Automobile instrument panel airbag cover welding strength test method

Abstract

The invention discloses a method for testing the welding strength of an airbag cover plate of an automobile instrument panel, which comprises the following steps: step 1: taking 8 test samples at the upper, lower, left, right and middle positions of a welded part of an airbag cover plate of an automobile instrument panel; step 2: placing the test samples in a horizontal test fixture in sequence and fixing them; step 3: applying a load in a lateral direction at a moving speed of 15 to 20 mm / min; step 4: recording the force value when a weld fracture or a crack of the test sample occurs, whichever occurs first; step 5: judging the standard, the welding strength is ≥320N for qualified, otherwise it is unqualified.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile parts testing, and is used for verifying the welding strength between an automobile instrument panel airbag cover and an upper cover of the instrument panel, and is specifically a method for testing the welding strength of an automobile instrument panel airbag cover. Background Art

[0002] In the existing airbag cover welding strength test technology, the airbag cover is fixed on a special fixture and a tensile force is applied in its normal direction to measure the welding strength of the airbag cover. This method has the following defects:

[0003] 1) Fixing and applying tension to the entire airbag cover may cause cracks in the fixed position of the airbag cover or the position where the tension is applied, and the part itself may be broken, resulting in the inability to fix it, and thus the airbag cover welding strength cannot be measured;

[0004] 2) Since the entire airbag cover is fixed and tension is applied, it is impossible to measure whether there are defects such as insufficient local welding depth and cold welding;

[0005] 3) It is necessary to invest in a high-range tensile machine, which requires a large investment;

[0006] 4) A specific fixture needs to be made for fixing, which increases the cost.

[0007] The utility model patent with the patent authorization announcement number CN203869798U discloses a test fixture for the opening force of the instrument panel airbag bracket and the welding strength of the soft instrument panel, which is composed of a base 1, a support mechanism 2 and a fastening mechanism 3. The fastening mechanism 3 is fixed to the support mechanism 2. The fastening mechanism 3 is composed of a clamping screw 32 and a clamping nut 32. The support mechanism 2 is composed of several support screws 21. The detection method of the device is to fix the airbag cover on a special fixture and apply a tensile force in its normal direction to measure the welding strength of the airbag cover. This method has the above-mentioned defects. Therefore, it is very beneficial to invent a method for testing the welding strength of the airbag cover of an automobile instrument panel. Summary of the invention

[0008] The present invention aims at the shortcomings of the current method for measuring the welding strength of airbag covers in the automobile industry, and provides a method for testing the welding strength of automobile instrument panel airbag covers, which can avoid the situation where the airbag cover itself is broken, resulting in the inability to fix it and measure the welding strength.

[0009] The technical solution of the present invention is achieved in that it comprises the following steps:

[0010] Step 1: Take 8 samples from the top, bottom, left, right and middle positions of the airbag cover weldment of the car dashboard;

[0011] Step 2: Place the samples in the horizontal test fixture and fix them in turn;

[0012] Step 3: Apply load in the lateral direction at a moving speed of 15 to 20 mm / min;

[0013] Step 4: Record the force value when weld fracture or specimen rupture occurs, whichever occurs first.

[0014] Step 5: Evaluation criteria: welding strength ≥ 320N is qualified, otherwise it is unqualified.

[0015] The horizontal test fixture comprises two corresponding fixed clamps and a movable clamp.

[0016] The above effective method is used to obtain the welding strength value of the instrument panel airbag cover area to judge the reliability of product design and processing technology. Generally, when the strength is ≥320N, it indicates that the welding quality between the airbag cover and the instrument panel upper cover is good, and the batch of parts is qualified and can be delivered to the OEM; when it is <320N, it is necessary to analyze the reasons from the perspectives of product design and processing technology and take corresponding countermeasures to make the value within the qualified range.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1) Testing the sample can avoid the airbag cover itself from breaking, which will cause it to be unable to be fixed and unable to measure the welding strength;

[0019] 2) Take samples from the airbag cover for measurement to promptly detect defects such as insufficient welding depth and cold welding;

[0020] 3) Testing the specimen does not require an additional high-range tensile testing machine, saving investment;

[0021] 4) No need to make specific fixtures for fixing, thus reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the existing method;

[0023] Figure 2 Schematic diagram of the instrument panel upper cover and airbag cover welded together

[0024] Figure 3 Welding strength sampling area (specimen width is 20mm)

[0025] Figure 4 1 / 2 cross section of the sampling area

[0026] Figure 5 Cross-section diagram of sampling area 3 / 4 / 5 / 6 / 7 / 8 DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings:

[0029] like Figures 2 to 5 As shown, the present invention comprises the following steps:

[0030] Step 1: Take 8 samples from the top, bottom, left, right and middle positions of the airbag cover weldment of the car dashboard;

[0031] Step 2: Place the samples in the horizontal test fixture and fix them in turn;

[0032] Step 3: Apply load in the lateral direction at a moving speed of 15 to 20 mm / min;

[0033] Step 4: Record the force value when weld fracture or specimen rupture occurs, whichever occurs first.

[0034] Step 5: Evaluation criteria: welding strength ≥ 320N is qualified, otherwise it is unqualified.

[0035] The above-mentioned effective method is used to obtain the welding strength value of the instrument panel airbag cover area to judge the reliability of product design and processing technology. Generally, when the strength is ≥320N, it indicates that the welding quality between the airbag cover and the upper cover of the instrument panel is good, and the batch of parts is qualified and can be delivered to the OEM; when it is <320N, it is necessary to analyze the reasons from the perspectives of product design and processing technology and take corresponding countermeasures to make the value within the qualified range. The present invention changes the tensile force applied in the normal direction in the prior art to the tensile force applied in the horizontal lateral movement direction, and does not require the manufacture of a specific fixture for fixing, thereby reducing costs. At the same time, it can avoid the situation where the airbag cover itself breaks, resulting in the inability to fix and measure the welding strength.

Claims

1. A method for testing the welding strength of an automobile instrument panel airbag cover, comprising the following steps: Step 1: Take 8 samples from the top, bottom, left, right and middle positions of the airbag cover weldment of the car dashboard; Step 2: Place the samples in the horizontal test fixture and fix them in turn; Step 3: Apply load in the lateral direction at a moving speed of 15 to 20 mm / min; Step 4: Record the force value when weld fracture or specimen rupture occurs, whichever occurs first. Step 5: Evaluation criteria: welding strength ≥ 320N is qualified, otherwise it is unqualified.

2. A method for testing the welding strength of an automobile instrument panel airbag cover according to claim 1, characterized in that: The horizontal test fixture comprises two corresponding fixed clamps and a movable clamp.

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