阅读说明：本技术 一种轴承套圈外圆磨削的磨削力测量方法 (Grinding force measuring method for cylindrical grinding of bearing ring ) 是由 张明柱 谢要宾 段成龙 李治伟 王东峰 韩建刚 于 2020-12-16 设计创作，主要内容包括：一种轴承套圈外圆磨削的磨削力测量方法,针对磨削轴承套圈的电磁无心夹具,在前后两个支撑点上分别安装测力传感器,当轴承套圈被磨削加工时,测力传感器精确测量轴承套圈所受支撑力,通过对轴承套圈在与砂轮未接触前及接触磨削后两种平衡状态下支撑力分别测量,计算出磨削时轴承套圈所受的法向磨削力和切向磨削力。本方案通过间接测量配合理论计算,方式简单,计算准确。通过精确测量砂轮的法向磨削力和切向磨削力,及时掌控砂轮的磨损程度,控制砂轮的磨削用量和修整时间,提高轴承套圈外圆的磨削质量和效率。(A grinding force measuring method for cylindrical grinding of a bearing ring is characterized in that force sensors are respectively installed on a front supporting point and a rear supporting point of an electromagnetic centerless clamp for grinding the bearing ring, the force sensors accurately measure supporting force borne by the bearing ring when the bearing ring is ground, and normal grinding force and tangential grinding force borne by the bearing ring during grinding are calculated by respectively measuring supporting forces of the bearing ring in two balanced states before the bearing ring is not contacted with a grinding wheel and after the bearing ring is contacted with the grinding wheel. The scheme is simple and accurate in calculation by matching indirect measurement with theoretical calculation. The abrasion degree of the grinding wheel is controlled in time by accurately measuring the normal grinding force and the tangential grinding force of the grinding wheel, the grinding amount and the dressing time of the grinding wheel are controlled, and the grinding quality and the grinding efficiency of the excircle of the bearing ring are improved.)

1. The grinding force measuring method for cylindrical grinding of the bearing ring is characterized by comprising the following steps of: the method comprises the following steps:

s1, respectively mounting force transducers on the front support and the rear support aiming at the electromagnetic centerless clamp for grinding the bearing ring, and measuring the supporting force of the corresponding supporting point;

s2, mounting the bearing ring on the end face of the electromagnetic centerless clamp, adsorbing the end face of the bearing ring through a magnetic pole, positioning the bearing ring through a front support and a rear support, and starting the main shaft to rotate;

s3, under the condition that the grinding wheel is not in contact with the bearing ring, the bearing ring is not subjected to grinding force of the grinding wheel, when the bearing ring rotates to reach a stable state, force measurement data of the force measurement sensors on the front support and the rear support are recorded, and the sum moment of the rotation around the center of the bearing ring, acted on the end face of the bearing ring by the electromagnetic centerless clamp, is calculated through an equation;

s4, under the condition that the grinding wheel is in contact with the bearing ring for grinding, the ring bears the normal grinding force and the tangential grinding force of the grinding wheel, when the bearing ring and the grinding wheel rotate to reach a stable state, force measurement data of the force measurement sensors on the front support and the rear support at the moment are recorded, and the normal grinding force and the tangential grinding force of the grinding wheel borne by the ring during grinding are calculated through an equation by combining the data measured twice.

2. The grinding force measuring method of cylindrical grinding of a bearing ring according to claim 1, characterized in that: in steps S1 and S2, the front and rear supports can be controlled to change their positions and inclination angles by an adjusting mechanism.

3. The grinding force measuring method of cylindrical grinding of a bearing ring according to claim 1, characterized in that: in step S4, the rotation of the bearing ring and the grinding wheel reaches a steady state, and the specific process is as follows:

when the bearing ring rotates around the axis of the bearing ring under the driving of the rotation of the main shaft, the bearing ring and the end surface of the magnetic pole can slide relatively due to the existence of the eccentric amount and the blocking effect of the front support and the rear support, the friction resultant force borne by the bearing ring forces the bearing ring to be attached to the front support and the rear support in the sliding process, and the bearing ring rotates around the center of the bearing ring due to the friction torque.

4. The grinding force measuring method of cylindrical grinding of a bearing ring according to claim 1, characterized in that: in the steps of S3 and S4, the sum moment of the rotation around the center of the ferrule, which acts on the end face of the ferrule by the electromagnetic clamp, is calculated according to the data obtained by the measuring sensor through a stress balance equation and a rotation torque balance equation in two orthogonal directions in a plane.

5. The grinding force measuring method of cylindrical grinding of a bearing ring according to claim 1, characterized in that: in step S4, according to the obtained data, the normal grinding force and the tangential grinding force of the grinding wheel borne by the ferrule during grinding are calculated by using the equilibrium equation of forces in two orthogonal directions in the plane and the equilibrium equation of the rotational torque.

Technical Field

The invention relates to the technical field of bearing ring cylindrical grinding, in particular to a grinding force measuring method for cylindrical grinding of a bearing ring.

Background

As is known, when a bearing ring is ground, the grinding force borne by the ring needs to be accurately mastered, the cutting amount is controlled to avoid the grinding burn phenomenon, and meanwhile, the abrasion condition of a grinding wheel is controlled to determine the dressing time of the grinding wheel. However, when the normal grinding force and the tangential grinding force applied to a workpiece are measured in the grinding process of the workpiece, in actual production equipment, a force sensor is not easy to be directly installed on a grinding wheel spindle, so that direct measurement is realized. The traditional method is to introduce an approximate calculation formula of electromagnetic attraction and indirectly obtain the grinding force of the grinding wheel by magnetic force. However, the magnetic circuit of the solenoid coil structure has a gap, so that a certain error exists in the calculated magnetic force, the electromagnetic centerless clamp has magnetic attraction, friction and radial fulcrum supporting force on the bearing ring, the bearing ring is complex in stress, and further the solved normal grinding force and tangential grinding force borne by the bearing ring have larger errors. Therefore, a method for accurately measuring the normal grinding force and the tangential grinding force applied to the workpiece in the grinding process is urgently needed.

Disclosure of Invention

The invention aims to solve the technical problems and provides a method for conveniently and accurately measuring the normal grinding force and the tangential grinding force applied to a workpiece in the grinding process.

The technical scheme adopted by the invention is as follows: a grinding force measuring method for cylindrical grinding of a bearing ring comprises the following steps:

s1, respectively mounting force transducers on the front support and the rear support aiming at the electromagnetic centerless clamp for grinding the bearing ring, and measuring the supporting force of the corresponding supporting point;

s2, mounting the bearing ring on the end face of the electromagnetic centerless clamp, adsorbing the end face of the bearing ring through a magnetic pole, positioning the bearing ring through a front support and a rear support, and starting the main shaft to rotate;

s3, under the condition that the grinding wheel is not in contact with the bearing ring, the bearing ring is not subjected to grinding force of the grinding wheel, when the bearing ring rotates to reach a stable state, force measurement data of the force measurement sensors on the front support and the rear support are recorded, and the sum moment of the rotation around the center of the bearing ring, acted on the end face of the bearing ring by the electromagnetic centerless clamp, is calculated through an equation;

s4, under the condition that the grinding wheel is in contact with the bearing ring for grinding, the ring bears the normal grinding force and the tangential grinding force of the grinding wheel, when the bearing ring and the grinding wheel rotate to reach a stable state, force measurement data of the force measurement sensors on the front support and the rear support at the moment are recorded, and the normal grinding force and the tangential grinding force of the grinding wheel borne by the ring during grinding are calculated through an equation by combining the data measured twice.

Further preferably, in steps S1 and S2, the front and rear supports can be controlled by an adjusting mechanism to change the position and the inclination angle thereof.

Further optimization, in step S4, the rotation of the bearing ring and the grinding wheel reaches a steady state, and the specific process is as follows:

when the bearing ring rotates around the axis of the bearing ring under the driving of the rotation of the main shaft, the bearing ring and the end surface of the magnetic pole can slide relatively due to the existence of the eccentric amount and the blocking effect of the front support and the rear support, the friction resultant force borne by the bearing ring forces the bearing ring to be attached to the front support and the rear support in the sliding process, and the bearing ring rotates around the center of the bearing ring due to the friction torque.

Further optimization, in the steps of S3 and S4, data are obtained according to the measuring sensor, and the sum moment of the rotation around the center of the ferrule, acted on the end face of the ferrule by the electromagnetic clamp, is calculated through a stress balance equation and a rotation torque balance equation in two orthogonal directions in a plane.

Further optimization, in the step S4, according to the obtained data, the normal grinding force and the tangential grinding force of the grinding wheel borne by the ferrule during grinding are calculated through a stress balance equation and a rotation torque balance equation in two orthogonal directions in the plane.

The invention has the beneficial effects that:

the invention provides a method for obtaining grinding force of a grinding wheel by measuring and calculating when an outer circle of a bearing ring is ground, wherein indirect measurement is matched with theoretical calculation, the method is simple, and the calculation is accurate. The abrasion degree of the grinding wheel is controlled in time by accurately measuring the normal grinding force and the tangential grinding force of the grinding wheel, the grinding amount and the dressing time of the grinding wheel are controlled, and the grinding quality and the grinding efficiency of the excircle of the bearing ring are improved.

Drawings

FIG. 1 is a force diagram of a bearing ring without grinding wheel contact;

fig. 2 is a force diagram of a bearing ring during contact grinding of a grinding wheel.

In the figure: 1. the main shaft electromagnetic clamp comprises a main shaft electromagnetic clamp magnetic pole end face, 2, a bearing ring, 3, an eccentricity amount, 4, a front support, 5, a rear support, 6, a force measuring sensor, 7 and a grinding wheel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

The measurement principle of the invention is as follows: two force sensors are arranged on the basis of the original front and rear supports of the electromagnetic centerless clamp, and the sensors can measure the supporting force of the front and rear supporting points in real time. Due to the action of electromagnetic attraction and front and back support, the bearing ring is adsorbed on the end face of the magnetic pole of the machine tool spindle. When the magnetic pole rotates around the axis of the magnetic pole under the driving of the rotation of the main shaft, due to the existence of the eccentricity 3 and the blocking effect of the front support and the back support, the bearing ring and the end face of the magnetic pole can slide relatively, in the sliding process, the bearing ring is subjected to a friction torque of the end face of the magnetic pole facing the magnetic pole and a friction resultant force which passes through the center of the bearing ring and is vertical to the straight line of the center of the bearing ring and the center of the magnetic pole, the friction resultant force forces the bearing ring to be attached to the front support and the back support, and the friction torque enables the bearing ring to rotate around the center of the bearing ring, so that. And under two states of grinding processing of the grinding wheel not contacting the bearing ring and the grinding wheel contacting the bearing ring, the bearing ring is subjected to stress measurement and calculation respectively, and the stress in the two states is combined through a pivot of resultant moment generated when the end surface of the magnetic pole rotates, so that the normal grinding force and the tangential grinding force borne by the bearing ring in the grinding process are calculated.

The present solution is described in detail below with reference to the attached drawings: the measurement steps are as follows:

step one, aiming at an electromagnetic centerless clamp for grinding a bearing ring, respectively mounting force transducers 6 on a front support 4 and a rear support 5, and measuring the supporting force of corresponding supporting points;

step two, mounting the bearing ring 2 on the end face 1 of the magnetic pole of the spindle electromagnetic clamp, adsorbing the end face of the bearing ring 2 through the magnetic pole, positioning the bearing ring through a front support and a rear support, and starting the spindle to rotate;

step three, under the condition that the grinding wheel 7 is not in contact with the bearing ring, the ring is not subjected to grinding force of the grinding wheel, and when the bearing ring reaches a stable rotation state, the supporting force F measured by the force sensors on the front support and the rear support is recorded₂、F₃When the bearing ring is stressed as shown in figure 1, besides the self-gravity, the bearing ring is also subjected to a friction torque M generated by the magnetic pole end face facing the bearing ring₀And a center O passing through the end face of the bearing ring₁And is perpendicular to O₁O₂(O₂Being the centre of rotation of the main shaft of the grinding machine) of friction force F₁The direction is the same as the rotation direction of the magnetic poles, and simultaneously, the magnetic pole is also supported by the supporting force and the friction force generated by the front and the back supports;

the calculation process is as follows: establishing a plane rectangular coordinate system by taking the center of the end face of the bearing ring as an origin, the horizontal direction as an x axis and the vertical direction as a y axis;

the balance equation of the plane arbitrary force system is established as

-f₃₁cos(α+β)+F₁sinθ+μ₁f₂₁sinα＝f₂₁cosα+μ₂f₃₁sin(α+β) (3)

f₂₁sinα+f₃₁sin(α+β)-μ₂f₃₁cos(α+β)＝F₁cosθ+μ₁f₂₁cosα+mg (4)

M₀+F₁·e-μ₁f₂₁·R-μ₂f₃₁·R＝0 (5)

Is represented by the formulae (1) to (5):

step four, under the condition that the grinding wheel is in contact with the bearing ring for grinding, the ring bears the normal grinding force and the tangential grinding force of the grinding wheel, and when the bearing ring and the grinding wheel reach a stable rotating state, the supporting force F measured by the force sensors on the front support and the rear support is recorded₂₁、F₃₁The bearing ring is stressed as shown in figure 2; in addition to the forces applied in the case of fig. 1, the bearing ring is subjected to its normal grinding force F by the grinding wheel_nAnd tangential grinding force F_t；

The calculation process is as follows: establishing a plane rectangular coordinate system O by taking the center of the end face of the bearing ring as an origin, the horizontal direction as an x axis and the vertical direction as a y axis₁、O₂Respectively the rotation centers of the bearing ring and the main shaft.

The balance equation of the plane arbitrary force system is established as

-f₃₂cos(α+β)+F₁₁sinθ+μ₁f₂₂sinα+F_n＝f₂₂cosα+μ₂f₃₂sin(α+β) (9)

f₂₂sinα+f₃₂sin(α+β)-μ₂f₃₂cos(α+β)＝F₁₁cosθ+μ₁f₂₂cosα+mg+F_t (10)

M₀+F₁₁·e+F_t·R-μ₁f₂₂·R-μ₂f₃₂R ═ 0 (11) and represented by the formulae (7) to (11):

tangential grinding force

Normal grinding force

In the formula, M₀See formula (6);

F₁the resultant friction force is generated by the magnetic pole end face to the bearing ring when the grinding wheel is not in contact with the ring;

F₁₁the friction resultant force is generated by the magnetic pole end face to the bearing ring when the grinding wheel contacts the ring;

F₂₁、F₃₁respectively supporting forces measured by the front and rear support upper sensors when the grinding wheel is not in contact with the ferrule;

F₂₂、F₃₂respectively supporting forces measured by the upper sensor are supported front and back when the grinding wheel contacts the ferrule;

f₂₁、f₃₁normal supporting forces on the front and rear supports when the grinding wheel is not in contact with the ferrule are respectively;

f₂₂、f₃₂normal supporting forces on the front and rear supports when the grinding wheel contacts the ferrule are respectively;

μ₁、μ₂friction factors of the front and rear supports respectively;

F_nfor normal grinding force, F_tIs tangential grinding force;

M₀the resultant moment of the end face of the magnetic pole in the clockwise direction around the center is obtained;

alpha is an included angle between the front support and the horizontal direction;

beta is an included angle between the front support and the rear support;

theta is an included angle between the eccentricity and the horizontal direction;

e is the eccentricity;

r is the excircle radius of the workpiece;

m is the mass of the bearing ring;

g is the acceleration of gravity;

in this scheme, two supports in front and back, its position of accessible guiding mechanism control and inclination's change.

In this scheme, bearing ring and emery wheel rotation reach steady state, and concrete process is: when the bearing ring rotates around its axle center under the main shaft rotation drives, because the existence of eccentric magnitude and the hindrance effect of front and back support, can take place relative slip between bearing ring and the magnetic pole terminal surface, the slip in-process, the frictional resultant force that the bearing ring received forces the bearing ring to hug closely on supporting in the front and back, friction torque makes the bearing ring rotatory around self center, and sensor data is not changing this moment, can understand: the spindle-ferrule-grinding wheel system undergoes a stabilization-change-stabilization process.

It should be noted that while the invention has been described in terms of the above-mentioned embodiments, other embodiments are also possible. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended that all such changes and modifications be covered by the appended claims and their equivalents.