Generally, the main scale is installed on the workbench (slide plate) of the machine tool, and moves with the cutting of the machine tool. The reading head is fixed on the bed, and the reading head is installed below the main scale as much as possible. The choice of its installation method must pay attention to the splashing direction of chips, cutting fluid and oil. If the reading head must be installed upward due to the limitation of the installation position, an auxiliary sealing device must be added. In addition, under normal circumstances, the reading head should be installed on the stationary part relative to the machine tool as much as possible. At this time, the output wire does not move and is easy to fix, while the ruler body should be installed on the part that moves relative to the machine tool (such as the slide plate).

Installation base

When installing the grating scale displacement sensor, the sensor cannot be directly installed on the rough and uneven machine tool body, let alone on the machine tool body with primer and paint. The grating main scale and the reading head are respectively installed on the two parts of the machine tool that move relative to each other. Use a micrometer to check the parallelism between the main scale installation surface of the machine tool workbench and the direction of movement of the guide rail. The micrometer is fixed on the bed, and the workbench is moved. The parallelism is required to be within 0.1mm/1000mm. If this requirement cannot be met, a grating scale base needs to be designed and processed.

The base requirements are as follows: (1) A base with the same length as the grating scale body should be added (it is best that the base is about 50mm longer than the grating scale). (2) The base is processed by milling and grinding to ensure that its plane parallelism is within 0.1mm/1000mm. In addition, a reading head base with the same height as the scale body base needs to be processed. The total error between the reading head base and the scale body base shall not exceed ±0.2mm. During installation, adjust the reading head position to achieve a parallelism of about 0.1mm between the reading head and the grating scale body, and a spacing of about 1~1.5mm between the reading head and the grating scale body.

Main scale installation

Use M4 screws to fix the grating main scale on the workbench mounting surface of the machine tool, but do not tighten it. Fix the micrometer on the bed and move the workbench (the main scale and the workbench move at the same time). Use a micrometer to measure the parallelism between the main scale plane and the direction of movement of the machine tool guide rail, adjust the position of the main scale M4 screw, and when the main scale parallelism meets the requirement of 0.1mm/1000mm, tighten the M2 screw thoroughly.

When installing the grating main scale, pay attention to the following three points:

(1) When installing the main scale, if you install a grating larger than 1.5M, you cannot install only the two ends like a bridge type, but you still need to have support in the entire main scale body. (2) After installation with a base, it is best to use a clip to clamp the midpoint (or several points) of the scale body. (3) When the clip cannot be installed, it is best to use glass glue to stick the grating scale body to fix the base scale and the main scale.

Reading head installation

When installing the reading head, if you find that the installation conditions are very limited, you can consider using accessories, such as angle aluminum and straight plate. First, you should ensure that the base surface of the reading head meets the installation requirements, and then install the reading head. The installation method is similar to the main scale. Finally, adjust the reading head to ensure that the parallelism between the reading head and the grating main scale is within 0.1mm, and the gap between the reading head and the main scale is controlled within 1~1.5mm. After installation, you can use your thumb to touch the reading head and the surface of the grating scale to see if it is smooth and flat.

Limit device

After all the grating line displacement sensors are installed, be sure to install limit devices on the machine tool guide rails to prevent the reading head from colliding with the two ends of the main scale when the machine tool is moving the product, thereby damaging the grating scale. In addition, when purchasing grating line displacement sensors, users should try to choose grating scales that exceed the machine tool processing size by about 100mm to leave a margin.

Sensor inspection

After the grating line displacement sensor is installed, you can connect the digital display, move the workbench, and observe whether the digital display counts normally.

Select a reference position on the machine tool and move the working point back and forth to the selected position. The readings of the digital display should be the same (or return to zero). Alternatively, you can use a micrometer (or vernier gauge) to adjust the micrometer and the digital display to zero (or memorize the starting data) at the same time, and return to the initial position after multiple round trips to observe whether the data of the digital display and the micrometer are consistent.

Through the above work, the installation of the grating scale linear displacement sensor is completed. However, for general machine tool processing environments, there are more iron filings, cutting fluids and oil stains. Therefore, the sensor should be equipped with a protective cover. The design of the protective cover is determined by enlarging the cross-section of the sensor's shape and leaving a certain space size. The protective cover is usually sealed with rubber to give it a certain waterproof and oil-proof ability.