JPH0544755A - Electromagnetic suspension system - Google Patents

Abstract

PURPOSE:To detect a stroke position without lengthening a suspension by forming a suspension unit into a double structure, and installing plural units of flux sensors in a part being set up in a magnetic field of a member at the side inserted into a clearance part together with a coil in the relative displacement direction. CONSTITUTION:A body side member 1 is formed into a dual structure consisting of a cylindrical inner column 1a and a bottomed cylindrical outer casing 1b, and a clearance 1c is installed in space between both of them. Each of almost half parts of those of inner diameter 1a and outer casing 1b is formed with a ferromagnetic body and the others with a nonmagnetic body, respectively. A clearance H is made in an inner circumferential surface of a magnetic outer cylinder 11 and two permanent magnets 1j, 1k are installed in this clearance, while other permanent magnets 1m, 1n are also installed in a magnetic cylindrical part as well, and both upper and lower magnetic field forming parts 1g, 1n are formed as reversed in their flux direction. A coil 3 is wound on the outer circumference of a wheel side member 2 and divided into six parts 3a-3f. Between coil parts, Hall elements 7a-7e as flux sensors are attached. With this constitution, any stroke position detection is detectable without lengthening a suspension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic suspension device.

[0002]

2. Description of the Related Art Conventionally, as an electromagnetic suspension device, for example, one disclosed in Japanese Patent Application Laid-Open No. 2-37016 is known. This conventional device includes an outer cylinder formed in a cylinder shape and fixed to the vehicle body side between a vehicle body and wheels, and a rod slidably provided in the outer cylinder and attached to the wheel side. A suspension unit having the same is provided, a permanent magnet is fixed to the outer circumference of the rod in the outer cylinder, and a coil is fixed to the inner circumference side of the outer cylinder facing the permanent magnet. In order to detect the relative position between them (stroke position of the suspension unit), a linear voltage difference transformer composed of a core made of a conductive magnetic member, a secondary coil for measuring induced electromotive force, and a primary coil for adding an initial imprinting current. However, it had a structure provided in series with the suspension unit.

Then, by controlling the direction and current of energization of the coil based on the position detection signal from the linear voltage differential transformer, a control force is generated in the axial direction of the coil of the suspension unit. Control to keep the height constant.

[0004]

However, in such a conventional electromagnetic suspension device, the relative position between the vehicle body and the wheels (stroke position of the suspension unit).
Since a linear voltage differential transformer was used as a position sensor to detect the voltage, there is a problem that the structure is complicated, the number of parts is large, and the cost is increased, and this linear voltage differential transformer is mounted on the stroke axis of the suspension unit. On the other hand, there was a problem that the basic length of the suspension became long because the structure was built in series.

The present invention has been made in view of the above-mentioned problems, and has a simple structure, and the relative position between the vehicle body and the wheels (stroke of the suspension unit) without increasing the basic length of the suspension. It is an object of the present invention to provide an electromagnetic suspension device capable of detecting a position).

[0006]

According to the present invention, a plurality of magnetic flux sensors capable of detecting magnetic flux are arranged together with a coil at a predetermined interval in the relative movement direction.
The above object was achieved.

That is, in the electromagnetic suspension device of the present invention, the suspension unit interposed between the vehicle body and the wheels is formed of a vehicle body side member and a wheel side member which are relatively movable, and the vehicle body side member and the wheel side member are provided. And one of them is formed in a double structure having a gap along the relative movement direction, and the other is inserted in the gap, and the double structure is formed in the gap by magnetic field forming means. A magnetic field in which magnetic flux flies in a direction orthogonal to the relative movement direction is formed, and at least in a portion disposed in the magnetic field of the member inserted in the gap portion, in a direction orthogonal to the relative movement direction and the magnetic field direction. The coil is wound, and a plurality of magnetic flux sensors capable of detecting magnetic flux are arranged at predetermined intervals in the relative movement direction.

[0008]

[Operation] In the electromagnetic suspension device of the present invention, when the coil is energized, the coil is energized in a direction orthogonal to the stroke direction and the magnetic field direction of the suspension unit, that is, a direction orthogonal to both the magnetic field direction and the energization direction, that is, , A driving force is generated along the stroke direction of the suspension unit. Therefore, this driving force causes the suspension unit to expand and contract.

On the other hand, when the suspension unit makes a stroke while the coil is not energized, the coil moves in the magnetic field to cause an induced current to flow in the coil. The input can be attenuated.

Further, regardless of whether the coil is energized or not, when the suspension unit strokes,
Of the plurality of magnetic flux sensors, the one located in the magnetic field detects the magnetic flux, and the stroke position of the suspension unit is detected thereby.

Therefore, based on the detected stroke position, the driving force acts against the input to the suspension unit, and the stroke of the suspension unit due to an external input can be suppressed.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall view showing the structure of an electromagnetic suspension device according to a first embodiment of the present invention. In this figure, S indicates a suspension unit. The suspension unit S has a vehicle body side member 1 connected to the vehicle body side and a wheel side member 2 connected to the wheel side.

The vehicle body side member 1 has a cylindrical inner pillar 1a and a bottomed cylindrical outer cylinder 1b provided at the axial center as shown in the figure.
Thus, a double structure having a gap 1c between them is formed. The inner pillar 1a is a rod portion 1 formed on the upper portion.
It is integrally formed with the outer cylinder 1b by screwing d into a screw hole 1f formed in the bottom of the outer cylinder 1b, and the tip of the rod portion 1d projects to the upper surface side of the bottom of the outer cylinder 1b. The bolt member 1e is formed in this state. The lower half of the cylinder 1a and the outer cylinder 1b are formed of a magnetic outer cylinder portion 11 and a magnetic cylinder portion 12 made of a ferromagnetic material, and the other portions are made of a non-magnetic material. The bolt member 1e is for mounting on the vehicle body.

Then, on the inner peripheral surface of the magnetic outer cylindrical portion 11, an upper outer permanent magnet 1j and a lower outer permanent magnet 1k are provided at a central portion with a predetermined space H, and the inner peripheral surface of the magnetic column portion 12 is provided. By providing the upper inner permanent magnet 1m and the lower inner permanent magnet 1n with a predetermined space H in the center, the upper outer permanent magnet 1j, the upper inner permanent magnet 1m, and the lower outer permanent magnet 1k and the lower An upper magnetic field forming portion 1g in which a gap between the inner permanent magnet 1n and the gap portion 1c is narrowed.
And a lower magnetic field forming portion 1h are formed. That is, based on the set polarities of the permanent magnets 1j, 1k, 1m, and 1n, the magnetic path A shown by the alternate long and short dash line in the drawing is formed,
In the upper and lower magnetic field forming portions 1g and 1h, the gap portion 1
Magnetic fields B ₁ and B ₂ in which magnetic fluxes fly in c are formed, and the directions of the respective magnetic fluxes are opposite. Incidentally, in this embodiment, the upper outer permanent magnet 1j and the upper inner permanent magnet 1m are set to have N poles on the inner peripheral side, and the lower outer permanent magnet 1k and the lower inner permanent magnet 1n are set to have S poles on the inner peripheral side. Has been done. Therefore, the permanent magnets 1j, 1k, 1m, 1n, the magnetic outer cylinder portion 11 and the magnetic cylinder portion 12 constitute the magnetic field forming means in the claims.

On the other hand, the wheel side member 2 is formed in a bottomed cylindrical shape having a bottom portion at its lower end portion, and a bolt 2a for attaching to the wheel side is provided upright at the lower end portion. Then, the wheel side member 2 is inserted into the gap portion 1c from the opening end portion,
A coil 3 is wound around the outer periphery of the vehicle body-side member 1 with a minute gap. The coil 3 includes first to sixth coils 3a along the relative movement directions of the members 1 and 2.
~ 3f divided into six parts, each coil 3a ~ 3f
Is wound around one bobbin 3g. And
The length of each of the coils 3a to 3f is such that the upper outer permanent magnet 1j (upper inner permanent magnet 1m) and the lower outer permanent magnet 1 are
k (the lower inner permanent magnet 1n) and the space H formed between
It is formed shorter. In addition, bearings 4a, 4b, and 4b are provided between the wheel side member 2 and the inner column 1a and the outer cylinder 1b.
4c is provided.

Hall elements 7a to 7e constituting the magnetic flux sensor 7 are attached to the positions of the coils 3a to 3f. The Hall elements 7a to 7e move together with the coil 3 in the gap 1c,
The output voltage is changed in response to the magnetic fluxes of the magnetic fields B ₁ and B ₂ , and in this embodiment, as shown in FIG. 2, with respect to the change of the magnetic flux density G, a certain predetermined magnetic flux density range (hysteresis) is obtained. one-way Hall element 7a which the output voltage V a g is abruptly changed between V ₁ ~V ₂ is used.

The coil 3 and the magnetic flux sensor 7 are connected to the control circuit 6. That is, the control circuit 6 is formed so as to energize or short-circuit the terminals of the coils 3a to 3f based on the input signals from the magnetic flux sensor 7, the acceleration sensor 8 and the load sensor 9. Further, a variable resistor is connected to these coils 3 at the time of energization and short circuit. By the way,
When the coil 3 is short-circuited, when the suspension unit S strokes, the coil 3 moves in a direction traversing the magnetic fields B ₁ and B ₂ of the magnetic field forming portions 1g and 1h, so that the coil 3 is proportional to the relative speed. The induced current is generated, and the induced current consumes electric power by the variable resistance, so that the moving energy is reduced, that is, the damping force is obtained. On the other hand, when the coil 3 is energized and driven, the energization is performed in a direction crossing the magnetic fields B ₁ and B ₂ of both the magnetic field forming portions 1g and 1h, so that the suspension unit S is driven in accordance with the energizing direction strength. The driving force acts in the extending direction and the driving force acts in the pressure direction. Incidentally, in the present embodiment for energizing the coil 3 is configured to perform control such that only energizing the coil in each field B _1, B _2, and both the magnetic field B _1, B _Since the directions of ₂ are opposite to each other, the upper magnetic field forming portion 1g of the coils 3a to 3f is
The coil in the magnetic field B ₁ and the coil in the magnetic field B ₂ of the lower magnetic field forming portion 1h are configured so that the energizing directions are opposite to each other.

The acceleration sensor 8 is attached to the vehicle body to detect the vertical acceleration of the vehicle body, and is provided for obtaining the vehicle body speed in the vertical direction. The load sensor 9 is provided at a mounting portion of the vehicle body side member 1 of the suspension unit S and is mounted on the suspension unit S.
It detects the input load from the vehicle and is provided to obtain the relative speed between the vehicle body side and the wheel side. The arithmetic unit of the control circuit 6 controls the vehicle posture to be kept constant based on the input from the magnetic flux sensor 7, and controls the damping force based on the input signals from the acceleration sensor 8 and the load sensor 9. Is becoming

Next, the operation of the embodiment will be described.
In the electromagnetic suspension device having the above-described configuration, the suspension unit S is provided between each of the four wheels of the automobile and the vehicle body, and the control circuit 6 and the sensors 7, 8, 9 are provided.
Also, each suspension unit S is provided and used.

(A) At the time of damping force control When the damping force is generated in the suspension unit S according to the running condition of the vehicle, the coils 3a to 3f are controlled.
Short circuit. Then, depending on the relative speed between the vehicle body side member 1 and the wheel side member 2, that is, the upper and lower magnetic field forming portions 1
A damping force (control force) is generated in direct proportion to the speed of the coil 3 passing through g and 1h. As described above, when the damping force control is performed, the damping force (control force) can be obtained without energizing the coil 3, that is, without consuming electric power at all.

(C) Attitude control At the time of attitude control, the coil 3 is energized in accordance with the vehicle status obtained based on the inputs from the sensors 7 to 9 so that the suspension unit S is axially moved upward or downward. Attitude control is performed by generating a driving force (control force) on the. in this case,
The direction and strength of the driving force (control force) change depending on the direction of energization and the power. Such a driving force (control force)
For example, by causing the vehicle height change to cancel
The vehicle height can be kept constant. Further, by generating the driving force (control force) in a direction that cancels the road surface input transmitted to the vehicle body via the suspension unit S, the road surface input to the vehicle body is canceled and a constant vehicle body posture is obtained.

As described above, in the apparatus of the embodiment of the present invention, the magnetic flux sensor 7 such as the hall element 7a is used as a means for detecting the stroke position of the suspension unit S, thereby increasing the basic length of the suspension. The feature is that the stroke position of the suspension unit S can be detected without needing to do so, and this increases the degree of freedom in space when mounted on a vehicle.

Further, in the apparatus of the embodiment of the present invention, the magnetic field B for flying magnetic flux in the radial direction in the gap portion 1c of the vehicle body side member 1
_The magnetic field B is formed on the wheel-side member 2 that forms the magnetic path A having ₁ and B ₂ and is inserted into the gap 1c so as to be relatively movable.
_{Since the} coil 3 is provided so as to traverse ₁ and B ₂ , there is no need to lengthen the magnetic path A even when the stroke of the suspension unit S is increased, and therefore, a constant and sufficient stroke is obtained regardless of the stroke size. It has the feature of being able to obtain control power.

Further, in the embodiment, by controlling so as to energize only the coil portion required to generate the control force (driving force) among the six divided coils 3a to 3f, the consumption is reduced. It has a feature that it can save power.

Next, another embodiment of the present invention shown in FIGS. 3 to 7 will be described. In the description of these embodiments, the same components as those in the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted. Only the differences will be described.

FIG. 3 is a sectional view showing an essential part of an electromagnetic suspension system according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in the mounting structure of the Hall element. That is, on the outer peripheral surface of the bobbin 30g around which each coil 30 is wound,
Vertical groove 20 in the stroke direction of the suspension unit S
Is formed, and the Hall element 70 is mounted in the vertical groove 20 so as to be arranged at the central position of each coil 30.

Next, FIG. 4 is a sectional view showing an essential part of an electromagnetic suspension system according to a third embodiment of the present invention.
In the embodiment, the coil 3 is replaced by 15 of the first to fifteenth coils 31.
In addition to being divided into a large number of parts, the hall element 71 is arranged at the central position of all the coils 31. In this embodiment, as shown in FIG. 5, as the Hall element 71, a proportional output type in which the change in the output voltage V is proportional to the change in the magnetic flux density G is used. When the voltage becomes equal to or higher than a predetermined voltage V ₃ (V ≧ V ₃ ), the coil 31 corresponding to the position where the Hall element 71 is provided is energized, and when the voltage becomes equal to or lower than the predetermined voltage V ₃ (V <V ₃ ) the Hall element. Energization control is performed such that the energization of the coil 31 corresponding to 71 is released.

Therefore, in this embodiment, by dividing the coil 3 into a large number, the useless energization range to the coil 3 is reduced, and thus power consumption can be saved and the upper and lower magnets 1j (1m) can be saved. ), 1k (1n) separation distance H can be narrowed, so that the facing area (area of magnetic field forming portions 1g, 1h) between the inner and outer magnets 1m (1n) and 1J (1k) should be increased accordingly. And
Since the magnetic resistance of the magnetic path A can be reduced, the control force can be strengthened.

Next, FIG. 6 is a sectional view showing an essential part of an electromagnetic suspension device according to a fourth embodiment of the present invention.
The apparatus according to the embodiment has an upper magnetic field forming unit 1g of all the coils 32.
The Hall element 72 is arranged only at the position corresponding to the coil 32 in the range passing through the magnetic field B _{1 of} the above. That is, in this embodiment, by detecting the coils 32 in the upper magnetic field forming unit 1g, the coils 32 in the lower magnetic field forming unit 1h are calculated from the preset positional relationship, and thus all the coils 32 are calculated. The energization control is performed. Incidentally, the Hall element 72 of this embodiment
As shown in FIG. 7, a type in which the output voltage V changes abruptly between V _{4 and} V ₅ with respect to a change in the magnetic flux density G at a predetermined magnetic flux density is used. Therefore, in the fourth embodiment, the number of Hall elements 72 installed can be reduced,
This has the feature that cost can be reduced.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the concrete constitution of the present invention is not limited to these embodiments. For example, in the embodiment, an example in which the vehicle body side member is formed in a double structure is shown, but the wheel side member and the vehicle body side of the embodiment device may be reversed and the wheel side member may be formed in a double structure. .. Further, in the embodiment, the case where the magnetic path having the upper and lower two sets of magnetic fields is formed has been shown, but the magnetic field for flying the magnetic flux may form one magnetic path. Further, in the embodiment, the magnetic field is formed by the permanent magnet, but the magnetic field may be formed by the electromagnet. Further, in the embodiment, the example in which the Hall element is used as the magnetic flux sensor is shown, but a magnetoresistive element or the like can be used in addition to this. Further, in the embodiment, both magnets and coils that form the magnetic field are formed in an annular shape and are arranged concentrically, but the shapes and arrangement relationship of both magnets and coils can be set arbitrarily. By changing the number of turns of each coil depending on the stroke position, the control force can be arbitrarily changed depending on the stroke position.

[0032]

As described above, in the electromagnetic suspension device of the present invention, the magnetic flux sensor capable of detecting the magnetic flux together with the coil is provided in at least a portion of the member inserted in the gap portion which is disposed in the magnetic field. Since a plurality of are arranged at a predetermined interval in the relative movement direction, the relative position between the vehicle body and the wheels (stroke position of the suspension unit) can be detected without increasing the basic length of the suspension. It is possible to obtain the effect that the above can be achieved, and in addition, it is possible to obtain the effect that the structure can be simplified.

[Brief description of drawings]

FIG. 1 is an overall view showing an electromagnetic suspension device of a first embodiment of the present invention.

FIG. 2 is an output voltage characteristic diagram with respect to the magnetic flux density of the Hall element used in the first embodiment device.

FIG. 3 is an enlarged cross-sectional view showing a main part of a second embodiment device of the present invention.

FIG. 4 is a sectional view showing a main part of a device according to a third embodiment of the present invention.

FIG. 5 is a characteristic diagram of output voltage with respect to magnetic flux density of the Hall element used in the device of the third embodiment.

FIG. 6 is an enlarged cross-sectional view showing a main part of a device according to a fourth embodiment of the present invention.

FIG. 7 is an output voltage characteristic diagram with respect to the magnetic flux density of the Hall element used in the fourth embodiment device.

[Explanation of symbols]

S Suspension unit A Magnetic path B ₁ Magnetic field B ₂ Magnetic field 1 Vehicle body side member 1c Gap 1j Upper outer permanent magnet (magnetic field forming means) 1k Lower outer permanent magnet (magnetic field forming means) 1m Upper inner permanent magnet (magnetic field forming means) 1n Lower inner permanent magnet (magnetic field forming means) 2 Wheel side member 3 Coil 7a Hall element (magnetic flux sensor) 11 Magnetic outer cylinder part (magnetic field forming means) 12 Magnetic cylinder part (magnetic field forming means) 70 Hall element (magnetic flux sensor) 71 holes Element (magnetic flux sensor) 72 Hall element (magnetic flux sensor)

Claims (1)

[Claims] 1. A suspension unit interposed between a vehicle body and a wheel is formed of a vehicle body side member and a wheel side member that are relatively movable, and one of the vehicle body side member and the wheel side member is relatively moved. A double structure having a gap portion along the direction, and the other is inserted into the gap portion, and a direction perpendicular to the relative movement direction in the gap portion by the magnetic field forming means in the double structure portion. A magnetic field in which the magnetic flux flies is formed, and a coil is wound in a direction orthogonal to the relative movement direction and the magnetic field direction at least at a portion of the member on the side inserted into the gap, which is disposed in the magnetic field, and the magnetic flux An electromagnetic suspension device, wherein a plurality of magnetic flux sensors capable of detecting the above are arranged at predetermined intervals in the relative movement direction.