CN110405304A - Pressure-applying mechanism, stringer and pressure-applying method - Google Patents

Abstract

The application discloses a pressure applying mechanism, a stringer and a pressure applying method. The pressure applying mechanism includes a driving part, a transmission part and a pressure applying part. The driving end of the driving part is connected to the first end of the transmission part through a pin. , the transmission part is installed on the rotating shaft, the second end of the transmission part is overlapped with the first end of the pressing part; the driving end of the driving part drives the first end of the transmission part to make the transmission part rotate around the rotating shaft, and the The second end presses against the first end of the pressing part, so that the pressing part presses the pressed object located at the second end of the pressing part. In this application, when the driving end of the driving part is driven, the first end of the transmission part is pushed to make the transmission part rotate around the rotating shaft, and the second end of the transmission part presses against the first end of the pressing part during the rotation process. Furthermore, the pressing part presses the object to be pressed at the second end of the pressing part, so that the object to be pressed is deformed by the pressure.

Description

Pressure-applying mechanism, stringer and pressure-applying method

technical field

The invention belongs to the technical field of battery component production, and relates to a pressure applying mechanism, a string welding machine and a pressure applying method.

Background technique

In the production process of battery components, there is a step of connecting battery slices in series by using ribbons, that is, two adjacent battery slices are connected together by a set of ribbons, and the first part of the ribbon is welded to the front busbar of the previous battery slice , the second part of the ribbon is welded to the busbar on the back of the last cell.

At present, there is a production method that stacks two adjacent battery sheets. Since the ribbon has a certain thickness, the battery sheet is also thin and brittle. Therefore, after the subsequent battery sheets and ribbons are stacked, welding and battery When string lamination is processed into battery panel components, slope loss is prone to occur between two adjacent battery sheets.

Therefore, it is necessary to add a process of flattening and deforming the welding ribbon and the corresponding structure in the equipment for battery string production, so as to flatten and deform the middle part of the welding ribbon used to connect two adjacent battery pieces in series, and then adapt to the battery. Lamination requirements.

Contents of the invention

The invention provides a pressure-applying mechanism, a stringer and a pressure-applying method. The technical solution is as follows:

In the first aspect, the present application provides a pressure applying mechanism, the pressure applying mechanism includes a driving part, a transmission part and a pressure applying part, the driving end of the driving part is connected to the first end of the transmission part through a pin On the rotating shaft, the second end of the transmission part overlaps with the first end of the pressing part; the driving end of the driving part drives the first end of the transmission part so that the transmission part rotates around the rotating shaft, and the second end of the transmission part The first end of the pressing part presses against, so that the pressing part presses the object to be pressed at the position of the second end of the pressing part.

By connecting the driving end of the driving part with the first end of the transmission part, the transmission part is installed on the rotating shaft, and the second end of the transmission part is lapped on the first end of the pressing part, and the driving end of the driving part is driven , push the first end of the transmission part, so that the transmission part rotates around the shaft, and the second end of the transmission part presses against the first end of the pressure application part during the rotation process, so that the pressure application part moves toward the pressure application part The object to be pressed at the second end of the second end is pressed to realize the effect that the object to be pressed is deformed due to pressure.

Optionally, the pressing mechanism provided by the present application further includes a supporting seat, and the pressing part is located in the guide groove of the supporting seat.

By arranging the support seat with the guide groove, the pressure exerting part is arranged in the guide groove, and the guide groove can guide the pressure exerting part in the process of realizing the pressure exerting action, so as to ensure the precise pressure exerted on the object to be pressed.

Optionally, the pressing mechanism provided by the present application further includes a spring, the spring is sleeved on the pressing part, the first end of the spring leans against the protrusion at the first end of the pressing part, and the second end of the spring leans against the protrusion at the first end of the pressing part. on the support stand.

By covering the pressing part with a spring, and the spring is located between the first end and the second end of the pressing part, the pressing part can be rebounded and reset after the pressing part is finished.

Optionally, a waist-shaped hole is provided on the first end of the transmission part or the driving end of the driving part, and the pin shaft is accommodated in the waist-shaped hole, and the driving end of the driving part passes through the pin shaft and the waist-shaped hole and the first end of the transmission part. end connection.

By setting a waist-shaped hole for accommodating the pin shaft on the first end of the transmission part or the driving end of the driving part, when the driving end of the driving part drives the first end of the transmission part, the transmission part can be wound around The rotation stroke of the rotating shaft realizes the rotation of the transmission part.

Optionally, the pressure applying mechanism provided by the present application also includes a base, the base is used to carry the object to be pressed, the object to be pressed is a long strip object, and the base is provided with a groove for accommodating the long strip object .

By providing a base with a groove for accommodating the object to be pressed to fix the object to be pressed, the pressing effect is ensured.

Optionally, the groove includes a pressure application area and a non-pressure application area, the pressure application area is opposite to the second end of the pressure application part, and the height of the pressure application area is higher than that of the non-pressure application area.

By setting the height of the groove to be different, a bending effect can be produced when pressing the pressed object.

Optionally, the pressurized area transitions to the non-pressurized area through the downslope.

By transitioning the pressure-applying area and the non-pressure-applying area through the downhill surface, the bending effect of the object to be pressed can be met when it is pressed to form a bend, and the bending effect of the object to be pressed can be reduced after being pressed and bent. probability of being damaged.

Optionally, the side of the second end of the pressing part away from the downhill surface is recessed inwardly.

By arranging the second end of the pressing part as an inner recess, when the object to be pressed is bent by pressure, the part opposite to the second end of the pressing part can be tilted to meet the bending of the object to be pressed. Require.

Optionally, the pressed object is a welding ribbon.

In the second aspect, the present application also provides a stringer, the stringer includes the pressing mechanism provided in the first aspect and various optional modes of the first aspect, the stringer also includes a ribbon supply Mechanism, cell feeding mechanism, welding mechanism, wherein: the ribbon feeding mechanism provides the ribbon to the second end position of the pressure applying part of the pressure applying mechanism, and the pressure applying mechanism applies pressure to deform the ribbon, and the battery sheet supply The material mechanism and the ribbon feeding mechanism work together to stack the battery slices and the pressed ribbons, and the welding mechanism heats the stacked ribbons and battery slices to weld the ribbons to the corresponding batteries on-chip to form battery strings.

By setting the pressure applying mechanism, the deformation of the welding ribbon can be realized, and through the cooperation of the welding ribbon feeding mechanism and the cell feeding mechanism, the sequential stacking of the deformed welding ribbon and the battery sheet can be realized, and the welding mechanism can be used to realize the The deformed ribbon is welded to the battery sheet to complete the welding of the battery string, which can reduce the probability of damage when the battery sheet is stacked while achieving the effect of lamination between adjacent battery sheets.

In a third aspect, the present application also provides a method for applying pressure, which includes:

The controller controls the driving end of the driving part to drive at the first predetermined timing according to the way the ribbon is connected to the cell;

The driving end of the driving part drives the first end of the transmission part, and the transmission part rotates around the rotating shaft. The welding ribbon is pressed;

The controller controls the driving part of the driving part to reset at the second predetermined timing, the driving end drives the transmission part to reset, and the pressing part retreats to complete a pressure shaping of the welding strip.

The drive and reset of the driving part is controlled by the controller. When the driving end of the driving part is driven, the transmission part is driven, and the transmission part is used to apply force to the pressing part, thereby completing the pressing of the object to be pressed and realizing the pressure The effect of deforming an object due to pressure.

It is to be understood that both the foregoing general description and the following detailed description are exemplary only and are not restrictive of the invention.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description serve to explain the principles of the invention.

Fig. 1 is a structural schematic diagram of a pressure applying mechanism provided by an embodiment of the present application;

Fig. 2 is a schematic cross-sectional view of a pressure applying mechanism provided by an embodiment of the present application;

Fig. 3 is a schematic diagram of a base provided by an embodiment of the present application.

Wherein, the reference signs are as follows:

10. Driving part; 11. Driving end; 20. Transmission part; 21. The first end of the transmission part; 211. Waist-shaped hole; 22. Rotating shaft; 23. The second end of the transmission part; 30. Pressure applying part; 31 , the first end of the pressing part; 32, the second end of the pressing part; 40, the pin shaft; 50, the object to be pressed; 60, the supporting seat; 61, the supporting surface; 70, the spring; 80, the base; 81. Groove; 811. Pressure application area; 812. Non-pressure application area.

Detailed ways

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with aspects of the invention as recited in the appended claims.

In the production of battery components, in order to increase the production capacity of the battery per unit area, it is usually used to reduce the coverage area of the front side of the battery or to reduce the gap between the batteries. For the battery assembly formed by connecting the battery slices with a ribbon, since the ribbon has a certain thickness, and the battery slice is relatively thin and fragile, when the ribbon connects two battery slices, there will be a certain gap between the two battery slices. This will reduce the production capacity of the cells per unit area. Therefore, in order to solve this problem, two adjacent cells can be stacked, but the welding strips between the stacked parts need to be crushed and deformed. Aiming at the flattening and deformation of the welding strip, the present application provides a pressing mechanism, the specific structure of which can be seen in Fig. 1-Fig. 3 .

Fig. 1 is a schematic structural view of a pressure applying mechanism provided by an embodiment of the present application. The pressure applying mechanism provided by the present application includes a driving part 10, a transmission part 20 and a pressing part 30. The driving end 11 of the driving part 10 connects with the pin shaft 40. The first end 21 of the transmission part is connected by transmission, the transmission part 20 is installed on the rotating shaft 22, the second end 23 of the transmission part overlaps with the first end 31 of the pressing part; the driving end 11 of the driving part 10 drives the second end of the transmission part One end 21, so that the transmission part 20 rotates around the rotating shaft 22, the second end 23 of the transmission part is pressed against the first end 31 of the pressing part, so that the pressing part 30 is positioned at the second end 32 of the pressing part The object to be pressed 50 at the position applies pressure.

In a possible implementation manner, the position where the transmission part 20 is installed on the rotating shaft 22 may be close to the second end 23 of the transmission part, or close to the first end 21 of the transmission part, or located in the middle of the transmission part 20 .

Optionally, the positions of the first end 21 of the transmission part and the second end 23 of the transmission part relative to the installation shaft 22 may form bends in the same direction. For example, the transmission part 20 may be a U-shaped structure or a structure similar to a U-shaped structure.

When the second end 23 of the transmission part overlaps with the first end 31 of the pressing part, it can generally be understood that the second end 23 of the transmission part is opposite to the first end 31 of the pressing part, and there may be no direct mechanical connection.

The driving unit 10 mentioned here can be a driving mechanism such as an air cylinder or an electric cylinder. The driving end 11 of the driving part 10 can be a component driven by the driver of the driving part 10. Taking the driving part 10 as an example of an air cylinder, the driving end 11 of the driving part 10 can be understood as a telescopic rod of the air cylinder.

In practical application, in order to connect the driving end 11 of the driving part 10 with the first end 21 of the transmission part through the pin shaft 40, some structures can be made on the driving end 11 of the driving part 10 or the first end 21 of the transmission part. Designed to facilitate the installation of the pin 40.

In a possible implementation, in order to enable the transmission part 20 to rotate around the rotating shaft 22 driven by the driving part 10, a waist-shaped hole 211 may also be provided at the first end 21 of the transmission part, as shown in FIG. 2 , the pin shaft 40 is accommodated in the waist-shaped hole 211 , and the driving end 11 of the driving part 10 is connected to the first end 21 of the transmission part through the pin shaft 40 and the waist-shaped hole 211 . Apparently, a waist-shaped hole may also be provided on the driving end 11 of the driving part 10 , so that the first end 21 of the transmission part is connected to the driving end 11 of the driving part 10 through the pin shaft 40 and the waist-shaped hole.

In this way, by setting the waist-shaped hole 211 for accommodating the pin shaft 40 at the first end 21 of the transmission part, the driving end 11 of the driving part 10 can be used to drive the first end 21 of the transmission part, so that the transmission part 20 can The rotation stroke around the rotating shaft 22 realizes the rotation of the transmission part 20 .

Generally speaking, in order to ensure that the pressing direction of the pressing part 30 is accurate, the pressing mechanism provided in the present application may further include a support seat 60 , and the pressing part 30 is located in a guide groove of the support seat 60 . By setting the support seat 60 with a guide groove, the pressure exerting part 30 is arranged in the guide groove, and the guide groove can guide the pressure exerting part 30 in the process of realizing the pressure applying action, so as to ensure precise pressure on the pressed object 50 .

Since the transmission part 20 and the pressing part 30 are overlapped, in order to ensure that the pressing part 30 can return to its original position after pressing the pressed object 50, the pressing mechanism provided by the present application can also include a spring 70. 70 is sleeved on the pressing part 30, the first end of the spring 70 leans against the protrusion of the first end 31 of the pressing part, and the second end of the spring 70 leans against the support seat 60, as shown in Figure 2 Show.

In practical applications, the support surface 61 of the support base 60 for supporting the spring 70 is located between the second end 23 of the transmission part and the pressed object 50, so that when the press part 30 is pressed downward, The spring 70 will be compressed as the first end 31 of the pressing part moves toward the above-mentioned supporting surface 61; after the pressing part 30 is finished applying pressure, and the transmission part 20 is reset by the drive part 10, the spring 70 will, due to its own elastic force, Push the protrusion of the first end 31 of the pressing part, and then drive the pressing part 30 to reset.

In this way, the pressure applying mechanism provided by the present application can place a spring 70 on the pressure applying part 30, and the spring 70 is located between the first end 31 of the pressure applying part and the second end 32 of the pressure applying part. 30 After the pressing is finished, the pressing part 30 is rebounded and reset.

The pressing mechanism provided by the present application may also include a base 80, please refer to FIG. 3, which is a schematic diagram of a base provided by an embodiment of the present application. The pressing object 50 is a strip-shaped object, such as a welding ribbon, a bus bar, etc., and a groove 81 for accommodating the strip-shaped object is provided on the base 80 .

The pressing mechanism provided in the present application is provided with a base 80 having a groove 81 for accommodating the object 50 to be pressed, so as to fix the object to be pressed, so as to ensure the pressing effect.

Optionally, the groove 81 may include a pressing area 811 and a non-pressing area 812 , the pressing area 811 is opposite to the second end of the pressing portion 30 , and the height of the pressing area 811 is higher than that of the non-pressing area 812 . Further, in order to realize the pressure exerted by the second end of the pressing part 30 on the pressed object 50 in the groove 81, the shape of the pressing area 811 in the groove 81 usually matches the shape of the second end of the pressing part 30, In order to accommodate the second end 32 of the pressing part.

In this way, by setting the height of the groove 81 to be different, a bending effect can be generated when pressing the object 50 to be pressed.

Further, the pressurized area 811 transitions to the non-pressurized area 812 through a downward slope. By transitioning the pressing area 811 and the non-pressing area 812 through a downward slope, the bending effect of the pressed object 50 can meet the requirements when it is pressed to form a bend, and the pressure on the pressed object 50 can be reduced. The probability of being damaged after bending.

In practical applications, according to the pressure deformation requirements of the object 50 to be pressed, the side of the second end 32 of the pressure applying portion away from the downhill surface can be recessed inward, as shown in FIG. 2 . By arranging the second end 32 of the pressing part to be inwardly recessed, when the pressed object 50 is pressed and bent, the part opposite to the second end 32 of the pressing part can be tilted to meet the requirements of the pressed object. The bending requirements of the pressed object 50.

Optionally, both ends of the groove 81 may be designed to open outwards, as shown in FIG. 3 , to facilitate the introduction and export of the pressed object 50 .

To sum up, in the pressure applying mechanism provided by the present application, the driving end of the driving part is connected with the first end of the transmission part, and the transmission part is installed on the rotating shaft, so that the second end of the transmission part overlaps the pressure applying part. On the first end, when the driving end of the driving part is driven, the first end of the transmission part is pushed, so that the transmission part rotates around the shaft, and the second end of the transmission part moves toward the first end of the pressing part during the rotation process. Pressing against, and then making the pressure exerting part exert pressure on the object to be pressed at the second end of the pressure exerting part, so as to achieve the effect that the object to be pressed is deformed by the pressure.

The present application also provides a stringer. The stringer includes a pressure applying mechanism. The stringer may also include a ribbon feeding mechanism, a cell feeding mechanism, and a welding mechanism. Wherein, the pressure applying mechanism is the pressure applying mechanism shown in Fig. 1-Fig. 3, for details, please refer to the description of Fig. 1-Fig.

Here, the ribbon feeding mechanism can be used to supply the ribbon to the second end of the pressing part of the pressing mechanism. Usually, the ribbon provided by the ribbon feeding mechanism can be a flat ribbon or a cylindrical ribbon. Generally, the ribbon feeding mechanism may include a ribbon reel, a ribbon pulling device, a cutter, a ribbon feeding device, etc., a ribbon is installed on the ribbon reel, and the ribbon pulling device pulls the welding ribbon from the ribbon reel. Ribbon, the cutter set at the predetermined position cuts the ribbon drawn by the ribbon pulling device to form a ribbon of predetermined length, and the ribbon feeding device feeds the cut ribbon to the pressure of the pressure mechanism at the second end position of the section.

The pressing mechanism applies pressure to deform the welding ribbon provided by the welding ribbon feeding mechanism.

The cell feeding mechanism and the ribbon feeding mechanism work together to stack the cells and the ribbons after pressure. The stacking process here is carried out according to the order of the cells and ribbons required for the battery string welding overlay processing. The cell feeding mechanism may include a magazine and a battery feeding device, the magazine is used to carry the battery, the battery feeding device sucks the battery from the magazine, and feeds the battery to the conveying device. In practical application, the cell sheet feeding mechanism and the ribbon feeding mechanism cooperate together to stack the cell sheet and the solder ribbon after pressure is applied to the conveying device.

The welding mechanism heats the stacked ribbons and battery sheets to weld the ribbons to the corresponding battery sheets to form a battery string. The heating here can be infrared heating.

To sum up, the stringer provided by this application realizes the pressure deformation of the ribbon by setting the pressure applying mechanism, and realizes the deformation of the ribbon and the welded ribbon through the cooperation of the ribbon feeding mechanism and the cell feeding mechanism. The cells are stacked in order, and the deformed ribbon is welded to the cells through the welding mechanism, and then the welding of the battery strings is completed. While the effect of stacking adjacent cells can be achieved, the stacking of cells is reduced. Probability of chip damage.

When using the pressure applying mechanism provided by the application to apply pressure to the welding strip, the application also provides a method for applying pressure, which can be applied to the pressure applying mechanism shown in Figures 1-3, or by The pressing mechanism shown in Fig. 1-Fig. 3 is implemented. The method of applying pressure may include the steps of:

S1. The controller controls the driving of the driving end of the driving part at the first predetermined timing according to the way the ribbon is connected to the cell;

In practical applications, in order to realize the control of the driving timing of the driving end of the driving part, the pressure applying mechanism may include a controller, or be electrically connected with the controller, or connected with the controller in communication, and the controller is preset with a code to control The processing module of the controller executes these codes to control the driving timing of the driving part.

When the controller controls the driving end of the driving part to extend out at the first predetermined timing according to the way the ribbon is connected to the battery slice, the driving end of the driving part drives the first end of the transmission part, that is, step S2 is executed.

S2. The driving end of the driving part drives the first end of the transmission part, and the transmission part rotates around the rotating shaft. The welding ribbon at the position is pressed;

S3. The controller controls the driving end of the driving part to reset at the second predetermined timing, and the driving end drives the transmission part to reset, and the pressing part retreats to complete a pressure shaping on the welding strip.

When the controller controls the driving end of the driving part to retract at the second predetermined timing according to the way the welding ribbon is connected to the battery, the driving end of the driving part resets, and the driving end drives the transmission part to reset, and the pressing part retreats to complete the bonding of the welding ribbon. A pressure shaping. Then continue to perform the step of applying pressure to the next pressure application position of the welding ribbon or the next pressure application position of the welding ribbon, so as to realize the function of automatically applying pressure and deforming the continuous feeding of multiple welding ribbons.

Obviously, in practical applications, the pressure applying mechanism can also apply pressure to deform different positions of the same welding ribbon, and only need to press one position of the welding ribbon to drive the welding ribbon to move, so that the next welding ribbon needs to be applied. The pressing part may be the second end of the pressing part, so that the second end of the pressing part can press and deform the next part of the welding ribbon that needs to be used.

In summary, the pressure application method provided by this application controls the driving and reset of the driving part through the controller, and when the driving end of the driving part is driven, the transmission part is driven to apply force to the pressure application part by the transmission part, and then completes Apply pressure to the object to be pressed to achieve the effect that the object to be pressed is deformed by the pressure.

Other embodiments of the invention will be readily apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present invention. These modifications, uses or adaptations follow the general principles of the present invention and include common knowledge or conventional technical means in the technical field not described in the present invention . The specification and examples are to be considered exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It should be understood that the present invention is not limited to the precise constructions which have been described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (10)

1. a kind of pressure exerting arrangement, which is characterized in that the pressure exerting arrangement includes driving portion, driving section and pressure unit, the driving The driving end in portion is sequentially connected by the first end of pin shaft and the driving section, and the driving section is mounted in shaft, the biography The second end in dynamic portion and the first end of the pressure unit overlap；

The driving end of the driving portion drives the first end of the driving section, so that the driving section is rotated around the shaft, The second end of the driving section is pressed against to the first end of the pressure unit, so that the pressure unit is to positioned at the pressure unit second Object pressure is pressed at end position.

2. pressure exerting arrangement according to claim 1, which is characterized in that the pressure exerting arrangement further includes support base, described to apply Splenium is located in the guide groove of the support base.

3. pressure exerting arrangement according to claim 2, which is characterized in that the pressure exerting arrangement further includes spring, the spring It is sheathed in the pressure unit, the first end of the spring is resisted against in the protrusion of the first end of the pressure unit, the spring Second end be resisted against on the support base.

4. pressure exerting arrangement according to claim 1, which is characterized in that the first end of the driving section or the driving portion Driving is provided with waist-shaped hole on end, and the pin shaft is contained in the waist-shaped hole, and the driving end of the driving portion passes through the pin Axis and the waist-shaped hole are connect with the first end of the driving section.

5. pressure exerting arrangement according to claim 1, which is characterized in that the pressure exerting arrangement further includes pedestal, the pedestal For carry it is described be pressed object, the object that is pressed is strip object, is provided on the pedestal for accommodating The groove of strip object is stated, the groove includes press region and non-pressure region, the pressure region and the pressure unit Second end is opposite, and the height in the pressure region is higher than the non-pressure region.

6. pressure exerting arrangement according to claim 5, which is characterized in that the pressure region is transitted to described by Caused by Sloping Surfaces Non- pressure region.

7. pressure exerting arrangement according to claim 5 or 6, which is characterized in that the pressure unit second end is far from the descending The side in face is recessed inwardly setting.

8. pressure exerting arrangement according to claim 1, which is characterized in that the object that is pressed is welding.

9. a kind of string welding machine, which is characterized in that the string welding machine includes such as pressure exerting arrangement described in any one of claims 1-8, The string welding machine further includes welding feeding machanism, cell piece feeding machanism, welding mechanism, in which: the welding feeding machanism to Welding is provided at second end position of the pressure unit of the pressure exerting arrangement, the pressure exerting arrangement carries out pressure change to the welding Shape, the cell piece feeding machanism and the welding feeding machanism cooperate jointly folds the welding after cell piece and pressure Put processing, the welding mechanism heats the welding that stacks that treated and cell piece, and welding is welded in corresponding electricity Pond on piece forms battery strings.

10. a kind of pressure method, which is characterized in that the pressure method includes:

Controller connects the mode of cell piece according to welding, and it is dynamic to carry out driving at the driving end of the first predetermined opportunity control driving portion Make；

The first end of the driving end driving driving section of the driving portion, the driving section are rotated around shaft, the driving section Second end is pressed against to the first end of pressure unit, and the pressure unit is applied to the welding being located at second end position of pressure unit Pressure；

The controller is resetted in the driving portion that the second predetermined opportunity controlled the driving portion, and the driving end drives the transmission Portion resets, and the pressure unit retracts, and completes the primary pressure shaping to welding.