JPH06217521A - Electromagnetic suspension - Google Patents

Abstract

(57) [Summary] [Purpose] Providing an electromagnetic suspension with a high frequency vibration suppression effect. [Configuration] cylindrical electrical coil (1 ₁ to 1 _6); the outer circumferential surface of the electrical coil and cover the upper and lower end faces, the magnetic path member (2 ₁ to 2 ₆ having an opening opposing the vertical opening of the electric coil in the vertical ); A rod (3) penetrating the opening of the magnetic path member and the internal space of the electric coil, at least the outer peripheral surface of which is a good electric conductor and at least the inside of the outer peripheral surface of which is a good magnetic conductor; A coil driver (4 ₁ ) for supplying current to the coil is provided. [Effect] There is a shock absorber function to suppress the vibration of the rod (3), and this function is high against high frequency vibration. Since no permanent magnet is required, all problems associated with using a permanent magnet, such as high cost, high weight, deterioration over time, and fragility against impact, are all improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension provided with a damping force adjusting mechanism by electromagnetic force.

[0002]

2. Description of the Related Art Most conventional suspensions in the related art include a shock absorber having a damping force adjusting valve on a piston in a cylinder. This shock absorber
Since the degree of flow between the upper and lower fluid spaces divided by the piston is adjusted, the damping force coefficient can be adjusted. Recently, in order to adjust not only the damping force but also the support pressure of the suspension, for example, a pressure regulating valve is inserted between the pressurized air source and the suspension to adjust the support pressure of the suspension. However, an air pump, an air accumulator, a pressure regulating valve, a fluid pipe, etc. are required, the structure of the suspension becomes complicated, and a considerable amount of power is required to drive the air pump.

For example, in Japanese Unexamined Patent Publication (Kokai) No. 2-111251, a small-diameter permanent magnet ring having a small diameter is arranged in a radially polarized permanent magnetic field ring, and a cylindrical electric coil is provided in a ring-shaped gap between the two. By inserting and energizing the electric coil, a relative force in the direction in which the central axis of the ring extends is generated between the electric field between the large-diameter and small-diameter permanent magnetic fields and the electric coil, according to Fleming's left-hand rule. Linear mode
A suspension incorporating the data is presented.

[0004]

This linear motor is
A relative thrust represented by Fleming's left-hand rule is generated between the magnetic field between the outer permanent magnet ring and the inner permanent magnet ring and the electric coil (current thereof) intersecting with the magnetic field. Therefore, for example, when the vehicle body vibrates with respect to the wheels, in order to suppress this, an electric current of a polarity that generates upward thrust is applied to the electric coil when the vehicle body sinks, and a reverse polarity current is applied when the vehicle body floats. It is necessary to switch the polarity of the voltage applied to the coil in response to the change in the vertical movement direction of the vehicle body, such as applying a current to the electric coil. That is, it is necessary to detect the moving direction of the vehicle body with respect to the wheels and determine the polarity of the coil applied voltage correspondingly. However, when the vibration frequency becomes high, such control of the voltage polarity cannot follow, so that the high frequency vibration cannot be suppressed after all. Further, there is a problem that the permanent magnet is fragile and vulnerable to an impact, and there is also a problem that the function is deteriorated (fluctuated) due to demagnetization in time series.

An object of the present invention is to provide an electromagnetic force suspension that solves this kind of problem.

[0006]

SUMMARY OF THE INVENTION An electromagnetic force suspension of the present invention is a cylindrical electric coil (1 ₁ to ₁₆ ); covers the outer peripheral surface and the upper and lower end surfaces of the electric coil, and opposes the upper and lower openings of the electric coil. magnetic path member having openings at upper and lower (2 ₁ to 2 _6); through the inner space of the opening as well as the electrical coil of the magnetic path member, an outer peripheral surface at least is electrically good conductor least inside of the outer peripheral surface There rod (3) is a magnetic conductor; and the coil driver for supplying current to the electrical coil (4 _1); comprises. The symbols in parentheses indicate the corresponding elements in the embodiments shown in the drawings and described later.

[0007]

[Operation] When the coil driver (4 ₁ ) energizes the electric coils (1 ₁ to ₁₆ ), the coil current causes the magnetic path members (2 ₁ to 2 ₆ ) and rod (3) magnetic flux is generated around the flows from the magnetic path member (2 ₁ to 2 ₆₎ to the rod (3) produces a magnetic flux component which is perpendicular to the outer peripheral surface of the rod (3). Electric coil (1 ₁ to ₁₆ ) and magnetic path member (2
_{When the} rod (3) moves relative to ( ₁ to ₂₆ ) in the direction in which its central axis extends (the direction orthogonal to the orthogonal magnetic flux component), the magnetic flux component is transferred to the good electrical conductor of the rod (3). An eddy current of a circulating shape flows, and due to the electromagnetic force between this eddy current and the magnetic flux component, between the magnetic path member (2 ₁ to ₂₆ ) and the rod (3), the rod (3) Electromagnetic force acts in a direction that hinders movement. That is, the magnetic flux flowing from the magnetic path member (2 ₁ to 2 ₆₎ to the rod (3) is to provide a braking force to the rod (3). This braking force follows the law of electromagnetic induction, and becomes larger as the moving speed of the rod (3) becomes faster. Therefore, the faster the vibration of the rod 3 is (the higher the vibration frequency is), the larger the braking force is automatically generated.
That is, the electromagnetic suspension of the present invention is a rod
There is a shock absorber function to suppress the vibration of (3),
This function is high against high frequency vibration. Since no permanent magnet is required, all problems associated with using a permanent magnet, such as high cost, high weight, deterioration over time, and fragility against impact, are all improved.

[0008] Electromagnets (1 ₁ , 2 ₁ ~) composed of electric coils (1 ₁ ~ ₁₆ ) and magnetic path members (2 ₁ ~ 2 ₆ ) are arranged in the direction in which the axis of the rod (3) extends.
When a plurality of (1 ₆ , 2 ₆ ) are arranged, the above-mentioned function is similarly emitted, and an AC current having a different phase between adjacent ones is supplied to each of the electric coils (1 ₁ to ₁₆ ). By doing so, the magnetic field exerted on the rod (3) by the electromagnet group (1 ₁ , 2 ₁ to _{16 6} , ₂₆ ) moves in the direction in which the axial center of the rod (3) extends,
An eddy current flows in a good electrical conductor of the rod (3) so as to hinder the movement of this magnetic field, and the electromagnetic force between this eddy current and the moving magnetic field causes thrust in the moving direction of the magnetic field to act on the rod (3). . When the rod (3) is connected to one of the wheels and the vehicle body of the vehicle and the electromagnet group (1 ₁ , 2 ₁ to _{16 6} , ₂₆ ) is connected to the other, the direction of this thrust is the direction from the wheel to the vehicle body. By setting the direction to support the vehicle body, the thrust becomes, so to speak, a spring force that supports the vehicle body, and this spring force can be adjusted by adjusting the alternating current level. Therefore, the suspension of the present invention positively increases the shock absorber function and the vehicle body support force in a manner of supplying alternating currents having different phases between the adjacent ones to the electric coils (1 ₁ to ₁₆ ). The active function to adjust is realized at the same time.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0010]

FIG. 1 shows the appearance of an embodiment of the present invention. Figure 1
A support plate 14 is fixed to the upper cover 11 of the suspension 10, and the support plate 14 supports a vehicle body (not shown). Cylinder 12 of suspension 10
A joint plate 15 is fixed to the lower end of the wheel, and the joint plate 15 is fixed to the stator housing of the wheel motor 21. Wheels 22 are fixed to the rotor of the wheel motor 21, and tires 23 are attached to the wheels 22.
A compression coil spring 13 is interposed between a washer fixed to the cylinder 12 and a washer fixed to the support plate 14, and the load of the vehicle body is substantially supported by the compression coil spring 13. FIG. 1 shows only one wheel of an electric vehicle.
The other three wheel portions of the electric vehicle are also equipped with the same suspension 10 as shown in FIG.

FIG. 2 shows a vertical cross section of the upper cover 11 and the cylinder 12 of the suspension 10 shown in FIG.
2 shows an enlarged vertical section of the pair of electromagnets (1 ₅ , 2 ₅ ) shown in FIG. In this embodiment, six sets of electromagnets (1 ₁ , 2 ₁ ) to (1 ₆ , 2 ₆ ) are press-fitted and fixed in the soft iron cylinder 12, and the rod 3 penetrates the center holes of these electromagnets. .

[0012] A set of electromagnets (1 _5, 2 _5), the two soft iron circular plates drilled in the center a circular opening of slightly larger inner diameter than the outer diameter of the rod 3, a cylindrical electrical coil 1 ₅ The inserted and integrated soft iron cylinder is interposed, and the two soft iron disks and the soft iron cylinder are integrally fixed to form a cylindrical electromagnet, and the outer diameters of the soft iron disk and the soft iron cylinder are: It can be press-fitted into the cylinder 12 to the same extent as the inner diameter of the cylinder 12. Note that the contact surface of the soft-iron disc and soft iron cylinder Li electrical coil 1 ₅ - there is a groove to draw the lead wire in a radial direction,
On the outer peripheral surface of the soft iron disc and the soft iron cylindrical body, a groove (not only for the self lead wire but also for other electromagnets) for laying the drawn lead wire in the vertical direction (direction along the central axis) There is a relatively wide groove) that also guides the lead wire of the. Adjacent electromagnets are joined to the center holes of the _six electromagnets (1 ₁ , 2 ₁ ) to (1 ₆ , 2 ₆ ) through alignment rods having the same shape as the rod 3, and the lead wire of each electromagnet is connected. These six electromagnets are inserted into the cylinder 12 after wiring in the groove on the outer peripheral surface, and are integrally mounted on the cylinder 12 as shown in FIG.

Referring to FIG. Electromagnet (1 ₁ , 2 ₁ ) ~
In this embodiment, the rod 3 penetrating the center hole of (1 ₆ , 2 ₆ ) is formed by press-fitting the hollow soft iron rod 31 into the aluminum pipe 32 to integrate them. In addition, pipe 3
2 may be a copper pipe. When is a direct current flows to the electric coil 1 _5, for example, as shown in FIG. 3 by a two-dot chain lines, electric coil 1 ₅ interlinked magnetic path (soft iron cylinder electromagnet - a soft iron disc - hollow soft iron rods 31 ) Is flowing magnetic flux,
There is a magnetic flux orthogonal to the outer peripheral surfaces of the aluminum pipe 32 and the soft iron rod 31. Then, for example, when the rod 3 moves up or down, this causes the electric conductor to move in the direction crossing the magnetic field, so that a current according to Fleming's right-hand rule is induced in the pipe 32 and the soft iron rod 31, The current is an eddy current that orbits a magnetic flux orthogonal to the outer peripheral surface of the pipe 32, and its level is proportional to the moving speed of the rod 3. Due to the eddy current and the magnetic flux that is orthogonal to each other, a force that complies with Fleming's left-hand rule, that is, a force to stop the movement of the rod 3 is generated. That is, when the rod 3 moves, an electric current that tries to restrain the movement is induced in the pipe 32 and the soft iron rod 31, and the higher the moving speed of the rod 3, the greater the force that restrains it. Accordingly, with respect to the relative vibration of the cylinder 12 and the rod 3, the faster the vibration is (the higher the vibration frequency is), the larger the damping force is generated in a self-aligning manner. The damping force becomes larger the higher the current level of the electrical coil 1 _5, may adjust the damping force by adjusting the current level. Since the soft iron rod 31 is a conductor, the above-described function appears even when the rod 3 is composed of only the soft iron rod 31, but by coating the aluminum pipe 32 having higher conductivity than soft iron, a strong vortex is obtained. An electric current is generated and a larger damping force is obtained. Pipe 32
May be a copper pipe.

As shown in FIG. 2, a plurality of electromagnets (1 ₁ ,
In the mode in which 2 ₁ ) to ( ₁₆ , 2 ₆ ) are arranged, a magnetic field that moves in the longitudinal direction (direction in which the central axis extends) is applied to the rod 3 by applying alternating current to each electromagnet with a phase difference. An electric current is added to the rod 3 to stop the moving magnetic field.
And the induced current interacts with the moving magnetic field to apply a thrust to the rod 3 in the moving direction of the magnetic field. By determining the moving direction of the magnetic field from the bottom to the top, this thrust corresponds to the spring force that supports the sprung load to some extent, and this thrust can be adjusted by adjusting the alternating current level. That is, in addition to the shock absorber function described above, an active function for positively adjusting the vehicle body supporting force can be realized.

FIG. 4 shows a suspension system utilizing the shock absorber function and the active function. This system performs damping force control and active control of all (four) suspensions of the electric vehicle shown in FIG. In the electric coils of each suspension, the coil drivers 4 ₁ to 4 ₄ have three-phase alternating current voltage W, V, U.
Is applied by phase allocation to each electric coil that generates thrust to support the sprung load. Although not shown in FIG. 4, electric coils of three suspensions (similar to 10) (not shown) are also connected to the coil drivers 4 ₂ to 4 ₄ , respectively. Coil driver 4
The configuration and function of _{2-4 4} is the same as 4 _1, describes the structure and function of the coil driver 4 ₁ below, 4 _2-4
The description of the configuration and function of ₄ will be omitted.

The coil driver 4 ₁ includes a phase driver (AC amplifier) for supplying the electric current of each phase W, V, U of the three-phase AC to each electric coil, and a controller. Each phase driver is supplied with each of the AC reference voltages of each phase (three sets having a phase difference of 2π / 3) and the DC voltage (power supply voltage) generated by the three-phase AC generator 35, and the controller is controlled. Device 3
An energization level instruction signal is given from 0. The controller calculates an amplification factor for causing a current of a level designated by the energization level instruction signal to flow through the electric coil, and supplies it to each phase driver. Each phase driver amplifies the AC reference voltage of each phase provided by the generator 35 by a given amplification factor, and controls.
The electric current of the level indicated by LA is generated and the electric coil is energized.

A vehicle height sensor 31 detects the distance of the vehicle body to the wheels (vehicle height) and outputs an electric signal representing the distance to the control device 30.
The acceleration sensor 32 detects vertical, horizontal, and longitudinal accelerations of the vehicle and gives electric signals to the control device 30, and the vehicle speed sensor 33 is based on the wheel rotation pulse generated by the wheel speed sensor. The vehicle speed is estimated and calculated, and an electric signal representing this is given to the control device 30, and the steering angle sensor 34 detects the rotation direction of the steering wheel and the rotation angle from the neutral point and controls the electric signals representing these. It is given to the device 30.

The control device 30 calculates a low frequency component of the vehicle height change from the vehicle height detected by the sensor 31, and calculates a required damping force based on the low frequency change velocity and the low frequency component of the vertical acceleration. Is converted to a suspension energization current level (damping force adjustment energization level). Further, based on the low-frequency component of the lateral acceleration, the low-frequency component of the longitudinal acceleration, and the estimated roll value of the vehicle body calculated based on the vehicle speed and the steering angle, pitching and rolling of the vehicle body (that is, The required thrust of each suspension for suppressing the (vehicle body attitude disturbance due to the vehicle operating state) is calculated, and this is converted into a suspension energization current level (vehicle attitude adjustment energization level). Then, the control device 30 calculates a weighting coefficient corresponding to the vehicle speed and the steering angle, weights and adds the damping force adjustment energization level and the vehicle body posture adjustment energization level based on the weighting coefficient, and the obtained electric signal ( the energization level instruction signal) is calculated in each of the suspension destined to provide a respective coil driver 4 _{1-4 4.} The weighting factor is
The higher the vehicle speed and the smaller the steering angle, the greater the weight of the damping force adjustment energization level and the smaller the weight of the vehicle body posture adjustment energization level.The lower the vehicle speed and the larger the steering angle, the smaller the weight of the damping force adjustment energization level. However, the weight of the vehicle body posture adjustment energization level is increased. As a result, an appropriate damping force (shock absorber function) for suppressing vertical vibration of the vehicle body and a sprung load supporting thrust (active suspension function) for suppressing disturbance of the vehicle height posture are generated. As described above, the suspension 10 of the present invention is
By energizing the electric coil, a strong damping force against high-frequency vibration is generated by self-aligning, and this is the same as when an alternating current is applied to the electric coil. Therefore, as described above, high-frequency vibration of the vehicle body is always suppressed as long as power is supplied for damping force adjustment or vehicle body posture adjustment. The low-frequency vibration of the vehicle body is suppressed by the above-mentioned energization level control.

[0019]

As described above, the rod (3) and the electromagnet (1 ₁ ~
The relative high frequency vibrations between 1 ₆ and 2 _{1 to} 2 ₆ ) are suppressed in a self-aligning manner, so that the high frequency vibration suppressing effect is high. In addition, by controlling the energization level of AC energization with the phase difference of a plurality of electromagnets (1 ₁ to ₁₆ and 2 ₁ to 2 ₆ ), it is possible to suppress low frequency vibration or relative displacement, and In the use mode of supporting, it is possible to always maintain the vehicle body posture properly. In addition, the suspension of the present invention can have a very simple and robust structure for both the rod (3) and the electromagnets (1 ₁ to ₁₆ and 2 ₁ to ₂₆ ). Compared with the conventional electromagnetic force suspension that uses a permanent magnet, it has advantages such as a simple structure, robustness, light weight, no characteristic deterioration, and thus low cost.

[Brief description of drawings]

FIG. 1 is a front view showing the appearance of an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of an upper cover and a cylinder 12 of the suspension 10 shown in FIG.

FIG. 3 is an enlarged vertical cross-sectional view of one electromagnet (1 ₅ , 2 ₅ ) shown in FIG.

4 is a block diagram showing a control system of the suspension 10 shown in FIG.

[Explanation of symbols]

1 ₁ to 1 _6: electrical coils 2 ₁ to 2 _6: magnetic path member 3: rod 31: hollow soft iron rod 32: Aruminyu - Mupaipu 41 _{to 6:} coil driver 10: Suspension 11: upper cover - 12: Cylinder 13 : Compression coil spring 14: Support plate 15: Joint plate 21: Wheel motor 22: Wheel 23: Tire 30: Control device 31: Vehicle height sensor 32: Acceleration sensor 33: Vehicle speed sensor 34: Steering angle sensor 35 : 3-phase AC generator 36: Power supply circuit

Claims (2)

[Claims] 1. A cylindrical electric coil; a magnetic path member which covers an outer peripheral surface and upper and lower end surfaces of the electric coil and has openings vertically facing the upper and lower openings of the electric coil; the opening of the magnetic path member and the electric path. An electromagnetic suspension comprising: a rod penetrating the inner space of the coil, at least the outer peripheral surface of which is a good electric conductor and at least the inner surface of the outer peripheral surface of which is a good magnetic conductor; and a coil driver which supplies a current to the electric coil. 2. A tubular magnetic path member having three or more inner flanges distributed at a predetermined pitch; two or more tubular electric coils each housed in a space between flanges of the magnetic path member; A rod penetrating the opening of the inner flange of the magnetic path member and the inner space of the electric coil, the rod having at least the outer peripheral surface being a good electric conductor and the inner side of the outer peripheral surface being a good magnetic conductor; and each of the electric coils. A coil driver that supplies alternating currents having different phases between those adjacent to each other.