JPH0379616B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an overvoltage prevention device for a motor rotation speed control system in a fan ventilation system suitable for livestock housing such as pigs, chickens, and cows.

Conventional technology and problems Recently, a high degree of precision and performance has been required for the environment inside the livestock barn, especially temperature control, and various methods are used to maintain the inside of the livestock barn at a constant temperature and provide the necessary ventilation amount. Control means are provided. Among these control methods, frequency control (inverter control) is known and used as a control method that can efficiently control the rotational speed of a motor and has low power consumption.

Furthermore, in recent years, so-called windowless pigpens have been seen, which have a highly airtight structure using thick heat insulating materials for the ceilings, walls, etc.

By the way, the temperature inside the livestock barn fluctuates depending on the outside temperature and sensible heat and latent heat from the livestock, but it is desirable to keep the temperature as constant as possible throughout the year. Conventionally, this temperature adjustment has been done by adjusting the outside temperature or humidity. Ventilation methods using fans are often used. This ventilation method installs a ventilation fan in the air passage that communicates the inside of the livestock barn with the outside of the livestock barn, and uses the fan to ventilate the interior of the livestock barn, exhausting dirty air from inside the barn, and uniformly distributing fresh air indoors. The intake and exhaust ports are arranged so that the temperature is kept at a constant temperature throughout the year (for example, in the case of a pigpen, the temperature for piglets is approximately 22°C).
℃) (Heat sources are external temperature, sensible heat from the animal, and latent heat). Therefore, in the summer, the fan is operated approximately 24 hours a day to blow in a large amount of air to remove latent heat (latent heat is removed by the difference between the outside humidity and the internal humidity), or in the winter, when the outside temperature is lower than the room temperature, it is normal to Since the indoor fan speed is rapidly cooled, the thermostat stops the fan until the temperature reaches the appropriate temperature, and the fan speed is reduced to ensure that the dirty air inside the room is exhausted to the outside. We try to ventilate the room as slowly as possible while allowing the room to adjust to the room temperature, but even in this situation there are times when the fans temporarily stop working.
Even when the fan is stopped, the intake port and the exhaust port are communicated with each other through the indoor space, so that the fan may spin unnecessarily due to the wind pressure of outside air.

Therefore, when changing the rotation speed of the fan using the frequency control method, static electricity is generated due to the idling of the fan, and this static electricity is accumulated in the circuit inside the inverter, which prevents the inverter control from working properly. Since the voltage exceeds the normal voltage, there was a problem in that the safety device was activated due to the overvoltage, cutting off the power supply and stopping the ventilation function.

Means for Solving the Problems Therefore, the present invention provides a fan ventilation system in which a ventilation fan is provided in a wind tunnel that communicates the inside and outside of a building, and the rotation speed of the fan is changed by frequency control. The automatic opening/closing system for adjusting air volume consists of a pair of lids that can be opened and closed in a double-door pattern. The lid is installed to open and close within the air passage of the wind barrel, and the fan is designed so that when the fan rotation speed increases, the opening degree of the opening/closing lid increases, and when the fan rotation speed decreases, the opening degree of the opening/closing lid decreases. The opening degree of the opening/closing lid is automatically adjusted according to the rotation speed, and a permanent magnet is placed on the opening/closing tip of one lid, and a magnetic material is placed on the opening/closing tip of the other lid. This is an attempt to solve the above problems.

Function When the ventilation fan is started, the air movement (suction or pressure) in the wind tunnel automatically opens the lid, ventilating the room, exhausting dirty air outside, and reducing the temperature to room temperature using frequency control. Correspondingly, the rotational speed of the fan is changed, thereby adjusting the air volume, so that the room temperature is maintained at a substantially constant temperature. Furthermore, when the fan is stopped, the automatic opening/closing lid closes, and the wind tunnel is automatically closed to isolate the outside from the inside, thereby preventing the fan from idling due to wind pressure.

Embodiment The drawing shows a pigpen A as an example of a livestock barn. Figure 1 is a vertical front view of pigsty A. Insulating material 3 is placed over the entire wall surface 1 and ceiling surface 2 of pigsty A, forming a windowless pigsty A with a highly airtight closed room structure. There is. Inside the pigpen A, a large number of pig fattening stalls 4 are arranged in parallel in the longitudinal direction (in the direction of the ridge). Although not shown in the diagram, in addition to the fattening shed, there are a weaning shed, a farrowing shed, and a mating/pregnancy shed, etc., so that the health management and breeding management of the pigs can be carried out efficiently and intensively. .

5 is a ventilation fan (roof fan) placed on the top of the roof 6 of pigsty A at predetermined intervals along the ridge direction.
5a is the cover, 5b is the fan drive motor,
7 is an exhaust port, 8 is an intake port, and 8a is a shielding plate.

By the way, the drive motor 5b of the fan 5 is configured to control the motor rotation speed by frequency control in order to maintain the inside of the pigsty A at a constant temperature, and the necessary amount of ventilation is always supplied to the inside of the pigsty A. It's becoming like that.

9 is a vent opened in the ceiling surface 2;
and the fan 5 are communicated via a rectangular tube-shaped wind tunnel 10. 11 is a heat insulating material.

Reference numerals 12 and 12a denote automatic opening/closing lids for adjusting the air volume, which are comprised of a pair of lids that can be opened and closed in a double-door shape and are provided in the air passage a near the ventilation fan 5, and each of them controls the wind of the wind barrel 10 via the fulcrum shaft 13. It is pivotably mounted in the path a so that it can be opened and closed in a double door shape. The drawing shows automatic opening/closing lids 12 and 12a on the ceiling surface 2.
The one attached to the ventilation hole 9 provided in the is shown. The automatic opening/closing lids 12, 12a are made of a relatively lightweight member such as a plywood board, a synthetic resin board, or aluminum, and a heat insulating material 14 is loaded inside. A weight 15 for balance is installed inside the opening/closing proximal end of each lid 12, 12a. Further, a permanent magnet 16 having an appropriate attraction force is disposed on the opening/closing tip side of one lid 12, and a magnetic body 17 such as an iron plate is disposed on the opening/closing tip side of the other lid 12a.

Note that the configuration may be such that the spacing between the magnet 16 and the magnetic body 17 can be adjusted.

Incidentally, the fulcrum shaft 13 of the automatic opening/closing lids 12, 12a is provided at a position slightly (W dimension) offset from the center of gravity G of each lid 12, 12a in the opening direction (upward in the illustrated example). The mass balance of 12a is set to be as small as possible. Therefore,
The rotation speed of the fan motor 5b is small, so even if the wind force is small, the lids 12, 12a can be smoothly opened upward as long as the force is strong enough to overcome the attraction force of the magnet 16. Then, when the fan motor 5b is fully rotated, the lids 12, 12a are fully opened and stand approximately vertically around the fulcrum shaft 13.
When the fan 5 rotates at 50%, it is in a half-open state, and when the motor 5b is stopped and there is no wind, it is turned into a horizontally closed state, and as the number of revolutions of the fan 5 increases, the opening degree of the opening/closing lids 12, 12a changes. becomes large and the number of rotations of fan 5 decreases, opening/closing lid 1
The opening degrees of the opening/closing lids 12 and 12a are automatically adjusted in response to increases and decreases in wind pressure in the air passage a due to changes in the rotational speed of the fan 5, so that the opening degrees of the opening and closing lids 12 and 12a are smaller than the opening degrees of the lids 2 and 12a. It is composed of And lids 12, 12
When the door a is closed, the magnet 16 maintains the closed state with an appropriate adhesion force and prevents it from opening by itself due to strong winds or the like from outside.

A sloped portion b as shown in FIG. 5 is provided on the lower surface of the opening/closing tip side of the automatic opening/closing lid 12, 12a, and the lid 12, 1
It may be configured such that the wind pressure hits the inclined portion b even when the device 2a stands up.

Although not shown in the figure, there are a plurality of temperature sensors (for example, sensors that operate when sensing temperatures lower than 22°C) connected to the fan motor 5b in the pigpen A.
(one that operates between 22°C and 25°C, one that operates at a higher temperature than 25°C, etc.), and the rotational speed of the fan motor 5b is always automatically set to the optimum rotational speed by frequency control in response to the high or low temperature of the room temperature. (inverter control).

Reference numeral 18 denotes a lid receiving plate attached to the vent 9. This receiving plate 18 supports the lids 12, 12a from below when the lid is closed, and closes the gap between the lids 12, 12a and the vent 9 to ensure airtightness. We are trying to further improve this.

In the above embodiment, a so-called negative pressure type (exhaust type) ventilation method using a ventilation fan as the ventilation fan 5 was explained. ) can also be used for ventilation methods. In the case of a positive pressure system, the lids 12, 12a are opened downward (see FIG. 7). In addition, fan 5 and lid 12,
The positional relationship of 12a can also be reversed.

In the above configuration, when the ventilation fan 5 is started, the inside of the wind tunnel 10 becomes negative pressure due to the suction force of the fan 5, so the automatic opening/closing lids 12, 12a overcome the suction force of the magnet 16, and the respective fulcrum shafts 13 and opens the ventilation port 9, the dirty air inside the pigpen A is discharged from the exhaust port 7 to the top of the roof 6 through the wind tunnel 10, and the outside air is released from the intake port 8. is inhaled into the pig house A, and the house is uniformly filled with fresh air.

By the way, the temperature inside the pigsty A is detected by a temperature sensor, and the rotation speed of the fan motor 5b is controlled based on the detection result (for example, in the summer, the rotation speed of the fan motor 5b is increased and a large amount of air is stored inside the pigsty A). (In winter, the outside temperature is lower than the room temperature, so the motor rotation speed is lowered to allow the animal to adjust to the room temperature and ventilate the room as slowly as possible.) The temperature is kept at a constant temperature throughout the year (for example, 22°C for piglets). The lid 1 automatically opens and closes according to the wind force that changes due to the increase and decrease of the motor rotation speed.
Since the opening degrees of the lids 2 and 12a are automatically adjusted and the opening degrees are maintained by the wind force passing through the wind tunnel 10 as long as the motor 5b is continuously rotated, no power or special opening/closing mechanism is required to open and close the lid. I don't. Moreover, the fulcrum shaft 13 of the lids 12, 12a is
The fan motor 5
When stoppage b, the lids 12 and 12a rotate slowly in the closing direction around the fulcrum shaft 13 without abruptly closing due to the weight of the lids themselves, and in combination with the suction force of the magnet 16, the vent 9 closes. be sure to close the wind tunnel 1.
The lower end side of 0 is in a sealed state. For this reason, Juan 5
When the system is stopped, the outside and the inside are cut off, so even if strong winds occur outside, the strong winds will flow from the exhaust port 7 to the wind tunnel 1.
0, and the air inside the livestock barn A does not leak to the outside through the wind tunnel 10, so the fan 5 will not idle due to wind pressure when the fan motor 5b is stopped. is prevented. This eliminates the inconvenience of static electricity generated by idling of the fan 5 accumulating in the circuit inside the inverter, so the inverter control always works normally, and overvoltage activates the safety device, cuts off the power, and stops the ventilation function. This prevents malfunctions such as the following. Further, the opening/closing lids 12, 12a are provided inside the wind cylinder 10, and the opening/closing operation thereof is always performed within the air path a of the wind cylinder 10.
No matter what degree of opening (degree of inclination) 12a is, the opening/closing lids 12, 12a will not be exposed outside the pigpen A, so the opening/closing lids 12, 12a will not flap or open under the influence of strong winds from outside. The degree will not be changed randomly. Therefore, the opening/closing lid 12,
12a is maintained at an appropriate opening degree corresponding to the rotational speed of the fan 5.

Note that the present invention is applicable not only to livestock barns but also to fan ventilation systems for other buildings, such as constant-temperature storage rooms.

Effects of the Invention As described above, the present invention provides a fan ventilation system in which a ventilation fan is provided in a wind tunnel that communicates the inside and outside of a building, and the rotation speed of the fan is changed by frequency control. The automatic opening/closing lid for adjusting air volume, which consists of a pair of double-door-shaped lids that can be opened and closed, opens the wind tunnel by sensing air movement when the fan starts, and automatically closes the tunnel in response to the fan stopping. The rotation speed of the fan is adjusted so that it opens and closes within the air passage of the body, and when the fan rotation speed increases, the opening degree of the opening/closing lid increases, and when the fan rotation speed decreases, the opening degree of the opening/closing lid decreases. The opening degree of the opening/closing lid is automatically adjusted accordingly, and a permanent magnet is placed on the opening/closing tip side of one lid, and a magnetic material is placed on the opening/closing tip side of the other lid, which improves ventilation. Since the automatic opening/closing lid automatically opens when the fan is started, indoor ventilation and temperature adjustment can always be performed accurately. In addition, when the fan stops, the automatic opening/closing lid reliably closes the wind tunnel and blocks air flow between the outside and the room, which prevents the fan from idling due to wind force when the fan stops. This eliminates the inconvenience of static electricity accumulated in the inverter's internal circuits due to idling, allowing the inverter control to always function normally, and preventing overvoltage from activating the safety device, cutting off the power, and stopping the ventilation function. This makes it possible to prevent malfunctions such as In addition, the opening degree of the automatic opening/closing lid will not be forcibly changed by wind pressure from outside the building, and the opening/closing lid will always be maintained at the correct opening degree corresponding to the number of rotations of the fan. When closed, the closed state is maintained by the moderate adhesion force of the magnet, so the opening/closing lid is configured to open and close within the wind channel of the wind barrel, and the opening/closing lid can be easily opened and closed due to strong winds from outside. This makes it possible to reliably prevent the fan from opening accidentally, thereby further enhancing the effect of preventing malfunctions caused by static electricity generated by the fan's idling.

[Brief explanation of drawings]

The drawings show an embodiment of an overvoltage prevention device for a motor rotation speed control system in a fan ventilation system according to the present invention, and FIG. 1 is a longitudinal sectional front view of a livestock barn equipped with the present invention, and FIG. Figure 3A is an enlarged front view of the automatic opening/closing lid, Figure 3B is a perspective view of the automatic opening/closing lid, Figure 4 is a bottom view of the automatic opening/closing lid mounting part, and Figure 5 is an enlarged front view of the automatic opening/closing lid. A front view showing another example of the lid, FIG. 6 is an explanatory diagram of the function of the automatic opening/closing lid, and FIG.
The figure is a longitudinal sectional front view of the present invention installed in a livestock barn that employs an intake type ventilation method. In the figure, 5 is a ventilation fan, 5b is a fan drive motor, 7 is an exhaust port, 8 is an intake port, 9 is a ventilation port,
10 is a wind tunnel, 12 and 12a are automatic opening/closing lids, 13 is a fulcrum shaft, 15 is a weight, 16 is a permanent magnet, 17 is a magnetic body, G is a center of gravity position of the lid body, and a is an air path.

Claims (1)

[Claims] 1. In a fan ventilation system in which a ventilation fan is installed in a wind barrel that communicates the inside and outside of a building, and the rotation speed of the fan is changed by frequency control, air is generated in the wind barrel near the fan when the fan is started. The automatic opening/closing lid for adjusting the air volume consists of a pair of lids that can be opened and closed in a double-door shape, which opens the wind trunk by sensing movement, and automatically closes the wind trunk in response to the stoppage of the fan. It is designed to open and close, and as the number of rotations of the fan increases, the opening degree of the lid increases.
The opening degree of the opening/closing lid is automatically adjusted in accordance with the rotational speed of the fan so that the opening degree of the opening/closing lid becomes smaller when the rotational speed of the fan decreases, and
An overvoltage prevention device for a motor rotation speed control system in a fan ventilation system, characterized in that a permanent magnet is disposed on the opening/closing tip side of one lid, and a magnetic material is placed on the opening/closing tip side of the other lid.