CN107768172B

CN107768172B - Rotary switch

Info

Publication number: CN107768172B
Application number: CN201711169139.9A
Authority: CN
Inventors: 李佳; 王维洲; 杨海斌; 魏战平; 袁辉; 刘俊利; 杨晓锋; 安伟平
Original assignee: XI'AN QING'AN ELECTRIC CONTROL CO Ltd
Current assignee: XI'AN QING'AN ELECTRIC CONTROL CO Ltd
Priority date: 2017-11-22
Filing date: 2017-11-22
Publication date: 2022-07-12
Anticipated expiration: 2037-11-22
Also published as: CN107768172A

Abstract

A rotary switch comprises a switch mounting plate, a first wiring terminal, a knob shaft sleeve, a switch panel and a knob. The knob shaft sleeve is sleeved on the outer circumferential surface of the knob shaft. Six first binding posts are uniformly distributed and embedded on the circumference of the switch mounting plate. The switch panel is sleeved on the knob shaft, and the end face of one end of the switch panel is attached to the end face of the switch mounting plate. The knob is sleeved on the knob shaft and is positioned at the outer end of the switch panel. Two ends of the reed are respectively fixed on the end surface of the knob shaft and the end surface of the second binding post. In the invention, in the rotation process of the knob, the input voltage of the power supply is respectively communicated with the short reed of the switch static contact and the long reed of the switch static contact through the reed of the knob moving contact, thereby ensuring two paths of power supply; in the process of switching each gear, when the rotary knob points to the transition region of the adjacent gear, one path of power supply is always kept. The invention eliminates the problem of magnetic radiation generated when the motor is frequently switched on and off during work conversion, and has the characteristics of safety and reliability.

Description

Rotary switch

Technical Field

The invention relates to a rotary switch which can continuously supply power without power failure when rotating each gear.

Background

At present, the complexity of equipment in various fields puts urgent demands on electromagnetic compatibility; the combined use puts an urgent need on the electromagnetic compatibility of the system; namely, the system-level electromagnetic compatibility requirement is directly transferred to the equipment-level electromagnetic compatibility requirement, and when the traditional switch is switched among gears, the power supply on-off of the motor is frequently switched, so that electromagnetic radiation is directly generated. The electromagnetic compatibility design of equipment is influenced, and the reliability of products is reduced; based on this, the switch is characterized in that: a long contact and short contact rotary switch has no instantaneous power-off and power supply state when each gear is switched, and has no instantaneous starting and stopping phenomenon of a motor when each gear is switched, so that the switch always keeps a continuous power supply and does not have a power-off state, the service life of the motor is prolonged, and no repeated impact current exists on a power supply and a controller for the motor, so that the circuit design of equipment is simpler, and the working reliability of a system is improved.

The traditional conversion is controlled by a rotary switch of a common contact, when the gears are converted, when a rotary knob points to a transition region of an adjacent gear, the motor is directly switched off from the original switch-on state, when the rotary knob points to the next gear, the motor is switched on again to work, and electromagnetic radiation appears in the conversion process.

Disclosure of Invention

The invention provides a rotary switch for overcoming the defect of electromagnetic radiation in the conversion process in the prior art.

The switch comprises a switch mounting plate, a first binding post, a knob shaft sleeve, a switch panel and a knob. The knob shaft sleeve is sleeved on the outer circumferential surface of the knob shaft, a first spring is arranged in an annular semicircular groove in the inner surface of the knob shaft sleeve, a first steel ball is arranged on the upper end face of the first spring, and only circumferential rotation can be generated between the knob shaft sleeve and the knob shaft through the first steel ball; the inner end surface of the knob shaft sleeve is provided with an axial blind hole, a second spring is arranged at the bottom of the blind hole, and a second steel ball is arranged on the outer end surface of the second spring, so that the second steel ball is positioned between the inner end surface of the knob shaft sleeve and the outer end surface of the shaft shoulder of the knob shaft. The inner surface of the switch mounting plate is sleeved on the outer surface of the knob shaft sleeve; the knob motion contact reed is sleeved on the circumferential surface of the knob shaft and is attached to the outer end face of the shaft shoulder of the knob shaft. Six first binding posts are uniformly distributed and embedded on the circumference of the switch mounting plate. The switch panel is sleeved on the knob shaft, and the end face of one end of the switch panel is attached to the end face of the switch mounting plate. The knob is sleeved on the knob shaft and is positioned outside the switch panel. One end of the reed is positioned in the center of the end face of the outer end of the knob shaft and is in contact fit with the end face of the knob shaft; the other end of the reed is fixed on the end face of the second binding post. And a blind hole for connecting the positive input end of the power supply is arranged on the end face of the second binding post.

The center of six first terminal one end terminal surfaces of equipartition on switch mounting panel's circumference has the axial blind hole respectively, be used for welding each cable in each blind hole respectively, wherein, controller stop shelves input and the first terminal end face that is located 12 points direction are connected, controller low-speed shelves input and the first terminal end face that is located 2 points direction are connected, controller high-speed shelves input and the first terminal end face that is located 4 points direction are connected, motor stop shelves input and the first terminal end face that is located 6 points direction are connected, motor low-speed shelves input and the first terminal end face that is located 8 points direction are connected, motor high-speed shelves input and the first terminal end face that is located 10 points direction are connected. The end surfaces of the other ends of the first binding posts respectively positioned in the directions of 12 points, 2 points and 4 points are respectively fixed with a switch static contact short reed; and switch stationary contact long reeds are respectively fixed on the end surfaces of the other ends of the first binding posts respectively positioned in the directions of the 6-point, the 8-point and the 10-point.

One end of the switch panel is an open end, and the outer circumferential surface of the open end is provided with a connecting plate which is radially protruded and used for being connected with the switch mounting plate; the other end of the switch panel is provided with an end plate, the center of the end plate is provided with a step-shaped through hole, and the inner surface of the through hole is in clearance fit with the knob shaft; the inner end surface of the switch panel end plate is provided with an annular boss which axially protrudes, and the inner end surface of the boss is contacted with the inner end surface of the knob moving contact reed, so that the knob moving contact reed and the knob moving contact reed can rotate relatively. Three position indication grooves are distributed on the outer end face of the switch panel end plate, and the positions of the three position indication grooves correspond to the positions of the first binding posts in the directions of 12 points, 2 points and 4 points respectively.

The switch mounting plate is round inside and square outside, the aperture of the inner hole of the switch mounting plate is the same as the outer diameter of the knob shaft sleeve, and a groove matched with the limit boss on the inner surface of the knob shaft sleeve is arranged on the outer surface of the switch mounting plate. Six through mounting holes of a first binding post are uniformly distributed on the end surface of the switch mounting plate; the inner surface of the mounting hole is a stepped surface matched with the outer surface of the first binding post, so that the axial positioning of each first binding post is realized. The switch mounting plate is provided with connecting holes at four square corners. And a blind hole for mounting the second binding post is arranged on the end surface of the switch mounting plate.

The circumferential surface of the knob shaft is stepped. The middle part of the knob shaft is provided with a shaft shoulder which is protruded radially. The shafts at the two ends of the shaft shoulder are respectively used for mounting the knob shaft sleeve and the knob. A shaft body for mounting a knob shaft sleeve is provided with a blind hole for mounting a first spring and a first steel ball in the radial direction, the end face of a shaft shoulder at the end is provided with three semicircular holes in contact with a second steel ball, and the positions of the semicircular holes correspond to the positions of a first binding post in the directions of 6 points, 8 points and 10 points respectively. The other side of the shaft shoulder is provided with a boss for sleeving a rotary knob moving contact reed.

The number of the switch stationary contact short reeds is three. One surface of each switch stationary contact spring is a concave arc surface, and the radius of the concave arc surface is the same as that of the outer circumferential surface of the knob moving contact spring. The other surface of each switch stationary contact short reed is provided with a boss, and the geometric center of each boss is provided with a guide post which is respectively communicated with the stop gear input end of the controller, the low-speed gear input end of the controller and the high-speed gear input end of the controller.

The number of the switch static contact long reeds is three, and the structural characteristics of the switch static contact long reeds are the same as those of the switch static contact short reeds. The length of the switch static contact long reed is 5mm larger than that of the switch static contact short reed, and when the knob moving contact reed matched with the switch static contact long reed rotates to a position between two adjacent switch static contact long reeds, the knob moving contact reed can be simultaneously connected with the two adjacent switch static contact long reeds.

The contact reed position of the knob moving contact is in a circular ring shape. The inner surface of the knob moving contact reed is matched with the lug boss of the knob shaft in a spot welding way; the inner surface of the knob moving contact reed is provided with a convex key. Two reeds are symmetrically distributed on the outer surface of the knob moving contact reed, one of the reeds is a short reed and is used for being matched with the three switch static contact short reeds, and the other reed is a long reed and is used for being matched with the three switch static contact long reeds.

The center of one end face of the first binding post is provided with a blind hole for connecting each lead, and the end face of the other end of the first binding post is provided with an installation boss for installing a switch static contact short reed or a switch static contact long reed. The circumferential surface of the first binding post is in a step shape matched with the first binding post mounting hole on the switch mounting plate.

The structure of the second binding post is similar to that of the first binding post. The difference lies in that the end face of the second binding post is not provided with the mounting boss.

The knob shaft sleeve is a hollow revolving body. The middle part of the inner surface of the knob shaft sleeve is provided with an annular groove matched with the first steel ball. The middle part of the outer surface of the knob shaft sleeve is provided with a radial boss for positioning the switch mounting plate. And a blind hole for placing a second spring and a second steel ball is arranged at the edge of the end face of one end of the knob shaft sleeve.

In the invention, in the rotation process of the knob, the input voltage of the power supply is respectively communicated with the short reed of the switch stationary contact and the long reed of the switch stationary contact through the contact reed of the knob movement, thereby ensuring two paths of power supply; in the process of switching each gear, when the rotary knob points to the transition region of the adjacent gear, one path of power supply is always kept.

The invention eliminates the problem of magnetic radiation generated when the motor is frequently switched on and off during work conversion, and has the characteristics of safety and reliability.

Drawings

Fig. 1 is a schematic structural view of a switch panel, in which 1a is a front view and 1b is a side view of 1 a.

Fig. 2 is a schematic structural diagram of the first terminal.

Fig. 3 is a schematic structural view of the knob, wherein 3a is a front view, 3b is a right side view of 3a, and 3c is a left side view of 3 a.

Fig. 4 is a schematic structural view of the knob shaft, in which 4a is a front view, 4b is a right side view of 4a, and 4c is a left side view of 4 a.

Fig. 5 is a schematic structural view of the knob shaft sleeve, wherein 5a is a front view and 5b is a side view of 5 a.

Fig. 6 is a schematic structural view of the stationary contact strip of the switch, in which 6a is a front view, 6b is a right side view of 6a, and 6c is a left side view of 6 a.

Fig. 7 is a schematic structural view of the stationary contact long reed of the switch, in which 7a is a front view, 7b is a right side view of 7a, and 7c is a left side view of 7 a.

FIG. 8 is a schematic view of the structure of the reed.

Fig. 9 is a schematic structural view of the moving contact spring of the knob, in which 9a is a front view and 9b is a sectional view of 9 a.

Fig. 10 is a schematic view of the knob shaft sleeve.

Fig. 11 is a schematic structural view of the knob shaft movement spring, in which 11a is a front view and 11b is a side view of 11 a.

Fig. 12 is a schematic structural view of a switch mounting plate assembly.

Fig. 13 is a schematic structural view of the present invention, in which 13a is a front view and 13b is a left side view of 13 a.

Fig. 14 is a cross-sectional view of fig. 13. In the figure:

1. a switch mounting plate; 2. a first terminal post; 3. a first steel ball; 4. a knob shaft; 5. a reed; 6. a first spring; 7. a second spring; 8. a second steel ball; 9. a knob; 10. the contact reed is moved by the knob; 11. a switch stationary contact short reed; 12. a switch panel; 13. a screw; 14. a second terminal; 15. a nut; 16. a controller stop input; 17. a power supply positive input terminal; 18. a controller low gear input; 19. a controller high-speed gear input end; 20. a motor stop input; 21. a low-gear input end of the motor; 22. the input end of the high-speed gear of the motor; 23. a switch stationary contact long reed; 24. a knob shaft sleeve; 25. a position indicating slot.

The specific implementation mode is as follows:

the present embodiment is a rotary switch, which includes a switch mounting plate 1, a first terminal 2, a knob shaft 4, a knob shaft sleeve 24, a switch panel 12, and a knob 9. Wherein, the knob shaft sleeve 24 is sleeved on the outer circumferential surface of the knob shaft 4, a first spring 6 is arranged in an annular semicircular groove on the inner surface of the knob shaft sleeve, a first steel ball 3 is arranged on the upper end surface of the first spring, and the first steel ball only can cause circumferential rotation between the knob shaft sleeve and the knob shaft; an axial blind hole is formed in the inner end face of the knob shaft sleeve, a second spring 7 is arranged at the bottom of the blind hole, and a second steel ball 8 is arranged on the outer end face of the second spring, so that the second steel ball is positioned between the inner end face of the knob shaft sleeve and the outer end face of the shaft shoulder of the knob shaft 4. The inner surface of the switch mounting plate 1 is sleeved on the outer surface of the knob shaft sleeve 24; the knob motion contact spring 10 is sleeved on the circumferential surface of the knob shaft 4 and is attached to the outer end face of the shaft shoulder of the knob shaft. Six first binding posts 2 are uniformly distributed and embedded on the circumference of the switch mounting plate. The switch panel 12 is fitted around the knob shaft, and an end face of one end of the switch panel is fitted to an end face of the switch mounting plate. The knob 9 is sleeved on the knob shaft and positioned at the outer end of the switch panel and fixedly connected through a screw 13.

The center of the 2 one end terminal surfaces of six first terminal posts of equipartition on switch mounting panel's circumference has the axial blind hole respectively, be used for welding each cable in each blind hole respectively, wherein, controller stop shelves input 16 and the first terminal end face that is located 12 some directions are connected, controller low-speed shelves input 18 with be located the first terminal end face of 2 some directions and be connected, controller high-speed shelves input 19 with be located the first terminal end face of 4 some directions and be connected, motor stop shelves input 20 with be located the first terminal end face of 6 some directions and be connected, motor low-speed shelves input 21 with be located the first terminal end face of 8 some directions and be connected, motor high-speed shelves input 22 with be located the first terminal end face of 10 some directions and be connected. One end of the reed 5 is positioned in the center of the end face of the outer end of the knob shaft 4 and is in contact fit with the end face of the knob shaft; the other end of the spring is fixed on the end face of the second binding post 12 through a nut. The second terminal post has a blind hole at its end for connection to the positive input terminal 17 of the power supply. The end surfaces of the other ends of the first binding posts respectively positioned in the directions of 12 points, 2 points and 4 points are respectively fixed with a switch static contact short reed 11; and switch stationary contact long reeds 23 are respectively fixed on the end surfaces of the other ends of the first binding posts in the directions of 6 points, 8 points and 10 points.

One end of the switch panel 12 is an open end, and the outer circumferential surface of the open end is provided with a connecting plate which is radially protruded and used for connecting with the switch mounting plate 1; the other end of the switch panel is provided with an end plate, the center of the end plate is provided with a step-shaped through hole, and the inner surface of the through hole is in clearance fit with the knob shaft 4; the inner end face of the switch panel end plate is provided with an annular boss which axially protrudes, and the inner end face of the boss is contacted with the inner end face of the knob moving contact reed 10, so that the knob moving contact reed and the knob moving contact reed can rotate relatively. Three position indication grooves are distributed on the outer end face of the switch panel end plate, and the positions of the three position indication grooves correspond to the positions of the first binding posts in the directions of 12 points, 2 points and 4 points respectively.

The switch mounting plate 1 is round inside and round outside, the aperture of the inner hole of the switch mounting plate is the same as the outer diameter of the knob shaft sleeve 24, and a groove matched with the limit boss on the inner surface of the knob shaft sleeve is arranged on the outer surface of the switch mounting plate. Six through mounting holes of the first binding post 2 are uniformly distributed on the end surface of the switch mounting plate; the inner surface of the mounting hole is a stepped surface matched with the outer surface of the first binding post, so that the first binding posts are axially positioned. The four corners of the switch mounting plate are respectively provided with a connecting hole. The switch mounting plate has a blind hole in its end face for mounting the second terminal 14.

The circumferential surface of the knob shaft 4 is stepped. The middle part of the knob shaft is provided with a shaft shoulder which is protruded radially. The shafts at the two ends of the shaft shoulder are used for mounting the knob shaft sleeve 24 and the knob 9 respectively. A shaft body for mounting a knob shaft sleeve is provided with a blind hole for placing a first spring 6 and a first steel ball 3 in the radial direction, the end face of a shaft shoulder at the end is provided with three semicircular holes which are contacted with a second steel ball 8, and the positions of the semicircular holes respectively correspond to the positions of a first binding post in the directions of 6 points, 8 points and 10 points. The other side of the shaft shoulder is provided with a boss for sleeving the knob moving contact spring 10.

The knob shaft sleeve 24 is a hollow revolving body. The middle part of the inner surface of the knob shaft sleeve is provided with an annular groove matched with the first steel ball 3. The middle part of the outer surface of the knob shaft sleeve is provided with a radial boss for positioning the switch mounting plate 1. And a blind hole for placing a second spring 7 and a second steel ball 8 is arranged at the edge of the end face of one end of the knob shaft sleeve.

There are three of the switch stationary contact stubs 11. One surface of each switch stationary contact spring is a concave arc surface, and the radius of the concave arc surface is the same as that of the outer circumferential surface of the knob moving contact spring 10. The other surface of each switch stationary contact short reed is provided with a boss, and the geometric center of each boss is provided with a guide post which is respectively communicated with the controller stop input end 16, the controller low-speed input end 18 and the controller high-speed input end 19.

The number of the switch stationary contact long reeds 23 is three, and the structural characteristics of the switch stationary contact long reeds are the same as those of the switch stationary contact short reeds. The length of the switch static contact long reed is 5mm larger than that of the switch static contact short reed, and when the knob moving contact reed 10 matched with the switch static contact long reed rotates to a position between two adjacent switch static contact long reeds, the knob moving contact reed can be simultaneously connected with the two adjacent switch static contact long reeds.

The knob moving contact reed is in a 10-bit circular ring shape. The inner surface of the knob moving contact reed is matched with the lug boss of the knob shaft 4 in a spot welding way; the inner surface of the knob moving contact reed is provided with a convex key. Two reeds are symmetrically distributed on the outer surface of the knob moving contact reed, one of the reeds is a short reed and is used for being matched with the three switch static contact short reeds 11, and the other reed is a long reed and is used for being matched with the three switch static contact long reeds 23.

The center of the end face of one end of the first binding post 2 is provided with a blind hole for connecting each lead, and the end face of the other end is provided with an installation boss for installing a switch static contact short reed or a switch static contact long reed. The circumferential surface of the first binding post 2 is in a step shape matched with the first binding post mounting hole on the switch mounting plate.

The structure of the second terminal 14 is similar to that of the first terminal. The difference lies in that the end face of the second binding post is not provided with the mounting boss.

In the embodiment, 6 first

binding posts

2, 1 second binding post 14 and a knob shaft sleeve 24 which are uniformly distributed are fixed together by plastic compression according to the appearance of the switch mounting plate 1, and the axes of small holes of the knob shaft sleeve 24 and the axes of 1 first binding post are ensured to be in the symmetry plane of the switch mounting plate.

And will again 3 stationary contact short reed 11 of switch and 3 stationary contact long reed 23 of switch require welded fastening according to the position that figure 13 indicates on 6 evenly distributed's the first terminal 2, and abrasive machining 3 stationary contact short reed 11 of switch and the hole that 3 stationary contact long reed 23 of switch constitute, guarantee with knob axle sleeve hole coaxial, will second spring 7 put into in the hole of 24 one ends of knob axle sleeve, the reuse second steel ball 8 compresses second spring 7, carry out the terminal surface circumference again and dash 3 points and make second steel ball 8 and second spring 7 can not drop.

And pressing the rotary knob moving contact reed 10 into the step excircle of the rotary knob shaft 4, ensuring that the inner hole of the rotary knob moving contact reed 10 protrudes out of a groove and is matched with the excircle groove of the rotary knob shaft 4, and grinding 2 contacts on the excircle of the rotary knob moving contact reed 10 to ensure that the contacts are matched with the axis of the rotary knob shaft 4. Putting the first spring 6 into an inner hole at the outer circle of the knob shaft 4, then compressing the first spring 6 by the first steel ball 3, and then performing circumferential punching for 3 points to prevent the first steel ball 3 and the first spring 6 from falling off;

and pressing the first steel ball 3 into the knob shaft 4, installing the knob shaft 4 into the knob shaft sleeve 24 to enable the first steel ball 3 to be matched with the annular groove of the knob shaft sleeve 24, matching the spherical concave point of the knob shaft 4 with the second steel ball 8 pressed into the knob shaft sleeve 24, and enabling the knob moving contact reed 10 to be in small interference contact fit with the switch stationary contact short reed and the 1 symmetrically distributed switch stationary contact long reed 23.

Then the inner hole of the switch panel 12 is in coaxial clearance fit with the excircle of the knob shaft 4, four holes are attached to one end face of the switch mounting plate 1, the knob 9 is matched with the gap part of the knob shaft 4, and then the screw 13 is screwed into the threaded hole of the knob 9 to lock the knob 9 on the knob shaft 4 by the screw.

Switch mounting panel 1 the another side will reed 5's hole and the 14 excircle cooperations of second terminal, the other end and the 4 terminal surface laminating of knob axle of reed 5 use nut 15 and the 14 external screw thread cooperation of second terminal and extrude reed 5, make reed 5 produce a terminal surface of little deformation extrusion knob axle 4.

Claims

1. A rotary switch is characterized by comprising a switch mounting plate, a first wiring terminal, a knob shaft sleeve, a switch panel and a knob; the knob shaft sleeve is sleeved on the outer circumferential surface of the knob shaft, a first spring is arranged in an annular semicircular groove in the inner surface of the knob shaft sleeve, a first steel ball is arranged on the upper end face of the first spring, and only circumferential rotation can be generated between the knob shaft sleeve and the knob shaft through the first steel ball; an axial blind hole is formed in the inner end face of the knob shaft sleeve, a second spring is arranged at the bottom of the blind hole, and a second steel ball is arranged on the outer end face of the second spring, so that the second steel ball is positioned between the inner end face of the knob shaft sleeve and the outer end face of the shaft shoulder of the knob shaft; the inner surface of the switch mounting plate is sleeved on the outer surface of the knob shaft sleeve; the knob motion contact reed is sleeved on the circumferential surface of the knob shaft and is attached to the outer end face of the shaft shoulder of the knob shaft; six first binding posts are uniformly distributed and embedded on the circumference of the switch mounting plate; the switch panel is sleeved on the knob shaft, and the end face of one end of the switch panel is attached to the end face of the switch mounting plate; the knob is sleeved on the knob shaft and is positioned at the outer end of the switch panel; one end of the reed is positioned in the center of the end face of the outer end of the knob shaft and is in contact fit with the end face of the knob shaft; the other end of the reed is fixed on the end surface of the second binding post; and a blind hole for connecting the positive input end of the power supply is arranged on the end face of the second binding post.

2. The rotary switch according to claim 1, wherein the six first terminals uniformly distributed on the circumference of the switch mounting plate have axial blind holes at the center of one end face, and the blind holes are used for welding cables, respectively, wherein the stop input end of the controller is connected with the end face of the first terminal in the 12-point direction, the low input end of the controller is connected with the end face of the first terminal in the 2-point direction, the high input end of the controller is connected with the end face of the first terminal in the 4-point direction, the stop input end of the motor is connected with the end face of the first terminal in the 6-point direction, the low input end of the motor is connected with the end face of the first terminal in the 8-point direction, and the high input end of the motor is connected with the end face of the first terminal in the 10-point direction; the end surfaces of the other ends of the first binding posts respectively positioned in the directions of 12 points, 2 points and 4 points are respectively fixed with a switch static contact short reed; and switch stationary contact long reeds are respectively fixed on the end surfaces of the other ends of the first binding posts respectively positioned in the directions of 6 points, 8 points and 10 points.

3. The rotary switch according to claim 2, wherein one end of the switch panel is an open end having a radially protruding connecting plate on an outer circumferential surface thereof for connection with the switch mounting plate; the other end of the switch panel is provided with an end plate, the center of the end plate is provided with a step-shaped through hole, and the inner surface of the through hole is in clearance fit with the knob shaft; the inner end surface of the switch panel end plate is provided with an annular boss which axially protrudes, and the inner end surface of the boss is contacted with the inner end surface of the knob moving contact reed, so that the knob moving contact reed and the switch panel end plate can rotate relatively; three position indication grooves are distributed on the outer end face of the switch panel end plate, and the positions of the three position indication grooves correspond to the positions of the first binding posts in the directions of 12 points, 2 points and 4 points respectively.

4. The rotary switch according to claim 1, wherein the switch mounting plate is inner and outer, the inner hole of the switch mounting plate has the same diameter as the outer diameter of the knob shaft sleeve, and the inner surface of the switch mounting plate has a groove matching with the limit boss on the outer surface of the knob shaft sleeve; six through mounting holes of a first binding post are uniformly distributed on the end surface of the switch mounting plate; the inner surface of the mounting hole is a stepped surface matched with the outer surface of the first binding post so as to axially position each first binding post; connecting holes are respectively arranged at four square corners of the switch mounting plate; and a blind hole for mounting the second binding post is arranged on the end surface of the switch mounting plate.

5. The rotary switch according to claim 2, wherein a circumferential surface of the knob shaft is stepped; the middle part of the knob shaft is provided with a shaft shoulder which protrudes in the radial direction; the shafts at the two ends of the shaft shoulder are respectively used for mounting a knob shaft sleeve and a knob; a shaft body for mounting a knob shaft sleeve is provided with a blind hole for mounting a first spring and a first steel ball in the radial direction, the end face of a shaft shoulder at the end is provided with three semicircular holes which are contacted with a second steel ball, and the positions of the semicircular holes respectively correspond to the positions of a first binding post in the directions of 6 points, 8 points and 10 points; the other side of the shaft shoulder is provided with a boss for sleeving a rotary knob moving contact reed.

6. The rotary switch according to claim 2, wherein said switch stationary contact reed has three; one surface of each switch stationary contact spring leaf is a concave arc surface, and the radius of the concave arc surface is the same as that of the outer circumferential surface of the knob moving contact spring leaf; the other surface of each switch static contact short reed is provided with a boss, and the geometric center of each boss is provided with a guide post which is respectively communicated with the stop gear input end of the controller, the low-speed gear input end of the controller and the high-speed gear input end of the controller;

the number of the switch static contact long reeds is three, and the structural characteristics of the switch static contact long reeds are the same as those of the switch static contact short reeds; the length of the switch static contact long reed is 5mm larger than that of the switch static contact short reed, and when the knob moving contact reed matched with the switch static contact long reed rotates to a position between two adjacent switch static contact long reeds, the knob moving contact reed can be simultaneously connected with the two adjacent switch static contact long reeds.

7. The rotary switch according to claim 5, wherein said knob moving contact reed is annular; the inner surface of the knob moving contact reed is matched with the lug boss of the knob shaft in a spot welding way; the inner surface of the knob moving contact reed is provided with a convex key; two reeds are symmetrically distributed on the outer surface of the knob moving contact reed, one of the reeds is a short reed and is used for being matched with the three switch static contact short reeds, and the other reed is a long reed and is used for being matched with the three switch static contact long reeds.

8. The rotary switch according to claim 6, wherein the center of the end face of one end of the first binding post is provided with a blind hole for connecting each lead, and the end face of the other end is provided with a mounting boss for mounting a switch stationary contact short reed or a switch stationary contact long reed; the circumferential surface of the first binding post is step-shaped and matched with the first binding post mounting hole on the switch mounting plate;

the structure of the second binding post is different from that of the first binding post in that the end face of the second binding post is not provided with the mounting boss.

9. The rotary switch of claim 1, wherein said knob shaft sleeve is a hollow solid of revolution; the middle part of the inner surface of the knob shaft sleeve is provided with an annular groove matched with the first steel ball; a radial boss is arranged in the middle of the outer surface of the knob shaft sleeve and used for positioning the switch mounting plate; and a blind hole for placing a second spring and a second steel ball is arranged at the edge of the end face of one end of the knob shaft sleeve.