The workpiece is positioned on the two parallel columns 2 by two V-shaped grooves, and the thrust bearing 1 is pressed against the right end of the workpiece to determine the longitudinal position. In order to avoid the influence of over positioning on the machining accuracy, the V-shaped seat 14 can be The left and right movements indicated by the arrows can be appropriately adjusted to the axis of the fixed V-shaped seat 13, so that the workpiece positioning base surface is in good contact with the positioning cylinder, and the positioning is stable. Because the fixed 镗 sleeve can easily ensure the center position of the 镗 sleeve is accurate, and the processing hole system can ensure high positional accuracy, the boring mold adopts the double yoke guiding fixed 镗 sleeve.
1 Analyze and calculate the tool setting error of 28±0.05.
The factors that cause the tooling error are: 1 the dimensional tolerance of the bottom hole axis of the two truss mounting sleeves 6, 10 to the F surface is ± /2. The bottom hole of the two truss mounting sleeves 6, 10 can be installed. After processing on the base, but due to the long hole distance, the deformation of the mast and the influence of the guide rail and other error factors, the bottom shaft tolerance T01, the inner and outer circles of the 3镗6, 10 have a coaxial tolerance T02; 4The standard mandrel axis to the F surface has a tolerance of T2/2. Although the four V-shaped blocks can be machined or mounted on the base and finally finished, the angle of the V-shaped groove is inaccurate, and the standard mandrel also has tolerances ( It is also considered that the four standard mandrels are cut together after being finished, but the distance from the standard mandrel to the F face is always limited by the two errors T2/2. According to the dimensional chain principle, the tooling error is.
(2) Analyze the parallelism tooling error of the hole 1 to the standard mandrel of the V-groove guide.
Analyze the parallelism tooling error of the hole 1 to the standard mandrel in the Z direction. In the Z direction, the factor of the parallelism tooling error is the same as the size of the knife error, and the extreme situation is: when the distance from the center of the pupil to the surface is different, the inner and outer circle of the sleeve 1 is fflshing. The bottom hole axis is at the 1 position from the Fd surface, the thick portion of the bushing 5 is on the upper portion, and the thin portion is on the lower side, so the center of the inner hole of the bushing 5 is moved downward by T01/2, and at the 2 position, the sleeve 6 is also thick. The upper part is on the upper part, and the thin part is on the lower side. The center of the inner hole of the cymbal sleeve 6 is moved downward relative to the center of the inner hole of the bushing by 3 at the position of the bottom hole of the front truss mounting ffa '镗 sleeve. L+ Ti/2, in / position, the thick portion of the bushing F 11 is below, the thin portion is shifted by Tqi/2 in the inner axis of the upper bushing relative to the axis of the bottom hole, and at the 2 position, the thickness of the bushing 10 The part is lower, the thin part moves up T02/2 in the inner hole axis of the upper jaw, at the 3 position; the distance from the standard mandrel axis to the F side of the left side is L2+T2/2, at the 4 position, the right side The distance from the standard mandrel to the F-plane is L-T2/2, at the 4 position, so that the left part of the hole 1 is the smallest to the standard mandrel axis, and the right part is to the standard The axis axis distance is the largest, and the parallelism tooling error appearing in the Z direction is: T11 is the parallelism tolerance of the hole 1 to the standard mandrel of the V-groove guide.
The hole 1 has a parallelism to the standard mandrel axis in the X direction. The main factors that cause this error are: the bottom hole of the truss truss has a dimensional tolerance from the symmetrical center plane of the fixed V-shaped block. If the rib bottom hole is symmetrical from the V-shaped block E, the L3 sleeve is 11 inside and outside. Round coaxiality error, the thin part of the installation is close to D, the thick part is close to D, the axis of the inner hole of the bushing is close to Tq1/2 with respect to the axis of the bottom hole of the truss, at the 2 position; the sleeve 10 is inner and outer Concentricity error, the thin part of the installation is close to E, and the thick part is close to D, so that the inner hole axis of the cymbal sleeve 10 is closer to Tq2/2 to the position of E at the 3 position; the bottom sill hole is at a distance from the V-shaped block. The symmetry center plane E is L3+T3/2, at the 1 position; the bushing 5 has a concentricity error due to the inner and outer circles. When the installation is thick, the thick part is against E, and the thin part is D. The inner hole axis of the bushing 5 is opposite to the inner hole axis. The bottom hole axis is far away from ETq1/2, at the 2 position; the 镗 sleeve 6 is also installed in a thick part due to the inner and outer circle coaxiality error, and the thin part is placed on the D, and the inner hole axis of the 镗 sleeve 6 is away from the ETq/ 2, in the 3 position, the parallelism generated in the X direction is extremely extreme.
The tooling error of the hole 1 to the standard mandrel axis parallelism in the X direction is: Analyze the symmetry tooling error of the hole 1 to the standard mandrel E, D. The axis 1 of the hole 1 has an inner and outer circle coaxiality error Tq1 for the standard mandrel axis E and D of the V-shaped groove guide, and the inner and outer circle coaxiality error Tq2 of the ferrules 6, 10 may be extreme. The distance from the bottom hole of the front and rear trusses to E is L3-T3/2, at the O1O1 position; the thin sides of the bushings 5 and 11 are also turned toward the E, the thick side is directed to the D, and the axis of the bushing is O2O2. Position; the thin side portion of the sleeves 6, 10 also leans toward E, the thick side portion leans toward D, and the inner diameter of the inner sleeve axis is at the O3O3 position. The opposite is still true. The symmetry of the hole 1 to the standard mandrel of the V-shaped groove guide is: E~i rE E 2 The error analysis of the machine is to ensure that the clamp positioning element <40h5 standard mandrel axis E is parallel to the feed direction of the table. The fixture is correct. (For a single-supported boring die, the mast and the spindle are rigidly connected, and the machine error must be extremely small). The factors that cause the machine error of the boring machine fixture are: the parallelism tolerance of the standard mandrel axis E to the front side B is T11eb; the parallelism tolerance of the front side B and the feeding direction is T11B machine; the straightness tolerance of the front side B is found. T, the machine error of the machining hole 1 is: the tolerance of the center distance between the other holes and the ferrule of the hole 1 is also the tool setting error of the center distance between the holes. The author has already explained the "calculation of machine tool and liquid core distance error", and will not be demonstrated here.
For the perpendicularity of the hole 3 and the hole 1, although the perpendicularity tolerance is not indicated, care should be taken. The rafter 9 is a rear-guided double-bearing guide rafter whose inner bore axis is parallel to the plane of the standard mandrel axis E, D and the axis of the bore 9 is aligned with the E- and V-shaped block symmetry center plane The perpendicularity error is the tool error. These two errors are in the case of installing the bracket assembly of the cymbal sleeve 9, and the tolerance adjustment can be made after the standard mast is installed, and the sag error of the inner hole axis of the 镗 sleeve 9 should be limited to the symmetry center plane of the E and V blocks. The tolerance of the hole 3 and the hole 1 is within 1/3 of the tolerance. The parallelism tolerance of the standard mandrel axis E and the plane B and the rotation of the rotary table 9 (the T angle (index) error are the machine errors of the perpendicularity of the machining hole 3 and the hole 1, and should also be made The machine error is limited to 1/3 of the tolerance of the two holes.