CN115890043A - Welding machine with automatic stopping function - Google Patents

Abstract

The invention relates to a welding machine (1) for welding at least two parts to be welded (2), the welding machine being configured to be movable along the parts to be welded (2), the welding machine (1) comprising at least one pair of drive wheels and at least two welding wheels for moving the welding machine (1), the welding machine (1) comprising a control unit (32) capable of controlling the current through the welding wheels, the welding machine (1) comprising at least one stopping device for stopping the welding machine (1), the stopping device comprising at least one sensor (36) capable of detecting a point on the parts to be welded (2), the control unit (32) being configured to stop the welding of the parts to be welded (2) by the welding wheels at a predetermined distance from the point.

Description

Welding machine with automatic stopping function

Technical Field

The invention relates to a welding device comprising electrodes in the form of welding wheels for welding together parts to be welded.

Background

Current welding machines comprise a drive wheel and 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. When the welding machine moves, current is supplied to the welding wheel through the current unit, and welding of the parts to be welded is ensured. The present welding machines are controlled by at least one operator who ensures in particular that the welding machine is stopped in the desired position on the parts to be welded.

To speed up the welding of the parts to be welded, the drive wheels of the welder are rotated at a speed higher than the speed of the prior art welders. This therefore makes it possible to increase the welding speed of the parts to be welded. However, one problem encountered with these welders is that the increase in rotational speed of the drive wheels makes it difficult for the operator to control the welder. In particular, an increase in the rotation speed of the driving wheel reduces the stopping tolerance, resulting in inaccuracies in the stopping area of the welding machine with respect to the parts to be welded, so that the weld carried out by said welding machine may be defective. In addition, inaccurate welder stop areas can pose a risk to the operator controlling the welder, especially when the machine is positioned along the parts to be welded placed above the operator.

Disclosure of Invention

The object of the present invention is therefore to overcome the above mentioned problems by proposing a welding machine capable of automatically stopping its welding at least in selected stopping areas on the parts to be welded, in other words, capable of stopping without operator intervention.

The invention therefore relates to a welding machine for welding at least two parts to be welded, which welding machine is configured to be movable along the parts to be welded, which welding machine extends in a main longitudinal extension and comprises: at least one pair of drive wheels for moving the welder relative to the parts to be welded; and at least two welding wheels capable of producing a weld of the parts to be welded by rolling the welding wheels against the at least two parts to be welded; the welding machine comprises a control unit able to control the current passing through the welding wheel, the welding machine being characterized in that it comprises at least one stopping device for stopping the welding machine, the at least one stopping device comprising at least one sensor able to detect a point on the part to be welded, the control unit being configured to stop the welding of the part to be welded by the welding wheel at a predetermined distance from said point.

The welding machine according to the invention can be used, for example, to weld together two raised edges and/or to an anchoring flange of a sealing membrane constituting a wall of a tank for storing and/or transporting cryogenic products such as liquefied natural gas. For example, the welding machine may weld the raised edges of two adjacent parts, referred to as the first part to be welded and the second part to be welded, in order to form a sealing membrane of the wall of the tank for storing and/or transporting the cryogenic product. Alternatively, the welder may weld at least one of the raised edges to the anchoring flange, forming a third part to be welded, the third part to be welded being arranged between two raised edges of two adjacent parts. Thus, note that the part to be welded may be one of a raised edge or an anchor flange.

To this end, the welding machine comprises at least one pair of driving wheels which, by means of driving means, ensure that the welding machine moves along the parts to be welded in a linear welding direction, also referred to as the forward travel 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 effects the welding by contacting at least one of the parts to be welded, which may be at least one of a raised edge or an anchor flange. More specifically, and according to a non-limiting example of the present invention, in performing welding of a part to be welded, the movement of the welder relative to the part to be welded causes the welding wheel to rotate against the part to be welded, and the current supplied by the power supply unit and passing through the welding wheel makes it possible to form a weld bead on the part to be welded.

The stopping means for stopping the welding machine comprise at least one sensor which makes it possible to automatically stop the welding machine when said sensor detects said point on the part to be welded. In other words, once the sensor detects the point on the part to be welded, the welding machine, in particular the control unit, executes a program that gradually stops the welding machine so that at least the welding wheel of the welding machine stops at a predetermined distance from the point.

According to one feature of the invention, the welding machine comprises at least one drive member capable of rotating the drive wheel, the drive member being capable of driving the welding machine at a speed greater than 4.5m/min.

Note that such automatic stop welding of the welder is advantageous in that it makes it possible to use the welder at high speed.

According to one feature of the invention, the sensor is configured to detect at least one change in shape of at least one of the parts to be welded.

The expression "change in shape of at least one of the parts to be welded" refers to, for example, a recess formed in the material of the at least one part to be welded. The recess may for example take the form of a notch. Thus, in this configuration of the point, the sensor may be a mechanical sensor, a laser sensor, a hall effect sensor, an inductive sensor, or an ultrasonic sensor.

According to one feature of the invention, the sensor is configured to detect at least one thickness variation of at least one of the parts to be welded. This thickness variation may take the form of blind or through holes.

In such a configuration of the points formed on at least one of the parts 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 feature of the invention, the sensor is configured to receive a signal from a marker representative of the position of said point.

Note that in this case, this point may be virtual, in other words not actually present on the parts to be welded. According to this example, the marker may be arranged at this point or at a non-zero distance from this point to allow transmission of a signal received by a sensor of a stopping device for stopping the welder, the signal causing a change of state of said sensor upon reception thereof. Note that the label is an indirect means of the sensor detecting this point.

According to one feature of the invention, the welding machine 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 welding machine.

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

In particular, the front and rear ends of the welder are defined, the terms "front" and "rear" being considered relative to the direction in which the welder travels forward along the parts to be welded. It will therefore be appreciated that the sensor is located at the front end of the welder so that during movement of the welder, detection of a point on the part to be welded is anticipated before the welding wheel reaches that point.

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

According to one feature of the invention, the welding machine comprises at least one body defining a volume in which the welding wheel and said at least one pair of driving wheels are at least partially arranged, the sensor being arranged outside the volume defined by the body of the welding machine.

It is particularly noted that the sensor is arranged outside the volume delimited by the body of the welder, so that during the movement of the welder along the part to be welded, the sensor is located between the front end of the welder and the point in the longitudinal direction before detection. Alternatively, the sensor may be carried by an exterior face 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, in particular when said sensor is a sensor laser.

A cooling system for cooling the welding wheel may be provided. This preferably includes an internal circuit that circulates the cooling liquid as close as possible to the welding wheels, the circuit also including a container, a pump and a cooling assembly carried by the trolley.

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

According to one feature of the invention, the control unit is configured to reduce the speed of the welder from the point detected by the sensor.

According to an alternative of the invention, the control unit is configured to stop the rotation of the driving wheel by means of a driving member of the welding machine when the sensor detects the point.

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

According to one feature of the invention, the welding machine comprises at least one human-machine interface placed on a fixed trolley independent of the body of the welding machine. Further, the power supply unit may be carried by the trolley.

According to a feature of the invention, the signal transmitted or detected by the sensor forms an angle of incidence comprised between 0 and 45 degrees with respect to the advancing direction of the welding machine. This feature has the advantage that it enables the sensor to detect the point of the welder before said sensor reaches the point formed on at least one of the parts to be welded.

According to a feature of the invention, the predetermined distance from the point, calculated between the point and the stop zone different from the point, is between 20 and 200mm, preferably between 50 and 100 mm.

In other words, the welding of the parts to be welded is stopped between 20 and 200mm from this point. Thus, the stop zone delimits the welding zone in the area without any weld seam.

The invention also relates to a welding method for welding at least two parts to be welded by means of a welding machine according to any one of the above-mentioned features, the welding method comprising: at least one first step in which the drive wheel is rotated so that the welding machine moves along the part to be welded in the longitudinal direction of forward travel of the welding machine; at least one second step, simultaneous to or subsequent to the first step, in which the welding wheels have an electric current passing through them so that a weld bead is formed along at least one of the parts to be welded; at least one third step in which the sensor detects a point on at least one of the parts to be welded; and at least one fourth step in which the control unit stops the welding of the parts to be welded by the welding wheel at a predetermined distance from this point.

According to one feature of the welding method, during the fourth step, the driving member reduces the forward travel speed of the welding machine starting from the detection of the point, and the control unit is configured to reduce the current intensity starting from the detection of the point.

It is also noted that the reduction of the forward travel speed of the welder and the reduction of the amperage are controlled by the control unit in a synchronized manner. This allows the welder to produce a uniform weld bead even at the end of welding, in other words, up to a welder stop area formed at a predetermined distance from the point.

According to one feature of the welding method, during the first step and the second step, the driving member increases the speed of forward travel of the welder, and the control unit is configured to increase the intensity of the current.

It is also noted that the increase in forward travel speed of the welder and the increase in amperage are controlled by the control unit in a synchronized manner. This allows the welder to produce a uniform bead from the start of the welding of the parts to be welded.

According to one feature of the welding method, the movement speed of the welder is greater than or equal to 4.5m/min, upstream of this point in the forward travel direction.

Drawings

Other features, details and advantages of the invention will become more apparent upon reading the following description with reference to the accompanying drawings, in which:

FIG. 1 is a perspective overall view of a tank for storing and/or transporting cryogenic products, comprising at least two parts to be welded constituting sealing membranes of the tank;

FIG. 2 is a perspective view of a welding machine according to the present invention capable of welding two parts to be welded as shown in FIG. 1;

FIG. 3 is a close-up view of two parts to be welded, at least one of which forms a point, according to a first example of the invention;

FIG. 4 is a close-up view of two parts to be welded, at least one of which forms a spot, according to a second example of the invention;

FIG. 5 is a close-up view of two parts to be welded, at least one of which forms a spot, according to a third example of the invention;

FIG. 6 is a top view of the welder of FIG. 2 showing a sensor detecting a point formed on one of the parts to be welded.

Detailed Description

It is noted, first of all, that although the drawings disclose the invention in detail for the purpose of achieving the invention, these drawings can of course be used to define the invention more clearly where applicable. It is also noted that the figures disclose only embodiments of the invention. Finally, like reference numerals refer to like elements throughout the several views of the drawings.

Fig. 2 shows a welding machine 1 configured to move along at least two parts 2 to be welded. More specifically, as shown in fig. 1, the parts to be welded 2 constitute a sealing membrane 6 of a wall 8 of a tank 10 for storing and/or transporting cryogenic products (for example liquefied natural gas).

The welding machine 1 may, for example, weld the first and second projecting edges 4a, 4b of the adjacent first and second parts to be welded 2a, 2 b. According to another example of the invention, the welding machine may weld at least one of the raised edges 4a, 4b of one of the first part to be welded 2a and/or the second part to be welded 2b to an anchoring flange 12, this anchoring flange 12 forming a third part to be welded 2c visible in fig. 3 to 6, said anchoring flange 12 being arranged between two adjacent raised edges 4. More specifically, the anchoring flange 12 visible in fig. 3 to 6 is fixed to an insulating portion forming part of the wall 8 of the tank 10 and is arranged between two adjacent raised edges 4. Such welding of at least two of the parts to be welded 2a, 2b, 2c forms a weld bead 14 on at least one of the first raised edge 4a and/or the second raised edge 4b, the weld bead 14 extending along the welding axis S, as shown in fig. 3 to 5. The weld bead 14 formed between at least two parts to be welded 2 is able to ensure, in particular, the seal between said parts to be welded 2, thus facilitating the sealing of the membrane 6 constituting the wall 8 of the tank 10 for storing and/or transporting the cryogenic product.

As can be seen in particular in fig. 2 and 6, the welding machine 1 comprises at least one main body 42, which main body 42 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. The body 42 of the welding machine 1 comprises in particular a front end 16 and a rear end 18, which are opposite to each other in the longitudinal direction L of the welding machine 1. It is also noted that the concept of front/rear of the body 42 of the welder 1 refers to the direction a of forward travel of the welder 1 along the part 2 to be welded, parallel to the welding axis S and to the longitudinal direction L of said welder 1. Furthermore, the main body 42 of the welding machine 1 comprises an upper face 20 and a lower face (not shown), the upper face 20 and the lower face being opposite to each other in a vertical direction V of the welding machine 1, the vertical direction V being perpendicular to its longitudinal direction L, the lower face being the face of the main body 42 of the welding machine 1 facing the part 2 to be welded.

As shown in fig. 6, the welding machine 1 according to the invention comprises at least one pair of driving wheels 24 and at least one driving member 26, the driving wheels 24 being intended to move the welding machine 1 relative to the parts 2 to be welded, the driving member 26 being able to rotate said at least one pair of driving wheels 24.

More specifically, the at least one pair of drive wheels 24 is arranged on the lower face of the main body 42 of the welding machine 1 such that it is in contact with at least one of the parts 2 to be welded. Thus, the rotation of the at least one pair of drive wheels 24 by the drive member 26 allows the pair of drive wheels 24 arranged in contact with the part 2 to be welded to move the welder 1 along the part 2 to be welded in a linear translational motion parallel to the forward direction of travel a of the welder 1. More specifically, each of the pair of drive wheels 24 is in contact with one of the raised edges 4 of one of the parts 2 to be welded. According to the illustrated example of the invention, the welder 1 comprises a first pair of driving wheels 24a and a second pair of driving wheels 24b, which are arranged at the front end 16 and the rear end 18, respectively, of the body 42 of the welder 1. It is further noted that the drive wheels 24 of each pair of drive wheels 24a,24b are opposite each other in a transverse direction T of the welding machine 1, which is perpendicular to the longitudinal direction L and the vertical direction V.

As mentioned above, the welder 1 comprises at least one drive member 26, which drive member 26 rotates the drive wheel 24, and may 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 24 moves the welding machine 1 along the parts to be welded at a speed of more than 4.5m/min.

The welding machine 1 according to the invention comprises at least two welding wheels 28, the welding wheels 28 being capable of rolling welding the parts to be welded 2 against at least two of the parts to be welded 2. It is therefore noted that the welding wheel 28 is capable of producing a weld bead 14 along at least two of the parts 2 to be welded, as described above. The welding machine 1 therefore 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 welding wheel 28b arranged in contact with the second raised edge 4b of the second part to be welded 2 b. Furthermore, the welding wheel 28 is arranged between the first pair of driving wheels 24a and the second pair of driving wheels 24b in the longitudinal direction L of the welding machine 1. It is also noted that the welding wheels 28 are arranged on the lower face of the body 42 of the welding machine 1 so that they are in contact with the parts 2 to be welded.

To perform the welding action, during operation of the welder 1, the welding wheels 28 are intended to have an electric current passing through them, which is provided by the power supply unit 30 shown in FIG. 2, and in this case is carried by a trolley 46 of the welder 1, which trolley is distinct from the main body 42 of the welder 1 including the drive wheels 24 and the welding wheels 28, which trolley will be described in detail in the detailed description below. Further, according to an example of the present invention, which is not shown, the power supply unit may be accommodated in a main body of the welder.

According to an example of the invention, the welding wheels 28 may rotate freely with respect to each driving wheel 24. Thus, during the movement of the welding machine 1, the welding wheel 28 rotates by direct contact of said welding wheel 28 against at least one of the parts 2 to be welded. Note that the drive member 26 of the drive wheel 24 does not directly act on the rotation of the 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, in which case the control unit 32 is housed on a trolley 46 and is able to control at least the current through the welding wheels 28.

According to the invention, as shown in fig. 6, the welding machine 1 comprises at least one stopping device 34 for stopping the welding machine 1, the stopping device 34 comprising at least one sensor 36, the sensor 36 being able to detect a point 38 on at least one of the parts 2 to be welded, in other words on at least one of the raised edges 4 or on the anchoring flange 12. For example, the point 38 is formed on at least one of the raised edges 4 of one of the parts 2 to be welded and/or on a visible portion of the anchoring flange 12. The expression "visible part of the anchoring flange 12" means that a part of the latter extends vertically beyond at least one of the raised edges 4. The control unit 32 is configured to stop the welding of the welding wheel 28 to the part to be welded 2 at a predetermined distance D from the point 38, the sensor 36 changing state when said point 38 is detected.

According to a first example of the invention, which can be seen in fig. 3, the point 38 formed on at least one part to be welded 2 is a variation of the shape of at least one part to be welded 2. More specifically, the shape change according to the example of fig. 3 is formed on the raised edges 4 of at least two parts 2 to be welded and on the anchoring flange 12 provided between the raised edges 4. In this case, therefore, this shape change is characterized by recesses in the material formed on each raised edge 4 of at least two parts 2 to be welded and on the anchoring flange 12, so that the recesses in the material are formed facing each other. Thus, in this configuration of point 38, sensor 36 of stop 34 may be a mechanical sensor, a hall effect sensor, an inductive sensor, a laser sensor, or an ultrasonic sensor.

Thus, the mechanical sensor may be a sensor rolling along one of the parts to be welded until it reaches the point formed by the recess in the material in this case, causing the triggering of a switch informing the stop 34 of the position of the welding machine 1 along the part to be welded. In the case where the sensors are laser sensors or ultrasonic sensors, these sensors detect the material constituting one of the parts to be welded at normal times. When these sensors detect this point, and therefore a recess in the material, which in this case represents this point, a change in the state of said sensors is triggered, informing the stop device 34 of the position of the welding machine 1 along the parts to be welded.

According to a second example of the invention, which can be seen in fig. 4, the point 38 formed on the at least one part to be welded 2 is a variation in the thickness of the at least one part to be welded 2. According to one example of the invention, the point 38 is the variation in thickness of one of the raised edges 4 of at least one of the parts to be welded 2, which the sensor 36 faces, this thickness being taken into account along a line parallel to the transverse direction T of the welder 1. According to another example of the invention, the point 38 is a variation of the thickness of the anchoring flange 12, considered along a line parallel to the transverse direction T of the welding machine 1. Such thickness variation may be characterized, for example, by a blind or through hole formed in one of the parts 2 to be welded. In this configuration of the point 38, the sensor 36 may take the form of an inductive sensor, a mechanical sensor, a hall effect sensor or an ultrasonic sensor, which makes it possible to directly detect the thickness variation of at least one of the parts 2 to be welded. According to another example of the invention, the sensor may be a laser sensor making it possible to detect a variation in the distance between the emission and the reception of the laser light at a point 38 formed on at least one of the parts 2 to be welded.

The inductive sensor makes it possible in particular to determine the distance separating the sensor from the material of at least one of the parts 2 to be welded, the reaching of which by the sensor (formed by a thickness change in this case) generates a change in the distance between the sensor and at least one of the parts 2 to be welded, resulting in a change in the state of the sensor.

It should also be noted that, independently of the first and second embodiments of the point 38, the point 38 is formed on at least one of the parts 2 to be welded so that it is different from the weld bead 14 formed by the welding wheel 28. In other words, point 38 is vertically offset from bead 14. This feature makes it possible to limit the risk of producing a poor weld at the point 38, in which case the weld bead 14 will not be formed on the shape or thickness variation of one of the parts 2 to be welded.

According to a third example of the invention, which can be seen in fig. 5, the sensor 36 is configured to receive a signal from a marker 40, which signal is indicative of the position of a point 38 on at least one of the parts 2 to be welded. Note that, therefore, in this configuration, the marks 40 may be arranged in a manner spatially offset from the points 38. As in the case described above, the detection of the mark 40 by the sensor 36 modifies the state of said sensor 36, so as to inform the stopping device 34 of the position of the welding machine 1 with respect to said point 38.

From the above, it will be understood that the sensor 36 according to the invention can send a signal, in particular determine the shape and/or thickness variation of at least one of the parts to be welded 2 representative of the point 38, or can receive a signal, in particular from the mark 40, the reception of the signal sent by the mark 40 being representative of the position of the point 38 and of the welding machine 1 with respect to said point 38.

As mentioned above, the body 42 of the welding machine 1 defines a volume in which the welding wheel 28 and the at least one pair of drive wheels 24 are at least partially disposed. More specifically, according to the example of the invention shown, two welding wheels 28 and two pairs of driving wheels 24 are arranged in the volume delimited by the body 42 of the welding machine 1.

Thus, according to the invention, as shown in fig. 2 and 6, said at least one sensor 36 is arranged outside the volume delimited by the body 42 of the welding machine 1. More specifically, the sensor 36 is arranged at a non-zero sensor distance F from the welding wheel 28, which sensor distance F is considered in the longitudinal direction L of the welding machine 1. In particular, the at least one sensor 36 is arranged at the front end 16 of the body 42 of the welder 1, in such a way as to be upstream of the welding wheel 28 in the forward travel direction a of the welder 1. According to a non-limiting example of the present invention, said at least one sensor 36 is arranged at a non-zero sensor distance F from the welding wheel 28, which is comprised between 150 and 300 mm. The at least one sensor 36 is arranged at a distance of between 0 and 150mm from the front end 16 of the body 42 of the welder 1. This arrangement of the sensor 36 relative to the welding wheel 28 makes it possible in particular to predict the stopping of the welding machine 1 before the welding wheel 28 reaches the point 38.

As described above, the control unit 32 is configured to stop the welding of the parts to be welded 2 by the welding wheel 28 at a predetermined distance D from the point 38, in other words in a stop zone 44 different from the point 38. Preferably, the stop of the welding performed by the welding wheel 28 is effective in a stop zone 44, which stop zone 44 is set at a predetermined distance D between 20 and 200mm from the point 38. Preferably, the predetermined distance D from the point 38 is between 50 and 100 mm. In other words, the control unit 32 is configured such that the welding wheel 28 forms the weld bead 14 up to a stop zone 44 formed at a predetermined distance D from the point 38. It is further noted that the control unit 32 also controls the drive member 26 in such a way that the welding machine 1 stops when the welding machine 1 reaches a stop area 44 which is arranged at a predetermined distance D from the point 38.

To this end, the control unit 32 is configured to reduce the intensity of the current delivered by the power supply unit 30 to the welding wheel 28, starting from the detection of the point 38 by the sensor 36. It is particularly noted that the stopping means 34 is configured to communicate with the control unit 32 such that when its sensor 36 detects a point 38 formed on one of the parts 2 to be welded, the stopping means 34 sends a signal to the control unit 32.

Thus, starting from the detection of the point 38, the control unit 32 reduces the intensity of the current delivered to the welding wheel 28 in a decreasing manner until it reaches zero when the welding machine 1, more specifically the welding wheel 28, is located in the stop region 44 at a predetermined distance D from the point 38. Likewise, the control unit 32 is configured to reduce the speed of the welder 1 starting from the detection of the point 38 by the at least one sensor 36. In other words, the control unit 32 commands the drive member 26 to reduce the rotational speed of the drive wheel 24 so that the speed greater than 4.5m/min from when the sensor 36 detects the point 38 becomes zero speed when the welding wheel 28 reaches the stop zone 44 at the predetermined distance D from the point 38. Thus, according to the invention, the control unit 32 is configured to synchronize the reduction in the intensity of the current delivered to the welding wheel 28 with the reduction in the speed of the welding machine 1, starting from the detection of the point 38 by the sensor 36.

As can be understood from the described features of the welder 1, the position of the stopping device 34 of the welder 1, in particular of its sensor 36, makes it possible to autonomously predict the stopping of the welder 1, in other words without intervention by an operator. In other words, the welding machine 1 itself ensures that its speed of movement and the intensity of the current it delivers to the welding wheel 28 are reduced in the intended manner, so that when the welding machine 1, and in particular the welding wheel 28, reaches the stop zone 44 of the parts to be welded, the speed and intensity have zero values.

According to an example of the invention that can be seen in fig. 6, the at least one sensor 36 receives and/or transmits a signal such that it forms an angle of incidence N between 0 ° and 45 ° with respect to the forward direction of travel a of the welder 1. This signal produces a reading point on the part to be welded until a point 38 is detected, which corresponds to the moment at which the control unit 32 starts to stop the welding of the part to be welded 2 by the welding wheel 28. Naturally, it should be understood that the signals sent and/or received by the sensor 36 are directed towards the front of the welder 1, in other words away from the body 42 of said welder 1.

The advantage of this feature is that it enables the sensor 36 to enhance the anticipation of the detection of the point 38 formed on one of the parts 2 to be welded, said sensor 36 being able to detect said point 38 before it reaches facing said point 38 during the operation of the welder 1. This enhances the anticipation of the stopping device 34 of the stopping of the welding machine 1.

Alternatively, the sensor 36 receives a signal from the mark 40, which corresponds to the moment at which the control unit 32 starts to stop the welding of the component 2 to be welded by the welding wheel 28.

As can be seen in fig. 2, the welding machine 1 comprises at least a trolley 46, distinct from its body 42, for carrying at least the power supply unit 30 for the welding wheel 28, at least one human-machine interface 48 enabling an operator to monitor the progress of the welding of the parts 2 to be welded, the control unit 32, and also at least one cooling system 50 for cooling the welding wheel 28. The cooling system 50 for cooling the welding wheel 28 may, for example, consist of an internal circuit that circulates the cooling liquid as close as possible to the weld, the circuit also comprising a container, a pump and a cooling assembly carried by the trolley. Such a cooling system is particularly able to prevent overheating of the welding wheel 28 during operation of the welding machine 1.

A welding method for welding at least two parts 2 to be welded by means of the above-described welding machine 1 will now be described with reference to fig. 1 to 6.

The welding method comprises at least one first step, in which the drive wheel 24 is rotated by the drive member 26 under the control of the control unit 32, in such a way as to move the welding machine 1 along the parts 2 to be welded in a forward direction of travel a of the welding machine 1 parallel to the longitudinal direction L. During this first step, the control unit 32 is configured to increase the forward travel speed of the welder 1 from zero speed to a speed greater than 4.5m/min. Thus, note that the speed of the welder 1 is increased until it reaches a steady speed of more than 4.5m/min. It is also noted that a movement speed greater than 4.5m/min corresponds to the speed of the welder 1 upstream of the point 38 with respect to the forward travel direction a of the welder 1.

The method also comprises a second step, subsequent or simultaneous to the first step, in which the welding wheels 28 have an electric current passing through them, so as to form a weld bead 14 along the parts 2 to be welded, in particular along the raised edges 4 of at least two parts 2 to be welded. Note that in this second step, the control unit 32 is configured to increase the intensity of the current delivered by the power supply unit 30 to the welding wheel 28. This increase in intensity is achieved by the control unit 32 in a manner synchronized with the increase in the speed of movement of the welder 1. Thus, it is noted that the current intensity through the welding wheel 28 increases in proportion to the increase in the speed of the welding machine 1, so that a uniform weld bead 14 is obtained in the second step.

After the second step, in a third step, the sensor 36 detects a point 38 on at least one of the parts 2 to be welded, either by means of a shape or thickness variation on one of these elements, or by receiving a signal transmitted by the mark 40 representative of the position of the point 38. Thus, in a fourth step, the control unit 32 stops the welding of the part to be welded 2 by the welding wheel 28 at a predetermined distance D from the point 38. Note that during the fourth step, the control unit 32 is configured such that it controls, starting from the detected point 38, the reduction of the forward travel speed of the welder 1 by means of the drive member 26, while reducing the intensity of the current supplied by the power supply unit 30 to the welding wheel 28. It is therefore noted that the reduction of the speed of the welder 1 and the reduction of the welding amperage are effected by the control unit 32 in a synchronized manner.

The advantage of this feature is that it makes it possible to reduce the rotation speed of the drive wheel 24 in proportion to the reduction in the intensity of the current passing through the welding wheel 28, so as to obtain a uniform weld bead 14 between the point 38 and the stop zone 44.

Thus, it is noted that at the end of the fourth step, the welding machine 1 is in the stop zone 44, its driving wheels 24 are in a state of rest, in other words in a state in which its rotation speed is zero, and its welding wheels 28 no longer have current passing through them.

The invention just described, however, is not limited to only the devices and configurations described and illustrated, but is also applicable to any equivalent device or configuration and any combination of such devices or configurations.

Claims (16)

1. A welding machine (1) for welding at least two parts (2) to be welded, said welding machine being configured to be movable along the parts (2) to be welded, said welding machine (1) extending in a longitudinal (L) main direction of extension (P) and comprising: at least one pair of driving wheels (24) for moving the welding machine (1) with respect to the part to be welded (2); and at least two welding wheels (28) capable of producing a weld of the parts to be welded (2) by rolling the welding wheels (28) against the at least two parts to be welded (2); the welding machine (1) comprises a control unit (32) able to control the current passing through the welding wheel (28), the welding machine (1) being characterized by comprising at least one stopping device (34) for stopping the welding machine (1), the stopping device comprising at least one sensor (36) able to detect a point (38) on the part to be welded (2), the control unit (32) being configured to stop the welding of the part to be welded (2) by the welding wheel (28) at a predetermined distance (D) from the point (38).

2. The welding machine (1) according to the preceding claim, comprising at least one driving member (26) able to rotate said driving wheel (24), said driving member (26) being able to drive said welding machine (1) at a speed greater than 4.5m/min.

3. The welding machine (1) according to any of the preceding claims, wherein the sensor (36) is configured to detect at least one shape change of at least one of the parts to be welded (2).

4. The welding machine (1) according to any of the preceding claims, wherein the sensor (36) is configured to detect at least one thickness variation of at least one of the parts to be welded (2).

5. The welding machine (1) according to claim 1 or 2, wherein the sensor (36) is configured to receive a signal from a marker (40) representing the position of the point (38).

6. Welder (1) according to any of the preceding claims, comprising at least two pairs of drive wheels (24, 24a, 24b), the welding wheel (28) being arranged between two pairs of drive wheels (26) in the longitudinal direction (L) of the welder (1).

7. Welder (1) according to any of the previous claims, wherein the sensor (36) is located at a non-zero sensor distance (F) from the welding wheel (28), the sensor distance (F) being considered in a longitudinal direction (L) of the welder (1).

8. Welding machine (1) according to any one of the previous claims, comprising at least one body (42) delimiting a volume in which said welding wheel (28) and said at least one pair of driving wheels (24) are at least partially arranged, said sensor (36) being arranged outside said volume defined by the body (42) of the welding machine (1).

9. Welder (1) according to any of the previous claims, wherein the control unit (32) is configured to reduce the current intensity starting from the detection of the point (38) by the sensor (36).

10. The welding machine (1) according to any one of the preceding claims, wherein the control unit (32) is configured to reduce the speed of the welding machine (1) starting from the detection of the point (38) by the sensor (36).

11. The welder (1) according to claims 9 and 10, wherein the control unit (32) is configured to synchronize the reduction of the current intensity with the reduction of the speed of the welder (1) starting from the detection of the point (38) by the sensor (36).

12. Welder (1) according to any of the previous claims, wherein the signals transmitted or detected by the sensor (36) form an angle of incidence (N) between 0 and 45 degrees with respect to a forward direction of travel (A) of the welder (1).

13. Welder (1) according to any of the previous claims, wherein the predetermined distance (D) from the point (38), calculated between the point (38) and a stop area (44) different from the point (38), is comprised between 20 and 200mm, preferably the predetermined distance (D) is comprised between 50 and 100 mm.

14. Welding method for welding at least two parts (2) to be welded by means of a welder (1) according to any of the preceding claims, the welding method comprising: at least one first step in which the driving wheel (24) is rotated so that the welding machine (1) moves along the part to be welded (2) in a forward direction of travel (A) in the longitudinal direction (L) of the welding machine (1); at least one second step, simultaneous with or subsequent to the first step, in which the welding wheel (28) is provided with an electric current passing through it, so as to form a weld bead (14) along at least one of the parts (2) to be welded; at least one third step in which the sensor (36) detects the point (38) on at least one of the parts to be welded (2); and at least one fourth step, in which the control unit (32) stops the welding of the parts to be welded (2) by the welding wheel (28) at the predetermined distance (D) from the point (38).

15. Welding method according to claim 14, wherein during a fourth step the drive member (26) reduces the forward travel speed of the welding machine (1) starting from the detection of said point (38), and the control unit (32) is configured to reduce the intensity of the current starting from the detection of said point (38).

16. Welding method according to any one of claims 14 to 15, wherein the speed of movement of the welding machine (1) in the forward direction of travel (a) upstream of said point (38) is greater than or equal to 4.5m/min.

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