Fasteners for applications with high requirements

The electric drive components in EVs, such as the engine, battery and power electronics, pose special challenges to the fasteners and functional components like valves. As a result, the fasteners and functional components for the technical aspects of the electric vehicle powertrain are very important. The best way to respond to the challenges that arise when developing these components, such as electrical insulation, compact design, light weight and resistance to corrosion, is provided by innovative fastener solutions. These also add value through ergonomic or automated assembly. ITW delivers components that meet these tough requirements.

Multifunctional components

The most important applications for fasteners in electric vehicle powertrains are the battery, the high-voltage routing, and the mechanical drivetrain with transmission and engine. Functional components like valves also play a decisive role. Degassing valves ensure the airflow in the event of a thermal runaway, and pressure compensation valves maintain safe operation in many applications. They are waterproof but ensure the pressure compensation with the environment. Emergency drainage valves drain any unwanted water penetration immediately. By acting in combination, these valves prevent overpressure and short circuits.

EV battery components

Degassing Valve:

The degassing valve is an important functional component for venting the battery housing. In the event of a thermal runaway, it enables safe and precise degassing, while also guaranteeing watertightness under normal operation up to IPX6K/9K. The valve is triggered once an adjustable differential pressure is reached. It is available in low-profile designs and with a bayonet interface. Customer adjusted designs are also available to meet individual requirements. In the case of low pressure peaks, the valve closes again and is once again watertight.

Balance Valve:

The balance valve plays an important role in compensating pressure differences in watertight housings with free air space. It uses a adjusted membrane that forms a water barrier while allowing an defined airflow. The ITW team designed this valve to be both cost efficient and compact. It can also compensate high sheet thickness tolerances and ensures watertightness up to IPX6K/9K.

Busbar Fixation:

The ITW team has developed a busbar fixation with a special fastening system that securely connects the high-voltage cables. This busbar system features a cover with a secure fastener that is assembled according to the poka-yoke principle. It secures the component correctly before it can be finally screwed into place. The system also features tolerance compensation and electrical insulation for the high-voltage cable.

Battery Module Fixation:

The ITW EV battery module fixation creates a secure connection and improves the noise, vibration and harshness properties (NVH). The fixation holds the various modules inside the battery pack together, and connects them to form a stiff module. The special ITW design uses molded material to ensure a secure fixation and prevent NVH-related problems.

Transmissions and motors

Blind Hole Fastener:

The blind hole fastener is a simple solution for securing NVH damping material and sound covers. It is attached axially to drilled or cast holes. It delivers high holding forces of ≥ 200 N and is incredibly easy to assemble. Thanks to its special design, the blind hole fastener can be removed with a simple rotating motion before being used again. Its modular construction makes the NVH blind hole fastener suitable for various applications.

High voltage and cable

Cable Channel High-Voltage:

The cable channel for high-voltage cables is an all-in-one solution for a range of pipes and cables. The integrated inserts, made of metal and/or plastic and TPE, shorten assembly times and can both improve aspects like noise emissions and provide a secure connection in the overall assembly. ITW’s expertise makes it possible to deliver this complete and integrated solution directly to our customers.

Support Brackets:

The support brackets provide a secure connection and support for cables of various different shapes and sizes. They offer cost-efficient advantages in terms of weight reduction, noise damping and reliable cable routing. They are designed according to modern FE methods for bionic design optimization. Their robustness ensures both excellent performance and secure cable fastening.

Spring Stem:

The spring stems from ITW were developed specifically for easy assembly in plastic modules. The spring element is designed to absorb the tolerance chains of the components. It also guarantees reliable pre-tension across the service life, even when the components are subject to thermal expansion and lateral contraction.

Shoulder Bolt Fastener:

The shoulder bolt fastener is easy to assemble in plastic elements. Its functional design features a large contact surface that significantly reduces the surface pressure required. As a result, this fastener can also be used in lightweight materials. The shoulder bolt fastener’s reliable hold and stability makes it the ideal solution for secure connections in plastic components.

Innovations from ITW Global Fasteners

The drainage valve – the airbag for directly cooled electronics

Innovations from ITW Global Fasteners ensure safety and longevity in electric vehicles. One of these innovations is the drainage valve, developed to improve sustainability.

• Suitable for cooled batteries or high-power electronics

• Triggered in the event of a leak in the coolant lines

•  Complete water protection up to IPX9 possible in normal operation

•  Fluid drained away upon reaching a critical level

•  Not sensitive to humidity and changes in climate

The drainage valve is the safe and reliable solution for internal cooling of batteries and high-voltage components. It acts as a kind of airbag for the electronics, preventing short-circuits in high-voltage components caused by unwanted leaks of water or coolant. This valve simplifies the sealing of the cooling system and is an important safety mechanism that stops leaks causing damage.

Other areas of research

Thanks to things like MUCELL technology or the development of compound materials, ITW is helping to make electric vehicles even more efficient and sustainable.

MUCELL technology for robust lightweight construction

MUCELL technology enables the construction of injection-molded components that are both light and robust. Components can be made up to 30% lighter depending on the design.

Compound materials for special applications

To reduce weight further, ITW developed compound materials to replace metal components and deliver specifically required properties. Using composites can create components with improved strength, corrosion resistance and other advantageous qualities.

Comprehensive laboratory tests

In our laboratory, we subject our components to thorough watertightness tests, especially for valves like our drainage valve. This process involves preparing the components, using special test stands, and carrying out pressure and leak tests. We analyze the data to ensure that the components meet watertightness standards. As a result, these tests guarantee that our products perform reliably in various applications.

Interview – Developing new ITW products

We at ITW are never afraid of a challenge and take innovative approaches to developing new products for electric powertrains. In this interview with Application Manager EV Manuel Kellner, you can find out how ITW helps its customers at a time of technological uncertainty and rapid advances in electrification.

ITW Global Fasteners: What are the challenges you face when it comes to developing new products for electric powertrains?

Manuel K.: We are currently in a very exciting time when it comes to product development in this area. As electrification continues at breakneck pace, bringing with it a combination of technological uncertainty and time pressure, there is a need for new expertise and skills. Thanks to our many years of experience with our innovative ITW fastening solutions, we are able to fall back on a broad repertoire that allows us to keep pace with the industry and give our customers the best possible support for their projects.

ITW Global Fasteners: What new skills does the transformation to electromobility call for?

Manuel K.: New requirements like technical cleanliness or the use of flame-protected materials require new expertise to make sure that electric vehicle components are safe and function properly.

ITW Global Fasteners: What measures has ITW already taken successfully in this regard?

Manuel K.: Every time we face a new challenge, our priority is to gain a deep technical understanding of all aspects and offer the best possible solutions. This includes our ability to design excellent seals on our self-developed IPX6K/IPX9K test stand that meet the new requirements. Or our in-house development of assembly and testing stations that guarantee 100% control with automatic traceability.

ITW Global Fasteners: Which products are currently the most demanding?

Manuel K.: One of our main focus areas at present is the development of degassing valves. Here, the valve must remain both robust and reliable throughout the vehicle’s lifetime. It must also meet requirements in terms of compactness, watertightness, flame protection and installation situation, and a complete quality control. This requires a lot of creativity to find the right solution.

ITW Global Fasteners: What can I as a customer expect from ITW here?

Manuel K.: Thanks to our broad-ranging expertise gained from past projects, we are able to quickly ask the right questions and get to the core of a problem. Through a comprehensive series of tests and preliminary investigations, we already have a diverse set of potential problem solvers to hand that can help us quickly find a solution. This means we are more than just supplier. We are a development partner that strives to create the ideal product for the specific need together with the customer.