Radial drilling of round hole sidewall

Abstract

This invention relates to the field of machining technology, specifically to an auxiliary device for radial drilling of the sidewall of a circular hole. It is mainly used in conjunction with a pneumatic drill to machine radial holes on the sidewall of a circular hole using a drill bit. The device includes a guide sleeve and a pre-positioning rod vertically connected to one end of the guide sleeve. A feed shaft is provided inside the guide sleeve. Positioning strips perpendicular to the pre-positioning rod and the feed shaft are symmetrically arranged at both ends of the pre-positioning rod away from the guide sleeve. A first guide groove with a length along its axial direction and communicating with the inner cavity of the guide sleeve is provided in the first guide groove. A connecting rod connected to the feed shaft is provided in the first guide groove. The device also includes a first pivot perpendicular to the axis of the feed shaft and a feed handle pivotally connected to the guide sleeve at one end via the first pivot. A strip-shaped through hole is provided on the feed handle, and the connecting rod is slidably connected within the strip-shaped through hole. This invention is used to machine radial holes inside large circular holes, ensuring that the drill bit is arranged radially along the large circular hole, facilitating convenient and quick positioning and drilling operations for the pneumatic drill, and improving the machining accuracy of the radial holes.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, and specifically relates to an auxiliary device for radial drilling of the sidewall of a circular hole. Background Technology

[0002] In the field of machining, workpieces with large circular holes are frequently encountered. The diameter of these holes is generally over 400mm, and components that rotate or slide axially within them are typically installed. Therefore, considering the need for lubrication or the addition of other parts, radial blind holes or tapered through holes with gradually decreasing diameters from the inside to the outside of the large circular hole are often provided on the sidewalls of these workpieces. For example, large bearings are installed in the work roll bearing housings and intermediate roll bearing housings of rolling mills. To ensure sufficient lubrication, reduce wear, and extend the service life of the bearings during operation, the sidewalls of the large circular holes in these bearing housings are designed with lubrication oil passages, which include interconnected axial oil holes and radial oil holes with blind hole structures. Another example is the cylinder liner of a large diesel engine used in the research and development testing phase. To monitor the temperature inside the combustion chamber of the cylinder liner during testing, a tapered hole structure with gradually decreasing diameters from the inside to the outside of the cylinder liner needs to be provided on the inner sidewall of the diesel engine cylinder liner to achieve precise assembly of the temperature sensor. Due to limitations such as the shape and location of the aforementioned radial oil holes and tapered holes, these radial holes all need to be drilled from the inside out along the radial direction of the large circular hole in the workpiece. This part of the operation is usually done by a fitter.

[0003] Currently, the method for machining the aforementioned radial holes by fitters is mainly determined by the diameter of the large circular hole on the workpiece. When the diameter of the large circular hole is greater than 600mm, a large-sized magnetic drill is used to machine the radial hole from the inside out within the large circular hole. When the diameter of the large circular hole is between 400-600mm, the large-sized magnetic drill cannot fit into the large circular hole of the workpiece, so a smaller pneumatic drill is required to machine the radial hole. The pneumatic drill bit has a feed bolt threaded on the side away from the drill bit along its axial direction. When machining the aforementioned radial holes with a pneumatic drill, the axis of the pneumatic drill bit must be arranged radially along the large circular hole to ensure the positional accuracy of the machined radial hole. Currently, the method often involves indirectly measuring the distance from the drill housing to the sidewalls of the large circular holes on both sides using a measuring tape, then adjusting the drill's angle until the distance from the drill housing to the sidewalls of the large circular holes on both sides is equal. Multiple layers of wooden blocks are then placed between the head of the feed bolt on the drill and the sidewall of the large circular hole furthest from the drill bit, ensuring the drill bit is axially pressed against the sidewall of the large circular hole. The drill is then turned on, causing the drill bit to rotate, and the feed bolt on the drill is rotated using a wrench to feed the drill bit and complete the machining of the radial holes. A commercially available drill can be used, such as the FUJI air drill (also known as a pneumatic drill), model F14CN. While this method can basically meet the machining requirements for the radial holes, it has the following drawbacks: 1. During the pre-positioning process of the pneumatic drill, it is necessary to repeatedly measure the distance between the pneumatic drill housing and the side walls of the large round holes on both sides, and adjust the placement and angle of the pneumatic drill. This is not only cumbersome and difficult to position, but also makes it difficult to guarantee the positioning and machining accuracy of the radial hole, wasting manpower and reducing machining efficiency. 2. During the drill bit feeding process, the wooden blocks are prone to loosening and falling, causing the pneumatic drill to be unstable and posing a safety hazard; 3. During the drill bit feeding process, it is necessary to manually turn a wrench to unscrew the feed screw on the pneumatic drill out of the drill housing, which is cumbersome and inefficient. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an auxiliary device for radial drilling of the sidewall of a circular hole, which improves the positioning accuracy and drilling feed accuracy of the pneumatic drill used for machining radial holes on the sidewall of a circular hole, improves the safety and reliability of drilling operations, saves manpower, and improves the machining efficiency of radial holes.

[0005] The technical solution adopted by the present invention to solve this technical problem is: a radial drilling auxiliary device for the sidewall of a circular hole, comprising a guide sleeve and a prepositioning rod vertically connected to one end of the guide sleeve, wherein a feed shaft capable of linear reciprocating along its axial direction is provided inside the guide sleeve; positioning strips are symmetrically arranged at both ends of the prepositioning rod, the positioning strips are perpendicular to the prepositioning rod and the feed shaft, and the distance from the center line of the feed shaft to the positioning strips on both sides is equal; The outer wall of the guide sleeve is provided with a first guide groove whose length is arranged along its axial direction. The first guide groove is connected to the inner cavity of the guide sleeve. A connecting rod that can reciprocate linearly along its length is provided in the first guide groove. The connecting rod and the feed shaft are synchronously connected in the axial direction of the feed shaft. It also includes a first pivot and a feed handle. The first pivot is perpendicular to the axis of the feed shaft. One end of the feed handle is pivotally connected to the guide sleeve through the first pivot, and the other end of the feed handle protrudes from the outer side wall of the guide sleeve. The feed handle is provided with a strip-shaped through hole that extends along the depth direction of the first guide groove. The connecting rod is located in the strip-shaped through hole and can move back and forth linearly along the length direction of the strip-shaped through hole.

[0006] Furthermore, the prepositioning rod includes an intermediate rod vertically fixedly connected to one end of the guide sleeve, and telescopic rods with adjustable axial positions are connected to both ends of the intermediate rod. The axes of the intermediate rod and the telescopic rods are parallel to each other, and the positioning strip is disposed at the end of the telescopic rod away from the intermediate rod. It also includes a fastening and fixing part for fastening the intermediate rod and the telescopic rod together.

[0007] Furthermore, the telescopic rod is provided with an axially penetrating guide hole, and the intermediate rod is inserted into the guide hole and slides axially with the telescopic rod.

[0008] Furthermore, the fastening positioning part includes an adjusting rod, an adjusting sleeve sleeved on the outside of the guide sleeve and capable of reciprocating along its axial direction, and a fastening bolt threaded onto the adjusting sleeve. The fastening bolt passes through the adjusting sleeve radially along the guide sleeve and is fastened to the outer wall of the guide sleeve. There are two adjusting rods, which are symmetrically distributed about the perpendicular bisecting plane of the prepositioning rod. The adjusting sleeve is provided with a second pivot that is perpendicular to both the prepositioning rod and the feed axis, and the telescopic rod is provided with a third pivot that is parallel to the second pivot; one end of the adjusting rod is pivotally connected to the adjusting sleeve through the second pivot, and the other end of the adjusting rod is pivotally connected to the telescopic rod through the third pivot.

[0009] Furthermore, both the end of the second pivot away from the feed axis and the end of the third pivot away from the intermediate rod are provided with axial limiting portions. The end of the adjusting rod connected to the adjusting sleeve is located between the axial limiting portion and the adjusting sleeve, and the end of the adjusting rod connected to the telescopic rod is located between the axial limiting portion and the telescopic rod.

[0010] Furthermore, both ends of the positioning strip protrude from the pre-positioning rod; the positioning strip is provided with an arc surface structure that transitions from the side away from the end face of the pre-positioning rod to the side away from the end face of the guide sleeve.

[0011] Furthermore, the feed shaft sidewall is provided with ratchet teeth, which are arranged radially outward from the end away from the prepositioning rod to the end closer to the prepositioning rod along the feed shaft; there are multiple ratchet teeth, which are evenly distributed along the axial direction of the feed shaft. The guide sleeve sidewall is provided with a fourth pivot and a stop rod parallel to the feed axis. The fourth pivot is perpendicular to the feed axis, and the stop rod is pivotally connected to the guide sleeve through the fourth pivot. One end of the anti-reverse rod is provided with a pawl that protrudes radially inward along the feed axis, and the other end of the anti-reverse rod is provided with an elastic limiting member that abuts against the guide sleeve. The pawl and the elastic limiting member are located on both sides of the fourth pivot. The pawl tip engages between two adjacent ratchet teeth on the feed axis.

[0012] Furthermore, the feed shaft includes a first shaft segment and a second shaft segment arranged axially adjacent to each other, the first shaft segment being located at one end near the prepositioning rod and the two being arranged coaxially; the first shaft segment and the second shaft segment are integrally formed as a whole structure; The outer diameter of the first shaft segment is larger than the outer diameter of the second shaft segment, and a positioning collar is coaxially fixedly provided on the outer side of the first shaft segment near the second shaft segment. The outer wall of the second shaft segment is provided with external threads, and the second shaft segment is a full-tooth screw structure; the ratchet is provided on the outer wall of the first shaft segment.

[0013] Furthermore, the first pivot is parallel to the prepositioning rod; the cross-section of the connecting rod is circular; a connecting hole is provided on the outer wall of the first shaft segment, one end of the connecting rod is inserted into the connecting hole with clearance fit, and a limiting nut is threadedly connected to the other end of the connecting rod; the feed handle is located between the limiting nut and the guide sleeve. A limiting ring plate is fixedly installed on the outer wall of the connecting rod. A compression spring is provided between the limiting ring plate and the feed handle, and the two ends of the compression spring abut against the limiting ring plate and the feed handle, respectively.

[0014] Furthermore, the first shaft segment is provided with a plurality of connecting holes, which are evenly distributed along the axial direction of the feed shaft.

[0015] Compared with the prior art, the beneficial effects of the present invention are: it provides an auxiliary device for radial drilling of the sidewall of a circular hole, which uses a feed shaft that can reciprocate linearly along the direction of the pre-positioning rod in the guide sleeve to assemble a pneumatic drill and drive the pneumatic drill to move synchronously axially. By setting the positioning strips at both ends of the pre-positioning rod to be equidistant from the center line of the feed shaft, the center lines of the feed shaft and the drill bit of the pneumatic drill pre-assembled on it are both located on the vertical bisector of the pre-positioning rod. By setting a feed handle to drive the feed shaft and the drill bit of the pneumatic drill pre-assembled on it to reciprocate linearly along the vertical center line of the pre-positioning rod, it is easier to realize the length adjustment of the entire device in the axial direction of the feed shaft. When machining radial holes inside a large circular hole using this invention, adjusting the length of the entire device along the feed axis by moving the feed handle makes it easier to assemble the device into the large circular hole of the workpiece. It also makes it easier to adjust the positioning bars at both ends of the pre-positioning rod and the drill bit to abut against the sidewall of the large circular hole. After the pneumatic drill is started, the drill bit is driven to drill radially from the inside out along the large circular hole. This ensures that the centerline of the drill bit on the feed axis is arranged radially along the large circular hole, facilitating convenient and quick adjustment, positioning, and drilling operations. The operation is simple, saves manpower, improves the positioning accuracy and drilling accuracy of the drill bit, and ensures that the radial hole axis is arranged radially along the large circular hole, thus improving the machining accuracy of the radial hole. Furthermore, the abutment of the positioning bars at both ends of the drill bit and the pre-positioning rod against the sidewall of the large circular hole makes the drill bit positioning structure safer and more reliable. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the axial structure of the present invention in one direction; Figure 2 This is a schematic diagram of the structure from another direction of the present invention; Figure 3 This is an exploded view of the connecting rod, feed handle, feed shaft, and first pivot in this invention; Figure 4 This is an exploded view of the guide sleeve, anti-reverse rod, pawl, elastic limiting member, and fourth pivot in this invention; Figure 5 It is along Figure 1 Schematic diagram of the cross-sectional structure along the AA direction; Figure 6 yes Figure 5 Schematic diagram of the assembly structure of the connecting rod, feed handle, and feed axis; Figure 7 It is along Figure 1 Schematic diagram of the cross-sectional structure in the middle BB direction; Figure 8 yes Figure 7 A schematic diagram of the assembly structure of the guide sleeve, anti-reverse rod, pawl, elastic limiter and fourth pivot; Figure 9 This is a schematic diagram of the assembly structure of an embodiment of the second pivot in this invention with the adjusting sleeve and the guide sleeve; Figure 10 This is a schematic diagram of the assembly structure of an embodiment of the fastening positioning part of the present invention with the intermediate rod and the telescopic rod; Figure 11 This is a schematic diagram of the structure of the present invention after assembly with a pneumatic drill; Figure 12 This is a schematic diagram of the drilling operation using the present invention; Reference numerals: 1-Guide sleeve; 11-First guide groove; 12-First spring mounting hole; 13-Limiting groove; 14-Fixing plate; 2-Pre-positioning rod; 20-Positioning strip; 21-Intermediate rod; 22-Telescopic rod; 23-Adjusting rod; 24-Fasting screw; 3-Feed shaft; 31-First shaft section; 32-Second shaft section; 33-Positioning collar; 34-Connecting hole; 4-First pivot; 5-Feed handle; 51-Connecting rod; 511-Limiting ring plate; 52-Strip 53-Through hole; 54-Limit nut; 6-Compression spring; 6-Adjusting sleeve; 61-Fastening bolt; 62-Second pivot; 621-Axial limiting part; 622-Smooth shaft section; 623-Threaded section; 63-Third pivot; 71-Ratchet; 72-Fourth pivot; 73-Anti-reverse rod; 731-Second spring mounting hole; 74-Pawl; 75-Elastic limiting element; 8-Large round hole; 81-Radial hole; 9-Pneumatic drill; 91-Drill bit; 92-Feed threaded hole. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The "radial hole" described below in the present invention includes, but is not limited to, radial blind holes provided on the sidewall of a large circular hole in a workpiece, tapered holes whose diameter gradually decreases from the inside to the outside along the radial direction of a large circular hole, and other radial holes that need to be drilled from the inside to the outside along the radial direction of the circular hole.

[0018] As attached Figure 1-12 As shown, an auxiliary device for radial drilling of the sidewall of a circular hole includes a guide sleeve 1 and a pre-positioning rod 2 vertically connected to one end of the guide sleeve 1. The guide sleeve 1 contains a feed shaft 3 capable of linear reciprocating along its axial direction. Positioning strips 20 are symmetrically arranged at both ends of the pre-positioning rod 2, perpendicular to the pre-positioning rod 2 and the feed shaft 3. The distance from the centerline of the feed shaft 3 to the positioning strips 20 on both sides is equal. A first guide groove 11, with its length arranged axially, is formed on the outer wall of the guide sleeve 1. The first guide groove 11 communicates with the inner cavity of the guide sleeve 1 and contains a... A connecting rod 51 capable of linear reciprocating motion along its length is included. One end of the connecting rod 51 is synchronously connected to the feed shaft 3 in the axial direction of the feed shaft 3. The system also includes a first pivot 4 and a feed handle 5. The first pivot 4 is perpendicular to the axis of the feed shaft 3. The feed handle 5 is pivotally connected to the guide sleeve 1 via the first pivot 4. The other end of the feed handle 5 protrudes from the outer wall of the guide sleeve 1. The feed handle 5 has a strip-shaped through hole 52 extending along the depth direction of the first guide groove 11. The connecting rod 51 is located within the strip-shaped through hole 52 and can move linearly back and forth along the length direction of the strip-shaped through hole 52. Pre-positioning rods 2 are symmetrically arranged on both sides of the feed shaft 3, with equal distances from the center line of the feed shaft 3. The synchronous axial connection between one end of the connecting rod 51 and the feed shaft 3 means that when the feed shaft 3 reciprocates axially, the connecting rod 51 moves synchronously with the feed shaft 3 in the axial direction. The connecting rod 51 is parallel to the first pivot 4.

[0019] For ease of explanation, in this invention, the end of the feed handle 5 near the first pivot 4 is the hinge end, and the end of the feed handle 5 away from the first pivot 4 is the control end. Moving the control end of the feed handle 5 causes it to swing around the first pivot 4 towards the pre-positioning rod 2. During this process, the feed handle 5 also swings relative to the connecting rod 51, and the connecting rod 51 slides within the strip-shaped through hole 52 of the feed handle 5. The sidewall of the strip-shaped through hole 52 abuts against the sidewall of the connecting rod 51, causing the connecting rod 51 and the feed shaft 3 to move along the length of the first guide groove 11 towards the pre-positioning rod 2, thereby realizing the movement of the feed shaft 3 along its own axial direction towards the pre-positioning rod 2. Conversely, by manipulating the control end of the feed handle 5, it swings around the first pivot 4 in a direction away from the pre-positioning rod 2. During this process, the feed handle 5 also swings relative to the connecting rod 51, and the connecting rod 51 slides within the strip-shaped through hole 52 on the feed handle 5. The wall of the strip-shaped through hole 52 abuts against the side wall of the connecting rod 51, causing the connecting rod 51 and the feed shaft 3 to move along the length direction of the first guide groove 11 in a direction away from the pre-positioning rod 2, thereby realizing the axial movement of the feed shaft 3 away from the pre-positioning rod 2. In summary, by manipulating the control end of the feed handle 5, the feed handle 5 can swing relative to the guide sleeve 1 around the first pivot 4. The side wall of the strip-shaped through hole 52 on the feed handle 5 drives the connecting rod 51 and the feed shaft 3 to reciprocate along its axial direction within the guide sleeve 1, thereby realizing the axial extension and retraction movement of the feed shaft 3.

[0020] When machining the radial hole 81 located on the side wall of the large circular hole 8 using the present invention, the workpiece is first fixed, and the center position of the pre-machined radial hole 81 is determined by marking a line on the side wall of the large circular hole 8 of the workpiece. The air drill 9 is fixedly assembled on the end of the feed shaft 3 away from the prepositioning rod 2. The drill bit 91 of the air drill 9 is located at the end away from the feed shaft 3 and is coaxial with the feed shaft 3. The control end of the feed handle 5 is moved to drive the feed shaft 3 to the limit position close to the prepositioning rod 2 so that the length of the feed shaft 3 extending out of the guide sleeve 1 is minimized, so that the air drill 9 and the overall structure after the present invention are assembled can be more easily put into the large circular hole 8 of the workpiece. After the pneumatic drill 9 and the integrated structure formed by the present invention are placed into the large circular hole 8, the direction is adjusted so that the drill bit 91 of the pneumatic drill 9 is coaxial with the pre-machined radial hole 81. The control end of the feed handle 5 is moved to drive the feed shaft 3 to move away from the pre-positioning rod 2 until the positioning strips 20 at both ends of the drill bit 91 away from the feed shaft 3 and the two ends of the pre-positioning rod 2 are in contact with the side wall of the large circular hole 8. It is required that the positioning strips 20 are parallel to the axis of the large circular hole 8 at this time. Finally, while turning on the pneumatic drill 9 to rotate the drill bit 91, continue to operate the control end of the feed handle 5 to drive the connecting rod 51 and the feed shaft 3 to move axially away from the pre-positioning rod 2. This causes the feed shaft 3 to drive the drill bit 91 to feed radially from the inside to the outside along the large circular hole 8 to complete the machining of the radial hole 81. After drilling, reverse the operation of the control end of the feed handle 5 to drive the feed shaft 3 to move in the opposite direction, causing the drill bit 91 to disengage from the formed radial hole 81. Finally, the entire assembly structure of the invention and the pneumatic drill 9 is removed from the large circular hole 8. It is required that the distance between the two positioning strips 20 at both ends of the pre-positioning rod 2 is less than the diameter of the large circular hole 8. During drilling, the length from the point where the tip of the drill bit 91 contacts the side wall of the large circular hole 8 to the pre-positioning rod 2 is greater than the radius of the large circular hole 8. To ensure the reliability of the pneumatic drill, it is necessary to manually hold the pneumatic drill handle.

[0021] This invention assembles a pneumatic drill 9 within a guide sleeve 1, allowing the feed shaft 3 to reciprocate linearly along the direction of the pre-positioning rod 2, and drives the pneumatic drill 9 to move synchronously axially. By setting the positioning strips 20 at both ends of the pre-positioning rod 2 to be equidistant from the center line of the feed shaft 3, the center lines of the feed shaft 3 and the drill bit 91 pre-assembled on it are both located on the vertical bisector of the pre-positioning rod 2. By setting the feed handle 5 to drive the feed shaft 3 and the drill bit 91 pre-assembled on it to reciprocate linearly along the vertical center line of the pre-positioning rod 2, the length adjustment of the entire device in the axial direction of the feed shaft 3 can be more easily achieved. When machining radial holes 81 on the sidewall of a large circular hole 8 using this invention, adjusting the length of the entire device along the feed shaft 3 by moving the feed handle 5 makes it easier to assemble the device into the large circular hole 8. It also makes it easier to adjust the positioning bars 20 at both ends of the pre-positioning rod 2 and the drill bit 91 to abut against the sidewall of the large circular hole 8. After the pneumatic drill 9 is started, the drill bit 91 is driven to drill radially from the inside out along the large circular hole 8. This ensures that the centerline of the drill bit 91 on the feed shaft 3 is arranged radially along the large circular hole 8, facilitating convenient and quick angle adjustment, positioning, and drilling operations of the pneumatic drill 9. The operation is simple, saves manpower, improves the positioning accuracy and drilling accuracy of the drill bit 91, and ensures that the axis of the radial hole 81 is arranged radially along the large circular hole 8, thus improving the machining accuracy of the radial hole 81. Furthermore, the abutment of the drill bit 91 and the positioning bars 20 against the sidewall of the large circular hole 8 makes the positioning structure of the drill bit safer and more reliable.

[0022] The guide sleeve 1 is mainly used to guide the feed shaft 3 and make it reciprocate along the length of the perpendicular bisector of the prepositioning rod 2. The prepositioning rod 2 is mainly used to cooperate with the feed shaft 3 to achieve positioning within the large circular hole 8 of the workpiece during drilling. The guide sleeve 1 and the prepositioning rod 2 can be fixedly connected by welding, bolts, or other methods. The prepositioning rod 2 can be a rod with a circular, rectangular, or triangular cross-section. The first guide groove 11 on the guide sleeve 1 is used to cooperate with the connecting rod 51 to make the connecting rod 51 move axially along the feed shaft 3. The connecting rod 51 and the first guide groove 11 can be directly slidably engaged, or they can be rolled together by rollers or balls. Preferably, the connecting rod 51 and the first guide groove 11 are slidably engaged along the axial direction of the feed shaft 3, which is simple in structure and easy to process and assemble.

[0023] The prepositioning rod 2 can be a single, integral structure or an assembly of multiple rod segments. In actual production, considering the need to machine radial holes 81 on the sidewalls of large circular holes 8 with different diameters, prepositioning rods 2 and feed shafts 3 of different lengths are required. Preferably, the prepositioning rod 2 includes an intermediate rod 21 vertically fixedly connected to one end of the guide sleeve 1, with telescopic rods 22 whose axial positions are adjustable at both ends of the intermediate rod 21. The axes of the intermediate rod 21 and the telescopic rods 22 are parallel to each other, and the positioning strip 20 is located at the end of the telescopic rod 22 away from the intermediate rod 21; it also includes a fastening and positioning part for fastening the intermediate rod 21 and the telescopic rod 22. During drilling operations, the distances from the two positioning strips 20 to the center line of the feed shaft 3 are equal. By adjusting the position of the telescopic rod 22 on the intermediate rod 21, the length of the entire prepositioning rod 2 can be adjusted, thereby adjusting the spacing of the positioning strips 20 at both ends of the prepositioning rod 2. This makes the invention applicable to the processing of radial holes 81 on the sidewalls of large circular holes 8 with different diameters, expanding the scope of application of the invention and saving costs.

[0024] The intermediate rod 21 can be fixed to one end of the guide sleeve 1 by welding or bolting. The cross-sections of the intermediate rod 21 and the telescopic rod 22 can be the same or different. The length of the pre-positioning rod 2 can be adjusted by a sliding groove and a slider that slide against each other, or by a roller and a sliding groove that roll together. Preferably, the telescopic rod 22 has an axially through guide hole, and the intermediate rod 21 is inserted into the guide hole and slides axially with the telescopic rod 22. The structure is simple and easy to process. The fastening and positioning part is used to fasten the intermediate rod 21 and the telescopic rod 22 together, such as... Figure 10 As shown, the fastening fixing part can be a fastening screw 24 that is threaded onto the telescopic rod 22 and fastened against the outer wall of the intermediate rod 21.

[0025] The drilling auxiliary device with the above structure requires adjusting the length of the two telescopic rods 22 extending out of the middle rod 21. Not only is the adjustment process cumbersome, but it can also easily lead to unequal distances between the positioning strips 20 at both ends of the telescopic rods 22 and the center line of the feed shaft 3 after adjustment, affecting the positioning accuracy and drilling accuracy of the drill bit 91. Preferably, the fastening and positioning part includes an adjusting rod 23, an adjusting sleeve 6 sleeved on the outside of the guide sleeve 1 and capable of reciprocating along its axial direction, and a fastening bolt 61 threadedly connected to the adjusting sleeve 6. The fastening bolt 61 passes radially through the adjusting sleeve 6 along the guide sleeve 1 and is fastened and abuts against the outer wall of the guide sleeve 1. There are two adjusting rods 23, which are symmetrically distributed about the perpendicular bisecting plane of the prepositioning rod 2. The adjusting sleeve 6 is provided with a second pivot 62 that is perpendicular to both the prepositioning rod 2 and the feed shaft 3. The telescopic rod 22 is provided with a third pivot 63 that is parallel to the second pivot 62. One end of the adjusting rod 23 is pivotally connected to the adjusting sleeve 6 through the second pivot 62, and the other end of the adjusting rod 23 is pivotally connected to the telescopic rod 22 through the third pivot 63. When the fastening bolt 61 is tightly abutted against the outer wall of the guide sleeve 1, the guide sleeve 1 and the adjusting sleeve 6 are tightly connected; by rotating the fastening bolt 61 outward to disengage it from the outer wall of the guide sleeve 1, the axial position of the adjusting sleeve 6 on the guide sleeve 1 can be adjusted. When the adjusting sleeve 6 moves axially on the guide sleeve 1, it will drive one end of the two adjusting rods 23 pivotally connected to it to move synchronously and swing around the second pivot 62. The two adjusting rods 23 and the end of the telescopic rod 22 pivotally connected to it will push the telescopic rod 22 to swing around the third pivot 63, thereby pushing the telescopic rod 22 to move axially on the intermediate rod 21, changing the position of the telescopic rod 22 on the intermediate rod 21, and finally realizing the overall length adjustment of the prepositioning rod 2. When the adjusting sleeve 6 moves towards the prepositioning rod 2 on the guide sleeve 1, both adjusting rods 23 push the telescopic rod 22 to move synchronously away from the guide sleeve 1 in the axial direction of the intermediate rod 21. Conversely, when the adjusting sleeve 6 moves away from the prepositioning rod 2 on the guide sleeve 1, both adjusting rods 23 push the telescopic rod 22 to move synchronously towards the guide sleeve 1 in the axial direction of the intermediate rod 21. That is, by adjusting the axial position of the adjusting sleeve 6 on the guide sleeve 1, the synchronous adjustment of the two telescopic rods 22 in the axial position of the intermediate rod 21 can be achieved, ensuring that the center lines of the positioning strips 20 at both ends of the prepositioning rod 2 are always equidistant from the center line of the guide shaft 3, simplifying the length adjustment process of the prepositioning rod 2, saving manpower, and ensuring the adjustment accuracy of the telescopic rod 22.

[0026] The inner wall of the adjusting sleeve 6 and the outer wall of the guide sleeve 1 can be directly axially slidably fitted, or ball bearings, rollers, etc., can be installed between them to achieve relative axial movement between the adjusting sleeve 6 and the guide sleeve 1. A simple axial sliding fit is preferred, i.e., a clearance fit between the inner hole of the adjusting sleeve 6 and the guide sleeve 1. In this case, the inner contour of the cross-section of the adjusting sleeve 6 and the outer contour of the cross-section of the guide sleeve 1 have the same shape. The shapes of the inner contour of the cross-section of the adjusting sleeve 6 and the outer contour of the cross-section of the guide sleeve 1 can be circular, elliptical, or rectangular polygonal structures. Preferably, the inner contour of the cross-section of the adjusting sleeve 6 and the outer contour of the cross-section of the guide sleeve 1 are both rectangular structures with adjacent side lengths of different values. This structure is simple, easy to manufacture and assemble, and avoids coaxial rotation of the adjusting sleeve 6 and the guide sleeve 1, which would affect the adjustment accuracy.

[0027] The second pivot 62 can be connected to the adjusting sleeve 6 by welding or bolting, and the third pivot 63 can be connected to the telescopic rod 22 by welding or bolting. To prevent the adjusting rod 23 from detaching from the second pivot 62 and the third pivot 63, specifically, both the end of the second pivot 62 away from the feed shaft 3 and the end of the third pivot 63 away from the intermediate rod 21 are provided with axial limiting portions 621. The end of the adjusting rod 23 connected to the adjusting sleeve 6 is located between the axial limiting portion 621 and the adjusting sleeve 6, and the end of the adjusting rod 23 connected to the telescopic rod 22 is located between the axial limiting portion 621 and the telescopic rod 22. The axial limiting portion 621 can be a nut threaded onto the second pivot 62 and the third pivot 63, or a cotter pin inserted into the second pivot 62 and the third pivot 63.

[0028] like Figure 9 As shown, more specifically, the second pivot 62 and the third pivot 63 are bolt structures, with the head of the bolt structure being the axial limiting part 621; the rod portion of the bolt structure includes a smooth shaft section 622 and a threaded section 623, with the smooth shaft section 622 located between the threaded section 623 and the head of the bolt structure; the threaded section 623 of the second pivot 62 is threadedly connected to the adjusting sleeve 6, and the threaded section 623 of the third pivot 63 is threadedly connected to the telescopic rod 22, with the adjusting rod 23 located between the threaded section 623 and the head of the bolt structure. The structure is simple and easy to assemble. The second pivot 62 and the third pivot 63 of the bolt structure can be directly purchased from the market without additional processing, saving costs.

[0029] The positioning strips 20 at both ends of the pre-positioning rod 2 are used to directly abut against the sidewall of the large circular hole 8 and cooperate with the drill bit 91 to achieve radial positioning of the drill bit 91 on the large circular hole 8. The positioning strip 20 can be a protruding ridge structure integrally formed with the pre-positioning rod 2, or it can be a rod structure fixed to the pre-positioning rod 2 by welding or bolt connection. The cross-section of the positioning strip 20 at the abutment with the sidewall of the large circular hole 8 can be a sharp angle structure or an arc-shaped surface structure. Preferably, both ends of the positioning strip 20 protrude from the pre-positioning rod 2; the positioning strip 20 has an arc-shaped surface structure that transitions from the side away from the end face of the pre-positioning rod 2 to the side away from the end face of the guide sleeve 1. During drilling, the surface of the positioning strip 20 that abuts against the large circular hole 8 is an arc surface, which avoids the sharp angle protrusions on the positioning strip 20 scratching the sidewall of the large circular hole 8 during drilling, thus improving the workpiece processing quality. As a further preferred option, the cross-section of the positioning strip 20 is a fan-shaped structure or a circular structure, which is easy to process.

[0030] The feed shaft 3 is used to assemble the pneumatic drill 9 and drive the drill bit 91 of the pneumatic drill 9 to feed synchronously. The feed shaft 3 and the guide sleeve 1 can be directly slidably connected, or rollers or balls can be provided between them, with both being axially relative to each other through rolling connection with the balls. Preferably, the outer contour of the cross-section of the feed shaft 3 and the inner contour of the cross-section of the guide sleeve 1 have the same shape, and the feed shaft 3 and the guide sleeve 1 are axially slidably connected. That is, the feed shaft 3 and the inner cavity of the guide sleeve 1 have a clearance fit, resulting in a simple structure and easy assembly.

[0031] The feed shaft 3 is used to connect to the pneumatic drill 9 and directly drive the drill bit 91 of the pneumatic drill 9 to feed. During use, the feed handle 5 must be moved away from the prepositioning rod 2 at all times to ensure the stability of the entire device when positioned inside the large circular hole 8 and during drilling. Once the feed handle 5 loses its thrust away from the prepositioning rod 2, the feed shaft 3 will retract under the action of external force. Preferably, the feed shaft 3 has ratchet teeth 71 on its sidewall, which are arranged radially from the end away from the prepositioning rod 2 to the end closer to the prepositioning rod 2. Multiple ratchet teeth 71 are provided, evenly distributed along the axial direction of the feed shaft 3. The guide sleeve 1 has a fourth pivot 72 and a stop rod 73 parallel to the feed shaft 3 on its sidewall. The fourth pivot 72 is perpendicular to the feed shaft 3, and the stop rod 73 is pivotally connected to the guide sleeve 1 via the fourth pivot 72. One end of the stop rod 73 has a pawl 74 protruding radially inward along the feed shaft 3, and the other end of the stop rod 73 has an elastic limiting member 75 abutting against the guide sleeve 1. The pawl 74 and the elastic limiting member 75 are located on both sides of the fourth pivot 72. The pawl tip of the pawl 74 engages between two adjacent ratchet teeth 71 on the feed shaft 3. When the feed axis 3 is in feed motion, the ratchet 71 and pawl 74 cooperate to ensure that the feed axis 3 can only move axially away from the pre-positioning rod 2. Even if the feed handle 5 is released or reversed, the pawl 74, under the support of the elastic limiting member 75, applies pressure to the feed axis 3 radially from the outside to the inside, thus reliably engaging the pawl 74 between the two ratchet teeth 71. The feed axis 3 cannot move in the opposite direction, preventing the feed handle 5 from coming loose or being accidentally reversed during drilling operations, which would cause the feed axis 3 to retract and improve the positioning stability and safety of the pneumatic drill 9 during drilling operations. Only after the anti-reverse rod 73 is pulled outwards near the end of the pawl 74, and the pawl 74 is pulled out between the two ratchet teeth 71, can the feed axis 3 be pushed axially towards the pre-positioning rod 2, thus resetting the feed axis 3. At this time, the elastic limiting member 75 is squeezed by the anti-reverse rod 73 and the guide sleeve 1, resulting in elastic compression deformation. A lug is generally welded to the outer wall of the guide sleeve 1, and the fourth pivot 72 passes through the lug to pivotally connect the lug to the anti-reverse rod 73.

[0032] The pawl 74 can protrude from the end face of the guide sleeve 1 away from the pre-positioning rod 2. Preferably, the guide sleeve 1 has a limiting groove 13 communicating with its inner cavity on its side wall. The pawl 74 extends into the inner cavity of the guide sleeve 1 through the limiting groove 13 and engages with the two ratchet teeth 71. During use, the pawl 74 is not exposed, avoiding scratching the operator and improving equipment safety. The elastic limiting element 75 can be an elastic rubber block or a spring. The elastic limiting element 75 can be fixedly connected to the guide sleeve 1 or the anti-reverse rod 73. The elastic limiting element 75 is generally a spring. The guide sleeve 1 has a first spring mounting hole 12 on its outer side wall, and the anti-reverse rod 73 has a second spring mounting hole 731. One end of the spring-structured elastic limiting element 75 is fitted into the first spring mounting hole 12 and abuts against the guide sleeve 1, and the other end of the elastic limiting element 75 is fitted into the second spring mounting hole 731 and abuts against the anti-reverse rod 73.

[0033] The end of the feed shaft 3 furthest from the pre-positioning rod 2 can be connected to the pneumatic drill 9 via other connectors, or it can be directly threaded or bonded to the pneumatic drill 9. Specifically, the feed shaft 3 includes a first shaft segment 31 and a second shaft segment 32 arranged axially adjacent to each other. The first shaft segment 31 is located at the end near the pre-positioning rod 2 and the two are arranged coaxially. The first shaft segment 31 and the second shaft segment 32 are integrally formed. The outer diameter of the first shaft segment 31 is larger than the outer diameter of the second shaft segment 32. A positioning collar 33 is coaxially fixed on the outer side of the end of the first shaft segment 31 near the second shaft segment 32. The outer wall of the second shaft segment 32 is provided with external threads, and the second shaft segment 32 is a full-thread screw structure. The ratchet 71 is provided on the outer wall of the first shaft segment 31. The pneumatic drill 9, which is assembled and connected to the present invention, has a feed threaded hole 92 coaxially arranged on the side away from the drill bit 91. During drilling operations, the second shaft section 32 is located in the feed threaded hole 92 of the pneumatic drill 9 and is threadedly connected to it. The side wall of the pneumatic drill 9 away from the drill bit 91 abuts axially with the positioning collar 33. The first shaft section 31 is located in the guide sleeve 1 and slides axially with it. When the feed shaft 3 is at its limit position close to the prepositioning rod 2, the positioning collar 33 abuts axially with the end face of the guide sleeve 1 away from the prepositioning rod 2 to achieve axial limiting of the feed shaft 3. It should be noted that the thread direction on the second shaft section 32 is the same as the drilling rotation direction of the drill bit 91.

[0034] The first pivot 4 is mainly used to pivot the feed handle 5 and the guide sleeve 1, allowing the feed handle 5 to swing relative to the guide sleeve 1. To ensure the swing amplitude of the feed handle 5, the distance between the connecting rod 51 and the first pivot 4 should be sufficiently large. Specifically, the guide sleeve 1 is provided with a fixing plate 14 that protrudes radially from its outer wall. The fixing plate 14 is provided with a hinge through hole, and the first pivot 4 is located in the hinge through hole. The fixing plate 14 is generally welded to the guide sleeve 1. The first pivot 4 can be a smooth shaft structure or a bolt. To save costs, the first pivot 4 generally adopts a bolt structure, and its screw is provided with an axial limiting component, which can be a cotter pin, nut, etc. The fixing plate 14 and the feed handle 5 are both located between the axial limiting component and the head of the bolt structure first pivot 4.

[0035] The feed handle 5 is mainly used to swing around the first pivot 4 to drive the connecting rod 51 and the feed shaft 3 to reciprocate along their axial direction. The strip-shaped through hole 52 on the feed handle 5 is used to connect with the connecting rod 51 to directly drive the connecting rod 51 to move. When drilling the radial hole 81 on the side wall of the large circular hole 8 using this device, the feed handle 5 can rotate around the axial line of the large circular hole 8 or around the radial line of the large circular hole 8. Considering that the axial depth of the large circular hole 8 on some workpieces is relatively large, if the feed handle 5 rotates around the axial line of the large circular hole 8, the control end of the feed handle 5 will always be located inside the large circular hole 8 and its length will be limited, which is inconvenient for operation. Preferably, the first pivot 4 is parallel to the prepositioning rod 2. When drilling radial holes 81 using this structure, the first pivot 4 is arranged radially along the large circular hole 8. At this time, the control end of the feed handle 5 extends outward along the axis of the large circular hole 8 to facilitate feed control. If necessary, a sleeve can be fitted onto the control end of the feed handle 5 to make it cooperate with the connecting rod 51 to form a lever structure, so that the connecting rod 51 and the feed shaft 3 can be driven to move axially with less force.

[0036] The connecting rod 51 is used to drive the feed shaft 3 to reciprocate axially under the drive of the feed handle 5. The cross-section of the connecting rod 51 can be a polygonal structure such as a circle, ellipse, or rectangle. Considering that the feed handle 5 needs to rotate relative to the connecting rod 51 during the movement, the connecting rod 51 is preferably a round rod structure. The connecting rod 51 and the feed shaft 3 can be plugged in, welded, or connected by bolts or threads. Preferably, the cross-section of the connecting rod 51 is a circular structure; a connecting hole 34 is provided on the outer wall of the first shaft segment 31, one end of the connecting rod 51 is inserted into the connecting hole 34 with clearance fit, and a limiting nut 53 is threadedly fitted on the outer side of the other end of the connecting rod 51; the feed handle 5 is located between the limiting nut 53 and the guide sleeve 1, and the space between them is clearance fited axially in the direction of the connecting rod 51.

[0037] As a further preferred embodiment, a limiting ring plate 511 is fixedly provided on the outer wall of the connecting rod 51. A compression spring 54 is sleeved on the outside of the connecting rod 51 between the limiting ring plate 511 and the feed handle 5. The two ends of the compression spring 54 abut against the limiting ring plate 511 and the feed handle 5, respectively. The limiting ring plate 511 is located between the feed shaft 3 and the connecting rod 51. The compression spring 54 is always in a compressed state, thus it always applies pressure to the limiting ring plate 511 and the entire connecting rod 51 along its axial direction toward the feed shaft 3, thereby ensuring that the connecting rod 51 is stably inserted into the connecting hole 34. The limiting ring plate 511 and the end of the connecting rod 51 inserted into the connecting hole 34 are arranged at intervals.

[0038] As a further preferred embodiment, the first shaft segment 31 is provided with a plurality of connecting holes 34, which are evenly distributed along the axial direction of the feed shaft 3. When machining radial holes 81 on the sidewalls of large circular holes 8 of different diameters, the length of the feed shaft 3 extending out of the guide sleeve 1 can be adjusted by adjusting the position of the connecting rod 51 on the feed shaft 3, thereby realizing the adjustment of the entire device in the axial direction of the feed shaft 3. When adjusting the axial position of the connecting rod 51 on the feed shaft 3, the connecting rod 51 is first pulled out of the original connecting hole 34 and held. At this time, the compression spring 54 is further compressed and a greater force is applied to the limiting ring plate 511 and the entire connecting rod 51 in the axial direction closer to the feed shaft 3. Then, the feed shaft 3 is adjusted to a suitable length extending out of the guide sleeve 1 and the connecting rod 51 is aligned with the new connecting hole 34. Finally, the connecting rod 51 is released, the compression spring 54 automatically resets and pushes the connecting rod 51 into the new connecting hole 34. The compression spring 54 in this structure also makes it easier and faster to adjust the axial position of the connecting rod 51 on the feed shaft 3.

[0039] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An auxiliary device for radial drilling of the sidewall of a circular hole, characterized in that, Includes a guide sleeve (1) and a prepositioning rod (2) vertically connected to one end of the guide sleeve (1). The guide sleeve (1) is provided with a feed shaft (3) that can reciprocate linearly along its axial direction. The prepositioning rod (2) is symmetrically provided with positioning strips (20) at both ends. The positioning strips (20) are perpendicular to the prepositioning rod (2) and the feed shaft (3). The center line of the feed shaft (3) is equidistant from the positioning strips (20) on both sides. The guide sleeve (1) has a first guide groove (11) arranged along its axial direction on its outer side wall. The first guide groove (11) is connected to the inner cavity of the guide sleeve (1). The first guide groove (11) is provided with a connecting rod (51) that can reciprocate linearly along its length direction. The connecting rod (51) and the feed shaft (3) are synchronously connected in the axial direction of the feed shaft (3). It also includes a first pivot (4) and a feed handle (5). The first pivot (4) is perpendicular to the axis of the feed shaft (3). One end of the feed handle (5) is pivotally connected to the guide sleeve (1) through the first pivot (4), and the other end of the feed handle (5) protrudes from the outer side wall of the guide sleeve (1). The feed handle (5) is provided with a strip-shaped through hole (52) that extends along the depth direction of the first guide groove (11). The connecting rod (51) is located in the strip-shaped through hole (52) and can move back and forth linearly along the length direction of the strip-shaped through hole (52).

2. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 1, characterized in that, The prepositioning rod (2) includes an intermediate rod (21) vertically fixedly connected to one end of the guide sleeve (1). The two ends of the intermediate rod (21) are connected to telescopic rods (22) whose axial positions are adjustable. The axes of the intermediate rod (21) and the telescopic rod (22) are parallel to each other. The positioning strip (20) is provided at the end of the telescopic rod (22) away from the intermediate rod (21). It also includes a fastening positioning part for fastening the intermediate rod (21) and the telescopic rod (22) together.

3. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 2, characterized in that, The telescopic rod (22) is provided with an axially penetrating guide hole, and the intermediate rod (21) is inserted into the guide hole and slides axially with the telescopic rod (22).

4. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 3, characterized in that, The fastening positioning part includes an adjusting rod (23), an adjusting sleeve (6) sleeved on the outside of the guide sleeve (1) and capable of reciprocating along its axial direction, and a fastening bolt (61) threaded onto the adjusting sleeve (6). The fastening bolt (61) passes through the adjusting sleeve (6) radially along the guide sleeve (1) and is fastened to the outer wall of the guide sleeve (1). There are two adjusting rods (23), and the two adjusting rods (23) are symmetrically distributed about the perpendicular bisecting plane of the prepositioning rod (2). The adjusting sleeve (6) is provided with a second pivot (62) that is perpendicular to both the prepositioning rod (2) and the feed shaft (3), and the telescopic rod (22) is provided with a third pivot (63) that is parallel to the second pivot (62); one end of the adjusting rod (23) is pivotally connected to the adjusting sleeve (6) through the second pivot (62), and the other end of the adjusting rod (23) is pivotally connected to the telescopic rod (22) through the third pivot (63).

5. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 4, characterized in that, The second pivot (62) is provided with an axial limiting part (621) at one end away from the feed shaft (3) and the third pivot (63) is provided with an axial limiting part (621) at one end away from the intermediate rod (21). The end of the adjusting rod (23) connected to the adjusting sleeve (6) is located between the axial limiting part (621) and the adjusting sleeve (6). The end of the adjusting rod (23) connected to the telescopic rod (22) is located between the axial limiting part (621) and the telescopic rod (22).

6. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 1, characterized in that, Both ends of the positioning strip (20) protrude from the prepositioning rod (2); the positioning strip (20) is provided with an arc surface structure that transitions from the side away from the end face of the prepositioning rod (2) to the side away from the end face of the guide sleeve (1).

7. The radial drilling auxiliary device for the sidewall of a circular hole according to any one of claims 1-6, characterized in that, The feed shaft (3) has ratchet teeth (71) on its side wall. The ratchet teeth (71) are arranged outwardly from the end away from the prepositioning rod (2) to the end close to the prepositioning rod (2) along the radial direction of the feed shaft (3). There are multiple ratchet teeth (71), and the multiple ratchet teeth (71) are evenly distributed along the axial direction of the feed shaft (3). The guide sleeve (1) has a fourth pivot (72) and a stop rod (73) parallel to the feed shaft (3) on its side wall. The fourth pivot (72) is perpendicular to the feed shaft (3), and the stop rod (73) is pivotally connected to the guide sleeve (1) through the fourth pivot (72). One end of the anti-reverse rod (73) is provided with a pawl (74) that protrudes radially inward along the feed shaft (3), and the other end of the anti-reverse rod (73) is provided with an elastic limiting member (75) that abuts against the guide sleeve (1). The pawl (74) and the elastic limiting member (75) are located on both sides of the fourth pivot (72). The pawl tip of the pawl (74) is engaged between two adjacent ratchet teeth (71) on the feed shaft (3).

8. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 7, characterized in that, The feed shaft (3) includes a first shaft segment (31) and a second shaft segment (32) arranged axially adjacent to each other. The first shaft segment (31) is located at one end close to the prepositioning rod (2) and the two are arranged coaxially. The first shaft segment (31) and the second shaft segment (32) are integrally formed. The outer diameter of the first shaft segment (31) is larger than the outer diameter of the second shaft segment (32), and a positioning collar (33) is coaxially fixed on the outer side of the first shaft segment (31) near the second shaft segment (32). The second shaft segment (32) has an external thread on its outer side wall, and the second shaft segment (32) is a full-tooth screw structure; the ratchet (71) is provided on the outer side wall of the first shaft segment (31).

9. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 8, characterized in that, The first pivot (4) is parallel to the prepositioning rod (2); the cross-section of the connecting rod (51) is circular; a connecting hole (34) is provided on the outer wall of the first shaft segment (31), one end of the connecting rod (51) is inserted into the connecting hole (34) with clearance fit, and a limiting nut (53) is threadedly connected to the other end of the connecting rod (51); the feed handle (5) is located between the limiting nut (53) and the guide sleeve (1); A limiting ring plate (511) is fixedly provided on the outer wall of the connecting rod (51). A compression spring (54) is provided between the limiting ring plate (511) and the feed handle (5) and sleeved on the outside of the connecting rod (51). The two ends of the compression spring (54) abut against the limiting ring plate (511) and the feed handle (5) respectively.

10. The radial drilling auxiliary device for the sidewall of a circular hole according to claim 9, characterized in that, The first shaft segment (31) is provided with a plurality of connecting holes (34), and the plurality of connecting holes (34) are evenly distributed along the axial direction of the feed shaft (3).

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