CN2147521Y

CN2147521Y - Capacitor torque sensor

Info

Publication number: CN2147521Y
Application number: CN 93200342
Authority: CN
Inventors: 马礼耀; 郭霄峰; 石玉良
Original assignee: FENGGUANG SCIENCE AND TECHNOLOGY DEVELOPMENT Co BEIJING
Current assignee: FENGGUANG SCIENCE AND TECHNOLOGY DEVELOPMENT Co BEIJING
Priority date: 1993-01-13
Filing date: 1993-01-13
Publication date: 1993-11-24
Anticipated expiration: 2003-01-13

Abstract

The utility model provides a new capacitor torque sensor, which is composed of an elastic axle (beam) and a capacitive displacement sensor, wherein, an electrode plate of the capacitive displacement sensor is connected with one end of the elastic axle, and the other electrode plate is connected with the other end of the elastic axle by a transitional sleeving tube. The sensor measures the magnitude of a torque by the relative variation of the number of electric apparatuses and the accumulation of pitches, the utility model eliminates the influences of stray capacities, etc., and the resolutions and the measuring accuracy are improved.

Description

Capacitor torque sensor

The utility model relates to a kind of torque measurement technology, refers to a kind of capacitor torque sensor especially.

In modern science and technology, the method for measuring moment of torsion is a lot, and commonly used have resistance-strain type, electromagnetic type, a photo-electric etc.∥ China Machine Press such as " non-electricity measure engineering manual " ∥ Xu national wealth--a kind of capacitor torque sensor is disclosed on the P867, it is to utilize moment of torsion to change gap or useful area between the capacitor plate, causes that electric capacitance change measures torque.Structural principle is shown in Fig. 1, Figure 1A, Figure 1B.

Sensor is by elastic shaft 1, sleeve pipe 2, and

capacitor plate

3,4 is formed.

Pole plate

3,4 shapes are identical, open 8 scallop holes on it, and the angle of each scallop hole is 22.5 °.Pole plate 4 is fixed on the X end of axle 1, and pole plate 3 is fixed on the end of sleeve pipe 2 near X, and with pole plate 4 coaxial and opposing parallel, the middle gap that keeps constitutes a variable condenser.The other end of sleeve pipe 2 is fixed on the Y end of axle 1.

Pole plate

3,4 is respectively drawn a lead and is connect capacitance bridge 6.

When axle 1 did not bear moment of torsion (non-loaded), the scallop hole on the two-plate staggered 11.25 ° mutually, at this moment bridge balance.When axle 1 was applied moment of torsion M, two-plate relatively rotated an angle, and the hole changes the overlapping area in hole, electric capacity between the two-plate is changed, the electric bridge out of trim, output signal u demonstrates the size of moment of torsion M at last through amplification, conversion, data processing with digital form.

Because this sensor is to utilize the absolute change amount of electric capacity to measure moment of torsion, lead capacitance, edge effect and other stray capacitances are very big to the measuring accuracy influence.

The purpose of this utility model provides a kind of novel capacitor torque sensor, utilizes the relative measure of the change moment of torsion of electric capacity, improves measuring accuracy.

The purpose of this utility model is to realize like this, be connected with displacement sensor of variable capacitor on the elastic shaft, displacement sensor of variable capacitor is meant a kind of grid shape capacitor-type displacement transducer, the pole piece that its sender electrode (transmitting electrode) is made by a plurality of metal formings is arranged by pitch and is formed (each pitch has 3 at least), and feedback connects amplitude on each pole piece in pitch, frequency is identical and electric signal that phase place is different; Receiving electrode is also arranged by the number of metal paillon foil and is formed, two electrodes are formed grid shape capacitor, wherein, one end of pole plate and elastic shaft is rigidly connected, another pole plate is rigidly connected by sleeve pipe or other transition piece and the elastic shaft other end, experience the torsional variation and the bending change of elastic shaft by two-plate, thereby reach the purpose of measuring moment of torsion.

Because the utility model, with holding grid displacement measurement technology generation, promptly utilize the relative variation of electric capacity and the measurement moment of torsion that adds up of pitch for the direct absolute size of measurement electric capacity, eliminated the influence of stray capacitance etc., improved resolution and measuring accuracy.

The contrast accompanying drawing further specifies the utility model below

Fig. 1 is the prior art principle schematic

Figure 1A is Fig. 1 sender electrode structural representation

Figure 1B is Fig. 1 receiving electrode structural representation

The torque sensor principle schematic of Fig. 2 for constituting by angular displacement sensor

Fig. 2 A is Fig. 2 sender electrode structural representation

Fig. 2 B is Fig. 2 receiving electrode structural representation

The torque sensor principle schematic of Fig. 3 for constituting by linear movement pick-up

Shown in Fig. 2, Fig. 2 B, Fig. 2 A, the pole piece that receiving electrode and sender electrode are made by a plurality of metal formings is arranged by pitch and is formed, and receiving electrode 3 is spoke-like, and each spoke is to receive pitch half, here totally 5 pitches.Sender electrode 4 has 40 fan-shaped pole pieces, is divided into 5 groups, and 8 every group constitute a pitch, and each pole piece numbers in order in the pitch, and then that sequence number is identical pole piece (as No. 1 pole piece) parallel connection is drawn a lead and connect the respective end (as 1 end) that drives output 8.

Ring-type coupling electrode 5 and sender electrode 4 are made on the same plane of same electrode plate, are separated by ground loop between them.

Receiving electrode plate 3 and sender electrode plate 4 are distinguished the end of relative fixed at sleeve pipe 2 and elastic shaft 1, midfeather remains in the 0.15mm, and the work of sensor is to transmit signal by the capacitive coupling that forms between the angular deformation of elastic shaft and sender electrode, receiving electrode, the coupling electrode to finish.

From oscillator 6, phase transformer 7 with drive the identical and phase place of amplitude, the frequency of output 8 each differs from 45 ° 8 road signals and delivers on 8 lead-in wires of sender electrode 4, on receiving electrode 3, form a composite signal by capacitive coupling.The phase place of composite signal is directly proportional with relative angular displacement between receiving electrode 3 and the sender electrode 4.When relative angular displacement whenever moved past a pitch, the composite signal phase place was changeed 360 °, moves a plurality of pitches, and signal changes a plurality of 360 °, realized that pitch adds up.When adding moment of torsion M on the axle 1,

electrode

3 and 4 relatively rotates an angle, thereby changes fullying recover from an illness mutually of composite signal.Signal is delivered to the variable quantity of measuring the composite signal phase place in the

circuit

9,10,11,12 through coupling electrode 5, provided moment of torsion M value by decoding display part 13 through calculation process.

Here, as long as equate with the stiffness of coupling of receiving electrode 3 between each pole piece of sender electrode 4; As long as lead capacitance, edge effect and other stray capacitances are consistent to sender electrode 4 each pole piece with electric capacity influence between the receiving electrode 3, stiffness of coupling variation between whole sender electrode and the receiving electrode and lead capacitance, edge effect and other stray capacitances etc. just can not be influential to measurement result.So this relative measure of the change moment of torsion that utilizes electric capacity between each pole piece of sender electrode and the receiving electrode, will be good than the absolute size of direct measurement electric capacity many.Owing to adopt a plurality of (being 5 here) to send the pitch parallel connection, the relative imbalance of stiffness of coupling between each pole piece of sender electrode and receiving electrode is compensated, measuring accuracy is further improved.

The torque sensor that the utility model is related both can use the capacitance-grid type angular displacement sensor, also can use the capacitance-grid type linear movement pick-up, and structural principle as shown in Figure 3.The sender electrode sheet 4 and the receiving electrode 3 of capacitance-grid type linear movement pick-up all are rectangles, and arrange in a line.This torque sensor mainly is made up of elastic bending axle 1, rigid support plate 2, sender electrode sheet 4, receiving electrode sheet 3 and coupling electrode 5.Its measuring principle as previously mentioned.

Claims

1, a kind of capacitor torque sensor, constitute by elastic shaft and capacitive displacement transducer, wherein, a battery lead plate of capacitance displacement sensor and an end of elastic shaft are rigidly connected, another battery lead plate is rigidly connected by sleeve pipe or other transition piece and elastic shaft, it is characterized in that: capacitance displacement sensor is a displacement sensor of variable capacitor, the pole piece that its sender electrode is made by a plurality of metal formings is arranged by pitch and is formed, feedback connects amplitude on each pole piece in pitch, frequency is identical and electric signal that phase place is different, the pole piece that receiving electrode is also made by the number of metal paillon foil is arranged by pitch and is formed, and two electrodes are formed grid shape capacitor.

2, by the described capacitor torque sensor of claim 1, it is characterized in that: sender electrode is made by a plurality of pitch parallel connections.