Small-sized independent thermal overload relay

Abstract

A small independent thermal overload relay comprises a shell, a wiring system, a bimetallic strip, a guide plate structure and an actuating mechanism, the wiring system comprises a plurality of wiring units, and each wiring unit comprises a first wiring terminal, a first contact plate, a second contact plate and a second wiring terminal. The first wiring terminal and the second wiring terminal are arranged on the two sides of the bimetallic strip in the length direction of the shell, and the bimetallic strip is electrically connected between the first contact plate and the second contact plate. According to the small-sized independent thermal overload relay, the wiring system, the guide plate structure and the actuating mechanism are arranged along the height direction of the shell, the plurality of wiring units are arranged along the width direction of the shell, and the contact plate, the wiring terminal and the bimetallic strip are arranged along the length direction of the shell, so that the overall structure of the thermal overload relay is compact and ordered; and the wiring terminal of the wiring unit is connected with the contactor for use through wiring, so that the thermal overload relay can be independently installed and is suitable for contactors of different models.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, in particular to a small independent thermal overload relay. Background Art

[0002] A thermal overload relay is a commonly used relay. During use, a bimetallic strip is connected in series in the main circuit controlled by the thermal overload relay. When the current in the main circuit flowing through the bimetallic strip is less than or equal to the rated current, the bimetallic strip is heated to a certain bending stroke, but it is not enough to activate the reset mechanism of the thermal overload relay to ensure the normal starting and operation of the load (such as a motor). When an overload current (greater than the rated current) or a phase failure occurs in the main circuit, the bimetallic strip is heated to a larger bending stroke and is sufficient to activate the thermal overload relay's operating mechanism to trip. In this way, the principle of thermal bending deformation of thermal elements (such as bimetallic strips) due to heat is used to control the connection and disconnection of electrical equipment circuits and achieve overload protection.

[0003] In the prior art, a small-frame thermal overload relay with a width of 45 mm generally has a plug-in installation structure. Since the plug-in thermal overload relay needs to be inserted and used in conjunction with a contactor, it is not applicable to contactors of different models and has poor applicability.

[0004] In the prior art, independently mounted thermal overload relays can be connected to contactors via wires and are not limited by the contactor model. However, due to the limited space of 45mm width, independently mounted thermal overload relays have many design difficulties. Utility Model Content

[0005] The purpose of the utility model is to overcome at least one defect of the prior art and provide a small independent thermal overload relay.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A small independent thermal overload relay includes a housing, a wiring system installed in the housing, a bimetallic strip, a guide plate structure and an actuating mechanism, wherein the wiring system, the guide plate structure and the actuating mechanism are arranged in sequence along the height direction of the housing, the wiring system includes a plurality of wiring units, and the plurality of wiring units are arranged in sequence along the width direction of the housing at intervals, the bimetallic strip is arranged in a one-to-one correspondence with the wiring unit, the thermal deformation of the bimetallic strip can drive the guide plate structure to slide along the width direction of the housing and push the actuating mechanism to operate, the wiring unit includes a first terminal, a first contact plate, a second contact plate and a second terminal, the first contact plate cooperates with the first terminal for external connection to a wire, the second contact plate cooperates with the second terminal for external connection to a wire, the first terminal and the second terminal are arranged on both sides of the bimetallic strip in the length direction of the housing, and the bimetallic strip is electrically connected between the first contact plate and the second contact plate.

[0008] Optionally, the first contact plate includes a first wiring portion that cooperates with the first wiring terminal and a first contact portion that is electrically connected to the bimetallic strip, and the first contact portion is stacked with the bimetallic strip in the width direction of the shell; the second contact plate includes a second wiring portion that cooperates with the second wiring terminal and a second contact portion that is electrically connected to the bimetallic strip, the second contact portion is located below the bimetallic strip and the first contact portion, and the second contact portion is electrically connected to the bimetallic strip through a soft connection.

[0009] Optionally, an insulating sheet is provided between the first contact portion and the second contact portion.

[0010] Optionally, the insulating sheet is an L-shaped sheet structure, one end of the insulating sheet is located below the first contact portion and the bimetallic sheet and above the second contact portion, and the other end is located between the bimetallic sheet and its adjacent bimetallic sheet.

[0011] Optionally, the first contact plate also includes a first connecting portion connected between the first wiring portion and the first contact portion, the first connecting portion is fixed in the shell by a fixing screw, the fixing screw is arranged corresponding to the wiring frame of the first wiring terminal, and the first connecting portion is provided with a positioning hole, and the shell is provided with a positioning protrusion that cooperates with the positioning hole; the shell is provided with a first wiring hole corresponding to the wiring frame of the first wiring terminal.

[0012] Optionally, the first connecting portion is vertically connected between the first wiring portion and the first contact portion, the length direction of the first wiring portion is set along the length direction of the shell, the width direction is set along the width direction of the shell, and the thickness direction is set along the height direction of the shell, the length direction of the first connecting portion is set along the height direction of the shell, the width direction is set along the width direction of the shell, and the thickness direction is set along the length direction of the shell, the length direction of the first contact portion is set along the length direction of the shell, the width direction is set along the height direction of the shell, and the thickness direction is set along the width direction of the shell.

[0013] Optionally, a fixing portion is provided at one end of the second contact portion close to the first terminal and away from the second terminal, extending along the length direction of the housing. The housing is provided with a fixing groove, and the fixing portion is inserted into the fixing groove with interference fit.

[0014] Optionally, the second contact plate also includes a second connecting portion vertically connected between the second wiring portion and the second contact portion, the length direction of the second wiring portion is set along the length direction of the shell, the width direction is set along the width direction of the shell, and the thickness direction is set along the height direction of the shell, the length direction of the second connecting portion is set along the height direction of the shell, the width direction is set along the length direction of the shell, and the thickness direction is set along the width direction of the shell, and the second contact portion is set parallel to the second wiring portion.

[0015] Optionally, the first wiring terminal and the second wiring terminal have the same structure, both comprising a wiring frame and a wiring screw provided on the top edge of the wiring frame;

[0016] The shell is provided with a first wiring hole corresponding to the wiring frame of the first wiring terminal and a second wiring hole corresponding to the wiring frame of the second wiring terminal. The bottom edge of the wiring frame of the first wiring terminal extends downward to provide a first blocking piece. The first blocking piece is used to block the first wiring hole together with the bottom edge of the wiring frame of the first wiring terminal after the wiring frame of the first wiring terminal is moved upward. The bottom edge of the wiring frame of the second wiring terminal extends downward to provide a second blocking piece. The second blocking piece is used to block the second wiring hole together with the bottom edge of the wiring frame of the second wiring terminal after the wiring frame of the second wiring terminal is moved upward.

[0017] Optionally, two symmetrical insulating covers are provided on the outside of the shell, which are respectively arranged corresponding to the first wiring terminals and the second wiring terminals of the multiple wiring units. Each insulating cover is provided with multiple insulating cavities corresponding one-to-one to the wiring screws of the multiple wiring units. The insulating cover is clamped on the shell, and the shell is provided with a positioning through hole and a fixing card hole. The insulating cover is provided with a positioning column that cooperates with the positioning through hole and a fixing buckle that cooperates with the card hole.

[0018] Optionally, a guide channel is provided in the shell, the guide plate structure is slidably arranged in the guide channel along the width direction of the shell, the top wall of the guide channel is provided with a sliding plane, and the guide plate structure is provided with a sliding protrusion that slides with the sliding plane.

[0019] Optionally, the guide plate structure includes a first guide plate, a second guide plate and a differential member, the first guide plate and the second guide plate are arranged side by side along the length direction of the shell, and the first guide plate is provided with a plurality of first transmission parts corresponding one-to-one to the bimetallic strips on the side facing the second guide plate; the second guide plate is provided with a second transmission part corresponding one-to-one to the first transmission part on the side facing the first guide plate, and the corresponding first transmission parts and second transmission parts are spaced apart in the width direction of the shell to form a clamping gap for accommodating the bimetallic strips; the differential member is hinged to the first guide plate and the second guide plate respectively, and the differential member is provided with a release part for resisting the actuator mechanism.

[0020] Optionally, the differential is stacked above the first guide plate and the second guide plate, and the differential is provided with a first hinge shaft and a second hinge shaft, the second hinge shaft is located between the first hinge shaft and the release part in the length direction of the shell, the first hinge shaft is arranged in an open groove on the first guide plate, and the notch of the open groove is toward the second guide plate along the length direction of the shell, and the second hinge shaft rotates through the through hole on the second guide plate.

[0021] Optionally, the width of the shell is 45 mm, and the shell is provided with three groups of bimetallic strips arranged in sequence and spaced apart along the width direction of the shell, and three wiring units arranged in sequence and spaced apart along the width direction of the shell.

[0022] Optionally, the action mechanism includes a first rocker rod, a tension spring, a rocker arm, a push rod and a second rocker rod, the first rocker rod is connected to the base through a first fulcrum, and can swing around the rotation center of the first fulcrum, and the rotation center of the first fulcrum is set along the length direction of the shell; the rocker arm is connected to the base through a second fulcrum, and can swing around the rotation center of the second fulcrum, and the rotation center of the first fulcrum is set along the length direction of the shell; one end of the tension spring is connected to the first rocker rod, and the other end of the tension spring is connected to the rocker arm, the rocker arm is coupled to the push rod, and the push rod is moved along the width direction of the shell; the second rocker rod is connected to the base through a third fulcrum, and can swing around the rotation center of the third fulcrum, and the rotation center of the third fulcrum is slid along the length direction of the shell, and the second rocker rod is provided with a driven part, and the driven part is arranged relative to the release part of the guide plate structure.

[0023] Optionally, it also includes a base and a switch mechanism, the base is installed in the shell, the action mechanism and the switch mechanism are installed on both sides of the base along the length direction of the shell, and the action mechanism drives the switch mechanism to switch the open and closed states in the tripped state.

[0024] Optionally, the switching mechanism includes a normally closed contact and a normally open contact, the normally closed contact includes a moving support, a relatively arranged moving static contact and a moving moving contact, the moving moving contact is arranged on the moving support, the normally open contact includes a moving close support, a relatively arranged moving static contact and a moving moving contact, the moving close moving contact is arranged on the moving close support, and the push rod of the action mechanism is provided with a first pushing portion for driving cooperation with the moving support and a second pushing portion for driving cooperation with the moving close support.

[0025] The small independent thermal overload relay of the utility model has a wiring system, a guide plate structure and an actuating mechanism arranged along the height direction of the housing, a plurality of wiring units of the wiring system arranged along the width direction of the housing, and a contact plate, a wiring terminal and a bimetallic strip of a single wiring unit arranged along the length direction of the housing. This makes the overall structure of the thermal overload relay compact and orderly, which is conducive to miniaturization design. Moreover, the wiring terminals of the wiring unit are connected to the contactor through wiring, so that the thermal overload relay can be installed independently and is applicable to contactors of different models, thereby improving applicability.

[0026] In addition, the first contact portion of the first contact plate is stacked and welded with the bimetallic strip in the width direction of the shell, and the second contact portion of the second contact plate located below the bimetallic strip is electrically connected to the bimetallic strip through a soft connection, which facilitates a compact layout between the first contact plate, the second contact plate and the bimetallic strip in the length and width directions of the shell, saving space occupied in the length and width directions of the shell.

[0027] In addition, the sliding plane cooperates with the sliding protrusion to limit and guide the sliding of the guide plate structure, which not only improves the sliding stability of the guide plate structure but also reduces the accuracy requirements of the guide channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the thermal overload relay of the utility model;

[0029] Figure 2 This is a structural diagram of a hidden cover plate of a thermal overload relay of the utility model;

[0030] Figure 3 This is a three-dimensional diagram of the hidden housing of the thermal overload relay of the utility model;

[0031] Figure 4 This is a schematic diagram of the structure of the wiring unit and bimetallic strip of the utility model;

[0032] Figure 5 This is a schematic diagram from one perspective of the first contact plate, the second contact plate and the bimetallic strip of the present invention;

[0033] Figure 6This is a schematic diagram of the first contact plate, the second contact plate and the bimetallic strip of the present invention from another perspective;

[0034] Figure 7 It is a structural diagram of the mounting base of the utility model;

[0035] Figure 8 This is a schematic diagram of the guide plate structure of the utility model from one perspective;

[0036] Figure 9 This is a schematic diagram of the guide plate structure of the present invention from another perspective;

[0037] Figure 10 This is a view of the hidden housing of the thermal overload relay of the utility model;

[0038] Figure 11 This is another view of the hidden housing of the thermal overload relay of the utility model;

[0039] Figure 12 It is a side view of the thermal overload relay of the utility model;

[0040] Figure 13 It is an exploded view of the insulating cover and the shell of the utility model.

[0041] Housing 100; first wiring hole 101; positioning through hole 102; fixing hole 103; mounting base 110; cover 120; base 130; rocker arm rib 131; second fulcrum 132; mounting cavity 140; positioning protrusion 141; fixing groove 142; first screw hole 143; countersunk groove 144; guide channel 150; sliding plane 151; second chamber 160; first partition 170; second partition 180; wiring unit 200; first wiring terminal 21 0; first shielding plate 211; first contact plate 220; first wiring portion 221; first connecting portion 222; positioning hole 2221; second screw hole 2222; first contact portion 223; second contact plate 230; second wiring portion 231; second connecting portion 232; second contact portion 233; fixing portion 234; first notch 2341; second notch 2342; second terminal 240; second shielding plate 241; flexible connector 250; insulating sheet 26 0; fixing screw 270; bimetallic strip 300; thermal element 310; guide plate structure 400; sliding protrusion 401; first guide plate 410; first transmission portion 411; opening slot 412; second guide plate 420; second transmission portion 421; through hole 422; differential member 430; tripping portion 431; first hinge axis 432; second hinge axis 433; clamping gap 440; action mechanism 500; first rocker arm 510; first fulcrum 511; tension spring 520; rocker arm Arm 530; rocker arm 531; push rod 540; first pushing portion 541; second pushing portion 542; second rocker arm 550; driven portion 551; switch mechanism 600; normally closed contact 610; moving-open static contact 611; moving-open movable contact 612; moving-open support 613; normally open contact 620; moving-close static contact 621; moving-close movable contact 622; moving-close support 623; insulating cover 700; insulating cavity 701; positioning column 702; fixing buckle 703. DETAILED DESCRIPTION

[0042] The following embodiments are given in conjunction with the accompanying drawings to further illustrate the specific implementation of the small independent thermal overload relay of the present invention. The small independent thermal overload relay of the present invention is not limited to the description of the following embodiments.

[0043] like Figure 1-Figure 3As shown, the small stand-alone thermal overload relay of this embodiment includes a housing 100, a wiring system installed in the housing 100, a bimetallic strip 300, a guide plate structure 400, and an actuating mechanism 500. The wiring system, the guide plate structure 400, and the actuating mechanism 500 are arranged in sequence along the height direction of the housing 100. The wiring system includes a plurality of wiring units 200, and the plurality of wiring units 200 are arranged in sequence and spaced apart along the width direction of the housing 100. The bimetallic strip 300 is arranged in a one-to-one correspondence with the wiring units 200 and is connected in series in the wiring units 200. The bimetallic strip 300 is driven to cooperate with the guide plate structure 400, and the guide plate structure 400 is driven to cooperate with the actuating mechanism 500. The thermal deformation of the bimetallic strip 300 can drive the guide plate structure 400 to slide along the width direction of the housing 100 and push the actuating mechanism 500 to operate. When the current flowing through the wiring system is less than or equal to the rated current value, the bimetallic strip 300 cannot push the guide plate structure 400, and the guide plate structure 400 cannot push the action mechanism 500; when the current flowing through the wiring system exceeds the rated current value or the phase is abnormal, the bimetallic strip 300 is deformed and bent by heat, and the thrust of the guide plate structure 400 against the action mechanism 500 is greater than the threshold value, thereby pushing the action mechanism 500 to produce a tripping action, and the action mechanism 500 switches from the initial state to the tripping state, causing the thermal overload relay to disconnect; after the bimetallic strip 300 cools down and recovers, it pushes the guide plate structure 400 to reset. It should be noted that the height direction of the housing 100 refers to Figure 1 In the vertical direction, the width direction of the housing 100 refers to Figure 1 In the vertical direction of the drawing, the length direction of the housing 100 is Figure 1 Center left and right direction.

[0044] like Figure 4As shown, the wiring unit 200 of this embodiment includes a first wiring terminal 210, a first contact plate 220, a second contact plate 230 and a second wiring terminal 240. The first contact plate 220 cooperates with the first wiring terminal 210 for external connection to a wire, and the second contact plate 230 cooperates with the second wiring terminal 240 for external connection to a wire. The first wiring terminal 210 and the second wiring terminal 240 are arranged on both sides of the bimetallic strip 300 in the length direction of the housing 100, and the bimetallic strip 300 is electrically connected between the first contact plate 220 and the second contact plate 230. In the small stand-alone thermal overload relay of this embodiment, the wiring system, guide plate structure 400, and actuating mechanism 500 are arranged along the height direction of the housing 100. The multiple wiring units 200 of the wiring system are arranged along the width direction of the housing 100. The contact plate, wiring terminal, and bimetallic strip 300 of a single wiring unit 200 are arranged along the length direction of the housing 100. This makes the overall structure of the thermal overload relay compact and orderly, facilitating miniaturization. In addition, the wiring terminals of the wiring unit 200 are connected to the contactor through wiring, allowing the thermal overload relay to be independently installed and compatible with different types of contactors, thereby improving applicability.

[0045] It should be noted that the first terminal block 210 and the second terminal block 240 can be provided in a variety of configurations. In a preferred configuration, the first terminal block 210 and the second terminal block 240 have the same structure, each comprising a terminal frame and a terminal screw disposed on the top edge of the terminal frame. One end of the first contact plate 220 / second contact plate 230 extends into the terminal frame. By rotating the terminal screw, the terminal frame moves upward with the terminal screw, causing the top edge of the terminal frame and one end of the first contact plate 220 / second contact plate 230 to clamp the wire. Preferably, the housing 100 of this embodiment has a width of 45 mm and includes three sets of bimetallic strips 300 spaced apart along the width of the housing 100, as well as three terminal units 200 spaced apart along the width of the housing 100. Of course, the width of the thermal overload relay is not limited to 45 mm.

[0046] In this embodiment, if Figure 4 and Figure 12As shown, the housing 100 is provided with a first wiring hole 101 corresponding to the wiring frame of the first wiring terminal 210, and a second wiring hole corresponding to the wiring frame of the second wiring terminal 240. A first shielding piece 211 extends downward from the bottom edge of the wiring frame of the first wiring terminal 210. The first shielding piece 211 is used to block the first wiring hole 101 together with the bottom edge of the wiring frame of the first wiring terminal 210 after the wiring frame of the first wiring terminal 210 is moved upward. A second shielding piece 241 extends downward from the bottom edge of the wiring frame of the second wiring terminal 240. The second shielding piece 241 is used to block the second wiring hole together with the bottom edge of the wiring frame of the second wiring terminal 240 after the wiring frame of the second wiring terminal 240 is moved upward. The provision of the shielding pieces for the wiring terminals improves the airtightness of the housing 100 and effectively prevents foreign matter from entering the housing 100.

[0047] Preferably, Figure 13 As shown, the housing 100 is provided with two symmetrical insulating covers 700, which are respectively arranged to correspond to the first terminal blocks 210 and the second terminal blocks 240 of the multiple wiring units 200. Each insulating cover 700 is provided with multiple insulating cavities 701 corresponding one-to-one to the wiring screws of the multiple wiring units 200. The insulating covers 700 are snap-fitted to the housing 100. The housing 100 is provided with positioning holes 102 and fixing holes 103. The insulating covers 700 are provided with positioning posts 702 that engage with the positioning holes 102 and fixing buckles 703 that engage with the fixing holes. The insulating covers 700 electrically isolate the wiring screws of the multiple wiring units 200, and the snap-fit ​​structure between the insulating covers 700 and the housing 100 is simple. The positioning posts 702 serve as positioning identification, and the fixing buckles 703 cooperate with the fixing holes 103 to secure the connection, facilitating automated assembly of the insulating covers 700.

[0048] Illustratively, the insulating cover 700 is provided with a positioning column 702 and two fixing buckles 703 symmetrically arranged on both sides of the positioning column 702; correspondingly, the shell 100 is provided with a positioning through hole 102 and two fixing buckles 103 symmetrically arranged on both sides of the positioning through hole 102.

[0049] like Figure 1 and Figure 7As shown, the shell 100 of this embodiment includes a mounting base 110 and a cover plate 120 that cover each other. The mounting base 110 and the cover plate 120 are arranged along the length direction of the shell 100. A first partition plate 170 is provided in the shell 100. The first partition plate 170 divides the interior of the shell 100 into a first chamber and a second chamber 160 located above the first chamber. The first chamber and the second chamber 160 are connected through a connecting port; a second partition plate 180 is provided in the first chamber. The second partition plate 180 divides the interior of the first chamber into mounting cavities 140 corresponding to the wiring units 200 one by one, and the wiring units 200 are installed in the mounting cavity 140; a guide channel 150 is formed between the top end of the second partition plate 180 and the first partition plate 170, and the guide plate structure 400 is slidably set in the guide channel 150 along the width direction of the shell 100.

[0050] like Figure 4-Figure 6 As shown, the first contact plate 220 of this embodiment includes a first connection portion 221 that cooperates with the first terminal 210 and a first contact portion 223 that is electrically connected to the bimetal 300. The first contact portion 223 is stacked with the bimetal 300 in the width direction of the housing 100 and is electrically connected to the bimetal 300 by welding. The second contact plate 230 includes a second connection portion 231 that cooperates with the second terminal 240 and a second contact portion 233 that is electrically connected to the bimetal 300. The second contact portion 233 is located below the bimetal 300 and the first contact portion 223, and is electrically connected to the bimetal 300 via a flexible connector 250. One end of the flexible connector 250 is welded to the second contact portion 233, and the other end of the flexible connector 250 is welded to a thermal element 310 wrapped around the bimetal 300. The thermal element 310 is a copper strip that is used to heat the bimetal 300 when overloaded. The first contact portion 223 of the first contact plate 220 is stacked and welded with the bimetallic strip 300 in the width direction of the housing 100, and the second contact portion 233 of the second contact plate 230 located below the bimetallic strip 300 is electrically connected to the bimetallic strip 300 via a flexible connection 250. This facilitates a compact layout of the first contact plate 220, the second contact plate 230, and the bimetallic strip 300 in the length and width directions of the housing 100, thereby saving space in the length and width directions of the housing 100.

[0051] like Figure 4 、 Figure 6 、 Figure 7 and Figure 12As shown, the installation structure of the first contact plate 220 of this embodiment, the first contact plate 220 of this embodiment also includes a first connecting portion 222 connected between the first wiring portion 221 and the first contact portion 223, the first connecting portion 222 is fixed in the shell 100 by a fixing screw 270, the fixing screw 270 is arranged corresponding to the wiring frame of the first wiring terminal 210, that is, corresponding to the first wiring hole 101 of the shell 100, and the first connecting portion 222 is provided with a positioning hole 2221, the side wall of the installation cavity 140 of the shell 100 is provided with a positioning protrusion 141 that cooperates with the positioning hole 2221, the side wall of the installation cavity 140 is provided with a first screw hole 143 that cooperates with the fixing screw 270, and the first connecting portion 222 is provided with a second screw hole 2222 that cooperates with the fixing screw 270. The first connecting portion 222 of the first contact plate 220 is attached to the side wall of the mounting cavity 140, and the first screw hole 143 and the second screw hole 2222 are quickly aligned by inserting the positioning protrusion 141 into the positioning hole 2221, and then fixed by the fixing screw 270, which facilitates quick installation and is firmly installed; and the fixing screw 270 is arranged corresponding to the wiring frame of the first wiring terminal 210 and the first wiring hole 101 of the housing 100. Through the first wiring hole 101 and the wiring frame of the first wiring terminal 210, wiring can be done in the wiring frame of the first wiring terminal 210, and the fixing screw 270 can be locked to fix the first contact plate 220, thereby improving space utilization.

[0052] like Figure 5 and Figure 6 As shown, the first connecting portion 222 of the first contact plate 220 is vertically connected between the first wiring portion 221 and the first contact portion 223. The length direction of the first wiring portion 221 is set along the length direction of the shell 100, the width direction is set along the width direction of the shell 100, and the thickness direction is set along the height direction of the shell 100. The length direction of the first connecting portion 222 is set along the height direction of the shell 100, the width direction is set along the width direction of the shell 100, and the thickness direction is set along the length direction of the shell 100. The length direction of the first contact portion 223 is set along the length direction of the shell 100, the width direction is set along the height direction of the shell 100, and the thickness direction is set along the width direction of the shell 100.

[0053] like Figure 5-Figure 7As shown, the mounting structure of the second contact plate 230 of this embodiment comprises a fixing portion 234 extending along the length of the housing 100 at one end of the second contact portion 233 of the second contact plate 230, located near the first terminal 210 and away from the second terminal 240. A fixing groove 142 is provided on the sidewall of the mounting cavity 140 of the housing 100, and a recessed groove 144 is provided on the bottom wall of the mounting cavity 140, communicating with the fixing groove 142. The second contact portion 233 is positioned within the recessed groove 144, and the fixing portion 234 is inserted through an interference fit within the fixing groove 142. The fixing portion 234 of the second contact plate 230 is riveted into the fixing groove 142, effectively preventing displacement or shaking of the second contact plate 230 after installation, ensuring a secure and reliable installation. Preferably, the fixing portion 234 is provided with a first notch 2341 and two symmetrical second notches 2342. The opening of the first notch 2341 faces the first terminal 210 along the length of the housing 100, while the openings of the two second notches 2342 are arranged in opposite directions along the width of the housing 100. The provision of the notches on the fixing portion 234 effectively prevents the fixing slot 142 from being squeezed and cracked during riveting, without affecting the firmness of the riveting.

[0054] like Figure 5 and Figure 6 As shown, the second contact plate 230 of this embodiment also includes a second connecting portion 232 vertically connected between the second wiring portion 231 and the second contact portion 233. The length direction of the second wiring portion 231 is set along the length direction of the shell 100, the width direction is set along the width direction of the shell 100, and the thickness direction is set along the height direction of the shell 100. The length direction of the second connecting portion 232 is set along the height direction of the shell 100, the width direction is set along the length direction of the shell 100, and the thickness direction is set along the width direction of the shell 100. The second contact portion 233 is arranged parallel to the second wiring portion 231, that is, the length direction of the second contact portion 233 is set along the length direction of the shell 100, the width direction is set along the width direction of the shell 100, and the thickness direction is set along the height direction of the shell 100.

[0055] like Figure 4As shown, an insulating sheet 260 is disposed between the first contact portion 223 of the first contact plate 220 and the second contact portion 233 of the second contact plate 230. The insulating sheet 260 effectively prevents a short circuit between the first contact plate 220 and the second contact plate 230, thereby preventing failure of the bimetallic strip 300 and improving the reliability of the thermal overload relay. Preferably, the insulating sheet 260 is an L-shaped sheet structure. One end of the insulating sheet 260 is horizontally disposed, located below the first contact portion 223 and the bimetallic strip 300 and above the second contact portion 233. The other end of the insulating sheet 260 is vertically disposed, located between the bimetallic strip 300 and its adjacent bimetallic strip 300. The bimetallic strip 300 serves as a heat source and is installed in an independent installation cavity 140 along with the wiring unit 200 of the corresponding phase. The bimetallic strips 300 of different phases are separated by the second partition 180. On this basis, the insulating sheet 260 is designed to be L-shaped, so that the upright end of the insulating sheet 260 is blocked between two adjacent bimetallic strips 300, further improving the thermal insulation effect and preventing interphase heat transfer.

[0056] like Figure 8 and Figure 9 As shown, the guide plate structure 400 of this embodiment includes a first guide plate 410, a second guide plate 420 and a differential member 430. The first guide plate 410 and the second guide plate 420 are arranged side by side along the length direction of the shell 100. A plurality of first transmission parts 411 corresponding to the bimetallic strip 300 are extended from the side of the first guide plate 410 facing the second guide plate 420; a second transmission part 421 corresponding to the first transmission part 411 is extended from the side of the second guide plate 420 facing the first guide plate 410. The corresponding first transmission parts 411 and the second transmission parts 421 are spaced apart in the width direction of the shell 100 to form a clamping gap 440 for accommodating the bimetallic strip 300; the differential member 430 is hinged to the first guide plate 410 and the second guide plate 420 respectively, and the differential member 430 is provided with a release part 431 for resisting the actuating mechanism 500. The bimetallic strip 300 deforms thermally to push the second transmission portion 421 of the second guide plate 420 , thereby driving the guide plate structure 400 to push the operating mechanism 500 ; the bimetallic strip 300 cools and recovers to push the first transmission portion 411 of the first guide plate 410 , thereby driving the guide plate structure 400 to reset.

[0057] Specifically, the differential member 430 is stacked above the first guide plate 410 and the second guide plate 420, and the differential member 430 is provided with a first hinge shaft 432 and a second hinge shaft 433, and the second hinge shaft 433 is located between the first hinge shaft 432 and the release portion 431 in the length direction of the shell 100, and the first hinge shaft 432 is arranged in the open groove 412 on the first guide plate 410, and the notch of the open groove 412 is toward the second guide plate 420 along the length direction of the shell 100, and the second hinge shaft 433 rotates and passes through the through hole 422 on the second guide plate 420.

[0058] like Figure 7 and Figure 8 As shown, the side walls of the first guide plate 410 and the second guide plate 420 cooperate with the side walls of the guide channel 150 and slide along the width direction of the housing 100. Simultaneously, a sliding plane 151 is provided on the top wall of the guide channel 150 (i.e., the bottom surface of the first partition plate 170), and the guide plate structure 400 is provided with a sliding protrusion 401 that slidably cooperates with the sliding plane 151. The top surface of the sliding protrusion 401, which is used to slide with the sliding plane 151, is preferably a curved surface. One or more sliding protrusions 401 are provided and can be disposed on the top surface of the first guide plate 410 and / or the second guide plate 420. The sliding plane 151 cooperates with the sliding protrusion 401 to limit and guide the sliding of the guide plate structure 400, thereby improving the sliding stability of the guide plate structure 400 and reducing the precision requirements of the guide channel 150.

[0059] like Figure 3 As shown, the small independent thermal overload relay of this embodiment further includes a base 130 and a switch mechanism 600. The base 130 is installed in the second chamber 160 of the housing 100. The actuating mechanism 500 and the switch mechanism 600 are installed on both sides of the base 130 along the length direction of the housing 100. The actuating mechanism 500 drives the switch mechanism 600 to switch the open and closed states in the tripped state.

[0060] The structure of the action mechanism 500 can be in various forms. A preferred form is as follows: Figure 10As shown, the action mechanism 500 includes a first rocking rod 510, a tension spring 520, a rocking arm 530, a push rod 540 and a second rocking rod 550. The first rocking rod 510 is connected to the base 130 through a first fulcrum 511 and can swing around the rotation center of the first fulcrum 511. The rotation center of the first fulcrum 511 is set along the length direction of the shell 100; the rocking arm 530 is connected to the base 130 through a second fulcrum 132 and can swing around the rotation center of the second fulcrum 132. The rotation center of the first fulcrum 511 is set along the length direction of the shell 100; one end of the tension spring 520 is connected to the first rocking rod 510, and the other end of the tension spring 520 is connected to the rocking arm 530, and the rocking arm 530 is coupled to the push rod 540. The rod 540 is arranged to move along the width direction of the shell 100; the second rocker arm 550 is connected to the base 130 through a third fulcrum and can swing around the rotation center of the third fulcrum. The rotation center of the third fulcrum is slidably arranged along the length direction of the shell 100. The second rocker arm 550 is provided with a driven portion 551. The driven portion 551 extends into the guide channel 150 through the connecting port and is arranged opposite to the tripping portion 431 of the differential member 430 of the guide plate structure 400. The thermal deformation of the bimetallic strip 300 drives the guide plate structure 400, so that the tripping portion 431 of the differential member 430 pushes the second rocker arm 550 to rotate, so that the second rocker arm 550 pushes the first rocker arm 510 to rotate, and then the action mechanism 500 switches from the initial state to the tripping state.

[0061] Specifically, one end of the first rocker arm 510 serves as a first fulcrum 511, and the other end is provided with a tension spring hanging post. The rocker arm 530 is U-shaped and includes a rocker arm bottom edge, a rocker arm 531 that cooperates with the second fulcrum 132, and a rocker arm driving rod for driving the push rod 540. A V-shaped rocker arm rib 131 is provided within the base 130, the bottom of which serves as the second fulcrum 132. The rocker arm 531 of the rocker arm 530 is supported and swings on the second fulcrum 132 at the bottom of the rocker arm rib 131, and the rocker arm 531 cooperates with the push rod 540. A tension spring 520 is connected to the tension spring hanging post of the first rocker arm 510 at one end and to the rocker arm bottom edge of the rocker arm 530 at the other end. The rocker arm bottom edge is provided with a tension spring hanging hole for mounting the tension spring 520. Of course, the action mechanism 500 may also adopt other existing structures.

[0062] like Figure 11As shown, the switch mechanism 600 of this embodiment includes a normally closed contact 610 and a normally open contact 620, the normally closed contact 610 includes a dynamic support 613, a relatively arranged dynamic static contact 611 and a dynamic movable contact 612, the dynamic movable contact 612 is arranged on the dynamic support 613, the normally open contact 620 includes a dynamic closing support 623, a relatively arranged dynamic closing static contact 621 and a dynamic closing movable contact 622, the dynamic closing movable contact 622 is arranged on the dynamic closing support 623, and the push rod 540 of the action mechanism 500 is provided with a first pushing portion 541 for driving and cooperating with the dynamic support 613 and a second pushing portion 542 for driving and cooperating with the dynamic closing support 623. The moving-off support member 613 and the moving-on support member 623 are both made of thin, strip-shaped elastic sheets. The moving-off support member 613 provides contact pressure when the moving-off static contact 611 contacts the moving-off movable contact 612 through its own elastic deformation, while the moving-on support member 623 provides contact pressure when the moving-on movable contact 622 contacts the moving-on static contact 621 through its own elastic deformation. When the actuating mechanism 500 is in the initial state, the moving-off static contact 611 contacts the moving-off movable contact 612, i.e., the normally closed contact 610 is in the closed state, and the moving-on static contact 621 and the moving-on movable contact 622 are separated, i.e., the normally open contact 620 is in the open state. When the actuating mechanism 500 is in the tripped state, the moving-off static contact 611 and the moving-off movable contact 612 are separated, i.e., the normally closed contact 610 is in the open state, and the moving-on static contact 621 and the moving-on movable contact 622 are in contact, i.e., the normally open contact 620 is in the closed state. Of course, as another embodiment, the switch mechanism 600 may also only include the normally closed contact 610 or the normally open contact 620 .

[0063] The operation process of the small independent thermal overload relay of this embodiment is as follows: Figure 10 As shown, the bimetallic strip 300 is thermally deformed and pushes the second guide plate 420 to slide to the left, and the first guide plate 410 and the differential 430 move with the second guide plate 420. The differential 430 pushes the second swing rod 550, causing the second swing rod 550 to swing clockwise around the rotation center of the third fulcrum and push the first swing rod 510 to swing clockwise around the rotation center of the first fulcrum 511. The swing of the first swing rod 510 drives one end of the tension spring 520 to move to the right, causing the tension spring 520 to store energy. When the rocker arm 530 reaches the tipping point, the tension spring 520 is rotated to the left. When the rotation limit is reached, the other end of the tension spring 520 drives the rocker arm 530 to swing rapidly around the fulcrum, causing the action mechanism 500 to switch to the tripped state. Due to the state change of the action mechanism 500, the elastic force of the tension spring 520 drives the rocker arm 530 to swing clockwise, and the lower end of the rocker arm 530 drives the push rod 540 to move to the left. The movement of the push rod 540 causes the switch mechanism 600 to switch the open and closed states (the normally closed contact 610 switches from the closed state to the open state, and the normally open contact 620 switches from the open state to the closed state).

[0064] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, or are conventionally placed directions or positional relationships during use. They are intended solely for ease of description and do not imply that the devices or components referred to must have a specific direction. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and description and should not be construed as indicating relative importance.

[0065] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A small independent thermal overload relay, comprising a housing (100), a wiring system installed in the housing (100), a bimetallic strip (300), a guide plate structure (400) and an action mechanism (500), wherein the wiring system, the guide plate structure (400) and the action mechanism (500) are arranged in sequence along the height direction of the housing (100), the wiring system comprises a plurality of wiring units (200), the plurality of wiring units (200) are arranged in sequence along the width direction of the housing (100), the bimetallic strip (300) and the wiring units (200) are arranged in a one-to-one correspondence, the thermal deformation of the bimetallic strip (300) can drive the guide plate structure (400) to slide along the width direction of the housing (100) and push the action mechanism (500) to operate, characterized in that: The wiring unit (200) comprises a first wiring terminal (210), a first contact plate (220), a second contact plate (230) and a second wiring terminal (240); the first contact plate (220) cooperates with the first wiring terminal (210) for connecting an external wire; the second contact plate (230) cooperates with the second wiring terminal (240) for connecting an external wire; the first wiring terminal (210) and the second wiring terminal (240) are arranged on both sides of a bimetallic strip (300) in the length direction of the housing (100), and the bimetallic strip (300) is electrically connected between the first contact plate (220) and the second contact plate (230).

2. The small independent thermal overload relay according to claim 1, characterized in that: The first contact plate (220) includes a first wiring portion (221) matched with the first wiring terminal (210) and a first contact portion (223) electrically connected to the bimetallic strip (300), and the first contact portion (223) is stacked with the bimetallic strip (300) in the width direction of the housing (100); the second contact plate (230) includes a second wiring portion (231) matched with the second wiring terminal (240) and a second contact portion (233) electrically connected to the bimetallic strip (300), the second contact portion (233) is located below the bimetallic strip (300) and the first contact portion (223), and the second contact portion (233) is electrically connected to the bimetallic strip (300) through a soft connection (250).

3. The small independent thermal overload relay according to claim 2, characterized in that: An insulating sheet (260) is provided between the first contact portion (223) and the second contact portion (233).

4. The small independent thermal overload relay according to claim 3, characterized in that: The insulating sheet (260) is an L-shaped sheet structure, one end of the insulating sheet (260) is located below the first contact portion (223) and the bimetallic sheet (300) and above the second contact portion (233), and the other end is located between the bimetallic sheet (300) and the adjacent bimetallic sheet (300).

5. The small independent thermal overload relay according to claim 2, characterized in that: The first contact plate (220) further includes a first connecting portion (222) connected between the first wiring portion (221) and the first contact portion (223); the first connecting portion (222) is fixed in the housing (100) by a fixing screw (270); the fixing screw (270) is arranged corresponding to the wiring frame of the first wiring terminal (210); the first connecting portion (222) is provided with a positioning hole (2221); the housing (100) is provided with a positioning protrusion (141) that cooperates with the positioning hole (2221); and the housing (100) is provided with a first wiring hole (101) corresponding to the wiring frame of the first wiring terminal (210).

6. The small independent thermal overload relay according to claim 5, characterized in that: The first connecting portion (222) is vertically connected between the first wiring portion (221) and the first contact portion (223); the length direction of the first wiring portion (221) is arranged along the length direction of the shell (100), the width direction is arranged along the width direction of the shell (100), and the thickness direction is arranged along the height direction of the shell (100); the length direction of the first connecting portion (222) is arranged along the height direction of the shell (100), the width direction is arranged along the width direction of the shell (100), and the thickness direction is arranged along the length direction of the shell (100); the length direction of the first contact portion (223) is arranged along the length direction of the shell (100), the width direction is arranged along the height direction of the shell (100), and the thickness direction is arranged along the width direction of the shell (100).

7. The small independent thermal overload relay according to claim 2, characterized in that: A fixing portion (234) is provided at one end of the second contact portion (233) close to the first terminal (210) and away from the second terminal (240) and extending along the length direction of the housing (100); the housing (100) is provided with a fixing groove (142), and the fixing portion (234) is inserted into the fixing groove (142) with interference fit.

8. The small independent thermal overload relay according to claim 2, characterized in that: The second contact plate (230) further includes a second connecting portion (232) vertically connected between the second wiring portion (231) and the second contact portion (233); the length direction of the second wiring portion (231) is arranged along the length direction of the shell (100), the width direction is arranged along the width direction of the shell (100), and the thickness direction is arranged along the height direction of the shell (100); the length direction of the second connecting portion (232) is arranged along the height direction of the shell (100), the width direction is arranged along the length direction of the shell (100), and the thickness direction is arranged along the width direction of the shell (100); the second contact portion (233) is arranged parallel to the second wiring portion (231).

9. The small independent thermal overload relay according to claim 1, characterized in that: The first connecting terminal (210) and the second connecting terminal (240) have the same structure, both comprising a connecting frame and connecting screws arranged on the top edge of the connecting frame; The housing (100) is provided with a first wiring hole (101) corresponding to the wiring frame of the first wiring terminal (210) and a second wiring hole corresponding to the wiring frame of the second wiring terminal (240); a first shielding piece (211) is provided on the bottom edge of the wiring frame of the first wiring terminal (210) extending downwards; the first shielding piece (211) is used to block the first wiring hole (101) together with the bottom edge of the wiring frame of the first wiring terminal (210) after the wiring frame of the first wiring terminal (210) is moved upwards; a second shielding piece (241) is provided on the bottom edge of the wiring frame of the second wiring terminal (240) extending downwards; the second shielding piece (241) is used to block the second wiring hole together with the bottom edge of the wiring frame of the second wiring terminal (240) after the wiring frame of the second wiring terminal (240) is moved upwards.

10. The small independent thermal overload relay according to claim 9, characterized in that: The housing (100) is provided with two symmetrical insulating covers (700), which are respectively arranged corresponding to the first wiring terminals (210) and the second wiring terminals (240) of the multiple wiring units (200). Each insulating cover (700) is provided with multiple insulating cavities (701) corresponding one-to-one to the wiring screws of the multiple wiring units (200). The insulating cover (700) is clamped on the housing (100). The housing (100) is provided with a positioning through hole (102) and a fixing clamp hole (103). The insulating cover (700) is provided with a positioning column (702) that cooperates with the positioning through hole (102) and a fixing clamp (703) that cooperates with the clamp hole.

11. The small independent thermal overload relay according to claim 1, characterized in that: A guide channel (150) is provided in the shell (100), the guide plate structure (400) is slidably arranged in the guide channel (150) along the width direction of the shell (100), the top wall of the guide channel (150) is provided with a sliding plane (151), and the guide plate structure (400) is provided with a sliding protrusion (401) that slides with the sliding plane (151).

12. The small independent thermal overload relay according to claim 1, characterized in that: The guide plate structure (400) includes a first guide plate (410), a second guide plate (420) and a differential member (430). The first guide plate (410) and the second guide plate (420) are arranged side by side along the length direction of the housing (100). The first guide plate (410) extends on one side facing the second guide plate (420) and is provided with a plurality of first transmission parts (411) corresponding to the bimetallic strips (300) one by one. The second guide plate (420) extends on one side facing the first guide plate (410). A second transmission part (421) is provided which corresponds to the first transmission part (411) in a one-to-one manner, and the corresponding first transmission part (411) and the second transmission part (421) are spaced apart in the width direction of the housing (100) to form a clamping gap (440) for accommodating the bimetallic strip (300); the differential member (430) is hinged to the first guide plate (410) and the second guide plate (420) respectively, and the differential member (430) is provided with a tripping part (431) for resisting the actuating mechanism (500).

13. The small independent thermal overload relay according to claim 12, characterized in that: The differential member (430) is stacked above the first guide plate (410) and the second guide plate (420), and the differential member (430) is provided with a first hinge shaft (432) and a second hinge shaft (433), the second hinge shaft (433) is located between the first hinge shaft (432) and the release portion (431) in the longitudinal direction of the housing (100), the first hinge shaft (432) is arranged in an open groove (412) on the first guide plate (410), and the notch of the open groove (412) is toward the second guide plate (420) along the longitudinal direction of the housing (100), and the second hinge shaft (433) is rotatably passed through the through hole (422) on the second guide plate (420).

14. The small independent thermal overload relay according to claim 1, characterized in that: The width of the housing (100) is 45 mm. The housing (100) is provided with three groups of bimetallic strips (300) arranged in sequence and spaced apart along the width direction of the housing (100), and three wiring units (200) arranged in sequence and spaced apart along the width direction of the housing (100).

15. The small independent thermal overload relay according to claim 1, characterized in that: The action mechanism (500) includes a first rocker (510), a tension spring (520), a rocker arm (530), a push rod (540) and a second rocker arm (550). The first rocker arm (510) is connected to the base (130) through a first fulcrum (511) and can swing around the rotation center of the first fulcrum (511). The rotation center of the first fulcrum (511) is arranged along the length direction of the shell (100). The rocker arm (530) is connected to the base (130) through a second fulcrum (132) and can swing around the rotation center of the second fulcrum (132). The rotation center of the first fulcrum (511) is arranged along the length direction of the shell (100). The invention relates to a housing (100) comprising a first rocker arm (510) and a second rocker arm (530). The first rocker arm (510) is connected to the housing (100) at one end thereof, and the second rocker arm (510) is connected to the first rocker arm (510) at the other end thereof, and the rocker arm (530) is coupled to the push rod (540). The push rod (540) is arranged to move along the width direction of the housing (100). The second rocker arm (550) is connected to the base (130) through a third fulcrum and can swing around the rotation center of the third fulcrum. The rotation center of the third fulcrum is arranged to slide along the length direction of the housing (100). The second rocker arm (550) is provided with a driven portion (551). The driven portion (551) is arranged relative to the release portion (431) of the guide plate structure (400).

16. The small independent thermal overload relay according to claim 1, characterized in that: The invention also includes a base (130) and a switch mechanism (600), wherein the base (130) is installed in the housing (100), and the action mechanism (500) and the switch mechanism (600) are installed on both sides of the base (130) along the length direction of the housing (100), and the action mechanism (500) drives the switch mechanism (600) to switch the open and closed states in the tripped state.

17. The small independent thermal overload relay according to claim 16, characterized in that: The switch mechanism (600) includes a normally closed contact (610) and a normally open contact (620). The normally closed contact (610) includes a movable support (613), a relatively arranged movable static contact (611) and a movable movable contact (612). The movable movable contact (612) is arranged on the movable support (613). The normally open contact (620) includes a movable closing support (623), a relatively arranged movable static contact (621) and a movable closing movable contact (622). The movable closing movable contact (622) is arranged on the movable closing support (623). The push rod (540) of the action mechanism (500) is provided with a first pushing portion (541) for driving and cooperating with the movable support (613) and a second pushing portion (542) for driving and cooperating with the movable closing support (623).

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