Torque is a special moment that causes an object to rotate, equal to
The product of force and lever, the SI unit is newton-meters. Torque sensor Yes
A common measuring instrument for measuring torque values, but torque sensors in
In the actual daily measurement and testing process, there are artificial operations such as connection selection
As a factor, additional measurement uncertainty may be introduced to give the amount of torque
Accurate traceability of values causes impact. For the current torque sensor measurement
The problems that may occur in the connection and the solutions are discussed in this paper
Summarize and analyze.
1 Current status of torque sensor quantity value traceability in China
According to the People's Republic of China national metrological verification system table
JJG2047-2006 Torque measuring instrument. Basis of torque sensor in our country
The accuracy and function of the different points belong to the standard torque meter and torque spanner
Calibrating devices and other standard instruments of torque measurement and torsimeter, torsion test
Machine and other working measuring instruments. According to the regulations mainly the People's Republic of China
National Metrological verification Regulation JJG 557-2011 Standard torsion instrument, JJG
797-2013 Torque wrench calibrator, JJG 995-2005 static torque
Measuring instrument and JG 1146-2017 working torque instrument, etc. Inspection equipment
It is mainly divided into four categories: torque standard machine, torque calibration lever weights,
Standard torque spreaders and various torques.
2 Research status of torque sensor detection and connection in our country
Research on error caused by connection mode to torque sensor detection
Research and control, now the domestic research is mostly focused on the forefront of ultra-high precision
The cutting-edge instruments and devices used in the connection scheme are often volumetric weight
Large, complex installation, high cost, such as flexible coupling and hydraulic lock
Shaft locking devices, etc., to solve the mounting and sensing due to connector processing
The sensor caused by factors such as the weight of the machine and the torque machine are not coaxial
The parasitic component of the problem is shown in Figure 1. However, such connection schemes
The installation is complicated, the cost is high, and the connection size is relatively simple, which can not be met
The connection requirements of torque sensors of various sizes cannot be widely adapted
For the pursuit of convenience, efficiency and cost of the inspection organization's first-line daily inspection
Survey. 3 Connection problems in the current torque sensor measurement
Sum impact analysis
The current torque sensor measurement and detection based on the national regulations
There is no uniform provision for its connection mode, and there are no relevant countries,
Industry standard, so the connection method mainly depends on the personal experience of the inspector
There are some factors that may affect the measurement efficiency and accuracy
The questions are as follows:
3.1 Structure, shape and size of input and output of torque sensor
Different, resulting in difficult connection with the measurement standard
At present, the structure and shape of input and output of torque sensor are lacking
Shape and size are uniformly limited to national standards or industry standards, so
The input and output of torque sensors are often based on their different uses and realities
Use scenarios for different specialized designs. This causes the torque sensor
It is difficult to connect with the measurement standard, and the inspection personnel can often only temporarily add
Custom special connector or select the laboratory existing connector stack group
Joint attempt connection. Temporary processing of customized special connectors takes a long time and success
This high, so many customers will not choose, there are connections superimposed combination
Use became common practice. And there is no superposition combination of existing connectors
Method when smoothly connected, often can only suspend or terminate the detection, which results
The connection and assembly time before the formal detection is greatly extended, which seriously affects
Detect the working efficiency of personnel.
3.2 Lack of quality control and grinding of the existing connecting parts in the laboratory
Loss and other factors caused by the connection does not fit, to the torque sensor measurement
The detection introduces an additional uncertainty component
Torque connectors are used as consumables in torque sensor detection.
Easy to be damaged and deformed due to wear, overload and other reasons, resulting in no
Adaptive connection. But inspectors often overlook its ability to withstand torque
And deformation state and continue to use until it is completely broken. Overload service
It will accelerate the wear and deformation speed of the connector, and there is fracture spatter
Risk of injury to testers.
The mismatch connection will introduce a large uncertainty to the test result data
Fixed degree component. Take the measurement standard of leverage weights as an example, as shown in Figure 2.
One end of the measured torque sensor is fixed vertically and the other end is twisted with a disk shape
The moment lever is connected in series by connecting piece. Torque lever on one end of the string hanging
Hang the weight, and the other end is connected to the disc torque lever by its own gravity
After stability, the ideal bearing torque value of the measured torque sensor, namely
Weight The product of gravity and the radius of the torque lever. But when connecting pieces
After the wear deformation causes the joint gap, the weight weight will cause the joint
Tilt, connector and torque sensor center axis is not parallel, string is not
Then tangent to the disc lever, the force arm corresponding to the gravity of the weight also occurs
The change ultimately results in the actual torque value and principle applied to the torque sensor
There is a big gap between the standard values.