JPH10160027A - Magnetic spring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the load possible to be reduced at the time of driving with the neutral point not changing even if there is deterioration with the passage of time and keeping powerful restoring torque at the time of standstill. SOLUTION: This device is composed so that it may include a function to energize a driving object, which mechanically makes rotational drive by torque produced by a motor, so that it may be in a preset rotational position when the motor is not driven and to produce torque opposite to the rotational direction simultaneously with the rotational drive of the driving object when the motor is electrified and torque is produced. In this case, a spring mechanism is a composition including a stator composed of permanent magnets 2a, 2b and a ferromagnetism body, a rotor installed coaxially with the stator with a space interposed between and composed of permanent magnets 3a, 3b, a ferromagnetism body and an electric coil 6 rotatable with respect to the stator, and a drive circuit 7 for determining current to the electric coil of the stator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic spring device for a motor positioning mechanism, and more particularly to a magnetic spring device used as a biasing device for a throttle valve of an automobile engine.

[0002]

2. Description of the Related Art Generally, as a biasing device of this type, a coil-shaped spring or a biasing force generated by a contraction of an elastic member is used. It is known by the technique described in JP-A-150449. This is because, in a throttle valve of an engine controlled by a motor, the throttle valve is urged in a valve closing direction by using a first urging means formed of a coiled spring, and is urged in a valve opening direction. It is urged by a second urging means made of an elastic member, and a position where both the urging forces are balanced is set to a position where the throttle valve is opened by a predetermined amount. Thus, during operation of the engine, the throttle valve is moved by the motor in the opening and closing directions against the urging forces of the first and second urging means. On the other hand, when the driving force of the motor is cut off due to the engine being stopped or the motor being disconnected, the first position of the throttle valve is not limited to any position.
And the second urging means moves to a position where the urging force is balanced, and stops with the throttle opened by a predetermined opening. In this way, the throttle opening required for moving the vehicle when the engine is restarted or the motor fails is ensured.

[0003]

However, such a conventional urging device has the following problems. (1) Since the initial position of the throttle valve to be driven is determined at a position where the biasing force in the valve closing direction and the biasing force in the valve opening direction are balanced, it is necessary to perform an adjustment operation in order to accurately match the predetermined opening degree of the throttle valve. I need. Furthermore, even if it is adjusted once, the initial position of the throttle valve may shift while the driver does not notice because the biasing force changes due to deterioration over time, etc., which indicates the controllability at the time of engine start and idling. Will worsen. (2) In order to keep the throttle valve to be driven at a predetermined opening when the motor is not driven, there is no influence from the holding torque when the motor is not driven, that is, the detent torque, disturbance received by the throttle valve, and the like. Thus, the urging forces of the first and second urging means need to be sufficiently large. However, at the time of driving the motor, the motor must drive the throttle valve against the urging force, so it is necessary to use a larger motor with higher output.

[0004]

In view of such a conventional problem, in the present invention, a first member made of a permanent magnet and a ferromagnetic material, and a driving member separated from the first member by an appropriate gap. And a mechanism for generating positive and negative biasing force around a magnetically stable point by a mutual magnetic action of a second member similarly made of a permanent magnet and a ferromagnetic material, Further, the above-mentioned problem is solved by changing the magnitude of the urging force by a current flowing through an electric coil provided in the magnetic circuit.

[0005]

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cylindrical yoke made of a ferromagnetic material such as iron, 2a is fixed to one end thereof in contact with the inner periphery of the yoke 1, and 2b is a permanent magnet magnetized in the radial direction of the yoke 1. 1 is a permanent magnet that is installed at a position mechanically displaced from the permanent magnet 2a by 180 degrees on the inner circumference and is magnetized in the opposite direction in the radial direction. Reference numeral 4 denotes a rotating shaft common to the driven object, and a driven object (not shown) is coaxially installed, and a motor as a driving means is also installed coaxially. Reference numeral 5 denotes an armature made of a ferromagnetic material, which is fixed to the rotating shaft 4. At both ends of the armature 5, permanent magnets 3a, 3b are installed. It is assumed that the permanent magnets 3a and 3b are respectively magnetized in opposite directions in the radial direction. Reference numeral 6 denotes an electric coil wound around the armature 5, which is fixed to the armature 5, so that the yoke 1 and the permanent magnet 2
The stators a and 2b are rotatable. 7
Is a drive circuit having a function of determining a current flowing through the electric coil 6.

Next, the operation of the present embodiment will be described. First, a case where the motor is not driven, that is, a case where no torque is applied to the rotating shaft 4 from outside will be described. In such a case, the drive circuit 7 includes the electric coil 6
Do not energize the At this time, the armature 5 is held at a position where the magnetic resistance is the smallest on the magnetic circuit passing from the permanent magnets 2a, 2b, 3a and 3b to the yoke 1 and the armature 5. When the armature 5 has an elongated shape in the radial direction about the rotation shaft 4 as in the present embodiment, the position is as shown in FIG.
The permanent magnets 3a and 3b at both ends of the armature 5 are closest to the permanent magnets 2a and 2b, respectively. Also,
In this case, the holding torque becomes as shown by a solid line (a) in FIG. 3 when the holding torque takes a positive direction in the direction in FIG. That is, even if the armature 5 is moved by a certain angle due to the action of an external force, a torque is applied to the armature 5 so as to return to the initial position, which is a magnetically stable point described above. Here, the energy products of the permanent magnets 2a, 2b, 3a and 3b and the dimensions of the yoke 1 and the armature 5 are determined so that the torque restored to the initial position is sufficiently larger than the detent torque of the motor and the disturbance received by the driven object. By doing so, the driven object is stably held at the initial position. This initial position does not change even if the characteristics of the permanent magnet change due to deterioration over time or the like.

Next, the case where the object to be driven is driven by the motor so as to be rotated by a predetermined angle will be described. In this case, the drive circuit 7 applies the above-described permanent magnet 2 to the electric coil 6.
a, 2b, 3a, and 3b are instructed to flow an electric current in a direction to cancel the magnetic flux created by them. Then, the holding torque of the present magnetic spring device in that case decreases as shown by the broken line (b) in FIG. Since the rotation angle of the driven object is determined at a position where the torque generated by the motor and the holding torque generated by the magnetic spring device are balanced, by increasing the magnitude of the current flowing through the electric coil 6, the output can be reduced accordingly. The positioning of the driven object can be performed by a small and small motor. Moreover,
The torque for stably holding the drive target at the initial position when the electric coil 6 is not energized can be made larger than the torque generated by the motor.

If the motor breaks down and continues to generate torque, or if the driven object is fixed while rotating at a certain angle, the drive circuit 7 applies the permanent magnets 2a, 2b, By instructing the current to flow in the direction to increase the magnetic flux generated by the motors 3a and 3b, the holding torque is increased as shown by the broken line (c) in FIG. Return to position,
It is possible to return from a fixed state to a normal state.

FIG. 4 is an explanatory diagram showing an application example when the present invention is applied to an engine throttle valve. As shown in FIG. 4, on the same axis as the rotating shaft 4 of the magnetic spring device of the present invention, a throttle valve 8 and a motor 10 to be driven and a position sensor 11 for detecting the opening of the throttle valve 8 are provided. ing. At this time, as shown in FIG. 5, the armature 5 and the throttle valve 8 of the magnetic spring device move the throttle valve 8 in the initial position where the armature 5 is held.
Is opened only by a predetermined minute opening degree. The outside of the yoke 1, the motor 10 and the position sensor 11 of the magnetic spring device is fixed to the throttle body 9 so as not to rotate. On the other hand, the amount of depression of the accelerator pedal 12 operated by the driver is signaled by an accelerator sensor 13 and sent to the ECU 14, and after the target opening of the throttle is determined, commands are sent to the motor drive circuit 15 and the magnetic spring device drive circuit 7, respectively. The value is sent. The signal from the position sensor 11 is always sent to the motor drive circuit 15 and is used for feedback control of the opening of the throttle valve 8, and it is always determined whether the operating states of the motor 10 and the throttle valve 8 are normal. Monitoring.

First, when the motor 10 is not driven, for example, when the engine is stopped, the throttle valve 8 is held in the above-described initial position in the magnetic spring device, that is, in a state where the throttle valve 8 is opened by a minute opening. The holding torque at this time is sufficiently larger than the detent torque of the motor 10 and can be set independently of the torque generated when the motor 10 is driven. With this operation, a constant throttle opening can be ensured even when the engine 10 does not generate torque due to disconnection or the like when the engine is started.

Next, during operation of the engine, when the driver operates the accelerator pedal 12, the signal is transmitted to the ECU 14 via the accelerator sensor 13. The ECU 14 performs a comprehensive calculation with signals from various sensors (not shown) and outputs a desired throttle opening to the motor drive circuit 15 and simultaneously outputs a signal indicating motor drive to the magnetic spring device drive circuit 7. The magnetic spring device drive circuit 7 supplies a current to the electric coil 6 in the direction of canceling the magnetic flux by this signal, and weakens the holding torque of the armature 5 to the extent that the torque generated by the motor 10 can sufficiently position the throttle valve 8. . With this operation, the motor drive circuit 15 can open the throttle valve 8 by the motor 10 based on the signal of the position sensor 11 at a predetermined opening.

Further, in the present configuration, an abnormal state in which the motor 10 continues to generate torque or the throttle valve 8 is stuck at the fully open position can be detected by the signal of the position sensor 11. In such a case, the ECU 14 sends an abnormal signal to the magnetic spring device drive circuit 7 so that the magnetic spring device drive circuit 7 applies the electric coil 6 in the opposite direction, that is, the magnetic flux in the magnetic circuit. Current can flow in the direction to increase Therefore, it becomes possible to return the throttle valve 8 to the initial position against the torque generated by the motor 10 or to escape from the fixed state.

FIG. 6 is an explanatory diagram showing an embodiment of the invention according to claim 5. The numbers of the components are the same as those described above. However, in the present embodiment, the electric coil is divided into two coils 6 a and 6 b and wound around the magnetic flux path of the yoke 1 on the stator side, is connected in series, and is connected to the drive circuit 7. In the embodiment of FIG. 1 described above, since the electric coil 6 performs a rotary motion together with the object to be driven by the torque generated by the motor or the like, a slack wiring or a slip ring or the like is provided between the drive circuit 7 and the electric coil 6. However, according to this configuration, since the electric coils 6a and 6b are fixed to the stator side, there is an advantage that it is not necessary to use the above-described power supply means.

FIG. 7 is an explanatory view showing an embodiment of the invention according to claim 6. In the above-described configuration, the energy product of the permanent magnets 2a, 2b, 3a, 3b used is such that a holding force enough to hold the driven object at a predetermined initial position sufficiently stably against the detent torque of the motor can be generated. If the torque generated when the motor is driven can drive the driven object against the holding torque in a state where the dimensions and the like of the yoke 1 are determined, a spring mechanism is used without using an electric coil as in this configuration. it can. In addition, since this configuration does not require an electric coil and a drive circuit, there is an advantage that a spring mechanism that has an initial position at a predetermined position and generates a biasing force in both positive and negative directions can be easily configured.

[0015]

As described above, according to the present invention, the configuration is such that the permanent magnets have a stable point at a certain angle around the rotation axis by the action of generating an attractive force between the permanent magnets. Since the magnetic spring that generates the restoring torque is formed on both sides in the rotation direction, and the magnetic flux is changed by the electric coil current in the magnetic circuit, the absolute value of the restoring force can be adjusted. Even if there is deterioration, the neutral point does not change, and the load at the time of driving can be reduced while the restoring torque at the time of stopping is increased, so that it is possible to drive with a small motor.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating the principle of an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an application example when the present invention is applied to an engine throttle valve.

FIG. 5 is an explanatory diagram showing an application example when the present invention is applied to an engine throttle valve.

FIG. 6 is an explanatory diagram showing another embodiment of the present invention.

FIG. 7 is an explanatory diagram showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 yoke 2a permanent magnet 2b permanent magnet 3a permanent magnet 3b permanent magnet 4 rotating shaft 5 armature 6 electric coil 6a electric coil 6b electric coil 7 drive circuit 8 throttle valve 9 throttle body 10 motor 11 position sensor 13 accelerator sensor 14 ECU 15 motor drive circuit

Claims (6)

[Claims] When the motor is not driven, the drive object is urged to a preset rotation position when the motor is not driven, and the motor is energized. A spring mechanism having a function of generating torque in a direction opposite to the rotation direction at the same time as the driven object is rotated when a torque is generated, wherein the spring mechanism includes a stator including a permanent magnet and a ferromagnetic material, A rotor comprising a permanent magnet, a ferromagnetic material, and an electric coil which is provided coaxially with the stator with a gap therebetween and is rotatable with respect to the stator, and a driving means for determining a current to the electric coil of the rotor A magnetic spring device comprising: 2. When the motor is not driven, the drive object is urged to a preset rotational position when the motor is not driven, and the motor is energized. A spring mechanism having a function of generating torque in a direction opposite to the direction of rotation at the same time as a driven object is rotated when torque is generated, wherein the spring mechanism is a fixed mechanism including a permanent magnet, a ferromagnetic material, and an electric coil. A stator, a driving means for determining a current to an electric coil of the stator, and a rotor comprising a permanent magnet and a ferromagnetic material which are installed coaxially with the stator with a gap therebetween and are rotatable with respect to the stator. A magnetic spring device characterized by being constituted. 3. When the motor is driven to generate a torque, the driving means energizes the current of the electric coil of the magnetic spring device so as to generate a magnetic field in a direction to cancel a magnetic flux generated by a permanent magnet. The magnetic spring device according to claim 1 or 2, wherein: 4. The driving device according to claim 1, wherein even if the motor is driven to generate torque, when any abnormality is detected in the motor or the driven object, the current of the coil of the magnetic spring device is immediately reduced to 0, 4. The magnetic spring device according to claim 1, wherein a current is applied to generate a magnetic field in a direction in which a magnetic flux generated by the permanent magnet is strengthened. 5. When the motor is not driven, the drive object is urged to a preset rotational position when the motor is not driven, and the motor is energized. A spring mechanism having a function of generating torque in a direction opposite to the rotation direction at the same time as the driven object is rotated when a torque is generated, wherein the spring mechanism includes a stator including a permanent magnet and a ferromagnetic material, A magnetic spring device comprising a permanent magnet rotatable with respect to the stator and a rotor made of a ferromagnetic material, which is installed coaxially with the stator with a gap therebetween. 6. The driving target is a throttle valve of an engine, and the magnetic spring device holds the throttle valve at an initial position opened by a predetermined amount when the motor is not driven, and when the motor is driven and the throttle valve rotates. And biasing toward the initial position.
A magnetic spring device according to any of the preceding claims.