CN209927119U - Roundness measuring system - Google Patents

Abstract

The utility model provides a roundness measuring system, comprising a roundness measuring frame, comprising a rotating shaft extending vertically, a connecting arm extending horizontally and fixed at point a of the rotating shaft, and a measuring arm extending vertically and fixed at point b of the connecting arm; The distance sensing device is fixed at point c of the measuring arm, and the sensing direction is parallel to the connecting arm, so as to detect the distance M between the sensing end and the surface of the measured circular part in the sensing direction; the inclination sensing device is used for the actual measurement of the sensing side. The inclination angle θ of the horizontal plane; the data acquisition and conditioning device communicates with the distance sensing device and the inclination angle sensing device to collect and condition the detection signal to form detection data; the data processing device receives the detection data, according to the distance between point a and point b L ₁ , The distance L ₂ between point b and point c, and the distances L ₃ , M and θ between the sensing end and c point, calculate the radial distance N between the sensing end and the surface of the circular part to be measured when the connecting arm is in a horizontal state at each angle, and calculate Using a preset program, calculate the roundness value of the measured circular part according to N.

Description

Roundness Measuring System

technical field

The utility model relates to the technical field of roundness measurement, in particular to a roundness measurement system.

Background technique

There are many large circular parts in hydropower equipment that need roundness measurement, such as the seat ring of the turbine, the leak-proof ring of the top cover and bottom ring, the generator stator, the upper and lower frames of the generator, the generator stator, rotor, Francis turbine The upper and lower o-rings of the runner, the journals of each guide bearing of the unit, the large shaft flange, etc.

A general roundness measurement system usually includes a round frame and a sensor for distance measurement. The circular measuring frame includes a rotating shaft arranged vertically and coaxially positioned with the measured circular part, a connecting arm extending horizontally with one end fixed to the top of the rotating shaft, and a measuring arm extending vertically with the top fixed on the other end of the connecting arm. The sensor is installed at the bottom of the measuring arm. During measurement, the rotating shaft rotates to multiple preset angles, and the sensor measures the radial distance between the sensing end of the sensor and the circumferential surface of the measured circular part at each angular position, so as to calculate the multi-point radius of the measured circular part. The point radius value calculates the roundness value.

However, due to the large size of the circular part, the connecting arm is usually long, and it is difficult to maintain the horizontal posture due to factors such as deflection and deformation, making it difficult to maintain the vertical posture of the measuring arm, and finally the sensing direction of the sensor may not be in the circular part. In the radial direction, the measured distance is not the radial distance. Therefore, in order to ensure the accuracy of the data, the angle calibration of the circular measuring frame is required before each measuring point is measured, and the operation is very complicated.

Utility model content

The purpose of the utility model is to overcome the above-mentioned defects of the prior art, and provide a roundness measurement system, which can avoid the angular deviation of the round measuring frame from affecting the roundness measurement accuracy in a simpler manner.

A further purpose of the present invention is to expand the applicable range of the roundness measuring system.

In particular, the present utility model provides a roundness measurement system, which includes:

A circular measuring frame, which includes a rotating shaft that extends vertically and is coaxially arranged with the circular part to be measured, a connecting arm that extends horizontally and is fixedly connected to point a at the top of the rotating shaft, and a vertical extending and top-end fixedly connected to point b of the connecting arm. measuring arm;

The distance sensing device is fixedly connected to point c at the bottom of the measuring arm, and the sensing direction of the sensing end is parallel to the connecting arm. The surface distance M of the tested circular part;

The inclination angle sensing device is installed on the connecting arm or the measuring arm, and is used to sense the inclination angle θ of the connecting arm relative to the horizontal plane during the actual measurement;

a data acquisition and conditioning device, in communication with the distance sensing device and the inclination sensing device in a preset manner, to collect and condition the detection signals thereof to form detection data; and

The data processing device communicates with the data acquisition and conditioning device in a preset manner to receive detection data, according to the distance L ₁ between point a and point b, the distance L ₂ between point b and point c, and the distance L between the sensing end and point c ₃ , M and θ, calculate the radial distance N between the sensing end and the surface of the tested circular part when the connecting arm is in a horizontal state at each preset angle, and use the preset program to calculate the tested circular part according to N roundness value.

Optionally, the data processing apparatus calculates N according to the following formula: N=L ₁ (1-cosθ)+Mcosθ+L ₃ (cosθ-1)+L ₂ sinθ.

Optionally, the distance sensing device is a non-contact displacement sensor.

Optionally, the inclination sensing device and the measuring arm are connected to the same end of the connecting arm.

Optionally, the circular measuring frame further includes: a positioning base for coaxial positioning with the measured circular part, the central axis of the positioning base extends in the vertical direction and is provided with a plurality of positioning positions that are rotationally symmetric relative to the central axis. a hole, on which the rotating shaft and the positioning base are coaxially mounted, and can rotate around the central axis of the positioning base, and the rotating shaft is provided with a positioning pin that can move up and down; And the circular measuring frame is configured so that the rotating shaft is manually rotated, and every time it rotates to an angle at which the positioning pin is opposite to the preset positioning hole, the positioning pin is moved down and inserted into the positioning hole, so as to prohibit the rotation of the rotating shaft, so that distance sensing can be performed. The device detects the distance M between the device and the surface of the measured circular part; or keeps the positioning pin at the position away from the positioning hole, and makes the motor run to drive the measuring arm to rotate continuously, so that the distance sensing device continuously detects the distance M between it and the measured circular part. The distance M from the surface.

Optionally, the circular measuring frame further includes: an electric lock, which controls the positioning pin after the positioning pin is moved up and out of the positioning hole; and an elastic element, which exerts downward elasticity on the positioning pin after the positioning pin is locked Pre-tightening force to push the positioning pin down into the positioning hole after the electric lock is unlocked.

Optionally, each of the rotating shaft and the connecting arm is provided with a limit hole through which the positioning pin passes; the elastic element is a compression spring sleeved on the positioning pin, the upper end of which abuts against the bottom surface of the connecting arm, and the lower end abuts against the shoulder of the positioning pin. The top surface; the top of the positioning pin is provided with a locking hole with an axis extending horizontally; and the electric lock is installed on the connecting arm, which includes a locking pin that can be driven to move horizontally, so that the locking pin can be inserted into or removed from the locking hole to complete the positioning pin. Lock and unlock.

Optionally, the circular measuring frame further comprises: a pulling rope connected to the top end of the positioning pin; and at least one fixed pulley mounted on the connecting arm, so that the pulling rope can be extended downward after bypassing the fixed pulley, so that the circular measuring frame can The lower part of the device drives the positioning pin to move up by pulling the pulling rope downward.

Optionally, the positioning base includes a vertically arranged sleeve and a first gear fixed on the top of the sleeve coaxially with the sleeve, a plurality of positioning holes are opened on the end face of the first gear; the lower end of the rotating shaft is rotatably inserted into the sleeve and the motor is vertically arranged and fixed to the connecting arm, and the output shaft is provided with a second gear that meshes with the first gear, so that when the motor is running, the second gear drives the motor to rotate around the first gear, so that the motor Drive the connecting arm to rotate.

Optionally, the circular measuring frame further comprises: a plurality of support rods, the upper end of each support rod supports the connecting arm; the arc-shaped sliding hoop is connected with the lower end of each support rod and is spaced from the cylindrical outer surface of the positioning base It surrounds the cylindrical outer surface, and the arc-shaped sliding hoop is provided with a plurality of openings, and a roller is installed at each opening, so that when the connecting arm drives the support rod and the arc-shaped sliding hoop to rotate, the roller can be positioned on the base of the positioning base. Roll on the outer cylindrical surface.

During actual operation, the roundness measuring system of the utility model uses an inclination sensing device to sense the inclination of the connecting arm relative to the horizontal plane, and directly detects the inclination between the sensing end of the distance sensing device and the measured circular part in the sensing direction. surface distance. According to the above-mentioned inclination, distance and some fixed parameters of the circular measuring frame, according to the preset formula, when the connecting arm and the measuring arm are in the design posture (the connecting arm extends horizontally and the measuring arm extends vertically), the sensing end and the measured circular part are calculated. The radial spacing of the surfaces enables accurate calculation of roundness. In other words, even if the connecting arm and measuring arm of the circular measuring frame are not in the design posture due to various factors such as deflection and deformation, the roundness can be accurately measured without the need for angle calibration, which greatly reduces the workload of the surveyors.

Further, the roundness measurement system of the present invention has a manual measurement mode and an automatic measurement mode, so that users can choose according to different measurement requirements, and the application range is wide. In manual measurement mode, the measurement points can be selected by yourself, with few measurement points and fast speed. In the automatic measurement mode, the distance sensing device is driven by the motor to rotate uninterruptedly, and the circular parts are continuously measured, and finally the outline of the entire circumference will be obtained. By adopting the roundness measuring system of the utility model, it is not necessary to design, manufacture, carry and operate various types of roundness measuring devices according to different circular parts, which reduces the cost of each link and also brings great convenience to the measuring personnel. .

Further, the roundness measuring system of the present invention is provided with a positioning pin and a plurality of positioning holes distributed along the circumferential direction of the positioning base. In the manual measurement mode, when measuring each measuring point, insert the positioning pin into a positioning hole to constrain the rotation degree of freedom of the rotating shaft, so that the measuring arm cannot be rotated, and the measurement result is more accurate. Moreover, since the angle at which each positioning hole is located is pre-designed, it is very convenient for the surveyor to determine the angular position of each measuring point.

Further, the roundness measuring system of the present utility model uses electric locks, elastic elements, pulling ropes, fixed pulleys and other structures to facilitate the measuring personnel to remotely control the positioning pins below the round measuring frame. Very convenient for measuring round parts with high mounting positions. Some components of hydropower equipment are more than ten meters above the ground.

Further, the roundness measurement system of the present invention is provided with a support rod and an arc-shaped sliding hoop, which not only realizes the support of the connecting arm, avoids large deflection and deformation, but also does not affect the rotation of the connecting arm. The design is very ingenious. In addition, the utility model also makes the connection point between the support rod and the connecting arm adjustable, and also makes the length of the support rod adjustable, so it is convenient to adjust the position of the connecting arm by adjusting the length of the support rod and the position of the connection point with the connecting arm , so that it is always in a horizontal position.

The above and other objects, advantages and features of the present invention will be more apparent to those skilled in the art from the following detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of example and not limitation with reference to the accompanying drawings. The same reference numbers in the figures designate the same or similar parts or parts. It will be understood by those skilled in the art that the drawings are not necessarily to scale. In the attached picture:

1 is a schematic block diagram of a roundness measurement system according to an embodiment of the present invention;

Fig. 2 is the working state schematic diagram of the circular measuring frame and the distance sensing device of the roundness measuring system according to an embodiment of the present invention;

3 is a schematic structural diagram of a circular measuring frame according to an embodiment of the present utility model;

Figure 4 is a schematic diagram of the state of the circular measuring frame shown in Figure 3 after the positioning pin is moved down and inserted into a positioning hole;

FIG. 5 is an enlarged view of part A of FIG. 4 .

Detailed ways

The embodiment of the present utility model provides a roundness measuring system for measuring the roundness of circular parts, which is especially suitable for the roundness measurement of various circular rotating shaft parts in hydroelectric power generation equipment.

FIG. 1 is a schematic block diagram of a roundness measuring system according to an embodiment of the present invention; FIG. 2 is a schematic diagram of the working state of a circular measuring frame and a distance sensing device of the roundness measuring system according to an embodiment of the present invention.

As shown in FIG. 1 , the roundness measurement system may generally include a circular measuring frame 10 , a distance sensing device 20 , a data acquisition and conditioning device 30 , a data processing device 40 and an inclination angle sensing device 70 .

The circular measuring frame 10 is used for installing the distance sensing device 20 , and can be manually operated or driven by a motor to drive the distance sensing device 20 to rotate around the measured circular part 60 . Specifically, as shown by the dotted line in FIG. 2 , the circular measuring frame 10 includes a rotating shaft 200 , a connecting arm 400 and a measuring arm 600 . The rotating shaft 200 extends in the vertical direction and is disposed coaxially with the measured circular part 60 . The connecting arm 400 extends in the horizontal direction and is fixedly connected to the rotating shaft 200 , and the connecting point is marked as point a. The measuring arm 600 extends in the vertical direction, and the top end is fixedly connected to the connecting arm 400, and the connecting point is marked as point b.

The distance sensing device 20 is fixedly connected to the bottom of the measuring arm 600, and the connection point is marked as point c. There is a gap between the sensing end (marked as the d end) of the distance sensing device 20 and the circumferential surface of the measured circular part 60 , and its sensing direction is parallel to the connecting arm 400 , that is, along the diameter of the measured circular part 60 . direction.

The dotted line in FIG. 2 shows an ideal design posture in which the connecting arm 400 extends horizontally, the measuring arm 600 extends vertically, and the sensing direction of the distance sensing device 20 is in the horizontal direction.

The ideal working state of the roundness measuring system is that the connecting arm 400 is driven by the rotating shaft 200 to rotate around the central axis of the measured circular part 60 (that is, rotate around the X axis), so as to drive the measuring arm 600 to rotate, thereby driving the distance sensing device. 20 rotates around the X axis. When the distance sensing device 20 rotates to a plurality of preset angles, it detects the value of the radial distance N between the distance sensing device 20 and the circumferential surface of the measured circular part 60 at each angle, and the radial direction refers to the measured circular part 60 the radial direction. N is the distance between the sensing end d and the point f on the circumferential surface of the circular part 60 to be tested, and the line connecting df is parallel to ab. Finally, as many N values as the number of measuring points are obtained (detecting i angles, i will get i N values). By calculating the N value of each measuring point of the measured circular part 60, the radius value of each point can be calculated (L _ar =L ₁ -L ₃ -N), and the roundness value can be finally calculated by the radius of each point.

However, since the length of the connecting arm 400 is relatively long, it is easy to flex and deform, causing the b end to sink. Or due to other factors, the connecting arm 400 is inclined and is no longer horizontal, and the measuring arm 600 is inclined accordingly, so that the sensing direction of the sensing end of the distance sensing device 20 is no longer parallel to the radial direction of the measured circular part 60 . The solid line part of FIG. 2 illustrates the situation in which the connecting arm 400 , the measuring arm 600 and the distance sensing device 20 are tilted and deviate from the ideal design posture, which is called the actual working posture. At this time, point b, point c and point d rotate to b ₁ , c ₁ and d ₁ positions, respectively.

When the connecting arm 400 , the measuring arm 600 and the distance sensing device 20 are in the actual working posture for measurement, the measuring person does not need to calibrate the angles of each component, but rotate the distance sensing device 20 with the measuring arm 600 around the X-axis to every angle. At a preset angle, the sensing end (d ₁ end) of the sensing end and the surface distance M of the tested circular part 60 in the sensing direction are detected. M is the distance between the sensing end d ₁ and the point f ₁ on the circumferential surface of the circular part 60 to be tested, and the connecting line of d ₁ f ₁ is parallel to ab ₁ . Then, the distance sensing device 20 forms a corresponding detection signal, including at least the information of the angle and the distance value corresponding to the angle. The distance sensing device 20 may be a non-contact displacement sensor, such as a non-contact eddy current displacement sensor.

The inclination angle sensing device 70 is installed on the connecting arm 400 or the measuring arm 600, and is used to sense the inclination angle of the connecting arm 400 relative to the horizontal plane during actual measurement, denoted as θ, and form a corresponding detection signal. The inclination sensing device 70 and the measuring arm 600 may be connected to the same end of the connecting arm 400 to allow it to sense the inclination more accurately. The inclination sensing device 70 may be a spirit level. The data acquisition and conditioning device 30 communicates with the distance sensing device 20 and the tilt angle sensing device 70 in a preset manner to collect and condition detection signals generated by the distance sensing device 20 and the tilt angle sensing device 70 to form detection data. The data acquisition and conditioning device 30 collects the detection signal through the Ethernet port, and after conditioning, the detection signal is input to the acquisition module for the data processing device 40 to read and analyze. The data acquisition and conditioning device 30 may include a sensor front-end power supply module, a sensor analog signal input module and a data acquisition module.

_The data processing device 40 communicates with the data acquisition and conditioning device ₃₀ in a preset manner to receive its detection data. The distances L ₃ , M and θ are used to calculate the radial distance N between the sensing end and the surface of the measured circular part 60 when the connecting arm 400 is in a horizontal state (ideal design attitude) at each preset angle.

The data processing device 40 is installed with a preset program designed according to a prescribed roundness error evaluation method. The preset program calculates the multi-point radius of the measured circular part 60 according to the above-mentioned multiple N values, and finally calculates accordingly. Get the roundness value and output the final result. The digital information processing device can be a computer, and the preset program can be software installed on the computer. There are 4 main methods for roundness error evaluation, including minimum area method, least squares circle method, minimum circumscribed circle method and maximum inscribed circle method, etc. These all belong to the standard and specification in the field of roundness measurement and will not be repeated here. .

In some embodiments, N is calculated using the following formula:

N=L ₁ (1-cosθ)+Mcosθ+L ₃ (cosθ-1)+L ₂ sinθ.

Obviously, the value range of θ is θ≥0°.

The derivation process of the above formula is described below. As shown in Figure 2, f ₁ e is the vertical line of ab ₁ , and p and r are the intersection points of the extension line of f ₁ f and ab ₁ and ab, respectively.

It can be seen from FIG. 2 that L _ap =L ₁ -(M+L ₃ )-L _pe .

where L _pe = L ₂ tan θ, and L _ar = L _ap cos θ. From this, it can be seen that N=L ₁ -L _ar -L ₃

=L ₁ -L _ap cosθ-L ₃

=L ₁ -(L ₁ -ML ₃ -L ₂ tanθ)cosθ-L ₃

=L ₁ (1-cosθ)+M cosθ+L ₃ (cosθ-1)+L ₂ sinθ.

3 is a schematic structural diagram of the circular measuring frame 10 according to an embodiment of the present utility model; FIG. 4 is a schematic diagram of the state of the circular measuring frame 10 shown in FIG. 3 after the positioning pin 310 is moved down and inserted into a positioning hole 121; A magnified image of A. The structure of the circular measuring frame 10 of this embodiment will be described in detail below with reference to FIGS. 3 to 5 .

As shown in FIGS. 3 and 4 , in some embodiments, the circular measuring frame 10 further includes a positioning base 100 and a motor 510 .

The central axis of the positioning base 100 extends along the vertical direction. The positioning base 100 is used for coaxial positioning with the measured circular part 60 (the axis should also extend vertically during measurement), and the two central axes use the X-axis. express. The coaxial positioning here means that when the circular measuring frame 10 is working, the position of the positioning base 100 is fixed and will not move or rotate relative to the measured circular part 60, and the positioning base 100 needs to be connected to the measured circular part 60. Measure the coaxiality of the circular part 60 (theoretical requirements, it is difficult to guarantee and do not need to guarantee 100% coaxiality in actual testing). The positioning base 100 is provided with a plurality of positioning holes 121 that are rotationally symmetrical relative to the central axis (X axis). In other words, the plurality of positioning holes 121 are distributed on a distribution circle, and the center of the distribution circle lies on the X-axis.

The rotating shaft 200 is coaxially mounted on the positioning base 100 and can rotate around the central axis (X-axis) of the positioning base 100 . The rotating shaft 200 is provided with a positioning pin 310 that can move up and down.

The motor 510 is used to directly or indirectly drive the rotating shaft 200 to rotate around the X-axis in a controlled manner. The measuring arm 600 may be provided with a plurality of mounting holes along the length direction, so that the distance sensing device 20 has a plurality of mounting positions. The fixed position of the top end of the measuring arm 600 and the connecting arm 400 can also be adjusted. Specifically, referring to FIG. 1 , the top end of the measuring arm 600 can be connected to a clamping piece 610 , and the clamping piece 610 is in a “U” shape, so as to be clamped on the connecting arm 400 . A fastening screw 620 is installed on the clamping member 610 . After the top of the measuring arm 600 is adjusted to a certain connection position, tighten the fastening screw, so that the end of the fastening screw 620 tightly abuts the surface of the connecting arm 400, so that the top of the measuring arm 600 is locked.

When measuring the roundness of a product by using the round measuring frame 10 of this embodiment, the measuring personnel can choose one of the following two measurement modes according to different measurement requirements.

(1) Manual measurement mode

The surveyor pre-sets the number of measuring points and the positions of the measuring points for the circular parts, and then checks one by one. Each measuring point is at the same angle with one positioning hole 121 , and these positioning holes are called preset positioning holes.

Keeping the motor 510 in a closed state, the surveyor manually operates the rotating shaft 200, the connecting arm 400 or the measuring arm 600 to rotate around the X-axis. Each time the positioning pin 310 is rotated to an angle at which the positioning pin 310 faces a predetermined positioning hole 121 , the positioning pin 310 is moved down and inserted into the positioning hole 121 to prohibit the rotation of the rotating shaft 200 , referring to FIG. 3 . The measuring personnel can then perform a single-point measurement on the measured circular part 60 , that is, the distance sensing device 20 can detect the distance M between the measured circular part 60 and the measuring point on the circumferential surface of the measured circular part 60 . After the measurement of the first measuring point is completed, the positioning pin 310 is moved up and away from the positioning hole 121 , referring to FIG. 1 . Then continue to operate the rotating shaft 200 to rotate until the angle at which the positioning pin 310 is opposite to the second preset positioning hole 121 , insert the positioning pin 310 into the positioning hole 121 , and then perform the second single-point measurement. Repeat the operation so many times to complete the measurement of multiple measuring points.

In manual measurement mode, the measurement points can be selected by yourself, with few measurement points and fast speed. The function of the positioning pin 310 and the positioning hole 121 is to constrain the rotational freedom of the rotating shaft 200, so that the measurement arm 600 cannot be rotated, so that the measurement result is more accurate. Moreover, since the angles of the positioning holes 121 can be designed and marked in advance, it is very convenient for the surveyor to determine the angular position of each measuring point. Preferably, a plurality of positioning holes 121 are evenly distributed on the distribution circle, a number of positioning holes 121 are provided, and the angle between adjacent positioning holes 121 is 360°/a.

(2) Automatic measurement mode

Keep the positioning pin 310 at the position that is separated from the positioning hole 121 as shown in FIG. 1 , turn on the motor 510, make the motor 510 run to drive the measuring arm 600 to rotate continuously, so that the distance sensing device 20 can continuously detect the distance sensing device 20 and the measured circular part. The pitch M of the surface of 60. This continuous detection can finally obtain the radius value of the entire circumference, which can draw a circumference outline and make the roundness calculation value more accurate. In addition, the manual operation of the measuring personnel is not required, the degree of automation is higher, and the unnecessary displacement of the distance sensing device 20 caused by improper operation of the manual operation can be avoided, thereby affecting the measuring accuracy.

With the circular measuring frame of the embodiment of the present invention, there is no need to design, manufacture, carry and operate various types of circular measuring devices according to different circular components. The cost of each link is reduced, and it also brings great convenience to the measurement personnel. It is very suitable for large-scale industrial equipment with many types of circular parts and different measurement requirements, such as hydroelectric power generation equipment.

When the circular part 60 to be tested does not have particularly high requirements on the roundness, and only needs to measure the roundness roughly or with general accuracy, the manual measurement mode can be selected. When it is necessary to focus on measuring some key measuring points, manual measurement mode can also be used.

When the measured circular part 60 has high requirements for roundness and needs to measure the roundness more accurately, the automatic measurement mode can be used to improve the automation level and the roundness measurement accuracy.

In some embodiments, as shown in FIGS. 3 to 5 , the circular measuring frame 10 further includes an electric lock 350 and an elastic element 320 . After the positioning pin 310 is moved up and out of the positioning hole 121 , the electric lock 350 locks the positioning pin 310 in a controlled manner so that it cannot move. After the positioning pin 310 is locked by the electric lock 350 , the elastic element 320 exerts a downward elastic preload force on the positioning pin 310 . After the electric lock 350 is unlocked, the elastic pre-tightening force urges the positioning pin 310 to move down and insert into the positioning hole 121 , which requires only the measuring personnel to exert upward force on the positioning pin 310 , which facilitates the design of the force applying structure. Specifically, as shown in FIG. 5 , the rotating shaft 200 and the connecting arm 400 are each provided with a limit hole through which the positioning pin 310 passes, which are a limit hole 201 and a limit hole 401 respectively. The elastic element 320 is a compression spring sleeved on the positioning pin 310 , its upper end abuts against the bottom surface of the connecting arm 400 , and its lower end abuts against the top surface of the shaft shoulder 311 of the positioning pin 310 . The top of the positioning pin 310 is provided with a locking hole 315 whose axis extends horizontally. The electric lock 350 is installed on the connecting arm 400 , and includes a locking pin 355 that can be driven to move horizontally, so that the locking and unlocking of the positioning pin 310 is completed by driving the locking pin 355 into or out of the locking hole 315 . The electric lock 350 is widely used in the prior art, and its specific structure is not repeated here.

As shown in FIGS. 3 and 5 , the circular measuring frame 10 further includes a pulling rope 340 and at least one fixed pulley 330 . The pull cord 340 is connected to the top end of the positioning pin 310 . The fixed pulley 330 is installed on the connecting arm 400 , and the number of the fixed pulley 330 can be one or more, for example, three. The pull rope 340 goes around the fixed pulley 330 and then extends downward. When the pull rope 340 moves, it drives the fixed pulley 330 to rotate. In this way, it is convenient to drive the positioning pin 310 to move upward by pulling the pulling rope 340 downward under the circular measuring frame 10 . In hydropower equipment, some circular components are at a high height from the ground, up to several meters or even more than ten meters. The embodiment of the present invention facilitates remote control of the positioning pin 310 through the pulling rope 340, and is very suitable for measuring a circular part with a high installation position.

In addition, the electric lock 350 can also be controlled remotely. For example, as shown in FIGS. 3 and 5 , the electric lock 350 includes a signal wire 351 . The signal wire 351 is bound with the rope and extends to the bottom of the circular measuring frame 10 , so that its end can reach the end of the pulling rope 340 . A control switch part 352 is connected to the end of the signal wire 351 , and the control switch part 352 is used to control the opening and closing of the electric lock 350 . Of course, in some alternative embodiments, a remote control or other wireless communication means may be provided to control the electric lock 350 .

In some embodiments, as shown in FIG. 3 , the circular measuring frame 10 further includes a plurality of support rods 710 and an arc-shaped sliding hoop 720 . The upper end of each support rod 710 supports the connecting arm 400 , and the lower end is connected to the arc-shaped sliding hoop 720 . At least part of the outer surface of the positioning base 100 is a cylindrical outer surface. The arc-shaped sliding hoop 720 is spaced apart from the cylindrical outer surface of the positioning base 100 to surround the cylindrical outer surface, and the arc-shaped sliding hoop 720 is provided with a plurality of openings 721 , and a roller 730 is installed at each opening 721 . When the connecting arm 400 drives the support rod 710 and the arc-shaped sliding hoop 720 to rotate, the roller 730 is rolled on the cylindrical outer surface of the positioning base 100 .

Specifically, the top end of each support rod 710 can be fixed to the connecting arm 400 , and the connecting points of the two can be adjusted to different positions in the length direction of the connecting arm 400 . As shown in FIG. 3 , the top end of the support rod 710 is connected to a clamping member 760 , and the clamping member 760 has a “U”-shaped structure to be clamped on the connecting arm 400 . A fastening screw 740 is installed on the clamping member 760 . After the top end of the support rod 710 is adjusted to a certain connection position, the tightening screw 740 is tightened, so that the end of the tightening screw 740 tightly abuts the surface of the connecting arm 400, so that the top end of the support rod 710 is locked. Each support rod 710 includes a two-way threaded sleeve 711 with internal threads at both ends and two screws 712 respectively screwed on both ends of the two-way threaded sleeve 711, so as to adjust the support by adjusting the screwing depth of at least one screw 712 The length of the rod 710.

By arranging the support rod 710 and the arc-shaped sliding hoop 720 , the support for the connecting arm 400 is realized to avoid excessive deflection and deformation, and the rotation of the connecting arm 400 is not affected, and the design is very ingenious. In addition, the connection point between the support rod 710 and the connection arm 400 is adjustable, and the length of the support rod 710 is adjustable, so that the position of the connection arm 400 can be adjusted by adjusting the length of the support rod 710 and the position of the connection point with the connection arm 400 , so that it is always in a horizontal position for more accurate measurements.

In some embodiments, as shown in FIG. 3 , the positioning base 100 includes a sleeve 110 and a first gear 120 . The sleeve 110 is arranged vertically (its axis is the aforementioned X-axis). The first gear 120 is fixed on the top of the sleeve 110 and coaxially disposed with the sleeve 110 . The aforementioned plurality of positioning holes 121 are formed on the end surface of the first gear 120 . The rotating shaft 200 can be a cylindrical structure, and the lower end of the rotating shaft 200 can be rotatably inserted into the sleeve 110 to realize the rotatable connection between the two. The motor 510 is arranged vertically (ie, the output shaft of the motor 510 extends vertically) and is fixed to the connecting arm 400 . A second gear 520 is mounted on the output shaft of the motor 510, and the second gear 520 meshes with the first gear 120, so that when the motor 510 is running, the second gear 520 and the motor 510 are rotated around the first gear 120, so that the motor 510 drives the connecting arm 400 to rotate. The diameter of the second gear 520 is smaller than the diameter of the first gear 120 to achieve the purpose of deceleration. Of course, in some alternative embodiments, the output shaft of the motor 510 can also be directly connected to the rotating shaft 200 to directly drive the rotating shaft 200 .

In some embodiments, as shown in FIG. 3 , the caliper 10 further includes a counterweight 800 . In order to balance the forces of the connecting arms 400 on both sides of the rotation axis, the connecting arms 400 can better maintain a horizontal posture and improve the measurement accuracy. The counterweight 800 and the measuring arm 600 are respectively installed on both ends of the connecting arm 400 , and the motor 510 can be arranged on the same side of the measuring arm 600 .

A threaded shaft 410 can be provided at the end of the connecting arm 400, and a plurality of annular counterweights 800 can be provided. on the threaded shaft 410 to lock the position of the counterweight 800 .

By now, those skilled in the art will recognize that although various exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, Numerous other variations or modifications consistent with the principles of the present invention are directly identified or derived from the disclosure of the present invention. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (9)

1. a roundness measuring system is characterized in that comprising: A circular measuring frame, which includes a rotating shaft that extends vertically and is coaxially arranged with the circular component to be measured, a connecting arm that extends horizontally and is fixedly connected to point a at the top end of the rotating shaft, and a connecting arm that extends vertically and is fixedly connected to the connection at the top end Measuring arm at point b of arm; The distance sensing device is fixedly connected to point c at the bottom of the measuring arm, the sensing direction of the sensing end is parallel to the connecting arm, and when the measuring arm rotates around the central axis of the rotating shaft to each preset angle, Detecting the surface distance M between the sensing end and the measured circular part in the sensing direction; an inclination angle sensing device, mounted on the connecting arm or the measuring arm, for sensing the inclination angle θ of the connecting arm relative to the horizontal plane during actual measurement; a data acquisition and conditioning device that communicates with the distance sensing device and the inclination angle sensing device in a preset manner to collect and condition detection signals thereof to form detection data; and The data processing device communicates with the data acquisition and conditioning device in a preset manner to receive the detection data, according to the distance L ₁ between point a and point b, the distance L ₂ between point b and point c, the sensing end The distances L ₃ , M and θ from point c, calculate the radial distance N between the sensing end and the surface of the measured circular part when the connecting arm is in a horizontal state at each preset angle, and use the preset The program calculates the roundness value of the measured circular part based on a plurality of N values. 2. The roundness measuring system according to claim 1, characterized in that, The distance sensing device is a non-contact displacement sensor. 3. The roundness measuring system according to claim 1, characterized in that, The inclination angle sensing device and the measuring arm are connected to the same end of the connecting arm. 4. The roundness measuring system according to claim 1, wherein the roundness measuring frame further comprises: The positioning base is used for coaxial positioning with the measured circular part, the central axis of the positioning base extends in the vertical direction and is provided with a plurality of positioning holes that are rotationally symmetrical relative to the central axis, and the rotating shaft and the The positioning base is coaxially mounted on it and can be rotated around the central axis of the positioning base, and the rotating shaft is provided with a positioning pin that can move up and down; and a motor for directly or indirectly driving the rotating shaft to rotate in a controlled manner; and the circular measuring frame is configured to: The rotating shaft is manually rotated, and when the positioning pin is rotated to an angle relative to the preset positioning hole, the positioning pin is moved down and inserted into the positioning hole, so as to prohibit the rotation of the rotating shaft , so that the distance sensing device detects its distance M from the surface of the circular part being measured; or The positioning pin is kept at a position away from the positioning hole, and the motor is operated to drive the measuring arm to rotate continuously, so that the distance sensing device can continuously detect the distance M from the surface of the circular part to be measured. 5. The roundness measuring system according to claim 4, wherein the circular measuring frame further comprises: an electric lock, which locks the locating pin in a controlled manner after the locating pin is moved up and out of the locating hole; The elastic element, after the locating pin is locked, exerts a downward elastic pre-tightening force on the locating pin, so as to urge the locating pin to move down and insert into the locating hole after the electric lock is unlocked. 6. The roundness measuring system according to claim 5, characterized in that, Each of the rotating shaft and the connecting arm is provided with a limit hole through which the positioning pin passes; The elastic element is a compression spring sleeved on the positioning pin, the upper end of which is abutted against the bottom surface of the connecting arm, and the lower end is abutted against the top surface of the shaft shoulder of the positioning pin; The top of the positioning pin is provided with a lock hole with an axis extending horizontally; and The electric lock is mounted on the connecting arm, and includes a locking pin that can be driven to move horizontally, so as to complete the locking and unlocking of the positioning pin by inserting or disengaging the locking pin into the locking hole. 7. The roundness measuring system according to claim 5, wherein the circular measuring frame further comprises: a pull cord attached to the top end of the dowel; and At least one fixed pulley is installed on the connecting arm, so that the pull rope goes around the fixed pulley and then extends downward, so as to drive the pull rope under the circular measuring frame by pulling the pull rope downward The positioning pin moves up. 8. The roundness measuring system according to claim 4, characterized in that, The positioning base comprises a vertically arranged sleeve and a first gear fixed on the top of the sleeve coaxially with the sleeve, and the plurality of positioning holes are opened on the end face of the first gear; The lower end of the shaft is rotatably inserted into the sleeve; and The motor is vertically arranged and fixed on the connecting arm, and a second gear meshing with the first gear is installed on the output shaft, so that when the motor is running, the second gear drives the motor Rotating around the first gear, so that the motor drives the connecting arm to rotate. 9. The roundness measuring system according to claim 4, wherein the circular measuring frame further comprises: a plurality of support rods, the upper end of each support rod supports the connecting arm; an arc-shaped sliding hoop, connected to the lower end of each of the support rods, and surrounding the cylindrical outer surface of the positioning base at a distance from the cylindrical outer surface, and The arc-shaped sliding hoop is provided with a plurality of openings, and a roller is installed at each of the openings, so that when the connecting arm drives the support rod and the arc-shaped sliding hoop to rotate, the roller can be positioned at the position of the roller. The cylindrical outer surface of the positioning base is rolled.

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