JP2001153447A - Damper for flow adjustment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of vibration and noises from a damper more effectively, by securing an indispensable minimum of an air current in the damper whatever sliding position a movable valve plate may be locked in by the fault of an actuator to drive the movable valve, and dispersing the air current passing a fixed valve plate finely, even if the number of small holes in the fixed valve plate is not increased specifically, in a damper for adjustment of flow the which is equipped with a fixed valve plate having many small holes and a movable valve plate having many valve holes corresponding to those small holes and overlapping the fixed valve plate and capable of sliding between the first sliding position and the second sliding position. SOLUTION: Each shape and position of many small holes Hf and many valve holes Hm is set so that it may minimize the total effective aperture of those small holes Hf, lying in the position straddling each small hole Hf that each valve hole Hm corresponds to and a small hole Hf adjacent to it when a movable valve plate Vm is in the second sliding position X2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control damper having a duct body having an air passage provided with a valve device for adjusting a flow rate of air flowing through the passage.

[0002]

2. Description of the Related Art In a conventional flow control damper having a butterfly type valve plate, an opening portion of a valve device V 'is in an open state as shown in FIG. The air flow flowing through the air passage is formed to be partially offset to a part of the air passage cross section locally when passing through the valve device V ′. Flows rapidly so as to return to the entire cross section of the air passage, so that a large turbulence is generated in the passing airflow before and after the valve device V ', which causes noise and vibration.

In order to solve such a problem, for example, as disclosed in Japanese Patent Application Laid-Open No. H10-160237, a valve device of a damper is fixed to a duct main body to close the passage, A predetermined first sliding position and a second sliding position with respect to the fixed valve plate;
A movable valve plate capable of reciprocating sliding between a sliding position and a fixed valve plate, a plurality of small holes communicating between the upstream side and the downstream side of the fixed valve plate are spaced apart from each other. A plurality of valve holes are formed in the movable valve plate corresponding to the plurality of small holes, and the movable valve plate slides from the first sliding position toward the second sliding position. There has already been proposed an arrangement in which the amount of displacement of each valve hole with respect to each small hole is gradually increased so that the total effective opening of each small hole is gradually reduced.

[0004] In this proposal, as the movable valve plate slides from the first sliding position to the second sliding position, the amount of displacement of each valve hole with respect to each small hole (accordingly, the movable valve plate is displaced). Since the total effective opening of the small holes can be gradually reduced by gradually increasing the amount of throttle of each small hole by the valve plate, the fixed valve plate that passes through the opening portion (a large number of small holes) of the valve device crosses the air passage. Can be distributed over substantially the entire surface of the duct body. For this reason, even with the installation of the valve device, the air can be allowed to flow and flow over substantially the entire area of the cross section of the air passage of the duct main body, and the air has passed through each small hole. Immediately after the air flow can interfere with each other moderately,
Therefore, there is an advantage that generation of turbulence before and after the valve device, and hence generation of vibration and noise from the damper, can be effectively suppressed.

[0005]

However, in the damper structure proposed above, when the movable valve plate is in the first sliding position, each valve hole is located at a position substantially corresponding to each corresponding small hole. Is maximized, and when the movable valve plate is in the second sliding position, each valve hole is completely closed by a fixed valve plate (an intermediate wall portion between two adjacent small holes). The position of the movable valve plate is set so as to minimize the total effective opening of the small holes (that is, the opening is zero) at the position. If such a situation occurs, the fully closed state of the damper cannot be released, and there is a possibility that the flow of air becomes substantially impossible.

In the above proposed damper structure, the more the number of openings (a large number of small holes) of the valve device, the more finely the air flow passing through the fixed valve plate is dispersed, so that vibration and noise from the damper are reduced. Can be more effectively suppressed, but there is a limit to increasing the number of the small holes.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is capable of minimizing the necessary damper in the damper even if the movable valve plate is locked in any sliding position due to a failure of an actuator for driving the movable valve plate. Airflow can be reliably ensured, and the airflow passing through the fixed valve plate can be finely dispersed without increasing the number of small holes in the fixed valve plate to reduce vibration and noise from the damper. It is an object of the present invention to provide a flow rate adjustment damper with a simple structure that can be suppressed more effectively.

[0008]

In order to achieve the above object, according to the present invention, a valve device provided in a duct body having an air passage and adjusting an air flow rate in the passage is provided in the duct body. A fixed valve plate that is fixed to close the passage, and is disposed so as to overlap with and contact the fixed valve plate, and reciprocates between a predetermined first sliding position and a second sliding position with respect to the fixed valve plate. A movable valve plate that is slidable; a large number of small holes communicating with an upstream side and a downstream side of the fixed valve plate are formed in the fixed valve plate at intervals from each other; A number of valve holes are formed in the movable valve plate corresponding to the holes, and each of the small holes is formed as the movable valve plate slides from the first sliding position to the second sliding position. Flow control damper wherein the amount of deviation of the position of each valve hole with respect to the diameter gradually increases to gradually reduce the total effective opening of the small hole In the movable valve plate is the first
When in the sliding position, each valve hole is located at a position substantially corresponding to each of the corresponding small holes to maximize the total effective opening of the small holes, and when the movable valve plate is in the second sliding position. When the valve hole is located at a position straddling the corresponding small hole and the small hole adjacent to the corresponding small hole, the total effective opening of the small hole is minimized. The shape and position of each of the large number of small holes and the large number of valve holes are set.

According to this feature, the sliding position of the movable valve plate (for example, the second sliding position, which is the minimum opening of the valve device) should occur due to the failure of the operating mechanism for driving the movable valve plate. Even if locked, the minimum necessary air flow in the damper is reliably ensured, and a situation in which the flow cannot be prevented is avoided. Further, in a state where the movable valve plate is at or near the second sliding position, each valve hole of the movable valve plate is located at a position straddling two adjacent small holes of the fixed valve plate. Since both small holes are partially opened at the same time, the air flow passing through the fixed valve plate can be finely dispersed without increasing the number of small holes in the fixed valve plate, and the dispersed air flow Can be moderately interfered with each other, whereby the generation of turbulent flow before and after the valve device can be effectively suppressed, so that the generation of vibration and noise from the damper can be more effectively suppressed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on embodiments of the present invention shown in the accompanying drawings.

FIG. 1 is a schematic view showing an example of a ventilation system incorporating a damper according to the present invention, FIG. 2 is an overall perspective view of the damper, and FIG. 3 is a front view of the damper viewed from an upstream side (FIG. 2). FIG. 4 is an enlarged plan view taken along arrow 4 of FIG. 3, FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 3, FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 8 is an enlarged sectional view taken along line 7-7 of FIG. 6, FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 7, and FIG.
FIG. 10 is an enlarged view of a portion viewed in the direction of arrow 10 in FIG. 3 (movable valve plate is in the first sliding position), FIG. 11 is a sectional view taken along line 11-11 of FIG. 10, and FIG. FIG. 13 is a sectional view taken along the line 13-13 in FIG. 12, showing a state in which the movable valve plate is in the second sliding position from the first sliding position. FIG. 15 is an explanatory view showing a change in a valve opening in FIG.
(A) is an explanatory view schematically showing the flow of the air flow when the damper of the present invention is opened, and (b) shows the flow of the air flow when the damper is opened in a conventional example using a butterfly valve plate. It is explanatory drawing shown simply.

First, in FIG. 1, a damper D for adjusting the air flow rate of the present invention is interposed in the middle of an air pipe P of a ventilation system such as a concert hall. Is connected to a blower fan F that supplies a predetermined amount of air. The downstream side of the pipe P is connected to an air outlet O to the room through a sound absorbing duct SD containing a sound absorbing material such as glass wool.

Next, referring to FIGS.
The structure of will be described specifically. The damper D includes a duct main body 1 having an air passage A, and a valve device V for adjusting a flow rate of air flowing through the passage A.

The duct body 1 is formed of a rectangular cylinder integrally having outward flange portions 1a and 1b at an upstream opening end and a downstream opening end, respectively. The part is an air passage A. Open ends of adjacent ducts are detachably connected to the flange portions 1a and 1b, respectively.

The valve device V is fixed to the duct body 1 so as to cross the air passage A and closes the passage A, and at least a part of one upstream surface of the fixed valve plate Vf. (Approximately the entire surface in the illustrated example) so as to overlap with and contact with the fixed valve plate Vf and a predetermined first sliding position X1 with respect to the fixed valve plate Vf.
And one movable valve plate Vm that can slide between the second sliding position X2 and the second sliding position X2.

The fixed valve plate Vf has a rectangular shape substantially matching the cross-sectional shape of the air passage A, and its outer peripheral portion is fixed along the inner peripheral surface of the duct main body 1 (in the illustrated example, screwing). It is detachably fixed to the duct body 1 via the plurality of angle members 2. Further, a ladder-shaped support frame 3 composed of a plurality of support plates extending elongated vertically and horizontally and connected to each other is fixed to the duct body 1 in the vicinity of the fixed valve plate Vf. The movable valve plate Vm is slidably held only in the direction crossing the air passage A between the fixed valve plate Vf and one surface on the upstream side.

The fixed valve plate Vf has a number of small holes Hf communicating the upstream side and the downstream side of the fixed valve plate Vf at equal intervals in the vertical and horizontal directions. The small holes Hf are formed over the entire surface, and each of the small holes Hf has a diameter of 1 in the illustrated example.
It is a 0 mm circular hole.

The movable valve plate Vm also has a number of valve holes Hm corresponding to the small holes Hf for communicating the upstream side and the downstream side, and the valve holes Hm are small holes Hf in the illustrated example.
It has the same shape, same size, and same pitch. Note that the two valve plates V
In the illustrated example, f and Vm are both formed by cutting a punched metal into a predetermined shape, but the material may be selected arbitrarily, and may be formed of, for example, a synthetic resin material.

When the movable valve plate Vm is at the first sliding position X1, which is a sliding limit to one side, the small holes are fully opened so that the respective valve holes Hm coincide with the corresponding small holes Hf. Position (see FIGS. 10, 11 and 14a),
At this time, in the illustrated example, about 5
3.6% are open.

When the movable valve plate Vm is in the second sliding position X2, which is the sliding limit to the other side, each valve hole Hm has a corresponding small hole Hf and a small hole adjacent thereto. H
At the maximum aperture position (see FIGS. 12, 13 and 14E) straddling f, about 25.2% of the air passage A in the illustrated example is opened. It is in a state of being left.

As shown in FIGS. 14A to 14E, the movable valve plate Vm is moved from the first sliding position X1 to the second sliding position X.
2, the amount of displacement of each valve hole Hm with respect to each small hole Hf (accordingly, the movable valve plate Vm
), The total effective opening of the small holes Hf gradually decreases. Thereby, the air flow rate in the air passage A can be adjusted in accordance with the sliding amount of the movable valve plate Vm, that is, the valve device V is fully opened when the movable valve plate Vm is at the first sliding position X1. And the minimum opening when in the second sliding position X2.

In particular, according to the present invention, when the movable valve plate Vm is at the first sliding position X1 shown in FIG. 14A, each valve hole Hm is located at a position substantially matching the corresponding small hole Hf. When the movable valve plate Vm is at the second sliding position X2 shown in FIG. 14 (e), the total effective opening of the small holes Hf is maximized, and each valve hole Hm corresponds to each small hole. A large number of small holes Hf and a large number of small holes Hf are located at positions straddling the hole Hf and the small holes Hf adjacent to the corresponding small holes Hf so as to minimize the total effective opening of the small holes Hf. The shape and position of each of the valve holes Hm are set.

For example, in the illustrated example, each small hole Hf and the valve hole Hm are circular holes of the same size, and adjacent small holes Hf, H
The distance a between f (valve holes Hm, Hm) is set smaller than the diameter D of each small hole Hf (valve hole Hm). Further, in the valve closing process in which the movable valve plate Vm moves toward the second sliding position X2, after one valve hole Vm reaches a position straddling two adjacent small holes Vf, Vf (that is, ( In (c) to (e)), of the two opening portions Hm1 and Hm2 of one valve hole Hm, the movable valve plate Vm gradually increases the opening as the movable valve plate Vm approaches the second sliding position X2. The valve opening H on the rear side in the sliding direction in which the opening is gradually reduced from the amount of change in the opening of the valve opening Hm1.
m2, so that the total opening of both valve openings Hm1 and Hm2 gradually decreases as the movable valve plate Vm approaches the second sliding position X2. , The diameter D of each small hole Hf (valve hole Hm), and the small hole Hf,
An interval a between Hf (valve holes Hm, Hm) is set.

Next, from the outside of the duct body 1, the movable valve plate Vm
Adjustment operation device AJ for finely and arbitrarily fine-adjusting the sliding amount of the air flow to finely and accurately adjust the flow rate of the air flow in the air passage A.
Will be described.

The adjusting operation device AJ includes a housing 4 mounted on the upper wall of the duct body 1, an operation handle 5 rotatably supported by the housing 4 via a first bearing b1, It comprises a first interlocking mechanism M1 for converting a rotational displacement into a swinging displacement of the drive lever 6, and a second interlocking mechanism M2 for converting the swinging displacement of the drive lever 6 into a sliding displacement of the movable valve plate Vm.

The first interlocking mechanism M1 includes an intermediate shaft 7 orthogonal to the operation handle 5 and rotatably supported on the housing 4 via a second bearing b2, and the intermediate shaft 7 and the operation handle 5
Screw gear mechanism 8 provided between and interlockingly rotating between them
The drive lever 6 is fixed to the intermediate shaft 7.

The second interlocking mechanism M2 includes a first short link 10 having one end pivotally connected 9 to the drive lever 6, and the first short link 10
A long link 12 having one end pivotally connected to the other end of the short link 10, a support shaft 13 rotatably supported by the housing 4 via a third bearing b3, and being parallel to the intermediate shaft 7; The second short link 14 whose base end is fixed to the other end of the long link 12 via the 13 and the long hole 14 a formed at the distal end of the second short link 14 slidably engages the front end. And an L-shaped engaging piece 15 whose base is fixed to the upper part of the movable valve plate Vm.

When the operation handle 5 is rotated,
The rotation is transmitted to the intermediate shaft 7 via the screw gear mechanism 8, whereby the drive lever 6 swings. The swing is
Further, the movable valve plate is transmitted to the second short link 14 via the first short link 10, the long link 12 and the support shaft 13, and via the engagement piece 15 as the second short link 14 swings. Vm slides in the left-right direction, that is, the direction crossing the air passage A. In this case, the rotational displacement of the operation handle 5 is reduced by the screw gear mechanism 8 and transmitted to the drive lever 6, and the movement of the lever 6 is controlled by the first short link 10, the long link 12, the support shaft 13, and the second short link. 14 is transmitted to the engagement piece 15 at a reduced speed, so that the movable valve plate V
m can be slid little by little with a relatively large operation displacement amount of the operation handle 5, whereby the sliding amount of the movable valve plate Vm can be finely adjusted by rotating the operation handle 5.

On the upper part of the housing 4, there is provided a display section I for indicating the degree of opening of the valve device V. That is, a pointer 16 fixed to the upper end of the intermediate shaft 7 and rotated integrally therewith is disposed above the housing 4, and a scale 17 engraved along the rotation locus of the pointer 16 is provided on the housing 4. The indicator 16 is provided on the upper surface of the display device. The scale 17 displays "open" indicating that the movable valve plate Vm is at the first sliding position X1 and each of the small holes Hf of the fixed valve plate Vf is most open (in the illustrated example, fully open). "Closed" indicating that the movable valve plate Vm is in the second sliding position X2 and each of the small holes Hf is most narrowed (in the illustrated example, substantially half-opened) is attached.

Next, the operation of the above embodiment will be described.
From the upstream side of the air pipe P of the ventilation system, a predetermined amount of air is supplied from a blower fan F, and the air flow flows downstream while being adjusted in air volume by a damper D, and is absorbed by a sound absorbing duct SD. , From the air outlet O.

In the valve device V of the damper D, the movable valve plate Vm is moved between the first sliding position X1 and the second sliding position X2 as the operating handle 5 is rotated. Can be moved and held. Thus, the movable valve plate Vm
Slides from the first sliding position X1 toward the second sliding position X2, the amount of displacement of the position of each valve hole Hm of the movable valve plate Vm with respect to each small hole Hf of the fixed valve plate Vf ( Accordingly, the amount of narrowing of each small hole Hf by the movable valve plate Vm gradually increases, and the total effective opening of the small hole Hf can be gradually reduced.
The opening degree of the valve device V can be continuously increased or decreased according to the sliding amount of the movable valve plate Vm.
The position can be easily confirmed from the relation between the scale 17 and the pointer 16 on the upper surface.

The opening portion of the valve device V (a large number of small holes H
f) are uniformly distributed over substantially the entire surface of the fixed valve plate Vf that crosses the air passage A, so that even with the special provision of the valve device V, the duct body 1 is offset over substantially the entire area of the cross section of the air passage. Air flow can be passed through without
The air flows immediately after passing through the small holes Hf can appropriately interfere with each other (see (a) of FIG. 14), and as a result, turbulence occurs before and after the valve device V, and as a result, the damper D It is possible to effectively suppress the generation of vibration and noise from the vehicle.

As described above, in the illustrated example, the movable valve plate V
When m is at the first sliding position X1 shown in FIG. 14 (a), each valve hole Hm is located at a position substantially corresponding to the corresponding small hole Hf, and the total effective opening of the small hole Hf is maximized. When the movable valve plate Vm is at the second sliding position X2 shown in FIG. 14E, each valve hole Hm is adjacent to the corresponding small hole Hf and the corresponding small hole Hf. In order to minimize the total effective opening of the small hole Hf at a position straddling the small hole Hf,
The shape and position of each of the many small holes Hf and many valve holes Hm are set. Therefore, it is assumed that the movable valve plate Vm is locked at any sliding position (for example, the second sliding position X2 which is the minimum opening degree of the valve device V) due to a failure of the operation mechanism of the movable valve plate Vm. However, the minimum necessary air flow in the damper is reliably ensured, and the situation in which the air flow cannot be prevented is reliably avoided. When the movable valve plate Vm is in the second sliding position X2
Or a state close to it (that is, (c) of FIG. 14)
In (e)), each valve hole Hm of the movable valve plate Vm is located at a position straddling two adjacent small holes Hf, Hf of the fixed valve plate Vf, and both small holes Hf, Hf are located. At the same time, the air flow passing through the fixed valve plate Vf can be finely dispersed without increasing the total number of the small holes Hf in the fixed valve plate, and the dispersed air flows can be appropriately dispersed. Therefore, the generation of turbulence before and after the valve device can be effectively suppressed, and the generation of vibration and noise from the damper can be more effectively suppressed.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the above embodiment, at the first sliding position X1 of the movable valve plate Vm, the valve hole Hm of the valve plate Vm and the fixed valve plate Vm
f is completely aligned with the small hole Hf (ie, both holes Hf).
Although the amount of displacement between the positions f and Hm is set to zero), in the present invention, the positions of the holes Hf and Hm may be slightly shifted at the first sliding position X1 of the movable valve plate Vm.

In the above embodiment, the shape and size of the valve hole Hm of the movable valve plate Vm and that of the small hole Hf of the fixed valve plate Vf are the same. The size may be slightly changed.

Further, in the above embodiment, the shape of the valve hole Hm of the movable valve plate Vm and the shape of the small hole Hf of the fixed valve plate Vf are circular. Shape, for example, rhombus, ellipse, oval, etc.

[0038]

As described above, according to the present invention, a fixed valve plate having a large number of small holes and a large number of valve holes corresponding to the small holes are overlapped with the fixed valve plate to form the first sliding plate. A movable valve plate that is slidable between a first sliding position and a second sliding position. In the flow control damper in which the amount of deviation of the position of each valve hole with respect to is gradually increased to gradually reduce the total effective opening of the small hole, each valve hole corresponds when the movable valve plate is at the first sliding position. The maximum effective opening of the small hole is located at a position substantially matching with the small hole, and when the movable valve plate is at the second sliding position, each valve hole corresponds to each small hole; Each of the plurality of small holes and the large number of valve holes is located at a position straddling the small hole adjacent to each corresponding small hole so as to minimize the total effective opening of the small holes. Since the position is set, the movable valve plate is locked at any sliding position (for example, the second sliding position which is the minimum opening of the valve device) due to a failure of the operating mechanism for driving the movable valve plate. Even so, the minimum necessary air flow in the damper is reliably ensured, and a situation in which the air flow is disabled can be reliably avoided. Further, in a state where the movable valve plate is at or near the second sliding position, each valve hole of the movable valve plate is located at a position straddling two adjacent small holes of the fixed valve plate, and both of them are provided. Because the small holes are partially opened at the same time, the air flow passing through the fixed valve plate can be finely dispersed without increasing the number of small holes in the fixed valve plate, and the dispersed air flows can be mutually separated. Since the interference can be made moderately, and the generation of turbulence before and after the valve device can be effectively suppressed, the generation of vibration and noise from the damper can be more effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a ventilation system incorporating a damper according to the present invention.

FIG. 2 is an overall perspective view of the damper.

FIG. 3 is a front view of the damper viewed from an upstream side (a view as seen from the arrow 3 in FIG. 2).

FIG. 4 is an enlarged plan view as viewed in the direction of arrow 4 in FIG. 3;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. 3;

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6;

8 is an enlarged sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is an enlarged sectional view taken along line 9-9 of FIG. 3;

FIG. 10 is an enlarged view of a portion viewed from arrow 10 in FIG. 3 (the movable valve plate is in a first sliding position).

FIG. 11 is a sectional view taken along line 11-11 of FIG. 10;

FIG. 12 is a view corresponding to FIG. 10, showing a state in which a movable valve plate is at a second sliding position.

13 is a sectional view taken along line 13-13 of FIG.

FIG. 14 is an explanatory diagram showing a change in a valve opening in a process in which a movable valve plate moves from a first sliding position to a second sliding position.

FIG. 15A is an explanatory view schematically showing the flow of airflow when the damper of the present invention is opened, and FIG. 15B is a conventional airflow using a butterfly valve plate when the damper is opened. Explanatory diagram schematically showing the flow of

[Explanation of symbols]

 1 duct body A air passage AJ adjustment operation device D damper Hf small hole Hm valve hole V valve device Vf Fixed valve plate Vm: movable valve plate X1: first sliding position X2: second sliding position

Continuing on the front page (72) Inventor Takeshi Nakanishi 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Masahide Sakai 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Construction Shares In-company (72) Inventor Hideo Yamamoto 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Shinji Ito 5-11-12 Nishishitsu, Sakura City, Chiba Prefecture (72) Inventor Muto Noboru 2-20-1 Takafunai, Kanazawa-ku, Yokohama-shi, Kanagawa F term (reference) 3H053 AA11 AA33 AA35 BA03 BB02 CA01 DA12 3H066 AA03 BA01 BA32 BA33 BA38 EA14 3L081 AA03 AB02 BA01 EA03 HA08 HB02 HB05

Claims (1)

[Claims] 1. A valve device (V) provided in a duct body (1) having an air passage (A) for adjusting an air flow rate in the passage (A) is fixed to the duct body (1). A fixed valve plate (Vf) that closes the passage (A), and a predetermined first sliding position (X1) that is disposed so as to overlap and contact the fixed valve plate (Vf) and is in contact with the fixed valve plate (Vf). Movable valve plate (Vm) capable of reciprocating sliding between the second sliding position (X2) and the second sliding position (X2)
The fixed valve plate (Vf) includes the fixed valve plate (V
f) a number of small holes (H
f) are formed at intervals from each other, and a plurality of valve holes (Hm) are formed in the movable valve plate (Vm) corresponding to the plurality of small holes (Hf), and the movable valve plate (Vm) is formed. ) Slides from the first sliding position (X1) to the second sliding position (X2), the amount of displacement of the position of each valve hole (Hm) with respect to each of the small holes (Hf) increases. In the flow control damper, wherein the total effective opening of the small hole (Hf) is gradually increased so as to gradually decrease, when the movable valve plate (Vm) is at the first sliding position (X1), each of the valve holes is reduced. (Hm) is located at a position substantially corresponding to each of the corresponding small holes (Hf) to maximize the total effective opening of the small holes (Hf), and the movable valve plate (Vm) is connected to the second slide. When in the moving position (X2), each of the valve holes (Hm)
Is located at a position straddling the corresponding small hole (Hf) and the small hole (Hf) adjacent to the corresponding small hole (Hf), and the total effective opening of the small hole (Hf). The shape and position of each of the large number of small holes (Hf) and the large number of valve holes (Hm) are set so as to minimize the flow rate adjustment damper.