An accelerating test device for maintaining the accuracy of a machine tool rotating shaft component and its usage method

Abstract

The present invention discloses an accelerated test device for maintaining the accuracy of a machine tool rotating shaft component and a usage method. The test device includes a stress loading part and a functional component installation part. The stress loading part includes a static / dynamic force loading device, a high and low temperature loading device, and a vibrator, which can simultaneously meet the requirements of cyclic loading of three-directional static / dynamic forces, vibration loads, and temperature loads for three different types of functional components, namely the main shaft, the CNC milling head, and the rotary table. The functional component installation part consists of a general installation device for the CNC milling head and the main shaft, and a special installation device for the rotary table. By simply replacing the installation device, the rapid installation of three different types of machine tool rotating shaft functional components, namely the main shaft, the CNC milling head, and the rotary table, can be achieved. The present invention solves the problems of single test object and poor versatility of the current accelerated test device for maintaining the accuracy of machine tool rotating shaft functional components, and fills the gap in the general-purpose accelerated test device for maintaining the accuracy of machine tool rotating shaft functional components at home and abroad.

Description

Technical Field

[0001] The present invention belongs to the technical field of performance testing of functional components, and relates to an accelerated test device for the accuracy retention of a machine tool rotating shaft component and a usage method thereof. Background Technique

[0002] Numerical control machine tools are the cornerstone of industrial modernization and are key manufacturing equipment for the development of high-end equipment such as aerospace, military, and automobiles, holding an important strategic position. Numerical control milling heads, numerical control rotary tables, and spindles are key rotating shaft functional components of numerical control machine tools and play a decisive role in the machining quality of parts. Accuracy retention is one of the key performance indicators of rotating shaft functional components, which describes the ability of rotating shaft functional components to maintain their original accuracy under normal usage conditions. The decline in the accuracy retention of rotating shaft functional components will lead to a reduction in the machining accuracy of machining equipment, thereby affecting the overall performance and stability of the equipment. Therefore, the research on the accuracy retention of rotating shaft functional components has important theoretical and practical significance.

[0003] Traditional testing methods for the accuracy retention of rotating shaft functional components mainly focus on on-site tracking testing, with a time span of up to several months or even years, resulting in low testing efficiency. Currently, with the development of accelerated testing technology, some accelerated test devices for the accuracy retention of rotating shaft functional components have been proposed. In 2014, Jing Guofeng et al. from Yantai Universal Machine Tool Accessories Group Co., Ltd. disclosed a detection device for the accuracy retention of a numerical control rotary table in patent CN104020716A. This device uses a magnetic powder brake to simulate the actual cutting load and apply torque to the tested rotary table, replacing the loading method of adding weights to the rotary table, accelerating the accuracy degradation process of the rotary table, and improving the detection efficiency of the accuracy retention of the numerical control rotary table to a certain extent. In 2018, Pan Shaogang et al. from Yantai Universal Machine Tool Equipment Co., Ltd. disclosed an experimental loading device for the accuracy retention of a numerical control rotary table in patent CN206862661U. This device uses the damping torque generated by a friction disc to load the numerical control rotary table, and compared with the loading torque provided by a magnetic powder brake, the change in the loading torque is smaller and the torque adjustment range is larger. In 2024, Wang Zhi et al. from Dalian University of Technology disclosed a method for evaluating the accuracy characteristics of an electric spindle based on dynamic vector force loading in patent CN118067517A, and the accuracy characteristics of the electric spindle are detected by applying torque and dynamic vector force to the electric spindle.

[0004] The above research shows that the accelerated test technology has achieved good applications in the performance testing field of functional components, but there are still the following problems: (1) Existing test devices are mostly used for spindles and rotary tables, lacking precision retention test devices for CNC milling heads and CNC rotary tilting tables; (2) The load environments faced by spindles, rotary tilting tables, and milling heads during actual service are similar, and there are commonalities in the requirements for test devices. However, existing test devices are mostly special-purpose devices that can only test functional components of the same type of rotating shaft and there is no general-purpose accelerated precision retention test device for functional components of rotating shafts that can uniformly cover the three types of CNC milling heads, CNC rotary tilting tables, and spindles; (3) Existing precision retention test devices for functional components of rotating shafts only apply static / dynamic forces or torques during loading and do not consider the effects of vibration and temperature changes on equipment precision degradation. Summary of the Invention

[0005] The purpose of the present invention is to provide an accelerated precision retention test device for machine tool rotating shaft components, which is used to solve the problems of the lack of accelerated precision retention test devices for functional components of machine tool rotating shafts and the difficulty in obtaining precision degradation data. By simply replacing the tooling fixtures, the performance tests of functional components of different types of rotating shafts can be completed, quickly obtaining precision degradation data of key functional components of machine tools and supporting the iterative upgrade of domestic key functional components.

[0006] The technical solution of the present invention:

[0007] An accelerated precision retention test device for machine tool rotating shaft components includes a stress loading part and a functional component installation part; the stress loading part includes a static / dynamic force loading device 1, a high and low temperature loading device 2, and a vibrator 3, simultaneously meeting the three-way static / dynamic force, vibration load, and temperature load cyclic loading requirements of three different types of functional components, namely spindles, CNC milling heads, and rotary tilting tables; the functional component installation part includes a general installation device 4 for CNC milling heads and spindles and a special installation device 5 for rotary tilting tables. By replacing the installation device, the rapid installation of functional components of three different types of machine tool rotating shafts, namely spindles, CNC milling heads, and rotary tilting tables, can be achieved.

[0008] Furthermore, the static / dynamic force loading device 1 mainly consists of a follow-up device and a loading device.

[0009] Further, the follow-up device includes a support base 101, a support base guide rail 102, an arc guide rail 103, an arc rack 104, a follow-up sliding plate 105, a rack 106, and a reduction motor 107. Among them, the support base 101 is installed on the support base guide rail 102. There are two support base guide rails 102 in total. A rack 106 parallel to it is arranged beside the support base guide rail 102. The rack 106 cooperates with the cylindrical gear at the bottom of the support base 101 and is driven by the reduction motor 107 to make the support base 101 move along the support base guide rail 102 and adaptively adjust its position according to the size of the functional component to be measured. A tooling turntable 108 is provided at the bottom of the follow-up sliding plate 105 for fixedly connecting with the loading device. According to the loading requirements of the turntable in the rotary swing table, the rotation speed of the tooling turntable 108 is adaptively adjusted to drive the loading device to achieve rotational following. The arc guide rail 103 and the arc rack 104 are fixed on the support base 101 and respectively cooperate with the guide rail slider 109 and the cylindrical gear 110 at the top of the follow-up sliding plate 105. By driving the follow-up sliding plate reduction motor 111 on the follow-up sliding plate 105, the loading device is driven to perform a circular motion along the arc guide rail 103, ensuring that the relative position of the loading device remains unchanged during the swinging processes of the rotary swing table and the CNC milling head, thereby realizing follow-up loading.

[0010] Further, the loading device includes a connection block 112, a connection plate 113, an eccentric wheel loading mechanism 114, a tension and compression sensor 115, a loading support plate 116, and a three-axis force sensor 117. Among them, the connection block 112 is connected to the tooling turntable 108 at the bottom of the follow-up sliding plate 105 by bolts. The tops of the three eccentric wheel loading mechanisms 114 are uniformly fixed around the connection block 112 through the connection plate 113. The bottoms of the eccentric wheel loading mechanisms 114 are connected to the loading support plate 116 through the tension and compression sensors 115. The bottom of the loading support plate 116 is placed on the general installation device 4 of the CNC milling head and the spindle or the special installation device 5 of the rotary swing table for the connection between the functional component to be measured and the loading device. Three different-direction forces are applied to the functional component to be measured through the three eccentric loading devices to realize three-axis static / dynamic force loading on the functional component to be measured. A three-axis force sensor 117 is arranged inside the loading support plate 116 for monitoring the magnitudes of the three-axis static and dynamic forces received by the functional component to be measured. The tension and compression sensor 115 is used for monitoring the magnitudes of the static and dynamic forces output by each eccentric wheel loading mechanism 114.

[0011] Further, the high and low temperature loading device 2 is a wind box, and its interior is used for installing functional components. A hatch is respectively provided at the top and the side of the wind box. The functional component to be measured is put into the interior of the high and low temperature loading device 2 through the hatch at the top. The operator performs assembly and debugging work from the hatch at the side. When all the hatches of the high and low temperature loading device 2 are closed, the high and low temperature loading device 2 applies cold and hot air to the interior through the internal air vents, causing the temperature of the internal space to change periodically.

[0012] Furthermore, the universal mounting device 4 for the CNC milling head and the spindle includes a turntable 401, a mounting bracket 402, a mounting box, and a simulation tool shank 405. The bottom of the turntable 401 is fixed to the upper surface of the vibrator 3, and its upper surface is connected to the mounting bracket 402. The mounting box is divided into a milling head mounting box 403 and a spindle mounting box 404, which are respectively used to place the CNC milling head and the spindle. They are not used simultaneously, and one of them is selected according to the loading requirement and placed on the mounting bracket 402. The bottom of the simulation tool shank 405 is matched with the CNC milling head or the spindle, and the top is connected to the loading support plate 116.

[0013] Furthermore, the special mounting device 5 for the swivel table includes a base 501, a swivel table mounting bracket 502, and a loading block 503. The base 501 is fixedly connected to the vibrator 3 by bolts. The bottom of the swivel table mounting bracket 502 is connected to the base 501, and the swivel table is placed on the top. There is a spacer 504 on the swivel table mounting bracket 502, and the mounting height of the swivel table is adjusted by replacing the spacer 504. A ball screw 505 is provided between the two swivel table mounting brackets 502, and the width of the swivel table mounting bracket 502 is adjusted by rotating the ball screw 505 according to the size of the swivel table. The top of the loading block 503 is connected to the loading support plate 116, and its bottom is fixedly connected to the swivel plane of the swivel table by bolts.

[0014] A method for testing with a precision retention acceleration test device for machine tool rotating shaft components is as follows:

[0015] The usage method when loading the CNC milling head or the spindle is as follows:

[0016] (1) Fix the turntable 401 to the upper surface of the vibrator 3, place the mounting bracket 402 above the turntable 401, and place the milling head mounting box 403 or the spindle mounting box 404 on the mounting bracket 402 according to the loading requirement.

[0017] (2) Open the hatch on the top of the high and low temperature loading device 2, use a crane to place the CNC milling head on the milling head mounting box 403 and lock it with bolts. At the same time, place the simulation tool shank 405 on the CNC milling head, or use a crane to place the spindle on the spindle mounting box 404 and lock it with bolts. At the same time, place the simulation tool shank 405 on the spindle.

[0018] (3) Drive the servo static / dynamic force loading device 1 to move along the support seat guide rail 102 above the CNC milling head or the spindle. At the same time, drive the servo slideway reduction motor 111 inside the servo slide 105 to rotate, drive the arc rack 104 to drive, and make the loading device move along the arc guide rail 103 until the triaxial force sensor 117 inside the loading support plate 116 in the loading device is coaxial with the simulation tool shank 405. Then, use bolts to fixedly connect the loading support plate 116 and the simulation tool shank 405, so that the loading support plate 116 is stably placed on the CNC milling head or the spindle.

[0019] (4) Close all the chamber doors of the high and low temperature loading device 2 and start the test.

[0020] Furthermore, the usage method when loading the numerically controlled rotary table is as follows:

[0021] (1) Connect the lower surface of the base 501 to the upper surface of the vibrator 3 through bolts. At the same time, place the rotary table mounting bracket 502 on the upper surface of the base 501, select the appropriate height of the spacer block 504 according to the size of the rotary table, and adjust the mounting bracket to the appropriate width through the ball screw 505 inside the numerically controlled rotary table mounting bracket 502;

[0022] (2) Open the top chamber door of the high and low temperature loading device 2, place the rotary table on the rotary table mounting bracket 502 through the overhead crane, place the loading block 503 on the turntable of the rotary table and fix it through bolts;

[0023] (3) Drive the servo static / dynamic force loading device 1 to move along the support seat guide rail 102 to above the rotary table. At the same time, drive the servo cross slide reduction motor 111 inside the servo cross slide 105 to rotate, drive the arc rack 104, and make the loading device move along the arc guide rail 103 until the lower surface of the loading support plate 116 in the loading device is parallel to the upper surface of the loading block 503. Then, fix the loading support plate 116 to the loading block 503 through bolts, and place the loading support plate 116 stably on the rotary table;

[0024] (4) Close all the chamber doors of the high and low temperature loading device 2 and start the test.

[0025] Advantages of the present invention:

[0026] (1) The load environments faced by the main shaft, rotary table and milling head during actual service are similar, and there is a commonality in the requirements for the test device. However, most of the existing test devices are special devices and can only test the same type of rotating shaft functional components. The accuracy retention acceleration test device for machine tool rotating shaft functional components proposed by the present invention can complete the accuracy retention acceleration tests of 3 types of rotating shaft functional components, namely the main shaft, milling head and rotary table, only by simply replacing the installation device, solving the problems of single test object and poor versatility of the current accuracy retention acceleration test device for machine tool rotating shaft functional components, and filling the gap of the general-purpose accuracy retention acceleration test device for machine tool rotating shaft functional components at home and abroad.

[0027] (2) The accuracy retention acceleration test device for machine tool rotating shaft functional components proposed by the present invention can realize the simultaneous loading of multiple stresses such as vibration, static / dynamic force and temperature, which is more in line with the actual service conditions of various functional components, and can provide a scientific basis for the iterative optimization of the rotating shaft functional components of domestic industrial machine tools. Description of the Drawings

[0028] Figure 1 This is a schematic diagram of the milling head loading of the accelerated test device for maintaining the accuracy of the rotating shaft functional components of the machine tool of the present invention.

[0029] Figure 2 This is a schematic diagram of the spindle loading of the accelerated test device for maintaining the accuracy of the rotating shaft functional components of the machine tool of the present invention.

[0030] Figure 3 This is a schematic diagram of the rotary table loading of the accelerated test device for maintaining the accuracy of the rotating shaft functional components of the machine tool of the present invention.

[0031] Figure 4 It is a schematic diagram of the structure of the follow-up static / dynamic force loading device; (a) Schematic diagram of the structure of the follow-up device (b) Schematic diagram of the structure of the follow-up carriage (c) Schematic diagram of the structure of the loading device.

[0032] Figure 5 It is a schematic diagram of the structure of the general installation device for the CNC milling head and the spindle.

[0033] Figure 6 It is a schematic diagram of the structure of the special installation device for the rotary table.

[0034] In the figure: 1 Follow-up static / dynamic force loading device; 2 High and low temperature loading device; 3 Vibration exciter; 4 General installation device for the CNC milling head and the spindle; 5 Special installation device for the rotary table; 101 Support seat; 102 Support seat guide rail; 103 Arc guide rail; 104 Arc rack; 105 Follow-up carriage; 106 Rack; 107 Reduction motor; 108 Tooling turntable; 109 Guide rail slider; 110 Cylindrical gear; 111 Follow-up carriage reduction motor; 112 Connecting block; 113 Connecting plate; 114 Eccentric wheel loading mechanism; 115 Tensile and compressive force sensor; 116 Loading support plate; 117 Triaxial force sensor; 401 Turntable; 402 Installation bracket; 403 Milling head installation box; 404 Spindle installation box; 405 Simulated tool shank; 501 Base; 502 Rotary table installation bracket; 503 Loading block; 504 Spacer block; 505 Ball screw. Detailed implementation manners

[0035] The following will describe in detail the specific implementation manners of the present invention in conjunction with the accompanying drawings and technical solutions.

[0036] As Figures 1-3As shown in the figure, an accelerated test device for maintaining the accuracy of a machine tool rotating shaft component includes a stress loading part and a functional component mounting part. The stress loading part includes a static / dynamic force loading device 1, a high and low temperature loading device 2, and a vibrator 3, which can simultaneously meet the requirements of three-way static / dynamic force, vibration load, and temperature load cyclic loading for three different types of functional components, namely the spindle, CNC milling head, and rotary table. The functional component mounting part includes a general mounting device 4 for the CNC milling head and the spindle, and a special mounting device 5 for the rotary table. By simply replacing the mounting device, the rapid installation of three different types of machine tool rotating shaft functional components, namely the spindle, CNC milling head, and rotary table, can be achieved.

[0037] The static / dynamic force loading device 1 is composed of a follower device and a loading device.

[0038] As Figure 4 As shown in (a), the follower device includes a support seat 101, a support seat guide rail 102, an arc guide rail 103, an arc rack 104, a follower slide 105, a rack 106, and a reduction motor 107. Among them, the support seat 101 is installed on the support seat guide rail 102. A rack 106 parallel to it is provided beside the support seat guide rail 102. The rack 106 is engaged with the bottom cylindrical gear of the support seat 101 and is driven by the reduction motor 107, so that the support seat 101 can move freely along the guide rail direction and adaptively adjust its own position according to the size of the functional component to be measured. As Figure 4 As shown in (b), a tooling turntable 108 is provided at the bottom of the follower slide 105 and is fixedly connected to the loading device. It can adaptively adjust the rotational speed of the tooling turntable according to the loading requirements of the rotary table in the rotary table, and drive the loading device to achieve rotational following. The arc guide rail 103 and the arc rack 104 are fixed to the support seat 101 by bolts and are respectively engaged with the guide rail slider 109 and the cylindrical gear 110 at the top of the follower slide 105. By driving the follower slide reduction motor 111 in the follower slide 105, the loading device can be driven to perform a circular motion along the arc guide rail 103, ensuring that the relative position of the loading device remains unchanged during the swinging process of the rotary table and the CNC milling head, thereby realizing follower loading.

[0039] As Figure 4As shown in (c), the loading device includes a connecting block 112, a connecting plate 113, an eccentric wheel loading mechanism 114, a tension and compression sensor 115, a loading support plate 116, and a three - axis force sensor 117. Among them, the connecting block 112 is connected to the tooling turntable 108 at the bottom of the follower slide 105 through bolts. The tops of the three eccentric wheel loading mechanisms 114 are distributed around the connecting block 112 through the connecting plate 113, and the bottoms are connected to the loading support plate 116 through the tension and compression sensors 115. The bottom of the loading support plate 116 is placed on the general installation device 4 for the numerical control milling head and the spindle or the special installation device 5 for the rotary table, which is used for the connection between the functional component to be measured and the loading device. Three different - direction forces are applied to the functional component to be measured through the three eccentric wheel loading mechanisms 114 to achieve three - axis static / dynamic force loading on the functional component to be measured. There is a three - axis force sensor 117 inside the loading support plate 116, which is used to monitor the magnitudes of the three - axis static / dynamic forces received by the functional component to be measured. The tension and compression sensors 115 placed at the bottoms of each eccentric wheel loading mechanism 114 are used to monitor the magnitudes of the static / dynamic forces output by each eccentric wheel loading mechanism 114.

[0040] As Figure 5 shown, the general installation device 4 for the numerical control milling head and the spindle includes a turntable 401, an installation bracket 402, a milling head installation box 403, a spindle installation box 404, and a simulated tool shank 405. Among them, one side of the turntable 401 is fixed to the upper surface of the vibrator 3, and the other side is connected to the installation bracket 402 through bolts. The milling head installation box 403 and the spindle installation box 404 are respectively used to place the numerical control milling head and the spindle. The milling head installation box 403 and the spindle installation box 404 are not used simultaneously, and one of them is selected according to the loading requirement and placed on the installation bracket 402. The bottom of the simulated tool shank 405 is matched with the numerical control milling head or the spindle, and the top is connected to the loading support plate 116.

[0041] As Figure 6 shown, the special installation device 5 for the rotary table includes a base 501, a rotary table installation bracket 502, and a loading block 503. Among them, the base 501 is fixedly connected to the vibrator 3 through bolts. The bottom of the rotary table installation bracket 502 is connected to the base 501, and the rotary table is placed on the top. The rotary table installation bracket 502 is provided with a spacer block 504, and the installation height of the numerical control rotary table can be adjusted by replacing the spacer block 504. At the same time, a ball screw 505 is provided in the middle, and the width of the rotary table installation bracket can be adjusted by rotating the ball screw 505 according to the size of the rotary table. The top of the loading block 503 is connected to the loading support plate 116, and the bottom is fixedly connected to the rotary table plane of the rotary table through bolts.

[0042] Embodiment 1

[0043] This embodiment takes a certain model of numerical control milling head and a certain signal numerical control rotary table as examples to illustrate the device and its usage method in detail:

[0044] The total weight of the CNC milling head is 1150 kg, the overall dimensions are 685*685*1409 mm, the spindle torque is 318 Nm, the maximum rotational speed is 7000 rpm, and the rotational range of the A-axis is ±105°. The total weight of the CNC milling head is 2400 kg, the overall dimensions are 2209*325*635 mm, the maximum rotational speed of the C-axis is 100 rpm, the swing range of the A-axis is ±120°, and the maximum rotational speed is 50 rpm.

[0045] Before the start of the test, as Figure 1 shown, the turntable 401 is fixed to the upper surface of the exciter 3. An installation bracket 402 is placed above the turntable 401, and the milling head installation box 403 is placed on the installation bracket 402. Subsequently, the top hatch of the high and low temperature loading device 2 is opened, and the CNC milling head is placed on the milling head installation seat box 403 by a crane and locked with bolts. At the same time, the simulated tool holder 405 is placed on the CNC milling head. The driving follower static / dynamic force loading device 1 moves along the support seat guide rail 102 to above the CNC milling head. At the same time, the follower slideway reduction motor 111 inside the follower slideway 105 is driven to rotate, driving the internal arc rack 104 to drive, so that the loading device moves along the arc guide rail 103 until the three-axis force sensor 117 inside the loading support plate 116 in the loading device is coaxial with the simulated tool holder 405. Subsequently, the loading support plate 116 is fixed to the simulated tool holder 405 with bolts, so that the loading support plate 116 is stably placed on the CNC milling head. Finally, all the hatches of the high and low temperature loading device 2 are closed, and the test is started.

[0046] During the test, the exciter 3 is turned on and the vibration amplitude is set to 1 mm and the vibration frequency is set to 65 Hz. The high and low temperature loading device 2 is turned on, and the cyclic temperature range is set to -20°C to 60°C. The tested CNC milling head is started, and the spindle rotational speed of the CNC milling head is set to 3000 rpm, and the swing speed of the A-axis is set to 105° / min. The turntable 401 is started, and the turntable rotational speed is set to 10 rpm to drive the C-axis of the milling head to rotate, ensuring that the loading conditions are more in line with the actual working conditions, so that all positions of the milling head can be loaded. The driving follower static / dynamic force loading device 1 is started, and the feed speed of the follower slideway 105 is set to 105° / min to follow the swing of the A-axis of the milling head. The three eccentric wheel loading mechanisms 114 are driven to simultaneously apply a 200 N dynamic force to the CNC milling head in the X / Y / Z three directions, and the force change frequency is 30 Hz. After the "heat-vibration-dynamic force" combined loading lasts for 120 min, the exciter 3, the high and low temperature loading device 2, and the driving follower static / dynamic force loading device 1 are turned off, the movement of the CNC milling head is stopped, the accuracy degradation data of the numerical control system are tested and recorded, and the above process is repeated until the loading time reaches 150 h. The spindle loading process is similar to the above steps and will not be described in detail.

[0047] After the numerical control milling head is loaded, disconnect the connection between the loading device and the numerical control milling head, drive the follow-up static / dynamic force loading device 1 away from the numerical control milling head, open the top hatch of the high and low temperature loading device 2, use a crane to remove the numerical control milling head from the milling head installation box 403, and remove the general installation device 4 for the numerical control milling head and the spindle.

[0048] Subsequently, as Figure 3 shown, connect the lower surface of the base 501 to the upper surface of the vibrator 3 with bolts. At the same time, place the rotary table installation bracket 502 on the upper surface of the base 501. Select a 300 mm height spacer 504 to adjust the installation height of the rotary table according to the size of the numerical control rotary table. And through the ball screw 505 inside the numerical control rotary table installation bracket 502, adjust the length of the installation bracket to 2300 mm to adapt to the size of the numerical control rotary table. Subsequently, open the top hatch of the high and low temperature loading device 2, place the numerical control rotary table on the numerical control rotary table installation bracket 502 with a crane, and place the loading block 503 on the rotary table of the numerical control rotary table and fix it with bolts at the same time. Then, drive the follow-up static / dynamic force loading device 1 to move above the numerical control rotary table along the support seat guide rail 102. At the same time, drive the follow-up slideway reduction motor 111 inside the follow-up slide 105 to rotate, drive the internal arc-shaped rack 104 to transmit, and make the loading device move along the arc-shaped guide rail 103 until the lower surface of the loading support plate 116 in the loading device is parallel to the upper surface of the loading block 503. Subsequently, fix the loading support plate 116 to the loading block 503 with bolts, so that the loading support plate 116 is stably placed on the numerical control rotary table. Finally, close all the hatches of the high and low temperature loading device 2 and start the test;

[0049] During the test, turn on the vibrator 3 and set the vibration amplitude to 0.5 mm and the vibration frequency to 65 Hz; turn on the high and low temperature loading device 2 and set the cyclic temperature range to -20°C to 60°C; start the measured numerical control rotary table, set the C-axis rotation speed of the numerical control rotary table to 30 rpm and the A-axis rotation speed to 500° / min; start the follow-up static / dynamic force loading device 1, set the feed speed of the follow-up slide 105 to 500° / min to perform follow-up on the A swing of the rotary table, and at the same time set the rotation speed of the tooling turntable 108 at the bottom of the follow-up slide to 30 rpm to perform rotational follow-up on the C-axis of the rotary table; drive the three eccentric wheel loading mechanisms 114 to simultaneously apply a 300 N dynamic force to the numerical control milling head in the X / Y / Z three directions, with the force change frequency of 30 Hz. After the "heat-vibration-dynamic force" combination is continuously loaded for 120 min, turn off the vibrator 3, the high and low temperature loading device 2, and the follow-up static / dynamic force loading device 1, stop the movement of the numerical control rotary table, test and record the precision degradation data of the rotary table, and repeat the above process until the loading time reaches 150 h.

Claims

1. An accelerated test device for maintaining the accuracy of a machine tool rotating shaft component, characterized in that, The precision retention acceleration test device for the rotating shaft components of the machine tool includes a stress loading part and a functional component installation part; the stress loading part includes a static / dynamic force loading device (1), a high and low temperature loading device (2) and a vibrator (3), which can simultaneously meet the requirements of cyclic loading of three-direction static / dynamic forces, vibration loads and temperature loads for three different types of functional components, namely the main shaft, the CNC milling head and the rotary table; the functional component installation part includes a general installation device (4) for the CNC milling head and the main shaft and a special installation device (5) for the rotary table. By replacing the installation device, the rapid installation of three different types of rotating shaft functional components of the machine tool, namely the main shaft, the CNC milling head and the rotary table, can be realized; The static / dynamic force loading device (1) mainly consists of a follower device and a loading device; The follower device includes a support seat (101), a support seat guide rail (102), an arc guide rail (103), an arc rack (104), a follower slide plate (105), a rack (106) and a reduction motor (107); among them, the support seat (101) is installed on the support seat guide rail (102), and there are two support seat guide rails (102) in total. A rack (106) parallel to it is arranged beside the support seat guide rail (102). The rack (106) is matched with the cylindrical gear at the bottom of the support seat (101) and is driven by the reduction motor (107) to make the support seat (101) move along the support seat guide rail (102) and adaptively adjust its position according to the size of the functional component to be measured; a tooling turntable (108) is arranged at the bottom of the follower slide plate (105) for fixedly connecting with the loading device. According to the loading requirements of the turntable in the rotary table, the rotation speed of the tooling turntable (108) is adaptively adjusted to drive the loading device to achieve rotational following; the arc guide rail (103) and the arc rack (104) are fixed on the support seat (101) and are respectively matched with the guide rail slider (109) and the cylindrical gear (110) at the top of the follower slide plate (105). By driving the follower slide plate reduction motor (111) on the follower slide plate (105), the loading device is driven to make a circular motion along the arc guide rail (103) to ensure that the relative position of the loading device remains unchanged during the swinging process of the rotary table and the CNC milling head, so as to realize follower loading.

2. The accuracy retention acceleration test device for the machine tool rotating shaft component according to claim 1, characterized in that, The loading device includes a connecting block (112), a connecting plate (113), an eccentric wheel loading mechanism (114), a tension-compression sensor (115), a loading support plate (116), and a three-axis force sensor (117); among them, the connecting block (112) is connected to a tooling turntable (108) at the bottom of the follower slide plate (105) by bolts, the tops of three eccentric wheel loading mechanisms (114) are uniformly fixed around the connecting block (112) through the connecting plate (113), the bottoms of the eccentric wheel loading mechanisms (114) are connected to the loading support plate (116) through the tension-compression sensor (115), the bottom of the loading support plate (116) is placed on the general installation device for the numerical control milling head and the spindle (4) or the special installation device for the rotary swing table (5), which is used for the connection between the functional component to be measured and the loading device, and three different-direction forces are applied to the functional component to be measured through three eccentric loading devices to achieve three-axis static / dynamic force loading on the functional component to be measured; a three-axis force sensor (117) is arranged inside the loading support plate (116) to monitor the magnitudes of the three-axis static and dynamic forces received by the functional component to be measured; the tension-compression sensor (115) is used to monitor the magnitudes of the static and dynamic forces output by each eccentric wheel loading mechanism (114).

3. The accuracy retention acceleration test device for the machine tool rotating shaft component according to claim 1, characterized in that, The high and low temperature loading device (2) is a bellows, and its interior is used to install functional components; a hatch is respectively arranged on the top and side of the bellows, the functional component to be measured is placed inside the high and low temperature loading device (2) through the hatch on the top, and the operator performs assembly and debugging work through the hatch on the side. When all the hatches of the high and low temperature loading device (2) are closed, the high and low temperature loading device (2) applies cold and hot air to the interior through the internal air blower to make the temperature of the internal space change periodically.

4. The precision retention acceleration test device for the machine tool rotating shaft component according to claim 1, wherein The general installation device for the numerical control milling head and the spindle (4) includes a turntable (401), an installation bracket (402), an installation box, and a simulation tool shank (405); among them, the bottom of the turntable (401) is fixed on the upper surface of the vibrator (3), and its upper surface is connected to the installation bracket (402); the installation box is divided into a milling head installation box (403) and a spindle installation box (404), which are respectively used to place the numerical control milling head and the spindle, and they are not used simultaneously. One of them is selected according to the loading requirement and placed on the installation bracket (402); the bottom of the simulation tool shank (405) is matched with the numerical control milling head or the spindle, and the top is connected to the loading support plate (116).

5. The accuracy retention acceleration test device for the machine tool rotating shaft component according to claim 1, characterized in that, The special installation device (5) for the rotary swing table includes a base (501), a rotary swing table mounting bracket (502), and a loading block (503); among them, the base (501) is fixedly connected to the vibrator (3) by bolts, the bottom of the rotary swing table mounting bracket (502) is connected to the base (501), the rotary swing table is placed on the top, a cushion block (504) is provided on the rotary swing table mounting bracket (502), and the installation height of the rotary swing table is adjusted by replacing the cushion block (504); a ball screw (505) is provided between the two rotary swing table mounting brackets (502), and the width of the rotary swing table mounting bracket (502) is adjusted by rotating the ball screw (505) according to the size of the rotary swing table; the top of the loading block (503) is connected to the loading support plate (116), and its bottom is fixedly connected to the rotary table plane of the rotary swing table by bolts.

6. A method for testing by using the precision retention acceleration test device for the machine tool rotating shaft component according to any one of claims 1-5, the steps are as follows: The usage method when loading the CNC milling head or the spindle is as follows: (1) Fix the upper surface of the rotary table (401) to the upper surface of the vibrator (3), place the mounting bracket (402) above the rotary table (401), and place the milling head mounting box (403) or the spindle mounting box (404) on the mounting bracket (402) according to the loading requirements; (2) Open the hatch on the top of the high and low temperature loading device (2), use the overhead crane to place the CNC milling head on the milling head mounting box (403) and lock it with bolts, and at the same time place the simulation tool holder (405) on the CNC milling head, or use the overhead crane to place the spindle on the spindle mounting box (404) and lock it with bolts, and at the same time place the simulation tool holder (405) on the spindle; (3) Drive the follow-up static / dynamic force loading device (1) to move along the support seat guide rail (102) above the CNC milling head or the spindle. At the same time, drive the follow-up slideway reduction motor (111) inside the follow-up slide plate (105) to rotate, drive the arc-shaped rack (104) to drive, and make the loading device move along the arc-shaped guide rail (103) until the triaxial force sensor (117) inside the loading support plate (116) in the loading device is coaxial with the simulation tool holder (405). Subsequently, fix the loading support plate (116) and the simulation tool holder (405) with bolts, so that the loading support plate (116) is stably placed on the CNC milling head or the spindle; (4) Close all the hatches of the high and low temperature loading device (2) and start the test.

7. A method for testing by using the precision retention acceleration test device for the machine tool rotating shaft component according to any one of claims 1-5, the steps are as follows: The usage method when loading the rotary swing table is as follows: (1) Connect the lower surface of the base (501) to the upper surface of the vibrator (3) by bolts. At the same time, place the rotary swing table mounting bracket (502) on the upper surface of the base (501), select the appropriate height of the cushion block (504) according to the size of the rotary swing table, and adjust the mounting bracket to the appropriate width through the ball screw (505) inside the CNC rotary swing table mounting bracket (502); (2)Open the top hatch of the high and low temperature loading device (2), place the rotary table on the rotary table mounting bracket (502) by means of a crane, place the loading block (503) on the turntable of the rotary table and fix it with bolts; (3)Drive the follow-up static / dynamic force loading device (1) to move along the support seat guide rail (102) to above the rotary table. At the same time, drive the follow-up slide plate reduction motor (111) inside the follow-up slide plate (105) to rotate, drive the arc rack (104), and make the loading device move along the arc guide rail (103) until the lower surface of the loading support plate (116) in the loading device is parallel to the upper surface of the loading block (503). Then fix the loading support plate (116) and the loading block (503) with bolts, and place the loading support plate (116) stably on the rotary table; (4)Close all the hatches of the high and low temperature loading device (2) and start the test.

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