At Marysville last week, Green Car Reports got to see this great change underway. Honda opted to combine its two assembly lines into a single flexible assembly plant concept. The project has been three years in the making behind the scenes, and Honda announced the project specific to the plant in March 2023.\u00a0<\/p>\n
The plant previously made the Acura Integra and TLX on one line, while the Accord was made on the other. Without interrupting the production flow (and temporarily moving Accord production at one point), that involved a series of transitions, with the added space allowing a much wider line, with a new sub-assembly strategy allowing for processes that EVs require and gas models don\u2019t\u2014and vice versa.\u00a0<\/p>\n
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Honda Accord assembly at Marysville<\/p>\n<\/div>\n
Mike Fischer, the leader for Honda\u2019s North American EV project, explained to GCR that this transformation of Ohio facilities is probably the single most important foundation for Honda manufacturing<\/strong>, moving forward, because it shows how Honda can maintain not just production flexibility but flexibility in how it keeps engineering and designing its vehicles<\/strong>. BEV and ICE vehicles can remain optimized for their respective strengths, and neither one will be hobbled for it on the manufacturing floor.\u00a0\u00a0<\/p>\nHonda is keeping the overall build time exactly the same after the line change, according to Fischer, who led the production launch of the 2013 Accord, which required some changes at the plant due to its extensive engineering changes like a strut layout, CVT automatic, and available hybrid versions. The upcoming BEV models and their subassemblies will take \u201ca little bit\u201d more build time than the current Accord, he said, adding that there\u2019s still opportunity for optimization and it should be the same or maybe a little less.<\/p>\n
Meanwhile, it\u2019s picking up the pace on that one line such that total output from the plant could potentially reach the previous peak production of about 950 vehicles a day, or an annual capacity of 220,000 from two lines.\u00a0<\/p>\n
It was no easy task. The upcoming EVs, which we previewed in October with a Honda 0 Series prototype drive, are set to have very little in common with Honda\u2019s gasoline vehicles<\/strong>, and they\u2019re going to be fundamentally different for many years. Honda has no plans to merge body structures or vehicle platforms among its gasoline and hybrid models.\u00a0<\/p>\n![\"Honda](\"https:\/\/images.hgmsites.net\/lrg\/honda-0-series-battery-cases_100955596_l.webp\" "\\"Honda")
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Honda 0 Series battery cases<\/p>\n<\/div>\n
<\/span>Honda seeding the future in with its bread and butter\u00a0<\/span><\/h2>\nFrom the concept-car proportions to the next-gen Asimo OS interface, to all-new switchgear and displays, to the calibration needs of their Level 3 automated driving system, and everything underneath, it\u2019s seriously hard to find commonalities. While the Accord\u2019s structure is primarily steel, the EVs will be built on an aluminum-focused body structure, with the aluminum battery pack an integral piece. They were designed with different priorities\u2014so as to have short overhangs and efficient cabins, with the force paths designed with no allowance for an engine in front, eliminating the need for high cowl crossmembers and sending force paths to thick side rails.\u00a0<\/p>\n
So it created a series of sub-assembly lines<\/strong> that could handle all the differences in the way an EV is assembled versus the way a gasoline or hybrid vehicle is assembled\u2014and widened the way for those sub-assemblies and for parts and components to get through.\u00a0<\/p>\nHonda had to upgrade its vehicle carriers for heavier EVs, redesigned its people-movers along the line for better ergonomics, and had to devise robots that would apply thermal gap filler to the pack on the vehicle line. It also had to design a process for battery pack assembly itself\u2014including the installation of cells from the nearby Honda-LG battery plant\u2014and for battery pack installation into the vehicle (below).\u00a0<\/p>\n
For the body structures of the new EVs, Honda is switching to a CDC weld technology\u2014a world first<\/strong>, employing pulses rather than a constant current to help make a lighter, stronger structure. If you expect fireworks of sparks at welding stations, it feels uneventful.<\/p>\n![\"Honda](\"https:\/\/images.hgmsites.net\/lrg\/honda-accords-going-through-inspection--marysville-oh_100955608_l.webp\" "\\"Honda")
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Honda Accords going through inspection – Marysville OH<\/p>\n<\/div>\n
ICE and hybrid vehicles pass through the EV battery pack area without stopping, while EVs may pass through some of the steps for elements like exhaust and fuel-system installation without stopping. Honda calls it \u201cmulti-platform flexibility.\u201d And to keep the rate of Accord Hybrid production running strong, Honda also created a new area for hybrid battery assembly.\u00a0<\/p>\n
LG pouch cells fill the modules that get installed into the EVs\u2019 battery packs on the Marysville line, as we saw demonstrated, but Honda hasn\u2019t yet confirmed the battery capacity. The pack is kept thin by Honda\u2019s unusual and innovative cooling strategy\u2014with water jackets machined into the pack case itself, allowing super-thin channels of coolant to circulate between that and a jacket cover that fits over it.\u00a0<\/p>\n
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Honda 0 Series battery case – quenching after casting<\/p>\n<\/div>\n
![\"Honda](\"https:\/\/images.hgmsites.net\/lrg\/honda-0-series-battery-pack_100955604_l.webp\" "\\"Honda")
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Honda 0 Series battery pack<\/p>\n<\/div>\n
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Friction stir welding of Honda 0 Series battery case halves<\/p>\n<\/div>\n<\/div>\n
<\/span>Honda\u2019s engine plant pivots to packs\u2014and maybe motors<\/span><\/h2>\nMeanwhile, the packs themselves are set to be made less than an hour\u2019s drive away, at Honda\u2019s Anna Engine Plant, where it\u2019s taking on a similar challenge: manufacturing some of the key components for the 0 Series\u2019 battery pack and powertrain without interrupting its throughput for the range of engines\u2014including Atkinson-cycle four-cylinders for the Accord Hybrid.\u00a0<\/p>\n
Honda has made about 30 million engines at Anna, and it has the production capacity to make more than 4,800 of them per day. Electric motors for the EVs, engineered by Honda but built by captive supplier Hitachi Astemo at present, are likely to be brought into Anna eventually, executives said.\u00a0<\/p>\n
With six 31-foot-tall, 6,000-pound die-cast machines at Anna, Honda will \u201cmegacast\u201d the battery-pack cases set to go into EVs at both Marysville and East Liberty. As Honda underscores, it\u2019s larger than anything it\u2019s ever die-cast<\/strong>.\u00a0<\/p>\nMegacasting uses less energy than gigacasting, and the die-cast process reduces scrap, eliminates the need for heat treating, and enables Honda to shift the energy used in the process from gas to electricity\u2014reducing the CO2 footprint.\u00a0<\/p>\n
In Honda\u2019s EVs, the pack is split into a front and rear section, with a friction stir welding process\u2014strongly joining the two pieces without melting\u2014bonding the \u201cbutt joint\u201d between the two sections.\u00a0<\/p>\n
Prior to machining, to make sure the cases, which serve as part of the structure of the EVs, are dimensionally in check\u2014and, given the shape, that it\u2019s stayed flat\u2014Honda has put to use a new \u201cphotogrammery\u201d method potentially employing more than 100 cameras that rapidly take a series of photos of the part, reconciling all the recorded geometries.\u00a0<\/p>\n
![\"Honda](\"https:\/\/images.hgmsites.net\/lrg\/honda-accord-hybrid-component-assembly--marysville-ohio_100955601_l.webp\" "\\"Honda")
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Honda Accord Hybrid component assembly – Marysville, Ohio<\/p>\n<\/div>\n
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