JPH0461747B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welding system using a dedicated machine, and particularly to an automatic welding device and a welding condition setting device for automatically welding a relatively wide variety of workpieces with high efficiency.

[Conventional technology]

Recently, the proportion of arc welding in the mass production process has been increasing, and in order to save labor and stabilize quality, welding work is shifting from semi-automatic work to automatic welding, including robots. It is moving rapidly. In this automatic welding technology, when the workpieces are relatively diverse but uniform to some extent, a special-purpose machine with a system of automated elemental equipment is widely used. That is,
Welding power source, wire feeding device, welding torch, torch position adjustment device, workpiece or torch traveling mechanism,
Automatic welding equipment consisting of a workpiece transport/clamp mechanism, a remote control box, etc. is commonly used. In this case, in conventional automatic welding equipment, one optimal welding condition is set for each joint.

[Problem to be solved by the invention]

However, workpieces such as automobile parts are often press-molded parts made of thin plates, and there is a problem in that burn-through problems are likely to occur due to poor workpiece precision. For this reason, for example, if welding conditions are set at low current and speed to prevent burn-through even at the maximum gap position, and the entire weld line is welded under these conditions, welding efficiency will deteriorate. Another problem arises: storage. Also,
Near the start of welding, poor penetration tends to occur and the bead tends to be convex, while near the end of welding, an excessive back bead that becomes red hot and has the risk of undercutting or burn-through occurs. I often do
Therefore, it is difficult to make the bead uniform over the entire weld line.

Therefore, there is a strong desire to improve the quality of welded parts such as bead appearance and penetration amount, to improve productivity, and to reduce the cost of welding work.

In order to solve the above problems, welding conditions on the same welding line should be changed according to changes in joint conditions such as workpiece shape, welding posture, gap, plate thickness, and tack attachment on the same welding line. , it is necessary to carefully control welding conditions so that welding can always be performed under the optimal welding conditions for the joint conditions.

When welding mass-produced products, the points of change in joint conditions for many workpieces tend to be at approximately the same location, so installing a limit switch or proximity switch at this point of change will speed up the welding process. During the welding process, the welding condition change position on the welding line can be detected by this limit switch or proximity switch. Then, using this detection signal, the optimum conditions for each section can be set. However, with this method, it is necessary to install a large number of additional equipment, which not only increases equipment costs, but also causes fluctuations in the change point due to changes in lots, and when the product type changes. teeth,
It is necessary to reset the limit switch, etc. Therefore, in order to automatically weld a wide variety of workpieces, a great deal of effort is required for welding preparation and changing conditions.

The present invention has been made in view of such problems, and provides a welding system that uses a special machine to easily and easily change welding conditions at any position within the same welding line. It is an object of the present invention to provide an automatic welding device and a welding condition setting device that can set conditions and can perform high quality and highly efficient welding at low equipment cost.

[Means to solve the problem]

The automatic welding apparatus according to the present invention includes a traveling means for relatively traveling and moving a workpiece and a welding torch, and a welding condition for setting predetermined welding conditions for a plurality of sections obtained by dividing a welding line at predetermined positions. a setting means, a division position setting means for setting data regarding the predetermined division position, a storage means for storing the set welding conditions, and a timer for starting time measurement from the time when the welding torch passes a starting point on the welding line. and when the traveling means is driven in a teaching mode, the effective welding time T of the welding line is measured by a timing means based on a torch switch signal or a traveling means driving signal, and this timing result and a welding condition change position are recorded. The temporal data at the changed position is calculated from the divided position setting data shown, and in the playback mode, the welding conditions are stored in the storage every time the time value of the time measuring means reaches the time indicated by the temporal data. The present invention is characterized by having a processing device that sequentially reads and outputs data from the processing device, and a welding execution device that performs welding based on the welding conditions output by the processing device.

Further, the welding condition setting device according to the present invention includes a welding condition setting means for setting predetermined welding conditions for a plurality of sections obtained by dividing a weld line at predetermined positions, and a dividing position setting means for setting data regarding the predetermined dividing positions. a storage means for storing the set welding conditions; a timekeeping means for inputting a first signal to start timing and inputting a second signal to stop timing; and data regarding the dividing position. and a calculation means for calculating temporal data regarding the division position from the time measurement result of the time measurement means, and a calculation means for reading and outputting the next sequential welding condition from the storage means each time the time measurement value of the time measurement means matches the time data. It is characterized by having an output means.

[Effect]

In the present invention, the welding condition setting means
Optimal predetermined welding conditions are set for a plurality of sections obtained by dividing the welding line at predetermined positions, and data regarding the predetermined division positions are set by the division position setting means. Then, the timer measures the welding line passing time during which the welding torch moves relatively from the starting point to the ending point on the welding line, and the processing unit responds to the dividing position based on this welding line passing time and data regarding the dividing position. Calculate the temporal data. Thereafter, during actual welding (playback mode), each time the time value of the timer reaches the time indicated by this temporal data, the arithmetic processing unit sequentially updates the welding conditions from the storage means and reads and outputs the welding conditions. let Therefore, the welding execution means executes welding based on the sequentially output welding conditions, thereby performing welding under predetermined welding conditions optimally set for each section of the weld line.

This main welding mode is then repeated for the same type of workpiece. On the other hand, if the type of workpiece is changed, the welding condition setting means and the dividing position setting means may respectively reset the data regarding the welding conditions and dividing positions. Therefore, changes in product types can be easily handled.

Note that the starting point or ending point at which the timing means starts or stops timing is arbitrarily set on the welding line, and typically, the starting point is the welding start position and the end point is the welding end position. corresponds to

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing the circuit configuration of an automatic welding apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a portion of the dedicated machine system.

As shown in FIG. 2, a workpiece 1 to be welded is fixed to a clamp jig 2, and a traveling carriage 3 is disposed near the workpiece 1. As shown in FIG. This traveling cart 3 is designed to reciprocate on a rail extending parallel to the welding line of the workpiece 1, and therefore,
The welding torch 5 disposed on the traveling carriage 3 can reciprocate along the welding line. Note that even if a driving means is provided on the clamping jig 2 side of the workpiece 1, the traveling carriage 3 and welding torch 5 and the object to be welded (workpiece 1) can be relatively moved in the same manner. A torch position adjusting device 4 is arranged on the traveling truck 3 so as to be movable up and down with respect to the traveling truck 3, and the welding torch 5 is fixed to the torch position adjusting device 4 via a suitable arm. Therefore, the welding torch 5 can move toward and away from the workpiece 1 in the vertical direction by raising and lowering the adjusting device 4.

A wire reel 9 around which welding wire 6 is wound is disposed in wire feeding device 8, and welding wire 6 is unwound from wire reel 9 and supplied to welding torch 5 at a predetermined speed. A welding power source 10 is connected between the wire feeding device 8 and the clamping jig 2, and the welding power source 10 is connected to the welding wire 6 and the workpiece 1 through the wire feeding device 8 and the clamping jig 2, respectively. Welding power is now available. As a result, an arc 7 is formed between the welding wire 6 and the workpiece 1, and welding is performed.

Further, the control device 12 is connected to a welding power source 10 and a drive device (not shown) for the traveling trolley 3 via a welding condition setting device 21.
2, the welding power source 2 is connected via the welding condition setting device 21.
4, the speed of the traveling trolley 3, the welding speed, etc. are controlled.

As described above, the traveling truck 3, welding torch 5, welding power source 10, welding condition setting device 21, and control device 12 constitute a dedicated machine system 22 as shown in FIG.

On the other hand, in the welding condition setter 21, the CPU
To the data transmission common bus 33 connected to 28,
Keyboard 23, Display 24, RAM 2
6, a ROM 27, a time counter 29, a torch switch input device 30, and an output device 31 are connected.

The input device 30 of the welding condition setting device 21 inputs a torch switch signal (TS1) given from the control device 12 of the special machine system 22, and this torch switch signal is inputted to the time counter 29 via the common bus 33. And time counter 29
starts counting time using this torch switch signal TS1 as a trigger.

From the keyboard 23, as shown in FIG.
Welding conditions such as welding current I _on , welding voltage V _on , and polarity ratio R _on as well as change points P _on and crater time C _on of these welding conditions are set and input. These data are stored in RAM26. Then, the setting values input from these keyboards 23 and
Information stored in the RAM 26 is displayed on the display 24. The ROM 27 stores a control program for the welding condition setting device 21. The CPU 28 performs predetermined calculations based on the count value of the time counter 29, reads predetermined welding conditions from the RAM 26, and outputs the welding conditions to the dedicated machine system 22 via the output device 31.
output to the welding power source 10.

It goes without saying that the circuit configuration of the welding condition setting device 21 is not limited to that of the above embodiment. In other words, various configurations can be adopted as long as the functions defined in the present invention are realized.

Next, the operation of the automatic welding apparatus and welding condition setting device configured as described above will be explained.

Now, as shown in Figure 3, the workpiece to be welded consists of two welding lines, and the joint status changes at two points in the welding line, so each welding line, It is assumed that three welding conditions need to be set for

The basic operations of the welding condition setting device 21 are roughly divided into a teaching mode and a playback mode as shown below.

First, in the teaching mode, the traveling trolley 3 is run at the same speed as the welding speed during actual welding, assuming welding between welding lines. When the tip of the wire 6 of the torch 5 reaches the welding start position and stop position of each welding line, the torch switch (TS1) signal is turned on and off, respectively, and this torch switch signal is used by the input device 30 to set the welding conditions. It is taken into the container 21.
Then, based on this torch switch signal, the time counter 29 starts counting when the torch switch is turned on at the welding start position, and stops counting when the torch switch is turned off at the welding stop position. The CPU 28 uses the on-off times of the torch switch and the on-times of the torch switch (effective welding time of the welding line) T ₁ and T ₂ determined by the time counter 29 as basic data and stores them in the RAM 2.
6.

Next, the operator marks the change position of the welding conditions at each welding line, measures the distance of the section to be changed, and calculates the index as the ratio of the length of each section when the total length of each welding line is 100. Settings are made via the keyboard 23. That is, for the first welding section of the welding line, welding current I ₁₁ , welding voltage V ₁₁ , and polarity ratio R ₁₁ are input into welding condition setting device 21 using keyboard 23 provided with a group of respective setting keys. Next, point P ₁₂ corresponding to the welding condition change point of welding line I is the first point when the total length of welding line I is 100.
An index is selected from 1 to 99 as the ratio of the length of the section, and this is input from the keyboard 23. At the same time, the welding conditions I ₁₂ , V ₁₂ , and R ₁₂ to be changed are input from the keyboard 23. Similarly, the point P ₁₃ where the second section of the welding line I changes to the third section and the welding conditions I ₁₃ , V ₁₃ , R ₁₃ to be changed are entered on the keyboard 2.
3. Input using each setting key group. Next, the crater time, which is the last section of weld line I, is also set to C ₁₃ ,
Input together with crater current I _c1 , crater voltage V _c1 , and crater polarity ratio R _c1 . These input data are stored in RAM26. Welding conditions I ₂₁ , V 21 , R ₂₁ , I ₂₂ , V ₂₂ , R ₂₂ , I ₂₃ , V ₂₃ , _which are similarly changed with condition change points P ₂₁ , P ₂₂ , P ₂₃ for the weld line
Input R ₂₃ , C ₂₃ (I _c2 , V _c2 , R _c2 ). Generally, one workpiece has n welding lines, and each welding line is divided into m sections.
The RAM 26 finally stores the welding condition change point P _on , welding current I _on , welding voltage V _on , polarity ratio R _on , and crater time C _on corresponding to the m-th section of the n-th welding line.

Next, during actual welding in the playback mode, the welding cart 3 is run at the same speed as in the teaching mode, and the torch switch ON signal TS1 from the control device 12 of the dedicated machine system 22 is set by the input device 30. It is taken into the container 21. The time counter 29 uses this signal as a trigger to start counting time. CPU28 is welding power source 10
The torch switch signal TS2 and each welding condition are output to the First, the welding conditions I ₁₁ , V ₁₁ , and R ₁₁ for the first section of the welding line I are read from the RAM 26, and these conditions are commanded to the output device 31. Output device 31
outputs signals related to each condition to the welding power source 10. Furthermore, the CPU 28 takes in the time T counted by the counter 29, and this value is stored in the RAM.
Condition change point of welding line I read from 26
The value calculated according to the formula T ₁₂ = P ₁₂ ×T ₁ /100 based on the data of P ₁₂ , that is, the welding condition of the second section I 12 at the time when it becomes equal to the passage time T ₁₂ of _section I. , V ₁₂ , and R ₁₂ are read from the RAM 26 and commanded to the output device 31 .

Similarly, the time T taken in from the time counter 29 is calculated based on the condition change point P ₁₃ to the third section of the welding line I according to the formula T ₁₃ = P ₁₃ ×T ₁ /100. When the value becomes equal to the value, the CPU 28 sets the welding condition I ₁₃ of the third section,
Read V ₁₃ and R ₁₃ from RAM 26 and output device 31
command. When the torch switch off signal, which is the end signal of the welding line I, is input to the input device 30, the crater welding conditions are output for only the time set at _C13 .

After _C13 has elapsed, the torch switch signal TS2 is turned off and welding is stopped. Thereafter, the time counter 29 stops counting time and resets the count value to zero. on the other hand,
The CPU 28 reads welding conditions ₂₁ , V ₂₁ and R ₂₁ corresponding to the first section of the next welding line from the RAM 26, and waits until the next torch switch ON signal TS1 is input. Changes in welding conditions for the welding line are also played back in the same manner as described above. Next, when the welding end signal of the welding line is detected by the torch switch input device 30,
Crater welding conditions are output only for the time set in C ₂₃ , and one cycle of welding work is completed. Next, the welding conditions for the first section of the weld line are
The counter 29 waits until a torch switch ON signal for welding the next workpiece is input.

After welding a predetermined number of workpieces in this way, if you want to automatically weld a different type of workpiece, run the traveling trolley 3 again in the teaching mode and input the torch switch signal to the setting device 21. At the same time, each welding condition and change point may be input again via the keyboard 23.

In this embodiment, the on/off signal of the torch switch is used as the signal input to the setting device 21, but it is also possible to input a traveling truck drive signal to the setting device 21 to start and stop driving the traveling truck. It may also be used as a reference signal for control.

In addition, although the torch switch signal TS1 was used as the trigger signal for counting the time of the time counter 29 in the playback mode, instead of this, it is detected that the welding current is actually flowing after the torch switch is turned on. A welding current detection signal from a welding current detector (WCR) may also be used.

Furthermore, in the above embodiment, the condition change setting time is 100% of the time when the welding command signal is supplied.
Although the time is set in units of 1%, it is of course possible to set the time in real time.

Furthermore, the movement pattern of the traveling trolley 3 is not limited to a constant speed, but may be any movement speed pattern that allows the position of change in welding conditions to be recognized.

Furthermore, the setting of welding conditions is not limited to the case where the welding current, welding voltage, and polarity ratio are input individually from the keyboard as in the above embodiment. For example, for a plurality of standard target joints, the relationship between the plate thickness, groove angle, etc. and predetermined welding conditions is experimentally determined for each joint, and this is stored in a storage device such as ROM. When setting welding conditions, the plate thickness, etc. or the code is input, the predetermined welding conditions are read from the storage device, and the settings are stored in the setting device 21.
It may also be input to the RAM 26.

Alternatively, the configuration may be such that the user can file the predetermined welding conditions for each target joint in a storage device such as a RAM.

Furthermore, in the above embodiment, when setting changes in welding conditions, 1 to 99 are input from the keyboard.
The index value of is input, but this change can also be set at the same time when the welding cart is run idle in teaching mode. That is, when the operator is looking at the welding line while the traveling truck is running idle and the welding torch comes to a position where he wants to change the welding conditions, he presses the change position setting key. The ON signal of this setting key is input to the setting device 21, and the CPU 28
The counter value of the time counter 29 at the time when the change position setting key is turned on is stored in the RAM 26. Then, in addition to the count value at the welding end position, the count value at the welding condition change point is also stored in the RAM 26. Therefore,
Automatic welding is possible in the same manner as in the above-described embodiments by calculating temporal data regarding changes in welding conditions in the welding speed (carriage running speed) during main welding based on these count values.

Note that this change position setting key may be provided within the setting device 21 or may be provided on a remote control box.

In addition, a time counter that measures the timing when the change position setting key is pressed is provided separately from the time counter 29 of the traveling trolley, and the timing results of both counters are temporarily stored, and after all data has been collected, calculation is performed. Processing may be performed to determine temporal data regarding changes.

〔Effect of the invention〕

According to the present invention, the effective welding time T of the welding line is measured and stored in advance using a torch switch signal or a drive signal of a traveling means such as a traveling truck, and the time data at the change position is obtained from the setting data of the welding condition change position. is calculated, and during welding, the welding condition setting values corresponding to the next section at the change point are reproduced and output to the welding power source. Therefore, the present invention has the following effects.

Since the welding conditions can be changed simply by changing the set values, the welding conditions can be changed at any position on the welding line. Therefore, the optimum welding conditions for each divided welding section can be easily set, and the quality and efficiency of the welded part are significantly improved.

In addition, even if the type of welding or workpiece is changed, there is no need to invest or labor to change the design or add equipment to a new dedicated machine system, and the conditions can be easily changed using a single welding condition setting device. It is possible.

Furthermore, since the conditions for each welding section of the same welding line as well as different types of workpieces can be stored, welding reproducibility is ensured, quality control is facilitated, and the functionality of the dedicated machine system is improved.

By using existing equipment such as a welding power source and traveling trolley, and simply adding a welding condition setting device, it is possible to automatically weld a wide variety of workpieces, so you can automatically weld a dedicated machine system with an extremely low investment in equipment costs. It can be constructed into a flexible automatic welding system similar to that of a welding robot.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the circuit configuration of an automatic welding device according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing the dedicated machine system, and Fig. 3 shows changes in welding conditions in the middle of the welding line and welding. It is a schematic diagram showing a model of conditions. 1; Workpiece, 3; Traveling trolley, 5; Welding torch,
6; Welding wire, 10; Welding power source, 12; Control device, 23; Keyboard, 26; RAM, 27;
ROM, 28; CPU, 29; Time counter, 3
0; input device; 31; output device.

Claims (1)

[Scope of Claims] 1. Traveling means for relatively traveling and moving the workpiece to be welded and the welding torch, and welding condition setting means for setting predetermined welding conditions for a plurality of sections obtained by dividing the welding line at predetermined positions. a division position setting means for setting data regarding the predetermined division position; a storage means for storing the set welding conditions; and a timekeeping means for starting time measurement from the time when the welding torch passes a starting point on the welding line. , when the traveling means is driven in the teaching mode, the effective welding time T of the welding line is measured by a timing means based on the torch switch signal or the traveling means drive signal, and a division indicating the timing result and the welding condition change position Temporal data at the changed position is calculated from the position setting data, and in the playback mode, the welding conditions are stored in the storage means each time the time value of the timer reaches the time indicated by the temporal data. An automatic welding device comprising: a processing unit that sequentially reads and outputs the data; and a welding execution unit that performs welding based on welding conditions output by the processing unit. 2. The automatic welding apparatus according to claim 1, wherein the traveling means relatively travels and moves the welding torch and the workpiece at a constant speed. 3. The automatic welding apparatus according to claim 1 or 2, wherein the setting means, storage means, timekeeping means, and arithmetic processing unit are housed in a portable container. 4 Welding condition setting means for setting predetermined welding conditions for a plurality of sections obtained by dividing the welding line at predetermined positions, division position setting means for setting data regarding the predetermined division positions, and storing the set welding conditions. a storage means for inputting a first signal to start timekeeping and inputting a second signal to stop timekeeping; Welding characterized by having a calculation means for calculating temporal data, and an output means for reading and outputting the next sequential welding condition from the storage means each time the time value of the time measurement means matches the temporal data. Condition setter.