JP2021186840A - Temperature/reaction force measuring device and temperature/reaction force measuring method - Google Patents

Abstract

To provide a temperature/reaction force measuring device and a temperature/reaction force measuring method, capable of estimating the molten state of a molten pool, and as a result, capable of contributing to training of welders and automatic welding using a robot.SOLUTION: A temperature/reaction force measuring device includes a temperature measuring probe 2, a linear motor 5 for inserting the tip of the temperature measuring probe 2 into a molten pool Wp, a temperature measuring part 4 for measuring a temperature of the molten pool Wp through the temperature measuring probe 2, and a reaction force measuring part 6 for measuring reaction force received by the temperature measuring probe 2 from the molten pool Wp, when inserting the tip of the temperature measuring probe 2 into the molten pool Wp.SELECTED DRAWING: Figure 1

Description

The present invention relates to a temperature / reaction force measuring device and a temperature / reaction force measuring method used for measuring the temperature and reaction force of a molten pool in welding, for example, welding using a non-consumable electrode.

In welding using non-consumable electrodes as described above, for example, in TIG welding, a TIG arc is generated from the tungsten electrode while supplying a shield gas to melt the workpiece, and the filler metal is inserted into the molten pool generated by this. I try to join them.

In this TIG welding, the TIG arc is stable and there are few fume, spatter, and slag. Therefore, in the case of butt welding and fillet welding, it is possible to obtain a well-shaped and good quality weld bead. A TIG welding apparatus using this non-consumable electrode is described in detail in, for example, Non-Patent Document 1.

In such TIG welding, a well-shaped and good-quality weld bead can be obtained, but if the filler metal is inserted at a speed faster than the penetration rate of the filler metal in the molten pool, the filler metal is not obtained. It remains in the molten pool in the molten state and becomes a welding defect.

Further, in the case of performing welding that penetrates to the back surface of the work piece by TIG welding, and in the case of so-called back wave welding, it is appropriate according to the viscosity received from the back side of the work piece and the reaction force due to surface tension. It is necessary to insert the filler metal into the molten pool at a high speed, but if the insertion speed of the filler metal is not appropriate, welding defects will occur in which the back surface of the workpiece melts down.

In order to prevent the occurrence of these welding defects, it is important to understand the phenomenon occurring in the molten pool, but the phenomenon in the molten pool changes depending on the heat capacity according to the material and thickness of the work piece. , It is covered with shield gas and cannot be visually confirmed.

Therefore, the welder determines the appropriate feeding speed of the filler metal by the melting condition of the molten metal obtained by the feeling of the hand when feeding the filler metal into the molten pool. Welding technology that relies on is difficult to hand down, and it is very difficult to train welders who can handle various materials.

In addition, for example, even if an attempt is made to automate by a robot, it is difficult to select the construction conditions because the appropriate feeding speed of the filler metal to the molten pool is unclear.

In order to know the melting condition of the molten pool, which is indispensable for determining the proper feeding speed of the filler metal as described above, without relying on the sense of the welder, in addition to the reaction force received from the molten pool through the filler metal. , It is necessary to measure the temperature of the molten pool.

Conventionally, for example, a double-coated optical fiber for temperature measurement is known for measuring the temperature of a high-temperature molten metal such as the above-mentioned molten pool.
This double-coated optical fiber for temperature measurement is provided with a metal protective tube on the outer periphery of the optical fiber, and further, a heat insulating material containing particles having a melting point higher than the temperature of the metal to be measured as an additive on the outer periphery of the protective tube. By adopting the double coating structure in this way, it is possible to insert the optical fiber into the molten metal while protecting it from high temperature (see Patent Document 1).

Further, like this double-coated optical fiber for temperature measurement, a high-temperature liquid temperature measuring device using an optical fiber used for measuring the temperature of a high-temperature molten metal is known.
The temperature measuring device for high-temperature liquid using this optical fiber is a device installed in a furnace that holds the molten metal, and has a temperature measuring nozzle whose one end is in contact with the molten metal and a metal tube-coated optical fiber that is previously wound in a drum. An optical fiber supply device that inserts one end from the other end of the temperature measuring nozzle and intermittently sends it into the molten metal in the furnace, and vibrates the metal tube-coated optical fiber back and forth in the supply direction when it is not sent into the molten metal. It has a nozzle clogging gas supply device that supplies nozzle clogging prevention gas to the temperature measuring nozzle, and a radiation thermometer that is connected to the other end of the metal tube coated optical fiber and measures the temperature of the molten metal. (See Patent Document 2).

Further, in Non-Patent Document 2, a fine horizontal hole is provided in the welding base material, an optical fiber is inserted through the horizontal hole, and the tip is fixed in a state of protruding from the groove surface, and then the groove surface is formed. On the other hand, a method for measuring the temperature of a weld metal by performing welding and taking in heat radiation from the weld metal covering the periphery of the optical fiber from the tip of the optical fiber and continuously measuring the temperature during solidification from the time of passing through a high heat source is disclosed.

Japanese Unexamined Patent Publication No. 07-151918 Japanese Unexamined Patent Publication No. 08-005465

"Welding / Joining Handbook", 2nd Edition, Japan Welding Society, published on February 25, 2003, pp. 237-251 Yasuhiro Ueno, Shinji Ishii, Yoshikichi Yamanaka, "Temperature measurement of weld metal by immersion type optical fiber thermometer that does not require emissivity correction"

In the double-coated optical fiber for temperature measurement described in Patent Document 1 described above, since a metal protective tube and a heat insulating material are provided on the outer periphery of the optical fiber, the temperature of the molten metal can be accurately measured. However, it is not possible to grasp the melting condition of the molten metal.

Further, the temperature measuring device for high-temperature liquid using an optical fiber described in Patent Document 2 can also continuously measure the temperature of the molten metal in the furnace, but it is assumed that the melting condition of the molten metal in the furnace can be grasped. Not done.

Further, in the method for measuring the temperature of the weld metal described in Non-Patent Document 2 described above, it is necessary to provide a fine lateral hole in the welding base material in advance and insert the optical fiber, and the groove surface has a groove surface. Although it is possible to measure the temperature during solidification from the time the weld metal passes through the high heat source, it is not possible to continuously measure the temperature following the molten pool moving with the high heat source, and as a result, the weld metal melts. It is difficult to know the condition.

That is, in the above-mentioned double-coated optical fiber for temperature measurement, the temperature measuring device for high-temperature liquid using optical fiber, and the temperature measuring method for weld metal, it is possible to measure the temperature of high-temperature metal, but the weld metal. It is not possible to continuously obtain the reaction force and temperature received from the weld metal, which is the degree of melting of the metal, and it has been a conventional problem to solve this problem.

The present invention has been made to solve the above-mentioned conventional problems, and by continuously acquiring and analyzing the temperature data and reaction force data of the molten pool, an appropriate filler metal for the molten pool. As a result, the purpose is to provide a temperature / reaction force measuring device and a temperature / reaction force measuring method that can contribute to the training of welders and automatic welding using robots. There is.

The first aspect of the present invention is a temperature / reaction force measuring device that measures the temperature and reaction force of the molten pool during welding, and the temperature measuring probe and the tip of the temperature measuring probe are connected to the molten pool. When the tip of the temperature measuring probe is inserted into the molten pool, the temperature measuring probe is released from the molten pool. It is equipped with a reaction force measuring unit that measures the reaction force received.

In the temperature / reaction force measuring device according to the first aspect of the present invention, the tip of the temperature measuring probe is inserted into the molten pool by the driving unit, so that the temperature measuring unit measures the temperature data of the molten pool and measures the reaction force. The reaction force data of the molten pool can be continuously measured by the unit.

Therefore, by analyzing the temperature data and the reaction force data continuously acquired by the temperature / reaction force measuring device according to the first aspect of the present invention, it is possible to estimate the molten state of the molten pool, whereby the molten pool can be estimated. It is possible to select an appropriate filler feed rate for the above.
In other words, since it is almost unnecessary to rely on welding technology that emphasizes the sense of the welder, it will greatly contribute to the training of welders and automatic welding using robots.

In addition, for example, when joining dissimilar metals of a Ni-based alloy and a steel material having different melting points and high-temperature strengths, temperature data of a molten pool using the temperature / reaction force measuring device according to the first aspect of the present invention. And by measuring the reaction force data, it is possible to select an appropriate filler feed rate based on the molten state of the molten pool estimated from the analysis of these data.

In the second aspect of the present invention, the temperature measuring probe is an optical fiber.

In the third aspect of the present invention, the temperature measuring probe is composed of an optical fiber and a covering body covering at least the tip of the optical fiber.

In the fourth aspect of the present invention, the covering body of the temperature measuring probe has a cylindrical shape, and the tip portion of the optical fiber is inserted into the hollow portion of the covering body forming the cylindrical shape. ..

In the fifth aspect of the present invention, the covering body of the temperature measuring probe is configured to be a filler metal.

A sixth aspect of the present invention includes a data logger that acquires and stores the temperature data of the molten pool measured by the temperature measuring unit and the reaction force data of the molten pool measured by the reaction force measuring unit. There is.

On the other hand, the seventh aspect of the present invention is a temperature / reaction force measuring method for measuring the temperature and reaction force of the molten pool during welding, in which the tip of a temperature measuring probe is inserted into the molten pool. The configuration is such that the temperature of the molten pool is measured and the reaction force received by the temperature measuring probe from the molten pool is measured.

According to the temperature / reaction force measuring device and the temperature / reaction force measuring method according to the present invention, the appropriate filler metal for the molten pool is obtained by continuously acquiring and analyzing the temperature data and the reaction force data of the molten pool. It is possible to select the feed rate, and as a result, it is possible to contribute to the training of welders and automatic welding using a robot, which is a very excellent effect.

It is an overall perspective explanatory view of the temperature / reaction force measuring apparatus which concerns on one Embodiment of this invention. It is a graph which shows the measurement result when the molten metal was measured by the temperature / reaction force measuring apparatus of FIG. An enlarged partial perspective explanatory view (a) showing an enlarged main part of the temperature / reaction force measuring device according to another embodiment of the present invention and a key point of the temperature / reaction force measuring device according to still another embodiment of the present invention. It is an enlarged partial perspective explanatory view (b) which shows the part enlarged.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a temperature / reaction force measuring device according to an embodiment of the present invention, and in this embodiment, a case where the heat source is TIG welding using a non-consumable electrode will be described as an example.

As shown in FIG. 1, in this temperature / reaction force measuring device 1, the molten pool Wp generated in the test piece W when welding is performed using the tungsten electrode (non-consumable electrode) Ta located at the tip of the welding torch T. It is a measuring device used to measure the temperature and reaction force of.

That is, the temperature / reaction force measuring device 1 melts via the temperature measuring probe 2 whose tip is inserted into the molten pool Wp, the stand 3 that supports the temperature measuring probe 2, and the temperature measuring probe 2. It is provided with a temperature measuring unit 4 for measuring the temperature of the pond Wp.

In this embodiment, as shown in the enlarged ellipse of FIG. 1, the temperature measuring probe 2 includes an optical fiber 21 for temperature measuring and a cylindrical stainless steel covering 22 (virtual lines other than the tip portion). The optical fiber 21 is protected from the heat of welding by inserting the tip of the optical fiber 21 into the hollow portion of the covering body 22. At this time, the optical fiber 21 is covered with a metal tube and has both high rigidity and heat resistance.
The base end of the optical fiber 21 in the temperature measuring probe 2 is connected to the temperature measuring unit 4, and the temperature measuring unit 4 measures the temperature from the brightness of the molten pool Wp transmitted through the optical fiber 21. ing.

The stand 3 that supports the temperature measuring probe 2 includes a rail 31 installed on the foundation E, a base 32 movably arranged on the rail 31, and a support column 33 arranged on the base 32. An arm 35 rotatably attached to the upper end of the support column 33 via a horizontal shaft 34 is provided. In the stand 3 of the illustrated example, the horizontal shaft 34 that supports the arm 35 can be fixed to the support column 33 at an appropriate position of the position adjusting groove 33a formed along the longitudinal direction thereof.

In this case, a linear motor (driving unit) 5 is attached to the upper surface of the base end portion of the arm 35 of the stand 3, and a groove 36 along the longitudinal direction thereof is formed on the upper surface of the arm 35. The temperature measuring probe 2 is fixed on the movable plate 51 of the linear motor 5 that slides along the groove 36 of the arm 35.

That is, the movable plate 51 of the linear motor 5 is operated after fixing the arm 35 at an appropriate position of the support column 33 at an appropriate angle so that the tip of the temperature measuring probe 2 fixed to the arm 35 faces the molten pool Wp. By doing so, the tip of the temperature measuring probe 2 can be inserted into the molten pool Wp.

Further, the temperature / reaction force measuring device 1 is a reaction force measuring unit that measures the reaction force that the temperature measuring probe 2 receives from the molten pool Wp when the tip of the temperature measuring probe 2 is inserted into the molten pool Wp. 6 is provided.

In this embodiment, the reaction force received by the temperature measuring probe 2 from the molten pool Wp is detected by the telescopic rod type load cell built in the linear motor 5 and converted into an electric signal, and the reaction force measuring unit 6 Then, the reaction force received by the temperature measuring probe 2 from the molten pool Wp is acquired based on the electric signal from the telescopic rod type load cell transmitted via the electric cable 7.

In addition, the reaction force measuring unit 6 performs a reciprocating operation (indicated by an arrow in FIG. 1) of the movable plate 51 of the linear motor 5 in order to insert the tip of the temperature measuring probe 2 into the molten pool Wp at a predetermined cycle. It is designed to be controlled.

Further, the temperature / reaction force measuring device 1 acquires and stores the temperature data of the molten pool Wp measured by the temperature measuring unit 4 and the reaction force data of the molten pool Wp measured by the reaction force measuring unit 6. The data analysis after the measurement is performed based on the temperature data and the reaction force data stored in the data logger 8 in accordance with the sampling period.

When measuring the temperature and reaction force of the molten pool Wp generated in the test piece W by TIG welding by the temperature / reaction force measuring device 1 having the above configuration, first, the test piece W is below the tungsten electrode Ta of the welding torch T. To set.

Next, the base 32 of the stand 3 is moved with respect to the rail 31 to position the support column 33 in the vicinity of the welding torch T, and the tip of the temperature measuring probe 2 fixed to the arm 35 is below the welding torch T (melting pond). The arm 35 is fixed at an appropriate position of the support column 33 at an appropriate angle so as to face the Wp assumed position).

After that, TIG welding is started, and the test piece W is melted by the TIG arc generated from the tungsten electrode Ta to generate a molten pool Wp in the test piece W.
In this state, the tip of the temperature measuring probe 2 is inserted into the molten pool Wp by reciprocating the movable plate 51 of the linear motor 5 in response to a command from the reaction force measuring unit 6.

By inserting the temperature measuring probe 2 into the molten pool Wp, the temperature of the molten pool Wp is continuously increased in the temperature measuring unit 4 based on the brightness of the molten pool Wp transmitted through the optical fiber 21 of the temperature measuring probe 2. It is measured.

On the other hand, in the reaction force measuring unit 6, the temperature measuring probe 2, particularly the temperature measuring probe 2, is based on the electric signal from the telescopic rod type load cell built in the linear motor 5 transmitted via the electric cable 7. The reaction force received from the molten pool Wp by the stainless steel covering 22 forming a circular tube is continuously measured.

At this time, the temperature data of the molten pool Wp measured by the temperature measuring unit 4 and the reaction force data of the molten pool Wp measured by the reaction force measuring unit 6 are stored in the data logger 8 at the same sampling period.

Here, FIG. 2 shows an example of temperature data and reaction force data of the molten pool Wp stored in the data logger 8 at the same sampling period.

In the graph of FIG. 2, the tip of the temperature measuring probe 2 starts to enter the molten pool Wp at about 2.4 seconds, and the tip of the temperature measuring probe 2 starts to enter the molten pool Wp between 2.45 and 2.5 seconds. It can be seen that the position P) of about 2 mm has been reached. During this time, it can be seen that the temperature measuring probe 2 starts to receive the reaction force F from the time when the tip thereof starts to enter the molten pool Wp, and receives the reaction force F of about 2.5 N at the bottom of the molten pool Wp. Further, it can be seen that the measured temperature Temp is slightly lowered when the tip of the temperature measuring probe 2 reaches the bottom of the molten pool Wp. In this measurement, when the tip of the temperature measuring probe 2 reaches the bottom of the molten pool Wp, it is set to return to the state before insertion (reverse), so that after the temperature measurement probe 2 is inverted. The reaction force F received from the molten pool Wp is decreasing.

Then, by analyzing the temperature data and reaction force data of the molten pool Wp stored in the data logger 8 shown in FIG. 2 at the same sampling period, it is possible to estimate the molten state of the molten pool Wp, thereby melting. It is possible to select an appropriate filler feed rate for the pond Wp.

Therefore, there is almost no need to rely on welding technology that emphasizes the sense of the welder, which greatly contributes to the training of welders and the automatic welding using robots.

In addition, for example, when joining so-called dissimilar metals such as IN100 (registered trademark) having high high temperature strength and low alloy steel by TIG welding, temperature / reaction force measurement according to this embodiment is performed. If the temperature data and reaction force data of the molten pool Wp are measured using the apparatus 1, the appropriate filler metal feeding speed is selected based on the molten state of the molten pool Wp estimated from the analysis of these data. You will get it.

In the above-described embodiment, the temperature measuring probe 2 of the temperature / reaction force measuring device 1 is formed by inserting the tip portion of the optical fiber 21 into the hollow portion of the stainless steel covering body 22 forming a circular tube. Therefore, the influence of the heat of welding on the optical fiber 21 can be suppressed to a small extent.

The temperature measuring probe 2 of the temperature / reaction force measuring device 1 does not necessarily have to have a configuration in which the tip end portion of the optical fiber 21 is inserted into the hollow portion of the covering body 22 forming a circular tube.

As another configuration, as shown in FIG. 3A, the optical fiber 21 itself fixed to the movable plate 51 may be the temperature measuring probe 2A, and in this case, the covering body 22 is required. Cost reduction can be realized by the amount that is not.

As yet another configuration, as shown in FIG. 3B, the covering body 22B of the temperature measuring probe 2B has a substantially half-split cylinder shape covering at least the tip of the optical fiber 21 on the movable plate 51. In this case, the cost can be reduced by the amount that the material of the covering body 22B can be reduced while suppressing the influence of the heat of welding on the optical fiber 21 to be small.

As yet another configuration, although not shown, for example, in TIG welding using a filler material, a filler metal formed in a circular tubular shape is adopted as a covering body of a probe for temperature measurement, and the filler metal having a circular tubular shape is used. By passing an optical fiber through the hollow portion, the filler metal may also serve as a temperature measuring probe.

Further, the covering body 22 forming the circular tubular shape of the probe 2 for temperature measurement may be made of the same material as the test piece W instead of stainless steel. In this way, the filler metal or the test piece may be used as the covering body. When a material made of the same material as W is used, it is possible to prevent foreign matter from being mixed with the molten metal, and as a result, the temperature and reaction force can be measured in a state closer to actual welding.

As yet another configuration, although not shown, the temperature measuring probe can be configured from a sheathed thermocouple.

Further, in the above-described embodiment, the case where the temperature / reaction force measuring device 1 measures the temperature and reaction force of the molten pool generated in the test piece W by TIG welding is shown, but is limited to TIG welding. It may be plasma welding.

The configuration of the temperature / reaction force measuring device and the temperature / reaction force measuring method according to the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the spirit of the invention.

1 Temperature / reaction force measuring device 2, 2A, 2B Temperature measuring probe 4 Temperature measuring unit 5 Linear motor (driving unit)
6 Reaction force measuring unit 8 Data logger 21 Optical fiber 22,22B Cover Ta Tungsten electrode (non-consumable electrode)
Wp melting pond

Claims (7)

It is a temperature / reaction force measuring device that measures the temperature and reaction force of the molten pool during welding.
A probe for temperature measurement and
A drive unit that inserts the tip of the temperature measurement probe into the molten pool,
A temperature measuring unit that measures the temperature of the molten pool via the temperature measuring probe,
A reaction force measuring unit that measures the reaction force that the temperature measuring probe receives from the molten pool when the tip of the temperature measuring probe is inserted into the molten pool.
A temperature / reaction force measuring device equipped with. The temperature / reaction force measuring device according to claim 1, wherein the temperature measuring probe is an optical fiber. The temperature / reaction force measuring device according to claim 1, wherein the temperature measuring probe comprises an optical fiber and a covering body covering at least the tip of the optical fiber. The temperature / reaction force measuring apparatus according to claim 3, wherein the covering body of the temperature measuring probe has a cylindrical shape, and the tip end portion of the optical fiber is inserted into a hollow portion of the covering body forming the cylindrical shape. .. The temperature / reaction force measuring device according to claim 3 or 4, wherein the covering body of the temperature measuring probe is a filler metal. One of claims 1 to 5, further comprising a data logger that acquires and stores the temperature data of the molten pool measured by the temperature measuring unit and the reaction force data of the molten pool measured by the reaction force measuring unit. The temperature / reaction force measuring device described in. It is a temperature / reaction force measurement method that measures the temperature and reaction force of the molten pool during welding.
A temperature / reaction force measuring method in which the tip of a temperature measuring probe is inserted into a molten pool to measure the temperature of the molten pool and the reaction force received by the temperature measuring probe from the molten pool.

Images