U.S. patent application number 09/924470 was filed with the patent office on 2002-02-21 for mount shelf for an electronic circuit board, which has an excellent air permeability at a condition that an electronic circuit board is positioned and mounted in a body plate and also has an excellent radiation performance with regard to a heat generated by a part of the electronic circuit.
Invention is credited to Komatsu, Kazuo.
Application Number | 20020021554 09/924470 |
Document ID | / |
Family ID | 18734714 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020021554 |
Kind Code |
A1 |
Komatsu, Kazuo |
February 21, 2002 |
Mount shelf for an electronic circuit board, which has an excellent
air permeability at a condition that an electronic circuit board is
positioned and mounted in a body plate and also has an excellent
radiation performance with regard to a heat generated by a part of
the electronic circuit
Abstract
A mount shelf for an electronic circuit board, includes a body;
a first guide which is supported by the body and has a first guide
plane; a second guide which is supported by the body and has a
second guide plane; a third guide which is supported by the body
and has a third guide plane; and a fourth guide which is supported
by the body and has a fourth guide plane. The first guide plane and
the second guide plane respectively have first contact planes on
which a first end plane portion of one straight first edge region
of an electronic circuit board can be contact at a same time. The
third guide plane and the fourth guide plane respectively have
second contact planes on which a second end plane portion of
another straight second edge region of the electronic circuit board
can be contact at the same time. The first guide and the second
guide are separated to a degree of a width in a direction in which
the first edge region or the second edge region of the electronic
circuit board is extended. The third guide and the fourth guide are
separated to the degree of the width.
Inventors: |
Komatsu, Kazuo; (Tokyo,
JP) |
Correspondence
Address: |
McGinn & Gibb, PLLC
Suite 200
8321 Old Courthouse Road
Vienna
VA
22182-3817
US
|
Family ID: |
18734714 |
Appl. No.: |
09/924470 |
Filed: |
August 9, 2001 |
Current U.S.
Class: |
361/690 |
Current CPC
Class: |
H05K 7/1425
20130101 |
Class at
Publication: |
361/690 |
International
Class: |
H05K 007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 11, 2000 |
JP |
243941/2000 |
Claims
What is claimed is:
1. A mount shelf for an electronic circuit board, comprising: a
body; a first guide which is supported by said body and has a first
guide plane; a second guide which is supported by said body and has
a second guide plane; a third guide which is supported by said body
and has a third guide plane; and a fourth guide which is supported
by said body and has a fourth guide plane, and wherein said first
guide plane and said second guide plane respectively have first
contact planes on which a first end plane portion of one straight
first edge region of an electronic circuit board can be contact at
a same time, and wherein said third guide plane and said fourth
guide plane respectively have second contact planes on which a
second end plane portion of another straight second edge region of
said electronic circuit board can be contact at the same time, and
wherein said first guide and said second guide are separated to a
degree of a width in a direction in which said first edge region or
said second edge region of said electronic circuit board is
extended and wherein said third guide and said fourth guide are
separated to said degree of said width.
2. The mount shelf for an electronic circuit board according to
claim 1, wherein said first contact plane includes two first slants
which are located opposite to each other, and slanted in directions
opposite to each other, and in forms of substantially circular cone
plane, and wherein said second contact plane includes two second
slants which are located opposite to each other, and slanted in
directions opposite to each other, and in forms of substantially
circular cone plane.
3. The mount shelf for an electronic circuit board according to
claim 1, wherein said first and second edge regions are
approximately parallel to each other.
4. The mount shelf for an electronic circuit board according to
claim 1, wherein said first end plane portion contains two first
end lines parallel to each other, and said second end plane portion
contains two second end lines parallel to each other.
5. The mount shelf for an electronic circuit board according to
claim 2, wherein said first slant and said second slant are both
formed in perfectly circular cone planes.
6. The mount shelf for an electronic circuit board according to
claim 2, wherein said first guide and said second guide have a
first plurality of protrusions respectively aligned in a straight
line direction, and wherein said third guide and said fourth guide
have a second plurality of protrusions respectively aligned in a
straight line direction, and wherein said first plurality of
protrusions are respectively constituted by said first slant, and
said second plurality of protrusions are respectively constituted
by said second slant.
7. The mount shelf for an electronic circuit board according to
claim 6, further comprising: a first positioning unit integrally
formed into said body; and a second positioning unit integrally
formed into said body, and wherein said first positioning unit has
a first plurality of grooves for guiding said first edge region,
and said second positioning unit has a second plurality of grooves
for guiding said second edge region, and wherein positions of said
first plurality of grooves correspond to positions of a first
plurality of valleys between said first plurality of protrusions,
respectively, and positions of said second plurality of grooves
correspond to positions of a second plurality of valleys between
said second plurality of protrusions, respectively.
8. The mount shelf for an electronic circuit board according to
claim 7, wherein a portion between said two first slants is formed
in a cylindrical plane, and a portion between said two second
slants is formed in said cylindrical plane.
9. A mount shelf for an electronic circuit board, comprising: a
body; and four guides which are supported by said body, and
respectively have axis lines parallel to each other, and are
extended in directions of axis lines, and wherein each of said four
guides has a plurality of concave grooves aligned in said direction
of said axis line, and wherein each of said plurality of concave
grooves has both sides crossing said axis line and a cylindrical
plane for connecting between said both sides, and wherein two said
cylindrical planes of said four guides can contact with one edge
region of said electronic circuit board at a same time, and the
other two cylindrical planes of said four guides can contact with
another edge region of said electronic circuit board at the same
time.
10. The mount shelf for an electronic circuit board according to
claim 9, wherein said cylindrical plane is partially
cylindrical.
11. The mount shelf for an electronic circuit board according to
claim 9, wherein said both sides are formed on a crossing tapered
plane which are not orthogonal to said axis line.
12. The mount shelf for an electronic circuit board according to
claim 11, wherein said tapered plane is a circular cone plane.
13. The mount shelf for an electronic circuit board according to
claim 12, wherein said circular cone plane is a perfectly circular
cone plane.
14. The mount shelf for an electronic circuit board according to
claim 13, wherein an outer circumference plane of each of said
guides is cylindrical between said plurality of concave
grooves.
15. A mount shelf for an electronic circuit board, comprising:
peripheral walls; and four support bars supported on said
peripheral walls in an inner space formed by said peripheral walls,
and wherein said four support bars position and support four-point
regions around edges of a rectangular electronic circuit board, and
wherein a streamline plane in which air stream in a direction from
two said support bars of said four support bars to said other two
support bars is not turbulent is formed on said support bar.
16. The mount shelf for an electronic circuit board according to
claim 15, wherein an interference obstacle to a flow of said air
stream flowing in said direction is not present except said four
support bars.
17. The mount shelf for an electronic circuit board according to
claim 15, wherein said streamline plane is formed on a front side
and a rear side of said air stream.
18. The mount shelf for an electronic circuit board according to
claim 15, wherein said four support bars have groove spaces for
positioning said four-point regions, and wherein circumference of
said groove space is formed on said streamline plane.
19. The mount shelf for an electronic circuit board according to
claim 15, wherein said streamline plane is formed symmetrically
about said axis line of said support bar.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a mount shelf for an
electronic circuit board. More particularly, the present invention
relates to a mount shelf for an electronic circuit board, which has
an excellent air permeability at a condition that an electronic
circuit board is positioned and mounted in a body plate and also
has an excellent radiation performance with regard to a heat
generated by a part of the electronic circuit.
[0003] 2. Description of the Related Art
[0004] As known in Japanese Laid Open Utility Model Application
(JU-A-Showa, 64-387) and Japanese Laid Open Patent Application
(JP-A-Heisei, 8-23181), an electronic circuit board is assembled in
an electronic apparatus, such as a computer and a communication
apparatus, and it is mounted in a body plate. The electronic
circuit board mounted in a shelf structure requires the protection
against heat generated by it. The shelf which is a mount technique
for improving the heat radiation performance is known as shown in
FIG. 1. The body plate for embodying the known shelf is constituted
by a side plate 101, a ceiling plate 102 and a bottom plate 103.
Opposite positioning grooves 106, 107 are formed on an upper guide
plate 104 and a lower guide plate 105 which are respectively
attached to edges of the ceiling plate 102 and the bottom plate
103. An electronic circuit board 108 is positioned in upper and
lower edge regions of the positioning grooves 106, 107, and
inserted towards the side plate 101. A large number of long holes
109, 110 are made in the ceiling plate 102 and the bottom plate
103. Guide rims 111, 112 are formed in the edges of the long holes
109, 110. Both ends of the rims 111, 112 are cylindrically formed.
A tip end of the electronic circuit board 108 is guided between the
planes of the cylinders adjacent to each other, and inserted
towards the side plate 101.
[0005] At that mount position, a connector 113 attached to the
electronic circuit board 108 is electrically connected to a
connector 114 attached to the side plate 101. The electrically
attached parts of the connectors 113, 114 are constituted by minute
metallic parts. In order to effectively connect such minute
metallic parts, the relatively positional relations must be
accurate between the long holes 109, 110 and the positioning
grooves 106, 107. The positional relations must be accurate as a
three-dimension, as represented by the three-dimensional
coordinates in FIG. 1. Actually, the dimensional setting must be
relationally accurate between a Z-axis direction distance A between
the side plate 101 and the upper and lower guide plates 105, 106,
X-axis direction distances B, C from the standard positions of the
upper and lower positioning grooves 106, 107 and a Y-axis direction
distance D between the upper and lower positioning grooves 106,
107. If such a dimensional setting is not accurate, a travel
direction E when the electronic circuit board is inserted is not
accurately coincident with the set Z-axis direction. Even if the
mount position is approximately accurate, the electrical connection
becomes imperfect between the connectors 113, 114. If the
unreasonably pushing force at the time of the insertion is
excessive, the electrical connection becomes imperfect. Such known
structure requires the highly precise design in order to attain the
excellently electrical connection. This results in the increase in
a manufacturing cost. Moreover, the plates constituting the large
number of holes resist the flow of the air flowing from a lower
portion to an upper portion. This resistance causes the flow to be
deteriorated. Thus, the air flow becomes the turbulent flow, which
causes the heat radiation performance to be poor.
[0006] The positioning accuracy is desired to be high.
[0007] In particular, it is desirable that the unreasonably
excessive force is not applied at the time of the insertion, the
insertion is smooth, and the positioning accuracy is high.
Moreover, the heat radiation performance is desired to be high. It
is further required to simplify the shelf structure and drop the
manufacturing cost.
[0008] Japanese Laid Open Patent Application (JP-A-Showa,
59-181692) discloses the following positioning apparatus of printed
circuit board. This positioning apparatus of printed circuit board
transfers the printed circuit board to a station to perform a
operation such as parts mounting. The positioning apparatus of
printed circuit board is provided with: a plurality of guide means
for guiding right and left end portions of the printed circuit
board to the station. One of the plurality of guide means can move
in a direction at right angles to a transferring direction of the
printed circuit board. The other of the plurality of guide means
cannot move. A plurality of positioning pins to be inserted in
reference holes of the printed circuit board are provided in the
transferring direction at established intervals. A part of the
plurality of positioning pins can move only in the direction at
right angles to the transferring direction of the printed circuit
board. Another part of the plurality of positioning pins can move
in both the direction at right angles to the transferring direction
of the printed circuit board and the transferring direction.
SUMMARY OF THE INVENTION
[0009] The present invention is accomplished in view of the above
mentioned problems. Therefore, an object of the present invention
is to provide a mount shelf for an electronic circuit board, in
which a positioning accuracy is high and a cost can be dropped.
[0010] Another object of the present invention is to provide a
mount shelf for an electronic circuit board, in which an
unreasonably excessive force is not applied at a time of an
insertion, an insertion is smooth, a positioning accuracy is high,
and a cost can be dropped.
[0011] Still another object of the present invention is to provide
a mount shelf for an electronic circuit board, in which a
positioning accuracy is high, a cost can be dropped, and a heat
radiation performance is high.
[0012] Still another object of the present invention is to provide
a mount shelf for an electronic circuit board, in which when a
shelf body is made of metal, the above-mentioned problems can be
effectively solved.
[0013] In order to achieve an aspect of the present invention, a
mount shelf for an electronic circuit board, includes: a body; a
first guide which is supported by the body and has a first guide
plane; a second guide which is supported by the body and has a
second guide plane; a third guide which is supported by the body
and has a third guide plane; and a fourth guide which is supported
by the body and has a fourth guide plane, and wherein the first
guide plane and the second guide plane respectively have first
contact planes on which a first end plane portion of one straight
first edge region of an electronic circuit board can be contact at
a same time, and wherein the third guide plane and the fourth guide
plane respectively have second contact planes on which a second end
plane portion of another straight second edge region of the
electronic circuit board can be contact at the same time, and
wherein the first guide and the second guide are separated to a
degree of a width in a direction in which the first edge region or
the second edge region of the electronic circuit board is extended
and wherein the third guide and the fourth guide are separated to
the degree of the width.
[0014] In this case, the first contact plane includes two first
slants which are located opposite to each other, and slanted in
directions opposite to each other, and in forms of substantially
circular cone plane, and wherein the second contact plane includes
two second slants which are located opposite to each other, and
slanted in directions opposite to each other, and in forms of
substantially circular cone plane.
[0015] Also in this case, the first and second edge regions are
approximately parallel to each other.
[0016] Further in this case, the first end plane portion contains
two first end lines parallel to each other, and the second end
plane portion contains two second end lines parallel to each
other.
[0017] In this case, the first slant and the second slant are both
formed in perfectly circular cone planes.
[0018] Also in this case, the first guide and the second guide have
a first plurality of protrusions respectively aligned in a straight
line direction, and wherein the third guide and the fourth guide
have a second plurality of protrusions respectively aligned in a
straight line direction, and wherein the first plurality of
protrusions are respectively constituted by the first slant, and
the second plurality of protrusions are respectively constituted by
the second slant.
[0019] Further in this case, the mount shelf for an electronic
circuit board further includes: a first positioning unit integrally
formed into the body; and a second positioning unit integrally
formed into the body, and wherein the first positioning unit has a
first plurality of grooves for guiding the first edge region, and
the second positioning unit has a second plurality of grooves for
guiding the second edge region, and wherein positions of the first
plurality of grooves correspond to positions of a first plurality
of valleys between the first plurality of protrusions,
respectively, and positions of the second plurality of grooves
correspond to positions of a second plurality of valleys between
the second plurality of protrusions, respectively.
[0020] In this case, a portion between the two first slants is
formed in a cylindrical plane, and a portion between the two second
slants is formed in the cylindrical plane.
[0021] In order to achieve another aspect of the present invention,
a mount shelf for an electronic circuit board, includes: a body;
and four guides which are supported by the body, and respectively
have axis lines parallel to each other, and are extended in
directions of axis lines, and wherein each of the four guides has a
plurality of concave grooves aligned in the direction of the axis
line, and wherein each of the plurality of concave grooves has both
sides crossing the axis line and a cylindrical plane for connecting
between the both sides, and wherein two the cylindrical planes of
the four guides can contact with one edge region of the electronic
circuit board at a same time, and the other two cylindrical planes
of the four guides can contact with another edge region of the
electronic circuit board at the same time.
[0022] In this case, the cylindrical plane is partially
cylindrical.
[0023] Also in this case, the both sides are formed on a crossing
tapered plane which are not orthogonal to the axis line.
[0024] Further in this case, the tapered plane is a circular cone
plane.
[0025] In this case, the circular cone plane is a perfectly
circular cone plane.
[0026] Also in this case, an outer circumference plane of each of
the guides is cylindrical between the plurality of concave
grooves.
[0027] In order to achieve still another aspect of the present
invention, a mount shelf for an electronic circuit board, includes:
peripheral walls; and four support bars supported on the peripheral
walls in an inner space formed by the peripheral walls, and wherein
the four support bars position and support four-point regions
around edges of a rectangular electronic circuit board, and wherein
a streamline plane in which air stream in a direction from two the
support bars of the four support bars to the other two support bars
is not turbulent is formed on the support bar.
[0028] In this case, an interference obstacle to a flow of the air
stream flowing in the direction is not present except the four
support bars.
[0029] Also in this case, the streamline plane is formed on a front
side and a rear side of the air stream.
[0030] Further in this case, the four support bars have groove
spaces for positioning the four-point regions, and wherein
circumference of the groove space is formed on the streamline
plane.
[0031] In this case, the streamline plane is formed symmetrically
about the axis line of the support bar.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is an axis projection view showing a known shelf;
[0033] FIG. 2 is an axis projection view showing an embodiment of a
mount shelf for an electronic circuit board according to the
present invention;
[0034] FIG. 3 is a front view showing a part of a guide (support
bar);
[0035] FIG. 4 is a front section view showing another guide;
[0036] FIG. 5 is a side view showing a positional relation between
a guide and an electronic circuit board;
[0037] FIG. 6 is a side view showing another positional relation
between a guide and an electronic circuit board;
[0038] FIG. 7 is a side section view showing still another
guide;
[0039] FIG. 8 is a front section view showing still another
guide;
[0040] FIG. 9 is a side view showing still another positional
relation between a guide and an electronic circuit board;
[0041] FIG. 10 is a side view showing still another positional
relation between a guide and an electronic circuit board; and
[0042] FIG. 11 is a plan view showing still another positional
relation between a guide and an electronic circuit board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Embodiments of the present invention will be described below
in detail with reference to the attached drawings.
[0044] As shown in FIG. 2, in an embodiment of a mount shelf for an
electronic circuit board according to the present invention, a
guide together with a body of a structure is disposed to form the
structure of the shelf. The body is constituted by a metallic
plate. Four guides 1, 2, 3 and 4 are fixed to and supported on the
metallic plate. The metallic plate constituting the body is
provided with a back board 5 usually oriented in a vertical
direction, and side plates 6 (only one side is shown) on both sides
which are usually oriented in the vertical direction and oriented
in the direction orthogonal to the back board 5. A Z-axis is set
for the direction orthogonal to the back board 5, a Y-axis is set
for the vertical direction, and an X-axis is set for the direction
orthogonal to the side plate 6. The three axes X, Y and Z create a
three-dimensional orthogonal coordinate system.
[0045] An upper guide plate 7 and a lower guide plate 8 are placed
between the side plates 6 on both the sides. A lower edge of the
upper guide plate 7 is parallel to an upper edge of the lower guide
plate 8, and it is oriented in the X-axis direction. A plurality of
upper guide grooves 9 are formed in the lower edge of the upper
guide plate 7 at a predetermined interval. A plurality of lower
guide grooves 11 are formed in the upper edge of the lower guide
plate 8 at the same predetermined interval. The plurality of upper
guide grooves 9 are arranged in the plurality of lower guide
grooves 11, under the positional correspondence. The predetermined
interval between the plurality of upper guide grooves 9 adjacent to
each other is equal to the predetermined interval between the
plurality of lower guide grooves 11 adjacent to each other.
[0046] The four guides 1, 2, 3 and 4 are constituted by the first
guide 1, the second guide 2, the third guide 3 and the fourth guide
4. The first guide 1 is placed at a position closer to the back
board 5 than the second guide 2. The third guide 3 is placed at a
position closer to the back board 5 than the fourth guide 4. A
height of the Y-axis direction of the first guide 1 is equal to a
height of the Y-axis direction of the second guide 2 with respect
to a standard surface, and a height of the Y-axis direction of the
third guide 3 is equal to a height of the Y-axis direction of the
fourth guide 4 with respect to the standard surface. A separation
distance between the first guide 1 and the second guide 2 is equal
to a separation distance between the third guide 3 and the fourth
guide 4. The four guides 1, 2, 3 and 4 have axis lines (12),
respectively. Those four axis lines (12) are parallel to each
other. The four guides 1, 2, 3 and 4 are formed symmetrically about
their axis lines (12), respectively, and their shapes and
dimensions are equal to each other.
[0047] The guides 1, 2, 3 and 4 (hereafter, represented by 1) have
the axis lines 12 as shown in FIG. 3, and configure a plurality of
positioning guide concave grooves 13. The positioning guide concave
groove 13 guides an electronic circuit board 14, especially in the
Y-axis direction, and further even in the X-axis direction. A
circumference plane of the positioning guide concave grooves 13 is
constituted by a small diameter cylindrical plane 15 sharing the
axis line 12, axis square planes 16 which are connected to the
small diameter cylindrical plane 15 and orthogonal to the small
diameter cylindrical plane 15 on both the sides, and truncated
circular cone planes 17 connected to the axis square planes 16 on
both the sides, respectively. The two truncated circular cone
planes 17 are located opposite to the direction of the axis line,
and inclined in the direction opposite to the axis line
direction.
[0048] The truncated circular cone plane 17 and the small diameter
cylindrical plane 15 are not limited to the perfectly circular cone
plane forming the closed circumference plane and the perfect
cylindrical plane. They may be created as a half circular cone
plane 17' and a half cylindrical plane 15', as shown in FIG. 4. The
half circular cone plane 17' and the half cylindrical plane 15' as
mentioned above are opposite to each other in the upper and lower
directions, in the first guide 1 and the third guide 3, and
opposite to each other in the upper and lower directions, in the
second guide 2 and the fourth guide 4. The circular cone plane is
the perfect circular cone plane or the approximately circular cone
plane, in this way. A spherical surface, an elliptically spherical
surface and a half elliptically spherical surface are the
approximately circular cone plane, and constitute a two-dimensional
slant similar to the circular cone plane. Such a two-dimensional
slant constitutes the two-dimensional slant for guiding the edges
of the electronic circuit board 14 in the X-axis direction and the
Y-axis direction, and then guiding to a groove space 18 formed
between the right and left axis square planes 16 opposite to each
other. The typical example of such a two-dimensional slant is the
circular cone plane. The cylindrical plane 15, the axis square
plane 16 and the circular cone plane 17 can be changed for a slant
flat plane 15", a quarter axis square plane 16" and a quarter
circular cone plane 17" as shown in FIG. 7.
[0049] FIG. 8 shows another embodiment which does not have the
function of guiding in the X-axis direction and has only the
function of guiding in the Y-axis direction. This first guide 1 is
a grooved circular cylinder in which a large diameter cylindrical
plane 19 and a small diameter cylindrical planes 21 are
reciprocally aligned. The structure symmetrical about the axis line
12 can protect the occurrence of the turbulent flow without any
interference with the flow adjustment property of an air flow 22,
as shown in FIG. 9.
[0050] The shortest distance in the Y-axis direction between the
small diameter cylindrical plane 15 of the third guide 3 and the
small diameter cylindrical plane 15 of the first guide 1 is
slightly longer than a width Dy in the Y-axis direction of the
electronic circuit board 14, as shown in FIGS. 5, 6. And, the
shortest distance in the Y-axis direction between the small
diameter cylindrical plane 15 of the fourth guide 4 and the small
diameter cylindrical plane 15 of the second guide 2 is slightly
longer than the width Dy. A distance between the axis line 12 of
the second guide 2 and the axis line 12 of the first guide 1 is
longer than a width Dz in the Z-axis direction of the electronic
circuit board 14. And, the distance between the axis line 12 of the
fourth guide 4 and the axis line 12 of the third guide 3 is longer
than the width Dz.
[0051] A body side connector 23 is attached to the inner side of
the back board 5, as shown in FIG. 2. A board side connector 24 is
attached to the electronic circuit board 14. One plane of the body
side connector 23 and one plane of the board side connector 24 are
positioned substantially coincident with the Y-Z plane or the plane
parallel to it (the plane orthogonal to the axis line 12), and
minute electrical contact portions such as solder balls of both the
connectors are joined to each other. When the installation of the
electronic circuit board 14 is ended, the electronic circuit board
14 is surrounded with the walls of four circumferences (the two
walls are the back board 5 and the side plate 6). However, the
ceiling side and the bottom sides are opened. Such walls of the
four circumferences serve for a heat radiation plate.
[0052] The upper and lower portions of a front edge located ahead
of the insertion direction of the electronic circuit board 14 are
firstly introduced into the plurality of upper guide grooves 9 of
the upper guide plate 7 and the plurality of lower guide grooves 11
of the lower guide plate 8, and then pushed and advanced while
swung in the range between a swung angle of a rotational angle
.theta.2 around the X-axis (refer to FIG. 5) and a swung angle of a
rotational angle .theta.1 around the Y-axis (refer to FIG. 10) in
the direction substantially orthogonal to the back board 5 (Z-axis
direction) towards the back board 5. A width of the X-axis
direction of the groove space 18 is slightly longer than a
thickness of the electronic circuit board 14 so that both the sides
of the electronic circuit board 14 come in contact with the two
axis square planes 16 opposite to each other at the same time.
Thus, as shown in FIGS. 5, 10, there may be a high possibility that
the upper portion of the front edge of the electronic circuit board
14 strikes the lower half of the truncated circular cone plane 17
of the second guide 2 and that the lower portion of the front edge
of the electronic circuit board 14 strikes the upper half of the
truncated circular cone plane 17 of the fourth guide 4. The
thus-striking upper or lower portion of the front edges of the
electronic circuit board 14 is introduced into the two-dimensional
slant 17 that is the circular cone plane, and guided in the X-axis
direction and the Y-axis direction. Its guide force is smoothly
applied to the electronic circuit board 14. The unreasonable force
is never applied to the electronic circuit board 14. So, the lower
edge of the electronic circuit board 14 is reasonably introduced
into the groove space 18.
[0053] There may be a high possibility that the upper portion of
the front edge of the electronic circuit board 14 receiving the
further pushed force strikes the lower half of the truncated
circular cone plane 17 of the first guide 1, in the same condition
as the situation shown in FIG. 10, and that the lower portion of
the front edge of the electronic circuit board 14 strikes the upper
half of the truncated circular cone plane 17 of the third guide 3.
Upon reception of the application force as mentioned above, the
lower edge and the upper edge of the electronic circuit board 14
are reasonably introduced into the groove spaces 18 of the first
guide 1 and the third guide 3. In the course of such introduction,
as shown in FIGS. 6, 11, at least three-point regions corresponding
to the upper and lower portions of the front edge of the electronic
circuit board 14 and the upper and lower portions of the rear edge
thereof are restricted by the first guide 1, the second guide 2,
the third guide 3 and the fourth guide 4. The electronic circuit
board 14 is minutely adjusted in the range between swung angles
.theta.3, .theta.4 smaller than the above-mentioned angels
.theta.1, .theta.2. Then, the minute adjustment force is applied to
the electronic circuit board 14 so that the bending forces are
generated in the upper and lower portions of the front edge of the
electronic circuit board 14 and in the upper and lower portions of
the rear side thereof. However, the introduction force applied to
the electronic circuit board 14 by the truncated circular cone
planes 17 at the four or three locations is smooth, and the
introduction force is gradually applied such that the simultaneous
restriction forces never give the large distortion to the
electronic circuit board 14.
[0054] The electronic circuit board 14 mounted in the shelf as
mentioned above disperses and discharges the heat generated by the
board 14 itself to peripheral portions, and its heat is dispersed
from the outer circumferences of the back board 5 and the side
plates 6 of the four circumferences. However, a part of the heat
increases the temperature of the inner air surrounded with the
walls of the four circumferences. Most of the air flow circulating
from the bottom side to the ceiling side is raised in a flow
adjustment manner on a flow path having no obstacle from the bottom
side to the ceiling side. The part 22 of the air flow strikes the
first guide 1, the second guide 2, the third guide 3 and the fourth
guide 4, as shown in FIG. 9. However, all the circumferences or the
part thereof is formed in the form of the cylinder (the form of the
streamline). Their flow adjustment properties are not broken, and
they are kept. Thus, the turbulent flow and the eddy action are
protected. Ascending air current is discharged smoothly and
quickly. Hence, the cooling effect is large.
[0055] The planes formed on the first guide 1, the second guide 2,
the third guide 3 and the fourth guide 4, such as the cylindrical
plane or the circular cone plane are formed as the guide planes and
the streamline planes. If the streamline planes are disposed even
on the front flow side and the rear flow side of the air flows
passing in the vicinities of the first guide 1, the second guide 2,
the third guide 3 and the fourth guide 4 serving as the support
bars for supporting the electronic circuit board 14 and the
positioning bars for positioning it, the turbulent flow protection
effect can be attained stronger. If they are formed especially
symmetrical about the axis line, the turbulent flow protection
effect is attained much stronger.
[0056] The mount shelf for the electronic circuit board according
to the present invention provides the high cooling effect, and
simultaneously provides the positioning effect while avoiding the
offset of the cooling effect. Moreover, the unreasonable force is
not applied at the time of the insertion, and the cooling effect is
provided at the same time.
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