JP3738151B2 - Axial fan protector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early detect the temperature rise by abnormality of an axial fan and surely protect it by heat-exchangeably laying a temperature detecting element along a core part having a winding wound thereon, and interrupting the current-carrying to the axial fan when the temperature of the core part detected by the temperature detecting element reaches a prescribed upper limit value. SOLUTION: When an axial fan 2 is locked by clogging of dust in the rotation of the axial fan 2 by the operation of a refrigerator or the like, a lock current is carried to the winding of a core part 4 to raise the temperature. This temperature rise is detected by a thermal fuse heat-exchangeably laid along the core part 4, and when the detected value reaches an upper limit value, the thermal fuse 9 is opened to interrupt the current-carrying to the axial fan 2. According to this, the axial fan can be surely protected. The thermal fuse 9 is arranged within a through-hole 7 located in the center of a retaining plate 6 mounted on the diagonal of a frame 3 and brought into contact with the core part 4 in such a manner as to be heat exchangeable. According to this, the thermal fuse 9 can be stably retained to ensure the detection of the temperature of the core part 4.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protection device for an axial fan used as a cooling fan or a condensing fan fan for a showcase or a refrigerator.
[0002]
[Prior art]
Conventionally, various blowers have been used in open showcases as disclosed in, for example, Japanese Patent Laid-Open No. 6-82143 (F25D17 / 06). In particular, a so-called axial fan composed of a bearer motor in which a stator winding is provided at the center of the core and a short-circuit ring (bearing coil) is provided at a position deviated from the center of the iron core is used for other induction motors. In comparison, loss due to heat generated by the coiling coil is large, and when a foreign substance is mixed in the motor of the axial fan, the axial fan is not easily rotated, stopped, or locked.
[0003]
Therefore, it is difficult to use in places with a lot of dust, places where outside air is introduced, places where it is difficult to see. Such a conventional axial fan 2 is shown in FIG. In this figure, 3 is a frame, 4 is a core portion around which an unillustrated bear winding is wound, 5 is a blade portion that is rotationally driven by the core portion, and 11 is a power cord. The core portion 4 is disposed in the center of the frame 3, and the blade portion 5 is positioned in the surrounding frame 3 and is driven to rotate by the core portion 4.
[0004]
In order to prevent inconvenience such as rotation failure due to heat generation, stoppage, or locking, the axial fan 2 has been conventionally protected as an impedance protection system (a core part 4 of the axial fan 2). A method in which abnormal heat generation of the axial fan 2 is suppressed by the turned winding resistance has been used.
[0005]
[Problems to be solved by the invention]
However, in the protection device using the impedance protection method, since the protection is based on the standard that abnormality such as ignition should not occur after 72 hours have passed since the axial fan 2 is locked, In many cases, the winding wound around the core part 4 exceeds the limit temperature, and it is incomplete as a protective device for use over a long period of six months or one year.
[0006]
Also, an axial fan that is attached to the ceiling surface of a showcase and used to form an air curtain at the opening is rarely inspected daily, and is difficult to find even if locked. For this reason, abnormalities may be noticed only when an axial fan is ignited.
[0007]
The present invention has been made to solve the problems of the related art, and it is an object of the present invention to provide a protection device that can detect and protect a temperature rise due to an abnormality of an axial fan quickly and reliably.
[0008]
[Means for Solving the Problems]
In other words, the axial fan protection device of the present invention has a core portion around which the winding is wound provided in the center portion of the frame, and the blade portion rotated by the core portion is placed in the frame outside the core portion. A temperature detecting element attached to the core portion in a heat exchange manner, a holding plate attached across an end portion of one surface of the frame and passing through a central portion of the one surface of the frame; And a temperature detection element disposed in the through hole and held by the holding plate, and in contact with the core portion in a heat exchange manner. When the temperature of the detected core part reaches a predetermined upper limit value, the energization to the axial fan is cut off.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a back view of an axial fan 2 to which the present invention is applied. In this figure, the same reference numerals as those in FIG. 2 are the same.
[0010]
The axial fan 2 according to the embodiment is provided in an open showcase or a refrigerator (not shown), 3 is a frame, the frame 3 is formed in a substantially rectangular shape, and a center winding (not shown) A core portion 4 made of a bear removing motor wound around the frame 3 is disposed and held at the tip of the crosspiece 3A... Extending from the four corners of the frame 3 toward the center (the center of the frame 3).
[0011]
Around the core portion 4, a blade portion 5 that is driven to rotate is disposed and accommodated in the frame 3. A holding plate 6 made of a vertically long rectangular steel plate is mounted on a diagonal line extending from the upper right corner to the lower left corner on the frame 3 serving as the back surface of the core portion 4. It is provided substantially along 3A. In addition, a through hole 7 (through hole) formed by cutting and raising so as to penetrate the holding plate 6 is provided in the approximate center of the holding plate 6.
[0012]
The through-hole 7 is formed to have a size capable of inserting a temperature detection element to be described later, and has a predetermined height dimension that is bent substantially perpendicularly to the holding plate 6 from the inside of the through-hole 7 on both sides in the longitudinal direction of the through-hole 7. Cut-and-raised pieces 8 and 8 having a size slightly higher than that of the temperature detecting element are formed.
[0013]
Then, in a state where the holding plate 6 is attached to the frame 3 diagonally, a through hole 7 is located substantially at the center of the holding plate 6, and the through hole 7 corresponds to the back surface of the core portion 4. A temperature fuse 9 as a temperature detecting element is inserted into the through hole 7 and fixed to the holding plate 6 with an adhesive tape 12 or the like.
[0014]
The thermal fuse 9 is inserted between the cut and raised pieces 8 and 8 and is attached to the back surface of the core portion 4 in a heat exchange manner. As a result, the temperature of the core portion 4 is detected by the thermal fuse 9.
[0015]
A lead wire 10 is connected to the thermal fuse 9, and both ends of the lead wire 10 are connected to a power supply circuit (not shown) of the axial flow fan 2. The thermal fuse 9 can cut off the power feeding circuit of the axial fan 2 when the temperature of the core 4 reaches a predetermined upper limit value (an upper limit temperature at which the axial fan 2 is not damaged or an upper limit temperature at which the axial fan 2 is not ignited). So that it is connected to the electrical circuit.
[0016]
Then, when an open showcase or a refrigerator is operated and the axial fan 2 is rotated and dust is clogged and a lock is generated, a large lock current flows through the windings of the core portion 4, and the temperature rises. .
[0017]
Then, the thermal fuse 9 attached to the core portion 4 in a heat exchange manner detects this, and when the upper limit value is reached, the thermal fuse 9 is opened to cut off the energization to the axial fan 2, The operation of the axial fan 2 is stopped.
[0018]
As described above, when the temperature fuse 9 is attached to the core portion 4 of the axial fan 2 in a heat exchange manner, and the temperature of the core portion 4 detected by the temperature fuse 9 reaches a predetermined upper limit value, the axial flow fan 2 is moved to. Therefore, even when the axial fan 2 is locked with foreign matter such as dust, the operation is stopped before the winding or smoke generation of the winding due to the temperature rise of the core 4 occurs. Will be able to.
[0019]
In particular, the holding plate 6 is attached along the diagonal line between the end portions of the back surface of the frame 3, and the central portion of the frame 3 is allowed to pass through, and the through hole 7 is formed in the holding plate 6 positioned at the central portion of the frame 3. The temperature fuse 9 is disposed in the through-hole 7 and is held by the holding plate 6 so as to contact the core portion 4 in a heat exchange manner. Therefore, the temperature fuse 9 is stably held, In addition, the temperature of the core part 4 can be reliably detected, and the operation itself of the axial fan 2 is not hindered.
[0020]
Further, since the holding plate 6 is disposed along the crosspieces 3A and 3A, an increase in ventilation resistance is suppressed to a minimum.
[0021]
Although the temperature fuse 9 is used in the embodiment, a bimetal thermo (shown by 9A) may be used as the temperature detection element. In that case, when the temperature of the core part 4 reaches the upper limit value, the circuit is opened and the power supply is cut off. When the abnormality is resolved, the circuit can be closed again and the operation can be started.
[0022]
【The invention's effect】
As described above in detail, according to the present invention, the core portion around which the winding is wound is provided in the center portion of the frame, and the blade portion rotated by the core portion is disposed in the frame outside the core portion. In the axial fan constructed as described above, a temperature detecting element is attached to the core portion in a heat exchange manner, and the axial fan is energized when the temperature of the core section detected by the temperature detecting element reaches a predetermined upper limit value. Since it cuts off, the operation | movement of an axial fan can be stopped based on the temperature rise of a core part.
[0023]
This makes it possible to accurately detect such abnormalities due to temperature rises in the core when a foreign matter enters the axial flow fan and locks it, thereby avoiding the inconvenience of smoke and ignition from the winding. It will be.
[0024]
In addition to the above, a holding plate is attached across the end of one surface of the frame, the center of the one surface of the frame is passed through, and a through hole is formed in the holding plate located at the center of the frame, thereby detecting the temperature. Is placed in the through-hole and held by the holding plate and is in heat contact with the core portion, so that the temperature detecting element can be stably held and the temperature of the core portion can be reliably detected. At the same time, the operation of the axial fan itself is not hindered.
[Brief description of the drawings]
FIG. 1 is a rear view of an axial fan equipped with a protection device of the present invention.
FIG. 2 is a rear view of a conventional axial fan.
[Explanation of symbols]
2 Axial fan 3 Frame 4 Core part 5 Blade part 6 Holding plate 7 Through hole 9 Thermal fuse

Claims (1)

  In the axial fan, in which the core portion around which the winding is wound is provided in the center portion of the frame, and the blade portion rotated by the core portion is disposed in the frame outside the core portion, the core A temperature detecting element attached to the heat exchanger, a holding plate that is attached between end portions of one surface of the frame and that passes through the center portion of the one surface of the frame, and the holding plate that is positioned at the center portion. The temperature detecting element is disposed in the through hole and held on the holding plate, and is brought into heat exchange contact with the core part and detected by the temperature detecting element. A protection device for an axial fan, wherein the energization to the axial fan is cut off when the temperature reaches a predetermined upper limit.

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