CN112033608B - Method for detecting air tightness of battery system - Google Patents

Abstract

The invention discloses a method for detecting the air tightness of a battery system, and belongs to the technical field of air tightness detection. The method for detecting the air tightness of the battery system comprises the following steps: selecting one product from products with the same specification as a comparison piece, and taking the rest products as to-be-detected pieces; setting a standard leak hole to enable the standard leak hole to accord with a preset detection standard; arranging a standard leak hole on the comparison piece to obtain an equivalent standard piece, and detecting the leakage amount of the equivalent standard piece to obtain an allowable leakage amount; detecting the leakage amount of the piece to be detected to obtain the leakage amount of the piece to be detected; and if the leakage amount of the to-be-measured piece is not more than the allowable leakage amount, the to-be-measured piece is qualified, otherwise, the to-be-measured piece is unqualified. According to the method for detecting the air tightness of the battery system, the comparison piece and the piece to be detected are products with the same specification, so that differential detection is realized, and the detection standard is refined; the standard leak is arranged according to the detection standard of the product, and the standard leak has definite technical indexes, so that the equivalent standard part has corresponding technical indexes, the accuracy of the detection indexes is improved, and the detection reliability of the product is improved.

Description

A kind of battery system air tightness detection method

technical field

The invention relates to the technical field of air tightness detection, in particular to a method for detecting air tightness of a battery system.

Background technique

The battery box is an important part of the power battery. It needs to meet the protection level requirements of the electrical equipment shell to avoid the short circuit of the power battery caused by the ingress of dust or water, which will affect the safe use. At present, the conventional air-tightness detection method of the battery box in the industry: use the direct-pressure air-tightness detector to measure, and inflate the box under test; detect the leakage of the box under test, when the leakage amount is not greater than the preset value, The tested box is qualified, otherwise it is unqualified.

Due to the different internal volumes and external contours of different boxes, the allowable leakage amounts are different. However, at present, unified test standards are used, which cannot accurately detect boxes of different volumes. The detection standard is single and not refined. The test standard is unable to carry out differential detection, and the detection accuracy is poor; there is no clear technical index for the qualified conditions of air tightness detection, which affects the allowable leakage volume, and the aperture and number of small leaks are unknown. The current value of the allowable leakage volume Relying on the experience, it has not been tested and verified, which makes the detection reliability of the battery box low.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for detecting the air tightness of a battery system, which can perform differential detection on products of different specifications, provide clear technical indicators, and improve detection accuracy and reliability.

For this purpose, the present invention adopts the following technical solutions:

A method for detecting air tightness of a battery system, comprising:

Among the products of the same specification, one product is selected as the control part, and the remaining products are the test parts;

Set standard leaks so that the standard leaks meet the preset detection standards;

Set standard leak holes on the control parts to obtain equivalent standard parts, detect the leakage of the equivalent standard parts, and obtain the allowable leakage;

Detect the leakage of the DUT to obtain the leakage of the DUT;

If the leakage of the DUT is not greater than the allowable leakage, the DUT is qualified, otherwise it is unqualified.

Optionally, when the product is a box, before the equivalent standard part is detected, the equivalent standard part is inflated, and then the equivalent standard part is kept in pressure.

Optionally, the box body includes an upper box cover and a lower box body, and standard leak holes are respectively provided at the upper box cover, the lower box body and the connection between the upper box cover and the lower box body.

Optionally, before testing the DUT, inflate the DUT, and then maintain the pressure in the DUT.

Optionally, after the equivalent standard part or the test piece is inflated, the pressure of the equivalent standard part or the test piece is 3-10KPa.

Optionally, after the DUT is detected, the DUT is exhausted.

Optionally, an air tightness detector is used to detect the leakage of the DUT.

Optionally, the control is sealed before the standard leak is provided on the control.

Optionally, a sealant layer is provided on the control piece.

Optionally, the detection standard is IP67 or IP68 or IPX9K.

Beneficial effects of the present invention:

The invention provides a method for detecting the air tightness of a battery system. The control part and the test part are products of the same specification, and differentiated detection is performed for products of different specifications, the detection standard is refined, and the detection accuracy is improved; The detection standard sets standard leaks, and the standard leaks and reference parts form equivalent standard parts. Both standard leaks and control parts have clear technical indicators, so that the equivalent standard parts have corresponding technical indicators. The leakage volume provides data support, improves the accuracy of detection indicators, and improves the detection reliability of products.

Description of drawings

1 is a flowchart of a method for detecting air tightness of a battery system provided by a specific embodiment of the present invention;

FIG. 2 is a flow chart of another method for detecting air tightness of a battery system provided by a specific embodiment of the present invention.

Detailed ways

In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved more clearly, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only the present invention. Some examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, unless otherwise expressly specified and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integrated ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

The battery box is an important part of the power battery. It needs to meet the protection level requirements of the electrical equipment shell to avoid short circuit of the power battery due to ash or water ingress, which will affect the safe use; when different products cannot be differentiated detection, or can not provide When there are clear technical indicators, it will lead to low reliability and accuracy of the tested products.

In order to solve the above problems, the present embodiment provides a method for detecting the air tightness of a battery system, which includes:

Among the products of the same specification, one product is selected as the control part, and the remaining products are the test parts;

Set standard leaks so that the standard leaks meet the preset detection standards;

Set standard leak holes on the control parts to obtain equivalent standard parts, detect the leakage of the equivalent standard parts, and obtain the allowable leakage;

Detect the leakage of the DUT to obtain the leakage of the DUT;

If the leakage of the DUT is not greater than the allowable leakage, the DUT is qualified, otherwise it is unqualified.

The reference piece and the test piece are products of the same specification. By setting a standard leak hole and installing it on the product of the corresponding specification, the air pressure drop standard in the product during the air tightness test of the product of different specifications can be tested, and the pressure drop of the product of different specifications can be refined. Testing standards are used to facilitate differentiated testing of products of different specifications and improve testing accuracy; standard leaks are set according to product testing standards, and standard leaks and reference parts form equivalent standard parts, and both standard leaks and control parts are It has clear technical indicators, so that the equivalent standard parts have corresponding technical indicators, which provides data support for the allowable leakage detected by the detection, improves the accuracy of the detection indicators, and improves the detection reliability of the product; the corresponding allowable leakage The quantitative value provides a quantitative judgment basis for air tightness detection. As long as the pressure drop value of the test piece is within the allowable leakage range, the test is qualified, otherwise it is unqualified, which further improves the reliability of the detection standard and further improves the Detection accuracy of products of different specifications.

Of course, products of the same specification can also be understood as products with an equivalent structure to the DUT. For example, when the DUT is a box, if the volume of the box is selected as an important testing standard indicator, the box of the equivalent structure product is the same as the box. The box body of the test piece needs to ensure the same volume, and the shape and material can be the same or different, wherein, preferably, the control piece and the test piece are exactly the same to improve the accuracy.

According to the protection requirements, the standard leak must first be breathable but not water permeable, so as to avoid short circuit of the power battery due to ash or water ingress, which affects safe use. Since the standard leaks meet the standard leaks that are not blocked by gas and liquid at the same time, it is necessary to adjust the size of the diameter of the leaks until the leaks are impermeable but breathable, so as to ensure that the product is airtight but permeable to meet the requirements of use; according to The product testing standard provides standard leaks under the equivalent conditions of the testing standards to meet the protection requirements of power battery water tightness testing, provide testing standards for subsequent actual power battery air tightness testing, and improve the reliability of testing standards; The detection conditions and adjustment requirements of standard leak holes, as well as the volume of the sealed box are all based on digital experiments, which provide experimental verification and data-supported judgment standards for the air tightness detection of the battery box, thereby further improving the detection. Standard reliability.

In this embodiment, according to the industry manufacturing standard, the air tightness detection standard of the battery system is IP67, that is, when the underwater depth is 1 meter and the underwater pressure is 10 kPa, the battery box is soaked in water for 30 minutes and is watertight. Then the battery box meets the IP67 testing standard. Therefore, in order to make the standard leak meet the preset detection standard, specifically, setting the equivalent conditions as IP67 requirements include: the underwater depth is 1 meter, the underwater pressure is 10 kPa, the soaking time is 30 minutes, and the protection level is 1 meter. Leak adjustment is required to obtain a standard leak. If the standard leak is installed on the control part, the equivalent standard part meets the IP67 test standard. In other embodiments, the detection standard can also be IP68 or IPX9K, that is, set corresponding equivalent conditions, adjust the leak to obtain the corresponding standard leak and allowable leakage, so that the tested product meets the corresponding detection requirements; the standard leak can be It is set according to different detection standards, and has strong versatility. The specific structure is the prior art, which will not be repeated.

In this embodiment, the air tightness detection includes: a gas source is passed through one side of the leak hole, and the gas leakage rate on the other side of the leak hole is detected. The test method is simple and improves the air permeability of the leak hole. Detection accuracy. If the leak detection hole is airtight, you need to increase the aperture to ensure that the leak hole is breathable and meets the production standards. Optionally, a gas flow meter is provided on the other side of the leak hole, and the leak rate is detected by the gas flow meter, which improves the measurement accuracy and obtains the exact leak rate, which is convenient for follow-up. Data calculation provides a basis for detection and judgment. Optionally, the gas source is an industrial gas source of 10 kPa.

In this embodiment, the water tightness detection includes: a water tank is provided on one side of the leak hole, an air source is used as a driving source to drive water in the water tank to inject water into one side of the leak hole, and the other side of the leak hole is detected. The test method is simple, and the detection accuracy of whether the leak is permeable is improved. When the leak is permeable to water, the aperture needs to be reduced to ensure that the leak is impermeable and meets the production standards. When the leak hole meets the above testing requirements at the same time, the standard leak hole is obtained.

In the case that the standard leak is impermeable but breathable, the size of its aperture will also affect the air permeability. Since the product only requires water resistance to meet the requirements, the leak is adjusted so that the standard leak is impermeable but reaches the maximum air permeability. When the aperture value is the critical state aperture value, the qualified rate of the product can be improved, and the products that meet the requirements can be avoided from being screened out. Specifically, the adjustment method of adjusting the aperture value of the standard leak hole to the critical size can be adjusted and tested continuously. and other methods, no further description is needed, and it can be adjusted to meet the preset aperture size.

In this embodiment, the product is a battery case, and the case includes an upper case cover, a lower case body, and installed components. During detection, the factors that may affect the leakage include: the welding parts of the components, the upper case cover and the lower case body The position where the connector is locked, the tiny leaks that exist on the locking surface of the lower case when the upper case is covered, optionally, standard leaks are set at the upper case cover, the lower case, and the connection between the upper case cover and the lower case. , so that the standard leak holes are set as far as possible in all possible leak points, so as to improve the consistency between the equivalent standard part and the DUT, thereby improving the reliability of the allowable leakage.

Optionally, before the standard leak hole is set on the control piece, the control piece is sealed to avoid leakage of the control piece itself, thereby increasing the allowable leakage amount, improving the accuracy of the allowable leakage amount, and further improving the detection reliability. Specifically, a sealant layer may be provided on the control piece, thereby improving the sealing performance of the control piece and reducing measurement errors due to possible leakage points.

Optionally, when the product is a box, before testing the equivalent standard parts, inflate the equivalent standard parts, and then maintain the pressure in the equivalent standard parts. The pressure drop before and after pressure holding is the allowable leakage, and the detection method is simple and reliable.

In the same way, optionally, before detecting the DUT, inflate the DUT, and then keep the pressure of the DUT. The detection method of the test piece and the equivalent test piece is the same, which can eliminate the detection difference caused by the influence factors such as different detection methods, detection conditions and environmental temperature changes, and improve the detection reliability.

Optionally, after inflating the equivalent standard part or the DUT, the pressure of the equivalent standard part or the DUT is 3-10KPa, so as to avoid the pressure being too low, which may lead to air leakage. If the internal pressure is too low, it will affect the measurement accuracy, and it is also avoided that the pressure is too high, which will lead to the deformation of the equivalent standard part or the DUT after inflation, which will affect the air tightness detection and the subsequent use of the product.

Optionally, after the DUT is detected, the DUT is exhausted for subsequent use.

Optionally, an air tightness detector is used to detect the leakage amount of the DUT, which is simple and convenient to operate.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the embodiments of the present invention. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (10)

1. A method for detecting the air tightness of a battery system is characterized by comprising the following steps:

selecting one product from products with the same specification as a comparison piece, and taking the rest products as to-be-detected pieces;

setting a standard leak hole to enable the standard leak hole to accord with a preset detection standard;

arranging the standard leak hole on the comparison piece to obtain an equivalent standard piece, and detecting the leakage amount of the equivalent standard piece to obtain an allowable leakage amount;

detecting the leakage amount of the piece to be detected to obtain the leakage amount of the piece to be detected;

and if the leakage amount of the piece to be tested is not more than the allowable leakage amount, the piece to be tested is qualified, otherwise, the piece to be tested is unqualified.

2. The method of claim 1, wherein when the product is a case, before the testing of the equivalent standard component, the equivalent standard component is inflated and then pressurized.

3. The method for detecting the airtightness of the battery system according to claim 2, wherein the case body comprises an upper case cover and a lower case body, and the standard leak holes are respectively provided at the upper case cover, the lower case body, and a joint between the upper case cover and the lower case body.

4. The method of claim 2, wherein before the step of testing the device under test, the device under test is inflated and then maintained.

5. The method for detecting the airtightness of the battery system according to claim 4, wherein after the equivalent standard component or the component to be measured is inflated, the pressure of the equivalent standard component or the component to be measured is 3 to 10 KPa.

6. The method for detecting the airtightness of a battery system according to claim 4, wherein the member to be tested is evacuated after the member to be tested is detected.

7. The method for detecting the airtightness of the battery system according to claim 1, wherein an airtightness detector is used to detect the leakage amount of the to-be-tested member.

8. The method for detecting the airtightness of a battery system according to any one of claims 1 to 7, wherein the control member is sealed before the standard leak is provided thereon.

9. The method for detecting the airtightness of a battery system according to claim 8, wherein a sealant layer is provided on the control member.

10. The method for detecting the airtightness of a battery system according to any one of claims 1 to 7, wherein the detection standard is IP67 or IP68 or IPX 9K.

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