Battery case welding inspection device and method

Abstract

The present invention relates to a battery case welding inspection device and method, the device comprising: a detection object fixing part on which a detection object having a weld part is mounted; a fluid supply part connected to the detection object so as to supply fluid to an inner space part of the detection object formed by the weld part; an acoustic signal detection part for detecting an acoustic signal of air leaking from the inner space part; and a control part, which analyzes the acoustic signal detected by the acoustic signal detection part, so as to determine the position and / or the size of a leaking portion of the detection object.

Description

Welding inspection device and method for battery cases

[0001] The present invention relates to a welding inspection device and method for a battery case, and more particularly, to a welding inspection device and method for a battery case capable of supplying fluid to a welding part of a battery case and detecting an acoustic signal of fluid leaking from the welding part to quickly and accurately detect welding defects in the welding part.

[0002] Recently, interest in electric vehicles has grown due to environmental concerns, high oil prices, and other factors, leading to the development of various electric vehicles. In particular, demand for electric vehicles has been rapidly increasing in recent years.

[0003] These electric vehicles are broadly categorized into battery-powered EVs, fuel cell EVs that use fuel cells as electric motors, hybrid EVs that use both electric motors and engines, and hydrogen-fueled cars (HFCs).

[0004] All electric vehicles are equipped with a battery module to store electrical energy. The battery module houses multiple battery cell units within a battery case and utilizes various cooling devices to dissipate the heat generated by the battery cell units. For example, battery modules can be either air-cooled or water-cooled, and a hybrid system that combines air and water cooling may be adopted if necessary.

[0005] Here, in the case of a water-cooled battery module, a cooling channel is formed in the battery case for the circulation of coolant, and the coolant circulating along the cooling channel is used to indirectly cool the battery cells. Furthermore, it is common for battery modules to form cooling channels by welding a cooling module to the battery case.

[0006] However, the conventional battery module described above has the problem that it is very difficult to detect welding defects, such as cracks, that occur during the process of welding the cooling module to the battery case. Therefore, there is a need to improve this issue.

[0007] Meanwhile, Korean Patent Registration No. 10-1957161 (Registration Date: 2019.03.06) discloses a 'battery cooling system for electric vehicles', and Publication Patent No. 10-2023-0073651 (Publication Date: 2023.05.26) discloses a 'device for generating an ultrasonic inspection plan for welds having anisotropy and inhomogeneity'.

[0008] The present invention was created in response to the above-described need, and its purpose is to provide a welding inspection device and method for a battery case capable of supplying fluid to an inspection object joined by welding so as to have an internal space, and detecting an acoustic signal of fluid leaking from the internal space to quickly and accurately detect welding defects in the inspection object.

[0009] In order to solve the above-described problem, a welding inspection device for a battery case according to one aspect of the present invention is characterized by including: a detection target fixing unit on which an inspection target having a welded portion is mounted; a fluid supply unit connected to the inspection target so as to supply fluid to an internal space of the inspection target formed by the welded portion; an acoustic signal detection unit that detects an acoustic signal of air leaking from the internal space; and a control unit that analyzes an acoustic signal detected by the acoustic signal detection unit to determine at least one of a position and a size of a leakage portion of the inspection target.

[0010] In addition, in the present invention, the fluid supply unit is characterized by including a fluid injection unit that is detachable from the inspection object so as to communicate with the internal space unit, and a fluid pump that is connected to the fluid injection unit and supplies fluid at a set pressure.

[0011] In addition, in the present invention, the fluid supply unit is characterized by further including a fluid discharge unit that is detachable from the inspection object so that the fluid circulating in the internal space unit is discharged, and is connected to the fluid pump.

[0012] In addition, in the present invention, the control unit is characterized in that it controls the fluid supply unit so that the pressure of the fluid supplied to the internal space unit through the fluid supply unit is controlled.

[0013] In addition, in the present invention, the fluid supply unit is characterized in that it supplies fluid to the internal space at a first set pressure under the control of the control unit, and then, when a set time has elapsed, reduces the pressure of the internal space and supplies the fluid to the internal space at a second set pressure.

[0014] In addition, a welding inspection method for a battery case according to one aspect of the present invention is characterized by including a step of mounting an inspection target that is joined to each other through welding to form a sealed internal space on a detection target fixing unit, a step of connecting a fluid supply unit to the inspection target, a fluid supply step of supplying fluid at a set pressure to the internal space through the fluid supply unit, and a leakage detection step of detecting whether the inspection target is leaking by detecting an acoustic signal of fluid leaking from the internal space.

[0015] In addition, the fluid supply step in the present invention is characterized by controlling the pressure of the fluid supplied to the internal space.

[0016] As described above, the welding inspection device and method for a battery case according to one aspect of the present invention, unlike the prior art, supplies fluid at a specific pressure to an inspection object joined through welding so as to have an internal space, and then detects an acoustic signal of the fluid leaking from the internal space of the inspection object using an acoustic signal detection unit, thereby having the effect of quickly and accurately detecting a welding defect in the inspection object.

[0017] FIG. 1 is a schematic diagram illustrating a welding inspection device for a battery case according to one embodiment of the present invention.

[0018] Figure 2 is a plan view illustrating an inspection object according to one embodiment of the present invention.

[0019] FIG. 3 is a schematic drawing showing an example of a defect in an inspection object according to one embodiment of the present invention.

[0020] FIG. 4 is a flowchart illustrating a welding inspection method for a battery case according to one embodiment of the present invention.

[0021] Hereinafter, an embodiment of a welding inspection device and method for a battery case according to the present invention will be described with reference to the attached drawings.

[0022] In this process, the thickness of lines and the sizes of components depicted in the drawings may be exaggerated for clarity and convenience. Furthermore, the terms described below are defined based on their functions within the present invention and may vary depending on the intent or custom of the user or operator. Therefore, the definitions of these terms should be based on the overall content of this specification.

[0023] Additionally, in this specification, when it is said that a part is "connected (or connected)" to another part, this includes not only cases where it is "directly connected (or connected)" but also cases where it is "indirectly connected (or connected)" with another member in between. In this specification, when it is said that a part "includes (or comprises)" a certain component, this does not mean that other components are excluded, but rather that other components can be "included (or comprised)" unless specifically stated otherwise.

[0024] In addition, the same reference numerals may refer to the same components throughout this specification. Even if the same or similar reference numerals are not mentioned or described in a specific drawing, they may be described based on other drawings. In addition, even if a part is not indicated by a reference numeral in a specific drawing, that part may be described based on other drawings. In addition, the number, shape, size, and relative size differences of detailed components included in the drawings of this application are set for the convenience of understanding, and do not limit the embodiments and may be implemented in various forms.

[0025] FIG. 1 is a schematic diagram illustrating a welding inspection device for a battery case according to an embodiment of the present invention, and FIG. 2 is a plan view illustrating an inspection target according to an embodiment of the present invention.

[0026] In addition, FIG. 3 is a drawing schematically showing an example of a defect in an inspection object according to an embodiment of the present invention, and FIG. 4 is a flowchart for explaining a welding inspection method for a battery case according to an embodiment of the present invention.

[0027] Referring to FIGS. 1 to 3, a welding inspection device (100) for a battery case according to an embodiment of the present invention may largely include a detection target fixing unit (110), a fluid supply unit (120), an acoustic signal detection unit (130), and a control unit (140).

[0028] In this embodiment, the welding inspection device (100) for a battery case can selectively attach and detach an inspection target (10) to a detection target fixing part (110), supply fluid to the inspection target (10) at a specific pressure, and then detect an acoustic signal of the fluid leaking through the inspection target (10) to detect the leak area and size of the inspection target (10).

[0029] In this embodiment, the fluid supplied to the inspection target (10) using the fluid supply unit (120) may be compressed air.

[0030] The detection target fixing part (110) is for fixing the inspection target (10) for inspection, and the inspection target (10) can be selectively placed thereon and the placed inspection target (10) can be fixed thereon. To this end, the detection target fixing part (110) may include a table part (111) on which the inspection target (10) is placed, and a clamp part (113) for fixing the inspection target (10).

[0031] At this time, the detection target fixing part (110) can be adjusted in the position of the clamp part (113) that fixes the inspection target (10) according to the size of the inspection target (10) on the table part (111). This is to improve the convenience of use by allowing inspection targets (10) of various sizes and shapes to be easily fixed. The clamp part (113) is provided in multiple numbers so that the inspection target (10) can be stably and tightly fixed, and can be attached to and detached from the table part (111) to support the corners of the inspection target (10).

[0032] The inspection object (10) according to the present embodiment has an internal space (10a) formed in a sealed form so that fluid can circulate inside, a cooling water inlet for injecting cooling water is formed on one side of the internal space (10a), and a cooling water discharge port for discharging cooling water is formed on the other side of the internal space (10a).

[0033] This inspection object (10) is formed by welding a first plate portion (11) and a second plate portion (13) to form a sealed internal space portion (10a). In addition, the shapes of the first plate portion (11) and the second plate portion (13) of the inspection object (10) can be changed in various ways depending on the device to be applied.

[0034] In particular, the inspection object (10) according to the present embodiment may be damaged at the welded portion of the first plate portion (11) and the second plate portion (13) that are joined by welding. In addition, the damaged portion of the welded portion where a defect occurs in the inspection object (10) is detected using the fluid supply portion (120), the acoustic signal detection portion (130), and the control portion (140).

[0035] A battery case used in a water-cooled battery module (not shown) can be used as the inspection object (10) according to this embodiment. In addition, the inspection object (10) can be modified in various ways as long as it is a product that circulates fluid.

[0036] The fluid supply unit (120) is connected to the cooling water inlet and cooling water outlet of the inspection object (10), respectively, so as to supply fluid to the internal space (10a) of the inspection object (10), and can circulate the fluid to the internal space (10a). This fluid supply unit (120) can supply the fluid to the inspection object (10) by maintaining the pressure of the fluid uniformly or adjusting the pressure of the fluid as controlled by the control unit (140).

[0037] In addition, the fluid supply unit (120) may include a fluid injection unit (121) that is detachably attached to the cooling water inlet of the inspection object (10) so as to communicate with the internal space (10a) of the inspection object (10), a fluid discharge unit (123) that is detachably attached to the cooling water outlet of the inspection object (10) so as to discharge the fluid circulating in the internal space (10a), and a fluid pump (125) for supplying the fluid. At this time, the fluid supply unit (120) may use compressed air as a fluid for leak testing of the inspection object (10).

[0038] The fluid pump (125) is connected to the fluid injection unit (121) and the fluid discharge unit (123), respectively, and can supply fluid at a set pressure. The control of the fluid pump (125) can be performed by the control unit (140).

[0039] In addition, the fluid pump (125) may vary the supply pressure of the fluid supplied to the inspection object (10) under the control of the control unit (140). For example, the fluid pump (125) may supply the fluid at a first set pressure under the control of the control unit (140), and after a set time has elapsed, reduce the fluid pressure in the internal space (10a), and then supply the fluid at a second set pressure. Through this, a leak test can be performed on the inspection object (10) under a wider range of pressure conditions.

[0040] And when the supply of fluid to the internal space (10a) of the inspection target (10) begins through the fluid supply unit (120), the presence or absence of a leak in the inspection target (10) is detected using the acoustic signal detection unit (130).

[0041] The acoustic signal detection unit (130) according to the present embodiment may be provided on the detection target fixing unit (110) so as to be close to the inspection target (10), and may provide acoustic signal data detected from the inspection target (10) to the control unit (140). The acoustic signal detection unit (130) may be provided with an acoustic sensor (131) (Acoustic Emission Sensor) so as to more accurately detect the acoustic signal generated from the inspection target (10). A plurality of acoustic sensors (131) may be provided spaced apart from each other above the inspection target (10).

[0042] For example, if no leakage occurs in the inspection object (10), an acoustic signal is detected within the set value range, and if a leakage occurs in the inspection object (10), the acoustic signal detected by the acoustic signal detection unit (130) goes beyond the set value range.

[0043] In this way, the sound signal data detected by the sound signal detection unit (130) can be provided to the control unit (140).

[0044] The control unit (140) can analyze the sound signal data detected by the sound signal detection unit (130) to determine whether there is an abnormality in the inspection target (10) and the location and size of the leak area in the inspection target (10). In addition, the control unit (140) can determine whether there is an abnormality in the inspection target (10) and the location and size of the leak area and then provide the information to a user terminal, etc.

[0045] In particular, the control unit (140) can control the fluid supply unit (120) so that the pressure of the fluid supplied to the internal space unit (10a) through the fluid supply unit (120) is controlled. For example, the control unit (140) can control the fluid supply unit (120) to change the pressure of the fluid supplied from the fluid supply unit (120) to the inspection target (10). Specifically, the control unit (140) can control the fluid supply unit (120) to supply the fluid while maintaining the pressure of the fluid supplied from the fluid supply unit (120) to the inspection target (10) at a first set pressure, and can control the fluid supply unit (120) to maintain the inside of the inspection target (10) at the first set pressure for a set time, depressurize the inside of the inspection target (10), and then supply the fluid to the depressurized inspection target (10) at a second set pressure.

[0046] That is, by controlling the fluid supply unit (120), the fluid can be supplied at a first set pressure, and after the set time has elapsed, the fluid pressure in the internal space unit (10a) can be reduced, and then the fluid pressure can be supplied at a second set pressure. Through this, the inspection target (10) can be subjected to a leak test under a wider range of pressure conditions, thereby further improving the reliability and performance of leak detection.

[0047] Meanwhile, the welding inspection device (100) for a battery case according to the present embodiment may simultaneously supply fluid through the fluid injection unit (121) and the fluid supply unit (120) without circulating the fluid into the internal space (10a) of the inspection target (10). In this way, when the fluid for a leak test is simultaneously supplied using the fluid injection unit (121) and the fluid supply unit (120), the internal space (10a) of the inspection target (10) can be quickly filled. Therefore, since the fluid can be quickly injected into the internal space (10a) of the inspection target (10), the time for injecting the fluid can be reduced, and the time for leak testing can be further reduced. In other words, a rapid leak test is possible.

[0048] A welding inspection method using a welding inspection device for a battery case according to an embodiment of the present invention configured as described above is described.

[0049] Referring to FIGS. 1 and 4, a welding inspection method for a battery case according to an embodiment of the present invention includes a step (S10) of connecting an inspection object (10) and a fluid supply unit (120), a fluid supply step (S20) of compressing fluid into the interior of the inspection object (10), and a leak detection step (S30) of detecting a leak occurring in the inspection object (10).

[0050] The fluid supply unit connection step (S10) can be used to fix the inspection target (10) by mounting it on the detection target fixing unit (110), and to connect the fluid injection unit (121) and the fluid discharge unit (123) to each end of the internal space (10a) of the inspection target (10).

[0051] The fluid supply step (S20) controls the fluid supply unit (120) through the control unit (140) to supply the fluid while maintaining the pressure of the fluid supplied to the internal space (10a) of the inspection target (10) at a preset pressure. In addition, the fluid supply step (S20) can circulate the compressed fluid introduced into the internal space (10a) through the fluid pump (125) so as to pass through the internal space (10a).

[0052] In addition, the fluid supply step (S20) and the fluid supply unit connection step (S10) can control the pressure of the fluid supplied to the internal space (10a). For example, the fluid supply step (S20) supplies the fluid from the fluid supply unit (120) to the inspection target (10) while maintaining the pressure of the fluid at a first set pressure, and maintains the first set pressure for a set time. After maintaining the first set pressure for the set time, the inside of the inspection target (10) is depressurized, and the compressed fluid is re-supplied to the inspection target (10) while maintaining the pressure of the fluid at a second set pressure.

[0053] The leakage detection step (S30) detects a leakage acoustic signal of a fluid leaking from the inspection target (10) using an acoustic signal detection unit (130). In this leakage detection step (S30), if the acoustic signal detection unit (130) does not detect a fluid leakage sound, a normal signal is transmitted to the control unit (140), and if a fluid leakage acoustic signal is detected, a leakage signal is transmitted to the control unit (140).

[0054] In addition, the leakage detection step (S30) can determine the location and size of the leakage area of ​​the inspection target (10) by analyzing the leakage acoustic signal data provided by the acoustic signal detection unit (130) in the control unit (140).

[0055] The welding inspection device and method for a battery case according to the present invention, which are configured as described above, can detect whether there is a fluid leak in the inspection object (10) through an acoustic signal detection unit (130) after supplying compressed fluid to the internal space (10a) of the inspection object (10) that is joined by welding to form an internal space (10a), and thus can quickly and accurately perform a welding defect inspection of the inspection object (10).

[0056] While the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible. Accordingly, the technical protection scope of the present invention should be defined by the following claims.

Claims

1. A detection target fixing part on which an inspection target having a welded part is mounted; A fluid supply unit connected to the inspection object to supply fluid to the internal space of the inspection object formed by the welding unit; An acoustic signal detection unit that detects an acoustic signal of air leaking from the internal space; and A control unit that analyzes the acoustic signal detected by the acoustic signal detection unit to determine at least one of the location and size of the leakage area of ​​the inspection target; A welding inspection device for a battery case, characterized by including:

2. In paragraph 1, The fluid supply unit comprises a fluid injection unit that is detached from the inspection object so as to communicate with the internal space; and A fluid pump connected to the above fluid injection unit and supplying fluid at a set pressure; A welding inspection device for a battery case, characterized by including:

3. In paragraph 2, A welding inspection device for a battery case, characterized in that the fluid supply unit further includes a fluid discharge unit that is detachable from the inspection object so that the fluid circulating in the internal space unit is discharged and is connected to the fluid pump.

4. In any one of paragraphs 1 to 3, A welding inspection device for a battery case, characterized in that the control unit controls the fluid supply unit so that the pressure of the fluid supplied to the internal space unit through the fluid supply unit is controlled.

5. In paragraph 4, A welding inspection device for a battery case, characterized in that the fluid supply unit supplies fluid to the internal space at a first set pressure according to the control of the control unit, and then, when a set time has elapsed, reduces the pressure of the internal space and supplies the fluid to the internal space at a second set pressure.

6. A step of mounting an inspection object that is joined to each other through welding to form a sealed internal space on a detection target fixing part and connecting a fluid supply part to the inspection object; A fluid supply step for supplying fluid to the internal space at a set pressure through the fluid supply unit; and A leakage detection step for detecting whether the inspection object is leaking by detecting an acoustic signal of a fluid leaking from the internal space; A welding inspection method for a battery case, characterized in that it includes:

7. In paragraph 6, A welding inspection method for a battery case, characterized in that the fluid supply step controls the pressure of the fluid supplied to the internal space.

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