High-precision length adjusting mechanism and length adjusting method thereof

Abstract

The invention relates to the technical field of length adjusting equipment, and particularly discloses a high-precision length adjusting mechanism which comprises a locking bolt, and the two ends of the locking bolt are in threaded connection with a locking nut and a locking thread sleeve correspondingly; a limiting ring and a lining which are nested on the locking bolt are further arranged between the locking nut and the locking thread sleeve, the limiting ring is close to one side of the locking nut, and the lining is close to one side of the locking thread sleeve; n convex keys or key grooves which are annularly and uniformly distributed are arranged on the end face, facing the locking screw sleeve, of the bushing; key grooves or convex keys matched with the convex keys on the bushing in number and position are arranged on the end face, facing one side of the bushing, of the locking screw sleeve; the end face, facing the limiting ring, of the lining is provided with m key grooves or protruding keys which are annularly and evenly distributed, the end face, facing the side of the lining, of the limiting ring is provided with protruding keys or key grooves matched with the key grooves in the lining in number and position, and n is smaller than m. According to the method, a thread length adjusting method and a gear length adjusting method are combined, the characteristic that the adjusting precision is determined through the tooth number and the tooth pitch of the gear is utilized, and high-precision adjustment is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of length adjustment equipment, and in particular to a high-precision length adjustment mechanism and a length adjustment method thereof. Background Art

[0002] Currently, the commonly used length adjustment methods are divided into two categories: length adjustment using threaded connection and length adjustment using gear and rack mechanism. However, the adjustment accuracy of these two commonly used adjustment methods is not high and there are various problems.

[0003] The bolts for adjusting the length are usually not allowed to rotate or loosen during the movement of the mechanism, otherwise it will cause the movement mechanism to get stuck or fail, affecting the safety and reliability of the structure. At present, the commonly used stop bolt connection structure is mainly composed of bolts, locking nuts and stop washers. This connection method can effectively prevent the bolts from loosening for non-moving components, but it does not play a good role for moving components. The length adjustment component of the bolt connection mechanism usually includes: a moving part and a fixed part. The transmission rod is divided into two rod bodies, the moving part is installed in one of the rod bodies, and the fixed part is installed in the other rod body. The fixed part is slidably connected to the moving part, and the sliding direction is consistent with the extension direction of the transmission rod. By adjusting the relative position of the moving part and the fixed part, the purpose of adjusting the overall length of the transmission rod is achieved. The defect of this type of length adjustment component is that its adjustment needs to be operated along the extension direction of the transmission rod, for example, the moving part is pushed to move along the extension direction of the rod body. When the transmission rod is installed at a large depth, it is difficult to provide sufficient operating space, and a linear gap for operation needs to be reserved, otherwise the sliding operation cannot be performed, occupying the parts layout space of the equipment, which is not conducive to compact design.

[0004] The working principle of gears and racks is to use the meshing between gears and racks to transmit power and motion. A gear is a disc-shaped device with a series of equally spaced teeth on its surface; while a rack is a long strip with grooves that match the gear teeth. When the gear and rack are in contact, the gear begins to rotate by applying an external force or through other power input methods. Since the teeth on the gear fit into the grooves on the rack, the rotation of the gear drives the rack to move in a specific direction. In this process, the size and number of teeth of the gear determine the speed and torque output of the gear, while the length and pitch of the rack determine the stroke length and accuracy of the rack. By adjusting the design parameters of the gear and rack, different speed and force transmission requirements can be achieved. The working principle of the gear rack type is based on the mechanical meshing design, and has the advantages of high transmission efficiency, accurate movement, and simple structure. It is widely used in various mechanical equipment, such as industrial machinery, automobiles, machine tools, etc. At the same time, gear racks also have certain disadvantages, such as noise, friction loss, etc., which need to be optimized and improved according to specific application requirements. Summary of the invention

[0005] The object of the present invention is to provide a high-precision length adjustment mechanism which has the advantages of length adjustment by threaded connection and length adjustment by gear and rack mechanism, and whose adjustment accuracy is determined by the number of gear teeth and pitch.

[0006] Another object of the present invention is to provide a specific length adjustment method for the above-mentioned high-precision length adjustment mechanism.

[0007] The present invention is achieved through the following technical scheme: a high-precision length adjustment mechanism, including a locking bolt, wherein the two ends of the locking bolt are respectively threadedly connected with a locking nut and a locking nut sleeve; a limiting ring and a bushing nested on the locking bolt are also arranged between the locking nut and the locking nut sleeve, the limiting ring is close to one side of the locking nut, and the bushing is close to one side of the locking nut sleeve; the end face of the bushing facing the locking nut sleeve is provided with n convex keys or keyways evenly distributed in an annular shape, and the end face of the locking nut sleeve facing the bushing is provided with keyways or convex keys that match the number and position of the convex keys on the bushing; the end face of the bushing facing the limiting ring is provided with m keyways or convex keys evenly distributed in an annular shape, and the end face of the limiting ring facing the bushing is provided with a convex key or keyway that matches the number and position of the keyways on the bushing, n<m.

[0008] In order to better implement the present invention, further, a limiting groove is arranged on the locking bolt, a protrusion matching the limiting groove is arranged on the inner side of the limiting ring, the protrusion on the inner side of the limiting ring is placed in the limiting groove of the locking bolt, and the protrusion of the limiting ring can reciprocate in the limiting groove.

[0009] In order to better realize the present invention, further, the end face of the bushing facing the locking nut is provided with n convex keys evenly distributed in an annular shape, and the end face of the locking nut facing the bushing is provided with keyways matching the number and positions of the convex keys on the bushing; the end face of the bushing facing the limit ring is provided with m convex keys evenly distributed in an annular shape, and the end face of the limit ring facing the bushing is provided with keyways matching the number and positions of the keyways on the bushing, n<m.

[0010] In order to better realize the present invention, further, the end face of the bushing facing the locking nut is provided with n convex keys evenly distributed in an annular shape, and the end face of the locking nut facing the bushing is provided with keyways matching the number and positions of the convex keys on the bushing; the end face of the bushing facing the limit ring is provided with m keyways evenly distributed in an annular shape, and the end face of the limit ring facing the bushing is provided with convex keys matching the number and positions of the keyways on the bushing, n<m.

[0011] In order to better realize the present invention, further, the end face of the bushing facing the locking nut is provided with n keyways evenly distributed in an annular shape, and the end face of the locking nut facing the bushing is provided with convex keys that match the number and position of the convex keys on the bushing; the end face of the bushing facing the limit ring is provided with m convex keys evenly distributed in an annular shape, and the end face of the limit ring facing the bushing is provided with keyways that match the number and position of the keyways on the bushing, n<m.

[0012] In order to better realize the present invention, further, the end face of the bushing facing the locking nut is provided with n keyways evenly distributed in an annular shape, and the end face of the locking nut facing the bushing is provided with convex keys that match the number and position of the convex keys on the bushing; the end face of the bushing facing the limit ring is provided with m keyways evenly distributed in an annular shape, and the end face of the limit ring facing the bushing is provided with convex keys that match the number and position of the keyways on the bushing, n<m.

[0013] In order to better implement the present invention, further, the convex keys arranged on both sides of the bushing are triangular keys or the keyways arranged on both sides of the bushing are triangular keyways corresponding thereto; the convex key arranged on the side of the limit ring toward the bushing is a triangular key or a triangular keyway matching the number and position of the keyways on the bushing; the convex key arranged on the side of the locking nut toward the bushing is a triangular key or a triangular keyway matching the number and position of the keyways on the bushing.

[0014] The method for length adjustment using the above-mentioned high-precision length adjustment mechanism comprises the following steps:

[0015] Step S1: Assembling the high-precision adjustment mechanism to put it in a locked state;

[0016] Step S2: first loosen the locking nut, then move the limiting ring and the bushing toward one side of the locking nut, at which time the convex key or keyway of the bushing is separated from the keyway or convex key of the locking nut sleeve;

[0017] Step S3: Screw in the locking screw sleeve, the rotation angle is The distance that the locking nut sleeve advances relative to the locking bolt is Where p is the pitch of the locking bolt;

[0018] Step S4: the sliding bushing is separated from the limiting ring, and the convex key or keyway of the bushing is re-engaged with the keyway or convex key of the locking nut;

[0019] Step S5: The locking bolt is driven to rotate back through the limiting ring, and the rotation angle is At this time, the distance that the locking bolt retreats is Where p is the pitch of the locking bolt;

[0020] Step S6: Turn the locking nut to make it contact with the limiting ring. In this way, the length adjustment is completed. At this time, the adjusted length is That is, the highest adjustment accuracy of the high-speed adjustment mechanism, so that the length can be adjusted by multiples of the highest adjustment accuracy according to the change of each rotation angle.

[0021] In order to better implement the method of the present invention, further, the specific process of assembling the high-precision adjustment mechanism in step S1 to put it in a locked state is:

[0022] Step S11: first screw the threaded sleeve onto the locking bolt;

[0023] Step S12: inserting the bushing into the locking bolt, and then combining the locking nut sleeve and the bushing through the cooperation of the keyway and the convex key;

[0024] Step S13: insert the limiting ring into the locking bolt, combine the limiting ring and the bushing through the cooperation of the keyway and the convex key, and fix the limiting ring and the locking bolt. At this time, the limiting ring can only slide radially on the locking bolt and cannot rotate on the locking bolt;

[0025] Step S14: Finally, screw in the locking nut so that the end face of the locking nut is pressed against the limiting ring, thereby completing the assembly of the high-speed adjustment mechanism.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) The present invention combines the advantages of both thread length adjustment and gear length adjustment, and utilizes the fact that the number of gear teeth and the pitch determine the adjustment accuracy, thereby achieving height precision adjustment of the rod, providing sufficient operating space, and requiring no linear gap to be reserved for operation. Direct sliding operation can be performed, which does not occupy the layout space of equipment parts and is conducive to the compact design of the mechanical structure.

[0028] (2) The present invention has a simple structure and reasonable configuration. It has low noise and friction loss during use, and can be easily optimized and improved according to specific application requirements. It can achieve high-precision adjustment of the rod. It has the advantages of high adjustment efficiency and accurate adjustment, and is suitable for wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments with reference to the following drawings:

[0030] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0031] Figure 2 It is a three-dimensional structural schematic diagram of the locking state of the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of the convex key and the keyway between the limit ring, the bushing and the locking nut in Example 3 of the present invention;

[0033] Figure 4 It is a schematic diagram of the structure of the convex key and the keyway between the limit ring, the bushing and the locking nut in Example 4 of the present invention;

[0034] Figure 5 It is a schematic diagram of the structure of the convex key and the keyway between the limit ring, the bushing and the locking nut in Example 5 of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of the convex key and the keyway between the limit ring, the bushing and the locking nut in Example 6 of the present invention;

[0036] Figure 7 It is a schematic diagram of the structure of another convex key and keyway in the present invention.

[0037] Among them: 1-locking bolt, 11-limiting groove, 2-locking nut, 3-limiting ring, 4-bushing, 5-locking nut sleeve. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Embodiment 1:

[0042] The main structure of this embodiment is as follows: Figure 1 As shown, it includes a locking bolt 1, and the two ends of the locking bolt 1 are respectively threadedly connected with a locking nut 2 and a locking nut sleeve 5; a limiting ring 3 and a bushing 4 embedded in the locking bolt 1 are also arranged between the locking nut 2 and the locking nut sleeve 5, the limiting ring 3 is close to the locking nut 2 side, and the bushing 4 is close to the locking nut sleeve 5 side; the end face of the bushing 4 facing the locking nut sleeve 5 is provided with n convex keys or keyways uniformly distributed in an annular shape, and the end face of the locking nut sleeve 5 facing the bushing 4 is provided with keyways or convex keys that match the number and position of the convex keys on the bushing 4; the end face of the bushing 4 facing the limiting ring 3 is provided with m keyways or convex keys uniformly distributed in an annular shape, and the end face of the limiting ring 3 facing the bushing 4 is provided with convex keys or keyways that match the number and position of the keyways on the bushing 4, n<m.

[0043] The method for length adjustment using the above-mentioned high-precision length adjustment mechanism comprises the following steps:

[0044] Step S1: Assemble the high-precision adjustment mechanism to put it in a locked state, such as Figure 2 As shown, the specific steps include:

[0045] Step S11: first screw the threaded sleeve 5 onto the locking bolt 1;

[0046] Step S12: insert the bushing 4 into the locking bolt 1, and then combine the locking nut 5 and the bushing 4 through the cooperation of the keyway and the convex key;

[0047] Step S13: insert the limiting ring 3 into the locking bolt 1, and combine the limiting ring 3 and the bushing 4 through the cooperation of the keyway and the convex key to fix the limiting ring 3 and the locking bolt 1. At this time, the limiting ring 3 can only slide radially on the locking bolt and cannot rotate on the locking bolt 1;

[0048] Step S14: finally screw in the locking nut 1 so that the end face of the locking nut is pressed against the limiting ring 3, thereby completing the assembly of the high-speed adjustment mechanism;

[0049] Step S2: first loosen the locking nut 2, and then move the limiting ring 3 and the bushing 4 toward the side of the locking nut 2, at which time the convex key or keyway of the bushing 2 is separated from the keyway or convex key of the locking nut sleeve 5;

[0050] Step S3: Screw in the locking screw sleeve 5, the rotation angle is The distance that the locking nut sleeve 5 advances relative to the locking bolt 1 is Wherein, p is the pitch of the locking bolt 1;

[0051] Step S4: the sliding bushing 4 is separated from the limiting ring 3, so that the convex key or keyway of the bushing 4 is re-engaged with the keyway or convex key of the locking nut 4;

[0052] Step S5: The locking bolt 1 is driven to rotate back through the limiting ring 3, and the rotation angle is At this time, the distance that the locking bolt 1 retreats is Wherein, p is the pitch of the locking bolt 1;

[0053] Step S6: Turn the locking nut 2 to make the locking nut 2 abut against the limiting ring 3. In this way, the length adjustment is completed. At this time, the adjusted length is That is, the highest adjustment accuracy of the high-speed adjustment mechanism, so that the length can be adjusted by multiples of the highest adjustment accuracy according to the change of each rotation angle.

[0054] Embodiment 2:

[0055] Based on the above embodiment, this embodiment further defines the connection relationship between the locking bolt 1 and the limiting ring 3, such as Figure 1 As shown, the locking bolt 1 is provided with a limiting groove 11, and the inner side of the limiting ring 3 is provided with a protrusion matching the limiting groove 11. The protrusion on the inner side of the limiting ring 3 is placed in the limiting groove 11 of the locking bolt 1, and the protrusion of the limiting ring 2 can reciprocate in the limiting groove 11. Since the limiting ring 3 must ensure synchronous rotation with the locking bolt 1, it is particularly limited that the inner side of the limiting ring 3 is provided with a protrusion, and the locking bolt 1 is provided with a limiting groove, and the two are embedded, so that it can be ensured that the limiting ring 3 cannot rotate in the locking bolt 1, and can only slide in the direction of the limiting groove. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0056] Embodiment 3:

[0057] On the basis of the above-mentioned embodiments, this embodiment further defines the relationship between the convex key and the keyway between the limiting ring 3, the bushing 4 and the locking screw sleeve 5, such as Figure 3 As shown, the end surface of the bushing 4 facing the locking nut 5 is provided with n convex keys evenly distributed in an annular shape, and the end surface of the locking nut 5 facing the bushing 4 is provided with keyways that match the number and position of the convex keys on the bushing 4; the end surface of the bushing 4 facing the limiting ring 3 is provided with m convex keys evenly distributed in an annular shape, and the end surface of the limiting ring 3 facing the bushing 4 is provided with keyways that match the number and position of the keyways on the bushing 4, n<m. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0058] Embodiment 4:

[0059] On the basis of the above-mentioned embodiments, this embodiment further defines the relationship between the convex key and the keyway between the limiting ring 3, the bushing 4 and the locking screw sleeve 5, such as Figure 4As shown, the end surface of the bushing 4 facing the locking nut 5 is provided with n convex keys evenly distributed in an annular shape, and the end surface of the locking nut 5 facing the bushing 4 is provided with keyways that match the number and position of the convex keys on the bushing 4; the end surface of the bushing 4 facing the limiting ring 3 is provided with m keyways evenly distributed in an annular shape, and the end surface of the limiting ring 3 facing the bushing 4 is provided with convex keys that match the number and position of the keyways on the bushing 4, n<m. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0060] Embodiment 5:

[0061] On the basis of the above-mentioned embodiments, this embodiment further defines the relationship between the convex key and the keyway between the limiting ring 3, the bushing 4 and the locking screw sleeve 5, such as Figure 5 As shown, the end surface of the bushing 4 facing the locking nut 5 is provided with n keyways evenly distributed in an annular shape, and the end surface of the locking nut 5 facing the bushing 4 is provided with convex keys that match the number and position of the convex keys on the bushing 4; the end surface of the bushing 4 facing the limiting ring 3 is provided with m convex keys evenly distributed in an annular shape, and the end surface of the limiting ring 3 facing the bushing 4 is provided with keyways that match the number and position of the keyways on the bushing 4, n<m. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0062] Embodiment 6:

[0063] On the basis of the above-mentioned embodiments, this embodiment further defines the relationship between the convex key and the keyway between the limiting ring 3, the bushing 4 and the locking screw sleeve 5, such as Figure 6 As shown, the end surface of the bushing 4 facing the locking nut 5 is provided with n keyways evenly distributed in an annular shape, and the end surface of the locking nut 5 facing the bushing 4 is provided with convex keys that match the number and position of the convex keys on the bushing 4; the end surface of the bushing 4 facing the limiting ring 3 is provided with m keyways evenly distributed in an annular shape, and the end surface of the limiting ring 3 facing the bushing 4 is provided with convex keys that match the number and position of the keyways on the bushing 4, n<m. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0064] Embodiment 7:

[0065] On the basis of the above-mentioned embodiments, this embodiment further defines the relationship between the convex key and the keyway between the limiting ring 3, the bushing 4 and the locking screw sleeve 5, such as Figure 7As shown, the convex keys arranged on both sides of the bushing 4 are triangular keys or the keyways arranged on both sides of the bushing 4 are triangular keyways corresponding thereto; the convex keys arranged on the side of the limit ring 3 facing the bushing 4 are triangular keys or triangular keyways matching the number and position of the keyways on the bushing 4; the convex keys arranged on the side of the locking nut 5 facing the bushing 4 are triangular keys or triangular keyways matching the number and position of the keyways on the bushing 4. The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0066] It can be understood that the working principles and working processes of the high-precision length adjustment mechanism structure according to an embodiment of the present invention, such as the locking bolt 1 and the locking nut 2 and other components, are prior art and are well known to technicians in this field, and will not be described in detail here.

[0067] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A high-precision length adjustment mechanism, characterized in that: The invention comprises a locking bolt (1), wherein the two ends of the locking bolt (1) are respectively threadedly connected with a locking nut (2) and a locking screw sleeve (5); a limiting ring (3) and a bushing (4) embedded in the locking bolt (1) are also arranged between the locking nut (2) and the locking screw sleeve (5); the limiting ring (3) is close to one side of the locking nut (2), and the bushing (4) is close to one side of the locking screw sleeve (5); the bushing (4) is arranged on the end surface facing the locking screw sleeve (5); There are n convex keys or keyways evenly distributed in an annular shape, and the end surface of the locking nut (5) facing the bushing (4) is provided with a keyway or convex key that matches the number and position of the convex keys on the bushing (4); the end surface of the bushing (4) facing the limiting ring (3) is provided with m keyways or convex keys evenly distributed in an annular shape, and the end surface of the limiting ring (3) facing the bushing (4) is provided with a convex key or keyway that matches the number and position of the keyways on the bushing (4), n<m.

2. A high-precision length adjustment mechanism according to claim 1, characterized in that: The locking bolt (1) is provided with a limiting groove (11), the inner side of the limiting ring (3) is provided with a protrusion matching the limiting groove (11), the protrusion on the inner side of the limiting ring (3) is placed in the limiting groove (11) of the locking bolt (1), and the protrusion of the limiting ring (2) can reciprocate in the limiting groove (11).

3. A high-precision length adjustment mechanism according to claim 1 or 2, characterized in that: The end surface of the bushing (4) facing the locking nut (5) is provided with n convex keys evenly distributed in an annular shape, and the end surface of the locking nut (5) facing the bushing (4) is provided with keyways matching the number and position of the convex keys on the bushing (4); the end surface of the bushing (4) facing the limiting ring (3) is provided with m convex keys evenly distributed in an annular shape, and the end surface of the limiting ring (3) facing the bushing (4) is provided with keyways matching the number and position of the keyways on the bushing (4), n<m.

4. A high-precision length adjustment mechanism according to claim 1 or 2, characterized in that: The end surface of the bushing (4) facing the locking nut (5) is provided with n convex keys evenly distributed in an annular shape, and the end surface of the locking nut (5) facing the bushing (4) is provided with keyways matching the number and position of the convex keys on the bushing (4); the end surface of the bushing (4) facing the limiting ring (3) is provided with m keyways evenly distributed in an annular shape, and the end surface of the limiting ring (3) facing the bushing (4) is provided with convex keys matching the number and position of the keyways on the bushing (4), n<m.

5. A high-precision length adjustment mechanism according to claim 1 or 2, characterized in that: The end surface of the bushing (4) facing the locking nut (5) is provided with n keyways evenly distributed in an annular shape, and the end surface of the locking nut (5) facing the bushing (4) is provided with convex keys that match the number and position of the convex keys on the bushing (4); the end surface of the bushing (4) facing the limiting ring (3) is provided with m convex keys evenly distributed in an annular shape, and the end surface of the limiting ring (3) facing the bushing (4) is provided with keyways that match the number and position of the keyways on the bushing (4), n<m.

6. A high-precision length adjustment mechanism according to claim 1 or 2, characterized in that: The end surface of the bushing (4) facing the locking nut (5) is provided with n keyways evenly distributed in an annular shape, and the end surface of the locking nut (5) facing the bushing (4) is provided with convex keys that match the number and position of the convex keys on the bushing (4); the end surface of the bushing (4) facing the limiting ring (3) is provided with m keyways evenly distributed in an annular shape, and the end surface of the limiting ring (3) facing the bushing (4) is provided with convex keys that match the number and position of the keyways on the bushing (4), n<m.

7. A high-precision length adjustment mechanism according to claim 1 or 2, characterized in that: The convex keys arranged on both sides of the bushing (4) are triangular keys or the keyways arranged on both sides of the bushing (4) are triangular keyways corresponding thereto; the convex keys arranged on the side of the limit ring (3) facing the bushing (4) are triangular keys or triangular keyways matching the number and position of the keyways on the bushing (4); the convex keys arranged on the side of the locking nut (5) facing the bushing (4) are triangular keys or triangular keyways matching the number and position of the keyways on the bushing (4).

8. A method for length adjustment using a high-precision length adjustment mechanism according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1: Assembling the high-precision adjustment mechanism to put it in a locked state; Step S2: first loosen the locking nut (2), then move the limiting ring (3) and the bushing (4) toward one side of the locking nut (2), at which time the convex key or keyway of the bushing (2) is separated from the keyway or convex key of the locking nut sleeve (5); Step S3: Screw in the locking screw sleeve (5) at an angle of The distance that the locking nut sleeve (5) moves forward relative to the locking bolt (1) is Wherein, p is the pitch of the locking bolt (1); Step S4: the sliding bushing (4) is separated from the limiting ring (3), and the convex key or keyway of the bushing (4) is re-engaged with the keyway or convex key of the locking nut (4); Step S5: The locking bolt (1) is driven to rotate back through the limiting ring (3) to an angle of At this time, the distance that the locking bolt (1) retracts is Wherein, p is the pitch of the locking bolt (1); Step S6: Turn the locking nut (2) to make the locking nut (2) abut against the limiting ring (3). In this way, the length adjustment is completed. At this time, the adjusted length is That is, the highest adjustment accuracy of the high-speed adjustment mechanism, so that the length can be adjusted by multiples of the highest adjustment accuracy according to the change of each rotation angle.

9. A method for length adjustment using a high-precision length adjustment mechanism according to claim 8, characterized in that: The specific process of assembling the high-precision adjustment mechanism to put it in a locked state in step S1 is: Step S11: first screw the threaded sleeve (5) onto the locking bolt (1); Step S12: insert the bushing (4) into the locking bolt (1), and then combine the locking nut (5) and the bushing (4) by means of the cooperation between the keyway and the convex key; Step S13: insert the limiting ring (3) into the locking bolt (1), and combine the limiting ring (3) and the bushing (4) through the cooperation of the keyway and the convex key, so as to fix the limiting ring (3) and the locking bolt (1). At this time, the limiting ring (3) can only slide radially on the locking bolt, and cannot rotate on the locking bolt (1); Step S14: Finally, screw in the locking nut (1) so that the end face of the locking nut is pressed against the limiting ring (3), thereby completing the assembly of the high-speed adjustment mechanism.

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