CN112683443B - An air-floating dynamic torque calibration device and calibration method - Google Patents

Abstract

The invention discloses an air floatation type dynamic torque calibration device and method, and belongs to the technical field of metering. The excitation motor, the torque sensor to be detected, the third laser range finder, the fourth laser range finder, the air floatation bearing and the auto-collimation light pipe are all installed on the base, the first laser range finder and the second laser range finder are respectively installed at the left end and the right end of the top of the air floatation bearing, the air floatation bearing supports the load shaft to be supported by the inner ring of the air floatation bearing, the rotor part of the excitation motor, the rotor part of the torque sensor to be detected, the first standard mass module, the first grating encoder, the air floatation bearing supports the load shaft, the second grating encoder, the second standard mass module and the plane mirror are sequentially fixed and locked by high-strength screws from left to right to form a rotating shaft system, the auto-collimation light pipe is installed on the right side of the base, and the lens of the auto-collimation light pipe is aligned with the plane mirror. The minimum calibration range of the invention is 200Nm, and the maximum calibration range can reach 2000 Nm; the calibration frequency range is 0-10 Hz.

Description

A kind of air-floating dynamic torque calibration device and calibration method

technical field

The invention relates to an air-floating dynamic torque calibration device and a calibration method, belonging to the technical field of measurement.

Background technique

The current status of torque calibration is mostly static calibration, there are problems such as no unified dynamic calibration specification, insufficient range (the maximum range is below 500Nm), and low accuracy, which cannot meet the torque measurement needs of various industrial fields.

In addition, the actual working state of many test systems is mostly in the form of dynamic loading, including typical sine, trapezoidal, sawtooth and other loading methods, which requires clarifying the dynamic characteristics of the torque sensor to ensure the reliability of its work.

In view of the above problems, it is very necessary to carry out research on the traceability technology of dynamic torque value. By studying the theory of dynamic torque value traceability, a dynamic torque calibration method is proposed, and a set of high-torque high-precision dynamic torque calibration device is developed to achieve accurate torque sensor accuracy. Dynamic calibration, improve equipment support capabilities, and enhance my country's technical foundation support and work support capabilities in this field.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose an air-floating dynamic torque calibration device and calibration method to solve the problems existing in the prior art.

An air-floating dynamic torque calibration device, the calibration device includes a base, the calibration device further includes an excitation motor, a torque sensor to be measured, a first laser range finder, a third laser range finder, and a first standard quality module , the first grating encoder, the air bearing, the air bearing supporting the load shaft, the second grating encoder, the second standard mass module, the second laser distance meter, the fourth laser distance meter, the plane mirror and the self-collimating light tube, wherein the excitation motor, the torque sensor to be measured, the third laser rangefinder, the fourth laser rangefinder, the air bearing and the self-collimating light tube are all mounted on the base, and the first laser The distance meter and the second laser distance meter are respectively installed on the left and right ends of the top of the air bearing, the air bearing supporting the load shaft is supported by the inner ring of the air bearing, the rotor part of the excitation motor , The rotor part of the torque sensor to be measured, the first standard mass module, the first grating encoder, the air bearing supporting the load shaft, the second grating encoder, the second standard mass module and the plane mirror pass high-strength screws in sequence from left to right A rotating shaft system is formed by being fixed and locked, the self-collimating light pipe is installed on the right side of the base, and the lens of the self-collimating light pipe is aligned with the plane mirror.

Further, the first laser range finder and the third laser range finder are installed radially and vertically at an angle of 90°, so that the ranging lasers emitted by the first laser range finder and the third laser range finder are in space. At an angle of 90°, the reflection point is on the radial end face of the disc of the first standard mass module.

Further, the second laser range finder and the fourth laser range finder are installed radially and vertically at an angle of 90°, so that the ranging lasers emitted by the second laser range finder and the fourth laser range finder are in space. At an angle of 90°, the reflection point is on the radial end face of the disc of the second standard mass module.

Further, the rotor and the stator of the torque sensor to be measured are connected by means of wireless communication.

Further, the first standard quality module and the second standard quality module are prefabricated parts with known mass and size.

An air-floating dynamic torque calibration method, based on the above-mentioned air-floating dynamic torque calibration device, the calibration method comprises the following steps:

Step 1. In the rotating shaft system, set the left side of the torque sensor to be measured, including the torque sensor to be measured as the excitation part, and set the right side of the torque sensor to be measured as the load part;

Step 2: Assemble the air-floating dynamic torque calibration device, do not install the first standard mass module and the second standard mass module for the time being, and assemble and form the remaining components of the rotating shaft system from left to right;

Step 3, energizing the stator of the excitation motor, and the rotor of the excitation motor drives the rotating shaft system without the first standard mass module and the second standard mass module to perform sinusoidal swing according to the set sinusoidal swing;

Step 3: Measure the moment of inertia I ₀ of the load part without the first standard mass module and the second standard mass module by the torsional pendulum method;

Step 4. Add the first standard mass module and the second standard mass module with a known moment of inertia into the rotating shaft system, and reassemble the rotating shaft system, wherein the standard mass module and the second standard mass module are The sum of the moment of inertia of the standard mass module is I ₁ ;

Step 5: Rotate the rotating shaft system to make a sinusoidal swing, measure the angle data of the load part synchronously through the first grating encoder and the second grating encoder, and perform a second differential on the measured angle data And after the comparison processing, the angular acceleration of the load part is obtained

Step 6. Calculate the dynamic torque value according to the following formula:

Further, in step 3 and step 5, through the self-collimating light pipe and the first laser rangefinder, the third laser rangefinder, the second laser rangefinder and the fourth laser rangefinder The instrument measures the real-time spatial attitude of the rotating shaft system at the same time, and obtains the measurement data under different measurement methods. Through synchronous measurement control, the difference of the measurement data is compared in time order, and the dynamic motion attitude error of the shaft system is analyzed to improve the dynamic torque measurement. accuracy,

In order to improve the measurement accuracy of the angle when the shafting rotates, the eccentricity of the shafting when the shafting is moved is detected in real time by a laser rangefinder. The first laser rangefinder and the third laser rangefinder are installed radially and vertically at a 90° angle. Taking the center of the initial axis section O as the origin of coordinates, the straight lines where the two ranging lasers emitted by the first laser range finder and the third laser range finder are located are set as the x-axis and the y-axis respectively, and a rectangular coordinate system is established, and Make the laser range finder in the positive direction of the coordinate axis. From the above coordinate system design, it can be known that the measuring point of the third laser range finder on the shaft system is located on the x-axis, and the first laser range finder on the shaft system. The measuring point is located on the y-axis, then the coordinate of the measuring point of the third laser rangefinder on the axis system is (X, 0), and the coordinate of the measuring point of the first laser rangefinder on the axis system is B(0 , Y),

Assuming that the axis of the shafting section rotates from the state of circle O, the axis is deviated and becomes the state of circle O', that is, its axis is translated from O(X ₀ , Y ₀ ) to O'(X' ₀ , Y' ₀ ), at this time , the measuring point of the third laser range finder moves from A(X ₁ , 0) to A'(X' ₁ , 0), and the measuring point of the first laser range finder changes from B(0, Y ₂ ) to B '(0, Y' ₂ ), at the same time, the variation of the distance measurement value of the third laser range finder is dLx, and the variation of the distance measurement value of the first laser range finder is dLy. By measuring, the real-time values of dLx and dLy can be obtained, then the real-time coordinate values of O'(X' ₀ , Y' ₀ ) can be obtained by calculating dLx and dLy, and the eccentric distance e of the shaft system can be calculated by the distance formula between two points in space, as follows:

After obtaining the real-time value of the shafting eccentricity distance e, the second laser rangefinder and the fourth laser rangefinder can also measure a set of shafting eccentricity data, which is consistent with the first laser rangefinder and the third laser rangefinder. The average value of the measured data can improve the accuracy of the measurement, and through the real-time measurement data of the self-collimating light tube, the inclination error data of the shaft system during the rotation process can be obtained, and the error data can be measured with the laser rangefinder. The joint analysis of the data can obtain the angle measurement error component δ of the grating encoder caused by the eccentricity of the shaft system, so that this error δ can be removed from the angle measurement data of the grating encoder, so as to achieve the purpose of improving the angle measurement accuracy.

In addition, according to the parallel axis theorem of the moment of inertia of the rigid body, through the eccentric distance e of the shaft system, the moment of inertia of the rigid body rotating around the main axis can also be obtained,

I'=I+me ²

Among them, I is the moment of inertia of the rigid body rotating around the shaft system when the shaft system is not deflected; I' is the moment of inertia of the rigid body rotating around the main axis when the shaft system is deflected; m is the mass of the rigid body,

Then, the dynamic torque value calculation formula can be expressed as follows:

The main advantages of the present invention are: an air-floating dynamic torque calibration device and a calibration method proposed by the present invention, the present invention decomposes and traces the dynamic torque amount to the moment of inertia and angular acceleration, and traces the source to the world through the moment of inertia and angular acceleration The basic unit, refer to Figure 4, the minimum calibration range is 200Nm, the maximum can reach 1000Nm; the calibration frequency range is 0 ~ 10Hz. The invention can realize the multi-range dynamic calibration of the torque sensor by adjusting the standard mass disc.

Description of drawings

Fig. 1 is the principle block diagram of a kind of air-floating dynamic torque calibration method of the present invention;

2 is a front view of the structure of an air-floating dynamic torque calibration device of the present invention;

Fig. 3 is the top view of Fig. 2;

Figure 4 is the traceability diagram of the dynamic torque calibration method;

Figure 5 is a schematic diagram of the eccentricity of the shafting section.

Among them, 1 is the excitation motor, 2 is the torque sensor to be measured, 3 is the first laser distance meter, 4 is the third laser distance meter, 5 is the first standard quality module, 6 is the first grating encoder, and 7 is the The air bearing supports the load shaft, 8 is the second grating encoder, 9 is the second standard mass module, 10 is the second laser rangefinder, 11 is the fourth laser rangefinder, 12 is a plane mirror, and 13 is an auto-collimation Light pipe, 14 is the base.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

2-3, an air-floating dynamic torque calibration device, the calibration device includes a base 14, the calibration device further includes an excitation motor 1, a torque sensor 2 to be measured, and a first laser distance meter 3 , the third laser rangefinder 4, the first standard mass module 5, the first grating encoder 6, the air bearing, the air bearing supporting the load shaft 7, the second grating encoder 8, the second standard mass module 9, the first Two laser rangefinders 10, a fourth laser rangefinder 11, a plane mirror 12 and an auto-collimating light pipe 13, wherein the excitation motor 1, the torque sensor to be measured 2, the third laser rangefinder 4, the fourth laser The range finder 11 , the air bearing and the self-collimating light pipe 13 are all mounted on the base 14 , and the first laser range finder 3 and the second laser range finder 10 are respectively mounted on the top of the air bearing The left and right ends of the air bearing support the load shaft 7 by the inner ring of the air bearing, the rotor part of the excitation motor 1, the rotor part of the torque sensor 2 to be measured, the first standard mass module 5, The first grating encoder 6, the air bearing support load shaft 7, the second grating encoder 8, the second standard mass module 9 and the plane mirror 12 are sequentially fixed and locked by high-strength screws from left to right to form a rotating shaft system. The self-collimating light pipe 13 is installed on the right side of the base 14 , and the lens of the self-collimating light pipe 13 is aligned with the plane mirror 12 .

Further, the first laser range finder 3 and the third laser range finder 4 are installed vertically at an angle of 90° radially, so that the measurement of the first laser range finder 3 and the third laser range finder 4 At an angle of 90° in space from the laser light, the reflection point is on the radial end face of the disc of the first standard mass module 5 .

Further, the second laser range finder (10) and the fourth laser range finder 11 are installed vertically at an angle of 90° radially, so that the second laser range finder 10 and the fourth laser range finder 11 emit light. The ranging laser is at an angle of 90° in space, and the reflection point is on the radial end face of the disc of the second standard mass module 9 .

Further, the rotor and the stator of the torque sensor 2 to be measured are connected by means of wireless communication.

Further, the first standard quality module 5 and the second standard quality module 9 are prefabricated parts whose quality and size are known.

Referring to FIG. 1, an air-float dynamic torque calibration method, based on the above-mentioned air-float dynamic torque calibration device, the calibration method includes the following steps:

Step 1, in the rotating shaft system, set the left side of the torque sensor 2 to be measured as the excitation part, and set the right side of the torque sensor 2 to be measured as the load part;

Step 2: Assemble the air-floating dynamic torque calibration device, do not install the first standard mass module 5 and the second standard mass module 9 for the time being, and assemble the remaining components of the rotating shaft system from left to right. ;

Step 3: Power on the stator of the excitation motor 1, and the rotor of the excitation motor 1 drives the rotating shaft system without the first standard mass module 5 and the second standard mass module 9 according to the set sinusoidal oscillation mode. sinusoidal swing;

Step 3: Measure the moment of inertia I ₀ of the load part without the first standard mass module 5 and the second standard mass module 9 by the torsion method;

Step 4. Add the first standard mass module 5 and the second standard mass module 9 with a known moment of inertia into the rotating shaft system, and reassemble the rotating shaft system, wherein the standard mass module 5 and the sum of the moment of inertia of the second standard mass module 9 is I ₁ ;

Step 5: Rotate the rotating shaft system to make a sinusoidal swing, measure the angle data of the load part synchronously through the first grating encoder 6 and the second grating encoder 8, and perform two steps on the measured angle data. After sub-differentiation and comparison processing, the angular acceleration of the load part is obtained

Step 6. Calculate the dynamic torque value according to the following formula:

In step 3 and step 5, the first laser rangefinder 3, the third laser rangefinder 4, the second laser rangefinder 10 and the fourth laser rangefinder are connected through the self-collimating light pipe 13 respectively. The distance meter 11 simultaneously measures the real-time spatial attitude of the rotating shaft system, obtains measurement data under different measurement methods, and compares the differences in the measurement data in time sequence through synchronous measurement control, analyzes the dynamic motion attitude error of the shaft system, and improves dynamic Accuracy of torque measurement.

Since the shaft center and axis will not be completely in the ideal position when the shaft system rotates, the angle data measured by the grating encoder will inevitably have certain errors. In order to improve the measurement accuracy of the angle when the shafting rotates, the eccentricity of the shafting movement is detected in real time by a laser range finder, as shown in Figure 5. The first laser range finder 3 and the third laser range finder 4 are installed vertically at a radial angle of 90°, and the center of the initial axis section O is the origin of the coordinates. The first laser range finder 3 and the third laser range finder The straight lines where the two ranging lasers emitted by the range finder 4 are respectively set as the x-axis and the y-axis, a rectangular coordinate system is established, and the laser range finder is placed in the positive direction of the coordinate axis. It can be known from the above coordinate system design that the measuring point of the third laser range finder 4 on the shaft system is located on the x-axis, and the measuring point of the first laser range finder 3 on the shaft system is located on the y-axis. Then, the coordinates of the measuring point of the third laser range finder 4 on the shaft system are , and the coordinates of the measuring point of the first laser range finder 3 on the shaft system are .

Suppose that the shafting section is rotated from the state of circle O, and the axis is deviated, and becomes the state of circle O', that is, its axis is translated from to. At this time, the measuring point of the third laser range finder 4 moves from to, and the measuring point of the first laser range finder 3 changes from to. Meanwhile, the variation of the distance measurement value of the third laser rangefinder 4 is dLx, and the variation of the distance measurement value of the first laser rangefinder 3 is dLy. The real-time values of dLx and dLy can be obtained through the two measurements before and after the laser rangefinder, then the real-time coordinate values can be calculated by dLx and dLy. The eccentric distance e of the shaft system is calculated by the distance formula between two points in space, and we get

After obtaining the real-time value of the shafting eccentricity distance e, the second laser rangefinder 10 and the fourth laser rangefinder 11 can also measure a set of shafting eccentricity data, which is consistent with the first laser The data measured by the distance meter 4 is averaged, which can improve the accuracy of the measurement. And through the real-time measurement data of the self-collimating light pipe 13, the inclination error data of the shaft system during the rotation process can be obtained, and the grating code caused by the eccentricity of the shaft system can be obtained by jointly analyzing this error data and the measurement data of the laser rangefinder. The angle measurement error component δ of the encoder can be removed, so that this error δ can be removed from the angle measurement data of the grating encoder, so as to achieve the purpose of improving the angle measurement accuracy.

In addition, according to the parallel axis theorem of the moment of inertia of the rigid body, through the eccentric distance e of the shaft system, the moment of inertia of the rigid body rotating around the main axis can also be obtained,

I'=I+me ²

Among them, I is the moment of inertia of the rigid body rotating around the shaft system when the shaft system is not deviated; I' is the moment of inertia of the rigid body rotating around the main axis when the shaft system is deviated; m is the mass of the rigid body.

Then, the dynamic torque value calculation formula can be expressed as follows:

The dynamic calibration range of the present invention is shown in Table 1,

Torque waveform Amplitude range Frequency Range Sine 200～1000Nm 0～10Hz

Table 1

The present invention can also have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations are all It should belong to the protection scope of the appended claims of the present invention.

Claims (7)

1. An air-floatation type dynamic torque calibration device comprises a base (14) and is characterized by further comprising an excitation motor (1), a torque sensor (2) to be tested, a first laser range finder (3), a third laser range finder (4), a first standard quality module (5), a first grating encoder (6), an air-floatation bearing supporting load shaft (7), a second grating encoder (8), a second standard quality module (9), a second laser range finder (10), a fourth laser range finder (11), a plane mirror (12) and a self-collimating light tube (13), wherein the excitation motor (1), the torque sensor (2) to be tested, the third laser range finder (4), the fourth laser range finder (11), the air-floatation bearing and the self-collimating light tube (13) are all installed on the base (14), first laser range finder (3) and second laser range finder (10) are installed respectively both ends about the air supporting bearing top, air supporting bearing supports load axle (7) by air supporting bearing's inner circle supports, excitation motor (1)'s rotor part, the rotor part of torque sensor (2) that awaits measuring, first standard quality module (5), first grating encoder (6), air supporting bearing support load axle (7), second grating encoder (8), second standard quality module (9) and plane mirror (12) loop through high strength screw fixation locking from a left side to the right side and form the rotating shaft system, auto-collimation light pipe (13) are installed the right side of base (14), the camera lens of auto-collimation light pipe (13) is aimed at plane mirror (12).

2. The air-float type dynamic torque calibration device as claimed in claim 1, wherein said first laser range finder (3) and said third laser range finder (4) are vertically installed in a radial direction at an angle of 90 ° so that the ranging laser light emitted from said first laser range finder (3) and said third laser range finder (4) forms an angle of 90 ° in space, and the reflection point is on the disk radial end face of said first proof mass module (5).

3. The air-float type dynamic torque calibration device as claimed in claim 1, wherein said second laser range finder (10) and said fourth laser range finder (11) are vertically installed in a radial direction at an angle of 90 ° so that the ranging laser emitted from said second laser range finder (10) and said fourth laser range finder (11) forms an angle of 90 ° in space, and the reflection point is on the disk radial end face of said second proof mass module (9).

4. The air-bearing type dynamic torque calibration device according to claim 1, wherein the rotor and the stator of the torque sensor under test (2) are connected by means of wireless communication.

5. The air-float type dynamic torque calibration device according to claim 1, characterized in that said first proof mass module (5) and second proof mass module (9) are prefabricated elements, of known mass and dimensions.

6. An air-floating type dynamic torque calibration method, based on any one of claims 1 to 5, characterized in that the calibration method comprises the following steps:

step one, in a rotating shaft system, the left side of a torque sensor (2) to be measured is arranged, the torque sensor (2) to be measured is used as an excitation part, and the right side of the torque sensor (2) to be measured is used as a load part;

step two, assembling the air floatation type dynamic torque calibration device, temporarily not installing the first standard mass module (5) and the second standard mass module (9), and assembling and molding the rest components of the rotating shaft system from left to right;

thirdly, powering up a stator of the excitation motor (1), and driving a rotating shaft system without the first standard mass module (5) and the second standard mass module (9) to do sinusoidal oscillation by a rotor of the excitation motor (1) according to a set sinusoidal oscillation mode;

step three, measuring the moment of inertia I of the load part without the first standard mass module (5) and the second standard mass module (9) by a torsional pendulum method ₀ ；

Fourthly, adding the first standard mass module (5) and the second standard mass module (9) with known rotational inertia into the rotating shaft system, and reassembling the rotating shaft system, wherein the sum of the rotational inertia of the standard mass module (5) and the second standard mass module (9) is I ₁ ；

Fifthly, the rotating shaft system rotates to do sinusoidal oscillation, angle data of the load part are synchronously measured through the first grating encoder (6) and the second grating encoder (8), the measured angle data are subjected to secondary differentiation and comparison processing, and then angular acceleration of the load part is obtained

Step six, calculating a dynamic torque value according to the following formula:

7. the air-floating type dynamic torque calibration method as claimed in claim 6, wherein in the third step and the fifth step, the auto-collimating light pipe (13) is used to measure the real-time spatial attitude of the rotating shafting simultaneously with the first laser range finder (3), the third laser range finder (4), the second laser range finder (10) and the fourth laser range finder (11) respectively, so as to obtain the measurement data in different measurement modes, and the measurement data differences are compared in time sequence by synchronous measurement control, so as to analyze the dynamic motion attitude error condition of the shafting and improve the accuracy of the dynamic torque measurement,

in order to improve the measurement accuracy of the angle when the shafting rotates, and detect the eccentricity condition when the shafting moves in real time through the laser range finders, the first laser range finder (3) and the third laser range finder (4) are vertically arranged in the radial direction at an angle of 90 degrees, the center of circle of the initial shaft section O is taken as the origin of coordinates, the straight lines of the two range finding lasers emitted by the first laser range finder (3) and the third laser range finder (4) are respectively set as an X axis and a y axis, a rectangular coordinate system is established, the laser range finders are positioned in the positive direction of coordinate axes, the coordinate system is designed to know that the measuring points of the third laser range finder (4) on the shafting are positioned on the X axis, the measuring points of the first laser range finder (3) on the shafting are positioned on the y axis, then the coordinates of the third laser range finder (4) on the shafting are (X,0), the coordinates of the measuring points of the first laser range finder (3) on the shafting are B (0), y) of the first group,

Assuming that the axis deviation occurs when the section of the axis system rotates from the circular O state to the circular O' state, i.e. the axis of the axis is O (X) ₀ ,Y ₀ ) Translated to O '(X' ₀ ,Y' ₀ ) At this time, the measuring point of the third laser range finder (4) is represented by A (X) ₁ 0) to A '(X' ₁ 0), the measuring point of the first laser range finder (3) is B (0, Y) ₂ ) Becomes B '(0, Y' ₂ ) Meanwhile, the variation of the distance measurement value of the third laser range finder (4) is dLx, the variation of the distance measurement value of the first laser range finder (3) is dLy, real-time values of dLx and dLy are obtained through two times of measurement before and after the laser range finder, and then O ' (X ') is obtained through calculation of dLx and dLy ' ₀ ,Y' ₀ ) Calculating the shafting eccentric distance e according to the space two-point distance formula to obtain the real-time coordinate value

After the real-time numerical value of the shafting eccentric distance e is obtained, a group of shafting eccentric data is also measured by the second laser range finder (10) and the fourth laser range finder (11), the average value is taken with the data measured by the first laser range finder (3) and the third laser range finder (4), the measurement accuracy is improved, the inclination angle error data of the shafting in the rotating process is obtained through the real-time measurement data of the autocollimation light pipe (13), the error data and the measurement data of the laser range finders are jointly analyzed to obtain the grating encoder angle measurement error component delta caused by the shafting eccentricity, so the error delta is removed from the angle measurement data of the grating encoder, and the purpose of improving the angle measurement accuracy is achieved,

In addition, according to the rigid body moment of inertia parallel axis theorem, the moment of inertia of the rigid body rotating around the main shaft is also obtained through the shafting eccentric distance e,

I'＝I+me ²

wherein, I is the moment of inertia of the rigid body rotating around the shafting when the shafting is not deviated; i' is the moment of inertia of the rigid body rotating around the main shaft when the shaft system is off-axis; m is the mass of the rigid body,

then, the dynamic torque value calculation formula may be expressed as follows:

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