Experience Extraordinary Exhilaration with a Premium Interior - Honda Prelude -

Negishi The Prelude is a specialty coupe that combines the client’s (Honda’s) distinctive sportiness with comfort. The seats were required to have a holding performance to enjoy sporty driving, along with a special, enveloping seating comfort. Additionally, design was a high priority, as the client even asked us to consider the seats as an element of the vehicle’s exterior, not just the interior.
As a result, the key to development was how to realize a distinctive seat design appropriate for mass production while meeting the requirements for comfort, safety, and other aspects. In particular, achieving a compact and stylish design for the upper part of the backrest presented challenges in many areas.

IkezawaThe most significant was the collar-like structure around the headrest, which involved really intense ideation to find a way to balance minimal assembly work with the required shape and strength. Ultimately, we devised a method of embedding a thick wire frame into the pad itself and forming the entire assembly as a single piece. (Fig 1) This resulted in a slim, high-backed seat with an imposing presence.
Another challenge was the headrest stitching. The curvature of the seam line, which was extremely sharp when viewed from the side, would meander as the seam allowance* was pulled when we tried to reproduce this line using conventional equipment. To overcome this, we achieved the distinctive shape of the headrest by adopting a new specialized sewing machine capable of cutting off the seam allowance while stitching. (Fig. 2)
* Extra margin of fabric added for sewing

MochizukiBased on the vehicle concept of a comfortable ride for passengers and enjoyable sporty driving for the driver, the seat cushions for the driver and the front passenger were designed separately. Specifically, we used separate urethane hardnesses for each seat. Additionally, the side supports, or bolsters are higher and firmer for the driver’s seat to better hold the driver in place while cornering, but lower and softer in the front passenger seat for a relaxing ride and ease in getting in and out. (Fig. 3) We also added a layer of low-resilience urethane to both seats to create an enveloping feel such as that in a luxury sedan.

Mori As with the seats, a high-quality appearance was required for the door trim. Since the coupe’s doors are fairly large, the stitch lines naturally become long. If the stitch lines need to be straight, even the slightest distortion during skin bonding can significantly impair the appearance.
In response, we adopted a new method by which the skin is strongly vacuum-drawn onto the mold and held in place in a vacuum before being pressure-bonded onto the substrate* (Fig. 4). This enabled us to achieve a premium-quality appearance.
* Base parts for skin bonding

Hara Furthermore, since the door trim also acts as a brace for the driver’s knee during sporty driving, high rigidity is required across the entire panel. To achieve this, the design incorporates numerous reinforcing ribs in a grid-like pattern on the backside, as well as more fastening points to secure the part more firmly to the vehicle body.
On the other hand, simply pursuing rigidity could turn the door itself into a hazard in the event of a side collision. Therefore, we added a small crease in the armrest so that it would intentionally deform and absorb the impact of a side collision. (Fig. 5)

Negishi The Prelude’s seat frame is an integrated frame in use since the 2020 model. It has continued to mature through the development of numerous subsequent models. Building on that, this high-back version marks the culmination of our work. Working alongside veteran staff members, project team members, many of whom were young, worked through a process of trial and error to bring these distinctive seats to the world. It is our sincere hope that both drivers and passengers will enjoy to the fullest this premium next-generation automotive cabin space, including the doors, created through the teamwork of all project members.