JPH08271002A - Range hood - Google Patents

Abstract

PURPOSE: To prevent contaminated air from staying around a ceiling portion of a cooking room even if a large amount of the contaminated air is generated from a range, by providing a local ventilation suction opening and a device for adjusting the section area of a communication passage for increasing and decreasing the section area of a passage allowing an exhaust fan and the suction opening to communicate with each other. CONSTITUTION: When a large amount of contaminated air is generated from a range during cooking operation and the contaminated air overflows sidewards of a range hood 1, a plurality of screws are tightened to make a distributing plate 9 approach a partition wall 6 in order that the section area of a communication passage between a local ventilation suction opening 4 and a centrifugal fan 2 is decreased. The suction amount through the local ventilation opening 4 is reduced and the suction amount through a total ventilation suction opening 5 is increased. The large amount of the contaminated air overflowing sidewards of the range hood 1 is quickly exhausted through the total ventilation suction opening 5 outdoors and the contaminated air is prevented from staying around a ceiling portion of the cooking room.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a range hood.

[0002]

2. Description of the Related Art As disclosed in, for example, Japanese Utility Model Laid-Open No. 3-46139, an exhaust fan and a casing for accommodating the exhaust fan are provided, and a local exhaust suction port is formed on a bottom wall of the casing. 2. Description of the Related Art There is known a range hood in which a suction port for whole ventilation is formed on a casing surrounding wall excluding a bottom wall. The range hood described above is arranged above a range such as a kitchen. The contaminated air generated in the range is sucked into the range hood from the local exhaust suction port, and then discharged to the outside through the exhaust fan and the exhaust duct.
Contaminated air that has not been captured by the local exhaust suction port and overflows to the side of the range hood is sucked into the range hood from the general ventilation suction port, and then discharged to the outside through the exhaust fan and exhaust duct. It In a conventional range hood including an exhaust fan and a casing accommodating the exhaust fan, a local exhaust suction port is formed on the casing bottom wall, and a general ventilation suction port is formed on the casing surrounding wall excluding the bottom wall. Is a fixed value of 100 to 10 to 20, the ratio of the suction amount through the local exhaust suction port and the suction amount through the general ventilation suction port is
It was not possible to change the values when using the range.

[0003]

During the cooking operation, a large amount of contaminated air is generated from the range, and the contaminated air that cannot be captured by the local exhaust suction port of the range hood is
A large amount may overflow to the side of the range hood. In this case, a conventional exhaust fan and a casing for accommodating the exhaust fan are provided, a local exhaust suction port is formed on the casing bottom wall, and a general ventilation suction port is formed on the casing surrounding wall excluding the bottom wall. In the range hood, the ratio of the suction amount through the local exhaust suction port to the suction amount through the general ventilation suction port is 100 to 10
Since it is a fixed value of 20, there is a problem that a large amount of contaminated air overflowing to the side of the range hood cannot be sufficiently captured by the general ventilation suction port, and contaminated air remains on the ceiling of the cooking chamber. It was The present invention has been made in view of the above problems, and includes an exhaust fan and a casing that accommodates the exhaust fan, and a casing having a local exhaust inlet formed in the casing bottom wall and excluding the bottom wall. A range hood with a suction port for general ventilation formed on the machine wall, and even if a large amount of contaminated air is generated from the range, a range hood that can prevent the occurrence of the situation where contaminated air stays on the ceiling of the cooking chamber The purpose is to provide.

[0004]

In order to solve the above problems, in the present invention, an exhaust fan and a casing for accommodating the exhaust fan are provided, and a local exhaust suction port is formed on the bottom wall of the casing. In addition, a suction port for general ventilation is formed on the casing surrounding wall excluding the bottom wall, and a communication passage cross-sectional area adjusting device for increasing or decreasing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan is further provided. Providing a characteristic range hood.

In a preferred embodiment of the present invention, the communication passage cross-sectional area adjusting device has a casing inner space having a first section including a local exhaust suction port, a second section including a general ventilation suction port and an exhaust fan. The partition device includes a partition wall that divides into compartments, the partition wall is formed with an opening, and the adjusting device further includes:
A rectifying plate that faces the partition wall and covers the opening and is disposed in the first compartment, and a distance adjusting device that adjusts a distance between the rectifying plate and the partition wall.

[0006] In a preferred aspect of the present invention, in the communication passage cross-sectional area adjusting device, the casing inner space includes a first section including a local exhaust suction port, a second section including a general ventilation suction port and an exhaust fan. The partition device includes a partition wall that divides into compartments, the partition wall is formed with an opening, and the adjusting device further includes:
A straightening vane facing the partition wall and covering the opening in the first section, and an angle adjusting device for adjusting an angle of the straightening vane with respect to the partition wall are included.

In a preferred aspect of the present invention, the communication passage cross-sectional area adjusting device includes a straightening plate disposed in a communication passage between the local exhaust suction port and the exhaust fan, and air flowing through the annular flow passage. An angle adjusting device is included for adjusting an angle formed by the straightening vane with respect to the flow.

In a preferred aspect of the present invention, the communication passage cross-sectional area adjusting device increases or decreases the area of the flow regulating plate disposed in the communication passage between the local exhaust suction port and the exhaust fan. It includes an area adjusting device.

In a preferred aspect of the present invention, the communication passage cross-sectional area adjusting device has a straightening plate disposed in the communication passage between the local exhaust suction port and the exhaust fan, and a surface including the straightening plate. And a moving device for moving the straightening vane in a direction substantially orthogonal to.

In a preferred aspect of the present invention, the range hood includes a control device for controlling the rotation speed of the exhaust fan. In a preferred aspect of the present invention, the range hood is a detection device that detects an exhaust air volume of an exhaust fan,
And a control device that controls the number of revolutions of the exhaust fan so that the exhaust air flow becomes a constant value based on the exhaust air flow detected by the detection device.

[0011]

The range hood according to the present invention is arranged above a range such as a kitchen. The contaminated air generated in the range is sucked into the range hood from the local exhaust suction port above the range, is exhausted to the outside through the exhaust fan and the exhaust duct. Not captured by the local exhaust inlet,
The contaminated air that has overflowed to the side of the range hood is sucked into the range hood from the suction port for overall ventilation, exhausted to the outside through the exhaust fan and the exhaust duct. If a large amount of contaminated air is generated from the range during cooking and the large amount of contaminated air that could not be captured by the local exhaust suction port of the range hood overflows to the side of the range hood, the communication passage The cross-sectional area adjusting device reduces the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. This reduces the amount of suction through the local exhaust suction port and increases the amount of suction through the general ventilation suction port. As a result, a large amount of contaminated air that overflows to the side of the range hood is discharged to the outside through the general ventilation suction port, and it is possible to prevent the contaminated air from staying on the ceiling of the cooking chamber.

The communication passage sectional area adjusting device divides the interior space of the casing into a first partition including a local exhaust suction port and a second partition including a general ventilation suction port and an exhaust fan. An opening is formed in the partition wall, and the adjusting device further includes a straightening plate facing the partition wall and covering the opening in the first partition, and between the straightening plate and the partition wall. When a distance adjusting device for adjusting the distance is included, the distance between the straightening vane and the partition wall is reduced by using the distance adjusting device so that a communication passage between the local exhaust suction port and the exhaust fan is formed. The cross-sectional area of can be reduced.

The communication passage sectional area adjusting device divides the interior space of the casing into a first partition including a local exhaust suction port and a second partition including a general ventilation suction port and an exhaust fan. An opening is formed in the partition wall, and the adjusting device further adjusts an angle of the straightening plate facing the partition wall and covering the opening in the first section, and an angle of the straightening plate with respect to the partition wall. When the angle adjusting device is included, the angle adjusting device is used to adjust the angle of the straightening vane with respect to the partition wall to reduce the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. be able to.

The communication passage cross-sectional area adjusting device adjusts the angle formed by the flow regulating plate with respect to the air flow flowing through the annular flow passage and the flow regulating plate disposed in the communication passage between the local exhaust suction port and the exhaust fan. In the case of including an angle adjusting device for adjusting, the angle adjusting device is used to adjust the angle formed by the straightening vane with respect to the air flow flowing through the annular flow path, so that the connection between the local exhaust suction port and the exhaust fan is adjusted. The cross-sectional area of the passage can be reduced.

In the case where the communication passage cross-sectional area adjusting device includes a rectifying plate disposed in the communication passage between the local exhaust suction port and the exhaust fan, and an area adjusting device for increasing or decreasing the area of the rectifying plate. Can increase the area of the baffle plate by using the area adjusting device, thereby reducing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan.

A communication passage cross-sectional area adjusting device is provided with a straightening vane disposed in a communication passage between a local exhaust suction port and an exhaust fan, and a straightening vane in a direction substantially orthogonal to a plane including the straightening vane. When a casing side wall is inclined or a filter is arranged between the straightening vane and the exhaust fan, the straightening vane is moved by moving the straightening vane. It is possible to reduce the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan by narrowing the gap between the casing side wall and the casing or the gap between the straightening vane and the filter.

When the range hood includes a control device for controlling the rotation speed of the exhaust fan, the range hood of the range hood can be reduced by reducing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. It is possible to prevent the reduction of the total exhaust amount by increasing the rotation speed of the exhaust fan.

The range hood controls the detection device for detecting the exhaust air volume of the exhaust fan, and the control for controlling the rotation speed of the exhaust fan so that the exhaust air volume becomes a constant value based on the exhaust air volume detected by the detection device. When equipped with a device, the rotation speed of the exhaust fan automatically increases in conjunction with the decrease in the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan, and the entire exhaust of the range hood is increased. Volume reduction is automatically prevented.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A range hood according to a first embodiment of the present invention will be described with reference to FIGS. The range hood 1 includes a double-sided suction centrifugal fan 2 having a main suction port 2a and a sub-suction port 2b, and a box-shaped casing 3 that houses the centrifugal fan 2. The bottom wall 3a of the casing 3 is formed with a local exhaust suction port 4, and the side wall 3b of the casing 3 is formed with a general ventilation suction port 5. A partition wall 6 forms an internal space of the casing 3 in a first section 7 including a suction port 4 for local exhaust and a suction port 5 for general ventilation.
And a second section 8 including the centrifugal fan 2.
The partition wall 6 is formed with an opening 6a facing the main suction port 2a of the centrifugal fan 2. In the first section 7,
A rectifying plate 9 that faces the partition wall 6 and covers the opening 6a is provided. The current plate 9 is attached to the partition wall 6 using a plurality of screws 10 so as to be close to and away from each other. The opening 6 a of the partition wall 6 is covered with the filter 11.
A filter 12 is arranged in the second section 8 so as to face the suction port 5 for general ventilation. An exhaust duct 13 connected to the centrifugal fan 2 extends outside the casing 3. The range hood 1 is arranged above a range such as a kitchen (not shown).

The operation of the range hood 1 will be described. Contaminated air generated in the kitchen or other range is sucked into the range hood 1 from the local exhaust suction port 4 above the range as shown by the double arrow, and passes through the filter 11 to remove oil mist. After that, it is discharged to the outside through the centrifugal fan 2 and the exhaust duct 13. Contaminated air that has not been captured by the local exhaust suction port 4 and has overflowed to the side of the range hood 1 is sucked into the range hood from the general ventilation suction port 5 as shown by the triple arrow, and the filter 12 is removed. After the oil mist is removed, the oil is discharged to the outside through the centrifugal fan 2 and the exhaust duct 13.

A narrow passage is formed between the flow regulating plate 9 and the partition wall 6, and the contaminated air flows into the passage at a high speed, so that the contaminated air overflows to the side of the casing 3. As a result, the rate of capturing the contaminated air by the local exhaust suction port 4 is improved. When a large amount of contaminated air is generated from the range during cooking work and a large amount of contaminated air that cannot be captured by the local exhaust suction port 4 of the range hood 1 overflows to the side of the range hood 1. , A plurality of screws 10 are tightened to bring the current plate 9 close to the partition wall 6 as shown by a dashed line in FIG. 2, and a communication path between the local exhaust suction port 4 and the centrifugal fan 2, more specifically, In particular, the cross-sectional area of the flow path formed between the flow regulating plate 9 and the partition wall 6 is reduced. As a result, the amount of suction through the local exhaust suction port 4 decreases and the amount of suction through the general ventilation suction port 5 increases. As a result, a large amount of contaminated air overflowing to the side of the range hood 1 is promptly discharged to the outside through the general ventilation suction port 5, and the occurrence of a situation in which contaminated air remains on the ceiling of the cooking chamber is prevented. To be done.

A range hood according to a second embodiment of the present invention will be described with reference to FIG. In the range hood 21, the straightening vane 29 is attached to the casing 23 so that the angle with respect to the partition wall 26 can be adjusted by a shaft member 30 fixed to one end of the straightening vane 29 and penetrating the side wall of the casing 23. Except for the above, the range hood 21 is the first
It has the same configuration as the range hood 1 according to the embodiment. In the range hood 21, the shaft member 30 is rotated in the direction of the arrow to adjust the angle of the straightening vane 29 with respect to the partition wall 26, and the other end of the straightening vane 29 is brought closer to the partition wall 26 as indicated by the alternate long and short dash line. As a result, the cross-sectional area of the communication passage between the local exhaust suction port 24 and the centrifugal fan 22, more specifically, the flow passage formed between the flow regulating plate 29 and the partition wall 26 can be reduced. Can, range hood 21
A large amount of contaminated air that has overflowed to the side can be promptly discharged to the outside through the intake port 25 for general ventilation, and the occurrence of a situation in which contaminated air remains on the ceiling of the cooking chamber can be prevented. .

A range hood according to a third embodiment of the present invention will be described with reference to FIG. In the range hood 41, the current plate 49 is arranged so as to be partially overlapped with the first portion 49a attached to the partition wall 46 with a predetermined gap therebetween, and the first portion 49a is arranged so as to be relatively movable. 1 part 49a
And a second portion 49b attached to the. Except for the above, the range hood 41 has the same configuration as the range hood 1 according to the first embodiment. Range hood 4
1, the second portion 49b of the straightening vane 49 is moved relative to the first portion 49a to increase the area of the straightening vane 49, as shown by the alternate long and short dash line, and the suction port 44 for local exhaust and the centrifugal fan are used. It is possible to reduce the cross-sectional area of the communication path between the range hood 42 and 42, more specifically, the annular flow path α formed around the rectifying plate 49, and a large amount of overflow to the side of the range hood 41 can be achieved. The contaminated air can be quickly discharged to the outside through the general ventilation suction port 45, and eventually the situation in which the contaminated air stays on the ceiling of the cooking chamber can be prevented.

A range hood according to a fourth embodiment of the present invention will be described with reference to FIG. The range hood 61 includes a double-sided suction centrifugal fan 62 having a main suction port 62a and a sub-suction port 62b, and a box-shaped casing 63 that houses the centrifugal fan 62. A local exhaust suction port 64 is formed on the bottom wall 63a of the casing 63, and a general ventilation suction port 65 is formed on the ceiling wall 63b of the casing 63.
Are formed. A current plate 69 is provided in the communication passage between the local exhaust suction port 64 and the centrifugal fan 62, facing the main suction port 62a of the centrifugal fan 62. A narrow annular flow path is formed between the current plate 69 and the side wall 63c of the casing 63. The current plate 69 is
The side wall 63 of the casing 63 is fixed to one end of the current plate 69.
By the shaft member 70 penetrating c, the air flow that flows in the communication path between the local exhaust suction port 64 and the centrifugal fan 62, more specifically, between the current plate 69 and the side wall 63c of the casing 63. It is attached to the casing 63 so that the angle with respect to the air flow flowing through the narrow annular flow path β formed can be adjusted. A filter 71 is arranged between the flow straightening plate 69 and the centrifugal fan 62, and a filter 72 is arranged so as to cover the whole ventilation suction port 65. The exhaust duct 73 connected to the centrifugal fan 62 has the casing 6
3 extends out. The range hood 1 is arranged above a range such as a kitchen (not shown).

The operation of the range hood 61 will be described. Contaminated air generated in the kitchen or other range is sucked into the range hood 61 from the local exhaust suction port 64 above the range as shown by the double arrow, passes through the filter 71, and the oil mist is removed. Then, it is discharged to the outside through the centrifugal fan 62 and the exhaust duct 73. The contaminated air that has not been captured by the local exhaust suction port 64 and has overflowed to the side of the range hood 61 flows from the general ventilation suction port 65 formed on the ceiling wall 63b of the casing 63, as indicated by the triple arrow. After being sucked into the range hood 61 and passing through the filter 72 to remove oil mist, the oil is discharged to the outside through the centrifugal fan 62 and the exhaust duct 73. A narrow annular flow passage β is formed between the flow regulating plate 69 and the side wall 63c of the casing 63, and the contaminated air flows into the annular flow passage β at a high speed, so that the contaminated air overflows to the side of the casing 63. The flow is suppressed, and the trapping rate of the contaminated air by the local exhaust suction port 64 is improved.

During cooking work, a large amount of contaminated air is generated from the range, and the local exhaust suction port 6 of the range hood 61.
When a large amount of contaminated air that could not be captured by 4 overflows to the side of the range hood 61, the shaft member 70 is rotated in the direction of the arrow so that the gap between the straightening plate 69 and the side wall 63c of the casing 63 is increased. To adjust the angle of the straightening vane 69 with respect to the air flow flowing through the narrow annular flow path β formed in, so that the other end of the straightening vane 69 approaches the inclined portion of the side wall 63c of the casing 63, as shown by the chain line. Accordingly, the communication path between the local exhaust suction port 64 and the centrifugal fan 62, more specifically, the disconnection of the narrow annular flow path β formed between the straightening plate 69 and the side wall 63c of the casing 63. The area can be reduced, and a large amount of contaminated air that has overflowed to the side of the range hood 61 is quickly discharged to the outside through the intake port 65 for general ventilation, and the contaminated air remains on the ceiling of the cooking chamber. Occurrence of a situation Can be prevented.

A range hood according to a fifth embodiment of the present invention will be described with reference to FIG. In the range hood 81, the current plate 89 includes a first portion 89a and a first portion 89a.
And a second portion 69b attached to the first portion 89a so as to be movable relative to each other. Except for the above, the range hood 81 has the same configuration as the range hood 61 according to the fourth embodiment. In the range hood 81, the second portion 89b of the straightening vane 89 is moved relative to the first portion 89a to increase the area of the straightening vane 89, as shown by the alternate long and short dash line. The cross-sectional area of the communication path between the centrifugal fan 82 and, more specifically, the annular flow path γ formed between the side wall 83c of the casing 83 and the current plate 89 can be reduced, and the range hood 81 can be reduced. A large amount of contaminated air that has overflowed to the side can be promptly discharged to the outside through the general ventilation suction port 85, and it is possible to prevent the occurrence of a situation in which contaminated air remains on the ceiling of the cooking chamber. .

A range hood according to a sixth embodiment of the present invention will be described with reference to FIG. In the range hood 101, the current plate 109 is attached to the filter 111 using a plurality of screws 110 so as to be able to approach and separate from each other. Except for the above, the range hood 101 has the same configuration as the range hood 61 according to the fourth embodiment. Range hood 101
In the above, as shown by the alternate long and short dash line, the casing side wall 103
The gap between the inclined part of c and the end of the current plate 109 is narrowed,
In addition, the gap between the flow straightening plate 109 and the filter 111 is narrowed so that the local exhaust suction port 104 and the centrifugal fan 102 are closed.
The cross-sectional area of the annular flow path δ formed between the side wall 103c of the casing 103 and the rectifying plate 109 can be reduced, and more specifically, the lateral side of the range hood 101 can be reduced. A large amount of contaminated air that has overflowed to the air can be promptly discharged to the outside through the general ventilation suction port 105, and eventually the contaminated air can be prevented from accumulating on the ceiling of the cooking chamber.

Although the range hood according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, double-sided suction centrifugal fans 2, 22, 42, 62, 8
Instead of 2, 102, a single-sided suction centrifugal fan having only a main suction port may be used, or an exhaust fan other than the centrifugal fan may be used. In the first to sixth embodiments, a rotation speed switching device that switches the rotation speed of the centrifugal fan between a normal value and a high speed value is provided, and the cross-sectional area of the communication passage between the local exhaust suction port and the centrifugal fan is set. When it is decreased, the rotation speed of the centrifugal fan may be switched to a high speed to prevent the reduction of the total displacement of the range hood.
In the first to sixth embodiments, a control device that detects the exhaust air volume of the centrifugal fan, and a control that controls the rotational speed of the centrifugal fan so that the exhaust air volume becomes a constant value based on the exhaust air volume detected by the detection device. By installing a device, the rotation speed of the centrifugal fan is automatically increased in conjunction with the reduction of the cross-sectional area of the communication passage between the local exhaust suction port and the centrifugal fan, and the overall exhaust volume of the range hood is reduced. May be prevented. In the first and sixth embodiments, instead of the screws 10 and 110, other known means may be used to move the flow straightening plates 9 and 109.

[0030]

[Effect] As can be seen from the above description, in the range hood according to the present invention, a large amount of contaminated air is generated from the range during cooking work, and contaminated air that cannot be captured by the local exhaust suction port of the range hood is generated. When a large amount of water overflows to the side of the range hood, the communication passage cross-sectional area adjusting device reduces the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. This reduces the amount of suction through the local exhaust suction port and increases the amount of suction through the general ventilation suction port. As a result, a large amount of contaminated air that overflows to the side of the range hood is discharged to the outside through the general ventilation suction port, and it is possible to prevent the contaminated air from staying on the ceiling of the cooking chamber.

The communication passage cross-sectional area adjusting device divides the interior space of the casing into a first partition including a suction port for local exhaust and a second partition including a suction port for general ventilation and an exhaust fan. An opening is formed in the partition wall, and the adjusting device further includes a straightening plate facing the partition wall and covering the opening in the first partition, and between the straightening plate and the partition wall. When a distance adjusting device for adjusting the distance is included, the distance between the straightening vane and the partition wall is reduced by using the distance adjusting device so that a communication passage between the local exhaust suction port and the exhaust fan is formed. The cross-sectional area of can be reduced.

The communication passage cross-sectional area adjusting device divides the interior space of the casing into a first partition including a suction port for local exhaust and a second partition including a suction port for general ventilation and an exhaust fan. An opening is formed in the partition wall, and the adjusting device further adjusts an angle of the straightening plate facing the partition wall and covering the opening in the first section, and an angle of the straightening plate with respect to the partition wall. When the angle adjusting device is included, the angle adjusting device is used to adjust the angle of the straightening vane with respect to the partition wall to reduce the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. be able to.

The communication passage cross-sectional area adjusting device determines the angle formed by the flow regulating plate with respect to the air flow flowing through the annular flow passage and the flow regulating plate disposed in the communication passage between the local exhaust suction port and the exhaust fan. In the case of including an angle adjusting device for adjusting, the angle adjusting device is used to adjust the angle formed by the straightening vane with respect to the air flow flowing through the annular flow path, so that the connection between the local exhaust suction port and the exhaust fan is adjusted. The cross-sectional area of the passage can be reduced.

In the case where the communication passage cross-sectional area adjusting device includes a rectifying plate arranged in the communication passage between the local exhaust suction port and the exhaust fan, and an area adjusting device for increasing or decreasing the area of the rectifying plate. Can increase the area of the baffle plate by using the area adjusting device, thereby reducing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan.

The communication passage cross-sectional area adjusting device includes a straightening plate disposed in the communication passage between the local exhaust suction port and the exhaust fan, and a straightening plate in a direction substantially orthogonal to a plane including the straightening plate. When a casing side wall is inclined or a filter is arranged between the straightening vane and the exhaust fan, the straightening vane is moved by moving the straightening vane. It is possible to reduce the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan by narrowing the gap between the casing side wall and the casing or the gap between the straightening vane and the filter.

When the range hood is provided with a control device for controlling the rotation speed of the exhaust fan, the range hood is reduced by reducing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. It is possible to prevent the reduction of the total exhaust amount by increasing the rotation speed of the exhaust fan.

The range hood controls the detection device for detecting the exhaust air volume of the exhaust fan, and the control for controlling the rotation speed of the exhaust fan so that the exhaust air volume becomes a constant value based on the exhaust air volume detected by the detection device. When equipped with a device, the reduction of the total displacement of the range hood by reducing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan is automatically adjusted to the rotation speed of the exhaust fan. Can be prevented by increasing.

[Brief description of drawings]

FIG. 1 is a perspective view of a range hood according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the range hood according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a range hood according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a range hood according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a range hood according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a range hood according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a range hood according to a sixth embodiment of the present invention.

[Explanation of symbols]

1, 21, 41, 61, 81, 101 Range hood 2, 22, 42, 62, 82, 102 Centrifugal fan 3, 23, 43, 63, 83, 103 Casing 4, 24, 44, 64, 84, 104 Local Exhaust suction port 5, 25, 45, 65, 85, 105 Ventilation suction port 9, 29, 49, 69, 89, 109 Rectifier plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhisa Niimura 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City Totou Kikai Co., Ltd. (72) Inventor Tsuyoshi Sato 2-9-9 Fuchinobe, Sagamihara City, Kanagawa Prefecture Within Fuji Industry Co., Ltd.

Claims (8)

[Claims] 1. An exhaust fan and a casing for accommodating the exhaust fan are provided, a local exhaust suction port is formed on a casing bottom wall, and a general ventilation suction port is formed on a casing surrounding wall excluding the bottom wall, A range hood further comprising a communication passage cross-sectional area adjusting device for increasing or decreasing the cross-sectional area of the communication passage between the local exhaust suction port and the exhaust fan. 2. The communication passage cross-sectional area adjusting device is a partition that divides the casing internal space into a first section including a local exhaust suction port and a second section including a general ventilation suction port and an exhaust fan. An opening is formed in the partition wall including a wall, and the adjusting device further includes a straightening plate disposed in the first compartment facing the partition wall and covering the opening, and the straightening plate and the partition wall. The range hood according to claim 1, further comprising a distance adjusting device that adjusts a distance therebetween. 3. A partition which divides a casing internal space into a first section including a local exhaust suction port and a second section including a general ventilation suction port and an exhaust fan. An opening is formed in the partition wall, the adjusting device further comprising a straightening plate facing the partition wall and covering the opening in the first compartment; and an angle of the straightening plate with respect to the partition wall. The range hood according to claim 1, further comprising an angle adjusting device for adjusting the. 4. The communication passage cross-sectional area adjusting device comprises a straightening vane arranged in a communication passage between a local exhaust suction port and an exhaust fan, and a straightening vane for an air flow flowing through the communication passage. The range hood according to claim 1, further comprising an angle adjusting device for adjusting an angle. 5. The communication passage cross-sectional area adjusting device includes a straightening vane disposed in the communication passage between the local exhaust suction port and the exhaust fan, and an area adjusting device for increasing or decreasing the area of the straightening vane. The range hood according to claim 1, wherein 6. A communication passage cross-sectional area adjusting device is provided with a straightening plate disposed in a communication passage between a local exhaust suction port and an exhaust fan, and in a direction substantially orthogonal to a plane including the straightening plate. The range hood according to claim 1, further comprising a moving device that moves the baffle plate. 7. The control device for controlling the number of revolutions of the exhaust fan is provided, as claimed in any one of claims 1 to 6.
The range hood according to item. 8. A detection device for detecting the exhaust air volume of the exhaust fan, and a control device for controlling the number of revolutions of the exhaust fan so that the exhaust air volume becomes a constant value based on the exhaust air volume detected by the detection device. The range hood according to any one of claims 1 to 6, further comprising: