插座蓋的注塑模具設(shè)計【proe和CAD圖紙】
插座蓋的注塑模具設(shè)計【proe和CAD圖紙】,proe和CAD圖紙,插座,注塑,模具設(shè)計,proe,以及,cad,圖紙
附錄 1
附錄
英文原文
Vo l. 44 Issue 4 2004
Jour nal of The Inst itution of Engineers, Singapore
3D RAPID REALIZATION
OF
IN ITIAL
DESIG N
FOR PLASTIC
INJECTION
MO ULDS
ABST RACT
Ma ria
L.H. Lowl and
K.S. Le ez
To provide an initial design of the mould assembly for customers prior to receiving the fina l
product CAD data is a prelimina ry work of any final plast ic inject ion mould design.Traditionally
and even up till now, this initia l design is always created using 2D CAD packages.The
information used for the initia l design is based on the technical discussion checklist, in which
most mould makers have their own standards. This technical discussion checklis t is also being
used as a quotation. This paper presents a met hodology of rapid realization of the initia l design in
3D solid based on the technical discuss ion checklist, which takes the role of the overa ll standard
template. Infor mationare extracted from databases and coupled with the basic information from
customer,these information are input into the technical discussion checklist. Rules and heuris tics
are also being used in the initia l mould design. A case study is provided to illustrate the use of the
standard template and to exhibit its real applica tion of rapid realization of the initia l design,for
plastic inject ion moulds.
INTRODUCTION
The most established met hod for producing plast ic parts in lar ge quantities is plast ic
inject ion mould ing. This is a highly cost- effective, precise and competent ma nufactur ing met hod,
which can be automated. However, costly tooling and machiner y are needed in this
ma nufactur ing process. The design of a plast ic injection mould is an integral part of plast ic
inject ion mould ing as the quality of the final plast ic part is greatly relia nt on the injection mould.
A plastic injection mould is a high precision tooling that is being used to mass produce plast ic
parts and is by itself an assembly of cavities, mould base and standard components etc. An
example of a n inject ion mould assembly is shown in Figure 1.
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
Over
the
years,
much
research
work
using
computer- aided
techniques
had
been
done
from
studying the ver y specific areas of mould design to studying mould design as a whole integrated
system. Knowledge-based systems such as IMOLD (Lee et al. 1997), ESMOLD (Chin et al.
1997), IKMOULD (Mok et al. 2001), etc were developed for injection mould design. Many
commercia l mould design software packages such as IMOLD, UG MoldWizard, R&B
MoldWorks, etc are also available today in the market for mould makers. However, the systems
and software packages mentioned above did not consider the initia l design prior to actual mould
design. These software packages assist in the preparation of the detailed mould design that
includes the core/cavity creation, cooling and ejection design. As a result, mould designers hardly
used the mould design software packages when they are doing their initial design because the
software does not catered for such a design process.
There is not much research being done on the initial design of plast ic injection moulds
except for Ye et al. (2000) who presented a n algor ithm for the initial design. The researchers first
deter mine the parting line for the plast ic part followed by the calculation of the number of
cavities required. The cavity layout is created based on the input information of the la yout patter n
and the orientation of each cavity. The mould base is loaded automa tically to accommoda te the
la yout. The researchers also proposed to use their initia l design as a guide tool for the quotation of
the mould. However, the research that is being done may not be applicable for most plast ic
inject ion mould ing industr ies. The calculation of the number of cavities required is mostly
deter mined by the customers who provides the product CAD file and they seldom seek opinion
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
from the mould makers, thus this step could be omitted to save time. Although exter nal undercuts
are identified in the product, the research did not consider the standard components that are
required in producing such undercuts, which in this case, the use of sliders. The research also did
not consider inter nal undercuts where lifters are required. Thus, the quotation derived would not
reflect the correct costing of the mould, and thus could be ver y misleading, since the use of these
types of standard components can increase the cost of producing such a mould substa ntia lly.
Alter natively, the authors (Low et al. 2002) proposed a methodology of standardizing the
cavity la yout design system for plastic injection mould such that only standard cavity layouts are
used. When only standard layouts are used, their layout configurations easily be stored in a
database for fast retr ieva l later in the mould design stage. research is being incor porated into the
rapid realiza tion of the initia l design for plastic injection mould in this paper.
There is a need to introduce a faster method of mould design since there are fewer very
exper ienced mould designers and coupled with the fact of today's market dema nds of having
shorter lead-time and higher quality products. This is fulfilled by the introduction of
standardization into mould design, since the design processes are repeatable for ever y mould
design project. This paper presents a met hodology of rapid realization of the initia l design in 3D
solid instead of 2D drawings using standardization method. The initia l design in 3D solid will be
based on the technical discuss ion checklist that acts as the overa ll standard template. Every sub-
design such as cavity layout design, gating system, mould base design etc will have its own
respective standard template. This is to enable timesa vings in the design stage as the fina l mould
design can be obtained directly by making minute changes to the initia l design.
INITI AL DESIGN OF PLASTIC INJECTION MOULD
The customers and the mould designers have to work closely together to obtain a mould that
could produce what is desired suitably. It would be costly to rectify the errors after the mould is
ma nufactured completely. Thus the initia l pla nning of how the la yout design of the mould is
likely to be is important. A typica l mould design project workflow chart is shown in Figure 2.
When the customers have decided to engage a particular mould- maker, the CAD file of the
product have to be provided to them. However, the mould-maker is always prepared to receive
newer versions of the product CAD file as changes are consta ntly made to it. The downside of
this is that the lead- time given to complete the mould still rema ins as it is. Thus, the time that was
lef t to complete the fina l mould design and ma nufacture the mould becomes shor ter.
When the product CAD file is first received, the assigned project engineer or mould designer
fills up a technical checklist during their first technical discussion with the customers. The
checklist records information such as the resin materia l to be used and its shr inkage value, the
number of cavities required by customers, the gating system, and the mould ing machine to be
used, the required type of mould base and other information needed to provide the basis of the
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
initia l design of the mould. Since this
checklist contains most of the basic infor mation, it doubles
up as a quotation.
This allows customers to decide whether to modify their
product CAD file to
produce a simpler mould that is
cheaper. After that, the mould designer
prepares an initia l design
based on the product CAD file and infor mation in the checklis t
Traditionally and
even up till
now, mould designers
are using 2D CAD packages
to create
the
initial design, although 3D CAD packages are readily available. Ironically, mould
designers
would then use the 3D CAD package only in their fina l mould design. When this
initial design is
completed, it will be presented on the next technical discussion. Modifications made to the initia l
design are nor ma lly done by marking and sketching the changes o n the printed drawing paper.
Though there is no fina l product CAD file at this stage, the mould-maker could go ahead to
purchase the raw materials and standard components subject to approval of the customers. After
the final product CAD file has been received, the mould designer would start the actual mould
design afresh using the 3D CAD package that they have. This is a time consuming met hod since
the initia l design is not related to the fina l mould design.
THE DESIGN STRUCTURE
Figure 3 shows the overa ll structure of the proposed system. In the proposed approach, the
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
standardization method utilizes standard mould designs, which are derived from the information
listed in the technical discussion checklist. This checklist takes on the role of the overa ll standard
template and must be used for every new mould project. The sub- designs will have their own
templates. Databases are used to record information such as types of standard components, types
of design, geometrical parameters and project data etc. Mould- making industries can easily adopt
the proposed approach since they are able to customize the databases to include their own
standards. A standard mould design uses only standard components such as the mould bases;
ejector pins and other accessories. Standard configuration of cavity la youts, that produces only
the same products in a bala nced la yout are used in a standard mould design. Calculations used in
a standard mould design are based on rules and heuris tics, which can be applied universa lly to
any organizations. Rules and heur ist ics make up a n impor tant sector of mould design since they
deter mine if the mould that is designed, is able to fit into the specified moulding machine or be
able to mass produce the product without any problems due to bad design. The hierarchical
organization of the assembly files of a standard mould design should also follow a single mould
assembly structure.
Provision had been made in this
system to present representations
of the core, cavity, slider
40
head
and lifter
head as
blocks
徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
in the initia l design. These blocks
can
be edited
to
trim to the
profile only when the fina l product CAD file
design, ejector pins/blades and cooling lines
has been received and confir med. Dur ing the initial
are still not included because these depend greatly
on the
final product
CAD file.
Since this paper focuses
on the
rapid realization of initia l design,
core/cavity parting, profile
creation, addition of ejector pins/blades
and cooling lines
will not be
discussed here. 3D solids
would be used as they have their advantages. The advantages of solid
modeling are better
visua lization, simplified
simulation, improved
producability, faster
drawing
product ion and facilitates an integrated design process.
Standardiza tion met hod
Standardiza tion met hod involves using standard mould designs, standard components and a
standard working met hod of mould design. This mea ns that every mould designer will design
moulds in exact ly the same met hod, use the same design assembly hierarchy tree, and use
standard components from a specified supplier. This allows the different teams involved in the
mould project to speak the same la nguage. The advantages are as follows: a) Easy follow ing-up
of mould project, b)Lower cost and faster deliver y of components and c) Proper mould project
ma nagement.
Databases
Four different types of databases are used in this system (Figure 3): a) LibYaYy database is
a collection of a ll standard components commonly used by the mould- making industry. b)
CoufiguYatiou database is used for a ll standard components and cavity la yout design. All the
different configurations are already pre-defined in the 3D solid files and only the required
configuration will be activated. c) PYOject database is a collection of a ll data that is input into the
technical discussion checklist and sub- designs inter faces, thus enables tracking and retrieval of
information that are unique to a particular project. The quantity of the var ious components and
their types that are to be used in the project are also recorded here, thus enabling an easy
generation of a n initial bill of mater ia ls (BOMs) when desired and d) Geometr ical paYameteYS
database is utilized where there is a need to change the geometrical parameters such as distances
between different cavities and locations of standard components etc.
SYSTEM IMPLEM ENTATION
A prototype of the rapid realization of initial design system for plastic injection mould has
been implemented using a PIII PC-compatible as the hardware. This prototype system utilizes
SolidWorks 2001 as the CAD software, Microsoft Visual C++ V6.0 as the programming language
and the SolidWorks API in a Windows environment. The rules, heuristics and formulations used
in this prototype system are based on the local mould making industr ies in Singapore.
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
Technical discussion checklist& mould assembly str uct ure
Before the sub- designs are utilized, the overall standard
template,
"Technica l Discussion
Checklist ",must
be used
first
(Figure
4). This
enables
the
mould
design to follow
a
standard
mould
assembly
str uct ure
using
the
initial
product
CAD
file,
the
basic
information
and
requirements from customers. It is impor tant to adhere to the same mould assembly str uct ure for
every mould design project within a n organization to ensure ever y mould designer follows the
same working met hods of designing. It also enables other mould designers to be able to locate a
certain design of a component easily.
The section "Project Tracking" records down the basic details of the project. In the section
known as the "Moulding Material", the resin to be used is chosen from the list. The shr inkage
value of the resin is entered into the space provided so that the initial product CAD file can be
scaled accordingly prior to mould design. The section on "Moulding Machine Details" allows
users to select the moulding machine to be used. The customers provide this information. Upon
select ing the required machine from the list, it extracts data from the mould ing machine database
and reflects the releva nt dimensional information onto the appropr iate spaces in the inter face. A
short extraction of the injection moulding machine database is depicted in Table 1。The section on
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
"Mould Information" records down information such as the type of cavity la yout and the number
of cavities that is required. All these information in this section will eventually be used in their
own individ ual sub-designs templates where users are able to input more infor mation or
to edit
the
current
selection
or
the
geometr ica l parameters.
The
last
section
records
down the
mould
materia ls
and
the type of
surface finishing required. This
information is
needed for
the
initial quotation
and the
procurement
of
mater ia ls
for
the
mould
project.
Finally,
enter ing the
person's
name
that had recorded the
infor mation and the date when the information is
recorded
ensures that a proper
project database.
record
is
kept. All the infor mation that
is
entered
is
listed
into
a mould
Shrinkage factor&core/ca vity creation
A representation of the core and a
representation of
the
cavity in the for m of
blocks
are
simultaneously
created
to
encapsulate
the
scaled
product
CAD
file.
A
default- offset value
is
applied to the range box of the scaled
part to give
the approxima te size of the blocks (Figure 5).
These values are commonly used by mould designers loca lly and can be edited.
Other accessories/secondar y components
The secondary components that may need to be selected during the initial mould design are
sliders, lifters and special inser ts. Sliders and lifters will be the source of concer n in the la yout
assembly level as they pla yed a part in determining the overa ll size of the la yout assembly. They
are initially categor ized into the general types and are available in three basic sizes: Small (S),
Medium (M) and Large (L). The respective sub- design templates for the sliders and lifters are
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
used to place the components to the appropr iate undercuts. They also functions as an inter face to
allow users to edit the geometr ica l parameters or configurations of the secondar y components. As
this is the initial design, ver y accurate positioning is not required but the secondar y components
have to be at its correct location and orientation.
the
Cavity layout
Only standard types of cavity la yout are used in this
types of available la youts are fixed, the different
prototype system (Low et al. 2002). As
types of layouts can be listed into a
configuration database
that enables
the
required
la yout to be activated
in the
mould
assembly
dur ing
the
mould
design.
This
provides
a
faster
method
of
designing.
The
desired
new
configuration
can
be
reloaded
via
the
sub-design
template
for
cavity layout.
In
addition,
the
orientation, the dista nces between cavities, which are known as geometr ica l parameters
be edited through the same inter face.
Selection of mould base size
can also
The secondar y components and
cavity layout are assembled
in the
la yout assembly. The
overa ll size
of the
la yout assembly needs
to be known in order to select the appropr iate mould
base size. The system
automa tically loads
the
sma llest possible
mould
base from the
available
configurations
of the
specified model of mould
base that has been selected.
Simulta neously, the
system
has
to
check
the
compatibility of
the
chosen
mould
base
with the
targeted
inject ion
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徐州 工 程 學 院 畢 業(yè) 設(shè) 計 (論文 )
mould ing machine that is
to be used for mould ing the products. Parameters that are checked are
the
tie-bar
dimensions,
platen dimensions,
mould
height
and
ma ximum
daylight
of
moulding
machine. A representation of the cla mping unit of the chosen inject ion moulding machine can be
activated to allow the user to verify the design visua lly.
Gating&r unner design
The standard design of gates and runner are pre-created and store in a library
database.
Depending
on
the
number
of
cavities
that
are
indica ted
ear lier,
the
appropr iate
configuration will be activated
in the initial mould design.
In this
prototype
system,
some
rules
and heur ist ics are also set for the gating and runner design. The available options
can be selected
only after the type of mould base has been chosen since they are dependent on the type of mould
base.
The rules for selection of the gating are:
1. For 2-plate mould, types of gating that can be used are a ll but pin- point gat
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