A method for machining throttling holes for small-diameter pipes

Abstract

A method for machining throttling pipe holes for small-diameter pipes is disclosed, relating to the machining of throttling pipe holes for small-diameter pipes in fields such as boilers and chemical engineering. This invention solves the problem of the high difficulty in machining throttling pipe holes. First, a pipe support fixture is used to support and fix the pipe. Then, a highest point positioning fixture is used to determine the highest point of the pipe. Further, a twist drill is used to uniformly machine multiple vertically arranged intermediate through holes along the length of the pipe from front to back. Even further, a split-type machining tool is used to machine two first groove arcs and two second groove arcs on the upper surface of the pipe. Finally, a pipe hole inner wall chamfering tool is used to chamfer the inner wall of the pipe at the connection points between the multiple intermediate through holes and the inner wall of the pipe. This completes the machining of the throttling pipe hole for the small-diameter pipe. This invention is used to machine throttling pipe holes with a fully penetrated weld structure, ensuring the quality of subsequent welding.

Description

Technical Field

[0001] This invention relates to the field of throttling hole processing for small-diameter pipes in boilers, chemical industries, and other fields, and specifically to a method for processing throttling holes for small-diameter pipes. Background Technology

[0002] With the continuous expansion of product types and the improvement of product technical parameters, several projects of our company have adopted throttling pipes with a full penetration structure. The pipe diameter is Φ89×13.5 mm, the length is 2500 mm, and there are 20 throttling pipe holes distributed throughout. The throttling pipe holes have a double groove structure, as shown below. Figure 1 As shown, the central through hole d is Φ8mm, the two grooves have arcs of R2.5 and R5 respectively, and the maximum cutting length is 32.5mm. Due to the small diameter, long length, and poor rigidity of the pipe, vibration occurs during machining, affecting the machining quality; the central through hole d is Φ8mm, resulting in a large cutting force, and the guide post is prone to breakage. Therefore, how to machine the throttling pipe hole becomes a critical process.

[0003] In summary, the main reasons for the high difficulty in machining throttling pipe holes are: the pipe diameter is small and the rigidity is poor, resulting in vibration during machining; it is difficult to align the highest point and the positioning is inaccurate; the diameter of the intermediate through hole is small, resulting in a large amount of cutting during machining and easy breakage of the guide post; and the chamfering of the inner wall of the through hole is difficult due to the small diameter. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of the difficulty in machining throttling pipe holes, and thus provide a method for machining throttling pipe holes for small-diameter pipes.

[0005] The technical solution of this invention is:

[0006] A method for machining throttling orifices for small-diameter pipes, the method being implemented through the following steps:

[0007] Step 1: Fix pipe 5:

[0008] First, install the pipe support fixture 1 on the machine tool worktable; then, install the pipe 5 on the pipe support fixture 1, and use the pipe support fixture 1 to support and fix the pipe 5.

[0009] Step 2: Determine the highest point of pipe 5:

[0010] After the pipe 5 is fixed by the pipe support fixture 1 described in step one, the highest point positioning fixture 2 is placed on the upper part of the pipe 5, and the highest point of the pipe 5 is determined by the highest point positioning fixture 2.

[0011] Step 3: Machining the central through hole of tube 5:

[0012] Install the twist drill on the machine tool tool holder, determine the machining position of the throttling pipe hole according to the highest point of the pipe 5 determined in step two, and use the twist drill to uniformly machine multiple vertically arranged intermediate through holes from front to back along the length of the pipe. The axis of each intermediate through hole is located at the highest point of the pipe 5.

[0013] Step 4: Machining the groove arc of pipe 5:

[0014] The split-type machining tool 3 is installed on the machine tool holder. The split-type machining tool 3 is used to machine two first groove arcs and two second groove arcs on the upper surface of the tube 5. The two first groove arcs are symmetrically arranged on the front and rear sides of the multiple intermediate through holes machined in step three with the axis of the multiple intermediate through holes machined in step three as the center. The two second groove arcs are symmetrically arranged on the front and rear sides of the two first groove arcs with the axis of the multiple intermediate through holes machined in step three as the center.

[0015] Step 5: Chamfer the inner wall of the pipe hole:

[0016] Install the pipe hole inner wall chamfering tool 4 on the electric drill, and use the pipe hole inner wall chamfering tool 4 to chamfer the inner wall of the multiple intermediate through holes processed in step three and the connection between them and the inner wall of the pipe. At this point, the throttling pipe hole processing of the small diameter pipe is completed.

[0017] Furthermore, the pipe support fixture 1 mentioned in step one includes a fixed platform 101, a channel steel 106, and multiple pipe clamping mechanisms. The fixed platform 101 is horizontally set on the machine tool workbench. The upper surface of the fixed platform 101 is provided with a horizontally arranged channel steel 106 along the length direction of the fixed platform. A horizontally arranged pipe 5 is placed at the upper opening of the channel steel 106. Multiple pipe clamping mechanisms are arranged evenly from front to back along the side of the channel steel 106 along the length direction of the fixed platform. The lower end of the pipe clamping mechanism is connected to the fixed platform 101, and the upper end of the pipe clamping mechanism is connected to the pipe 5.

[0018] Furthermore, each pipe clamping mechanism includes a pipe fixing bolt 102, a pipe fixing nut 103, a washer 104, and a support block 105. The upper surface of the fixing platform 101 is sequentially machined with multiple evenly arranged fixing platform connection threaded holes along its length from front to back. The lower end of the pipe fixing bolt 102 connects to the corresponding fixing platform connection threaded hole. The washer 104 is horizontally positioned above the pipe 5. One end of the washer 104 has its lower surface in contact with the upper surface of the pipe 5, and the other end of the washer 104 has a washer connection hole that corresponds to the fixing platform connection threaded hole. The upper end of the pipe fixing bolt 102 passes through the washer connection hole and connects to the pipe fixing nut 103. A support block 105 is provided on the side of the pipe fixing bolt 102 away from the pipe 5. The lower end of the support block 105 contacts the upper surface of the fixing platform 101, and the upper end of the support block 105 contacts the lower surface of the washer 104.

[0019] Furthermore, the highest point positioning fixture 2 mentioned in step two includes a support frame 201, a level 202, and a pointer 203. The support frame 201 has a U-shaped cross-section and is fastened to the upper part of the pipe 5. The level 202 is located above the support frame 201 and is connected to the upper surface of the support frame 201 by magnetic attraction. A vertically arranged pointer mounting hole is machined in the middle of the upper surface of the middle wing plate of the support frame 201. The pointer 203 is vertically inserted into the pointer mounting hole, and the pointer 203 is clearance-fitted with the pointer mounting hole. The lower end of the pointer 203 contacts the upper surface of the pipe 5.

[0020] Furthermore, the split-type machining tool 3 described in step three includes a guide post 301, a guide post fixing screw 303, a tool shank 305, two profile inserts 302, and four insert fixing bolts 304. Two insert mounting slots are machined on the upper and lower sides of the tool shank's head. These two slots are symmetrically arranged on the upper and lower sides of the tool shank's center line. The two profile inserts 302 are respectively installed in the two insert mounting slots. Each profile insert 302 is connected to the tool shank 305 by two insert fixing bolts 304. A guide post removal hole 306 is provided at the center of the front surface of the tool shank 305's head. The guide post disassembly hole 306 penetrates through both ends of the tool bar. A guide post locking groove is provided at the center of the upper surface of the head of the tool bar 305. The guide post locking groove is connected to the guide post disassembly hole 306. Two guide post locking threaded holes are respectively provided on the left and right end faces of the head of the tool bar 305. Both guide post locking threaded holes are perpendicular to the guide post locking groove. The guide post 301 is inserted into the front end of the guide post disassembly hole 306. The guide post fixing screw 303 is screwed into the two guide post locking threaded holes in sequence. The guide post 301 is connected to the tool bar 305 through the guide post fixing screw 303.

[0021] Further, the pipe bore inner wall chamfering tool 4 mentioned in step four includes a tool bar 401, a chamfering blade 402, a spring 403, a spring stop 404, and a stop fixing screw 405. The tool bar 401 is a circular rod-shaped structure, and the outer diameter of the tool bar 401 is smaller than the inner diameter of the middle through hole of the pipe 5. A blade mounting groove is radially opened on the lower side of the tool bar 401, and a blade through hole communicating with the side of the guide rod is opened at the bottom of the blade mounting groove. The chamfering blade 402 has a T-shaped cross-section, and the chamfering blade 402 has a top and bottom... The sides are respectively machined into bevels. The chamfering blade 402 is installed in the blade mounting groove, and the head end of the chamfering blade 402 passes through the blade through hole. The end of the chamfering blade 402 is provided with a spring 403. The end of the spring 403 away from the chamfering blade 402 is provided with a spring stop 404. The side of the spring stop 404 and the tool bar 401 are respectively provided with two stop connection threaded holes. The stop fixing screw 405 is screwed into the two stop connection threaded holes. The spring stop 404 is connected to the tool bar 401 through the stop fixing screw.

[0022] Furthermore, the diameter of the central through hole on the tube 5 described in step three is 8 mm.

[0023] Furthermore, the radius of the first groove arc in step four is 2.5 mm, and the radius of the second groove arc is 5 mm.

[0024] Furthermore, the distance between the two first groove arcs in step four is 30mm, and the distance between the two second groove arcs is 65mm.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The throttling pipe hole processing method described in this invention ensures the processing quality of throttling pipe holes with full penetration structure. Through theoretical analysis and preliminary simulation experiments, a pipe support fixture was designed to improve the overall rigidity of the pipe and ensure processing stability. Simultaneously, a positioning fixture for the highest point of the pipe was designed to ensure the throttling pipe hole is located at the highest point and maintains circumferential accuracy during processing. Furthermore, this invention designs and manufactures a split-type machining tool, adding a guide post removal hole to the tool holder for guide post replacement, reducing production costs. This invention also designs a pipe hole inner wall chamfering tool, enabling chamfering of the inner wall of small-diameter through holes. Through these measures, this invention ensures the processing quality of throttling pipe holes and reduces the production cycle.

[0027] 2. This invention successfully processed a fully penetrated throttling pipe hole, ensuring the quality of subsequent welding and providing a method for processing throttling pipe holes with similar structures. In particular, it provides an idea for processing throttling pipe holes on small-diameter pipes using a drilling machine or boring machine. Attached Figure Description

[0028] Figure 1This is a schematic diagram of the throttling pipe hole of the fully welded structure described in this invention;

[0029] Figure 2 This is a schematic diagram illustrating the machining of the small-diameter pipe throttling orifice described in this invention;

[0030] Figure 3 This is a front view of the pipe support fixture described in this invention;

[0031] Figure 4 This is a side view of the pipe support fixture described in this invention;

[0032] Figure 5 This is a front view of the highest point positioning fixture described in this invention;

[0033] Figure 6 This is a side view of the highest point positioning fixture described in this invention;

[0034] Figure 7 This is a front view of the split-type machining tool described in this invention;

[0035] Figure 8 This is a side view of the pipe hole inner wall chamfering tool described in this invention;

[0036] Figure 9 This is a partial cross-sectional view of the pipe hole inner wall chamfering tool described in this invention.

[0037] In the diagram: 1. Pipe support fixture; 101. Fixed platform; 102. Pipe fixing bolt; 103. Pipe fixing nut; 104. Pad; 105. Support block; 106. Channel steel; 2. Highest point positioning fixture; 201. Support frame; 202. Level; 203. Pointer; 3. Split-type machining tool; 301. Guide post; 302. Profile cutting tool; 303. Guide post fixing screw; 304. Cutting tool fixing bolt; 305. Tool holder; 306. Hole for removing guide post; 4. Pipe hole inner wall chamfering tool; 401. Tool holder; 402. Chamfering cutting tool; 403. Spring; 404. Spring stop block; 405. Stop block fixing screw; 5. Pipe. Detailed Implementation

[0038] Specific implementation method one: Combining Figures 1 to 9 This embodiment describes a method for machining a throttling orifice for small-diameter pipes. The method is implemented through the following steps:

[0039] Step 1: Fix pipe 5:

[0040] First, install the pipe support fixture 1 on the machine tool worktable; then, install the pipe 5 on the pipe support fixture 1, and use the pipe support fixture 1 to support and fix the pipe 5.

[0041] Step 2: Determine the highest point of pipe 5:

[0042] After the pipe 5 is fixed by the pipe support fixture 1 described in step one, the highest point positioning fixture 2 is placed on the upper part of the pipe 5, and the highest point of the pipe 5 is determined by the highest point positioning fixture 2.

[0043] Step 3: Machining the central through hole of tube 5:

[0044] Install the twist drill on the machine tool tool holder, determine the machining position of the throttling pipe hole according to the highest point of the pipe 5 determined in step two, and use the twist drill to uniformly machine multiple vertically arranged intermediate through holes from front to back along the length of the pipe. The axis of each intermediate through hole is located at the highest point of the pipe 5.

[0045] Step 4: Machining the groove arc of pipe 5:

[0046] The split-type machining tool 3 is installed on the machine tool holder. The split-type machining tool 3 is used to machine two first groove arcs and two second groove arcs on the upper surface of the tube 5. The two first groove arcs are symmetrically arranged on the front and rear sides of the multiple intermediate through holes machined in step three with the axis of the multiple intermediate through holes machined in step three as the center. The two second groove arcs are symmetrically arranged on the front and rear sides of the two first groove arcs with the axis of the multiple intermediate through holes machined in step three as the center.

[0047] Step 5: Chamfer the inner wall of the pipe hole:

[0048] Install the pipe hole inner wall chamfering tool 4 on the electric drill, and use the pipe hole inner wall chamfering tool 4 to chamfer the inner wall of the multiple intermediate through holes processed in step three and the connection between them and the inner wall of the pipe. At this point, the throttling pipe hole processing of the small diameter pipe is completed.

[0049] Specific Implementation Method Two: Combining Figures 1 to 4 This embodiment describes a pipe support fixture 1, which includes a fixed platform 101, a channel steel 106, and multiple pipe clamping mechanisms in step one. The fixed platform 101 is horizontally positioned on the machine tool worktable. A horizontally arranged channel steel 106 is positioned on the upper surface of the fixed platform along its length. A horizontally arranged pipe 5 is placed at the upper opening of the channel steel 106. Multiple pipe clamping mechanisms are evenly arranged along the side of the channel steel 106 from front to back along the length of the fixed platform. The lower end of each pipe clamping mechanism is connected to the fixed platform 101, and the upper end is connected to the pipe 5. This configuration secures the pipe 5 to the channel steel 106 using multiple pipe clamping mechanisms, forming a unified structure that increases overall rigidity, resists cutting deformation forces, and is simple and convenient to operate. Other components and connections are the same as in specific embodiment one.

[0050] Specific implementation method three: Combining Figures 1 to 4 This embodiment describes a pipe clamping mechanism comprising a pipe fixing bolt 102, a pipe fixing nut 103, a washer 104, and a support block 105. The upper surface of the fixing platform 101 has multiple evenly arranged fixing platform connecting threaded holes machined sequentially from front to back along its length. The lower end of the pipe fixing bolt 102 connects to the corresponding fixing platform connecting threaded hole. The washer 104 is horizontally positioned above the pipe 5. One lower surface of the washer 104 contacts the upper surface of the pipe 5, and the other upper surface of the washer 104 has a washer connecting hole corresponding to the fixing platform connecting threaded hole. The upper end of the pipe fixing bolt 102 passes through the washer connecting hole and connects to the pipe fixing nut 103. A support block 105 is located on the side of the pipe fixing bolt 102 away from the pipe 5. The lower end of the support block 105 contacts the upper surface of the fixing platform 101, and the upper end of the support block 105 contacts the lower surface of the washer 104. With this configuration, a detachable support block 105 is provided on the other side of the pipe 5. By replacing the support block 105 with one of different heights, it can accommodate pipes 5 with different diameters, ensuring the horizontal accuracy of the pad 104. Finally, the pipe 5 is positioned vertically using the pipe fixing bolts 102 and the pipe fixing nuts 103. Additionally, the horizontal positioning of the pipe 5 is achieved through the two side flanges of the channel steel 106. Other components and connections are the same as in specific embodiments one or two.

[0051] Specific implementation method four: Combination Figure 1 , Figure 2 , Figure 5 and Figure 6 This embodiment describes the highest point positioning fixture 2 described in step two, which includes a support frame 201, a level 202, and a pointer 203. The support frame 201 has a U-shaped cross-section and is fastened to the upper part of the pipe 5. The level 202 is positioned above the support frame 201 and is magnetically connected to the upper surface of the support frame 201. A vertically arranged pointer mounting hole is machined in the center of the upper surface of the middle flange of the support frame 201. The pointer 203 is vertically inserted into the pointer mounting hole with a clearance fit, and its lower end contacts the upper surface of the pipe 5. With this configuration, the level 202 is magnetically attached to the surface of the support frame 201, and the pointer 203 is located in the middle of the support frame 201. During placement, the support frame 201 is adjusted, and when the level 202 is in a horizontal position, the pointer 203 is tapped to determine the highest point of the pipe 5. Other components and connections are the same as in specific embodiments one, two, or three.

[0052] Specific Implementation Method Five: Combining Figure 1 , Figure 2 and Figure 7This embodiment describes a split-type machining tool 3, which includes a guide post 301, a guide post fixing screw 303, a tool shank 305, two profile inserts 302, and four insert fixing bolts 304. The tool shank 305 has two insert mounting slots machined on its upper and lower sides at its head. These slots are symmetrically arranged on the upper and lower sides of the tool shank's center line. The two profile inserts 302 are respectively installed in the two insert mounting slots. Each profile insert 302 is connected to the tool shank 305 by two insert fixing bolts 304. A guide post removal hole is provided at the center of the front surface of the tool shank 305. 306, the guide post disassembly hole 306 penetrates through both ends of the tool holder. A guide post locking groove is formed at the center of the upper surface of the tool holder 305's head, communicating with the guide post disassembly hole 306. Two coaxially arranged guide post locking threaded holes are formed on the left and right end faces of the tool holder 305's head, both perpendicularly communicating with the guide post locking groove. The guide post 301 is inserted into the front end of the guide post disassembly hole 306, and guide post fixing screws 303 are sequentially screwed into the two guide post locking threaded holes. The guide post 301 is connected to the tool holder 305 via the guide post fixing screws 303. With this configuration, a contour insert 302 is designed according to the throttling pipe hole structure for machining the throttling pipe hole. To ensure uniform force during machining, symmetrical contour inserts 302 are designed, and the contour inserts 302 are fixed to the tool holder 305 by insert fixing bolts 304. The guide post 301 is fixed to the tool holder 305 using guide post fixing screws 303. Because the profile insert 302 experiences significant force during machining, and the guide post 301 is relatively thin, it is prone to breakage. Therefore, a guide post removal hole 306 is designed on the tool holder 305. If the guide post 301 breaks, it can be hammered out from one end of the tool holder 305 using a round steel bar. By designing a split machining tool 3 and a guide post removal hole 306, the replaceability of the vulnerable profile insert 302 and guide post 301 is ensured, reducing manufacturing costs. Other components and connections are the same as in specific embodiments one, two, three, or four.

[0053] Specific Implementation Method Six: Combination Figure 1 , Figure 2 , Figure 8 and Figure 9This embodiment describes a chamfering tool 4 for the inner wall of the pipe hole, which includes a tool bar 401, a chamfering blade 402, a spring 403, a spring stop 404, and a stop fixing screw 405. The tool bar 401 is a circular rod-shaped structure, and its outer diameter is smaller than the inner diameter of the central through hole of the pipe 5. A blade mounting groove is radially formed on the lower side of the tool bar 401, and a blade through hole communicating with the side of the guide rod is formed at the bottom of the blade mounting groove. The chamfering blade 402 has a T-shaped cross-section. The top and bottom sides of the first end are machined into bevels. A chamfering insert 402 is installed in the insert mounting groove, with the first end of the chamfering insert 402 passing through the insert through hole. A spring 403 is provided at the end of the chamfering insert 402. A spring stop 404 is provided at the end of the spring 403 away from the chamfering insert 402. Two stop connection threaded holes are respectively opened on the side of the spring stop 404 and the tool holder 401. The stop fixing screw 405 is screwed into the two stop connection threaded holes. The spring stop 404 is connected to the tool holder 401 through the stop fixing screw. With this configuration, a pipe hole inner wall chamfering tool 4 is designed to address the issue of small pipe hole diameters. The pipe hole inner wall chamfering tool 4 is used to process the inner wall of the pipe hole to ensure that the flow rate is not affected. When the chamfering tool 4 enters the pipe hole, the chamfering blade 402 is compressed and retracts directly into the tool holder 401. As it passes through the pipe hole, the chamfering blade 402 is automatically ejected by the pressure of the spring 403 and comes into contact with the inner wall of the pipe hole. The tool holder 401 is mounted on a hand drill; as it rotates, the chamfering blade 402 performs the chamfering. When it exits the pipe hole, it is again subjected to the pressure of the pipe hole, causing the chamfering blade 402 to retract into the tool holder 401 until it exits the pipe hole. Other components and connections are the same as in specific embodiments one, two, three, four, or five.

[0054] Specific implementation method seven: Combining Figure 1 In this embodiment, the diameter of the central through hole on the tube 5 described in step three is 8 mm. Other components and connections are the same as in specific embodiments one, two, three, four, five, or six.

[0055] Specific implementation method eight: Combination Figure 1 In this embodiment, the radius of the first groove arc in step four is 2.5 mm, and the radius of the second groove arc is 5 mm. Other components and connections are the same as in specific embodiments one, two, three, four, five, six, or seven.

[0056] Specific Implementation Method Nine: Combining Figure 1 In this embodiment, the distance between the two first groove arcs in step four is 30mm, and the distance between the two second groove arcs is 65mm. Other components and connections are the same as in specific embodiments one, two, three, four, five, six, seven, or eight.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for machining a throttling orifice for small-diameter pipes, characterized in that: The method is implemented through the following steps: Step 1: Fix the pipe (5): First, the pipe support fixture (1) is installed on the machine tool workbench; then, the pipe (5) is installed on the pipe support fixture (1) and the pipe support fixture (1) is used to support and fix the pipe (5); Step 2: Determine the highest point of pipe (5): After the pipe (5) is fixed by the pipe support fixture (1) described in step one, the highest point positioning fixture (2) is placed on the upper part of the pipe (5) and the highest point of the pipe (5) is determined by the highest point positioning fixture (2). Step 3: Machining the central through hole of pipe (5): Install the twist drill on the machine tool holder, determine the machining position of the throttling hole according to the highest point of the tube (5) determined in step two, and use the twist drill to uniformly machine multiple vertically arranged intermediate through holes from front to back along the length of the tube. The axis of each intermediate through hole is located at the highest point of the tube (5). Step 4: Machining the groove arc of pipe (5): Install the split machining tool (3) on the machine tool holder, and use the split machining tool (3) to machine two first groove arcs and two second groove arcs on the upper surface of the tube (5). The two first groove arcs are symmetrically arranged on the front and rear sides of the multiple intermediate through holes machined in step three with the axis of the multiple intermediate through holes machined in step three as the center. The two second groove arcs are symmetrically arranged on the front and rear sides of the two first groove arcs with the axis of the multiple intermediate through holes machined in step three as the center. The split-type machining tool (3) includes a guide post (301), a guide post fixing screw (303), a tool shank (305), two profile inserts (302), and four insert fixing bolts (304). Two insert mounting slots are machined on the upper and lower sides of the head of the tool shank (305). These two slots are symmetrically arranged on the upper and lower sides of the tool shank's center line. Two profile inserts (302) are respectively installed in the two insert mounting slots. Each profile insert (302) is connected to the tool shank (305) via two insert fixing bolts (304). A guide post removal hole (306) is provided at the center of the front surface of the head of the tool shank (305). The guide post disassembly hole (306) passes through the two ends of the tool bar. The upper surface of the tool bar (305) has a guide post locking groove in the center. The guide post locking groove is connected to the guide post disassembly hole (306). The left and right ends of the tool bar (305) have two coaxially arranged guide post locking threaded holes. The two guide post locking threaded holes are perpendicular to the guide post locking groove. The guide post (301) is inserted into the front end of the guide post disassembly hole (306). The guide post fixing screw (303) is screwed into the two guide post locking threaded holes in sequence. The guide post (301) is connected to the tool bar (305) through the guide post fixing screw (303). Step 5: Chamfer the inner wall of the pipe hole: Install the pipe hole inner wall chamfering tool (4) on the electric drill, and use the pipe hole inner wall chamfering tool (4) to chamfer the inner wall of the pipe hole at the connection between the multiple intermediate through holes processed in step three and the inner wall of the pipe. Thus, the throttling pipe hole processing of the small diameter pipe is completed.

2. The method for processing throttling holes for small-diameter pipes according to claim 1, characterized in that: The pipe support fixture (1) mentioned in step one includes a fixed platform (101), a channel steel (106) and multiple pipe clamping mechanisms. The fixed platform (101) is horizontally set on the machine tool workbench. The upper surface of the fixed platform (101) is provided with a horizontally arranged channel steel (106) along the length direction of the fixed platform. A horizontally arranged pipe (5) is placed at the upper opening of the channel steel (106). Multiple pipe clamping mechanisms are arranged evenly from front to back along the side of the channel steel (106) along the length direction of the fixed platform. The lower end of the pipe clamping mechanism is connected to the fixed platform (101), and the upper end of the pipe clamping mechanism is connected to the pipe (5).

3. The method for processing throttling holes for small-diameter pipes according to claim 2, characterized in that: Each pipe clamping mechanism includes a pipe fixing bolt (102), a pipe fixing nut (103), a washer (104), and a support block (105). Multiple evenly arranged fixed platform connection threaded holes are machined sequentially from front to back along the length direction on the upper surface of the fixed platform (101). The lower end of the pipe fixing bolt (102) connects to the corresponding fixed platform connection threaded hole. The washer (104) is horizontally positioned above the pipe (5), with the lower surface of one end of the washer (104) contacting the upper surface of the pipe (5). The upper surface of the other end of the pad (104) is machined with a pad connection hole, which corresponds to the threaded hole of the fixed platform. The upper end of the pipe fixing bolt (102) passes through the pad connection hole and is connected to the pipe fixing nut (103). A support block (105) is provided on the side of the pipe fixing bolt (102) away from the pipe (5). The lower end of the support block (105) contacts the upper surface of the fixed platform (101), and the upper end of the support block (105) contacts the lower surface of the pad (104).

4. The method for processing throttling holes for small-diameter pipes according to claim 3, characterized in that: The highest point positioning fixture (2) mentioned in step two includes a support frame (201), a level (202) and a pointer (203). The support frame (201) has a U-shaped cross section and is fastened to the upper part of the pipe (5). The level (202) is located above the support frame (201). The level (202) is connected to the upper surface of the support frame (201) by magnetic attraction. The middle of the upper surface of the middle wing plate of the support frame (201) is machined with a vertically arranged pointer mounting hole. The pointer (203) is vertically inserted into the pointer mounting hole. The pointer (203) is clearance-fitted with the pointer mounting hole, and the lower end of the pointer (203) is in contact with the upper surface of the pipe (5).

5. A method for processing throttling holes for small-diameter pipes according to claim 4, characterized in that: The pipe hole inner wall chamfering tool (4) mentioned in step four includes a tool bar (401), a chamfering blade (402), a spring (403), a spring stop (404), and a stop fixing screw (405). The tool bar (401) is a circular rod-shaped structure. The outer diameter of the tool bar (401) is smaller than the inner diameter of the middle through hole of the pipe (5). A blade mounting groove is radially opened on the lower side of the tool bar (401). A blade through hole is opened at the bottom of the blade mounting groove, which is connected to the side of the tool bar (401). The chamfering blade (402) has a T-shaped cross-section. The upper and lower sides of the chamfering blade (402) are respectively The blade is machined into a bevel, and the chamfering insert (402) is installed in the insert mounting groove. The head end of the chamfering insert (402) passes through the insert through hole. The end of the chamfering insert (402) is provided with a spring (403). The end of the spring (403) away from the chamfering insert (402) is provided with a spring stop (404). The side of the spring stop (404) and the tool bar (401) are respectively provided with two stop connection threaded holes. The stop fixing screw (405) is screwed into the two stop connection threaded holes. The spring stop (404) is connected to the tool bar (401) through the stop fixing screw (405).

6. A method for processing throttling holes for small-diameter pipes according to claim 1 or 5, characterized in that: The diameter of the through hole in the tube (5) mentioned in step three is 8 mm.

7. A method for processing throttling holes for small-diameter pipes according to claim 6, characterized in that: The radius of the first groove arc mentioned in step four is 2.5mm, and the radius of the second groove arc is 5mm.

8. A method for processing throttling holes for small-diameter pipes according to claim 7, characterized in that: The distance between the two first groove arcs mentioned in step four is 30mm, and the distance between the two second groove arcs is 65mm.

Images