JPS6235566Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a vertical movement device in a soldering device or a flux coating device.

(Prior Art) In general, a vertically moving type soldering device uses a cam to move either the object to be soldered or a bath of molten solder liquid up and down, and immerses the object to be soldered in the molten solder liquid. I try to solder it. In this type of vertically moving soldering device using a cam, when the drive system is new, the gears that transmit the drive force are less likely to buckle, but as time passes, the gears gradually wear out and noticeable buckles occur between the gears. If this occurs, it will seriously impede the soldering characteristics.

For example, in FIG. 4, which shows a cam drive system modeled to explain backlash, if there is a backlash 33 between the drive shaft 31 of the cam 30 and the rotary operating rod 32, the cam 30 When pushing up the cam follower 34 for raising and lowering the liquid tank, as shown in FIG.
2, the cam 30 also rotates. When the cam 30 passes the top dead center, as shown in FIG. The vehicle automatically moves downward and suddenly stops. As a result, the cam follower 34 also drops instantaneously, and impact vibrations occur in the liquid tank before the solder solidifies after soldering, which may cause serious defects in the finished product.

Similarly, in a device in which the object to be soldered is moved up and down relative to the solder tank by the cam 30, when the object to be soldered is about to descend from the top dead center, the molten solder at the bottom dead center Mechanical wear causes the object to be soldered to vibrate immediately before contacting the surface, immediately before leaving the solder liquid surface, and during the process of reaching top dead center.

When the soldering object tries to descend from the top dead center, the electrical components inserted into the printed wiring board may fall over or come off from the printed wiring board. In addition, the wobbling just before contact with the solder liquid surface may cause problems such as solder particles being thrown in when the flux evaporates and short circuits between the leads of components. Due to the wobbling just before the solder comes off, problems such as incorrect soldering, icicle-like solder dripping, and pattern shoots may occur.
Furthermore, there are other problems such as poor soldering quality, deterioration of toughness, and wrinkly soldering that loses its luster due to rattling during the process of reaching top dead center.

(Problems to be Solved by the Invention) As mentioned above, when moving up and down the object to be soldered or a liquid tank containing molten solder liquid, the vibration caused by the bumping of the drive system for the up and down movement causes There is a problem that a good finish cannot be obtained.

The present invention was developed in view of the above points, and when either one of the objects to be soldered and the liquid tank is moved up and down relative to each other, the problem arises due to bumps in the drive system for the up and down movement. The purpose is to effectively prevent vibrations.

[Structure of the idea]

(Means for Solving the Problems) The present invention provides a cam that moves up and down relatively between an object to be soldered and a liquid tank in which the object to be soldered is immersed, In a vertical movement device in which a motor is connected to the drive shaft of this cam via a gear transmission, the drive shaft is driven by a mechanical friction braking force that is set smaller than the rotational force of the drive shaft. A mechanical friction type brake mechanism for braking is provided inside the soldering object or the liquid tank, and the mechanical friction type brake mechanism is operated near the top dead center and bottom dead center of either the soldering object or the liquid tank that moves up and down. It is equipped with a brake timing detection device to

(Function) The present invention uses a brake timing detection device to apply a mechanical friction brake when either the soldering object or the liquid tank moves up and down and is near the top dead center or bottom dead center. The mechanism is actuated to apply a predetermined braking force to the drive shaft that is smaller than its rotational force.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, reference numeral 1 denotes a liquid tank fixedly installed on a fixed frame (not shown). This liquid tank 1 contains molten solder liquid melted by a heater, and the printed wiring board is coated in this solder liquid. The bottom surface of such objects to be soldered is immersed and soldered.

Reference numeral 2 designates a pair of transport rails 2 for transporting holders of objects to be soldered; the transport rails 2 are removed above the liquid tank 1, and a pair of lifting rails 3 are disposed in the removed portion. ing. The pair of elevating rails 3 are vertically movably supported by four cylindrical guides 5, which have pillars 4 at the bottom of both ends fixed to a fixed frame, and are provided between the opposing pillars 4 on both sides. A pair of eccentric disk-shaped cams 8 in which cam followers 7 at the center of a pair of cross beams 6 face each other.
is moved up and down by the conveyor rail 2 and the liquid tank 1.
moved upward or downward between

The pair of cams 8 are fitted and fixed to a drive shaft 9 rotatably supported by a fixed frame via bearings, and one end of this drive shaft 9 is connected to the gear transmission 1.
0, that is, it is connected to the motor 13 via the transmission gear 11 and reduction gear 12.

Further, the drive shaft 9 is being driven by a mechanical friction braking force that is set smaller than the rotational force of the drive shaft 9 driven by the motor 13 between the cam 8 on one side of the drive shaft 9 and the gear transmission 10. A mechanical friction type brake mechanism 14 is provided for braking. This mechanical friction type brake mechanism 14 has a second
As shown in the drawings and FIG. 3, a disk 15 is fitted and fixed to the drive shaft 9, and a brake body 17 attached to a fixed base plate 16 is fitted to the edge of the disk 15. This brake body 1
7 has inside thereof a pair of pressing bodies 22 that move forward and backward against both sides of the disk 15, and these pressing bodies 22 on both sides push the disk 15 by fluid pressure, respectively.
When this fluid pressure is released, the brake body 17 is pushed back from the side surface of the disc 15 by the restoring force of the spring inside the brake body 17.

Further, a brake timing detection device 20 is provided for the disk 15. As shown in FIGS. 2 and 3, this brake timing detection device 20 is connected to the base 15 of the disk 15.
A brake timing cam 18 is fitted and fixed to a, and a detection portion 21 of a limit switch 19 is in contact with the outer peripheral surface of this brake timing cam 18. The brake timing cam 18 is formed by a fixed plate 23 and a rotation adjustment plate 24, and by adjusting the overlapping angle of the rotation adjustment plate 24 with respect to the fixed plate 23, the convex portion of the brake timing cam 18 can be adjusted. The entire angle can be changed. Further, the fixing plate 23 is attached to the disk 15.
is screwed to the base 15a of the rotation adjusting plate 2.
4 is attached to the side surface of the fixed plate 23 by screws or the like. The positions of the protrusions of the brake timing cam 18 are such that when the object to be soldered reaches near the top dead center and the bottom dead center, the brake timing cam 18 operates the limit switch 19, and the protrusions on both sides of the brake body 17 are The pressing body 22 is set to press both sides of the disk 15.

In addition, in the figure, 25 is a bearing, and 26 is a mounting base.

Then, the rotation of the motor 13 is controlled by the gear transmission 1.
The solder is transmitted to the drive shaft 9 through the speed reducer 12 and the transmission gear 11, moves the lifting rail 3 up and down by the eccentric disc-shaped cam 8, and transfers the solder from the transport rail 2 to the lifting rail 3 at the top dead center. At the same time as transferring the holder of the accessory, the lower surface of the object to be soldered held in the holder at the bottom dead center is immersed in the molten solder liquid in the liquid bath 1 and soldered, and the holder is again placed at the top dead center. It is carried out from the lifting rail 3 to the transport rail 2.

During such soldering, when the object to be soldered is near the top dead center or bottom dead center, the brake timing cam 18 of the brake timing detection device 20 operates the limit switch 19, thereby causing the brake body to The pressing bodies 22 on both sides of the disk 17 press both sides of the disk 15, and the drive shaft 9 rotates while being braked. In this way, when the object to be soldered is near the top dead center or the bottom dead center, the drive system of the lifting rail 3 is operated while being braked, so that the play of the drive system, for example, of the reducer 12 is reduced. Vibration of the elevating rail 3 caused by backlash of gears is eliminated, and good soldering is achieved.

In addition, conventionally, in fields other than soldering, it has been done to prevent vibrations caused by backlash by applying a load to the output side. There are those that apply braking force, and those that apply a load to the output side using a spring.
Based on Arago's rotating plate principle, the lower the rotational speed of the rotating plate, the smaller the braking force that acts on it. A device that does not provide braking force and applies a load to the output side using a spring is effective when the range of movement of the output side is limited, but it is effective when the movement range of the output side is limited. The mechanical friction type brake mechanism of the present invention is most suitable for applying a constant braking force to a vertical movement device for soldering. .

In the above embodiment, the liquid tank 1 is fixed and the object to be soldered is moved up and down. However, conversely, the liquid tank 1 is moved by a cam to the object to be soldered which is waiting at a predetermined position. It can also be applied to objects that move up and down.

Furthermore, in the above embodiment, the soldering apparatus has been described, but if flux liquid is placed in the liquid tank 1 instead of the molten solder liquid, the apparatus can be used as it is as a vertically moving flux applicator.

[Effect of idea]

According to the present invention, the drive shaft of the cam that moves up and down either the soldering object or the liquid tank is driven by a mechanical friction braking force that is set smaller than the rotational force of the drive shaft. By providing a mechanical friction type brake mechanism that brakes the soldering object or the liquid tank, and operating this mechanical friction type brake mechanism near the top dead center and bottom dead center of the vertical movement of either the soldering object or the liquid tank, By applying a constant braking force to the drive shaft of the cam, it is possible to suppress the vibration caused by the bumping of the drive system during vertical movement, and it is possible to suppress the vibration of the electrical components inserted into the object to be soldered. It is possible to prevent falling and coming off, and to perform reliable and high quality soldering and flux application. In particular, it is highly effective in preventing impact when the soldering object and the soldering surface are separated from each other, thereby preventing any adverse effects on the soldering object.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the vertical movement device of the present invention, Fig. 2 is a partially cutaway plan view of the main part thereof, Fig. 3 is a sectional view taken along the line - - of Fig. 2, and Fig. 4 is FIG. 2 is a cross-sectional view of a modeled cam drive system for explaining problems in the conventional example. DESCRIPTION OF SYMBOLS 1... Liquid tank, 3... Elevating rail for soldered objects, 8... Cam, 9... Drive shaft, 10... Gear transmission, 13... Motor, 14... Mechanical friction type brake mechanism, 20...Brake timing detection device.

Claims (1)

[Claims for Utility Model Registration] A cam is provided between an object to be soldered and a tank of liquid in which the object to be soldered is immersed, and which moves one of them up and down relatively, and the drive shaft of this cam is In a vertical movement device connected to a motor via a gear transmission, a machine that brakes the drive shaft while it is being driven by a mechanical friction braking force that is provided to the drive shaft and is set to be smaller than the rotational force of the drive shaft. a mechanical friction type brake mechanism; and a brake timing detection device that operates the mechanical friction type brake mechanism near the top dead center and bottom dead center of either the soldering object or the liquid tank. vertical movement device.