JPH0351736A - Inspection of airtightness of vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for inspecting the airtightness of panel joints of a vehicle body, and in particular, a method for checking the presence or absence of rain leakage at the joints between roof panels and side panels. Regarding.

(Prior art) - In a, when a roof panel and a side panel are joined on the roof side, the external appearance of the joint is joined by brazing in consideration of the design. Most of the joints, which are otherwise difficult to match, are spot welded and then the gaps between the joints are sealed with a dust sealer.

For this reason, if the dust sealer does not sufficiently seal the gap, the airtightness of the joint will be reduced, and water leaks will likely occur at the joint when a completed vehicle is inspected for water leaks.

Vehicle water leak tests have traditionally been carried out by recreating conditions similar to driving in the rain or car washes.For example, the vehicle is transported through a shower booth with multiple showers, We test for water leaks by spraying water vigorously from various angles. As a result of the inspection, if water leakage occurs at the joint between the roof panel and side panel, the joint will be corrected and then
A water leak test is performed again in the same manner.

However, when using the above method, when a water leak occurs at a joint, the water gets wet from around the leakage area, making the interior of the car dirty.Furthermore, depending on the leakage area, surrounding parts may have to be replaced. Ta.

(Problems to be Solved by the Invention) The present invention eliminates such inconveniences and makes it possible to inspect vehicles for water leaks (also to check for rain leaks at the joints between roof panels and side panels). The purpose of the present invention is to provide a method for inspecting the airtightness of a vehicle body.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a method for testing the airtightness of a joint between a roof panel and a side panel of a vehicle body, in which the joint is covered with a sealing material. A closed space is formed between the part and the sealing material, the space is reduced to a certain negative pressure, and the airtightness of the joint is determined based on whether or not the negative pressure in the space decreases thereafter. It is characterized by

(Function) According to the above means, the present invention reduces the pressure in the closed space between the joint and the sealing material to a constant negative pressure, so that when there is a gap in the joint, the pressure is reduced. Since air is sucked into the space from the outside through the gap and the negative pressure in the space decreases, it is determined that the airtightness of the joint between the roof panel and the side panel is insufficient. In addition, when there is no gap in the joint, air is not sucked into the space from the outside, so the initial negative pressure is maintained, and it is determined that the airtightness of the joint between the roof panel and the side panel is sufficient. Ru.

(Example) An example of implementing the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a perspective view of a joint 3 between a roof panel 1 and a side panel 2 of a vehicle body whose airtightness is tested by the method of the present invention. The joint 3 is provided on the roof side along the longitudinal direction of the vehicle body, and the roof front and rear sides of the joint 3 are brazed 4 so as to be flat on the panel surface, as shown by hidden lines in FIG. As shown in the cross-sectional view shown in the second figure, the roof panel side edge 5 bent into an L-shape is joined to the roof panel upper edge 6 by spot welding, and the upper edge is joined by spot welding. The gap between the mating edges of both panels is filled with a dust sealer 8.
is sealed by. At the joint 3 of this concave groove,
After performing an airtightness test, a resin cover 9 formed along the shape of the groove is fitted and buried.

As shown in FIGS. 3 and 4, the apparatus for carrying out the method of the present invention includes: a sealing material 10 that covers and closes the opening 7 of the joint 3 from above, and a mounting base 11 to which the sealing material 10 is attached. , a pipe 12 provided to penetrate the sealing material IO and the mounting base 11 , a differential pressure sensor 14 connected to the pipe 12 via a hose 13 , and the differential pressure sensor 14
and a vacuum pump 15 connected via a hose 13 to the vacuum pump 15. The sealing material 10 is molded using silicone rubber suitable as a sealing material,
As shown in FIG. 4, the opening is formed in a size that covers and closes the entire circumference of the opening 7 of the joint 3 on the lower surface side, and the shape of both side edges 16 on the lower surface side changes in the longitudinal direction of the vehicle body. Part 7
It is formed according to.

Next, a method for testing the airtightness of panel joints according to the present invention will be described using the above-mentioned apparatus.

As shown in FIG. 4, sealing material I
The both side edges 16 of the O are placed together and the sealing material IO is pressed against the joint 3 from above by applying a load of 2 to 10 kg/c+j to close the opening 7 so that no air leaks. Next, the vacuum pump 15 that communicates with the space 17 formed by closing the opening 7 through the hose 13 and the pipe 12 in the sealing material 9 reduces the pressure of the space 17 to a constant negative pressure, for example - Set to 400mg. After a certain period of time has elapsed, the differential pressure sensor 14 measures the decrease in the negative pressure in the space 17, and air is sucked from the outside into the reduced pressure space 16 based on the change in the decrease in the negative pressure. The airtightness of the joint portion 3 is determined depending on whether or not the joint portion 3 is present.

As a result of measurement by the differential pressure sensor 14, when the negative pressure in the space 17 decreases, the space 17 is depressurized because the opening 7 is closed by the sealing material IO to prevent air from leaking. Air is sucked into the space 17 through the gap in the joint 3, and it is determined that the airtightness of the joint 3 is insufficient. Furthermore, when there is no gap in the joint 3, air is not sucked into the space 17 from the outside.
It is determined that the initial negative pressure is maintained and the airtightness of the joint 3 is sufficient.

In this example, by determining the airtightness of the joint 3 between the roof panel 1 and the side panel 2 as described above, the present embodiment reproduces the situation similar to actually driving in the rain or washing a car and prevents water from leaking. It is possible to check for rain leaks in a vehicle using a simple method without conducting a leak test, and in reality, it is possible to check whether rain leaks occur from the gap in the joint 3 due to insufficient airtightness of the joint 3. Even in the case of rain, rain leakage can be inspected without contaminating the interior of the car due to water leakage.

In this embodiment, the rain leakage inspection method for the joints between the roof panel and the side panels has been described, but the present invention also applies to each panel joint of the vehicle body other than the above-mentioned joints, etc. A sealed space is formed between the joint and the sealing material using a sealing material, and a rain leakage test can be performed in the same manner as in the embodiment described above.

(Effects of the Invention) As is clear from the above description, the present invention forms a closed space at the joint between the roof panel and the side panel using a sealing material, and maintains the space under constant negative pressure. The airtightness of the joint can be determined based on the presence or absence of a decrease in negative pressure after depressurization, and the presence or absence of rain leakage at the joint can be confirmed, without actually conducting a water leak test on the vehicle body. To provide an airtightness inspection method for a vehicle body that can be carried out in a simple manner without soiling the interior of the vehicle due to water leakage during water leakage inspection.

[Brief explanation of drawings]

1 to 4 show an example of the implementation of the present invention.
The figure is a perspective view of the joint between the roof panel and the side panel of a car body, which is tested for rain leakage by the method of the present invention, Figure 2 is a cross-sectional view of the joint, and Figure 3 is a sealing material according to the present invention. FIG. 4 is a perspective view of the provided device, and a sectional view when a space is formed at the joint with a sealing material. l...Roof panel 2...Side panel 3...
Joint part 10... Sealing material 17... Space part

Claims (1)

[Claims] In a method for testing the airtightness of a joint between a roof panel and a side panel of a vehicle body, the joint is covered with a sealing material to form a closed space between the joint and the sealing material;
A method for inspecting the airtightness of a panel joint, comprising: reducing the pressure in the space to a constant negative pressure, and then determining the airtightness of the joint based on whether or not the negative pressure in the space decreases.