking the inside air is provided on the conveyor 24.
When the setting conditions such as the inclination angle and the width dimension of the work are changed, the suction flow rate is controlled by the damper or the rotation speed of the blower motor 63a is controlled to cope with the change of the setting conditions.

For example, when the inclination angle of the conveyor 24 becomes large, the chimney effect also appears remarkably, so the suction force at the balance port 61 is controlled to be large. Further, when the width of the work is large, the opening between the pair of endless chains for conveying the work becomes large, and the chimney effect becomes remarkable, so the suction force at the balance port 61 is controlled to be large.

The blower 63 may be automatically controlled so as to eliminate the pressure difference by detecting the pressure difference between both ends of the chamber.

From the inert gas injection pipe 32 to the chamber
The flow rate of the inert gas supplied into the chamber 31 is controlled according to the oxygen concentration detected in the chamber.

[0024]

According to the present invention, the inside of the chamber is forcibly sucked out by the suction machine from the work carrying-in side, which acts as the outside air inlet of the chamber due to the chimney effect, so that the negative pressure against the chimney effect is exerted. The inert gas injected into the chamber can also be distributed to both ends of the chamber in a well-balanced manner by generating the gas on the work loading side, and the inert atmosphere can be stably and uniformly formed in the chamber. As a result, the tunnel furnace in which the work transfer angle is not horizontal can be used as an atmosphere furnace with a simple structure, the conventional shutter is not required, the conveyor need not be divided, and the oxygen concentration is highly stable. Further, by adjusting the suction flow rate and the like of the suction device, it is possible to easily deal with variable setting conditions such as the work transfer angle.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a jet type soldering device of the present invention.

FIG. 2 is an exploded perspective view showing a chamber air suction port portion of the same soldering device.

FIG. 3 is a sectional view showing an example of a conventional jet type soldering device.

FIG. 4 is a cross-sectional view showing another example of a conventional jet soldering device.

FIG. 5 is a sectional view showing still another example of a conventional jet soldering device.

[Explanation of symbols]

 24 Conveyor 31 Chamber 35 Workpiece loading port 36 Workpiece loading port 45 Jet solder bath 61 Chamber air suction port 63 Suction machine

Front page continuation (72) Inventor Takuya Sato 11 591 Kamihirose Higashikubo, Sayama City, Saitama Prefecture Tamura Corporation Co., Ltd.

Claims (1)

[Claims] 1. A conveyor for transporting a workpiece while inclining upward, and a workpiece loading inlet and a workpiece loading outlet are provided at both ends thereof along the conveyor for forming an inert atmosphere by injecting an inert gas. In a jet type soldering device having a chamber and a jet type solder bath for soldering a work by molten solder jetted from a nozzle in the chamber, in the vicinity of a work carrying-in port located at a descending side end of the chamber. A jet type soldering apparatus comprising: an open chamber air suction port; and a suction device connected to the chamber air suction port to suck the chamber air to the outside.