The automotive chassis-putting it all together

Let’s start with a guessing game. Do you know how many parts the average car contains? Unless you’re an avid automobile enthusiast (or, perhaps, a trivia game devotee) you probably don’t, so here’s the answer: around 30,000 if you count right down to the last nuts and bolts. An engine alone has about 1,800 separate parts. 

The point I’m making is simple; that’s a lot of bits to put together to create the final product, so the opportunity for problems in automotive manufacturing is immense. What if everything doesn’t fit together? To complicate things further, those 30,000 parts won’t all be made a single manufacturer, either. Rather, they’re likely to be sourced from a wide range of suppliers, the vast majority of which are making a component that at some stage will have to fit together with another piece made by a different manufacturer. There’s no great leap of faith required to see that things could easily go wrong.

When it comes to putting all these pieces together, then, where do we look to avoid issues? There’s a simple answer. Measurement.

What is a chassis?

Before we get to examining that assertion in detail, though, let’s take a closer look at the automobile chassis. It’s the framework or structural “skeleton” of the vehicle, typically composed of the following:

  • Frame (can be unibody, or not)
  • Suspension system (springs, shock absorbers, control arms, bushings)
  • Wheels and tires
  • Axles
  • Engine mounts
  • Transmission mounts
  • Exhaust system (pipes, mufflers, catalytic converters)
  • Fuel tank
  • Steering systems (steering column, gearbox, tie rods, steering linkage)
  • Electrics and wiring
  • Subframe
  • Crossmembers and bracing (to increase structural rigidity)
  • Body panels (not technically part of the structure, but considered so)

And, of course, on top of the above, all the nuts, bolts, and other parts required for everything to be assembled. Obviously, the exact nature and in some cases number of these components varies from vehicle to vehicle, but you get the idea. To build a vehicle, with parts from multiple suppliers, manufacturing processes must be exact.

The importance of measurement

This reality means that measurement, and the role of measurement systems, is central in automotive manufacturing. There’s also more to it than just that. When we look more closely at how measurement affects various processes, we can see why:

  • All the parts we’ve already referenced must meet specific dimensional and tolerance requirements, be of a consistent quality, and able to perform as expected. Furthermore, defects and deviations must be identified early in the manufacturing process both to allow time for correction and to ensure that faulty vehicles are avoided. Measurement is required to assure that this is the case.
  • Measurement data can be used throughout manufacturing for process optimization, to monitor and analyze manufacturing performance in areas such as machining and assembly. The data highlights problem areas, opportunities to improve processes and enhance efficiency, and to reduce waste.
  • Accurate measurement is an essential contributor to vehicle safety, central for instance to the manufacturing of braking systems – where there is no margin for error.
  • Automotive manufacturers must adhere to strict standards and regulations many of which include specific measurement requirements that, if not met, can result in both legal issues and fines.
  • Cost is an ongoing challenge for automotive manufacturers and precise measurement helps to control material usage and reduce waste. By continually monitoring dimensions and tolerances, manufacturers can minimize the need for reworking or scrapping defective parts.

Measurement also plays a role in supply chain management, helping to ensure that different suppliers provide parts that meet specified quality standards and dimensions. As we alluded to earlier, without accurate and precise measurement how could an automotive manufacturer be sure everything would fit together?

Measurement use cases

Let’s see how the broader themes referenced above are applied in practice by looking at three measurement use cases.

  1. Component dimensions – Accurate measurements are critical when the individual components of an automobile – engine parts, transmission, suspension systems, etc. – are being manufactured. These parts must meet strict dimensional tolerances and that cannot be achieved without ongoing measurement.
  2. Alignment – Using the example of body panels, these must fit together seamlessly with gaps between panels being consistent and within specified tolerances. Without consistent measurement in this area, issues related to alignment, wind noise, water leaks, and others would arise.
  3. Tires and tire quality – tires are critical to vehicle safety and measurement is central to their production processes from the precise drawing of the wires that make up the tire cords to tread depth, balance, and roundness of the final product.

There are numerous other use cases that demonstrate the importance of measurement in automotive manufacturing too, ranging from the calibration of specific systems to overall vehicle quality control. The bottom line is that measurement systems must, if they are not already, be a central part of any automotive manufacturing process. Manufacturing requires enormous investment; failing to invest in maintaining accuracy makes no sense and can lead to catastrophic failures.

That’s why the machines that are used to make components – machine tools in particular – need to be accurately measured. The tool blades that shape these components play a critical role and must be maintained throughout their lifecycle, so that their accuracy is not compromised, and replacement can be planned more efficiently as they degrade through usage.

Without a measurement system in place to ensure consistent, precise, and traceable componentry is manufactured, the risk of serious problems that threaten the viability of the end product arising is multiplied considerably. For proof let’s end how this blog began, by looking at a number!

In fact, another number you probably don’t know; that manufacturing fuel injectors requires high quality, EDM-machined holes drilled at a diameter lower than 145µm. You see the point: successful manufacturing outcomes depend on accurate measurement systems.

About Conoptica

Conoptica is a leading source of high accuracy measurement systems and has been providing high tech camera-based measurement solutions since 1993. We make sure that the metal working industry has access to key quantitative data about their products and tools.

Talk to us to find out how our innovations can support your machine tools and enhance production accuracy, efficiency – and reduce costs in the manufacturing process.

Get in touch today.