A positioning tool for machining a U-drill

Abstract

The application relates to the field of five-axis machine tool positioning tooling, in particular to a positioning tooling for machining a U drill, which comprises a mandrel, one end of the mandrel is used for being connected with a five-axis numerical control machine tool, the other end of the mandrel is provided with a positioning mechanism, the positioning mechanism comprises a clamping assembly and a supporting assembly, an installation groove is arranged at the end of the mandrel, the axis of the installation groove and the axis of the mandrel are located on the same line, the clamping assembly is installed in the installation groove of the mandrel, and the clamping assembly is used for clamping the end of an elongated shaft part; the supporting assembly is installed at the end of the mandrel, and the supporting assembly is used for clamping the machining end of the elongated shaft.

Description

Technical Field

[0001] This application relates to the field of positioning fixtures for five-axis machine tools, and in particular to a positioning fixture for machining U-drills. Background Technology

[0002] Five-axis CNC machine tools are high-tech, high-precision machine tools specifically designed for machining complex curved surfaces. When manufacturing U-drills, due to the high precision requirements, their ends typically need to be machined into curved surfaces. Therefore, U-drills are usually machined using a five-axis CNC machine tool. One end of the U-drill is inserted into a mandrel on the machine tool's worktable, and a fixture at the mandrel clamps the end of the U-drill. This allows the five-axis machine tool to drive the mandrel to rotate, thereby rotating the U-drill and facilitating the machining of its end with the cutting tool.

[0003] However, during the end machining of a U-drill on a five-axis CNC machine tool, since the U-drill is a slender shaft-like part, and one end of the U-drill is clamped by the fixture on the machine tool, when the tool is milling or turning the other end of the U-drill, the U-drill is prone to deformation due to the lack of support points at the machining end of shaft-like parts such as the U-drill, or vibration during rotation, which will affect the machining effect of the U-drill.

[0004] In traditional machine tools, the machining of slender shaft parts can be aided by installing a center rest or follow post to clamp the machining end of the slender shaft, thereby reducing vibration and deformation of slender shaft parts such as U-drills during machining. However, auxiliary fixtures such as center rests and follow posts usually occupy a large space, while the machining area of ​​a five-axis CNC machine tool is limited, making it impossible to install space-consuming auxiliary fixtures. This can easily lead to poor machining results for shaft parts such as U-drills. Summary of the Invention

[0005] In order to improve the machining effect of U-shaped parts such as drills, this application provides a positioning fixture for machining U-shaped drills.

[0006] This application provides a positioning fixture for machining U-drills, employing the following technical solution:

[0007] A positioning fixture for machining U-drills includes a mandrel. One end of the mandrel is connected to a five-axis CNC machine tool, and the other end of the mandrel is provided with a positioning mechanism. The positioning mechanism includes a clamping component and a supporting component. An installation groove is formed at the end of the mandrel, and the axis of the installation groove is on the same straight line as the axis of the mandrel. The clamping component is installed in the installation groove of the mandrel and is used to clamp the end of a slender shaft part. The supporting component is installed at the end of the mandrel and is used to clamp the machining end of the slender shaft.

[0008] By adopting the above technical solution, the mandrel is mounted on a five-axis CNC machine tool, and a positioning mechanism is set at the end of the mandrel. The clamping component in the positioning mechanism clamps the end of the U-drill, while the support component at the end of the mandrel clamps the side wall of the machining end of the U-drill. This provides support for the machining end of the U-drill, thereby reducing vibration or deformation during machining. Furthermore, because the support component is located at the end of the mandrel, it can move with the mandrel, maintaining the stability of slender shaft parts such as U-drills during machining without requiring additional space on the five-axis CNC machine tool, thus facilitating improved machining results for U-drills and similar shaft parts.

[0009] In one specific implementation, the clamping assembly includes a chuck, a connector, and a piston rod. An oil reservoir is formed on the bottom wall of the mounting groove at the end of the mandrel. A cylinder cover is installed inside the mandrel between the oil reservoir and the mounting groove, separating the oil reservoir and the mounting groove. The piston rod is slidably installed in the oil reservoir along the axial direction of the mandrel, with its peripheral sidewall fitting against the inner wall of the oil reservoir, dividing the oil reservoir into two chambers. The connector is slidably installed in the mounting groove along the axial direction of the mandrel and connected to the piston rod. The chuck is also slidably installed in the mounting groove along the axial direction of the mandrel, with one end extending out of the mounting groove and the other end connected to the end of the connector away from the piston rod. The chuck is used to clamp the end of shaft-like parts. An oil passage communicating with the oil reservoir is formed on the inner wall of the mandrel. The oil passage is connected to an external oil supply source and is used to inject oil into the oil reservoir and drive the piston rod to move.

[0010] By employing the above technical solution, oil is injected into the oil reservoir from an external oil source to the side away from the cylinder head. This pushes the piston rod towards the cylinder head, causing the piston rod to move the connecting piece away from the cylinder head. This, in turn, moves the chuck away from the cylinder head, facilitating the release of the U-drill's end and enabling its disassembly. When clamping the U-drill's end is required, oil is injected into the oil reservoir from an external oil source to the side near the cylinder head. This pushes the piston rod away from the cylinder head, causing it to move the chuck towards the cylinder head via the connecting piece, thus clamping the U-drill's end and facilitating its machining.

[0011] In one specific implementation, the connector includes a connecting sleeve, a guide rod is fixedly installed at one end of the piston rod near the cylinder head, the guide rod passes through the side wall of the cylinder head and extends into the mounting groove, the connecting sleeve is slidably installed in the mounting groove along the axial direction of the mounting groove, and one end of the connecting sleeve is connected to the end of the guide rod located in the mounting groove, and the other end of the connecting sleeve is connected to the clamp.

[0012] By adopting the above technical solution, when the piston rod moves in the oil reservoir, the piston rod drives the connecting sleeve to move through the guide rod, thereby causing the connecting sleeve to drive the chuck to move, thus facilitating the clamping or releasing of the end of the U-drill.

[0013] In one specific implementation, the inner wall of the mounting groove on the mandrel away from the oil reservoir is provided with a pressing slope. The pressing slope extends from the end of the mandrel toward the oil reservoir. The inner diameter of the mounting groove at the end of the pressing slope near the oil reservoir is smaller than the inner diameter of the mounting groove at the end of the pressing slope away from the oil reservoir. The side wall of the outer ring of the chuck is provided with an abutting slope corresponding to the pressing slope. The abutting slope is used to abut the pressing slope.

[0014] By adopting the above technical solution, when the connecting sleeve moves towards the cylinder head under the drive of the piston rod, the connecting sleeve drives the chuck to move towards the cylinder head, so that the contact slope on the chuck contacts the compression slope, thereby causing the chuck to undergo elastic deformation, thereby clamping the end of the U-drill, thus facilitating the fixing of the U-drill on the mandrel for processing.

[0015] In one specific implementation, the support assembly includes a support base and support cylinders. The support base is installed on one side of the mandrel end located in the mounting groove, with one end of the support base extending away from the mounting groove. The support cylinders are all installed on the end of the support base away from the mandrel, and the support cylinders are used to clamp the sidewall at the machined end of the shaft part.

[0016] By adopting the above technical solution, after the end of the U-drill is clamped by the chuck, the side wall at the machining end of the U-drill is clamped by the support cylinder, so that the machining end of the U-drill is supported, thereby making it easier for the U-drill to remain stable during the machining process, so as to improve the machining effect of the U-drill.

[0017] In one specific implementation scheme, the support assembly includes a connecting plate, a support shell, an end cap, a sliding sleeve, and a clamping sleeve. The connecting plate is coaxially mounted on the end of the mandrel with a mounting groove, and the connecting plate is used for inserting shaft-like parts. The end cap is mounted on the end of the connecting plate away from the mandrel. The support shell is mounted on the end of the end cap away from the connecting plate. A support hole for shaft-like parts to pass through is formed at the axial center of the support shell. An annular groove is formed on the inner wall of the support hole near the end cap. The top wall of the end cap closes the side of the annular groove near the end cap. The sliding sleeve is slidably mounted in the support hole, and the lower end of the sliding sleeve... The sidewall is also slidably connected to the sidewall of the inner ring of the end cap, and the outer sidewall of the sliding sleeve closes the annular groove. A guide plate is installed on the outer sidewall of the sliding sleeve, the guide plate extends into the annular groove, and the peripheral sidewall of the guide plate fits against the inner sidewall of the annular groove away from the sliding sleeve. The clamp is installed at the end of the support shell away from the end cap, and the clamp is used for inserting and clamping shaft parts. The clamp is connected to the sliding sleeve. An air passage communicating with the annular groove is opened on the sidewall of the support shell. The air passage is used to communicate with an external air source, and the external air source introduces compressed air into the annular groove through the air passage, thereby driving the sliding sleeve to slide along the axial direction of the mandrel.

[0018] By adopting the above technical solution, when the end of the U-drill is clamped, the external air source inflates the support shell through the air channel, thereby pushing the guide plate towards the end cover, causing the sliding sleeve to move towards the end cover, and thus the sliding sleeve pulls the clamping sleeve towards the end cover, so that the clamping sleeve can clamp the machining end of the U-drill, thereby supporting the machining end of the U-drill and keeping the U-drill stable during the machining process, thus facilitating the improvement of the machining effect of the U-drill.

[0019] In one specific implementation, a guide ring is installed on the inner wall of the support shell at the end of the support hole away from the end cap, and the guide ring is located between the support shell and the jacket. The inner wall of the inner ring of the guide ring is provided with a guide slope, one end of which extends from one end of the guide ring to the other end. The inner diameter of the guide ring at the end of the guide slope away from the end cap is larger than the inner diameter of the guide ring at the end of the guide slope near the end cap. The end of the jacket near the guide slope is provided with a variable diameter slope corresponding to the guide slope, and the variable diameter slope is used to abut against the guide slope.

[0020] By adopting the above technical solution, when the sliding sleeve pulls the jacket to move towards the end cover, the variable diameter inclined surface on the jacket abuts against the guide inclined surface of the guide ring on the support shell, thereby causing the guide inclined surface to squeeze the variable diameter inclined surface, causing the jacket to undergo elastic deformation, thereby clamping the middle of the U-drill with the jacket to maintain the stability of the U-drill.

[0021] In one specific implementation, a buffer sleeve is also installed on the inner wall of the inner ring of the jacket. The buffer sleeve is made of rubber and is used to cover shaft-like parts.

[0022] By adopting the above technical solution, when the chuck clamps the U-drill, the chuck clamps the U-drill through the buffer sleeve, and the buffer sleeve can protect the side wall of the U-drill to reduce damage to the side wall of the U-drill.

[0023] In one specific implementation scheme, the air passage includes a first air inlet, a first air outlet, a second air inlet, and a second air outlet. One end of the first air inlet is connected to an external air source, and the other end is connected to an annular groove on the side of the guide plate near the end cover. One end of the first air outlet is connected to an annular groove on the side of the guide plate near the end cover, and the other end is connected to an external air source. One end of the second air inlet is connected to an external air source, and the other end is connected to an annular groove on the side of the guide plate away from the end cover. One end of the second air outlet is connected to an annular groove on the side of the guide plate away from the end cover, and the other end is connected to an external air source.

[0024] By adopting the above technical solution, compressed air is supplied from the first air inlet to the side of the guide plate near the end cap within the annular groove via an external air source. Compressed air on the other side of the guide plate is discharged by opening the second air outlet. This allows the compressed air to be used as power to move the guide plate away from the end cap, facilitating the release of the U-drill from the clamp. Conversely, compressed air is supplied from the second air inlet to the side of the guide plate away from the end cap within the annular groove via an external air source. An air outlet is opened to discharge compressed air from the side of the guide plate near the end cap, allowing the guide plate to move towards the end cap. This allows the clamp to hold the U-drill, facilitating its machining.

[0025] In one specific implementation, a sealing ring is provided on the inner wall of the support hole at the annular groove, the sealing ring being used to maintain the sealing between the outer wall of the sliding sleeve and the inner wall of the support hole.

[0026] By adopting the above technical solution, a sealing ring is set on the inner wall of the support hole to maintain the sealing between the outer wall of the sliding sleeve and the inner wall of the support hole, thereby facilitating the maintenance of the sealing within the annular groove.

[0027] In summary, this application includes at least one of the following beneficial effects:

[0028] 1. This application provides a support component on the mandrel, which facilitates clamping and positioning of the side wall at the machining end of the U-drill mounted on the mandrel, thereby supporting the machining end of the U-drill and maintaining its stability during machining, thus improving the machining effect of the U-drill.

[0029] 2. This application delivers compressed air into the annular groove of the support shell, thereby facilitating the sliding of the guide plate within the annular groove via compressed air. This facilitates the movement of the sliding sleeve via the guide plate, which in turn facilitates the movement of the clamping sleeve, thereby achieving the clamping or loosening of the U-drill. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the positioning fixture used in this application for machining U-drills.

[0031] Figure 2 This is a schematic diagram of the clamping component in Embodiment 1 of this application.

[0032] Figure 3 This is an exploded view of the clamping component in Embodiment 1 of this application.

[0033] Figure 4 This is a schematic diagram of the arrangement of the second oil inlet and the second oil outlet in Embodiment 1 of this application.

[0034] Figure 5 This is a schematic diagram of the arrangement of the first oil inlet and the first oil outlet in Embodiment 1 of this application.

[0035] Figure 6 This is a schematic diagram of the support component in Embodiment 2 of this application.

[0036] Figure 7 This is an exploded view of the support component in Embodiment 2 of this application.

[0037] Figure 8 This is a schematic diagram of the installation of the support component in Embodiment 2 of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Mandrel; 11. Mounting groove; 12. Oil reservoir; 13. Connecting groove; 14. First oil inlet channel; 15. First oil outlet channel; 16. Second oil inlet channel; 17. Second oil outlet channel; 18. Extrusion slope; 2. Positioning mechanism; 21. Clamping assembly; 211. Chuck; 2111. Abutting slope; 212. Piston rod; 213. Guide rod; 214. Connecting sleeve; 2141. Snap ring; 215. Cylinder cover; 22. Support assembly; 221. Support 222. Support cylinder; 223. Connecting plate; 224. Support shell; 2241. Support hole; 2242. Annular groove; 2243. First air passage; 2244. Second air passage; 2245. Guide ring; 2246. Guide slope; 225. End cap; 226. Sliding sleeve; 2261. Guide plate; 2262. Limiting ring; 227. Jacket; 2271. Connecting ring; 2272. Variable diameter slope; 228. Buffer sleeve; 3. U-drill. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the accompanying drawings.

[0041] Example 1:

[0042] This application discloses a positioning fixture for machining U-drills, referring to... Figure 1 and Figure 2 The device includes a spindle 1, one end of which is connected to the C-axis of a five-axis machine tool. A positioning mechanism 2 is installed at the end of the spindle 1 away from the machine tool. The positioning mechanism 2 includes a clamping component 21 and a supporting component 22. A mounting groove 11 is provided at the end of the spindle 1 away from the machine tool. The axis of the mounting groove 11 is on the same straight line as the axis of the spindle 1. The clamping component 21 is installed in the mounting groove 11, and the supporting component 22 is installed at the end of the spindle 1 where the clamping component 21 is installed.

[0043] Reference Figure 1 and Figure 2 One end of the U-drill 3 is clamped by the clamping component 21 in the mounting groove 11, and then the side wall at the processing end of the U-drill 3 is clamped by the supporting component 22, so that the U-drill 3 remains stable during processing and reduces vibration and deformation.

[0044] Reference Figure 2 and Figure 3The clamping assembly 21 includes a chuck 211, a connector, and a piston rod 212. An oil reservoir 12 is formed on the bottom wall of the mounting groove 11 at the end of the spindle 1. The oil reservoir 12 is arranged along the axis of the spindle 1. A cylinder cover 215 is fixedly installed on the inner wall of the spindle 1 between the oil reservoir 12 and the mounting groove 11, blocking the oil reservoir 12 from the mounting groove 11. The oil reservoir 12 is used to store oil. The piston rod 212 is slidably installed in the oil reservoir 12 along its axial direction, and the peripheral sidewall of the piston rod 212 is in contact with the inner sidewall of the oil reservoir 12. An O-shaped fitting is installed on the peripheral sidewall of the piston rod 212. An O-ring (not shown in the figure) is used to maintain a seal between the peripheral sidewall of the piston rod 212 and the inner sidewall of the oil reservoir 12. The piston rod 212 divides the oil reservoir 12 into two chambers. The chamber on the side of the oil reservoir 12 away from the cylinder head 215 is the push chamber, and the chamber on the other side of the oil reservoir 12 is the reset chamber. A guide rod 213 is fixedly installed at one end of the piston rod 212 near the cylinder head 215. The guide rod 213 is arranged along the axis of the spindle 1, and one end of the guide rod 213 passes through the sidewall of the cylinder head 215 and extends into the mounting groove 11.

[0045] Reference Figure 2 and Figure 3 The connector includes a connecting sleeve 214, which is slidably installed in the mounting groove 11 along the axial direction of the mounting groove 11. One end of the connecting sleeve 214 is fixedly connected to the end of the guide rod 213 located in the mounting groove 11. The other end of the connecting sleeve 214 has an opening for the U-drill 3 to be inserted. A retaining ring 2141 is also fixedly provided on the peripheral side wall of the end of the connecting sleeve 214 away from the guide rod 213. The retaining ring 2141 is integrally formed with the connecting sleeve 214, and the diameter of the retaining ring 2141 is larger than the diameter of the connecting sleeve 214. A limiting groove for the retaining ring 2141 to slide is provided on the inner wall of the mounting groove 11. The chuck 211 is slidably installed in the mounting groove 11 along the axial direction of the mandrel 1. One end of the chuck 211 extends out of the mounting groove 11, and the other end is engaged with the retaining ring 2141. The chuck 211 is elastic.

[0046] Reference Figure 2 and Figure 3 An extrusion slope 18 is provided on the inner wall of the mounting groove 11 on the mandrel 1 at the end away from the oil reservoir 12. One end of the extrusion slope 18 is located at the end of the mandrel 1, and the other end extends into the mounting groove 11 at an incline. The inner diameter of the mounting groove 11 at the end of the extrusion slope 18 away from the oil reservoir 12 is larger than the inner diameter of the mounting groove 11 at the end of the extrusion slope 18 close to the oil reservoir 12. The collet 211 has a contact slope 2111 on the outer wall of the end of the mandrel 1 away from the oil reservoir 12, which is in contact with the extrusion slope 18.

[0047] Reference Figure 4 and Figure 5 The mandrel 1 has a connecting groove 13 at the end away from the mounting groove 11. The connecting groove 13 is used to place the pipeline, and the inner wall of the connecting groove 13 has an oil passage for supplying oil to the oil storage tank 12. The oil passage includes a first oil inlet 14, a first oil outlet 15, a second oil inlet 16, and a second oil outlet 17. One end of the first oil inlet 14 is connected to the connecting groove 13, and the other end extends along the inner wall of the mandrel 1 to the oil storage tank 12 and is connected to the pushing chamber in the oil storage tank 12. One end of the first oil outlet 15 is connected to the connecting groove 13, and the other end also extends along the inner wall of the mandrel 1 to the oil storage tank 12 and is connected to the pushing chamber in the oil outlet 15. One end of the second oil inlet channel 16 is connected to the connecting groove 13, and the other end extends along the inner wall of the mandrel 1 to the oil storage tank 12, and communicates with the reset chamber in the oil storage tank 12. One end of the second oil outlet channel 17 is connected to the connecting groove 13, and the other end also extends along the inner wall of the mandrel 1 to the oil storage tank 12, and communicates with the reset chamber in the oil storage tank 12. The first oil inlet channel 14, the first oil outlet channel 15, the second oil inlet channel 16, and the second oil outlet channel 17 located in the connecting groove 13 are all connected to an external oil supply source (not shown in the figure) through pipes (not shown in the figure). The external oil supply source is equipped with components for storing oil, components for controlling the opening and closing of the oil circuit, and components for driving the oil to be transported in the oil circuit. These are all prior art in the field and will not be described in detail here.

[0048] Reference Figure 3 and Figure 5 When it is necessary to clamp the end of the U-drill 3, oil is injected from the first oil inlet 14 into the push chamber of the oil reservoir 12, thereby increasing the pressure in the push chamber and discharging the oil in the reset chamber through the second oil outlet 17. This pushes the piston rod 212 toward the cylinder head 215, causing the piston rod 212 to move the connecting sleeve 214 away from the cylinder head 215 via the guide rod 213. This causes the retaining ring 2141 at the end of the connecting sleeve 214 to move the chuck 211 away from the cylinder head 215, thus causing the chuck 211 to open under the action of elastic force. (Refer to...) Figure 3 and Figure 4Then, one end of the U-drill 3 is inserted into the connecting sleeve 214. By injecting oil from the second oil inlet 16 into the reset chamber in the oil reservoir 12, the pressure in the reset chamber is increased, and the oil in the push chamber is discharged through the first oil outlet 15, thereby pushing the piston rod 212 away from the cylinder head 215. This causes the piston rod 212 to pull the connecting sleeve 214 toward the cylinder head 215 via the guide rod 213. This causes the connecting sleeve 214 to drive the spring collet 211 toward the cylinder head 215 via the retaining ring 2141. This causes the contacting inclined surface 2111 at the end of the collet 211 to contact the pressing inclined surface 18, thereby causing the collet 211 to undergo elastic deformation, thus clamping the end of the U-drill 3.

[0049] Reference Figure 1 The support component 22 includes a support base 221 and a support cylinder 222. The support base 221 is fixedly installed at the end of the mandrel 1 and located on one side of the mounting groove 11. One end of the support base 221 extends away from the mandrel 1. The support cylinder 222 is fixedly installed at the end of the support base 221 away from the mandrel 1. The support cylinder 222 is a gripper cylinder, which is existing technology in the field and will not be described in detail here. The support cylinder 222 is used to clamp the middle part of the U-drill 3.

[0050] The working principle of this embodiment is as follows: When the end of the U-drill 3 needs to be machined, the lower end of the mandrel 1 is mounted on a five-axis machine tool. Then, one end of the U-drill 3 is passed through the chuck 211 and inserted into the connecting sleeve 214. The oil circuit is controlled by an external oil supply source to increase the oil in the reset chamber, thereby increasing the pressure in the reset chamber and reducing the pressure in the pushing chamber. This causes the piston plate to move the guide rod 213 away from the mounting groove 11, and the guide rod 213 pulls the connecting sleeve 214 towards the cylinder head 215. This causes the connecting sleeve 214 to move the chuck 211 and the U-drill 3 towards the cylinder head 215, and the chuck 211 clamps the end of the U-drill 3 under the action of the pressing inclined surface 18, thereby limiting the end of the U-drill 3. Then, the side wall of the U-drill 3 is clamped by the supporting cylinder 222 to support the machined end of the U-drill 3, thereby reducing the vibration and deformation of the U-drill 3 during machining.

[0051] When it is necessary to remove the U-drill 3 from the mandrel 1, the U-drill 3 is released by the support cylinder 222, and the oil circuit is switched by the external oil supply source, thereby increasing the pressure of the oil in the pushing chamber and decreasing the pressure of the oil in the reset chamber, thereby pushing the piston rod 212 to move away from the cylinder head 215, thereby pushing the connecting sleeve 214 to move away from the cylinder head 215 through the guide rod 213, thereby causing the connecting sleeve 214 to drive the chuck 211 and the U-drill 3 to move away from the cylinder head 215, so that the contact slope 2111 on the chuck 211 gradually separates from the extrusion slope 18, thereby allowing the chuck 211 to recover its deformation under the action of elastic force, thereby releasing the U-drill 3, thus making it easy to remove the U-drill 3 from the mandrel 1.

[0052] Example 2:

[0053] Reference Figure 6 and Figure 7 The difference between this embodiment and Embodiment 1 is that the support component 22 includes a connecting plate 223, a support shell 224, an end cap 225, a sliding sleeve 226, and a clamping sleeve 227. One end of the connecting plate 223 is fixedly installed on the end of the mandrel 1 where the chuck 211 is installed, and the other end of the connecting plate 223 extends away from the mandrel 1. The connecting plate 223 is coaxially arranged with the mandrel 1, and the interior of the connecting plate 223 is hollow. A hole for the U-drill 3 to pass through is provided at the end of the connecting plate 223. The end cap 225 is fixedly installed on the end of the connecting plate 223 away from the mandrel 1, and a clearance groove for the U-drill 3 to pass through is provided at the axial center of the end cap 225.

[0054] Reference Figure 7 and Figure 8 One end of the support shell 224 is fixedly installed on the end of the connecting plate 223 away from the spindle 1, and the end cap 225 is embedded in the end of the support shell 224 near the connecting plate 223. The other end of the support shell 224 extends away from the end cap 225. The support shell 224 has a support hole 2241 at its axis for the U drill 3 to pass through. An annular groove 2242 is formed on the inner wall of the support hole 2241 near the end cap 225. The end cap 225 closes the side of the annular groove 2242 near the connecting plate 223. The sliding sleeve 226 is slidably installed in the support hole 2241 along the axial direction of the support shell 224. The outer wall of the upper end of the sliding sleeve 226 is in contact with the inner wall of the support hole 2241 of the support shell 224, and the outer wall of the lower end of the sliding sleeve 226 is in contact with the side wall of the clearance groove of the end cover 225. The outer wall of the sliding sleeve 226 closes the side of the annular groove 2242 near the sliding sleeve. Sealing rings (not shown in the figure) are embedded on the inner wall of the support hole 2241 of the support shell 224, above the annular groove 2242, and on the side wall of the clearance groove of the end cover. The sealing rings are also O-rings. The sealing rings abut against the side wall of the sliding sleeve 226. The sealing rings are used to maintain the airtightness of the annular groove 2242.

[0055] Reference Figure 7 and Figure 8 A guide plate 2261 is fixedly installed on the side wall of the sliding sleeve 226 near the annular groove 2242. The guide plate 2261 extends into the annular groove 2242 and slides within the annular groove 2242. The side wall of the guide plate 2261 away from the sliding sleeve 226 is in contact with the inner wall of the annular groove 2242 away from the sliding sleeve 226. The guide plate 2261 divides the annular groove 2242 into two chambers. The chamber located in the annular groove 2242 near the end cap 225 is the relaxation chamber, and the chamber located in the annular groove 2242 on the other side of the guide plate 2261 is the tensioning chamber.

[0056] Reference Figure 8 The inner wall of the support shell 224 is provided with air passages connected to an external air source. These air passages include a first air passage 2243 and a second air passage 2244. One end of the first air passage 2243 is located on the side wall of the support shell 224 and connected to an external reversing valve (not shown in the figure) via a pipe (not shown in the figure). The other end of the first air passage 2243 extends to the annular groove 2242 and communicates with the relaxation chamber within the annular groove 2242. One end of the second air passage 2244 is located on the top wall of the support shell 224 and connected to an external reversing valve (not shown in the figure) via a pipe (not shown in the figure). The first air passage 2243 (not shown) is connected to an external reversing valve (not shown in the figure). The other end of the second air passage 2244 extends downward to the annular groove 2242 and communicates with the tensioning chamber in the annular groove 2242. The reversing valve is also connected to an external air source through a pipe. The gas in the relaxation chamber enters and exits through the first air passage 2243 and is controlled by the reversing valve. The gas in the tensioning chamber enters and exits through the second air passage 2244 and is also controlled by the reversing valve. The specific control principle is the prior art in this field and will not be elaborated here.

[0057] Reference Figure 7 and Figure 8The sleeve 227 is fixedly installed on the inner wall of the inner ring of the slide sleeve 226 along the axial direction of the spindle 1. The sleeve 227 is elastic, and a connecting ring 2271 is fixedly installed on the side wall of the sleeve 227 near the slide sleeve 226. A limiting ring 2262 is fixedly installed on the side wall of the slide sleeve 226 near the connecting ring 2271. The connecting ring 2271 is inserted into the limiting ring 2262. A guide ring 2245 is fixedly provided on the inner wall of the support hole 2241 of the support shell 224 at the end away from the end cap 225. The guide ring 2245 is integrally formed with the support shell 224 and is located between the support shell 224 and the jacket 227. The end of the guide ring 2245 near the end cap 225 is used to limit the end of the sliding sleeve 226 away from the end cap 225. A guide slope 2246 is provided on the inner wall of the inner ring of the guide ring 2245. The guide slope 2246 extends from the guide ring 224. The end of the sleeve 245 away from the end cap 225 extends obliquely to the other end of the guide ring 2245. The inner diameter of the guide ring 2245 at the end of the guide slope 2246 away from the end cap 225 is larger than the inner diameter of the end of the guide ring 2245 at the end of the guide slope 2246 near the end cap 225. A variable diameter slope 2272 corresponding to the guide slope 2246 is fixedly provided on the side wall of the sleeve 227 near the guide ring 2245. The variable diameter slope 2272 is used to abut against the guide slope 2246. Several variable diameter grooves are formed on the side wall of the end of the sleeve 227 away from the end cap 225 along the axial direction of the sleeve 227. The variable diameter grooves are used to allow the end of the sleeve 227 to elastically contract.

[0058] Reference Figure 7 and Figure 8 A buffer sleeve 228 is detachably installed on the inner wall of the inner ring of the jacket 227. The buffer sleeve 228 is made of flexible rubber material and is used to cover the U-drill 3.

[0059] The working principle of this embodiment is as follows: When it is necessary to clamp the U-drill 3, one end of the U-drill 3 is inserted from the end of the support shell 224 into the buffer sleeve 228, and the end of the U-drill 3 is inserted into the clamping assembly 21 at the end of the mandrel 1. The clamping assembly 21 clamps the end of the U-drill 3. Then, an external air source is supplied to the second air passage 2244 through a reversing valve, thereby increasing the pressure in the tension chamber and releasing the gas in the relaxation chamber, thereby pushing the guide plate 2261 toward the end cover 225. The sliding sleeve 226 is slid towards the end cover 225, causing the sliding sleeve 226 to move the connecting ring 2271 through the limiting ring 2262. This causes the clamping sleeve 227 to move towards the end cover 225, so that the variable diameter inclined surface 2272 at the end of the clamping sleeve 227 abuts against the guide inclined surface 2246, thereby squeezing the end of the clamping sleeve 227. This causes the end of the clamping sleeve 227 away from the end cover 225 to compress the buffer sleeve 228 on the U-drill 3, thereby clamping the side wall at the machining end of the U-drill 3 and thus supporting the U-drill 3.

[0060] When it is necessary to disassemble the U-drill 3, the clamping assembly 21 is driven to release the end of the U-drill 3. Then, the external air source delivers compressed gas to the relaxation chamber through the reversing valve and releases the gas in the tension chamber, thereby pushing the guide plate 2261 away from the end cover 225. This drives the sliding sleeve 226 to move away from the end cover 225, so that the sliding sleeve 226 drives the clamp 227 to move away from the end cover 225 through the limiting ring 2262. This causes the variable diameter inclined surface 2272 at the end of the clamp 227 to gradually separate from the guide inclined surface 2246, so that the clamp 227 gradually recovers its deformation, thereby releasing the U-drill 3 and making it easy to remove the U-drill 3 from the mandrel 1.

[0061] The above are preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be included within the scope of protection of this application.

Claims

1. A positioning fixture for machining U-drills, comprising a mandrel (1), one end of which is connected to a five-axis CNC machine tool, characterized in that: The other end of the mandrel (1) is provided with a positioning mechanism (2). The positioning mechanism (2) includes a clamping component (21) and a supporting component (22). The end of the mandrel (1) is provided with a mounting groove (11), and the axis of the mounting groove (11) is on the same straight line as the axis of the mandrel (1). The clamping component (21) is installed in the mounting groove (11) of the mandrel (1), and the clamping component (21) is used to clamp the end of the slender shaft part. The supporting component (22) is installed at the end of the mandrel (1), and the supporting component (22) is used to clamp the machined end of the slender shaft part. The supporting component (22) includes a support base (221) and a supporting cylinder (222). 1) The support base (221) is installed on one side of the mandrel (1) located in the mounting groove (11). One end of the support base (221) extends away from the mounting groove (11). The support cylinders (222) are all installed on the end of the support base (221) away from the mandrel (1). The support cylinders (222) are used to clamp the side wall at the machining end of the shaft part. The support assembly (22) includes a connecting plate (223), a support shell (224), an end cover (225), a sliding sleeve (226), and a clamping sleeve (227). The connecting plate (223) is coaxially installed on the end of the mandrel (1) where the mounting groove (11) is opened. The connecting plate (223) is used for the insertion of shaft parts. The end cover (225) is used to install the connecting plate (223). At the end away from the spindle (1), the support shell (224) is installed on the end of the end cover (225) away from the connecting plate (223). The support shell (224) has a support hole (2241) at its axial center for shaft parts to pass through. The support shell (224) has an annular groove (2242) on the inner wall of the support hole (2241) near the end cover (225). The top wall of the end cover (225) closes the side of the annular groove (2242) near the end cover (225). The sliding sleeve (226) is slidably installed in the support hole (2241), and the outer side wall of the lower end of the sliding sleeve (226) is also slidably connected to the side wall of the inner ring of the end cover (225). The outer side wall of the sliding sleeve (226) closes the annular groove (2241) near the end of the connecting plate (223). 2) Enclosed: A guide plate (2261) is installed on the outer wall of the sliding sleeve (226). The guide plate (2261) extends into the annular groove (2242), and the peripheral sidewall of the guide plate (2261) fits against the inner sidewall of the annular groove (2242) away from the sliding sleeve (226). The clamp (227) is installed at the end of the support shell (224) away from the end cover (225), and the clamp (227) is used for inserting and clamping shaft parts. The clamp (227) is connected to the sliding sleeve (226). An air passage communicating with the annular groove (2242) is opened on the side wall of the support shell (224). The air passage is used to communicate with an external air source, and the external air source introduces compressed air into the annular groove (2242) through the air passage.This drives the sliding sleeve (226) to slide along the axis of the spindle (1). A guide ring (2245) is installed on the inner wall of the support shell (2241) away from the end cap (225), and the guide ring (2245) is located between the support shell (224) and the clamp (227). A guide slope (2246) is provided on the inner wall of the inner ring of the guide ring (2245), and one end of the guide slope (2246) extends from one end of the guide ring (2245) to the guide ring. At the other end of (2245), the inner diameter of the guide ring (2245) located at the end of the guide slope (2246) away from the end cap (225) is larger than the inner diameter of the guide ring (2245) located at the end of the guide slope (2246) near the end cap (225). The end of the sleeve (227) near the guide slope (2246) is provided with a variable diameter slope (2272) corresponding to the guide slope (2246), and the variable diameter slope (2272) is used to abut against the guide slope (2246).

2. The positioning fixture for machining a U-drill according to claim 1, characterized in that: The clamping assembly (21) includes a chuck (211), a connector, and a piston rod (212). An oil reservoir (12) is formed on the bottom wall of the mounting groove (11) at the end of the mandrel (1). A cylinder cover (215) is installed inside the mandrel (1) between the oil reservoir (12) and the mounting groove (11), separating the oil reservoir (12) and the mounting groove (11). The piston rod (212) is slidably mounted in the oil reservoir (12) along the axial direction of the mandrel (1), with its peripheral sidewall fitting against the inner wall of the oil reservoir (12), thus dividing the oil reservoir (12) into two chambers. The connecting member is slidably installed in the mounting groove (11) along the axial direction of the mandrel (1), and the connecting member is connected to the piston rod (212). The chuck (211) is also slidably installed in the mounting groove (11) along the axial direction of the mandrel (1), and one end of the chuck (211) extends out of the mounting groove (11), and the other end is connected to the end of the connecting member away from the piston rod (212). The chuck (211) is used to clamp the end of the shaft part. An oil passage is opened on the inner wall of the mandrel (1) and communicates with the oil storage tank (12). The oil passage is connected to an external oil supply source, and the oil passage is used to inject oil into the oil storage tank (12) and drive the piston rod (212) to move.

3. A positioning fixture for machining a U-drill according to claim 2, characterized in that: The connector includes a connecting sleeve (214). A guide rod (213) is fixedly installed at one end of the piston rod (212) near the cylinder head (215). The guide rod (213) passes through the side wall of the cylinder head (215) and extends into the mounting groove (11). The connecting sleeve (214) is slidably installed in the mounting groove (11) along the axial direction of the mounting groove (11). One end of the connecting sleeve (214) is connected to the end of the guide rod (213) located in the mounting groove (11). The other end of the connecting sleeve (214) is connected to the clamp (211).

4. A positioning fixture for machining a U-drill according to claim 2, characterized in that: The inner wall of the mounting groove (11) on the mandrel (1) away from the oil reservoir (12) is provided with a pressing slope (18). The pressing slope (18) extends from the end of the mandrel (1) toward the oil reservoir (12). The inner diameter of the mounting groove (11) at the end of the pressing slope (18) near the oil reservoir (12) is smaller than the inner diameter of the mounting groove (11) at the end of the pressing slope (18) away from the oil reservoir (12). The side wall of the outer ring of the chuck (211) is provided with a contacting slope (2111) corresponding to the pressing slope (18). The contacting slope (2111) is used to contact the pressing slope (18).

5. A positioning fixture for machining a U-drill according to claim 1, characterized in that: A buffer sleeve (228) is also installed on the inner wall of the inner ring of the jacket (227). The buffer sleeve (228) is made of rubber and is used to cover shaft parts.

6. A positioning fixture for machining a U-drill according to claim 1, characterized in that: The air passage includes a first air inlet, a first air outlet, a second air inlet, and a second air outlet. One end of the first air inlet is connected to an external air source, and the other end is connected to the annular groove (2242) on the side of the guide plate (2261) near the end cover (225). One end of the first air outlet is connected to the annular groove (2242) on the side of the guide plate (2261) near the end cover (225), and the other end is connected to an external air source. One end of the second air inlet is connected to an external air source, and the other end is connected to the annular groove (2242) on the side of the guide plate (2261) away from the end cover (225). One end of the second air outlet is connected to the annular groove (2242) on the side of the guide plate (2261) away from the end cover (225), and the other end is connected to an external air source.

7. A positioning fixture for machining a U-drill according to claim 1, characterized in that: A sealing ring is provided on the inner wall of the support hole (2241) at the annular groove (2242), and the sealing ring is used to maintain the sealing between the outer wall of the sliding sleeve (226) and the inner wall of the support hole (2241).

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