JPH02299777A - Method and device for preventing strain of sheet metal welding - Google Patents

Abstract

PURPOSE:To eliminate the temperature in the welding direction and to relax complicated deformation by cooling the vicinity of a weld zone of sheet metals to be butt- welded so that the temperature is always made uniform in the welding direction. CONSTITUTION:Electronic coolers 11 are operated so as to regulate the temperature at blocks A, B and C to the set temperature, respectively. When a welding torch 5 starts to perform welding from one end of the weld zone 3, the temperature of the vicinity of the weld zone 3 of the starting part (block A) rises by welding heat. Temperature sensors 12 detect the temperature of the electronic coolers 11 changed by the temperature-rise of the vicinity of the weld zone 3 and send this accuracy to a cooler controller 13. The cooler controller 13 facilitates cooling of the coolers 11 and drops the temperature and maintains it at the set temperature. Although the temperature-rise part moves in the welding direction in accordance with the progress of welding, detection of the temperature and cooling facilitation of the coolers 11 are carried out in order in the same way. In addition, in the blocks through which the welding torch 5 passed, since these blocks are undercooled in that condition, cooling is restricted so that the temperature does not drop below the set temperature.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method and device for preventing distortion in thin plate welding, and particularly to a method and apparatus for preventing distortion that occurs when welding thin plates that are butt welded. Regarding the device.

[Prior art] Generally, when butt welding thin plates with a thickness of about 3 mm or less by arc welding, etc., the work is done while suppressing the deformation (distortion) that occurs during welding. There is.

As shown in FIG. 4, in conventional welding, a thin plate 1 (base material) to be welded is set on a mounting table 2, and restraints are placed at positions corresponding to both sides of the welded part 3. Ingredients 4
(one side not shown) restrains the thin plate 1 in the vertical direction.

Then, by moving the welding torch 5 in the welding direction F while welding while maintaining this restraint, deformation occurs in the thin plate 1 along the welding direction F<in), deformation in the direction transverse to this (lateral), Alternatively, deformation around the axis (angle) passing through the welded portion 4 is forcibly suppressed.

[Problems to be Solved by the Invention] However, even if the thin plate 1 is restrained by the restraint jig 4 as in the past, deformation cannot be avoided, that is, even if restrained with a strong force, When welding is completed and the restraint is released, the remaining thermal stress causes shrinkage and deformation. In particular, in the thin plate 1, the deformation suppressing effect of the adjacent portions of the base material itself is weak, so longitudinal deformation is likely to occur, and together with the temporal change in temperature distribution as welding progresses, This is a complex deformation that includes lateral or angular deformation.

For this reason, there has been a problem in recent precision overlap welding that requires high finishing accuracy that it takes a great deal of effort and time to correct this complicated deformation.

The present invention was devised in view of the busy number of articles on the market, and to provide a distortion prevention method and device capable of alleviating complex deformations of thin plates.

"Means for Solving the Problems" The first aspect of the present invention is to cool the vicinity of the welded part of a thin plate to be butt welded so that the temperature thereof is always uniform in the welding direction.

The second aspect of the present invention is a device for carrying out the first invention, which includes a plurality of coolers arranged in parallel in the welding direction on both sides of the Ff joint of thin plates to be butt welded, and a plurality of coolers arranged in parallel in the welding direction. This system consists of a temperature sensor that detects the temperature of each of the above, and a cooler control device that increases or decreases the cooling temperature of each of the coolers based on the information from these temperature sensors.

[Function] According to the method of the first invention, the temperature difference in the welding direction that occurs when thin plates are welded is eliminated, and complex deformation is alleviated.

Further, according to the configuration of the second invention, the cooler appropriately cools the vicinity of the welded portion of the thin plate. Then, when welding is started, the temperature sensor detects the temperature of each cooler, which changes as welding progresses, and sends the information to the cooler control device. The cooler control device compares the detected temperature with the set cooling temperature, and if there is a difference, accelerates or suppresses cooling to eliminate the difference, so that the temperature is uniform in the welding direction. let

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

First, an embodiment of the distortion prevention device for thin plate welding according to the present invention will be described with reference to FIGS. 1 and 2. FIG. In the figure, the same components as the conventional ones are denoted by the same reference numerals, and the explanation thereof will be omitted.

This thin plate welding distortion prevention device; 〃 is an electronic cooler 11 which is a cooler provided to cool the vicinity of the welded part 3 of the thin plate 1.
, a temperature sensor 12 that detects the temperature of each electronic cooler 11 , and a cooler control device 13 that appropriately controls the electronic cooler 11 based on information from the temperature sensor 12 .

The electronic cooler 11 has a rectangular parallelepiped plate shape, and is buried in the upper part of the mounting table 2 so that the upper surface serving as the cooling surface is exposed. A plurality of welding devices are arranged in parallel along the welding direction F at positions corresponding to both sides of the welded portion 3 of the thin plate 1. In this embodiment, a total of 1 large dais is provided, each with a king dai. In other words, the vicinity of the welded part 3 of the thin plate 1 is divided into three blocks <A, B, C) at equal vertical intervals, and one electronic cooler 11 is arranged in each block without any gaps.

The temperature sensor 12 is provided in each electronic cooler 11 and is configured to sense its actual temperature and sequentially transmit the information.

These electronic cooler 11 and temperature sensor 12 are each connected to a cooler control device 13.

The cooler control device 13 controls the electronic cooler 11 so that the temperature To is lower than the normal temperature (room temperature) inputted in advance.
For example, it is formed so that the cooling output can be adjusted to below 0° C., which is enough to prevent condensation.

An input section 1 that inputs information from the temperature sensor 12
4, the detected temperature t and the set temperature 1゛o are compared,
The calculation unit (CI
ILI) 15 and an output section 16 for outputting a signal to the electronic cooler 11 to operate its regulating cooling, so that the electronic cooler 11 can maintain the set temperature To.

A restraining jig 4 (only the position shown in FIG. 2) similar to the conventional one is provided on this pond and the mounting table 2, and is adapted to restrain both sides of the welded portion 3 of the thin plate 1. Therefore, the vicinity of the welded part 3 of the thin plate 1 is set to be sandwiched between the two -L plates 17 that engage with the restraint jig 4 and the electronic cooler 11, above and below. It turns out. and welding 11
The welding torch 5 connected to the welding section 18 is moved so as to face the welding part 3 and pass between the upper plates 17, so as to butt weld the thin plates 1.

Next, an embodiment of the method for preventing distortion in thin plate welding according to the present invention will be described as an effect of the above embodiment.

When butt welding the thin plate 1, the thin plate 1 is
In addition to setting as shown in the figure, cooling is performed as shown in FIG. 3 in parallel with the welding operation using the welding torch 5.

First, the electronic cooler 11 is activated to bring the temperatures in blocks A, B, and C to the set temperature TO, respectively. At this time, the temperature of each electronic cooler 11 is t+, t2. If ts does not reach the set temperature, it is determined that some kind of failure has occurred, and the work is interrupted and inspected.

In parallel with the welding work, the welding torch 5 performs the control indicated by α in FIG. 3 in each block A, D, and C.
When welding is started from one end of the welding part 3, the vicinity of the welding part 3 at this starting part (block A in FIG. 1) is as follows.
The temperature increases due to welding heating. The temperature sensor 12 is
The temperature of the electronic cooler 11 that has changed due to the temperature increase near the welding part 3 is detected, and this information is sent to the cooler control device allffl13. In order to eliminate this change (temperature rise), the cooler control device 13 controls the electronic cooler 11.
to lower its temperature and maintain it at the set temperature To.

As welding progresses, the temperature rising portion moves in the welding direction, but in the same way, the temperature tz of the electronic cooler 11 in the 11th
, ts detection and cooling acceleration, and welding torch 5
In the block through which the temperature has passed, the block will become supercooled if left as is, so cooling is limited so that the temperature does not fall below the set temperature To.

Therefore, the part where the welding torch 5 is located is cooled more than other parts, and the vicinity of the welding part 3 other than the welding point is always cooled to a uniform temperature.

In this way, electronic coolers 11 are provided on both sides of the welding part 3,
Since feedback control is performed by the temperature sensor 12 and the cooler control device W13, the temperature in the welding direction F near the welding portion 3 can be equalized reliably and quickly. That is, the increase in the temperature of the welded part 3 due to welding is prevented from spreading to adjacent parts, thereby preventing excessive thermal stress from remaining and preventing harmful deformation in thin plate welding.

In particular, by constantly equalizing the temperature in the welding direction, complex deformation caused by temporal changes in temperature distribution can be alleviated. This results in a significant reduction in the amount of effort and time expended in conventional complex deformity correction.

In addition, the welded part 3 after being heated to a high temperature is heated to an electronic cooler 1.
1, it is rapidly cooled to a set temperature T o lower than room temperature, so the amount of deformation can be suppressed compared to natural cooling, which further improves product quality.
-I can.

Furthermore, since the temperature of the electronic cooler 11 is detected to determine all the temperature distribution during welding work, the installation process is less troublesome than, for example, the case where the temperature of the base material is detected by a temperature sensor. etc., so it has no effect on welding work and is extremely practical. Since the electronic cooler 11 is arranged in parallel using the mounting table 2, it can be easily applied to conventional welding equipment and is highly versatile.

In the above embodiment, the electronic coolers 11 are provided directly in the welding direction F, but any number of electronic coolers 51 may be provided depending on the working space, and the greater the number, the more fine-grained control can be achieved. The cooler was electronic, but
Any type of cooler will work as long as it can respond quickly to temperature control.

Furthermore, the thin plate to which the present invention is applied has a thickness of 31II
11 or less, but it is particularly useful for materials other than carbon steel that require residual heat during welding, and for high alloy materials such as stainless steel that are precision welded.

[Effects of the Invention 1 In summary, according to the present invention, the following effects are achieved.

(1) The area near the weld of a thin plate to be butt welded is cooled so that the temperature is always uniform in the welding direction, eliminating the temperature difference in the welding direction that occurs when thin plates are welded, and preventing complicated deformation. eased.

(2) In addition, a plurality of coolers are installed in parallel in the welding direction on both sides of the welded part of the thin plate to be butt welded, and a temperature sensor detects the temperature of each cooler, and each cooler is Since the welding device is equipped with a cooler control device that raises and lowers the cooling temperature of the welding device, temperature differences in the welding direction can be reliably and quickly eliminated, and complex deformation can be alleviated and the amount of deformation can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the distortion prevention device for thin plate welding according to the present invention, FIG. A flowchart showing an embodiment, and FIG. 4 is a perspective view showing a conventional strain prevention device for contacting a thin plate 7fg. In the figure, 1 is a thin plate, 3 is a welded part, 11 is an electronic cooler, 12 is a temperature sensor, 13 is a cooler control device, F
is the welding direction. Patent applicant F. Ishikawa + Harima Heavy Industries Co., Ltd. agent Patent attorney Nobuo Kinutani (1 other person) Figure 2 Figure 3

Claims (1)

[Claims] 1. A method for preventing distortion in thin plate welding, which comprises cooling the vicinity of the welded part of a thin plate to be butt welded so that the temperature thereof is always uniform in the welding direction. 2. A plurality of coolers installed in parallel in the welding direction on both sides of the welded part of the thin plate to be butt welded, a temperature sensor that detects the temperature of each of the coolers, and a temperature sensor that detects the temperature of each of the coolers based on the information from the temperature sensor. A distortion prevention device for thin plate welding, characterized in that it is equipped with a cooler control device for increasing and lowering the cooling temperature of the thin plate.