JP2023051868A - Welding machine with automatic stop function - Google Patents

Abstract

To provide a welding machine capable of automatically stop welding in a stop region selected on a welding object part.SOLUTION: The present invention relates to a welding machine (1) for welding at least two welding object parts (2), which is configured to be movable along the welding object parts (2). The welding machine (1) comprises: at least one pair of drive wheels intended to move the welding machine (1); and at least two welding wheels. The welding machine (1) comprises: a control unit (32) capable of controlling current passing through the welding wheels. The welding machine (1) comprises at least one stop device for stopping the welding machine (1) comprising at least one sensor (36) capable of detecting a point on the welding object part (2), The control unit (32) is configured to stop the welding of the welding object part (2) by means of the welding wheel at a predetermined distance from the point.SELECTED DRAWING: Figure 2

Description

The present invention relates to a welder with an electrode in the form of a welding wheel for welding together parts to be welded.

Current welders comprise a drive wheel, a welding wheel for welding the parts to be welded, and a drive member capable of rotating at least the drive wheel along the parts to be welded. The welding wheel is supplied with current by a current unit when the welder is moving, ensuring welding of the parts to be welded. Current welders are controlled by at least one operator who, among other things, ensures that the welder stops at the desired position on the parts to be welded.

In order to speed up the welding of the parts to be welded, the drive wheels of the welder are rotated at speeds higher than those of welders found in the prior art. Therefore, the welding speed of the parts to be welded can be increased. However, a problem with these welders is that as the speed of rotation of the drive wheel increases, it becomes difficult for the operator to control the welder. In particular, increasing the rotational speed of the drive wheel reduces the stop tolerance and causes inaccuracies in the stop area where the welder stops relative to the parts to be welded, resulting in poor welds produced by the welder. there is a possibility. Additionally, inaccurate welder stop areas can pose a hazard to the operator controlling the welder, especially when the machine is positioned along parts to be welded that are positioned above the operator.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to propose a welding machine capable of automating at least the stopping of welding in selected stopping areas on the parts to be welded, in other words capable of stopping without operator intervention. This is to overcome the above problems.

The present invention therefore relates to a welding machine for welding at least two parts to be welded, the welding machine being arranged to be movable along the parts to be welded, the welding machine extending in a longitudinal main direction of extension, At least one pair of drive wheels intended to move the welder relative to the parts to be welded and producing a weld of the parts to be welded by rolling the welding wheels against at least two parts to be welded. and at least two welding wheels capable of performing welding, the welder comprising a control unit capable of controlling the current passing through the welding wheels, and the welder being capable of detecting at least one point on the part to be welded. at least one stopping device for stopping the welding machine comprising two sensors, the control unit being arranged to stop the welding of the parts to be welded by the welding wheel at a predetermined distance from the point.

The welder according to the invention welds together and/or to a fixed flange two raised edges of a sealing membrane that constitutes the wall of a tank for storing and/or transporting cryogenic products such as liquefied natural gas, for example. can be used to For example, a welder may weld two adjacent parts, called a first welded part and a second welded part, so as to form a closed membrane on the wall of a tank for storing and/or transporting cryogenic products. may be welded on the raised edge. Alternatively, the welder may weld at least one of the raised edges to the stationary flange to form a third welded part located between two raised edges of two adjacent parts. good. Note that the part to be welded can thus be either the raised edge or the fixed flange.

For this purpose, the welding machine comprises at least a pair of drive wheels which, by means of drive members, ensure the movement of the welding machine along the parts to be welded in the linear direction of welding, also called forward direction of the welding machine. The drive member may be, for example, an electric, hydraulic, pneumatic or mechanical drive member. Preferably, in the context of the present invention the drive member is an electric motor.

The welding wheel enables the production of a weld by contacting at least one of the parts to be welded, which may be at least one of a raised edge or a fixed flange. More specifically, according to a non-limiting example of the present invention, during welding of the parts to be welded, movement of the welder relative to the parts to be welded causes rotation of the welding wheel relative to the parts to be welded, An electric current is supplied by the power supply unit and passes through the welding wheel to enable the formation of a weld bead on the parts to be welded.

A stopping device for stopping a welding machine comprising at least one sensor allows automating the stopping of the welding machine when the sensor detects a point on the part to be welded. In other words, when the sensor detects a point on the part to be welded, the welder, in particular the control unit, initiates a step of gradually stopping the welder so that at least the welding wheel of the welder stops at a predetermined distance from the point. implement.

According to one feature of the invention, the welder comprises at least one drive member capable of rotating a drive wheel, the drive member being capable of driving the welder at speeds exceeding 4.5 m/min. can.

It should be noted that the advantage of such automation of stopping welding by the welder is that it allows the welder to be used at high speeds.

According to one aspect of the invention, the sensor is configured to detect at least one shape change of at least one part to be welded.

The expression "shape change of at least one part to be welded" means, for example, a recess formed in the material of at least one part to be welded. This recess may, for example, take the form of a notch. Thus, in such a configuration of points, the sensor may be a mechanical sensor, a laser sensor, a Hall effect sensor, an inductive sensor, or an ultrasonic sensor.

According to one aspect of the invention, the sensor is configured to detect at least one thickness change of at least one component to be welded. This thickness variation can take the form of blind holes or through holes.

In such configurations of points formed in at least one part to be welded, the sensor may be an inductive sensor, a Hall effect sensor, a mechanical sensor, a laser sensor, or an ultrasonic sensor.

According to one aspect of the invention, the sensor is arranged to receive signals from markers representing the position of the point.

In this case, the points may be virtual, in other words, points that do not physically exist on the parts to be welded. According to this example, a marker is placed at or from a point to enable transmission of a signal received by a sensor of the stop device to stop the welder, causing a change in state of the sensor upon receipt of the signal. It may be placed at zero distance. A marker is an indirect means of point detection by a sensor.

According to one feature of the invention, the welder comprises at least two pairs of drive wheels, the welding wheels being arranged between the two pairs of drive wheels in the longitudinal direction of the welder.

According to one feature of the invention, the sensor is at a non-zero sensor distance from the welding wheel, the sensor distance being considered in the longitudinal direction of the welder.

In particular, the front and rear ends of the welder are defined, the terms front and back being considered relative to the direction of advance of the welder along the parts to be welded. It will therefore be appreciated that a sensor is placed at the front end of the welder to anticipate detection of a point on the part to be welded before the welding wheel reaches that point while the welder is moving.

According to a non-limiting example of the invention, the sensor distance between the sensor and the welding wheel is between 150 mm and 300 mm and the distance between the front end of the welder and the sensor is between 0 mm and 150 mm.

According to one aspect of the invention, a welder comprises at least one body defining a volume in which a welding wheel and at least one pair of drive wheels are at least partially disposed, the sensor being detected by the body of the welder. Located outside the defined volume.

In particular, the sensor is defined by the body of the welder such that, prior to detection, it is longitudinally positioned between the front end of the welder and a point during travel of the welder along the parts to be welded. Note that it is placed outside the volume. Alternatively, the sensor may be supported by the outer surface of the front end of the welder. According to another alternative, the sensor may be within the volume defined by the body of the welder, particularly if the sensor is a sensor laser.

A cooling system may be provided for cooling the welding wheel. It preferably consists of an internal circuit for circulating coolant as close as possible to the welding wheel, which further comprises a container, a pump and a cooling assembly supported by a trolley.

According to one feature of the invention, the control unit is arranged to reduce the intensity of the current starting from the detection of the point by the sensor.

According to one aspect of the invention, the control unit is arranged to reduce the speed of the welder starting from the detection of the point by the sensor.

According to an alternative form of the invention, the control unit is arranged to stop rotation of the drive wheel by the drive member of the welder upon detection of the point by the sensor.

According to one feature of the invention, the control unit is arranged to synchronize the reduction of the intensity of the current with the reduction of the speed of the welder starting from the detection of the point by the sensor.

According to one aspect of the invention, the welder comprises at least one man-machine interface arranged on a fixed trolley independent of the body of the welder. Also, the power supply unit may be supported by a trolley.

According to one feature of the invention, the signal transmitted or detected by the sensor is at an angle of incidence between 0 and 45 degrees with respect to the advancing direction of the welder. An advantage of such a feature is that it allows the sensor of the welder to detect the point before it reaches the point formed on at least one of the parts to be welded.

According to one feature of the invention, the predetermined distance from the point calculated between the point and the stopping area different from the point is 20-200 mm, preferably the distance is 50-100 mm. .

In other words, the welding of the parts to be welded is stopped 20-200 mm from the point. The stop area thus defines the weld area of the weld-free area.

The invention also relates to a welding method for welding at least two parts to be welded by a welding machine according to any one of the above characteristics, the welding method comprising: along the parts to be welded in the longitudinal direction in which the welder advances Welding to form a weld bead along at least one component to be welded, simultaneously with or after the first step, in which the drive wheel is rotated to move the welder. at least one second step in which the wheels have a current passing through them; at least one third step in which the sensors detect points on the at least one part to be welded; and at least one fourth step of stopping the weld of at a predetermined distance from the point.

According to one characteristic of the welding method, during the fourth step, the driving member slows down the advancing speed of the welder starting from the detection of the point, and the control unit reduces the intensity of the current starting from the detection of the point. configured to reduce

Also, the control unit synchronously controls the reduction of the forward speed of the welding machine and the reduction of the current intensity. This allows the welder to produce a uniform weld bead even at the edge of the weld, in other words up to the welder stop area formed at a predetermined distance from the point.

According to one feature of the welding method, the drive member increases the advancing speed of the welder and the control unit is arranged to increase the intensity of the current during the first and second steps.

Also, the increase in forward speed of the welder and the increase in current intensity are synchronously controlled by the control unit. This allows the welder to produce a uniform weld bead immediately after starting welding of the parts to be welded.

According to one characteristic of the welding method, the travel speed of the welder upstream of the point in the forward direction is 4.5 m/min or more.

Further features, details and advantages of the invention will become more clearly apparent from the description provided below by way of example, with reference to the drawings.

1 is an overall perspective view of a tank for storing and/or transporting cryogenic products, including at least two parts to be welded that constitute the sealing membrane of the tank; FIG. 2 is a perspective view of a welder according to the invention, capable of welding the two parts to be welded shown in FIG. 1; FIG. 1 is an enlarged view of two parts to be welded with points created on at least one of them according to a first example of the invention; FIG. Fig. 4 is an enlarged view of two parts to be welded with points created on at least one of them according to a second example of the invention; Fig. 4 is an enlarged view of two parts to be welded with points created on at least one of them according to a third example of the invention; FIG. 3 is a top view of the welder of FIG. 2 showing sensors detecting points made on one of the parts to be welded;

First, it should be noted that while the drawings disclose the invention in detail for its implementation, the drawings of course serve to define the invention more clearly where applicable. It is also noted that the drawings merely disclose embodiments of the invention. Finally, like reference numerals refer to like elements throughout the drawings.

FIG. 2 shows a welder 1 configured to move along at least two parts 2 to be welded. More specifically, the parts to be welded 2 constitute a sealing membrane 6 of the wall 8 of a tank 10 for storing and/or transporting cryogenic products, such as liquefied natural gas, as can be seen in FIG. do.

The welder 1 may, for example, be capable of welding first raised edges 4a and second raised edges 4b of adjacent first and second parts to be welded 2a and 2b, respectively. According to another example of the invention, the welder is adapted to cut at least one of the raised edges 4a, 4b on one of the first welded part 2a and/or the second welded part 2b as shown in FIG. It may be welded to a fixed flange 12 forming a third welded part 2c seen in FIGS. More specifically, the fixed flange 12 seen in FIGS. 3-6 is fixed to the insulation forming part of the wall 8 of the tank 10 and is located between two adjacent raised edges 4. . This welding of at least two of the parts to be welded 2a, 2b, 2c is applied to at least one of the first raised edge 4a and/or the second raised edge 4b extending along the welding axis S, FIGS. A weld bead 14 seen at 5 is formed. The weld bead 14 formed between at least two parts 2 to be welded makes it possible, inter alia, to ensure a tight seal between the parts 2 to be welded and thus for storing and/or transporting cryogenic products. contributes to the sealing of the membrane 6 that constitutes the wall 8 of the tank 10 of.

The welding machine 1, which can be seen in particular in FIGS. 2 and 6, has at least one body 42 which has a substantially parallelepiped shape and extends in a main direction of extension P parallel to the longitudinal direction L of the welding machine 1. Prepare. The body 42 of the welder 1 comprises in particular a front end 16 and a rear end 18 facing each other in the longitudinal direction L of the welder 1 . It should also be noted that the concept of front and rear of the body 42 of the welder 1 refers to the advancing direction A of the welder 1 along the part to be welded 2 parallel to the welding axis S and the longitudinal direction L of the welder 1 . Furthermore, the body 42 of the welder 1 comprises an upper surface 20 and a lower surface (not shown) facing each other in a vertical direction V of the welder 1 perpendicular to its longitudinal direction L, the lower surface facing the part 2 to be welded. This is the surface of the body 42 of the welder 1 .

The welding machine 1 according to the invention, seen in FIG. 6, rotates at least one pair of drive wheels 24 intended to move the welding machine 1 relative to the parts 2 to be welded. and at least one drive member 26 capable of

More specifically, at least one pair of drive wheels 24 are arranged on the underside of the body 42 of the welder 1 so as to contact at least one of the parts 2 to be welded. Rotation of the at least one pair of drive wheels 24 caused by the drive member 26 is therefore such that the pair of drive wheels 24 placed in contact with the part to be welded 2 rotates the welder 1 parallel to the advance direction A of the welder 1 . It is possible to move along the part 2 to be welded in a linear translational motion. More specifically, each of the wheels of the pair of drive wheels 24 contacts one of the raised edges 4 on one of the parts 2 to be welded. According to the illustrated example of the invention, the welder 1 includes a first pair of drive wheels 24a and a second pair of drive wheels 24a located respectively at the front end 16 and the rear end 18 of the body 42 of the welder 1. A wheel 24b is provided. It should be noted that the drive wheels 24 of each of the pair of drive wheels 24a, 24b face each other in the transverse direction T of the welder 1 perpendicular to the longitudinal direction L and the vertical direction V. As shown in FIG.

As mentioned above, the welder 1 comprises at least one drive member 26 that rotates a drive wheel 24 and can take the form of an electric, hydraulic, pneumatic or mechanical drive member 26 . Preferably, the drive member 26 according to the invention is an electric motor. According to the invention, the at least one drive member 26 is capable of rotating the drive wheel 24 such that the drive wheel moves the welder 1 along the parts to be welded at a speed of more than 4.5 m/min. .

The welding machine 1 according to the invention comprises at least two welding wheels 28 with which the parts 2 to be welded can be welded by rotating the welding wheels 28 relative to the parts 2 to be welded. It should therefore be noted that welding wheel 28 is capable of producing weld bead 14 along at least two parts 2 to be welded, as described above. The welder 1 thus comprises at least one first welding wheel 28a arranged in contact with the first raised edge 4a of the first part to be welded 2a and a second wheel 28a of the second part to be welded 2b. a second welding wheel 28b placed in contact with the raised edge 4b of the . A welding wheel 28 is arranged between the first pair of drive wheels 24a and the second pair of drive wheels 24b in the longitudinal direction L of the welder 1 . The welding wheel 28 is arranged on the lower surface of the main body 42 of the welding machine 1 so as to come into contact with the part 2 to be welded.

In order to carry out the welding operation, the welding wheels 28 are intended to have a current passing through them during operation of the welding machine 1, the current being supplied by a power supply unit 30 shown in FIG. In that case, it is supported by a trolley 46 of the welder 1 which is different from the main body 42 of the welder 1 comprising the drive wheel 24 and the welding wheel 28, the trolley being explained in detail below in the detailed description. Also, according to an example of the invention not shown, the power supply unit may be housed in the body of the welder.

According to one example of the present invention, welding wheel 28 is freely rotatable relative to each of drive wheels 24 . The welding wheel 28 is thus rotated by direct contact of the welding wheel 28 with at least one of the parts 2 to be welded during movement of the welder 1 . It should be noted that the drive member 26 of drive wheel 24 does not directly affect the rotation of welding wheel 28 . According to another example of the invention, at least one drive member 26 is configured to rotate a welding wheel 28 along the part 2 to be welded. The welding machine 1 further comprises at least one control unit 32 , housed in this case in the trolley 46 and capable of at least controlling the current passing through the welding wheel 28 .

According to the invention, as shown in FIG. 6, the welder 1 is capable of detecting at least one point 38 on at least one part to be welded 2, in other words at least one raised edge 4 or fixed flange 12. At least one stopping device 34 for stopping the welding machine 1 with one sensor 36 is provided. For example, points 38 are formed on at least one raised edge 4 on one of the parts 2 to be welded and/or on visible portions of the fixing flange 12 . The expression “visible part of the fixing flange 12 ” means that part of the fixing flange that extends vertically beyond the at least one raised edge 4 . The control unit 32 is arranged to stop the welding of the parts 2 to be welded by the welding wheel 28 at a predetermined distance D from the point 38 and the sensor 36 changes state upon detection of the point 38 .

According to a first example of the invention, which can be seen in FIG. 3 , the point 38 formed on at least one of the parts 2 to be welded is a shape change of the at least one part 2 to be welded. More specifically, the shape change according to the example of FIG. 3 is formed on the raised edges 4 of at least two parts to be welded 2 and on the fixing flanges 12 arranged between the raised edges 4 . This shape change is therefore in this case by means of a material recess formed in each of the raised edges 4 of the at least two parts to be welded 2 and in the fixing flange 12 such that the material recesses are formed opposite each other. Characterized. Thus, in such a configuration of point 38, sensor 36 of stopping device 34 may be a mechanical sensor, a Hall effect sensor, an inductive sensor, a laser sensor or an ultrasonic sensor.

The mechanical sensor thus rotates along one of the parts to be welded, in this case until it reaches a point formed by a recess in the material, and determines the position of the welder 1 along the part to be welded by the stop device. It may also be a sensor that causes the triggering of a switch that informs 34 . If the sensors are laser or ultrasonic sensors, they normally detect the material that constitutes one of the parts to be welded. When these sensors detect a point, in this case a recess in the material representing the point, a change of state of the sensor is triggered and informs the stop device 34 of the position of the welder 1 along the part to be welded.

According to a second example of the invention, which can be seen in FIG. 4, the points 38 formed on at least one of the parts 2 to be welded are thickness variations of the at least one part 2 to be welded. According to one example of the invention, the point 38 is the thickness change of one of the raised edges 4 of the at least one welded part 2 opposite which the sensor 36 is arranged, the thickness being the welder 1 is considered along a straight line parallel to the transverse direction T of . According to another example of the invention, the point 38 is the thickness variation of the fixed flange 12 , the thickness being considered along a straight line parallel to the transverse direction T of the welder 1 . This thickness variation may be characterized, for example, by a blind or through hole made in one of the parts 2 to be welded. In such a configuration of point 38, sensor 36 takes the form of an inductive, mechanical, Hall effect or ultrasonic sensor that allows direct detection of thickness variations in at least one part 2 to be welded. can take According to another example of the invention, the sensor is a laser sensor making it possible to detect the distance change between transmission and reception of the laser at a point 38 formed on at least one of the parts 2 to be welded. There may be.

The inductive sensor makes it possible in particular to determine the distance separating the sensor from the material of the at least one part 2 to be welded, the arrival of the sensor to the point formed by the thickness change in this case being the distance between the sensor and at least It produces a distance change with one welded part 2 and thus causes a change in the state of the sensor.

Also independently of the first and second embodiments of the points 38, the points are formed on at least one of the parts to be welded 2 differently than the weld bead 14 formed by the welding wheel 28. Please note that In other words, point 38 is vertically offset from weld bead 14 . Such a feature makes it possible to limit the risk of an unsound weld at point 38, where weld bead 14 is over a shape or thickness change in one of the parts 2 to be welded. not formed.

According to a third example of the invention, which can be seen in FIG. 5, sensor 36 is arranged to receive signals from markers 40 representing the position of points 38 on at least one part 2 to be welded. It should therefore be noted that in such a configuration the marker 40 may be positioned so as to be spatially offset from the point 38 . As before, detection of marker 40 by sensor 36 changes the state of sensor 36 and thus informs stopping device 34 of the position of welder 1 relative to point 38 .

From the above, the sensor 36 according to the invention can in particular transmit signals for determining changes in the shape and/or thickness of the at least one part to be welded 2 representing the point 38 or in particular from the marker 40 It will be appreciated that a signal may be received and the reception of the signal transmitted by marker 40 is indicative of point 38 and the position of welder 1 relative to point 38 .

As noted above, body 42 of welder 1 defines a volume in which welding wheel 28 and at least one pair of drive wheels 24 are at least partially disposed. More specifically, according to the illustrated example of the invention, two welding wheels 28 and two pairs of drive wheels 24 are arranged within the volume defined by the body 42 of the welder 1 .

Therefore, according to the invention, at least one sensor 36 is arranged outside the volume defined by the body 42 of the welder 1, as can be seen in FIGS. More specifically, the sensor 36 is at a non-zero sensor distance F from the welding wheel 28 , the sensor distance F being considered in the longitudinal direction L of the welder 1 . In particular, the at least one sensor 36 is arranged at the front end 16 of the body 42 of the welder 1 such that it is upstream of the welding wheel 28 in the advancing direction A of the welder 1 . According to a non-limiting example of the present invention, at least one sensor 36 is positioned at a non-zero sensor distance F from welding wheel 28 of 150 mm to 300 mm. At least one sensor 36 is arranged at a distance of 0 mm to 150 mm from the front end 16 of the body 42 of the welder 1 . Such an arrangement of the sensor 36 with respect to the welding wheel 28 makes it possible in particular to anticipate the stopping of the welder 1 before the welding wheel 28 reaches the point 38 .

As mentioned above, the control unit 32 is arranged to stop the welding of the parts 2 to be welded by the welding wheel 28 at a predetermined distance D from the point 38 , in other words at a stop area 44 different from the point 38 . Preferably, the stop of welding by welding wheel 28 is effective at stop area 44 located at a predetermined distance D from point 38 of 20 mm to 200 mm. Preferably, the predetermined distance D is 50-100 mm from point 38 . In other words, control unit 32 is configured such that welding wheel 28 forms weld bead 14 to stop area 44 formed at predetermined distance D from point 38 . The control unit 32 also controls the drive member 26 such that the welder 1 stops when a stop area 44 located at a predetermined distance D from the point 38 is reached.

For this purpose, the control unit 32 is arranged to reduce the intensity of the current supplied by the power supply unit 30 to the welding wheel 28 starting from the detection of the point 38 by the sensor 36 . In particular, the stop device 34 is configured to communicate with the control unit 32 so as to send a signal to the control unit 32 when its sensor 36 detects a point 38 formed on one of the parts 2 to be welded. Please note that

Thus, starting from the detection of point 38, the control unit 32 controls until zero intensity is reached when the welder 1, and more specifically the welding wheel 28, is positioned at a predetermined distance D from the point 38 in the stop area 44. The intensity of the current supplied to welding wheel 28 is reduced. Similarly, the control unit 32 is arranged to reduce the speed of the welder 1 starting from the detection of the point 38 by the at least one sensor 36 . That is, the control unit 32 controls from a speed greater than 4.5 m/min when the sensor 36 detects the point 38 to a speed of 0 when the welding wheel 28 reaches the stopping area 44 at a predetermined distance D from the point 38 . The drive member 26 is commanded to slow the rotational speed of the drive wheel 24 so as to reach the speed. Therefore, according to the invention, the control unit 32 synchronizes the decrease in the intensity of the current supplied to the welding wheel 28 with the decrease in speed of the welder 1 starting from the detection of the point 38 by the sensor 36. Configured.

Due to the characteristics of the welder 1 as described above, the position of the stop device 34 of the welder 1, in particular its sensor 36, makes it possible to predict the stop of the welder 1 autonomously, in other words without operator intervention. It will be understood that In other words, the welding machine 1 itself adjusts its travel speed and the welding wheel 28 such that when the welding machine 1, in particular the welding wheel 28, reaches the stop area 44 of the part to be welded, this speed and intensity have a zero value. ensure that the intensity of the current supplied to the is reduced in a predictable manner.

According to an example of the invention, which can be seen in FIG. 6, the at least one sensor 36 emits a signal such that the signal forms an angle of incidence N with respect to the advancing direction A of the welding machine 1 between 0° and 45°. receive and/or transmit; The signal produces a reading point on the part to be welded until the detection of point 38, corresponding to the moment when the control unit 32 starts to stop the welding of the part to be welded 2 by the welding wheel 28. Of course, it will be appreciated that the signals transmitted and/or received by the sensor 36 are directed toward the front of the welder 1 , in other words away from the body 42 of the welder 1 .

An advantage of such a feature is that it allows the sensor 36 to increase the likelihood of detecting a point 38 formed on one of the parts 2 to be welded, the sensor 36 detecting during operation of the welder 1 The point 38 can be detected before its arrival facing the point 38 . This improves the prediction of stopping of the welding machine 1 by the stopping device 34 .

Alternatively, the sensor 36 receives a signal from the marker 40 corresponding to the moment when the control unit 32 starts to stop the welding of the part 2 to be welded by the welding wheel 28 .

As can be seen in FIG. 2, the welding machine 1, unlike its body 42, comprises at least a trolley 46 intended to carry a power supply unit 30 for at least the welding wheel 28 and an operator holding the parts to be welded. at least one man-machine interface 48 allowing to monitor the progress of two welds, at least a control unit 32 and further comprising at least one cooling system 50 for cooling the welding wheel 28. A cooling system 50 for cooling the welding wheel 28 may consist, for example, of an internal circuit that circulates coolant as close as possible to the welding wheel, supported by a container, a pump and a trolley. and a cooling assembly. Such a cooling system makes it possible in particular to prevent the welding wheel 28 from overheating during operation of the welding machine 1 .

A welding method for welding at least two parts to be welded 2 using the welding machine 1 described above will be described with reference to FIGS. 1 to 6. FIG.

The welding method consists in rotating the drive wheel 24 by means of the drive member 26 under the control of the control unit 32 so as to move the welder 1 along the part to be welded 2 in a forward direction A of the welder 1 parallel to the longitudinal direction L. at least one first step of allowing During this first step, the control unit 32 is arranged to increase the forward speed of the welder 1 from zero speed to over 4.5 m/min. Note therefore that the speed increase of the welder 1 increases until a steady speed of over 4.5 m/min is reached. Also, the travel speed exceeding 4.5 m/min corresponds to the speed of the welder 1 upstream of the point 38 with respect to the advance direction A of the welder 1 .

Following the first step, or simultaneously with the first step, the method is characterized in that the welding wheel 28 along the parts 2 to be welded, in particular along the raised edges 4 of at least two parts 2 to be welded, It further includes a second step of having a current pass through the welding wheel to form a weld bead 14 . Note that in this second step, control unit 32 is configured to increase the intensity of the current supplied to welding wheel 28 by power supply unit 30 . This increase in strength is performed by the control unit 32 in synchronism with the increase in the moving speed of the welder 1 . It should therefore be noted that the intensity of the current passing through the welding wheel 28 increases in proportion to the increase in speed of the welder 1 so as to obtain a uniform weld bead 14 during the second step.

Following the second step, in a third step the sensor 36 transmits a point 38 on at least one part to be welded 2 by a change in shape or thickness of one of these elements or by a marker 40. detected by receiving a signal representing the position of the point 38 . Therefore, in a fourth step, the control unit 32 causes the welding wheel 28 to stop welding the part 2 to be welded at a predetermined distance D from the point 38 . It should be noted that during the fourth step, the control unit 32 reduces the intensity of the current supplied from the power supply unit 30 to the welding wheel 28 and controls the welding machine 1 starting from the detection of the point 38 by the driving member 26 . It is configured to control the reduction in forward speed. Therefore, the reduction in the speed of the welding machine 1 and the reduction in the intensity of the welding current are synchronously realized by the control unit 32 .

An advantage of such a feature is that the rotational speed of the drive wheel 24 is increased proportionally to the reduction in the intensity of the current passing through the weld wheel 28 to obtain a uniform weld bead 14 between the point 38 and the stop area 44. It is possible to reduce

Thus, at the end of the fourth step, the welding machine 1 is in the stop area 44, its drive wheel 24 is at rest, ie with zero rotational speed, and its welding wheel 28 no longer carries current. not

However, the present invention as just described is not limited to the means and arrangements merely described and illustrated, but also applies to any equivalent means or arrangements and any combination of such means or arrangements. .

Claims (16)

A welding machine (1) for welding at least two parts (2) to be welded, arranged to be movable along the parts (2) to be welded, said welding machine (1) being longitudinally ( L) at least one pair of drive wheels (24) extending in the main direction of extension (P) and intended to move said welding machine (1) relative to said parts to be welded (2); at least two welding wheels (28) capable of producing a weld of said parts (2) to be welded by rolling said welding wheels (28) against said parts (2) to be welded. , said welding machine (1) comprises a control unit (32) capable of controlling the current passing through said welding wheel (28), said welding machine (1) being able to control the said control unit ( 32) is configured to stop welding of said part to be welded (2) by said welding wheel (28) at a predetermined distance (D) from said point (38). comprising at least one drive member (26) capable of rotating said drive wheel (24), said drive member (26) driving said welder (1) at a speed exceeding 4.5 m/min. Welder (1) according to claim 1, capable of Welder (1) according to any one of claims 1 and 2, wherein the sensor (36) is arranged to detect at least one shape change of the at least one part (2) to be welded. . Welder (1) according to any one of the preceding claims, wherein the sensor (36) is arranged to detect at least one thickness change of the at least one part (2) to be welded. ). Welder (1) according to claim 1 or 2, wherein the sensor (36) is arranged to receive a signal from a marker (40) representing the position of the point (38). comprising at least two pairs of drive wheels (24, 24a, 24b), said welding wheel (28) being arranged between said two pairs of drive wheels (26) in the longitudinal direction (L) of said welder (1); Welder (1) according to any one of claims 1 to 5, wherein Claim wherein said sensor (36) is at a non-zero sensor distance (F) from said welding wheel (28), said sensor distance (F) being considered in said longitudinal direction (L) of said welder (1). Item 7. Welder (1) according to any one of items 1 to 6. at least one body (42) defining a volume in which the welding wheel (28) and the at least one pair of drive wheels (24) are at least partially disposed; Welder (1) according to any one of the preceding claims, arranged outside the volume defined by the body (42) of 1). 9. The claim 1-8, wherein the control unit (32) is arranged to reduce the intensity of the current starting from the detection of the point (38) by the sensor (36). Welder (1). 10. Any one of claims 1 to 9, wherein the control unit (32) is arranged to reduce the speed of the welder (1) starting from the detection of the point (38) by the sensor (36). A welder (1) according to any one of claims 1 to 3. The control unit (32) is arranged to synchronize the decrease in intensity of the current with the decrease in speed of the welder (1) starting from the detection of the point (38) by the sensor (36). Welding machine (1) according to claims 9 and 10, wherein 12. Any of claims 1 to 11, wherein the signal transmitted or detected by said sensor (36) forms an angle of incidence (N) between 0 and 45 degrees with respect to the advancing direction (A) of said welder (1). A welder (1) according to claim 1. A predetermined distance (D) from said point (38), calculated between said point (38) and a stop area (44) different from said point (38), is between 20 and 200 mm, preferably Welder (1) according to any one of the preceding claims, wherein said distance (D) is between 50 and 100 mm. A welding method for welding at least two parts to be welded (2) by means of a welding machine (1) according to any one of claims 1 to 13, said welding method comprising: at least one first step in which the drive wheel (24) is rotated to move the welder (1) along the part to be welded (2) in a longitudinal (L) direction in which the and, simultaneously with or after said first step, said welding wheel (28) directing a current therethrough so as to form a weld bead (14) along at least one said part to be welded (2). and at least one third step in which said sensor (36) detects said point (38) on at least one part to be welded (2), said control unit (32) stopping welding of the parts (2) to be welded by the welding wheel (28) at the predetermined distance (D) from the point (38). During said fourth step, said driving member (26) slows down the forward speed of said welding machine (1) starting from the detection of said point (38), said control unit (32) controls said point ( 15. The welding method of claim 14, configured to reduce the intensity of the current starting from the detection of 38). 16. Welding method according to any one of claims 14 to 15, wherein the travel speed of the welding machine (1) upstream of the point (38) in the forward direction (A) is equal to or greater than 4.5 m/min.

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