JPH11201541A - Exhaust gas guide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small exhaust gas guide for guiding exhaust gas without lowering the ventilation capacity. SOLUTION: The exhaust gas guide comprises a conical body 4 having side face 4a curved inward, and a fixed part 6 being secured to the circular face of a shorter diameter (hereinafter, referred to fixed face) 4b out of a pair of circular faces 4a, 4b on the opposite sides of the curved side face 4a of the body 4 wherein the surface of the body 4 is coated with a thin film of electromagnetic wave absorbing material (electromagnetic wave absorbing layer) 8. The fixed part 6 comprises a thin tubular magnet 10, and an iron pan 12 is bonded to the fixed face 4b in order to hold the magnet 10. The exhaust gas guide 2 is fixed to the central part of a vent K by the magnetic force of the magnet 10 and the exhaust gas flow from the vent K is discharged radially while being guided along the curved side face 4a of the body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust guide mounted on a casing having an air-cooling fan at a ventilation opening and for guiding a blowing direction of a blowing flow discharged from the ventilation opening.

[0002]

2. Description of the Related Art Conventionally, housings of various electronic devices are provided with vents for discharging heat trapped in the housing to the outside in order to prevent malfunctions of electronic circuits and destruction of circuit elements due to heat generation. ing. In particular, for those which generate a large amount of heat and cannot sufficiently radiate heat due to natural heat convection ventilation, an air cooling fan is attached to the ventilation opening to forcibly perform air cooling (ventilation).

[0003] By the way, when such an air-cooling fan is used, the blowout flow from the ventilation port has considerable momentum.
Depending on the arrangement state of the housing, for example, there is a problem that a piece of paper such as a document or a powder sample is blown off. In particular, when using an electronic balance that measures the weight precisely, if equipment with an air-cooling fan is operating nearby, the blowout flow from the air-cooling fan disturbs the surrounding air flow, and The influence on the operation of the electronic balance, such as the fact that the display does not stand still, causes a problem that the measurement takes a long time or the measurement cannot be performed accurately.

On the other hand, as shown in FIG. 9, a ventilation port cover 100 having a U-shaped cross section is attached near a ventilation port K to which an air-cooling fan F is attached, and the blow-out flow from the ventilation port K is There is known one that forcibly guides in a direction perpendicular to the blowing direction.

[0005]

However, when the ventilation port cover 100 is used, the flow from the ventilation port K hits the ventilation port cover 100 from directly in front and greatly disturbs the flow of the blowing flow. There has been a problem that the flow velocity is greatly reduced, and the ventilation capacity of the air-cooling fan, that is, the cooling performance in the housing is reduced.

In order to alleviate the decrease in the flow velocity of the blowout flow, it is conceivable to mount the ventilation port cover 100 at an angle. In this case, however, the amount of protrusion from the housing G becomes large, and this obstructs the surroundings. There was a problem. Further, since the ventilation port cover 100 is fixed at the edge of the ventilation port K, various sizes are prepared according to the size of the ventilation port K so as not to block the ventilation port K. There was also the problem of having to do it.

The present invention has been made to solve the above problems.
It is an object of the present invention to provide a small exhaust guide that guides an exhaust flow without reducing the ventilation capacity.

[0008]

According to a first aspect of the present invention, there is provided an air-cooling fan having a ventilation hole, the air-blowing fan being discharged from the ventilation hole. An exhaust inductor for inducing a flow blowing direction,
The air-cooling fan is characterized in that it is composed of a main body formed in a conical shape and having a side surface curved inward, and a vertex side of the main body is fixed on an extension of a rotation axis of the air-cooling fan.

In the exhaust guide of the present invention having the above-described structure, the blowout flow discharged from the ventilation port by the air cooling fan is guided along the side surface of the main body, and is discharged radially around the ventilation port. . As described above, according to the exhaust guide of the present invention, the blowout flow from the ventilation port is not blown out strongly in a certain direction, but is dispersed radially and its wind pressure is weakened. Can be reduced, and thus the influence on precision instruments such as an electronic balance arranged around can be reduced.

Further, the exhaust guide of the present invention is mounted on an extension of the rotation axis of the air-cooling fan, that is, at a position where a motor for driving the air-cooling fan is mounted and a blowout flow is not discharged. By installing the inductor, the turbulence that has conventionally occurred near this mounting position is prevented, and the blowout flow flows more smoothly, minimizing the reduction in ventilation capacity due to the installation of the exhaust inductor. Can be minimized.

Further, the exhaust guide of the present invention can be used for ventilation ports of various sizes because the mounting position is fixed irrespective of the size of the ventilation port. Since it is covered by the main body of the exhaust air guide, foreign substances such as fingers and sticks from the outside hardly enter the rotating part of the air-cooling fan, and safety can be improved.

In the meantime, the side surface of the main body is defined as a first derivative of the intersection of the plane including the extension of the rotation axis of the air-cooling fan and the side surface of the main body as a function. Is desirably curved so as not to have an inflection point. Here, the inflection point is a point at which the curve changes from concave to convex or from convex to concave, and when the curve has a second derivative, a point at which the sign of the second derivative changes. It is.

FIG. 8A is an example of a function (curve) in which the first derivative has an inflection point, and FIG. 8B is a graph showing the first derivative. (C) is an example of a function (curve) in which the first derivative has no inflection point, and (d) is a graph showing the first derivative. That is, since the curve of the first derivative represented by a function having no inflection point has a smooth change in the slope, the turbulence of the airflow hardly occurs as shown by the arrow in FIG. A curve represented by a function having a function inflection point has a sharp change in the slope of the curve.
As shown by the arrow in (a), turbulence (vortex) of the air flow is likely to occur.

Next, a third aspect of the present invention is directed to the first aspect.
Alternatively, in the exhaust inductor according to claim 2, a fixing means for fixing the main body to the housing is provided on a vertex side of the main body. As described above, if the fixing means is provided in the exhaust induction device in advance, attachment to the housing can be facilitated. As the fixing means, a bolt, a nut, a double-sided adhesive sheet, a magic tape, a suction cup, and the like can be considered. In particular, as described in claim 4, if a magnet is used as the fixing means, the casing is made of a material that adsorbs the magnet. If so, it can be easily attached and detached.

When an electronic circuit or the like is housed in the housing, electromagnetic waves generated in the housing leak out of the ventilation opening, which is an opening of the housing, to cause an external device to malfunction. Conversely, electromagnetic waves may enter from outside through the ventilation holes, causing the electronic circuits in the housing to malfunction.

Therefore, as described in claim 5, the main body is
The main body may be formed of a material having electromagnetic wave absorption, or a main body may be formed with a film having electromagnetic wave absorption on at least the side surface. In this case, a part of the electromagnetic wave that is going to pass through the ventilation opening is absorbed by the exhaust inductor, so that the invasion and leakage of the electromagnetic wave from the ventilation opening can be reduced.

When the exhaust inductor of the present invention has an electromagnetic wave absorbing performance as described above, the widest part of the main body is formed so as to be larger than the ventilation opening so that the electromagnetic waves can be effectively absorbed. It is desirable.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view illustrating the entire configuration of the exhaust inductor according to the present embodiment, and FIG. 1B is a cross-sectional view taken along the line A-A.

As shown in FIG. 1, the exhaust guide 2 of the present embodiment is formed in a conical shape, and has a body 4 whose side surface 4a is curved inward, and a pair of body 4 sandwiching the curved side surface 4a of the body 4. Of the circular surfaces 4b and 4c, the fixing portion 6 is attached to the short-diameter surface (hereinafter referred to as a fixing surface) 4b. The surface of the main body 4 is covered with a thin film (electromagnetic wave absorbing layer) 8 made of an electromagnetic wave absorbing material.

The main body 4 is made of hinoki wood by lathing. The fixed surface 4b has a diameter of 60 mm, the release surface 4c facing the fixed surface 4b has a diameter of 142 mm, and the fixed surface 4b is separated from the release surface. The thickness up to 4c is formed to be 37 mm, and as shown in FIG. 1B, the side surface 4a is expressed by the equation (1) with the center line of the main body 4 as the y-axis and the release surface as the x-axis. It is formed so that it may become a curved line. Where α
= 26.4, β = 105.4, and γ = 2.28.

Y = β / (x−α) −γ (1) The electromagnetic wave absorbing layer 8 covering the main body 4 is composed of 3 parts by weight of tin oxide (SnO ₂ ) having an average particle size of 1.5 μm and an average particle size of 1.5 μm. 1.0 μm diameter zinc ferrite (ZnO.Fe ₂ O ₃ )
2 parts by weight of cuprous oxide (Cu ₂ O) having an average particle size of 2.3 μm is mixed with an acrylic resin paint, and
And dried. The thickness of the electromagnetic wave absorbing layer 8 after drying is about 50 μm.

On the other hand, the fixing portion 6 has a thin cylindrical magnet 10 having a diameter slightly smaller than the fixing surface 4b, and an iron tray (60 mm in diameter × thickness) for attracting and holding the magnet 10. 5 mm) 12. In addition,
The tray 12 is adhered to the fixing surface 4b of the main body 4 using an epoxy resin-based elastic adhesive.

Next, FIG. 2A is a perspective view showing a state of use of the exhaust inductor 2 of this embodiment, and FIG. 2B is an explanatory diagram showing a positional relationship between the exhaust inductor 2 and an air cooling fan. As shown in FIG. 2, the exhaust guide 2 of the present embodiment is attached to a ventilation port K of a metal housing G. Note that the ventilation port K is
Is punched to form a large number of square ventilation holes H. As shown in FIG. 2B, an air-cooling fan F is provided inside the ventilation port K, and a motor M for driving the air-cooling fan F is fixed to the center of the ventilation port K. .

The exhaust guide 2 of the present embodiment is mounted at a position facing the mounting portion of the motor M with the ventilation port K interposed therebetween by the magnetic force of the magnet 10 constituting the fixed portion 6. The outlet flow discharged from the ventilation port K to which the exhaust guide 2 of this embodiment is attached is guided along the curved surface of the main body side surface 4a and is discharged radially.

Therefore, according to the exhaust guide 2 of the present embodiment, the blowout flow from the ventilation port K is not blown out strongly in a certain direction, but is dispersed radially and the wind pressure is weakened. The influence on the surrounding airflow can be reduced, and thus the influence on precision instruments such as an electronic balance arranged around can be reduced.

In the exhaust guide 2 of the present embodiment, the motor M which is a portion of the ventilation port K where the blowout flow is not discharged is provided.
By mounting the exhaust guide 2 in addition to being mounted at the mounting position, the occurrence of turbulent flow that has conventionally occurred near the mounting position is prevented. Moreover, since the curve defining the shape of the main body side surface 4a for inducing the outlet flow is set so that the first derivative of the function representing the curve has no inflection point, the presence of the exhaust inductor 2 Nevertheless, the outlet flow from the ventilation port K flows smoothly, and it is possible to minimize a decrease in ventilation capacity due to the installation of the exhaust guide 2.

Further, in the exhaust guide 2 of this embodiment, since the mounting position is fixed irrespective of the size of the ventilation port K, it can be used for ventilation ports K of various sizes. Also,
Since the ventilation port K is covered by the main body 4 of the exhaust guide 2, the foreign matter such as a finger or a stick does not easily enter the rotating portion of the air-cooling fan F from the outside, and safety can be improved.

Further, in the exhaust inductor 2 of this embodiment,
An electromagnetic wave absorbing layer 8 is formed on the surface of the main body 4, and the electromagnetic wave absorbing layer 8 absorbs an electromagnetic wave that is going to pass through the ventilation port K, so that the penetration and leakage of the electromagnetic wave from the ventilation port K can be reduced. Can be. Here, an experimental result comparing the effect of attaching the exhaust guide 2 of the present embodiment to the ventilation port K with the case where the ventilation port cover 100 which is a conventional device is attached and the case where nothing is attached is shown below. Shown in

It should be noted that the exhaust inductor 2 of this embodiment is made of carbon,
It was attached to the ventilation port on the back of the tubular electric resistance heating furnace housing G of a sulfur analyzer (HORIBA, EMIA520). As shown in FIG. 3, the ventilation port K of the housing G includes a large number of ventilation holes H formed by punching a rectangular shape around a portion G1 to which the motor M is attached.

The vertical and horizontal dimensions of the ventilation port K are as follows:
The diameter of the rotation track of the air-cooling fan is 110 mm, which is substantially the same as the diameter, and the vertical and horizontal dimensions of the motor mounting portion G1 are 58 mm, which is approximately the same as the diameter of the motor M. In addition, the ventilation port cover 100 used for comparison has a surface facing the ventilation port K formed in a 140 mm × 140 mm square, and the facing surface is arranged at a position 60 mm from the ventilation port K,
It is configured to be fixed at both left and right edges of the ventilation port K. [Experiment 1] First, a change in ventilation capacity between the case where the exhaust guide 2 of the present embodiment is attached to the ventilation port K, the case where the ventilation port cover 100 of the conventional device is attached, and the case where nothing is attached. In order to clarify the above, the total amount of air discharged from the ventilation port K in each case was obtained.

Hereinafter, a method of calculating the amount of exhaust air will be described. That is, first, as shown in FIG. 4A, in each of eight directions (up, upper left, left, lower left, lower, lower right, right, upper right) as viewed from the center of the ventilation port K, 30 mm from the center. (Inside), 42mm (middle), 55mm (outside)
Wind speed measuring device (manufactured by Nippon Kagaku Kogyo Co., Ltd., KANOMAX)
The wind speed of the outlet flow is measured by using an ANEMAMASTER MODEL 6061).

Next, an annular area sandwiched between two concentric circles having a diameter of 60 mm and 110 mm centered on the center of the ventilation port K is divided into 16 partial areas Pi (where the wind speed measurement points are four corners). i = 1 to 16), and for each partial region Pi, an average wind speed Vav of the partial region Pi is obtained from the measured values of the wind speed at the four corners. The average wind speed Vav is shown in FIG.
As shown in (b), the measured values of the wind velocities at the four corners of the partial area Pi are calculated according to equation (2) as Va, Vb, Vc, and Vd.

Vav = (Va + Vb + Vc + Vd) / 4 (2) When the area of the partial region Pi is A, the partial region P
Since the exhaust air amount Q at i can be calculated by the equation (3), the total exhaust air amount is obtained by adding the exhaust air amount Q for all the partial areas P1 to P16.

Q = A [cm ² ] × Vav [cm / sec] = A · Vav [cm ³ / sec] = A · Vav × 10 ⁻³ [L / S] (3) L: Litter (= 1000 [ cm ³ ]) Table 1 shows the measurement results of the wind speed at each measurement point and the calculated value of the total exhaust air volume in each of the above cases.

[0035]

[Table 1]

As shown in Table 1, when the total exhaust air amount (55.0 [L / sec]) when not mounted is 100%, the total exhaust air amount when the exhaust inductor 2 of this embodiment is attached. (5
(3.8 [L / sec]) is 97.8%, which is the total amount of exhaust air (51.
5 [L / sec]) is 93.7%. That is, the exhaust guide 2 of the present embodiment is more
This experiment revealed that the decrease in total exhaust air volume (ventilation efficiency) was small. [Experiment 2] Next, the influence of the outlet flow from the ventilation port K on the surrounding equipment was measured using an electronic balance (AE-163, manufactured by Mettler).
(Type) was quantitatively measured.

As shown in FIG. 5, the electronic balance T has a total of 3 parts on the ceiling, left and right side parts for taking in and out of the sample.
Slide shutters S1, S2, S3
Is provided. Here, FIG. 6 is an explanatory diagram showing the outer dimensions and arrangement of the housing G and the electronic balance T. FIG.
Is a plan view, and (b) is a front view.

As shown in FIG. 6, the external dimensions of the electronic balance T are 280 mm in height, 185 mm in width, and 410 mm in depth.
On the other hand, the outer dimensions of the housing G are 535 mm in height,
The width is 500 mm and the depth is 520 mm. On the rear side of the housing G, 90 mm from the upper surface and 190 mm from the left side.
The air-cooling fan F is mounted so that the rotation axis is positioned at mm.

The housing G and the electronic balance T are placed on a desk, respectively. The housing G is 800 mm above the floor, and the electronic balance T is 706 mm above the floor. The distance from the back of the housing G to the front of the electronic balance T is 1320 mm,
The distance from the right side of the housing G to the right side of the electronic balance T is 4
The housing G and the electronic balance T are arranged at a position of 56 mm.

In such an arrangement state, the electronic balance T
The three shutters S1 to S3 are all closed (fully closed), and in a state where the air flow in the electronic balance T is suppressed, the switch button is pressed to set the shutter to zero (the display value is cleared to 0). With the shutter fully closed, only the shutter S1 on the ceiling is opened, only the shutter S2 on the right is opened, and the shutter S on the left is opened.
3, the shutter was set to any one of release and all shutters S1 to S3 were released (fully open), and the fluctuation range of the display value was observed. Table 2 shows the results.

[0041]

[Table 2]

As shown in Table 2, the mounting of the exhaust inductor 2 of the present embodiment can reduce the fluctuation of the indicated value more reliably than when the exhaust inductor 2 is not mounted, and the level becomes almost the same as when the air-cooling fan F is stopped. That is, it was confirmed by this experiment that the influence of the exhaust air on surrounding devices could be reduced. [Experiment 3] Finally, with the same equipment and the same arrangement as in Experiment 2,
Right front corner FR, left front corner FL, right rear corner R of electronic balance T
R, left rear corner RL, and front center FC (FIG. 5)
), The upper, middle and lower three places respectively, for a total of 1
The wind velocities at five locations were measured using a wind velocimeter (same as that used in Experiment 1). The shutters S1 to S3 of the electronic balance T were fully closed. Table 3 shows the measurement results and the average wind speed at 15 locations.

[0043]

[Table 3]

As shown in Table 3, the installation of the exhaust guide 2 of the present embodiment results in a wind speed one order of magnitude lower than when it was not installed.
It was confirmed that the level was almost the same as when the air-cooling fan F was stopped, that is, the result confirmed the result of Experiment 2. According to the above experiment, the exhaust guide 2 of the present embodiment can reduce the influence on the surrounding devices to the same extent as the conventional vent cover 100, and furthermore, the ventilation capacity is reduced as compared to when the vent cover 100 is attached. Has been confirmed to be small.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and can be implemented in various modes. For example, in the above embodiment, the thin film (electromagnetic wave absorbing layer) 8 made of an electromagnetic wave absorbing material is formed on the surface of the main body 4, but the main body 4 itself may be made of the electromagnetic wave absorbing material.

In the above embodiment, wood is used as the material of the main body 4. However, the exhaust guide 2 shown in FIG.
Like FIG. 2, a metal plate may be formed into a container shape by pressing. Further, when the magnet 10 is not attracted to the housing G,
As shown in FIG. 7 (b), a U-shaped arm 20 is formed around a circular metal plate having substantially the same size as the motor mounting portion G1.
a of the arm 30a using the adapter 30 with the
Is inserted into the ventilation hole of the ventilation port K and bent, thereby fixing the adapter 30 to the ventilation port K.
It may be attached to.

Further, in the above embodiment, the magnet 10 is used as a fixing means for fixing the exhaust guide 2 to the housing G. However, any method such as using a double-sided adhesive tape, a bolt and a nut, and a fastener can be used. May be fixed in any suitable manner.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating an overall configuration of an exhaust inductor according to an embodiment, and an AA cross-sectional view thereof.

FIG. 2 is an explanatory diagram illustrating a usage state and the like of the exhaust inductor of the embodiment.

FIG. 3 is an explanatory diagram illustrating a configuration of a ventilation port of a housing used in an experiment.

FIG. 4 is an explanatory diagram illustrating a method of calculating an exhaust air amount of an outlet flow discharged from a ventilation port.

FIG. 5 is a perspective view illustrating a schematic configuration of an electronic balance used in an experiment.

FIG. 6 is an explanatory diagram illustrating an arrangement relationship between an electronic balance and a housing during an experiment.

FIG. 7 is an explanatory diagram illustrating a modification example of the present embodiment.

FIG. 8 is a graph for explaining a side shape of the main body.

FIG. 9 is an explanatory diagram illustrating a usage state and the like of a conventional vent cover.

[Explanation of symbols]

2, 22 ... exhaust guide 4 ... body 4a ... side surface 4b ... fixed surface 4c ... release surface 6 ... fixed part
DESCRIPTION OF SYMBOLS 10 ... Magnet 12 ... Receiving tray 30 ... Adapter 30a ... Arm part 1
00: Ventilation port cover F: Air cooling fan G: Housing G1: Motor mounting part H: Vent hole K: Ventilation port M: Motor S1-S3: Sliding shutter T: Electronic balance

Claims (6)

[Claims] 1. An exhaust inductor attached to a housing provided with an air-cooling fan at a ventilation opening, for guiding a blowing direction of a blowing flow discharged from the ventilation opening, wherein the exhausting inductor is formed in a cone shape and has a side surface. Is a body having an inwardly curved shape, wherein the apex side of the body is fixed on an extension of a rotation axis of the air-cooling fan for use. 2. When a cross line between a plane including an extension of a rotation axis of the air cooling fan and a side surface of the main body is represented by a function,
The exhaust inductor according to claim 1, wherein the side surface of the body is curved such that its first derivative has no inflection point. 3. The exhaust guide according to claim 1, wherein a fixing means for fixing the main body to the housing is provided on a vertex side of the main body. 4. The exhaust inductor according to claim 3, wherein the fixing means is a magnet. 5. The exhaust inductor according to claim 1, wherein the main body is made of a material having electromagnetic wave absorption. 6. The exhaust inductor according to claim 1, wherein the main body has a coating having an electromagnetic wave absorbing property formed on at least a side surface thereof.