What are the points for attention in adjusting the straightness of the guide rail of the precision engraving machine?

Adjusting the straightness of the guide rail of the die precision engraving machine is a key link to ensure the accuracy of the equipment. The following matters should be paid attention to during operation to avoid accuracy deviation or equipment damage due to improper operation:

First, the preliminary preparation and environmental requirements

environmental stability

Ensure that the workshop temperature is constant (it is recommended to control it at 20 5℃), so as to avoid the influence of temperature difference on the straightness of the guide rail caused by thermal expansion and contraction.

Stay away from vibration sources (such as punching machine and large motor), vibration will lead to distortion of measurement data and affect adjustment accuracy.

Calibration of tools and instruments

Use high-precision measuring tools (such as laser interferometer, precision level and dial indicator), and the tools should be calibrated in advance and within the validity period.

Prepare special adjustment tools (such as wrenches, feelers, and adjustment pads) to avoid parts damage caused by using non-standard tools.

Second, the mechanical structure inspection

Pretreatment of guide rail installation base surface

Check whether the installation surface of the guide rail has burrs, bumps or oil stains, polish it with sandpaper and clean it with alcohol to ensure the smoothness of the installation surface (roughness ≤Ra1.6μm).

Use a level to detect the flatness of the installation base surface, and the error should be controlled within 0.02mm/m/m. If it is out of tolerance, the base surface should be ground or replaced.

Installation status of guide rail assembly

Confirm the fit clearance between the slide block of the guide rail and the guide rail. If the clearance is too large (more than 0.01mm), the slide block or the guide rail needs to be replaced to avoid the rapid attenuation of accuracy after adjustment.

Check whether the guide rail fixing screw is loose or slippery. If it exists, replace the screw and tighten it evenly according to the specified torque (for example, M8 screw torque is about 20-25 nm).

Three, straightness adjustment operation points

Measurement benchmark and method

Transverse straightness (perpendicular to the direction of movement): fix the dial indicator on the machine tool, with the meter head touching the side of the guide rail and moving along the guide rail all the way. The reading deviation should be ≤0.01mm/500mm.

Longitudinal straightness (parallel to the direction of motion): use laser interferometer to measure the straightness of the whole length of the guide rail, and the whole error is controlled within 0.03mm/m/m.

Diagonal straightness: For long guide rails, it is necessary to measure the diagonal twist, and the error is ≤ 0.02 mm/m..

Adjustment sequence and strength control

Adjust the Fixed side guide rail (usually marked with "fixed") first, and then adjust the driven side guide rail ("Moving") to avoid mutual interference between the two sides.

When adjusting, increase or decrease the adjusting pad (thickness tolerance of ±0.005mm) or fine-tuning screw at the bottom of the guide rail, and the adjustment amount shall not exceed 0.01mm at a time, so as to gradually approach the target value, and it is forbidden to make large-scale adjustment at one time.

Every adjustment needs to be repeated for 3 times to ensure data stability and avoid straightness change caused by stress release.

Four, fasteners and lubrication system processing

Screw fastening strategy

"Diagonal step-by-step tightening" method is adopted: all screws are pre-tightened to 50% torque, and then tightened to standard torque in diagonal order for three times to avoid uneven deformation of the guide rail.

After tightening, check the fit between the guide rail and the installation surface with a feeler gauge. The 0.03mm feeler gauge should not be inserted, otherwise the cushion block needs to be readjusted.

Synchronous inspection of lubrication system

After adjustment, it is necessary to clean the surface of the guide rail, and apply special guide rail oil (such as ISO VG32 lubricating oil) to ensure the smooth lubrication pipeline, so as to avoid the straightness being affected by the wear of the guide rail caused by dryness.

V. Accuracy Verification and Trial Operation

Full stroke test

After the adjustment is completed, let the engraving machine run back and forth for 20-30 times within the full travel range, simulate the actual processing state, measure the straightness again, and allow the fluctuation of error ≤0.005mm/m, otherwise it is necessary to check whether there is mechanical interference.

Workpiece verification

Use standard test pieces (such as aluminum alloy plates) for engraving test, and measure the dimensional accuracy of the workpiece. If the deviation of the workpiece exceeds 0.05mm due to straightness error (depending on the processing requirements), it is necessary to readjust the guide rail.

Six, safety and protection precautions

Wear dust mask and gloves during operation to avoid metal debris splashing and injuring people or polluting the guide rail.

During the adjustment, it is forbidden to power on the equipment, disconnect the power supply and hang the warning sign of "under maintenance" to prevent misoperation.

If the disassembly of the guide rail is involved, it is necessary to mark the relative position of the slider and the guide rail to avoid the accuracy deviation caused by positional dislocation during reassembly.

summary

The straightness adjustment of guide rail is a fine operation, which needs to be combined with high-precision measurement, uniform stress control and multiple verifications to ensure that each step of operation meets the requirements of equipment accuracy. If you are inexperienced, it is recommended to refer to the equipment manual or contact the manufacturer's technicians for assistance to avoid equipment failure caused by operational errors.