KYB TECHNICAL REVIEW No. 67 OCT. 2023

TechnologyIntroduction

Installation of a Flexible Manufacturing System forTransmission Pumps
MATSUNOSHITA Tomohiro, NISHIDA Hideyuki, YOSHIMURA Takashi

1Note 1) Acronym for Continuously Variable Transmission.
Note 2) Acronym for Automatic Transmission.

Introduction

During the initial stage of the transmission vane pumps(hereinafter "PV") business, we planned to produce anumber of PVs for CVT Note 1) of the same design/geometry. Then, we built a high-speed, large-lot
manufacturing system to reduce the cost ofmanufacturing.
However, today's customer needs have diversified. To
match such a variety of needs, there has been a tendency
to manufacture more types of product in smaller
quantities (Fig. 1).

As a result, we became busy with many frequent
events while developing a new CVT PV and a new AT
PV. In addition, the geometry and machining details ofthese products were not compatible with theirconventional counterparts (Fig. 2), which made it difficult
to additionally manufacture them on the existing lines inoperation. Then, we needed to add flexible productionlines partly because of the necessity of global CVT
restructuring.

Planned number of units (thousand units/month)

Existing modelof CVT PV

New model ofAT PV

New model ofCVT PV

6Kseries

Fig. 2

2Fig. 1

Global production of CVT PV

If we tried to implement mixed production of theincreasing number of product models using the existinghigh-speed, large-lot manufacturing system, we needed
to extensively modify the system, thereby incurring highcosts for production preparation. Since it was alsodifficult to reduce the number of production lines because
then only a limited number of models could be subjected
to mixed production, lower production efficiency or
higher cost of manufacturing was anticipated if we
received less orders for the product.
Under this situation of the transmission PV business,
we received from a customer an order for a new modelthat was considered as the last CVT PV. On the other
hand, in the course of the activity for "departure fromheavy reliance on a single customer", which is one of ourbusiness policies, we received for the first time an orderfrom a second customer for a new product, a PV for ATNote 2).

Pump geometry

Purpose, Targets, and Requirements

2. 1 Purpose
In preparing a manufacturing system for the newmodels of AT PV and CTV PV, the Production
Engineering Dept. carried out activities with the purposeof "establishing a compact, flexible manufacturingsystem that can accept mixed production of various
models and allows labor saving".
2. 2 Targets
While maintaining quality, we set a cycle time of 40
seconds, which is twice the conventional time, based on
the number of units of inquiry. The personnel andinvestment targets were set to 1/2 of the conventional
values. The processing cost targets for the three processesof body machining, cover machining, and assembly were
set to be no higher than the conventional values.
To implement flexible manufacturing, targets werealso set for set-up time and production preparation cost
for additional models.
Furthermore, we set space requirements for theinstallation of process equipment. We aimed to be able to―5―

Installation of a Flexible Manufacturing System for Transmission Pumps

apply these requirements for enhanced space efficiency
to all production sites (Table 1).
Table 1Cycle timeLine personnel
Operationalavailability
Set-up timeProduction space

Targets for production lines

Body machining
40 sec./unit
One person/shift

Cover machining
40 sec./unit
One person/shift

Assembly
40 sec./unit
Two persons/shift

Not less than 78%

Not less than 78%

Not less than 85%

20 min. or less/20 min. or less/
9.5 min. or less/sessionsessionsessionThree processes to be included in a global PV area (10 m x 28 m)

2. 3 Requirements
To achieve the targets, the following four requirements
were established:
1. A manufacturing system built in a global PV area Note 3)
shall be able to be introduced at any production site.
2. Set-up work shall be able to be conducted efficiently
and safely.
3. A traceability system also supporting manualtransport shall be established to prevent outflows of
non-conforming products and to store quality
records.
4. The required contamination level shall be maintained.
Note 3)A unified manufacturing area for all production sites ofpump business units.

3

3. 2 Layout Review
Conventionally, the body machining, cover machining,
and assembly lines were allocated to separate areas andoccupied a layout space of about 2.5 global PV areas.
To build a manufacturing system with a more efficientuse of line space and with a high degree of freedom forequipment installation applicable to any production site,
we reviewed the layout with the aim of putting threelines in a global PV area (Fig. 3).
We placed importance on flexibility so as to support avariety of product geometries. For this purpose, wedecided to select manual transport by operators, insteadof the conventional automatic in-process transport.
We allocated a group of operators to the machiningzone involving quality concerns and another group to theinspection process and then leveled out the tasks. As aresult, the personnel target was achieved even for manualtransport, making it possible to build a manufacturingsystem that can ensure both quality and flexibility.
Furthermore, we worked with the Production Control
Dept. to determine the optimal layout of the parts inlet
and product outlet chutes, achieving both efficient in-line
work of operators and a straight material transport route(Fig. 4).

Activities

Related departments discussed the manufacturing
processes. They reviewed the processes on the premisethat the line transport is manually done by operators withpriority placed on the flexibility of the production lines
and that automation for ensuring quality and productivity
is implemented for each production equipment.
3. 1 Simulation
Through process design reviews (DRs) and repetitive
discussions with related departments, we reviewed
various combinations of tasks together with theProduction Dept. and KPS Note 4) Improvement Dept. andperformed repeated simulation using corrugatedcardboard Note 5) (Photo 1).

Fig. 3

Layout before review

Fig. 4

Layout after review

Note 4) Acronym for Kayaba Production System.
Note 5) Make simulation equipment from corrugated cardboard
and pipes to simulate transport and set-up works.

Photo 1

Simulation using corrugated cardboard

3. 3 Process Integration
In order to put the three lines in the layout spacedescribed above, we conducted process integration foreach of the processes as follows, achieving the spacetarget.
3. 3. 1 Process Integration of Machining
Equipment
To achieve process integration, we introduced small
work clamps as machining jigs. This substantiallydownsized the machining jigs, achieving a shift from theconventional machining process using flat jigs to a―6―

KYB TECHNICAL REVIEW No. 67 OCT. 2023

process using cradle jigs Note 6) (Fig. 5).
This shift enabled multi-face machining. The
conventional six processes needed to accomplish
machining were integrated into four processes. The fewer
processes helped reduce the time of manual handlingwork, while the higher degree of freedom of jigs enabledeasier set-up changes for other models.

The cover bolt tightening process needed toaccommodate different bolt pitches that varied by model.
We provided the nut runner with multiple moving shafts
to accommodate cover bolts in various positions without
mechanical set-up work (Photo 3).

Note 6) A mechanism in which swinging the jig like a cradle
will enable machining not only in a single direction but
also at different angles.

Photo 3Fig. 5

Machining jig

3. 3. 2 P rocess Integration of Assembly
Equipment
We reviewed the process allocation within the cycle
time setting of 40 seconds and decided to integrate twoto three processes into a single equipment unit. This
integration helped reduce the number of equipment units
used and the number of attachments/detachments,
contributing to lower processing cost. We also ensured
mountability and a wider moving range of the set-up jigs
so as to accommodate various product geometries andspecifications that vary by model.
As examples of process integration of assembly
equipment, the following describes plug and cover bolt
tightening processes.
The AT PV uses three plugs of two different types.
These plugs need to be tightened in three directions. To
accept plugs in different orientations, we provided theplug tightening machine with a cradle mechanism toallow work to swing around the Y-axis and another swing
mechanism to allow work to swing around the X-axis, inaddition to the regular X-Y axes.
We also installed a socket changer in the equipment toenable automatic socket changes without the need for a
set-up change by an operator, making it possible totighten multiple types of plugs in a single equipment unit
(Photo 2).

Cover bolt tightening machine

3. 4 Quality Improvement Measures
When building a new manufacturing system this time,
we also tried to maintain or improve the quality level ofthe conventional manufacturing system.
3. 4. 1 Establishment of a Traceability System
We achieved traceability by engraving a serial number
for identification on individual body/cover parts in theleading process of the machining line and by reading theserial number of all workpieces with cameras (Photo 4)
installed in the processes from machining to assembly.

Photo 4 Serial number reading camera

In this system, the serial number read in individual
processes is written to the edge PLC Note 7) along withinformation about the product model and processprogress as well as a timestamp. The next process reads
the information from the edge PLC to identify thecondition of the previous process, preventing a process
skip or outflow of non-conforming products.
Note 7)A programmable logic controller (PLC) for primaryprocessing between the manufacturing system and theserver that collects and stores data. It is intended toreduce the server load and increase the processing
speed.

Furthermore, quality data output from equipment units
is automatically stored in the server, preventing
inappropriate behavior such as data falsification (Fig. 6).

Photo 2Plug tightening machine―7―

Installation of a Flexible Manufacturing System for Transmission PumpsPhoto 5Fig. 64Traceability system

In the machining process, MT-LINKi Note 8) wasintroduced as an equipment monitoring system. This
monitoring system obtains a history of thermal changes
per cycle, enabling the prediction of possible causes oflower machining accuracy and determination of thedimensions during dimensional adjustment.
This system has also allowed system users to obtain
information about the equipment condition and alarm
history during production, thereby enabling nonoperating analysis without relying on hearing fromoperators (Fig. 7).
Note 8) MT-LINKi is a registered trademark of FANUCCORPORATION.

Results

We successfully installed the three production lines(body machining, cover machining, and assembly) in asingle global area as planned.
Mass production was launched in December 2021 for
AT PV and in April 2023 for CVT PV. The production
has continued so far with no complaints.
We also achieved the productivity and line personnel
targets, namely, a cycle time of 40 seconds/unit and four
persons/shift respectively.
The operational availability target was achieved in themachining process, but not achieved in the assembly
process on a monthly average basis. Continual
improvement is under way to achieve the target (Table2).
Table 2

Cycle timeLine personnel
Operational
availabilityFig. 7

MT-LINKi screen

3. 4. 2 Contamination Quality Control
While we built a manual transport production systemthat is totally different from the conventional high-speed,large-lot manufacturing system, we decided to maintainthe conventional contamination quality control.
In the machining process, a preliminary cleaning
before the inspection and distribution processes removes
chips and cutting fluid. This cleaning is intended toimprove the inspection accuracy and prevent carry-overof such contaminants to subsequent processes.
To satisfy the contamination standard for the products,
we added a palletization process to the last part of themachining process. In the palletization process, anoperator puts all parts for a unit of the product into acleaning pallet to be cleaned immediately before
assembly (Photo 5).
Through this process, we prevented the occurrence of
missing or excessive parts in the assembly process andimproved the contamination level by reducing the workin process after cleaning.

Cleaning pallet5

Results of newly-installed production lines
Body cover machining
AssemblyTargets
ResultTargets
Result40 sec./unit
40 sec./unit
40 sec./unit
40 sec./unit
Two persons/ Two persons/ Two persons/ Two persons/
shift
shift
shift
shift
Not less thanNot less than
84.5%
78.9%
78%
85%

In Closing

We have successfully built a manufacturing system
based on a new concept. This system is now used tomanufacture two models of AT PV/CVT PV that havejust been designed.
We will manufacture more product models in the new
manufacturing system, hoping that the system will be a"flexible manufacturing system" in the true sense of thosewords.
Finally, we would like to take this opportunity to
deeply thank all those concerned who extended support
to this project.

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KYB TECHNICAL REVIEW No. 67 OCT. 2023

Authors 

MATSUNOSHITA Tomohiro

NISHIDA Hideyuki

Joined the company in 1993.
Production Engineering Dept.,
Mobility Devices Headquarters.,
Automotive Components Operations.
Engaged in design of machining
process and introduction of machining
equipment.

Joined the company in 2009.
Production Engineering Dept.,
Mobility Devices Headquarters.,
Automotive Components Operations.
Engaged in design of machining
process and introduction of machining
equipment.

YOSHIMURA Takashi
Joined the company in 2005.
Group Leader, Production Engineering
Dept., Mobility Devices Headquarters.,
Automotive Components Operations
Engaged in design of assembly
process and development of specialpurpose machine control systems.

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