With the increase of weight, the cost of small automatic concrete mixer is bound to be higher and higher, the weight is smaller, and the quality of concrete can not be guaranteed. Therefore, don't relax the inspection and maintenance of symmetrical system at any time, so in daily situation, how should we deal with the weighing problem of small automatic concrete mixer?
1、 The root cause of weighing error of small mixer
First, we need to find a source of uncertainty, the load cell. Load cell is an electrical component, through which we can measure the weight of raw materials we need.
Shear beam load cell and S-shaped tension load cell are generally used in small and medium blenders. In the mixing plant, the measurement of aggregate, powder and water is mainly based on the shear beam load cell, while the S-shaped tension load cell is mainly used for the weighing of admixture.
2、 Common fault causes and treatment methods of small mixer sensor
1. Unweighted reading of small mixer
This kind of fault is generally more common, the weighing value is zero, no matter whether the above exists or not, the weighing value is always zero.
Main causes and treatment methods
A. Sensor damage: when there are raw materials on the sensor, detect the voltage value of the sensor output signal line. If the two values are the same, the sensor is damaged. If there is a significant difference between the two values, the sensor works normally. According to the output signal of the sensor detected in the figure below, the working principle and boundary mode of different brands of sensors are roughly the same. The following figure shows the wiring principle of the six wire sensor.
B. There is a short circuit on the line: if the sensor is not damaged, the following line can check whether there is a damaged road by observing whether the line is damaged or cut off along the induction line (when installing a small mixer).
C. Signal transmitter fault: after eliminating the above two reasons, we check the signal transmitter, and the detection method is basically the same as that of the sensor to detect whether there is voltage signal in its output signal, and whether its value changes when the weight changes.
D. The junction box is not well contacted: This is mainly due to the wire head is not firmly connected during wiring.
2. The weighing value of small mixer fluctuates up and down.
This phenomenon shows that the weight value of a certain weight fluctuates up and down, exceeding the normal error range.
The main reasons are as follows: 1. 2. There is a high frequency signal transmitter near the small mixer (including mobile signal tower and UHV substation).
Processing method a: if the silo attached to the sensor mounting base is in a large mechanical vibration range, the deformation of the sensor will change constantly, so the measured weight value will float up and down.
Treatment B: for the signal interference near the small simple mixer, the station under construction should choose a reasonable site at the beginning of construction, away from these interference sources.
Maintenance of weighing system of small mixer
The load cell is a kind of precision electronic components, which needs to be kept away from dust, water and other substances. It is necessary to keep the sensor clean. Therefore, some protective covers can be added on the sensor. At the same time, the weighing system needs to be recalibrated at intervals.
When checking the fault of the weighing system, we can use the elimination method to reduce the root cause of the problem to a small range.