Some standard content:
JB/T9924-1999
This standard is revised on the basis of JB/Z168-89 "Grinding Surface Waviness". This standard is consistent with the technical content of JB/Z168-89, and has only been re-edited according to relevant regulations. This standard replaces JB/Z168-89 from the date of implementation. Appendix A of this standard is the appendix of the standard. This standard is proposed by the National Technical Committee for Standardization of Metal Cutting Machine Tools. This standard is under the jurisdiction of the Grinding Machine Branch of the National Technical Committee for Standardization of Metal Cutting Machine Tools. Responsible drafting units of this standard: Beijing No. 2 Machine Tool Factory, Wuxi Machine Tool Factory This standard was first issued in September 1981. It was first revised in March 1989. This is the second revision64www.bzxz.net
1 Scope
Machinery Industry Standard of the People's Republic of China
Grinding Surface Waviness
This standard specifies the evaluation method and principles for grinding surface waviness. JB/T 9924--1999
Replaces JB/Z168--89
This standard is applicable to cylindrical surfaces, conical surfaces and planes processed by circular grinding. It can also be used as a reference for grinding bearing raceways, gear tooth surfaces, thread helical surfaces, planes processed by end face grinding and other grinding surfaces. 2 Definitions
This standard adopts the following definitions.
2.1 The waviness of the ground surface (hereinafter referred to as waviness) is the periodic ups and downs formed on the surface of the part mainly due to the vibration of the machine tool-workpiece-grinding wheel system during the grinding process.
This standard only comprehensively evaluates the waviness from the geometric shape characteristics, and does not involve other physical characteristics of the surface. 2.2 Waviness curve
The total geometric shape error of the part surface consists of three parts: surface roughness, waviness and shape error (see Figure 1). When measuring the cross-sectional profile curve, a certain filtering method is adopted to limit and weaken the roughness and shape error components of the machined surface, so that the obtained measurement curve is called the waviness curve.
Cross-sectional profile curve
Surface roughness component
Waviness component
Shape error component
3Waviness measurement direction
The waviness value refers to the value obtained on each section perpendicular to the reference plane. If a certain measurement direction is not specified, the waviness value refers to the value obtained on the section perpendicular to the reference plane and along the machining texture direction (in general, the maximum amplitude of the waviness generated by vibration occurs in the machining texture direction). 4Filtering method
In order to obtain the waviness curve or determine its measurement result, any type of filtering method or a combination thereof is allowed. 4.1 Rolling filter
Approved by the State Machinery Industry on May 20, 1999
Implemented on January 1, 2000
JB/T9924--1999
Use a probe with a large radius of curvature in a plane perpendicular to the processing texture direction, and move along the cross-sectional profile curve in the waviness measurement direction. The trajectory of its center greatly reduces the influence of surface roughness (see Figure 2). This radius of curvature is called the rolling radius of curvature, represented by R.
Axe-shaped probe
Processing texture
Vertical processing direction
4.2 Electrical cut-off filtering
Rolling movement trajectory
Use the amplitude-frequency characteristics of the electrical filter circuit to limit the surface roughness component with a low-pass filter, or limit the shape error component with a high-pass filter.
4.2.1 For linear waviness, a low-pass filter can be used. On the amplitude-frequency characteristic diagram, the wavelength (mm) corresponding to 70.7% of the amplitude is called the high-pass cutoff value (see Figure 3).
K-the amplitude quantity allowed to pass. The cutoff wavelength value is 2.5 mm Figure 3
4.2.2 For circular waviness, a high-pass filter can be used. On the amplitude-frequency characteristic diagram, the frequency f, (wave/cycle) corresponding to 70.7% of the amplitude is called the low-pass cutoff value (see Figure 4). K.%t
, wave/cycle
K-the amplitude quantity allowed to pass. The cutoff frequency value is 15 waves/cycle Figure 4
4.3 Geometric filtering
JB/T 9924-1999
On the cross-sectional profile curve with limited surface roughness, read the amplitude value within a wave distance range to limit and weaken the shape error component.
4.4 When different filtering methods are used to limit the surface roughness, if there are differences in the measurement results, the rolling filter shall prevail. 5 Parameters for evaluating waviness
5.1 The basic parameter for evaluating waviness is the amplitude value W5.1.1 For linear waviness: The amplitude value W of a wave on the waviness curve refers to the coordinate distance between the peak and the connecting line of two adjacent troughs (see Figure 5).
5.1.2 For circular waviness: The amplitude value W of a wave on the waviness curve refers to the difference in radius between adjacent peaks and valleys (see Figure 6) Figure 6
5.2 The characterization parameter for evaluating waviness is the average amplitude value W,5.2.1 For linear waviness: W, refers to the arithmetic mean of the five largest amplitudes on the waviness curve within the measurement length 1 (see Figure 7). When the number of waves within the measurement length is less than 5, the average amplitude of all waves within the measurement length is taken as the W, value. Note: The standard value of the measuring length is 100 mm. When the instrument measuring length or the total length of the workpiece measured surface is less than 100 mm, the instrument measuring length or the total length of the workpiece measured surface is taken as the measuring length. AAAAA
(Wi+W,+W.+wa+Ws)
JB/T 9924—1999
5.2.2 For circular waviness: W. refers to the arithmetic mean of the 5 maximum amplitudes on the waviness curve of the same cross section (see Figure 8). 5.2.3 When the waviness is required to be a certain value, it means that the average amplitude W. of the surface cannot be greater than this value, but it can be smaller. -(w+w,+w
6 Series values of the curvature radius, cutoff value and average amplitude of waviness of the probe 1+ws)
6.1 The series values of the rolling circle curvature radius R are: 0.25, 0.8, 2.58.0, 25mm. The series value of the curvature radius r (see Figure 2) of the axe probe in the plane of the processing texture direction is: 0.25, 0.8 mm. For general pre-grinding surfaces, the standard value of R value is 8.0 mm; the standard value of r value is 0.8 mm. Note: When the waviness cannot be measured according to the R value of 8.0 mm or the r value of 0.8 mm (such as the end grinding surface with a large roughness distance, the bearing raceway surface with a small curvature radius, etc.), other R and, values can be selected according to the series value, and indicated in the relevant technical documents. 6.2 The series value of the high-pass cut-off value is: 0.08, 0.25, 0.8, 2.5, 8.0 mm. For general grinding surfaces, the p value is selected according to the surface roughness Ra value to be measured (see Table 1).
Surface roughness Ra value
≥0. 02～~0. 32
>0. 322. 5
Note: When the waviness cannot be measured according to the input value specified in the table (such as end grinding surface with large roughness), other input values can be selected according to the series value, and it shall be noted in the relevant technical documents.
6.3 The series values of the low-pass cutoff value f of the circumferential waviness are: 5, 15, 45 waves/week. For general grinding surfaces, the standard value of f is 15 waves/week.
Note: When the waviness cannot be measured according to the f value of 15 waves/week (such as cylindrical surfaces with very small or large diameters, miniature or large bearing raceways, etc.), other values other than the W value can be selected according to the series value or the W value different from the W value can be controlled separately, and it shall be noted in the relevant technical documents. 6.4 The allowable values of the average amplitude of corrugation W are arranged according to the common ratio of 1.6, and the values are as follows: 0.04, 0.063, 0.10, 0.16, 0.25, 0.40, 0.63, 1.0, 1.6, 2.5, 4.0, 6.3, 10, 16μm7 Corrugation marking
When marking the corrugation on the drawing, before the national standard makes the "marking" provision, the allowable values of the average amplitude W shall be directly indicated in the technical requirements of the drawing; when the national standard stipulates "marking", it shall be implemented in accordance with that standard. 68
JB/T 9924-1999
Appendix A
(Appendix of the standard)
Evaluation regulations
A1 Since there are many types of corrugation curves, the graph should be analyzed when evaluating the average amplitude W, and the reading should be correct and reasonable. The following are two special cases.
A1.1 When there is a low-frequency wave superimposed with an obvious high-frequency wave, the amplitude value should be read within the low-frequency wave range, as shown in Figure A1. M
W.=-(Wi+w+Ws+W,+Ws)
A1.2 If there are small waves superimposed on some or several waves of the basic frequency wave, the amplitude value should be read within the basic wave distance range, as shown in Figure A2. AMM
W,=(w.+w.+w.+w.+ws)
A2 When measuring the circular waviness on an existing roundness meter, it is allowed to use the axe-shaped probe of the instrument as a rolling filter. If there is a difference in the measurement result with the standard probe, the standard probe shall be used. A3 Surface defects (such as grooves, pores, scratches, etc.) should not be included in the evaluation process, nor can they replace the evaluation basis for surface appearance quality (such as spiral lines, etc.).
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