Parts Reduction Design by TRIZ II- To break down conventional designs and stay one step ahead -Yoshiharu Isaka (Senior Consultant, IDEA Inc.)
The 9th Japan TRIZ Symposium 2013

Contents
3
1. Purpose and Theme of Presentation
4
Good Designs can Be Made by Trimming!
5
2. Way of Thinking in Trimming
6
Composition of the Muffler for a Motorcycle
10Function model of the Muffler
11
Trimming idea
12
3. Further trimming?
Trimming model substituting with outer cylinder 13
14
Idea substituting with outer cylinder
18
Further reduction from the trimming idea
20
4. Trimming for a new invention
21
Front brake of the motorcycle
23
Function model of the master cylinder
27
5. Parts reduction trimming case study30
6. Summary
The 9th Japan TRIZ Symposium 20132

Purpose and Theme of Presentation
Main Theme of the symposium this year
“Change Risk to Chance with TRIZ!"
PurposeTechnology should evolve to avoid the risk of goods
commoditization and to maintain domination in the market. To
achieve this, conventional designs have to be broken down, but there
are cases where it is difficult to find contradictions in conventionallyfollowed structures. Therefore, it will be shown that there is a chance
to tie to a good design by an expert’s view or a new invention by
applying trimming.

Theme
Proposal of a view that breaks down conventional designs bytrimming
The 9th Japan TRIZ Symposium 20133

Good Designs can Be Made by Trimming!
It has always been said that a simple design decreasing thenumber of components is a "Good design,“ a design of experts.
If so, how can such a design be made? This seems to bedependent on individual skills, something that cannot be taught, andsomething that is not taught even if one asks for it.
Besides, the most effective method for circumventing a patentright is to develop a new invention that decreases the composition
requirements from the former patent, but it seems that littleinformation exist that shows a concrete way how to achieve this.
As trimming shows a view to decrease the number of components,
it is a method which has the possibility for a simple design or an ideathat exceeds the prior invention. Therefore, I will introduce cases
which can serve as a trigger to break down the conventional design.

4Way of Thinking in TrimmingComponent 1
ActionActionComponent 3

ActionTargetActionTargetActionComponent 2④ New component
ActionComponent 1①

ActionActionAction②Component 3③⑤ Component 2 ① Delete the action itself② Substitute the component with another③ Provide the action by the component itself④ Substitute with another new cheap component⑤ Delete the component

5Composition of the Muffler for a Motorcycle

Muffler

Structure of anexpansion type muffler

6

Automobile
Noise Test Method

Source: Japan Automobile
Manufacturers Association HP

7

Noise Regulation Value（単位：ｄＢ）
定常近接加速走行騒音 排気騒音 走行騒音乗用車

72

小型
軽自動車
第二種
原付自転車
第一種

72716865

二輪自動車

96769473908471

The regulation values
for the motorcycles
are severer thanthose for the cars.
Application to theimported cars …
Composition ratioby sound source(acceleration noise)
Source: Japan Automobile
Manufacturers Association HP

8Adoption Reason for Expansion Type Muffler
1. The resonance type is not effective for single cylinders
2. No durable and practicable noise absorbing material found3. The active type is not practicable for lowering the exhaust soundbecause of the wide frequency
Therefore, the communication path area was narrowed down for noise
reduction, and it was tried to recover the resulting power reduction by
expanding the muffler volume
4. Even if cost is put on the muffler, it doesn't become an immediate charmquality.
5. As specification can be decided by simulation, and development in a shortterm is possible, a new method is not tried to be examined.
Though there are needs for downsizing, the conventional method
is followed because of development efficiency etc., and themuffling method hasn’t changed
As the same structure has been adopted for a long time, therewill be an impact if the structure can be made simpler
9Function model of the Muffler
createresistancecreateexpansionchamber gas

createexhaust gas

flow insound energy

flows out

resistancecreateflow infirst lead tube

hold

hold
createfirst partition

holdattenuate

expansionchamber

second lead tube

holdexhaust gas

createsecond partition

createoutercylinderflows out

holdAs our objective is to reduce parts maintaining the current
expansion type muffling method and not to think of a newone, the solving of harmful effects will be neglected, andphysical actions relevant to the structure will be targeted.
10Ideas obtained by trimming
An idea that substitutes the action ofcommunicating vessel with the partition
AZ

BCC

BZviewA

An idea to substitute the communicatingvessel with the partition and the outer cylinder
BA

B

A

B-B

A-A
11

Further trimming?
Seeing the function model, an idea could be generated bysubstituting the action of the communicating vessel with thepartition and the outer cylinder to trim it, and it was announced lastyear.
It was a new idea through trimming, and it could provide a simple
structure that was conventionally not available ( it was not an
introduction of something already in actual use as a trimming casestudy ).
However, as it was a trimming of just the communicating vessel
and hadn’t reached the perspective of trimming the partition, it was
yet insufficient from the viewpoint of reducing the components.
As the ultimate form is to also trim the partition and realize withjust the component outer cylinder ( only one component ), further
trimming will be considered.
12Trimming model substituting with the outercylinder only
Is not possible to achieve the actionsof the communication vessel and thepartition by the outer cylinder only?
作る

抵抗

膨張室ガス
作る

作る

抵抗

流出する

音エネルギ

流入する

作る

第２連通管

流出する

保持する

第１連通管

排気ガス

減衰する

排気ガス

流入する

第１連通路

作る

保持する

膨張室

作る
作る

第１隔壁
保持する

第２連通路

作る

保持する

作る

外筒

作る

第２隔壁
保持する

13

Idea substituting with the outer cylinder only
To form the expansion
chamber with theouter cylinder only

The hint isa sushi roll

It is possible todivide into rooms
if rolled spirally

14

Idea substituting by the outer cylinder only

15

Association of ideas

Doesn’t it need
to be a spiral topartition rooms?

This also can divide into
3 rooms and provide a
communicating vessel
These kinds of ideas can begenerated even though it isnecessary to consider thesealing of the overlapping parts
16

Reduction comparisons of components
Original:
partition +communicating vessel

Substituting withpartition

Substituting withpartition and outercylinderSubstituting withouter cylinder

Partition: 3
Outer cylinder : 1

Partition: 4Outer cylinder: 1

Partition: 2
Outer cylinder: 1

Specification

Number ofcomponents

Partition: 4
Lead tube 4Outer cylinder: 1① Delete the action itself② Substitute the component with another③ Provide the action by the component itself④ Substitute with another new cheap component⑤ Delete the component

Try to force yourself tothink of various
substitution targets inthe view shown throughtrimming
17

Further reduction from the trimming idea
When generating trimming ideas, we generally tend to
search for ideas with high feasibility rating. Consequently,
we are apt to get easily satisfied saying like "Thecommunicating vessel could be trimmed, …”

To go further ahead, more components should betrimmed.
Based on the already-generated trimming ideas, isn’t itpossible to generate further ideas where the partition canbe trimmed by thinking without the restriction ofmanufacturing, etc. and disregarding the feasibility?
18

Association of ideas
DCBA

DCB

A

C-C

B-B

D-D

A-A

This is an idea, which was forcibly generated disregarding
feasibility, decreasing the number of partitions from 4 to 3 andcomposing 3 expansion chambers. When you consider thealternative, clues and chances to new manufacturing
technology development can be obtained from this.
19Trimming for a new invention
As the view by trimming is “Reduction of components,”
whereas problem solving is “Solution of contradictions,” isit not possible to use trimming to complete a new invention
without infringing an existing patented invention?
If the patented invention consists of A, B and C･Patent infringing case[ニ] (includes all compositions A, B and C)･Patent non-infringing case[イ] (includes compositions A and B, but not C )[ロ] (includes compositions B and C, but not A )[ハ] (includes compositions A and C, but not B )Since purposes, actions, effects and detailed descriptionsof the invention are taken into consideration as thetechnical range, trimming is examined including cases
where the composition requirement is an attribute
20

Front brake of the motorcycle

Thrust piston type master cylinder･ To increase the breaking force, caliper
pistons with 4 or 6 pots are commonplace･ Should be effective without enlarging thelever stroke･ However, delicate lever operation should
be possible
21

Radial piston type master cylinder･ Delicate lever operation is possible because
the brake lever can be lengthened･ As the piston diameter can be enlarged, theoil feed amount can be increased, so a shortstroke can give a reaction even in 6 pots, etc.
To enable such idea generations …
22

Function model of thrust piston type mastercylinderUsing “Goldfire Innovator TM ”
Seal, return spring, reservoirtank, etc. are omitted

23

Function model for trimming

Using “Goldfire Innovator TM ” 24

Trimming for a new invention examination
Attribute

ActionComponent 1
ActionComponent 3

ActionTargetActionComponent 2⑥④ New component
Attribute

Component 1①

Action⑤ Component 2

ActionActionAction②Component 3Action

Target③⑥ Substituting the Action of the Attribute
Proposed addition25

Application scene of trimming
Function

Maturestage
Growthstage
Launchingstage

DeclinestageTrimmingTime

Up to now, trimming was regarded to be applicable atthe decline stage of the technology evolution pattern,but, as it is also applicable for generating newinventions circumventing patent rights, it can also beapplied at stages other than the declination. ->Trimming can be used as an tool for idea generation
which not only resolves contradictions.
26Parts reduction trimming case studyStructure of the oil pump heavily used in car engines
in previous times

Simplification and cost-cutting design by notcontradiction resolution but parts reduction
27

Parts reduction trimming case
The installation of the fuel tank on aportable engine such as brush cutters wasachieved just by tucking it with the fan caseand the bracket from the recoil starter
A simplification and cost-cutting design
making mounting bolt, etc. unnecessary
Recoilstarter

Fan case

Fuel tank28

Use of trimming
Purpose"Good design“ reducing components"New invention“ circumventing patent rights

realizationEffect
Design improvement through an expert's viewpoint canbe enabled systematically independent of individual skills
Point
１． It is easy to generate ideas when "Substituting with othercomponents" is applied if multiple substitute targets arechecked up
2. It is easy to go ahead if associated or developed from thetrimming idea disregarding the feasibility, etc.
3. It is easy to lead to inventions if thinking about trimming not
only the component but also the attribute29

Summary
As trimming can be used from the view how to decrease components
even where contradictions cannot be defined, it can easily used also forreviewing systems which are thought to have no alternatives
As trimming can be used as a tool to generate ideas circumventing
rights of patented inventions which seem to have no alternative
compositions, it should also be used for the purpose of strengthening
one’s own patents
As any stage of technological evolution asks for simplifying thedesign, we should consider to use trimming actively instead of justapplying it at the decline phase in the evolutionary stage
For trimming, by drawing accurate function models, the view ofdeleting and substituting functions in the function model is easy to leadto ideas which can not be gotten by just looking on pictures or things
The 9th Japanese TRIZ symposium 201330

EndThank you for your attention
IDEA Inc. can support problem solving also forthemes which have been thought impossible such as
inescapable patents, unchangeable designs ordramatic cost reductions.
Only those who use TRIZ will benefit from it.
The important thing is to implement it early.

The future is createdwith TRIZ.
The 9th Japanese TRIZ symposium 201331