JP5538303B2 - Ventilation fan - Google Patents

Description

  The present invention relates to a ventilating fan having a shutter that prevents inflow of outside air.

  A conventional shutter of a ventilation fan is provided with a long shutter support frame inside the ventilation fan frame, and supports the arm part that is bent on both sides of the shutter on the shutter support frame by a support shaft. An end is connected to a shutter connecting rod by a shaft, and the shutter is rotated about a support shaft and opened by pulling the connecting rod with a pulling string via a switch with a pulling string (hereinafter simply referred to as a switch).

  Such a ventilation fan has an overlapping portion between shutters or between a shutter and a ventilation fan frame to prevent inflow of outside air and entry of light. Therefore, when the shutter is closed, a collision sound is generated between the shutters or between the shutter and the ventilation fan frame, and it is required to reduce the collision sound. A cushioning material generally formed of rubber or the like has been attached to the upper end portion of the conventional shutter and the lower bent portion of the ventilation fan frame. Or there exists a technique which forms a protrusion part in a shutter and absorbs an impact sound (for example, refer patent document 1).

  In addition, the load applied to the switch for operating the shutter is large, and there is a problem that the switch breaks down, and there is a demand for reducing the load on the switch.

  When the mechanism of the ventilating fan as in the above-described conventional example is grasped from the viewpoint of energy, there is a correlation between the work required for the shutter operation and the potential energy of the shutter. The shutter is opened and converted into the potential energy of the shutter as much as the load is applied to the pull string and the work is applied to the shutter via the connecting rod. When the shutter is closed, the potential energy is converted into kinetic energy, and the kinetic energy is converted into a collision sound. Reducing the work required for the shutter operation is equivalent to reducing the potential energy that the shutter has when it is open, and is equivalent to reducing the collision energy when the shutter is closed.

  That is, by reducing the pulling load of the shutter and reducing the work necessary for the shutter operation, it is possible to reduce the load on the switch and at the same time reduce the shutter collision sound when the shutter is closed.

Japanese Patent No. 3853026

  Although the impact sound using a buffer material like the invention described in Patent Document 1 or a conventional general ventilation fan is alleviated, the load on the switch does not change.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the ventilation fan which reduced the load to a switch. Moreover, it aims at obtaining the ventilation fan which reduced the collision sound when a shutter closes.

  In order to solve the above-described problems and achieve the object, the present invention has a cylindrical ventilation fan frame in which the indoor side and the outdoor side are open and a blower is installed inside, a plate-shaped shielding part, A shaft support part that is pivotally supported by the ventilation fan main body so that the shielding part is suspended and closes the outdoor opening of the ventilation fan frame, and the shielding part is lifted to the outdoor side to open the outdoor opening of the ventilation fan frame. A plurality of shutters each having an operation part transmitted to the opposite side of the shielding part across the shaft support part, and the operation force is transmitted to each operation part of the plurality of shutters. And an opening / closing member that rotates each of the plurality of shutters so that the respective shielding portions rise to the outdoor side all at once, and each of the plurality of shutters is below the shaft support portion when the shielding portion is suspended. Indoor side of the vertical line passing through the shaft support so that the center of gravity is located at Wherein the shielding portion is bent such that a portion of the shielding portion enters.

  According to the present invention, the operation load of the shutter is reduced and the load on the switch is reduced, so that the failure of the switch is reduced. In addition, the shutter impact noise is reduced, and the buffer material can be reduced.

FIG. 1 is an exploded perspective view of a fan according to an embodiment of the present invention. FIG. 2 is a side sectional view of the ventilation fan according to the embodiment. FIG. 3 is a perspective view of the shutter of the ventilation fan according to the embodiment. FIG. 4 is a side view of the shutter of the ventilation fan according to the embodiment. FIG. 5 is a side view of a shutter of a general ventilation fan. FIG. 6 is a diagram illustrating the relationship between the height of the center of gravity of the shutter and the distance from the fulcrum to the center of gravity. FIG. 7 is a diagram illustrating the entire shutter mechanism.

  Hereinafter, embodiments of a ventilation fan according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is an exploded perspective view of a fan according to an embodiment of the present invention. FIG. 2 is a side sectional view of the ventilation fan according to the embodiment. FIG. 3 is a perspective view of the shutter of the ventilation fan according to the embodiment. FIG. 4 is a side view of the shutter of the ventilation fan according to the embodiment.

  A fan motor (blower) provided with a motor 10 for driving the blades 9 is provided inside a rectangular tube-shaped ventilation fan frame 1 having an indoor side and an outdoor side opened, and the indoor side opening 11 of the ventilation fan frame 1 has a An orifice 12 serving as a wind tunnel for the blades 9 is provided. Further, the outdoor opening 13 of the ventilation fan frame 1 is provided with a belt-like shutter support plate 2 as a support member in the longitudinal direction of the inner side of the ventilation fan frame 1, and a plurality of shutters 3 for preventing the inflow of outside air. Deploy. The shutter 3 is provided with arm portions 3a on both sides of the shutter 3 so that the shutter 3 can be rotated via a support shaft 4 provided on the shutter support plate 2. The arm 3a has a hole 3c for passing the support shaft 4 as a shaft support portion. It is provided. The arm portion 3a as the operation portion is further provided with a hole 3d so that a connecting rod 6 as an opening / closing member for opening and closing a plurality of shutters 3 simultaneously (simultaneously) can be attached via the shaft 5.

  The switch 7 includes a pull string 8 and a bar 15 to which the pull string 8 is connected, and drives and stops the motor 10 according to an operation on the pull string 8.

  The connecting rod 6 is formed in an L shape, and is connected to a plurality of shutter holes 3d on the vertical side and the horizontal tip is connected to the pull string 8 of the switch 7 through a bar 15. ing. By doing so, a force is applied to the hole 3d of the arm portion 3a via the bar 15 and the connecting rod 6 by pulling the pull string 8, and the shutter that normally closes the outdoor opening 13 of the ventilation fan frame 1 is applied. 3, the shutter 3 rotates around the support shaft 4 and opens.

  When the shutter 3 is viewed from the side, the upper end portion 3b and the lower end portion 3g of the shutter 3 are arranged so as to overlap so that light and outside wind do not enter, and the shutter 3 is bent so as to maintain a gap of about 3 mm. This gap is for reducing metal noise caused by the collision between the shutters when the shutter is closed. A buffer material is provided in this gap, or a contact portion of the shutter 3 is provided on the resin shutter support plate 2. The shutter 3 is received at a position where the shutters 3 do not hit each other. The flat surface portion 3e as the shielding portion is bent so as to be located on the indoor side of the support shaft 4 (hole 3c). When the shutter 3 is closed, the center of gravity 3f of the shutter 3 is bent so as to be positioned on the vertical line of the support shaft 4 (hole 3c).

  The fact that the work required for the shutter operation is reduced by arranging the center of gravity 3f of the shutter 3 on the vertical line of the rotation support as described above will be described with reference to FIG. FIG. 5 is a side view of a shutter of a general ventilation fan. FIG. 5A shows a state in which the shutter is closed, and FIG. 5B shows a state in which the shutter is rotated by θ from the closed state. The distance from the shutter fulcrum (hole 3c) to the shutter power point (hole 3d) is r1, the distance from the fulcrum to the center of gravity 3f is r2, and the angle between the fulcrum and the force point when the shutter is closed with respect to the horizontal direction. Let α be the angle formed by the fulcrum and the center of gravity 3f with respect to the vertical direction. Pulling the drawstring 8 and when the shutter 3 rotates by θ, the force to support the shutter is Fsh, the shutter mass is Wsh, the horizontal distance between the fulcrum and the force point is L1, and the horizontal distance between the fulcrum and the center of gravity 3f is L2. . At this time, considering the moment balance around the fulcrum, the following equation (1) is established.

  Fsh · L1 = Wsh · L2 (1)

  The relationship between L1, L2, and θ is expressed by the following formula (2) in the range of θ + β ≦ π.

  L2 = r2 · sin (β + θ) (2)

  If L1 and Wsh are constant from Expression (1), Fsh is proportional to L2. Although depending on the magnitude of β from equation (2), the practical range is β + θ ≦ (π / 2). If r2 is constant at this time, L2 at the same angle θ becomes smaller as β becomes smaller. Get smaller. That is, as β is smaller, in other words, as the position of the center of gravity is closer to the vertical line from the fulcrum, the force Fsh that supports the shutter is smaller.

  Also, it can be seen from Equations (1) and (2) that Fsh decreases as r2 decreases. If the center of gravity 3f of the shutter can be positioned upward (in other words, if the height of the center of gravity 3f is brought close to the hole 3c), r2 becomes small, but the area when the shutter is closed is reduced to reduce r2. I can't. That is, if the distance from the hole 3c to the lower end 3g is shortened, the original function of the shutter for blocking the air path is impaired. Although it is possible to make the height of the center of gravity 3f close to the hole 3c by attaching a weight to the arm portion 3a, extra material is required and the cost is increased. FIG. 6 is a diagram illustrating the relationship between the height of the center of gravity of the shutter and the distance from the fulcrum to the center of gravity. As is apparent from FIG. 6, when the height of the center of gravity is constant, r2 decreases as β decreases.

  Although Fsh can be reduced by increasing L1 from the equation (1), the amount of work required to open the shutter by the same angle changes as long as the right side of the equation (1) is constant. Absent. It is necessary to lengthen the operating distance of the drawstring 8 as Fsh is reduced. In this way, even if the force to support the shutter is reduced, if the amount of work applied to the shutter does not change, the impact force when the shutter closes is not reduced, so noise is not reduced.

  FIG. 7 is a diagram illustrating the entire shutter mechanism. The connecting rod 4 is connected to the ventilation fan frame 1 by a spring 14. A solid line arrow indicates a force acting on the connecting rod 6, and a broken line arrow indicates a force acting on the shutter 3. The force (operation load) by which the connecting rod 6 is pulled by the pull string 8 is F0, the spring 14 is the force pulling the connecting rod 6, Fsp, the connecting rod 6 is the force pulling the shutter 3, Fsh, and the mass of the connecting rod 6 is Wcon. Then, when the balance of the force of the connecting rod 6 is considered, the following formula (3) is established.

  F0−Fsp + Wcon−3 · Fsh = 0 (3)

  In Expression (3), the second term and the fourth term on the left side are the dominant forces that influence F0. If Wcon in the third term is large, F0 is small, but the effect is small, and if Wcon is large, the material cost increases. Fsp is a force necessary for the shutter lock mechanism that prevents the shutter 3 from being opened when an external force is applied to the shutter 3 by an external wind or the like. Although a detailed description of the shutter lock mechanism is omitted, Fsp requires a certain level of force independently of Fsh, so it is practically difficult to reduce F0 by reducing Fsp. .

  If Fsh is small, F0 is small and the force applied to the switch 7 is small. As F0 becomes smaller and the force applied to the switch 7 becomes smaller, the failure of the switch 7 is reduced. Further, when the switch 7 is mechanically operated, the power consumption is small, so that energy consumption can be suppressed.

  In the present embodiment, the flat portion of the shutter is disposed on the indoor side of the vertical line passing through the support shaft, and the center of gravity of the shutter is located vertically below the support shaft. For this reason, β in FIG. 5 becomes 0 °, and Fsh can be reduced, and thus F0 can be reduced.

  In the above description, the configuration in which the center of gravity 3f of the shutter 3 is located on the vertical line of the support shaft 4 (hole 3c) when the shutter 3 is closed (β = 0 °) is taken as an example. If a part of the shutter 3 is located on the indoor side of the support shaft 4 below the vertical axis of the support shaft 4, the angle β becomes small even if the center of gravity 3 f of the shutter 3 is not positioned vertically below the support shaft 4. The effect of reducing such force can be obtained.

  Thus, according to the present embodiment, since the load applied to the switch 7 that operates the shutter 3 is small, the occurrence of a failure of the switch 7 can be suppressed.

DESCRIPTION OF SYMBOLS 1 Ventilation fan frame 2 Shutter support plate 3 Shutter 3a Arm part 3b Upper end part 3c, 3d hole 3e Plane part 3f Center of gravity 3g Lower end part 4 Support shaft 5 Axis 6 Connecting rod 7 Switch 8 Pull string 9 Blade 10 Motor 11 Indoor side opening 12 Orifice 13 Outdoor opening 14 Spring

Claims (3)

A cylindrical ventilation fan frame in which the indoor side and the outdoor side are opened, and a blower is installed inside,
A plate-shaped shielding portion, the shaft support of the shielding portion for supporting the upper rotatably in the shield portion prior Symbol ventilating fan body so as to close the outdoor side opening of the ventilating fan frame is suspended within one end a plurality of shutters that closed the arm provided,
A downward operating force is transmitted to the other end of each arm of each of the plurality of shutters, and each of the plurality of shutters is rotated so that the shielding portions of each of the plurality of shutters rise all at once to the outdoor side. An opening and closing member to be moved;
With
In each of the plurality of shutters, the shielding portion is bent so that a part of the shielding portion below the shaft support portion enters the indoor side with respect to a vertical line passing through the shaft support portion, ventilators but characterized and Turkey to position the center of gravity below the prior SL shaft support when in a state of being suspended.   2. The ventilation fan according to claim 1, wherein each of the plurality of shutters has a center of gravity located on a vertical line passing through the shaft support portion in a state where the shielding portion is suspended. It has a drawstring switch that drives and stops the blower according to the operation on the drawstring,
The ventilation fan according to claim 1 or 2, wherein an operation force for the drawstring is transmitted to the other end portion of the arm as the operation force.

Images