As previously discussed, after monthly production reached
10,000 units in December 1959, a second phase of construction expanded the body
production line at the Motomachi Plant and a new stamping plant was
constructed. Later, an aluminum casting plant, the No. 1 Machining Plant, a die
plant, the No. 2 Assembly Line, a plating plant, and other facilities were
added, and operations began by the autumn of 1962. In conjunction with this
expansion of facilities, monthly production increased to 20,000 units in
October 1961, and reached a hoped-for 30,000 units in October 1963. The
Motomachi Plant No. 2 Machining Plant was completed at the end of that year,
followed by an expansion of the stamping plant. In addition, a small-part
machining plant was installed in January 1964 to mass produce parts requiring
high precision, such as piston pins.
In order to raise its international competitiveness in
response to the liberalization of passenger-car imports discussed above
(implemented in 1965) and the liberalization of automotive capital (implemented
in 1975), Toyota continued to expand its plants with the aim of building mass
production systems and achieving monthly production of 50,000 units. At that
time, a major shift in the thinking about how Toyota's production plants should
be began to emerge. That thinking centered on the idea that plants should be
economical and specialized, while being functional, efficient, and highly
flexible and capable of raising quality and productivity while reducing costs.1
A move was afoot to have plants specialize according to function, with center plants
focusing on vehicle assembly, while others focused on engines, powertrain
components, suspension components, and so on, including on course materials,
such as cast and forged parts, to respond efficiently to the diversification of
vehicles and their specifications.
The forging shop at the Honsha Plant increased its forging
presses and upset forging machines starting in about 1962 and moved forward
with automation. As a result, continuous automated forging of connecting rods
from rough forging to burr removal using forging presses became possible.
Automation of upset forging2 also advanced, allowing for the automation of
processes from heating to upset forging in the making of axle components such
as drive pinions. Despite this automation, however, the Honsha Plant Forging
Plant was approaching the limits of increasing production capacity.
As a result, Toyota decided in September 1963 to construct a
new forging plant (the Chita Forging Plant) at a site near the Chita Plant of
Aichi Steel Works, Ltd. and outsource operation of the new plant to Aichi
Steel. Construction began in December of that year, and operations commenced in
July 1964. Today, Aichi Steel's forging business (the plant facilities and
structures were transferred to Aichi Steel) is Toyota's largest source of
forged parts.
With the aim of achieving monthly production of 50,000
units, Toyota adopted a basic policy of dedicating the Honsha Plant to truck
production and the Motomachi Plant to passenger car production. In order to
increase production capacities in accordance with this policy, Toyota decided
to construct the Kamigo Plant as a dedicated engine production facility. In
June 1964, the Kamigo Plant Construction Committee chaired by Toyota Motor Co.,
Ltd. Director Hideo Tsutsumi adopted the following construction policies:
1.Facility planning policy: Increase equipment to reduce
personnel by half.
2.Production products: Engines and transmissions.
3.Production scale: Initially, 10,000 units of M engines
monthly, with the possibility of increasing monthly production to 100,000 units
including transmissions.
Construction of the plant began in October that year, the
first engine was produced in September 1965, and a completion ceremony was
conducted in November.3 The plant was Japan's first dedicated engine plant,
capable of performing integrated engine production from casting to machining
and assembly.
Low-frequency induction furnaces4 were added to the casting
line melting equipment for iron and aluminum, and the shell-mold method was
introduced throughout the molding process from core to main-mold manufacture.
In addition, innovative equipment including an improved conveyor system and a
series of sand processing facilities were installed to create a cutting-edge
plant.
Transfer machines were installed over a wide range of
machining processes, and automated conveyors linked the individual transfer
machines. Also, automated transfer equipment was installed on general-purpose
and special-purpose machines and individual machines were linked by automated
conveyors to establish continuity of all machining processes on a level not
previously seen.
With Toyota’s mass production system organized as explained
in Part 1, other suppliers apart from parts manufacturers also moved to form
cooperative associations similar to the Kyohokai. In April 1962, the
Seihokai-an association of companies manufacturing molds, jigs, gauges and
other equipment-was established, and the Eihokai-an association of companies in
areas including construction, plants and equipment as well as electric
equipment-was formed in November 1962. Later, in 1983, the Seihokai and Eihokai
combined to form a new Eihokai.
Source: Toyota Motor Corporation
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