JP2549062Y2 - 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. As shown in FIG. 3, this conventional device is provided between a vehicle body and wheels, an outer cylinder 51 formed in a cylindrical shape and fixed to the vehicle body, and slidably provided in the outer cylinder 51. A suspension unit having a rod 52 attached to the wheel side;
Inside, a permanent magnet 53 is fixed to the outer circumference of the rod 52, and a coil 54 is fixed to the inner circumference side of the outer cylinder 51 facing the permanent magnet 53, and the outer circumference of the permanent magnet 53 and the outer cylinder 51 are fixed. In order to form a strong magnetic field B in the annular gap 55 formed between the outer cylinder 51 and the inner circumference, a magnetic path surrounding the outer cylinder 51 and the rod 52 is formed.

[0003] By controlling the direction of current supply to the coil 54 and the current, an axial control force (electromagnetic force) of the suspension is generated, and for example, control is performed to keep the vehicle height constant.

[0004] In Fig. 3, broken lines indicate isomagnetic flux density lines.

[0005]

However, such a conventional electromagnetic suspension device has the following problems.

That is, even if the magnetic force of the permanent magnet 53 itself is strong, if the cross-sectional area of the magnetic path is small, magnetic saturation occurs at the minimum cross-sectional area, so that a strong driving force (electromagnetic force) due to the strong magnetic field B is generated. In order to generate the magnetic field, it is necessary to enlarge the minimum sectional area of the magnetic path. However, in the conventional structure, the thickness (radius) of the rod 52 constituting the magnetic path constituting member in the magnetic field forming direction is the same at the portion provided to be overlapped with the permanent magnet 53 and at other portions. As indicated by the density line (dashed line), the effective cross-sectional area of the magnetic path decreases as the distance from the upper and lower ends of the permanent magnet decreases. Therefore, in order to prevent magnetic saturation at the minimum cross-sectional area, the rod 5
It is necessary to enlarge the diameter of the suspension unit 2 itself, and therefore, the outer diameter of the suspension unit S becomes large, which is a space limitation when mounted on a vehicle.

The present invention has been made in consideration of the above-mentioned problem, and a sufficient magnetic path cross-sectional area is ensured without increasing the outer diameter of the suspension unit to obtain a driving force (magnetic force) due to magnetic saturation. It is an object of the present invention to provide an electromagnetic suspension device capable of preventing a decrease in the above.

[0008]

According to the present invention, in order to achieve the above object, a suspension unit interposed between a vehicle body and a wheel includes a vehicle body-side member and a wheel-side member formed to be relatively movable. A permanent magnet that forms a magnetic field in a direction that intersects the relative movement direction of the two members, and a part of the permanent magnet that forms a magnetic path of the magnetic field. A magnetic path forming member provided on the surface opposite to the magnetic field forming direction is provided, and the other of the vehicle body side and wheel side members can move in the magnetic field along the relative movement direction of the two. A thick portion protruding in the thickness direction of the permanent magnet is formed in a magnetic path forming member portion other than a portion provided with a coil and being provided so as to overlap with the permanent magnet. The thickness gradually increases as the distance increases in the direction of road formation And a means of tapered portion is formed.

[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 power supply direction and the power supply direction, that is, along the stroke direction of the suspension unit.

Accordingly, the suspension unit is extended or shortened by the driving force.

Thus, the stroke of the suspension unit due to the external input can be suppressed by acting the driving force against the input to the suspension unit.

In addition, since the thick portion protruding in the thickness direction of the permanent magnet is formed in the magnetic path forming member other than the portion provided to overlap with the permanent magnet, the outer diameter of the suspension unit is increased. Without this, it is possible to secure a sufficient magnetic path cross-sectional area and prevent a reduction in driving force (electromagnetic force) due to magnetic saturation.

Further, since the thickness of the magnetic path forming member is formed with a tapered portion whose thickness gradually increases as the distance from the end face of the permanent magnet in the magnetic path forming direction increases, the thickness of the permanent magnet and the thickness of the permanent magnet are increased. Leakage of magnetic flux between the parts can be prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

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.

The vehicle body-side member 1 has a cylindrical inner column 1a and a bottomed cylindrical outer cylinder 1b provided at an axial center as shown in the figure.
Thus, a double structure having a gap 1c therebetween is formed. The inner column 1a includes a rod portion 1 formed on an upper portion.
d is screwed into a screw hole 1f formed in the bottom of the outer cylinder 1b to be formed integrally with the outer cylinder 1b, and the tip of the rod 1d protrudes toward the upper surface of the bottom of the outer cylinder 1b. In this state, the bolt member 1e is formed. The lower half of the cylinder 1a and the outer cylinder 1b is formed of a magnetic outer cylinder (magnetic path forming member) 11 and a magnetic inner cylinder (magnetic path forming member) 12 made of a ferromagnetic material. Is formed of a non-magnetic material. And, on the inner peripheral surface of the magnetic outer cylinder portion 11,
The upper outer permanent magnet 1j is held at a predetermined interval H in the center.
And a lower outer permanent magnet 1k.
The upper inner permanent magnet 1j and the upper inner permanent magnet 1j are provided on the inner peripheral surface of the inner permanent magnet 1 by providing the upper inner permanent magnet 1m and the lower inner permanent magnet 1n while maintaining a predetermined interval H at the center.
m, lower outer permanent magnet 1k and lower inner permanent magnet 1
An upper magnetic field forming part 1g and a lower magnetic field forming part 1h, in which the distance between the gaps 1c is reduced, are formed between the upper magnetic field forming part 1g and the lower magnetic field forming part 1h.

Further, the magnetic outer cylinder portion 11 is located in the inner circumferential direction more than the magnetic field forming portions 1g and 1h in which the upper outer permanent magnet 1j and the lower outer permanent magnet 1k are provided in a predetermined interval H. A thick portion 11a is formed, and both end portions of the thick portion 11a are connected to both permanent magnets 1j,
1k, the taper portions 11b, 11b are formed such that the thickness gradually increases in the inner circumferential direction from the opposite end surfaces toward the center.
11c is formed. Further, the magnetic inner cylinder portion 12
Is a magnetic field forming unit 1 in which an upper inner permanent magnet 1m and a lower inner permanent magnet 1n are provided so as to overlap with each other at a predetermined interval H.
g, 1h, a thicker portion 12a is formed in the outer peripheral direction than the portion, and both ends of the thicker portion 12a are located at the center from both end faces of the permanent magnets 1m, 1n facing each other. The tapered portions 12b and 12c are formed so that the thickness gradually increases in the outer peripheral direction as it goes. FIG. 2 is an enlarged view of a main part showing details of the tapered portion 12c, and a broken line in the drawing indicates an equal magnetic flux density line.

Further, each of the permanent magnets 1j, 1k, 1m,
1n is divided into four in the circumferential direction, and the polarity directions of the two permanent magnets 1j, 1k, 1m, 1n are set so that the magnetic field direction is the radial direction sandwiching the circumferential gap 1c. ing. In this embodiment, 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 of the upper magnetic field forming unit 1g and the lower magnetic field forming unit 1h are opposite to each other. Lower outer permanent magnet 1
k and the lower inner permanent magnet 1n are set such that the inner peripheral side is an S pole. That is, since the lower half of the cylinder 1a and the outer cylinder 1b is formed by the magnetic outer cylinder 11 and the magnetic inner cylinder 12 made of a ferromagnetic material, the permanent magnets 1j, 1k, 1m, and 1n are used. A magnetic path A indicated by a dashed line in the figure is formed, and in the upper and lower magnetic field forming portions 1g and 1h, the magnetic fields B in the radial direction and in the directions opposite to each other are formed.
₁ and B ₂ are formed. The bolt member 1e
Is for vehicle body mounting.

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 erected 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. The coil 3 includes first to sixth coils 3a along the relative movement direction of the two members 1 and 2.
-3f, and each coil 3a-3f
Are wound around one bobbin 3g. And
The length of each of the coils 3a to 3f alone is the upper outer permanent magnet 1j (upper inner permanent magnet 1m) and the lower outer permanent magnet 1m.
k (lower inner permanent magnet 1n)
It is formed shorter.

Bearings 4a and 4b are provided between the wheel side member 2 and the inner pillar 1a and the outer cylinder 1b.

A bobbin at a position between the coils 3a to 3f is provided with a Hall element (not shown) as a stroke sensor 7. 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 Each coil 3a to 3h for forming portions 1g and 1h
, 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 is formed so as to be able to energize or short-circuit between the terminals of each of the coils 3a to 3f. It is configured to connect. Incidentally, when the coil 3 is short-circuited, when the suspension unit S strokes, 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 relative speed to the coil 3 is increased. Is generated, and the induced current consumes power by the variable resistor, so that the moving energy is reduced, that is, a damping force is obtained. On the other hand, when the coil 3 is energized and driven,
When a current is applied across the magnetic fields B ₁ , B ₂ of the two magnetic field forming portions 1 g, 1 h, a driving force acts on the suspension unit S in the extending direction or the pressure direction in accordance with the direction of the current. Or driving force.

The control circuit 6 individually turns on and off the energization of each of the coils 3a to 3f in accordance with the stroke position of the suspension unit S based on the input signal from the stroke sensor 7, and controls the energization direction. Is provided. That is, the energization switching section 6a, together with the control for energizing only the coils in each field B _1, B within ₂ is performed, since the directions of both the magnetic field B _1, B ₂ is in opposite directions, both the magnetic field forming portion 1g, in order to match the direction of action of the driving force in 1h, among the coils 3a to 3f, a magnetic field B ₂ of the coil and the lower magnetic field forming part 1h which is in the magnetic field B ₁ of the upper magnetic field forming portion 1g The energization to the coils 3a to 3f is performed so that the energization directions to the coils located inside are opposite to each other, and the switching control of the energization direction to the coils 3a to 3f according to the stroke position of the suspension unit S. Is made.

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 attached to 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 where the vehicle body side member 1 of the suspension unit S is mounted, and detects an input load from the suspension unit S. The load sensor 9 is provided to determine a relative speed between the vehicle body side and the wheel side. ing. 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 performs damping force control based on input signals from the acceleration sensor 8 and the load sensor 9. Has become.

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 When the damping force is generated in the suspension unit S in accordance with the running condition of the vehicle, each of the coils 3a to 3f
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 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, a damping force can be obtained without consuming any power.

(B) Attitude Control At the time of attitude control, the coil 3 is energized in accordance with 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 (electromagnetic force) to control the posture. In this case, the direction and the intensity of the driving force change depending on the direction of the energization and the electric power.

By generating such a driving force, for example, in a direction to cancel a change in vehicle height, the vehicle height can be kept constant. Further, by generating the driving force in such a direction as to cancel 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 can be obtained.

As described above, in the device according to the present invention, the upper outer permanent magnet 1j and the lower outer permanent magnet 1k are provided at the predetermined interval H in the magnetic outer cylinder 11 more inwardly than the portion where the upper outer permanent magnet 1k is provided. A thick portion 11a is formed at a predetermined interval H in the magnetic inner cylindrical portion 12.
A thick portion 12 which is thicker in the outer peripheral direction than a portion where the upper inner permanent magnet 1m and the lower inner permanent magnet 1n are provided in an overlapping manner.
2, the minimum effective cross-sectional area of the magnetic path A is increased by the thickness R as shown in FIG. 2, thereby increasing the outer diameter of the suspension unit S without increasing the outer diameter. It has a feature that a sufficient magnetic path cross-sectional area can be secured to prevent a reduction in driving force (electromagnetic force) due to magnetic saturation.

The thick portions 11a and 12a have their ends gradually increasing in the inner circumferential direction from the end surfaces of the outer permanent magnets 1j and 1k and the inner permanent magnets 1m and 1n toward the center. The tapered portions 11b, 11c and 12b, 12c are formed so that the leakage of magnetic flux between the end portions of the permanent magnets and the thick portions 11a, 12a can be prevented. ing.

In performing the damping force control and the posture control, the apparatus according to the present invention forms the gap 1c and moves the magnetic outer cylinder portion 11 and the magnetic cylindrical portion 12 facing each other to the two opposing surfaces thereof. 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
n) forms a magnetic path A around the _two magnetic fields B ₁ and B ₂ , and sets the direction of energization to each of the plurality of divided coils 3 a to 3 f to a direction intersecting one of the magnetic fields B _1. due to a structure having a energization switching section 6a for switching so that in the opposite directions by the coil intersects the other of the magnetic field B _2,
It is not necessary to lengthen the magnetic path A even when the stroke of the suspension unit S is increased, and therefore, it has a feature that a constant and sufficient driving force and damping force can be obtained regardless of the magnitude of the stroke. .

In the embodiment, of the six divided coils 3a to 3f, the control is performed such that only the coil portion necessary for generating the control force (driving force) is energized, thereby reducing the consumption. It has the feature that power 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. Although the coils are provided on the wheel-side members, the permanent magnets and the coils may be provided in reverse.

In the embodiment, the case where the magnetic path is formed between the upper and lower two sets of permanent magnets has been described. However, the magnetic path may be formed by one permanent magnet and the magnetic path constituting member.

Further, in the embodiment, the magnetic field is formed only by the permanent magnet, but the control force may be reinforced by the electromagnet.

In the embodiment, the permanent magnets and coils for forming the magnetic field are formed in a ring shape and are arranged concentrically. However, the shapes and arrangement relations of the permanent magnets and coils are arbitrarily set. can do.

[0039]

As described above, in the electromagnetic suspension device of the present invention, the magnetic path forming member other than the portion provided to overlap the permanent magnet has the thick portion protruding in the thickness direction of the permanent magnet. Since the thick portion is formed with a tapered portion whose thickness gradually increases as it moves away from the end surface of the permanent magnet in the direction in which the magnetic path is formed, sufficient thickness can be obtained without increasing the outer diameter of the suspension unit. Driving force (magnetic force) by magnetic saturation by securing magnetic path cross-sectional area
Can be prevented from decreasing.

In addition, since the thick portion has a tapered portion whose thickness gradually increases as the distance from the end surface of the permanent magnet in the magnetic path forming direction increases, the gap between the end portion of the permanent magnet and the thick portion is formed. Can be prevented from leaking.

[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 an enlarged sectional view showing a main part of the device according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a main part of a conventional device.

[Explanation of symbols]

S Suspension unit A Magnetic path B 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 11 Magnetic outer cylinder ( Magnetic path forming member) 11a Thick part 11b Taper part 11c Taper part 12 Magnetic inner cylinder part (magnetic path forming member) 12a Thick part 12b Taper part 12c Taper part

Claims (1)

(57) [Scope of request for utility model registration] 1. A suspension unit interposed between a vehicle body and a wheel is formed by a vehicle body-side member and a wheel-side member formed to be relatively movable. A permanent magnet that forms a magnetic field in a direction that intersects the relative movement direction of the two, and a magnet that is partially provided on the surface of the permanent magnet opposite to the magnetic field forming direction to form a magnetic path of the magnetic field. A road forming member is provided, and a coil is provided on the other of the vehicle-body-side and wheel-side members so as to be movable in a magnetic field along a relative movement direction of the both, and a portion other than a portion provided in a manner overlapping with the permanent magnet is provided. A thick portion protruding in the thickness direction of the permanent magnet is formed in the magnetic path forming member portion, and a tapered portion whose thickness gradually increases as the distance from the end face of the permanent magnet in the magnetic path forming direction is formed in the thick portion. Electromagnetic suspenders characterized by Deployment apparatus.