A positioning device for a stepping motor

Abstract

The present invention discloses a positioning device for a stepping motor, mainly relating to the technical field of positioning devices, including a housing unit and a positioning unit. The housing unit is arranged on the periphery of the positioning unit, and the positioning unit is arranged on the stepping motor and used to determine the single-turn zero point and the stroke zero point of the stepping motor and reset these two zero points. In the present invention, the positioning device is arranged on the stepping motor, and the infrared emitting tube fixed on the circuit board of the sensor housing emits light, the infrared receiving tube senses the light, and the rotation of the gear and the special disc are used to position and reset the single-turn zero point and the stroke zero point of the motor. This structure can effectively reduce the positioning error and has high positioning accuracy; the outer shell of the positioning part is sealed, not affected by the outside world, and does not require maintenance; there is a half-turn margin in the negative direction; the volume is small.

Description

Technical Field

[0001] The present invention relates to a positioning device, in particular to a positioning device for a stepping motor used in a scanner. Background Art

[0002] Most of the existing stepping motors do not have a positioning device, and only a positioning device is provided on the moving part for zero point and stroke positioning. Such a positioning method is prone to errors and is very unsuitable for some relatively precise instrument and equipment that require accurate determination of the zero point and stroke positioning of the stepping motor. Therefore, it is necessary to design a positioning device that can be directly installed on the stepping motor to meet the actual use requirements. Summary of the Invention

[0003] The present invention provides a positioning device for a stepping motor with a simple structure, which solves the problem of the lack of a motor positioning device in the prior art.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: it includes a housing unit and a positioning unit. The housing unit is arranged outside the positioning unit. The positioning unit is arranged on the stepping motor and is used to determine the single-turn zero point and the stroke zero point of the stepping motor and reset these two zero points.

[0005] Preferably, the housing unit includes a circuit board housing, a first sensor housing and a second sensor housing. The circuit board housing is arranged above the stepping motor. Both the first sensor housing and the second sensor housing are located below the circuit board housing. The first sensor housing is provided with a first round hole, a second round hole and a third round hole of the first sensor housing. The second sensor housing is arranged in front of the first sensor housing. The stepping motor shaft sequentially penetrates through the first sensor housing and the second sensor housing and extends out.

[0006] Preferably, the positioning unit includes a circuit board, a sensor group, a gear group and a disc. The circuit board is arranged above the stepping motor and is located inside the circuit board housing. The sensor group is arranged on the circuit board. The gear group includes a stepping motor shaft gear, a first driven gear and a second driven gear. The stepping motor shaft gear is arranged on the stepping motor shaft. Both the first driven gear and the second driven gear are arranged on the first sensor housing. The first driven gear and the second driven gear are simultaneously engaged with the stepping motor shaft gear. The disc is arranged on the stepping motor shaft and is located in front of the stepping motor shaft gear, the first driven gear and the second driven gear. The disc is composed of two semi-circles with different diameters.

[0007] Preferably, the sensor group includes a first sensor and two second sensors. The first sensor includes an infrared emitting tube 1 and an infrared receiving tube 1. The second sensor includes an infrared emitting tube 2 and an infrared receiving tube 2. The infrared emitting tube 1 and the two infrared emitting tubes 2 are arranged in the second sensor housing. The infrared receiving tube 1 and the two infrared receiving tubes 2 are arranged in the first sensor housing. The infrared emitting tube 1 and the infrared receiving tube 1 are arranged facing each other. The two infrared emitting tubes 2 and the two infrared receiving tubes 2 are respectively arranged facing each other.

[0008] Preferably, the number of teeth of the stepping motor shaft gear, the first driven gear, and the second driven gear are 11, 12, and 13 respectively.

[0009] Preferably, a through first driven gear circular hole is provided near the edge of the first driven gear, and a through second driven gear circular hole is provided near the edge of the second driven gear.

[0010] Preferably, symmetric first transition edge and second transition edge are provided outside the junction of the two semi - circles on the disc. Disc holes 1 and 2 are respectively provided on two different semi - circles of the disc. Disc hole 1, the first driven gear circular hole, and the second circular hole of the first sensor housing correspond to each other. Disc hole 2, the second driven gear circular hole, and the third circular hole of the first sensor housing correspond to each other.

[0011] Preferably, the disc is made of a black light - impermeable material. Both the first sensor housing and the second sensor housing are made of black light - impermeable materials. The stepping motor shaft gear is made of a wear - resistant material. Both the first driven gear and the second driven gear are made of black light - impermeable materials.

[0012] With the above - mentioned structure, the present invention has the following advantages: The positioning device is arranged on the stepping motor. The infrared emitting tube fixed on the circuit board of the sensor housing emits light, the infrared receiving tube senses light, and cooperates with the rotation of gears and a special disc to perform the positioning and reset of the single - turn zero point and the stroke zero point of the motor. This structure can effectively reduce the positioning error and has high positioning accuracy. The positioning parts are all provided with outer shells for sealing, are not affected by the outside world, and do not require maintenance. There is a half - turn margin in the negative direction. It has a small volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a three - dimensional structure schematic diagram of the present invention;

[0014] Figure 2 is a three - dimensional structure schematic diagram of the present invention after removing the circuit board housing and the second sensor housing;

[0015] Figure 3 is a three - dimensional structure schematic diagram of the present invention after removing the circuit board housing, the second sensor housing, the circuit board, and the disc;

[0016] Figure 4This is a three-dimensional structural schematic diagram of the present invention after removing the circuit board housing, the second sensor housing, the first sensor housing, the first driven gear, the second driven gear, and the disc;

[0017] Figure 5 This is an enlarged elevation structure schematic diagram of the disc;

[0018] Figure 6 This is an enlarged three-dimensional structure schematic diagram of the first sensor housing.

[0019] In the figure, 1. Circuit board housing; 2. Stepper motor; 3. First sensor housing; 4. Second sensor housing; 5. Circuit board; 6. First infrared emitter; 7. Second infrared emitter; 8. Disc; 9. Stepper motor shaft; 10. Stepper motor shaft gear; 11. First driven gear; 12. Second driven gear; 13. Circular hole of the second driven gear; 14. First circular hole of the first sensor housing; 15. Circular hole of the first driven gear; 16. First circular hole of the disc; 17. Second circular hole of the disc; 18. First infrared receiver; 19. Second infrared receiver; 20. First transition edge; 21. Second circular hole of the first sensor housing; 22. Third circular hole of the first sensor housing; 23. Second transition edge. Detailed implementation manners

[0020] To clearly illustrate the technical features of this solution, the present invention will be elaborated in detail below through specific implementation manners and in conjunction with its attached drawings.

[0021] As Figure 1 shown, the whole includes a housing unit and a positioning unit. The housing unit is arranged around the positioning unit. The housing unit includes the circuit board housing 1, the first sensor housing 3, and the second sensor housing 4. The circuit board housing 1 is arranged above the stepper motor 2, and both the first sensor housing 3 and the second sensor housing 4 are located below the circuit board housing 1. As Figure 6 shown, the first sensor housing 3 is provided with the first circular hole 14, the second circular hole 21, and the third circular hole 22 of the first sensor housing. The second sensor housing 4 is arranged in front of the first sensor housing 3. The stepper motor shaft 9 penetrates through the first sensor housing 3 and the second sensor housing 4 in sequence and extends out. The positioning unit is arranged on the stepper motor 2 and is used to determine the single-turn zero point and the stroke zero point of the stepper motor 2 and reset these two zero points. As Figure 2 and Figure 3 shown, the positioning unit includes the circuit board 5, a sensor group, a gear group, and the disc 8. The circuit board 5 is arranged above the stepper motor 2 and is located inside the circuit board housing 1. As Figure 4As shown, the sensor group is arranged on the circuit board 5. The sensors include Sensor 1 and two Sensor 2s. Sensor 1 includes infrared emitter 1 6 and infrared receiver 1 18. Sensor 2 includes infrared emitter 2 7 and infrared receiver 2 19. Infrared emitter 1 6 and two infrared emitters 2 7 are arranged in sensor housing 2 4. Infrared receiver 1 18 and two infrared receivers 2 19 are arranged in sensor housing 1 3. Infrared emitter 1 6 and infrared receiver 1 18 are arranged facing each other. Two infrared emitters 2 7 and two infrared receivers 2 19 are respectively arranged facing each other. The gear set includes stepper motor shaft gear 10, driven gear 1 11 and driven gear 2 12. Stepper motor shaft gear 10 is arranged on stepper motor shaft 9. Driven gear 1 11 and driven gear 2 12 are both arranged on sensor housing 1 3. Driven gear 1 11 and driven gear 2 12 are simultaneously engaged with stepper motor shaft gear 10, as Figure 3 shown, a through-hole driven gear 1 circular hole 15 is arranged near the edge of driven gear 1 11. A through-hole driven gear 2 circular hole 13 is arranged near the edge of driven gear 2 12. The number of teeth of stepper motor shaft gear 10, driven gear 1 11 and driven gear 2 12 are 11, 12 and 13 respectively, as Figure 2 shown, the disc 8 is arranged on stepper motor shaft 9 and in front of stepper motor shaft gear 10, driven gear 1 11 and driven gear 2 12, as Figure 5 shown, the disc 8 is composed of two semi-circles with different diameters. Symmetrical transition edges 1 20 and transition edges 2 23 are arranged outside the junction of the two semi-circles on the disc 8. Disc holes 1 16 and disc holes 2 17 are respectively arranged on the two different semi-circles of the disc 8. Disc hole 1 16, driven gear 1 circular hole 15 and sensor housing 1 circular hole 2 21 correspond to each other. Disc hole 2 17, driven gear 2 circular hole 13 and sensor housing 1 circular hole 3 22 correspond to each other. The disc 8 is made of a black light-tight material. Sensor housing 1 3 and sensor housing 2 4 are both made of black light-tight materials. Stepper motor shaft gear 10 is made of a wear-resistant material. Driven gear 1 11 and driven gear 2 12 are both made of black light-tight materials.

[0022] The positioning of the stepper motor 2 includes the positioning of the single-turn zero point and the positioning of the stroke zero point, and the single-turn zero point and the stroke zero point are reset through the positioning unit. The reset process is to first find the single-turn zero point and then find the stroke zero point. The single-turn zero point is the zero point position reached within one rotation (360°) of the stepper motor 2. The stroke zero point is the zero point position reached within the entire stroke of the stepper motor 2 to complete the task;

[0023] A stepper motor 2 is selected with a stroke of 200 steps for one full rotation (360°). The single-turn stroke of the stepper motor 2 is 360°, and the single-turn stroke range is from -180° to +180°. When the stepper motor 2 is in the initial state, the single-turn zero point and the stroke zero point are both at the starting position, that is, the disk hole one 16, the driven gear one round hole 15, and the sensor housing one round hole two 21 are aligned with each other, the disk hole two 17, the driven gear two round hole 13, and the sensor housing one round hole three 22 are aligned with each other. At the same time, the transition edge one 20 and the transition edge two 23 on the disk 8 are vertical, where the transition edge one 20 is located at the upper end, and the sensor housing one round hole one 14 faces the upper transition edge one 20. The entire disk 8 is black and opaque, and the area outside the disk 8 is regarded as transparent;

[0024] There are two directions for the realization of single-turn zero point reset: clockwise rotation and counterclockwise rotation. After the stepper motor 2 starts to work, the sensor one is turned on. At this time, the infrared emitter one 6 is in the emission state, and the infrared receiver one 18 is in the receiving state. The stepper motor shaft 9 starts to drive the stepper motor shaft gear 10 and the disk 8 to rotate. If the small-radius semi-circle of the disk 8 is located above, that is, in front of the sensor housing one round hole one 14, the disk 8 cannot block the infrared ray, then the infrared ray emitted by the infrared emitter one 6 passes through the disk 8 and the sensor housing round hole one 14 and is received by the infrared receiver one 18. The stepper motor shaft 9 drives the disk 8 to rotate synchronously in the clockwise direction until the transition edge one 20 of the disk 8 just crosses the sensor housing round hole one 14, and the infrared ray emitted by the infrared emitter one 6 is blocked by the disk 8 and cannot be received by the infrared receiver one 18. At this time, the stepper motor shaft 9 will rotate counterclockwise according to the program setting until the transition edge one 20 of the disk 8 just turns to the position of the sensor housing round hole one 14, that is, the transition edge one 20 of the disk 8 is vertical and exactly at the position where the infrared ray emitted by the infrared emitter one 6 changes from opaque to transparent. The stepper motor shaft 9 immediately stops rotating, and the single-turn zero point of the stepper motor 2 is reset; if the large-radius semi-circle of the disk 8 is above the sensor housing one round hole one 14, then the infrared ray emitted by the infrared emitter one 6 is blocked by the disk 8 and cannot be received by the infrared receiver one 18. The stepper motor shaft 9 drives the disk 8 to rotate synchronously in the counterclockwise direction until the transition edge one 20 of the disk 8 just turns to the position of the sensor housing round hole one 14, that is, the transition edge one 20 of the disk 8 is vertical and exactly at the position where the infrared ray emitted by the infrared emitter one 6 changes from opaque to transparent. The stepper motor shaft 9 immediately stops rotating, and the single-turn zero point of the stepper motor 2 is reset;

[0025] The travel of the driving component of the stepper motor 2 always needs to rotate more than 1 full circle to complete the task. Therefore, it is necessary to locate the zero point of the travel and reset it. The reset of the zero point of the travel is achieved by the gear set. This device can make the stepper motor 2 return to the zero point of the travel at any angular position within the effective travel. In order to reach the position of the zero point of the travel, the computer program defines that the stepper motor shaft 9 always rotates counterclockwise. That is, there is only one direction for the reset of the zero point of the travel, which is counterclockwise rotation. When the disc hole 16, the circular hole 15 of the driven gear 1, and the second circular hole 21 of the sensor housing 1 are aligned, and at the same time, the disc hole 17, the circular hole 13 of the driven gear 2, and the third circular hole 22 of the sensor housing 1 are aligned, the infrared rays emitted by the two infrared emitting tubes 2 are simultaneously received by the two infrared receiving tubes 2. This position is the zero point of the travel;

[0026] The formula for the alignment from the first alignment of the disc hole 16, the circular hole 15 of the driven gear 1, and the second circular hole 21 of the sensor housing 1 and the simultaneous alignment of the disc hole 17, the circular hole 13 of the driven gear 2, and the third circular hole 22 of the sensor housing 1 to the next simultaneous alignment is: the product of the number of teeth of the stepper motor shaft gear 10, the number of teeth of the driven gear 1 11, and the number of teeth of the driven gear 2 12 (the product of the least common multiples of the number of teeth of the three gears) divided by the number of teeth of the stepper motor shaft gear 10, that is, (11×12×13)÷11 = 156 (circles). When the stepper motor shaft 9 rotates less than 156 circles, the corresponding positions of the disc hole 16, the circular hole 15 of the driven gear 1, and the second circular hole 21 of the sensor housing 1 and the disc hole 17, the circular hole 13 of the driven gear 2, and the third circular hole 22 of the sensor housing 1 are different and no longer aligned. The infrared rays emitted by the two infrared emitting tubes 2 will not reach the two infrared receiving tubes 2. That is, the zero point of the travel is not reset. 156× + 360° = + 56160°, that is, the angle that needs to be rotated from one zero point of the travel to another zero point of the travel is + 56160°. The total travel < + 56160° can return to the current zero point of the travel. If the total travel ≥ + 56160°, it will reach the next zero point of the travel. Therefore, the entire travel cannot exceed + 56160°;

[0027] Through the computer program, it is set that the single - circle zero - point reset is executed before the zero - point reset of the travel is executed. The positive - direction limit of the available travel is: 0° < limit < + 55980° (+ 56160° - 180° = + 55980°. The reason for subtracting 180° is that if the single - circle zero - point reset is executed within the range of + 55980° to + 56160°, it will reach + 56160°), and the negative - direction limit is: 0° > limit > - 180° (0° - 180° = - 180°. The reason for subtracting 180° is that if the single - circle zero - point reset is executed within the range of 0° to - 180°, it will reach 0°). The total travel is 56160°, and the total travel range is from - 180° to + 55980°.

[0028] Among them, the above - mentioned sensor group and gear group are both prior arts.

[0029] The above specific embodiments shall not be construed as limiting the scope of protection of the present invention. For those skilled in the art of this technology, any alternative improvement or transformation made to the embodiments of the present invention shall fall within the scope of protection of the present invention.

[0030] Where the present invention is not described in detail, it is common knowledge to those skilled in the art of this technology.

Claims

1. A positioning device for a stepping motor, characterized in that: It includes a housing unit and a positioning unit. The housing unit is arranged around the positioning unit. The positioning unit is arranged on the stepping motor to determine the single-turn zero point and the stroke zero point of the stepping motor and reset these two zero points. The housing unit includes a circuit board housing, a first sensor housing, and a second sensor housing. The circuit board housing is arranged above the stepping motor. The first sensor housing and the second sensor housing are both located below the circuit board housing. The first sensor housing is provided with a first round hole, a second round hole, and a third round hole of the first sensor housing. The second sensor housing is arranged in front of the first sensor housing. The stepping motor shaft penetrates through the first sensor housing and the second sensor housing in sequence and extends out. The positioning unit includes a circuit board, a sensor group, a gear group, and a disc. The circuit board is arranged above the stepping motor and is located inside the circuit board housing. The sensor group is arranged on the circuit board. The gear group includes a stepping motor shaft gear, a first driven gear, and a second driven gear. The stepping motor shaft gear is arranged on the stepping motor shaft. The first driven gear and the second driven gear are both arranged on the first sensor housing. The first driven gear and the second driven gear are simultaneously engaged with the stepping motor shaft gear. The disc is arranged on the stepping motor shaft and is located in front of the stepping motor shaft gear, the first driven gear, and the second driven gear. The disc is composed of two semi-circles with different diameters. A through first round hole of the first driven gear is arranged near the edge of the first driven gear. A through second round hole of the second driven gear is arranged near the edge of the second driven gear. Symmetrical first transition edge and second transition edge are arranged on the outside at the junction of the two semi-circles of the disc. Disc hole one and disc hole two are respectively arranged on the two different semi-circles of the disc. Disc hole one, the first round hole of the first driven gear, and the second round hole of the first sensor housing correspond to each other. Disc hole two, the second round hole of the second driven gear, and the third round hole of the first sensor housing correspond to each other. The positioning of the stepping motor includes the positioning of the single-turn zero point and the positioning of the stroke zero point, and the single-turn zero point and the stroke zero point are reset through the positioning unit. The reset process first finds the single-turn zero point and then finds the stroke zero point. The single-turn zero point is the zero point position reached within one rotation of the stepping motor. The stroke zero point is the zero point position reached within the entire stroke of the stepping motor to complete the task. When the stepping motor is in the initial state, both the single-turn zero point and the stroke zero point are at the starting position, that is, disc hole one, the first round hole of the first driven gear, and the second round hole of the first sensor housing are aligned with each other. Disc hole two, the second round hole of the second driven gear, and the third round hole of the first sensor housing are aligned with each other. At the same time, the first transition edge and the second transition edge on the disc are vertical, where the first transition edge is located at the upper end, and the first round hole of the first sensor housing is facing the upper first transition edge.

2. The positioning device of the stepper motor according to claim 1, wherein: The number of teeth of the stepping motor shaft gear, the first driven gear, and the second driven gear are 11, 12, and 13 respectively.

3. The positioning device of the stepping motor according to claim 2, wherein: The described sensor group includes Sensor One and two Sensor Twos. Sensor One includes Infrared Transmitter One and Infrared Receiver One. Sensor Two includes Infrared Transmitter Two and Infrared Receiver Two. Infrared Transmitter One and the two Infrared Transmitter Twos are arranged in Sensor Housing Two. Infrared Receiver One and the two Infrared Receiver Twos are arranged in Sensor Housing One. Infrared Transmitter One and Infrared Receiver One are arranged facing each other. The two Infrared Transmitter Twos and the two Infrared Receiver Twos are respectively arranged facing each other.

4. The positioning device of the stepping motor according to claim 3, characterized in that: The described disc is made of a black light - impermeable material. Both Sensor Housing One and Sensor Housing Two are made of black light - impermeable materials. The stepping motor shaft gear is made of a wear - resistant material. Both Driven Gear One and Driven Gear Two are made of black light - impermeable materials.

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