JPH04197815A - Electromagnetic suspension unit - Google Patents

Abstract

PURPOSE:To keep constant the distance between a radial magnetic field and a driving coil so as to enhance controllability and save power consumption by forming the radial magnetic field in either one of a car body side member and a wheel side member, and also providing the other with the driving coil, and providing a control circuit for transmitting electricity to the driving coil. CONSTITUTION:A suspension unit S comprises a car body side member 1 and a wheel side member 2. A magnetic field generating portion 1g comprising a space portion 1c narrowed by swelling an outer tube 1b inward and swelling an inner pole 1a outward is formed in the car body side member 1 and also a magnetic path A is formed by a magnet 1f provided to a rod portion 1b so as to form a radial magnetic field B in the magnetic field generating portion 1g. The wheel side member 2 is inserted into the space portion 1c and a driving coil 3 is wound around the outer periphery of the member 2 with a small space between the coil 3 and the car body side member 1. A control circuit 6 controls electricity transmission to and shortcircuiting of the driving coil 3 according to input from a stroke sensor 7a or the like.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an electromagnetic suspension device.

(Prior Art) Conventionally, as an electromagnetic suspension device, one described in, for example, Japanese Utility Model Application Publication No. 1-116710 is known.

This conventional suspension system has a cover formed in a cylindrical shape and fixed to the vehicle body between the vehicle body and the wheels, and a piston that is slidably provided inside the cover and attached to the wheel side. A unit is provided, a fixed coil and a control coil are provided in the cover, and the fixed coil is provided in the piston.

Then, by controlling the direction of energization and current to each coil, a control force (attractive/repulsive force) is generated in the axial direction of the coil, thereby controlling, for example, keeping the vehicle height constant.

(Problem to be Solved by the Invention) However, as described above, in such conventional electromagnetic suspension devices, the suspension was controlled by the control force generated in the axial direction of the electromagnetic coil, so the suspension unit When the distance between the electromagnetic coils changes, the attraction/repulsion between the coils changes accordingly, making accurate control difficult.

Further, while generating the control force, the entire electromagnetic coil must be energized at all times, resulting in a problem of extremely large power consumption.

The present invention has been made by focusing on the above-mentioned problems, and has excellent controllability by being able to obtain a constant control force even when the suspension unit strokes.Furthermore, the present invention is an electromagnetic device that has low power consumption and high drive efficiency. The purpose is to provide a suspension device.

(Means for Solving the Problems) In order to achieve the above-mentioned object, in the electromagnetic suspension device of the present invention, a suspension unit interposed between a vehicle body and a wheel is attached to a vehicle body formed to be relatively movable in the axial direction. A radial magnetic field is formed in a circumferential gap in one of the vehicle body side member and the wheel side member, and the other of the vehicle body side member and the wheel side member is formed by a side member and a wheel side member. Inserted into the gap, a drive coil consisting of a plurality of coils is wound around a portion disposed in the gap in a direction intersecting the relative movement direction and the radial direction, and controls energization of the drive coil. A control circuit is provided, and the control circuit is configured to energize only a predetermined coil of the drive coil based on a detection signal from a stroke sensor that detects a stroke position of the suspension unit.

(Function) In the electromagnetic suspension device of the present invention, when the drive coil is energized, it is energized in a direction perpendicular to the radial magnetic field. A driving force is generated in the direction of relative movement between the member and the wheel side member.

Therefore, this driving force causes the suspension unit to expand or shorten.

Therefore, this driving force can be applied to resist the input to the suspension unit, thereby suppressing the stroke of the suspension unit due to external input.

In performing such control, the control circuit selectively energizes predetermined drive coils based on input from the stroke sensor. In this case, it is only necessary to energize the coils involved in generating the drive force.

In this way, power is supplied only to a predetermined drive coil rather than to the entire drive coil, so power consumption can be saved.

On the other hand, when the drive coil is not energized, when the suspension unit is stroked by an external input, the drive coil moves within a radial magnetic field, and an induced current is generated in the drive coil in proportion to the relative speed.

Then, by consuming this induced current by the drive coil and other resistances, input energy to the suspension unit can be consumed, and damping force is generated.

In this way, damping force can be generated even if no current is applied to the drive coil.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

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

In this figure, S indicates a suspension unit. This suspension unit S includes 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 is made of a magnetic material, and has a cylindrical inner column 1a and a bottomed cylindrical outer tube 1b, which are provided at the thin end as shown in the figure, with a gap 1C between them. It is formed into a double structure. The inner column 1a is integrally formed with the outer tube 1b by fastening the tip of the rod portion 1d to a bolt member 1e with a rod portion 1d formed at the upper part passing through the bottom of the outer tube 1b. . Further, a cylindrical magnet 1f is provided on the outer periphery of the rod portion 1d, and is fixed by the fastening force between the rod portion 1d and the bolt member 1e. Incidentally, the bolt member 1e is for mounting on a vehicle body.

Then, in the vehicle body side member 1, the lower road half of the outer cylinder 1b is made to bulge inward, and the lower road half of the inner column 1a is made to bulge outward, thereby narrowing the interval between the gap parts 1C. A magnetic field forming section 19 is formed.

That is, since the vehicle body side member 1 is formed of a magnetic material, the magnet 1f causes the magnetic path A shown in the figure to be
is formed, and in this magnetic field forming portion 19, a radial magnetic field B is formed as shown in FIG. Note that the direction of the magnetic path A differs depending on the polarity direction of the magnet 1f.

In addition, the inner column 1 located between the magnetic field forming part 19 and the magnet 1f
A reinforcing coil 1h is wound around the outer periphery of a.

On the other hand, the wheel side member 2 is formed into a bottomed cylindrical shape having a bottom at the lower end, and a port 2a for attachment to the wheel side is provided upright at the lower end. This wheel side member 2 is inserted into the gap 1C from the open end, and has a small gap on its outer periphery with respect to the vehicle body side member 1, and the drive coil 3
is wrapped around it.

This drive coil 3 is divided into six parts, first to sixth coils 38 to 3f, along the direction of relative movement of both members 1 and 2, and each part is provided in parallel. Incidentally, each of the coils 38 to 3f is wound around a bobbin (not shown), and the first and sixth coils 3 at the upper end and the lower end
Coils a and 3f have a larger number of turns than the other coils 3b to 3e.

Further, as shown in FIG. 3, the base ends of arms 8a and 8b extending in the horizontal direction are fastened to the bolt member 1e to the vehicle body side and the bolt 2a for attachment to the wheel side. Between the tips of the arms 8a and 8b, there is a stroke sensor 7 that can be expanded and contracted according to the expansion and contraction of the suspension unit S.
A is attached.

Further, bearings 4a, 4b, and 4c are provided between the wheel side member 2, the inner column 1a, and the outer cylinder 1b.

Further, a dust boot 5 is provided between the lower end of the wheel side member 2 and the lower end of the outer cylinder 1b.

The drive coil 3 and reinforcing coil 1h are connected to a control circuit 6.
It is connected to the.

That is, the control circuit 6 energizes the reinforcing coil 1h so that a magnetic field is generated in the same direction as the magnetic field mill formed in the vehicle body side member 1.

Further, this control circuit 6 is formed to be able to energize or short-circuit the terminals of each of the coils 3a to 3f with respect to the drive coil 3, and furthermore, when energized or short-circuited, these A variable resistor (not shown) is connected to the drive coil 3.

Incidentally, when the drive coil 3 is short-circuited, when the suspension unit S strokes, the drive coil 3 moves in a direction across the radial magnetic field B, and an induced current proportional to the moving speed is generated in the drive coil 3. By consuming power from this induced current using a variable resistor, the moving energy is reduced, that is, a damping force is obtained.

On the other hand, when the drive coil 3 is energized and driven, the energization is made in a direction that crosses the radial magnetic field B, so that depending on the direction and strength of energization, a driving force acts in the direction of extension of the suspension unit S. A driving force acts on the amount of pressure.

The control circuit 6 performs energization/short-circuit control of the drive coil 3 based on inputs from the stroke sensor γa, acceleration sensor 7b, and load sensor 7c.

As described above, the stroke sensor 7a is provided between the vehicle body side member 1 and the wheel side member 2 of the suspension unit S, and the sensor 7a itself is formed so as to be expandable and retractable according to the stroke of the suspension unit S. The stroke amount of the suspension unit S is configured to be detectable based on the amount of expansion and contraction of the suspension unit S.

The acceleration sensor 7b is attached to the vehicle body to detect the vertical acceleration of the vehicle body, and is provided to determine the body speed in the vertical direction.

The load sensor 7C is provided at the mounting portion of the vehicle body side member 1 of the suspension unit S to detect the input load from the suspension unit S, and is provided to determine the relative speed between the vehicle body side and the wheel side. ing.

In the calculation section of the control circuit 6, the stroke sensor 7
Based on the input from the stroke sensor a, control is performed to keep the vehicle posture constant, and damping force control is performed based on the input signals from the acceleration sensor a and the load sensor 7c, while based on the input signal from the stroke sensor 7a, All coils 3a
~3f, the coils in the portion facing the magnetic field forming portion 1g are calculated, and control is performed such that only these coils are selectively energized.

The damping force control described above is performed, for example, as disclosed in Japanese Patent Application No. 1-1A Y792 filed by the applicant of the present application.

Next, the operation of the embodiment will be explained.

The electromagnetic suspension device configured as described above includes a suspension unit S provided between each of the four wheels of the automobile and the vehicle body, and a control circuit 6 and each sensor 7a, 7b, 7.
c is also provided and used for each suspension unit S.

(B) When controlling damping force When generating a damping force in the suspension unit S according to the driving situation of the vehicle, each coil 38 to 3f
short circuit.

Then, a damping force is generated depending on the relative speed between the vehicle body side member 1 and the wheel side member 2, and in direct proportion to the speed of the drive coil 3 passing through the magnetic field forming section 19.

A diagram showing the damping force characteristics at this time is shown in FIG. 4, and by arbitrarily selecting the resistance value of the variable resistor, the damping force characteristics can be selected within the range H in FIG. 4.

In this way, when performing damping force control, the drive coil 3
In other words, damping force (control force) can be obtained without consuming any electric power.

(b) Attitude control When performing attitude control, the drive coil 3 is energized according to the vehicle situation obtained based on the input from each sensor 7a to 7c, and the suspension unit S is driven upward or downward in the axial direction. Generate force and control posture.

In this case, the direction and strength of the driving force change depending on the direction of energization and electric power, and FIG. 5 shows the control force characteristics at this time.

At this time as well, by arbitrarily changing the resistance value of the variable resistor 6a, the driving force changes within the range of H1 and H2. still,
The current direction is opposite between H1 and H2.

For example, by generating such driving force in a direction that cancels out changes in vehicle height, the vehicle height can be kept constant. Furthermore, by generating the control force in a direction that cancels out the road surface input transmitted to the vehicle body via the suspension unit S, the road surface input to the vehicle body can be canceled and a constant vehicle body posture can be obtained.

In the case of performing posture control as described above, when the suspension unit S strokes, the stroke amount from the neutral position is detected by the stroke sensor γa, and based on the detection signal, the control means 6 controls each of the coils 38 to 38 at this time. To determine which coil among 3f is placed within the radial magnetic field B, the stroke amount in FIG. 6 is the second to fifth coils 3b to 3e, and the stroke amount in FIG. 7 is the first to fourth coils. 38-3d), control is performed to selectively energize only that coil.

In addition, the second. 6. In FIG. 7, 2 indicates the area of the radial magnetic field B in the vertical direction.

In this way, power consumption can be saved by always energizing only the necessary coils according to the stroke position of the suspension unit S.

In performing the damping force control and attitude control as explained above, the apparatus according to the embodiment of the present invention forms a radial magnetic field B,
Since the drive coil 3 is configured to move within this magnetic field B, the distance between the radial magnetic field B and the drive coil 3 is always kept constant even when the suspension unit S strokes, thereby keeping the generated control force constant. can be kept,
It is characterized by excellent controllability without the problem that the control force changes depending on the stroke amount.

Further, by dividing the drive coil 3 and connecting them in parallel, the inductance is lowered and the response is improved compared to the case of series connection.

Furthermore, by controlling the drive coil 3 to energize only those parts necessary for generating control force, it is possible to save power consumption.

Moreover, when generating a damping force in the suspension unit S, there is no need to apply a drive current to the drive coil 3, and the control force (damping force) can be obtained without consuming electric power. have.

In addition, in this embodiment, a reinforcing coil is provided in the part where the magnetic field is formed in the axial direction in the middle of the magnetic field formed by the magnet, and the magnetic field is energized so that the magnetic field is generated in the same direction. Therefore, this part prevents the magnetic flux density from decreasing and obtains a strong magnetic force in the radial magnetic field, thereby providing a strong control force. The outer diameter of the magnet can be reduced compared to the case where the magnet is formed, and the suspension unit can be made more compact.

Although the embodiments of the present invention have been described above 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 was shown in which the vehicle body side member was formed into a double structure, but the wheel side member and the vehicle body side of the embodiment device may be reversed to form the wheel side member into a double structure. .

Further, in the embodiment, a permanent magnet is used as the magnetic field forming means in the vehicle body side member, but the magnetic field may be formed using an electromagnet.

(Effects of the Invention) As explained above, in the electromagnetic suspension device of the present invention, a radial magnetic field is formed in one of the vehicle body side member and the wheel side member, and a drive coil consisting of a plurality of coils is formed in the other of both members. Since the control circuit is provided to energize only a predetermined coil of the drive coil, the distance between the radial magnetic field and the drive coil is constant, and the generated control force does not change depending on the stroke of the suspension unit. It has the effect of excellent controllability, saves power consumption because the entire drive coil is not energized, and can generate control force (damping force) even when the drive coil is not energized. This also provides the effect of saving power consumption.

[Brief explanation of the drawing]

FIG. 1 is an overall view showing an electromagnetic suspension device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing main parts of the embodiment device.
Fig. 3 is an external view of the embodiment device, Fig. 4 is a damping force characteristic diagram of the embodiment device, Fig. 5 is a driving force characteristic diagram of the embodiment device, and Fig. 6 is a diagram of the driving force characteristic of the embodiment device.
7 and 7 are explanatory diagrams of the operation of the embodiment device. S... Suspension unit A... Magnetic path B... Radial magnetic field 1... Vehicle body side member 1c... Gap portion 19... Magnetic field forming part 2... Wheel side member 3... Drive coil 6...Control circuit 7a...Stroke 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 formed to be relatively movable in an axial direction, and the vehicle body side member and the wheel A radial magnetic field is formed in a circumferential gap on one side of the side member, and the other of the vehicle body side member and the wheel side member is inserted into the gap, and a portion disposed within the gap is provided with a radial magnetic field. , a drive coil made up of a plurality of coils is wound in a direction intersecting the relative movement direction and the radial direction, and a control circuit for controlling energization of the drive coil is provided, and the control circuit controls the stroke position of the suspension unit. An electromagnetic suspension device characterized in that the electromagnetic suspension device is configured to energize only a predetermined coil of the drive coil based on a detection signal from a stroke sensor that detects the stroke.