An Innovative Welding System: The Ultimate in Rationalization
Honda began producing the T360 mini truck at Saitama Factory(currently Saitama Factory's Wako Plant) in June 1963, with production of the Honda Sports S500 beginning at Hamamatsu the following August. With the production of these models, Honda had at last achieved its dream of becoming an automobile manufacturer.
The welding line for the L700 light van, which debuted in September 1965. The line operators performed their work using bulky welding guns and auxiliary cables.
Initially, the white bodies of these models - the welded and assembled body prior to painting - were comprised of medium- to small-sized pressed sections. Although such pressed parts were easy to make, they added to the steps required for welding and assembly.
Soichiro Honda's philosophy on manufacturing was "the fewer the steps involved in a process, the higher the quality and efficiency." In keeping with that philosophy, the company sought to manufacture quality vehicles while demonstrating the efficiency it needed to compete with well-established automakers. Therefore, Honda adopted a new "building block" system for white-body production. Designed to build car bodies with large, one-piece formed panels, the new system was the embodiment of Mr. Honda's original concept for the new N360.
The accompanying welding line began with a subassembly welding process in which various body parts such as the side panels, roof, and floor were assembled. Next, the main assembly welding process combined these parts into an integrated body, and an additional welding process was performed on the assembled unit.
Then, in 1967, Honda introduced a new body-welding system to the line at Sayama Factory (now, Saitama Factory's Sayama Plant) which was intended as a production facility for the N360. That system consisted of PW (press welder) welding machines and a GW (general welding) machine. These were responsible for the subassembly process and main assembly process, respectively. Both machines were designed for enhanced accuracy and quality in body welding, along with a reduced cycle time. However, the press welders of that time had poor welding efficiency and the operators had to correct many of the machine-welded points by hand.
The general welder was by comparison a highly efficient, integrated system capable of building the entire body frame in a single process and at a high level of quality. Still, it had the inflexibility of a dedicated welding machine, and as such, it required a setup of several hours for the N360 or any of the LN360 series models each time the settings were changed.
The additional welding process was one in which the line was covered with a number of portable welding guns hanging down from the ceiling via bulky auxiliary cables. Each operator, having to work with one of these heavy units, would continually grapple with the cables. It is no wonder, then, that they often referred to their workplace as "the portable jungle."
The N360's anticipated monthly production volume was 5,000 units per month when the line first went into operation. However, the car was such a hit upon its March 1967 release that Honda had to implement several dramatic changes to the line in order to meet the demand.
"Dedicated (welding) lines like the one created for the N360 required considerable investment each time the production volume for a target model was changed," recalled Nobuji Maezawa, who as technical adviser at Sayama Factory's Second Plant was in charge of the design of welding machines. "We used to argue that the new welding lines we were designing would have to accommodate the inevitable expansion of Honda's model line," he said.
Personnel from Sayama's Second Plant (formerly the Manufacturing Machinery Plant) and the H1300 Special Planning Office got together in 1969 in order to collaborate on modifications to the subassembly press welder. Their purpose was to better equip Suzuka Factory in producing the Honda 1300. The result of that effort was a new sliding general welder developed for the main assembly process. The system employed a modular structure for increased flexibility in the production of multiple models, permitting the separation of the main unit and fixture jig (which facilitated the welding). The new machine made it much easier to change settings from one model to the next, shortening the changeover time to 15 minutes.
An improved sliding general welder (GW) was introduced to the line at Sayama in 1970. This unit was equipped with a changeover mechanism that could automatically change the dedicated welding jig attached to the main unit. Such an addition would enable the Sayama and Suzuka factories to handle the same models on each of their welding lines.