Honda Accord Hybrid teardown (Part 1)

Sport Hybrid i-MMD PCU and vehicle chassis components

2014/02/17

Summary

Honda Accord Hybrid
Honda Accord Hybrid on display at Honda headquarters' Welcome Plaza Aoyama
* Click on the photo for a larger image.

 In January 2014, the disassembly of the Honda Accord Hybrid was conducted at the Benchmarking Center of the Hiroshima Prefectural Technology Research Institute in Kure, Hiroshima prefecture. The event was organized by the Automotive Technology Innovation Center of the Hiroshima Industrial Promotion Organization. The first day of the event, January 17, was spent for preliminary disassembly. The final teardown took place on January 20 through 22. Nearly all components were removed from the car during the preliminary disassembly. The drive unit, Power Control Unit (PCU), and Intelligent Power Unit (IPU) consisting of the lithium-ion battery pack were disassembled during the final teardown.

 Reported in part 1 is the summary of the PCU, which is one of the key components of the SPORT HYBRID i-MMD (Intelligent Multi-Mode Drive) system located in the engine room as well as chassis components of the Honda Accord Hybrid. Disassembly of the IPU and the electric servo brake system will be covered in Part 2, and the drive unit in Part 3 of the Honda Accord Hybrid teardown report, respectively.


Related Reports:
Honda Fit Hybrid teardown: Part 1, Part 2 (Dec. 2013)
Toyota Aqua (Prius c) teardown: Part 1, Part 2 (Nov. 2012)
Nissan Leaf teardown: Part 1 (Mar. 2012), Part 2 (Sep. 2012), Part 3 (Nov. 2012)



Main specifications of Honda Accord Hybrid

(click for more details)

Model name DAA-CR6
Body type 5-seater 4-door mid-size sedan
Dimensions Length: 4,915 Width: 1,850 Height: 1,465 mm with 2,775 mm wheelbase
Weight LX grade: 1,620kg, EX grade: 1,630kg
Fuel efficiency (JC08 test mode) 30.0 km/liter

Note) The LX grade of the Honda Accord Hybrid was used during the benchmarking activity.

 

 



Key component suppliers

 

Component Supplier
Engine 2.0-liter (1,993cc) in-line 4-cylinder Atkinson-cycle gasoline engine
(max. output: 105kW/143ps, max. torque: 165Nm/16.8kgf-m), type: LFA
Honda (in-house)
Cylinder head cover MAHLE
Spark plug NGK Spark Plug
VTEC hydraulic control valve (spool valve) Keihin
Throttle body
Intake manifold Metts
Cylinder block
Chain case Yamada Manufacturing
Engine Management System (EMS) Keihin
Electric water pump (for cooling engine) Aisin Seiki
Radiator T.RAD
Radiator fan Mitsuba
Radiator hose Nichirin
EGR cooler Maruyasu Industries
EGR valve MAHLE
Air-fuel ratio sensor Denso
Catalytic converter Yutaka Giken
Pre-silencer Sankei Giken Kogyo
Engine mount bracket Nissin Kogyo
Air cleaner ROKI
Air-flow meter Hitachi Automotive Systems
e-CVT AC synchronous motor (max. output: 124kW/169ps,
max. torque: 307Nm/31.3kgf-m), type: MF8
Honda (in-house)
Motor housing Yanagawa Seiki
Side cover
Ball bearing Nachi-Fujikoshi
Flywheel case Metts
Ball bearing (for differential) NSK
Oil pump housing Yamada Manufacturing
Air conditioning Electric compressor Denso
Water pump (for HVAC system)
HVAC system fan
Battery Lithium-ion battery pack Blue Energy
Battery ECU Keihin
Contactor board Yazaki
Junction board
Battery monitoring unit
Leak sensor
Relays Denso
Battery wiring module Sumitomo Electric Industries
Cooling fan motor Shinano Kenshi
Cooling fan body Valeo
Auxiliary battery Panasonic
PCU Capacitor Nichicon
  Plastic housing Tada Plastic Industrial
Reactor Sumitomo Electric Industries
  Plastic housing Tada Plastic Industrial
DC-DC converter Shindengen Electric
Manufacturing
PCU housing Metts
PCU cover Yanagawa Seiki
Radiator (for cooling the PCU) T.RAD
Water pump (for cooling the PCU) Aisin Seiki
Water hose (for cooling the PCU) Yamashita Rubber
Safety Disc brake Nissin Kogyo
ECU-integrated VSA modulator
Electric servo brake system
Pedal feel simulator
Brake master cylinder
Servo (brushless) motor Mitsuba
Reduction gear, ball screw NTN
Servo brake ECU Honda Elesys
Brake hose Hitachi Metals
(the former Hitachi Cable)
Airbag inflator Daicel Safety Systems
Honking and security horn Mitsuba
Vehicle approaching alert system Denso
Door lock/unlock buzzer
Seatbelt Takata
Rear-view camera Sony
Interior, exterior Rear window glass Nippon Sheet Glass
Windshield, side window glass Asahi Glass
Side mirror lamp Koito Manufacturing
Headlamp bulb Mitsubishi Electric
Sylvania
  Philips
Fog lamp bulb
AFS (headlamp control system), fog/rear lamps,
license plate lamp, reflector
Stanley Electric
Air conditioner panel
Interior lamp Daiichi Denso Buhin
Start-stop switch Honda Lock
Side mirror
Lever combination switch Toyo Denso
Seat TS Tech
Roof lining Howa Textile Industry
Center display, ETC Panasonic
Non-glare inner mirror Gentex
Speaker Pioneer
Center panel switch Alps Electric
Voice recognition microphone Fujitsu
Cigar lighter socket Valeo Japan-Interior Valeo Niles
Other Electric Power Steering (EPS) Showa
Steering column Yamada Manufacturing
(via Showa)
Wire harness Yazaki, Sumitomo Electric Industries
High-voltage cable Sumitomo Electric Industries
Fuel tank Yachiyo Industry
Fuel tube Sanoh Industrial,
Yamashita Rubber
Fuel pump Denso
TV tuner Mitsubishi Electric
Radio tuner Clarion
Radio antenna (distributor) Yokowo

 

 



Before disassembly

 

Before disassembly A rear view of the Honda Accord Hybrid
The Honda Accord Hybrid with the engine hood removed before teardown. The silver-colored box pointed by the arrow contains the Power Control Unit (PCU). A rear view of the Honda Accord Hybrid. The Intelligent Power Unit (IPU) containing the lithium-ion battery pack is placed in the trunk directly behind the rear seat.

 

 



Power Control Unit (PCU)

 

Power Control Unit (PCU)
PCU PCU
The PCU removed from the engine room. The PCU coolant tank is removed on the right-side photo. The PCU comprises a power module that converts direct current to alternating current, or vice versa, a reactor that boosts the voltage to 700V maximum, and the motor ECU that controls the drive motor and the generator. The DC-DC converter is mounted in the Intelligent Power Unit (IPU) together with lithium-ion battery pack. The red arrow in the right-side photo points to the high-voltage cable connector to the drive motor, the white arrow points to the high-voltage cable connector to the lithium-ion battery, and the blue arrow points to the high-voltage cable connector to the generator.
The PCU is 420mm in length, 220mm in width (300mm including the high-voltage cable connector to the drive motor), and 170mm in height. The PCU weighs 17.6kg.

 

Motor ECU Current sensor
Motor ECU Current sensor
The PCU with the top cover removed. The cover is supplied by Yanagawa Seiki, and the harness by Sumitomo Electric Industries. The white arrows point to the current sensors. The circuit board at the center is the motor ECU that controls the drive motor and the generator. An inner view of the current sensor. The three items seen over the circuit board are the sensor cores made of magnetic coils. They are used to detect phase currents of a three-phase AC power circuit.

 

Intelligent Power Module (IPM)
IPM IPM
The left-side photo shows the Intelligent Power Module (IPM) which is mounted under the motor ECU. The IPM consists of a power module that converts direct current to alternating current or vice versa, the gate driver, and the ECU for the Voltage Control Unit (VCU). The circuit board in the left-side photo is the gate driver and the ECU for the VCU. The shield plates, bus bars, power modules and heat sinks are mounted in this order under the board.
The right-side photo shows the rear view of the IPM with an array of heat sinks. The IPM weighs 3.58kg including the heat sinks.

 

IPM cover Rear side of the PCU
IPM cover Rear side of the PCU
The rear view of the cover metal on which the motor ECU is mounted. The IPM is protected by a black resin coat for insulation. The IPM cover weighs 1.62kg. The PCU with the undercover removed. The red arrow points to the capacitor supplied by Nichicon, and the white arrow to the reactor supplied by Sumitomo Electric Industries.
The high-voltage cable connector at the left end of the photo connects to the generator.

 

Capacitor Reactor
Capacitor Reactor
The capacitor supplied by Nichicon is 320(115)mm in length, 150(70)mm in width, and 60mm in height (figures in parentheses are for the encircled part). The plastic housing by Tada Plastic Industrial is used. The capacitor weighs 2.58kg The reactor supplied by Sumitomo Electric Industries can boost voltage to 700V maximum to drive the motor. The plastic housing by Tada Plastic Industrial is used. The reactor is 130mm in length, 110mm in width and 65mm in height and weighs 3.38kg.

 

PCU components PCU radiator, water pump
PCU components PCU radiator, water pump
The PCU components, shown from left to right on the photo, are mounted from top to bottom in that order in an actual PCU configuration. The red arrow points to the motor ECU, the white arrow to the current sensor, the blue arrow to the IPM, the yellow arrow to the reactor, and the green arrow to the capacitor. The radiator supplied by T.Rad for cooling the PCU is shown together with the water pump supplied by Aisin Seiki and water hose supplied by Yamashita Rubber. The PCU radiator is located between the engine-cooling radiator and the left front wheel.
The PCU radiator is 345mm in length, 200mm in width and 25mm in height. The electric water pump housing has a 70mm outside diameter.

 

 



Chassis components

 

Underfloor components
Underfloor components Underfloor components
A bottom view of the engine room with the undercover removed. The drive unit is mounted on the subframe with the electrically-controlled CVT to the right and the engine to the left. A flexible joint is seen under the engine. A rear bottom view of the vehicle. A double-wishbone rear suspension is seen at the center of the photo and the fuel tank supplied by Yachiyo Industry behind it.

 

Suspension
Suspension Suspension
The suspensions removed from the drive unit. The left-side photo shows the front strut suspension removed from under the engine room. The lower left of the photo points to the vehicle's front. The red arrow points to the drive shaft, the blue arrow to the electric power steering and the yellow arrow to the subframe.
The right-side photo shows the double-wishbone rear suspension. The lower left of the photo points to the vehicle's front.
The white arrow points to the Amplitude Reactive Dampers in both photos. The inner pistons have sub-valves that react to only small strokes. The dampers provide a large damping force when a large stroke is applied and only a small damping force when the stroke is small. This contributes to higher driving stability and ride comfort.

 

All-aluminum front subframe VSA modulator
All-aluminum front subframe VSA modulator
The all-aluminum subframe is assembled with the Friction Stir Welding (FSW) process. The top of the photo points to the vehicle's front. The subframe is 1,100mm in width at top, 830mm at bottom, and 1,000mm in length. The gasoline-fueled Accord has an aluminum and steel front subframe. The ECU-integrated Vehicle Stability Assist (VSA) modulator supplied by Nissin Kogyo. The modulator is mounted at the right end (near the right front wheel) at the center of the engine room. The VSA is a system that integrates the Antilock Brake System (ABS) and Traction Control System (TCS) and suppresses skidding.

 

Electric Power Steering (EPS)
EPS EPS
Electric Power Steering (EPS) supplied by Showa. The ECU of the EPS supplied by Showa is mounted in the dashpanel in front of the driver's seat. The ECU weighs 1.2kg.

 

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