JP3219837B2 - Control device for resistance welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output data in a control device of a resistance welding machine for welding a work at an electrode portion by passing a large current through the electrode to a work pressurized between electrodes. The present invention also relates to speeding up character data transfer, simplifying wiring, and standardizing a protocol for input / output data communication.

[0002]

2. Description of the Related Art Conventionally, a control device for a resistance welding machine optimizes welding data and the like detected in response to changes in welding conditions and the like, and performs input and output of welding data and the like to and from outside by serial communication. In this case, the system uses a unique communication protocol that mixes input / output data and character data in one communication line.

[0003]

That is, in general, the input / output of the control device for a resistance welding machine is often connected to a sequencer of an external device. In this case, the input / output is wired with a wire for each input / output point. However, due to advances in wiring technology, the wiring between specific devices can be simplified by using the conventional technology.However, a device that separates input / output data and character data in order to connect to a sequencer is ultimately needed. Will be needed. In addition, I / O response affects the responsiveness of the entire system, so high speed is required. However, in a system where input / output data and character data coexist, if the amount of character data to be transferred increases, high speed However, there is a disadvantage that the responsiveness of input / output data required is deteriorated. That is, when one multi-jig control panel controls a plurality of resistance welding control devices as in a multi-welding machine, EIA standard RS-
485, the input / output of the control device is performed by serial communication using hardware of a multi-drop method as shown in FIG.
The system in this case is also advantageous in terms of cost. However, when using this multi-welding machine as a welding robot, stationary welding machine, or portable welding machine, a device for converting serial communication data to normal input / output is required for each resistance welding control device. Therefore, there is a problem that the cost is higher than that of the conventional system.

If input / output information, program data, and monitor data are mixed with data on serial communication, not only the transmission time of control input / output, which requires high speed, is reduced, but also dedicated serial data is required. In addition to the need for a conversion device, a welding robot system that welds various plate sets with a single unit requires a pressure control function for the electrode pressing force, but the pressure control function is built into the resistance welding control device. If this is done, the external shape of the entire device will become large, and this resistance welding control device with a pressure control function will be an obstacle when used for a multi-welding machine that does not require pressure control and has little extra space. was there.

Accordingly, an object of the present invention is to make a communication line for input / output data and a communication line for character data function independently,
Accordingly, it is an object of the present invention to provide a resistance welding machine control device that adapts a communication protocol of input / output data to a communication protocol of a sequencer and causes the resistance welding machine control device to function as a slave station of the sequencer.

[0006]

That is, the present invention provides each of the following:
Each has a data communication function for input / output data and character data
Between the plurality of welding control devices and the plurality of welding control devices.
Equipped with multiple serial communication lines provided in serial,
The plurality of serial communication lines are used for input / output data serial communication.
A communication line and a serial communication line for character data are available.
And stored in a single communication cable.
One connector is connected to the end of the cable.
And a control device for a resistance welding machine.

[0007]

In the control device for a resistance welding machine constructed as described above, the communication line of the input / output data for directly controlling the welding operation by the resistance welding machine and the welding data of the resistance welding machine are used for a small amount of work and welding conditions. Since the communication lines for character data that can be changed and detected sequentially are also detected independently of each other, the response speed of input / output data is not affected by the amount of character data or the transfer timing, so that welding can be performed smoothly. In addition, a welding control device such as a timer device for directly controlling welding can directly connect to a sequencer, thereby eliminating the need for a dedicated serial data conversion device. In a system that uses, the two types of communication lines are accommodated in a single communication cable, thereby improving maintainability.

[0008]

As a result, according to the present invention, input / output data such as a start signal can be transferred at high speed without being affected by character data, and character data such as teaching data and monitor data can also be input / output data. Independent communication network without being affected by
Since the communication protocol of input / output data is the same as the communication protocol of the sequencer used in the welding control system,
In addition to the ease of maintenance, there is an effect that both communication protocols used in the welding control system can be standardized.

[0009]

Next, the configuration of an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the welding control device 1 of the resistance welding machine is divided into a base unit 2, a contactor unit 3, a timer unit 4, and an option unit 5 which are molded with a resin so as to be selectively assembled with each other. . That is, the base unit 2 is a unit for connecting the welding control device 1 to the welding power source 6 and the welding transformer 7, and includes three sets of cable entry holes 8 and two sets (4
There are a bolt 10 for connecting a cabtire cable 9 and a conductive connecting plate 11 of the present invention, and three types of wire insertion methods are possible according to the installation mode of the welding control device 1. FIG. 4b is used for mounting the welding control device 1 below the breaker 12 of the welding power source 6 as shown in FIG. 5b. 4c is used for directly attaching the welding control device 1 to the welding transformer 7 as shown in FIG. 5c.

The contactor unit 3 includes a thyristor SCR for opening and closing the welding current, a CR absorber 13 for protecting the thyristor SCR, a current transformer CT for detecting the welding current,
It mainly includes circuit components related to the high-voltage welding power supply 6, such as a gate signal generation circuit 14 for sending a firing signal to the thyristor SCR, a down transformer 15 for supplying a control power supply and a synchronization signal from the welding power supply 6.

The timer unit 4 is a communication circuit 1 for inputting and outputting information such as welding data to and from an external circuit such as a sensor.
6 and a control circuit for controlling welding, a microcomputer 17 for managing and controlling the entire welding control apparatus 1 including data correction according to a preset program.

The option unit 5 supplies additional functions, and includes a PIO option circuit 18 for contact input / output for a normal input / output function and an EPV for electrode pressure control.
The option circuit 19 and the like can be selected. When the option unit 5 is not used, the timer unit 4
Attach the lid on top. Next, FIG. 6 shows a communication system diagram when the welding control device 1 for a resistance welding machine thus configured is used as a multi-welding machine, and is connected between a welding power source 6 and a welding transformer 7 and mainly includes a contactor. Welding control device (SCM) 1 consisting of unit 3 and timer unit 4
In the case of this embodiment, up to 15 units can be linked and used, and a general-purpose sequencer 21 of a jig control panel via a branch box 20 at the end, and a teaching box (TB) or a reset box (RB) 22 and a repeater 23 connected to another repeater or a host computer. In this case, LINK1 is used for transferring input / output data, and LINK2 and LINK3 are used for transferring character data using the same communication protocol.
INK2 is used for centralized management by a host computer via a repeater 23, and LINK3 is used for connecting devices such as a teaching box or reset box 22. The link cable A is a cable in which three communication lines from LINK1 to LINK3 are housed in one cable, and a connector which can be attached and detached with one touch at both ends of the cable, and is mainly controlled by the timer unit 4. LIN inside the resistance welding control device 1
It has a dedicated CPU for processing K1 input / output data communication at high speed, and can support various communication protocols.

Next, the operation of this embodiment will be described.
The welding control device (SC) for the resistance welding machine thus configured
M) 1, in this case, a welding control device (SCM) 1 which is connected between the welding power source 6 and the welding transformer 7 and can be linked up to a maximum of 15 units mainly composed of the contactor unit 3 and the timer unit 4; 20 is connected to a general-purpose sequencer 21 of a jig control panel, a teaching box or reset box 22, and a repeater 23 connected to another repeater or a host computer. As a result, in the case of this embodiment, the welding control device (SC
M) 1 has a built-in input / output transfer function by serial communication as standard equipment. Even if multiple resistance welding control devices (SCM) 1 are used like a multi-welding machine, only one input / output signal line is required. The connection is completed simply by connecting the link cable of the PIO option circuit 18 and the connection portion of the link cable is formed as a connector.
It has an electrode pressure control function of the PV option circuit 19,
In addition to supporting various welding systems, when these options are not used, the option unit 5 is not required, so that the space efficiency is good. In addition, it has an independent three-channel serial communication line for each function of input / output, data, and centralized management, so that the resistance welding control device 1 can be accessed at high speed as a remote I / O of a sequencer. In addition, since all power is supplied from the welding power source, there is an effect that there is no need to supply a control power from the outside. The input / output data communication line that directly controls the welding work by the resistance welding machine and the character data communication line that sequentially changes the welding data of the resistance welding machine by detecting even small changes in the work and welding conditions are independent of each other. Therefore, the response speed of the input / output data is not affected by the amount of the character data or the transfer timing, so that the welding can be smoothly performed, and the welding of the timer unit 4 or the like which directly controls the welding is performed. Since the control device 1 is directly connected to the sequencer 21, a dedicated serial data conversion device can be dispensed with. In a system using a plurality of resistance welding machine control devices 1, these two types of communication lines are connected by one. By putting it in a book communication cable, maintainability can be improved. As a result, in this case, input / output data such as a start signal Data can be transferred at high speed without being affected by data, and character data such as teaching data and monitor data can be constructed as an independent communication network without being affected by input / output data. Since the communication protocol of the output data is the same as the communication protocol of the sequencer used in the welding control system, maintenance is easy and both communication protocols used in the welding control system can be standardized.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of the entire resistance welding control device 1.

FIG. 2 is a perspective view showing an assembled state of the entire resistance welding control device 1;

FIG. 3 is a perspective view illustrating an entire disassembled state of the resistance welding control device 1.

FIG. 4 is an explanatory diagram showing a connection state of the base unit 2 which differs depending on a use method.

FIG. 5 is a perspective view showing an assembled state of the resistance welding control device 1 corresponding to FIG.

FIG. 6 is a communication system diagram using the resistance welding control device 1 as a multi-welding machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding control device 2 Base unit 3 Contactor unit 4 Timer unit 5 Optional unit 6 Welding power supply 7 Welding transformer 8 Cable entry hole 9 Cap tire cable 10 Connection bolt 11 Conductive connection plate 12 Breaker 13 CR absorber 14 Gate signal generation circuit 15 Down transformer 16 Communication circuit 17 Microcomputer 18 PIO option circuit 19 EPV option circuit 20 Branch box 21 General-purpose sequencer 22 Teaching box or reset box 23 Repeater SCR Thyristor CT Current transformer CT

Claims (1)

(57) [Claims] 1. An input / output data and a character data, respectively.
A plurality of welding control devices having a data communication function;
Multiple cereals provided serially between welding control devices
A communication line, wherein the plurality of serial communication lines have a serial line for input / output data.
A communication line and a serial communication line for character data are available.
Then, it is housed in one communication cable, and one connector is provided at the end of the one communication cable.
Control device for resistance welding machine characterized by being connected
Place.