CN113489382A

CN113489382A - Integrated motor starting protector

Info

Publication number: CN113489382A
Application number: CN202110777022.9A
Authority: CN
Inventors: 赵晓东; 赵云文; 刘利东; 汤建国; 葛玲莉
Original assignee: Changshu Tianyin Electromechanical Co Ltd
Current assignee: Changshu Tianyin Electromechanical Co Ltd
Priority date: 2021-07-09
Filing date: 2021-07-09
Publication date: 2021-10-08
Anticipated expiration: 2041-07-09
Also published as: CN113489382B

Abstract

An integrated motor starting protector comprises a shell, wherein the shell is provided with a starter accommodating cavity, a first pin accommodating cavity and a second pin accommodating cavity, a positive temperature coefficient thermistor left supporting flange and a positive temperature coefficient thermistor right supporting flange are arranged in the starter accommodating cavity, the first pin accommodating cavity and the second pin accommodating cavity are respectively formed by surrounding of the sides of the pin accommodating cavities, and a shell first jack and a shell second jack are arranged on the shell; the shell cover is matched with the position of the shell opening on the side, facing downwards, of the shell; the starter is established and is held the intracavity at the starter, and hold the position in chamber and the first, second jack of shell and insert to join in marriage at the position that corresponds to first, second base pin, characteristics: extend left on the left wall body of shell and have the protector to insert to inlay the seat, the front side that the front end that the protector inserted the seat stretches out the shell, the trailing flank that the shell was stretched out to the rear end, the protector is inserted the seat and is had the protector and hold the chamber, and the shape that the protector held the chamber is the U font, and the protector holds the chamber with the protector and inserts and inlay the cooperation. The requirements for miniaturization of volume, modularization of structure, rapidness of assembly and convenience of inspection, maintenance and replacement are met.

Description

Integrated motor starting protector

Technical Field

The invention belongs to the technical field of refrigeration compressors, and particularly relates to an integrated motor starting protector which is used for starting and protecting a refrigeration compressor motor.

Background

The starting protector is a general name of the starter and the protector. Since the motor of the conventional refrigeration compressor is a low-power single-phase ac motor, a starter is required to assist the starting at the time of starting, and an overload protector (i.e., the aforementioned "protector") is required to perform protection after the compressor enters a normal operation state. In particular, the overload protector ensures that the power supply is cut off when the overload situation occurs in the running process of the refrigeration compressor, so that the compressor is prevented from overheating and causing damage.

Earlier, the starter and the protector were generally designed as separate split structures and each connected in a separate electrical assembly in the electrical circuit of the refrigerant compressor. For example, three sockets are formed in the starter, and are plugged into a compressor standard interface (conventionally referred to as a "three-wire post") of the refrigeration compressor, which is formed by three conductive rods (also referred to as "conductor rods"), and the protector is packaged in an independent state in a separately configured box body such as a bakelite box, and is connected to an electrical circuit of the refrigeration compressor through a transition junction box or a terminal block on the starter. Since the electrical connection is performed manually, it is easy to make mistakes, it is difficult to ensure the quality of the electrical connection and to improve the assembly efficiency of the product, and the electrical reliability of the system is affected by too many connectors.

From the above description, it can be determined without doubt that: combining the starter and the protector has a good positive significance, and is not disclosed in the published chinese patent documents, such as CN2606490Y (motor start, protector), CN2606491Y (integrated motor start, protector), CN2664280Y (motor starter with improved structure), CN100581043C (energy-saving integrated single-phase ac motor start, protector), CN102386815A (integrated motor start protector with improved structure), CN101369790A (energy-saving integrated single-phase ac motor start, protector), CN206211857U (refrigeration compressor start protector without power consumption), CN106385204A (refrigeration compressor start protector without power consumption) and CN104734570A (start protector without power consumption energy-saving single-phase ac motor start), to name a few.

As is known in the art, as various electronic and electrical components are miniaturized, modularized, and convenient to install and/or maintain, the motor start protector is also developed. However, since the shape of the protector disclosed in the above-mentioned patent is not limited to a cylindrical shape, it is necessary to extend a cylindrical protector seat on the outer wall of the rectangular housing at a position located at one corner of the outer wall of the housing, and insert the protector into the protector seat (see, specifically, CN104734570A mentioned above), which, on one hand, limits the idea of the protector that tends to be flat, on the other hand, is not enough to ensure the miniaturization of the volume of the whole housing (for designing the starter and the housing of the protector) and to meet the desired strength requirement, and on the other hand, makes the shape of the whole housing mismatched, which results in that the mold for manufacturing the plastic housing becomes complicated and increases the mold cost, which, on the other hand, is not conducive to efficient and automatic assembly in the production process.

Chinese patent CN101320661B recommends "overload protector with explosion-proof structure", which realizes the design of the protector to be flat and can block the arc that may be generated when the moving contact is disconnected from the meter contact, so as to avoid leakage to the outside and even initiate the explosion of combustible gas or steam. However, this patent does not give any technical teaching of the integration with the starter, and therefore it is necessary to make a rational design, and the technical solutions described below are made in this context.

Disclosure of Invention

The invention aims to provide an integrated motor starting protector which is beneficial to meeting the requirements of miniaturization of volume, modularization of structure, rapidness of assembly, convenience of inspection and maintenance and replacement and economy and low cost.

The object of the present invention is achieved by an integrated motor starting protector comprising a housing having a starter receiving chamber, a first pin receiving chamber I and a second pin receiving chamber II, a PTC thermistor left support flange and a PTC thermistor right support flange corresponding to each other being formed in the middle of the starter receiving chamber and protruding from the surface of the chamber bottom wall of the starter receiving chamber, the first pin receiving chamber I and the second pin receiving chamber II each being surrounded by pin receiving chamber ledges at positions corresponding to the left side of the starter receiving chamber, a housing first insertion hole I formed in the housing and at a position corresponding to the first pin receiving chamber I, the housing first insertion hole I communicating the first pin receiving chamber I with the outside, a second plug hole II of the shell is formed in the position, corresponding to the second plug pin accommodating cavity II, of the shell, and the second plug pin accommodating cavity II is communicated with the outside through the second plug hole II of the shell; the shell cover is matched with the part of the shell opening on the side, facing downwards, of the shell; the starter is arranged in the starter accommodating cavity in a state of being supported between the left supporting flange of the positive temperature coefficient thermistor and the right supporting flange of the positive temperature coefficient thermistor, and is respectively inserted and matched with the first jack I and the second jack II of the shell at positions corresponding to the first pin accommodating cavity I and the second pin accommodating cavity II.

In a specific embodiment of the invention, a first electric inserting sheet limiting stop pin I, a second electric inserting sheet limiting stop pin II and a positive temperature coefficient thermistor probing limiting cavity are formed on one side of the shell cover facing to the starter accommodating cavity of the shell, the first electric inserting sheet limiting stop pin I and the second electric inserting sheet limiting stop pin II correspond to each other, and the positive temperature coefficient thermistor probing limiting cavity is positioned between the first electric inserting sheet limiting stop pin I and the second electric inserting sheet limiting stop pin II; the starter comprises a positive temperature coefficient thermistor, a first electric inserting piece I and a second electric inserting piece II, wherein the positive temperature coefficient thermistor is arranged in a longitudinal state, the upper part of the positive temperature coefficient thermistor is supported between a left supporting flange of the positive temperature coefficient thermistor and a right supporting flange of the positive temperature coefficient thermistor, the lower part of the positive temperature coefficient thermistor stretches into a limited cavity, the front side of the first electric inserting piece I is electrically contacted with the rear side of the positive temperature coefficient thermistor, the rear side of the first electric inserting piece I is limited by the first electric inserting piece limiting blocking pin I, the first electric inserting piece I is provided with a first electric inserting piece pin I and an electric connecting pin, the first electric inserting piece pin I stretches into the first pin containing cavity I and corresponds to the first inserting hole I of the shell, the electric connecting pin is inserted into the shell cover and extends to the lower part of the shell cover, the rear side of a second electric inserting piece II is in electrical contact with the front side of the positive temperature coefficient thermistor, the front side of the second electric inserting piece II is limited by a second electric inserting piece limiting baffle pin II, the second electric inserting piece II is provided with a second electric inserting piece pin II, a first external electric connecting pin I and a second external electric connecting pin II, the second electric inserting piece pin II extends into the second pin accommodating cavity II and corresponds to a second inserting hole II of the shell, and the first external electric connecting pin I and the second external electric connecting pin II are inserted into the shell cover and extend to the lower part of the shell cover; the shell first jack I and the shell second jack II are electrically connected with the compressor three-wire column in a plugging mode in a use state; and the shell cover buckling feet are respectively formed on the outer walls of the front side and the rear side of the shell, and a shell cover buckling foot extends on each of the wall bodies of the front side and the rear side of the shell cover, and the positions of the shell cover buckling feet correspond to the positions of the pair of shell cover buckling foot fixing seats and are matched with the shell cover buckling foot fixing seats in an inserting way.

In another specific embodiment of the present invention, the protector includes a shield, a shield cover, an insert spring, an electric heating wire, a bimetal, a first electrical connector i, a second electrical connector ii, a stationary contact pin, a movable contact piece, and a protector pin, a stationary contact pin insert flange cavity, an insert spring positioning cavity, an insert spring pin support cavity, an electric heating wire cavity, and an electrical connector positioning cavity are formed on the right side of the shield, the stationary contact pin insert flange cavity is located above the rear portion of the right side of the shield and a pair of stationary contact pin positioning flange insert grooves are formed on a cavity bottom wall of the stationary contact pin insert flange cavity in correspondence with each other, the pair of stationary contact pin positioning flange insert grooves penetrate through a cavity bottom wall of the stationary contact pin insert flange cavity to communicate with the outside, the insert spring positioning cavity corresponds to a lower portion of the stationary contact pin insert flange cavity and a insert spring positioning insert groove is formed on a cavity bottom wall of the insert spring positioning cavity, the insert positioning insert pin penetrates through a cavity bottom wall of the insert spring insert groove to communicate with the outside, the spring pin supporting cavity is formed at the edge part of the rear lower part of the right side of the protective cover at the position corresponding to the spring positioning cavity and is communicated with the spring positioning cavity, the electric heating wire cavity is formed at the center position of the right side of the protective cover, the electric connecting piece positioning cavity is positioned in front of the right side of the protective cover, an electric connecting piece positioning embedded foot groove penetrating through the cavity bottom wall of the electric connecting piece positioning cavity is formed on the cavity bottom wall of the electric connecting piece positioning cavity, the base part of the inserting spring is positioned in the spring positioning cavity and is bent at the base part of the inserting spring to form an inserting spring positioning embedded foot, the inserting spring positioning embedded foot is embedded and fixed with the inserting spring positioning embedded foot inserting groove, an inserting spring used for being connected with an electric circuit in series extends from one side of the inserting spring facing to the spring pin supporting cavity, the inserting spring foot is tightly attached to and supported on the spring pin supporting cavity and extends out of the lower surface of the protective cover, an electric heating wire inserting spring electric connecting lug extends from the front side surface of the base part of the inserting spring, the electric heating wire inserting spring electric connecting lug extends into the electric heating wire cavity, the electric heating wire is embedded in the electric heating wire cavity in a C-shaped state, a first connecting end I of the electric heating wire is connected with the electric heating wire inserting spring electric connecting lug, a second connecting end II of the electric heating wire is connected with a first electric connecting piece I, a bimetallic strip covers the right side of the electric heating wire, the first electric connecting piece I is arranged in the electric connecting piece positioning cavity, an electric connecting piece limiting strip extends from the lower part of the first electric connecting piece I, the second connecting end II of the electric heating wire is connected with the electric connecting piece limiting strip, an electric connecting piece positioning embedded foot extends from the electric connecting piece limiting strip and corresponds to the electric connecting piece positioning embedded foot groove, the electric connecting piece positioning embedded foot is embedded in the electric connecting piece positioning embedded foot groove, and the second electric connecting piece II is welded and fixed with the first electric connecting piece I, the static contact pin is arranged in the static contact pin inserting flange cavity, a pair of static contact pin inserting flanges are formed on the static contact pin and correspond to the pair of static contact pin positioning flange inserting grooves, the pair of static contact pin inserting flanges and the pair of static contact pin positioning flange inserting grooves are fixedly inserted and embedded, a static contact is fixed on the static contact pin, one end of the static contact pin, facing the protective cover, penetrates through the protective cover to form a static contact pin electric connecting end, one end of the movable contact piece and the second electric connecting piece II form an integral structure, the middle part of the movable contact piece is attached to the right side of the bimetallic strip, the other end of the movable contact piece is formed into a free end, a movable contact is fixedly welded at a position corresponding to the static contact, the protector pin is embedded on the right side of the protective cover, a protector pin extends to form an electric connecting piece, and the protector pin electric connecting piece is also embedded and matched with the right side of the protective cover, the tail end of the protector pin electric connecting sheet is folded and unfolded to form a protector pin electric connecting sheet electric connecting lug, the protector pin electric connecting sheet electric connecting lug is electrically connected with the static contact pin electric connecting end, the protective cover covers the right side of the protective cover and is fixed with the protective cover, and the protective cover accommodating cavity of the protective cover inserting seat are matched in inserting and embedding.

In a further embodiment of the present invention, a pair of housing cover pressing claws extending at an upper portion of the shroud cover and coming into contact with an upward-facing side surface of the housing is further formed at a position on the shroud cover and between the pair of housing cover pressing claws to form a protector pin insertion cavity in which the protector pin is inserted and electrically connected to the compressor three-terminal in a plug-in manner in a state of use.

In a further specific embodiment of the present invention, a plug spring auxiliary leg connecting plate extends on a front side surface of the plug spring and at a position corresponding to a lower portion of the heating wire plug spring electrical connection lug, a plug spring auxiliary leg extends on a side of a lengthwise middle portion of the plug spring auxiliary leg connecting plate that faces downward, the plug spring auxiliary leg is supported on the plug spring auxiliary leg supporting portion of the shield and extends to a lower portion of the shield; a spring-inserted auxiliary foot yielding cavity is formed on the left side of the protective cover and at a position corresponding to the spring-inserted auxiliary foot.

In yet another specific embodiment of the present invention, a protector electrical lug defining cavity having the same shape as the protector pin electrical lug and communicating with the protector pin insertion cavity is formed on the right side of the protector cover cap and at a position corresponding to the protector pin electrical lug, a stationary contact pin electrical connection terminal passing hole is formed in the protector electrical connection tab defining cavity and at a position corresponding to the stationary contact pin electrical connection terminal, the protector pin electrical connection tab is embedded in the protector electrical connection tab defining cavity and the protector pin electrical connection tab is formed to correspond to a front side of the stationary contact pin electrical connection terminal passing hole, and the static contact pin electric connecting end of the static contact pin penetrates upwards through the protective cover at a position corresponding to the static contact pin electric connecting end through hole to ensure that the protector pin electric connecting piece electric connecting lug is electrically connected with the protector pin electric connecting piece in a welding mode.

In a more specific embodiment of the present invention, a moving contact flange is formed at a central left side of the moving contact and at a central position corresponding to the bimetal, and the moving contact flange is in contact with a central position of a right side of the bimetal.

In a further specific embodiment of the present invention, a pair of shroud cover inserting and embedding fixing columns are formed on the left side of the shroud cover, a pair of fixing column inserting and embedding holes penetrating through the shroud cover are formed on the shroud cover and at positions corresponding to the pair of shroud cover inserting and embedding fixing columns, and the pair of shroud cover inserting and embedding fixing columns and the pair of fixing column inserting and embedding holes are inserted and embedded and fixed; the left side surface of the protective cover is formed into a protective cover arc surface matched with the left cavity wall of the protective cover accommodating cavity of the protective cover inserting seat; the pair of fixing post inserting and embedding holes are in a diagonally distributed position relation with each other on the shield, and the pair of shield covers are inserted and embedded with the fixing posts to be in a diagonally distributed position relation with each other on the shield covers.

In a still more specific embodiment of the present invention, an electrical connection pin hole penetrating through the cover is formed in the cover and at a position corresponding to the electrical connection pin, the electrical connection pin is inserted into the electrical connection pin hole and extends to a position below the cover, a cover pin slot penetrating through the cover is formed at the front end of the cover, and the first external electrical connection pin i and the second external electrical connection pin ii are inserted into the cover and extend to a position below the cover at a position corresponding to the cover pin slot.

In yet another specific embodiment of the present invention, the protector insert seat includes a protector support restriction plate, an insert seat front side plate, and an insert seat rear side plate, the protector support restriction plate and the left wall body of the housing constitute an integral structure, the front end of the protector supporting limit plate extends out of the front side surface of the shell, the rear end of the protector supporting limit plate extends out of the rear side surface of the shell, a front side plate of the inserting and embedding seat extends upwards in a state of being vertical to the front end of the protector supporting limit plate, a protector front inserting and embedding groove is formed on one side of the front side plate of the inserting and embedding seat facing the rear side plate of the inserting and embedding seat, and the rear side plate of the inserting and embedding seat extends upwards in a state of being vertical to the rear end of the protector supporting limit plate, a protector rear inserting and embedding groove is formed on one side of the inserting and embedding seat rear side plate facing to the inserting and embedding seat front side plate, and a space formed by the protector supporting limiting plate, the inserting and embedding seat front side plate and the inserting and embedding seat rear side plate which are matched together is formed into the protector accommodating cavity; the protective cover cap and the front end of the protective cover are in inserted fit with the front inserting and embedding groove of the protector, the protective cover cap and the rear end of the protective cover are in inserted fit with the rear inserting and embedding groove of the protector, and the bottom surface of the protective cover cap is supported on the protective cover supporting limiting plate.

According to the technical scheme provided by the invention, the protector inserting and embedding seat with the U-shaped protector accommodating cavity extends leftwards on the left wall body of the shell, so that the protector and the protector accommodating cavity can be inserted and embedded and matched, and the requirements on miniaturization of volume, modularization of structure, quickness in assembly, convenience in inspection and maintenance and replacement, economy and cheapness are met.

Drawings

FIG. 1 is a block diagram of an embodiment of the present invention.

Fig. 2 is a perspective assembly structure view of the protector shown in fig. 1.

Fig. 3 is a schematic view of the bottom of the housing shown in fig. 1.

Detailed Description

In order to clearly understand the technical spirit and the advantages of the present invention, the applicant below describes in detail by way of example, but the description of the example is not intended to limit the technical scope of the present invention, and any equivalent changes made according to the present inventive concept, which are merely in form and not in material, should be considered as the technical scope of the present invention.

In the following description, all the concepts related to the directions or orientations of up, down, left, right, front and rear are based on the position state of fig. 1.

First, the applicant needs to state that: in the actual usage state, i.e. when the present invention is mounted on a refrigeration compressor motor (simply referred to as "refrigeration compressor"), the state of fig. 1 is turned 180 ° with respect to the state shown in fig. 1, so that the upper portion and the orientation mentioned below are exactly the lower portion and the orientation mentioned below with respect to the usage state, and the front and rear mentioned below are exactly the opposite in the usage state, and the same is true in all cases; the state shown in fig. 3 is the actual state. Based on the foregoing, it is not intended that all of the following descriptions of directionality or orientation be interpreted as limiting.

Referring to fig. 1 and 3, there is shown a housing 1 having a starter receiving chamber 11 shown in fig. 3, a first pin receiving chamber i 12 and a second pin receiving chamber ii 13, a ptc thermistor left support flange 111 and a ptc thermistor right support flange 112 corresponding to each other are formed in the starter receiving chamber 11 and in the middle of the starter receiving chamber 11 with a surface projecting from the chamber bottom wall of the starter receiving chamber 11, the first pin receiving chamber i 12 and the second pin receiving chamber ii 13 are each surrounded by a pin receiving chamber step 16 at a position corresponding to the left side of the starter receiving chamber 11, that is, the first pin receiving chamber i 12 and the second pin receiving chamber ii 13 are surrounded by a pin receiving chamber step 16 at a position of the housing 1 facing the wall body of the one side of the starter receiving chamber 11, a first housing insertion hole I14 a is formed in the housing 1 at a position corresponding to the first pin receiving chamber I12, the first pin receiving chamber I12 is communicated with the outside through the first housing insertion hole I14 a, a second housing insertion hole II 14b is formed in the housing 1 at a position corresponding to the second pin receiving chamber II 13, and the second pin receiving chamber II 13 is communicated with the outside through the second housing insertion hole II 14 b; a cover 2 is shown, which cover 2 cooperates with a portion of the housing 1 facing downwards (upwards if in use, the same applies hereinafter) at the housing opening 14c (shown in fig. 3); a starter 3 and a protector 4 are shown, the starter 3 being disposed in the starter accommodating chamber 11 in a state of being supported between the left PTC thermistor supporting flange 111 and the right PTC thermistor supporting flange 112 and being inserted into the case cover 2, and being fitted into the first case insertion hole I14 a and the second case insertion hole II 14b at positions corresponding to the first pin accommodating chamber I12 and the second pin accommodating chamber II 13, respectively.

The technical key points of the technical scheme provided by the invention are as follows: a protector inserting seat 15 extends leftwards on the left wall body of the housing 1, the front end of the protector inserting seat 15 protrudes out of the front side surface of the housing 1, the rear end of the protector inserting seat 15 protrudes out of the rear side surface of the housing 1, the protector inserting seat 15 is provided with a protector accommodating cavity 151, the shape of the protector accommodating cavity 151 is in a U shape, and the protector 4 and the protector accommodating cavity 151 are inserted and embedded in cooperation.

A first electrical insert piece limiting stop pin I21, a second electrical insert piece limiting stop pin II 22 and a positive temperature coefficient thermistor probing limiting cavity 23 are formed on one side of the shell cover 2 facing the starter accommodating cavity 11 of the shell 1, the first electrical insert piece limiting stop pin I21 and the second electrical insert piece limiting stop pin II 22 correspond to each other, namely the first electrical insert piece limiting stop pin I21 and the second electrical insert piece limiting stop pin II 22 correspond to each other in a front-back manner, the positive temperature coefficient thermistor probing limiting cavity 23 is positioned between the first electrical insert piece limiting stop pin I21 and the second electrical insert piece limiting stop pin II 22, the starter 3 comprises a positive temperature coefficient thermistor 31, a first electrical insert piece I32 and a second electrical insert piece II 33, the positive temperature coefficient thermistor 31 is arranged in a longitudinal state, and the upper edge part of the positive temperature coefficient thermistor 31 is supported on the left supporting flange 111 of the positive temperature coefficient thermistor and the positive temperature coefficient thermistor The lower part of the first electrical insert I32 is inserted into the limited cavity 23 of the PTC thermistor, the front side of the first electrical insert I32 is electrically contacted with the rear side of the PTC thermistor 31 through a press-holding spring in a shape of a Chinese character 'ji', the rear side of the first electrical insert I32 is limited by the first electrical insert limiting stop pin I21, the first electrical insert I32 is provided with a first electrical insert pin I321 and an electrical connection pin 322, the first electrical insert pin I321 is inserted into the first pin accommodating cavity I12 and corresponds to the first insertion hole I14 a of the shell, the electrical connection pin 322 is inserted into the shell cover 2 and extends to the lower part of the shell cover 2, the rear side of the second electrical insert II 33 is electrically contacted with the front side of the PTC thermistor 31 through a spring in a shape of a Chinese character 'ji', the front side of the second electric inserting piece II 33 is limited by the second electric inserting piece limiting stop pin II 22, the second electric inserting piece II 33 is provided with a second electric inserting piece pin II 331, a first external electric connecting pin I332 and a second external electric connecting pin II 333, the second electric inserting piece pin II 331 extends into the second pin accommodating cavity II 13 and corresponds to the second jack II 14b of the shell, and the first external electric connecting pin I332 and the second external electric connecting pin II 333 are inserted and matched with the shell cover 2 and extend to the lower part of the shell cover 2; the first shell jack I14 a and the second shell jack II 14b are electrically connected with the three-wire column of the compressor in a plugging mode in a use state.

Referring to fig. 2 in combination with fig. 1 and 3, the protector 4 includes a shield 41, a shield cover 42, a plug spring 43, a heating wire 44a, a bimetal 44b, a first electrical connector i 45, a second electrical connector ii 46, a stationary contact pin 47, a movable contact 48 and a protector pin 49, a stationary contact pin insertion flange cavity 411, a plug spring positioning cavity 412, a plug spring pin support cavity 413, a heating wire cavity 414 and an electrical connector positioning cavity 415 are formed on the right side of the shield 41, the stationary contact pin insertion flange cavity 411 is located above the rear portion of the right side of the shield 41 and a pair of stationary contact pin positioning flange insertion grooves 4111 corresponding to each other are formed on the cavity bottom wall of the stationary contact pin insertion flange cavity 411, the pair of stationary contact pin positioning flange insertion grooves 4111 penetrate through the cavity bottom wall of the stationary contact pin insertion flange cavity 411 to communicate with the outside, the plug spring positioning cavity 412 corresponds to the lower portion of the stationary contact pin insertion flange cavity 411 and a plug spring positioning insertion groove 4121 is formed on the cavity bottom wall of the plug spring positioning cavity 412, the spring positioning insertion groove 4121 penetrates the cavity bottom wall of the spring positioning cavity 412 to communicate with the outside, the spring positioning support cavity 413 is formed at the edge portion of the rear lower portion of the right side of the shield 41 at a position corresponding to the spring positioning cavity 412 and communicates with the spring positioning cavity 412, the electric heating wire cavity 414 is formed at the right side center position of the shield 41, the electric connector positioning cavity 415 is located at the right side front of the shield 41 and an electric connector positioning insertion groove 4151 penetrating the cavity bottom wall of the electric connector positioning cavity 415 is formed on the cavity bottom wall of the electric connector positioning cavity 415, the base of the insertion spring 43 is located in the spring positioning cavity 412 and bent at the base of the insertion spring 43 to form a spring positioning insertion foot 431, the spring positioning insertion foot 431 is inserted and fixed with the spring positioning insertion groove 4121, a spring insertion foot 432 for connecting with an electric circuit (also called "electric circuit") in series is extended from the side of the insertion spring 43 facing the spring positioning insertion cavity 413, the insertion spring leg 432 is closely and supported on the insertion spring leg supporting chamber 413 and protrudes out of the lower surface of the shield 41, a heating wire insertion spring electrical connection ear 433 extends on the front side surface of the base of the insertion spring 43, the heating wire insertion spring electrical connection ear 433 extends into the heating wire chamber 414, the heating wire 44a is embedded in the heating wire chamber 414 in a C-shaped state, a heating wire first connection end i 441 of the heating wire 44a is connected with the heating wire insertion spring electrical connection ear 433, a heating wire second connection end ii 442 of the heating wire 44a is connected with a first electrical connection member i 45 by welding, as a preferable scheme, a heating wire limiting boss 4141 is formed at the center position of the heating wire chamber 414, the bimetal piece 44b covers the right side of the heating wire 44a, the first electrical connection member i 45 is disposed in the electrical connection member positioning chamber 415, an electrical connection member limiting strip 451 extends from the lower portion of the first electrical connection member i 45, the heating wire second connection terminal ii 442 is connected by welding to an electrical connector defining bar 451, an electrical connector positioning insert 4511 extends from the electrical connector defining bar 451 at a position corresponding to the electrical connector positioning insert groove 4151, the electrical connector positioning insert 4511 is fitted into the electrical connector positioning insert groove 4151, the second electrical connector ii 46 is fixed by welding to the first electrical connector i 45, the stationary contact pin 47 is disposed in the stationary contact pin insertion flange cavity 411, a pair of stationary contact pin insertion flanges 471 is formed on the stationary contact pin 47 at a position corresponding to the pair of stationary contact pin positioning flange insertion grooves 4111, the pair of stationary contact pin insertion flanges 471 is inserted into the pair of stationary contact pin positioning flange insertion grooves 4111, and a stationary contact 472 is fixed to the stationary contact pin 47, the stationary contact pin 47 penetrates the shield cover 42 toward an end of the shield cover 42 to form a stationary contact pin electrical connection terminal 473, one end of the movable contact piece 48 is formed integrally with the second electric connector II 46, the middle of the movable contact piece 48 is in contact with the right side of the bimetal piece 44b, the other end of the movable contact piece 48 is formed as a free end and is fixedly welded with a movable contact 481 at a position corresponding to the fixed contact 472, the protector pin 49 is embedded at the right side of the shield cover 42, and the protector pin 49 is extended with a protector pin electric connecting piece 491, the protector pin electrical connector 491 is also fitted to the right side of the cover 42, and the end of the protector pin electrical connector 491 is folded to form a protector pin electrical connector 4911, the protector pin electrical connection lug 4911 is electrically connected to the stationary contact pin electrical connection terminal 473, the shield cover 42 is fixed to the shield 41 at a position corresponding to the right side of the shield 41, and is fitted in the protector accommodating chamber 151 of the aforementioned protector insertion seat 15 together with the hood 41. A pair of housing cover pressing claws 421 extend from the upper portion of the housing cover 42, the pair of housing cover pressing claws 421 contact with the upward-facing side surface of the housing 1, a protector pin insertion cavity 422 is formed in the housing cover 42 at a position between the pair of housing cover pressing claws 421, and the protector pin 49 is inserted into the protector pin insertion cavity 422 and electrically connected to the compressor three-pin terminal in a plugging manner in a use state.

The movable contact spring 48 and the second electric connector II 46 form an integral structure, so that the manufacturing process can be simplified, the manufacturing cost can be reduced, and the manufacturing efficiency can be improved. The movable contact 481 and the fixed contact 472 described above are preferably silver contacts.

Continuing to refer to fig. 2 in conjunction with fig. 1 and 3, a plug spring auxiliary leg connecting plate 434 for facilitating electrical connection and having a function as desired with respect to the plug spring leg 432 extends on the front side surface of the plug spring 43 at a position corresponding to the lower side of the heating wire plug spring electrical connecting lug 433, a plug spring auxiliary leg 4341 extends on the side of the middle portion of the plug spring auxiliary leg connecting plate 434 in the lengthwise direction facing downward, and the plug spring auxiliary leg 4341 is supported on the plug spring auxiliary leg supporting portion 417 of the shield 41 and extends to the lower side of the shield 41; a spring auxiliary leg relief chamber 423 is formed on the left side of the shroud cover 42 at a position corresponding to the spring auxiliary leg 4341.

As can be seen from the schematic views of fig. 2 and 3, the insertion spring leg 432 and the insertion spring auxiliary leg 4341 correspond to an insertion spring leg fitting cavity 1512 (also referred to as "insertion spring leg avoiding cavity") formed in the cavity bottom wall of the protector accommodating cavity 151.

A protector electrical connector defining cavity 425 having the same shape as the protector pin electrical connector 491 and communicating with the protector pin insertion cavity 422 is formed on the right side of the aforementioned protector cover cap 42 and at a position corresponding to the aforementioned protector pin electrical connector 491, a stationary contact pin electrical connection terminal passing hole 4251 is formed in the protector electrical connection terminal defining cavity 425 at a position corresponding to the aforementioned stationary contact pin electrical connection terminal 473, the protector pin electrical connection terminal 491 is embedded in the protector electrical connection terminal defining cavity 425 and the aforementioned protector pin electrical connection terminal electrical connection lug 4911 is formed in front of the stationary contact pin electrical connection terminal passing hole 4251, and the stationary contact pin electrical connection terminal 473 of the aforementioned stationary contact pin 47 is passed through the aforementioned protector cover 42 upward at a position corresponding to the stationary contact pin electrical connection terminal passing hole 4251 to be electrically connected to the aforementioned protector pin electrical connection terminal electrical connection lug 4911 by soldering.

Preferably, a movable contact piece flange 482 is formed at the left side of the middle of the movable contact piece 48 and at a central position corresponding to the bimetal piece 44b, and the movable contact piece flange 482 is in contact with the central position of the right side of the bimetal piece 44 b.

A pair of shroud cover insertion fixing posts 424 are formed on the left side of the shroud cover 42, a pair of fixing post insertion holes 416 penetrating the shroud 41 are formed in the shroud 41 at positions corresponding to the pair of shroud cover insertion fixing posts 424, and the pair of shroud cover insertion fixing posts 424 are inserted and fixed in the pair of fixing post insertion holes 416; the left side surface of the protector 41 is formed as a protector arcuate surface that matches the left cavity wall of the protector accommodating cavity 151 of the protector insert seat 15.

In the present embodiment, the pair of fixing post insertion holes 416 are formed in a diagonally distributed positional relationship with each other on the shroud 41, and the pair of shroud cover insertion fixing posts 424 are formed in a diagonally distributed positional relationship with each other on the shroud 42.

Preferably, after the pair of hood cover insertion fixing posts 424 are completely inserted into the pair of fixing post insertion holes 416 and slightly protrude out of the left side surface of the hood 41, the ends of the pair of hood cover insertion fixing posts 424 are melted by heating and form an expanded edge after cooling, so that the hood 41 and the hood cover 42 are sufficiently secured to each other.

Since the operating principle of the protector 4 is a known technology, for example, refer to the patent documents mentioned in the above background art column by the applicant, and the following description will be made only briefly, since the protector 4 is connected in series to an electric circuit, that is, an electric line, when the bimetal 44b is heated and deformed by the heating wire 44a, an urging force is generated to push the movable contact 48 upward, the movable contact 481 is separated from the fixed contact 472, the circuit, that is, the circuit, is disconnected, and the refrigeration compressor motor is protected. On the contrary, when the heating wire 44a or the heat radiation of the external environment is at a temperature lower than the temperature at which the bimetal 44b is sensed and deformed, the bimetal 44b is reset, the moving and

stationary contacts

481 and 472 are closed (electrically contacted with each other), and the motor circuit of the refrigeration compressor is turned on again. As explained for the protector 4, the applicant is not repeated here, since the aforementioned operating principle of the starter 3 is also common knowledge and can likewise be referred to the patent documents mentioned in the background section.

Continuing to refer to fig. 2, an electrical connection pin hole 24 penetrating the housing cover 2 is formed on the housing cover 2 at a position corresponding to the electrical connection pin 322, the electrical connection pin 322 is inserted into the electrical connection pin hole 24 and extends to the lower side of the housing cover 2, a housing cover pin slot 26 penetrating the housing cover 2 is formed at the front end of the housing cover 2, and the first external electrical connection pin i 332 and the second external electrical connection pin ii 333 are inserted (fixed) into the housing cover 2 at a position corresponding to the housing cover pin slot 26 and extend to the lower side of the housing cover 2 for electrically connecting with an external circuit.

Referring to fig. 3 in conjunction with fig. 1, a housing cover pin fixing seat 17 is formed on each of the front and rear outer walls of the housing 1, and a housing cover pin 25 extends on each of the front and rear walls of the housing cover 2, the position of the housing cover pin 25 corresponding to and mating with the pair of housing cover pin fixing seats 17.

With particular reference to fig. 1 and 3, the protector insert 15 includes a protector support stopper 152, an insert front plate 153 and an insert rear plate 154, the protector support stopper 152 is integrally formed with the left wall of the housing 1, a front end of the protector support stopper 152 protrudes from the front side of the housing 1, a rear end thereof protrudes from the rear side of the housing 1, the insert front plate 153 extends upward in a state perpendicular to the front end of the protector support stopper 152, a protector front insert groove 1531 is formed on the insert front plate 153 on a side facing the insert rear plate 154, the insert rear plate 154 extends upward in a state perpendicular to the rear end of the protector support stopper 152, a protector rear insert groove 1541 is formed on the insert rear plate 154 on a side facing the insert front plate 153, and the protector support stopper 152, the protector rear insert rear plate 153, The space formed by the co-operation of the front panel 153 and the rear panel 154 constitutes the aforementioned U-shaped protector accommodating chamber 151; the front end of the shroud 42 and the shroud 41 are fitted into the front protector fitting groove 1531, the rear end of the shroud 42 and the shroud 41 are fitted into the rear protector fitting groove 1541, and the bottom surface of the shroud 42 is supported by the protector support/limit plate 152.

In conclusion, the technical scheme provided by the invention overcomes the defects in the prior art, successfully completes the invention task and truly realizes the technical effects of the applicant in the technical effect column.

Claims

1. An integrated motor starting protector includes a housing (1), the housing (1) having a starter accommodating chamber (11), a first pin accommodating chamber I (12) and a second pin accommodating chamber II (13), a PTC thermistor left support flange (111) and a PTC thermistor right support flange (112) which are formed in the starter accommodating chamber (11) and located in the middle of the starter accommodating chamber (11) and which are protruded from the surface of the chamber bottom wall of the starter accommodating chamber (11) in left-right correspondence with each other, the first pin accommodating chamber I (12) and the second pin accommodating chamber II (13) each being surrounded by a pin accommodating chamber rib (16) at a position corresponding to the left side of the starter accommodating chamber (11), a housing first insertion hole I (14a) being formed in the housing (1) and at a position corresponding to the first pin accommodating chamber I (12), the first pin receiving cavity I (12) is communicated with the outside through the first plug jack I (14a) of the shell, a second plug jack II (14b) of the shell is formed on the shell (1) and at a position corresponding to the second pin receiving cavity II (13), and the second plug jack II (13) is communicated with the outside through the second plug jack II (14b) of the shell; the shell cover (2), the shell cover (2) is matched with the part of the shell opening (14c) at the downward side of the shell (1); a starter (3) and a protector (4), the starter (3) being disposed in the starter accommodating chamber (11) in a state of being supported between the PTC thermistor left support flange (111) and the PTC thermistor right support flange (112) and being fitted into the housing first insertion hole I (14a) and the housing second insertion hole II (14b) at positions corresponding to the first pin accommodating chamber I (12) and the second pin accommodating chamber II (13), respectively, characterized in that a protector insert seat (15) extends leftward on a left wall body of the housing (1), a front end of the protector insert seat (15) protrudes out of a front side surface of the housing (1), a rear end of the protector insert seat (15) protrudes out of a rear side surface of the housing (1), and the protector insert seat (15) has a protector accommodating chamber (151), the protector accommodating cavity (151) is U-shaped, and the protector (4) is in insertion fit with the protector accommodating cavity (151).

2. The integrated motor starting protector according to claim 1, wherein a first electrical insert limiting stop pin I (21), a second electrical insert limiting stop pin II (22) and a positive temperature coefficient thermistor probing limiting cavity (23) are formed on one side of the housing cover (2) facing the starter accommodating cavity (11) of the housing (1), the first electrical insert limiting stop pin I (21) and the second electrical insert limiting stop pin II (22) correspond to each other, and the positive temperature coefficient thermistor probing limiting cavity (23) is located between the first electrical insert limiting stop pin I (21) and the second electrical insert limiting stop pin II (22); the starter (3) comprises a PTC thermistor (31), a first electrical blade I (32) and a second electrical blade II (33), the PTC thermistor (31) being arranged in a longitudinal position and the upper part of the PTC thermistor (31) being supported between the left PTC thermistor support flange (111) and the right PTC thermistor support flange (112) while the lower part of the PTC thermistor projects into the limiting chamber (23), the front side of the first electrical blade I (32) being in electrical contact with the rear side of the PTC thermistor (31) while the rear side of the first electrical blade I (32) is defined by the first electrical blade limiting stop pin I (21), the first electrical blade I (32) having a first electrical blade I (321) and an electrical connection pin (322), the first electric inserting piece pin I (321) extends into the first pin accommodating cavity I (12) and corresponds to the first inserting hole I (14a) of the shell, the electric connecting pin (322) is inserted into the shell cover (2) and extends to the lower part of the shell cover (2), the rear side of the second electric inserting piece II (33) is electrically contacted with the front side of the positive temperature coefficient thermistor (31), the front side of the second electric inserting piece II (33) is limited by the second electric inserting piece limiting baffle pin II (22), the second electric inserting piece II (33) is provided with a second electric inserting piece pin II (331), a first external electric connecting pin I (332) and a second external electric connecting pin II (333), the second electric inserting piece pin II (331) extends into the second inserting hole II (13) and corresponds to the second inserting hole II (14b) of the shell, the first external electric connecting pin (332) and the second external electric connecting pin I (333) and the shell cover (2) Is inserted and extends below the shell cover (2); the shell first jack I (14a) and the shell second jack II (14b) are electrically connected with the compressor three-wire column in a plugging mode in a use state; and a shell cover buckling pin fixing seat (17) is respectively formed on the outer walls of the front side and the rear side of the shell (1), a shell cover buckling pin (25) extends on each wall body of the front side and the rear side of the shell cover (2), and the position of the shell cover buckling pin (25) corresponds to and is inserted into the shell cover buckling pin fixing seats (17).

3. The integrated motor start protector according to claim 1, wherein the protector (4) comprises a shield (41), a shield cover (42), an insertion spring (43), an electric heating wire (44a), a bimetal (44b), a first electric connector I (45), a second electric connector II (46), a stationary contact pin (47), a movable contact spring (48) and a protector pin (49), a stationary contact pin insertion flange cavity (411), an insertion spring positioning cavity (412), an insertion spring pin support cavity (413), an electric heating wire cavity (414) and an electric connector positioning cavity (415) are formed on the right side of the shield (41), the stationary contact pin insertion flange cavity (411) is located above the rear portion of the right side of the shield (41) and a pair of stationary contact pin positioning flange insertion grooves (4111) corresponding to each other are formed on the cavity bottom wall of the stationary contact pin insertion flange cavity (411), the pair of stationary contact pin positioning flange insertion grooves (4111) penetrates through the bottom cavity wall of the stationary contact pin insertion flange cavity (411) to communicate with the outside, a spring positioning cavity (412) corresponding to the lower part of the static contact pin inserting flange cavity (411) and provided with a spring positioning inserting groove (4121) on the cavity bottom wall of the spring positioning cavity (412), the spring positioning inserting groove (4121) penetrates through the cavity bottom wall of the spring positioning cavity (412) to be communicated with the outside, a spring pin supporting cavity (413) corresponding to the spring positioning cavity (412) is formed at the edge part of the rear lower part of the right side of the shield (41) and communicated with the spring positioning cavity (412), an electric heating wire cavity (414) is formed at the right side central position of the shield (41), an electric connecting piece positioning cavity (415) is positioned in front of the right side of the shield (41) and provided with an electric connecting piece positioning inserting groove (4151) penetrating through the cavity bottom wall of the electric connecting piece positioning cavity (415) on the cavity bottom wall of the electric connecting piece positioning cavity (415), the base part of the spring (43) is positioned in the spring positioning cavity (412) and a bent base part of the spring (43) is formed A spring-inserting positioning-inserting leg (431), the spring-inserting positioning-inserting leg (431) being fixedly inserted into the spring-inserting positioning-inserting leg slot (4121), a spring-inserting leg (432) for connecting an electric circuit in series extending from a side of the spring (43) facing the spring-inserting leg supporting cavity (413), the spring-inserting leg (432) being closely attached to and supported by the spring-inserting leg supporting cavity (413) and protruding from a lower surface of the shield (41), a heating wire-inserting spring electrical-connecting lug (433) extending into the heating wire cavity (414) extending from a front side of a base portion of the spring (43), a heating wire (44a) being embedded in the heating wire cavity (414) in a C-shaped state, a first connecting end i (441) of the heating wire (44a) being connected to the heating wire-inserting spring electrical-connecting lug (433), and a second connecting end (442) of the heating wire (44a) being connected to a first electrical connector ii (45), a bimetal strip (44b) is covered on the right side of the heating wire (44a), a first electric connector I (45) is arranged in the electric connector positioning cavity (415), an electric connector limiting strip (451) extends from the lower part of the first electric connector I (45), a second heating wire connecting end II (442) is connected with the electric connector limiting strip (451), an electric connector positioning embedded foot (4511) extends from the electric connector limiting strip (451) at a position corresponding to the electric connector positioning embedded foot groove (4151), the electric connector positioning embedded foot (4511) is embedded in the electric connector positioning embedded foot groove (4151), a second electric connector II (46) is welded and fixed with the first electric connector I (45), a static contact foot (47) is arranged in the static contact foot embedded flange cavity (411), a pair of static contact foot embedded flanges (471) is formed on the static contact foot (47) at a position corresponding to the pair of static contact foot positioning embedded foot grooves (4111) ) A pair of stationary contact pin insertion flanges 471 inserted into and fixed to a pair of stationary contact pin positioning flange insertion grooves 4111, and a stationary contact 472 fixed to a stationary contact pin 47, one end of the stationary contact pin 47 passing through the shield cover 42 toward the one end of the shield cover 42 is formed as a stationary contact pin electrical connection terminal 473, one end of the movable contact piece 48 is formed as an integral structure with the second electrical connection member II 46, a middle portion of the movable contact piece 48 is brought into contact with a right side of the bimetal 44b, the other end of the movable contact piece 48 is formed as a free end and is welded and fixed with a movable contact 481 at a position corresponding to the stationary contact 472, a protector pin 49 inserted into a right side of the shield cover 42 is extended from the protector pin 49, and a protector pin electrical connection piece 491 is also inserted into and fitted to a right side of the shield cover 42, the tail end of the protector pin electric connection piece (491) is folded to form a protector pin electric connection piece electric connection lug (4911), the protector pin electric connection piece electric connection lug (4911) is electrically connected with the static contact pin electric connection end (473), the protective cover cap (42) is fixed with the protective cover (41) at the position corresponding to the right side of the protective cover (41), and is in inserted fit with the protective cover (41) and the protective cover accommodating cavity (151) of the protective insertion seat (15).

4. The integrated motor start protector according to claim 3, wherein a pair of case cover pressing claws (421) extend from an upper portion of the shield cover (42), the pair of case cover pressing claws (421) are in contact with an upward facing side surface of the case (1), a protector pin insertion cavity (422) is further formed in the shield cover (42) at a position between the pair of case cover pressing claws (421), and the protector pin (49) is inserted into the protector pin insertion cavity (422) and electrically connected to the compressor three-terminal in a plug-in manner in a use state.

5. The integrated motor start protector according to claim 3, wherein a plug spring auxiliary leg connecting plate (434) extends on a front side surface of the plug spring (43) at a position corresponding to a lower portion of the heating wire plug spring electrical connection lug (433), a plug spring auxiliary leg (4341) extends on a side of the plug spring auxiliary leg connecting plate (434) facing downward at a middle portion in a length direction thereof, the plug spring auxiliary leg (4341) is supported on a plug spring auxiliary leg supporting portion (417) of the shield (41) and extends to a lower portion of the shield (41); a spring-assisted foot relief chamber (423) is formed on the left side of the shroud cover (42) at a position corresponding to the spring-assisted foot (4341).

6. The integrated motor start protector according to claim 1, wherein a protector electrical connection piece defining cavity (425) having the same shape as the protector pin electrical connection piece (491) and communicating with the protector pin insertion cavity (422) is formed at a position corresponding to the protector pin electrical connection piece (491) on the right side of the protector cover cap (42), a stationary contact pin electrical connection terminal passing hole (4251) is opened in the protector electrical connection piece defining cavity (425) and at a position corresponding to the stationary contact pin electrical connection terminal (473), the protector pin electrical connection piece (491) is inserted in the protector electrical connection piece defining cavity (425) and the protector pin electrical connection piece electrical connection lug (4911) corresponds to a front side of the stationary contact pin electrical connection terminal passing hole (4251), and the stationary contact pin electrical connection terminal (473) of the stationary contact pin (47) corresponds to a front side of the stationary contact pin electrical connection terminal passing hole (4251) Is positioned upwardly through the shroud cover (42) for the protector pin electrical connection lug (4911) to be soldered thereto.

7. An integrated motor start protector according to claim 3 characterized in that a moving contact piece flange (482) is formed at the left side of the middle of the moving contact piece (48) and at the center position corresponding to the bimetal (44b), the moving contact piece flange (482) being in contact with the center position of the right side face of the bimetal (44 b).

8. The integrated motor starting protector according to claim 3, wherein a pair of shroud cover inserting and embedding fixing posts (424) are formed on the left side of the shroud cover (42), a pair of fixing post inserting and embedding holes (416) penetrating through the shroud (41) are formed on the shroud (41) and at positions corresponding to the pair of shroud cover inserting and embedding fixing posts (424), and the pair of shroud cover inserting and embedding fixing posts (424) are inserted and embedded and fixed with the pair of fixing post inserting and embedding holes (416); the left side surface of the protective cover (41) is formed into a protective cover arc surface matched with the left cavity wall of a protective cover accommodating cavity (151) of the protective cover inserting seat (15); the pair of fixing post insertion holes (416) are formed in a diagonally distributed positional relationship with each other on the shroud (41), and the pair of shroud cover insertion fixing posts (424) are formed in a diagonally distributed positional relationship with each other on the shroud cover (42).

9. The integrated motor start protector according to claim 2, characterized in that an electrical connection pin hole (24) penetrating the cover (2) is formed in the cover (2) at a position corresponding to the electrical connection pin (322), the electrical connection pin (322) is inserted into the electrical connection pin hole (24) and extends below the cover (2), a cover pin slot (26) penetrating the cover (2) is formed in the front end of the cover (2), and the first external electrical connection pin i (332) and the second external electrical connection pin ii (333) are inserted into the cover (2) at a position corresponding to the cover pin slot (26) and extend below the cover (2).

10. The integrated motor start protector according to claim 3, wherein the protector insert seat (15) includes a protector support limit plate (152), an insert seat front side plate (153) and an insert seat rear side plate (154), the protector support limit plate (152) constitutes an integrated structure with the left wall body of the housing (1), and the protector support limit plate (152) has a front end protruding out of the front side surface of the housing (1) and a rear end protruding out of the rear side surface of the housing (1), the insert seat front side plate (153) extends upward in a state perpendicular to the front end of the protector support limit plate (152) and a protector front insert groove (1531) is formed in a side of the insert seat front side plate (153) facing the insert seat rear side plate (154), the insert seat rear side plate (154) extends upward in a state perpendicular to the rear end of the protector support limit plate (152), a protector rear insert groove (1541) is formed on one side of the insert seat rear side plate (154) facing the insert seat front side plate (153), and a space formed by the protector support limit plate (152), the insert seat front side plate (153) and the insert seat rear side plate (154) in a co-operation mode is formed as the protector accommodating cavity (151); the front end of the protective cover (42) and the front end of the protective cover (41) are in inserted fit with the front insertion groove (1531) of the protector, the rear end of the protective cover (42) and the rear end of the protective cover (41) are in inserted fit with the rear insertion groove (1541) of the protector, and the bottom surface of the protective cover (42) is supported on the protector supporting limit plate (152).