JPS6364267B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-head welding device, and more particularly to a welding device that automatically performs predetermined welding by sequentially determining and controlling a welding position positioning mechanism, multiple welding head mechanism, electrode polishing mechanism, etc. be.

Conventionally, fine leads have often been connected by manual soldering or manual welding. In the welding work, most of the tasks such as positioning and setting of welding conditions are based on the sensory skills of the operator, and thus require a high level of skill.
Therefore, equipment has been developed for welding patterns that are relatively aligned, but these are welding machines with a simple welding position using a transparent target, or one welding head with one welding power source. This is a welding machine that prepares and performs a single operation. Further, a welding machine equipped with a multi-head is also being considered, but in this case as well, a plurality of welding power source systems are arranged in a one-to-one correspondence. As is well known, installing a large number of welding power sources, which account for 1/3 of the cost of manufacturing a welding device, increases the manufacturing cost and increases the number of man-hours for adjusting and managing the equipment.

Furthermore, it is conceivable to use an NC device as a positioning method for welding, but this would be extremely expensive.

The purpose of the present invention is to solve these problems by being able to drive multiple welding heads with a single welding power source, automatically and accurately positioning fine patterns without visual inspection or NC, and furthermore, it is possible to drive multiple welding heads with a single welding power source. To provide an inexpensive multi-head welding device which can automatically perform pressurization and series energization of a plurality of heads.

To achieve the above object, the multi-head welding device of the present invention is a device for welding connectors and components having a plurality of lead terminals to pre-soldered connection patterns, and includes a single-axis table driven by a step motor. a welding positioning mechanism that includes interlocking reference patterns, optically detects the position of the reference patterns, and further detects the presence or absence of a part to be welded to automatically position the welding using the step motor;
After driving the upper welding head of the part to be welded to perform upper welding, the lower welding head is driven to perform lower welding, and by switching one welding power source, multiple welding heads can be welded. A plurality of welding head mechanisms for sequentially supplying power, a mechanism that moves the head arm horizontally and drives a polishing mechanism at a predetermined period to polish the tip of the head electrode to polish the welding head, and detects the welding position. When an AND condition is established between the sensor signal for detecting the presence or absence of the welded part, and the signal for normal pressure force, this is used as a trigger to energize the welding head, thereby applying multiple welding head pressures. It is characterized by having a circuit that sequentially determines and controls each operation of series energization of the welding head and polishing of the tip of the head electrode.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a multi-head welding apparatus showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the state of a welded part of the welding apparatus of FIG. 1.

As shown in Fig. 1, the welding heads 2 are located above and below the printed board 1, and during welding, the upper head of the welding heads 2 moves downward, and the lower head moves upward. The structure is such that the printed board 1 is sandwiched between the two. The positional relationship between this welding head 2 and printed board 1 is as shown in FIG.

Welding head 2 has vertical movement and head arm 2.
-5 swinging motion is performed, of which the vertical motion is for pressurizing the component lead at the welding position and applying welding current. The former, that is, the vertical movement, is driven by two air cylinders 8,
The latter, that is, the swinging motion of the head arm, is performed using a 90° rotary air actuator 11.
Driven by

When electricity is applied to the welding head 2, electricity is passed between the two electrode chips 2-1 and 2-2 to generate heat due to contact resistance at the contact point between the electrode and the component lead, melting the solder prepared in advance. At the same time, welding current is applied to melt the contact points between the base metal copper foil and the component leads and form nuggets.
Generally, such a welding method is called a parallel gap welding method. The timing of energization is such that the upper welding head 2 is energized for approximately 0.2 seconds, and then the lower welding head 2 is energized. In Fig. 1, two welding heads 2 are energized by one welding power source 3. It's on. In addition, although only one head arm 2-5 is provided in FIG. 1, by applying this, the welding head arm 2-5 can be
It is also possible to prepare a plurality of welding heads 5 and energize a plurality of welding heads with one welding power source 3. This makes it possible to realize an inexpensive series welding device.

To set the possible force, when the upper and lower welding heads 2 are inserted, the welding heads 2 come to rest in a position where the upper and lower pressures are balanced, and the final energizing force is set by starting energization by the pressure switch built into the welding head 2. do.
However, a matching condition logic is incorporated so that energization is started only when the pressure switches of the upper and lower welding heads 2 are both in the "on" state.

As shown in FIG. 1, the printed board 1 is mounted on a single-axis table, and a stopper 10 for coarse positioning and a clamp bin 9 for fine positioning are installed to clamp the printed board 1. It has a structure that allows it to be clamped from both sides. The clamp pin 9 is composed of two pins, a long taper pin for coarse positioning and a small straight pin for fine positioning.

This one-axis table is driven by a step motor 7, and in this case, it receives a position signal of a welding position and performs positioning, but slight deviations occur due to the inertial force of the table. In order to correct this, a (+) or (-) correction pulse is added to the instruction pulse of the step motor 7 to achieve accurate positioning.

In order to detect the welding position, a reference pattern 13 with black and white Yin and Yang and flatness is provided, and an optical detection device 12 positioned perpendicular to this pattern detects the black and white and recognizes the position. By doing so, a method is adopted in which the pattern of the printed board 1 serving as the workpiece is substituted for recognition. The yin and yang of black and white is determined by the amount of reflected light, and this differs from visual perception of black and white, so care must be taken.

When welding continuously, the contact resistance fluctuates due to carbide, dust, etc. on the tip of the electrode, so polishing is required at the same time as the specified welding is completed.
In the apparatus shown in FIG. 1, each time one printed board 1 is completed, the welding head 2 is swung to a polishing position 14 to perform polishing. Polishing position 14
The head 2, which has swung forward, picks up the sand paper attached to both sides and completes the polishing by operating the drive motors 15, 16 for the X and Y axes of the polishing table.

FIG. 3 is a control system block diagram of a multi-head welding apparatus showing an embodiment of the present invention, and FIG. 4 is an operation time chart in FIG. 3.

The sequential determination control of energization first detects the position of the welding position, then determines the presence or absence of a part, then determines the pressing force of the welding head 2, and when the conditions match, inputs a signal to start energization to the welding power source 3. do. At this time, a start signal is again input to the welding power source 3 in order to energize the lower welding head 2 0.1 sec after the upper welding head 2 is energized. In addition, the energization switching between the upper welding head 2 and the lower welding head 2 is as follows:
Another signal is input from the sequential determination control section 18 to the selector control circuit 20. This selector control circuit 20
is the secondary side of the power supply 3 and the welding transformers 23 and 24
It is placed between the primary side of the welding current and performs energization switching without being affected by the welding current. Inside the selector control circuit 20, a non-contact photocoupler type solid state relay is used, and since this relay uses a triac, it has a structure that can withstand relatively large currents. By effectively utilizing this non-contact relay, it is possible to make full use of a plurality of welding heads 2 with one power source, and to perform welding in a short time.

Sequentially, the determination control unit 18 inputs information signals such as the position information of each mechanism, the welding position, and the pressurization signal of the welding head 2 from the sensor 25, and controls the motor drive circuit 21 and the electromagnetic valve drive circuit 22 depending on the match of the conditions. Then, the moving motor 7, the polishing table motor 15, 1
6. Give necessary output signals to the welding power source 3 and selector control circuit 20 to perform predetermined operations.

To explain the operation sequence in Fig. 4, the fourth
The clamp valve 9 in Figure 4a and the stopper valve 10 in Figure 4B remain on until the printed board 1 is welded, and the connector sensor in Figure 4e and the position detection sensor in Figure 4d After driving and stopping the moving motor 7 shown in Fig. 4c according to the welding position signal shown in Fig. 4, the head upper and lower valves shown in Fig. 4f are driven to operate the welding head, and the welding power source shown in Fig. 4i is turned on several times. Welding head 2 is energized and the head swing valve shown in Fig. 4g is activated.
Polishing operation is performed by swinging. Polishing is carried out by driving the polishing table motor shown in FIG. 4j when welding of a plurality of leads and also a plurality of parts are completed.

As explained above, according to the present invention, since the welding power source is used effectively, only one welding power source is required, and all of the welding power sources can be used for the same purpose, thereby reducing the cost of the device. Become. Furthermore, since an optical detector is used as a welding positioning method, the device is inexpensive, easy to maintain and manage, and accurate positioning is possible. Further, by determining the welding position signal and the position of the mechanism, it is possible to automatically perform a series of welding step operations such as a series welding operation of welding energization and an operation of polishing the tip of the electrode in response to changes in conditions.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a multi-head welding device showing an embodiment of the present invention, FIG. 2 is a partially enlarged view of a welding part in the device of FIG. 1, and FIG. 3 is a perspective view of a multi-head welding device showing an embodiment of the present invention. Control system block diagram,
FIG. 4 is an operation time chart of FIG. 3. 1: Printed board, 1-1: Solder plating pad, 2: Welding head, 2-1 to 2-4: Electrode chip, 2-5: Head arm, 3: Welding power source,
4: Sequencer, 5: Control power supply, 6: Operation panel, 7: Table drive motor, 8: Head pressure cylinder, 9: Clamp, 10: Stopper, 1
1: Swing actuator, 12: Mark sensor, 13: Reference pattern, 14: Polishing plate, 15, 16: Polishing plate drive motor, 17: Connector, 17-1 to 17-4: Each part of the connector,
18: sequential determination control section, 20: selector control circuit, 21: motor drive circuit, 22: electromagnetic valve drive circuit, 23, 24: welding transformer, 25: sensor.

Claims (1)

[Claims] 1 A device for welding connectors and components having multiple lead terminals to pre-soldered connection patterns, which is equipped with a reference pattern linked to a single-axis table driven by a step motor, and the position of the reference pattern is determined optically. The welding positioning mechanism uses the step motor to automatically position the welding position by detecting the presence or absence of the part to be welded. After welding, the lower welding head is driven to perform lower welding, and a multiple welding head mechanism is used to sequentially supply power to multiple welding heads by switching one welding power source, and the head arm is held horizontally. A mechanism for polishing the tip of the head electrode by moving the welding head and driving the polishing mechanism at a predetermined period to polish the welding head, and a sensor for detecting the signal of a sensor for detecting the welding position and the presence or absence of the part to be welded. When the AND condition between the signal and the normal welding force signal is established, this is used as a trigger to energize the welding head, thereby performing the following operations: welding head pressurization, series energization of multiple welding heads, and polishing of the tip of the head electrode. A multi-head welding device characterized by having a circuit for sequential determination control.