Thin-walled tube machining mandrel capable of being finely adjusted in axial direction
By using elastic parts and steel ball structures on the thin-walled pipe machining mandrel, the problem of axial dimension elongation of metal thin-walled pipes in vehicle processing is solved, ensuring processing accuracy and convenience, and avoiding scrapping. High-precision outer circumferential machining is achieved.
Patent Information
- Application Number
- CN202420840194.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-22
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-04-22
AI Technical Summary
During the processing of metal thin-walled pipes, as the length of the pipe increases, the axial dimensions will extend, resulting in the circularity, coaxiality and straightness accuracy of the outer circular processing that cannot reach the specified value, resulting in scrapping.
A thin-walled pipe machining mandrel with axial fine-tuning is designed. By improving the fastening method of both ends of the mandrel, using elastic parts and steel ball structures to release axial stress, including a combination of end face lock nuts, springs and steel balls. Reduce the impact of axial stress on machining accuracy, and ensure accuracy and convenience through segmented welding connections and part pickup design.
Effectively prevent the elongation of the axial dimension of the thin-walled tube, ensure the accuracy of the outer circular processing, reduce the impact of processing stress on roundness, coaxiality and straightness, avoid scrapping, and simplify the installation of the mandrel and Pickup process.
Smart Images
Figure CN222221902U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of mechanical processing, and relates to a processing device for pipe products, in particular to a processing mandrel for thin-walled pipes with axial micro-adjustability. Background Art
[0002] Thin-walled tube processing often involves deep hole processing. For some thin-walled metal tubes, the deep hole has basically reached the required inner diameter in the blank state, and only the special outer circle and end face need to be machined. Machining the outer circle is a mature technology, but for this kind of thin-walled metal tube, when machining the outer circle, as the length of the thin-walled metal tube processed at one time increases, the technical problem of axial dimension elongation occurs.
[0003] The machining of thin-walled tubes generally requires mandrel positioning. There are various types of mandrel designs, such as the T-type push-out structure mandrel that combines pneumatics and mechanics to overcome the shortcomings of a single mechanical structure, the mandrel with two nuts pushing the sleeve to expand and squeeze the inner hole of the thin-walled tube, the mandrel with a rubber seal ring for the inner hole, and the mandrel with positive and negative nuts on both sides to push the pull rod to expand. These mandrels are widely used in industries such as coils, aerospace, and coal mining. Therefore, the inner hole expansion technology is mature. A metal thin-walled tube, whose deep hole has basically reached the required inner diameter in the blank state, only needs to be machined for the special outer circle and end face. However, when machining the outer circle of this metal thin-walled tube, it is found that the axial dimension will be elongated, especially for metal thin-walled tubes with longer lengths. This axial dimension has a larger elongation range due to axial stress, and even torsion may occur. At this time, if the two ends of the mandrel are tightened with traditional nuts, the axial stress will only be released radially toward the thin wall, resulting in the roundness, coaxiality, and straightness accuracy of the outer circle machining failing to reach the specified value and being scrapped due to excessive tolerance. Utility Model Content
[0004] In order to solve the above problems, the utility model provides a thin-walled tube processing mandrel with axial fine adjustment, which can release axial stress and prevent the thin-walled tube from being scrapped by processing by improving the fastening method of both ends of the mandrel.
[0005] The technical solution of the utility model is as follows:
[0006] A thin-walled tube processing mandrel with axial fine adjustment includes a mandrel shaft body, a boss is provided at the left end of the mandrel shaft body to limit the left movement of the thin-walled tube, and an end face locking nut is detachably connected to the right end of the mandrel shaft body. The diameter of the end face locking nut is larger than the outer diameter of the mandrel shaft body so that the right movement of the thin-walled tube is limited when it is installed on the mandrel shaft body; wherein, an elastic member is provided at one end of the boss or the end face locking nut facing the thin-walled tube, and the boss or the end face locking nut contacts and limits the thin-walled tube through the elastic member; the elastic member has supporting force and elastic force.
[0007] Furthermore, the elastic member is arranged in the end face locking nut, specifically on the outer ring surface of the end face locking nut, and the elastic member can be removed from the core shaft body along with the end face locking nut.
[0008] Furthermore, the elastic part includes steel balls and springs. The spring is arranged in the outer ring of the end face locking nut. Several steel balls are evenly distributed outside the outer ring surface of the end face locking nut. Each steel ball is connected to a separate spring, and the other end of the spring is fixed in the end face locking nut.
[0009] Furthermore, the end locking nut is provided with a cylindrical blind hole matching the number and diameter of the steel balls, and the steel balls partially extend out of the cylindrical blind hole of the end locking nut when the spring is in an uncompressed state.
[0010] Furthermore, the closed end of the blind hole of the end face locking nut is the threaded end of the special screw, and the nut of the special screw is arranged outside the end face locking nut.
[0011] Furthermore, it also includes a piece remover, which is arranged on the outside of the left end boss of the core shaft body. The height of the left end boss of the core shaft body is higher than the inner diameter of the thin-walled tube and lower than the outer diameter of the thin-walled tube.
[0012] Furthermore, the core shaft body is a hollow shaft.
[0013] Furthermore, the left end of the core shaft body is a left sleeve, and the right end of the core shaft body is a right sleeve. The left sleeve has a claw plate at the end, and the right sleeve has an external thread at the end. The end face locking nut is installed on the right sleeve through the external thread of the right sleeve.
[0014] Furthermore, at least two concave sections are provided on the outer axial surface of the mandrel shaft body. The concave sections are used to reduce the interaction force between the mandrel and the thin-walled tube, so as to facilitate the installation and removal of the thin-walled tube on the mandrel.
[0015] Furthermore, when the elastic member is arranged on the boss, the structure provided is the same as the structure provided on the end face locking nut, and a structural form of a steel ball, a spring and a blind hole can be adopted.
[0016] Advantages of the utility model
[0017] 1. The mandrel of the utility model is connected by welding the left sleeve, the mandrel and the right sleeve in sections, which ensures the accuracy and reduces the weight.
[0018] 2. The right end fastening part of the utility model is provided with an end face locking nut, a special screw, a spring, and a steel ball, which are used to reduce the influence of axial stress on the thin-walled tube during processing, and adapt to the technical problem that the axial G end dimension of the thin-walled tube will be elongated when the outer circle is machined. The technical problem that the roundness, coaxiality, and straightness accuracy of the thin-walled tube cannot reach the specified value due to the influence of axial stress and the tube is scrapped due to excessive tolerance is solved, and the outer circle dimension requirements are guaranteed.
[0019] 3. The utility model is provided with a pick-up device at the left end, which solves the problem of difficulty in picking up the parts after processing. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a structural diagram of a thin-walled tube processing mandrel with axial fine adjustment according to the utility model;
[0021] Figure 2 yes Figure 1 Right view of;
[0022] Figure 3 yes Figure 1 AA section view;
[0023] Figure 4 The utility model is a stereoscopic diagram of a thin-walled tube processing mandrel with axial fine adjustment.
[0024] In the figure, 1-left sleeve, 2-removal device, 3-steel ball, 4-end locking nut, 5-spring, 6-special screw, 7-thin-wall tube, 8-core shaft body, 9-right sleeve. DETAILED DESCRIPTION
[0025] Embodiment 1:
[0026] A thin-walled tube processing mandrel with axial fine adjustment includes a mandrel shaft body 8, a boss is provided at the left end of the mandrel shaft body 8 to limit the left movement of the thin-walled tube 7, and an end face locking nut 4 is detachably connected to the right end of the mandrel shaft body 8. The diameter of the end face locking nut 4 is larger than the outer diameter of the mandrel shaft body 8 so that the right movement of the thin-walled tube 7 is limited when it is installed on the mandrel shaft body 8; wherein, an elastic member is provided at one end of the boss or the end face locking nut 4 facing the thin-walled tube 7, and the boss or the end face locking nut 4 contacts and limits the thin-walled tube 7 through the elastic member; the elastic member has supporting force and elastic force.
[0027] The elastic member is arranged on the end face locking nut 4 , specifically on the outer ring surface of the end face locking nut 4 , and the elastic member can be removed from the core shaft body 8 along with the end face locking nut 4 .
[0028] The elastic member includes a steel ball 3 and a spring 5. The spring 5 is arranged in the outer ring of the end face locking nut 4. Several steel balls 3 are evenly distributed outside the outer ring surface of the end face locking nut 4. Each steel ball 3 is connected to a separate spring 5, and the other end of the spring 5 is fixed in the end face locking nut 4.
[0029] The end locking nut 4 is provided with cylindrical blind holes matching the number and diameter of the steel balls 3 , and the steel balls 3 partially extend out of the cylindrical blind holes of the end locking nut 4 when the spring 5 is in an uncompressed state.
[0030] The closed end of the blind hole of the end face locking nut 4 is the threaded end of the special screw 6 , and the nut of the special screw 6 is arranged outside the end face locking nut 4 .
[0031] It also includes a taker 2, which is arranged on the outside of the left end boss of the core shaft body 8. The height of the left end boss of the core shaft body 8 is higher than the inner diameter of the thin-walled tube 7 and lower than the outer diameter of the thin-walled tube 7.
[0032] The core shaft body 8 is a hollow shaft.
[0033] The left end of the core shaft body 8 is the left sleeve 1, and the right end of the core shaft body 8 is the right sleeve 19. The left sleeve 1 has a claw plate at the end, and the right sleeve 9 has an external thread at the end. The end face locking nut 4 is installed on the right sleeve through the external thread of the right sleeve 9.
[0034] When the elastic member is arranged on the boss, the structure is the same as that when it is arranged on the end face locking nut, and a structural form of a steel ball, a spring and a blind hole can be adopted.
[0035] Example 2
[0036] The mandrel includes a left sleeve 1, a taker 2, and a steel ball 3. Another important part of the mandrel is the end face locking nut 4, which includes a spring 5, a special screw 6, a mandrel shaft 8, and a right sleeve 9. The left side of the mandrel is connected to the machine tool, and the right side is tightened. By screwing the end face locking nut to contact the thin-walled tube, screwing the special screw drives the spring to squeeze the steel ball to press the end face of the thin-walled tube to adapt to the technical problem that the axial G end size of the thin-walled tube will be elongated when turning the outer circle.
[0037] The mandrel is positioned through the center holes on both sides, and the center holes on both sides and the left end clamping surface are used as processing references to ensure the overall coaxiality requirements of the mandrel.
[0038] The fastening part at the right end of the core shaft is composed of an end locking nut, a spring, a special screw, and a steel ball. The outer circle of the end locking nut is knurled for easy hand twisting. The special screw is slotted. The special screw is twisted to squeeze the spring. The spring pushes the steel ball to tighten the end face of the thin-walled tube. During the processing, the thin-walled tube squeezes the spring through the steel ball to reduce the influence of the axial processing stress on the outer roundness, coaxiality, and straightness.
[0039] One end of the end face locking nut is provided with evenly distributed arc grooves to ensure that the steel ball is exposed from the arc groove and will not fall off. The other end is provided with a countersunk hole concentric with it to control the travel of the special screw.
[0040] The mandrel is connected to the machine tool claw through the left sleeve end face. The claw needs to be processed to a soft claw state to match its mandrel to ensure coaxiality requirements.
[0041] The main body of the mandrel is welded by the left sleeve, the mandrel body and the right sleeve. The left sleeve and the right sleeve have step holes in the middle, the mandrel has a through hole in the middle, and the outer circle is stepped, which not only ensures the accuracy requirements but also reduces the overall weight. The purpose of the segmented design is to facilitate the processing of the hollow hole in the mandrel body.
[0042] When turning the outer circle of a thin-walled tube, a machining allowance must be left and the cutting must be done in two steps. Part of the machining stress can be eliminated by forward and reverse cutting.
[0043] Since the thin-walled tube is longer, the machine tool size and model should be selected to suit it.
[0044] The remover is step-shaped, and the right end face should be lower than the outer circle of the thin-walled tube to facilitate tool withdrawal. Four evenly distributed threaded holes are set on the outer circle to be used for removing parts after processing is completed.
[0045] The outer diameter of the mandrel needs to be polished before first use.
[0046] The mandrel needs to be protected after use to prevent rust during repeated use.
[0047] The periphery and sharp corners of the mandrel need to be blunted to improve safety benefits.
[0048] When the inner hole of the incoming material is unstable, the following expansion mandrels are designed as needed: a T-type push-out structure mandrel that combines pneumatic and mechanical forces, a mandrel that uses nuts at both ends to push the sleeve to expand and squeeze the inner hole of a thin-walled tube, a mandrel that uses a rubber sealing ring to expand the inner hole, and a mandrel that uses positive and negative nuts on both sides to push the pull rod to meet the processing function.
[0049] Example 3
[0050] A thin-walled tube processing mandrel with axial micro-adjustability, the mandrel parts include 1 left sleeve, 2 takers, 3 steel balls, 4 end face locking nuts, 5 springs, 6 special screws, 7 thin-walled tubes, and 8 right sleeves. The mandrel body is welded and connected by 1 left sleeve, 8 mandrel shaft body, and 9 right sleeve, 2 takers pass through 9 right sleeve, 8 mandrel shaft body from the right end, and lean against 1 left sleeve end face, 4 end face locking nuts are connected to 9 right sleeve by threads, 3 steel balls are embedded in 4 end face locking nut circular arc grooves, 6 special screws are turned to squeeze 5 springs, and 5 springs push the steel balls to expose the circular arc grooves of 4 locking nut end faces without falling off. Before the first use of the mandrel, the outer circle needs to be polished. The mandrel is connected to the machine tool claw through the end face of the left sleeve 1. The claw needs to be processed to a soft claw state to match the mandrel to ensure the coaxiality requirements. The right end is supported by the machine tool against the top hole of the right sleeve 9. The end face locking nut 4 is screwed by hand to make the 3 steel balls press against the right end face of the 7 thin-walled tube. The left end face of the 7 thin-walled tube is close to the right end face of the 2 remover, and the 7 thin-walled tube is positioned. When machining the outer circle of the 7 thin-walled tube, a machining allowance should be left, and the cutting should be done twice. The machining stress should be eliminated through positive and negative cutting. After the machining is completed, the end face locking nut 4 is unscrewed, and the 2 remover is driven to push out the 7 thin-walled tube through the threaded hole set in the 2 remover. The mandrel needs to be protected after use to prevent rust when it is reused. The utility model has the advantage of adapting to the technical problem that the axial G end size of the thin-walled tube will be elongated when machining the outer circle through the end face locking nut.
[0051] The steel balls are 20 evenly distributed in a circle.
[0052] Prepare a 7 thin-walled tube, check whether its inner hole meets the required inner diameter, and the appearance is required to be good. Check all parts of the mandrel, especially the outer diameter and roughness, which must meet the use requirements. The left sleeve 1 at the left end of the mandrel is connected to the machine tool claw. The claw needs to be processed to the soft claw state to match its mandrel to ensure the coaxiality requirements. The 7 thin-walled tube is inserted into the mandrel so that its left end face is against the 2 picker. The mandrel is tightened through the top hole set by the 9 right sleeve. Turn the 4 end face locking nut to contact the 7 thin-walled tube. Turn the 6 special screws to drive the 5 spring to squeeze the 3 steel balls to press the right end face of the 7 thin-walled tube. The 7 thin-walled tube is positioned. When machining the outer circle of the 7 thin-walled tube, leave a machining allowance, cut twice, and eliminate the machining stress through positive and negative cutting. After the machining is completed, unscrew the 4 end face locking nut, and drive the 2 picker to push out the 7 thin-walled tube through the threaded hole set by the 2 picker. The mandrel needs to be protected after use to prevent rust when reused.
Claims
1. A thin-walled tube processing mandrel with axial fine adjustment, characterized in that: The invention comprises a mandrel shaft body (8), the left end of which is provided with a boss to limit the leftward movement of a thin-walled tube (7), and the right end of which is detachably connected with an end face locking nut (4), the diameter of which is larger than the outer diameter of the mandrel shaft body (8) so that when the thin-walled tube (7) is installed on the mandrel shaft body (8), the rightward movement is limited; wherein, an elastic member is provided at one end of the boss or the end face locking nut (4) facing the thin-walled tube (7), and the boss or the end face locking nut (4) contacts and limits the thin-walled tube (7) through the elastic member; and the elastic member has a supporting force and an elastic force.
2. The axially fine-adjustable thin-walled tube processing mandrel according to claim 1, characterized in that: The elastic member is arranged on the end face locking nut (4), specifically on the outer ring surface of the end face locking nut (4), and the elastic member can be removed from the core shaft body (8) along with the end face locking nut (4).
3. The axially fine-adjustable thin-walled tube processing mandrel according to claim 2, characterized in that: The elastic member comprises a steel ball (3) and a spring (5). The spring (5) is arranged in the outer ring of the end face locking nut (4). A plurality of steel balls (3) are evenly distributed outside the outer ring surface of the end face locking nut (4). Each steel ball (3) is connected to a separate spring (5). The other end of the spring (5) is fixed in the end face locking nut (4).
4. The axially fine-adjustable thin-walled tube processing mandrel according to claim 3, characterized in that: The end face locking nut (4) is provided with cylindrical blind holes matching the number and diameter of the steel balls (3); the steel balls (3) partially extend out of the cylindrical blind holes of the end face locking nut (4) when the spring (5) is in an uncompressed state.
5. The axially fine-adjustable thin-walled tube processing mandrel according to claim 4, characterized in that: The closed end of the blind hole of the end face locking nut (4) is the threaded end of the special screw (6), and the nut of the special screw (6) is arranged outside the end face locking nut (4).
6. The axially fine-adjustable thin-walled tube processing mandrel according to claim 1, characterized in that: It also includes a taker (2), which is arranged on the outside of the left end boss of the mandrel shaft body (8), and the height of the left end boss of the mandrel shaft body (8) is higher than the inner diameter of the thin-walled tube (7) and lower than the outer diameter of the thin-walled tube (7).
7. The axially fine-adjustable thin-walled tube processing mandrel according to claim 1, characterized in that: The core shaft body (8) is a hollow shaft.
8. The axially fine-adjustable thin-walled tube processing mandrel according to claim 7, characterized in that: The left end of the mandrel shaft body (8) is a left shaft sleeve (1), and the right end of the mandrel shaft body (8) is a right shaft sleeve (9). The left shaft sleeve (1) is a structure with a claw plate at the end, and the right shaft sleeve (9) is a structure with an external thread at the end. The end face locking nut (4) is installed on the right shaft sleeve through the external thread of the right shaft sleeve (9).
9. The axially fine-adjustable thin-walled tube processing mandrel according to claim 1, characterized in that: At least two concave sections are arranged on the outer axial surface of the core shaft body (8).