Mazda presents mass-production EV
Mazda Motor Corp. unveiled its first mass-production electric vehicle, the Mazda MX-30, at the 2019 Tokyo Motor Show.
A new addition to Mazda's car lineup, the MX-30 is the automaker's third new-generation model. Aiming to offer an experience that lets customers relax and be themselves and deepens the bond between car and owner, the model is intended to invite new ways of using a vehicle.
Spaces in and around the center console give the cabin an open feel, and environmentally conscious materials such as cork and fabrics made from recycled materials are used in ways that bring out their natural appeal, creating a comfortable interior space. In addition, the MX-30 adopts freestyle doors so customers can invent new and creative ways of using the car. The center-pillar-less Freestyle doors have custom-designed hinges that allow the front doors to open to 82° and rear doors to open to 80°. This is meant to not only make entering and exiting the car and loading and unloading cargo easier but also provide easier access for strollers and wheelchairs. In addition to improving access, the company says the wide-opening doors open up new possibilities for enjoying the car: "drivers can stop by the park, open up the doors, and listen to the sounds of nature; or use the car like a base camp from which to enjoy outdoor activities with friends."
The model adopts Mazda's new electric-drive technology, e-Skyactiv. The high-voltage components that comprise the e-Skyactiv system include the motor, battery pack, inverter, and DC-DC converter. The direct current from the battery is converted to alternating current by the inverter to drive the motor, while the DC-DC converter steps down the voltage to supply power to the car’s 12 V auxiliary equipment.
The motor, inverter, DC-DC converter, and junction box are integrated into a single high-voltage unit that is mounted toward the front of the car. The size of the high-voltage battery mounted beneath the floor was carefully chosen to minimize CO2 emissions throughout its lifecycle, from resource extraction through to battery disposal. To limit the height of the battery pack, it uses a high-density battery module and thin busbar wiring as part of a scheme that minimizes the size of wiring between high-voltage parts, as well as a thin cooling system. As a result, it minimizes the impact on interior space and helps secure roomy comfort in the cabin. As an additional measure, the battery case is joined to the body to effectively help increase overall rigidity. The normal and rapid charging ports are packaged as a set that is accessed from the right rear fender, with the onboard AC charger positioned in the luggage area.
Another feature is a control scheme that minimizes energy loss throughout the system, including loss from the inverter, the motor, and in converting battery power into drive power. This combines with control between the system and the vehicle that reduces power consumption to maximize the amount of energy that goes directly toward powering the MX-30.
The MX-30 adopts a refrigerant cooling system that cools the battery pack when the temperature rises. Thin cooling tubes attached to the bottom plane of the battery module make contact with a heat exchanger. This structure contributes to realizing a compact battery pack. A sensor constantly monitors the battery’s temperature and controls the flow of coolant as needed. Cooperative control between the air-conditioning and battery cooling systems achieves effective cooling performance for both systems.
To prevent direct contact with the high-voltage components, the system adopts a cover and a control system that instantly shuts down power flow when it detects any irregularities. It also features a protective structure that protects the battery from external forces in the event of a collision, along with a mechanism to block off the high-voltage power.
The e-Skyactiv system can be charged using AC power or rapid-charged using DC power. The model supports DC charging with either the CHAdeMO or COMBO standard. AC charging of up to 6.6 kW is also supported.
The MX-30 further evolves Mazda’s i-Activsense active safety system. Turn-Across Traffic functionality is added to the existing Smart Brake Support (SBS) with vehicle, pedestrian, nighttime pedestrian, and bicycle monitoring functions already built into the system to help prevent collisions when turning across traffic at intersections. When turning left at an intersection (on left-hand drive units), the forward-sensing camera and milliwave radar sensors monitor oncoming traffic. When the system determines there to be a chance of a collision occurring, it automatically applies the brakes to help prevent impact or mitigate damage that may occur. The function only operates at low speeds and is programmed to monitor nearby vehicles.
The MX-30 also introduces new Road Keep Assist technology, which helps keep the car on the right track even in the absence of lane markings. When travelling at speeds of approximately 60 km/h or greater, the forward-sensing camera monitors elements such as grass and curbs along the edges of unmarked roads. When the system determines there to be a chance of the vehicle drifting off the road, it assists steering operations to prevent that from happening.
Emergency Lane Keeping with Blind Spot Assist helps prevent collisions when changing lanes. The system uses 24 GHz milliwave radar sensors to monitor the areas behind and to the sides of the car when traveling at speeds of 60 km/h or greater. If the driver steers to change lanes when there is a threat of colliding with a vehicle approaching from the rear, the system assists steering operations to help prevent impact or mitigate damage that may occur.