There are many types of pipe square, such as hot-rolled square rectangular tubes, galvanized square rectangular tubes, stainless steel square rectangular tubes, etc. Due to differences in materials and production processes, there are many methods for measuring the length of square and rectangular tubes. Today we will introduce to you four commonly used length measurement methods for rectangular tubes. We hope it will be helpful to you:

(1) Encoder length measurement

The principle is to install an encoder at the oil cylinder, use the oil cylinder to push the square and rectangular pipe to move on the roller table and install a series of photoelectric switches at equal distances on the other side. When the steel pipe is pushed by the oil cylinder and the end of the pipe touches the photoelectric switch, the recorded code is The meter reading is used to calculate the stroke of the oil cylinder so that the length of the square and rectangular tube can be calculated. The characteristic is that the square and rectangular tube needs to be raised when measuring length. In addition, there are certain errors in photoelectric switch detection, which may require sufficient measurement.

(2) Improvement of encoder length measurement

This is an indirect measurement method. By measuring the distance between the two end faces of the pipe square and their respective reference points, the length of the square rectangular tube is indirectly measured. Set up one length-measuring trolley at each end of the square and rectangular pipe, with the initial position being zero and the distance L. Then move the editor length to the walking distance (L2, L3) of the respective square and rectangular tube ends, then L-L2-L3 is the length of the square and rectangular tube. This measurement method overcomes the difficulties of the large size of the square rectangular tube, the complex environment of the production site, and the inability of the measurement mechanism to pass through the lower support platform of the square rectangular tube.

(3) Camera length measurement

Camera length measurement uses image processing to measure the length of square and rectangular tubes. The principle is to install a series of equidistant photoelectric switches on a certain section of the square and rectangular tube conveying roller and add a light source and camera to another section. When the square tube passes through this area, the length of the square tube can be determined based on the position of a photoelectric switch on the screen that captures the image through the camera. The characteristic is that it can realize online measurement, and the length data of the square and rectangular pipe can be obtained when it passes through the length measurement area without any interval. The disadvantage is that if a special light source is not used, the square and rectangular tube will be interfered with by external light. When a special light source is used, the brightness of the square and rectangular tube after chamfering is high and the reflection of light is strong, which can easily cause reading errors.

(4) Grating ruler length measurement

Two fixed-length grating rulers are installed outside both ends of the square rectangular tube. A rodless cylinder is used to drive the grating ruler close to both ends of the square rectangular tube. The interference phenomenon of light is used to measure the length of the square rectangular tube. It is characterized by high accuracy. However, grating scales are expensive and difficult to maintain and are sensitive to the effects of dust and site vibration.