General Principles For The Design Of Automobile Checking Fixtures

Introduction

Automobile parts have many complex surfaces and irregular shapes that cannot be detected using traditional measurement methods. The manufacturing requirements for the shape, size, and position of the simulation blocks on the automobile Checking Fixture are high, sometimes requiring accuracy to 0.05mm or even higher. Therefore, the automobile Checking Fixture must undergo three-dimensional measurement to ensure its accuracy requirements are met, and it also requires professional designers to design it.

There are many types of automotive parts with strong specificity. Most automotive Checking Fixtures are non-standard equipment, which are generally designed specifically based on the inspection content and product structure characteristics, as well as the production conditions and actual needs of the enterprise. The design quality of the Checking Fixture has a direct impact on production efficiency, product quality, development cycle, processing time, etc. Facts have shown that using a reasonably designed Checking Fixture for online inspection can meet the requirements of drawing dimensions, facilitate operation, be practical, and effectively ensure product quality, greatly improving labor productivity. Therefore, when designing automotive Checking Fixtures, it is necessary to consider several basic requirements and principles

The principle of processability requires that automotive Checking Fixtures should have good performance, meet the requirements of assembly processes, be simple and lightweight, operate quickly, and be easy to manufacture.

The Principle Of Manufacturability

The principle of manufacturability refers to the design of Checking Fixtures that can meet the following assembly and testing requirements for products:

1. Automotive parts are generally composed of single or multiple components, and some Checking Fixtures have extremely complex structures and multiple operation sequences. Currently, there are many manual inspections, and a certain amount of operational space is reserved during design
2. The interior parts have certain plastic deformation during inspection, and the design of the Checking Fixture should fully consider the deformation area and direction of the product when setting up locators and clamps
3. As high-precision equipment, Checking Fixtures have certain requirements for the production environment. It is inevitable that smoke, metal or waste will be generated in the production workshop, which will damage the exposed smooth working surface on the Checking Fixtures and require measures such as masking

The Principle Of Economy

Second, the principle of economy, which means analyzing the content of product testing under the premise of clarifying the production program, and then developing a design plan for Checking Fixtures based on the size of the product batch. The actual welding tooling used may not be overly complex, and it’s essential to promote the concept of “small Checking Fixtures for significant benefits” based on the specific conditions of the workpiece.

For example, some tooling can be designed to be used only for workpiece positioning, with the task of fixing the workpiece in a designated position according to product drawings and testing requirements, without clamping. During the inspection, simply place the workpiece into the inspection fixture. If it can be placed, it can be determined that the product is qualified. This tooling not only meets the inspection requirements but also improves production efficiency, minimizing the complexity of processing operations.

In addition, when designing Checking Fixtures, it is necessary to consider using universal standardized components as much as possible, so that they can be organically combined with the inspection body. Flexible use of this design method can simplify the Checking Fixtures, reduce the cost of making them, shorten the processing cycle, and also ensure the progress of making them. Where possible, try to design universal Checking Fixtures, combined Checking Fixtures, or flexible Checking Fixtures that do not require adjustment or slight adjustment for assembly and testing of similar types of workpieces. According to the production program, if it is mass production, the existing equipment can be slightly modified into a special machine for specific structural parts, which can also receive significant economic benefits. If necessary, mechanized and highly automated Checking Fixtures can be used to significantly improve the level of inspection technology, thereby enhancing the production competitiveness of the enterprise.

Principle of Reliability

Reliability refers to the ability of a product to complete a specified function within a specified time and under given conditions. He not only directly reflects the quality of each component of the product, but also affects the quality and performance of the entire product. Reliability is divided into inherent reliability, operational reliability, and environmental adaptability. Reliability metrics typically include reliability, failure-free rate, and failure rate

The Checking Fixture must have installation reliability, ensuring that all stressed components have sufficient strength and rigidity during the service life of the Checking Fixture. The operating position should be located in an easily accessible area for workers to ensure production safety.

1. Principles to be followed in the reliability design process of Checking Fixtures

1) Reliability design should have clear reliability indicators and reliability evaluation plans

2) Reliability design must be integrated into all aspects of functional design, and while meeting basic functions, various factors that affect reliability should be fully considered

3) The design should be targeted at the failure modes (i.e., the manifestation of system, component, and component failure or malfunction) to minimize or control the possible failure (malfunction) modes of the product during its life cycle

4) During design, advanced design principles and reliability design techniques should be actively adopted based on previous successful experiences. However, before adopting new technologies, new components, new processes, and new materials, it is necessary to conduct experiments and rigorously demonstrate their impact on reliability.

5) When designing product reliability, it is necessary to weigh factors such as product performance, reliability, cost, and time to make the best design plan.

2. Main contents of reliability design of Checking Fixtures

1) Establish a reliability model to predict and allocate reliability indicators. This should be done repeatedly during the product design phase. As the technical design continues to deepen and mature, modeling and reliability index allocation should also be constantly revised and improved

2) Conduct various reliability analyses, such as failure mode impact and criticality analysis, fault tree analysis, to identify and determine weak links. After discovering potential hazards, improve the design to eliminate hazards and weak links.

3) Adopt various effective reliability design methods, such as formulating and implementing reliability design criteria, reducing design margins, simple design, and environmental resistance design, and combine these reliability design methods with product performance design work to reduce product failure rates and ultimately achieve reliability requirements.

Principle of Artistic Quality

The design of the Checking Fixture is required to be aesthetically pleasing, ensuring that the operator feels physically and mentally relaxed, providing a sense of aesthetic enjoyment, while also meeting functional and economic requirements. The law of aesthetic form includes the principles of formal beauty, such as change and unity, balance and stability, proportion and scale, contrast and coordination, and other aesthetic principles that integrate various aesthetic factors. It is also an aesthetic principle that adapts to modern industry and science and technology.