Electromechanical module for driving the movement of a head of a dummy

Abstract

This utility model discloses an electromechanical module for driving the movement of a simulated head mold. A pitch rod and a pitch double slide block are fixed parallel to each other on the lower side of the head shape plate of the simulated head mold. A support frame is fixed to the shoulder base plate of the simulated head mold. A rotary drive motor drives a rotating disk mounted on the support frame to rotate. A pitch drive motor fixed on the rotating disk drives a nut push rod to move up and down through a screw and nut mechanism. The first hinge shaft at the upper end of the nut push rod can slide into the long strip slide block on the pitch double slide block, driving the pitch double slide block to rotate. The lower end of the pitch rod can rotate around a second hinge shaft parallel to the first hinge shaft and is mounted on the support frame. A pitch angle sensor and a rotation angle sensor can sense the rotation angle of the rotating disk and the second hinge shaft respectively and transmit them to the control system. The control system controls the start, stop and turn of the pitch drive motor and the rotary drive motor. This utility model can control the precise movement of the simulated head mold, and the head will not shake under force when it is stationary.

Description

Technical Field

[0001] This utility model relates to a dental clinical simulation teaching device, and in particular to an electromechanical module that drives the head movement of a simulated head model. Background Technology

[0002] In dental clinical simulation teaching systems, the head model, which simulates head movement, is mostly a purely mechanical mechanism on the market, requiring the operator to manually change the head's direction. Although robots are now widely used in various industries, they are not practical in the field of dental simulation teaching. The reason for this is not necessarily due to the lower manufacturing cost of purely mechanical components, but rather because purely mechanical components are more durable to operators, especially younger students who may handle them carelessly, resulting in a lower failure rate and easier maintenance.

[0003] However, the drawbacks of purely manual mechanical components are also obvious. Operators must use force to operate the handles on the mechanical components to lock or loosen the mechanical joints, which is disadvantageous for female trainees with less strength, as they often perform practical operations without locking the head positioning. The handles take up a lot of space in the head and neck of the mannequin, causing designers to find that when they want to improve the design of the moving parts inside the mannequin's mouth, they will interfere with the original manual mechanical components of the head. If designers want to upgrade the mannequin system, for example, to add voice control or to add sensors to the head and neck to read posture data, the original manual mechanical mechanism is useless.

[0004] Therefore, the mechatronics design is very attractive to users at the application level, and many schools with relatively ample financial resources have purchased electrically driven head-movement prosthetic head molds. However, a common problem is:

[0005] When the device is stationary, the head shakes due to mechanical clearances, and the amplitude of shaking increases with repeated use, which is unacceptable in the field of dental clinical simulation teaching.

[0006] The motor makes a lot of noise when it runs;

[0007] Motors and moving parts have a limited lifespan;

[0008] Insufficient precision in motion position control;

[0009] The electronic components of the motion assembly are susceptible to malfunction due to water and air contamination during clinical simulation treatment;

[0010] Assembly and debugging are troublesome during the production stage, and maintenance operations such as replacing faulty parts after a failure are difficult.

[0011] Because the structural components themselves take up a lot of space, there is not enough room for future functional expansion (such as introducing voice control functions, body pressure sensing functions, etc.);

[0012] When the head shape makes a pitching motion, it is achieved by rotating the head shape plate, which is quite different from the pitching motion of a real person's head produced by the bending of multiple cervical vertebrae, resulting in a poor simulation effect. Utility Model Content

[0013] To overcome the above-mentioned defects, this utility model provides an electromechanical module for driving the head movement of a simulated head model. This electromechanical module has high precision in controlling the movement position, the head will not shake under force when it is stationary, the motor components have low operating noise, long service life, convenient assembly, debugging and maintenance, compact size, and is not easily contaminated.

[0014] The technical solution adopted by this utility model to solve its technical problem is as follows: an electromechanical module for driving the head movement of a simulated head mold, including a support frame, a pitch drive motor, a lead screw and nut mechanism, a nut push rod, a pitch rod, a pitch double slide block, a rotary drive motor, a rotary disk, a pitch angle sensor, a rotation angle sensor, and a control system. Based on the simulated head mold in an upright position, the head shape of the simulated head mold is located directly above the shoulder body. The pitch rod and the pitch double slide block are fixedly installed parallel and spaced on the lower side of the head shape plate of the simulated head mold. The pitch double slide block has a long strip-shaped slide groove with an angle to the vertical direction. The support frame is fixedly installed on the shoulder body base plate of the simulated head mold. The rotary disk, capable of rotating around a vertically extending axis, is installed inside the support frame. The rotary drive motor is fixedly installed on the support frame and can drive the rotary disk to rotate in both directions. The pitch drive motor is fixedly installed on the rotary disk, and the power output shaft of the pitch drive motor is along... Extending vertically, the lower end of the lead screw of the lead screw and nut mechanism is coaxially fixed to the power output shaft of the pitch drive motor. The nut of the lead screw and nut mechanism is circumferentially stopped and axially slidable, installed in the support frame. The lower end of the nut top rod is fixedly installed on the nut of the lead screw and nut mechanism. The upper end of the nut top rod is provided with a first hinge shaft extending horizontally. The first hinge shaft is slidably inserted into a long strip groove on the pitch double slide block. The lower end of the pitch rod is rotatable around a second hinge shaft parallel to the first hinge shaft and is installed above the support frame. The pitch angle sensor and the rotation angle sensor are respectively installed on the support frame. The pitch angle sensor and the rotation angle sensor can respectively sense the forward and reverse rotation angles of the rotating disk and the second hinge shaft. The pitch angle sensor and the rotation angle sensor communicate with the control system and transmit their sensed data to the control system. The control system controls the start, stop and direction of the pitch drive motor and the rotation drive motor.

[0015] As a further improvement of this utility model, a lead screw outer cylinder is also provided. The lower end of the lead screw outer cylinder is fixedly installed on the pitch drive motor or the rotary disk. The lead screw outer cylinder is sleeved on the outside of the lead screw nut mechanism and the nut push rod with a gap. The upper end of the nut push rod can extend out of the upper end of the lead screw outer cylinder by a set distance. The side wall of the lead screw outer cylinder is provided with a vertically extending limiting groove. The outer circumferential side wall of the nut of the lead screw nut mechanism is provided with a radially protruding limiting rod. The limiting rod can slide vertically and is inserted into the limiting groove.

[0016] As a further improvement of this utility model, an upper limit switch, a lower limit switch, and a first locking screw are also provided. The upper limit switch and the lower limit switch are respectively mounted on the outer wall of the lead screw outer cylinder, which can move in the vertical direction. The first locking screw can lock the upper limit switch and the lower limit switch, which are adjusted in the vertical direction, on the outer wall of the lead screw outer cylinder. The upper limit switch and the lower limit switch are arranged at intervals in the vertical direction. When the limit rod on the nut of the lead screw nut mechanism slides up and down to the upper limit position and the lower limit position, it can trigger the upper limit switch and the lower limit switch, respectively. The upper limit switch and the lower limit switch communicate with the control system to transmit signals that the nut of the lead screw nut mechanism has reached the upper limit position and the lower limit position, respectively.

[0017] As a further improvement of this utility model, the upper end of the lead screw outer cylinder extends a certain distance beyond the upper end of the support frame. An L-shaped pitch fixing shaft seat is fixedly installed on the upper end of the lead screw outer cylinder. One side wall of the L-shaped structure of the pitch fixing shaft seat is a horizontal plane covering the opening of the end face of the lead screw outer cylinder. A through hole matching the outer circumferential surface of the upper end of the nut push rod is provided on this horizontal plane. The upper end of the nut push rod can slide through the through hole. The other side wall of the L-shaped structure of the fixing shaft seat is a vertical surface extending in the vertical direction. An opening groove extending vertically is formed in the middle of the vertical surface. The lower end of the pitch rod is inserted into the opening groove and is rotatably installed on the side wall of the opening groove through a second hinge shaft. The support frame can be hidden inside the shoulder of the simulated head mold. The upper end of the lead screw outer cylinder, the pitch fixing shaft seat, the pitch rod, and the pitch double sliding block together form the neck joint of the simulated head mold.

[0018] As a further improvement of this utility model, a flange copper sleeve is also installed on the upper end of the support frame, and the outer cylinder of the lead screw is a T-shaped cylindrical structure with an upper outer diameter smaller than the lower outer diameter. The upper end of the outer cylinder of the lead screw is rotatably inserted into the flange copper sleeve. A first thrust bearing is fixedly installed on the annular step surface formed between the two ends of the outer cylinder of the lead screw, and the first thrust bearing is tightly abutted against the lower end surface of the flange copper sleeve at the upper end of the support frame.

[0019] As a further improvement of this utility model, a horizontally extending pitch motor shaft plate is fixedly provided inside the support frame. The pitch motor shaft plate is provided with a rotating shaft hole. A vertical shaft is fixedly provided on the lower side of the rotating disk. The vertical shaft is rotatably inserted into the rotating shaft hole on the pitch motor shaft plate, and the lower end of the vertical shaft extends to the lower side of the pitch motor shaft plate. A radially outwardly expanding convex ring is formed at the lower end of the vertical shaft. A second thrust bearing and a third thrust bearing are fixedly installed on the upper and lower sides of the pitch motor shaft plate, respectively. The second thrust bearing and the third thrust bearing are both sleeved on the outside of the vertical shaft. The upper side of the second thrust bearing is tightly against the lower side of the rotating disk, and the lower side of the third thrust bearing is tightly against the annular step surface at the upper end of the radially outwardly expanding convex ring at the lower end of the vertical shaft.

[0020] As a further improvement of this utility model, the pitch motor through-shaft plate is provided with two positioning pins spaced apart along the rotation direction of the rotating disk, and the rotating limiting block is provided eccentrically on the lower side of the rotating disk, and the rotating limiting block on the lower side of the rotating disk stops between the two positioning pins.

[0021] As a further improvement of this utility model, the pitch motor's through-shaft plate is provided with a left rotation limit switch and a right rotation limit switch at intervals. The left rotation limit switch and the right rotation limit switch can move along a circular path coaxial with the rotation axis to adjust the left rotation limit position and the right rotation limit position, respectively. A second locking screw is also provided, which can lock and fix the adjusted left rotation limit switch and the right rotation limit switch to the pitch motor's through-shaft plate. When the rotation limit block on the lower side of the rotating disk rotates to the left rotation limit position and the right rotation limit position, it can trigger the corresponding left rotation limit switch and the right rotation limit switch. The left rotation limit switch and the right rotation limit switch communicate with the control system to transmit signals that the rotating disk has rotated to the left rotation limit position and the right rotation limit position, respectively.

[0022] As a further improvement of this utility model, the power output end of the rotary drive motor is coaxially fixed with a small synchronous pulley, the rotating disk forms a large synchronous pulley, and a synchronous belt and a tension adjustment mechanism are also provided. The synchronous belt is tightly sleeved on the outside of the small synchronous pulley and the large synchronous pulley for transmission, and the tension adjustment mechanism can adjust the tension of the synchronous belt.

[0023] As a further improvement of this utility model, an attitude sensor is also fixedly installed on the head shape plate of the simulated head mold. The attitude sensor can acquire the head shape attitude data of the simulated head mold, and the attitude sensor communicates with the control system to transmit the head shape attitude data of the simulated head mold to the control system.

[0024] The beneficial effects of this utility model are as follows: The head tilt adjustment of this utility model is achieved through a tilt drive motor and a lead screw and nut mechanism. Simultaneously, head rotation is driven by a synchronous belt transmission system, resulting in significantly lower noise levels and a longer service life compared to traditional technologies. It overcomes the head swaying issue when stationary, allowing for the selection of smaller, more precise stepper motors, saving internal space. This utility model uses a stepper motor with angle sensor feedback, supplemented by an attitude sensor to detect motion status, resulting in high precision position control. During head tilt and left / right rotation, mechanical limits are used to prevent accidental tilt and rotation exceeding the range, avoiding damage to the entire electromechanical module. Both the tilt and rotation drive motors are stepper motors, which maintain torque when stationary and do not experience a surge in current even under stall conditions, unlike other types of motors, making them very safe and durable. This utility model also incorporates a stepper motor in the tilt mechanism that simulates the movement of the head mold's neck. In the rotational motion mechanism, the angle range of pitch and rotation is set by adjusting the position of the limit switch to make it more realistic. Simultaneously, this application also uses a posture sensor to read head position data and pitch and rotation angle sensors to read pitch and lateral rotation angle data, ensuring precise control of head pitch and lateral rotation angles. All transmission and drive mechanisms of this invention are housed inside the sealed shoulder body of the simulated head model, preventing water vapor and debris generated during simulated dental treatment from contaminating the electromechanical module. The new electromechanical module that drives the neck movement of the simulated head mold is fixed upward to the rear of the head shape plate of the simulated head mold. It replaces the original manually adjustable mechanical structure of the simulated head mold head with the most convenient connection and fixing method. The axis of the second hinge shaft is designed in the center between the head shape plate and the top plate of the support frame, so that the head pitching movement looks more realistic. This utility model also has three sets of thrust bearings installed axially in the pitching component. Even if the axial installation is very tight and without gaps, the entire pitching component rotates smoothly and the mechanism will not shake during the movement. Attached Figure Description

[0025] Figure 1 This is the first perspective view of the present invention;

[0026] Figure 2 for Figure 1 Enlarged view of section A in the middle;

[0027] Figure 3 for Figure 1 Enlarged view of section B in the middle;

[0028] Figure 4 This is a second perspective view of the present invention;

[0029] Figure 5 for Figure 2 Enlarged view of section C;

[0030] Figure 6 This is a third perspective view of the present invention;

[0031] Figure 7 This is a schematic diagram of the first structure of the rotation control mechanism of this utility model;

[0032] Figure 8 This is a schematic diagram of the second structure of the rotation control mechanism of this utility model;

[0033] Figure 9 This is a schematic diagram of the first structure of the rotary transmission mechanism of this utility model;

[0034] Figure 10 This is a schematic diagram of the second structure of the rotary transmission mechanism of this utility model;

[0035] Figure 11 This is a schematic diagram of the transmission principle of the pitch drive motor and lead screw and nut mechanism of this utility model;

[0036] Figure 12 This is a front view of the head-shaped pitch joint of this utility model;

[0037] Figure 13 This is the first front view of the rotating component structure principle of this utility model;

[0038] Figure 14 This is the second main view of the rotating component structure principle of this utility model;

[0039] Figure 15 This is a perspective view of the pitch drive motor and lead screw and nut mechanism of this utility model.

[0040] Figure 16 This is a perspective view of the rotating disk of this utility model;

[0041] Figure 17 This is a front view of the rotating disk of this utility model;

[0042] Figure 18 This is a perspective view of the pitch double sliding block of this utility model;

[0043] Figure 19 This is a perspective view of the pitch fixing bearing of this utility model;

[0044] Figure 20 This is a perspective view of the nut push rod of this utility model. Detailed Implementation

[0045] Example: An electromechanical module for driving the head movement of a simulated head mold includes a support frame, a pitch drive motor 1, a lead screw and nut mechanism 2, a nut 14 push rod 3, a pitch rod 4, a pitch double slide block 5, a rotation drive motor 6, a rotary disk 7, a pitch angle sensor 8, a rotation angle sensor 9, and a control system. With the simulated head mold in an upright position as a reference, the head shape of the simulated head mold is located directly above the shoulder body. The pitch rod 4 and the pitch double slide block 5 are fixedly installed parallel and spaced on the lower side of the head shape plate 10 of the simulated head mold. The pitch double slide block 5 is provided with a long strip slide 11 that forms an angle with the vertical direction. The support frame is fixedly installed on the shoulder base plate 12 of the simulated head mold. The rotating disk 7 is rotatable around a vertically extending vertical axis 35 and is installed inside the support frame. The rotary drive motor 6 is fixedly installed on the support frame and can drive the rotating disk 7 to rotate in both directions. The pitch drive motor 1 is fixedly installed on the rotating disk 7, and the power output shaft of the pitch drive motor 1 extends in the vertical direction. The screw and nut mechanism 2... The lower end of the lead screw 13 is coaxially fixed to the power output shaft of the pitch drive motor 1. The nut 14 of the lead screw nut mechanism 2 is circumferentially stopped and axially slidable, and is installed in the support frame. The lower end of the nut 14 push rod 3 is fixedly installed on the nut 14 of the lead screw nut mechanism 2. The upper end of the nut 14 push rod 3 is provided with a first hinge shaft 15 extending horizontally. The first hinge shaft 15 is slidably inserted into the elongated slide groove 11 on the pitch double slide block 5. The lower end of the pitch rod 4 is rotatable around a second hinge shaft 16 parallel to the first hinge shaft 15 and is installed above the support frame. The pitch angle sensor 8 and the rotation angle sensor 9 are respectively installed on the support frame. The pitch angle sensor 8 and the rotation angle sensor 9 can respectively sense the forward and reverse rotation angles of the rotating disk 7 and the second hinge shaft 16. The pitch angle sensor 8 and the rotation angle sensor 9 communicate with the control system and transmit their sensed data to the control system. The control system controls the start, stop and turn of the pitch drive motor 1 and the rotation drive motor 6.

[0046] The pitch drive motor 1 is preferably a low-power 57-type stepper motor. The lead screw 13 of the lead screw and nut mechanism 2 is preferably a ball screw 13 with an outer diameter of 12mm and a lead of 2mm. The support frame is preferably an L-shaped frame structure formed by fixing and splicing the top plate 17, bottom plate 18, left side plate 19, right side plate 20, middle plate 21 and rotary motor fixing plate 22. The support frame is fixed to the shoulder body bottom plate 12 of the simulated head mold shoulder body, and the support frame and the pitch drive motor 1 and lead screw and nut mechanism fixed on it are... Structure 2, nut 14 push rod 3, rotary drive motor 6 and rotary disk 7 are all hidden in the shoulder body of the simulated head mold. The pitch angle sensor 8 and rotation angle sensor 9 are preferably potentiometer-type sensors with sensitive sensing. The structure of nut 14 push rod 3 is preferably a sleeve-like structure at the lower end and a rod-like structure at the upper end. The sleeve-like structure at the lower end of nut 14 push rod 3 is sleeved on the outside of the lead screw 13 of the lead screw nut mechanism 2, and the lower end of nut 14 push rod 3 is fixedly connected to nut 14 of the lead screw nut mechanism 2 through a flange.

[0047] The top of the nut 14 and the top rod 3 are preferably machined with stepped surfaces on both sides. The pitch double slide block 5 is machined into a U-shaped structure with the opening facing downwards. The top of the nut 14 and the top rod 3 is inserted into the U-shaped structure of the pitch double slide block 5. A horizontally extending through hole is opened on the side wall of the top of the nut 14 and the top rod 3. The first hinge shaft 15 passes through the through hole and slides into the long strip slide groove 11 on the side wall of the U-shaped structure of the pitch double slide block 5, so that the top of the nut 14 and the top rod 3 are hingedly connected to the pitch double slide block 5. When the nut 14 and the top rod 3 move axially, it drives the first hinge shaft 15 to slide in the long strip slide groove 11 of the pitch double slide block 5, so that the head plate 10 makes pitch movement with the second hinge shaft 16 as the center. In the design, it is best to design the axis of the second hinge shaft 16 at the center position of the top plate of the head plate 10 and the support frame, so that the head pitch movement looks more realistic.

[0048] When the head model of this invention performs pitch motion, it is driven by converting the rotational motion of the lead screw 13 into linear motion. If the ratio of the lead of the lead screw 13 to its outer diameter is small enough, i.e., the helix angle is small enough, it will approach the friction angle. In addition, if a stepper motor is used for the pitch drive motor 1, the stepper motor will maintain torque when powered on but stationary, thus providing a relatively large self-locking function in the linear motion direction. Even without an external braking mechanism, it can be ensured that after the head model pitch angle is adjusted, when the head model is stationary, the operator's force will not cause the head model to shift in the pitch direction. Moreover, if a ball screw 13 is used, the mechanical clearance itself is extremely small, and the clearance of the lead screw 13 does not cause the output end clearance to amplify. Therefore, the clearance of the lead screw 13 will not cause the head model to wobble significantly in the pitch direction due to clearance amplification, unlike gear clearance.

[0049] The angle in the pitch direction is read using a pitch angle sensor 8. The angle in the rotation direction is sensed and read using an angle sensor mounted coaxially with the rotating disk 7.

[0050] The system also includes a lead screw outer cylinder 23, the lower end of which is fixedly mounted on the pitch drive motor 1 or the rotary disk 7. The lead screw outer cylinder 23 is loosely fitted around the lead screw nut mechanism 2 and the outer side of the nut 14 push rod 3. The upper end of the nut 14 push rod 3 can extend a set distance beyond the upper end of the lead screw outer cylinder 23. The side wall of the lead screw outer cylinder 23 is provided with a vertically extending limiting groove 24. The outer circumferential side wall of the nut 14 of the lead screw nut mechanism 2 is provided with a radially protruding limiting rod 25. The limiting rod 25 is slidably inserted into the limiting groove 24. When the lead screw 13 rotates, because the limiting rod 25 on the side of the nut 14 is embedded in the limiting groove 24 on the side of the lead screw outer cylinder 23, the nut 14 can only move up and down along the axial direction of the lead screw 13, and the movement distance of the nut 14 is limited by the length of the limiting groove 24, which can prevent the nut 14 from falling off the lead screw 13. The length of the limiting groove 24 of the lead screw outer cylinder 23 serves as a mechanical limit for the pitch movement. If the pitch motor malfunctions, the pitch limit contact rod 25 will hit the mechanical limit, causing the motor to stall. In this example, a stepper motor is used. Even under stall conditions, stepper motors do not experience a surge in current like other types of motors, making them very safe and durable.

[0051] The system also includes an upper limit switch 26, a lower limit switch 27, and a first locking screw 28. The upper limit switch 26 and the lower limit switch 27 are respectively mounted on the outer wall of the lead screw outer cylinder 23, which can move vertically. The first locking screw 28 can lock the upper limit switch 26 and the lower limit switch, which have been adjusted vertically, on the outer wall of the lead screw outer cylinder 23. The upper limit switch 26 and the lower limit switch 27 are arranged at intervals in the vertical direction. When the limit rod 25 on the nut 14 of the lead screw nut mechanism 2 slides up and down to the upper limit position and the lower limit position, it can trigger the upper limit switch 26 and the lower limit switch 27, respectively. The upper limit switch 26 and the lower limit switch 27 communicate with the control system to transmit signals that the nut 14 of the lead screw nut mechanism 2 has reached the upper limit position and the lower limit position, respectively.

[0052] Upper limit switch 26 and lower limit switch 27 are used to set the pitch angle range. They are mounted on the lead screw outer cylinder 23 via a pitch limit switch mounting bracket. The contacts of the upper limit switch 26 and lower limit switch 27 are exposed on the limit groove 24 on the side of the lead screw outer cylinder 23. As the nut 14 of the lead screw nut mechanism 2 moves axially, the limit contact rod 25 protrudes from the limit groove 24. The signal emitted after touching the limit switch during movement can be read by the control system to identify whether the pitch movement exceeds the specified range. The upper limit switch 26 and lower limit switch 27 are fixed to the slot of the limit switch mounting bracket by the first locking screw 28 and can be moved up and down to set the pitch angle range. Because the number of rotations of the lead screw 13 and the change in pitch angle are not linearly related, this poses a challenge to the positioning of the limit switches. This can be addressed by machining length markings on the edge of the limit groove 24 of the lead screw outer cylinder 23 to facilitate the positioning and adjustment of the limit switches.

[0053] The upper end of the lead screw outer cylinder 23 extends a certain distance beyond the upper end of the support frame. An L-shaped pitch fixing shaft seat 29 is fixedly installed on the upper end of the lead screw outer cylinder 23. One side wall of the L-shaped structure of the pitch fixing shaft seat 29 is a horizontal plane covering the opening of the end face of the lead screw outer cylinder 23. A through hole 30 matching the outer circumferential surface of the upper end of the nut 14 push rod 3 is provided on this horizontal plane. The upper end of the nut 14 push rod 3 can slide through the through hole 30. The other side wall of the L-shaped structure of the fixing shaft seat is a vertical surface extending in the vertical direction. An opening groove 31 extending vertically is formed in the middle of the vertical surface. The lower end of the pitch rod 4 is inserted into the opening groove 31 and is rotatably installed on the side wall of the opening groove 31 through the second hinge shaft 16. The support frame can be hidden in the shoulder of the simulated head mold. The upper end of the lead screw outer cylinder 23, the pitch fixing shaft seat 29, the pitch rod 4, and the pitch double sliding block 5 together form the neck joint of the simulated head mold.

[0054] The upper end of the lead screw outer cylinder 23 extends a certain distance beyond the upper end of the support frame and is hinged to the pitch rod 4 through the side wall of the L-shaped pitch fixing seat 29. The through hole 30 on the pitch fixing seat allows the upper end of the nut 14 push rod 3 to pass through and guide it. It can also be sealed by setting a sealing device. The upper end of the lead screw outer cylinder 23 extending to the outside of the support frame, the pitch fixing seat, the pitch rod 4, and the pitch double sliding block 5 form the neck joint of the imitation head model.

[0055] The pitch angle sensor 8 is mounted on the side of the pitch double slide block 5 via a first fixing bracket 47. A sensing element that cooperates with the pitch angle sensor 8 is mounted on the pitch fixing shaft seat 29. The pitch angle sensor 8 senses the angle between itself and the sensing element to determine the head shape pitch angle. The pitch angle sensor 8 is fixedly mounted on the side of the pitch double slide block 5 via the first fixing bracket, and the fixing bracket rotates with the pitch double slide block 5, causing the angle sensor to rotate as well. A second fixing bracket 48 is provided on the pitch fixing shaft seat 29. The second fixing bracket has a protruding shaft that can be inserted into the rotatable inner ring hole of the pitch angle sensor 8. The angle signal change caused by the rotation of the inner ring of the pitch angle sensor 8 can be read by the control system. The second mounting bracket 48 is designed with an oblong mounting hole. Its mounting position on the pitch fixing shaft seat 29 can be adjusted through the oblong mounting hole to ensure that the convex shaft, the inner ring of the sensor, and the second hinge shaft 16 are concentric. In this way, when the pitch double slide block 5 rotates, it can drive the sensor to rotate around the second hinge shaft 16 as the center, thereby outputting the pitch angle. This application does not directly lengthen the second hinge shaft 16 and insert it into the inner ring of the angle sensor to passively rotate the sensor. This seems to make the structure simpler. However, if this were done, the second hinge shaft 16 would have to be fixed to the pitch fixing shaft seat 29 with a set screw, so that it would not rotate but only allow the angle sensor to rotate with the pitch double slide block 5. But in reality, this would cause the pitch shaft to deform due to the tightening of the set screw, causing the pitch rod 4 at the head plate 10 end of the pitch shaft to jam and become unable to rotate.

[0056] A flange copper sleeve 32 is also installed on the upper end of the support frame. The lead screw outer cylinder 23 is a T-shaped cylindrical structure with an upper outer diameter smaller than the lower outer diameter. The upper end of the lead screw outer cylinder 23 is rotatably inserted into the flange copper sleeve 32. A first thrust bearing 33 is fixedly installed on the annular step surface formed between the two ends of the lead screw outer cylinder 23. The first thrust bearing 33 abuts tightly against the lower end surface of the flange copper sleeve 32 at the upper end of the support frame. The flange copper sleeve 32 and the lead screw outer cylinder 23 have low rotational friction, which can improve the rotational friction of the lead screw outer cylinder 23. The first thrust bearing 33 can eliminate the gap between the lead screw outer cylinder 23 and the top plate of the support frame.

[0057] A horizontally extending pitch motor shaft plate 34 is fixedly installed within the support frame. The pitch motor shaft plate 34 has a rotating shaft hole. A vertical shaft 35 is fixedly installed on the lower side of the rotating disk 7. The vertical shaft 35 is rotatably inserted into the rotating shaft hole on the pitch motor shaft plate 34, and the lower end of the vertical shaft 35 extends to the lower side of the pitch motor shaft plate 34. A radially expanding protruding ring 36 is formed at the lower end of the vertical shaft 35. A second thrust bearing 37 and a third thrust bearing 38 are fixedly installed on the upper and lower sides of the pitch motor shaft plate 34, respectively. The second thrust bearing 37 and the third thrust bearing 38 are both sleeved on the outside of the vertical shaft 35. The upper side of the second thrust bearing 37 is tightly against the lower side of the rotating disk 7, and the lower side of the third thrust bearing 38 is tightly against the annular step surface at the upper end of the radially expanding protruding ring 36 at the lower end of the vertical shaft 35.

[0058] The upper end of the vertical shaft 35 is fixed to the central hole of the rotary disk 7 through the rotating shaft hole of the pitch motor through the shaft plate 34. The vertical position of the vertical shaft 35 can be adjusted, which ensures that there is no axial clearance after the entire pitch assembly is installed. Three sets of thrust bearings are installed in the axial direction of the pitch assembly, so that even if the axial installation is very tight and there is no clearance, the entire pitch assembly will rotate smoothly.

[0059] The rotation angle sensor 9 and the pitch angle sensor 8 are identical in form. The rotation angle sensor 9 is mounted on the base plate of the support frame through the rotation angle sensor 9 mounting bracket 49. The vertical shaft 35 of the rotating disk 7 passes through the inner ring hole of the angle sensor, driving its inner ring to rotate and generating an angle change signal for the control system to read.

[0060] The pitch motor's through-shaft plate 34 is provided with two positioning pins 39 spaced apart along the rotation direction of the rotating disk 7. The rotating disk 7 is provided with an eccentric rotation limit block 40 on its lower side, which stops between the two positioning pins 39.

[0061] The two locating pins 39 on the pitch motor's through-shaft plate 34 form a mechanical limit on the rotation range of the rotating disk 7, preventing excessive rotation of the rotating disk 7 from damaging the entire mechanism. If the rotary drive motor 6 malfunctions, the rotation limit block 40 will contact the locating pins 39 to mechanically limit the rotation, causing the motor to stall. In this example, the rotary drive motor 6 is a stepper motor. Even under stall conditions, stepper motors do not experience a surge in current like other types of motors, making them very safe and durable. The mechanical limit structure also includes an arc-shaped hole concentric with the rotation shaft hole on the pitch motor's through-shaft plate 34, into which the rotation limit block 40 can be slidably inserted.

[0062] The pitch motor's via plate 34 is equipped with a left rotation limit switch 41 and a right rotation limit switch 42 spaced apart. The left and right rotation limit switches 41 and 42 can move along a circular path coaxial with the rotation axis to adjust their left and right rotation limit positions, respectively. A second locking screw 43 is also provided to lock the adjusted left and right rotation limit switches 41 and 42 onto the pitch motor via plate 34. When the rotation limit block 40 on the lower side of the rotating disk 7 rotates to its left and right rotation limit positions, it triggers the corresponding left and right rotation limit switches 41 and 42. The left and right rotation limit switches 41 and 42 communicate with the control system, transmitting signals indicating that the rotating disk 7 has reached its left and right rotation limit positions, respectively. The installation positions of the left and right rotation limit switches 41 and 42 on the pitch motor via plate 34 are fixed according to the required rotation angle range. When the rotation limit block 40 on the lower plane of the rotating disk 7 touches the left rotation limit switch 41 and the right rotation limit switch 42 during rotation, it will be detected by the control system.

[0063] The rotary drive motor 6 has a small synchronous pulley 44 coaxially fixed at its power output end, and the rotating disk 7 forms a large synchronous pulley. A synchronous belt 45 and a tension adjustment mechanism are also provided. The synchronous belt 45 is tightly fitted around the small and large synchronous pulleys for transmission. The tension adjustment mechanism can adjust the tension of the synchronous belt 45. The most challenging aspect of designing the rotational motion of the simulated head mold driven by the rotary drive motor 6 in the past was the unavoidable mechanical clearance (commonly gear clearance) in the transmission components. Even a small clearance near the rotating shaft can be amplified in the simulated head mold. For example, a mechanical clearance of 0.1mm at the rotating shaft can cause the outer ring of the head to wobble by 2mm when subjected to force, which is unacceptable in dental clinical simulation surgery. Using mechanical parts with ultra-low clearance would lead to uncontrolled costs and offer little improvement.

[0064] The rotary drive motor 6 of this invention no longer uses a reduction gearbox with unavoidable mechanical backlash. Instead, we directly use a stepper motor with brakes that is relatively low-cost, easy to control, and durable, and executes the rotational motion of the head mold through a synchronous pulley assembly.

[0065] Since the stepper motor shaft can rotate freely when power is lost, this invention adopts an electronically controlled brake integrated with the stepper motor to overcome this defect. The control system enables the stepper motor to brake effectively when power is lost.

[0066] This invention uses a synchronous belt pulley assembly instead of a gear reducer to reduce speed and amplify torque. This allows for the selection of stepper motors with relatively small output torque, resulting in smaller size and lighter weight, thus freeing up valuable design space.

[0067] The rotary drive motor 6 is fixed to the fixed plate of the support frame. The small synchronous pulley 44 is mounted on the power output shaft of the rotary drive motor 6. The rotating disk 7, which serves as the large synchronous pulley, is fixed to the bottom surface of the pitch drive motor 1. The small synchronous pulley 44 is preferably a 15-tooth synchronous pulley, and the large synchronous pulley is preferably a 45-tooth synchronous pulley. The synchronous belt 45 is preferably a polyurethane-coated steel wire synchronous belt 45.

[0068] In this embodiment, the tension adjustment mechanism consists of an oblong hole 50 designed on the rotary motor mounting plate of the support frame and a timing belt 45 tension adjustment bolt 51. After the rotary drive motor 6 is mounted on the rotary motor mounting plate via the bolt and nut 14 mechanism, a bolt hole is designed on the middle plate of the support frame. The timing belt 45 tension adjustment bolt passes through the bolt hole from the opposite side of the rotary motor and rests against the side wall of the rotary drive motor 6 on the output shaft plane. With the screws fixing the rotary drive motor 6 loose, the timing belt 45 tension adjustment bolt is tightened. With the timing belt 45 tightened, the screws fixing the rotary motor are then tightened. Because the timing belt 45 is rigid and elastic, there is no gap in the meshing with the large and small timing pulleys 44 when it is tightened. Therefore, as long as the rotary motor brake is effective, the operator will not shake when rotating the head of the simulation head mold with a little force.

[0069] An attitude sensor 46 is also fixedly installed on the head shape plate 10 of the simulated head model. The attitude sensor 46 can acquire the head shape attitude data of the simulated head model and communicates with the control system to transmit the head shape attitude data of the simulated head model to the control system. The attitude sensor 46 is fixedly installed on the head shape plate 10 near the pitch double slide block 5. The control system can use it to read in real time the angles of the three axes, as well as the gravitational acceleration and angular acceleration, during the movement of the simulated head model's head shape. This data helps the control system optimize the smoothness of the simulated head model's movement through algorithms.

Claims

1. An electromechanical module for driving the movement of a simulated head model, characterized in that: The system includes a support frame, a pitch drive motor (1), a lead screw and nut mechanism (2), a nut push rod (3), a pitch rod (4), a pitch double slide block (5), a rotary drive motor (6), a rotary disk (7), a pitch angle sensor (8), a rotation angle sensor (9), and a control system. Based on the head mold standing upright, the head shape of the head mold is located directly above the shoulder. The pitch rod and the pitch double slide block are fixedly installed parallel to each other on the lower side of the head mold's head shape plate (10). The pitch double slide block has a long strip slide (11) with an angle to the vertical direction. The support frame is fixedly installed on the shoulder base plate (12) of the head mold. The rotary disk, capable of rotating around a vertically extending axis, is installed inside the support frame. The rotary drive motor is fixedly installed on the support frame and can drive the rotary disk to rotate in both directions. The pitch drive motor is fixedly installed on the rotary disk, and its power output shaft extends vertically. The lower end of the lead screw (13) of the nut mechanism is coaxially fixed to the power output shaft of the pitch drive motor. The nut (14) of the lead screw nut mechanism is circumferentially stopped and axially slidable in the support frame. The lower end of the nut top rod is fixedly installed on the nut of the lead screw nut mechanism. The upper end of the nut top rod is provided with a first hinge shaft (15) extending in the horizontal direction. The first hinge shaft is slidably inserted into the long strip groove on the pitch double slide block. The lower end of the pitch rod is rotatable around a second hinge shaft (16) parallel to the first hinge shaft and is installed above the support frame. The pitch angle sensor and the rotation angle sensor are respectively installed on the support frame. The pitch angle sensor and the rotation angle sensor can respectively sense the positive and negative rotation angles of the rotating disk and the second hinge shaft. The pitch angle sensor and the rotation angle sensor communicate with the control system and transmit their sensed data to the control system. The control system controls the start, stop and turn of the pitch drive motor and the rotation drive motor.

2. The electromechanical module for driving the head movement of the simulated head model according to claim 1, characterized in that: It is also provided with a lead screw outer cylinder (23), the lower end of which is fixedly installed on the pitch drive motor or the rotary disk. The lead screw outer cylinder is sleeved on the outside of the lead screw nut mechanism and the nut push rod with a gap. The upper end of the nut push rod can extend out of the upper end of the lead screw outer cylinder by a set distance. The side wall of the lead screw outer cylinder is provided with a vertically extending limiting groove (24). The outer circumference of the nut of the lead screw nut mechanism is provided with a radially protruding limiting rod (25). The limiting rod can slide up and down and is inserted into the limiting groove.

3. The electromechanical module for driving the head movement of the simulated head model according to claim 2, characterized in that: It is also equipped with an upper limit switch (26), a lower limit switch (27) and a first locking screw (28). The upper limit switch and the lower limit switch are respectively installed on the outer wall of the lead screw outer cylinder, which can move in the vertical direction. The first locking screw can lock the upper limit switch and the lower limit switch, which are adjusted in the vertical direction, on the outer wall of the lead screw outer cylinder. The upper limit switch and the lower limit switch are arranged at intervals in the vertical direction. When the limit rod on the nut of the lead screw nut mechanism slides up and down to the upper limit position and the lower limit position, it can trigger the upper limit switch and the lower limit switch respectively. The upper limit switch and the lower limit switch communicate with the control system to transmit the signal that the nut of the lead screw nut mechanism has reached the upper limit position and the lower limit position.

4. The electromechanical module for driving the head movement of the simulated head model according to claim 2, characterized in that: The upper end of the lead screw cylinder extends a certain distance beyond the upper end of the support frame. An L-shaped pitch fixing shaft seat (29) is fixedly installed on the upper end of the lead screw cylinder. One side wall of the L-shaped structure of the pitch fixing shaft seat is a horizontal plane covering the opening of the end face of the lead screw cylinder. A through hole (30) matching the outer circumferential side surface of the upper end of the nut rod is provided on the horizontal plane. The upper end of the nut rod can slide through the through hole. The other side wall of the L-shaped structure of the fixing shaft seat is a vertical surface extending in the vertical direction. An opening groove (31) extending vertically is formed in the middle of the vertical surface. The lower end of the pitch rod is inserted into the opening groove and is rotatably installed on the side wall of the opening groove through the second hinge shaft. The support frame can be hidden in the shoulder of the simulated head mold. The upper end of the lead screw cylinder, the pitch fixing shaft seat, the pitch rod and the pitch double sliding block together form the neck joint of the simulated head mold.

5. The electromechanical module for driving the head movement of the simulated head model according to claim 4, characterized in that: The upper end of the support frame is also equipped with a flange copper sleeve (32). The outer cylinder of the screw is a T-shaped cylindrical structure with an upper outer diameter smaller than the lower outer diameter. The upper end of the outer cylinder of the screw is rotatably inserted into the flange copper sleeve. A first thrust bearing (33) is fixedly installed on the annular step surface formed between the two ends of the outer cylinder of the screw. The first thrust bearing is tightly against the lower end surface of the flange copper sleeve at the upper end of the support frame.

6. The electromechanical module for driving the head movement of the simulated head model according to claim 1, characterized in that: A horizontally extending pitch motor shaft plate (34) is fixedly installed inside the support frame. The pitch motor shaft plate has a rotating shaft hole. A vertical shaft is fixedly installed on the lower side of the rotating disk. The vertical shaft (35) is rotatably inserted into the rotating shaft hole on the pitch motor shaft plate, and the lower end of the vertical shaft extends to the lower side of the pitch motor shaft plate. A radially expanding convex ring (36) is formed at the lower end of the vertical shaft. A second thrust bearing (37) and a third thrust bearing (38) are fixedly installed on the upper and lower sides of the pitch motor shaft plate, respectively. The second thrust bearing and the third thrust bearing are both sleeved on the outside of the vertical shaft. The upper side of the second thrust bearing is tightly against the lower side of the rotating disk, and the lower side of the third thrust bearing is tightly against the annular step surface at the upper end of the radially expanding convex ring at the lower end of the vertical shaft.

7. The electromechanical module for driving the head movement of the simulated head model according to claim 6, characterized in that: The pitch motor has two locating pins (39) spaced apart along the rotation direction of the rotating disk on its shaft plate. The rotating disk has a rotation limit block (40) eccentrically positioned on its lower side. The rotation limit block on the lower side of the rotating disk stops between the two locating pins.

8. The electromechanical module for driving the head movement of the simulated head model according to claim 7, characterized in that: The pitch motor's shaft plate is provided with a left rotation limit switch (41) and a right rotation limit switch (42) spaced apart. The left and right rotation limit switches can move along a circular path coaxial with the rotation axis to adjust the left and right rotation limit positions, respectively. A second locking screw (43) is also provided, which can lock the adjusted left and right rotation limit switches onto the pitch motor's shaft plate. When the rotation limit block on the lower side of the rotating disk rotates to the left and right rotation limit positions, it can trigger the corresponding left and right rotation limit switches. The left and right rotation limit switches communicate with the control system to transmit signals that the rotating disk has rotated to the left and right rotation limit positions, respectively.

9. The electromechanical module for driving the head movement of the simulated head model according to claim 1, characterized in that: The rotary drive motor has a small synchronous pulley (44) fixedly mounted on the power output end on the same axis. The rotating disk forms a large synchronous pulley. It also has a synchronous belt (45) and a tension adjustment mechanism. The synchronous belt is tightly fitted on the outside of the small synchronous pulley and the large synchronous pulley for transmission. The tension adjustment mechanism can adjust the tension of the synchronous belt.

10. The electromechanical module for driving the head movement of the simulated head model according to claim 1, characterized in that: An attitude sensor (46) is also fixedly installed on the head shape plate of the simulated head mold. The attitude sensor can acquire the head shape attitude data of the simulated head mold. The attitude sensor communicates with the control system to transmit the head shape attitude data of the simulated head mold to the control system.

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