JPH0612469Y2 - Ventilation fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a ventilation fan of a type in which a shutter is opened and closed by the wind pressure of the ventilation fan itself.

2. Description of the Related Art Conventionally, this type of ventilation fan generally has a structure as shown in FIG. In the figure, 101 is a ventilation fan main body, 102
Is a frame forming an outer frame of the ventilation fan main body 101,
A shutter 103 that opens and closes the opening of the frame body 102 is provided at the rear portion. The shutter 103 is rotatably provided with a plurality of support rods 104 standing on the frame 102 as fulcrums. The three shutters 103 are one shutter connecting fitting 1
Since it is movably connected to 05, it always rotates in conjunction with each other. A motor 106 rotates the blade 107, and is fixed to the frame body 102. When the motor 106 is energized, the blades 107 start to rotate, and the wind pressure generated thereby causes the shutter 103 to open with the support rod 104 as a fulcrum, but the shutter 103 only slightly opens due to the weight of the shutter 103 itself. Therefore, in addition to the opening force due to the wind pressure using a large weight of the shutter connecting fitting 105 itself, the moment in the opening direction due to the weight of the shutter connecting fitting 105 overcomes the moment in the closing direction due to the weight of the shutter 103. As shown in the figure, when the shutter 103 is opened and the dirty air in the room is ventilated and the motor is de-energized, the blades 107 stop rotating and the opening force due to the wind pressure gradually weakens.
The moment of 03 in the closing direction due to its own weight overcomes the moment in the opening direction due to the own weight of the shutter coupling member 105 to close the shutter 103. As a result, the shutter 103 can prevent the wind from blowing into the room from the ventilation fan main body 1 due to the external wind.

Problems to be Solved by the Invention In such a conventional configuration, even if a shutter 103 having a small specific gravity such as aluminum is used, the shutter 103
The shutter coupling member 105, which has a weight exceeding the moment in the closing direction due to its own weight, is very heavy and large. Considering that the shutter 103 made of steel plate is used, the shutter connecting metal fitting 105 which is more than twice as heavy as that made of aluminum is required, which is very difficult in terms of size and weight. . However, since the shutter 103 made of aluminum is much more expensive than the shutter 103 made of steel plate, it has been a factor of increasing the cost of the ventilation fan main body 101 as a whole. Further, in the conventional shutter 103 made of aluminum, when the shutter 103 and the supporting rod 104 are used for a long period of time, the weight of the shutter is increased due to the adhesion of oil dust to the shutter 103 and the supporting rod 104, and the frictional force at the supporting rod 104 is increased. Due to various factors such as installation in a place where the pressure difference between the indoor and outdoor is large, the shutter does not open or the shutter does not open to a predetermined angle, so a predetermined exhaust air volume cannot be obtained or noise increases. There was such a problem.

The present invention solves such a problem, and an inexpensive and heavy shutter made of steel plate is heavy, and it is possible to perform a reliable and smooth opening / closing operation without using a large shutter connecting fitting. The purpose is.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a shutter provided on a frame so as to be openable and closable, a shutter connecting member movably connected to the shutter, and both ends of a ring-shaped portion. And a kick spring that elastically deforms the linear parts in a direction approaching each other and supports one end of the linear part in the frame body and the other end in the shutter connecting fitting to urge the shutter in the opening direction. However, when the shutter is closed, the support point of the kick spring on the shutter connecting fitting is on a straight line connecting the virtual center of rotation of the support point when the shutter is opened and closed and the connection point of the kick spring on the frame body or below the straight line. The ventilation fan is located at.

With this configuration, when the motor is energized, the blades rotate, and the wind pressure and the force of the kick spring caused by it causes the kick spring to have a moment to overcome the closing moment even with a shutter made of steel plate. Therefore, the shutter can be opened, and when the motor is de-energized, the blades stop rotating and the opening force due to wind pressure disappears, and the moment in the closing direction due to the weight of the shutter overcomes the moment in the opening direction of the kick spring. close. Then, the force for opening the shutter needs to be larger as the opening angle of the shutter is larger. On the other hand, the component of the force acting in the vertical direction of the kick spring, that is, the force for pulling up the shutter connecting fitting to open the shutter is required. The larger the opening angle of the shutter, the larger. In order for the shutter to actually open, in addition to the force of the kick spring, the wind pressure by the blades is required. This wind pressure is a component of the force for opening the shutter and the force acting in the vertical direction of the kick spring. From the characteristics of (1), a large change is not required from the time of closing the shutter to the opening of the predetermined angle, and therefore the force for fully opening the shutter to the predetermined angle does not need to be particularly large, so that the shutter can be reliably and It will be opened smoothly.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in FIG. 1, the frame body 2 forming the outer frame of the ventilation fan main body 1 is provided with three shutters 3 that open the front part and the rear part and open and close the rear opening. Each of these shutters 3 is rotatably provided with a support bar 4 standing on the frame 2 as a fulcrum. And three shutters 3
Is movably connected to one shutter connecting member 5, the three shutters always interlock with each other to perform the same rotating operation. Further, in the frame body 2, a motor 6 having blades 7 fixed
Is fixed. Furthermore, the kick spring 8 having linear portions at both ends of the ring-shaped portion is elastically deformed in a direction in which the linear portions come close to each other, and one end thereof is connected to the shutter connecting fitting 5.
The other end is supported by the frame body 2 and biases the shutter 3 in the opening direction via the shutter connecting fitting 5. Shutter 3
When is opened and closed, as shown in FIG. 2, the connecting point between the shutter 3 and the shutter connecting fitting 5 draws an arcuate locus around the support rod 4. On the other hand, at this time, the support point of the kick spring 8 on the shutter coupling member 5 also draws an arcuate locus from the virtual center point 0 with the same radius of curvature as the arcuate locus.
The support point is located on the straight line L connecting the support point of the kick spring 8 on the frame body 2 and the virtual center point 0 when the shutter 3 is closed. Therefore, the position of the support point of the kick spring 8 on the shutter connecting member 5 is closest to the position D of the support point on the frame body 2 when the shutter 3 is closed, and is separated as the shutter 3 is opened. , The position C is the farthest when it is opened up to a predetermined angle (about 60 °). Therefore, the repulsive force Pr of the kick spring 8 is
It is the largest when the shutter 3 is closed, and becomes gradually smaller as it opens, but the component of the force acting in the vertical direction of the kick spring 8 at this time, that is, when the shutter connecting metal member 5 is pulled down to open the shutter 3. As shown in FIG. 3, the force Pv is 0 when the shutter 3 is closed, and gradually increases as the opening angle of the shutter 3 increases. When the position of the support point of the kick spring 8 on the shutter connecting fitting 5 when the shutter 3 is closed is above the straight line L, the kick spring 8 acts in the direction of pulling the shutter connecting fitting 5 upward, and This is not good for opening 3. On the other hand, the relationship between the force Po required for actually opening the shutter 3 and the force Ps for closing the shutter 3 and the opening angle of the shutter 3 is shown by the curves Po and Ps in FIG. Fourth
As is clear from the figure, the force Po for opening the shutter 3
And the force Pv of the kick spring 8 are substantially constant without abrupt change, and this difference is necessary as the minimum wind pressure due to the rotation of the blade 7. By the way, the actual wind pressure Pw by the blades 7 becomes smaller as the shutter 3 opens and becomes closer to horizontal as shown by the curve Pw in FIG. However, in the embodiment, as described above, even when the shutter 3 is fully opened up to a predetermined angle, a particularly large wind pressure is not required, and the shutter 3 can be reliably and smoothly opened by the wind pressure normally generated. it can. Further, since it is not necessary to increase the force of the kick spring 8 due to insufficient wind pressure, the curve Ps and the curve Pv in FIG. 4 do not intersect, and the shutter 8 does not remain open midway.
The shutter 8 is surely closed.

As shown in FIG. 5 in place of the kick spring 8 described above, even if a simple tension spring 8a is hooked on the shutter connecting fitting 5 in a direction in which a force acts downward, the tension spring 8a does not exert a force in the direction in which the shutter 3 is opened. To work.

The relationship between the pulling force Pv 'of the tension spring 8a and the opening angle of the shutter 3 is shown by the curve Pv' in FIG. 6, and as is clear from the figure, the force Po for opening the shutter 3 and the tension spring 8a. The difference from the pulling force Pv ′ becomes significantly large when the shutter 3 is fully opened. However, as described above in the description of the kick spring 8, the wind pressure, on the contrary, decreases near the time when the shutter 3 is fully opened. Therefore, in the case of the tension spring 8a, the shutter 3 may not be sufficiently opened. . Therefore, the tensile force Pv 'is increased (6th
It is possible to deal with the opening of the shutter 3 by the curve Pv ″ in the figure). In this case, the force Ps for closing the shutter 3 and the pulling force P of the tension spring 8a.
In some cases, v ′ may be in equilibrium with the shutter 3 being closed (indicated by a point X in FIG. 6), and the shutter may remain open and may not close.

In the configuration in which the kick spring 8 of the present embodiment is used to open and close the shutter 3, unlike the configuration in which the tension spring 8a is employed, the shutter 3 does not remain open during the closing process, and the shutter 3 is not opened. When opening, it can be opened with a substantially constant wind pressure that does not change significantly on the way, so that the opening operation can be performed smoothly and reliably.

In the embodiment, the support point of the kick spring 8 on the shutter coupling member 5 is set to the virtual center point 0 of the arcuate locus when the shutter 3 is opened and closed when the shutter 3 is closed.
Although it is assumed that the kick spring 8 is positioned on the straight line L connecting the supporting points of the frame body 2, it may be positioned below the straight line L. In short, when the shutter 3 is closed, the kick spring 8 may be positioned.
Of the shutter connecting metal fitting 5 is closer to the supporting point of the frame body 2 than in other states during the opening / closing operation of the shutter 3, that is, in the direction in which the kick spring 8 pulls the shutter connecting metal fitting 5 upward. You don't have to be in a position to do it.

Advantages of the Invention As is clear from the above embodiments, according to the present invention, an inexpensive steel plate shutter can be opened and closed with a single kick spring, resulting in a large cost reduction and the minimum shutter required to open the shutter. The wind pressure does not need to increase significantly as the shutter moves from the closing to the opening, and may be a substantially constant force, and since the kick spring does not act at least on the opening of the shutter when the shutter is closed, the shutter can be smoothly and It is possible to provide a ventilating fan that can perform stable opening and closing operations of a shutter without any hindrance such that the shutter opens reliably and does not close while being opened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the opening and closing of a shutter of a ventilation fan according to an embodiment of the present invention, and FIG.
The figure is an explanatory view of the force generated by the kick spring of the ventilation fan, 4th
The figure is an explanatory view showing the force required to open the shutter of the ventilation fan, the force to close the shutter, the force acting in the vertical direction of the kick spring, and the relationship between the wind pressure by the blades and the opening angle of the shutter. A cross-sectional view of a shutter opening view of a ventilation fan using a tension spring, Fig. 6 shows the force required to open the shutter of the ventilation fan, the force to close the shutter, and the relationship between the tension force of the tension spring and the opening angle of the shutter. FIG. 7 is a sectional view of the conventional ventilation fan when the shutter is opened. 2 ... Frame body, 3 ... Shutter, 5 ... Shutter connecting metal fitting, 8 ... Kick spring.

Claims (1)

[Scope of utility model registration request] 1. A shutter provided on a frame so as to be openable and closable,
A shutter connecting member movably connected to the shutter, and linear portions at both ends of the ring-shaped portion, the linear portions are elastically deformed in a direction toward each other, and one end of the linear portion is formed in the frame body.
A kick spring that supports the other end of the shutter connecting member to urge the shutter in the opening direction, and a support point of the kick spring on the shutter connecting member when the shutter is closed is the shutter opening / closing of this supporting point. A ventilation fan located on or below a straight line connecting the virtual center of rotation at the time and the connection point of the kick spring in the frame.