U.S. patent application number 09/737872 was filed with the patent office on 2001-05-31 for electronic apparatus, manufacturing method therefor, 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 | 20010001978 09/737872 |
Document ID | / |
Family ID | 15952806 |
Filed Date | 2001-05-31 |
United States Patent
Application |
20010001978 |
Kind Code |
A1 |
Hosoi, Takashi ; et
al. |
May 31, 2001 |
Electronic apparatus, manufacturing method therefor, and mold
device
Abstract
An electronic apparatus such as a portable computer comprises an
electronic apparatus frame and a raised portion provided on that
region of the electronic apparatus frame which engages an ejector
pin projecting from inside a mold device and formed thicker than
the other part of the electronic apparatus frame.
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: |
15952806 |
Appl. No.: |
09/737872 |
Filed: |
December 18, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09737872 |
Dec 18, 2000 |
|
|
|
PCT/JP99/01764 |
Apr 2, 1999 |
|
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Current U.S.
Class: |
164/91 ; 164/271;
164/98 |
Current CPC
Class: |
B22D 17/2236
20130101 |
Class at
Publication: |
164/91 ; 164/98;
164/271 |
International
Class: |
B22D 019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 1998 |
JP |
10-173024 |
Claims
What is claimed is:
1. An electronic apparatus comprising: a frame; and a raised
portion provided on that region of said frame which engages an
ejector pin projecting from inside a mold device and formed thicker
than the peripheral portion of said engaging region at the
least.
2. An electronic apparatus according to claim 1, wherein said
raised portion is surrounded by ribs for reinforcement.
3. An electronic apparatus comprising: a frame; and a protrusion
provided on that region of said frame which engages an ejector pin
projecting from inside a mold device and formed projecting from the
peripheral portion of said engaging region at the least.
4. In a mold device including a first mold and a second mold for
forming a frame of a metallic material and having an ejector pin
adapted to push out a molded piece from the first mold after the
molded piece is formed, a depression being formed in that part of
said first mold from which the ejector pin projects so that the
part pushed out by means of the ejector pin forms a raised
portion.
5. A mold device according to claim 4, wherein said depression is
surrounded by grooves for forming ribs for reinforcement.
6. A method of manufacturing an electronic apparatus, comprising
the steps of: introducing molten metal into a mold having a first
mold section and a second mold section, said first mold section has
a recess so that a molding has a thick-wall part that may contact
an ejector pin; solidifying the molten metal in the mold, thereby
to form a molding; and pushing the thick-wall part of the molding
with the ejector pin, thereby to take the molding from the mold.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of Application No. PCT/JP99/01764,
filed Apr. 2, 1999.
[0002] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No. 10-173024,
filed Jun. 19, 1998, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a manufacturing method for an
electronic apparatus frame, and more particularly, to a case where
a molded piece is taken out of a mold device.
[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 device
of about 100.degree. to 350.degree. and molded.
[0005] FIG. 1 shows a configuration of a conventional electronic
apparatus frame. In this electronic apparatus frame 1, a molten
metal is introduced through a sprue 2, a molten metal inlet portion
of a mold device (which will be described with reference to that
portion of this drawing which corresponds to the shape of the
electronic apparatus frame just molded and the sectional view of
FIG. 2 showing the mold device 10), 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] A molded piece is formed as the molten metal is thus
introduced into the mold device 10. In order to take out the molded
piece from the cavity 4, the molded piece is pushed out by means of
ejector pins 7.
[0007] In order to enable the molded piece to be pushed out by
means of the ejector pins 7, the ejector pins 7 are provided in the
mold device 10, as shown in FIG. 2.
[0008] In the case where a light metal is used as the material of
the electronic apparatus frame 1, the electronic apparatus frame 1
is thinned in general. If a magnesium alloy is the material, the
wall thickness of the frame ranges from about 0.7 to 1.0 mm. When
the molded piece is pushed out of the mold device, therefore, those
regions which are pushed in by means of the ejector pins 7 may be
hollowed by the push force, possibly leaving push indentations 8
shown in FIG. 3.
[0009] If the electronic apparatus frame 1 is provided with a large
number of irregularities, such as bosses and ribs, the push force
increases correspondingly. In some cases, therefore, the push
indentations 8 may be formed more clearly in the pushed regions of
the electronic apparatus frame 1 that is thinned, as mentioned
before.
[0010] Such deformation that is attributable to the push force is
not limited to the case of the light metal for use as the material,
and is also caused in the case of a synthetic resin. In the case of
the synthetic resin, the deformation appears as a phenomenon such
as blushing.
[0011] If the push indentations 8 or depressions are formed, the
external appearance is not favorable, and the products are not
mass-producible.
[0012] When the ejector pins 7 are pushed in, moreover, not only
the pushed regions but also the entire molded piece may possibly
subjected to deformation such as deflection by means of the push
force. If such deformation occurs, it cannot serve for the
utilization of the electronic apparatus frame 1, and inevitably
causes malformation.
BRIEF SUMMARY OF THE INVENTION
[0013] This invention has been contrived in consideration of these
circumstances, and its object is to provide an electronic apparatus
having a frame that cannot be deformed when it is pushed out of a
mold device by means of ejector pins, a manufacturing method
therefor, and the mold device.
[0014] According to a preferred embodiment, an electronic apparatus
of this invention comprises a frame and a raised portion provided
on that region of the frame which engages an ejector pin projecting
from inside a mold device and formed thicker than the peripheral
portion of the engaging region at the least.
[0015] In a mold device of this invention including a first mold
and a second mold for forming a frame of a metallic material and
having an ejector pin adapted to push out a molded piece from the
first mold after the molded piece is formed, moreover, a depression
is formed in that part of the first mold from which the ejector pin
projects so that the part pushed out by means of the ejector pin
forms a raised portion.
[0016] Further, an electronic apparatus manufacturing method of
this invention for molding an electronic apparatus including a
frame of a metallic material by means of a mold device formed
having a depression such that a part pushed out by means of an
ejector pin forms a raised portion comprises a flowing process for
diffusing a molten metal into the mold device, a solidifying
process for solidifying the molten metal introduced into the mold
device in the flowing process, thereby forming a frame, and an
unloading process for pushing out a raised portion of a molded
piece formed in the solidifying process, thereby taking out the
molded piece from the mold device.
[0017] 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
[0018] 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.
[0019] FIG. 1 is a perspective view showing the shape of a prior
art electronic apparatus frame;
[0020] FIG. 2 is a sectional view showing a configuration of a
prior art mold device;
[0021] FIG. 3 is a perspective view showing a state of push
indentations in the prior art electronic apparatus frame;
[0022] FIG. 4 is a perspective view showing the shape of a portable
computer as an electronic apparatus according to one embodiment of
this embodiment;
[0023] FIG. 5 is a perspective view showing a configuration of an
electronic apparatus frame of the electronic apparatus of the same
embodiment;
[0024] FIG. 6 is a plan view showing the shapes of raised portions
and ribs of the electronic apparatus frame constituting the
electronic apparatus of the same embodiment;
[0025] FIG. 7 is a sectional view showing a configuration of a mold
device of the same embodiment;
[0026] FIGS. 8A and 8B are views showing 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 first mold and a second mold of the mold device are
disengaged, and FIG. 8B is a view showing a state in which a molded
piece is pushed out of the first mold by means of ejector pins;
[0027] FIG. 9 shows a flowchart for the electronic apparatus
manufacturing method of the same embodiment;
[0028] FIG. 10 is a partial sectional view showing a state of an
electronic apparatus frame of an electronic apparatus according to
a modification of the present invention and illustrating the
formation of a mound portion;
[0029] FIG. 11 is a partial sectional view showing a state of an
electronic apparatus frame of an electronic apparatus according to
a modification of the present invention and illustrating the
formation of a thick-walled portion projecting into the electronic
apparatus frame; and
[0030] FIG. 12 is a partial sectional view showing a state of an
electronic apparatus frame of an electronic apparatus according to
a modification of the present invention and illustrating the
formation of a thick-walled portion projecting outward from the
electronic apparatus frame.
DETAILED DESCRIPTION OF THE INVENTION
[0031] One embodiment of the present invention will now be
described with reference to FIGS. 4 to 8B.
[0032] FIG. 4 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.
[0033] 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.
[0034] FIG. 5 shows the shape of the electronic apparatus frame 20
that cannot be deformed even if it is pushed out by means of
ejector pins 39 according to the present invention. In this
drawing, raised portions 21 are formed protruding for a given
height from the frame body of the electronic apparatus frame 20,
and moreover, ribs 22 that extend in gentle slopes from the top
portion of each raised portion 21 toward the peripheral portion are
arranged at intervals of, for example, about 90.degree.. FIG. 6 is
a plan view of this state taken from the topside.
[0035] A mold device 30 arranged in the following manner is used to
manufacture the electronic apparatus frame 20 having the
aforementioned construction and prevent the push force of the
ejector pins 39 from creating push indentations.
[0036] The mold device 30 shown in FIG. 7 is composed of a first
mold 31 and a second mold 32 that are in engagement with each
other, and has a cavity 35 formed therein as the first mold 31 and
the second mold 32 engage each other. In introducing a molten metal
into the cavity 35, it is introduced through a sprue 33, a molten
metal inlet, and is diffused by means of a runner 34 so that a
substantially parallel molten metal flow is introduced into the
cavity 35.
[0037] The molten metal, diffused and introduced by means of the
runner 34, fills the cavity 35, and is introduced into depressions
36 that are formed in the first mold 31. The depressions 36 are
formed by depressing those regions of the first mold 31 for the
ejector pins 39 to a given depth, and the raised portions 21 are
provided on a molded piece 50 as the molten metal get into the
depressions 36 and solidifies.
[0038] If the wall thickness of the electronic apparatus frame 20
ranges from about 0.7 to 1.0 mm, for example, the height of
projection of the raised portions 21 ranges from about 0.84 to 1.2
mm, which is about 20% greater than the wall thickness of the
frame.
[0039] The depressions 36 are located individually on ejector
projection regions 37 in the first mold 31. Through holes 38 are
formed in the first mold 31 so as to be continuous with the ejector
projection regions 37, and the ejector pins 39 can get into and out
of the through holes 38, individually.
[0040] The ejector pins 39 are passed through the through holes 38,
individually. The ejector pins 39 are movable along the through
holes 38. When they project downward, their respective lower end
portions project from the inner wall surface of the cavity 35 of
the first mold 31.
[0041] A spring 40 for use as urging means is located on each
ejector pin 39. The springs 40 serve to give urging force to the
ejector pins 39 so that the pins 39 project from the inner wall
surface of the cavity 35 of the first mold 31. To apply this urging
force, the one-end side of each spring 40 is attached to a
stationary mold 41. The stationary mold 41, which is located above
the first mold 31, can be driven in the vertical direction.
[0042] The stationary mold 41 is provided with recesses 42 having a
given size. The recesses 42 are designed to receive the respective
upper ends of the springs 40. If the stationary mold 42 is driven
downward, therefore, corresponding urging force can be applied to
the ejector pins 39.
[0043] The raised portions 21 are formed on the molded piece 50 as
the molten metal flows into the depressions 36. In some cases,
however, the raised portions 21 alone may fail to prevent general
deformation, such as deflection, of the electronic apparatus frame
20 when those portions are pushed in by means of the ejector pins
39. To avoid this, the molded piece 50 has the ribs 22 that are
arranged at the given angular intervals around the raised portions
21.
[0044] The ribs 22 are in the form of slopes with a sufficient
length that gently decline from the outer peripheral edge portion
of the top portion of each raised portion 21. Since the ribs 22
gently decline from the depressions 36, moreover, the molten metal
in the depressions 36 can easily go around.
[0045] Further, the ribs 22 have a length such that the molded
piece 50 never undergoes deformation such as deflection when the
raised portions 21 are pressed by means of the ejector pins 39.
Furthermore, the length of the ribs 22 is restricted in
consideration of the attachment of any other electronic component
or the like.
[0046] In order to form these ribs 22 on the molded piece 50,
grooves 43 corresponding to the ribs 22 are formed around the
depressions 36 of the mold device 30. The aforesaid ribs 22 can be
formed in a manner such that the molten metal gets into the grooves
43.
[0047] The molten metal that fills the inside of the cavity 35
reaches an air vent 44 on the other end side of the runner 34 with
respect to the cavity 35. The air vent 44 serves to discharge air
in the cavity 35 from the cavity 35 to the outside. Thus, the
molten metal introduced into the cavity 35 can prevent generation
of voids therein as it reaches a molten metal reservoir 45.
[0048] The following is a description of a method for manufacturing
the electronic apparatus frame 20 by means of the mold device 30
constructed in this manner. This manufacturing method is shown in
FIG. 9.
[0049] First, the molten metal is caused to flow into the cavity 35
and fill it (flowing process). Thereafter, the loaded molten metal
is solidified by cooling (solidifying process). The molded piece 50
must be taken out of the cavity 35 when it is formed (unloading
process).
[0050] Accordingly, the first mold 31 and the second mold 32 must
be disengaged from each other, as shown in FIG. 8A, to allow the
molded piece 50 to be taken out. When the first mold 31 and the
second mold 32 are disengaged and opened, however, the molded piece
50 is left adhering to the first mold 31 on the molded piece 50
that is formed having a rib structure and bosses the electronic
apparatus frame 20 usually has or irregularities such as the
aforesaid depressions 36 and the ribs 22.
[0051] Therefore, the molded piece 50 in this state expected to be
taken out of the first mold 31. To attain this, the molded piece 50
is pushed out by means of the ejector pins 39, as shown in FIG.
8B.
[0052] In this case, the raised portions 21 and the ribs 22 are
formed on the molded piece 50 as the molten metal is introduced
into the mold device 30. Since the raised portions 21 and the ribs
22 are provided on the regions for the projection of the ejector
pins 39, however, the raised portions 52 receive the push force of
the ejector pins 39 and are pushed out.
[0053] The molded piece 50 can be pushed out of the mold device 30
by means of the ejector pins 39 so that it is ready to be removed
outward. Since those portions of the molded piece 50 which
correspond to the sprue 33 and the runner 34 in the mold device 30
are not disengaged yet, however, they are cut off after the molded
piece 50 is taken out. Thus, the electronic apparatus frame 20 is
formed.
[0054] According to the manufacturing method for the electronic
apparatus frame 20 constructed in this manner and the mold device
30, the engaging portions at which the molded piece 50 is pushed
out by means of the ejector pins 39 are formed of the raised
portions 21. If the push force of the ejector pins 39 is received
by means of the raised portions 21, therefore, the electronic
apparatus frame 20 cannot be subjected to any apparent deformation
such as depressions if the electronic apparatus frame 20 is
thinned.
[0055] Accordingly, the external appearance of the electronic
apparatus frame 20 can be improved, and at the same time,
occurrence of malformation that is attributable to deformation
during the extrusion can be prevented. Thus, the formation of the
raised portions 21 improves the efficiency of mass production for
the electronic apparatus frame 20.
[0056] Since the ribs 22 are provided at the given angular
intervals so that they extend like gentle slopes from the top
portion of each raised portion 21, moreover, malformation of the
electronic apparatus frame 20, such as depression or deflection,
can be prevented more securely.
[0057] Since the thinned electronic apparatus frame 20 is
reinforced by means of the ribs 22, in particular, the general
shape of the electronic apparatus frame 20 can be satisfactorily
prevented from suffering deflection.
[0058] Since the mold device 30 is previously formed having the
depressions 36 and the grooves 43 before the raised portions 21 and
the ribs 22 are formed, moreover, the molded piece 50 having the
raised portions 21 and the ribs 22 can be formed by only
introducing the molten metal into the cavity 35 of the mold device
30 and allowing it to solidify. If the ejector pins 39 are received
by means of the raised portions 21, therefore, the molded piece 50
can be prevented from being deformed when the molded piece 50 is
removed. Thus, the formation of the electronic apparatus frame 20
can be improved in efficiency, and therefore, its cost can be
lowered.
[0059] 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.
[0060] According to the embodiment described above, the raised
portions 21 are shaped so that their respective top portions are
substantially circular, as shown in FIGS. 5 and 6. Alternatively,
however, the top portion of each raised portion 21 may have a
square shape or any other shape.
[0061] Further, the ribs 21 are not limited to the form of gentle
slopes, and may be designed so that they extend for a given length
without varying in height, for example.
[0062] Furthermore, the raised portions 21 may be replaced with any
other structures such as protrusions that are formed by mounding
those portions of the electronic apparatus frame 20 which engage
the ejector pins 39 so that the ejector pins 39 can be caused to
abut against their corresponding mound portions 23, as shown in
FIG. 10. In this case, the mold device 30 is internally shaped
corresponding to this arrangement so that the mound portions 23 can
be e formed by only introducing the molten metal into the mold
device 30.
[0063] Further, the mound portions 23 for use as the protrusions
may be replaced with thick-walled portions 24 that are formed on
the engaging portions for the ejector pins 39 so as to project into
the electronic apparatus frame 20, as shown in FIG. 11. Each
thick-walled portion 24 includes a top portion 24a and a slanting
portion 24b that gently declines from the top portion 24a toward
the peripheral portion. In this configuration, the slanting portion
24b serves for reinforcement when each ejector pin 39 abuts against
the top portion 24a.
[0064] In FIG. 12, moreover, each thick-walled portion 24 is formed
projecting into the electronic apparatus frame 20. Alternatively,
however, a thick-walled portion 25 may be formed projecting outward
from the electronic apparatus frame 20, as shown in FIG. 11. In
this case, as in the aforesaid case, the thick-walled portion 25
has a top portion 25a and a slanting portion 25b. If a plurality of
thick-walled portions 25 are formed on the bottom wall surface of
the lower frame 14 of the portable computer 10 shown in FIG. 4, for
example, the thick-walled portions 25 can be made to function as
contact portions to engage a disk or the like.
[0065] Further, various modifications may be effected without
departing from the spirit of the invention.
[0066] 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.
* * * * *