JPH0228070A - Assembly accuracy control method for car body by laser scar - Google Patents

Abstract

PURPOSE:To easily further well control assembly accuracy of a car body by providing a laser scar, serving as the reference point in the time of assembly, in two or more steel plate parts, forming the car body, to be discriminated and measured by a magnetic sensor and performing positioning and building or the like of each steel plate part. CONSTITUTION:In assembly of a car body, first for steel plate parts of front door 2, rear door 3, main body 4 and a center pillar 5, laser scars 1, linearly arranged even in every of vertical and lateral directions in a proper assembly condition, are provided as the reference point. And using an assembly jig or the like, temporary positioning is performed of each steel plate part 2 to 5. Next using a magnetic sensor, each laser scar 1 is discriminated and measured, thus a position relation between each steel plate part 2 to 5 is accurately detected. While being based on the detected position relation, a position of each steel plate part 2 to 5 is corrected and reconfirmed. Thereafter discriminating and measuring the laser scar 1 in an important part of the car body completed in its assembly, the car body is inspected for dimensions.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for controlling the assembly accuracy of a vehicle body using laser marks, in which the assembly accuracy is managed using laser marks formed on steel plate parts constituting the vehicle body as a reference point.

Conventional technology Vehicle body assemblies, that is, car bodies, are made up of a large number of press-formed steel plate parts joined together by welding or other means.After the painting process, important functional parts such as the engine and suspension are removed. Since it can be mounted, it is required not only to ensure sufficient strength and rigidity, but also to have high assembly accuracy. For this reason, when assembling a vehicle body, each steel plate component must be positioned and joined with high precision, and many types of assembly jigs are required depending on the process. In particular, recent automated assembly lines require several times higher positional accuracy than manual assembly, and therefore assembly jigs have become an extremely important element in vehicle body assembly technology.

As a method for positioning individual steel plate parts, the pin locate method uses holes in the steel plate parts to locate the assembly reference position and positions the entire steel plate part with high precision.It is generally used in conjunction with a clamp, and is used to locate the opening surface or seal rubber. The shape bone is used to ensure positional accuracy by supporting the functional aspects of steel plate parts such as the contact surface, and is applied to parts with clearly uneven shapes such as small brackets, by providing a support that matches the shape of the part. There is a self-locating method, in which parts that are sent in are automatically placed in the correct position.

SUMMARY OF THE INVENTION Incidentally, when positioning steel plate parts, it is important to have consistent standards throughout the entire process. However, it is difficult to set a reference point so that it is always at the optimal position in each process, and for example, positioning holes are subject to positional restrictions due to strength and complexity issues, and assembly jigs are complicated. This made it expensive and inconvenient. Moreover, in addition to the use of assembly jigs, the process of building materials such as doors relies on the skills of skilled workers, which has been a major obstacle to the realization of automated assembly lines with high assembly accuracy.

Means for Solving the Problems The present invention solves the above-mentioned problems by irradiating laser light onto the steel plate parts that make up the vehicle body to form laser marks that serve as reference points during assembly. Based on the positional information determined and measured by the magnetic sensor, the positioning of each steel plate part and the accuracy of the building materials are adjusted, and after assembly is completed, the deviation of the laser marks is measured to manage the dimensional accuracy of the vehicle body. According to the means, since the tissue changes caused by receiving the laser beam, that is, the laser marks, can be identified by a magnetic sensor by magnetizing them, the laser marks can be detected on parts such as doors and hoods that become the surface of the car body and are exposed to the outside. Even if it is installed, it can be hidden with paint, so there is no need to worry about spoiling the aesthetics. Therefore, it is possible to set a reference point at the optimal position for each steel plate member, and it is easy to set a consistent reference point throughout the entire process, improving the accuracy of positioning and building materials, and distinguishing them using magnetic sensors.・By using the position information of each measured laser mark, the assembly accuracy of the vehicle body can be managed.

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 6. An overview of the general assembly process for vehicles is the body assembly process in which a large number of press-formed steel plate parts are joined together by welding or other methods to form a single body (body assembly). The painting process aims to prevent rust and add beauty to the body, the sacrificial process involves attaching various units and parts to the painted car body to give it the functionality of a vehicle, and the completion process involves inspecting the various functions and performance of the vehicle. It consists of a vehicle inspection process, and the first body assembly process is a fundamental process that is important for accuracy in a vehicle assembly factory. Therefore,
A laser mark 1 is formed by irradiating a laser beam onto each steel plate component for constructing a car body in a single item or a subassembly state at a reference position when assembling the car body. These laser marks 11 are tissue changes that occur when exposed to laser light, and can be detected by a magnetic sensor by turning into stone and sulfiding, so they can be hidden in the subsequent painting process by adjusting the laser light settings. It can be used as a laser mark. Therefore, there is no need for restrictions on the position of parts such as doors and hoods that form the surface of the vehicle body and require aesthetic appearance, and they can be set at optimal positions to achieve the purpose.

To explain in more detail an example of a method for controlling the assembly accuracy of a car body using laser marks, as shown in Fig. 1, first, the steel plate parts, such as the front door 2, rear door 3, main body 4, and center pillar 5, are checked in the correct assembly state. Laser marks 1 lined up in a straight line in either the vertical or horizontal directions are provided as reference points, and the steel plate parts are temporarily positioned using an assembly jig or the like. Next, each laser mark is discriminated and measured using a magnetic sensor, and the positional relationship between each steel plate member can be accurately known based on the positional information. By correcting and reconfirming the temporarily positioned position of the steel plate component using the position information obtained in this way, highly accurate positioning of the steel plate component on the automatic assembly line becomes possible. Furthermore, at the end of the car body assembly process, it is possible to perform a dimensional inspection of the car body by identifying and measuring laser marks at key points on the assembled car body. It will also be possible to automate the precision control of vehicle bodies.

Another use of laser IT is to mark the relationship between a door and a main body in doorless repair.

As shown in FIG. 6, the doorless replacement line is a vehicle assembly method in which the completed vehicle body is painted, the doors are removed, and the doors and main body are replaced on separate lines. This method has the advantage of making it easier to get in and out of the car body, improving work efficiency inside the car body, and shortening the walking distance for workers because the parts storage area on the line side can be moved closer to the line side. However, after the sacrifice of the door and main body is completed, it is necessary to rebuild the door to the main body. A laser mark 1' is formed as a phase mark when the vehicle body assembly is completed. When the front door 2 is rebuilt, the magnetic sensor is used to identify the laser traces and the position of the front door 2 is adjusted while building materials are used, making it possible to carry out construction material work with high precision and efficiency.

In addition, FIG. 4 shows a robot for installing two front doors in which magnetic sensors 6 are arranged in a straight line.
, laser marks 1 on front door 2 and center pillar 5
It is possible to determine the location and adjust the position, and implement highly accurate building materials.

Advantages of the Invention According to the present invention, a consistent reference point can be set in the car body assembly process to improve assembly accuracy.
As a result, the quality and reliability of the vehicle as a whole will also improve.

In addition, because there are no restrictions on the position of the reference point and no holes are required for positioning, it has the effect of simplifying the structure of the assembly jig and greatly contributes to promoting automation of assembly lines. Therefore, it is economically advantageous.

[Brief explanation of the drawing]

FIG. 1 is a side view of a vehicle body showing one embodiment of the present invention, FIG. 2 is a perspective view showing an example of the structure of the vehicle body, FIG. 3 is a side view of the vehicle body showing a phase mark between the front door and the main body, and FIG. FIG. 5 is a perspective view showing an outline of a robot for front door construction materials, FIG. 5 is a view showing a general assembly process outside the vehicle body, and FIG. 6 is a view showing an assembly process for a doorless sacrifice. 1.Laser marks, 2.Front door, 3.Rear door, 4.Main body, 5.Center Figure 1 (and 1 other person)

Claims (1)

[Claims] The steel plate parts that make up the car body are irradiated with laser light to form laser marks that serve as reference points during assembly, and the laser marks are determined and measured using magnetic sensors.Based on the position information, each steel plate part is positioned and the accuracy of the building material is determined. A method for controlling the assembly accuracy of a car body using laser marks, characterized in that the dimensional accuracy of the car body is managed by adjusting the laser marks and measuring the deviation of the laser marks after the assembly is completed.