JPS6336124A - Torque sensor - Google Patents

Abstract

PURPOSE:To increase sensor sensitivity by forming a main sensor body in triple ring structure and increasing the quantity of relative variation in the opposite position of a detection tooth. CONSTITUTION:A torque sensor 1 is so constituted as to generate inductance variance at coils 25C1 and 25C2 provided to an external ring 25 by the opposition position variation between an internal ring 33 rotated by an output shaft 6 and an intermediate ring 29 provided to a displacement shaft 8, corresponding to torque applied to the output shaft 6. Consequently, even when the torque applied to the output shaft 6 is large, the torque is accurately detected. Further, the external ring 25, intermediate ring 29, and internal ring 33 do not contact one another, so the durability is superior and the detection accuracy increases.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to motors 1 to 1 in which torque is detected from changes in inductance of a detection coil.

(Conventional anti-collision) In the torque sensor shown in "Measurement and Control", Volume 17, No. 9, three rings 60° 70 .80 are fixed, and their rings 60, 70, 80 are arranged in the axial direction of the shaft 90 to be measured.

The rings 60, 70, 80 are made of magnetic material, and have a plurality of detection teeth 65, 75.
A plurality of 85 are formed.

Roughly, on the shaft 90 to be measured, there is a tubular stator 11 bent into a ring shape at a position facing the detection teeth 65, 75°85.
0 is externally fitted, and each stator 110 has a detection tooth 65.
, 75, 85 are open over the entire inner circumference.

In addition, a detection coil 100 is arranged in each stator 1''10 so as to circulate inside the stator 110 multiple times, and when each detection coil 100/\\ is energized, the two stators 110
．． and three rings 60, 70, 80 form two magnetic circuits 1-4. +2 is formed.

Then, torque is applied to the shaft to be measured 90, and the shaft to be measured 90
When torsional deformation occurs, the rings 60, 70, 80 rotate relative to each other, so that the gap length between the opposing detection teeth (detection teeth 65 and 75 and detection teeth 75 and 85) changes.

Therefore, since the magnetic resistance of the magnetic circuits L1 and L2 changes, a -inductance change occurs in the detection coil 100.

The change in inductance corresponds to the torque applied to the shaft 90 to be measured, and therefore the torque applied to the shaft 90 to be measured can be detected based on the change in inductance.

(Problems to be Solved by the Invention) As understood from the above explanation, in the conventional torque sensor, the three rings 60, 70, and 80 are densely arranged in a narrow area along the axial direction of the shaft to be measured 90. It is provided on the measurement axis 90 itself.

Therefore, each ring 60, 70, 80 is rotated relative to each other only by the torsional deformation of the measured object 11j90 within the narrow region, so the change in the gap length is extremely small.

Therefore, since the inductance change occurring in the detection coil 100 is small, the sensor sensitivity is low.

For this reason, when the strength of the shaft 90 to be measured is increased by increasing the bending or torsional rigidity of the shaft 90 to be measured, a problem arises in that torque detection becomes difficult.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a 1-Herc sensor with high sensor sensitivity.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a torsion shaft that twists and deforms due to a torque to be measured, and a triple ring in which three rings are concentrically arranged at the same axial position. A sensor body having a structure, and a pair of adjacent rings among the three rings are connected to one end and the other end of the torsion shaft, respectively, and opposing circumferential surfaces of both rings are made of a magnetic material. A plurality of detection teeth are each formed, and the other ring is statically supported with respect to both of the rings, and includes a detection coil magnetically coupled to the rain detection teeth.

(Function) In the torque sensor according to the present invention, the torsional deformation of the shaft to be measured expanded by the torsional shaft is transmitted to the sensor main body having a 3,000-ring structure, and two of the three rings are According to a change in the opposing position of the detection teeth provided on the ring, a change in the inductance of the detection coil corresponding to the torque to be measured is detected.

(Embodiments) Hereinafter, preferred embodiments of the torque sensor according to the present invention will be described based on the drawings.

A first embodiment is shown in FIG. 1, part 1 to lux sensor 1.
is built into the steering gear 2 of the vehicle, and is used to detect the steering torque transmitted from the steering wheel (not shown) to the steering gear 2.

In Fig. 1, a stub shaft 3 is located inside the gear case 21.
is inserted, and the stub shirts 1 to 3 are supported by roller bearings 30 and are rotatable.

Further, the stub shaft 3 is formed into a cylindrical shape, and a torsion bar 5 is inserted into the cylinder.

One end of the torsion bar 5 is fixed to one end of the stub shirts 1 to 3 by a knock pin 9A, and the other end of the torsion bar 5 projects from the other end of the stub shaft 3, and the projecting portion is fixed to the pinion by a knock pin 9B. It is fixed to gear 7.

The pinion gear 7 has roller bearings 7A on both ends.

A worm wheel 11 is fixed to the pinion gear 7 with a screw 13.

A worm wheel 15 is meshed with the worm wheel 11.

Rough pinion gear 7 has needle roller bearing 1
7 is provided, and this needle roller bearing 1
The stub shaft 3 is rotatably supported and guided by 7.

Note that the stub shaft 3 is provided with a stopper 19 that comes into contact with the pinion gear 7, so that the torsional deformation of the torsion bar 5 is kept within a certain angle.

With the above configuration, when one heel is applied to the stub shaft 3, the stub shirt 1 rotates, and the rotational movement is transmitted to the pinion gear 7 via the torsion bar 5 and output.

Here, an outer ring 25 is fixed to the inner circumferential surface of the gear case 21 at a position facing the outer circumferential surface of the stub shaft 3 by a snap ring 23, and the worm wheel 11
A middle ring 29 is fixed by a snap ring 27 so as to face the outer ring 25 at the same axial position as the outer ring 25.

A snap ring 3 is attached to the outer peripheral surface of the rough stub shaft 3.
1, the inner ring 33 is fixed at the same axial position as the middle ring 29 and facing the middle ring 33.

As understood from the above explanation, the sensor body of the torque sensor 1 includes the outer ring 25. Middle ring 29 and inner ring 33
It has a triple ring structure in which each ring is arranged at the same axial position.

Also, outer ring 25. Middle ring 29. The inner rings 33 are positioned and arranged by stoppers 35, 37, 39, respectively.

As shown in FIG. 2, the outer ring 25 is composed of a ring 25A made of a non-magnetic material such as plastic, and a ring 25B fixed to the inner peripheral surface of the ring 25A with an adhesive or the like.

The ring 25B is made of a magnetic material such as ferrite or permalloy, and has two grooves S formed on its inner peripheral surface.

Further, within each groove S, coils 25G+ and 25C2 (detection coils) are disposed so as to circulate within each groove S a plurality of times.

Lead wires 25L+ and 25L2 are connected to both ends of each coil 25CI and 25C2, respectively, and each lead wire 25L+ and 25L2 is drawn out to the outside of the ring 25A.

Note that the ring 25B is the piece 2 as understood from FIG.
5B+, 25B2, and 25B3, so both ends of each lead wire 25L+, 25L2 can be easily pulled out of the ring 25A, and the outer ring 25
is easily assembled.

The middle ring 29 has a cross-sectional shape in FIG. 1, and has a ring 29A projecting from the outer peripheral surface of a disk fixed to the worm wheel 11.

Further, as shown in FIGS. 3 to 5, the ring 29A is made of a non-magnetic material such as plastic, and three rings 29B are molded with the ring 29A.

As shown in FIG. 6, each ring 29B has a plurality of teeth 29B2 on the inner peripheral surface of a ring-shaped base 29B1 made of a magnetic material.
are integrally formed.

The inner ring 33 has a cross-sectional shape in FIG. 1, and has a ring protruding from the outer circumferential surface of a disc fixed to the outer circumferential surface of the stub shaft 3.

The inner ring 33 is entirely made of a magnetic material, and has a convex shape (teeth) along the center line of the outer peripheral surface of the ring, as can be understood from FIG. 7 and FIG. )33
A is integrally formed, and a plurality of teeth 33B and 133C are provided around the outer peripheral surface of the ring with the convex shape 33A in between.

Outer ring 25. The two middle rings and the inner ring 33 are constructed as described above, and both coils 25C+ of the outer ring 25
, when 25C2 is energized, both coils 25C+
, 25C2, as can be seen from FIG. 9, the outer ring 25, the middle ring 29. inner ring 3
3 form two magnetic circuits, e+, l, 2.

With the above configuration, when torque is input from the stub shirts 1 to 3, the inner ring 33 is rotated by the stub shirts 1 to 3, but the middle ring 29 is fixed to the frame wheel 11 rotated by the hexion bar 5. Because it is 1
~-The twisting flea of the version 5 is smaller than the inner ring, and therefore the inner ring 33 is displaced relative to the two middle rings.

FIG. 10 shows a cross-sectional view taken along line X-X in FIG. 1, and when torque is applied to the stub shaft 3 in the clockwise direction in FIG. 10, the inner ring 33 moves clockwise in the figure. As a result, the opposing area between each tooth 29B2 of the middle ring 29 and each tooth 33C of the inner ring 33 increases. For this reason, each tooth 29B2
Since the magnetic flux passing between and each tooth 33C increases, the ninth
In the magnetic circuit shown in the figure, the magnetic resistance of 1 decreases.

As a result, the inductance of the coil 25C1 of the outer ring 25 increases.

On the other hand, FIG. 11 shows a cross-sectional view along the X-knee and X-work lines in FIG. 1, and when torque is applied to the stub shaft 3 in the clockwise direction in FIG. The area facing each tooth 33B of 33 is reduced. Therefore, the magnetic flux passing between each m 29 B 2 and each tooth 33B decreases, and the magnetic resistance of the magnetic circuit 12 in FIG. 9 increases.

As a result, the inductance of the coil 25C2 of the outer ring 25 decreases.

In addition, the cross section taken along the line P--P in Figure 1 is a magnetic circuit, e.

And e2 is the magnetic path, but since the inner ring 33 is formed with a convex shape 33A along its outer circumferential surface, even if the opposing positions of the middle ring 29 and the inner ring 33 change, this portion Magnetic circuit to open, el.

, e2, and there is no change in the inductance of both coils 25C0 and 25C2.

Furthermore, both coils 25C1 and 25C2 of the outer ring 25
is orbiting around the outer circumference of ring 25B, so middle ring 2
9 rotates relative to the outer ring 25, there is no change in the magnetic flux passing through the teeth 29B2 of the inner ring 29.
Therefore, no change occurs in the magnetic flux passing between the outer ring 25 and the middle ring 29. Therefore, the inductance of each coil 25C+ and 25C2 does not change just by rotating the middle ring 29.

As explained above, when torque is applied to the stub shaft 3 and the relative position between the middle ring 29 and the inner ring 33 changes, both the coils 25CIJ5 and 25C2 of the outer ring 25
Then, an inductance change occurs, and the torque applied to the stub shaft 3 can be measured using this inductance change.

FIG. 12 shows a magnetic equivalent circuit showing how the inductance of both coils 25C+ and 25C2 of the outer ring 25 is increased or decreased by the displacement of the inner ring 33. In the figure, when the inner ring 33 moves left and right, The inductance of the coil 25C1 and coil 25C2 changes.

FIG. 13 shows a circuit diagram for detecting the torque input from the stub shaft 3 based on the inductance changes of both coils 25C1 and 25C2 detected by the torque sensor 1 as described above.

In the figure, coil 25C+, coil 25C2° resistance 105. A rebridge is formed in the resistor 115,
An alternating current voltage is applied to this bridge from an oscillator 120.

Then, the differential voltage output from the connection point M of the bridge and the neutral point of the variable resistor 110 (for zero point adjustment) is input to the differential amplifier 125, and the voltage amplified by the differential amplifier 125 is It is input to the detector 130.

Further, the phase detector 130 receives an applied voltage from the oscillator 120, phase-detects the output of the differential amplifier 125, and outputs a voltage proportional to the torque applied to the stub shirts 1 to 3 to the temperature compensator 135.

The output signal of a temperature sensor 140 such as a thermistor provided near the outer ring 25 is input to the temperature compensator 135, so that the sensor sensitivity and zero point are compensated in response to the temperature near the outer ring 25. After being done, temperature compensator 1
35, a voltage or pulse proportional to the torque to be measured;
Alternatively, the frequency is output.

In this way, the output signal from the temperature sensor 140 is temperature-compensated.
The reason for inputting to the device 135 is that both coils 25C1 and 25C
The change in inductance in 2 is also caused by a change in temperature, and although the change in temperature at the zero point is small because the change in inductance is detected in the differential mode, the change in sensitivity with temperature becomes large.

Note that the temperature compensator 135 is a discrete circuit.

It is preferable to form the groove with a TC circuit, microprocessor, or the like.

Further, in this embodiment, in order to accurately measure the torque of ±1.0 n-Kq, a torsion bar 5 (torsion mechanism) and one stopper for regulating the amount of torsional deformation of the torsion bar 5 are provided.

Therefore, when a torque of ±1.0 m-KCI is applied to the torsion bar 5, the torsion angle changes by ±θdeg.

The initial opposing positions of the teeth of the two middle rings and the inner ring 33 are determined by the following formula (1>) in FIG.

Setting as in (2) improves measurement accuracy.

θ1-θ, >k, 0...(1) θ2
=03〉k2θ1...(2) Just 1
), kl is preferably set to about 2.0 to 3.5, and in this example O=3 dcg.

θ, −θ4 = 10de(], and + = 3.33.

In addition, in equation (2), k2 is preferably set to about 1.5 to 3.0, and in this example, θ2=03=20(Ie!:I
, k2=2.

By setting the opposing positions of the teeth of the middle ring 29 and inner ring 33 in this way, when the inductance change of both coils 25C+ and 25C2 is detected by differential voltage, a linear characteristic can be obtained when 1-rook is near zero. It will be done.

In addition, since the sensor output voltage does not decrease as the torque increases even in the vicinity of torque overload, accurate torque detection is possible.

As explained above, i to silk sensor 1 in this embodiment
Now outer ring 25. Since the middle ring 29 and the inner ring 33 have a triple ring structure at the same axial position,
The relative position change between the middle ring 29 and the inner ring 33 can be made large, and the torsion bar 5 can amplify the torsional displacement relative to the torque to be measured.

Furthermore, the inductance changes of the two coils 25C1 and 25C2 are measured when differential.

Therefore, even if the torque to be measured is extremely small, i~
It becomes possible to detect torque with extremely high accuracy based on the output of Luxen l.

Also, unlike strain gauge-type torque measuring instruments that use contact members such as slip rings to transmit signals from the shaft to the outside, the outer ring 25°, the middle ring 29, and the inner ring 33 are non-contact. Therefore, the durability d3 and reliability of the torque sensor 1 can be improved.

Although magnetostrictive torque sensors can detect the torque to be measured without contact, the zero point and sensitivity are extremely unstable due to the temperature characteristics of the magnetostrictive material. Since the temperature compensator 135 is provided at , the torque detection characteristic becomes almost linear. Therefore, temperature compensation for torque detection can be performed with extremely high accuracy.

Also, outer ring 25. Middle ring 29. Since the inner ring 33 is made of a combination of magnetic and non-magnetic materials, it is easy to assemble the torque sensor 1, and injection molding of non-magnetic materials (plastic, etc.) is possible, making molding easy and reducing costs. can be achieved.

Next, a second embodiment of the torque sensor according to the present invention will be described.

FIG. 14 shows an output section of a transmission equipped with a herb lux sensor 1 according to the present invention.

In the same figure, a parking gear 53 is installed at one end opening of a transmission case 51 on the outer periphery of the output shaft 6 (torsion shaft).
An inner ring 33 that goes around the outer peripheral surface of the output shaft 6 is fixed to the parking gear 53 by a snap ring 52.

Further, the outer ring 25 or the snap ring 50 is fixed to the opening of the transmission case 51 at the same axial position as the inner ring 33 with a predetermined gap therebetween.

Roughly speaking, a cylindrical displacement shaft 8 is spline-coupled to the outer periphery of the output lN16 at a spline portion 40 so that torsional deformation on the output side of the output l sleeve 6 can be transmitted, and the displacement shirt 1-8 has a middle ring. The two are fixed with screws 57 via a mounting ring 55.

The parking gear 53 and the inner ring 33 are positioned by key grooves, and the displacement shaft 8 and the mounting ring 55 are positioned by at least two key grooves.

Furthermore, the mounting ring 55 is made of a plate material, and therefore has high rigidity in the axial direction and torsional direction of the displacement shaft 8, but has low rigidity in the circumferential direction of the -force displacement shirt +-8. . Therefore, even if there is an error in the circumferential direction of the displacement shaft 8, the middle ring 29 will not be forcibly eccentric.

The mounting ring 55 and the middle ring 29 are provided with a plurality of screws 5.
7, and since the screws 57 are arranged in one state, the middle ring 29 is positioned and fixed to the mounting ring 55 (displacement shirt 1-8) during assembly.

Therefore, positioning adjustment of the middle ring 29 with respect to the outer ring 25 and the inner ring 33 is not necessary, and assembly is easy.

Further, the middle ring 29 is inserted directly between the outer ring 25 and the inner ring 33 at the same axial position as the outer ring 25 and the inner ring 33.
are opposed to each other with a small gap between them.

The gap between the outer ring 25 and the middle ring 29 is set to be larger than the gap between the middle ring 29 and the inner ring 33 to prevent the outer ring 25 and the middle ring 29 from coming into contact with each other. (generally, the outer ring 25 and the inner ring 29 have a maximum resistance of 600
0 rpm).

Roughly speaking, the gap between the middle ring 29 and the inner ring 33 is made as small as possible. For this reason, 1 that occurs when they come into contact with each other
Since a guide (not shown) is provided to prevent q scratches, the middle ring 29 and the inner ring 33 can be maintained at a predetermined relative position to each other. Therefore, even if there is an error in the circumferential direction of the displacement shaft 8, the two middle rings and the inner ring 33
Since the relative position of the displacement shaft 8 is accurately determined, torque detection can be performed accurately, and there is no need to improve circumferential precision in forming the displacement shaft 8, so costs can be reduced.

As explained above, the middle ring 29 and the inner ring 33 are respectively output to the displacement shirt 1! Since they are connected to the Ti 1116, they each rotate around the same axis.

When torque is applied to the output shaft 6, since a load is applied to the output side of the output shaft 6, the opposing positions of the middle ring 29 and the inner ring 33 are relatively changed due to the torsion of the output shaft 6.

Here, the outer ring 25 is formed into a ring shape from a magnetic material such as Ferrite 1 or permalloy, and as understood from FIG. 15, three rings 25A+, 2 are formed in the axial direction.
It is said that it can be divided into 5A2 and 25Δ3.

Furthermore, two grooves S are formed in a circumferential manner on the surface facing the middle ring 29, and within each i74 S, coils 25C+ and 25C2 (detection coils) are disposed in each groove S by circulating a plurality of times. It is set up.

Lead wires 2511 and 2512 are connected to both ends of both coils 25C1 and 25C2, respectively.
5L+ and 25L2 are passages 2 formed in the outer ring 25.
5a to the outside of the outer ring 25.

As shown in Fig. 16, the middle ring 29 is formed by fixing three rings 29B to a ring 29A made of a non-magnetic material such as metal or plastic. XVII arrow view and XV in Fig. 16
The I arrow view is shown in each case.

In addition, each ring 29B is made of a magnetic material,
A ring-shaped base 29B as shown in FIG.

A plurality of teeth 29B2 are formed on the inner peripheral surface of the base 29B1.

And as understood from FIGS. 15 to 18, the base 2
9B1 is opposed to the outer ring 25, and teeth 29B
2 is opposed to the inner ring 33.

Note that the width of the teeth 29B (the axial width of the middle ring 29) is set larger than the width of the outer ring 25 and the inner ring 33 facing the magnetic pole surfaces, so that the width of the teeth 29B is larger than the width of the outer ring 25 and the inner ring 33 facing the magnetic pole surfaces. Even if an error occurs or the bearing rattles, or even if the output shaft 6 undergoes thermal expansion and the inner ring 33 moves in its own axial direction, the magnetic flux is reliably transferred from the outer ring 25 and inner ring 33 to the middle ring. Therefore, the change in magnetic resistance of the magnetic circuits 1 and !2 (described later) is hardly affected by the error in the axial direction of the middle ring 29, so the error in the sensor output is extremely small and accurate torque detection is possible. .

The inner ring 33 is entirely made of magnetic material, and the 15th
19 to 21, a convex shape (i) 33A is integrally formed along the center line of the outer peripheral surface, and teeth 338.33C are arranged in the inner ring with the convex shape 33A in between. A plurality of them are each formed around the outer peripheral surface of 33.

Note that FIG. 21 shows a side view of the inner ring 33.

Furthermore, in this embodiment, the positioning of the two middle rings and the inner ring 33 is achieved by the output 1NI6 and the displacement shaft 8 having a structure in which at least one or more spline teeth are missing, as can be understood from FIG. positioning is easy.

Outer ring 25. Since the middle ring 29 and the inner ring 33 are constructed as described above, when both coils 25C1 and 25C2 are energized, these three outer rings 25. Middle ring 29. Two magnetic circuits with inner ring 33! 1 and e, 2 are formed.

Also, the sectional view taken along the line X-X and XI-XI in FIG.
Linear cross-sectional views are shown in FIGS. 10 and 11, respectively, and when torque is applied to the output shaft 6, a difference in torsion angle by 1 herk occurs between the output shaft 6 and the displacement shaft 8 (for example, the output shaft 6 is applied with a torque of about 170 m-Kg and the output shaft 6 is twisted by about 5 degrees, the twist angle generated in the displacement shirt 1-8 with respect to the output shaft 6 is about 5 degrees), therefore, the inner 1 nong 33 is displaced relative to the middle ring 29.

Therefore, as explained in the bending first embodiment, the magnetic circuit, e+
,! 22 changes in magnetic resistance, resulting in coil 25C1
and the inductance of 25C2 changes (the detailed principle is the same as in the first embodiment).

Then, based on the change in inductance, the torque applied to the output lllll6 can be detected in the same manner as in the first embodiment.

Although the torque sensor 1 in this embodiment detects the torque applied to the output shaft 6, it is of course possible to detect the torque of the input shaft as well.

As explained above, the torque sensor 1 provided in this embodiment has the coil 25C1 provided on the outer ring 25 due to the change in the facing position of the inner ring 33 rotated by the output shaft 6 and the middle ring 29 provided on the displacement shaft 8. and 25C2
Since the inductance change occurs in correspondence with the torque applied to the output shaft 6, accurate torque detection is possible even when the torque applied to the output shaft 6 is large.

Also, outer ring 25. Since the two middle rings and the inner ring 33 are non-contact, they have excellent durability and extremely reliable detection accuracy.

Next, a third embodiment of the torque sensor according to the present invention will be described based on FIGS. 24 to 26.

Note that in FIGS. 24 to 26, the same parts as in FIGS. 14 to 23 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, a shaft with low torsional rigidity is used as the output shaft 6, and a hollow shaft with high torsional rigidity is used as the displacement shaft 8.

The two middle rings are fixed to the displacement shaft 8 via a dock clutch 59 provided at one end of the displacement shaft 8.

24 and 25 show the torque sensor configured as described above, and FIG.
The figure shows a cross-sectional view of the XXVI-XXV construction line.

And as understood from FIG. 26, displacement shirt 1-
8 and the middle ring 29 have a coupling structure that does not cause backlash in their rotational direction.

In addition, in Fig. 24, the construction XXV-T in Fig. 26 is
Middle ring that falls on the XXV line cross section 29. Displacement shaft 1~8
and parking gear 53 are shown.

Further, when torque is applied to the output shaft 6 and the output shaft 6 is twisted by about 5 degrees or more, the displacement shaft 8 comes into contact with the parking gear 53 via the dock clutch 59. It is set to act as a stopper that restricts the rotation of.

Also, if the input torque is small (e.g. 89m-K
g or less), the torque is transmitted from the input side to the output side via the output shaft 6.

Also, when the input torque becomes large and the output shaft 6 is deflected by about 5 degrees, the dock clutch 59 comes into contact with the parking gear 53, so that the torque to that extent is transmitted through the output shaft 6, and the torque beyond that is transmitted to the displacement shaft. 8 from the input side to the output side.

Therefore, even when a small torque is input, the relative positional change between the two middle rings and the inner ring 33 can be increased, and as a result, the sensor output becomes larger, so that more accurate torque detection is possible.

In addition, even if the output shaft 6 is moved further to detect a very small torque, the torque exceeding the preset torque value will be received by the displacement shirt 1 to 8, so the output There is no problem such as damage to the shaft 6.

Particularly when the torque sensor 1 is used in a transmission, accurate torque can be detected, making it possible to precisely control gear shift shock, creep torque, or during cruising.

Next, a fourth embodiment of the torque sensor according to the present invention will be described.

As shown in FIG. 27, in this embodiment, the i-silk sensor 1 according to the present invention is used to detect the torque of the automatic transmission 1-lance axle 26 and the reduction gear shaft 10, and the reduction gear shaft 10 is formed in a cylindrical shape. 12 is inserted into the displacement shirt 1 into the cylindrical portion.

One end of the displacement shaft 12 has a key 14 and a snap ring 1.
6 is fixed to the reduction gear shaft 10 (torsion shaft), and therefore the displacement shaft 12 can rotate together with the reduction gear IN110.

Further, the side cover 18 extends in a cylindrical shape along the axial direction of the reduction gear shaft 10, and a cap 2 is attached to the extending end.
0 is fixed with a bolt 22.

Here, an outer ring 25 is fixed to the inner circumferential surface of the extending portion of the side cover 18 by a cap 20 and a rotation stopper (not shown).

In addition, an outer ring 2 is provided on the circumferential surface of one end of the reduction gear shaft 10.
Two middle rings are fitted in the same axial positions as 5, and the two middle rings are fixed to the reduction gear shaft 10 by dowel pins (not shown).

Furthermore, a middle ring 29 is provided on the circumferential surface of the free end of the displacement shaft 12.
The inner ring 33 is located at the same axial position as the snap ring 2.
4 and a rotation stopper (not shown).

The outer ring 25 is made of a magnetic material such as ferrite, or permalloy, and has two grooves S formed on its inner peripheral surface. In each groove S, a coil 25C1 and a coil 25G2 (detection coil) are arranged so as to circulate within each groove S a plurality of times.

As shown in FIG. 28, lead wires 25L+ are connected to both ends of the coil 25C1 and the coil 25C2.

25L2 are connected respectively, both lead wires 25L+
, 25L2 are drawn out to the outside of the outer ring 25.

Furthermore, as can be understood from FIG. 28, the outer ring 25 can be divided into three parts along its axial direction, which makes it easy to pull out both lead wires 25L+ and 25L2 to the outside, and also allows the torque sensor 1 to be easily pulled out. Assembly is easy.

FIG. 29 shows cross-sectional views of the two middle rings, and FIGS. 30 and 31 show the
XX arrow view, OJ: and XXX arrow view are shown respectively.

As can be understood from FIGS. 29 to 31, the two middle rings are made of non-magnetic material 29 such as metal or plastic.
Three rings 29B made of magnetic material are molded by A.

Each ring 29B has a ring-shaped base 2 as shown in FIG.
A plurality of m 2 formed on the inner peripheral surface of 9B1 and the base 29B.
9 B 2.

Note that the width of the teeth 29B (width in the axial direction of the middle ring 29) is set to be 52 wider than the facing width of the RA positive surfaces of the outer ring 25 and the inner ring 33. If a direction error occurs, or if thermal expansion occurs in the output @6 and the inner ring 33 moves in its own axial direction, the magnetic flux will be transferred to the outer ring 25 and the inner ring 3.
Make sure to enter the middle ring 29 from 3. Hence the magnetic circuit! 1 and 52 (Ii) are almost unaffected by the error in the axial direction of the middle ring 29. Therefore, the error in the sensor output is extremely small and accurate torque detection is possible.

Also, the gap between the outer ring 25 and the middle ring 29 is
The gap between the outer ring 25 and the inner ring 33 is set larger than that between the outer ring 25 and the inner ring 33 to prevent contact between the outer ring 25 and the inner ring 29 and avoid damage to the outer ring 25 and the inner ring 29 due to contact. 25 and medium ring 29 maximum 6000
rl) with a relative velocity of the order of m).

Roughly speaking, the gap between the two middle rings and the inner ring 33 is made as small as possible. For this reason, a guide (not shown) is provided to prevent damage caused by contact with each other, so that the two middle rings and the inner ring 33 can maintain a predetermined relative position with respect to each other. Therefore, even if there is an error in the circumferential direction of the displacement shaft 8, the relative positions of the middle ring 29 and the inner ring 33 are accurately determined, so that 1 to 1 torque detection is performed accurately, and when the displacement shaft 8 is formed, Since there is no need to increase accuracy in the circumferential direction, costs can be reduced.

The inner ring 33 is made of a magnetic material, and FIG. 32 shows a cross-sectional view of the inner ring 33, FIG. 33 shows a side view of the inner ring 33 as viewed from the xxxm arrow in FIG. 32, and FIG. 34 shows a side view of the inner ring 33. It is shown.

As can be understood from FIGS. 28 and 32 to 34, the inner ring 33 is integrally formed with a convex (teeth) 33A along the center line of the outer circumferential surface, and this convex 33A
A plurality of m33B and teeth 33C are integrally formed around the outer peripheral surface of the inner ring 33 with the inner ring 33 sandwiched therebetween.

In the above configuration, both coils 25C+ of the outer ring 25
, 25C2, the outer ring 25., 25C2 is energized as shown in FIG. Two magnetic circuits 1 and 12 are formed by the middle ring 29 and the inner ring 33.

When torque is applied to the reduction gear 1t10, a relative torsional angle displacement occurs between the reduction gear shaft 10 and the displacement shirts 1 to 12 (for example, when the applied torque is approximately 170 m-K (), the reduction gear shaft 10
If the plate angle is about 5 degrees, the relative angular displacement will be about 5 degrees).

Therefore, as can be understood from FIG. 10 showing the sectional view taken along the line X-X in FIG. 28 and FIG. 11 showing the sectional view taken along the line XI-XI in FIG. When the two rings are displaced clockwise relative to the inner ring 33, the magnetic resistance of the magnetic circuit β1 increases, and the magnetic circuit,
The reluctance of e2 decreases.

The inductance of the coil 25C1 decreases, while the inductance of the coil 25C2 increases (note that
The detailed principle is substantially the same as the first embodiment).

By detecting the change in inductance of both coils 25C1 and 25C2, it becomes possible to detect the torque applied to the reduction gear shaft 10 as explained in FIGS. 12 and 13.

In this embodiment, two middle rings and an inner ring 33 are used.
and set the relative angle as shown in Figure 10 or 11 (
In order to make the torque applied to the reduction gear shaft zero), the reduction gear @10, the displacement shaft 12. Middle ring 29. The inner ring 33 is installed in one way, with a rotation stopper and a lock pin.

This is done with a snap ring.

Therefore, the positions of the middle ring 29 and the inner ring 33 can be adjusted at the same time as the torque sensor 1 is assembled.
Also, delicate position adjustment of the inner ring 33 is not required, making assembly easy.

As explained above, in the torque sensor 1 in this embodiment, the reduction gear shaft 10 is used as a torsion shaft, and the torque applied to the output side of the reduction gear 01110 is transmitted to the input side by the displacement shaft 12. Detects changes in inductance of two coils 25C+ and 25C2 provided in .

Since torque is detected based on the change in inductance, accurate torque detection is possible even when the applied torque is extremely large.

Furthermore, outer ring 25. 2 middle rings and 33 inner rings
are arranged in a non-contact manner, resulting in excellent durability and reliability.

(Effects) As is clear from the above explanation, the torque sensor according to the present invention has a sensor body with a triple ring structure, and therefore the relative change in the opposing position of the detection teeth can be maximized, resulting in expansion due to the torsion axis. The torsional deformation of the measured shaft can be directly transmitted to the sensor body.

Therefore, even when the 1-lux to be measured is extremely small, the sensor sensitivity is extremely high because the inductance change of the detection coil is large.

Since the torque to be measured is detected based on the change in inductance, highly accurate torque detection is possible regardless of the nature of the shaft to be measured.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of the first embodiment of the torque sensor according to the present invention, FIG. 2 is a cross-sectional view of the outer ring shown in FIG. 1, and FIG. 3 is a cross-sectional view of the inner ring in FIG. Figure, 4th
The figures are as shown in Fig. 3 (Pu). Fig. 5 is a plan view taken in the direction of arrow V in Fig. 3. Fig. 6 is a partially cutaway view showing the magnetic material in Fig. 3. A perspective view, FIG. 7 is a sectional view of the inner ring drilled in FIG. 1, FIG. 8 is a plan view showing the ■ arrow direction in FIG. 7, and FIG. 9 is a cross-sectional view of the inner ring drilled in FIG. An explanatory diagram showing the magnetic circuit composed of the inner ring and the inner ring, FIG.
XX cross-sectional view in Figure 8, Figure 11 is Figure 1,
5, 25, and 28, and FIG. 12 is an explanation showing a magnetic constant circuit of the magnetic circuit formed by the outer ring, middle ring, and inner ring shown in FIG. 1. 13 is an electrical configuration diagram of a torque detector that measures the torque to be measured based on the detection signal detected by the l-lux sensor in FIG. 1, and FIG. 14 is an electrical configuration diagram of the torque sensor according to the present invention. 15 is an explanatory diagram showing the configuration of the torque sensor shown in FIG. 14 in an enlarged manner, FIG. 16 is a sectional view of the middle ring in FIG. 14, and FIG. FIG. 18 is a plan view taken in the direction of the Xv■ arrow in FIG. 16, FIG. 19 is a sectional view of the inner ring in FIG. 14, and FIG. 2nd plan view showing the XX arrow position in the
1 is a side view of the inner ring shown in FIG. 14, FIG. 22 is an explanatory diagram showing a magnetic circuit formed by the outer ring, middle ring, and inner ring in FIG. 14, and FIG. 23 is a side view of the inner ring shown in FIG. 14. FIG. 24 is an explanatory diagram showing the spline connection between the output shaft and the displacement shaft of the torque sensor according to the present invention.
25 is a configuration explanatory diagram showing an enlarged view of the torque sensor in FIG. 24. FIG. X X VI -X X Vl in the diagram
A line cross-sectional view, FIG. 27 is a third view of the torque sensor according to the present invention.
28 is a configuration explanatory diagram showing an enlarged view of the 1-lux sensor portion in FIG. 27, FIG. 29 is a sectional view of the middle ring shown in FIG. 27, and FIG. FIG. 31 is a plan view showing the XXXX artificial body in FIG. 29, and FIG. 32 is a plan view showing the
Figure 33 is a cross-sectional view of the middle 1st song in the figure, Figure 32 is a plan view showing the arrow direction, Figure 34 is the 27th
35 is an explanatory diagram showing the magnetic circuit formed by the tattling, middle ring and inner ring in FIG. 27, and FIG. 36 is a partially cutaway diagram showing a conventional 1-herc sensor. This is a perspective view. 1... Torque sensor 2... Steering gear 3... Stub shaft 5... l Hesion bar 25... Outer ring 29... Middle ring 33... Inner ring 25C+, 25C2... Coil 25B ...Magnetic ring 29B...Magnetic ring 29B2...Teeth" 33A...Convex 338.330...Teeth, el, 12...Magnetic circuit 6...Output shaft 8...・Displacement shaft 10...Reduction gear shaft 12...Displacement shaft 26...Automatic transaxle Fig. 2 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 1 O port Fig. 12 Port 33 Fig. 13 Fig. Fig. 16 Fig. 19 Fig. 2I Fig. 22 Fig. 23 Fig. 26 Double W Fig. 33 Fig. 35 Fig. 36

Claims (1)

[Claims] (1) It has a torsion shaft that twists and deforms due to the torque to be measured, and a sensor body with a triple ring structure in which three rings are arranged concentrically at the same axial position; adjacent to each other among the three rings. A pair of matching rings are connected to one end and the other end of the torsion shaft, respectively, a plurality of detection teeth made of magnetic material are formed on the opposing peripheral surfaces of both rings, and the other ring is connected to both the rings. A torque sensor comprising: a detection coil that is supported stationary and magnetically coupled to both of the detection teeth.