SpecialFeature
1Development and Production of Car Air-Conditioning
Compressors Geared toward the Age of ElectricPowered Vehicles Ahead of the World

The new Prius Plug-in Hybrid (PHV) released by Toyota Motor Corporation (TMC) inFebruary 2017 is fitted with the ESBG27 car air-conditioning compressor newly
developed and produced by Toyota Industries. The compressor enables the vehicle’s
air conditioner to demonstrate sufficient heating capability under sub-zerotemperatures while in EV mode that does not run the engine. It contributes to animprovement in both in-vehicle comfort and environmental performance.

n How a Car Air-Conditioning System Works

Heating

CoolingWarming up
vehicle interior

We have always remained the leader of the global electriccompressor market, with our products constantly evolving
with time. In the first-generation Prius hybrid vehicle (HV), ourcompressor was powered by the vehicle’s engine, which wasa cause of lower fuel efficiency because the engine had to bealways turned on to operate the air conditioner. For the secondgeneration Prius, we took advantage of the HV’s high-capacity
battery and developed a compressor that was powered by amotor instead of the engine. This was the world’s first electriccompressor mounted on a mass-produced car. Following that,
we released a compressor integrated with an inverter, which
controls the motor’s revolutions, and achieved reduced size,
lighter weight and significantly easier vehicle mounting. Then,as HVs became ever more popular, we considerably improved
the compressor’s heating and cooling capability and operational
quietness, for which we have earned high acclaim among many

Heart of a car airconditioning system,
powered by theengine or a motor tocompress refrigerant
used for coolingvehicle interiorRefrigerant absorbing
heat in vehicle interior

Expansion valve
Gas injection

Cooling unit
(expansion, evaporationand heat absorption)

Condenser(heat release andliquefaction)

Cooling vehicle interior

Releasing heat from refrigerant
into vehicle interiornn Toyota Industries’ Electric Compressors Sought
after in the Age of Electric-Powered Vehicles

What is a car
air-conditioning
compressor?

Compressor(compression)customers. Consequently, in April 2016, our cumulative unit
sales reached a milestone of 10 million electric compressors.

Expansion valve

Compressor
compressing
refrigerant

Compressor
compressing
refrigerantnn ESBG27 Offering Much Higher Heating
Performance in EV Mode

Refrigerant absorbing heatfrom vehicle exterior

Releasing heat from refrigerant
to vehicle exterior

Absorbing heat from the atmosphere

Releasing heat into the atmosphere

A conventional electric-powered vehicle needs to operate both
its air conditioner and electric heater to warm up the vehicle
interior when the engine is not operating, such as in EV mode.
This consumes a considerable amount of electricity, resulting ina shorter EV driving range.
The new Prius PHV has adopted an air conditioner with a heatpump, which can efficiently warm up the interior on its own in acold climate, even at –10ºC, without using heat from the engine
or an electric heater. This was made possible by our originallydeveloped ESBG27, the world’s first electric compressor with agas injection function to be installed in a mass-produced car. The
product has contributed to a longer EV driving range, greater fuelefficiency and higher in-vehicle comfort.

Throttle

Toyota Industries Continuously Meeting Changing Customer Needs

ESBG27 electric compressor

World Market Shares ofElectric Compressors

Electric Compressor Sales(Million units)

2.0Toyota Industries offers a range of car air-conditioning compressors, from a compact, lightweight fixeddisplacement type and a variable-displacement type with greater fuel efficiency for internal-combustion vehicles toan electric type for electric-powered vehicles. With this broad product lineup, we have satisfied the diverse needsof customers.
In recent years, enforcement of more stringent environmental regulations around the world and growing
environmental consciousness among users have encouraged an increasing number of governments to implement atax break program for electric-powered vehicles, including PHV, electric vehicles (EV) and fuel cell vehicles (FCV).
These trends have spurred electrification of vehicles by automakers. Amid this environment, we have been
leveraging our accumulated strengths in developing electric compressors that meet customer needs at a higher
level and providing these compressors to automakers worldwide.

1.5

Toyota Industries Report 2017

ToyotaIndustries
holding more than
70% share

1.00.50(FY) 2009

24

No.1

2010

2011

2012 20132014 2015

2016

2017

Survey by
Toyota Industries Corporation (FY2017)25

Special Feature 1 Development and Production of Car Air-Conditioning Compressors Geared

Development and Production of a New Electric Compressor
Effectively Utilizing Our Accumulated Technologies and Know-How
Matched to the Age of Electric-Powered Vehicles
The launch of production of the new ESBG27 electric compressor presented the world’s first challenge for us to ensurestable mass production of the product that has become more complex with the addition of a gas injection function while
maintaining a high level of quality.
Design, production engineering, quality assurance and manufacturing departments utilized their expertise in respective
fields and closely collaborated to overcome issues one by one. As a result of their concerted efforts, mass production of theESBG27 successfully commenced as planned in September 2016.
In this section, four key project members talk about efforts undertaken in each department and about the strengths ofToyota Industries underpinning its development capability.

nn Development Targets of the New ESBG27
Electric Compressor
Tsubai: Even though thedevelopment of the ESBG27
was officially launched in 2012,
we actually started developing
an electric compressor utilizinga heat pump for better heating
performance in 2010, along withresearch into a gas injection
Shinji TsubaiGroup manager, Group No. 31, Engineering
method, anticipating market
Office No. 3, Engineering Department,
needs and more stringent
Compressor Divisionenvironmental regulations.
The overall goal was to achieve sufficient heating capability at
sub-zero temperatures by using only an air conditioner. Thisobjective was made in response to customer complaints that theconventional heating technique requires the engine to run andthus consumes more fuel. While keeping that goal in mind, we
set high targets from a comprehensive viewpoint for operational
quietness, power saving, compactness, weight reduction andcost benefits in developing this compressor.

Okagawa: In the area ofproduction engineering, ourwork was to integrate two setsof additional processes into anexisting electric compressor
production line: one for mounting
new structures and functions
added to the ESBG27 and one
Yoshihiro Okagawa
Group manager, Electric Products Assemblyfor inspecting these. I rememberGroup, Assembly Production Engineeringthat in the very initial stage ofOffice, Production Engineering Department,
Compressor Divisiondevelopment when the productspecifications were not yet finalized, project members from thefour departments got together and examined every detail ofthe design drawings of the production line. It had to be easy
for operators to work with, both in terms of assembly andinspection, and less prone to errors.
Maeda: Our objective in the field of quality assurance was toestablish processes to assemble components into a productin the simplest possible manner for reducing quality risks andpreventing defects. Initially, the ESBG27 had a rather complex
shape and structure, so we worked closely with members of theother three departments to make it simpler.

Heating by a Heat Pump with Gas Injection Function

Vehicle interiorElectricityVehicle exterior

Compressor

Absorbingheat from theatmosphere

Evaporator

Gas injection

Condenser

The conventional heat pump heating technique shows lower
heating performance in a cold climate, as it absorbs less heat fromthe atmosphere. The gas injection function serves to expand thepossible heating temperature range by recompressing a portion ofcompressed refrigerant by a compressor.

Releasingheat into
vehicle interior

Expansion
valve
Refrigerant (gas)26

Toyota Industries Report 2017

Refrigerant (liquid)

HeatEnergy input into compressor

Car air conditioner of the Prius PHV

toward the Age of Electric-Powered Vehicles Ahead of the World

Takayama: In terms of manufacturing, we also dealt with theaddition of new processes resulting from an increase in thenumber of components in the ESBG27 through collaboration
among the four departments. As a result, we were able toensure that the new line allows operators to work easily andefficiently, eliminating the need for increased staffing.

nn Characteristics of the ESBG27 and Issues
Associated with its Development andManufacture
Tsubai: The adoption of a new “gas injection” mechanism in theESBG27 imposed challenges such as creating a route in which
refrigerant flows. But ultimately, we were able to achieve thetargeted heating capability. The ESBG27 contributed to a nearly
30% increase* in the heating capability of the car air-conditioning
system of the new Prius PHV in a cold climate. In recognition,
we received the Technology Development Award from TMC.
Of course, this was not an accomplishment of the design
process alone; we all faced and overcame difficulties.
Okagawa: The most difficult challenge in the area of productionengineering was to deal with an increase in the numberof components used in the ESBG27 compared with ourconventional electric compressors and integrate corresponding
processes into a production line. We had to come up with thebest way to incorporate processes to mount new functional
components and inspect the proper functioning of thesecomponents. Working with the Quality Assurance Department,
we devoted considerable efforts to determine reliable inspection
conditions in order to assuredly perform a quality check during
the limited time that components flow on the line and to define amethod and level of inspection that can satisfy automakers.
Maeda: We should obviously
challenge ourselves in pursuing
higher performance in ourcompressors whether it is a newstructure, new mechanism ornew assembly process. On theother hand, new things always
entail quality risks and likely
Hiroki Maeda
create more defects. In resolving
Working group leader, Electric ProductsGroup, Quality Assurance Office No. 3, Quality
this contradiction and finding aAssurance Department, Compressor Division
trade-off, we sought to faithfully
follow the concept of “jikoutei-kanketsu (build in quality withownership)” to ensure that no defective products are sent topost-processes, along with measures to prevent defects in thefirst place.
Takayama: The mass production line of the new compressor
went into operation in September 2016, and currently wemanufacture around 5,000 units each month. We meticulously
created a robust line and were able to meet the performanceand quality targets and the scheduled launch of production.
A very important point was to devise standardized proceduresfor processes that had relied on operators’ experience and skills,
so that anyone can perform the task.
* Compared with the conventional heat pump heating system at the temperature of –10ºC.
Surveys by Toyota Industries Corporation and DENSO Corporation.

nn Strengths Underpinning Toyota Industries’
Development Capabilities That Generate a
Number of World Firsts
Maeda: While I was working on this project, I realized that ourprocess from the launch of product design to mass production
has become increasingly mature. This can be attributed tomany factors. One of them is our accumulated know-how fromthe development of previous models. Thus, we did not have tostruggle with anything that was unexpected. Our strengths stemfrom activities to carefully identify defects in each process andeliminate various risks. I think we should continue to hone ourstrengths in the future as well.
Okagawa: In the field of production engineering alone, we havean advanced set of proprietary technologies derived from thein-house development of production equipment. We also haveachieved higher degrees of speed, precision and automation
throughout the entire production lines. These enable us to excel
in swiftly manufacturing products that demand extremely highquality and at the required quality level.
Tsubai: We hold the world’s top share in the compressor
market. As such, we do business with various automakers andare well positioned to capture information on what their next
goals are and what kind of vehicles they envision, which allows
us to provide designs finely matched to these needs. With
demand for electric compressors expected to progressively
increase, I hope to start development of a next-generation
model soon, which is quieter to operate and demonstrates
better heating performance at even lower temperatures with lessenergy consumption.
Takayama: Setting oursights higher, those of us atmanufacturing departments
would like to promote humanresources development, engage
in improvement activities andenhance our manufacturing
Hideki Takayama
capabilities further. Our goal isSupervisor, Assembly Section, Manufacturing
Department No. 1, Compressor Division
to combine the comprehensive
strengths of Toyota Industries to gain greater customer
satisfaction and continue to win out over the global competition.
Tsubai: Exactly. We will continue to develop compressors withgreater product appeal.

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