Views is a PR magazine published by Komatsu Ltd. Construction

930E dump truck and PC5500 hydraulic excavator in
operation using Komatsu’s Autonomous Haulage
System at Rio Tinto’s West Angelas Mine
2
2009
No.
Views is a PR magazine published by Komatsu Ltd.
Construction & Mining Equipment Marketing Division
2-3-6, Akasaka, Minato-ku, Tokyo 107-8414, Japan
http://www.komatsu.com
E-mail: views@komatsu.com
• Product photos in this magazine may show optional equipment.
• Product specifications are subject to change without notice.
• Available models may vary by region or country.
• Models shown in this magazine may be positioned for photographic purposes, with
the bucket up. For safety reasons, please leave the equipment in a secure position.
• All rights reserved. No part of this magazine may be reproduced without the prior
written permission of Komatsu Ltd.
• The comments expressed in this magazine are those of the contributors, and are not
necessarily endorsed by Komatsu Ltd.
Bulldozer Operation Methods
for Saving on Fuel Consumption
and Improving Fuel Efficiency
By Yasushi Shikata, Komatsu Ltd.
he basic job of a bulldozer is to dig and carry earth. Productivity and fuel consumption are highly
dependent on factors such as site geography, including level or sloping ground, as well as soil
composition. In addition, since a bulldozer predominantly operates at full power using its own weight,
it is difficult to save on fuel consumption while working. Useful bulldozer operation methods that boost fuel
efficiency by improving productivity and saving on fuel consumption during idling periods such as waiting
for a dump truck are provided herein. We use results from the D155-6 model to illustrate this point.
T
Please note the fuel efficiency data shown here may vary depending on the actual work site, machine condition and operator skill.
1. Avoid High Idling and Practice Idling Stops
When waiting for a dump truck at the dumping
site, for example, it is possible to curb fuel
consumption by avoiding high idling whenever
possible. Specifically, use either low idling or
depress the decelerator pedal to slow down the
engine speed. Test results are as follows:
(1) Switching from high idling to low idling for
30 minutes a day saves on fuel consumption
by 1,710r(452 U.S. gal) a year.
(2) Turning the engine off rather than using low
idling for one hour a day saves on fuel
consumption by 2,430r(642 U.S. gal) a year.
Fuel consumption [ /h] (test data using D155-6)
High-idling
position
Decelerated
slow state
Low-idling
position
Ratio 0.0
1.00
0.49
0.42
0.2
0.4
0.6
0.8
1.0
2. Start Dozing from the Front of the Dozing Zone
The most effective way to doze on
level ground is to shorten the distance
that the heavy load is carried by
dozing front-to-back (from point A to
point B to point C in the illustration).
With this technique, you start from
point A, which is 3 to 5 m (10 to 16 ft)
back from point X at the forefront of
the dozing area. After finishing dozing
from point A, move further back in
increments of 3 to 5 m (10 to 16 ft)
each time to start a new dig.
This method increases the full load on the
blade each time by using a downward gradient and
enhances productivity by keeping the digging
ground even. In contrast, making repeated digging
from back-to-front results in elongating the digging
distance and requires blade control (up/down operation) to prevent shoe slippage. Consequently, the
dozed ground easily becomes uneven, making it
more difficult to keep a full load on the blade.
Compared with the back-to-front method, the
front-to-back method improves fuel efficiency
(productivity per liter) by 11%.
2
Views 2009 No.2
Dozing start point
Point X
Point A
Point B
Point C
Starting from the front of the
dozing zone (red line)
(recommended)
Starting from the rear of the
dozing zone (blue line)
Comparison of dozing front-to-back and back-to-front
Back-to-front (blue line)
(test data using D155-6)
Front-to-back (red line)
1.00
1.12
Productivity
(m3/h)
1.00
1.01
Fuel consumption
(ℓ/h)
1.00
1.11
Productivity per
liter (m3/ℓ)
Ratio 0.0
0.2
0.4
0.6
0.8
1.0
1.2
3. Doze Earth with a Downward Gradient
If site conditions allow, you can significantly
improve productivity and enhance fuel efficiency
(productivity per liter) by dozing earth with a
downward gradient. You can dig and carry a larger
amount of soil in a downward direction as compared with level ground. Moreover, time taken to
advance is shorter, leading to higher productivity.
While fuel consumption per hour is the same, a
downward gradient of seven degrees realizes blade
capacity almost 1.2 times higher than dozing on
level ground at the same engine power.
Dozing with a downward gradient also
effectively utilizes the weight of the bulldozer,
so you can expect greater efficiency from larger
blades such as full U-blades. It may be less
effective with smaller blades.
Further, reversing up a downward gradient of
seven degrees in reverse 2nd gear (R2) provides for
greater fuel efficiency than reverse 1st gear (R1).
Although less fuel is consumed in R1, since the
speed is also much lower, the bulldozer can move
approximately 20% further in R2 using the same
amount of fuel.
As a reference, productivity is much lower
when dozing uphill since you are working against
gravitational force. However, fuel consumption
may not necessarily increase simply because it takes
longer for each cycle of dozing earth uphill.
Level ground and downward gradient of seven degrees
Level ground
(test data using D155-6)
Downward gradient
(ℓ/h)
1.00
1.20
1.00
1.00
Productivity per
liter (m3/ℓ)
1.00
1.20
Productivity
(m3/h)
Fuel consumption
Ratio 0.0
0.2
0.4
0.6
(ℓ/h)
R1
R2
0.70
Travel speed (km/h)
1.00
0.81
1.00
Fuel efficiency
(km/ℓ)
Ratio 0.0
0.2
0.4
0.6
0.8
1.0
Level ground and upward gradient of seven degrees
Upward gradient
(test data using D155-6)
Level ground
0.58
Productivity
(m3/h)
1.00
Fuel consumption
0.98
1.00
0.59
1.00
Ratio 0.0
4. Other Important Notes
0.2
0.4
0.6
0.8
1.0
• The digging procedure should be in the order
1 to ●
3 as shown in the illustration.
●
• The depth of the trench should not exceed the
height of the blade.
• The space between trenches should be
approximately half the width of the blade.
x.
pro
Ap
Bench
Hi
gh
e
f th
hal
d
bla
h
idt
ew
Height of blade
cli
ff
1
(3) Minimize spillage from blade.
You can improve operating efficiency by minimizing spillage from the blade while dozing. One
method to achieve this is slot dozing. This method is
particularly useful at sites where material is prone to
spill from the sides of the blade due to large loads of
relatively soft earth or movement downhill, and at
sites where the load must be carried a long way.
1.2
0.87
1.00
Fuel consumption
Productivity per
liter (m3/ℓ)
(2) Doze again in soil where a full load on the
blade is difficult.
At sites where it is difficult to fill the blade since the
ground is hard or the soil is rocky, reverse after the
first dozing and doze once more to fill the blade as
much as possible before carrying the material.
1.0
Comparison of R1 and R2 on downward gradient of
seven degrees (test data using D155-6)
(ℓ/h)
(1) Avoid shoe slippage and stalling.
Dozing or ripping while shoes are slipping or
keeping the torque converter stalled will increase
fuel consumption and cause irregular wear to
undercarriages.
(a) Select speed level most suitable for the load.
(b) Depress the decelerator pedal, lower engine
speed and adjust blade or ripper load.
0.8
* The chart above shows an example of a downward gradient of seven degrees
(approx. 12%). As a rough guide, a downward gradient of 10% improves
efficiency by around 1.1 to 1.5 times.
3
2
Bench
Hi
gh
cli
ff
Views 2009 No.2
3
Barrick Gold Increases its Mining Profile
in Tanzania Utilizing
Komatsu Equipment
Customers in Focus
By Kevin Hughes, Nairobi Liaison Office, Komatsu Ltd.
arrick Gold Corporation, one of the largest
international mining companies, operates
the Bulyanhulu (underground), Tulawaka
and North Mara gold mines in Tanzania, East
Africa. In August 2007, Barrick announced the
development of the Buzwagi Project, managed by
its wholly owned subsidiary, Pangea Minerals
Limited (PML).
Buzwagi is located in northwest Tanzania,
and will be the second largest mining operation in
the country. Production is expected to begin in
mid-2009, generating 250 thousand to 260 thousand
oz of gold per year in its first five full years of
operation. Proven and probable reserves at Buzwagi
are 3.3 million oz of gold and 79 million kg
(175 million lb) of copper. The expected mine life
based upon proven and probable reserves is more
than 15 years. With continued exploration indicating additional reserves, it is anticipated that the
mine may be extended.
B
PML Opts for Komatsu Mining Equipment
To enable the Buzwagi Project to achieve its
production goal, Komatsu was chosen as the principal mining equipment supplier. In the process of
selecting the right manufacturer and distributor as
well as the type of equipment, PML had to give
serious consideration to the fundamental issue of
delivery to meet its start date objectives, in addition
to productivity, reliability and product support.
Mina North Mara
Mina Tulawaka
Mina Bulyanhulu
Mina Buzwagi
TANZANIA
Dar es Salaam
Komatsu and its distributor in Tanzania,
Panafrican Mining Services Tanzania Ltd., were
able to demonstrate their abilities and meet all the
requirements of the tender process. In April 2007,
a purchase agreement was signed for the delivery
of a number of large-sized machines including
two units of PC4000 hydraulic excavators and
seven units of HD1500 rigid dump trucks.
As the mine progresses, additional HD1500
dump trucks will be added to the fleet, reaching a
total of 15 haulage units at the height of production.
Mr. Dave Anthony, general manager of the
Buzwagi Mine, reports, “Komatsu and Panafrican
Mining Services have met or exceeded every
commitment up until now. Through the process
of pioneer assembly and maintenance to the
start-up of operations of the PML workshop,
these people have been a pleasure to work with.
This is a true partnership.”
Product Support Major Key to PML Decision
for Komatsu Equipment
Through the combined efforts of the Komatsu
Nairobi Liaison Office and Panafrican Mining
Services, both had demonstrated their capability to
support the Komatsu fleet throughout the tender
phase. As a result, PML opted for a full five-year
Maintenance and Repair Contract (MARC)
agreement with the Komatsu distributor.
Mr. Gavin Pearson, managing director of
Panafrican Mining Services, notes, “From the
PC2000 hydraulic excavator loading HD1500 dump truck
4
Views 2009 No.2
Mr. Asa Mwaipopo (third from left), mining manager of the Buzwagi Mine, and staff
initial stages of tendering, the communications
with Barrick (PML) and Komatsu have been open
and transparent, and we would not have been able
to achieve the outcomes without the support of the
Komatsu team.”
Mr. Fred Owen, manager of the Buzwagi
Project at Panafrican Mining Services, says,
“Komatsu has continued to offer both the customer
and us support through operator and technical
training to ensure that the fleet is run properly as
well as ensuring that the
Panafrican Mining Services
maintenance team is well
equipped to manage any technical issues that may arise.”
The geographical location
of the Buzwagi Project has and
will continue to present a number of challenges, particularly
in terms of development of the
PC4000 during commissioning
region and the environment. It
is also recognized that the continued success of
the project will be determined largely based on
the ability to provide continuous, first-rate support and deliver optimal
equipment performance.
To this end, Komatsu
and Panafrican Mining
Services will continue to
focus on the implementation of internal systems
and processes to meet their
obligations and guarantees
to the customer, and thus
ensure the success of
the project.
Support Staff of Komatsu and Panafrican Mining Services
Mr. Gavin Pearson,
managing director of
Panafrican Mining Services
Mr. Fred Owen, manager of
the Buzwagi Project at
Panafrican Mining Services
Komatsu Nairobi Liaison Office staff (from left): Mr. Yuji “Jimmy”
Yamamoto, technical support manager; Mr. Kevin Hughes, general
manager; Mr. Masaaki Kamizono, marketing manager; and
Mr. Robert Finney, assistant technical manager
Views 2009 No.2
5
Komatsu PC130 Hydraulic Excavator
Goes to Work in Antarctica
By Mrs. Lisa Flattery, Marubeni-Komatsu Ltd
Customers in Focus
ollowing a stringent tender and selection
process, British Antarctic Survey (BAS)
has taken delivery of their first Komatsu
machine, a PC130 hydraulic excavator, for use at
the centre’s Halley Research Station on the Brunt
Ice Shelf in Antarctica.
The hydraulic excavator began its journey to
Antarctica at the beginning of December 2008,
sailing from Grimsby via Capetown and arriving
at the site at the end of that month. The PC130,
which has been put through the Komatsu Dealer
Qualified program and provided by U.K. distributor Marubeni-Komatsu Ltd, will be used for
snow management and general snow operations
around the site during the construction of a new
F
research station.
Halley Research Station
The new complex, the sixth to be
ANTARCTICA
constructed since
1956, replaces the
current Halley V
Research Station.
Located 16,093 km
(10,000 mi) from the
U.K. on the Brunt Ice Shelf,
the new station will allow longrunning research on global climate
change to continue at the site where the Antarctic
ozone hole was discovered.
The PC130 is used mainly for snow
management and general snow operations.
PC130 hydraulic excavator being loaded
on board for its journey to Antarctica
6
Views 2009 No.2
Komatsu PC130 Modified to Meet Extreme
Weather Conditions
To ensure the machine is reliable in a climate
where typical Antarctic summer temperatures are
around -20ºC (-4ºF), a number of modifications
have been made to the hydraulic excavator by
BAS. Special fuel that can be used in temperatures
as low as -47ºC (-53ºF) will be utilized in the
machine since normal fuel would simply
freeze up.
Dealer Qualified Scheme Ensures Reliability
Backed by Support
The Marubeni-Komatsu Dealer Qualified Scheme
is designed to provide peace of mind for anyone
purchasing previously owned Komatsu equipment.
Machines are put through a rigorous assessment
and inspection process, whereby any parts that
need to be replaced are naturally genuine Komatsu
parts. All Dealer Qualified machines come with a
3-month/500-hour power line warranty.
Cambridge-based BAS is a world leader in
research into global environmental issues. With an
annual budget of around £45 million, five
Antarctic Research Stations, two Royal Research
Ships and five aircraft, BAS undertakes an interdisciplinary research program and plays an active
and influential role in Antarctic affairs. BAS
has joint research projects with over 40 U.K.
universities and has more than 120 national
and international collaborations. The centre is
a component of the Natural Environment
Research Council.
Mr. Martin Bell, plant manager at BAS,
comments on the purchase: “After a tender process
of four weeks, the Komatsu unit was chosen from
a number of invited distributors based on meeting
all of our requirements. The Komatsu PC130 is a
great machine and is very useful around our vast
site. It’s smooth and has a good capacity for its
size. I’ve been very impressed with the help and
support we’ve received from Marubeni-Komatsu.”
Note: For safety reasons, please make sure the cabin door is closed during operation.
Views 2009 No.2
7
Komatsu Products and Service
Are the “Right Choice” for
Satisfied Chinese Customer
Customers in Focus
By Atsushi Takagi, Komatsu (China) Ltd.
Beijing
Nanjing
Shanghai
CHINA
Hangzhou
Hong Kong
n August 2008, Komatsu released the PC56-7
mini hydraulic excavator, which was developed
specifically for the Chinese market. It is said
that mini hydraulic excavators are used for
approximately 2,000 hours annually at construction sites in China. In this issue of Views, we
feature one customer’s appraisal of the PC56-7.
Mr. Yu Tianzhi, deputy manager of Nanjing
Jinsheng Realty Co., Ltd, a company primarily
engaged in construction and real estate businesses
in Nanjing, the capital of Jiangsu Province,
highlights the purchase of the mini hydraulic
excavator and the start of a satisfying relationship
with Komatsu.
“I met Mr. Zhao Shuqing, manager of the
Nanjing branch of Komatsu distributor Nanjing
Gangjia Construction Machinery Co., Ltd, in
2007,” Mr. Yu begins, “but it didn’t result in the
purchase of a Komatsu machine. Then, at the end
of 2008, one of our mini hydraulic excavators
from another company started to have problems,
and we were dissatisfied with the kind of service
we received.
“Of course, there were other companies that
enthusiastically recommended their new products,
but Mr. Zhao had provided us with a lot of information on Komatsu’s new products and sales
campaigns, among other things, throughout the
two years we had known each other. He did more
than strongly recommend the PC56-7; he introduced us to a customer who was actually using it.
That allowed us to learn firsthand about usage,
I
8
Views 2009 No.2
maintenance, service and other key matters.
Based on this, I proposed to our board of directors that we purchase the PC56-7, and it didn’t
take long for them to agree.
“On the day of the delivery, a serviceman
from Nanjing Gangjia provided an excellent indepth explanation to our operators, including
equipment operating instructions and maintenance
procedures, as well as fueling and lubrication
methods. He even gave us his cell phone number
for emergencies. All these things increased our
trust in Nanjing Gangjia immensely and made
us feel like a true partner of both the distributor
and Komatsu.”
Approximately a month after purchasing the
PC56-7, Mr. Yu is pleased with its performance
to date. “Although the machine has already
logged more than 200 hours,” he says, “it’s still in
tip-top condition. The fact that it is fuel-efficient
is a major benefit. Plus, I believe it’s great that
Komatsu equips even a mini hydraulic excavator
with an economy mode—the ideal feature in
times such as these. We haven’t had any trouble
with the machine thus far, so may never need
that cell phone number. Oh, actually I did call
Mr. Zhao once—to invite him for dinner.”
PC56-7 at work at one of Nanjing Jinsheng
Realty Co., Ltd’s construction projects
The PC56-7 has already logged
more than 200 hours since delivery.
Mr. Yu was in high spirits throughout the
interview. Nanjing Jinsheng recently decided to
purchase a PC200 as well on account of the excellent evaluation of the PC56-7. “Good products,
good service,” comments Mr. Yu upon wrapping
up the interview. “I definitely made the right
choice with Komatsu.” These words were not
merely flattery, but truly heartfelt.
CURRENT
TOPICS
Mr. Yu Tianzhi (right), deputy manager of Nanjing Jinsheng
Realty Co., Ltd, shaking hands with Mr. Zhao Shuqing,
manager of the Nanjing branch of Komatsu distributor
Nanjing Gangjia Construction Machinery Co., Ltd
Strengthening Construction and
Mining Equipment Operations in China
Relocation of KCCM and Construction of a New Plant
To further expand construction and mining equipment operations in China, Komatsu will relocate the operations of Komatsu (Changzhou) Construction Machinery Corp. (KCCM) to another site in Changzhou and
build a new plant. Production is slated to commence in 2010.
One of Komatsu’s core production sites, KCCM was established in 1995 and began operations with the
production of wheel loaders. The company steadily expanded its production volume to include large
hydraulic excavators and dump trucks for mining use. The new plant has a site area of 281,099 m2
(3,025,750 ft2), roughly double the current site, and will help meet expected growth in demand in the
construction and mining equipment markets.
Establishment of KC Techno Center
Amid continued growth in the Chinese market, Komatsu will establish Komatsu (China) Ltd.’s KC Techno
Center adjacent to KCCM’s new plant as part of efforts to strengthen product support activities. The functions of the center, which is expected to open in 2010, are indicated below.
1. Demonstration Center for Komatsu Group Products
The center will be used to display construction equipment and other Komatsu Group products and demonstrate their performance, efficient application and operating methods to customers and distributors to
increase understanding and proficiency.
2. Comprehensive Training Center
The center will hold a wide range of educational programs, from management and IT to sales, service and
construction engineering.
3. Remarketing Center (used equipment, Reman business, etc.)
The center also aims to reinforce and expand the businesses of used equipment and Reman (remanufactured)
components.
Views 2009 No.2
9
TOPICS
Autonomous Haulage System—
Komatsu’s Pioneering Technology Deployed
at Rio Tinto Mine in Australia
CURRENT
omatsu’s Autonomous Haulage System,
FrontRunner, is being deployed at Rio
Tinto’s West Angelas Mine, East Pilbara
operation, in Western Australia. This is the second
deployment of the proprietary system following
delivery of the first fleet to Codelco’s copper
mines in Chile.
The FrontRunner system is comprised solely
of Komatsu mining equipment, specifically, five
units of autonomous dump trucks that use the
930E electric drive dump truck as a base machine,
as well as a super-large PC5500 hydraulic excavator, D475A bulldozer, WD900 wheel dozer and
GD825 motor grader.
The autonomous trucks navigate in the
complex mining environment and can haul
a 290-tonne (320-U.S.-ton) payload of overburden
and ore without a driver. At the West Angelas
K
10
Views 2009 No.2
AUSTRALIA
Mine, the trucks are
West Angelas Mine
operated and conBrisbane
trolled entirely using
Perth
a supervisory comSydney
puter at an operations
Melbourne
center. In the future, the
trucks will be controlled
24 hours a day from a
remote operations center
located more than 1,000 km
(621 mi) away in Perth. All data from the trucks
in use at the mine, including information on the
location of the vehicles and their running status, can
be verified via the supervisory computer. This is
expected to contribute to a significant increase in
productivity at the mine where it is difficult to
secure sufficient manpower.
Outline of Autonomous Haulage System
Autonomous Haulage System (AHS) is a comprehensive fleet management system for mines. The
dump trucks, which are equipped with vehicle controllers, a high-precision global positioning system
(GPS), an obstacle detection system and a wireless
network system jointly developed by Komatsu
Ltd., Komatsu America Corp. and Modular Mining
Systems, Inc., are operated and controlled via a
supervisory computer, enabling them to be
unmanned. Information on target course and speed
is sent wirelessly from the supervisory computer to
the driverless dump trucks, while the GPS is used
to ascertain their position. When loading, the dump
trucks are automatically guided to the loading spot
after computing the position of the bucket of the
GPS-fitted hydraulic excavator or wheel loader.
The supervisory computer also sends information
on a specific course to the dumping spot.
From a safety perspective, the fleet control
system prevents collisions with other dump trucks,
service vehicles or other equipment at the mining
site. In case an obstacle detection system detects
another vehicle or person inside the hauling course
under AHS operation, the vehicles will reduce
speed or stop immediately, making the system
extremely safe and reliable.
In addition, AHS enables stable operation
under grueling conditions such as at high altitudes
or in sparsely populated, arid desert areas. At the
same time, by optimizing operations, the system
contributes to reducing maintenance costs,
conserving energy and curbing CO2 emissions.
How AHS Works
GPS satellite
Supervisory computer
Wireless LAN
Workstations
Repeater
Data
Dumping site
Loading site
- Approaches
automatically to the
dumping spot
- Precise dumping
- Approaches
automatically to a
loading machine
Hauling road
Views 2009 No.2
11
Making Inroads in Hybrid
Technology to Power the
Future
n May 2008, Komatsu announced the world’s
first commercially available hybrid construction
equipment, the PC200-8 Hybrid hydraulic excavator. We spoke with Mr. Hikosaburo Hiraki, who
was centrally involved from the outset with the
development of the Komatsu Hybrid System,
which contributes to reductions in CO2 emissions
and fuel consumption.
I
Views: Can hybrid systems be effective in
hydraulic excavators?
Mr. Hiraki: Actually, hybrid systems are more
effective in hydraulic excavators than passenger
cars. When a car travels on an ordinary road, the
driver will typically apply the brakes (decelerate)
about once every 5 to 10 minutes. In contrast, the
upper structure of a hydraulic excavator turns at a
rate of once every seven seconds when loading,
generating energy each time it slows down. Since
the structure turns and reduces speed at a high frequency by efficiently storing energy, it makes the
hybrid system a perfect fit.
Views: How is the hybrid system of a passenger
car different from that of the PC200-8?
Mr. Hiraki: It may seem surprising, but the
kinetic energy of the PC200-8 hydraulic excavator
is about the same as that of a standard passenger
car. Kinetic energy is proportional to the multiplication of the mass and the square of velocity. As
such, there is little difference in the kinetic energy
of a passenger car that is light and moves quickly
and that of the PC200-8, which is heavy and
moves slowly, but the upper structure turns
quickly. We therefore believed it was possible to
take certain aspects of the hybrid system of a passenger car and apply them to the PC200-8 hybrid
system. With this in mind, we pursued further
research into the hybrid system of the passenger
car, confident that we could utilize it in construction equipment. However, because the upper
structure of hybrid excavators are required to
turn frequently, it was imperative to identify
how to efficiently store in a small device the
12
Views 2009 No.2
instantaneous energy generated while turning in
order to make hybrid construction equipment a
reality. Eventually, we developed a capacitor that
could store and discharge electric energy instantaneously. In the PC200-8 hybrid system, the
electricity discharged from the capacitor is used
to assist the engine when it is accelerating, which
is the major difference from the hybrid system of
a passenger car.
Views: It seems that some of the people who
viewed the PC200-8 Hybrid for the first time
were disappointed that it looked almost the
same as conventional models. Is there a reason
the exteriors look the same?
Mr. Hiraki: We commenced development based
on the idea that as long as conventional and
hybrid systems existed together, the appearance
should be similar. The reason for this is to make
it possible to mass produce this machine on
standard factory production lines rather than
equipment solely for research purposes.
Originally, however, the shape and size were such
that it looked nothing like conventional construction equipment. In the end, I am proud we found
a way to make it look the same, which is what we
do at Komatsu.
Our basic policy is to make all core components in-house. We have always manufactured
engines and hydraulic devices internally, but
electric motors were a whole different realm.
Komatsu always seeks to challenge unfamiliar
territory, however, which is our policy and part of
our corporate characteristics. Through in-house
production, we can make refinements according
to our needs and provide outstanding products
to customers.
Views: What other areas were particularly
difficult during development?
Mr. Hiraki: Since the voltage used by hybrid
systems is higher than conventional construction
equipment, we had to be vigilant in ensuring a safe
design. Simply switching off the power doesn’t necessarily make construction equipment safe, and we
needed to consider every possible scenario for how
the machine would be used. This meant we had to
think of each and every possible safety measure.
We visited the factory on numerous occasions to
seek advice and considered various scenarios
before deciding on the safest possible design. In
addition to guaranteeing human safety, we also
enhanced monitoring to ensure the proper operating condition of the construction equipment itself,
or in other words, improved fault diagnostics.
We extensively conducted logic checks as well
as preliminary tests using actual equipment. It took
a long time, for example, to resolve unexpected
variations in voltage that occurred when the
environmental temperature was -30°C (-22°F).
Views: What has been the result at
customers’ sites?
Mr. Hiraki: Some customers have achieved
a 30% or 40% reduction in fuel consumption,
surpassing the 25% reduction our test results
showed.
Outline of the Komatsu Hybrid System
The proprietary Komatsu Hybrid System converts
energy generated when the upper structure of a
hydraulic excavator reduces its speed while turning,
stores the energy in the capacitor and uses it to assist
the power of the engine via the power generation
motor when the engine accelerates.
While standard equipment normally uses a
hydraulic motor to turn the upper structure, we have
developed an electric motor exclusively for the
Hybrid. Through the use of this new motor, which
Mechanism
recovers energy generated when the upper structure’s turns slow down, we have achieved a hybrid
hydraulic excavator.
Compared with the standard PC200-8, we have
achieved an average reduction in fuel consumption of
25% via test results. Furthermore, in field tests with
our customers, we confirmed a maximum reduction of
41% at a job site where the machine’s upper structure
turns more frequently.
Fuel Economy
Fuel Consumption
(Estimation of Average Use*)
Measured Data from
Customers’ Actual Use
25% Reduction
Maximum of 41% Reduction
100
80
-30%
-31%
60
Turning of the
upper structure
Electric power assistance
during engine acceleration
-41%
40
20
Inverter
Power generation
motor
Utilizes electricity discharged
from the capacitor when
the engine accelerates
Recovers energy when
turning slows down during
loading operation
Capacitor
Efficiently and instantaneously stores
and discharges electric energy
0
Engine
Electric motor to turn
the upper structure
PC200-8 PC200-8
Standard Hybrid
model
Company A Company B Company C
(waste soil
disposal)
(civil
engineering)
(sludge
disposal)
Actual results of the
PC200-8 Hybrid model
* Computed according to Komatsu’s internal-use standard concerning normal use
of construction equipment
Views 2009 No.2
13