CN103017992B - Device and method for measuring static rigidity of rolling linear guide rail pair - Google Patents

Abstract

The invention discloses a static stiffness measurement device and method of a rolling linear guide rail pair. A servo motor is used to drive a trapezoidal screw to drive a loading nut to load the rolling linear guide rail pair. By changing the installation position of the guide rail pair and the type of fixture on the guide rail, the There are three loading methods of vertical, deflection and pitch loading on the guide rail pair. There are measuring points corresponding to different loading methods distributed on the upper and lower fixtures of the guide rail, which are used to measure the deformation and displacement of the guide rail pair during loading. The invention respectively realizes the automatic measurement of the vertical static stiffness, deflection static stiffness and pitch static stiffness of the rolling linear guide rail pair, has large loading load and high measurement accuracy, and can meet the needs of different guide rail series for different loading modes.

Description

Device and method for measuring static stiffness of rolling linear guide rail pair

technical field

The invention belongs to the technical field of measurement, in particular to a device and method for measuring the static stiffness of a rolling linear guide pair.

Background technique

Rolling linear guide rails are generally composed of guide rails, sliders, reversers, rolling elements and cages. It is a rolling support for relative reciprocating linear motion. The sliding contact, and the rolling element can achieve infinite circulation in the raceway and the slider with the help of the reverser. The rolling linear guide pair has the advantages of small friction coefficient, high running accuracy, no crawling, wear resistance, high rigidity, and small thermal deformation, and is widely used as a guide component for high-precision CNC machine tools and machining centers.

Static stiffness is an important index that affects the performance and bearing capacity of rolling functional parts, and is the basic requirement for rolling linear guides. The static stiffness of the rolling linear guide pair refers to the ability of the rolling linear guide pair to carry a constant load. When the rolling linear guide pair is subjected to an external load, there will be deformation displacement in the vertical and horizontal directions, as well as angular displacement in several directions. This elastic deformation has a great influence on the mechanical performance. Static deformation will not only change the assembly accuracy of parts and affect the processing quality, but also affect the vibration resistance, productivity, noise, working life, motion balance, and heat and wear etc. At present, my country has achieved certain results in the theoretical research on the static stiffness of the rolling linear guide pair, but the development of the domestic guide rail static stiffness measurement device is still in its infancy, and the actual static stiffness experimental tests of related products by various manufacturers are still far from satisfactory. Requirements, to a certain extent, limit the optimization and improvement of product performance, and bring great difficulties to the actual selection of users. Therefore, it is important to develop a static stiffness test device with high precision, large load, and wide versatility, and use it to test and analyze the static stiffness in the design stage of rolling linear guides to ensure the stiffness of rolling linear guides. actual meaning.

After searching the literature of the existing technology, it was found that the rolling linear guide rail pair static stiffness test machine designed by Fang Jian and others of Huazhong University of Science and Technology in 2006 was loaded by a hydraulic system, and the static stiffness was generated by the data collected by the force sensor and the inductance micrometer. Stiffness curve, different types of guide rails are installed through T-shaped slots, and the loading hydraulic cylinder can adjust the loading position left and right through the ball screw; the maximum loading load of this testing machine is 30KN, and the loading load range is small, which cannot meet the static stiffness measurement of large-sized guide rail pairs. Yes, the hydraulic loading system has high requirements for constant pressure control. When loading, the position of the hydraulic cylinder needs to be adjusted through the screw to load the guide rail pair. The operation is inconvenient, and there are only devices and methods for vertical loading. In addition, the Chinese Invention Patent Publication No. CN102279100A, named Rolling Linear Guideway Stiffness Testing Machine, this patent introduces an experimental device and method that uses a servo motor to drive a screw to load a rolling linear guideway through a beam and detect the static stiffness; The test device puts the transmission structure in the base, and the surface of the base of the test bench will be slightly deformed in the vertical direction under heavy load, which will have a certain impact on the measurement accuracy. The control of the servo motor is more complicated when the constant voltage is loaded. The test device can only carry out vertical tension and compression loads, without eccentric load and pitch loading on the guide rail, the installation and disassembly of the displacement sensor is inconvenient, and the design of the guide rail fixture cannot meet the needs of various guide rail installation tests. Therefore, in terms of measuring the static stiffness of rolling linear guide rail pairs, there is still a lack of automatic measuring devices that can carry out large load loading and adapt to various guide rails and various load modes.

Contents of the invention

The object of the present invention is to provide a high precision, high load, high versatility measuring device and method for measuring the static stiffness of a rolling linear guide pair capable of measuring various loading modes.

The technical solution to realize the object of the present invention is: a static stiffness measurement device for a rolling linear guide rail pair, including a loading assembly, a supporting assembly, a clamping assembly, a measuring assembly and a data processing module. The loading assembly includes a servo motor, a reducer , a loading trapezoidal screw, a loading nut and an anti-rotation beam; the support assembly includes a base, a pair of uprights, an upper beam, a magnetic table base, and a table panel; the clamping assembly includes a force sensor force rod, an upper fixture connector, and a guide rail The upper fixture and the lower fixture of the guide rail; the measurement components include force sensors and laser displacement sensors, and the data processing module is the computer processing system required for data processing; the servo motor is connected to the reducer, the reducer is installed on the upper beam, and the trapezoidal screw passes through the upper The bearing in the beam is connected with the reducer, the loading nut is installed on the trapezoidal screw, and moves up and down with the rotation of the trapezoidal screw, the anti-rotation beam is fixedly installed on the loading nut, and there are through holes at both ends of the anti-rotation beam. It can be set on a pair of uprights symmetrically installed on the left and right sides and can move up and down. The upper ends of the pair of uprights are installed with upper beams, and the lower ends of the uprights are fixedly installed on the base. The force sensor is used to measure the load size. The force sensor is connected with the force sensor force rod through the thread. The upper fixture of the guide rail is connected with the force sensor force rod through the upper fixture connector. The lower fixture of the guide rail is installed on the table. The magnetic table is placed on On the surface of the table panel, the laser displacement sensor is installed on the bracket corresponding to the magnetic table base. The center position of the light projection of the laser displacement sensor is vertically aligned with the corresponding measuring point in the vertical, deflection or pitch load mode. The laser displacement sensor, force sensor and servo The motors are respectively connected with the computer processing system; the servo motor, the reducer, a loaded trapezoidal screw, the loaded nut, the force sensor, the force sensor force rod, the coaxial line of the upper fixture connector; the anti-rotation beam, the upper beam, and the table panel , The plane of the base is parallel.

Compared with the prior art, the present invention has significant advantages: (1) The table panel of the measuring device is equipped with a lower fixture for installing guide rails, and different fixtures can be realized by switching the upper and lower fixtures of different guide rails and changing the installation position of the fixtures. The model rail pair is loaded in the form of vertical, deflection and pitch, and has the characteristics of strong versatility. (2) Since the trapezoidal screw is used for loading, the trapezoidal screw has good self-locking performance, so the measuring device can keep the loading force constant, and it is convenient to measure the static stiffness under constant load. (3) Due to the large load, in order to reduce the influence of the deformation of the test bench itself on the test accuracy during the test loading, the transmission part composed of the servo motor and the reducer is placed on the upper beam of the measuring device, and the base of the measuring device is taken as a whole. The overall rigidity of the measuring device reduces deformation and improves the accuracy of measurement results. (4) The load of the present invention can reach 600KN, the precision of the high-precision pressure sensor used can reach 0.3‰, and the detection precision of the laser displacement sensor can reach the μm level. This measurement method can obtain the measurement result of the static stiffness of the high-precision guide rail pair. (5). By rationally arranging the measuring points corresponding to different load modes, the number of displacement sensors can be reduced. Laser displacement sensors are used to detect the displacement of the measuring points, which is easy to install and adjust, and improves the measurement efficiency.

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic diagram of the structural composition and connection assembly of the rolling linear guide pair static stiffness measuring device of the present invention.

Figure 2 is a schematic diagram of the vertical loading structure.

Fig. 3 is a three-dimensional exploded view of the clamping part.

Fig. 4 is a schematic diagram of the deflection upper fixture and the deflection loading structure.

Fig. 5 is a schematic diagram of the pitch upper fixture and the pitch loading structure.

Figure 6 is a schematic diagram of the distribution of measuring points for vertical or deflection loading.

Figure 7 is a schematic diagram of the distribution of measuring points for pitch loading.

Detailed ways

The invention uses a servo motor to drive a trapezoidal screw to drive the loading nut to load the rolling linear guide rail pair. By changing the installation position of the guide rail pair and the type of fixture on the guide rail, three loading methods can be performed on the guide rail pair: vertical, deflection and pitch loading. The force sensor and the laser displacement sensor sample the load and deformation of the tested guide rail pair respectively. The force sensor is fixed on the loading nut and can rise and fall with it. The center position of the laser displacement sensor and the corresponding measurement of different loading methods Points are aligned vertically. By processing the collected load and displacement data, the static stiffness curve of the rolling linear guide can be drawn, so as to realize the experimental measurement of the static stiffness of the rolling linear guide, and the load range of the measurement is large, the versatility is strong, and the precision is high. The specific content is as follows:

With reference to Figures 1 to 5, the measuring device for the static stiffness of the rolling linear guide rail pair of the present invention includes a loading assembly, a supporting assembly, a clamping assembly, a measuring assembly and a data processing module. The loading assembly includes a servo motor 5, a reducer 6, A loading trapezoidal screw 7, loading nut 8 and anti-rotation beam 3; the support assembly includes a base 1, a pair of columns 2, an upper beam 4, a magnetic table base 14 (reference numerals 1401, 1402, 1403 in Fig. 2 , 1404 refer to the magnetic bases) (four magnetic bases 1401, 1402, 1403, 1404 are required for vertical and pitch static stiffness detection, and two magnetic bases 1401, 1402, 1403, 1404 are required for deflection static stiffness detection), table panel 16; The clip assembly includes a force sensor force application rod 10, an upper fixture connector 11, a guide rail upper fixture 12, and a guide rail lower fixture 15; the measurement assembly includes a force sensor 9 and a laser displacement sensor 13 (reference numerals 1301, 1302, 1303 and 1304 refer to laser displacement sensors, the number of which corresponds to the magnetic base), the data processing module is the computer processing system required for data processing; the servo motor 5 is connected to the reducer 6, and the reducer 6 is installed on the upper beam 4, the trapezoidal screw 7 is connected with the reducer 6 through the bearing in the upper beam 4, the loading nut 8 is installed on the trapezoidal screw 7, and moves up and down with the rotation of the trapezoidal screw 7, and the loading nut 8 is fixedly installed with Anti-rotation crossbeam 3, the two ends of anti-rotation crossbeam 3 have through holes, can be set on a pair of columns 2 symmetrically installed on the left and right sides and can move up and down. The lower end is fixedly installed on the base 1, and a table panel 16 is installed on the base 1; a force sensor 9 for measuring the load is fixedly installed on the loading nut 8, and the force sensor 9 is connected with a force sensor force rod 10 by threads, and the force sensor 10 is connected on the guide rail. The fixture 12 is connected with the force sensor force rod 10 through the upper fixture connector 11, the lower fixture 15 of the guide rail is installed on the table panel 16, the magnetic table base 14 is placed on the surface of the table panel 16, and the laser displacement sensor 13 is installed on the corresponding magnetic table base On the bracket of 14, the center position of the light projection of the laser displacement sensor 13 is vertically aligned with the corresponding measuring point in the vertical, deflection or pitch load mode, and the laser displacement sensor 13, the force sensor 9 and the servo motor 5 are respectively connected with the computer processing system; Motor 5, reducer 6, a loading trapezoidal screw 7, loading nut 8, force sensor 9, force sensor force rod 10, upper fixture connector 11 coaxial line; anti-rotation beam 3, upper beam 4, table panel 16. The planes of the base 1 are parallel.

Referring to Fig. 1, the base 1 of the rolling linear guide pair static stiffness measuring device of the present invention is processed by casting, and holes are opened at both ends of the upper surface for installing a pair of columns 2, and heat treatment is carried out by annealing, quenching, etc., and its interior is welded. The reinforcing rib is used to enhance the overall rigidity of the base 1 .

In conjunction with Fig. 3, the upper part of the upper fixture connector 11 of the rolling linear guide pair static stiffness measuring device of the present invention is a plate-like part, on which bolt holes are evenly distributed along the circumferential direction, and are used to connect with the force sensor force rod 10 through bolts, Its position and size correspond to the bolt hole on the force sensor force rod 10, and its lower part is a stud, which is used to connect with the lower guide rail upper fixture 12 through threads.

3 to 5, the guide rail upper fixture 12 is a vertical loading upper fixture 1201, a deflection loading upper fixture 1202 or a pitch loading upper fixture 1203, a vertical loading upper fixture 1201, a deflection loading upper fixture 1202 or a pitch loading upper fixture 1203. The lower surface is distributed with measuring points for measuring the deformation displacement of vertical, deflection and pitch loading; screw holes and countersunk holes are set on the fixture 12 on the guide rail, and the screw holes and countersunk holes are determined according to the threaded holes on the slider of the guide rail pair 17 At the same time, there is a threaded hole at the symmetrical center of the upper surface of the vertical loading fixture 1201, or the deflection loading fixture 1202 is also provided with a threaded hole on the left or right side of the screw hole, or the pitch loading fixture 1203 There are also threaded holes on the front or rear side of the screw holes. These threaded holes are used to connect with the screw rod at the lower part of the force sensor force rod 10. If a deflection moment or a pitching moment above 1.5KNm is to be applied to the guide rail pair, the thread needs to be If a force of more than 10KN is applied vertically, the offset distance between the center of the threaded hole and the symmetrical center of the screw hole on the slider of the guide rail should be 150mm, and the diameter of the threaded hole should be at least 30mm.

In conjunction with Fig. 3, the shape of the lower clamp 15 of the guide rail is an I-shape, the upper part is provided with threaded holes, and the lower part is provided with screw holes, the threaded holes are determined according to the distribution of the screw holes of the guide rail pair 17 guide rails, and according to the threaded holes of the table panel 16 The position of the screw holes is determined by the distribution of the screw holes, and the lower surface of the protruding part on both sides of the upper part is distributed with measuring points for measuring the displacement when the vertical load is applied.

In combination with Fig. 2 to Fig. 7, the present invention uses the above-mentioned static stiffness measuring device of the rolling linear guide rail to measure the static stiffness of the rolling linear guide rail by switching different fixtures on the guide rail and detecting the displacement of the measuring point at a specific position. The steps are as follows:

(1) Take a section of the guide rail pair 17 as the measurement object before the measurement: the length of the guide rail of the intercepted rolling linear guide rail pair 17 is shorter than the length of the lower fixture 15 of the guide rail.

(2) Preparatory work before measurement: install the lower fixture 15 of the guide rail and the pair of guide rails 17 on the corresponding position of the table panel 16 according to the vertical, deflection or pitch loading method to be measured, and install the upper fixture 12 of the guide rail and the upper fixture connector in sequence 11. Adjust the position of the loading nut 8, connect the upper fixture connector 11 to the force sensor force rod 10, the center position of the light projection of the laser displacement sensor 13 is vertically aligned with the corresponding measurement points of different load modes, and turn on the computer processing system. And check whether the connected system works normally.

The corresponding position of installing the lower fixture 15 of the guide rail and the pair of guide rails 17 to the table panel 16 according to the loading method that needs to be measured is: when loading vertically, the lower fixture 15 of the guide rail is installed on the symmetrical plane position of the table panel 16 of the test bench, Install the guide rail pair 17 on the guide rail lower fixture 15, and move the position of the guide rail pair 17 slider so that it is located directly below the force sensor force rod 10; At the eccentric position of the axis of the rod 10, install the guide rail pair 17 on the lower fixture 15 of the guide rail, and move the position of the slider of the guide rail pair 17 so that it is located in the middle of the guide rail (to ensure that the load action line is located outside the slider area of the guide rail pair 17 ); during pitch loading, install the lower fixture 15 of the guide rail on the symmetrical plane position of the table panel 16, install the guide rail pair 17 on the lower guide rail fixture 15, and move the position of the slider of the guide rail pair 17 so that it is located at the position of the guide rail pair 17 At the pitch loading position at one end of the guide rail (to ensure that the line of action of the loaded load is located outside the slider area of the guide rail pair 17).

Installing the upper clamp 12 and the upper clamp connector 11 of the guide rail in sequence, adjusting the position of the loading nut 8, and connecting the upper clamp connector 11 to the force sensor applying rod 10 is: on the slider of the guide rail pair 17, install it with screws The upper clamp 12 on the guide rail is screwed into the screw rod of the upper clamp connector 11 in the threaded hole of the upper clamp 12 on the guide rail, and the upper clamp connector 11 is aligned with the axis of the bolt hole of the force sensor force rod 10. , drive the servo motor 5 to adjust the position of the loading nut 8 so that the lower surface of the force sensor force rod 10 is in close contact with the upper clamp connector 11 and generate a pre-tightening force, and the upper clamp connector 11 and the force sensor force rod 10 are connected by bolts .

The measurement points corresponding to the different load modes of vertically aligning the light projection center position of the laser displacement sensor 13 are: when vertically loaded, the measurement points are: symmetrical about the left and right sides of the slide block A of the guide rail pair 17, vertically loaded Measuring point 1 and measuring point 2 on the lower surface of fixture 1201 are respectively 5~10 mm away from the left and right sides of the slider of guide rail pair 17, and measuring point 3 and measuring point 4 on the lower surface of guide rail lower fixture 15 are from the left and right sides of the guide rail lower fixture 15. , D is 5~10mm, these 4 measuring points are all located on the symmetrical plane B at the front and back of the slider; when the deflection is loaded, the measuring points are: symmetrical about the symmetrical plane A of the left and right sides of the slider of the guide rail pair 17, and when the deflection is loaded Measuring point 1 and measuring point 2 on the lower surface of fixture 1202 are respectively 5~10mm away from the left and right surfaces of the slider. The measuring point 1 and measuring point 2 are located on the symmetrical plane B at the front and rear of the slider; when the pitch is loaded, the measuring point is : It is symmetrical about the front and back symmetry plane B of the slide block of the guide rail pair 17, the measuring points 5, 6, 7, and 8 on the lower surface of the upper fixture 1203 under pitch loading are 5-10 mm away from the left and right surfaces of the slider, and the measuring points 5, 6 and Measuring points 7 and 8 are respectively located on both sides of the guide rail of the guide rail pair 17 .

(3) Preload the tested guide rail pair 17 first, and the preloaded load value is 1~5% of the rated dynamic load of the guide rail pair 17, which is mainly used to eliminate the gap between various components.

(4) On the basis of preloading, set the indication values of the force sensor 9 and the laser displacement sensor 13 to the initial values, and then carry out measurement loading, and within the rated dynamic load range of 5%-50%, press no more than Load and maintain constant pressure for 30-60s at intervals of 5% sequentially, and collect the loads of each constant pressure stage and the corresponding displacement data in different loading modes at the same time. The corresponding displacement data during the different load modes is: during vertical loading, the deformation displacement of the guide rail pair 17 in the vertical direction is ,in , is the displacement of the lower surface of the upper fixture 1201 relative to the upper surface of the table top 16 when vertically loaded, , is the displacement of the lower surface of the lower fixture 15 of the guide rail relative to the upper surface of the table panel 16; when the deflection is loaded, the deformation angular displacement of the guide rail pair in the deflection direction is ,in, , For the displacement of the upper fixture 1202 relative to the upper surface of the table panel 16 for deflection loading, the distance between the measuring points 1 and 2 is ; When the pitch is loaded, the deformation angular displacement of the guide rail pair in the pitch direction is ,in, , , , is the displacement of the lower surface of the upper fixture 1203 relative to the upper surface of the table panel 16, the distance between the measuring points 5 and 6 or the measuring points 7 and 8 is L, and L is not less than the length of the slide block of the guide rail pair 17 .

(5) Process the sampled data, fit all the data points, eliminate abnormal points, and draw the static stiffness curves of the rolling linear guide pair 17 under different load modes (the vertical static stiffness takes N as the abscissa unit, Draw the static stiffness curve for the ordinate unit; Nm is the abscissa unit for the yaw and pitch static stiffness, mrad is the ordinate unit to draw the static stiffness curve), and the reciprocal of the slope of the curve is the static stiffness value of the guide rail pair 17.

(6) After loading to 50% of the rated dynamic load of the guide rail pair 17, the unloading condition is performed, and the change of the load and displacement is measured in real time until the unloading is zero, and the data collection work is ended at the same time.

Through the above implementation process, the automatic measurement of the vertical static stiffness, deflection static stiffness and pitch static stiffness of the rolling linear guide rail pair is realized by adopting the device and its method of the present invention, the loading load is large, the measurement accuracy is high, and it can meet the needs of different guide rail series. The need for different loading methods of vertical, deflection, and pitch.

Claims (9)

1. A rolling linear guide rail pair static stiffness measuring device, characterized in that it includes a loading assembly, a supporting assembly, a clamping assembly, a measuring assembly and a data processing module, and the loading assembly includes a servo motor (5), a speed reducer (6 ), a loading lead screw (7), a loading nut (8) and an anti-rotation beam (3); the support assembly includes a base (1), a pair of columns (2), an upper beam (4), a magnetic table ( 14), table panel (16); the clamping assembly includes a force sensor force rod (10), an upper clamp connector (11), a guide rail upper clamp (12), and a guide rail lower clamp (15); the measuring assembly includes a force sensor ( 9) with the laser displacement sensor (13), the data processing module is the computer processing system required for data processing; the servo motor (5) is connected with the reducer (6), and the reducer (6) is installed on the upper beam (4), The trapezoidal screw (7) is connected to the reducer (6) through the bearing in the upper beam (4), and the loading nut (8) is installed on the trapezoidal screw (7), and moves up and down with the rotation of the trapezoidal screw (7). Movement, the anti-rotation beam (3) is fixedly installed on the loading nut (8), and the two ends of the anti-rotation beam (3) have through holes, which can be sleeved on a pair of columns (2) installed symmetrically on the left and right sides and can be moved up and down Move, the upper end of a pair of columns (2) is then equipped with upper crossbeam (4), and column (2) lower end is then fixedly installed on the base (1), and table panel (16) is installed on the base (1); Loading nut ( 8) A force sensor (9) for measuring the load is fixedly installed on the top, the force sensor (9) is connected with a force sensor force rod (10) through a thread, and the upper clamp (12) of the guide rail is connected to the upper clamp connector (11) The force sensor force bar (10) is connected, the clamp (15) under the guide rail is installed on the table panel (16), the magnetic table base (14) is placed on the surface of the table panel (16), and the laser displacement sensor (13) is installed on the corresponding On the bracket of the magnetic table base (14), the light projection center position of the laser displacement sensor (13) is vertically aligned with the corresponding measuring point in the vertical, deflection or pitch load mode, and the laser displacement sensor (13), force sensor (9) and The servo motor (5) is respectively connected with the computer processing system; the servo motor (5), the reducer (6), a loading trapezoidal screw (7), the loading nut (8), the force sensor (9), and the force applied by the force sensor The bar (10), the upper clamp connector (11) are coaxial; the planes of the anti-rotation beam (3), the upper beam (4), the table panel (16), and the base (1) are parallel. 2. The static stiffness measuring device of rolling linear guide rail pair according to claim 1, characterized in that the upper part of the upper fixture connector (11) is a disc-like part, on which bolt holes are evenly distributed along the circumferential direction, for connecting with The force sensor force rod (10) is connected by bolts, its position and size correspond to the bolt holes on the force sensor force rod (10), and its lower part is a stud, which is used to connect with the lower guide rail upper fixture (12) through threads to connect. 3. The static stiffness measurement device for rolling linear guide rails according to claim 1, characterized in that the guide rail upper fixture (12) is a vertical loading upper fixture (1201), a deflection loading upper fixture (1202) or a pitch loading upper fixture (1203), the lower surface of the vertical loading upper fixture (1201), the deflection loading upper fixture (1202) or the pitch loading upper fixture (1203) is distributed with measuring points for measuring the deformation displacement during vertical, deflection and pitch loading; the guide rail upper fixture Set screw holes and countersunk holes on (12), determine the position and diameter of the screw holes and countersunk holes according to the threaded holes on the slider of the guide rail pair (17), and load the symmetrical center of the upper surface of the upper fixture (1201) vertically at the same time There are also threaded holes at the position, or the deflection loading upper fixture (1202) also has threaded holes on the left or right side of the screw holes, or the pitch loading upper fixture (1203) also has threaded holes on the front or rear side of the screw holes Holes, these threaded holes are used to be connected with the screw rod of force sensor force rod (10) bottom. 4. The static stiffness measuring device of rolling linear guide rail according to claim 1, characterized in that the lower clamp (15) of the guide rail is in the shape of an I-shaped, the upper part is provided with threaded holes, and the lower part is provided with screw holes, according to the guide rail pair (17) The threaded holes are determined by the distribution of the screw holes of the guide rail, and the position of the screw holes is determined according to the distribution of the threaded holes of the table panel (16). The lower surface of the protruding part on both sides of the upper part is distributed with the measurement of displacement when vertical loading point. 5. A method for measuring static stiffness utilizing the rolling linear guide pair static stiffness measuring device according to claim 1, 2, 3 or 4, characterized in that the steps are as follows: (1) intercept a section of guide rail pair (17) before measurement as the measurement object: the guide rail length of the intercepted rolling linear guide rail pair (17) is shorter than the length of the lower fixture (15) of the guide rail; (2) Preparatory work before measurement: install the lower fixture (15) and the pair of guide rails (17) on the corresponding position of the table panel (16) according to the vertical, deflection or pitch loading method to be measured, and install the upper fixture on the guide rail in sequence (12), the upper fixture connector (11), adjust the position of the loading nut (8), connect the upper fixture connector (11) to the force sensor force rod (10), the light projection of the laser displacement sensor (13) The center position is vertically aligned with the corresponding measurement points of different load modes, and the computer processing system is turned on to check whether the connected system is working normally; (3) Preload the tested guide rail pair (17) first, and the preloaded load value is 1 to 5% of the rated dynamic load of the guide rail pair (17); (4) On the basis of preloading, set the indication values of the force sensor (9) and the laser displacement sensor (13) to the initial value, and then carry out measurement loading, and within the range of 5%-50% of the rated dynamic load range , according to the interval of no more than 5% of the loading and maintaining constant pressure for 30-60s, and at the same time collect the load of each constant pressure stage and the corresponding displacement data in different loading modes; (5) Process the sampled data, fit all data points, eliminate abnormal points, and draw the static stiffness curves of the rolling linear guide pair (17) under different load modes, and the reciprocal of the slope of the curve is the guide rail pair (17) Static stiffness value; (6) After loading to 50% of the rated dynamic load of the guide rail pair (17), carry out the unloading condition, measure the change situation of load and displacement in real time simultaneously, until the unloading is zero, and end the data acquisition work simultaneously. 6. The method for measuring static stiffness of a rolling linear guide according to claim 5, characterized in that in step (2), the lower fixture (15) and the guide rail pair (17) are installed on the table panel according to the loading method to be measured The corresponding position of (16) is: when loading vertically, install the lower fixture (15) of the guide rail on the symmetrical plane position of the table panel (16) of the test bench, and install the guide rail pair (17) on the lower fixture of the guide rail (15) , move the position of the slider of the guide rail pair (17) so that it is located directly below the force sensor force rod (10); when deflecting loading, install the lower clamp (15) of the guide rail to the axis of the force sensor force rod (10) At the eccentric position, install the guide rail pair (17) on the guide rail lower fixture (15), and move the position of the guide rail pair (17) slider so that it is located in the middle of the guide rail; when pitching, place the guide rail lower fixture (15) Install it on the symmetrical plane of the table panel (16), install the guide rail pair (17) on the guide rail lower fixture (15), and move the position of the guide rail pair (17) slider so that it is located on the guide rail of the guide rail pair (17) at the pitch loading position at one end. 7. The method for measuring the static stiffness of rolling linear guide rail pair according to claim 5, characterized in that in the step (2), the described installation of the upper clamp (12) and the upper clamp connector (11) of the guide rail in sequence, and the adjustment of the loading nut ( 8) position, the upper clamp connector (11) is connected to the force sensor force rod (10) is: the upper clamp (12) on the guide rail is installed on the slider of the guide rail pair (17) by screws, and the upper clamp on the guide rail Screw the screw rod of the upper clamp connector (11) into the threaded hole of (12), and make the upper clamp connector (11) align with the axis of the force sensor force rod (10) bolt hole, and the screw-in length is 1/2 of the screw thread length. Drive the servo motor (5) to adjust the position of the loading nut (8) so that the lower surface of the force sensor force rod (10) is in close contact with the upper fixture connector (11) and produces a pre-tightening force, and the upper fixture connector ( 11) and the force sensor force rod (10). 8. The method for measuring the static stiffness of rolling linear guide rails according to claim 5, characterized in that in step (2), the center position of the light projection of the laser displacement sensor (13) is vertically aligned with the corresponding measurement of different load modes. The point is: during vertical loading, the measurement points are: about the symmetry plane A of the slide block of the guide rail pair (17), the measuring point 1 and the measuring point 2 on the lower surface of the upper fixture (1201) are respectively separated from the guide rail pair ( 17) The left and right sides of the slide block are 5-10mm, and the measuring point 3 and measuring point 4 on the lower surface of the guide rail lower fixture (15) are 5-10mm away from the left and right sides C and D of the guide rail lower fixture (15). The points are all located on the front and rear symmetry plane B of the slider; during deflection loading, the measurement point is: the measurement point on the lower surface of the upper fixture (1202) under deflection loading with respect to the symmetry plane A of the left and right sides of the slider of the guide rail pair (17) Measuring point 1 and measuring point 2 are respectively 5-10 mm away from the left and right surfaces of the slider. The measuring point 1 and measuring point 2 are located on the symmetrical plane B at the front and back of the slider; when pitching and loading, the measuring point is: about the guide rail pair (17) The symmetry plane B at the front and back of the slider is symmetrical, and the measuring points 5, 6, 7, and 8 on the lower surface of the upper fixture (1203) for pitch loading are 5-10mm away from the left and right surfaces of the slider, and the measuring points 5, 6 and 7 are , 8 are positioned at the guide rail both sides of guide rail pair (17) respectively. 9. The method for measuring the static stiffness of rolling linear guide rail pairs according to claim 5, characterized in that in step (4), the displacement data corresponding to the different loads is: when vertically loaded, the guide rail pair (17) in the vertical direction The deformation displacement is Among them, s ₁ and s ₂ are the displacements of the lower surface of the upper fixture (1201) relative to the upper surface of the table top (16) under vertical loading, and s ₃ and s ₄ are the displacements of the lower surface of the lower fixture (15) of the guide rail relative to the top surface of the table top ( 16) The displacement of the upper surface; when the deflection is loaded, the deformation angular displacement of the guide rail pair in the deflection direction is Among them, s ₁ and s ₂ are the displacement of the upper fixture (1202) relative to the upper surface of the table panel (16) under deflection loading, and the distance between measuring points 1 and 2 is l; The deformation angular displacement is Among them, s ₅ , s ₆ , s ₇ , and s ₈ are the displacements of the lower surface of the pitching upper fixture (1203) relative to the upper surface of the table panel (16), and the distance between measuring points 5 and 6 or measuring points 7 and 8 The distance is L, and L is not less than the length of the slider of the guide rail pair (17)