Field programmable welding controller

Details Field programmable welding controller Field programmable welding controller

2000-08-03

2003-08-19

Patel, Ramesh (Department: 2121)

Data processing: generic control systems or specific application

Generic control system, apparatus or process

Plural processors

C700S002000, C700S019000, C700S020000, C700S018000, C700S086000, C700S249000, C219S130510, C219S130310, C219S109000, C219S110000, C219S132000, C219S13700R, C318S568110, C901S042000

Reexamination Certificate

active

06609033

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to welding machines and, more particularly, to welding controllers that control the operation of the welding machines and that can be easily reprogrammed to change the operation of the welding machine.
2. Background of the Invention
Known resistance welding machines are described, for example, in U.S. Pat. Nos. 4,985,612 and 5,808,885. These prior art welding machines are typically installed in automobile production lines or other assembly lines. A representative hardware architecture for such a known welding machines is shown in FIG.
2
. Prior art welding controller
53
for controlling the welding machine may include a central processing unit (CPU)
53
a
, a memory having a PROM (“programmable read only memory”) or EPROM (“erasable programmable read only memory”)
53
b
and a RAM (random access memory)
53
c
, a switching element
53
d
such as a transistor or a thyristor, an input/output port (I/O)
53
e
, and a serial communications port (SIO)
53
f.
In such welding controller systems, programs and data are written into the EPROM
53
b
and sequential welding data are written into RAM
53
C. The EPROM
53
b
generally contains a sequential welding program, a current control program and a communications program. The communications program operates to permit an operator to select the sequential welding program or to input sequential welding data. The sequential welding program permits the operator to change the sequential welding data. Sequential welding data includes the welding time, welding current, and other welding parameters, for the welding operation. The CPU
53
a
executes programs stored in EPROM
53
b
based upon the sequential welding data stored in RAM
53
c
. Further, CPU
53
a
executes the communications program to write sequential welding data into RAM
53
c
. The sequential welding data may be input into RAM
53
c
by an input device
54
, as discussed below.
EPROM
53
b
usually must be erased using a physical process, such shining an ultraviolet light on EPROM
53
b
. Therefore, EPROM
53
b
must be physically removed from the welding controller
53
in order to change the programs or data stored in EPROM
53
b
. Further, new programs and data are written into the EPROM
53
b
in the following manner:
(1) Programs and data are first prepared using a computer
51
and the new programs and data are transferred to ROM writing device
52
;
(2) EPROM
53
b
is placed in ROM writing device
52
;
(3) The programs and data, which have been transferred to ROM writing device
52
, are written into EPROM
53
b
; and
(4) EPROM
53
b
is placed in a socket within the welding controller
53
. For example, EPROM
53
b
is inserted into a ROM socket of printed circuit board
59
that is disposed within a control box
60
as shown in FIG.
3
.
The input device
54
is used to input sequential welding data and is connected to connector
54
b
of the welding controller
53
via a cable
54
a
. Input device
54
includes CPU
54
c
, a memory such as ROM
54
d
and RAM
54
e
, a keyboard
54
f
, a display
54
g
, and a serial communications port (SIO)
54
h
. The communications program may be executed, for example, using keyboard
54
f
. Based on the communications program, the sequential welding data input by the input device
54
is transferred to the welding controller
53
through the serial communications ports (SIO)
54
h
and
53
f
and is then written into the RAM
53
c
of the welding controller
53
. In the alternative, the operator can manually input the sequential welding data using a touchscreen display
54
g.
When starting switch
59
is actuated, CPU
53
a
controls the welding machine based upon the programs stored in EPROM
53
b
and sequential welding data in RAM
53
c
. For example, CPU
53
a
moves welding electrodes
56
such that workpiece
57
is held between the electrodes
56
under pressure. Further, CPU
53
a
provides control signals to switching element
53
d
in order to control the welding current that is supplied to the electrodes
56
via a welding transformer
58
.
Typically, welding specifications are changed or additional functions may be required after the welding machine has been installed on an automobile production line or other manufacturing environment. In addition, bugs may exist in the programs or data. In such cases, the programs or data in EPROM
53
b
must be rewritten. However, according to known welding controllers, in order to rewrite the programs or data in EPROM
53
b
, EPROM
53
b
attached to the printed board
59
must be physically removed and replaced with an EPROM having the new programs and data. Thus, in order to replace the EPROM
53
b
, the following operations are required: the power must be turned off, door
60
a
of control box
60
is opened, old EPROM
53
b
is removed, new EPROM
53
b
placed in the appropriate socket of printed circuit board
59
, door
60
a
is closed, and the power is turned on again.
If a plurality of resistance welding machines (for example, usually about ten) have been installed in an automobile production line or other manufacturing environment, a corresponding number of welding controllers
53
are required to control each welding machine. In order to minimize floor space requirements for the welding control system, control box
60
may be installed in an awkward location and it may be difficult to open and close door
60
a
. Because of this, the printed circuit board
59
may be disposed near other devices, such as the welding transformer, welding gun or robot controller. In such cases, replacement of EPROM
53
b
of welding controller
53
may be quite difficult due to space restraints and it may take a long time to replace EPROM
53
b
. Further, when replacing EPROM
53
b
, other ICs on the printed circuit board
59
may be electrostatically destroyed or a pin of EPROM
53
b
may be damaged. Finally, if the factory does not have ROM writing device
52
in order to prepare new EPROM
53
b
, new EPROM
53
b
must be prepared elsewhere and then delivered to the factory.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present teaching to provide welding controllers that overcome some or all of the problems of the prior art.
According to one aspect of the present teachings, a write program for writing programs or data into a first memory is stored in a second memory. When welding operation programs or sequential welding data is input into the CPU from external equipment, the CPU executes the write program to write the inputted program or data into the first memory. Thus, welding operation programs or sequential welding data can be easily written into the first memory from an external source without replacing the first memory. Preferably, the CPU may execute a write operation when a predetermined writing command is input from the external source.
According to another aspect of the present teachings, the CPU may control the welding machine when a mode select switch is set for a welding mode. In addition, the CPU may execute a write operation when the mode select switch is set for a writing mode. Therefore, even when the welding mode switch is set to the welding mode and a predetermined writing command is input into the CPU from the external source, the CPU preferably may execute the write operation. In this case, welding operation programs or sequential welding data can be written into the first memory from the external source at any time, irrespective of the selected mode. Further, if a predetermined writing command is input into the CPU from the external source while the CPU is executing a program to control the welding operation, the CPU may preferably complete the welding control instructions before executing the write operation. As a result, the occurrence of welding defects can be prevented or reduced.
In another aspect of the present teachings, the CPU may determine whether welding operation programs or data have been properly written into the first memory. Thus, any improperly wri

Affiliated with

Also associated with

Rating

Field programmable welding controller does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Field programmable welding controller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Field programmable welding controller will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3105722