CN211980542U - Overload protector - Google Patents

Abstract

The application discloses overload protector relates to current overload protection technical field for solve current overload protector's the problem that the reliability is low. The application provides an overload protector includes: the first pin is connected with the bimetallic strip, and a movable contact is fixed at one end of the bimetallic strip, which is far away from the first pin; the relative both sides of movable contact are provided with first stationary contact and second stationary contact, first stationary contact is connected with the second pin, second stationary contact connecting resistance, the one end and the third pin that the second stationary contact was kept away from to resistance are connected, first pin and third pin all are used for being connected with the power, the one end that first stationary contact was kept away from to the second pin is used for being connected with the input of load, the one end that resistance was kept away from to the third pin is used for being connected with the output of load, when overload or when overflowing appear in the load, the movable contact separates with first stationary contact, contact with the second stationary contact. The application provides an overload protection ware can avoid the load to transship or by burning when overflowing.

Description

Overload protector

Technical Field

The application relates to the technical field of current overload protection, in particular to an overload protector.

Background

Along with the rapid development of informatization, the dependence of people on electronic equipment and electronic products is larger and larger, the electronic equipment and the electronic products can not be powered off, the safety problem of using the electric appliance is more and more prominent, in order to ensure the electricity utilization safety, people set an overload protector in the electric appliance, and the power supply is automatically disconnected through the overload protector when the circuit is over-current, so that dangerous accidents are avoided.

The existing overload protector 011 is designed with a bimetallic strip 01 inside, one end of the bimetallic strip 01 is connected with an L-line (live line), the other end is provided with a movable contact 02, the overload protector 011 is also provided with a stationary contact 03 inside, a resistor 04 is connected in parallel at two ends of the movable contact 02 and the stationary contact 03, and a load 05 is connected between the stationary contact 03 and an N-line (zero line), as shown in fig. 1. When the circuit normally operates, the movable contact 02 is in contact with the fixed contact 03 to form a closed loop, the current supplies power to the load 05 through the bimetallic strip 01, and the electrical equipment normally operates. When overload or overcurrent occurs in the circuit, the current in the circuit is increased, the current generates heat when passing through the bimetallic strip 01, so that the bimetallic strip 01 is heated and deformed, the movable contact 02 is separated from the fixed contact 03, the input voltage is applied to the resistor 04 and the load 05, and the load 05 is approximately broken because the resistance value of the resistor 04 is very large, so that the safety of electrical equipment in the load 05 is protected.

However, the overload protector 011 has the following problems in the using process: when the bimetal 01 is turned off, the resistance of the resistor 04 is very large, and the current flowing through the resistor 04 can be reduced to a low level, but a weak current flows through the load 05, so that the safety of the circuit is not high.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an overload protector for solve current overload protector's the problem that the reliability is low.

The embodiment of the application adopts the following technical scheme:

an embodiment of the present application provides an overload protector including: the device comprises a first pin, a second pin and a third pin, wherein one end of the first pin is connected with a bimetallic strip, and one end of the bimetallic strip, which is far away from the first pin, is fixedly provided with a movable contact; a first fixed contact and a second fixed contact are arranged on two opposite sides of the movable contact, the first fixed contact is connected with the second pin, one end of the second fixed contact is connected with a resistor, one end of the resistor, far away from the second fixed contact, is connected with the third pin, the first pin and the third pin are both used for being connected with a power supply, one end of the second pin, far away from the first fixed contact, is used for being connected with an input end of a load, one end of the third pin, far away from the resistor, is used for being connected with an output end of the load, and when the load works normally, the movable contact is in contact with the first fixed contact; when the load is overloaded or overcurrent, the movable contact is separated from the first fixed contact and is in contact with the second fixed contact.

Because the thermal expansion coefficients of all component layers in the bimetallic strip are different, when the temperature changes, the deformation of the active layer in the bimetallic strip is larger than that of the passive layer in the bimetallic strip, and therefore the whole bimetallic strip can bend towards one side of the passive layer. Wherein, the active layer with higher expansion coefficient is called as the active layer; the lower expansion coefficient is called the passive layer. According to the embodiment of the application, through the characteristics of the bimetallic strip, one end of the bimetallic strip is connected with a power supply through the first pin, one end, far away from the first pin, of the bimetallic strip is fixed with one end of the movable contact, the movable contact can be connected with a load through the first fixed contact to conduct a load circuit, the movable contact is separated from the first fixed contact and is in contact with the second fixed contact, the movable contact can be connected with the resistor through the second fixed contact to break the load circuit, therefore, when the load works normally, the movable contact of the bimetallic strip is connected with the first fixed contact, at the moment, the load is in a conducting state, and the load circuit works normally; when the load is overloaded or overcurrent, the current flowing in the circuit in which the load is positioned will be increased, the bimetallic strip can be heated and deformed to bend towards one side, at the moment, the movable contact of the bimetallic strip is separated from the first fixed contact and is connected with the second fixed contact, the load is in an open circuit state, the input voltage provided by the power supply is completely loaded to two ends of the resistor until the power supply is disconnected, when the circuit is cooled to normal temperature, the bimetallic strip can recover the original position, namely, the movable contact is in contact with the first fixed contact, and the load works again.

In some embodiments of the present application, the resistor is a PTC thermistor.

In some embodiments of the present application, further comprising: the bimetallic strip, the movable contact, the first fixed contact, the resistor and the second fixed contact are all arranged in the protective shell, so that dust can be prevented from falling on the surfaces of the bimetallic strip, the movable contact, the first fixed contact, the resistor and the second fixed contact, and the contact sensitivity among the components is reduced.

In some embodiments of the present application, an end of the bimetal strip, an end of the first stationary contact, and an end of the resistor, which are away from the first pin, are all extended to the outside of the protective housing, so that an overload protector can be conveniently connected to the load circuit where the load and the power supply are located.

In some embodiments of the present application, further comprising: the mounting bracket, the mounting bracket sets up the inside of protective housing, the bimetallic strip with resistance all is fixed to be set up on the mounting bracket to realize the fixed and installation of bimetallic strip and resistance.

In some embodiments of the present application, the resistor is disposed adjacent to the bimetal to continuously supply heat to the bimetal such that the movable contact of the bimetal is maintained in contact with the second stationary contact and separated from the first stationary contact.

In some embodiments of the present application, the mounting bracket is made of an insulating material.

In some embodiments of the present application, the first pin, the second pin, and the third pin are any one or any several of a metal plate, a metal sheet, or a wire, so as to ensure that the connection between the overload protector and the power supply and the overload is simple and convenient, and easy to implement.

In some embodiments of the present application, further comprising: the connecting part is fixedly arranged on the outer side wall of the protective shell, and the overload protector can be installed at the corresponding position of the electrical equipment through the connecting part.

In some embodiments of the application, connecting portion are the buckle, the buckle be used for with the trip joint of corresponding position department on the electrical equipment that the load belongs to is convenient for the dismantlement and the installation between overload protection ware and the electrical equipment.

Drawings

Fig. 1 is a schematic structural diagram of an overload protector in the prior art;

fig. 2 is a schematic structural diagram of an overload protector in an embodiment of the present application.

Reference numerals:

100-overload protector; 1-a first pin; 2-a second pin; 3-a third pin; 4-bimetallic strip; 5-moving contact; 6-a first stationary contact; 7-a second stationary contact; 8-resistance; 9-a power supply; 10-load.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Referring to fig. 2, an embodiment of the present application provides an overload protector 100 including: the pin comprises a first pin 1, a second pin 2 and a third pin 3, wherein one end of the first pin 1 is connected with a bimetallic strip 4, and one end of the bimetallic strip 4, which is far away from the first pin 1, is fixedly provided with a movable contact 5; a first fixed contact 6 and a second fixed contact 7 are arranged on two opposite sides of the movable contact 5, the first fixed contact 6 is connected with the second pin 2, one end of the second fixed contact 7 is connected with a resistor 8, one end of the resistor 8, far away from the second fixed contact 7, is connected with the third pin 3, the first pin 1 and the third pin 3 are both used for being connected with a power supply 9, one end of the second pin 2, far away from the first fixed contact 6, is used for being connected with an input end of a load 10, one end of the third pin 3, far away from the resistor 8, is used for being connected with an output end of the load 10, and when the load 10 works normally, the movable contact 5 is in contact with the first fixed contact 6; when the load 10 is overloaded or overcurrent, the movable contact 5 is separated from the first stationary contact 6 and contacts the second stationary contact 7.

Because the thermal expansion coefficients of the component layers in the bimetallic strip 4 are different, when the temperature changes, the deformation of the active layer in the bimetallic strip 4 is larger than that of the passive layer in the bimetallic strip 4, so that the whole bimetallic strip 4 can bend towards one side of the passive layer. Wherein, the active layer with higher expansion coefficient is called as the active layer; the lower expansion coefficient is called the passive layer. In the embodiment of the application, through the above characteristics of the bimetal strip 4, one end of the bimetal strip 4 is connected with the power supply 9 through the first pin 1, one end of the bimetal strip 4, which is far away from the first pin 1, is fixed with one end of the movable contact 5, the movable contact 5 can be connected with the load 10 through the first fixed contact 6, a load circuit is conducted, the movable contact 5 is separated from the first fixed contact 6, is contacted with the second fixed contact 7, and can be connected with the resistor 8 through the second fixed contact 7, and the load circuit is disconnected, so that when the load 10 normally works, the movable contact 5 of the bimetal strip 4 is connected with the first fixed contact 6, at this time, the load 10 is in a conducting state, and the load circuit normally works; when the load 10 is overloaded or overcurrent, the current flowing through the circuit in which the load 10 is located will increase, the bimetal 4 will be heated and deformed to bend to one side, at this time, the movable contact 5 of the bimetal 4 is separated from the first fixed contact 6 and connected with the second fixed contact 7, the load 10 is in an open circuit state, the input voltage provided by the power supply 9 is completely loaded to two ends of the resistor 8 until the power supply 9 is disconnected, when the circuit is cooled to normal temperature, the bimetal 4 will recover to the original position, that is, the movable contact 5 is contacted with the first fixed contact 6, and the load 10 resumes working, in the above technical scheme, the load 10 is completely disconnected from the load circuit when the circuit is abnormal (overloaded or overcurrent), no weak current flows through the load 10, no safety hazard exists, and the reliability of the overload protector 100 is further improved.

It should be noted that: the power supply 9 comprises a first power line and a second power line, one end, far away from the bimetallic strip 4, of the first pin 1 is connected with the first power line in the power supply 9, one end, far away from the resistor 8, of the third pin 3 and one end, far away from the resistor 8, of the output end of the load 10 are connected with the second power line in the power supply 9 through the third pin 3, wherein one of the first power line and the second power line is a live wire, and the other is a zero line. For convenience of description, the first power line in fig. 2 is a live line (i.e., L in fig. 2), the second power line is a neutral line (i.e., N in fig. 2), that is, one end of the first pin 1 away from the bimetal 4 is connected to the live line, one end of the third pin 3 away from the resistor 8, and an output end of the load 10 are both connected to the neutral line.

In addition, in the technical scheme in the prior art, a weak current passing through the resistor can also flow through the load, that is, the state of the resistor is affected by the load, at this time, if the load is not constant, the current passing through the resistor is not constant, the heat generated by the resistor is not constant, if the heat generated by the resistor is less, the bimetal can possibly recover to the original position, and the input voltage can be reconnected to the two ends of the load, thereby causing danger.

The current through resistance 8 in this application can not flow through load 10, and resistance 8's state can not receive the influence of load 10 promptly, and the current that so passes through resistance 8 is invariable, and the heat that its produced is also invariable to bimetallic strip 4 can not resume the normal position, and the input voltage can not be switched in again at load 10's both ends, and then can not cause danger.

Because resistance heat generation is inconstant among the prior art, consequently bimetallic strip among the prior art can frequent appearance open or close when transshipping or overflowing, causes bimetallic strip fatigue easily, and at the in-process that bimetallic strip repeated switch, the resistance generates heat greatly moreover, leads to overload protector's temperature very high, and then has reduced overload protector's life, in order to solve above-mentioned problem, in some embodiments of this application, resistance 8 is PTC thermistor.

The PTC (positive Temperature coefficient) thermistor, i.e. the PTC thermistor, has a resistance value which increases stepwise with the increase of the Temperature of the PTC thermistor body, i.e. the higher the Temperature is, the larger the resistance value of the PTC thermistor is, therefore, when the movable contact 5 is connected to the second stationary contact 7, the Temperature of the PTC thermistor increases, the resistance value of the PTC thermistor increases, the standby power consumption becomes smaller, the Temperature rise of the entire overload protector 100 becomes small, and the service life of the overload protector 100 is prolonged.

Meanwhile, the PTC thermistor has wide working temperature range, the normal temperature device is suitable for minus 55 ℃ to 315 ℃, the high temperature device is suitable for being used at the temperature higher than 315 ℃ (the highest temperature can reach 2000 ℃ at present), and the low temperature device is suitable for being used at the temperature of minus 273 ℃ to minus 55 ℃, so that the PTC thermistor is easy to match. The PTC thermistor has a small volume, which is advantageous for reducing the volume of the overload protector 100. Meanwhile, the resistance value of the PTC thermistor has a wide selection range and can be selected randomly from 0.1-100 k omega.

In some embodiments of the present application, further comprising: the protective housing, bimetallic strip 4, movable contact 5, first stationary contact 6, resistance 8 and second stationary contact 7 all set up in the protective housing, can avoid the dust in the air to fall on the surface of above-mentioned part through the above-mentioned setting to reduce the contact sensitivity between each part, can also guarantee under the higher condition of outdoor air humidity, well contact between the above-mentioned each part, overload protector 100 can normal use, still be favorable to realizing that overload protector 100 develops to the modularization.

In some embodiments of the present application, an end of the first pin 1 away from the bimetal strip 4, an end of the second pin 2 away from the first stationary contact 6, and an end of the third pin 3 away from the resistor 8 all extend to the outside of the protection casing, so that the connection between the overload protector 100 and the external power source 9 and the load 10 is convenient.

Of course, the bimetal 4 may also include a fixed end and a movable end connected to each other, at least a portion of the fixed end extends to the outside of the protective shell, a movable contact 5 is fixed to one end of the movable end far from the fixed end, and the fixed end is used as the first pin 1 to realize the connection between the bimetal 4 and the power source 9.

In some embodiments of the present application, further comprising: the installing support, the installing support setting is in the inside of protective housing, and bimetallic strip 4 and resistance 8 are all fixed to be set up on the installing support to realize that bimetallic strip 4 and resistance 8 are fixed and the installation in the protective housing.

Wherein, for dismantling to be connected between resistance 8 and bimetallic strip 4 and the installing support, after using one end time, loss will take place for resistance 8 and bimetallic strip 4, is convenient for to the change and the maintenance of resistance 8 and bimetallic strip 4.

The protective shell comprises a shell with an opening on one side and a baffle arranged at the opening, wherein the baffle is used for opening or closing the opening, so that when the resistor 8 and the bimetallic strip 4 need to be replaced and maintained, the opening is only required to be opened through the baffle.

Based on the embodiment, the shell and the baffle can be connected in a clamping connection mode, a threaded connection mode or a hinged connection mode and the like.

Exemplarily, the inner side wall of the shell of the protective shell is provided with a hook at the edge close to the opening, and the baffle is provided with a buckle at the corresponding position close to the surface of the bottom shell.

In some embodiments of the present application, the resistor 8 is disposed close to the bimetal 4, so that when the load 10 is overloaded or overcurrent, the bimetal 4 can be continuously heated by the heat generated by the current passing through the resistor 8, if the power supply 9 is not turned on, the bimetal 4 will always maintain a deformed state, and the movable contact 5 and the second stationary contact 7 always maintain a connected state, so that the overload protector 100 has a "self-locking" function, and the reliability of the overload protector 100 is further improved.

In the embodiment where the resistor 8 is disposed close to the bimetal 4, and the resistor 8 is a PTC thermistor, the PTC thermistor has high sensitivity and can detect a temperature change of 10 ℃ to 6 ℃, and when an external temperature rises abnormally, the PTC thermistor is also heated to heat the bimetal 4, so as to disconnect input voltages applied to two ends of the load 10, thereby further improving the reliability of the overload protector 100.

In some embodiments of the present application, the mounting bracket is made of an insulating material, so that the current at the connection point with the bimetal 4 and the connection point between the two electrodes of the resistor 8 and the mounting bracket can be prevented from being conducted through the mounting bracket, thereby improving the safety of the overload protector 100.

In some embodiments of the present application, the overload protector 100 further includes: insulators are arranged between the bimetallic strip 4 and the mounting bracket and between the resistor 8 and the mounting bracket, so that the safety of the overload protector 100 is improved.

In addition, the mounting bracket and the protective shell can adopt an integrated molding technology, so that the number of parts in the overload protector 100 can be reduced, and the mounting steps of the overload protector 100 can be reduced.

Of course, the mounting bracket and the protective shell can be detachably connected, so that the mounting bracket can be mounted in the protective shell after the components such as the resistor 8 are mounted on the mounting bracket, and the components such as the resistor 8 can be mounted simply.

In some embodiments of the present application, the mounting bracket is made of an insulating ceramic material, so that the resistor 8 can supply heat to the bimetal 4 through the mounting bracket on the basis of ensuring that the components mounted on the mounting bracket are insulated.

In some embodiments of the present application, the first pin 1, the second pin 2, and the third pin 3 are any one or more of a metal plate, a metal sheet, and a wire, and since the material of the metal plate, the metal sheet, and the wire is convenient, the above connection manner is simple and convenient, and is easy to implement.

If the first pin 1, the second pin 2 and the third pin 3 are metal plates or metal sheets, the connection reliability between the overload protector 100 and the power supply 9 and the load 10 can be ensured.

Meanwhile, the ends of the first pin 1, the second pin 2 and the third pin 3, which are located outside the protective shell, are all provided with labels, for example, the end of the first pin 1, which is located outside the protective shell, is provided with a "pin 1" or a "1"; one end of the second pin 2, which is positioned outside the protective shell, is provided with a pin 2 or a pin 2; the end of the third pin 3 outside the protective shell is provided with a "pin 3" or "3", so that the connection between the overload protector 100 and the power supply 9 and the load 10 is more convenient.

Or the ends of the first pin 1, the second pin 2 and the third pin 3, which are positioned outside the protective shell, are distinguished by different colors.

Similarly, if the first pin 1, the second pin 2, and the third pin 3 are wires, the requirement on the position relationship between the overload protector 100 and the electrical equipment is low, that is, the overload protector 100 can be installed at any position on the electrical equipment.

The first pin 1, the second pin 2 and the third pin 3 select wires of different colors so as to distinguish the first connection part, the second connection part and the third connection part.

In some embodiments of the present application, the overload protector 100 further includes: and the outer side wall of the protective shell is fixedly provided with a connecting part so as to realize the connection between the overload protector 100 and corresponding electrical equipment.

In some embodiments of this application, be equipped with the screw hole on the above-mentioned installation department, be provided with the screw hole that corresponds with it on the electrical equipment, when concrete installation, pass above-mentioned screw hole with the nut in proper order for fixed connection is firm reliable between installation department and the electrical equipment.

In some embodiments of the present application, the connection portion is a buckle, and the buckle is used for being clamped with a hook at a corresponding position on an electrical apparatus where the load 10 is located, so that the installation and the detachment between the installation portion and the electrical apparatus are simple and convenient.

In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An overload protector, comprising: the device comprises a first pin, a second pin and a third pin, wherein one end of the first pin is connected with a bimetallic strip, and one end of the bimetallic strip, which is far away from the first pin, is fixedly provided with a movable contact; a first fixed contact and a second fixed contact are arranged on two opposite sides of the movable contact, the first fixed contact is connected with the second pin, one end of the second fixed contact is connected with a resistor, one end of the resistor, far away from the second fixed contact, is connected with the third pin, the first pin and the third pin are both used for being connected with a power supply, one end of the second pin, far away from the first fixed contact, is used for being connected with an input end of a load, one end of the third pin, far away from the resistor, is used for being connected with an output end of the load, and when the load works normally, the movable contact is in contact with the first fixed contact; when the load is overloaded or overcurrent, the movable contact is separated from the first fixed contact and is in contact with the second fixed contact.

2. The overload protector of claim 1, wherein the resistor is a PTC thermistor.

3. The overload protector according to claim 1 or 2, further comprising:

the bimetallic strip, the movable contact, the first fixed contact, the second fixed contact and the resistor are all arranged in the protective shell.

4. The overload protector of claim 3, wherein an end of the first leg distal from the bimetal strip, an end of the second leg distal from the first stationary contact, and an end of the third leg distal from the resistor extend to an exterior of the protective case.

5. The overload protector of claim 4, further comprising:

the mounting bracket is arranged in the protective shell, and the bimetallic strip and the resistor are fixedly arranged on the mounting bracket.

6. The overload protector of claim 5, wherein the resistor is disposed proximate the bimetal.

7. An overload protector according to claim 5 or claim 6, wherein the mounting bracket is formed from an insulating material.

8. The overload protector of claim 3, wherein the first pin, the second pin, and the third pin are metal sheets or wires.

9. The overload protector of claim 3, further comprising:

the connecting part is fixedly arranged on the outer side wall of the protective shell.

10. The overload protector according to claim 9, wherein the connecting portion is a clip, and the clip is used for being clipped with a hook at a corresponding position on the electrical equipment where the load is located.

Images