JPH0411565A - Steering wheel - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation by suppressing the influence of the external tubulence to a detecting means by installing a cover connected with a spoke so as to cover a detecting means for detecting the relative shift of an outside ring for an inside ring. CONSTITUTION:An inside ring 6 is fixed at the top edge of a spoke 4, and an outside ring 7 is nipped on the top edge side 15a of a bending beam 15. When a steering wheel is revolution-operated, the outside ring 7 is relatively shifted for an inside ring 6. The relative shift is detected by the relative shift of a pair of coils L1 installed on the spoke 4 and a magnet 20 which is installed on the bending beam 15. A cover 18 is inserted from the lower part of the bending beam 15 so as to cover the magnet 20 and the coil L1, and fitted on both the sides of the spoke 4. Accordingly, the external turbulence such as electromagnetic waves is grounded through the cover 18, spoke 4, etc., and the steering wheel is protected from the influence of the external turbulence, and the erroneous operation is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes a steering force sensor that detects the steering force of a steering wheel in a vehicle such as a truck and is used for controlling power steering, etc. It concerns the steering wheel.

[Prior Art] Conventionally, in a power steering device for a vehicle, a steering force sensor or a steering amount sensor is attached to a steering shaft to detect the steering force or amount of steering, and based on the steering force or amount of steering, the control is performed during steering. There are known devices that compensate for cutting delay.

However, since the steering force sensor and steering amount sensor detect the distortion and displacement of the steering shaft, they are affected by the inertia of the steering wheel itself, making it difficult to quickly detect accurate steering force and steering amount. there were.

Therefore, a technique has been proposed in which a steering force sensor is disposed on the steering wheel itself, as described in Japanese Patent Laid-Open No. 62-105770.

The steering wheel described in this publication includes an internal ring connected and fixed to a pair of spokes protruding from a boss, a bending beam whose base end is fixed to the boss side, and a bending beam that is movable relative to the spokes in the rotational direction. a spoke cover supported and to which the tip of the bending beam is fixed; an outer ring connected to the spoke cover and supported so as to be movable relative to the inner ring in a rotational direction of the ring portion; It consists of an attached strain gauge.

By rotating the steering wheel, the outer ring is moved relative to the inner ring, the spoke cover is moved relative to the spokes, and the bending beam is moved relative to the spoke cover. It is elastically bent and distorted in the direction of movement. As a result, the strain gauge detects the bending strain of the bending beam and senses the steering force and its direction.

According to this configuration, the steering force can be sensed more accurately than when various sensors are arranged on the steering shaft itself.

[Problems to be Solved by the Invention] However, in the technology described in the above-mentioned Japanese Patent Application Laid-Open No. 62-105770, the strain gauge and its related electric circuit are affected by external disturbances such as electromagnetic waves, resulting in malfunction. There was a risk.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a steering wheel with a steering wheel sensor that can avoid the influence of external disturbances.

"Means for Solving the Problems" In order to achieve the above object, the present invention includes spokes protruding radially from a boss attached to a steering shaft, an internal ring connected to the spokes, and an inner ring connected to the spokes. an outer ring that covers the inner ring and is movable relative to the inner ring and the spokes in the direction of rotation of the steering wheel; a detection means that is supported relative to the spokes and detects relative displacement of the outer ring with respect to the inner ring; and a shield cover provided to cover the means and connected to the spokes.

[Operation] According to the above configuration, by rotating the outer ring of the steering wheel, the outer ring and the inner ring move relative to each other, and the relative displacement is detected. Therefore, the steering force can be obtained by appropriately processing the relative displacement value detected by the detection means.

In addition, a shield cover is provided to cover the detection means supported by the spokes, and the cover is connected to the spokes, so disturbances are grounded through the cover, spokes, etc., and the detectors etc. are protected from disturbances. protected from the effects of

[Example] Hereinafter, an example embodying the present invention is shown in FIGS. 1 to 12.
This will be explained in detail based on the figures.

FIG. 11 is a schematic plan view showing the steering wheel 1. FIG. This steering wheel 1 includes a boss 3 attached to a steering shaft 2, and from the boss 3 there are two
Book spokes 4 are provided to protrude radially. The boss 3 and spokes 4 are each made of metal. Further, a ring portion 5 is provided on the tip end side of each spoke rim 4.

FIG. 1 is a sectional view illustrating the main parts of the steering wheel 1, and shows the structure of two spokes 4. As shown in FIG. Here, assuming that both spokes 4 have the same structure, only one will be described below.

The ring portion 5 is composed of an internal ring 6 and an external ring 7 covering the outer periphery thereof. The inner ring 6 is made of metal and is fixed to the tip of each spoke 4 by welding. The boss 3, the spokes 4, and the inner ring 6 may be made of metal and connected by welding, or may be integrally formed by die-casting aluminum.

The outer ring 7 is made of a lightweight metal material such as aluminum, and is provided so as to cover the periphery of the inner ring 6 with a certain gap therebetween. This external ring 7 is composed of an upper member 8a and a lower member 8b which are divided into upper and lower halves. In addition, an upper holder 9 and a lower holder 10, which will be described later, are attached to these upper and lower members 8a and 8b through their screw holes 11 (second
, see Figure 3), the tightening is fixed via screws 12. Further, the outer periphery of the outer ring 7 is covered with a skin 39 made of leather to improve its appearance.

Both the upper and lower holders 9 and 10 are made of ABS resin,
It is made of hard synthetic resin such as polypropylene (PP). 1st. As shown in FIG. 3, both holders 9 and 10 are attached to the distal end side of each spoke 4 so as to cover the periphery of the spoke 4 with a predetermined gap.

Also, 1st. As shown in FIG. 4, both holders 9 and 10 are formed with a pair of corresponding insertion holes 13, and both holders 9 and 10 are connected to each other through screws 14 and nuts 14a inserted into the respective insertion holes 13. The upper holder 9 and the lower holder IO have substantially the same shape. As shown in Figure 2.3.9, both holders 9. A pair of screw holes 11 are formed on both sides of lO. on the other hand,
The difference between both holders 9°lO is that the upper holder 9
Both sides of the boss 3 are bent downward to form a bent portion 9a. In this embodiment, as shown in FIG. 3, the gap S between the inner surfaces of these bent portions 9a and the spokes 4 is set to 1 mm. Similarly, both holders 9 and 100 are different in that a pair of clamping portions 10a are protruded from the boss 3 side of the lower holder 10.

As shown in Figures 1.2 and 4.9, both the holders 9.
Support walls 22 are formed in the lO, respectively, and are located above and below the spokes 4 and extend in the width direction of the spokes 4. A pair of through holes 24 extending in a direction perpendicular to the width direction of the spokes 4 are formed on both sides of each support wall 22 . A support shaft 23 is inserted through each of the through holes 24, and is tightened and fixed via a nut 25 on the boss 3 side. On the ring portion 5 side of each of these support shafts 23, a roller 26 is rotatably attached as a guide member that is interposed between the spokes 4 and the outer ring 7 and guides the relative movement of these two members 4, 7. ing.

Moreover, between the roller 26 and the spokes 4, both members 2
A leaf spring 51 is interposed as a biasing member for biasing the connection between the two. This leaf spring 51 has a channel shape,
Both bent ends of the spoke 4 are attached by being engaged with engagement recesses 4a formed on the side surfaces of the spokes 4. In the installation state, the leaf spring 51 and the roller 26 are in pressure contact with each other, so that the spoke 4 and the roller 26 are in pressure contact with each other.
This suppresses vertical play between the spokes 4 and both holders 9 and 10, and also between the spokes 4 and the outer ring 7. .

As shown in FIGS. 1 and 2, the boss 3 is lower than the support wall 22.
A support hole 29 that penetrates the spoke 4 in the vertical direction is formed at the center of the side. This support hole 29 has a shaft 28
is loosely fitted. Also, the shaft 28 has a flange 3 at its upper part.
0 and the lower C-ring 31 restrict vertical movement relative to the spokes 4. A roller 27 serving as a guide member is attached to the upper part of this shaft 28 and is rotatable while contacting the support wall 22 .

Further, at a position closer to the boss 3 than the roller 27, a through hole 32 is formed in the spoke 4, passing through the spoke 4 in the vertical direction. A fixed shaft 35 is fixed to this through hole 32 . The fixed shaft 35 is restricted from moving up and down relative to the spokes 4 by a flange 33 at the top and a C ring 34 at the bottom. On both upper and lower sides of the two shafts 28.35, both the shafts 2
Compression springs 36 serving as biasing members each having a substantially U-shape are interposed between 8 and 35, respectively. These compression springs 36 are for pressing the shaft 28 to press the roller 27 against the side surface of the support wall 22. In other words, the leaf spring 5
1 and the roller 26 are in contact with each other, and the outer ring 7 is pressed against the outer ring 7.
The rollers 27 and the support wall 22 are in pressure contact with each other to prevent horizontal play between the spokes 4 and the support wall 22. As a result, lateral rattling between the spokes 4 and the outer ring 7 can be suppressed. Both the holders 9 attached to the outer ring 7,
Since a gap S is provided between the spokes 10 and the spokes 4 connected to the inner ring 6, relative movement between the outer ring 7 and the inner ring 6 is allowed within the range of the gap S.

Therefore, the ring portion 5. That is, by rotating the outer ring 7, both holders 9, 10 are moved integrally in the operating direction. Further, during the movement, the one roller 26 moves while being pressed against the plate spring 51, and the other roller 27 rolls while being pressed against the support wall 22, causing both rings 6. 7 is smoothly guided.

Further, as shown in FIG. 1, a plate-shaped support body 37 that integrally supports a printed circuit board 43 is attached to the lower side of the spoke 4. The support body 37 is made of an insulating material such as ABS resin, and as shown in FIG.
side), there is a box-shaped mounting portion 37 with a fitting recess 37a.
b is formed, and a pair of through holes 38 are formed in the fitting recess 37a. The support body 37 supports the printed circuit board 43 by superimposing it on its surface, and a single positioning claw 44 for the printed circuit board 43 is provided protruding near the mounting portion 37b.

Further, a positioning hole 46 for the printed circuit board 43 is similarly formed on the tip end side (ring portion 5 side) of the support body 37. Furthermore, protrusions 37c are formed on both sides of the support body 37, extending in the longitudinal direction thereof.

On the other hand, as shown in FIGS. 7 and 8, a positioning hole is provided on the − side of the base end side (boss 3 side) of the printed circuit board 43 to be engaged with the positioning claw 44 of the support body 37. 46 is provided transparently. Further, a support hole 45 is transparently provided on the front end side (ring portion 5 side) of the printed circuit board 43, and is positioned to correspond to the positioning hole 40 of the support body 37. Further, on both sides of the printed circuit board 43, the protruding portions 37 of the support body 37 are provided.
A recess 43a to be fitted is formed corresponding to c.

Therefore, when the printed circuit board 43 is superimposed on the surface of the support 37, the positioning claws 44 of the support 37 engage with the positioning holes 46 of the printed circuit board 43, and the support
The concave portion 43a of the printed circuit board 43 fits into the protruding portion 37c of 7, and the support hole 45 of the printed circuit board 43 corresponds to and communicates with the positioning hole 40 of the support body 37.

With the printed circuit board 43 supported in this manner, the base end of the support body 37 is attached through the through hole 37 of the portion 37b.
, connect the spoke 4 via the bolt 17 and nut 17a.
The tightening is fixed. Further, the distal end side of the support body 37 is positioned and fixed to the spoke 4 through a support hole 45 and a positioning hole 40 via a screw 41 and a nut 41a.

As shown in FIGS. 1 and 2, a bending beam 15 made of aluminum alloy is attached below the support body 37 and the printed circuit board 43.

As shown in FIG.
A plate-shaped mounting portion 15 is provided on the base end side (boss 3 side) to be fitted into the fitting recess 37a of the support body 37.
a is formed. Further, for this installation, a pair of threaded holes 16 are provided on both sides of the portion 15a to communicate with the through holes 38 of the fitting recess 37a, and another threaded hole 19 is provided between the two threaded holes 16. is drilled.

On the other hand, a mounting portion 15b is formed on the tip end side (ring portion 5 side) of the bending beam I5, which extends laterally and is bent upward (downward in FIG. 4). For this attachment, a magnet 20 extending in the width direction of the spoke 4 is fixed to the inner surface of the portion 15b with an adhesive.

The bending beam 15 is attached to the spoke 4 via the bolt 17 and nut 17a with the proximal end portion 15a fitted into the fitting recess 37a of the support 37. The tightening is fixed integrally. In addition, in this fixed state, the tip side of the bending beam 15, that is, the mounting portion 15b is attached to the lower holder 10.
It is fitted and held between both the holding parts 10a.

In this clamped state, the bending beam 15 can be bent laterally around the proximal end portion 15a.

Therefore, when the outer ring 7 is rotated, the rotational force becomes a steering force proportional to the amount of relative movement of the outer ring 7 with respect to the inner ring 6. Further, the steering force at this time is transmitted to the tip side of the bending beam 15 through the clamping portion 10a, and further transmitted to the steering shaft 2 via the bending beam 15 from the spokes 4 through the boss 3.

Further, in this embodiment, when a steering force of 5 kg is applied to the outer ring 7, the bending amount on the tip side of the bending beam 15 is set to be 1 mm. Thereby, when the bending beam 15 is bent by 1 mm, the inner surface of the bent portion 9a of the upper holder 9 comes into contact with the side surface of the spoke 4.

On the tip side of the printed circuit board 43, a magnet 2 attached to the tip portion 15b of the bending beam 15 is attached.
A pair of coils L1 and L2 extending in the width direction of the spoke 4 are attached at a position close to the spoke 4.

That is, as shown in FIGS. 7 and 8, a pair of mounting recesses 43b are formed on the leading edge of the printed circuit board 43, centered at the center thereof.
is formed. In this attachment, a portion of each coil L1, L2 is fitted into the recess 43b and fixed with an adhesive. Also, in this fixed state, each coil L
1, L2 glue portion 52 is located close to the surface of the printed circuit board 43.

As the bending beam 15 bends, the magnet 20 is moved relative to the coils L1 and L2, so that the magnetic flux in the coils L1 and L2 changes, and the change in magnetic flux becomes a detection signal. The steering force is detected.

Further, the printed circuit board 43 includes the coil Ll.

Various circuits such as a detection circuit for detecting changes in the magnetic flux of L2 and converting them into changes in voltage are incorporated.

FIG. 12 shows an electric circuit built into the printed circuit board 43. As shown in FIG. This electric circuit includes a high frequency oscillation circuit 48 for detecting changes in inductance of the coils L1 and L2 due to changes in magnetic flux, a bridge circuit 47 including the pair of coils L1 and L2, and coils L1 and L2 of the bridge circuit 47. It is composed of a conversion circuit 49 that converts an inductance change into a voltage change, and an amplifier circuit 50 that amplifies the difference between the two outputs of the conversion circuit 49.

In this embodiment, the detection means is constituted by the coils L1 and L2, a printed circuit board 43, etc. equipped with an electric circuit, and as shown in FIG.
Below each coil Ll.

A shielding cover 18 made of aluminum is attached to cover the entire printed circuit board 43 including L2 and the bending beam 15.

As shown in FIG. 10, the cover 18 is formed into a gutter-like shape by a bottom wall 18a and side walls 18b on both sides, and a through hole 18c is formed at the base end of the bottom wall 18a. Then, through the through hole 18c, the bolt 2 is inserted into the base end side of the cover 18 or the screw hole 19 of the bending beam 15.
1, the tightening is fixed. Also, this cover 1
Reference numeral 8 is for shielding the coils L1, L2 and the electric circuits related thereto to protect them from external disturbances, and in the fixed state, both side walls 18b are fitted to the side surfaces of the spokes 4 and connected.

Next, the operation of the steering wheel 1 with the steering wheel sensor configured as described above will be explained.

In FIG. 1.2.11, when the ring portion 5 is gripped by hand and rotated clockwise or counterclockwise, the steering force acts on the ring portion 5. At this time, the steering force is transmitted from the outer ring 7 constituting the ring part 5 to the upper and lower holders 9 and 10 supporting it, and further from the clamping part 10a of the lower holder 10 to the bending beam 1.
5 is transmitted to the distal end side. As a result, the bending beam 15 transmits the steering force to the spoke 4 while deforming centering on the base end side against the elastic force. Also, the outer ring 7 deforms the inner ring 6 and the spokes 4 by an amount corresponding to the steering force, that is, by the amount by which the bending beam 15 is deformed.
is moved relative to.

The magnet 20 located on the tip side of the bending beam 15 is connected to a pair of coils L1 and L2 located near it.
It will be displaced relative to. Here, as shown in FIG. 12, both coils Ll.

Since a high frequency is applied to L2 from the high frequency oscillation circuit 48, the magnetic flux in the coils L1 and L2 changes depending on the positional relationship of the magnet 20 with respect to the coils L1 and L2. Therefore, as the magnet 20 moves, the magnetic flux of each of the coils L1 and L2 increases or decreases, and the inductance increases or decreases. By converting this increase/decrease in inductance into a voltage in the conversion circuit 49 and amplifying the difference between the two voltage outputs in the amplifier circuit 50, a small displacement amount of the magnet 20 and a relative displacement between the outer ring 7 and the spokes 4 can be realized. The amount of displacement is detected.

The pair of coils L1 and L2 are so-called anti-phase type sensors in which the inductance of one increases and the inductance of the other decreases as the magnet 20 moves. Further, during the operation of this steering force sensor, noise vibrations that are different from the detection direction, that is, the rotational operation direction of the ring portion 5, such as vibrations in the longitudinal direction of the spokes 4 or vibrations in the vertical direction perpendicular to the spokes 4, act. However, the coil Ll.

There is no problem because the changes in inductance of L2 act to cancel each other out.

Then, the output signal from the amplifier circuit 50 is inputted to, for example, a hydraulic controller of a power steering device, so that the power steering device is started and powered with an optimal force corresponding to the steering force corresponding to the output signal. Steering is activated.

In this embodiment, since the bending beam 15 is fixed to its proximal end side or to the spoke 4, the bending beam 15 is bent by a predetermined amount due to the steering force, and the steering force is transmitted to the spoke 4. is transmitted to the steering shaft 2 via the steering shaft 2, and the steering shaft 2 is rotated. Also, when a steering force of 5 kg or more is applied, the bending beam 15 is bent by 1 mm,
The inner surface of the bent portion 9a of the upper holder 9 comes into contact with the spoke 4, and the steering force is applied to the bending beam 15 and both upper and lower holders 9. The signal is transmitted to the spokes 4 via the lO, and further transmitted to the steering shaft 2 via the boss 3, so that the steering shaft 2 is rotated. and outer ring 7
When the steering force is no longer applied to the bending beam 15
The elastic force causes the outer ring 7 to return to its original position relative to the inner ring 6.

As described above, in the steering wheel 1 of this embodiment, the magnet 20 as a magnetic flux changing member is attached to the distal end side of the bending beam 15 as a deformable member, and the base end thereof is integrally connected to the support body 37 as a spoke. 4, and the coil L1 is attached to the tip side of the support 37 via the printed circuit board 43.
, L2 are attached to make the entire steering force sensor integral.

Therefore, the steering force sensor can be integrally assembled in advance before being assembled to the steering wheel l, and the sensor can be tested alone. That is, a single steering force sensor can be adjusted in accordance with changes in load, and each sensor can be evaluated and adjusted in advance. Furthermore, since the steering force sensor that has been integrally formed in advance can be assembled to the steering wheel 1, variations in the assembly position can be prevented. In particular, when assembling the coils L1 and L2, which require positional accuracy, the printed circuit board 43 is accurately positioned on the support 37, and each coil L1 and L2 is mounted in the recess 43b. Since the sensor is accurately positioned, it is possible to prevent the detection accuracy of the sensor from decreasing due to variations in positional accuracy.

Furthermore, unlike devices that use conventional strain gauges to detect steering force, stress does not directly act on the detection section, so there is no deterioration, and durability and reliability can be improved. Furthermore, since there is no need to attach strain gauges manually, mass productivity can also be improved.

Also, in this embodiment, rollers 26, 2 are provided between the spokes 4 and the outer ring 7 for guiding their relative movement.
A plate spring 51 and a compression spring 36 are provided to bias the connection between each roller 26 and the spoke 4, and between the roller 27 and the outer ring 7, with the roller 27 interposed therebetween. Therefore, the relative movement between the spokes 4 and the outer ring 7 is limited to each roller 26, 27.
In addition to being guided smoothly by the springs 51 and 36, the rolling of the rollers 26 and 27 is prevented from wobbling, which in turn allows the steering force sensor to function smoothly. In addition, since rattling can be prevented by each spring 51, 36, delicate tolerances when assembling each member can be absorbed.

Furthermore, in this embodiment, a cover 18 is provided to cover the entire printed circuit board 43 including the coils L1 and L2, and both side walls 18b of the cover 18 are fitted and connected to the side surfaces of the spokes 4. Therefore, external disturbances such as electromagnetic waves are grounded through the cover 18, spokes 4, boss 3, steering shaft 2, and the like. As a result, each coil L
L.

L2, electric circuits, etc. can be protected from the influence of disturbances, and malfunctions can be prevented.

Further, since the cover 18 is connected to the spoke 4 and the spoke 4 is also used as a shield member, members such as leads for shielding can be omitted, and the number of parts can be reduced.

Note that this invention is not limited to the above embodiments,
The present invention can be implemented as follows by changing a part of the structure as appropriate without departing from the spirit of the invention.

(1) In the embodiment described above, the shielding cover 18 was made of aluminum, but it may also be made of iron, copper, or the like.

(2) In the above embodiment, each coil L1. Although the entire printed circuit board 43 including L2 is covered by the cover 18, only each coil may be covered.

(3) In the above embodiment, the bending beam 15 is attached to each of the two spokes 4, but if the bending beam is attached to only one spoke, or if there are three or more spokes, the number of each spoke may be changed. The same number of bending beams may be installed.

(4) In the embodiment described above, the magnet 20 was provided as the magnetic flux changing member, but metal or coil may be used instead of the magnet.

(5) In the above embodiment, the coil Ll is used as the detector.

Although coil L2 is provided, a Hall element, a magnetoresistive element, or the like may be used as a magnetic sensor in addition to the coils L1 and L2.

[Effects of the Invention] As described in detail above, according to the present invention, a steering wheel with a steering force sensor exhibits an excellent effect of being able to avoid the influence of disturbances.

[Brief explanation of the drawing]

1 to 12 show an embodiment embodying the present invention, FIG. 1 is a sectional view illustrating the main parts of the steering wheel, and FIG. 2 is a part illustrating the main parts of the steering wheel. A broken bottom view, FIG. 3 is a cross-sectional view taken along line A-A in FIG. 1, FIG. 4 is a cross-sectional view taken along line B-B in FIG. 1, and FIG. Figure 6 is a perspective view of the support, Figure 7 is a plan view of the printed circuit board, Figure 8 is a front view of the same, Figure 9 is a perspective view of the lower holder, and Figure 10 is the cover. A perspective view, FIG. 11 is a schematic plan view showing the steering wheel, and FIG. 12 is an electric circuit diagram of the steering force detection device. 2...Steering shaft, 3...Boss, 4...
・Spoke, 5...Ring part, 6...Inner ring,
7... External ring, 18... Cover 43... Printed circuit board, L1, L2... Coil (43, L1, L
2 etc. constitute the detection means). Patent applicant: Toyoda Gosei Hino Motors Co., Ltd. Agent: Patent attorney On 1) Hironobu (and 1 other person) 43b Rabbit diagram for Rizu Figure 1 Steering wheel ＼

Claims (1)

[Claims] 1. A boss (
spokes (4) projecting radially from the spokes (4); an inner ring (6) connected to the spokes (4); ), an outer ring (7) that is movable relative to the steering wheel in the direction of rotation of the steering wheel; and a detection means that is supported relative to the spokes (4) and detects a relative displacement of the outer ring (7) with respect to the inner ring. (L1, L2, 43), and the detection means (L1,
L2, 43), and the spokes (4
) and a shield cover (18) connected to the steering wheel.