An auxiliary support vibration suppression device for turning small diameter thin-walled pipes

Abstract

The present invention discloses an auxiliary support vibration suppression device for turning of small-diameter thin-walled pipe fittings, comprising a mandrel, one end of which is a connecting portion, which is used to be connected to a fixture of a workpiece; the other end of the mandrel is a first sealing portion, a second sealing portion is provided on the mandrel section between the first sealing portion and the connecting portion, the mandrel section between the second sealing portion and the first sealing portion is a supporting portion, the first sealing portion and the second sealing portion are used to cooperate with the inner wall of the workpiece to form a seal, and a grease film is formed between the first sealing portion, the second sealing portion and the supporting portion and the inner wall of the workpiece. The device can provide auxiliary support and supplement the rigidity of the thin-walled pipe fittings during the turning process of small-diameter thin-walled pipe fittings due to a slight interference fit; the oil film formed between the device and the inner wall of the pipe fitting can absorb vibration, thereby suppressing the self-excited chatter of turning, and effectively improving the processing quality of small-diameter thin-walled pipe fittings.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing micro-turning, in particular to an auxiliary support vibration suppression device suitable for turning of small-diameter thin-walled pipe fittings. Background Art

[0002] With the rapid development of aviation technology, higher requirements are placed on the quality of aviation parts. Thin-walled pipes are key flexible components of inertial navigation systems. Their manufacturing accuracy will directly affect the performance of gyroscopes. Thin-walled pipes are processed at the micron and submicron levels, and their size, shape, residual stress, surface quality and other processing accuracy are extremely high. Their processing accuracy has a significant impact on the performance of thin-walled pipes. However, due to the extremely thin wall thickness of thin-walled pipes, it is necessary not only to improve their rigidity through auxiliary supports during fine processing, but also to suppress their self-excited chatter during the turning process.

[0003] At present, a thin-walled pipe drilling fixture with an internal floating support is disclosed in a patent with application number 202010548891.X. In this application, an internal support for supporting thin-walled pipes is disclosed, which includes a support shaft, a sliding sleeve, a support rod, an arc-shaped elastic plate, a transmission shaft, a flexible transmission member, a No. 1 spring, a mounting plate, a brake motor and a spherical screw; the outer side of the annular fixing plate is fixedly connected to the mounting plate; the support shaft passes through the floating block; the support shaft and the mounting plate are connected through the No. 1 spring and the spherical screw; one end of the No. 1 spring is fixedly connected to the end face of the support shaft; the other end of the No. 1 spring is in conflict with the mounting plate; conical holes are evenly spaced along the circumferential direction on the mounting plate; the spherical screw is connected to the end face of the support shaft after passing through the conical hole; the spherical screw The spherical surface of the nail contacts the conical surface of the conical hole; a through hole is set in the middle of the support shaft; the transmission shaft is rotatably connected in the through hole; one end of the transmission shaft is connected to the rotating shaft of the brake motor through the flexible transmission member; the brake motor is fixedly connected to the mounting plate; two groups of positive thread segments and reverse thread segments are arranged at intervals on the cylindrical surface of the other end of the transmission shaft; the positive thread segments and the reverse thread segments are correspondingly provided with the sliding sleeves; the sliding sleeves are evenly spaced along the circumferential direction with hinge seats; the support shaft is evenly spaced along the circumferential direction with rectangular through grooves; the hinge seats slide in the rectangular through grooves; one support rod is hinged on each of the two hinge seats in the corresponding group; the free ends of the two support rods are hinged to the middle of the lower surface of the arc-shaped elastic plate; the arc-shaped elastic plate is in the shape of an arc in the free state. However, the structure of the support component is too complicated, and it is difficult to achieve support for thin-walled pipes with small diameters due to the complicated structure. Summary of the invention

[0004] The purpose of the present invention is to enhance the rigidity of thin-walled pipes by auxiliary supports during fine turning of small-diameter thin-walled pipes, and at the same time suppress the self-excited vibration during the turning of thin-walled pipes, thereby controlling the processing error. To this end, an auxiliary support vibration suppression device for turning small-diameter thin-walled pipes is provided.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An auxiliary support vibration suppression device for turning small-diameter thin-walled pipe fittings comprises a mandrel, one end of the mandrel is a connecting portion, and the connecting portion is used to be connected to a fixture of a workpiece; the other end of the mandrel is a first sealing portion, and a second sealing portion is provided on the mandrel section between the first sealing portion and the connecting portion, the first sealing portion and the second sealing portion cooperate with the inner wall of the workpiece to form a seal, and the mandrel section between the first sealing portion and the second sealing portion is a supporting portion, and a grease film is formed between the first sealing portion, the second sealing portion and the supporting portion and the inner wall of the workpiece.

[0007] As a further technical solution, the first sealing portion is an annular groove.

[0008] As a further technical solution, the second sealing portion is an annular groove.

[0009] As a further technical solution, the cylindrical diameter of the boss of the annular groove is d2=0.99D, and the height of the boss is h=0.03D; the width w of the groove and the boss is equal, w=0.03D; D is the diameter of the workpiece.

[0010] As a further technical solution, the support portion is cylindrical.

[0011] As a further technical solution, the length of the supporting portion is equal to the length of the thin-walled portion in the workpiece.

[0012] As a further technical solution, the diameter of the support portion is equal to d1=0.93D, where D is the diameter of the workpiece.

[0013] As a further technical solution, the connecting portion is a tapered thread.

[0014] The mechanism of the present invention is: the device originally has a clearance fit with the thin-walled pipe fitting, but due to the formation of a grease film, the device and the thin-walled pipe fitting have a slight interference fit, which can effectively play a supporting and vibration-suppressing effect; since the device has a small structure and gap seals are used at both ends, the structure is simple and the grease can be effectively sealed.

[0015] Beneficial effects achieved by the present invention:

[0016] The device can provide auxiliary support and supplement the rigidity of thin-walled pipes due to the slight interference fit during the turning process of small-diameter thin-walled pipes. The oil film formed by the device and the inner wall of the pipe can absorb vibration, thereby suppressing the self-excited chatter of the turning process and effectively improving the processing quality of small-diameter thin-walled pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an axonometric drawing of the device;

[0018] Figure 2 This is an enlarged view of the mandrel of the device;

[0019] Figure 3 This is the axonometric drawing of the machined fixture;

[0020] Figure 4 This is the front view of the thin-walled pipe;

[0021] Figure 5 It is the right view of the thin-walled pipe;

[0022] Figure 6 This is the axonometric view of the assembly after the thin-walled pipe is assembled;

[0023] Figure 7 for Figure 6 sectional view of

[0024] Figure 8 This is the effect diagram of the core rod vibration suppression and auxiliary support of the device.

[0025] Reference numerals:

[0026] 1. Auxiliary support vibration suppression device, 1-1. First sealing part, 1-2. Support part, 1-3. Connecting part, 1-4. Second sealing part;

[0027] 2. Clamp, 2-1. Connecting hole, 2-2. Threaded hole, 2-3. Air spindle suction cup;

[0028] 3. Thin-walled pipe fittings, 3-1. Thin-walled holes, 4. Hydraulic oil or grease. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0031] For the convenience of description, if the words "left" and "right" appear in the present invention, they only indicate that they are consistent with the left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0032] It should be noted that the auxiliary support vibration suppression device for turning small-diameter thin-walled pipe fittings proposed in the present invention is generally suitable for thin-walled pipe fittings with an inner diameter D≤20mm, the length of the thin-walled part of the thin-walled pipe fitting is L≤3D, and the wall thickness at the thinnest part is t≤0.2mm. Of course, it is not limited to this type of pipe fitting, and can also be used to process other pipe fittings.

[0033] The specific structure of the device is described below in conjunction with the accompanying drawings:

[0034] The auxiliary support vibration suppression device for turning of small-diameter thin-walled pipes proposed in this embodiment includes a mandrel 1, one end of the mandrel 1 is a connecting portion 1-3, and the connecting portion 1-3 is used to connect with a fixture 2 of the thin-walled pipe; the other end of the mandrel 1 is a first sealing portion 1-1, and a second sealing portion 1-4 is provided on the mandrel section between the first sealing portion 1-1 and the connecting portion 1-3, and the first sealing portion 1-1 and the second sealing portion 1-4 cooperate with the inner wall of the thin-walled pipe to form a seal, and the mandrel section between the first sealing portion 1-1 and the second sealing portion 1-4 is a support portion 1-2, and a grease film is formed between the first sealing portion 1-1, the second sealing portion 1-4 and the support portion 1-2 and the inner wall of the thin-walled pipe. The device originally has a clearance fit with the thin-walled pipe, but due to the formation of the grease film, the device and the thin-walled pipe are slightly interference fit, which can effectively play the role of supporting vibration suppression; because the device has a small structure and gap seals are used at both ends, the structure is simple and the grease can be effectively sealed.

[0035] As a further technical solution, the first sealing part 1-1 is an annular groove. In this embodiment, two circles of annular grooves are arranged; the cylindrical diameter of the boss of the annular groove is d2=0.99D, and the height of the boss is h=0.03D; the width w of the groove and the boss is equal, w=0.03D; D is the diameter of the thin-walled pipe fitting.

[0036] As a further technical solution, the second sealing part 1-4 is also an annular groove. Similarly, two circles of annular grooves are also set in this embodiment; the cylindrical diameter of the boss of the annular groove is d2=0.99D, and the height of the boss is h=0.03D; the width w of the groove and the boss is equal, w=0.03D; D is the diameter of the workpiece.

[0037] As a further technical solution, the support part 1-2 is cylindrical, the length of the support part is equal to the length of the thin-walled part of the workpiece, and the diameter of the support part is equal to d1=0.93D, where D is the diameter of the workpiece.

[0038] As a further technical solution, the connection portion is a tapered thread structure, which cooperates with the thread of the clamp 2 of the thin-walled pipe fitting to achieve the fixation of the auxiliary support vibration suppression device in the thin-walled pipe fitting.

[0039] The specific processing and installation methods are described below:

[0040] The present invention is an auxiliary support vibration suppression device for turning small-diameter thin-walled pipe fittings, which is implemented on an ultra-precision lathe. As shown in the figure, firstly, a connecting hole 2-1 between the fixture and the device is processed on the initial fixture, and the auxiliary support device without the sealing part 1-1 and the supporting structure 1-2 processed is installed on the processed fixture 2 through the connecting part 1-3 between the device and the fixture, and the sealing part 1-1, the sealing part 1-4 and the supporting part 1-2 are processed on the device according to the required parameters, and the sealing part 1-1, the sealing part 1-4 and the supporting part 1-2 are immersed in hydraulic oil or evenly coated with grease, and then the thin part is positioned by positioning the convex surface and the mandrel. The thin-walled pipe fitting 3 is clamped by the threaded hole 1-4. At this time, the gap between the core rod and the inner wall of the thin-walled pipe fitting 3 is filled with hydraulic oil or grease 4 to form a grease film, and due to the presence of the core rod sealing part 1-1 and the sealing part 1-4, the grease is sealed therein. The fixture is installed on the machine tool through the air spindle suction cup 1-5. During the external cylindrical turning of the thin-walled pipe fitting, due to the presence of the oil film, the original clearance fit between the core rod and the thin-walled pipe fitting is changed into a slight interference fit, thereby playing a role in auxiliary support and suppressing cutting vibration.

[0041] Embodiment 1:

[0042] In this embodiment, a thin-walled pipe with an inner diameter of D = 20 mm, a thin-walled portion length of L = 50 mm, and a wall thickness of t = 0.2 mm is processed.

[0043] First, a connecting hole 2-1 between the device and the fixture, i.e., a tapered thread bottom hole, is machined on the original fixture; a steel rod with the same diameter as the inner diameter of the thin-walled hole is prepared and a tapered thread of the device connecting part 1-3 is machined, the steel rod is installed on the machined original fixture, and ultra-precision turning of the steel rod is performed according to the following parameters:

[0044] The diameter of the device is d=0.99D=19.8mm, the length of the supporting part 1-2 is l=L=50mm, and its diameter is d1=0.92D=18.4mm; the sealing part 1-1 is two annular grooves in the middle position and one end of the core rod, and its boss cylindrical part d2=d=19.8mm, and its sealing step height is h=0.03D=0.6mm, and the width w of the groove and the boss is equal, w=0.03D=0.6mm.

[0045] Grease is evenly applied to the sealing part 1-1 and the supporting part 1-2, and then the thin-walled pipe is positioned by the device and clamped through the threaded hole 2-2. At this time, the gap between the supporting part 1-2 and the inner wall of the thin-walled pipe 3 is filled with grease to form a grease film, and due to the presence of the sealing part 1-1 and the sealing part 1-4, the grease is sealed therein. The fixture is installed on the machine tool through the air spindle suction cup. During the external cylindrical turning of the thin-walled pipe, due to the presence of the grease film, the original clearance fit between the core rod and the thin-walled pipe is changed into a slight interference fit, thereby playing a role in auxiliary support and suppressing self-excited vibration during the cutting process of the thin-walled pipe.

[0046] Embodiment 2:

[0047] In this embodiment, a thin-walled pipe with an inner diameter of D = 15 mm, a thin-walled portion length of L = 40 mm, and a wall thickness of t = 0.1 mm is processed.

[0048] First, the taper thread bottom hole for connecting the device and the fixture is machined on the original fixture. A steel rod with the same diameter as the inner diameter of the thin-walled hole is prepared and the taper thread of the device connection part is machined. The steel rod is installed on the processed original fixture and ultra-precision turned according to the following parameters:

[0049] The diameter of the device is d=0.99D=14.85mm, the length of the supporting part 1-2 is l=L=40mm, and its diameter is d1=0.92D=13.35mm; the sealing part 1-1 and the sealing part 1-4 are two annular grooves at both ends of the core rod support part, and the boss cylindrical part d2=d=14.85mm, and the sealing step height is h=0.03D=0.45mm, and the width w of the groove and the boss is equal, w=0.03D=0.45mm.

[0050] The sealing part 1-1 and the supporting part 1-2 are immersed in high-viscosity hydraulic oil, and then the thin-walled pipe fitting is positioned 2 by the device 1 and clamped through the threaded hole. At this time, the gap between the supporting part 1-2 and the inner wall of the thin-walled pipe fitting 3 is filled with hydraulic oil to form an oil film, and due to the presence of the core rod sealing part, the high-viscosity hydraulic oil is sealed therein. The fixture is installed on the machine tool through the air spindle suction cup 1-5. During the outer cylindrical turning process of the thin-walled pipe fitting 3, due to the presence of the oil film, the original clearance fit between the core rod and the thin-walled pipe fitting is changed into a slight interference fit, thereby playing a role in auxiliary support and suppressing self-excited vibration during the cutting process of the thin-walled pipe fitting.

[0051] Embodiment 3:

[0052] This embodiment processes a thin-walled pipe with an inner diameter of D = 10 mm, a thin-walled portion length of L = 30 mm, and a wall thickness of t = 0.1 mm;

[0053] First, the taper thread bottom hole for connecting the device and the fixture is machined on the original fixture. A steel rod with the same diameter as the inner diameter of the thin-walled hole is prepared and the taper thread of the device connection part is machined. The steel rod is installed on the processed original fixture and ultra-precision turned according to the following parameters:

[0054] The diameter of the device is d=0.99D=9.9mm, the length of the supporting part 1-2 is l=L=30mm, and its diameter is d1=0.92D=9.2mm; the sealing part 1-1 and the sealing part 1-4 are two annular grooves at both ends of the core rod support part, and the boss cylindrical part d2=d=9.9mm, and the sealing step height is h=0.03D=0.3mm, and the width w of the groove and the boss is equal, w=0.03D=0.3mm.

[0055] The sealing part 1-1 and the supporting part 1-2 are immersed in a relatively high viscosity hydraulic oil, and then the thin-walled pipe fitting is positioned by the mandrel and clamped by the threaded hole. At this time, the gap between the device and the inner wall of the thin-walled pipe fitting is filled with hydraulic oil to form an oil film, and due to the presence of the mandrel sealing part, the hydraulic oil is sealed therein. The fixture is installed on the machine tool through the air spindle suction cup. During the external cylindrical turning of the thin-walled pipe fitting, due to the presence of the oil film, the original clearance fit between the mandrel and the thin-walled pipe fitting is changed into a slight interference fit, thereby playing a role in auxiliary support and suppressing self-excited vibration during the cutting process of the thin-walled pipe fitting.

[0056] Finally, it should be noted that relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An auxiliary support vibration suppression device for turning small-diameter thin-walled pipes, comprising a mandrel, characterized in that: One end of the mandrel is a connecting part, and the connecting part is used to be connected to the fixture of the workpiece; the other end of the mandrel is a first sealing part, and a second sealing part is provided on the mandrel section between the first sealing part and the connecting part, and the mandrel section between the second sealing part and the first sealing part is a supporting part, and the first sealing part and the second sealing part are used to cooperate with the inner wall of the workpiece to form a seal, and a grease film is formed between the first sealing part, the second sealing part and the supporting part and the inner wall of the workpiece; The first sealing portion is an annular groove; The second sealing portion is an annular groove; The cylindrical diameter of the boss of the annular groove is d2=0.99D, and the height of the boss is h=0.03D; the width w of the groove and the boss is equal, w=0.03 D; D is the diameter of the workpiece; A connecting hole between the fixture and the device is machined on the initial fixture, and the auxiliary support vibration suppression device without a sealing part and a supporting structure is installed on the machined fixture through the connecting part. The first sealing part, the second sealing part and the supporting part are machined on the device according to the required parameters, and the first sealing part, the second sealing part and the supporting part are immersed in hydraulic oil or evenly coated with grease. The thin-walled pipe fitting is then positioned by the positioning convex surface and the mandrel, and clamped through the threaded hole. The gap between the mandrel and the inner wall of the thin-walled pipe fitting is filled with hydraulic oil or grease to form a grease film, and the grease is sealed therein due to the presence of the first sealing part and the second sealing part of the mandrel. The fixture is installed on the machine tool through the air spindle suction cup. In the process of turning the outer circle of the thin-walled pipe fitting, the original clearance fit between the mandrel and the thin-walled pipe fitting is changed into a slight interference fit.

2. The auxiliary support vibration suppression device for turning of small-diameter thin-walled pipes according to claim 1, characterized in that: The supporting part is cylindrical.

3. The auxiliary support vibration suppression device for turning of small-diameter thin-walled pipes according to claim 1, characterized in that: The length of the supporting portion is equal to the length of the thin-walled portion of the workpiece.

4. The auxiliary support vibration suppression device for turning of small-diameter thin-walled pipes according to claim 1, characterized in that: The diameter of the support portion is equal to d1=0.93D, where D is the diameter of the workpiece.

5. The auxiliary support vibration suppression device for turning of small-diameter thin-walled pipes according to claim 1, characterized in that: The connecting portion is a tapered thread.

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