JPH0645268Y2 - Overload detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an overload detection device for detecting an overload of an electric device such as a motor.

[Prior Art] Electric parts such as motors are used in various fields. For example, in a grain drying device that feeds drying air to dry grains while circulating them in the machine, the grains are circulated and circulated. In this case, it is used as a drive source or as a means for feeding dry air.

This type of electrical component requires an overload detection device that detects an overload due to an abnormal increase in the required work amount (driving force) or a drop in the power supply voltage. Therefore, in the past,
An ammeter is connected to these electric components to detect an increase in current (abnormal current value) that occurs when an overload occurs, thereby preventing problems when an overload condition occurs.

[Problems to be Solved by the Invention] However, in the conventional overload detection device, although the overload detection device is indispensable for ensuring safety, the structure of the ammeter and its wiring is complicated. However, there was a drawback in that it was time-consuming to manufacture and the cost was inevitably high. Also, due to the complicated structure, malfunction (erroneous detection)
The incidence of was also high.

In consideration of the above facts, an object of the present invention is to obtain an overload detection device which has a simple structure, is easy to install, is low in cost, and can reliably detect an overload.

[Means for Solving the Problem] In the overload detection device according to the present invention, a first temperature detection member which is made of a temperature indicating material having reversibility and which changes color depending on temperature, is directly fixed to an electric cord, A second temperature detecting member made of a temperature indicating material that is reversible and changes color according to temperature, and is interposed between the first temperature detecting member and the second temperature detecting member to connect the two and And a heat insulating member that blocks transmission.

[Operation] In the overload detection device having the above configuration, when the electric component connected to the electric cord is in an overloaded state and the current value becomes high, the electric cord generates heat and the first temperature detection is directly fixed to the electric cord. The member discolors due to the heat generated by the electric cord.
On the other hand, the second temperature detection member changes color due to a change in atmospheric temperature. In this case, since the second temperature detecting member is thermally insulated from the first temperature detecting member by the heat insulating member and heat transfer is blocked, heat generation of the electric cord affects the discoloration of the second temperature detecting member. There is no.

Here, the color of the first temperature detecting member and the color of the second temperature detecting member are compared, and the overload state can be determined by the degree of color change of the first temperature detecting member.

In this case, since the structure is extremely simple, the mounting is easy and no malfunction (erroneous detection) occurs.

[Embodiment] FIG. 1 shows a front view of an overload detection device 10 according to an embodiment of the present invention, and FIG. 2 shows a sectional view thereof.

The overload detection device 10 includes a detection unit 12 that is a first temperature detection member, a detection unit 14 that is a second temperature detection member, and an insulation unit 16 that is a heat insulation member.

The detection unit 12 is formed in a thin rectangular sheet shape with a temperature indicating material that has reversibility and changes color according to temperature,
One end in the longitudinal direction is fixed around the outer circumference of the electric cord 18 in a wound state.

On the other hand, the detection unit 14 has the same reversibility as the detection unit 12 and is formed into a thin rectangular sheet shape with a temperature indicating material that changes color according to temperature, and one end in the longitudinal direction is detected via the insulating unit 16. It is connected to the other end of the portion 12.

The insulating portion 16 is made of a material having an extremely low thermal conductivity, and heat is not transferred between the detecting portion 12 and the detecting portion 14. Therefore, even if the detection unit 12 discolors due to the heat generation of the electric cord 18, this heat generation is not transmitted to the detection unit 14 and the discoloration does not occur.

As shown in FIG. 3, the electric cord 18 is a motor of the mechanical device 20.
Further, the overload detection device 10 is connected to the control panel 24 of the mechanical device 20.

Next, the operation of this embodiment will be described.

When the motor 22 of the mechanical device 20 to which the electric cord 18 is connected becomes overloaded and the current value becomes high, the electric cord 18 generates heat, and the detection unit 12 of the overload detection device 10 directly fixed to the electric cord 18 is The heat generated by the electric cord 18 causes the color to change. On the other hand, the detection unit 14 changes color only when the atmospheric temperature changes.
That is, in this case, the detecting unit 14 is separated by the insulating unit 16.
12 electrical insulation because it is thermally insulated from heat transfer
The heat generation of 18 does not affect the discoloration of the detection unit 14.

Here, the color of the detection unit 12 and the color of the detection unit 14 are compared, and the overload state can be determined based on the degree of color change of the detection unit 12.

In this case, since the structure is extremely simple, the mounting is easy and the cost is low, and the overload can be reliably detected without malfunction (erroneous detection).

Further, since the detection unit 12 can be fixed by being wound around the outer circumference of the electric cord 18, the mounting position thereof can be easily changed arbitrarily.

Note that, in the present embodiment, the detection unit 12 and the detection unit 14 are configured such that the entirety thereof is formed in the shape of a thin sheet of a temperature indicating material that has reversibility and changes color according to temperature, but is not limited to this. Alternatively, the temperature indicating material may be coated on the outer circumference of another material having heat insulating properties.

In addition, using temperature-indicating paint (temperature-indicating ink) as the temperature-indicating material,
It may be configured to be applied to the surface of another material.

Further, in this embodiment, the insulating portion 16 is plate-shaped (linear).
However, the present invention is not limited to this, and the detection section 12 or the detection section 14 may have a curved shape or a bent shape other than a rectangular shape. In this case, the visibility is improved and the warning effect is further enhanced.

[Effect of the Invention] As described above, in the overload detection device according to the present invention,
A first temperature detecting member made of a temperature indicating material having reversibility and changing color according to temperature and fixed directly to an electric cord, and a second temperature detecting member having a temperature indicating material having reversibility and changing color according to temperature. Since the temperature detecting member and the heat insulating member that intervenes between the first temperature detecting member and the second temperature detecting member to connect them and prevent heat transfer are provided, a simple structure is provided. This has the effects of facilitating mounting, reducing costs, and being able to reliably detect overload.

[Brief description of drawings]

FIG. 1 is a front view of an overload detection device according to an embodiment of the present invention, FIG. 2 is a sectional view of the overload detection device, and FIG. 3 is a schematic configuration diagram showing a mounting position of the overload detection device. 10 …… Overload detector, 12 …… Detector, 14 …… Detector, 16 …… Insulator, 18 …… Electrical cord.

Claims (1)

[Scope of utility model registration request] 1. A first temperature detecting member which is made of a temperature indicating material which is reversible and changes color according to temperature, and a first temperature detecting member which is directly fixed to an electric cord, and a temperature indicating material which is reversible and changes color according to temperature. And a heat insulation member that intervenes between the first temperature detection member and the second temperature detection member to connect them and block heat transfer. Detection device.