CN113306705B

CN113306705B - Centrifugal circuit automatic switch

Info

Publication number: CN113306705B
Application number: CN202110681750.XA
Authority: CN
Inventors: 王衡; 王蕾
Original assignee: Xian Aviation Brake Technology Co Ltd
Current assignee: Xian Aviation Brake Technology Co Ltd
Priority date: 2021-06-19
Filing date: 2021-06-19
Publication date: 2022-08-23
Anticipated expiration: 2041-06-19
Also published as: CN113306705A

Abstract

When the rotation speed of central shaft of transmission component reaches to the defined value, two centrifugal blocks mounted in the inner cavity of the shaft overcome the elastic force of spring and push top cylinder to move along the guide portion of the shaft. The top barrel pressing spring acts on the rocker arm in the circuit opening and closing assembly, the rocker arm rotates and presses the micro switch through the spring piece, and the micro switch achieves circuit switching. The action rotating speed of the centrifugal sensor at a specified rotating speed can be adjusted through a spring and an adjusting shim. When the rotating speed of the shaft is reduced to a specified value, the centrifugal force on the centrifugal block is correspondingly reduced, and the centrifugal block, the top barrel and the rocker arm all return to the original positions under the action of the restoring force of the spring. The invention is applied to the electronic anti-skid brake system of the airplane, when the airplane wheel slides deeply, the brake can be released quickly, the brake pressure is released quickly, the tire dragging and the explosion of the airplane wheel are prevented, and the brake efficiency and the reliability and the safety of the airplane landing are improved.

Description

Centrifugal circuit automatic switch

Technical Field

The invention relates to an automatic shutter of a low-voltage direct-current centrifugal circuit, in particular to an automatic shutter of a low-voltage direct-current centrifugal circuit of an airplane.

Background

The aircraft antiskid braking system is an important airborne device of an aircraft, not only performs braking control on landing and sliding of the aircraft, but also controls the direction and turning of the ground sliding of the aircraft, and in order to complete the tasks, the aircraft braking system must have the following functions: the tire dragging and tire explosion during the braking process are avoided, and the maximum ground friction force is kept by a certain sliding amount; the brake device has the advantages that better brake effect and direction control capability are ensured under various runway states, particularly on a runway covered by water or ice; the brake is ensured to be stable and soft, and discomfort of passengers and resonance of the landing gear are avoided. In recent years, a new generation of airplanes develops rapidly, the weight, the flying speed, the landing speed and the like of the airplanes are increased continuously, the requirements of the airplanes on the reliability and the safety of an anti-skid brake system are higher and higher, and particularly the safety and the reliability of the take-off and landing brake of the airplanes in accumulated water, accumulated snow, oil stains and rubber polluted runways are realized. From the reports and statistical data of airplane accidents both at home and abroad in recent years, most of the accidents that the tires of airplane drag and the tires are broken due to the fact that an antiskid braking system does not work normally when the airplane takes off and lands account for a large proportion. In order to improve the reliability and the safety of the aircraft in the take-off and landing process and avoid tire burst caused by tire dragging during the landing and braking of the aircraft, redundancy design is adopted for normal skid prevention of the aircraft brake, and electronic skid prevention and tire dragging skid prevention are adopted.

The electronic antiskid principle is that the reference deceleration-speed difference control is used as the auxiliary bias regulation, the speed sensor outputs a frequency signal in direct proportion to the rotating speed of the airplane wheel, the signal is processed and operated by the antiskid brake control box, the sliding state of the airplane wheel is judged, corresponding antiskid current is given according to the sliding depth of the airplane wheel, the control box integrates the brake current and the antiskid current, and the brake pressure is regulated to make the friction coefficient between the tire and the runway close to shorten the distance of skid running.

The tire is dragged to prevent skidding, and the tire is prevented from being seriously worn or even dragged to slide and burst when the airplane brakes. The working principle is that the tire dragging sliding speed of a main wheel is automatically judged in the landing and braking process of the airplane, when the tire dragging sliding speed reaches a set threshold value, a circuit is automatically switched on, the brake pressure is quickly released by using an electromagnetic valve, the slipping of airplane wheels and the serious tire dragging sliding of the airplane wheels are eliminated, and the risk of tire burst caused by the serious tire dropping of the brake wheels is avoided.

In order to realize the antiskid of the dragged tire when the airplane is braked, the speed of the main machine wheel when the main machine wheel slides in a tire-releasing mode can be timely and automatically judged, the centrifugal circuit automatic shutter is arranged on the front wheel and the main machine wheel of the airplane, the rotating speed of the wheels is sensed through a gear, and a circuit for preventing the antiskid of the dragged tire is switched on or switched off when the rotating speed of the front wheel and the main machine wheel reaches a specified value under the action of the centrifugal force of an internal part centrifugal block and the elastic force of a spring. The normally open type centrifugal circuit automatic shutter is arranged on the front wheel of the airplane, senses the speed of the front wheel of the airplane (the speed of the front wheel is the airplane speed), when the speed of the front wheel is lower than a specified value, an internal circuit is open, meanwhile, a tire dragging anti-skid circuit is open, and when the speed of the front wheel is increased to the specified value, the internal circuit is connected; the normally closed centrifugal circuit automatic switch is installed on a main wheel of an airplane to sense the speed of the main wheel of the airplane, when the speed of the main wheel is higher than a specified value, an internal circuit is opened, a tire dragging anti-skid circuit is opened, and when the speed of the main wheel is lower than the specified value, the internal circuit is connected. When the internal circuit of the normally-open type centrifugal circuit automatic switch and the normally-closed type centrifugal circuit automatic switch are closed simultaneously, the tire dragging anti-skid circuit is connected. The tire dragging anti-skid circuit is connected, the hydraulic electromagnetic valve closes the brake oil inlet pipeline, the brake device is connected with the oil return pipeline, the brake pressure is released rapidly, the phenomena of skidding and serious tire dragging skidding of airplane wheels are eliminated, tire burst caused by serious tire dropping of the brake wheels is avoided, and the safe landing of the airplane in the brake process is ensured.

The conventional electronic anti-skid brake system for the airplane adjusts the brake pressure according to the sliding state of the airplane wheel to realize the anti-skid of the dragged tire, but can not quickly release the brake for the airplane wheel which is seriously dragged in the landing brake process of the airplane. After searching for circuit switch products at home and abroad, no report about a related centrifugal circuit automatic switch is searched yet.

The invention with publication number CN1564799A discloses a centrifugal switch structure, which can reduce the contact noise generated during the switching action of the motor in the household electrical appliance, and the centrifugal switch structure is applied to the household electrical appliance, has larger volume and heavier weight, and is not suitable for the installation requirement of the airplane.

A multi-contact centrifugal switch is disclosed in patent publication No. CN 104021980B. In the patent, a multi-contact centrifugal switch centrifugal seat is arranged on a rotating shaft in equipment, and an airplane wheel shaft is thick, so that the product cannot be miniaturized, and the structure cannot be arranged outside the airplane wheel, so that the disassembly and the maintenance are inconvenient.

In the prior art, an antiskid circuit of an aircraft brake system is switched on by a landing switch on an aircraft, namely, as long as the circuit is always in a switched-on state after the aircraft lands on the ground, the circuit can be switched off only after an aircraft landing gear is lifted off, and the antiskid brake circuit of the aircraft can not be switched on or switched off timely by depending on the ground sliding state of the aircraft, so that the antiskid brake system of the aircraft is in a charged state after being grounded, the service life of the antiskid brake system of the aircraft is shortened, and the power consumption of the aircraft is increased.

Disclosure of Invention

The invention provides a centrifugal circuit automatic switch, aiming at overcoming the defect that the brake cannot be quickly released when a wheel seriously drags a tire in the landing and braking process of an airplane in the prior art.

The invention comprises a cover, a shell, a transmission component and a circuit opening and closing component; the cover and the shell are combined into a shell of the centrifugal circuit automatic switch, the appearance of which is L-shaped; the transmission assembly comprises a shaft, a centrifugal block, a top barrel, a blocking sleeve, a gear, an upper cover and a large spring; the circuit opening and closing assembly comprises a support, a microswitch and a spring piece;

in the transmission assembly, the shaft is horizontally mounted within a horizontal section of the housing. The end head of the shaft with the centrifugal block cavity is provided with a top cylinder, and the connecting section of the top cylinder is positioned in the centrifugal block cavity and is sleeved on the outer circumferential surface of the shaft in a clearance fit manner; a gear is arranged at the end head of the other end of the shaft; a leather cup is sleeved in the middle of the shaft. And a first bearing is arranged between the inner end surface of the leather cup and the outer end surface of the centrifugal block cavity. A ball bearing is sleeved on the shaft on one side of the outer end face of the leather cup; the blocking sleeve is sleeved on the end head of the top cylinder in a clearance fit manner; a plurality of steel balls are arranged in the blocking sleeve, and the steel balls are in rolling fit with the outer circumferential surface of the top cylinder. The centrifugal block is provided with two centrifugal blocks which are embedded in the centrifugal block cavity of the shaft. An upper cover is fixed on the end surface of the inner end of the shaft; the large spring is sleeved on the outer circumferential surface of the top cylinder.

In the circuit opening and closing assembly, a mounting plate of a support is fixed on the inner surface of the vertical section of the shell, and a fit clearance is formed between the lower surface of the support and the outer surface of the centrifugal block cavity positioned on the shaft; a small spring is placed in the seat block of the seat, and the center line of the small spring is parallel to the center line of the shaft. The micro switch is arranged on the support. An outlet sealing assembly is hermetically arranged above the microswitch, a plug is arranged at the upper end of the outlet sealing assembly, and the outlet sealing assembly is packaged at the upper end of the vertical section shell through the plug. And a lead of an external connecting circuit penetrates through the plug and the outlet sealing assembly and is connected with the wiring terminal of the microswitch.

The outer circumferential surface of the bearing, the outer circumferential surface of the ball bearing and the outer circumferential surface of the cup are attached to the stepped inner surface of the housing. The locking thread insert is sleeved on the outer circumferential surface of the shell, and an end plate of the locking thread insert is in clearance fit with the outer circumferential surface of the gear.

A positioning stop block of the ball bearing is arranged between the leather cup and the ball bearing; a gear locking nut is arranged on one side of the gear; the retainer ring is positioned in the locking screw sleeve and sleeved on the outer circumferential surface of the gear, and the axial positioning of the ball bearing is realized through the retainer ring.

The middle part of the rocker arm is hinged on the rocker arm fixing rod of the support through a shaft pin; the inner side surface of the upper end of the rocker arm corresponds to the contact button on the side surface of the micro switch, and the contact gap between the rocker arm and the contact button is adjusted through a screw so as to switch on or switch off the contact button; the inner side surface of the lower end of the rocker arm is contacted with the outer end surface of a blocking sleeve sleeved on the transmission assembly. And a spring sheet for protection is arranged on the surface of the contact button.

The middle part of the rocker arm is provided with a mounting hole of a pin shaft 4, and the pin shaft hole is in rotating fit with the pin shaft; the lower end of the rocker arm is U-shaped, and two side wall plates of the U-shaped rocker arm are respectively attached to the outer end face of the top cylinder.

The horizontal section of the shell is a revolving body and is a shell of the transmission assembly; the inner surface of the horizontal section is step-shaped, and a mounting surface of a first bearing, a leather cup assembly and a ball bearing are respectively formed; the outer circumferential surface of the horizontal section is also in a step shape, the outer circumferential surface at the end head of the outer end of the horizontal section is a thread surface, and a locking piece installation groove extending axially is arranged on the thread surface.

The vertical section of the shell is positioned in the middle of the outer circumferential surface of the horizontal section and is perpendicular to the axis of the horizontal section. The vertical section is a rectangular shell with one side being open, and forms a shell of the centrifugal circuit automatic shutter circuit opening and closing assembly after being matched with the cover; the cavity on the inner surface of the vertical section is used for installing the micro switch and the support. A sleeve protruding out of the upper end face of the vertical section is arranged at the geometric center of the upper end face of the vertical section and is used for installing the outlet sealing assembly and the plug. Two connecting lug plates are symmetrically distributed on the lower side of the outer circumferential surface of the horizontal section.

The inner diameter of the upper cover is larger than the outer diameter of the top cylinder, so that the upper cover and the top cylinder are in clearance fit. The inner circumferential surface of the upper cover is stepped, and the inner end surface of the upper cover forms a positioning surface of the large spring. The outer diameter of the upper cover is the same as that of the centrifugal block cavity of the shaft.

The centrifugal block is in a rectangular block shape. The upper surface of the centrifugal block is a cambered surface with one higher end and one lower end, the maximum radius of the cambered surface is the same as the inner diameter of a centrifugal block cavity of the shaft, and the minimum radius is 7.25mm smaller than the inner diameter of the centrifugal block cavity; the lower surface of the cambered surface is also a cambered surface, and the radius of the cambered surface is larger than the outer diameter of the small spring. The inner surface of one end of the centrifugal block is provided with an annular convex block which protrudes radially, the inner diameter of the annular convex block is the same as the outer diameter of the top cylinder, and the inner surface of the annular convex block is attached to the end surface of the small spring; the centrifugal mass compresses the small spring as it moves along the shaft. The end face of one end with the largest radius of the centrifugal block is a vertical face, the end face of one end with the smallest radius of the centrifugal block is an inclined face, and an included angle formed between the inclined face and the vertical face is 8 degrees. A blind hole for adjusting the gravity center of the centrifugal block is arranged at the geometric center of the inclined plane; the central line of the blind hole is vertical to the inclined plane.

The outer circumferential surface of the shaft is stepped and is used for mounting a first bearing, a leather cup assembly and a ball bearing respectively. An annular groove is processed on the end surface of the inner end of the shaft to form a cavity for mounting the centrifugal block; the bottom surface of the groove is provided with an installation hole of the upper cover. And an axial blind hole is formed in the center of the end face with the groove. The inner surface of the axial blind hole is in a step shape, the large inner diameter section of the axial blind hole is phi 6 multiplied by 10mm, and the small inner diameter section of the axial blind hole is phi 4 multiplied by 8 mm.

The support is composed of a horizontal plate and a vertical plate which are vertical to each other; the outer side edge of the horizontal plate is provided with a U-shaped groove, the width between the two side walls of the groove is the same as that of the rocker arm, and the two side walls of the groove are in clearance fit; mounting holes of shaft pins are formed in the end heads of the two side walls of the groove, and the rocker arm is hinged with the support through the shaft pins; the bottom of the groove is provided with a blind hole for mounting a small spring.

In the invention, when the wheel rotates, the rotating speed of the wheel is transmitted through the gear, and the rotating speed sensed by the gear is transmitted to the shaft through the key. When the rotating speed of the shaft reaches a specified value, two centrifugal blocks arranged in the inner cavity of the shaft overcome the elastic force of the spring under the action of centrifugal force, and the top cylinder is pushed to move along the guide part of the shaft. The top barrel pressing spring acts on the rocker arm and forces the rocker arm to rotate through the shaft pin. The rocker arm presses the micro switch through the spring piece, so that the micro switch realizes the switching of the circuit. The action rotating speed of the centrifugal sensor under the specified rotating speed can be adjusted through the spring and the adjusting shim. When the rotating speed of the shaft is reduced to a specified value, the centrifugal force on the centrifugal block is correspondingly reduced, and the centrifugal block, the top barrel and the rocker arm all return to the original positions under the action of the restoring force of the spring.

The invention is applied to an electronic anti-skid brake system of an airplane, when the airplane wheel slides deeply, the brake can be released quickly, the brake pressure is released quickly, and the tire dragging and the explosion of the airplane wheel are prevented.

The invention has the following beneficial effects:

1. the invention drives the micro switch to work by the centrifugal force generated by the centrifugal block driven by the rotation of the shaft, realizes the automatic circuit opening and closing, and can set the circuit opening and closing rotation speed according to the actual use requirement.

The airplane wheel rotates to drive the centrifugal sensor shaft to rotate through the gear, two centrifugal blocks arranged in the inner cavity of the shaft generate an outward centrifugal force in a centrifugal mode and rotate around the centrifugal force at a fixed point, the spring is axially pressed, and when the rotating speed of the shaft reaches a specified value, the two centrifugal blocks arranged in the inner cavity of the shaft overcome the elastic force of the spring and push the top barrel to move along the guide portion of the shaft under the action of the centrifugal force. The top barrel pressing spring acts on the rocker arm and forces the rocker arm to rotate through the shaft pin. The rocker arm presses towards the microswitch through the spring piece, so that the microswitch realizes the circuit conversion. The action rotating speed of the centrifugal sensor under the specified rotating speed can be adjusted through the spring and the adjusting shim. When the rotating speed of the shaft is reduced to a specified value, the centrifugal force on the centrifugal block is correspondingly reduced, and the centrifugal block, the top barrel and the rocker arm return to the original positions under the action of the return force of the spring.

2. The invention has strong environmental adaptability and is suitable for working under various climatic conditions.

The cover assembly has sealing pad, shaft with designed cup mechanism assembly, outlet with designed sealing assembly, and working area inside the casing and isolated from outside atmosphere.

3. The invention has compact structure and stable operation.

In the invention, the working cavity for mounting the centrifugal block is integrated on the shaft, so that working parts are reduced, and the product structure becomes compact; two centrifugal blocks in the shaft cavity are symmetrically designed, and the centrifugal force generated by the rotation of the shaft is circumferentially offset with each other, so that the high-speed stable rotation of the shaft is realized.

4. The invention utilizes the centrifugal principle to convert the rotation of the shaft into the axial displacement

In the prior art, a landing switch on an airplane is used for switching on an antiskid circuit of an airplane brake system, the airplane is always in a switching-on state after landing, the circuit can be switched off only after an undercarriage is lifted off, and the antiskid brake circuit of the airplane cannot be switched on or off timely depending on the ground sliding state of the airplane, so that the antiskid brake system of the airplane is in a grounded electrified state. The invention utilizes the centrifugal principle to convert the rotation of the shaft into the axial displacement of the top cylinder, automatically judges the rolling speed of the airplane wheel, realizes the automatic opening and closing of the antiskid circuit of the airplane, prolongs the service life of a brake system and reduces the power consumption on the airplane.

5. The invention utilizes the lever principle to reverse the axial displacement of the top cylinder, so that the opening and closing process is more sensitive.

The rocker arm part is an equal-arm lever, the fulcrum is arranged in the middle of the rocker arm, the rocker arm can rotate around the pin shaft, and the rocker arm reverses the movement displacement of the top cylinder along the shaft. The power arm of the rocker arm is designed into a Y shape, so that the contact area of the rocker arm and the top cylinder is increased, and the pressing opening and closing process of the microswitch is more sensitive.

6. The structure is light.

The weight is an important technical index for designing the airborne equipment of the airplane, and the weight of the structure is only 0.35 kg. The invention of publication No. CN1564799A discloses a centrifugal switch structure capable of reducing contact noise generated during switching operation of a motor in a household electrical appliance, and the centrifugal switch structure is applied to a household electrical appliance, but the product has a large volume and a heavy weight and is not suitable for use in an airplane.

7. And the external installation is convenient for regular maintenance.

At present, a multi-contact centrifugal switch centrifugal seat is installed on a rotating shaft in equipment, and an airplane wheel shaft is thick and cannot be installed on the airplane wheel shaft in structure. The invention is engaged with the gear of the airplane wheel through the gear, and is arranged outside the airplane wheel through the two mounting holes on the shell, thereby being convenient to disassemble and maintain.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a left side view of the invention with the lid removed.

FIG. 3 is a schematic structural view of a rocker arm; fig. 3a is a front view, and fig. 3b is a side view.

FIG. 4 is a schematic diagram of a centrifugal mass; fig. 4a is a front view, and fig. 4b is a side view.

FIG. 5 is a schematic structural view of the upper cover; fig. 5a is a front view, fig. 5b is a side view, and fig. 5c is a sectional view a-a.

FIG. 6 is a schematic view of the shaft construction; fig. 6a is a front view, and fig. 6b is a left side view.

FIG. 7 is an assembled axial schematic view of an eccentric mass;

FIG. 8 is a schematic structural view of the housing; fig. 8a is a front view, fig. 8b is a left side view, and fig. 8c is a right side view.

FIG. 9 is a schematic view of the lock nut; fig. 9a is a front view, and fig. 9b is a plan view.

FIG. 10 is a schematic view of the stand; fig. 10a is a front view, fig. 10b is a side view, and fig. 10c is a plan view.

Fig. 11 is a structural schematic view of the lock nut.

In the figure: 1. a screw; 2. a rocker arm; 3. a small spring; 4. a shaft pin; 5. a cover; 6. a blocking sleeve; 7. a stopper spacer; 8, steel balls; 9. a top cylinder; 10. an upper cover; 11. a large spring; 12. a centrifugal block; 13. a shaft; 14. a ball bearing; 15. locking the nut; 16. a gear; 17. a key; 18. a cup mechanism assembly; 19. a support; 20. a housing; 21. a microswitch; 22. a spring plate; 23. an outlet seal assembly; 24. a plug; 25. an insulating spacer; 26. sealing gaskets; 27. a retainer ring; 28 locking the threaded sleeve; the washer is locked 29.

Detailed Description

The embodiment is a centrifugal circuit automatic switch, which comprises a rocker arm 2, a small spring 3, a shaft pin 4, a cover 5, a blocking sleeve 6, a stop washer 7, a steel ball 8, a top cylinder 9, an upper cover 10, a large spring 11, a centrifugal block 12, a shaft 13, a ball bearing 14, a lock nut 15, a gear 16, a key 17, a leather cup 18, a support 19, a shell 20, a microswitch 21, a spring leaf 22, an outlet sealing assembly 23, a plug 24, an insulating washer 25, a sealing washer 26 and a retainer ring 27; a lock screw 28; and a lock washer 29. Wherein:

the cover 5 and the housing 20 are combined to form a housing of the centrifugal circuit automatic shutter, and the housing is divided into a horizontal section and a vertical section, so that the housing is in an L shape. A shaft 13, a centrifugal block 12, a top cylinder 9, an upper cover 10 and a large spring 11 are arranged in the horizontal section to form a transmission component of the automatic centrifugal circuit shutter; in the vertical section, a support 19, a microswitch 21 and a spring plate 22 are included, which constitute the circuit opening and closing assembly of the centrifugal circuit automatic shutter.

In the transmission assembly, the shaft 13 is mounted horizontally in a horizontal section of the housing. A top cylinder 9 is arranged at one end of the shaft with the centrifugal block cavity, and the connecting section of the top cylinder is positioned in the centrifugal block cavity and is sleeved on the outer circumferential surface of the shaft in a clearance fit manner; a blocking sleeve 6 is sleeved on the end face of the top cylinder in a clearance fit mode, and a plurality of steel balls 8 are arranged in the blocking sleeve; the steel balls are matched with the outer circumferential surface of the top barrel 9 in a rolling mode, and when the top barrel rotates, the blocking sleeve is kept static through the steel balls, so that the static attachment between the blocking sleeve and the rocker arm 2 is guaranteed. A leather cup 18 is sleeved on the middle part of the shaft. A first bearing is arranged between the inner end surface of the leather cup and the outer end surface of the centrifugal block cavity. A ball bearing 14 is sleeved on the shaft 13 on one side of the outer end face of the leather cup, and a positioning stop block of the ball bearing is arranged between the leather cup and the ball bearing. At the end of the other end of the shaft is mounted a gear 16 by means of a key 17 and the axial positioning of the gear is achieved by means of a gear lock nut 15.

The lock nut 28 is fitted around the outer circumferential surface of the housing with its end plate in clearance fit with the outer circumferential surface of the gear 16. A retainer 27 is located within the lock nut 28 and is fitted over the outer circumferential surface of the gear 16, and axial positioning of the ball bearing 14 is achieved by the retainer 27. The outer circumferential surface of the bearing, the outer circumferential surface of the ball bearing 14 and the outer circumferential surface of the cup 18 are all in abutment with the stepped inner surface of the housing. Two centrifugal blocks 12 are embedded in the centrifugal block cavity of the shaft 13 and limited in the centrifugal block cavity of the shaft by the upper cover 10, the upper cover 10 is fixedly connected with the shaft 13 by two screws, and when the shaft rotates, the centrifugal blocks synchronously rotate.

In the circuit switching assembly, a mounting plate of a support 19 is fixed on the inner surface of the shell 20, and a fit clearance is formed between the lower surface of the support and the outer surface of a centrifugal block cavity of the shaft 13, so that the support and the centrifugal block cavity are not interfered; a small spring 3 is placed in the seat block of the seat with its centre line parallel to the centre line of the shaft 13. The microswitch 21 is mounted on the support. An outlet sealing assembly 23 is hermetically arranged above the microswitch, a plug 24 is arranged at the upper end of the outlet sealing assembly, the outlet sealing assembly is packaged at the upper end of the vertical section shell through the plug, and the plug is fastened through a threaded sleeve arranged at the end of the vertical section. The lead wires of the external connection circuit pass through the plug and outlet seal assembly 23 and are connected to the terminals of the microswitch 21. The lead is arranged in the protective sleeve.

The middle part of the rocker arm 2 is hinged on a rocker arm fixing rod of the support 19 through a shaft pin 4; the inner side surface of the upper end of the rocker arm corresponds to the contact button on the side surface of the micro switch 21, and the contact gap between the rocker arm and the contact button is adjusted through a screw 1 to switch on or off the contact button; the inner side surface of the lower end of the rocker arm is contacted with the outer end surface of a blocking sleeve sleeved on the transmission assembly. A spring piece 22 for protection is attached to the surface of the contact button.

In this embodiment, the upper cover 10 is fixedly connected with the end surface of the shaft 13 through a screw; a large spring 11 is positioned between the upper cover and the top cylinder 9, and the top cylinder 9 moves along the axial direction of the shaft under the action of thrust. In order to reduce the friction between the top cylinder 9 and the rocker arm 2, a steel ball 8, a spacer 6 and a stop washer 7 are mounted on the top cylinder 9. The other end of the shaft 13 is mounted in a housing 20, and in order to ensure the smoothness of shaft transmission and the external sealing performance of a product, a first bearing, a ball bearing 14 and a leather cup 18 are pressed between the housing and the outer diameter of the shaft. A retainer ring 27 is located on the outside of the ball bearing to limit axial movement of the ball bearing; the locking nut 28 is mounted on the housing by means of an internal thread. A locking washer 29 is arranged between the locking screw sleeve 28 and the shell 20 to prevent the locking screw sleeve 28 from loosening when the centrifugal circuit automatic shutter works. The gear 16 is connected to the shaft 13 by means of a key 17, and a locking nut 15 locks the gear to the end of the shaft. The rocker arm 2, the small spring 3, the micro switch 21 and the spring piece 22 are all arranged on a support 19, and the support 19 is fixed on the shell 20 through three countersunk head screws. The rocker arm 2 can rotate around a shaft pin 4, and a screw 1 is screwed at the upper end of the rocker arm 2 and is used for adjusting the working state of the microswitch. In order to adjust the operating speed of the centrifugal sensor, the small spring 3 is attached, and the spring force of the small spring 3 is adjusted by increasing or decreasing the number of adjusting shims as necessary. An outlet sealing assembly 23 and a plug 24 in the lead wire outlet hole, and a sealing gasket 26 are arranged between the matching surfaces of the cover 5 and the shell body so as to realize the isolation of the inner cavity of the centrifugal circuit automatic shutter from the surrounding medium. The insulating gasket 25 is used for ensuring the absolute isolation of the welding points of the lead-out wires and the binding posts from the inner wall of the shell. Two mounting holes with the diameter of 6.5 mm are machined in the shell 20, and the surfaces of the mounting holes are used for positioning when a product is mounted so as to ensure the accuracy of gear meshing.

The housing 20 is shaped like an "L". Wherein the horizontal section is a revolving body; the vertical section is a rectangular shell with an opening on one side, and the inner surface is circular. The horizontal section is the shell of the transmission component of the centrifugal circuit automatic shutter, and the transmission component is arranged in the horizontal section. This vertical section, in cooperation with the cover 5, is the housing of the centrifugal circuit automatic shutter circuit opening and closing assembly. Wherein, the inner surface of the horizontal section is step-shaped, and a mounting surface of the first bearing, a leather cup mechanism assembly 18 and the ball bearing 14 are respectively formed; the outer circumferential surface of the horizontal section is also in a step shape, the outer circumferential surface at the end head of the outer end of the horizontal section is a thread surface, and a locking piece mounting groove which extends axially is arranged on the thread surface. The vertical section is positioned in the middle of the outer circumferential surface of the horizontal section and is perpendicular to the axis of the horizontal section. The inner circular cavity of the inner surface of the vertical section is used for mounting the microswitch 21 and the support 19. At the geometric centre of the upper end face of the vertical section there is a sleeve projecting from the end face for mounting the outlet seal assembly 23 and the plug 24. Two connection lug pieces are symmetrically distributed on the lower side of the outer circumferential surface of the horizontal section, and the embodiment is fixed on the brake device through the connection lug pieces.

The upper cover 10 is annular, and the inner diameter of the upper cover is larger than the outer diameter of the top cylinder, so that the upper cover and the top cylinder are in clearance fit. The inner circumferential surface of the upper cover is stepped, and the inner end surface of the upper cover forms a positioning surface of the large spring 11. The outer diameter of the upper cover is the same as that of the centrifugal block cavity of the shaft 13. Lightening holes are distributed on the upper cover.

The rocker arm 2 is of a flat plate structure. The upper end of the rocker arm is provided with a mounting hole of a screw 1; the middle part of the rocker arm is provided with a mounting hole of a pin shaft 4, and the pin shaft hole is in running fit with the pin shaft; the lower end of the rocker arm is U-shaped, and two side wall plates of the U-shaped rocker arm are respectively attached to the outer end face of the top cylinder 9. When the shaft 13 rotates, the centrifugal block 12 generates displacement under the action of centrifugal force, so that the inner end surface of the centrifugal block is attached to the end surface of the upper cover 10; the centrifugal block applies pressure to the small spring attached to the centrifugal block in the moving process, so that the small spring moves towards the end head of the inner end of the shaft 13, and the lower end of the rocker arm is pushed to move. The movement of the lower end of the rocker arm causes the upper end of the rocker arm to move in the opposite direction, pressing the contact button, and turning on the micro-power switch 21. The surfaces of the two side wall plates at the lower end of the rocker arm and the surface of the top barrel are convex cambered surfaces, and the contact area and the friction force are reduced through the cambered surfaces. And a fixing hole of a large spring is arranged beside the pin shaft hole.

The centrifugal block 12 is rectangular. The upper surface of the centrifugal block is a cambered surface with one higher end and one lower end, the maximum radius of the cambered surface is the same as the inner diameter of the centrifugal block cavity of the shaft 13, and the minimum radius is 7.25mm smaller than the inner diameter of the centrifugal block cavity; the lower surface of the centrifugal block is also a cambered surface, and the radius of the cambered surface is larger than the outer diameter of the large spring 11. The inner surface of one end of the centrifugal block is provided with an annular convex block which protrudes radially, and the inner diameter of the annular convex block is the same as the outer diameter of the top barrel 9; a large spring is arranged in an inner hole of the annular lug; the centrifugal mass compresses the small spring as it moves along the shaft 13. The end face of one end with the largest radius of the centrifugal block is a vertical face, the end face of one end with the smallest radius is an inclined face, and an included angle formed between the inclined face and the vertical face is 8 degrees. A blind hole for adjusting the gravity center of the centrifugal block is arranged at the geometric center of the inclined plane; the central line of the blind hole is vertical to the inclined plane. The diameter of the blind hole is 2mm, and the depth is 2 mm.

The shaft 13 is a stepped cylinder. The outer circumferential surface of the shaft is stepped to mount the first bearing, cup mechanism assembly 18 and ball bearing 14, respectively. An annular groove is processed on the end surface of the inner end of the shaft to form a cavity for mounting the centrifugal block; on the bottom surface of this groove there are two symmetrical threaded through holes for mounting the cover 10. The center of the end face with the groove is provided with an axial blind hole, the inner surface of the blind hole is in a step shape, the diameters of the blind hole are respectively 6mm and 4mm, the depth of the blind hole with the diameter of 6mm is 10mm, the depth of the blind hole with the diameter of 4mm is 8mm, and the torque resistance of the shaft is improved through the blind hole.

The locking screw sleeve 28 is in a circular shell shape, the outer end of the locking screw sleeve is provided with an end plate, and the inner end of the locking screw sleeve is an open end. The inner surface of the locking screw sleeve is a thread surface matched with the outer circumferential surface of the shell. The center of the end plate at the outer end of the locking screw sleeve is provided with a through hole, the inner diameter of the through hole is the same as the outer diameter of the second step of the gear 16, and the through hole and the gear are in clearance fit. 16 rectangular grooves are uniformly formed in the end face of the open end of the locking screw sleeve, and the locking gasket is turned upwards and clamped into any groove during assembly, so that the locking screw sleeve is prevented from loosening. 4 tooling holes are uniformly distributed on the periphery of the center hole of the end plate at the outer end of the locking threaded sleeve so as to operate during assembly.

The support 19 is composed of a horizontal plate and a vertical plate which are perpendicular to each other. The outer side edge of the horizontal plate is provided with a U-shaped groove, the width between the two side walls of the groove is the same as that of the rocker arm 2, and the two side walls are in clearance fit. And mounting holes of shaft pins 4 are formed in the end heads of the two side walls of the groove, and the rocker arm is hinged with the support through the shaft pins. The bottom of the groove is provided with a blind hole for installing the small spring 3. The outer side surface of the vertical plate is attached to the inner surface of the housing 20 and is fixedly connected to the vertical plate by screw holes distributed on the vertical plate. The upper surface of the horizontal plate is used for placing the microswitch 21. The appearance of the vertical plate is adapted to the inner profile of the book case.

The outer circumferential surface of the gear 16 is a stepped surface, wherein the largest outer diameter section at one end of the gear is an outer circumferential surface which is a tooth surface, and the tooth surface is engaged with the inner gear ring of the wheel. The outer diameter of the second-stage step surface positioned in the middle of the gear is the same as the diameter of the central hole on the end plate of the locking threaded sleeve 28. The end face of the other end of the gear is attached to the end face of the ball bearing inner ring.

The gear 16 has the same inner diameter as the outer diameter of the shaft 13 and has a larger inner diameter at one end thereof having a tooth surface than the lock nut 15. The gear has a keyway in its inner surface for securing the gear to the shaft by a key.

Claims

1. A centrifugal circuit automatic switch is characterized by comprising a rocker arm, a cover, a shell, a transmission assembly and a circuit switching assembly; the cover and the shell are combined into a shell of the centrifugal circuit automatic switch, the appearance of which is L-shaped; the transmission assembly comprises a shaft, a centrifugal block, a top barrel, a blocking sleeve, a gear, an upper cover and a large spring; the circuit opening and closing assembly comprises a support, a microswitch and a spring piece;

in the transmission assembly, a shaft is horizontally arranged in a horizontal section of the shell; the end of the shaft with the centrifugal block cavity is provided with a top cylinder, and the connecting section of the top cylinder is positioned in the centrifugal block cavity and is sleeved on the outer circumferential surface of the shaft in a clearance fit manner; a gear is arranged at the end head of the other end of the shaft; a leather cup is sleeved in the middle of the shaft; a first bearing is arranged between the inner end surface of the leather cup and the outer end surface of the centrifugal block cavity; a ball bearing is sleeved on the shaft on one side of the outer end face of the leather cup; the blocking sleeve is sleeved on the end head of the top cylinder in a clearance fit manner; a plurality of steel balls are arranged in the blocking sleeve, and each steel ball is in rolling fit with the outer circumferential surface of the top cylinder; two centrifugal blocks are embedded in the centrifugal block cavity of the shaft; an upper cover is fixed on the end face of the inner end of the shaft; the large spring is sleeved on the outer circumferential surface of the top barrel;

in the circuit opening and closing assembly, a mounting plate of a support is fixed on the inner surface of the vertical section of the shell, and a fit clearance is formed between the lower surface of the support and the outer surface of the centrifugal block cavity positioned on the shaft; a small spring is arranged in a support block of the support, and the central line of the small spring is parallel to the central line of the shaft; the micro switch is arranged on the support; an outlet sealing assembly is hermetically arranged above the microswitch, a plug is arranged at the upper end of the outlet sealing assembly, and the outlet sealing assembly is packaged at the upper end of the vertical section shell through the plug; a lead of an external connecting circuit passes through the plug and the outlet sealing assembly and is connected with a binding post of the microswitch;

the middle part of the rocker arm is hinged on the rocker arm fixing rod of the support through a shaft pin; the inner side surface of the upper end of the rocker arm corresponds to the contact button on the side surface of the microswitch, and the contact clearance between the rocker arm and the contact button is adjusted through a screw so as to switch on or off the contact button; the inner side surface of the lower end of the rocker arm is contacted with the outer end surface of a blocking sleeve sleeved on the transmission assembly; and a spring sheet for protection is arranged on the surface of the contact button.

2. The automatic centrifugal circuit shutter according to claim 1, wherein an outer circumferential surface of said bearing, an outer circumferential surface of said ball bearing and an outer circumferential surface of said cup are fitted to the stepped inner surface of said housing; the locking screw sleeve is sleeved on the outer circumferential surface of the shell, and an end plate of the locking screw sleeve is in clearance fit with the outer circumferential surface of the gear.

3. The automatic centrifugal circuit shutter according to claim 1, wherein there is a positioning stopper of said ball bearing between said cup and said ball bearing; a gear locking nut is arranged on one side of the gear; the retainer ring is positioned in the locking screw sleeve and sleeved on the outer circumferential surface of the gear, and the axial positioning of the ball bearing is realized through the retainer ring.

4. The automatic centrifugal circuit shutter according to claim 1, wherein said rocker arm has a mounting hole for a pin shaft in the middle thereof, and the pin shaft hole is rotatably fitted to the pin shaft; the lower end of the rocker arm is U-shaped, and two side wall plates of the U-shaped rocker arm are respectively attached to the outer end face of the top cylinder.

5. The automatic centrifugal circuit shutter according to claim 1, wherein said horizontal section of said housing is a solid of revolution, being a housing of said transmission assembly; the inner surface of the horizontal section is step-shaped, and a mounting surface of a first bearing, a leather cup assembly and a ball bearing are respectively formed; the outer circumferential surface of the horizontal section is also in a step shape, the outer circumferential surface at the end head of the outer end of the horizontal section is a thread surface, and a locking piece mounting groove extending axially is arranged on the thread surface;

the vertical section of the shell is positioned in the middle of the outer circumferential surface of the horizontal section and is perpendicular to the axis of the horizontal section; the vertical section is a rectangular shell with one open side, and forms a shell of the circuit opening and closing component of the automatic centrifugal circuit opening and closing device after being matched with the cover; the cavity on the inner surface of the vertical section is used for mounting a micro switch and a support; a sleeve which is protruded out of the upper end face of the vertical section is arranged at the geometric center of the upper end face of the vertical section and is used for installing the outlet sealing assembly and the plug; two connecting lug plates are symmetrically distributed on the lower side of the outer circumferential surface of the horizontal section.

6. The automatic centrifugal circuit shutter according to claim 1, wherein said upper cover has an inner diameter larger than an outer diameter of said top case so as to be fitted with a clearance therebetween; the inner circumferential surface of the upper cover is in a step shape, and a positioning surface of a large spring is formed on the inner end surface of the upper cover; the outer diameter of the upper cover is the same as that of the centrifugal block cavity of the shaft.

7. The automatic centrifugal circuit shutter according to claim 1, characterized in that said centrifugal block is rectangular; the upper surface of the centrifugal block is a cambered surface with one higher end and one lower end, the maximum radius of the cambered surface is the same as the inner diameter of a centrifugal block cavity of the shaft, and the minimum radius is 7.25mm smaller than the inner diameter of the centrifugal block cavity; the lower surface of the cambered surface is also a cambered surface, and the radius of the cambered surface is greater than the outer diameter of the small spring; the inner surface of one end of the centrifugal block is provided with an annular convex block which protrudes in the radial direction, the inner diameter of the annular convex block is the same as the outer diameter of the top cylinder, and the inner surface of the annular convex block is attached to the end face of the small spring; compressing the small spring when the centrifugal block moves along the shaft; the end face of one end with the maximum radius of the centrifugal block is a vertical face, the end face of one end with the minimum radius of the centrifugal block is an inclined face, and an included angle between the inclined face and the vertical face is 8 degrees; a blind hole for adjusting the gravity center of the centrifugal block is arranged at the geometric center of the inclined plane; the central line of the blind hole is vertical to the inclined plane.

8. The automatic centrifugal circuit shutter according to claim 1, wherein the outer circumferential surface of said shaft is stepped for mounting a first bearing, a cup assembly and a ball bearing, respectively; an annular groove is processed on the end surface of the inner end of the shaft to form a cavity for mounting the centrifugal block; the bottom surface of the groove is provided with an installation hole of the upper cover; an axial blind hole is formed in the center of the end face of the groove; the inner surface of the axial blind hole is in a step shape, the large inner diameter section of the axial blind hole is phi 6 multiplied by 10mm, and the small inner diameter section of the axial blind hole is phi 4 multiplied by 8 mm.

9. The automatic centrifugal circuit shutter according to claim 8, characterized in that said support consists of a horizontal plate and a vertical plate perpendicular to each other; the outer side edge of the horizontal plate is provided with a U-shaped groove, the width between the two side walls of the groove is the same as that of the rocker arm, and the two side walls of the groove are in clearance fit; mounting holes of shaft pins are formed in the end heads of the two side walls of the groove, and the rocker arm is hinged with the support through the shaft pins; the bottom of the groove is provided with a blind hole for mounting a small spring.