CN209981105U - Three-phase protector and electrical equipment - Google Patents

Abstract

Three-phase protector and electrical equipment. The three-phase protector includes: the static terminal assembly is provided with a first static terminal and a second static terminal, wherein the first static terminal is provided with a first static contact, and the second static terminal is provided with a second static contact; the movable terminal assembly comprises a movable arm, wherein the movable arm is provided with a fixed end and a free end provided with a first movable contact and a second movable contact; a disc configured to actuate the movable arm when a temperature exceeds a predetermined value; and a housing for accommodating the stationary terminal assembly, the movable terminal assembly and the disc, wherein the stationary terminal assembly is an injection molded part, further comprising an injection molded part formed by curing an injection molding material for molding the first stationary terminal and the second stationary terminal together and insulating them from each other, and the movable arm and the disc are fixed to the injection molded part by a rivet. An electrical apparatus includes the three-phase protector. The disclosed three-phase protector achieves high reliability and long life with a simple structure.

Description

Three-phase protector and electrical equipment

Technical Field

The utility model relates to a three-phase protector and electrical equipment, electrical equipment includes this three-phase protector.

Background

The protector is a protector for connecting or disconnecting a circuit connection by deformation and/or inversion of a disk when a predetermined temperature is exceeded.

Three-phase protectors are often used in various conventional electrical apparatuses (e.g., motors) using alternating current. Three-phase protectors generally have two pairs of electrical contacts, which are deformed and/or flipped to open the two pairs of electrical contacts when the current and/or temperature of the electrical apparatus exceeds a predetermined value, thus protecting the electrical apparatus.

For a small three-phase protector with limited internal space (such as a three-phase protector bound on a motor winding), a simple structure and high reliability are generally desired, and the existing small three-phase protector cannot completely meet the requirement. In addition, the existing small three-phase protector is easy to burn out, so that the service life is short.

SUMMERY OF THE UTILITY MODEL

To address the above-described deficiencies in the prior art, it is an object of the present invention to provide an improved three-phase protector with a simple structure for achieving high reliability. Another object of the present invention is to provide an improved three-phase protector with a longer service life.

In one aspect, the utility model provides a three-phase protector, three-phase protector includes: the static terminal assembly is provided with a first static terminal and a second static terminal, a first static contact is arranged on the first static terminal, and a second static contact is arranged on the second static terminal; the movable terminal assembly comprises a movable arm, the movable arm is provided with a free end and a fixed end, a first movable contact and a second movable contact are arranged on the free end, the first fixed contact and the first movable contact form a first pair of electric contacts, and the second fixed contact and the second movable contact form a second pair of electric contacts; a disc configured to actuate the movable arm of the moving terminal assembly when a temperature exceeds a predetermined value; and a housing for accommodating the stationary terminal assembly, the movable terminal assembly and the disc, wherein the stationary terminal assembly is an injection molded part, the stationary terminal assembly further includes an injection molded part formed by curing an injection molded material for molding the first stationary terminal and the second stationary terminal together and insulating them from each other, and the movable arm and the disc are fixed to the injection molded part by a rivet.

In some configurations, the three-phase protector further includes a first wire, a second wire, and a third wire, the first and second stationary terminals pass through the injection-molded part, respective first ends of the first and second stationary terminals are provided with the first and second stationary contacts, respectively, respective second ends of the first and second stationary terminals opposite to the first ends are electrically connected with the first and second wires, respectively, and the third wire is electrically connected with a fixed end of the movable arm.

In some configurations, the three-phase protector further includes a cover plate, and the disc, the movable arm, and the cover plate are stacked on the injection-molded part in this order from bottom to top and fixed to the injection-molded part by the rivet.

In some configurations, the injection molded part includes a first portion and a second portion, the first portion being closer to the two pairs of electrical contacts relative to the second portion in a length direction of the first and second stationary terminals, the first portion including a central ridge extending along the length direction, a first ramp and a second ramp sloping downward from the central ridge toward the first and second stationary terminal sides, respectively.

In some configurations, the first portion further includes a third ramp that slopes downward from a side of the central spine proximate the two pairs of electrical contacts in the length direction.

In some configurations, the second portion has a base portion, a first protruding portion and a second protruding portion that protrude in a height direction from both sides of the base portion in a width direction, which is a direction perpendicular to the length direction in a plane formed by the first and second stationary terminals, respectively, and a rivet hole through which a rivet passes is provided on the base portion between the first protruding portion and the second protruding portion, and the height direction is a direction perpendicular to the plane formed by the length direction and the width direction.

In some configurations, the housing is a plastic housing.

In some configurations, the three-phase protector further includes an arc isolation disposed between the first pair of electrical contacts and the second pair of electrical contacts, the arc isolation configured to isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other.

In some configurations, the arc chute is an insulating barrier molded integrally with the housing, the insulating barrier extending vertically upward within the housing from a bottom wall of the housing by a height that is greater than or equal to a height of the two pairs of electrical contacts.

In another aspect, the present disclosure provides an electrical device comprising the above-described three-phase protector.

With the above-described structure, the three-phase protector of the present disclosure achieves high reliability and a high service life with the simplest structure.

Drawings

The various objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention, taken in conjunction with the accompanying drawings. The drawings are merely exemplary of the invention and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views.

Fig. 1 is a schematic view showing an appearance of a three-phase protector according to the present disclosure;

fig. 2 is a schematic diagram illustrating a three-phase protector according to the present disclosure in a state where a housing is removed;

fig. 3 is an exploded schematic view of a three-phase protector according to the present disclosure;

fig. 4A is a top view of a three-phase protector according to the present disclosure with the outer housing removed;

FIG. 4B is a cross-sectional view taken along line A-A of FIG. 4A;

FIG. 4C is a cross-sectional view taken along line B-B of FIG. 4A;

fig. 5 is a perspective view of a stationary terminal assembly of a three-phase protector according to the present disclosure;

fig. 6A is a schematic top view of a three-phase protector according to the present disclosure, with a portion of the upper surface of the housing omitted to more clearly show the internal structure; and

fig. 6B is a sectional view taken along line a-a of fig. 6A.

Detailed Description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred embodiments of the disclosure are shown. It should be understood, however, that the present disclosure can be embodied in many different forms and is not limited to the embodiments described below; rather, the embodiments described below are intended to provide a more complete disclosure of the present disclosure, and to fully convey the scope of the disclosure to those skilled in the art. It is also to be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

It should be understood that like reference numerals refer to like elements throughout the several views. In the drawings, the size of some of the features may be varied for clarity.

Unless otherwise defined, terms (including technical and scientific terms) used herein shall have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Unless otherwise indicated, the terms "comprising" and "including" as used in the specification and claims should be interpreted in an open-ended fashion, that is, the terms "comprising" and "including" should be interpreted as being synonymous with the terms "including at least" or "including at least".

As used herein, unless otherwise noted, the terms "upper", "lower", "top", "bottom", "left", "right", and the like, are relative orientations of the protector in the state shown in fig. 1-3.

The term "disc" as used in the present invention refers to a heat sensitive element that is capable of deforming and/or flipping when the temperature exceeds a predetermined value.

It is to be understood that the terminology used in the description is for the purpose of describing particular embodiments only, and is not intended to be limiting of the disclosure. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

To the above-mentioned defect among the prior art, the utility model provides a three-phase protector. Referring to fig. 1-5, one embodiment of a three-phase protector 100 according to the present disclosure is shown.

Fig. 1 shows the appearance of a three-phase protector 100 according to the present disclosure. As shown in fig. 1, the three-phase protector includes a housing 1 and a lead wire 7. The housing 1 is preferably made of plastic or similar material. The plastic is Preferably Polyphenylene Sulfide (PPS) plastic or similar material. Polyphenylene Sulfide (PPS) has excellent high temperature resistance, corrosion resistance, and insulating properties. In the case of adopting the plastic shell, compared with the metal shell, the insulating sleeve does not need to be arranged outside the shell, so that the parts are reduced, and the rapid transmission of the temperature is facilitated. However, the material of the housing 1 is not limited to plastic, but may be made of any suitable material (e.g., metal, etc.). The wire 7 includes a first wire 71, a second wire 72, and a third wire 73.

Fig. 2 and 3 show the internal structure of the three-phase protector 100 according to the present disclosure in a state where the housing 1 is removed. Fig. 4A is a top view of a three-phase protector according to the present disclosure with the outer shell removed. Fig. 4B is a sectional view taken along line a-a of fig. 4A. FIG. 4C is a cross-sectional view taken along line B-B of FIG. 4A;

as shown in fig. 2 and 3, the three-phase protector 100 includes, in addition to the housing 1 and the lead 7 described above, a stationary terminal assembly 2, a disc 3, a movable terminal assembly 4, an optional cover plate 5, a rivet 6, and a seal portion 8. The static terminal assembly 2, the disc 3, the moving terminal assembly 4 and the cover plate 5 are arranged from bottom to top in sequence. The stationary terminal assembly 2, the disc 3, the moving terminal assembly 4 and the cover plate 5 may each have a rivet hole 9 through which the rivet 6 passes. The static terminal assembly 2, the disc 3, the movable terminal assembly 4 and the cover plate 5 are fixed together by rivets 6. The rivet 6 may be a rivet or the like.

As shown in fig. 3 and 5, the stationary terminal assembly 2 may include a first stationary terminal 21 and a second stationary terminal 22. The first stationary terminal 21 and the second stationary terminal 22 may be molded integrally by injection molding (e.g., insert molding). The first stationary terminal 21 and the second stationary terminal 22 are insulated from each other. The injection molded stationary terminal assembly 2 further includes an injection molded portion 23. The injection molding portion 23 is formed by solidifying a molten material (e.g., resin or the like) used for injection molding.

In the context of the present invention, the length direction of the first and second stationary terminals 21 and 22 is referred to as the length direction of the three-phase protector (hereinafter referred to as the length direction). A direction perpendicular to the longitudinal direction of the first and second fixed terminals 21 and 22 in a plane formed by the first and second fixed terminals 21 and 22 is referred to as a width direction of the three-phase protector (hereinafter, referred to as a width direction). A direction perpendicular to a plane formed by the longitudinal direction of the three-phase protector and the width direction of the three-phase protector is referred to as a height direction of the three-phase protector (hereinafter, referred to as a height direction).

In the injection-molded stationary terminal assembly, the first stationary terminal 21 and the second stationary terminal 22 pass through the injection portion 23 in parallel with each other in the length direction. Both ends of the first stationary terminal 21 in the length direction and both ends of the second stationary terminal 22 in the length direction protrude from the injection molded part 23. The first stationary terminal 21 and the second stationary terminal 22 have a first stationary contact 210 and a second stationary contact 220, respectively, at their respective first ends in the length direction. Second ends of the first and second stationary terminals 21 and 22 in the longitudinal direction are connected to a first lead wire 71 and a second lead wire 72, respectively. The first end is opposite the second end. The injection molded part 23 of the stationary terminal assembly 2 may be provided with the staking hole.

The disc 3 is a heat sensitive element. The disc 3 is disposed under the moving terminal assembly 4 and fixed to the injection molded portion 23 of the stationary terminal assembly 2 together with the moving terminal assembly 4 by the rivet 6. The disc 3 can deform and/or turn over to drive the stationary terminal assembly 2 to move when the temperature exceeds a predetermined value. In one example, the disc may be a bimetal. A "bimetal" is a metal element obtained by combining two or more layers of alloys having different thermal expansion coefficients, which is deformed by heat generation when a temperature exceeds a predetermined value.

As shown in fig. 2 and 3, in one example, the moving terminal assembly 4 includes a moving arm 40 and a first moving contact 41 and a second moving contact 42 disposed on the moving arm. The movable arm 40 may be a resilient element. The movable arm 40 has a fixed end (an end provided with a staking hole) and a free end (an end opposite to the staking hole). A first movable contact 41 and a second movable contact 42 are provided on the free end. The first and second movable contacts 41 and 42 correspond to the first and second stationary contacts 210 and 220, respectively, to form two pairs of electrical contacts. In one example, the fixed end is a common end and the free end is a bifurcated structure. The bifurcation structure may be a U-shaped bifurcation structure, a V-shaped bifurcation structure, or other form of bifurcation structure. The first movable contact 41 and the second movable contact 42 are provided on the two prongs, respectively. When the disc is deformed and/or flipped, the disc applies an upward force to the movable arm 40, so that the free end of the movable arm 40 bounces, and the first and second movable contacts 41 and 42 are disconnected from the first and second stationary contacts 210 and 220, respectively. The third wire 73 is electrically connected to the fixed end of the movable arm 40. The two pairs of electrical contacts are located away from the conductor 7 relative to the location of the rivet (i.e. where the rivet 6 or the rivet hole 9 is located).

Due to the adoption of the static terminal assembly structure and the riveting connection structure, the three-phase protector disclosed by the invention is simple in structure and low in manufacturing cost, and meanwhile, the riveting connection structure enables the disc 3 to be in closer contact with the movable arm 40 of the movable terminal assembly 4, so that heat transfer from the movable arm 40 to the disc 3 is quicker, the heat sensitivity of the three-phase protector is improved, and the reliability of the three-phase protector is greatly improved. Furthermore, the arrangement of the two pairs of electrical contacts on the side remote from the conductor 7 leaves sufficient space for the riveting in a limited space.

The cover plate 5 is disposed above the fixed end of the movable arm 40 for pressing the stationary terminal assembly 2, the disc 3, and the movable terminal assembly 4 to restrict their movement in the up-down direction. The cover plate 5 may be a copper block. The cover plate 5 may also be made of any other material.

In one example, as shown in fig. 3 and 5, the injection molded part 23 may include a first part 231 and a second part 232. The first portion 231 is located on a side close to the two pairs of electrical contacts in the length direction with respect to the second portion 232. The second portion 232 has a base 2321, a first projection 2322 and a second projection 2323. The first protruding part 2322 and the second protruding part 2323 protrude from the base 2321 in the height direction on both sides of the base 2321 in the width direction, respectively. The staking hole is provided at a position of the base 2321 between the first and second protruding portions 2321 and 2322. The first and second protrusions 231 and 232 restrict movement of the riveted members in the width direction.

In one example, as shown in fig. 2, the cover plate 5 is configured such that an upper surface of the cover plate 5 is flush with upper surfaces of the first and second protrusions 231 and 232 when assembled over the moving terminal assembly 4.

In one example, as shown in fig. 3, 4B, 4C, and 5, the first portion 231 includes a central ridge 2311, a first slope 2312, a second slope 2313, and a third slope 2314. The central ridge 2311 extends in the longitudinal direction. The first and second slopes 2312 and 2313 are respectively inclined downward at the same slope from both sides of the central ridge 2311 in the width direction. The third inclined surface 2314 is inclined downward from a side of the central ridge 2311 in the longitudinal direction near the first end. The shape of the first portion of the injection-molded part 23 is such that it can better support the disc 3 so that it will exert a force on the movable arm 40 only when the temperature exceeds a predetermined value, thereby improving the reliability of the three-phase protector.

The sealing portion 8 is used for enclosing the structure composed of the fixed terminal assembly 2, the disc 3, the moving terminal assembly 4 and the cover plate 5 in the housing 1. The sealing portion 8 may be made of epoxy resin. The sealing portion 8 may also be made of any insulating sealing material.

Fig. 6A is a schematic top view of a three-phase protector according to the present disclosure, with a portion of the upper surface of the housing omitted to more clearly show the internal structure. Fig. 6B is a sectional view taken along line a-a of fig. 6A.

As shown in fig. 6A and 6B, the three-phase protector 100 may further include an arc isolation portion 10. The arc barrier 10 is disposed between a first pair of electrical contacts formed by the first movable contact 41 and the first stationary contact 210 and a second pair of electrical contacts formed by the second movable contact 42 and the second stationary contact 220. The arc isolation 10 is configured to isolate an arc generated between the first pair of electrical contacts and an arc generated between the second pair of electrical contacts from each other. The arc barrier 10 may be made of any insulating material capable of isolating an arc. For example, the arc chute 10 may be made of polyphenylene sulfide (PPS) plastic or similar material.

In one example, as shown in fig. 6A and 6B, the arc chute 10 may be an insulating barrier. Although the example in the drawings illustrates one embodiment of the arc isolation part in the form of an insulating barrier, it may be appreciated by those skilled in the art that the arc isolation part may not be limited to an insulating barrier as long as it can isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other. For example, the arc isolation part may be an arc isolation cover, an arc isolation sleeve, or the like.

In a preferred embodiment, the insulating spacer is formed in one piece with the housing 1, for example by moulding. The insulating spacer may be of the same material as the housing 1. An insulating partition is provided within the housing 1 between the two pairs of electrical contacts and extends vertically upwards from the bottom wall of the housing 1 to a certain height. The height is greater than or equal to the height of the two pairs of electrical contacts. In one example, the insulating partition extends from the bottom wall of the housing 1 up to the top wall of the housing 1. The length of the insulating spacer in the length direction is sufficiently long to isolate an arc generated between the first pair of electrical contacts from an arc generated between the second pair of electrical contacts. For example, the length of the insulating spacer in the length direction exceeds the extent of the area in which the two pairs of electrical contacts are located.

Although some embodiments of the insulating spacer have been exemplified above, it will be appreciated by those skilled in the art that the number, shape, arrangement, etc. of the insulating spacers are not limited as long as they can isolate the arc generated by the first pair of electrical contacts from the arc generated by the second pair of electrical contacts. For example, the insulating spacer may also be integrally molded with the injection molded part 23, or the insulating spacer may be a separate component.

In the current small-size three-phase protector that can bind on motor winding, because three-phase protector's space is limited, can't set up parts such as arc control device among the large-scale circuit breaker, consequently current small-size three-phase protector is often burnt out easily, therefore life is lower. The three-phase protector according to the present disclosure eliminates the risk of the arc breaking the three-phase protector to burn out by providing only the above-described arc isolation portion (e.g., by merely molding the integrated partition plate inside the plastic case), thereby greatly improving the service life of the three-phase protector through a simple structure.

In another aspect, the present invention also provides an electrical apparatus on which a three-phase protector 100 of the type described above can be mounted and used. This can improve the safety performance of the electrical device.

The three-phase protector 100 according to the present disclosure can be applied to various motors, for example, motors for electric devices such as water pumps, juice makers, soymilk makers, mixers, dust collectors, and electric tools.

The operation principle of the three-phase protector 100 according to the present disclosure will be described below. When the motor protected by the three-phase protector has excessive current and/or excessive temperature, the heat generated by the motor is conducted to the disc 3 through the shell 1 and/or the excessive current flows through the movable arm 40 of the movable terminal assembly 4, so that the movable arm 40 generates heat and conducts the heat to the disc 3, and when the temperature of the disc 3 exceeds a preset value, the disc 3 is deformed and/or overturned, so that upward acting force is applied to the movable arm 40, the movable arm bounces upwards, and the two pairs of electric contacts are disconnected, thereby protecting the motor.

An assembling process of the three-phase protector 100 according to the present disclosure will be described below. First, the stationary terminal assembly 2 is injection molded. Then, the fixed terminal assembly 2, the disc 3, the moving terminal assembly 4 and the cover plate 5 are riveted together in sequence by riveting. The wires are then connected and the necessary calibration and debugging is performed. Finally, the integrally assembled components are placed in the housing 1 and are enclosed in the housing 1 by the seal portions 8.

Although the present disclosure has been described with reference to exemplary embodiments, those skilled in the art will appreciate that various modifications and variations can be made to the exemplary embodiments of the present disclosure without materially departing from the spirit and scope of the disclosure. Accordingly, all such modifications and variations are intended to be included herein within the scope of this disclosure as defined by the following claims. The scope of the disclosure is defined by the appended claims, and equivalents of those claims are intended to be embraced therein.

Claims (10)

1. A three-phase protector, the three-phase protector comprising:

the static terminal assembly is provided with a first static terminal and a second static terminal, a first static contact is arranged on the first static terminal, and a second static contact is arranged on the second static terminal;

the movable terminal assembly comprises a movable arm, the movable arm is provided with a free end and a fixed end, a first movable contact and a second movable contact are arranged on the free end, the first fixed contact and the first movable contact form a first pair of electric contacts, and the second fixed contact and the second movable contact form a second pair of electric contacts;

a disc configured to actuate the movable arm of the moving terminal assembly when a temperature exceeds a predetermined value; and

a housing for accommodating the stationary terminal assembly, the moving terminal assembly and the disc,

it is characterized in that the preparation method is characterized in that,

the stationary terminal assembly is an injection-molded part, and further includes an injection-molded part formed by curing an injection-molded material for molding the first stationary terminal and the second stationary terminal together and insulating them from each other, and the movable arm and the disc are fixed to the injection-molded part by a rivet.

2. The three-phase protector according to claim 1, further comprising a first lead, a second lead, and a third lead, wherein the first and second stationary terminals pass through the injection molded part, respective first ends of the first and second stationary terminals are respectively provided with the first and second stationary contacts, respective second ends of the first and second stationary terminals opposite to the first ends are respectively electrically connected to the first and second leads, and the third lead is electrically connected to the movable arm.

3. The three-phase protector according to claim 1, further comprising a cover plate, wherein the disc, the movable arm and the cover plate are stacked on the injection-molded part in this order from bottom to top and fixed to the injection-molded part by the rivet.

4. The three-phase protector of claim 3, wherein the injection molded portion includes a first portion and a second portion, the first portion being closer to the two pairs of electrical contacts than the second portion in a length direction of the first and second stationary terminals, the first portion including a central ridge extending along the length direction, a first inclined surface and a second inclined surface, the first inclined surface and the second inclined surface being inclined downward from the central ridge toward the first stationary terminal side and the second stationary terminal side, respectively.

5. The three-phase protector of claim 4, wherein the first portion further comprises a third ramp surface that slopes downward from a side of the central spine adjacent the two pairs of electrical contacts in the length direction.

6. The three-phase protector according to claim 4, wherein the second part has a base portion, a first projecting portion and a second projecting portion that project in a height direction from both sides in a width direction of the base portion, respectively, a rivet hole through which a rivet passes being provided on the base portion between the first projecting portion and the second projecting portion, wherein the width direction is a direction perpendicular to the length direction in a plane formed by the first stationary terminal and the second stationary terminal, and the height direction is a direction perpendicular to a plane formed by the length direction and the width direction.

7. The protector of claim 1, wherein the housing is a plastic housing.

8. The three-phase protector according to any one of claims 1-7, further comprising an arc isolation portion disposed between the first pair of electrical contacts and the second pair of electrical contacts, the arc isolation portion configured to isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other.

9. The three-phase protector of claim 8, wherein the arc splitter is an insulating barrier molded integrally with the housing, the insulating barrier extending vertically upward from a bottom wall of the housing within the housing by a height that is greater than or equal to a height of the two pairs of electrical contacts.

10. An electrical apparatus, characterized in that it comprises a three-phase protector according to any one of claims 1-9.

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