U.S. patent application number 09/737870 was filed with the patent office on 2001-05-31 for electronic apparatus, electronic apparatus manufacturing method, and mold device.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Hosoi, Takashi, Ono, Yasuo, Takaki, Nobuyuki.
Application Number | 20010001979 09/737870 |
Document ID | / |
Family ID | 15952709 |
Filed Date | 2001-05-31 |
United States Patent
Application |
20010001979 |
Kind Code |
A1 |
Hosoi, Takashi ; et
al. |
May 31, 2001 |
Electronic apparatus, electronic apparatus manufacturing method,
and mold device
Abstract
In an electronic apparatus such as a portable computer provided
with an electronic apparatus frame having a boss portion, a
protrusion is formed in a position for the boss portion, the
electronic apparatus comprising a boss separator formed having a
retaining hole and attached to the protrusion to form the boss
portion.
Inventors: |
Hosoi, Takashi; (Tokyo,
JP) ; Takaki, Nobuyuki; (Tokyo, JP) ; Ono,
Yasuo; (Yokohama-shi, JP) |
Correspondence
Address: |
Finnegan, Henderson, Farabow
Garrett & Dunner, L.L.P.
1300 I Street, N.W.
Washington
DC
20005-3315
US
|
Assignee: |
Kabushiki Kaisha Toshiba
|
Family ID: |
15952709 |
Appl. No.: |
09/737870 |
Filed: |
December 18, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09737870 |
Dec 18, 2000 |
|
|
|
PCT/JP99/01762 |
Apr 2, 1999 |
|
|
|
Current U.S.
Class: |
164/113 ;
164/312 |
Current CPC
Class: |
B22C 9/06 20130101 |
Class at
Publication: |
164/113 ;
164/312 |
International
Class: |
B22D 017/04; B22D
017/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 1998 |
JP |
10-173019 |
Claims
What is claimed is:
1. In a mold device comprising pin members provided projecting from
an upper mold or a lower mold in order to form a frame having pores
arranged at given pitches, the lower mold or the upper mold opposed
to the respective projecting end portions of the pin members having
a depression such that said pin members can be formed projecting
longer than the wall thickness of the frame and that an inflow
bypass portion kept at a given space from the respective projecting
end portions of said pin members can be provided in positions for
the pin members.
2. An electronic apparatus manufacturing method for molding a frame
of an electronic apparatus having pores arranged at given pitches,
by means of the mold device according to claim 1, comprising: a
flowing process for causing a molten metal to flow in said inflow
bypass portion and diffuse throughout the interior of the mold
device; a solidifying process for solidifying the molten metal
introduced into the mold device in said flowing process, thereby
forming a molded piece; and a working process for forming
penetrating pores by machining a raised portion corresponding to
said depression of the molded piece formed in said solidifying
process and making the raised portion flush with the other
portion.
3. In an electronic apparatus comprising a frame formed having
pores arranged at given pitches, said pores being initially
surrounded by a raised portion formed having pore shapes deeper
than the wall thickness of said frame, the electronic apparatus
having a machined surface around the penetrating pores formed by
machining the raised portion so that the raised portion is flush
with the other portion of the frame.
4. In an electronic apparatus comprising a frame formed having
pores arranged at given pitches, said pores being initially
surrounded by a raised portion formed having pore shapes deeper
than the wall thickness of said frame, said penetrating pores being
formed by removing the raised portion by machining.
5. An electronic apparatus according to claim 3, wherein said frame
is formed of a magnesium alloy as a material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of PCT Application No.
PCT/JP99/01762, filed Apr. 2, 1999, which was not published under
PCT Article 21(2) in English.
[0002] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No. 10-173019,
filed Jun. 19, 1998, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0003] This invention relates to an electronic apparatus having a
frame of a light metal used in a personal computer or the like, a
manufacturing method for the electronic apparatus, and a mold
device for forming the frame of the electronic apparatus.
[0004] Recently, magnesium alloys have been mainly used as the
material of an electronic apparatus frame of a light metal. These
alloys are molded by die-casting or thixotropy. In either of these
molding methods, which use different equipment mechanisms, an alloy
melted at 580.degree. to 750.degree. is injected into a mold of
about 100.degree. to 350.degree. and molded.
[0005] FIG. 6 shows a configuration of a conventional electronic
apparatus frame 1. In molding this electronic apparatus frame 1, a
molten metal is poured through a sprue 2 (this drawing shows the
shape of the electronic apparatus frame just molded, and in the
description to follow, various parts of a mold device will be
described corresponding to the shape of the electronic apparatus
frame just molded), and the molten metal is introduced into a
desired mold through a runner 3. The introduced molten metal
diffuses throughout a cavity 4 and finally reaches an air vent 5.
Further, a molten metal reservoir 6 is coupled to the air vent 5.
When the molten metal is introduced through the sprue 2, therefore,
air can be discharged to the outside through the air vent 5.
Thereupon, the frame can be formed without containing any voids
therein.
[0006] In order to change the shape of the electronic apparatus
frame 1 of FIG. 6 just molded into a utilizable shape, moreover,
the sprue 2, runner 3, air vent 5, or molten metal reservoir 6 is
cut off thereafter to shape the electronic apparatus frame 1.
[0007] After the molten metal is solidified in the cavity 4, the
solidified frame shape is taken out. In the case where the
electronic apparatus frame 1 is provided with pores 7 for heat
radiation to the outside or for use as a speaker, for example, the
pores 7 are formed by punching at given pitches. Thus, the
narrow-pitch pores 7 are formed in the electronic apparatus frame 1
in the aforesaid manner.
[0008] However, punching the cavity shape to form the pores 7 one
by one after the frame shape is formed in the cavity 4 requires
post-forming, which entails higher cost. Accordingly, there is a
demand for a manufacturing method capable of rapidly forming the
pores 7 without entailing high cost.
[0009] Hereupon, there may be proposed a manufacturing method in
which the molten metal is poured into the cavity 4 that is provided
with pins projecting therein, and the frame shape having the pins
formed thereon is taken out of the mold device.
[0010] In the case where the pins are arranged at narrow pitches,
according to this manufacturing method, however, the fluidity of
the molten metal between the pins worsens if the molten metal is a
magnesium alloy, for example. In some cases, the molten metal may
possibly fail to penetrate into the regions between the pins, thus
leaving unfilled portions.
[0011] If the frame used is formed of a magnesium alloy, moreover,
burrs are inevitably formed as the frame shape is punched at narrow
pitches, since the electronic apparatus frame 1 is thinned. Since
the burrs arouse a problem on the external appearance of products,
they must be removed in an additional laborious process.
BRIEF SUMMARY OF THE INVENTION
[0012] This invention has been contrived in consideration of these
circumstances, and its object is to provide an electronic apparatus
with a frame having a good external appearance and shape, lowered
in cost, and capable of affording rapid formation of pores at
narrow pitches, an electronic apparatus manufacturing method, and a
mold device.
[0013] According to a preferred embodiment, a mold device of this
invention is a mold device comprising pin members provided
projecting from an upper mold or a lower mold in order to form a
frame having pores arranged at given pitches, the lower mold or the
upper mold opposed to the respective projecting end portions of the
pin members having a depression such that the pin members can be
formed projecting longer than the wall thickness of the frame and
that an inflow bypass portion kept at a given space from the
respective projecting end portions of the pin members can be
provided in positions for the pin members.
[0014] Further, an electronic apparatus manufacturing method of
this invention is an electronic apparatus manufacturing method for
molding a frame of an electronic apparatus having pores arranged at
given pitches, by means of the mold device according to claim 1,
comprising a flowing process for causing a molten metal to flow in
the inflow bypass portion and diffuse throughout the interior of
the mold device, a solidifying process for solidifying the molten
metal introduced into the mold device in the flowing process,
thereby forming a molded piece, and a working process for forming
penetrating pores by machining a raised portion corresponding to
the depression of the molded piece formed in the solidifying
process and making the raised portion flush with the other
portion.
[0015] Furthermore, an electronic apparatus of this invention is an
electronic apparatus comprising a frame formed having pores
arranged at given pitches, the pores being initially surrounded by
a raised portion formed having pore shapes deeper than the wall
thickness of the frame, the electronic apparatus having a machined
surface around the penetrating pores formed by machining the raised
portion so that the raised portion is flush with the other portion
of the frame.
[0016] Additional objects and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0017] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate presently
preferred embodiments of the invention, and together with the
general description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
[0018] FIG. 1 is a perspective view showing the shape of a prior
art electronic apparatus frame;
[0019] FIG. 2 is a perspective view showing a configuration of a
portable computer as an electronic apparatus according to one
embodiment of this embodiment;
[0020] FIG. 3 is a sectional view showing the shape of a mold
device of the same embodiment;
[0021] FIG. 4 is a partial enlarged view of the mold device;
[0022] FIG. 5 is a perspective view showing the shape of an
electronic apparatus frame used for the electronic apparatus;
[0023] FIG. 6 shows a flowchart for a manufacturing method for the
electronic apparatus;
[0024] FIG. 7 is a perspective view showing the shape of a molded
piece; and
[0025] FIG. 8 is a sectional view illustrating a manufacturing
method for the electronic apparatus having the electronic apparatus
frame of the same embodiment, in which FIG. 8A is a view showing a
state in which a raised portion of the molded piece left uncut, and
FIG. 8B is a view showing the molded piece with the raised portion
off.
DETAILED DESCRIPTION OF THE INVENTION
[0026] One embodiment of the present invention will now be
described with reference to FIGS. 2 to 8B.
[0027] FIG. 2 is an external view showing the shape of a portable
computer 10 such as a note-type personal computer. In this drawing,
the portable computer 10 comprises a computer body 11 and a display
unit 12 that is rockably supported on the computer body 11. The
computer body 11 is provided with a frame 13, and this frame 13 is
design so that a lower frame 14 and an upper frame 15 are suitably
joined by means of, for example, screws or the like. However, the
lower frame 14 and the upper frame 15 may be joined by means of any
other arrangement than this.
[0028] In the description to follow, the frame that is applied to
the portable computer 10 or some other electronic apparatus will be
described as an electronic apparatus frame 20.
[0029] The electronic apparatus frame 20 of the light metal
personal computer, formed of a magnesium alloy or the like,
sometimes may require a large number of pores 21 arranged at short
pitches, as shown in FIG. 5, in order to fulfill a function to cool
the inside of the personal computer or to serve as a speaker for
external sounding. A mold device 30 shown in FIG. 3 is used to
provide this electronic apparatus frame 20.
[0030] The mold device 30 includes an upper mold 31 and a lower
mold 32, which engage each other to form the mold device 30. The
mold device 30 is provided with a sprue 33, for use as a molten
metal inlet, and a runner 34 for guiding a molten metal in
introduction into the mold and in uniform diffusion. The molten
metal guided by means of the runner 34 is introduced into a cavity
35 of the mold device 30.
[0031] The molten metal is a molten magnesium alloy. Alternatively,
an aluminum alloy may be used for the molten metal, for
example.
[0032] In order to form the pores 21 in the aforesaid electronic
apparatus frame 20, the cavity 35 is provided with pin members 36
in those parts which correspond to the pores 21 of the mold device
30, individually. The pin members 36, which have a length such that
they project a little longer than the wall thickness of the
electronic apparatus frame 20, are provided on the upper mold
31.
[0033] The lower mold 32, which faces those parts of the upper mold
31 on which the pin members 36 are provided, is provided with an
inflow bypass portion 37 shown in FIG. 4. This inflow bypass
portion 37 is located in a depression 38 that is depressed below
the other parts of the cavity 35. The depression 38 has a depth
such that the gap between the inflow bypass portion 37 and the
respective projecting end portions of the pin members 36 is
substantially equal to the width of the other parts of the cavity
35.
[0034] An air vent 39 is formed in the other end of the cavity 35.
The air vent 39 serves to discharge air in the mold device 30 to
the outside of the mold device 30. The air vent 39 further
communicates with a molten metal reservoir 40. Thus, the molten
metal introduced into the mold device 30 can reach the molten metal
reservoir 40 without producing voids in the cavity 35.
[0035] The following is a description of a manufacturing method for
manufacturing the electronic apparatus frame 20 by means of the
mold device 30 constructed in this manner. FIG. 6 shows a flowchart
for the manufacturing method.
[0036] In injection-molding the electronic apparatus frame 20 of a
light metal, a pressure of about 250 tons, for example, is applied
to a molten magnesium alloy. By the application of this pressure,
the molten metal is introduced into the cavity 35 in the mold
device 30. In the mold device 30, however, the pin members 36 are
arranged at pitches (hereinafter referred to as narrow pitches)
such that the molten metal cannot be introduced satisfactorily, and
the fluidity of the molten magnesium alloy is unfavorable (i.e., if
the molten metal comes into contact with the respective inner wall
surfaces of the upper mold 31 and the lower mold 32 that are
touched by the molten metal, the touched portion is cooled and
solidified first, so that the fluidity is unsatisfactory).
Accordingly, the fluidity worsens between the individual pin
members 36 that are arranged at the narrow pitches. Unfilled
portions may be created as this is done, and those portions may
form voids, possibly causing malformation.
[0037] In order to prevent the occurrence of the malformation, the
molten metal is caused to flow into the inflow bypass portion 37 in
the depression 38 of the lower mold 32, and the molten metal is
caused to flow in the region between the inflow bypass portion 37
and the pin members 36 after it is made to flow first in the
aforesaid portion (flowing process).
[0038] Thus, as the molten metal flows from one end of the cavity
35 to the other end, a normal molten metal flow such that the
molten metal gets into the positions between the individual pin
members 36 is produced along with a faster molten metal flow in the
inflow bypass portion 37 in which the molten metal easily flows.
Accordingly, a molten metal flow is generated such that the molten
metal penetrates from the inflow bypass portion 37 into the gaps
between the pin members 36 that are located on the upper side. In
consequence, most of the molten metal that penetrates into the gaps
between the pin members 36 is directed upward from the inflow
bypass portion 37, so that the molten metal can easily get into the
positions between the individual pin members 36.
[0039] Thereafter, the molten metal solidifies in the cavity 35 to
form a molded piece 41 shown in FIG. 7 (solidifying process). This
molded piece 41 has a raised portion 42 that is provided
corresponding to the depression 38.
[0040] As shown in FIGS. 8A and 8B, moreover, the raised portion 42
is formed having holes 43 that are provided corresponding to the
pin members 36 and have a depth greater than the wall thickness of
the electronic apparatus frame 20. Thus, the lower end side of the
holes 43 further projects beyond the wall thickness of the
electronic apparatus frame 20.
[0041] Then, the pores 21 can be provided penetrating the
electronic apparatus frame 20 by subjecting the raised portion 42,
a to-be-removed portion, to cutting work (or any other machining)
by means of, for example, a milling machine so that it is flush
with the other part of the molded piece 41 (working process).
[0042] As this cutting work is carried out, a cut surface (machined
surface) 44 is formed in the region around the pores 21 from which
the raised portion 42 is removed.
[0043] According to the mold device 30 constructed in this manner,
the electronic apparatus frame 20, and the manufacturing method
therefor, the mold device 30 is provided with pin members 36, the
depression 38 is formed in the mold device 30 so that the length of
projection of the pin members 36 is greater than the wall thickness
of electronic apparatus frame 20, and the region between the
depression 38 and the respective projecting end portions of the pin
members 36 forms the inflow bypass portion 37. Accordingly, the
molten metal from the inflow bypass portion 37 can be caused to
penetrate into the regions between the pin members 36, thereby
preventing creation of unfilled portions.
[0044] Thus, although the pin members 36 are arranged at the narrow
pitches, the molten metal can be caused easily to get into the
intermediate regions.
[0045] Further, the raised portion 42 is formed on the molded piece
41 by means of the mold device 30, and the pores 21 are formed in
the electronic apparatus frame 20 by removing the raised portion 42
by cutting work or the like. As compared with the case where the
narrow-pitch pores 21 are bored by pressing or by means of a drill
or the like, therefore, the cost for a working apparatus can be
lowered, and the working time can be shortened.
[0046] Furthermore, creation of burrs that are usually formed
around the respective openings of the pores 21 when boring or
pressing is effected can be restrained, so that the external
appearance and shape of the electronic apparatus frame 20 can be
improved.
[0047] Since the magnesium alloy is used as the material of the
electronic apparatus frame 20, moreover, there may be provided the
electronic apparatus frame 20 that is highly stiff and strong
enough despite its reduced thickness.
[0048] Although the one embodiment of the present invention has
been described above, the present invention can be modified
variously. The following is a description of the modification.
[0049] According to the embodiment described above, the described
electronic apparatus frame 20 has the narrow-pitch pores 21.
However, the present invention is not limited to this embodiment
and may be also applied to other components and the like.
[0050] Further, all the pores 21 need not be arranged at narrow
pitches, and the present invention may be also applied to a
configuration that has various pitches such that some of pitches
are narrow.
[0051] Furthermore, various modifications may be effected without
departing from the spirit of the present invention.
[0052] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *