KR20240109398A - Ultrasonic welding determination system and ultrasonic welding determination method using the system - Google Patents

Abstract

The present invention provides an ultrasonic welding device, a vibration sensor attached to the ultrasonic welding device to detect vibration generated from the ultrasonic welding device, a visual sensor for detecting movement of the ultrasonic welding device, and data measured by the vibration sensor and the visual sensor. It relates to an ultrasonic welding determination system characterized by including a control unit that collects and analyzes and a method of determining ultrasonic welding quality using the system.

Description

Ultrasonic welding determination system and ultrasonic welding determination method using the system {ULTRASONIC WELDING DETERMINATION SYSTEM AND ULTRASONIC WELDING DETERMINATION METHOD USING THE SYSTEM}

The present invention relates to an ultrasonic welding discrimination system and an ultrasonic welding discrimination method using the system, by comparing data measured from a vibration sensor that detects vibration generated in an ultrasonic welding device and a visual sensor that detects movement of the ultrasonic welding device. It is characterized by determining welding quality.

A pouch-type secondary battery includes an electrode assembly, an electrode tab, an electrode lead, and a pouch case.

Here, the electrode assembly Ea is formed in a structure in which a plurality of electrodes and separators positioned between the electrodes are alternately stacked, as shown in FIG. 1 .

In addition, it is natural that, in addition to the commonly used liquid electrolyte, the electrolyte may be replaced with a solid electrolyte or a semi-solid electrolyte in the form of a gel that is intermediate between a liquid and a solid by adding additives to the solid electrolyte.

Next, the electrode tab Et includes a plurality of anode tabs and a plurality of cathode tabs protruding and extending from the plurality of anodes and the plurality of cathodes, respectively, and the plurality of anode tabs and the plurality of cathode tabs are respectively stacked and used by a method such as welding. are combined with

As for the electrode tab Et, both the anode tab and the cathode tab may protrude in the same direction of the electrode assembly Ea, or the anode tab and the cathode tab may protrude in different directions.

Meanwhile, the electrode tab (Et) is laminated at the opposite end connected to the electrode and joined by welding, and the electrode lead (El) is joined to the electrode tab (Et) formed as above by a method such as welding and extends outside the pouch case. becomes an electrode terminal.

Various known methods such as ultrasonic welding and laser welding can be used to weld the electrode lead (El) and the electrode tab (Et).

The electrode assembly (Ea) of this pouch-type secondary battery is a form in which a plurality of electrodes and separators are alternately stacked, and a bundle of electrode tabs (Et) protruding from the plurality of electrodes are stacked at the opposite end connected to the electrode, and are formed by welding. It is joined.

Additionally, the electrode lead El is joined to the stacked electrode tab Et by welding to form a terminal.

For such welding, methods such as laser welding and ultrasonic welding are used.

Among them, laser welding is a method in which a laser beam is irradiated to a welded area, the welded area is melted by the energy of the laser beam, and then the melted part is solidified and joined.

Meanwhile, ultrasonic welding is a method of joining by applying ultrasonic vibration while applying a load to the welded area to generate vibrational frictional heat. Its application range is wide, covering not only metals but also dissimilar materials including non-metals.

In addition, ultrasonic welding has the advantage of being a welding method without high-temperature fusion or addition of third metals compared to conventional welding methods, and is therefore widely used in the secondary battery manufacturing process.

In general, an ultrasonic welding device used for ultrasonic welding performs ultrasonic welding by arranging an anvil that supports an object to be welded and a horn that applies ultrasonic vibration. At this time, after welding is completed, the horn and anvil are separated from the welding object, but there is a problem that the welding object is stuck to the horn, etc. and cannot be separated.

In order to solve the sticking problem, conventional ultrasonic welding devices are equipped with an after burst function that generates vibration in the horn to separate the welding object when the horn is separated from the welding object.

However, in the related art, when monitoring the after burst function, the after burst setup point is set depending on the engineer's experience, so there is a problem that the accuracy of the after burst is reduced and as a result, the welding quality deteriorates.

Korean Patent Publication No. 10-2022-0053314

Therefore, the present invention was created to solve the above problems, and its purpose is to provide a weld discrimination system and a weld discrimination method that can improve the quality of ultrasonic welding.

Other objects and advantages of the present invention can be understood from the following description and will be more clearly understood by practicing the present invention. Additionally, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the patent claims.

According to the present invention, an ultrasonic welding device; A vibration sensor attached to the ultrasonic welding device and detecting vibration generated from the ultrasonic welding device; a visual sensor that detects movement of the ultrasonic welding device; and a control unit that collects and analyzes data measured by the vibration sensor and vision sensor. It provides an ultrasonic welding discrimination system comprising:

The ultrasonic welding device includes a vibrating unit that contacts an object to be welded and performs ultrasonic welding; and a support portion supporting the welding object contacted by the vibrating portion. may include.

The vibration sensor may be installed on the vibration unit and the support unit, respectively, and the visual sensor may be installed at a predetermined distance from the ultrasonic welding device.

The vibration unit includes a converter unit that generates vibration; and a horn coupled to the converter unit to apply ultrasonic vibration directly to the welding object. It includes: an anvil supporting the opposite side of the welding object in contact with the horn; may include.

The vibration sensor may be installed on the horn and anvil, respectively.

The ultrasonic welding device includes a converter supporter that fixes and supports the converter unit; and an anvil support supporting the anvil; It may further include that the vibration sensor may be installed on any one of the horn and the converter support, and may be installed on any one of the anvil and the anvil support.

At least one of the horn and the anvil is capable of reciprocating movement so as to come into contact with each other, and the ultrasonic welding can be performed with the horn, the object to be welded, and the anvil all in close contact.

The visual sensor detects movement of at least one of the horn and anvil,

The control unit may evaluate the quality of welding based on data measured by the vision sensor and the vibration sensor.

The vibration sensor may be an accelerometer sensor.

The vision sensor may be a laser displacement sensor.

According to the present invention, preparing an object to be welded; Preparing the ultrasonic welding device above; Setting up the vibration sensor and vision sensor; Welding the object by applying ultrasonic vibration to the object to be welded using the ultrasonic welding device; and analyzing data measured by the vibration sensor and the vision sensor using the control unit. It includes: a vibrating unit that contacts an object to be welded and performs ultrasonic welding; and a support portion supporting the welding object contacted by the vibrating portion. It includes, wherein the welding step includes: a starting step in which welding is performed by contacting the vibrating part and the supporting part with both sides of the object to be welded; and an ending step of separating the vibrating part in contact with one side of the welding object; It provides an ultrasonic welding discrimination method comprising:

In the termination step, the vibrating unit may separate from the welding object and vibrate at the same time to separate the welding object.

The vibration sensor detects vibration of the vibration unit and the support unit, the visual sensor detects movement of the vibration unit, and in the step of analyzing the data, the control unit detects the vibration of the vibration sensor and the visual sensor in the end step. Welding quality can be determined by comparing measured data.

In the step of analyzing the data, the control unit may determine welding quality by comparing the sequential relationship between the movement of the vibrating part measured by the visual sensor and the vibration of the vibrating part measured by the vibration sensor.

The control unit may determine that the welding quality is good when the movement of the vibrating unit in the end step precedes the vibration of the vibrating unit.

According to the present invention, welding efficiency can be improved by accurately determining the quality of ultrasonic welding.

Figure 1 shows the contact state of a conventional electrode assembly and electrode leads.
Figure 2 shows the ultrasonic welding discrimination system of the present invention.
Figure 3 shows the operating process of the horn and anvil of Figure 2.
Figure 4 shows a flow chart of the ultrasonic welding determination method of the present invention.
Figure 5 shows a data graph showing a good welding state.
Figure 6 shows a data graph showing a welding defect state.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately define the concept of terms in order to explain his or her invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle of definability.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so they can be replaced at the time of filing the present application. It should be understood that various equivalents and variations may exist.

Additionally, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Since the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically shown for clearer description. . Therefore, the size or ratio of each component does not entirely reflect the actual size or ratio.

The present invention relates to an ultrasonic welding discrimination system and an ultrasonic welding discrimination method using the system, by comparing data measured by a vibration sensor that detects vibration generated in an ultrasonic welding device and a visual sensor that detects movement of the ultrasonic welding device. It is characterized by determining welding quality.

(Ultrasonic welding discrimination system)

Figure 2 shows the ultrasonic welding discrimination system of the present invention.

The ultrasonic welding discrimination system includes an ultrasonic welding device, a vibration sensor (Sen1), a vision sensor (Sen2), and a control unit.

The ultrasonic welding apparatus includes a vibrating part 110 that contacts the welding object W to perform ultrasonic welding, and a support part 120 supporting the welding object W contacted by the vibrating part 110.

The vibration unit 110 and the support unit 120 may be fixed and supported on a die, etc., as shown in FIG. 2, and their positions may be moved according to the movement of the die.

The type of the welding object W is not particularly limited, and may be anything that includes a metal material and is separated from each other. For example, the welding object W may be an electrode lead El and an electrode tab Et, or a bus bar and an electrode lead El.

The vibration unit 110 includes a converter unit 110b and a horn 110a, as shown in FIG. 2.

The converter unit 110b serves to generate ultrasonic vibration from supplied electric energy using the piezoelectric effect of the piezoelectric element.

The horn 110a is combined with the converter unit 110b to apply ultrasonic vibration directly to the welding object W. That is, the horn 110a serves to apply vibration transmitted from the converter unit 110b to the welding object W and simultaneously pressurizes the welding object W to perform welding.

The vibration unit 110 further includes a converter support 110c that connects the horn 110a and the converter unit 110b and fixes and supports the converter unit 110b.

The vibrating unit 110 may be provided to move back and forth in the horizontal and vertical directions. Accordingly, the vibrating part 110 moves so that the horn 110a contacts and presses the welding object W prior to welding.

The support portion 120 includes an anvil 120a as shown in FIG. 2.

The anvil 120a serves to support the opposite side of the welding object W in contact with the horn 110a.

The anvil 120a cannot cause vibration on its own. However, the anvil 120a may be vibrated by the vibration of the horn 110a while it is in indirect contact with the horn 110a and the welding object W.

The support portion 120 is coupled to the anvil 120a and includes an anvil support 120b supporting the anvil 120a.

The support unit 120, like the vibrating unit 110, may be provided to move back and forth in the horizontal and vertical directions. Accordingly, the support portion 120 moves so that the anvil 120a can contact and support the rear surface of the welding object W.

Welding using the ultrasonic welding device is performed with the horn 110a, the welding object W, and the anvil 120a all in close contact, and at least one of the horn 110a and the anvil 120a is used in the welding. It does not proceed when separated from the object (W).

Figure 3 simply shows the process of welding the welding object W by operating the horn 110a included in the vibration unit 110 and the anvil 120a included in the support unit 120.

First, the horn 110a and the anvil 120a move so as to contact one surface of the welding object W and the other surface opposite to the one surface, respectively, as shown in FIG. 3. That is, the anvil (120a) supports the other side of the welding object (W), and the horn (110a) moves toward one side of the welding object (W) supported by the anvil (120a) to form the welding object ( Move to pressurize W).

Thereafter, ultrasonic welding is performed by the vibration of the horn 110a, and after welding of the welding object W is completed, the horn 110a retreats and moves away from the welding object W.

Afterwards, the horn 110a further vibrates so that the welded object W falls off the surface.

The vibration sensor (Sen1) is attached to the ultrasonic welding device and serves to detect vibration generated in the ultrasonic welding device.

The vibration sensor Sen1 is installed on the vibration unit 110 and the support unit 120, respectively, as shown in FIG. 2, and measures vibration occurring in the vibration unit 110 and the support unit 120 in real time.

Specifically, the vibration sensor Sen1 may be installed on any one of the horn 110a and the converter support 110c, and may simultaneously be installed on any one of the anvil 120a and the anvil support 120b.

The vibration sensor Sen1 is preferably an accelerometer sensor.

The accelerometer sensor is a sensor that measures vibration or movement acceleration of a structure, and generally uses a piezoelectric accelerometer. However, the present invention is not limited to this and any accelerometer sensor can be used as long as it can precisely measure ultrasonic vibration, etc.

The visual sensor (Sen2) serves to detect movement of the ultrasonic welding device.

The visual sensor Sen2 is not attached to the ultrasonic welding device as shown in FIG. 2, but is installed at a predetermined distance from the ultrasonic welding device.

The visual sensor Sen2 may detect movement of at least one of the horn 110a and the anvil 120a.

The vision sensor (Sen2) is preferably a laser displacement sensor.

The laser displacement sensor performs measurement by applying triangulation, and detects the amount of displacement of a moving object by combining a light projection element and a linear image sensor.

The ultrasonic welding determination system of the present invention is characterized by determining the quality of welding based on data measured by the vibration sensor (Sen1) and the vision sensor (Sen2).

The control unit determines the quality of welding by collecting and analyzing data measured by the vibration sensor (Sen1) and the vision sensor (Sen2).

Hereinafter, the determination of welding quality in the control unit will be described in more detail in the ultrasonic welding determination method to be described later.

(Ultrasonic welding determination method)

Figure 4 shows a flow chart of the ultrasonic welding determination method of the present invention.

The ultrasonic welding determination method includes a welding object preparation step (S1), an ultrasonic welding device preparation step (S2), a vibration sensor and visual sensor preparation step (S3), a welding step (S4), and an analysis step (S5).

Welding object preparation step (S1)

This is the step of preparing the welding object, and is the step of preparing two different welding objects for the purpose of joining.

For example, the welding object may be an electrode tab and an electrode lead, or an electrode lead and a bus bar.

The two welding objects are prepared by positioning the parts to be welded in contact with each other, as shown in FIG. 1.

Ultrasonic welding device preparation step (S2)

This is the step of preparing the ultrasonic welding device of the present invention.

The ultrasonic welding device includes a vibrating part that contacts the welding object to perform ultrasonic welding, and a support part that supports the welding object contacted by the vibrating part.

More specifically, the horn of the vibrating part and the anvil of the support part are located on both sides of the welding object. Then, the anvil contacts and supports one side of the object to be welded, and the horn contacts the other side to press it with a certain force.

Vibration sensor and vision sensor preparation step (S3)

In the step of setting the vibration sensor and visual sensor of the present invention, the vibration sensor and visual sensor are provided as shown in FIG. 2.

Specifically, the vibration sensor may be installed on any one of the horn and converter supports, and may simultaneously be installed on any one of the anvil and anvil supports.

Additionally, the visual sensor is not attached to the ultrasonic welding device, but is installed at a predetermined distance from the ultrasonic welding device. At this time, the visual sensor is provided to detect movement of the vibrating part and the support part of the ultrasonic welding device.

Welding stage (S4)

This is a step of welding by applying ultrasonic vibration to the welded object using an ultrasonic welding device. Specifically, this is a step in which welding is performed by ultrasonic vibration of the horn included in the vibrating part of the ultrasonic welding device.

The welding step can be divided into a start step and an end step.

Specifically, the welding step includes a starting step in which welding is performed by contacting the vibrating part and the support part with both sides of the welding object, respectively, and an ending step in which the vibrating part in contact with one side of the welding object is spaced apart.

The welding progresses as the horn pressing the welded object vibrates ultrasonically at the beginning stage.

The end stage corresponds to the subsequent process after welding is completed, and is the stage where the vibrating part retreats and falls away from the welded object. At this time, the vibrating part may separate from the welding object and vibrate at the same time to separate the welding object. That is, the horn that is separated from the welding object in the end stage vibrates not for the purpose of welding, but to separate the partially adhered welding object.

Analysis stage (S5)

This is the stage where the control unit analyzes data measured from the vibration sensor and vision sensor.

More specifically, this is the step where the control unit analyzes the data obtained from each sensor to determine the quality of the welding.

In particular, in the present invention, the quality of the welding is determined depending on whether the vibrating part performs vibration and movement at an appropriate timing to eliminate the sticking phenomenon at the end stage.

That is, the control unit determines the welding quality by comparing the sequential relationship between the movement of the vibrating part measured by the visual sensor and the vibration of the vibrating part measured by the vibration sensor.

For example, when the movement of the vibrating part precedes the vibration of the vibrating part, the welding quality is determined to be good. In this case, the movement of the vibrating part detected by the visual sensor precedes the vibration of the vibrating part detected by the vibration sensor, and since the vibration of the horn included in the vibrating part is not transmitted to the anvil, the vibration sensor attached to the anvil does not detect vibration.

Figure 5 is a graph showing data measured from each vibration sensor and vision sensor when welding quality is good.

Referring to the results of FIG. 5, as shown in FIG. 5(c), after the displacement of the horn is changed, only the vibration of the horn is observed (FIG. 5(a)), and no vibration is observed from the anvil (FIG. 5(b)). .

This means that additional vibration of the vibrating part to prevent seizure occurred at an appropriate timing.

Conversely, when the vibration of the vibrating part precedes the movement of the vibrating part, the welding quality is determined to be poor. In this case, the vibration of the vibrating part detected by the vibration sensor precedes the movement of the vibrating part detected by the visual sensor, and the vibration of the horn included in the vibrating part is transmitted to the anvil, so the vibration sensor attached to the anvil detects the vibration.

Figure 6 is a graph showing data measured from each vibration sensor and vision sensor when welding quality is poor.

Referring to the results of FIG. 6, as shown in FIG. 6(c), after the displacement of the horn is changed, vibration of the horn is observed (FIG. 6(a)), and at the same time, vibration is observed at the anvil (FIG. 6(b)). .

This means that the additional vibration of the vibrating part to prevent seizure occurred at an inappropriate timing. In this case, even if the vibration ends, the welded object may remain stuck to a part of the horn, making it difficult to use the welded object.

Therefore, the control unit included in the ultrasonic welding system of the present invention can accurately determine the quality of welding based on the above results.

Above, the present invention has been described in more detail through drawings and examples. However, since the configurations described in the drawings or examples described in this specification are only one embodiment of the present invention and do not represent the entire technical idea of the present invention, at the time of filing this application, various equivalents and It should be understood that variations may exist.

110: Vibration unit
110a: horn
110b: converter unit
110c: converter support
120: support part
120a: anvil
120b: Anvil support
Sen1: Vibration sensor
Sen2: Vision sensor
W: Weld object
Ea: electrode assembly
Et: electrode tab
El: electrode lead

Claims (15)

ultrasonic welding device;
A vibration sensor attached to the ultrasonic welding device and detecting vibration generated from the ultrasonic welding device;
a visual sensor that detects movement of the ultrasonic welding device; and
a control unit that collects and analyzes data measured by the vibration sensor and vision sensor; Ultrasonic welding discrimination system comprising:
According to paragraph 1,
The ultrasonic welding device,
A vibrating unit that contacts the welding object to perform ultrasonic welding; and
a support portion supporting the welding object contacted by the vibrating portion; Ultrasonic welding discrimination system including.
According to paragraph 2,
The vibration sensor is installed on the vibration unit and the support unit, respectively,
An ultrasonic welding discrimination system in which the visual sensor is installed at a predetermined distance from the ultrasonic welding device.
According to paragraph 2,
The vibrating part,
A converter unit that generates vibration; and
A horn coupled to the converter unit to apply ultrasonic vibration directly to the welding object; Including,
The support part,
an anvil supporting the opposite side of the welding object in contact with the horn; Ultrasonic welding discrimination system including.
According to clause 4,
An ultrasonic welding discrimination system in which the vibration sensor is installed on the horn and anvil, respectively.
According to clause 4,
The ultrasonic welding device,
A converter supporter that fixes and supports the converter unit; and
an anvil support supporting the anvil; It further includes,
The vibration sensor is installed on any one of the horn and converter supports, and the ultrasonic welding discrimination system is installed on any one of the anvil and anvil supports.
According to clause 4,
At least one of the vibration unit and the support unit is provided to be capable of reciprocating movement so as to come into contact with each other,
The ultrasonic welding is an ultrasonic welding discrimination system in which the horn, the welding object, and the anvil are all in close contact with each other.
According to clause 4,
The visual sensor detects movement of at least one of the horn and anvil,
The control unit is an ultrasonic welding determination system that evaluates the quality of welding based on data measured from the vision sensor and vibration sensor.
According to paragraph 1,
An ultrasonic welding discrimination system in which the vibration sensor is an accelerometer sensor.
According to paragraph 1,
An ultrasonic welding discrimination system in which the visual sensor is a laser displacement sensor.
Preparing an object to be welded;
Preparing the ultrasonic welding device of claim 1;
Setting the vibration sensor and vision sensor of claim 1;
Welding the object by applying ultrasonic vibration to the object to be welded using the ultrasonic welding device; and
Analyzing data measured by the vibration sensor and the vision sensor with the control unit of claim 1; Including,
The ultrasonic welding device,
A vibrating unit that contacts the welding object to perform ultrasonic welding; and
a support portion supporting the welding object contacted by the vibrating portion; Including,
The welding step is,
A starting step in which welding proceeds by contacting the vibrating part and the supporting part with both sides of the welding object; and
An ending step of separating the vibrating part in contact with one side of the welding object; Ultrasonic welding determination method comprising:
According to clause 11,
In the termination step, the vibrating unit is spaced apart from the welding object and simultaneously vibrates to separate the welding object.
According to clause 12,
The vibration sensor detects vibration of the vibration unit and the support unit,
The visual sensor detects movement of the vibrating unit,
In the step of analyzing the data,
An ultrasonic welding determination method in which the control unit determines welding quality by comparing data measured by the vibration sensor and the vision sensor in the end step.
According to clause 13,
In the step of analyzing the data,
An ultrasonic welding determination method in which the control unit determines welding quality by comparing the sequential relationship between the movement of the vibrating part measured by the visual sensor and the vibration of the vibrating part measured by the vibration sensor.
According to clause 14,
The control unit determines that the welding quality is good when the movement of the vibrating unit in the end step precedes the vibration of the vibrating unit.