CN2487102Y - Heating unit for heat overload relay - Google Patents

Abstract

The utility model relates to a heating component used in thermal overload relay, and when an overload current passes an electric load part, the circuit is broken because of the heat generated by the heating device and the bending of a bimetallic strip. Wherein, the heating element of the bimetallic strip which is made of materials which can generate resistance heat when the electric current flows comprises a plate- shaped heating plate with preset area and thickness which is arranged on the bimetallic trip, therefore, the heating component can be assembled without the ordered equipments of winding coils, and the relay operation precision of the thermal overload can be improved.

Description

The heating component that is used for thermal overload relay

The present invention relates to a kind of thermal overload relay, relate in particular to a kind of heating component that is used for thermal overload relay, wherein when producing overcurrent in electrical load, the heating by heater makes the bimetal leaf bending, and circuit disconnects then.

Usually, thermal overload relay is a kind of by cutting off the equipment of current protection electrical load apparatus, and just when when there is overcurrent at electrical load such as motor upper reaches, bimetal leaf is because the heat that heater produced and bending, thus the connection of cut-out circuit.

Fig. 1 is a vertical cross section, the thermal overload relay of the heating component that contains routine techniques is shown, and Fig. 2 is a perspective view, and the heating component of routine techniques is shown.

In the thermal overload relay of routine, comprise that the heater 10 of heater coil 12 and main bimetal leaf 13 is installed in the lower house 1.

Upper shell 5 is assembled in the top of lower house 1.In addition, switching mechanism 20 and contactor 30 are installed in the upper shell 5, thereby can be according to the ruuning situation cut-off/close circuit of heater 10.

Wherein, main bimetal leaf 13 is longer in vertical direction, thereby vertically places in the lower house 1.

In addition, shift unit 14 is connected the upper end 13a of main bimetal leaf 13, and the projecting part 14a of this shift unit 14 promotes temperature-compensating bimetal leaf 21 according to the degree of crook of main bimetal leaf 13, after this switching mechanism 20 and contactor 30 operations.

As shown in Figure 2, the heater coil 12 that wire is made is around main bimetal leaf 13 peripheries, and connector 15 and terminal block 16 be weldingly fixed on the two ends of heater coil 12 respectively, thereby realizes being electrically connected.

Therefore, if there is overcurrent at heater coil 12 upper reaches on main bimetal leaf 13, the heat that is produced owing to heater coil 12 makes the upper end 13a bending of main bimetal leaf 13 so, and shift unit 14 moves towards the right of Fig. 1 subsequently.

In addition, along with moving of shift unit 14, the projecting part 14a of shift unit 14 promotes the bottom of temperature-compensating bimetal leaf 21 to the right, switching mechanism 20 work then, and contactor 30 separates, thus open circuit.

Yet the heating component of routine techniques is to constitute like this, promptly heater coil 12 directly on main bimetal leaf 13, so need the equipment for customizing of winding around so that on main bimetal leaf 13, twine heater coil 12.In addition, even adopt special equipment to twine heater coil on main bimetal leaf, winding around needs the long time so, so operating efficiency and mass productivity reduction.

And in the heating component of routine techniques, resistance value (calorific capacity) is by the decision of the length of heater coil 12.Therefore, if the length of heater coil 12 is longer, heater coil must twine many times on the main bimetal leaf 13 of limited length so, therefore may produce electric short circuit owing to the tight spacing of heater coil 12.

Therefore, an object of the present invention is to provide a kind of heating component that is used for thermal overload relay, this heating component is easy to assembling by board-like heating plate is fixedly mounted on the main bimetal leaf, and does not use the equipment for customizing of winding around.

Another object of the present invention provides a kind of heating component that is used for thermal overload relay, be installed on the main bimetal leaf by the heating plate that will have predetermined thickness and capacity, can obtain accurate resistance value, and, main bimetal leaf is accurately crooked by accurate calorific capacity, thereby can improve the operating accuracy of thermal overload relay.

For realizing these purposes of the present invention, as specific and general description at this, the invention provides a kind of heating component that is used for thermal overload relay, bending by bimetal leaf makes switching mechanism work cut off the circuit connection, the wherein bending of bimetal leaf, be that the heat that the heater block made of material by the heat that can have a resistance when electric current flows through produces causes, and this heater block include predetermined area and thickness and abut the board-like heating plate of bimetal leaf securely.

From the detailed description below in conjunction with accompanying drawing, above-mentioned purpose, feature and advantage with other of the present invention will become more obvious.

Included accompanying drawing helps darker understanding of the present invention, and constitutes the part of this specification, and accompanying drawing shows embodiments of the invention, and is used for explaining principle of the present invention with describing.

In the accompanying drawings:

Fig. 1 illustrates the vertical cross section of the thermal overload relay of the heating component that contains routine techniques;

Fig. 2 illustrates the perspective view of conventional heating component;

Fig. 3 illustrates the vertical cross section of the thermal overload relay that contains with good grounds heating component of the present invention;

Fig. 4 illustrates the perspective view according to heating component of the present invention;

Fig. 5 illustrates the perspective view of heating component according to another embodiment of the present invention;

Fig. 6 illustrates the detail view of the heating plate of heating component according to another embodiment of the present invention.

To describe the details of the preferred embodiments of the present invention now, wherein example is shown in the drawings.

Fig. 3 illustrates the vertical cross section of the thermal overload relay that contains with good grounds heating component of the present invention, and Fig. 4 illustrates the perspective view of heating component according to an embodiment of the invention.

According to thermal overload relay of the present invention, comprise heater 60, this heater has main bimetal leaf 61 and heater coil 65, they are installed in upper shell 52 and the lower house 51, and switching mechanism 70 and contactor 80 are housed, so that change the operating state of circuit according to the ruuning situation of heater 60.

Main bimetal leaf 71 in the heater 70 is bar shaped in vertical direction, and vertically places in the lower house.In addition, shift unit 63 is connected the free end of main bimetal leaf 71, i.e. upper end.

Particularly, as shown in Figure 4, the heating plate 65 that vertically long plate is made is fixed on a side of main bimetal leaf 61.

The method that the heating plate utilization is for example welded is fixed on a side of main bimetal leaf 61, the heat that has a resistance when electric current being arranged with convenient heating plate 65 upper reaches, and with heat transferred to main bimetal leaf 61.

The side that the end 66a of connector 66 and lead-in wire 67 and 67a are connected to heating plate 65, thus be electrically connected with circuit, the opposite side of heating plate 65 is connected in terminal block 68, and heat has a resistance when flowing through with convenient electric current.

The ruuning situation that below description is comprised the thermal overload relay of heating component of the present invention.

If on the heating plate 65 that is fixed in main bimetal leaf 61 overcurrent is arranged, heating plate 65 produces heat so, simultaneously, and the bending of main bimetal leaf 61 owing to the heat of heating plate 65 generations.

At this, main bimetal leaf 61 is along with the bending of temperature rising value, and the curvature value of main bimetal leaf 61 is determined by following formula 1. $D=\frac{\mathrm{k\ΔT}{L}^2}{t}----1$

In the superincumbent formula 1, D represents curvature value, and K represents proportionality constant, and Δ T is poor with heated temperatures before heating, and L is the effective length of main bimetal leaf 61, and t represents the thickness of main bimetal leaf 61.

Therefore, if the material of heating plate 65 and size are suitably definite and satisfy formula 1, can obtain the accurate resistance value of heating plate so.

As mentioned above, because the heat that heating plate 65 produces and when crooked, shift unit 63 moves according to the degree of crook of the upper end 61a of main bimetal leaf 61 right towards Fig. 3 as the upper end of main bimetal leaf 61 61a.Simultaneously, the bottom of the ledge 63a of shift unit 63 contact temperature-compensating bimetal leaf 73, temperature-compensating bimetal leaf 73 is promoted to the right subsequently.

As mentioned above, temperature-compensating bimetal leaf 73 is shifted device 63 and promotes, thereby switching mechanism 70 starts, and contactor 80 separates and open circuit.

Fig. 5 illustrates the perspective view of heating component according to another embodiment of the present invention, and Fig. 6 illustrates the detail view of the heating plate of heating component shown in Figure 5.

Aforesaid heating plate is a flat type, yet heating plate 65 according to another embodiment of the present invention ' such plate of formation promptly forms the tortuous belt that connects.

Wish that above-mentioned heating plate forms like this, promptly carry out the processing of blank cutting type and plate is processed into continuous belt by metal die.

And, as shown in Figure 6, heating plate 65 ' middle part 65a crooked on Width, thereby be fixed by welding in main bimetal leaf 61 ' both sides, and two ends 65d and 65e are outstanding, so that connect connector and the terminal block that is electrically connected with circuit.

As shown in Figure 6, aforesaid heating plate 65 ' crooked middle part 65a be positioned at main bimetal leaf 61 ' lateral edges, near both sides the 65b placed in the middle crooked middle part 65a and 65d abut against securely main bimetal leaf 61 ' two surfaces on, therefore, when overcurrent being arranged at heating plate 65 ' upper reaches, heating plate produces heat, therefore main bimetal leaf 61 ' distortion.

The heating component that is used for thermal overload relay according to the present invention can be made in simple mode, promptly utilize metal die molded with the blank cutting method to metallic plate, and the equipment of the winding around that need not customize or anchor clamps, so the productivity ratio of assembly and efficient can improve.

And according to the present invention, heating plate can have predetermined size and area easily, so can obtain accurate resistance value.Therefore, main bimetal leaf carries out bending with the specific exactly determined predetermined extent of calorific capacity, thus the opening operation of executive circuit accurately, and can improve the precision of thermal overload relay.

Because the present invention is not breaking away under its design or the principal character situation and can several forms realize, not limited by aforesaid any details so be to be understood that the above embodiments, unless otherwise prescribed, but should in appended claim restricted portion, briefly constitute, therefore all fall in the claim scope or be equivalent to improvement and variation in these scopes, all will be understood that to be included in the appended claim.

Claims (6)

1. heating component that is used for thermal overload relay, this relay makes the bimetal leaf bending by the heat that heater block produces, and the bending of bimetal leaf makes switching mechanism work, thereby open circuit, it is characterized in that heater block made by the material of the heat that can have a resistance when electric current flows through, and include predetermined area and thickness and plate-shaped heating panel that abut bimetal leaf securely.

2. heating component according to claim 1 is characterized in that heating plate is fixed by welding on the bimetal leaf.

3. heating component according to claim 1 is characterized in that heating plate is for having predetermined area and being fixed on lip-deep square configuration of bimetal leaf.

4. heating component according to claim 1 is characterized in that heating plate makes like this, and the plate that is about to preliminary dimension is undertaken molded by sheet metal processing and forms meander-shaped.

5. heating component according to claim 4 is characterized in that the middle bent of heating plate, and is fixed on two surfaces of bimetal leaf and abuts bimetal leaf.

6. according to claim 1,2,3,4 or 5 described heating components, it is characterized in that the circuit connecting section part is fixed on the two ends of heating plate, make electric current can flow through heating plate.

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