JPH0533945Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] This invention relates to a torque sensor.

[Prior art and its problems]

In general, a strain gauge type and a magnetic type are used for torque sensors.As shown in Fig. 5, the structure of the former is that a strain gauge 31 is installed on a shaft 30 on which torque acts, and the strain gauge 31, the strain is taken out as a change in electrical resistance, and since torque acts on the shaft 30, a slip ring 33 is used to take out the lead wire 32 from the strain gauge 31, and a brush is attached to this slip ring 33. 34 are in sliding contact.

In the case of the latter magnetic type, as shown in FIG. 35 are connected by a strain material 38, and guided to a processing circuit 40 by a pick-up coil 39 of an external fixed part to detect the phase difference of the disk due to strain.

However, the former method has problems such as high noise because the electrical output is transmitted through sliding electrodes, and a lack of long-term reliability because the strain gauge is bonded to the shaft. The latter type is a non-contact type compared to the former type, so it is better against noise, but it is difficult to detect torque when the shaft is stationary. Another problem is that the signal processing circuit system becomes complicated.

This invention solves the problems of the conventional ones as described above, and aims to provide a torque sensor that can simplify the electric circuit and reduce the number of nozzles during signal transmission. purpose.

[Means for solving problems]

In order to solve the above-mentioned problems, this invention provides a fixing member at each end of a pair of torsional bars, one of which is on the fixed side and the other is on the torque acting side, and which are coaxial. The end faces of the torsional bar and the end faces of the fixing member can be brought into sliding contact with each other, and an annular recess is formed in the center of the outer peripheral surface of both the fixing members, and A supporting member is disposed on the outside via a sealing member, and the recessed portions of both fixing members are formed into a sealed portion, and further,
A hole communicating with each of the sealing parts is formed in the supporting member, a fluid supply source is connected to one of the holes, a fluid measuring member is connected to the other hole, and a fluid measuring member is connected to both the fixing members. , Throttle holes penetrating in the axial direction are formed in a fan shape on a concentric circle centered on the axis of the torsional bar and have the same dimensions in the radial direction, and through these throttle holes, Communication is possible between the two sealed parts, and when a torque is applied to the other torsional bar and the angle changes with respect to one of the torsional bars, a communication area between the two sealed parts by the aperture hole is proportional to the angular change. It employs means configured to change.

[Effect]

By adopting the above-mentioned means, this invention
The angle of one torsional bar changes linearly with respect to the other torsional bar depending on the magnitude of the applied torque, and as a result of this change in the angle of the torsional bar, the area of communication between the two aperture holes communicating between the two sealed parts increases. Since the pressure changes linearly, the oil pressure or flow rate passing through both of these throttle holes also changes linearly. Therefore, if the oil pressure or flow rate passing through both throttle holes is detected using a pressure gauge or the like, the acting torque can be linearly detected.

〔Example〕

Embodiments of this invention shown in the drawings will be described below.

FIG. 1 shows a torque sensor according to this invention. First, the ends 3 and 4 of a pair of cylindrical torsion bars 1 and 2 are placed adjacent to each other. is provided with recessed parts 5a and 6a on the outer circumferential surface of the central part, outer circumferential edges 5b and 6b on the outside, and inner circumferential edges 5c and 6 on the inner side.
Fixing members 5 and 6 provided with c are integrally provided.

The end faces of the torsional bars 1 and 2 and the end faces of the outer peripheral edges 5b and 6b of the fixing members 5 and 6 are in sliding contact with each other.

Further, the outer peripheral edges 5b, 6 of the fixing members 5, 6
In b, throttle holes 11 and 12 are drilled with the same size in the radial direction, and are fan-shaped on concentric circles centered on the axes of the torsional bars 1 and 2 and are capable of communicating with each other. .

Further, on the outside of both the fixing members 5 and 6, an annular shape is provided for fitting an oil seal 8 at a position opposite to the outer circumferential edges 5b and 6b and the inner circumferential edges 5c and 6c of both the fixing members 5 and 6. A hole 7a is formed, and a cylindrical support member 7 is fitted therein, so that the outer peripheral edge 5b of the fixing members 5, 6,
6b and inner peripheral edge portions 5c, 6c, and the support member 7, oil seals 8 are respectively located,
As a result, the recessed portions 5 of both the fixing members 5 and 6
a and 6a are shielded from the outside air.

Further, both the fixing members 5 and 6 of the supporting member 7
Holes 9, 1 are provided at positions facing the recesses 5a, 6a.
One hole 9 is connected to a diaphragm pump, and the other hole 10 is connected to a pressure gauge to which a pressure sensor is attached.

Next, the operation of the above will be explained. First, one of the torsional bars 1 and 2 is set as a fixed side, and the other is set as a torque acting side.

After such a state is established, pressure is applied to the inside of the sealed portion 13 formed by the recessed portion 5a of the fixing member 5 and the support member 7 through the diaphragm pump and the hole 9 of the support member 7. Then, this pressure is transmitted to the inside of the annular recess 5a, and also to the outer peripheral edge 5 of the fixing member 5.
Transmitted to the sealing part 14 formed by the recess 6a of the fixing member 6 and the support member 7 through the throttle hole 11 drilled in b and the throttle hole 12 drilled in the outer peripheral edge 6b of the fixing member 6. The pressure is then transmitted through a hole 10 drilled in the support member 7 to a pressure gauge provided with a pressure sensor.

Therefore, it is possible to detect the torque acting on the torsional bar by comparing the pressure transmitted to the pressure gauge before torque is applied and the pressure transmitted to the pressure gauge after torque is applied. It is.

When detecting this torque, the throttle holes 1 formed in the outer peripheral edges 5b and 6b of the fixing members 5 and 6 are
1 and 12 are fan-shaped on concentric circles centered on the axes of the torsional bars 1 and 2, as shown in FIG. 2, and since the torque change of the torsional bars is linear, The cross-sectional area of the matching portion of the throttle holes 11 and 12 also changes linearly, so that the matching of the fan-shaped throttle holes 11 and 12 changes in accordance with the angle change of the torsional bars 1 and 2 caused by torque. Since the cross-sectional area, that is, the effective throttle area 15 changes linearly, the magnitude of the pressure transmitted to the pressure gauge changes linearly, and the magnitude of the torque can be detected.

That is, FIGS. 3 and 4 show the operating principle of the torque sensor according to this invention.
As the angle of the torsional bar 24 changes due to strain, the effective throttle area 25 of the hole passing through both ends changes, and this is detected as a change in air or oil pressure or flow rate.

Therefore, the torque sensor of this invention has fewer nozzles than the conventional strain gauge type, and does not require complicated circuits such as signal processing compared to the magnetic type. It can be operated with a simple circuit.

[Effect of idea]

By configuring this idea as described above,
This is because the angle of the torsional bar changes linearly according to the magnitude of the applied torque, and the communication area of the two throttle holes that communicate between the two sealing parts changes linearly according to the change in the angle of the torsional bar. The oil pressure or flow rate passing through both of the throttle holes also changes linearly. Therefore, if a change in oil pressure or flow rate through both throttle holes is detected,
It is possible to detect the magnitude of the torque acting on the torsional bar. Torque can be linearly detected over the entire measurement range of the hole, and torque detection accuracy is significantly increased. Also, unlike the conventional nozzle, the electric nozzle is small, so the circuit system can be simplified and the overall cost can be reduced. Furthermore, torque can be detected even when the torsional bar is not rotating, and changes in air or oil pressure or flow rate can be detected linearly during measurement, so it has a wide range of applications. Furthermore, since it is sufficient to make sliding contact between the end surfaces of the torsional bar, high precision is not required for machining the torsional bar, and the present invention has excellent effects such as easy machining.

[Brief explanation of the drawing]

Fig. 1 is a schematic longitudinal sectional view of the torque sensor according to this invention, Fig. 2 is a schematic diagram showing the effective aperture area of the aperture hole drilled in the fixed member, and Figs. 3 and 4 illustrate the operating principle of the aperture hole. FIG. 5 is a schematic diagram showing a conventional strain gauge type torque sensor, and FIG. 6 is a schematic diagram showing a conventional magnetic type torque sensor. 1, 2, 21, 22... torsional bar,
3, 4...End part, 5, 6...Fixing member, 5a, 6
a... hollow part, 5b, 6b... outer peripheral edge part, 5c,
6c... Inner peripheral edge, 7... Support member, 7a... Annular hole, 8... Oil seal, 9, 10... Hole, 1
1, 12, 23, 24...pressure restrictor hole, 13, 1
4... Sealing part, 15, 25... Effective aperture area, 3
0, 35...shaft, 31...gauge, 32...lead wire, 33...slip ring, 34...brush, 36...disc, 37...permanent magnet, 38...
Strain material, 39...Pick-up coil, 40...
...processing circuit.

Claims (1)

[Scope of utility model registration request] Fixing members 5 and 6 are respectively disposed at the ends of a pair of torsional bars 1 and 2, one of which is on the fixed side and the other is on the torque acting side, and which are coaxial. 2
and between the end surfaces of the fixing members 5 and 6, respectively, and furthermore, annular recesses 5a and 6 are provided in the center of the outer peripheral surfaces of both the fixing members 5 and 6.
At the same time, a supporting member 7 is provided on the outside of both the fixing members 5 and 6 via a sealing member 8, and the depressions 5a and 6a of both the fixing members 5 and 6 are sealed with the sealing parts 13 and 6a. 14, and further includes holes 9 in the support member 7 communicating with the respective sealing parts 13 and 14,
10 is drilled to connect a fluid supply source to one hole 9, and a fluid measuring member is connected to the other hole 10, and further penetrates both the fixing members 5 and 6 in the axial direction. The throttle holes 11 and 12 are formed in a fan shape concentrically around the axes of the torsional bars 1 and 2 and have the same dimensions in the radial direction.
2, and when torque acts on the other torsional bar 2 and changes its angle with respect to one torsional bar 1, the two sealing parts 13 and 14 are sealed by the throttle holes 11 and 12. A torque sensor characterized in that a communication area between portions 13 and 14 is configured to change in proportion to a change in angle.