JP3047934B2 - Torque detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque detector for detecting a torque acting on a rotating body.

[0002]

2. Description of the Related Art Conventionally, as a steering torque detecting device,
For example, as disclosed in JP-A-63-78876, a drive shaft (input shaft) and a steering shaft (output shaft) are connected via an elastic shaft, and a magnetic resistance generated by relative rotation between the input shaft and the output shaft. There is known a device that detects a change in the value.

[0003]

However, according to such a conventional torque detecting device, an elastic shaft (torsion bar) is coaxially arranged and fixed between the input shaft and the output shaft. When expanding and contracting the axis with the axis,
It is necessary to replace the input shaft or the output shaft, or to install a telescopic mechanism separately.

[0004] An object of the present invention is to provide a torque detecting device in which a mechanism capable of extending and contracting in the axial direction is integrated into the torque detecting device to save space.

[0005]

According to the present invention, there is provided a torque detecting device for detecting a torque acting on a rotating body, wherein the torque detecting device is provided on an input side and rotates on an input shaft side. A rotating unit, an output shaft side rotating unit provided on the output side and rotating, a plurality of units provided around a rotation center of the output shaft, one end of which is held by the input shaft side rotating unit; A torque transmission unit having an end held by the output shaft-side rotation unit and transmitting the torque from the input shaft-side rotation unit to the output shaft-side rotation unit; A torque transmission unit having a bent portion that bends by elasticity in accordance with a relative rotation direction shift generated between the output shaft side rotation unit, the input shaft side rotation unit and the output shaft side rotation unit; To detect the relative angle of deviation of the rotation direction between And stage, radially inward of the bend portion
The input shaft-side rotation unit and the output shaft-side rotation unit are accommodated in the formed hollow portion, so that the relative position in the axial direction of the output shaft-side rotation unit can be moved .
And a spline coupling part configured as described above.

[0006]

According to the torque detecting device of the present invention, the input shaft side rotating device and the output shaft side rotating device can be relatively moved in the axial direction inside the torque detecting device.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment in which the present invention is applied to a steering shaft of a column portion of a vehicle will be described below. As shown in FIG. 3, a steering device 45 for a vehicle according to a first embodiment of the present invention is configured such that an input steering shaft 47 connected to a steering wheel 46 has one end 49a of an output steering shaft 49 via a steering torque detecting device 48. Connected to
The other end 49 b of the output side steering shaft 49 is connected to the steering shaft 51 via a universal joint 50. The universal joint 50 and the steering shaft 51 are built in a housing 52. A telescopic mechanism 53 is provided inside the steering torque detector 48.

As shown in FIGS. 1 and 2, the cylindrical sensor 43 having a bottomed cylindrical shape of the steering torque detecting device 48 is provided.
A serration portion 43a is formed on the inner peripheral wall of the substrate, and a resin coating layer is formed on the serration portion 43a.
The large-diameter cylindrical groove 44 of the output side steering shaft 49 is fitted into the serration 43a so as to be movable in the axial direction.

Next, FIG. 4 shows a conceptual diagram of a torque detecting section of the steering torque detecting device 48. An elastic leaf spring 3 as a torque transmitting means is provided on a support plate 1 as a handle side rotating means and a support plate 2 as a steering shaft side rotating means.
However, it is press-fitted and fixed symmetrically with respect to the center of rotation with its longitudinal direction coinciding with the direction connecting the support plate 1 and the support plate 2.

The inner teeth 4a and the outer teeth 5a are made of a magnetic material such as iron, and rotate together with the support plate 1 on the handle side. The internal teeth 20a and the external teeth 7a rotate together with the support plate 2. The housing 8 is fixed to the vehicle body, and has coils 11 and 1 serving as detecting means therein.
2 built-in. Each of the coils 11 and 12 is configured by winding an input conductor and two output conductors together, and the outputs of the coils 11 and 12 are connected to an electronic control unit (ECU) 13. Coils 11 and 1
When an electric current is applied to the input conductor 2 of the coil 2, the coil 12 generates a magnetic field in one magnetic circuit as shown by a dotted line in FIG. 4 through the internal teeth 4a and the external teeth 5a, and detects the generated magnetic field. Also do. Similarly, the coil 11 forms a magnetic circuit between the internal teeth 20a and the external teeth 7a. Then, when relative rotation occurs between the support plate 1 on the handle side and the support plate 2 on the steering shaft side, the deviation angle of the relative rotation direction is detected by a magnetic change. I have.

Next, the details of the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a front view of the steering torque detecting device according to the present embodiment. The support plate 1 is fixed to an iron gear 20 by bolts 14.
The screw holes 15 are for fixing the support plate 1 to the handle side by screws, and one end of the elastic leaf spring 3 as a torque transmission means is press-fitted and fixed to a notch 16 of the support plate 1. FIG. 6 is a sectional view taken along the line AOB of FIG.
And is fixed to the gear 20 on the steering wheel side. For this reason, the support plate 1, the gear 20, and the gear 5 rotate integrally. The gear 20 has internal teeth 20a on its outer periphery, and the gear 5 has external teeth 5a on its inner periphery. On the other hand, the support plate 2 as a steering shaft side rotating means has a spline portion 2a and a stepped portion 2b, and the spline portion 2a is fitted with the steering shaft and rotates together with the steering shaft. A support ring 21 is press-fitted and fixed to the support plate 2, and the outer periphery of the support ring 21 is connected and fixed to the housing 8 via a bearing 22.
The gear 4 is fixed to the support plate 2 by a bolt (not shown), and the gear 7 is fixed to the gear 4 by a bolt (not shown) like a gear 20 via a spacer. Therefore, the support plate 2 and the gear 4 on the steering shaft side
And the gear 7 rotate integrally. Further, internal teeth 4 a are provided on the outer periphery of the gear 4, and external teeth 7 a are provided on the inner periphery of the gear 7. The internal teeth 20a and the external teeth 7a, and the internal teeth 4a and the external teeth 5a face each other with a small gap. An outer ring 2 made of iron is provided on the outer periphery of the gear 20.
The outer ring 23 is provided to make the strength of the magnetic coupling between the gear 20 and the magnetic body 31 such as iron uniform. For the same reason, gear 7
, An outer ring 25 made of iron is provided on the outer periphery of the gear 5, and an outer ring 26 made of iron is provided on the outer periphery of the gear 4. Reference numeral 27 denotes a bobbin made of resin and has the coil 11 as a detecting means inside. Similarly, the resin bobbin 28 has the coil 12 as a detecting means inside. An iron ring 32 is disposed between the resin bobbins 27 and 31, and iron rings 33 and 34 are provided at both ends of the resin bobbins 27 and 31. As a result, when a current flows through the input conductor of the coil 11, the ring 33, the outer ring 23, the gear 20, the inner teeth 20a, the outer teeth 7a, the gear 7, the outer ring 24, and the ring 3
One magnetic circuit is formed through the two. Similarly, when a current is applied to the input lead wire of the coil 12, one magnetic circuit passes through the ring 32, the outer ring 25, the gear 5, the outer teeth 5a, the inner teeth 4a, the gear 4, the outer ring 26, and the ring 32. It is formed. The reason for providing the two coils 11 and 12 as the detecting means is that the output values of the coils 11 and 12 are used as a differential transformer, and that the fluctuation is reduced even if the output value largely fluctuates due to drift or the like. This is to make it possible. One end of the plate-like elastic member 3 is press-fitted and fixed to the support plate 1 and the lower end is press-fitted and fixed to the support plate 2. When relative rotation occurs between the support plate 1 and the support plate 2, the rotation direction is changed. The bent portion at the center of the plate-like elastic body 3 is bent according to the displacement.

FIG. 7 is a sectional view taken along line DD of FIG. In FIG. 7, reference numerals 35 and 36 denote two-stage cylindrical pins as rotation angle regulating means, which have tapered surfaces 37 and 38 on the outer periphery thereof, and a two-stage notch 41 provided on the support plate 1. It is inserted into a notch 16 provided in the support plate 2. Since the pins 35 and 36 have a small gap 42 between the two-step notch 41 of the support plate 1 and the narrow portion thereof, the support plate 1 and the support plate 2 7, the relative rotational deviation can be obtained only up to 1.5 ° clockwise or 1.5 ° counterclockwise in FIG. The presence of the pins 35 and 36 as the rotation angle restricting means prevents the bent portion at the center of the elastic leaf spring 3 from being excessively bent and damaged. Furthermore, if the two-stage notch 41 of the support plate 1 has a wide portion, the elastic plate springs 3 may be temporarily held by the support plate 1 and the support plate 2 for some reason.
Even when the connection cannot be established, the large-diameter portions of the stepped pins 35 and 36 and the wide portion of the two-step notch 41 contact each other, so that the support plate 1 and the support plate 2 are separated by a predetermined distance. I won't go any further.

Next, FIG. 8 is a sectional view taken along the line EE of FIG.
Here, since the EE cross-sectional view is the same as the FF cross-sectional view of FIG. 6, the FF cross-sectional view is omitted. As can be seen from FIG. 8, the internal teeth 20a provided on the outer circumference of the gear 20 and the external teeth 7a provided on the inner circumference of the gear 7 face each other at a small interval. The magnetic resistance of the above-described magnetic circuit changes due to a change in the distance to the magnetic circuit 7a.

FIG. 9 is a side view of the elastic leaf spring 3 as a torque transmitting means, and FIG. 10 is a front view thereof. As can be seen from FIGS. 9 and 10, concave portions 3 a and 3 b for press-fitting the support plates 1 and 2 are provided at both ends of the elastic leaf spring 3. Next, the operation of the first embodiment having the above configuration will be described.

When a steering torque is applied to the handle 54, the support plate 1 fixed to the handle also rotates together with the handle, and the steering torque is fixed to the steering shaft via the elastic leaf spring 3 as a torque transmitting means. The steering shaft is transmitted to the support plate 2 as a rotating means. At this time, since a relative rotation direction shift occurs between the support plate 1 and the support plate 2, the central portion of the elastic leaf spring 3 as a bent portion is bent by elasticity. Due to the relative rotational deviation between the support plate 1 and the support plate 2, the internal teeth 2
The distance between Oa and the external teeth 7a and between the internal teeth 4a and the external teeth 5a change. Accordingly, the magnetic resistance of the magnetic circuit formed by the coil 11 and the magnetic resistance formed by the magnetic circuit formed by the coil 12 change, and this is changed by the coil 11 and the coil 1.
The second output conductor outputs each change to the ECU 13 . The ECU 13 calculates the output signals from the coils 11 and 12 and converts them into a detected steering torque value.

In this embodiment, the torque is transmitted from the support plate 1 to the support plate 2 by the elastic leaf spring 3 having a bent portion which is bent by elasticity. Since the elastic plate spring 3 is provided with a plurality around the rotational center of the steering shaft, the number of the elastic leaf spring increases, with it, slide be sampled and compared with the case of connecting the shaft in the central portion The rigidity in the direction and the radial direction is improved.

Since a plurality of the elastic leaf springs 3 are provided in a plane parallel to a plane perpendicular to the rotation direction of the steering shaft,
The relative rotation between the support plate 1 and the support plate 2 easily occurs without reducing the rigidity in the thrust direction and the radial direction, that is, the sensitivity of torque detection can be improved.

[0018]

As described above, according to the torque detecting device of the present invention, a torque transmitting means having a bent portion is provided between an input shaft and an output shaft, and a spline which can extend and contract in an axial direction is provided therein. Since the structure is provided, there is an effect that space can be saved. Further, there is an effect that the output side steering shaft can be easily attached to the telescopic mechanism of the input side steering shaft of the vehicle by a simple operation.

Furthermore, when the input shaft and the output shaft are extended and contracted in the axial direction, the input and output shafts do not need to be replaced, and there is no need to separately install a telescopic mechanism, so that the structure is simplified. There is. In addition, since the torque transmitting means having the bent portion is formed around the rotation center of the steering shaft, the sensitivity of torque detection can be improved and the rigidity of the steering shaft can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA shown in FIG.

FIG. 3 is a schematic sectional view showing an embodiment of the present invention applied to a steering device of a vehicle.

FIG. 4 is a schematic diagram showing an outline of an embodiment of the present invention.

FIG. 5 is a front view showing the embodiment of the present invention.

FIG. 6 is an AOB sectional view shown in FIG. 5;

FIG. 7 is a sectional view taken along line DD shown in FIG. 6;

FIG. 8 is a sectional view taken along line EE shown in FIG. 6;

FIG. 9 is a front view showing a torque transmission unit according to the embodiment of the present invention.

FIG. 10 is a side view showing a torque transmission unit according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Support plate (input shaft side rotation means) 2 Support plate (output shaft side rotation means) 3 Elastic leaf spring (torque transmission means) 11, 12 Coil (detection means) 35, 36 Rotation angle restriction means 43 Body sensor ( 43a serration connection part 44 large-diameter cylindrical groove part 47 input side steering shaft (input shaft side rotation means) 48 steering torque detecting device 49 output side steering shaft (output shaft side rotation means)

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yosuke Setaka 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-63-210740 (JP, A) JP-A-58- 52537 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01L 3/04 G01L 3/10

Claims (1)

(57) [Claims] 1. A torque detecting device for detecting a torque acting on a rotating body, comprising: an input shaft side rotating means provided on an input side and rotating; and an output shaft side rotating provided on an output side and rotating. Means, a plurality of which are provided around the rotation center of the input / output shaft, one end of which is held by the input shaft side turning means, and the other end of which is held by the output shaft side turning means, and A torque transmitting means for transmitting from the input shaft-side rotating means to the output shaft-side rotating means, wherein a relative rotating direction generated between the input shaft-side rotating means and the output shaft-side rotating means. Torque transmitting means having a bent portion that bends by elasticity in accordance with the deviation of the input shaft; and detecting means for detecting a relative angle of deviation in the rotational direction between the input shaft-side rotating means and the output shaft-side rotating means. And housed in a hollow portion formed radially inward of the bent portion.
And a spline coupling unit configured to be able to move an axial relative position between the input shaft side rotating unit and the output shaft side rotating unit.