JPH023665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention performs soldering by pressing a pressing tool having a notch on the printed circuit board in order to avoid contact with electronic components disposed at the edge of the printed circuit board. This invention relates to a printed circuit board holding device in a carrierless soldering device that can be detached after soldering is completed.

FIG. 1 is a side sectional view showing an example of a mode in which a volume, which is an electronic component, is disposed at the edge of a printed circuit board. In this figure, 1 is a printed circuit board, 2
3 and 4 are the resistance elements and mounting terminals of the volume 2;
is inserted into. 5 is a rotation axis of the volume 2.

In this way, when the volume 2 is disposed on the edge 1a of the printed circuit board 1 in the conveyance direction, as shown in FIG. , the resistance terminal 3 and the mounting terminal 4 contact the holding claw 6, making it impossible to engage the printed circuit board 1, and furthermore, the rotation shaft 5
There were drawbacks such as the fact that the retaining claws 6 came into contact with the retaining plate 7.

For this reason, soldering has also been performed by simply placing the printed circuit board 1 on the holding claws 6 without holding it therebetween. Incidentally, in the process of flux treatment and preheating, it is sufficient to simply place the printed circuit board 1, but in the process of soldering, especially when soldering is performed in a jet-type soldering bath, There was a drawback that the printed circuit board 1 was pushed up by the ejection force and was heated by the solder melt, causing warping and detachment.

Furthermore, as shown in FIG. 3, it has been considered to engage the edge portion 1b of the printed circuit board 1 in the direction perpendicular to the conveyance direction with the holding claw 6;
Since a is not engaged, there is a drawback that the printed circuit board 1 is greatly warped due to the heat generated by the solder melt.

Therefore, even if an attempt is made to prevent the printed circuit board 1 from warping by placing the printed circuit board 1 on the warp prevention tool 8, the volume 2 is disposed at the center of the edge 1a of the printed circuit board 1. If it is, the warp prevention tool 8 cannot be held in the center,
Since it is shifted toward the holding claw 6 side, it has disadvantages such as not being effective as a warpage prevention tool 8 against warpage of the printed circuit board 1.

This invention was made in order to eliminate the above-mentioned drawbacks, and a notch is provided on the edge of the printed circuit board placed on the holding claw in the conveying direction to prevent the pressing tool from coming into contact with the volume. The present invention provides a printed circuit board holding device that uses a pressing tool formed with a section, and can automatically move the pressing tool up and down to engage and disengage a printed circuit board placed on a holding claw. This invention will be explained below.

FIG. 4 is a plan view showing an embodiment of the present invention, FIG. 5 is an enlarged sectional view taken along the line X-X of FIG. 4, and FIG.
Figures a, b, and c are a plan view, a side view, an enlarged sectional view taken along the Y-Y line, and a seventh
The figure shows a side view of the printed circuit board warpage prevention device.
FIG. 8 is an explanatory diagram showing the operation of the printed circuit board holding device. In these figures, 11 indicates the entire carrierless soldering device. 12 is a base of the carrierless soldering device 11; 13 is a pair of endless conveyance chains; 14 is a holding claw attached to each of the conveyance chains 13; Place both end edges 1a. Reference numeral 15 denotes a chain guide of the conveyance chain 13, and reference numeral 16 denotes a pair of pressing tools that press and engage both end edges 1a in the conveyance direction (direction of arrow A) of the printed circuit board 1 placed on each of the holding claws 14. As shown in FIG. 6b, a notch 16a is formed to avoid contact with the volume 2. 17 is an air cylinder for moving the pressing tool 16 up and down; 18 is a rod of the air cylinder 17, and the pressing tool 16 is tightened and fixed with a nut 19 so as to be adjustable. 20 is a fitting for the air cylinder 17; 21 is a fitting for fixing the fitting 20;
A slider 21a for moving the pressing tool 16 and the air cylinder 17 in synchronization with the travel of the printed circuit board 1 and the holding claws 14 is a U-shape that connects one slider 21 in parallel with respect to the conveyance direction of the printed circuit board 1. The connector 22 is a rod that guides each slider 21, and each slider 21 is slidably fitted therein. 23 is a bearing for fixing the rod 22; 24 is an endless running chain for moving the slider 21 a predetermined distance in the direction of arrow A; a portion of the chain is fixed to the slider 21; In addition,
The movement of the traveling chain 24 in the direction of the arrow A is transmitted by the same drive source as the conveying chain 13 via an electromagnetic clutch (described later), and the movement of the traveling chain 24 in the direction of the arrow A
(in the opposite direction) is performed by the operation of an air cylinder, which will be described later (FIG. 8). 25 is a chain guide of the traveling chain 24. 26 is a warpage prevention plate that engages both end edges 1b of the printed circuit board 1 in a direction perpendicular to the conveying direction (direction of arrow A);
To prevent a printed circuit board 1 from warping due to heating by a solder melt. Reference numeral 27 denotes a warpage prevention plate 26 for engaging and disengaging the warpage prevention plate 26 from the printed circuit board 1.
28 is a rod of the air cylinder 27, 29 is a connecting plate,
It is fixed to the rod 28 with a nut 30. 3
Reference numeral 1 denotes a rod that connects the warpage preventing plate 26 and the connecting plate 29, and is adjustable with a nut 32. 33 is a fixture for the air cylinder 27; 34 is an air cylinder that moves the anti-warpage plate 26 in the front and back direction of the conveyance direction of the printed circuit board 1 via the fixture 33; 35 is a rod for the air cylinder 34; It is fixed to the fixture 33 by 36. Reference numeral 37 denotes a rod, and as shown in FIG. 4, the fitting 33 of the air cylinder 27 is fitted in a slidable manner. Reference numeral 38 is a mounting base for fixing the rod 37 of the air cylinder 34, and 39 is a guide provided integrally with the mounting base 38, which is screwed into the threaded rod 40. 41 is a handle of the screw rod 40;
42, in order to smoothly slide the mounting base 38 by the rotation of the screw rod 40, a gasket 43 formed in an elongated plate moves the anti-warpage plate 26 in a direction perpendicular to the conveyance direction of the printed circuit board 1. 44 and 45 are long connecting plates that connect the sliders 43 together; 46 is the screw rod 40; This is a bearing that rotatably supports the shaft, and is attached to the connecting plate 44. 47 is a gasket for smoothly sliding the connecting plate 45; 48 is a guide provided integrally with the connecting plate 45; a screw hole is formed therein, and a screw rod 49 is screwed therein; 5
0 is a bearing that rotatably supports the screw rod 49, and is attached to the slider 21. 51 is a handle of the threaded rod 49, 52 is a sprocket of each traveling chain 24, and 53 is a connecting shaft connecting one end side of each sprocket 52.

Further, in FIG. 8, 61 is a solder tank of the jet type. 62 is a phototube for detecting that the printed circuit board 1 has been conveyed to the front of the solder tank 61; 63 is a phototube for detecting the holding claw 14 or the gap between the holding claws; 64 is an electromagnetic clutch that controls the carrying chain 13; By engaging and disengaging from a motor (not shown) serving as a drive source for traveling, the traveling chain 24 is made to travel or is set in a free state. 65 is an air cylinder for returning the pressing tool 16 to its original position, and 66 is a rod of the air cylinder 65, which is connected to the slider 21 (FIG. 5) via a connecting plate 67.

Next, the operation will be explained.

First, a preparatory operation before soldering in the solder bath 61 will be described.

First, the number of holding claws 14 corresponding to the distance _L1 shown in FIG. 8 is set in a preset counter attached to a power distribution board (not shown). That is,
The air cylinder 17 operates to lower the pressing tool 16, press the printed circuit board 1 and engage it with the holding claws 14, perform soldering in the solder bath 61, and after completing the soldering, raise the pressing tool 16. The preset counter is set to a value obtained by dividing the traveling distance _L1 until the holding claw 14 is moved by the pitch p of the holding pawl 14, and adding a number from 1 to 2, depending on the margin.

Next, turn the handle 41 to
6 is set at a position (some distance away from the printed circuit board 1) where it can be engaged with the printed circuit board 1 by the operation of each air cylinder 27, 34 at both end edges 1b in the direction perpendicular to the conveyance direction of the printed circuit board 1. ,
The handle 51 is turned to set each anti-warpage plate 26 to the center with respect to the direction perpendicular to the running direction of the printed circuit board 1, thereby completing the soldering preparation operation.

Next, the operation of engaging and disengaging the pressing tool 16 from the printed circuit board 1 will be explained.

The printed circuit board 1 is placed on the holding claws 14 and is transported in the direction of arrow A by the movement of the transport chain 13. Next, the front edge 1b of the printed circuit board 1 that has been transported is detected by the phototube 62 shown in FIG. 8, and at the same time, a timer (not shown) is activated. The operating time of this timer is set to the time during which the printed circuit board 1 travels a distance L ₂ before the solder bath 61. Next, when the timer times up, each air cylinder 17, 27, 3
4 start operating at the same time. When the air cylinder 17 starts operating, the pressing tool 16 is lowered to press the printed circuit board 1 and fix it to the holding claws 14. Furthermore, when the air cylinders 27 and 34 start operating, the anti-warp plate 26 is lowered, moved horizontally, and raised to be placed on both end edges 1b of the printed circuit board 1. The details of the operation of the anti-warpage plate 26 are explained in the ninth section.
This will be described later based on the figures.

Further, at the same time as the time is up, the electromagnetic clutch 64 is activated to drive the connecting shaft 53 and run the travel chain 24 at the same speed as the conveyance chain 13. 1 with pressing tool 1 placed on it.
6 and the anti-warp plate 26 run at the same speed and are soldered in the solder bath 61. Thereafter, when the printed circuit board 1 has completed traveling the distance _L1 , a limit switch (not shown) is turned on by the count-up of a counter previously set in the switchboard, and the press tool 16 is raised by the air cylinder 17. At the same time, the electromagnetic clutch 64 is operated to release the engagement with the connecting shaft 53, thereby setting the traveling chain 24 in a free state. Next, the air cylinder 65 is operated to move the pressing tool 16 in the direction opposite to the direction of arrow A and return it to its original position.

Next, the operation of the anti-warp plate 26 will be explained with reference to FIGS. 7 and 9.

FIGS. 9a to 9e are explanatory diagrams showing the operation of the warp prevention plate 26. FIG.

Initially, the anti-warp plate 26 is placed above the printed circuit board 1 and below the printed circuit board 1, as shown in FIG. 9a.
It is set at a position separated by a predetermined distance ι before and after both end edges 1b in the conveyance direction (direction of arrow A).
Next, as shown in FIG. 8, when the pressing tool 16 is engaged with the printed circuit board 1, a limit switch (not shown) is turned on, and the air cylinder 27 shown in FIG.
As a result of this operation, the anti-warpage plate 26 is lowered below the level of the printed circuit board 1 to the position shown in FIG. 9b. Next, when a limit switch (not shown) is turned on, the air cylinder 34 is operated to horizontally move the anti-warpage plate 26 at the same level, and as shown in FIG. 9c, both butterfly edges 1b of the printed circuit board 1 are
position with a very small gap between the front and rear. Next, when a limit switch (not shown) is turned on, the air cylinder 27 is actuated to raise the anti-warp plate 26 so that it engages with the lower surface of the printed circuit board 1 as shown in FIG. 9(d).

In this way, the four sides of the printed circuit board 1 are
The printed circuit board 1 is conveyed while being held down by the warp prevention plate 26 and soldered in the solder bath 61.

Next, when the soldering is completed and the printed circuit board 1 has traveled the distance _L1 , the pressing tool 16 rises and at the same time, the air cylinder 34 moves the anti-warp plate 26 horizontally at the same level. As shown in Figure e, it is separated from the printed circuit board 1.
Next, a limit switch (not shown) is turned on.
Due to the operation of the air cylinder 27, the anti-warp plate 26 is raised and returned to its original position as shown in FIG. 9a.

As explained above, the present invention forms a notch in order to avoid contact with electronic components disposed at the edge of a printed circuit board, and also presses the printed circuit board placed on the holding claw from above. A pressing tool is used to fix the holding claw to the holding claw, and the pressing tool is fixed to the printed circuit board before soldering, and the pressing tool is moved up and down to enable the printed circuit board to be detached by moving it up and down in order to release it after the soldering is completed. a drive source, a slider fixed integrally with the drive source in order to move the printed circuit board in the same direction as the running direction of the printed circuit board while pressing the printed circuit board with a pressing tool, and a drive source that moves the slider only when necessary. After soldering is completed, a drive source that releases the pressure of the pressing tool and returns the pressing tool to its original position forms a printed circuit board holding device in a carrier-less soldering machine, so a volume is attached to the edge of the printed circuit board. Even if electronic components such as This prevents the printed circuit board from being pushed up and detached from the holding claws, and prevents the printed circuit board from warping due to heating of the solder melt, etc. Furthermore, the pressing tool can be pressed against the printed circuit board and released automatically, which saves labor. This has the advantage of reducing labor costs.

[Brief explanation of drawings]

Fig. 1 is a side cross-sectional view showing an example of an embodiment in which a volume, which is an electronic component, is arranged at the edge of a printed circuit board, and Fig. 2 shows a state in which the printed circuit board shown in Fig. 1 engages with a U-shaped holding claw. FIG. 3 is a plan view showing a case where the short edge of the printed circuit board shown in FIG. 1 is engaged, and FIG. 4 shows an embodiment of the present invention. A plan view, FIG. 5 is a sectional view taken along line X-X in FIG. 4, and FIGS. 6 a, b, and c are plan views, side views, and Y
- An enlarged sectional view taken along the Y line, FIG. 7 is a side view showing the printed circuit board warpage prevention device, FIG. 8 is an explanatory view showing the operation of the printed circuit board holding device, and FIGS. 9 a to 9
FIG. 3e is an explanatory diagram showing the operation of the warpage prevention plate of the printed circuit board. In the figure, 1 is a printed circuit board, 2 is a volume, 11
is a carrierless soldering device, 12 is a base, 1
3 is a conveyance chain, 14 is a holding claw, 16 is a pressing tool,
16a is a notch, 17, 27, 34, 65 are air cylinders, 20, 33 are fittings, 21, 43 are sliders, 21a is a coupling, 22, 37 are rods,
24 is a traveling chain, 26 is a warpage prevention plate, 38 is a mounting base, 40, 49 are screw rods, 42, 47 are packings, 44, 45 are connecting plates, 53 is a connecting shaft, 61 is a solder bath, 62, 63 are The photocell 64 is an electromagnetic clutch.

Claims (1)

[Claims] 1. A carrier-less soldering device that performs soldering by placing a printed circuit board on the holding claws of a conveyance chain, which has a notch to avoid contact with electronic components disposed at the edge of the printed circuit board. together with a pressing tool that presses the printed circuit board from above and fixes it to the holding claw; the pressing tool is fixed to the printed circuit board before soldering; and the pressing tool is moved up and down to remove it after soldering is completed. and a driving source for pressing the pressing tool against the printed circuit board and moving it in the same direction as the conveyance direction of the printed circuit board. Consisting of a slider that is fixed in one piece, a drive source that moves this slider only when necessary, and a drive source that releases the pressure of the pressing tool and returns the slider to its original position after soldering is completed. A holding device for a printed circuit board in a carrierless soldering device, characterized by: