JPH04163219A - Electromagnetic suspension device - Google Patents

Abstract

PURPOSE:To secure constant driving force and damping force so as to improve controllability by forming a radial magnetic field forming part at one of a body side member and a wheel side member, and disposing a coil in the other magnetic field forming part position between both members, thereby keeping constant distance between the magnetic field forming part and the coil. CONSTITUTION:A suspension unit S is provided with a body side member 1 and a wheel side member 2. A magnetic body is used for the body side member 1 formed into double structure provided with a gap part 1c between an inner column 1a and an outer cylinder 1b. A magnetic field forming part 1g is formed at the body side member 1, and a reinforcing coil 1h is wound around the outer periphery of the inner column 1a positioned between the magnetic field forming part 1g and a magnet 1f. The wheel side member 2 is inserted into the gap part 1c, and a coil 3 is wound around the outer periphery of the wheel side member 2. The coil 3 and the reinforcing coil 1h are further connected to a control circuit 6. Current application is formed in the direction of crossing the magnetic field of the magnetic field forming part 1g at the time of applying a current to the coil 3 so as to allow driving force to act upon the expansion/ contraction direction of the suspension unit S.

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.

Furthermore, the electromagnetic coil must always be energized while the control force is being generated, resulting in a problem of extremely large power consumption.

The present invention has been made by focusing on the above-mentioned problem, and its first object is to provide an electromagnetic suspension device that can obtain a constant control force even when the suspension unit strokes and has excellent controllability. A second object is to provide an electromagnetic suspension device with low power consumption and high drive efficiency.

(Means for Solving the Problems) In the present invention, in order to achieve the first object, a magnetic field forming portion that forms a magnetic field in the radial direction is formed in one of the vehicle body side member and the wheel side member, and A coil was placed at the position of the other magnetic field forming section.

Furthermore, in order to achieve the second objective, a plurality of coils were provided and they could be connected in parallel or in series. Also, the coil was shorted.

That is, in the electromagnetic suspension device of the present invention according to claim 1, the suspension unit interposed between the vehicle body and the wheel is formed of a vehicle body side member and a wheel side member made of a magnetic material, and One of the member and the wheel side member is formed into a double structure having an inner part and an outer part with a circumferential gap in between, and the other member is formed into the double structure part so as to be relatively movable. A magnetic field forming portion that forms a radial magnetic field in the gap is formed in the double structure portion, and at least a portion of the member inserted into the gap that is disposed within the gap of the magnetic field forming portion , the coil is wound in a direction perpendicular to the direction of relative displacement between the vehicle body side member and the wheel side member.

Note that a plurality of the coils may be provided and connected in parallel.

Further, a circuit may be provided in which both ends of the single or plural coils are short-circuited via a variable resistor.

Further, a plurality of the coils may be provided, and a switching means may be provided for switching the connection between at least some of these coils between series and parallel.

(Function) In the electromagnetic suspension device of the present invention, when the coil is energized, the coil is energized in a direction perpendicular to the magnetic field of the magnetic field forming section.
A driving force is generated in a direction perpendicular to both the direction of the magnetic field and the direction of energization, that is, 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.

In the device according to the second aspect, by providing a plurality of coils and connecting them in parallel, it is possible to flow a large current and obtain a large driving force compared to a case where the coils are connected in series with the same number of turns.

In the device according to the third aspect, when the suspension unit is stroked by an input from the outside, the coil relatively moves within the magnetic field of the magnetic field forming section, and an induced current is generated in the coil in proportion to the relative speed. This induced current is consumed by the variable resistor, thereby consuming the input energy to the suspension unit and achieving damping. Note that, if the number of turns is the same, the induced current generated in this coil will be larger when connected in parallel than when connected in series.

The range of this damping force characteristic can be changed by changing the resistance value of the variable resistor, and the higher the resistance value, the higher the damping force range.

In the device according to claim 4, the connection of the coils is switched between series connection and parallel connection.

As mentioned above, the driving force during energization or the damping force during short circuit is smaller when connected in parallel than when connected in series, and larger when connected in parallel. Simply by switching the connections, you can change the range of driving force or damping force.

(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 cylinder 1b by fastening the tip of the rod part 1d to the bolt member 1e with the rod part 1d formed at the upper part passing through the bottom of the outer cylinder 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 long upper portion 1d and the bolt member 1e. It should be noted that the above-mentioned bolt member 1e is for use in the number of vehicle bodies.

In the front vehicle body side member 1, the lower path half of the outer cylinder 1b is bulged inward, and the lower path half of the inner column 1a is bulged outward to narrow the gap 1c. A magnetic field forming section 1g is formed. That is, this vehicle body side member 1 is
Since it is made of magnetic material, the magnet 1f causes
A magnetic path A indicated by a dashed line in the figure is formed, and in this magnetic field forming portion 19, a magnetic field is formed in the radial direction 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 its lower end, and a bolt 2a for attachment to the wheel side is provided upright at the lower end. The wheel side member 2 is inserted into the gap 1C from the open end, and a coil 3 is wound around the outer periphery of the wheel side member 2 with a slight gap between the wheel side member 2 and the vehicle body side member 1.

This coil 3 is wound with first to sixth coils 38 to 3f. In addition, each of the coils 3a to 3f is
First and sixth coils 3a are wound around a bobbin (not shown) and have upper and lower ends.

Coil 3f has a larger number of turns than the other coils 3b to 3e.

Furthermore, bear links 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 coil 3 and the reinforcing coil 1h are connected to a control circuit 6.

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 38 to 3f to the coil 3 by connecting them in series as shown in FIG. 3 or in parallel as shown in FIG. The terminals of the coils 3a to 3f are formed such that they can be energized or short-circuited between the terminals, and furthermore, a variable resistor is connected to these coils 3 when energized or short-circuited. It is configured.

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 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. Coil qb is switched to parallel connection or series connection, and both coils 3a and 3b are short-circuited, and both coils 3
The configuration is such that a and 3b are energized and driven.

<Chart 1> By the way, when the coil 3 is short-circuited, when the suspension unit S strokes, the coil 3 moves in a direction that crosses the magnetic field of the magnetic field forming part 19, so that an induction proportional to the relative speed is applied to the coil 3. A 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 coil 3 is energized and driven, the magnetic field forming section 19
By energizing in a direction that crosses the magnetic field, a driving force is applied in the extension direction of the suspension unit S or a driving force is applied to the pressure surface, depending on the direction and strength of the energization.

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

That is, as shown in FIG. 2, the number of coils 38 to 3f that cross the magnetic field forming section 19 is three, and
The length of ~3f is ρ. When closed, the generated force F8 in the case of series connection is expressed by the following equation 0, while the generated force EP in the case of parallel connection is expressed by the equation 0 below.

That is, −1 s x−”””−explosion...■ However, B:
Magnetic flux density in the magnetic field forming section Relative speed between the coil and the magnetic field = Winding length per coil R: Resistance value per coil.

Therefore, FS/FP = 1 s/ (3/2) = 12, and the parallel connection provides 12 times as much control power as the series connection.

Note that the control circuit 6 includes a vehicle height sensor 7a and an acceleration sensor 7b.
Control is performed based on inputs from the load sensor and load sensor C.

The vehicle height sensor γa 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. ing.

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 γa, and performs damping force control based on the input signals from the acceleration sensor 7b and the load sensor 7c. It becomes.

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

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.
, γC are 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 coil 3 passing through the magnetic field forming section 19.

A diagram showing the damping force characteristics at this time is shown in FIG. 6. If the coils 3 are connected in parallel as shown in FIG. 4, the control force increases, resulting in high damping force characteristics. By arbitrarily selecting the resistance value of , the damping force characteristic can be selected within the range of Hl shown in FIG.

On the other hand, in the case of series connection as shown in FIG. 3, the control force becomes small 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 coil 3 is not energized, that is, the damping force (control force) can be obtained without consuming any power.

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

In this case, the direction and strength of the 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 3a to 3f are connected in parallel or in series, and Hil, H
l2 indicates the case of parallel connection, and by arbitrarily changing the current value, the control force changes within the range of Hil and Hl2. Note that the direction of current flow is opposite between Hil and Hl2. On the other hand, in the case of series connection, Lol, Lo
The control force changes within a range of 2.

For example, by generating such control 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 performing the damping force control and attitude control as explained above, in the apparatus according to the embodiment of the present invention, in the magnetic field forming section 19,
Since a magnetic field is formed in the radial direction and the coil 3 is configured to move within this magnetic field, the distance between the magnetic field and the coil 3 is always kept constant even when the suspension unit S strokes, thereby reducing the generated control force. It has the feature that it can be kept constant and has excellent controllability without the problem that the control force changes depending on the stroke amount.

Furthermore, by making it possible to connect the coils 3 in parallel, it is possible to obtain a large control force compared to the length of the coils 3, resulting in high efficiency. It has the characteristics that the inductance is reduced and the response is improved.

Moreover, when generating a damping force in the suspension unit S, there is no need to apply a driving current to the coil 3, and the control force (damping force) can be generated without consuming electric power.
It has the characteristic of being able to obtain

In addition, in this embodiment, a reinforcing coil 1h is provided in the middle of the magnetic field formed by the magnet 1f at a portion where the magnetic field is formed in the axial direction, so that a magnetic field is generated in the same direction as the magnetic field generated by the magnet 1f. Since this part is energized, the magnetic flux density is prevented from decreasing in this part, and a strong control force can be obtained.

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 heavy 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. .
□ Also, in the embodiment, the magnetic field is formed by a permanent magnet in the vehicle body side member, but the magnetic field may be formed by an electromagnet.

(Effects of the Invention) As explained above, in the electromagnetic suspension device of the present invention, one of the vehicle body side member and the wheel side member has a radial direction.
A magnetic field forming part that forms this magnetic field is formed, and a coil is disposed at the position of the other magnetic field forming part of both members.
Even when the suspension unit strokes and the vehicle body side member and the wheel side member move relative to each other, the distance between the magnetic field forming part and the coil can be kept constant. Driving force and damping force can be obtained, and the effect of ``excellent controllability'' can be obtained.

In the device according to claim 2, since a plurality of coils are provided and the coils are connected in parallel, a large current can be passed and a large drive can be achieved compared to a case where the coils are formed with the same number of turns using a single coil or series-connected coils. The effect is that it is possible to obtain force and damping force, and that efficiency can be improved.

In the device according to claim 3, since a circuit is provided that short-circuits the coil through a variable resistor, the damping force can be obtained by consuming the input to the suspension unit when the suspension unit strokes. ,
The effect is that damping force can be obtained without consuming any power.

In the device according to claim 4, a plurality of coils are provided and the coils can be switched between series connection and parallel connection, so that when connected in parallel, the same number of windings can be achieved with one coil or series connected coils. Compared to the case where the drive force and damping force are formed, it is possible to flow a large current and obtain a large driving force and damping force, improving efficiency. Moreover, by simply switching the connection, the driving force and damping force can be adjusted to be high or low. This provides the effect of being able to switch ranges.

[Brief explanation of drawings]

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 connection of the coils. 5 is a circuit diagram showing the main parts 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 a drive diagram of the device of the first embodiment. It is a force characteristic diagram. S...Suspension unit...Vehicle side member 1a...Inner column (mountain side member) '1b-...Outer tube (outer member) 1c...Gap portion 19...Magnetic field forming portion 2... Wheel side member 6...control circuit □

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, and the vehicle body side member and the wheel side member One of the members is made of a magnetic material and has a double structure including an inner part and an outer part with a circumferential gap in between, and the other member is
inserted into the double structure portion so as to be relatively movable, a magnetic field forming portion forming a radial magnetic field in the gap is formed in the double structure portion, and at least the magnetic field forming portion of the member inserted into the gap An electromagnetic suspension device characterized in that a coil is wound in a direction perpendicular to a direction of relative displacement between a vehicle body side member and a wheel side member at a portion disposed within a gap. 2) The electromagnetic suspension device according to claim 1, wherein a plurality of said coils are provided and connected in parallel. 3) The electromagnetic suspension device according to claim 1 or 2, further comprising a circuit in which both ends of the coil are short-circuited via a variable resistor. 4) The electromagnetic suspension device according to claim 1 or 3, characterized in that a plurality of said coils are provided, and a switching means is provided for switching connection of at least some of these coils between series and parallel connections.