A scratch device for measuring the shrinkage strain ratio of titanium alloy pipes

Abstract

The present invention belongs to the field of mechanical technology, and discloses a titanium alloy pipe automatic scratching device which is based on a screw guide rail horizontal and vertical motion system base controlled by a servo motor, clamps a titanium alloy pipe by concentric chucks with servo motors at both ends, and cooperates with a pressure sensor and a spring-type force feedback pressure balance system scratcher to ensure that the titanium alloy pipe does not deform during the scratching process and the scratching depth is controllable; the scratching quality is improved, the labor intensity is reduced, and the work efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of machinery and relates to a scratch device for measuring the shrinkage strain ratio of a titanium alloy pipe. Background Art

[0002] Titanium alloy tubes are widely used in the aviation field due to their low density, corrosion resistance, and high strength. In the process of studying the forming process of titanium alloy tubes, it was found that the changes in titanium alloy tubes mainly occurred in the changes in tube wall thickness and tube diameter. The shrinkage strain ratio of titanium alloy tubes is a value that measures the degree of the above changes. Therefore, before processing titanium alloy tubes, it is very necessary to measure the shrinkage strain ratio value of this batch of titanium alloy tubes and use this value to guide the work of part forming process parameters. The scratch depth and precision of titanium alloy tubes directly affect the accuracy of shrinkage strain ratio measurement, resulting in a large deviation in the final shrinkage strain ratio measurement value.

[0003] The current method for measuring the shrinkage strain ratio of titanium alloy pipes is to use a graduated chuck with a top clamp and a carbide scratching head located on the slidable dovetail groove on the side of the titanium alloy pipe to create scratches. It can be divided into three steps: preparation before scratching, scratching work, and adjustment after scratching.

[0004] The specific operations are as follows: (1) Preparation before scratching: Push the scratching device to the target position, rotate the scratcher thread to extend it and contact the outer wall of the titanium alloy tube, and at the same time generate a certain pressure on the titanium alloy tube. (2) Scratching operation: Scratching the titanium alloy tube axially and radially by pushing the scratcher to slide in the dovetail groove or controlling the indexing chuck to drive the titanium alloy tube to rotate to a specific angle. (3) Adjustment after scratching: Rotate the scratcher thread to retract it, adjust the position of the scratcher and the angle of the indexing chuck before performing the next scratching operation.

[0005] The above-mentioned scratching method has the following problems: (1) The size range of titanium alloy tubes applicable to the method of clamping with a graduated chuck and a center is limited. When clamping a small-diameter titanium alloy tube, the contact range between the center and the titanium alloy tube is small, resulting in loose clamping. If the center pressure is increased, it is easy to damage the tube wall. (2) The pressure exerted on the titanium alloy tube by the manually controlled scratcher cannot be accurately controlled, resulting in the control of the scratch depth of the titanium alloy tube can only rely on personal experience and feel. If the scratch depth is too deep, it will exceed the specified depth range and cause the titanium alloy tube to be scrapped. If the scratch depth is too shallow, it will produce scratches with poor uniformity and clarity, which will affect the accuracy of subsequent measurements. (3) When the scratcher is used to apply pressure to the tube wall on one side for scratching, the thin-walled titanium alloy tube with poor rigidity is easily deformed by the lateral pressure, resulting in the appearance of a "spiral line" with no connection between the beginning and the end of the radial scratch and the appearance of uneven depth in the axial scratch. The above phenomenon is likely to cause the titanium alloy tube to be scrapped or the accuracy of the test data to deteriorate. (4) The scratching efficiency of manual rotation, translation and pressure is low. The workload is large when scratching batches of titanium alloy pipes, and deviations caused by human factors are prone to occur, which increases the deviation of scratch size and accuracy, affecting the subsequent measurement test results. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a titanium alloy pipe automatic scratching device based on a screw guide rail horizontal and vertical motion system base controlled by a servo motor, which clamps the titanium alloy pipe through concentric chucks with servo motors at both ends, and cooperates with a pressure sensor and a spring-type force feedback pressure balance system scratcher to ensure that the titanium alloy pipe does not deform during the scratching process and the scratch depth is controllable.

[0007] A scratching device for measuring the shrinkage strain ratio of a titanium alloy pipe comprises an X-direction moving mechanism of the scratcher, a Y-direction moving mechanism of the scratcher, a titanium alloy pipe rotating mechanism, a scratching working mechanism, and a quick-change plug.

[0008] The X-direction moving mechanism of the scratcher is formed by the X-direction moving servo motor 8 in cooperation with the X-direction lead screw 4, the X-direction nut 10, the X-direction guide rail 2, and the slider 3 to control the movement of the Y-direction moving mechanism of the scratcher and the scratching working mechanism along the X direction.

[0009] The X-direction moving mechanism of the scratcher is based on the base 1. Two X-direction guide rails 2 are installed on the top of the base. Two sliders 3 that can slide along the X-direction are arranged on each X-direction guide rail 2. The X-direction lead screw 4 is located on the top of the base 1 between the two X-direction guide rails 2 and is connected to the X-direction base A6 and the X-direction base B7 located at both ends of the X-direction guide rail 2 through the deep groove ball bearing A5. An X-direction moving servo motor 8 is installed on the outside of the X-direction base B7 at the right end and is connected to the end of the lead screw through the coupling A9 inside the X-direction base B7. The X-direction moving servo motor 8 controls the rotation of the lead screw, driving the X-direction nut 10 on the X-direction lead screw, the X-direction slider and the Y-direction mechanism base 11 connected above it to move along the X-direction.

[0010] The Y-direction moving mechanism of the scratcher is installed above the X-direction moving mechanism of the scratcher, and a mechanism capable of controlling the Y-direction movement is formed by the Y-direction servo motor 17 in cooperation with the Y-direction lead screw 13, the Y-direction guide rail 12, the slider 3, the Y-direction right-hand screw nut 19, and the Y-direction left-hand screw nut 20, so as to control the scratcher and the force feedback device on the scratching working mechanism to approach or move away from each other along the Y-direction.

[0011] The Y-direction moving mechanism of the scratcher is based on the X-direction nut 10 and the Y-direction mechanism base 11 connected above the slider 3 of the X-direction guide rail. Two Y-direction guide rails 12 perpendicular to the X-direction are installed above the support. Each Y-direction guide rail 12 has two sliders 3 that can slide along the Y-direction. The Y-direction lead screw 13 is located above the base between the two Y-direction guide rails 12, and is connected to the Y-direction mechanism support A15 and the Y-direction mechanism support B16 located at both ends of the Y-direction guide rail 12 through the deep groove ball bearing B14. A Y-direction moving servo motor 17 is installed on the outside of the Y-direction mechanism support A15 located at the front end, and is connected to the end of the Y-direction lead screw 13 through the coupling B18 inside the Y-direction mechanism support A15. The Y-direction servo motor 17 can control the rotation of the lead screw, driving the Y-direction left-handed nut 19, the Y-direction right-handed nut 20, the slider 3 and the scratcher base 30 connected above it and the force feedback base 31 to move toward or away from each other along the Y-direction.

[0012] The titanium alloy tube rotating mechanism is composed of an active rotating mechanism and a passive rotating mechanism, which are installed above the X-direction base A6 and the X-direction base B7 of the X-direction moving mechanism. The active rotating mechanism controls the three-jaw chuck 29 to rotate around the axis by rotating the servo motor 27. The active rotating mechanism and the passive rotating mechanism rely on the three-jaw chuck 29 to clamp the titanium alloy tube, and the titanium alloy tube is controlled to rotate around the axis by rotating the servo motor 27.

[0013] The active end bearing seat 21 is located on the X-direction base A6, and the passive end bearing seat 22 is located on the X-direction base B7. The active rotating shaft 23 is connected to the active end bearing seat 21 through the self-aligning ball bearing 25 and the deep groove ball bearing C26, and the passive rotating shaft 24 is connected to the passive end bearing seat 22 through the self-aligning ball bearing 25 and the deep groove ball bearing C26. The active rotating shaft 23 is connected to the rotary servo motor 27 installed on the outside of the active end bearing seat 21 through the coupling C28. The titanium alloy pipe that needs to be scribed can be clamped by the three-jaw chuck 29 installed on the inner end faces of the two rotating shafts, and can rotate around the axial direction of the titanium alloy pipe.

[0014] The scratching mechanism includes a scratcher working end and a force feedback mechanism. The scratcher working end and the force feedback mechanism are both located on the Y-direction moving mechanism and are placed on both sides of the axis of the titanium alloy pipe. The scratching working end and the force feedback mechanism are controlled by the Y-direction moving mechanism to move closer to and farther from each other, so as to keep the force balance during the scratching process of the titanium alloy pipe and prevent bending and deformation. At the same time, the compression amount of the compression spring 38 can be controlled by controlling the Y-direction feed amount, so as to ensure that the actual pressure of the scratching process is controllable and the scratching depth is controllable.

[0015] The scratching mechanism is installed above the Y-direction moving mechanism. The scratcher base 30 and the force feedback base 31 are respectively connected to the Y-direction right-hand screw nut 20, the Y-direction left-hand screw nut 19 and the slider 3 of the Y-direction guide rail, and are respectively located on both sides of the titanium alloy pipe. The scratcher support 32 and the force feedback support 33 are respectively installed above the scratcher base 30 and the force feedback base 31. The scratcher 34 is located on the scratcher support 32, at the same height as the axis of the titanium alloy pipe clamped by the three-jaw chuck 29. It is guided by the guide sleeve 36 located on the scratcher support 32 and can move forward and backward along the axis of the scratcher. The force feedback rod 35 is located on the force feedback support 31, coaxial with the scratcher 34, and is guided by the guide sleeve 36 located on the force feedback support and can move forward and backward along the axis. The front end of the scratcher 34 is a pointed tip for scratching. The front end of the force feedback rod 35 is threaded and screwed with the plane end 37 with internal threads. The contact amount between the plane end 37 and the titanium alloy pipe can be controlled by controlling the screw connection distance between the two. A locking screw 40 is installed in the threaded hole on the side of the plane end 37. A stepped shaft structure is made on the side of the scratcher 34 and the force feedback rod 35 away from the titanium alloy pipe. One end of the compression spring 38 located inside the scratcher support 32 and the force feedback support 33 cooperates with the stepped shaft structure, and the other end contacts with the pressure sensor 39 installed on the outside of the support, which constantly feedbacks the current axial force of the scratcher 34 and the force feedback rod 35.

[0016] The quick-change plug is a rigid stepped cylinder with a handle, which is inserted into both ends of the titanium alloy pipe before the scratching operation to enhance the rigidity of the clamped parts at both ends of the titanium alloy pipe and ensure that the titanium alloy pipe does not deform.

[0017] Beneficial effects of the present invention:

[0018] (1) The present invention has a flexible structure and can quickly locate the axial center position of the titanium alloy pipe through the three-jaw chucks at both ends. It is applicable to a wide range of titanium alloy pipe sizes. Shrinkage strain ratio measurement of titanium alloy tube using scratch work.

[0019] (2) The present invention adopts a scratching system that uses a pressure sensor in conjunction with a servo motor. By accurately controlling the pressure of the scratching device, the scratching depth and uniformity can be effectively controlled, greatly improving the scratching quality.

[0020] (3) The present invention adopts a quantifiable pressure balance structure of a scratcher and a force feedback rod in conjunction with a spring and a pressure sensor to prevent the titanium alloy tube from deforming during the scratching process. The problem of "spiral" scratches and uneven axial scratch depth caused by unilateral force deformation of the titanium alloy tube is eliminated.

[0021] (4) Since the force feedback rod of the pressure balance structure of the present invention is made of hard alloy material, the rigidity of the pressure balance structure is ensured, and at the same time, the polytetrafluoroethylene force feedback end head will not produce destructive indentations on the titanium alloy pipe, thereby protecting the surface quality of the pipe. The self-lubricating property of polytetrafluoroethylene ensures that the axial and radial scratching of the pipe can be carried out smoothly under the dual pressure of the scratching needle and the force feedback end head.

[0022] (5) The present invention adopts an automatic control system that is coordinated with a servo motor and a pressure sensor, which has a high degree of automation, effectively reduces the labor intensity of batch titanium alloy pipe scratching work, and improves the scratching efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the scratch device for measuring the shrinkage strain ratio of titanium alloy pipes.

[0024] Figure 2 Schematic diagram of the X-axis cross section of the scratch device used to measure the shrinkage strain ratio of titanium alloy tubes.

[0025] Figure 3 Schematic diagram of the Y-axis cross section of the scratch device used to measure the shrinkage strain ratio of titanium alloy pipes.

[0026] Figure 4 This is a cross-sectional schematic diagram of the scratch working mechanism of the scratch device used to measure the shrinkage strain ratio of titanium alloy pipes.

[0027] In the figure: 1 base; 2X guide rail; 3 slider; 4X screw; 5 deep groove ball bearing A; 6X base A; 7X base B; 8X moving servo motor; 9 coupling A; 10X nut; 11Y mechanism base; 12Y guide rail; 13Y screw; 14 deep groove ball bearing B; 15Y mechanism support A; 16Y mechanism support B; 17Y moving servo motor; 18 coupling B; 19Y left-hand nut; 20Y right-hand nut ; 21 active end bearing seat; 22 passive end bearing seat; 23 active rotating shaft; 24 passive rotating shaft; 25 self-aligning ball bearing; 26 deep groove ball bearing C; 27 rotating servo motor; 28 coupling C; 29 three-jaw chuck; 30 scratcher base; 31 force feedback base; 32 scratcher support; 33 force feedback support; 34 scratcher; 35 force feedback rod; 36 guide sleeve; 37 flat end; 38 compression spring; 39 pressure sensor; ; 40 anti-loosening screw. DETAILED DESCRIPTION

[0028] The specific implementation method of the present invention is described below in conjunction with the accompanying drawings and technical solutions.

[0029] (1) Place the quick-change plugs into the ends on both sides of the titanium alloy tube, adjust the opening and closing sizes of the jaws of the three-jaw chucks 29 on both sides, place the titanium alloy tube in the center of the three-jaw chuck 29 and clamp it. At this time, the rotating servo motor 27 controls the active rotating shaft 23 to drive the three-jaw chuck 29 to drive the titanium alloy tube to rotate around the axis.

[0030] (2) The X-axis moving servo motor 8 controls the rotation of the X-axis lead screw 4, driving the Y-axis moving mechanism of the scratcher and the scratching working mechanism to move to the initial position.

[0031] (3) The Y-axis moving servo motor 17 controls the rotation of the Y-axis lead screw 13, driving the Y-axis left-hand screw 19 and the Y-axis right-hand screw 20 on the Y-axis lead screw 13 to approach each other until the scratcher 34 contacts the titanium alloy tube, and the value on the pressure sensor 39 on the side of the scratcher 34 increases. The thread on the rotating plane end 37 controls the extension of the plane end 37 on the force feedback rod 35, so that the value on the pressure sensor 39 on the side of the force feedback rod 35 is the same as the value on the pressure sensor 39 on the side of the scratcher 34, and the anti-loosening screw 40 is tightened to lock the extension of the plane end 37 (calibration process). At this time, the titanium alloy tube is in a state of force balance in its axial direction, and the titanium alloy tube does not bend or deform.

[0032] (4) The Y-axis moving servo motor 17 controls the rotation of the Y-axis lead screw 13, driving the Y-axis left-hand screw 19 and the Y-axis right-hand screw 20 on the Y-axis lead screw 13 to approach each other with the same feed amount. Since the feed amount is the same, the compression amount of the compression spring 38 by the scratcher 34 and the force feedback rod 35 is also the same, and the values ​​on the pressure sensors 39 on both sides also change synchronously until they reach the specified value.

[0033] (5) Control the X-direction moving servo motor 8 to drive the scratcher 34, the force feedback rod 35 and the flat end 37 to move along the X-direction to complete an axial scratching work on the titanium alloy tube. Control the rotation servo motor 27 to drive the three-jaw chuck 29 and the titanium alloy tube to rotate 90°, 180°, and 270°, and then repeat the above X-direction movement to complete the axial scratching work on the titanium alloy tube.

[0034] (6) Control the scratcher 34, the force feedback rod 35 and the flat end 37 to move away from the titanium alloy tube by the Y-direction moving servo motor 17 until there is no contact with the titanium alloy tube. Control the X-direction moving servo motor 8 to drive the scratcher 34, the force feedback rod 35 and the flat end 37 to move to the specified position. Control the scratcher 34, the force feedback rod 35 and the flat end 37 to move close to the titanium alloy tube by the Y-direction moving servo motor 17 until the value on the pressure sensor 39 reaches the specified value. Control the rotation servo motor 27 to drive the three-jaw chuck 29 and the titanium alloy tube to rotate 360° to complete a circumferential scratching operation. Repeat the above operation to complete the remaining two circumferential scratching operations.

Claims

1. A scratch device for measuring shrinkage strain ratio of titanium alloy pipe, characterized in that: It consists of five parts: scratcher X-axis moving mechanism, scratcher Y-axis moving mechanism, titanium alloy pipe rotating mechanism, scratching working mechanism, and quick-change plug; The X-direction moving mechanism of the scratcher is based on a base (1), two X-direction guide rails (2) are installed above the base, and each X-direction guide rail (2) is provided with two sliders (3) that can slide along the X-direction. The X-direction lead screw (4) is located above the base (1) between the two X-direction guide rails (2), and is connected to the X-direction base A (6) and the X-direction base B (7) located at both ends of the X-direction guide rail (2) through a deep groove ball bearing A (5); an X-direction moving servo motor (8) is installed on the outer side of the X-direction base B (7) at the right end, and is connected to the end of the lead screw through a coupling A (9) inside the X-direction base B (7); the X-direction moving servo motor (8) controls the rotation of the lead screw, and drives the X-direction nut (10) on the X-direction lead screw (4), the X-direction slider (3) and the Y-direction mechanism base (11) connected above it to move along the X-direction; The Y-direction moving mechanism of the scratcher is based on an X-direction nut (10) and a Y-direction mechanism base (11) connected above the slider (3) of the X-direction guide rail. Two Y-direction guide rails (12) perpendicular to the X-direction are installed above the support. Each Y-direction guide rail (12) has two sliders (3) that can slide along the Y-direction. The Y-direction lead screw (13) is located above the base between the two Y-direction guide rails (12). The Y-direction mechanism supports A (15) and B (16) located at both ends of the Y-direction guide rail (12) are connected to the Y-direction mechanism through a deep groove ball bearing B (14). ) connection; a Y-direction moving servo motor (17) is installed on the outer side of the Y-direction mechanism support A (15) at the front end, and is connected to the end of the Y-direction lead screw (13) through a coupling B (18) inside the Y-direction mechanism support A (15); the Y-direction moving servo motor (17) controls the rotation of the Y-direction lead screw (13), driving the Y-direction left-handed screw nut (19), the Y-direction right-handed screw nut (20), the slider (3) and the scratcher base (30) and the force feedback base (31) connected thereto on the Y-direction lead screw (13) to move toward or away from each other along the Y direction; The titanium alloy tube rotating mechanism is composed of an active rotating mechanism and a passive rotating mechanism, which are installed above the X-direction base A (6) and the X-direction base B (7) of the X-direction moving mechanism; the active rotating mechanism controls the three-jaw chuck (29) to rotate around the axis through a rotating servo motor (27); the active end bearing seat (21) is located on the X-direction base A (6), and the passive end bearing seat (22) is located on the X-direction base B (7); the active rotating shaft (23) is connected to the active end bearing seat (21) through a self-aligning ball bearing (25) and a deep groove ball bearing C (26); the passive rotating shaft (24) is connected to the passive end bearing seat (22) through a self-aligning ball bearing (25) and a deep groove ball bearing C (26); the active rotating shaft (23) is connected to the rotating servo motor (27) installed outside the active end bearing seat (21) through a coupling C (28); The scratching working mechanism comprises a scratching device working end and a force feedback mechanism. The scratching device working end and the force feedback mechanism are both located on a Y-direction moving mechanism and are respectively placed on both sides of the axis of the titanium alloy pipe. The scratching device working end and the force feedback mechanism are controlled to move closer to or farther from each other by the Y-direction moving mechanism. The compression amount of the compression spring (38) can also be controlled by controlling the Y-direction feed amount. The scratching device base (30) and the force feedback base (31) are respectively connected to a Y-direction right-hand screw nut (20), a Y-direction left-hand screw nut (19) and a slider (3). A scratching device support (32) and a force feedback support (33) are respectively installed above the scratching device base (30) and the force feedback base (31). The scratching device (34) is located on the scratching device support (32) and is at the same height as the axis of the titanium alloy pipe clamped by the three-jaw chuck (29). The force feedback rod (35) is located on the force feedback support (33), is coaxial with the scratcher (34), and is guided by the guide sleeve (36) located on the force feedback support; the front end of the scratcher (34) is a pointed end for scratching; the front end of the force feedback rod (35) is threaded and is screwed to a plane end head (37) with an internal thread, and the contact amount between the plane end head (37) and the titanium alloy pipe is controlled by controlling the screw connection distance between the two; a locking screw (40) is installed in the threaded hole on the side of the plane end head (37); the scratcher (34) and the force feedback rod (35) are both made with a stepped shaft structure on the side away from the titanium alloy pipe, and the compression spring (38) located inside the scratcher support (32) and the force feedback support (33) has one end matched with the stepped shaft structure and the other end in contact with a pressure sensor (39) installed on the outside of the support; The quick-change plug is a rigid stepped cylinder with a handle, which is inserted into both ends of the titanium alloy pipe before the scratching operation to enhance the rigidity of the clamped parts at both ends of the titanium alloy pipe.

2. The scratching device for measuring the shrinkage strain ratio of a titanium alloy pipe according to claim 1, wherein the tip of the scratcher (34) is a polytetrafluoroethylene force feedback terminal.

3. The scratch device for measuring the shrinkage strain ratio of a titanium alloy pipe according to claim 1 or 2, wherein the force feedback rod (35) is made of cemented carbide material.

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