Non-contact on-machine detection method for radial runout of boring tool spindle

Abstract

The application discloses a non-contact in-machine detection method for radial runout of a boring tool spindle, and specifically comprises the following steps: S1, acquiring physical parameters of the boring tool spindle according to the boring tool spindle structure; S2, calculating the static deflection and the maximum transient deflection of the boring tool spindle based on the physical parameters of the boring tool spindle; S3, designing the position and shape of the measuring points according to the physical parameters of the boring tool spindle in S1, the static deflection and the maximum transient deflection of the boring tool spindle in S2 and the measuring parameters of the laser displacement sensor; S4, determining the installation position of the laser displacement sensor according to the position and shape of the measuring points; and S5, calculating the radial runout of the boring tool spindle according to the measuring data of the laser displacement sensor. The radial runout of the boring tool spindle is obtained according to the test signals and by using a spatial geometry solving method through arranging three laser displacement sensors at the set positions, so that the non-contact in-machine rapid and accurate detection of the radial runout of the boring tool spindle is realized, the error is reduced, the measuring precision is improved, and a technical support is provided for improving the boring hole geometric precision.

Description

Technical Field

[0001] This invention relates to the field of boring tool inspection technology, and in particular to a non-contact in-machine inspection method for the radial arcing of the boring tool spindle. Background Technology

[0002] In deep hole precision boring, the boring bar spindle has structural characteristics such as single-edge, variable cross-section, and large overhang. During operation, the precision boring bar spindle is affected by factors such as bearing clearance, unbalanced mass of the single-edge boring bar, and bending stiffness of the tool spindle. This results in fluctuations in spindle speed due to factors such as axis tilt angle, unbalanced mass, and vibration. Consequently, the dynamic centrifugal force of the boring bar spindle changes dynamically, causing dynamic variations in the radial displacement of the boring bar spindle. This affects the instantaneous cutting depth at the moment of entry and during the cutting process, directly leading to out-of-tolerance form and position errors in the machined hole, and severely restricting the accuracy of deep hole precision boring.

[0003] Current research primarily employs contact testing or the finite element method to detect the radial displacement of boring machine spindles during operation. When measuring radial displacement at the insert of the boring machine spindle using contact testing, the discontinuity of the insert and the radial displacement itself can easily lead to substantial cutting during the measurement process. The finite element method struggles to accurately establish the physical boundaries affecting the radial displacement of the boring machine spindle, and its modeling accuracy relies on accurate experimental methods for correction. Summary of the Invention

[0004] To address the problem of low accuracy in detecting the radial displacement of boring tool spindles in existing technologies, this invention proposes a non-contact on-machine detection method for the radial displacement of boring tool spindles. By arranging three laser displacement sensors at set positions, the radial displacement of the boring tool spindle is obtained based on the test signals and using spatial geometry solution methods, thus achieving non-contact, rapid, and accurate on-machine detection of the radial displacement of the boring tool spindle.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A non-contact in-machine detection method for radial arcing of boring tool spindles specifically includes the following steps:

[0007] S1: For the boring tool spindle structure, obtain the physical parameters of the boring tool spindle;

[0008] S2: Based on the physical parameters of the boring spindle, calculate the static deflection and maximum transient deflection of the boring spindle;

[0009] S3: Based on the physical parameters of the boring spindle in S1, the static deflection and maximum transient deflection of the boring spindle in S2, and the measurement parameters of the laser displacement sensor, design the position and shape of the measuring point;

[0010] S4: Determine the installation location of the laser displacement sensor based on the position and shape of the measuring point;

[0011] S5: Calculate the radial displacement of the boring tool spindle based on the measurement data from the laser displacement sensor.

[0012] Preferably, in S1, the boring spindle includes a telescopic axial motion spindle, a boring bar, and a boring tool.

[0013] Preferably, in S1, the physical parameters of the boring spindle include bearing clearance, inner / outer diameter of the boring spindle, material density, elastic modulus, Poisson's ratio, axial length, axis inclination angle, radial deviation distance of the boring bar, unbalanced mass, and rotational speed.

[0014] Preferably, S2 includes:

[0015] S2-1: Calculate the bending stiffness of the boring spindle based on its physical parameters:

[0016]

[0017] In formula (1), k b The value represents the bending stiffness of the boring bar spindle; n represents the total number of spindle segments; k bi This represents the bending stiffness of the i-th segment of the boring bar spindle;

[0018] in:

[0019]

[0020] In formula (2), E i I i κ represents the bending stiffness of the i-th segment of the boring bar spindle; N represents the number of load types experienced by the boring bar spindle; j The j-th type of load coefficient is derived from the classical beam deflection deformation theory and the deflection superposition method. This represents the length of the i-th axis segment;

[0021] S2-2: Calculate the resultant force of the boring spindle during stable operation based on its physical and operating parameters:

[0022] F Rs =F g +F ce (3)

[0023] In formula (3), F Rs F represents the resultant force when the boring tool spindle is running stably; g F represents the gravity vector of the boring tool spindle; ce This represents the centrifugal force vector of the boring tool spindle;

[0024] The expression for dynamic load is as follows:

[0025] FRd =F g +γF ce (4)

[0026] In formula (4), F Rd F represents the dynamic load on the boring tool spindle. g F represents the gravity vector of the boring tool spindle; ce γ represents the centrifugal force vector of the boring tool spindle; γ represents the dynamic load coefficient.

[0027] S2-3: Determine the static deflection and maximum transient deflection of the boring spindle based on the bending stiffness of the boring spindle in S2-1 and the resultant force and dynamic load of the boring spindle in S2-2:

[0028]

[0029] In formula (5), w Rs This represents the static deflection of the boring tool spindle; w Rd This represents the maximum transient deflection of the boring tool spindle.

[0030] Preferably, in S2-2, the working parameters are the tool spindle speed and the boring radius.

[0031] Preferably, in step S3, the method for determining the position of the measuring point is as follows: the position along the spindle axis of the tool is 8-12 mm closer to the tool tip.

[0032] Preferably, in step S3, the shape of the measuring point is a circular light reflection area, and the diameter of the circular light reflection area / the diameter of the laser spot area is ≥2.

[0033] Preferably, the measuring points are mirror-polished using P2000 polishing sandpaper, and the roughness of the measuring points is ≤Ra0.2.

[0034] Preferably, in step S4, the optimal installation position of the laser displacement sensor is the distance L between the probe and the ideal rotation axis of the boring tool spindle. f The calculation is as follows:

[0035] L f =[R+w Rs +L B -(S t +{w Rd} min ), R+w Rs +L B +(S t +{w Rd} max (6)

[0036] In formula (6), L fThis indicates the distance by which the probe of the laser displacement sensor deviates from the ideal axis of rotation of the boring tool spindle; R represents the distance by which the boring tool spindle deviates from the ideal axis or the boring radius; w Rs L represents the static deflection of the boring tool spindle. B S represents the measurement reference distance of the laser displacement sensor. t Indicates the measurement range of the laser displacement sensor; w Rd This represents the maximum transient deflection of the boring tool spindle.

[0037] Preferably, in step S5, the radial displacement of the boring tool spindle is calculated as follows:

[0038]

[0039] In formula (7), (x0, y0) represents the radial displacement of the boring tool spindle; δ3(t), δ6(t), δ 12 (t) represents the radial displacement data of the boring tool spindle measured by the laser displacement sensors located at the 12 o'clock, 3 o'clock, and 6 o'clock positions, respectively.

[0040] In summary, by adopting the above technical solution, the present invention has at least the following beneficial effects compared with the prior art:

[0041] This invention achieves non-contact, rapid, and accurate on-machine detection of the radial displacement of the boring tool spindle by arranging three laser displacement sensors at a set position and using spatial geometry to solve the test signal. This reduces errors and improves measurement accuracy, providing technical support for improving the geometric accuracy of boring holes. Attached image description:

[0042] Figure 1 This is a schematic diagram of a non-contact in-machine detection method for the radial flare of a boring tool spindle according to an exemplary embodiment of the present invention. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to embodiments and specific implementation methods. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0044] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] like Figure 1 As shown, the present invention provides a non-contact on-machine detection method for the radial arcing of a boring tool spindle, comprising the following steps:

[0046] S1: For the boring tool spindle structure, obtain the physical parameters of the boring tool spindle.

[0047] In this embodiment, the boring spindle includes a telescopic axial motion spindle, a boring bar, and a boring tool; the physical parameters of the boring spindle include bearing clearance, inner / outer diameter of the boring spindle, material density, elastic modulus, Poisson's ratio, axial length, axis inclination angle, radial deviation distance of the boring bar, unbalanced mass, and rotational speed.

[0048] S2: Based on the physical parameters of the boring tool spindle, calculate the static deflection and maximum transient deflection of the boring tool spindle through mechanical analysis and analytical methods.

[0049] In this embodiment, S2 specifically includes the following steps:

[0050] S2-1: Based on the physical parameters of the boring tool spindle, the bending stiffness of the boring tool spindle is calculated using the potential energy method. The corresponding formulas are as follows:

[0051]

[0052] In formula (1), k b The value represents the bending stiffness of the boring bar spindle; n represents the total number of spindle segments; k bi This represents the bending stiffness of the i-th segment of the boring bar spindle;

[0053] in:

[0054]

[0055] In formula (2), E i I i κ represents the bending stiffness of the i-th segment of the boring bar spindle (calculated using a basic formula from mechanics of materials); N represents the number of load types experienced by the boring bar spindle; j The j-th type of load coefficient is derived from the classical beam deflection deformation theory and the deflection superposition method. This represents the length of the i-th axis segment.

[0056] S2-2: Based on the physical parameters and operating parameters of the boring spindle (including the spindle speed and boring radius), the mechanical boundary of the boring spindle is established using vector analysis. The resultant force formula for the boring spindle during stable operation is as follows:

[0057] F Rs =F g +F ce (3)

[0058] In formula (3), F Rs F represents the resultant force when the boring tool spindle is running stably; g F represents the gravity vector of the boring tool spindle; ce This represents the centrifugal force vector of the boring tool spindle.

[0059] Considering the influence of factors such as eccentric mass, structural form, and manufacturing errors, the boring spindle is induced to undergo unsteady motion around its axis. In this case, there exists a dynamic load coefficient γ, and the expression for the dynamic load is as follows:

[0060] F Rd =F g +γF ce (4)

[0061] In formula (4), F Rd F represents the dynamic load on the boring tool spindle. g F represents the gravity vector of the boring tool spindle; ce γ represents the centrifugal force vector of the boring tool spindle; γ represents the dynamic load coefficient.

[0062] S2-3: Determine the static deflection and maximum transient deflection of the boring spindle based on the bending stiffness of the boring spindle in S2-1 and the resultant force and dynamic load of the boring spindle in S2-2.

[0063]

[0064] In formula (5), w Rs F represents the static deflection of the boring tool spindle; Rs This represents the resultant force when the boring tool spindle is running stably; k b Indicates the bending stiffness of the boring tool spindle; w Rd F represents the maximum transient deflection of the boring tool spindle; Rd This indicates the dynamic load on the boring bar spindle.

[0065] S3: Based on the physical parameters of the boring spindle in S1, the radial displacement boundary of the boring spindle in S2, and the measurement parameters of the laser displacement sensor, design the position and shape of the measuring point.

[0066] In this embodiment, a laser displacement sensor is used to detect the radial displacement of the boring tool spindle (i.e., the laser displacement sensor illuminates the boring tool spindle with a laser beam). Since the spot size of the laser displacement sensor is usually φ20~50μm, based on the structure and physical parameters of the boring tool spindle in S1, the resultant force of the boring tool spindle, and the dynamic load, the measuring point is selected near the cutting tool insert on the boring tool shank (considering the radial displacement calculation, the influence of centrifugal force, and gravity on radial displacement, the position of the measuring point along the spindle axis is generally 8~12mm near the tool tip). The area is then ground into a circular light-reflecting region, and the diameter of the circular light-reflecting region and the diameter of the laser spot satisfy the condition that the diameter of the circular light-reflecting region / the diameter of the laser spot region ≥ 2.

[0067] In this embodiment, P2000 polishing sandpaper is used to mirror polish the measuring points. The polishing quality of the measuring points is evaluated by the surface roughness index, and the roughness of the measuring points is ≤Ra0.2.

[0068] S4: Determine the installation location of the laser displacement sensor based on the position and shape of the measuring point.

[0069] In this embodiment, the optimal installation position of the laser displacement sensor is the distance L between the probe and the ideal rotation axis of the boring tool spindle. f The calculation is as follows:

[0070] L f =[R+w Rs +L B -(S t +{w Rd} min ), R+w Rs +L B +(S t +{w Rd} max (6)

[0071] In formula (6), L f This indicates the distance by which the probe of the laser displacement sensor deviates from the ideal axis of rotation of the boring tool spindle; R represents the distance by which the boring tool spindle deviates from the ideal axis or the boring radius; w Rs L represents the static deflection of the boring tool spindle. B S represents the measurement reference distance of the laser displacement sensor. t Indicates the measurement range of the laser displacement sensor; w Rd This represents the maximum transient deflection of the boring tool spindle.

[0072] S5: When solving for the radial displacement (x0, y0), according to the matrix operation rules, based on the two-dimensional vector decomposition of the radial displacement, the measurement error is reduced and the collected displacement data is conveniently calculated. Considering the force and radial offset state of the boring spindle, this invention designs and uses three laser displacement sensors, which are respectively arranged at the 12, 3 and 6 points of the measuring point. Based on this, the radial displacement of the boring spindle containing the radial displacement can be derived.

[0073]

[0074] In formula (7), (x0, y0) represents the radial displacement of the boring tool spindle; δ3(t), δ6(t), δ 12 (t) represents the radial displacement data of the boring tool spindle measured by the laser displacement sensors located at the 12 o'clock, 3 o'clock, and 6 o'clock positions, respectively.

[0075] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A non-contact on-machine detection method for the radial arcing of a boring tool spindle, characterized in that, Specifically, the following steps are included: S1: For the boring tool spindle structure, obtain the physical parameters of the boring tool spindle; S2: Based on the physical parameters of the boring spindle, calculate the static deflection and maximum transient deflection of the boring spindle; S3: Based on the physical parameters of the boring spindle in S1, the static deflection and maximum transient deflection of the boring spindle in S2, and the measurement parameters of the laser displacement sensor, design the position and shape of the measuring point; S4: Determine the installation location of the laser displacement sensor based on the position and shape of the measuring point; S5: Calculate the radial displacement of the boring bar spindle based on the measurement data from the laser displacement sensor; In S3, the method for determining the position of the measuring point is as follows: the position along the spindle axis of the tool is 8~12mm close to the tool tip; In step S4, the optimal installation position of the laser displacement sensor is the distance by which the probe deviates from the ideal rotation axis of the boring tool spindle. The calculation is as follows: In formula (6), R represents the distance by which the probe of the laser displacement sensor deviates from the ideal axis of rotation of the boring tool spindle; R represents the distance by which the boring tool spindle deviates from the ideal axis or the boring radius. This indicates the static deflection of the boring tool spindle; This indicates the measurement reference distance for the laser displacement sensor; Indicates the measurement range of the laser displacement sensor; This represents the maximum transient deflection of the boring tool spindle; In step S5, the radial displacement of the boring tool spindle is calculated as follows: In formula (7), ( , () indicates the radial displacement of the boring tool spindle; The data represent the radial displacement data of the boring tool spindle measured by laser displacement sensors located at positions 12, 3, and 6 of the measuring point.

2. The non-contact on-machine detection method for radial arcing of a boring tool spindle as described in claim 1, characterized in that, In S1, the boring spindle includes a telescopic axial motion spindle, a boring bar, and a boring tool.

3. The non-contact on-machine detection method for radial arcing of a boring tool spindle as described in claim 1, characterized in that, In S1, the physical parameters of the boring spindle include bearing clearance, inner / outer diameter of the boring spindle, material density, elastic modulus, Poisson's ratio, axial length, axis inclination angle, radial deviation distance of the boring bar, unbalanced mass, and rotational speed.

4. The non-contact on-machine detection method for radial arcing of a boring tool spindle as described in claim 1, characterized in that, S2 includes: S2-1: Calculate the bending stiffness of the boring spindle based on its physical parameters: In formula (1), This indicates the bending stiffness of the boring bar spindle; n indicates the total number of spindle segments of the boring bar spindle. This represents the bending stiffness of the i-th segment of the boring bar spindle; in: In formula (2), This represents the bending stiffness of the i-th segment of the boring bar spindle; N represents the number of load types experienced by the boring bar spindle. The j-th type of load coefficient is derived from the classical beam deflection deformation theory and the deflection superposition method. This represents the length of the i-th axis segment; S2-2: Calculate the resultant force of the boring spindle during stable operation based on its physical and operating parameters: In formula (3), This represents the resultant force when the boring tool spindle is running stably. This represents the gravity vector of the boring tool spindle; This represents the centrifugal force vector of the boring tool spindle; The expression for dynamic load is as follows: In formula (4), This indicates the dynamic load on the boring bar spindle; This represents the gravity vector of the boring tool spindle; This represents the centrifugal force vector of the boring tool spindle; Indicates the dynamic load factor; S2-3: Determine the static deflection and maximum transient deflection of the boring spindle based on the bending stiffness of the boring spindle in S2-1 and the resultant force and dynamic load of the boring spindle in S2-2: In formula (5), This indicates the static deflection of the boring bar spindle; This represents the maximum transient deflection of the boring tool spindle.

5. A non-contact on-machine detection method for the radial arcing of a boring tool spindle as described in claim 4, characterized in that, In S2-2, the working parameters are the tool spindle speed and the boring radius.

6. The non-contact on-machine detection method for radial arcing of a boring tool spindle as described in claim 1, characterized in that, In S3, the shape of the measuring point is a circular light reflection area, and the diameter of the circular light reflection area / the diameter of the laser spot area is ≥2.

7. A non-contact on-machine detection method for radial arcing of a boring tool spindle as described in claim 6, characterized in that, The measuring points were mirror-polished using P2000 polishing sandpaper, and the roughness of the measuring points was ≤Ra0.2.

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