A servo motor for a robot

Abstract

The utility model discloses a steering engine for robot, including installation casing, translucent light guide casing and PCB board, translucent light guide casing fixed mounting is in the upper end surface of installation casing, and the PCB board fixed mounting is in the upper end surface of translucent light guide casing, and the inside of translucent light guide casing is provided with light guide chamber, and the outside of translucent light guide casing forms annular luminous surface, and the light guide chamber is provided with light emitting component. Setting up light emitting component in the inside of steering engine, through translucent light guide casing, the light of light emitting component is guided to the outside of translucent light guide casing and forms annular luminous surface, thereby through the light of light emitting component as built -in atmosphere lamp, need not to set up external atmosphere lamp, avoid external atmosphere lamp to occupy space, influence mechanical movement, reduce cost, simplify product structure, improve the appearance performance through the color and the lighting mode of light emitting component, increase light effect, promote atmosphere, increase man -machine interaction experience.

Description

Technical Field

[0001] This utility model relates to the field of servo motor technology, and in particular to a servo motor for robots. Background Technology

[0002] A servo motor is a precision-controlled servo drive device. Due to its high-precision position control characteristics, it has been widely used in fields requiring precise angle adjustment, such as robot joints and smart hardware. In particular, servo motors are required at all joints in products such as bionic robots and educational robots.

[0003] In the prior art, in order to reflect the working status of the servo motor and facilitate troubleshooting, dot-shaped indicator lights are set for status feedback. However, when the servo motor is installed on the product, the indicator lights are covered by the product's housing components, making them difficult to observe. Therefore, in order to facilitate troubleshooting, improve appearance, enhance lighting effects, and improve the atmosphere, independent ambient lights are often set around the servo motor. The ambient lights provide feedback on the working status of the servo motor and enhance the lighting effects.

[0004] However, when servo motors are used in the joints of multi-degree-of-freedom robots, the complex mechanical linkages at the joint connections result in extremely limited installation space for external decorations. It is difficult to install ambient lights at the joints. Even if ambient lights are forcibly installed, a separate mounting bracket needs to be designed for them, which not only increases the structural complexity but also causes the joints to expand, affecting the robot's movement flexibility. Furthermore, external wiring is easily pulled by mechanical movement, posing a risk of wire breakage and affecting system reliability. Therefore, it is necessary to improve this approach. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a servo motor for robots that incorporates an ambient light inside, eliminating the need for an external ambient light, reducing costs, simplifying product structure, improving appearance, enhancing lighting effects, and improving the overall ambiance.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a servo motor for a robot, comprising a mounting housing, a semi-transparent light guide housing, and a PCB board. The semi-transparent light guide housing is fixedly mounted on the upper surface of the mounting housing, and the PCB board is fixedly mounted on the upper surface of the semi-transparent light guide housing. A light guide cavity is provided inside the semi-transparent light guide housing, and an annular light-emitting surface is formed on the outer surface of the semi-transparent light guide housing. A light-emitting component is provided inside the light guide cavity, and a control circuit is provided on the PCB board. A motor, a reduction gear set, an output shaft, and a potentiometer are provided inside the mounting housing. The motor is driven by the reduction gear set, the reduction gear set is driven by the output shaft, and the output shaft is connected to the potentiometer. The light-emitting component, the motor, and the potentiometer are electrically connected to the control circuit.

[0007] In a further technical solution, the light-emitting component includes at least one LED light group, and each LED light group includes at least one LED bead, which is soldered and fixed to the lower end face of the PCB board.

[0008] In a further technical solution, the servo motor is equipped with stop, running, and fault states.

[0009] When the machine is stopped, all LEDs are turned off.

[0010] During operation, each LED bead flashes regularly, lights up sequentially, or remains constantly lit.

[0011] In the fault state, each LED bead flickers at a high frequency.

[0012] In a further technical solution, the light-emitting component includes three sets of LED light groups: the first set of LED light groups is red LED light group, the second set of LED light groups is green LED light group, and the third set of LED light groups is blue LED light group.

[0013] In a further technical solution, the green and blue LED lights are turned off in the event of a fault, while the red LED lights flash at a high frequency or remain constantly lit.

[0014] In a further technical solution, the mounting housing includes a lower cover and a middle cover. The lower cover is located on the lower end face of the middle cover, and the semi-transparent light guide housing is located on the upper end face of the middle cover. A threaded hole is provided at each of the four corners of the upper end face of the lower cover. A vertically penetrating lower screw hole is provided at each of the four corners of the upper end face of the middle cover. A vertically penetrating middle screw hole is provided at each of the four corners of the semi-transparent light guide housing. A vertically penetrating upper screw hole is provided at each of the four corners of the PCB board. The upper screw hole, middle screw hole, lower screw hole, and threaded hole at the same corner are aligned vertically. The servo is also provided with four fastening screws, each of which passes through the upper screw hole, middle screw hole, and lower screw hole in sequence and is threadedly connected to the threaded hole.

[0015] In a further technical solution, the semi-transparent light guide housing includes a U-shaped light guide frame, a middle light guide strip, and an annular light guide ring. The middle light guide strip is formed between the U-shaped light guide frame and the annular light guide ring. The left and right sides of the upper end face of the middle light guide strip are respectively connected to the lower end faces of the U-shaped light guide frame and the annular light guide ring. The U-shaped light guide frame, the middle light guide strip, the annular light guide ring, and the PCB board enclose and form a socket groove. A connecting socket is provided in the socket groove. The connecting socket is welded and fixed to the lower end face of the PCB board and electrically connected to the control circuit. The outer side of the U-shaped light guide frame, the two outer end faces of the middle light guide strip, and the outer side of the annular light guide ring form an annular light-emitting surface.

[0016] In a further technical solution, two light guide pillars are provided on the side of the middle light guide strip facing the U-shaped light guide frame. The upper ends of the two light guide pillars extend upward and connect with both ends of the U-shaped light guide frame. A light guide baffle is provided on the side of the middle light guide strip facing the annular light guide ring. The upper part of the light guide baffle extends upward and connects with the lower end face of the annular light guide ring. The light guide chamber is set inside the U-shaped light guide frame. The upper part of the motor protrudes from the upper end face of the mounting housing and is inserted into the annular light guide ring. The potentiometer is set below the U-shaped light guide frame. The potentiometer is provided with multiple connection pins. Each connection pin passes through the gap between the two light guide pillars and is soldered and fixed to the PCB board.

[0017] In a further technical solution, a socket limiting strip is horizontally provided in the middle of the upper end face of the middle light guide strip, and a socket limiting groove is provided on the lower end face of the corresponding connecting socket at the position of the socket limiting strip, and the socket limiting strip and the socket limiting groove are matched for limiting.

[0018] In a further technical solution, a positioning groove is provided in the middle of the lower end face of the middle light guide strip, which runs horizontally through the middle light guide strip. A positioning strip is provided on the upper part of the corresponding mounting housing at the position of the positioning groove, and the positioning strip is inserted into the positioning groove.

[0019] The advantages of this invention compared to existing technologies after adopting the above structure are as follows: A light-emitting component is installed inside the servo motor. The light from the light-emitting component is evenly guided to the outer surface of the semi-transparent light guide shell to form a ring-shaped light-emitting surface. Thus, the light from the light-emitting component serves as a built-in ambient light, eliminating the need for an external ambient light, avoiding space occupation and interference with mechanical movement, reducing costs, and simplifying the product structure. The color and lighting method of the light-emitting component enhance the appearance, increase the lighting effect, improve the atmosphere, and enhance the human-machine interaction experience. The color or flashing of the light-emitting component provides feedback on the servo motor's fault status, helping to quickly locate the faulty motor and pinpoint the fault point, facilitating repair. The light-emitting component, potentiometer, and motor are all directly soldered and fixed to the PCB board to form an integrated circuit, eliminating the need for wire connections and improving connection stability and reliability. The mounting shell, semi-transparent light guide shell, and PCB board are stacked, facilitating manufacturing and assembly. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is an exploded view of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the semi-transparent light guide shell of this utility model;

[0024] Figure 4 This is a cross-sectional view of the present invention.

[0025] In the picture:

[0026] 11. Lower cover, 111. Threaded hole, 12. Middle shell, 121. Lower screw hole, 122. Positioning strip;

[0027] 2. Semi-transparent light guide housing, 21. U-shaped light guide frame, 22. Middle light guide strip, 221. Light guide column, 222. Light guide baffle, 223. Socket limiting strip, 224. Positioning groove, 23. Annular light guide ring, 24. Light guide cavity, 25. Annular light-emitting surface, 26. Middle screw through hole, 27. Socket groove;

[0028] 3. PCB board, 31. Screw holes;

[0029] 4 LED beads;

[0030] 51 Motor, 52 Reduction gear set, 53 Output shaft;

[0031] 6 potentiometers, 61 connection pins;

[0032] 7. Connecting socket; 71. Socket limiting groove;

[0033] 8. Fastening screws. Detailed Implementation

[0034] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0035] A type of servo motor for robots, such as Figures 1 to 4As shown, the device includes a mounting housing, a semi-transparent light guide housing 2, and a PCB board 3. The semi-transparent light guide housing 2 is fixedly mounted on the upper surface of the mounting housing, and the PCB board 3 is fixedly mounted on the upper surface of the semi-transparent light guide housing 2. A light guide cavity 24 is provided inside the semi-transparent light guide housing 2, and an annular light-emitting surface 25 is formed on the outer surface of the semi-transparent light guide housing 2. A light-emitting component is provided inside the light guide cavity 24. A control circuit is provided on the PCB board 3. A motor 51, a reduction gear set 52, an output shaft 53, and a potentiometer 6 are provided inside the mounting housing. The motor 51 is connected to the reduction gear set 52, the reduction gear set 52 is connected to the output shaft 53, and the output shaft 53 is connected to the potentiometer 6. The light-emitting component, the motor 51, and the potentiometer 6 are electrically connected to the control circuit. Traditional servo motors only have dot-shaped indicator lights to show the working status, which are difficult to see after installation on a product. They also lack ambient lighting functionality. Installing ambient lights on a product requires designing a mounting bracket and connecting wires, resulting in a complex structure, high cost, and difficulty in installing them in confined spaces such as robot joints. Even if installation is possible, it will affect mechanical movement. This invention, however, incorporates a light-emitting component inside the servo motor. The light from the light-emitting component is evenly guided to the outer surface of the semi-transparent light guide shell 2 to form a ring-shaped light-emitting surface 25. Thus, the light from the light-emitting component serves as a built-in ambient light, eliminating the need for an external ambient light source. The lighting design avoids the space-consuming and mechanically disruptive nature of external ambient lighting, reducing costs and simplifying the product structure. The color and illumination method of the light-emitting components enhance the visual appeal, lighting effects, atmosphere, and human-machine interface. The color or flashing of the light-emitting components provides feedback on servo motor malfunctions, helping to quickly locate faulty motors and pinpoint the problem for easier repair. The light-emitting components, potentiometer 6, and motor 51 are all directly soldered and fixed to the PCB board 3 to form an integrated circuit, eliminating the need for wire connections and improving connection stability and reliability. The mounting housing, semi-transparent light guide housing 2, and PCB board 3 are stacked for easy manufacturing and assembly.

[0036] Specifically, the light-emitting component includes at least one LED group, and each LED group includes at least one LED bead 4, which is soldered and fixed to the lower end face of the PCB board 3. The LED bead 4 is a surface-mount LED bead, which is soldered onto the PCB board 3 via SMT and electrically connected to the control circuit through the flexible circuit on the PCB board 3.

[0037] Specifically, the servo is set to a stop state, a running state, and a fault state. In the stop state, all LED beads 4 are off; in the stop state, all LED beads 4 are off to indicate that the servo is not powered on.

[0038] In operation, each LED bead 4 flashes regularly, lights up sequentially, or remains constantly lit; flashing LED bead 4 creates a breathing light effect, sequential lighting of LED bead 4 creates a marquee effect, and keeping LED bead 4 constantly lit creates a normal ambient light effect. The lighting effects can be customized by setting the program through the control circuit, increasing the human-computer interaction experience.

[0039] In the fault state, each LED bead 4 flashes at a high frequency. The LED bead 4 flashes at a high frequency of 10Hz to attract attention and help to quickly locate the fault.

[0040] Specifically, the light-emitting component includes three sets of LED lights: the first set is red LEDs, the second set is green LEDs, and the third set is blue LEDs. These three sets of LEDs, each a different color, form RGB lighting. Through PWM dimming, 16 million colors can be displayed, enriching the color display and facilitating more customized scenes, further enhancing the human-computer interaction experience.

[0041] Specifically, in a fault condition, the green and blue LED lights are off, while the red LED lights flash at high frequency or remain constantly lit. Since humans are more sensitive to red, the high-frequency flashing or constant lighting of the red LED lights attracts attention, conforming to the ISO 3864 safety color standard. Red has a higher warning priority than other conditions.

[0042] Specifically, the mounting housing includes a lower cover 11 and a middle shell 12. The lower cover 11 is located on the lower end face of the middle shell 12, and the semi-transparent light guide shell 2 is located on the upper end face of the middle shell 12. A threaded hole 111 is provided on each of the four corners of the upper end face of the lower cover 11. A vertically penetrating lower screw hole 121 is provided on each of the four corners of the upper end face of the middle shell 12. A vertically penetrating middle screw hole 26 is provided on each of the four corners of the semi-transparent light guide shell 2. A vertically penetrating upper screw hole 31 is provided on each of the four corners of the PCB board 3. The upper screw hole 31, middle screw hole 26, lower screw hole 121 and threaded hole 111 on the same corner are aligned vertically. The servo is also provided with four fastening screws 8. Each fastening screw 8 passes through the upper screw hole 31, middle screw hole 26 and lower screw hole 121 and is threadedly connected to the threaded hole 111. During assembly, the motor 51 and potentiometer 6 are first soldered onto the PCB board 3. Then, the PCB board 3 is connected to the semi-transparent light guide housing 2 and the middle housing 12 in sequence. Next, the output shaft 53 and the reduction gear set 52 are installed inside the middle housing 12 and the output shaft 53 is connected to the potentiometer 6. Finally, the lower cover 11 is fastened to the lower end face of the middle housing 12. At this time, the upper screw holes 31, middle screw holes 26, lower screw holes 121 and threaded holes 111 on the four corners are aligned vertically. Finally, the fastening screws 8 are threaded through the upper screw holes 31, middle screw holes 26 and lower screw holes 121 and threaded into the threaded holes 111 in sequence. Only four fastening screws 8 are needed to connect the various components of the servo motor, which facilitates assembly and disassembly, improves production efficiency, and facilitates subsequent maintenance.

[0043] Specifically, the translucent light guide housing 2 includes a U-shaped light guide frame 21, a middle light guide strip 22, and an annular light guide ring 23. The middle light guide strip 22 is formed between the U-shaped light guide frame 21 and the annular light guide ring 23. The left and right sides of the upper end face of the middle light guide strip 22 are connected to the lower end faces of the U-shaped light guide frame 21 and the annular light guide ring 23, respectively. The U-shaped light guide frame 21, the middle light guide strip 22, the annular light guide ring 23, and the PCB board 3 enclose and form a socket groove 27. A connecting socket 7 is provided in the socket groove 27. The connecting socket 7 is welded and fixed to the lower end face of the PCB board 3 and electrically connected to the control circuit. The outer side of the U-shaped light guide frame 21, the two outer end faces of the middle light guide strip 22, and the outer side of the annular light guide ring 23 form an annular light-emitting surface 25. Since the servo motor needs to communicate with the product for power and data transmission via the connector 7, and the connector 7 is relatively large, it would create a significant protrusion after being soldered onto the PCB board 3. Traditional servos have the PCB board 3 completely enclosed within the servo motor housing to cover the connector 7 and prevent it from protruding. However, in this invention, the PCB board 3 is externally mounted, which not only reduces the size of the servo motor but also helps dissipate heat from the electronic components on the PCB board 3. To address the issue of the connector 7 protruding, a socket groove 27 is formed by the U-shaped light guide frame 21, the intermediate light guide strip 22, the annular light guide ring 23, and the PCB board 3, thus embedding the connector 7 inside the servo motor and preventing protrusion. Since the connector 7 is not transparent, the light from the light-emitting component would be blocked by it. Therefore, the intermediate light guide strip 22 guides the light between the U-shaped light guide frame 21 and the annular light guide ring 23, preventing the light from being interrupted at the connector 7 and maintaining the surrounding effect of the annular light guide ring 23.

[0044] Specifically, two light guide pillars 221 are provided on the side of the middle light guide strip 22 facing the U-shaped light guide frame 21. The upper ends of the two light guide pillars 221 extend upward and connect with the two ends of the U-shaped light guide frame 21. A light guide baffle 222 is provided on the side of the middle light guide strip 22 facing the annular light guide ring 23. The upper part of the light guide baffle 222 extends upward and connects with the lower end face of the annular light guide ring 23. The light guide chamber 24 is located inside the U-shaped light guide frame 21. The upper part of the motor 51 protrudes from the upper end face of the mounting housing and is inserted into the annular light guide ring 23. The potentiometer 6 is located below the U-shaped light guide frame 21. The potentiometer 6 is provided with multiple connection pins 61. Each connection pin 61 passes through the gap between the two light guide pillars 221 and is soldered and fixed to the PCB board 3. The motor 51 is welded and fixed to the PCB board 3 through the annular light guide ring 23, thereby making full use of the installation space and reducing the size of the servo motor. When the light-emitting component emits light, the light shines on the U-shaped light guide frame 21 and the two light guide pillars 221 through the light guide chamber 24. The light is guided to the middle light guide strip 22 by the two light guide pillars 221. The middle light guide strip 22 then guides the light to the annular light guide ring 23 through the light guide baffle 222, thereby making the translucent light guide shell 2 emit light as a whole, forming the annular light guide ring 23, improving the light guiding efficiency and increasing the uniformity of the brightness display.

[0045] Specifically, a socket limiting strip 223 is horizontally arranged in the middle of the upper surface of the intermediate light guide strip 22, and a socket limiting groove 71 is opened in the lower surface of the corresponding connecting socket 7 at the position of the socket limiting strip 223. The socket limiting strip 223 and the socket limiting groove 71 are matched for limiting. During assembly, the socket limiting strip 223 and the socket limiting groove 71 can quickly position and install the semi-transparent light guide shell 2 and the PCB board 3, which facilitates the alignment of each upper screw hole 31 and each middle screw hole 26, improves assembly efficiency, and at the same time plays a limiting and fixing role, fixing the lower part of the connecting socket 7, preventing the low connection strength caused by the connecting socket 7 being fixed to the PCB board 3 only by the pins, and preventing desoldering.

[0046] Specifically, a positioning groove 224 is provided in the middle of the lower end face of the intermediate light guide strip 22, extending horizontally through the intermediate light guide strip 22. Correspondingly, a positioning strip 122 is provided on the upper part of the mounting housing at the position of the positioning groove 224, and the positioning strip 122 is inserted into the positioning groove 224. During assembly, the positioning strip 122 and the positioning groove 224 enable quick positioning and installation of the translucent light guide housing 2 and the mounting housing, facilitating the alignment of the various middle screw holes 26 and the various lower screw holes 121, thereby improving assembly efficiency.

[0047] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. A servo motor for a robot, characterized in that: The system includes a mounting housing, a semi-transparent light guide housing (2), and a PCB board (3). The semi-transparent light guide housing (2) is fixedly mounted on the upper surface of the mounting housing, and the PCB board (3) is fixedly mounted on the upper surface of the semi-transparent light guide housing (2). The interior of the semi-transparent light guide housing (2) is provided with a light guide cavity (24), and the outer surface of the semi-transparent light guide housing (2) forms an annular light-emitting surface (25). The light guide cavity (24) is provided with a light-emitting component, and the PCB board (3) is provided with a control circuit. The mounting housing is provided with a motor (51), a reduction gear set (52), an output shaft (53), and a potentiometer (6). The motor (51) is connected to the reduction gear set (52) for transmission, the reduction gear set (52) is connected to the output shaft (53) for transmission, and the output shaft (53) is connected to the potentiometer (6). The light-emitting component, the motor (51), and the potentiometer (6) are electrically connected to the control circuit, respectively.

2. A servo motor for a robot according to claim 1, characterized in that: The light-emitting component includes at least one LED light group, and each LED light group includes at least one LED bead (4), which is soldered and fixed to the lower end face of the PCB board (3).

3. A servo motor for a robot according to claim 2, characterized in that: The servo motor is equipped with a stop state, a running state, and a fault state. When the machine is stopped, each of the LED beads (4) is turned off; During operation, each LED bead (4) flashes regularly, lights up sequentially, or remains constantly lit. In the fault state, each LED bead (4) flashes at high frequency.

4. A servo motor for a robot according to claim 3, characterized in that: The light-emitting component includes three groups of LED lights: the first group of LED lights is red LED lights, the second group of LED lights is green LED lights, and the third group of LED lights is blue LED lights.

5. A servo motor for a robot according to claim 4, characterized in that: In the fault state, the green LED group and the blue LED group are turned off, and the red LED group flashes at high frequency or remains constantly lit.

6. A servo motor for a robot according to claim 1, characterized in that: The mounting housing includes a lower cover (11) and a middle shell (12). The lower cover (11) is disposed on the lower end face of the middle shell (12), and the semi-transparent light guide housing (2) is disposed on the upper end face of the middle shell (12). A threaded hole (111) is provided at each of the four corners of the upper end face of the lower cover (11). A vertically penetrating screw hole (121) is provided at each of the four corners of the upper end face of the middle shell (12), and a vertically penetrating middle screw hole (2) is provided at each of the four corners of the semi-transparent light guide housing (2). The PCB board (3) has a vertical through hole (31) at each of its four corners. The upper screw through hole (31), middle screw through hole (26), lower screw through hole (121) and threaded hole (111) at the same corner are aligned vertically. The servo motor is also provided with four fastening screws (8). Each fastening screw (8) passes through the upper screw through hole (31), middle screw through hole (26) and lower screw through hole (121) and is threaded to the threaded hole (111).

7. A servo motor for a robot according to any one of claims 1 to 6, characterized in that: The semi-transparent light guide housing (2) includes a U-shaped light guide frame (21), a middle light guide strip (22), and an annular light guide ring (23). The middle light guide strip (22) is formed between the U-shaped light guide frame (21) and the annular light guide ring (23). The left and right sides of the upper end face of the middle light guide strip (22) are respectively connected to the lower end face of the U-shaped light guide frame (21) and the annular light guide ring (23). The U-shaped light guide frame (21), the middle light guide strip (22), the annular light guide ring (23), and the PCB board (3) enclose and form a socket groove (27). A connecting socket (7) is provided in the socket groove (27). The connecting socket (7) is welded and fixed to the lower end face of the PCB board (3) and electrically connected to the control circuit. The outer side of the U-shaped light guide frame (21), the two outer end faces of the middle light guide strip (22), and the outer side of the annular light guide ring (23) form the annular light-emitting surface (25).

8. A servo motor for a robot according to claim 7, characterized in that: Two light guide pillars (221) are provided on the side of the middle light guide strip (22) facing the U-shaped light guide frame (21). The upper ends of the two light guide pillars (221) extend upward and are connected to both ends of the U-shaped light guide frame (21). A light guide baffle (222) is provided on the side of the middle light guide strip (22) facing the annular light guide ring (23). The upper part of the light guide baffle (222) extends upward and is connected to the lower end face of the annular light guide ring (23). The light guide chamber (24) is located inside the U-shaped light guide frame (21). The upper part of the motor (51) protrudes from the upper end face of the mounting housing and is inserted into the annular light guide ring (23). The potentiometer (6) is located below the U-shaped light guide frame (21). The potentiometer (6) is provided with multiple connection pins (61). Each connection pin (61) passes through the gap between the two light guide pillars (221) and is welded and fixed to the PCB board (3).

9. A servo motor for a robot according to claim 7, characterized in that: A socket limiting strip (223) is provided horizontally in the middle of the upper end face of the intermediate light guide strip (22), and a socket limiting groove (71) is provided on the lower end face of the corresponding socket limiting strip (223). The socket limiting strip (223) and the socket limiting groove (71) are matched for limiting.

10. A servo motor for a robot according to claim 7, characterized in that: The middle of the lower end face of the intermediate light guide strip (22) is provided with a positioning groove (224) that runs horizontally through the intermediate light guide strip (22). Correspondingly, the upper part of the mounting housing is provided with a positioning strip (122) at the position of the positioning groove (224), and the positioning strip (122) is inserted into the positioning groove (224).

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