A keel structure with variable bending stiffness

Abstract

The present invention specifically relates to a keel structure with variable bending stiffness, which solves the problems of slow response speed, small stiffness variation range and poor applicability of existing variable stiffness technologies when applied to posture correction belts. A keel structure with variable bending stiffness comprises a first keel and a second keel that are arranged in parallel and fixedly connected; it is characterized in that: the upper part of the second keel is penetrated by N pins that are loosely matched with it, the top end of each pin is movably penetrated by the first keel, the top of the first keel is provided with N upper limit mechanisms to prevent the pins from being ejected, and the bottom is provided with N lower limit mechanisms to prevent the pins from being separated; the side of each pin is provided with a response drive mechanism to drive the pin to move up and down. The structural design of the present invention is reasonable and reliable, and the insertion depth of the pin in the second keel is adjusted by the response drive mechanism, thereby adjusting the amplitude of the pin shaking, thereby realizing the function of variable bending stiffness.

Description

Technical Field

[0001] The invention relates to a keel structure for medical equipment, in particular to a keel structure with variable bending rigidity. Background Art

[0002] Existing variable stiffness technologies are mostly realized by improving material properties, electrorheological technology, magnetorheological technology, etc. Among them, variable stiffness materials include shape memory alloys and piezoelectric ceramics.

[0003] However, practice has shown that the existing variable stiffness technology has the following problems when applied to posture correction belts: First, shape memory alloys achieve stiffness changes through phase changes, and when used in posture correction belts, there are problems such as discontinuous stiffness changes and slow response speeds; second, piezoelectric ceramics achieve continuous stiffness changes through piezoelectric effect, but have problems such as small stiffness change range and difficulty in adapting to curved surface structures; third, electrorheological technology utilizes the rheological properties of electrorheological fluids to undergo rapid and reversible phase changes in an electric field, thereby achieving stiffness adjustment, and magnetorheological technology utilizes the principle that the fluidity of magnetorheological fluids changes with the magnetic field to achieve stiffness adjustment, but both electrorheological fluids and magnetorheological fluids have problems with poor sedimentation and redispersion, which limits the application of electrorheological technology and magnetorheological technology in posture correction belts. Summary of the invention

[0004] In order to solve the problems of slow response speed, small stiffness variation range and poor applicability of the existing variable stiffness technology when applied to posture correction belts, the present invention provides a keel structure with variable bending stiffness.

[0005] The present invention is implemented by adopting the following technical scheme: a keel structure with variable bending stiffness, comprising a first keel and a second keel arranged in parallel and fixedly connected; the upper part of the second keel is penetrated by N pins which are loosely matched with it, and N is a positive integer greater than or equal to 2; the top end of each pin is movably penetrated by the first keel, and the top of the first keel is provided with N upper limit mechanisms for preventing the pins from being ejected, and the bottom is provided with N lower limit mechanisms for preventing the pins from being disengaged; and the side of each pin is provided with a response driving mechanism for driving the pin to move up and down.

[0006] Furthermore, the response drive mechanism includes a stepper motor fixed on a base and passed through the first keel, and a microcontroller electrically connected to the stepper motor; a vertical screw located on the lower side of the first keel is fixedly connected to the output shaft of the stepper motor, and an internal threaded sleeve threadedly connected to the screw is sleeved on the screw, and the outer wall of the internal threaded sleeve is fixedly connected to the side wall of the pin.

[0007] Furthermore, the upper limit mechanism is an end cover which is arranged above the pin and whose lower part is screwed on the top of the first keel.

[0008] Furthermore, the lower limit mechanism includes an annular baffle, the diameter of the middle through hole of the annular baffle is larger than the diameter of the middle part of the pin, and the diameter of the middle through hole is smaller than the diameter of the pin head; the annular baffle is fixedly connected to the bottom surface of the first keel by a plurality of screws equidistantly distributed along the circumference.

[0009] Furthermore, the bottom surface of the first keel is fixedly connected with a plurality of U-shaped plates with openings facing the pins and located outside the screw rod, and the inner bottom wall of the U-shaped plate is provided with a gasket fixedly fitted therewith and in contact with the bottom end of the screw rod.

[0010] Furthermore, the stepper motor is electrically connected to the microcontroller via a stepper motor driver; the outer side wall of the internal threaded sleeve is fixedly connected to the side wall of the pin via a connecting rod.

[0011] Furthermore, N grooves are provided on the upper surface of the II keel, the upper part of the groove is in the shape of an inverted cone that is wide at the top and narrow at the bottom, and the middle and lower parts are cylindrical. The bottom end of the pin is in the shape of an inverted cone, and the middle and lower parts of the groove are gap-matched with the straight section of the pin.

[0012] Furthermore, the first keel and the second keel are fixedly connected by a plurality of support rods located at the ends.

[0013] Through the above technical solution, the beneficial effects of the present invention are:

[0014] (1) The present invention drives the pin to move up and down by responding to the driving mechanism, thereby controlling the insertion and dissociation of the pin in the second keel and the insertion depth of the pin during insertion. The adjustment of the insertion depth can adjust the amplitude of the pin shaking, thereby realizing the function of variable bending stiffness.

[0015] (2) The structural design of the response drive mechanism in the present invention receives the electrical signal emitted by the external load (for example, the electromyographic signal of the human body collected when it is used in the posture correction belt) through the microcontroller, and sends out pulse signals and direction signals in real time according to the electrical signal to control the stepper motor to rotate a certain angle in a specific direction, thereby driving the screw to rotate a certain angle. The rotation of the screw drives the internal thread sleeve to move up and down along the screw, converting the angular displacement of the screw into the linear displacement of the internal thread, thereby driving the pin to move up and down, thereby achieving the purpose of adjusting the insertion depth of the pin in the second keel and realizing the function of variable bending stiffness.

[0016] (3) The present invention can be applied to the keel part of the posture correction belt. When the wearer has a bad posture or performs large-scale activities, the response drive mechanism can receive the change of the electromyographic signal, and the microcontroller sends the signal to the stepper motor driver in real time. The stepper motor driver receives the signal and controls the stepper motor to produce corresponding actions and adjust the structure. By controlling the insertion and disengagement of the pin and the insertion depth of the pin during insertion, the purpose of changing the bending stiffness is achieved, thereby realizing automatic control and increasing the flexibility of the wearer.

[0017] (4) The present invention directly responds through the adjustment method of the insertion depth, and the response speed is fast. At the same time, the bending stiffness variation range of this action mode is larger than the bending stiffness variation range of pressure-changing ceramics, etc., which increases the applicability of the keel structure when used in posture correction belts.

[0018] (5) The present invention can also be applied to other structures that require variable bending stiffness, and can be particularly applied to variable bending stiffness structural parts in the field of medical devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 yes Figure 1 A three-dimensional schematic diagram of the arrangement of the first keel, the second keel and the pins;

[0021] Figure 3 yes Figure 2 Schematic diagram of the plane;

[0022] Figure 4 yes Figure 1 Schematic diagram of the structure of the medium response drive mechanism;

[0023] Figure 5 It is a curve diagram of the change of the pin insertion degree and the bending rigidity of the present invention.

[0024] In the figure, 1-the first keel, 2-the second keel, 3-the pin, 4-the stepper motor, 5-the microcontroller, 6-the screw, 7-the internal thread sleeve, 8-the end cover, 9-the annular baffle, 10-the screw, 11-the U-shaped plate, 12-the gasket, 13-the stepper motor driver, 14-the connecting rod, 15-the groove, and 16-the support rod. DETAILED DESCRIPTION

[0025] A keel structure with variable bending stiffness, such as the attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 As shown; it includes a first keel 1 and a second keel 2 which are arranged in parallel and fixedly connected; two pins 3 which are loosely matched with the second keel 2 are passed through the upper part, and the top end of each pin 3 is movably passed through the through hole of the first keel 1 (each pin corresponds to a through hole, and the inner diameter of the through hole is larger than the outer diameter of the pin head), and two upper limit mechanisms for preventing the pin 3 from being ejected are arranged at the top of each through hole of the first keel 1, and two lower limit mechanisms for preventing the pin 3 from being disengaged are arranged at the bottom of the through hole; a response driving mechanism for driving the pin 3 to move up and down is arranged on the side of each pin 3.

[0026] The present invention drives the pin 3 to move up and down by responding to the driving mechanism, thereby controlling the insertion and dissociation of the pin 3 in the second keel 2 and the insertion depth of the pin 3 during insertion. Because the pin 3 and the second keel 2 are clearance-matched, the pin 3 has a shaking amount in the gap, and the adjustment of the insertion depth can adjust the amplitude of the shaking of the pin 3. First, the function of variable bending stiffness is realized; second, through the adjustment method of the insertion depth, direct response is achieved, and the response speed is fast. At the same time, the bending stiffness variation range of this action mode is larger than that of the bending stiffness variation range of the pressure-changing ceramic, which increases the applicability of the present keel structure when applied to the posture correction belt. Among them, the upper limit mechanism and the lower limit mechanism can limit the position of the upper part of the pin 3, and on the basis of ensuring that the upper part of the pin 3 is movably connected with the first keel 1, prevent the pin 3 from being separated from the first keel 1 during the up and down movement.

[0027] When in use, the spacing between the first keel 1 and the second keel 2 is a fixed value, and the first keel 1 and the second keel 2 are both made of semi-flexible materials. When the wearer of the posture correction belt has a bad posture or performs large-scale activities, the response drive mechanism receives the electromyographic signal, and drives the pin 3 to move up and down between the first keel 1 and the second keel 2 according to the electromyographic signal, thereby controlling the insertion and dissociation of the pin 3 in the second keel 2 and the insertion depth of the pin 3 during insertion. When the pin 3 is inserted, as the insertion depth of the pin 3 in the second keel 2 decreases, the shaking amplitude of the pin 3 gradually increases, thereby achieving the purpose of instantly changing the bending stiffness. The present invention overcomes the problems of slow response speed, small stiffness variation range, and poor applicability of the existing variable stiffness technology when applied to the posture correction belt.

[0028] As attached Figure 1 , Attachment Figure 4 As shown; the response drive mechanism includes a stepper motor 4 fixedly passed through the first keel 1 on the base and a microcontroller 5 electrically connected to the stepper motor 4; the output shaft of the stepper motor 4 is fixedly connected to a vertical screw 6 located on the lower side of the first keel 1, and the screw 6 is sleeved with an internal threaded sleeve 7 threadedly connected thereto, and the outer side wall of the internal threaded sleeve 7 is fixedly connected to the side wall of the pin 3.

[0029] When in use, the electromyographic signal is collected by the electromyographic sensor or the electromyographic acquisition system, the microcontroller 5 receives the electromyographic signal, and sends out pulse signals and direction signals in real time according to the electromyographic signal to control the stepping motor 4 to rotate a certain angle in a specific direction, drive the screw 6 to rotate a certain angle, and the rotation of the screw 6 drives the internal threaded sleeve 7 to move up and down along the screw 6, and converts the angular displacement of the screw 6 into the linear displacement of the internal threaded sleeve 7, thereby driving the pin 3 to move up and down, thereby achieving the purpose of adjusting the insertion depth of the pin 3 in the II keel 2 and realizing the function of changing the bending stiffness.

[0030] As attached Figure 1 , Attachment Figure 2 , Attachment Figure 3As shown; the upper limit mechanism is arranged above the pin 3 and the lower part is screwed on the end cover 8 at the top of the first keel 1.

[0031] This structural design has the advantages of reliable connection and convenient installation and removal, which reduces the difficulty of assembling the keel structure.

[0032] As attached Figure 1 , Attachment Figure 3 As shown; the lower limit mechanism includes an annular baffle 9, the diameter of the middle through hole of the annular baffle 9 is larger than the diameter of the middle part of the pin 3, and the diameter of the middle through hole is smaller than the diameter of the head of the pin 3; the annular baffle 9 is fixedly connected to the bottom surface of the first keel 1 by a plurality of screws 10 distributed equidistantly along the circumferential direction.

[0033] This structural design realizes the detachable connection of the lower limit mechanism, and the connection is firm, which further reduces the assembly difficulty of the keel structure and increases the structural reliability of the present invention.

[0034] As attached Figure 1 , Attachment Figure 4 As shown; the bottom surface of the first keel 1 is fixedly connected with a plurality of U-shaped plates 11 with openings facing the pin 3 and located on the outside of the screw 6, and the inner bottom wall of the U-shaped plate 11 is provided with a gasket 12 fixedly fitted therewith and in contact with the bottom end of the screw 6.

[0035] The combined structural design of the U-shaped plate 11 and the gasket 12 provides a rotation support function for the screw rod 6 , thereby increasing the stability of the screw rod 6 during rotation.

[0036] As attached Figure 1 , Attachment Figure 4 As shown; the stepper motor 4 and the microcontroller 5 are electrically connected via a stepper motor driver 13; the outer wall of the internal threaded sleeve 7 and the side wall of the pin 3 are fixedly connected via a connecting rod 14.

[0037] The structural design of the stepper motor driver 13 increases the stability and accuracy of the signal transmission of the response drive mechanism, and further improves the reliability of signal transmission when the present invention is used.

[0038] As attached Figure 1 , Attachment Figure 3 As shown; the upper surface of the II keel 2 is provided with two grooves 15, the upper portion of the groove 15 is wide on the upper and narrow on the lower portion, and the middle and lower portions are cylindrical. The bottom end portion of the pin 3 is inverted cone-shaped, and the middle and lower portions of the groove 15 are gap-matched with the straight section of the pin 3.

[0039] This structural design makes it easy to position the pin 3 when it is out of the groove 15 and to insert it into the groove, further improving the convenience of the present invention when in use.

[0040] As attached Figure 1As shown; the first keel 1 and the second keel 2 are fixedly connected by a plurality of support rods 16 located at the end.

[0041] This structural design can make the distance between the first keel 1 and the second keel 2 a constant value, further increasing the structural reliability of the present invention.

[0042] During the use of the present invention, the variation curve of the insertion degree of the pin 3 and the bending stiffness is shown in the attached figure. Figure 5 As shown. Myoelectric sensors can be placed on the abdomen and back of the wearer of the posture correction belt to collect myoelectric signals. When the posture of the wearer of the posture correction belt is correct, the myoelectric signals are stable and the motor is not triggered to work. The two pins 3 are dissociated from the second keel 2, that is, the pins 3 are not inserted into the second keel 2. When the wearer of the posture correction belt has a bad posture, has a tendency to hunchback or leans forward, the microcontroller 5 receives the gradually increasing abdominal myoelectric signals emitted by the myoelectric sensors in real time, and controls the stepper motor 4 to move forward, driving the pin 3 to move downward until it is inserted into the groove 15. The specific moving speed is determined by the program written in the microcontroller, and can be pre-set according to the user's physical characteristics, such as how large the myoelectric signal corresponds to how large the moving speed is, and then the moving speed is calculated and output in real time through the corresponding program; as the insertion depth of the pin 3 in the groove 15 increases, the shaking amplitude of the pin 3 gradually decreases, the bending stiffness of the keel structure gradually increases, the posture correction belt produces a certain correction force, and begins to play a posture correction role; when the pin 3 is fully inserted into the groove 15, the bending stiffness The degree is at a maximum value; at this time, the wearer of the posture correction belt is restrained by the correction force and begins to change his bad posture. When the wearer of the posture correction belt performs active and large-scale activities, such as bending over to pick up something or exercising, the microcontroller 5 receives in real time the stable and unchanging abdominal electromyographic signals and the continuously enhanced back electromyographic signals emitted by the electromyographic signal sensor, controls the stepper motor 4 to move in the opposite direction, drives the pin 3 to move upward, and the pin 3 and the second keel 2 begin to dissociate, and the insertion depth of the pin 3 in the groove 15 gradually decreases; as the insertion depth of the pin 3 in the groove 15 decreases, the shaking amplitude of the pin 3 gradually increases, the bending stiffness of the keel structure gradually decreases, and the correction force generated by the posture correction belt begins to weaken until the pin 3 and the second keel 2 are completely dissociated, thereby completing a posture correction action.

[0043] When the pin 3 and the second keel 2 are completely separated, the bending stiffness of the present invention is the sum of the bending stiffness of the first keel 1 and the second keel 2, that is, (Wherein, w is the width of the first keel 1 and the second keel 2, t is the thickness of the first keel 1 and the second keel 2, and E is the elastic modulus); when the pin 3 and the second keel 2 are fully inserted, the first keel 1 and the second keel 2 are regarded as a whole, and the stiffness is , where δ is the distance between the first keel 1 and the second keel 2; when δ=2t, the bending stiffness can be expanded by 28 times, and the bending stiffness is greatly increased. It is worth noting that there is a critical value L for the insertion depth of the pin 3 in the second keel 2. When the insertion depth of the pin 3 in the second keel 2 is greater than the critical value L, the bending stiffness no longer increases with the increase of the insertion depth of the pin 3. Therefore, the depth of the groove in the present invention is greater than the critical value L.

[0044] During the specific implementation process, the first keel 1 and the second keel 2 are both made of semi-flexible materials; the semi-flexible material can be a composite material of one or several different materials with stiffness compatibility, such as fiber strips, memory alloy aluminum materials, memory alloy steel materials, titanium alloys, carbon fibers, etc., depending on the needs of the users.

[0045] The top of the end cover 8 is integrally provided with a limit plate that fits on the upper surface of the first keel 1; the U-shaped plate 11 is fixedly connected to the first keel 1 by a screw 1; during use, the response drive mechanism of the present invention can be realized by means of an electromagnet or a dielectric elastomer inversion effect; the support rod 16 is a distal support rod.

[0046] This structure can also be used in conjunction with other electronic devices such as pressure sensors, and is applicable to other fields of engineering, mechanics, architecture, and materials. For example, it can be used to adjust the load force on the chassis of a truck, and as a supporting experimental device for load testing of materials in engineering mechanics. When the load changes, the bending stiffness can be changed through the dissociation of the structure, so as to be better applied in practical production processes.

[0047] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, other implementation methods can certainly be easily made by replacement or modification based on the technical contents disclosed in this specification. Therefore, all changes and improvements made to the principles and process conditions of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A keel structure with variable bending stiffness, comprising a first keel (1) and a second keel (2) arranged in parallel and fixedly connected; characterized in that: N pins (3) are inserted into the upper part of the second keel (2) and are loosely matched with the pins (3), where N is a positive integer greater than or equal to 2; the top end of each pin (3) is movably inserted into the first keel (1), and the top of the first keel (1) is provided with N upper limit mechanisms for preventing the pins (3) from being ejected, and the bottom is provided with N lower limit mechanisms for preventing the pins (3) from being separated; a response drive mechanism is provided on the side of each pin (3) for driving the pins (3) to move up and down; the response drive mechanism comprises a stepper motor (4) whose base is fixedly inserted into the first keel (1) and a microcontroller (5) electrically connected to the stepper motor (4); a position controller (5) is fixedly connected to the output shaft of the stepper motor (4) A vertical screw rod (6) is disposed at the lower side of the first keel (1), an internally threaded sleeve (7) is sleeved on the screw rod (6) and is threadedly connected thereto, and the outer wall of the internally threaded sleeve (7) is fixedly connected to the side wall of the pin (3); the upper limit mechanism is an end cover (8) which is disposed above the pin (3) and whose lower part is screwed onto the top of the first keel (1); the lower limit mechanism comprises an annular baffle plate (9), the diameter of the middle through hole of the annular baffle plate (9) is larger than the diameter of the middle part of the pin (3), and the diameter of the middle through hole is smaller than the diameter of the head of the pin (3); the annular baffle plate (9) is fixedly connected to the bottom surface of the first keel (1) by a plurality of screws (10) which are equidistantly distributed along the circumference.

2. A keel structure with variable bending stiffness according to claim 1, characterized in that: A plurality of U-shaped plates (11) with openings facing the pins (3) and located outside the screw rods (6) are fixedly connected to the bottom surface of the first keel (1), and the inner bottom wall of the U-shaped plate (11) is provided with a gasket (12) fixedly fitted thereto and in contact with the bottom end of the screw rod (6).

3. A keel structure with variable bending stiffness according to claim 1, characterized in that: The stepper motor (4) and the microcontroller (5) are electrically connected via a stepper motor driver (13); the outer side wall of the internal thread sleeve (7) and the side wall of the pin (3) are fixedly connected via a connecting rod (14).

4. A keel structure with variable bending stiffness according to any one of claims 1 to 3, characterized in that: The upper surface of the second keel (2) is provided with N grooves (15), the upper portion of the groove (15) is in the shape of an inverted cone that is wide at the top and narrow at the bottom, and the middle and lower portions are in the shape of a cylinder. The bottom end portion of the pin (3) is in the shape of an inverted cone, and the middle and lower portions of the groove (15) are clearance-matched with the straight section of the pin (3).

5. A keel structure with variable bending stiffness according to any one of claims 1 to 3, characterized in that: The first keel (1) and the second keel (2) are fixedly connected via a plurality of support rods (16) located at the ends.

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