JB/T 8772.5-1998 This standard is formulated based on JB/T 8771.4-1998 "Part 5 of Inspection Conditions for Machining Centers: Inspection of Positioning Accuracy and Repeated Positioning Accuracy of Workpiece Clamping Pallets" (this standard is equivalent to the draft international standard ISO/DIS 10791-5). It is the same as JB/T 8771.5-1998 in terms of inspection items and inspection methods, while the tolerance is compressed on the basis of JB/T 8771.5-1998 according to the requirements of machine tool accuracy classification. This standard specifies the requirements and inspection methods for the repeated positioning accuracy of each pallet and the positioning accuracy of a group of pallets associated with a specific machine tool. This standard applies to pallets for single precision vertical and horizontal machining centers. This standard does not apply to pallets for precision machining center manufacturing systems. JB/T 8772.5-1998 Test conditions for precision machining centers Part 5: Test of positioning accuracy and repeatability of workpiece holding plates JB/T8772.5-1998 Standard download decompression password: www.bzxz.net

JB/T 8772.5—1998wwW.bzxz.Net
This standard is formulated based on JB/T8771.5—1998 "Testing conditions for machining centers Part 5: Inspection of positioning accuracy and repeat positioning accuracy of workpiece clamping pallets" (this standard is equivalent to ISO/DIS10791-5 "Testing conditions for machining centers Part 5: Inspection of positioning accuracy and repeat positioning accuracy of workpiece clamping pallets"), and its inspection items, inspection methods and other contents are the same as those of JB/T8771.5, while the tolerances are compressed on the basis of JB/T8771.5 according to the requirements of machine tool accuracy classification. This standard is one of the standards in the series of inspection conditions for precision machining centers. This series of standards includes the following 13 parts, which can be used simultaneously or separately:
Part 1: Geometric accuracy inspection of horizontal and attached spindle head machine tools (horizontal Z axis); Part 2: Geometric accuracy inspection of vertical machining centers; Part 3: Geometric accuracy inspection of integral universal spindle head machine tools with horizontal main rotary axis (vertical Z axis (to be formulated), Part 4: Positioning accuracy and repeat positioning accuracy inspection of linear and rotary axes; Part 5: Positioning accuracy and repeat positioning accuracy inspection of workpiece clamping pallets; Part 6: Feed rate, speed and interpolation accuracy inspection (to be formulated); Part 7: Precision inspection of fine-machined test pieces; Part 8: Spherical evaluation using the circular inspection method (to be formulated), Part 9: Tool conversion and pallet conversion action time Assessment (to be formulated); Part 10: Assessment of thermal deformation (to be formulated); Part 11: Assessment of noise emission (to be formulated); Part 12: Assessment of vibration intensity (to be formulated); Part 13: Assessment of safety measures (to be formulated). This standard is proposed and managed by the National Technical Committee for Standardization of Metal Cutting Machine Tools. The drafting units of this standard: Beijing Machine Tool Research Institute, Kunming Precision Machine Tool Research Institute, Ningjiang Machine Tool Factory. The main drafters of this standard: Qian Wenming, Hong Ning, Wang Guikang, Liu Yan. 659
1 Scope
Machinery Industry Standard of the People's Republic of China
Test conditions of precision machining centresPart 5: Tests for accuracy and repeatability ofpositioning of work-holding palletsJB/T 8772. 5--1998
This standard specifies the requirements and inspection methods for the repeat positioning accuracy of each pallet and the positioning accuracy of a group of pallets associated with a specific machine tool.
This standard applies to the pallets of a single precision vertical and horizontal machining center. This standard does not apply to the pallets of a precision machining center manufacturing system. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision and the use of this standard The parties shall explore the possibility of using the latest versions of the following standards. GB/T17421.1-1998 General Rules for Inspection of Machine Tools Part 1: Geometrical Accuracy of Machine Tools under No-Load or Finishing Conditions ISO230-2:1997 General Rules for Inspection of Machine Tools Part 2: Determination of Positioning Accuracy and Repeatability of Coordinate Axes of CNC Machine Tools 3 General Requirements
3.1 When using this standard, reference should be made to GB/T17421.1 and ISO230-2, especially when inspecting tool accuracy. The indicator should have a resolution of 0.001 mm.
3.2 The meaning of the common letters in the drawings of this standard: -M and N represent the horizontal axis of the machine tool: In the approach direction function of the pallet, for horizontal machining centers, M and N refer to the X-axis and Z-axis (or Z-axis and X-axis) axes: for vertical machining centers, M and N refer to the X-axis and Y-axis (or Y-axis and X-axis) axes. -P represents the vertical axis of the machine tool: for horizontal machining centers, P refers to the Y-axis axis; for vertical machining centers, P refers to the Z-axis axis.
-R represents the rotation axis of the pallet: for horizontal machining centers, R refers to the B-axis axis; for vertical machining centers, R refers to the C-axis axis.
-K is a common letter used in formulas to represent the axes M, N, P and R. 3.3 When inspecting machine tools, it is not necessary to inspect all items in this standard due to the structural characteristics. When inspection is required for acceptance purposes, the user may obtain the manufacturer's consent to select some inspection items that he is interested in, but these items must be clearly stated when ordering the machine tool. 3.4 The inspection tools specified in this standard are only some examples. Other inspection tools with the same indication and at least the same accuracy and resolution may be used.
National Machinery Industry Fan 1998-07-17 approved 660
1998-12-01 implementation
4 Repeatable positioning accuracy of each pallet on the machine tool 4.1 Installation of inspection tools
JB/T8772.5-1998
Place a gauge block in the pallet reference groove according to Figure 1, and place a square ruler close to the gauge block on the pallet table. If the pallet is used to fix the workpiece or fixture with different datums (such as the datum is a locating hole or a side locator), the inspection tool should be placed at the same position from the datum. The corresponding relationship between the axis (M, N, P and R) in Figure 1 and the actual axis of the machine tool should be indicated in Table 2 according to 3.2. N
4.2 Formula for calculating deviation from each reading
α is the reading of the indicator, W is the repeatable positioning accuracy of the pallet along (or around) each axis, and the deviation value is calculated from each reading according to the following formula. am = a
ap = αs
ar = (a2 -as)/d
-positioning approach sequence number;
where: i-
i pallet sequence number;
Wik = ajKmax
—ajKmin
KM, N, P and R (i.e. X, Y, Z and B or C). Note: Subscript 2 indicates that the indicator is closer to the rotation axis of the pallet. 4.3 Filling difference
JB/T 8772.5-1998
The tolerance of the repeat positioning accuracy of each pallet is shown in Table 1. Table 1 Repeatability of positioning accuracy of each pallet Pallet short side length L
>500800
>800~～1 250
>1250～2000
4.4 Inspection tools
Wx.Wy, Wz
Indicator, gauge block, angle ruler or special fixture, or other inspection tools with the same measurement results. 4.5 Inspection method
Any length L
0.010/1000
If possible, all axes should be locked. Fix a special fixture or angle ruler (or other inspection tools) on the positioning reference used by the fixture of the pallet. The inspection tools on each pallet should be fixed at the same position. The indicator should be fixed in a position that does not affect the loading and unloading of the pallet (automatic exchange of pallets). If direct contact between the probe and the inspection tool is to be prevented, the readings can be taken with a gauge block placed each time between the inspection tool and the probe. The indicator is set to zero only on the first approach to the first positioning of the first pallet. Each pallet is loaded and unloaded (automatically exchanged) 5 times without re-adjusting the indicator, and 5 readings of each indicator are recorded. The deviation a in different directions is calculated from each reading according to 4.2. Note: The αR deviation can also be measured with the help of an autocollimator, as long as the reflector is placed in the same position relative to the positioning reference for the fixture on different pallets. The repeatability error of each pallet is calculated separately. The error is calculated as the maximum difference in the indicator readings. 4.6 Record of measured deviations
An example of a record table for the actual deviation and error calculation of the repeatability accuracy of each pallet is shown in Table 2. The table and the header should be marked with the corresponding relationship between the universal letters and the actual axis of the machine tool according to 3.2 and Figure 1. Table 2 Repeatable positioning accuracy of each pallet
aijKmim
aiKmny
ajKmin
az —aa
aiKmax
agKmin
5 Positioning accuracy of a group of pallets associated with a machine tool 5.1 Installation of inspection tools
JB/T8772.5—1998
Table 2 (end)
ajKmay
The inspection result is determined by the readings taken during the above inspection. For this purpose, the installation of the inspection tools is the same as 4.1. 5.2 Formula for calculating deviation
a is the reading of the indicator, A is the positioning accuracy of a set of pallets along (or around) each axis, and the deviation value is calculated from each reading according to the following formula. Ak=ajkKx-ajKmm
Usually, two i values ​​are different from two i values. In particular, if the maximum and minimum values ​​of α in the above formula belong to the same i pallet, then for the specific K axes it means: Ak-Wik5.3 Tolerance
The positioning accuracy tolerance of a set of pallets is shown in Table 3. Table 3 Permissible positioning accuracy of a group of pallets
Length of short side of pallet L
>500～800
>800～1250
>1 250--2 000
5.4 Inspection tools
Ax, Ay, Az
Indicator, gauge block, angle ruler or special fixture, or other inspection tools with the same measurement results. 5.5 Inspection method
Inspection method is the same as 4.5.
Any length L
0. 020/1 000
JB/T 8772.5-1998
The positioning accuracy error of a group of pallets is calculated according to 5.2 using the readings measured during the above inspection. The error is calculated as the maximum difference of the indicator readings of the group of pallets.
5.6 Measured Deviation Record
A set of pallet positioning accuracy measured deviation and error calculation record table example is shown in Table 4. The table and the table header should be marked according to 3.2 and Figure 1 corresponding to the relationship between the general letter and the actual axis of the machine tool, the single value of ajkm and ajkm in Table 4 should be taken from the corresponding MNP and R column of the i pallet in Table 2 Positioning Accuracy of a Set of Pallets
aijMmx
agj Mmin
aiNmax
ajPmax
aijpmn
aij Rmax
aiji min
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