JPS6336980A - Automatic preheater - Google Patents

Abstract

PURPOSE:To enable heating of materials to be welded to a prescribed preheating temp. in a short period by detecting the preheating temp. of the materials to be welded and controlling the moving speeds of heaters and the supply electric power to the heaters according to the preheating temp. CONSTITUTION:A carriage for preheating on which the heaters H1-H4 are mounted are movably provided to a rail 18 in the upper part of the materials 10-13 to be welded. The preheating temp. of the materials to be welded is detected by temp. detectors 20, 21 and is compared with the set temp. from a temp. setter 24 in a comparator 23. A command to maintain the constant preheating temp. is outputted from a commander 25 to a carriage speed controller 26 by which the carriage speed is controlled. On the other hand, the speed command is compared with the set speed from a speed setter 28 in a comparator 27 and the supply electric power is controlled by an electric power regulator 30 according to the deviation thereof. The materials to be welded are, therefore, preheated quickly to the prescribed temp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic preheating device for preheating high tensile steel, alloy steel, etc. before welding.

[Conventional technology]

When welding a welded part made of this type of steel, it is necessary to heat the welded member to a predetermined temperature of 711 degrees before welding.

As a means for preheating, a gas burner 2 having a plurality of nozzles 1 arranged as shown in FIG. 13 is used because of its ease of use. However, in this gas burner 2, dew condensation occurs, resulting in welding defects. For this reason, preheating is performed using an electric heater.

FIG. 14 and FIG. 15 are block diagrams of preheating devices using heaters, and both devices have a temperature detector consisting of a thermo-lightning pair placed near the heater 3.4.

In the device shown in FIG. 14, the temperature detection signal from the temperature detector 3 is fed to the SCR power regulator 6 through the programmer 5 to adjust the amount of power supplied to the heater 3, and in the device shown in FIG. The temperature detection signal from the temperature detector 4 is fed back to the fully automatic controller 7 to adjust the amount of power supplied to the heater 4 so that the preheating temperature is kept constant. Note that 8 is a recorder.

[Problem that the invention seeks to solve]

However, in the above-mentioned apparatus, it takes several minutes to complete the preheating operation after the welding process is started, and therefore it takes time to reach a predetermined preheating temperature, resulting in poor welding efficiency.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide an automatic preheating device that can heat a device to a predetermined preheating temperature in a short time.

[Means for solving problems]

The present invention provides a heater for heating a member to be welded, a moving mechanism for moving the heater according to a welding part of the member to be welded, and a mechanism that detects at least a preheating temperature of the member to be welded and supplies power to the heater in accordance with the preheating temperature. Alternatively, the automatic preheating device is equipped with a control means for controlling one or both of the moving speeds of the moving mechanism to achieve the above object.

[Effect]

By providing such a means, at least the preheating temperature of the workpiece to be welded can be detected, and one or both of the power supplied to the heater and the moving speed of the heater moving mechanism can be controlled by the control means according to this preheating temperature. be done.

〔Example〕

A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of the automatic preheating device. In the same figure, reference numerals 10, 11, 12, and 13 indicate members to be welded used for bridge truss chords, etc., and weld grooves 14, 15, 16, and 17 are formed at the welding locations. A rail 18 on which a welding cart (not shown) on which a welding device is mounted is mounted on the member 13 to be welded. Now, on this rail 18 there are heaters H1 and H2 as shown in FIG.
, H3, and H4 are placed thereon. In addition, each heater H1, H2, H3, H4 is 1
A welding device with a power of 2 kW and dimensions of 360 x 720+ nm is used, and the welding grooves 14 to 17 are arranged in the longitudinal direction, and the welding members 10 to 13 are spaced close to each other. Moreover, temperature detectors 20, 21, . . . each consisting of a roller-type thermocouple are provided on the rear side with respect to the traveling direction (b) of the preheating cart 19 of each of the heaters H1 to H4.

Each temperature detection signal outputted from these temperature detectors 20, 21, . . .
The temperature is sent to the temperature setter 24 and compared with the optimum preheating temperature set in the temperature setting device 24. The comparison output of this comparator 23 is sent to a command device 25, and from this command device 25, the welding member 10 is
A truck speed command that keeps the preheating temperature of ~13 constant is sent to the truck speed control device 26. Further, the truck speed command sent from the command unit 25 is sent to another comparator 27.
The speed is sent to the speed setter 28 and compared with the set speed of the truck set in the speed setter 28. And this comparator 27
The comparison output is sent to the command unit 29, and from this command unit 29, a power supply command or power 8 regulator is sent to keep the preheating temperature of the welded parts 10 to 13 constant according to the deviation between the truck speed command and the truck set speed. It is designed to be sent out on the 30th.

Next, the operation of the apparatus constructed as described above will be explained according to the first flowchart shown in FIG. When power is supplied to each of the heaters H1 to H4 by the power regulator 30 and each heater H1 to H4 generates heat, and the preheating trolley 19 starts running in the traveling direction (b) by the trolley speed control device 26, in step s1. The preheating temperatures of the members to be welded 10 to 13 heated by the heaters H1 to H4 are detected by the temperature detectors 20 and 21, respectively. Each of these temperature detection signals is sent to the comparator 23, and in step S2, the detected temperature tn and the preheating set temperature to are compared.

As a result of this comparison, if each temperature matches, step s3
Then, the command unit 25 issues a truck speed command v to maintain the truck speed.
n is sent to the truck speed controller 26.

Further, as a result of the comparison by the comparator 23, if the detected temperature tn is higher than the preheating set temperature to, the process moves to step s4, and a bogie speed command vn for increasing the bogie speed according to the deviation between the detected temperature tn and the preheating set temperature to. is sent to the bogie speed control device 26, and conversely, if the detected temperature tn is lower than the preheating set temperature to, the process moves to step s5 and a bogie speed command is issued to reduce the bogie speed according to the deviation between the detected temperature in and the preheating set temperature to. V
n to the truck speed control device 26. Therefore, the preheating cart 19 travels on the rail 18 at a speed corresponding to the preheating temperature of each member to be welded 10 to 13, for example, 15 cm/lll1n.

At the same time, the bogie speed command Vn is sent to the comparator 27 and compared with the bogie set speed vO in step s6. As a result of this comparison, if the speeds match, step s
Moving on to step 7, a power supply command for maintaining the heater heat generation amount is sent from the command unit 29 to the power regulator 30. Also, the comparator 27
As a result of the comparison, the bogie speed command vn is the bogie set speed VO.
If the speed is faster than that, the process moves to step s8 and the truck speed command vn
A power supply command for increasing the amount of heat generated by the heater according to the deviation between the set speed of the bogie and the set speed of the bogie ■0 is sent to the power regulator 30, and conversely, if the bogie speed command vn is slower than the set speed of the bogie VO, the process moves to step S9 and is detected. A power supply command vn for speeding up the truck is sent to the power regulator 30 in accordance with the deviation between 1g degree tn and the preheating set temperature to. Therefore, the preheating cart 19 moves the rail 18 at a speed corresponding to the preheating temperature of each member to be welded 10 to 13.
Each heater H1 to H4 at this time
Weld each member to be welded 10 to 13 with a calorific value according to the running speed.
is heated to about 100°C.

In addition, if the length in the longitudinal direction of each heater H1 to H4 is twice as long, the heaters will be heated up to 100°C at a running speed of 30 cIl/akin.

In this way, in the first embodiment, the speed of the preheating cart is controlled in accordance with the preheating temperature, and the amount of heat generated by the heaters H1 to H4 is controlled in accordance with the speed of the preheating cart. ~13 can be controlled to an optimal constant preheating temperature. And the running preheating trolley 1
If the welding device is run on the rail 18 following step 9, the time from preheating to completion of welding can be considerably shortened.

Next, a second embodiment of the present invention will be described with reference to a block diagram shown in FIG. 4 and a second preheating flowchart shown in FIG. Note that the same parts as in FIG. 1 are given the same reference numerals. This device sends the 7H degree detection signal output from the temperature detector 20 to the comparator 23, compares it with the preheating set temperature to set in the temperature setting device 24, and sends the comparison result to the command device 31. I am trying to send it to . In response to the comparison result, the command unit 31 sends a power supply command to the power regulator 30 to control the amount of power supplied to the heaters H1 and H2-\.

With such a configuration, after the temperature detection in step slO, if the comparison result by the comparator 23 in step sll matches each temperature, the process moves to step s12 and the command is sent from the command unit 31 to the power regulator 30. A power supply command is sent to maintain the amount of power supplied to heaters H1 and H2. Further, as a result of the comparison by the comparator 23, if the detected temperature tn is higher than the preheating set temperature to, the process moves to step s+, and the heater H is adjusted according to the deviation between the detected temperature tn and the preheating set temperature to.
1. Supply power command vn to reduce the amount of power supplied to H2
is sent to the power regulator 30, and conversely, if the detected temperature tn is lower than the preheating set temperature to, the process moves to step s14 and the heater H is adjusted according to the deviation between the detected temperature tn and the preheating set temperature to.
1. Supply power command vn to increase the amount of power supplied to H2
is sent to the power regulator 30. Note that at this time, the traveling speed of the preheating truck is constant. Thus, the power supply to each heater H1, H2 is controlled from 1:L to 3 depending on the preheating temperature.
The preheating temperature of the welding member becomes constant, and the welding device can be run following the preheating cart to immediately perform welding.

Next, a third embodiment of the present invention will be described with reference to a block diagram shown in FIG. 6 and a third preheating flowchart shown in FIG. In this device, the amount of power supplied to each heater is kept constant, and a command unit 32 sends out the next command in response to the comparison result of the comparator 23.

That is, if the detected temperature in and the preheating set temperature to match, the process moves to step s22, where the command unit 32 sends a truck speed command to support the truck speed to the truck speed control device 26, and if the detected temperature tn If the temperature is higher than the preheating set temperature to, the process moves to step s23 and a bogie speed command v is given to increase the bogie speed according to the deviation between the detected temperature tn and the preheating set temperature to.
n to the truck speed control device 26, and conversely the detected temperature tn
If it is lower than the preheating set temperature to, the process moves to step s24, and the bogie speed control device 26 issues a bogie speed command to reduce the bogie speed according to the deviation between the detected temperature tn and the preheating set temperature to.
It will be sent to China.

Even if iR'j is formed in this way, the preheating temperature of the welding part 1 remains constant, and the welding device can be run on the rail 18 following the preheating cart and welding can be performed immediately.

Next, a fourth embodiment of the present invention will be described with reference to a block diagram shown in FIG. 8 and a second preheating flowchart shown in FIGS. 9 and 10. This device is provided with a tacho generator 33 for detecting the speed of the truck, and the output of the tacho generator 33 is sent to a comparator 27 through a filter 34 in control means B. The control of the truck speed control and installation system is executed according to the fourth preheating flowchart shown in FIG. 9, and the control of the power regulator 30 system is executed according to the fifth preheating flowchart shown in FIG. 10. This is what I did. Therefore, even with such a configuration, the same effects as those of the above embodiments can be achieved.

Note that FIGS. 11 and 12 show schematic configuration diagrams when the welding device 40 is combined. In this case, a speed control device 41 can be provided to synchronize the traveling speed of the preheating cart 19 and the traveling speed of the welding device 40 or to control the welding so as not to affect welding. Note that when the welding device 40 is controlled to travel, the applied voltage and the like in the welding device are varied so that the best welding can be performed.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a daily motion welding device that can be heated to a predetermined preheating temperature in a short time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a first embodiment of an automatic preheating device according to the present invention, FIG. 2 is a partial cross-sectional view of the device of the present invention, and FIG. 3 is a first preheating flowchart of the device of the present invention. 5 and 5 are diagrams showing a second embodiment of the device of the present invention, and FIG.
5 is a block diagram, FIG. 5 is a second preheating flowchart, and FIGS. 6 and 7 are diagrams showing a third embodiment of the apparatus of the present invention. FIG. 6 is a block diagram, and FIG. is a third preheating flowchart, FIGS. 8 to FO are diagrams showing a fourth embodiment of the apparatus of the present invention, in which FIG. 8 is a block diagram, and FIGS. 9 and 10 are a fourth preheating flowchart. Chart,
FIGS. 11 and 12 are schematic configuration diagrams of a combination of the present invention apparatus and one welding apparatus, and FIGS. 13 to 15 are diagrams showing conventional apparatuses. lO~13... Member to be welded, 18... Rail, 19
... Preheating trolley, 20.21 ... Temperature detector, 23°27 ... Comparator, 24 ... Temperature setting device, 25.29
...Commander, 26...Bogie speed control device, 28...
・Speed setting device, 30...Power regulator. To the applicant's representative and patent attorney Takehiko Suzue: Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9.

Claims (1)

[Claims] In an automatic preheating device that preheats the workpiece before welding,
a heater that heats the member to be welded; a moving mechanism that moves the heater according to the welding location of the member to be welded;
It is characterized by comprising a control means for detecting at least a preheating temperature of the member to be welded and controlling either or both of the power supplied to the heater and the moving speed of the moving mechanism according to the preheating temperature. Automatic preheating device.