JPH04197816A - Electromagnetic suspension unit - Google Patents

Abstract

PURPOSE:To keep constant the relation between a radial magnetic field and a driving coil so as to obtain constant controlling forces by winding a driving oil inside the radial magnetic field in the direction of the magnetic field and in the direction perpendicular to the direction of the axis of the magnetic field, and also, providing a yoke portion with an auxiliary magnetic field forming means. CONSTITUTION:A suspension unit S comprises a car body side member 1 and a wheel side member 2. The car body side member 1 is formed into a dual structure having a space portion 1c defined between an inner pole 1a and an outer tube 1b and has a permanent magnet (main magnetic field forming means) 1f provided on the outer periphery of a rod portion 1d and a magnetic field forming portion 1g is formed which narrows the space 1c; i.e., a magnetic path A is formed by the permanent magnet 1f and a predetermined portion of the path A is formed into a yoke portion 1p to form an axial magnetic field a1 and also a radial magnetic field a2 is formed in the magnetic field generating portion 1g. A reinforcing coil (auxiliary magnetic field forming means) 1h is wound around the outer periphery of the yoke portion 1p of the inner pole 1a. 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.

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 is 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.

The present invention has been made by focusing on the above-mentioned problem, and is an electromagnetic suspension device which has excellent controllability without changing the control force even when the suspension unit strokes, and which can reliably obtain high control force. is intended to provide.

(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 formed to be relatively movable in the axial direction. The suspension unit is formed of a vehicle body side member and a wheel side member, and the suspension unit has a magnetic field having an axial magnetic field and a radial magnetic field by a main magnetic field forming means provided on the outer periphery of a yoke portion made of a magnetic material. A path is formed, and the member of the vehicle body side member and the wheel side member on which the yoke portion is not formed is disposed within the radial magnetic field of the magnetic path, and a drive coil is arranged in the direction of the magnetic field. and a means that is wound in a direction perpendicular to the axial direction, and is provided with a sub magnetic field forming means on the yoke portion so as to generate a magnetic field in the same direction as the magnetic field formed in this part by the main magnetic field forming means. did.

(Function) In the electromagnetic suspension device of the present invention, when the drive coil is energized, it is energized in a direction that intersects the direction of the magnetic field of the radial magnetic field and the axial direction of the suspension unit. A driving force is generated in the direction of relative movement between the vehicle body side 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.

Further, in the present invention, a magnetic path having an axial magnetic field and a radial magnetic field is formed by the main magnetic field forming means, but in the yoke part, the axial magnetic field is reinforced by the sub magnetic field forming means. ing.

Therefore, the magnetic flux density in the yoke portion is prevented from decreasing, and the strength of the magnetic field generated in the magnetic field forming portion is accordingly increased, thereby increasing the driving force and damping force generated.

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

FIG. 1 is an overall view showing the configuration of an electromagnetic suspension device according to a first 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 provided at the axial center 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 permanent magnet (main magnetic field forming means) If 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 of the gap 1c. A magnetic field forming section 19 is formed.

That is, since the vehicle body side member 1 is made of a magnetic material, the permanent magnet 1f forms a magnetic path A shown in the dashed line in the figure. As shown in Fig. 2, the part of the inner column 1a from the part facing the magnetic field forming part 1q to the permanent magnet 1f is the yoke part 1p.
The magnetic field forming section 19 forms an axial magnetic field a1 as shown in FIG.
, a radial magnetic field a2 is formed. still,
The direction of the magnetic path A differs depending on the polarity direction of the permanent magnet 1f.

Further, a reinforcing coil (sub-magnetic field forming means) lh is wound around the outer periphery of the yoke portion 1p of the inner column 1a. This reinforcing coil 1h is connected to the yoke portion 1p by the permanent magnet 1f.
It is configured to form a magnetic field in the same direction as the axial magnetic field a1 formed in the axial direction.

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 constructed by winding first to sixth coils 3a to 3f in parallel. Each of the coils 38 to 3f is wound around a bobbin (not shown), and the first and sixth coils 3a and 3f at the upper and lower ends have a larger number of turns than the other drive coils 3b to 3e. has been done.

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 formed in the vehicle body side member 1.

Furthermore, this control circuit 6 can switch the connection state of each of the coils 3a to 3f to the drive coil 3 by connecting them in series as shown in FIG. 3 or connecting them in parallel as shown in FIG. The coils 3a to 3f are formed in such a way that they can be energized or short-circuited between the terminals of the coils 3a to 3f, and a variable resistor is connected to these drive coils 3 when energized or short-circuited. is configured to do so.

FIG. 5 is a circuit diagram showing the configuration of the control circuit 6. In this case, only the portion that controls the first coil 3a and the second drive coil 3b is shown.

This control circuit 6 includes a variable resistor 6a, and provides signals of 0 and 1 to terminals ■, ■, ◎, and ■, respectively, in combinations shown in Figure 1, thereby controlling the first coil 3a and the second coil 3a. The configuration is such that the drive coil 3b is switched between parallel connection and series connection, and both coils 3a and 3b are short-circuited, and both coils 3a and 3b are energized and driven.

<Chart 1> By the way, when the drive coil 3 is short-circuited, when the suspension unit S strokes, the drive coil 3 moves in a direction crossing the radial magnetic field a2, so that the drive coil 3 has a force proportional to the moving speed. An induced current is generated, and this induced current consumes power by the variable resistor 6a, thereby reducing moving energy, that is, providing damping force.

On the other hand, when the drive coil 3 is energized and driven, the energization is performed in a direction that crosses the radial magnetic field a1, so that depending on the direction and strength of energization, a driving force acts in the extension direction of the suspension unit S. A driving force acts on the pressure surface.

Incidentally, the damping force and driving force (hereinafter referred to as control force) generated as described above are larger when the drive coils 3 are connected in parallel than when they are connected in series.

That is, as shown in FIG. 2, the number of coils 3a to 3f that cross the magnetic field forming section 19 is three, and
When the length of ~3f is reduced by 2 degrees, the generated force F in the case of series connection is expressed by the following formula 0, while the generated force Fp in the case of parallel connection is expressed by the formula 0 below.

That is, B2 (3L)2 ・F・" 6RX = and -■ However, B: Magnetic flux density in the magnetic field forming section Statement: Relative velocity between the coil and the magnetic field [: Winding length per coil R: Resistance value per coil.

Therefore, FP/FS=18/(3/2)=12, and the parallel connection provides 12 times the control power as the series connection.

The control circuit 6 includes a vehicle height sensor 7a and an acceleration sensor γb.
Control is performed based on input from the load sensor 7c.

The vehicle height sensor 7a is provided between the vehicle body side member 1 and the wheel side member 2 of the suspension unit S, and is configured to be able to detect the vehicle height based on the stroke amount of both.

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 vehicle 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. It's leaning.

The calculation section of the control circuit 6 performs control to keep the vehicle attitude constant based on the input from the vehicle height sensor a, and performs damping force control based on the input signals from the acceleration sensor a and the load sensor 7c. It becomes.

This damping force control is performed, for example, as disclosed in Japanese Patent Application No. 1-177792 by the present inventor.

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 also includes a control circuit 6 and each sensor 7a, 7b,
AC 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 in accordance with the relative speed between the vehicle body side member 1 and the wheel side member 2, that is, in direct proportion to the speed of the drive coil 3 passing through the radial magnetic field a2.

A diagram showing the damping force characteristics at this time is shown in FIG. 6. If the drive coils 3 are connected in parallel as shown in FIG. By arbitrarily selecting the resistance value of the resistor, the damping force characteristic can be selected within the Hi range shown in FIG.

On the other hand, in the case of series connection as shown in FIG. 3, the control force becomes small, resulting in a low damping force characteristic, and the damping force characteristic can be selected within the range of Lo shown in FIG.

In this way, when performing damping force control, the drive coil 3
In other words, damping force can be obtained without consuming any 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 (control force) change depending on the direction of energization and electric power, and FIG. 7 shows the control force characteristics at this time.

At this time, the magnitude of the control force differs depending on whether the coils 38 to 3f are connected in parallel or in series, and Hil, H
i2 indicates the case of parallel connection, and by arbitrarily changing the resistance value of the variable resistor 6a, the driving force (control force) changes within the range of Hil and Hi2. Furthermore, Hil and Hi
2, the current direction is reversed.

On the other hand, in the case of series connection, the driving force changes within the range of Lol and Lo2.

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 driving 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 this way, in this embodiment, the suspension unit S generates a control force, which is a damping force or a driving force, as necessary.
It is possible to control the input to the vehicle body and the posture of the vehicle body.

In performing the damping force control and attitude control as explained above, in the apparatus according to the embodiment of the present invention, a radial magnetic field a2 is applied to the magnetic path A.
is formed, and the drive coil 3 is configured to move within this magnetic field a2, so that even if the suspension unit S strokes, the distance between the radial magnetic field a2 and the drive coil 3 is always kept constant, and as a result, the generated The control force can be kept constant, and there is no problem that the control force changes depending on the stroke amount, and the controllability is excellent.

Furthermore, 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 damping force (control force) can be obtained without consuming electric power. I am taking good care of you.

Further, in the middle of the magnetic field formed by the permanent magnet 1f as the main magnetic field forming means, a reinforcing coil 1h as a sub-magnetic field forming means is provided in the portion of the yoke part 1p that forms the axial magnetic field a1, so that the reinforcing coil 1h is provided as a sub-magnetic field forming means. Since the current is applied so that a magnetic field is generated in the same direction as the magnetic field, a decrease in magnetic flux density is prevented in this part, and a large magnetic force is obtained in the magnetic field forming part 19, thereby obtaining a large control force. In this way, in order to strengthen the magnetic force, the outer diameter of the suspension unit S can be increased because the reinforcing coil 1h is provided in series with the permanent magnet 1f instead of increasing the size of the permanent magnet 1f itself. It has the characteristic of being able to strengthen the magnetic force without any damage.

Furthermore, by making it possible to connect the drive coils 3 in parallel,
It is said that a large control force can be obtained compared to the length of the drive coil 3, resulting in high efficiency, and the inductance is reduced compared to a case where the entire length of the drive coil 3 is the same in series, improving responsiveness. It has characteristics.

Next, a second embodiment shown in FIG. 8 will be described.

This second embodiment is an example in which the magnetic path A is formed across both the vehicle body side member and the wheel side member.

The suspension unit S shown in FIG. 8 is composed of a piston rod 21 as a vehicle body side member and a cylinder 22 as a wheel side member.

The piston rod 21 is made of a magnetic material, and a piston 21a also made of a magnetic material is integrally provided at the lower end.

The piston 21a defines the inside of the cylinder 22 into an upper chamber 22a and a lower chamber 22b, and the inside is filled with a fluid such as oil.

Note that 21b is an orifice hole that communicates both chambers.

Further, an accumulator 23 is connected to the lower chamber 22b.

An electromagnetic coil 24 as a main magnetic field forming means is provided at the lower end of the piston rod 21.
By energizing, a magnetic path A as shown in the figure is formed.

That is, the cylinder 22 is made of a magnetic material, and a small diameter portion 22c is formed at the upper end of the cylinder 22 so as to narrow the distance from the piston rod 21. The guide bushing 25a, the guide member 25, and the seal member 26 are made of a non-magnetic material such as resin.

Therefore, when the electromagnetic coil 24 is energized, an axial magnetic field a1 is formed using the piston rod 21 as a yoke, and the magnetic field is passed from the piston 21a to the cylinder 22 in the radial direction, causing the small diameter portion 22c of the cylinder 22 and the piston rod 21 to form an axial magnetic field a1. A radial magnetic field a2 is formed between the two.

A piston 21 is disposed within the small diameter portion 22c of the cylinder 22.
A drive coil 28 is provided with a small gap 27 therebetween. This drive coil 28 has a radial magnetic field a2
It is wound in a direction perpendicular to the direction of the magnetic field and the axial direction.

Further, a reinforcing coil 29 is provided in a recess formed on the outer periphery of the intermediate portion of the piston rod 21 so as to be in series with the electromagnetic coil 24 .

In the electromagnetic suspension of the second embodiment configured as above, the magnetic path A is formed by energizing the electromagnetic coil 24 and the reinforcing coil 29, and in this case, as in the first embodiment, the axial magnetic field The suspension unit S is constructed by reducing the outer diameter of the electromagnetic coil 24 compared to the case where the magnetic flux density of a1 is prevented from decreasing and the magnetic path A with the same magnetic force is formed only by the electromagnetic coil 24. can be made more compact.

Further, by energizing the drive coil 28, a driving force can be generated in the direction of expansion and contraction of the suspension unit S.

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 is shown in which the vehicle body side member is 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. .

(Effects of the Invention) As described above, in the electromagnetic suspension device of the present invention, the drive coil is wound within the radial magnetic field in the direction of this magnetic field and the direction intersecting the axial direction, and the drive coil is wound around the yoke portion. Since the means is provided with a magnetic field forming means, the following effects can be obtained.

In other words, when the drive coil is energized, a driving force is obtained in the direction of expanding and contracting the suspension unit, but since the drive coil is installed across the radial magnetic field, even when the suspension unit strokes, the radial magnetic field is Since the relationship between the drive coil and the drive coil is kept constant, a constant control force can be obtained, and therefore excellent controllability can be obtained.

In addition, a sub-magnetic field forming means is provided separately from the main magnetic field forming means to prevent a decrease in magnetic flux density in the yoke part, so the magnetic field of the magnetic field forming part is strengthened and a large control force (
In this way, in order to obtain a large control force, it is possible to prevent the main magnetic field forming means from increasing in size and to make the suspension unit more compact.

[Brief explanation of the drawing]

Fig. 1 is an overall view showing the electromagnetic suspension device according to the first embodiment of the present invention, Fig. 2 is an enlarged sectional view showing the main parts of the device according to the first embodiment, and Figs. 3 and 4 show the connections of the coils. Circuit diagram, Fig. 5 is a circuit diagram showing the main part of the control circuit of the device of the first embodiment, Fig. 6 is a damping force characteristic diagram of the device of the first embodiment, and Fig. 7 is the driving force of the device of the first embodiment. The characteristic diagram and FIG. 8 are cross-sectional views showing an electromagnetic suspension device according to a second embodiment of the present invention. S... Suspension unit A... Magnetic path al... Axial magnetic field a2... Radial magnetic field 1... Vehicle body side member 1f... Permanent magnet (main magnetic field forming means) 1h... Reinforcement Coil (auxiliary magnetic field forming means) 2...Wheel side member 3...Drive coil 21...Piston (vehicle body side member) 22...Cylinder (wheel side member) 24...Electromagnetic coil (main magnetic field forming means) Forming means) 28.--Drive coil

Claims (1)

[Scope of 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 the axial direction, and the suspension unit includes: A magnetic path having an axial magnetic field and a radial magnetic field is formed by a main magnetic field forming means provided on the outer periphery of the yoke portion formed of a magnetic material, and the yoke portion between the vehicle body side member and the wheel side member A drive coil is arranged in the radial magnetic field of the magnetic path and wound in a direction intersecting the direction of the magnetic field and the axial direction on the member on which the yoke part is not formed. An electromagnetic suspension device characterized in that the magnetic field forming means is provided to generate a magnetic field in the same direction as the magnetic field formed in this region by the main magnetic field forming means.