JP2996258B2 - Electromagnetic suspension device - Google Patents

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, an electromagnetic suspension device described in Japanese Patent Application Laid-Open No. 2-37016 is known.

[0003] In this conventional apparatus, an outer cylinder formed in a cylindrical shape and fixed to a wheel side is provided between a vehicle body and a wheel, and slidably provided in the outer cylinder and attached to the vehicle body side. A suspension unit having a rod is provided,
In the outer cylinder, a cylindrical permanent magnet is fixed to the outer periphery of the rod, and a coil is fixed to the inner peripheral side of the outer cylinder facing the permanent magnet. In order to form a strong radial magnetic field in the annular gap formed between the outer cylinder and the circumference, a magnetic path is formed by the outer cylinder and the rod.

[0004] By controlling the direction of current flow and the current to the coil, an axial control force (electromagnetic force) of the coil of the suspension unit is generated, for example, control is performed to keep the vehicle height constant.

[0005]

However, such a conventional electromagnetic suspension device uses a cylindrical permanent magnet to generate a magnetic field in a radial direction.
There were the following problems. That is, when the cylindrical permanent magnet is radially magnetized so that the inner peripheral surface side is the S pole and the outer peripheral side is the N pole, as shown in FIG. By arranging S magnetic poles and arranging N magnetic poles on both upper and lower ends of the cylindrical magnetic material 51 so as to face each other in the axial direction, from the inner circumferential direction of the cylindrical magnetic material 51 to the outer circumferential direction. A radial radial magnetic field B is formed, whereby the cylindrical magnetic material 51 is radially magnetized. However, as described above, since the magnetic flux direction of the magnetic field B is non-parallel in the circumferential direction, a difference occurs in the magnetic flux density between the inner circumferential side and the outer circumferential side of the cylindrical magnetic material 51. Therefore, it is difficult to perform strong magnetization due to deterioration of the electromagnetic suspension, and therefore, it is impossible to generate a strong control force (electromagnetic force) as an electromagnetic suspension device.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an electromagnetic suspension device that can generate a strong control force (electromagnetic force).

[0007]

According to the present invention, the above object is achieved by using, as a ring-shaped permanent magnet, a magnet that is magnetized by a parallel magnetic field while being divided into a plurality in the circumferential direction.

That is, according to the present invention, a suspension unit interposed between a vehicle body and a wheel is formed by a vehicle body-side member and a wheel-side member which are formed to be relatively movable, and both the vehicle-body-side and the wheel-side member are provided. Is provided with an annular permanent magnet that forms a magnetic field in a radial direction that intersects the relative movement direction of both the vehicle-body-side and wheel-side members. And a coil is wound around the insertion portion in a direction intersecting the relative movement direction and the magnetic field direction, and the annular permanent magnet is divided into a plurality in the circumferential direction. In a state of being magnetized by a parallel magnetic field in a state in which the magnetic field is in a state of being held.

[0009]

In the electromagnetic suspension device of the present invention, when the coil is energized, the coil is energized in a direction intersecting the relative movement direction (stroke direction of the suspension unit) of both the vehicle body side and the wheel side members and the magnetic field direction. A driving force (electromagnetic force) is generated in a direction intersecting both the direction and the energizing direction, that is, in the stroke direction of the suspension unit.

Accordingly, the suspension unit is extended or shortened by the driving force. Therefore, the drive force acts against the input to the suspension unit, and the stroke of the suspension unit due to the external input can be suppressed.

Further, the annular permanent magnet which forms the magnetic field in the radial direction is separately magnetized in a parallel magnetic field in a state of being divided into a plurality in the circumferential direction in advance, so that the magnetic flux density in the inner and outer circumferential directions is made uniform. Efficient magnetization in the set state is performed. Therefore, a strong control force (electromagnetic force) is generated by the strong radial magnetic field.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is an overall view showing the configuration of an electromagnetic suspension device according to an embodiment of the present invention. In this figure, S
Indicates a suspension unit. The suspension unit S includes a vehicle body-side member 1 connected to the vehicle body.
And a wheel-side member 2 connected to the wheel side.

As shown in the figure, the vehicle-body-side member 1 includes an inner cylinder 1a and an outer cylinder, the upper end of which is screwed and integrated with the outer periphery of a canopy plate 1f and the central cylindrical portion 1p of the canopy plate 1f. 1b and 1b to form an inner / outer double-covered cylindrical structure having a cylindrical gap 1c between them.

A lower half of the inner cylinder 1a and the outer cylinder 1b is formed by a magnetic inner cylinder 12 and a magnetic outer cylinder 11 made of a ferromagnetic material, and the other members are made of a non-magnetic material. ing. In addition, the outer peripheral side of the magnetic outer cylindrical portion 11 is formed in a tapered shape so that the thickness becomes smaller toward the upper and lower ends, and the magnetic inner cylindrical portion 12 is formed.
The inner peripheral side is formed in a tapered shape so that the thickness becomes smaller toward the upper and lower ends.

On the inner peripheral surface of the magnetic outer cylinder portion 11, an upper outer permanent magnet 1j and a lower outer permanent magnet 1k are provided at a central portion at a predetermined interval H, and the inner peripheral surface of the magnetic inner cylinder portion 12 is provided. The surface is provided with an upper inner permanent magnet 1m and a lower inner permanent magnet 1n while maintaining a predetermined interval H in the center, thereby forming an upper outer permanent magnet 1j, an upper inner permanent magnet 1m, and a lower outer permanent magnet 1k. Magnetic field forming portion 1g in which the gap of the gap 1c is narrowed between the upper magnetic field forming portion 1g and the lower inner permanent magnet 1n.
And a lower magnetic field forming portion 1h.

Each of the permanent magnets 1j, 1k, 1m, 1n
As shown in FIG. 2 and FIG. 3, the magnetic inner cylinder portion 12 and the magnetic outer cylinder portion 11 each of which is bonded are divided vertically into four pieces in the circumferential direction, and the magnetic field direction is the circumferential direction. The polar directions of the two permanent magnets 1j, 1k, 1m, 1n are set so as to be in the radial direction with the gap 1c interposed therebetween.
The magnetization of each of the permanent magnets 1j, 1k, 1m, 1n is performed for each of the pieces. Specifically,
As shown in FIGS. 4 and 5, for each piece, which is divided into four, the magnetization is performed by forming a parallel magnetic field B ₀ towards its inner periphery direction. That is, in this embodiment, the magnetizing operation of each of the permanent magnets 1j, 1k, 1m, 1n is performed in a state of being integrated with the magnetic inner cylinder 12 and the magnetic outer cylinder 11.

The pieces that have been magnetized as described above are assembled to the vehicle body-side member 1 in a state where they are combined in a ring shape as shown in FIGS. That is, the upper end of the magnetic outer cylinder portion 11 is attached to the inner peripheral side of the lower end of the outer cylinder 1b, and each piece is screwed to the outer cylinder 1 with the screw 14.
b, and at the lower end thereof, an annular connecting member 15 having an L-shaped cross section is attached to the outer periphery thereof, and each piece is fixed to the annular fixing member 15 with a screw 16 so that the outer cylinder 1b can be fixed. Assembly is performed.

On the other hand, the magnetic inner cylinder portion 12 has annular connecting members 17 and 1 having an L-shaped cross section on its inner peripheral sides at both upper and lower ends.
8 and each piece is connected to each of the annular connecting members 1.
It is assembled in a ring shape by fixing to screws 7 and 18 from above and below with screws 19 and 20, respectively. The inner cylinder 1a is assembled to the inner cylinder 1a by screwing the inner periphery of the upper annular connecting member 17 into a small-diameter threaded portion 1d formed at the tip of the inner cylinder 1a. A guide member 21 is screwed onto the inner periphery of the lower annular connecting member 18.

In the upper magnetic field forming section 1g and the lower magnetic field forming section 1h, the upper outer permanent magnet 1j and the upper inner permanent magnet 1m have N poles on the inner peripheral side so that the magnetic field directions are opposite to each other. , The lower outer permanent magnet 1k and the lower inner permanent magnet 1n are set such that the inner peripheral side is an S pole. That is, the lower half of the inner cylinder 1a and the outer cylinder 1b is formed by the magnetic outer cylinder portion 11 and the magnetic inner cylinder portion 12 made of a ferromagnetic material.
1k, 1m, and 1n form a magnetic path A indicated by a dashed line in the figure. In the upper and lower magnetic field forming portions 1g and 1h, the magnetic fields B ₁ and B _{2 in the} radial direction and opposite to each other are formed.
Are formed.

At the center of the upper surface of the canopy plate 1f, a bolt member 1e for attachment to the vehicle body is formed so as to protrude.

On the other hand, the wheel-side member 2 is formed in a bottomed cylindrical shape having a bottom at the lower end, and a bolt 2a for mounting to the wheel is provided at the lower end. The wheel-side member 2 is inserted into the gap 1c from the opening end,
A coil 3 is wound around the outer periphery of the body 3 with a small gap with respect to the vehicle body side member 1.

[0023] The coil 3 is divided into a plurality of coils 3 ₁ to 3 _n along a relative movement direction of the both members 1, each coil 3 ₁ to 3 _n are wound on a single bobbin 3k . The length of each of the coils 3 _{1 to} 3 _n alone is the distance H formed between the upper outer permanent magnet 1j (upper inner permanent magnet 1m) and the lower outer permanent magnet 1k (lower inner permanent magnet 1n). It is formed shorter.

The inner peripheral side of the upper end of the wheel side member 2 and the outer peripheral side of the guide member 21 which is the vehicle body side member 1
Bearings 4a and 4b are provided for guiding sliding between the vehicle body side and wheel side members 1 and 2 respectively.

Further, the bobbin 3k of each coil 3 ₁ to 3 _n mutual position, (not shown) Hall element as a stroke sensor 7 is mounted. The Hall element changes its output voltage in response to the magnetic fluxes of the magnetic fields B ₁ and B ₂ by relatively moving in the gap 1 c together with the coil 3. By detecting this output voltage, the Hall element forming portions 1g, each coil for 1h 3 ₁ to 3 _n
, That is, the stroke position of the suspension unit S.

The coil 3 is connected to a control circuit 6. That is, the control circuit 6, or current between terminals of the coil 3 ₁ to 3 _n, is formed to be capable of or short circuit, further, when the current and during a short-circuit, the variable with respect to the coils 3 It is configured to connect a resistor.

Incidentally, when the coil 3 is short-circuited, when the suspension unit S makes a stroke, the coil 3 moves in a direction crossing the magnetic fields B ₁ , B ₂ of the two magnetic field forming portions 1g, 1h, so that the coil 3 An induced current proportional to the relative speed occurs, and this induced current consumes power through a variable resistor, thereby reducing the moving energy.
That is, a damping force is obtained.

On the other hand, when the coil 3 is energized and driven, energization is performed in a direction crossing the magnetic fields B ₁ and B ₂ of the two magnetic field forming portions 1 g and 1 h, so that the suspension is controlled in accordance with the direction of the energization. A driving force acts in the extension direction of the unit S or a driving force acts in the pressure direction.

Further, the control circuit 6, based on said input signal from the stroke sensor 7, the coil 3 ₁ to 3 in accordance with the stroke position of the suspension unit S
There is provided an energization switching means 6a for individually turning ON / OFF the energization for _n and switching control of the energization direction.

That is, the energization switching means 6a controls each magnetic field B
_1, together with the control as only energizing the coil with the B ₂ in is performed, since the directions of both the magnetic field B _1, B ₂ is in opposite directions, the action of the drive force in both the magnetic field forming unit 1 g, 1h to match the direction, each coil 3 ₁ to 3
Of _n, the upper magnetic field forming unit coil and the lower magnetic field forming unit 1h each coil 3 ₁ to 3 such that current direction in the coil in a magnetic field B ₂ in the opposite directions to each other in a magnetic field B ₁ of 1g
with energization of the _n is made, in which switching control of the current direction of each coil 3 ₁ to 3 _n is performed in accordance with the stroke position of the suspension unit S.

The control circuit 6 performs control based on inputs from the stroke sensor 7, the acceleration sensor 8, and the load sensor 9.

The acceleration sensor 8 is mounted on the vehicle body to detect the vertical acceleration of the vehicle body, and is provided for obtaining the vehicle speed in the vertical direction.

The load sensor 9 is provided at a portion of the suspension unit S where the vehicle body-side member 1 is mounted, and detects an input load from the suspension unit S.
It is provided to determine the relative speed between the vehicle body side and the wheel side.

The arithmetic unit of the control circuit 6 performs control to keep the vehicle attitude constant based on the input from the stroke sensor 7, and controls the acceleration sensor 8 and the load sensor 9.
Is configured to perform damping force control based on an input signal from the controller.

Next, the operation of the embodiment will be described.

In the electromagnetic suspension device having the above-described structure, 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 also provided for each suspension unit S. Is used.

(A) Damping Force Control In order to generate a damping force in the suspension unit S according to the running condition of the vehicle, each of the coils 3 _{1 to} 3 _n
Short circuit. Then, according to the relative speed between the vehicle body side member 1 and the wheel side member 2, that is, both upper and lower magnetic field forming units 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 performing the damping force control, the coil 3 is not energized, that is, the damping force (control force) can be obtained without consuming any power.

(B) Attitude Control At the time of attitude control, the coil 3 is energized according to the vehicle situation obtained based on the input from each of the sensors 7 to 9 and the suspension unit S is turned upward or downward in the axial direction. To generate a driving force (control force) to perform attitude control. In this case, the direction and strength of the driving force (control force) change depending on the direction of power supply and the power. Such driving force (control force)
Is generated in such a direction as to cancel the change in vehicle height, thereby making the vehicle height constant. Also, by generating the driving force (control force) in a direction to cancel the road surface input transmitted to the vehicle body via the suspension unit S,
By canceling the road surface input to the vehicle body, a constant vehicle body posture can be obtained.

[0039] As described above, in the present invention embodiment apparatus, annular permanent magnet 1j that forms a magnetic field B _1, B ₂ in the radial direction, 1k, 1 m, a 1n, divided into four in advance circumferential direction By individually magnetizing these in the parallel magnetic field B ₀ , efficient magnetization can be performed in a state where the magnetic flux density in the inner and outer peripheral directions is uniform, and therefore, the strong radial magnetic field B 0 has a characteristic of _1, a strong control force by B ₂ (the electromagnetic force) can be generated.

When the permanent magnet is assembled to the magnetic material after the magnetization process, the permanent magnet is demagnetized, and the demagnetizing effect increases as the volume difference between the permanent magnet and the magnetic material increases. In the apparatus, each of the divided permanent magnets 1j, 1k, 1m, and 1n is magnetized in a state of being bonded to each of the divided magnetic inner cylinder portions 12 and the magnetic outer cylinder portions 11, thereby reducing the amount after the magnetization process. It is characterized in that the number of magnets can be reduced, and hence the thickness of the permanent magnets 1j, 1k, 1m, 1n in the radial direction can be reduced, and a magnetic field having a high magnetic flux density can be formed at low cost.

Further, in the apparatus of the present invention, the magnetic outer cylindrical portion 11 and the magnetic inner cylindrical portion 12 are formed so that the thickness thereof is gradually reduced so that the magnetic resistance becomes smaller in the vertical direction. Variations in the magnetic resistance due to the length of the magnetic path A are reduced, whereby the magnetic field forming portions 1g, 1h
Thus, the degree of non-uniformity of the magnetic flux densities of the magnetic fields B ₁ and B ₂ formed can be reduced.

In the apparatus according to the present invention, a magnetic flux sensor such as a Hall element is used as the stroke sensor 7 for detecting the stroke position of the suspension unit S, so that the suspension can be extended without increasing the basic length of the suspension. The stroke position of the unit S can be detected, which has a feature that the degree of freedom in space when mounted on a vehicle is increased.

Further, in performing the damping force control and the posture control, in the apparatus of the present invention, the gap 1c is formed and the magnetic outer cylinder 11 and the magnetic cylinder 12 facing each other are moved relative to each other. Two magnets (an upper outer permanent magnet 1j, a lower outer permanent magnet 1, and an upper inner permanent magnet) which are separated in the same direction and oppose each other to form magnetic fields B ₁ and B ₂ in opposite directions with the gap 1c interposed therebetween. 1m, lower inner permanent magnet 1
de and n), to form a magnetic path A over the two magnetic fields B _1, B _2, and the energizing direction for each coil 3 ₁ to 3 _n which is divided into a plurality of intersecting with one of the magnetic field B ₁ due to a structure having a current switching means for switching so that in the opposite directions between the coil intersects the coil and the other magnetic field B _2, the need to increase the magnetic path a, even if increasing the stroke of the suspension unit S is Therefore, there is a characteristic that a constant and sufficient control force can be obtained regardless of the magnitude of the stroke.

In the embodiment, of the plurality of divided coils 3 _{1 to} 3 _n , control is performed such that only a coil portion necessary for generating a control force (driving force) is energized. The feature is that power consumption can be saved.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration of the present invention is not limited to these embodiments.

For example, in the embodiment, an example is shown in which a radial magnetic field is formed between the double structural portions formed on the vehicle body side member. However, as in the conventional apparatus, between the outer cylinder and the rod which move relatively to each other. A radial magnetic field may be formed. Further, in the embodiment, the case where the magnetic path is formed between the upper and lower two sets of the magnetic field forming parts has been described, but the magnetic path may be formed by one set of the magnetic field forming part and the magnetic member. . Further, in the embodiment, the permanent magnets are provided in both the inner and outer directions in order to generate the radial magnetic field, but the permanent magnets may be only one of the inner and outer sides. 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.

[0047]

As described above, in the electromagnetic suspension device of the present invention, the annular permanent magnet which forms the magnetic field in the radial direction is divided into a plurality in the circumferential direction, and is magnetized. In this case, since the magnets are magnetized by a parallel magnetic field, the magnets are efficiently magnetized in a state where the magnetic flux density in the inner and outer peripheral directions of the permanent magnet is uniform, and therefore, strong control by a strong radial magnetic field is performed. An effect that a force (electromagnetic force) can be generated is obtained.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a divided state of an inner permanent magnet and a magnetic inner cylinder which are main parts of the embodiment device.

FIG. 3 is a perspective view showing a divided state of an outer permanent magnet and a magnetic outer cylinder which are main parts of the embodiment device.

FIG. 4 is an explanatory view showing a method of magnetizing an outer permanent magnet in the apparatus according to the embodiment.

FIG. 5 is an explanatory diagram showing a method of magnetizing an inner permanent magnet in the apparatus according to the embodiment.

FIG. 6 is an explanatory view showing a method of magnetizing a permanent magnet in a conventional device.

[Explanation of symbols]

S Suspension unit B ₀ Parallel magnetic field B ₁ Magnetic field B ₂ Magnetic field 1 Body side member 1j Upper outer permanent magnet 1k Lower outer permanent magnet 1m Upper inner permanent magnet 1n Lower inner permanent magnet 2 Wheel side member 3 Coil

Claims (1)

(57) [Claims] 1. A suspension unit interposed between a vehicle body and wheels is formed by a vehicle-side member and a wheel-side member formed to be relatively movable, and one of the vehicle-body-side and wheel-side members is provided. Is provided with an annular permanent magnet that forms a magnetic field in the radial direction that intersects the relative movement direction of both the vehicle body-side and wheel-side members. A coil is wound around this insertion portion in a direction intersecting the relative movement direction and the magnetic field direction, and the annular permanent magnet is parallelly divided into a plurality in the circumferential direction. An electromagnetic suspension device which is magnetized by a magnetic field.