Production Capacity
Increase with the Goal of Reaching 10,000 Vehicles/Month
Toyota invested a total of 4.6 billion yen in the Five-Year
Facility Modernization Plan it began in 1951, with a focus on updating and
streamlining existing facilities and establishing new production facilities for
the R engine and the Crown passenger car. After introducing 1.4 billion yen
worth of imported machinery and many other automated machines, the Honsha Plant
established a production structure capable of achieving the goal of 3,000
vehicles per month. By October of 1956, the plant was already producing 5,074
vehicles per month.
In June 1956, in response to robust demand for automobiles
and to prepare for further demand increases in the future, Toyota developed its
Production Facility Enhancement Plan, which contained the goal of reaching
monthly production of 10,000 vehicles. This plan covered the next approximately
two and a half years until October 1958 and focused on establishing dedicated
automated machinery and equipment, as well as continuous production line
processes.
Molding work on a
turntable with a sand slinger
In the casting plants, Toyota installed a mold conveyor line
for casting cylinder blocks in 1955. The conveyor line linked together the
various steps involved, such as the mold-making step for making molds out of
sand, the pouring step for pouring molten cast iron into the mold, and the
mold-removing step for extracting the cast product from the sand mold, and made
it possible to manage them on a single line.
Next, a 7-ton cupola furnace for melting cast iron was
installed, first at the No. 1 Special Foundry in November 1957, then at the
Malleable Casting Foundry in December of the same year, and then at the
Ordinary Casting Foundry in July 1958. In January 1958, a tunnel-type
continuous annealing furnace began operating with a monthly production capacity
of 600 tons, and the aforementioned mold conveyor line was also extended and a
sand slinger (a molding machine that makes molds by feeding and compacting
molding sand) was added. A shot blast for removing molding sand adhered to cast
products was also installed, enhancing the back-end processing capability for
casting.
In terms of new casting technologies, the shell molding
method that forms molds by mixing and baking silica sand with a phenol resin
was introduced in 1954. Then in 1957, Toyota used this manufacturing method to
develop an internally made shell machine and began using it to make cores for
transmission cases.
A six-inch upsetter
manufactured by Ajax
In June 1957, Toyota installed a 2,000-ton forging press
made by Ajax Manufacturing Company of the United States and switched the
manufacturing of ring gears from hammer forging to die forging. Furthermore, by
the end of that year, Toyota installed two roll forging machines made by
National Corporation of the United States, introducing a total of 11 forging
machines by the end of 1958.
Conventional hammer forging employs several separate hammer
forging machines―one for forming a rough shape, another for finishing the
workpiece by forging it into the required dimensions and shape, and yet another
for punching out burrs to form the workpiece into the final external shape. Die
forging, on the other hand, utilizes multiple forging dies mounted on a single
forging press to handle multiple processes. Toyota's switch to die forging thus
significantly improved work efficiency and also reduced the number of forging
machines needed. Die forging also made it possible to simultaneously produce
two parts from a single piece of material by using a forging die shaped for two
workpieces, increasing both productivity and product precision.
A 950-ton billet shear
manufactured by Buffalo
Along with increases in the speed of forging processes,
efforts were also made to increase the speed of the front-end process for
preparing materials. In February 1954, Toyota installed a 950-ton Buffalo
Billet Shear that could cold-shear steel stock into the desired lengths. This
machine improved shearing work efficiency (as measured by the number of process
steps) by approximately ten times. Moreover, because it performed precise
shearing, material waste was reduced, enabling Toyota to achieve a drastic
reduction in the volume of material required.
To cope with the faster speeds of the forging processes, it
became necessary to more quickly heat the material. Therefore, Toyota in 1956
installed a rotary hearth furnace and a high-speed furnace (tunnel furnace).
Capable of rapid heating as well as heating with automatic feeding using a
conveyor, these furnaces increased heating capacity by approximately 30 percent
compared to conventional furnaces.
A transfer machine
for steering gear box machining
Regarding its machining plants, Toyota installed a transfer
machine for processing the F engine cylinder block in Machining Plant No. 1 in
June 1956. Subsequently, the engine assembly plant of Machining Plant No. 1 was
modified in April 1958 to handle assembly and testing of the R and F gasoline
engines and the D diesel engine. As a result, the entire process from engine
assembly to testing was automated using a conveyor.
After Machining Plant No. 4 (1,900 square meters) was
completed in September 1956, the machining of gears from Machining Plant No. 2
and the suspension-related assembly from Machining Plant No. 3 were transferred
there. Then in February 1958, a heat treatment plant was added to the north
side of Machining Plant No. 4 and a continuous gas carburizing furnace for
carburizing and quenching gears was installed. The adoption of this furnace led
to automation of all processes, thereby improving productivity, stabilizing
quality, and reducing costs.
Meanwhile, at Machining Plant No. 3, a transfer machine for
processing steering gear boxes was installed in May 1958. The transfer machine
performed seven process steps completely automatically, except for the loading
and unloading of workpieces.
Flow of stamping
processes linked by a conveyor
In the stamping plants, Toyota added six hydraulic presses
in 1957 and achieved a continuous stamping line by linking various machines via
belt conveyors. These steps shortened the time required for manufacturing
stamped parts, increased production capacity, and reduced the number of stamped
parts that had to be kept on hand from two months-worth to one month-worth.
Furthermore, between March and July of the same year, Toyota added four
hydraulic and three mechanical presses. Along with these additions, roll
feeders for feeding steel plates into presses and iron hands for extracting
formed panels from presses were installed, improving the efficiency of stamping
operations.
Stamping work using a
profile die sinking machine
In February 1957, Toyota built a new stamping mold plant.
This action was taken in response to the increased number of stamping molds
required due to an increase in the number of vehicle models produced, as well
as to the need to produce molds quickly during vehicle redesigns. By installing
advanced mold-manufacturing machines, such as high-performance copy shaping
machines, high-precision planers, and precision boring machines, Toyota strove
to improve the efficiency of its mold-manufacturing and mold-repairing
operations.
As a result of the promoting of capacity increases in
various production areas toward achieving a monthly production of 10,000
vehicles, Toyota recorded a monthly production of 9,080 vehicles in June 1959,
just prior to the completion of the Motomachi Plant.
Source: Toyota Motor Corporation
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