JP3985632B2 - Eddy current reducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk type eddy current reduction device for assisting a main brake used in a vehicle such as an automobile. More specifically, the present invention is excellent in magnetic efficiency during braking, has a simple structure, and does not brake from a braking position of a permanent magnet. The present invention relates to an eddy current reduction device that reduces the power required for switching to a position and reduces the size and weight.
[0002]
[Prior art]
In braking systems for automobiles such as trucks and buses, in addition to foot brakes, which are the main brakes, exhaust brakes, which are auxiliary brakes, stable deceleration on long downhill slopes, etc. In order to prevent burning, an eddy current reduction device is used.
[0003]
One of the conventional eddy current reduction devices is a method in which an eddy current is generated in an opposing conductor while rotating using a permanent magnet, and the rotation is braked by a Lorentz force. Since this method is general, it is not shown in the figure, but usually a guide cylinder configured to contain a permanent magnet and move the permanent magnet to the switching position inside, and a rotor connected to the rotating shaft of the vehicle body outside the guide cylinder It consists of parts.
[0004]
[Problems to be solved by the invention]
In the eddy current reduction device in which the permanent magnet is disposed so as to face the brake disk, the holding body is moved in the direction to approach the brake disk during braking, and the permanent magnet is made to face and approach the brake disk. On the other hand, during non-braking, it is necessary to move the holding member in the direction away from it, and to separate the distance between the permanent magnet and the braking disk to some extent.
[0005]
The present invention reduces the power required to disconnect the permanent magnet from the braking disk when switching from braking to non-braking, and reduces the size and weight of equipment such as cylinders required for this. An object is to provide an eddy current reduction device of the type.
[0006]
[Means for Solving the Problems]
The gist of the present invention is the following eddy current reduction devices (1) to (4).
(1) A braking disk attached to a rotating shaft of a vehicle, a guide cylinder supported by a non-rotating portion via a support plate and disposed on the side of the braking disk, and housed in the guide cylinder, A holding ring that is movable in the direction of the rotation axis of the braking disk, and a plurality of permanent magnets that are opposed to the braking disk in the circumferential direction of the holding ring and in which adjacent magnetic poles are arranged in opposite directions, An eddy current reduction device capable of moving a permanent magnet back and forth between a braking position and a non-braking position in a rotational axis direction, comprising an attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet. , when the permanent magnet is in the braking position, when the detected value of the suction force detecting means is equal to or larger than a first set value, an eddy current reduction apparatus characterized in that the permanent magnet is moved to the non-braking position is there.
(2) A braking disk attached to a rotating shaft of a vehicle, a guide cylinder supported by a non-rotating portion via a support plate and disposed on the side of the braking disk, and housed in the guide cylinder, A holding ring that is movable in the direction of the rotation axis of the braking disk, and a plurality of permanent magnets that are opposed to the braking disk in the circumferential direction of the holding ring and in which adjacent magnetic poles are arranged in opposite directions, An eddy current reduction device capable of moving a permanent magnet back and forth between a braking position and a non-braking position in a rotational axis direction, comprising an attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet. An eddy current reduction device characterized in that, when the permanent magnet is in the non-braking position, the permanent magnet holds the non-braking position when the value detected by the attraction force detecting means is equal to or greater than a second set value. It is.
(3) a braking disk attached to the rotating shaft of the vehicle, a guide cylinder supported by a non-rotating portion via a support plate and disposed on the side of the braking disk, and housed in the guide cylinder, A holding ring that is movable in the direction of the rotation axis of the braking disk, and a plurality of permanent magnets that are opposed to the braking disk in the circumferential direction of the holding ring and in which adjacent magnetic poles are arranged in opposite directions, An eddy current reduction device capable of moving a permanent magnet back and forth between a braking position and a non-braking position in a rotational axis direction, comprising an attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet. The permanent magnet moves to the non-braking position and the permanent magnet is in the non-braking position when the permanent magnet is in the braking position and the detection value by the attraction force detecting means is equal to or greater than the first set value. When the suction force If the detected value by means out of the above second setting value, the permanent magnet is an eddy-current deceleration apparatus characterized by holding the non-braking position.
(4) In the eddy current reduction device described in the above (1) to (3), the eddy current reduction device is attached to a vehicle equipped with the device as means for directly or indirectly detecting the attractive force generated in the braking disk and the permanent magnet. A displacement meter that measures the displacement of the support plate, a load meter provided on the piston rod, a vehicle speed sensor that detects the vehicle speed of the vehicle on which the device is mounted , or a tachometer that measures the rotational speed of the braking disk is used. be able to.
[0007]
In the present invention, “first set value” and “second set value” are defined, and these are different set values. This is because the suction force at the time of braking and the suction force at the time of non-braking are completely different and cannot be treated as the same. That is, the value set when the vehicle is in the braking state is referred to as the “first setting value”, and the value set when the vehicle is in the non-braking state is the “second setting value”. As a result, the permanent magnet is in the non-braking position when it is equal to or greater than the “first set value”, and the permanent magnet is held in the non-braking position when it is originally equal to or greater than the “second set value”. .
[0008]
In the present invention, “the detected value is equal to or greater than the set value” means a state in which the detected suction force is equal to or stronger than the predetermined suction force. The value converted into the value detected by the “set value” is the “set value”.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Recently, demands for eddy current reduction devices have also diversified, and there has been a strong demand for improving mountability on vehicles so as to reduce manufacturing costs and enable mounting on small vehicles. In order to improve the mountability, it is required to be small and light, and to have a simple structure and excellent economy.
[0010]
In response to the above request, assuming a disk-type eddy current reduction device, the magnetic pole surface of the permanent magnet is made to approach and approach the braking disk, and a braking torque is generated on the disk itself (hereinafter referred to as “magnet pole surface facing”). In some cases, "method" is being studied. With this method, the magnetic field lines of the permanent magnet can be added to the braking disk with a short magnetic path length, so that the magnetic resistance of the magnetic circuit is reduced, the magnetic efficiency is improved, and the braking torque can be increased.
[0011]
FIG. 1 and FIG. 2 are sectional views showing an example of the configuration of a “magnet pole face facing type” eddy current reduction device using the permanent magnet of the present invention. FIG. 1 shows a device configuration during braking, and FIG. 2 shows a device configuration during non-braking.
[0012]
In this eddy current reduction device, a braking disk 2 made of a ferromagnetic material held on a rotating shaft 1 to which a tachometer 11 is attached, and a guide cylinder made of a non-magnetic material arranged on the side of the braking disk 2. It is composed of three. The guide tube 3 is supported by a non-rotating part of a vehicle or the like via a support plate 10, and a holding ring made of a ferromagnetic material capable of moving back and forth in the vertical direction with respect to the braking surface of the braking disk 2. 4 is accommodated, and the guide cylinder 3 is provided with a cylinder 5 for moving the holding ring 4 back and forth. On the other hand, a ferromagnetic material (pole piece) 8 is disposed on the end surface of the guide cylinder 3 facing the braking disk.
[0013]
A plurality of permanent magnets 7 are arranged in the circumferential direction on the side surface of the retaining ring 4 facing the braking disk 2. The direction of the magnetic pole of the permanent magnet 7 faces the braking surface of the braking disk 2, and the magnetic poles of the adjacent permanent magnets are arranged in opposite directions. A plurality of ferromagnetic materials 8 facing the magnetic pole surface of each permanent magnet 7 are arranged so as to make a pair with the permanent magnet 7 in the circumferential direction.
[0014]
The drive mechanism of the permanent magnet 7 is such that a cylinder 5 is disposed on the outer end wall of the guide tube 3, and a piston rod 6 fitted to the cylinder 5 passes through the outer end wall of the guide tube 3 and is coupled to the holding ring 4. Yes. With this configuration, the holding ring 4 can be moved forward and backward in the direction perpendicular to the brake disk 2 by the operation of the cylinder 5.
[0015]
During braking, the piston rod 6 of the cylinder 5 moves to the right as shown by the arrow in FIG. 1, the holding ring moves forward in the direction of the rotation axis of the braking disk 2, and the permanent magnet 7 approaches the braking disk. To do.
[0016]
At this time, when each of the permanent magnets 7 passes through the ferromagnetic material 8 and crosses the braking disk 2 that rotates the magnetic field lines perpendicular to the braking surface of the braking disk 2, an eddy current is generated in the braking disk 2 due to a change in magnetic flux in the braking disk. Flow and braking torque are generated.
[0017]
When switching to non-braking, the operation of the cylinder 5 is switched, and the holding ring 4 directly connected to the piston rod 6 is moved to the left as shown by the arrow in FIG. The magnetic force exerted on the braking disk 2 by the permanent magnet 7 away from the (pole piece) 8 is weak.
[0018]
In the “magnet pole face facing type” eddy current reduction device using permanent magnets shown in FIGS. 1 and 2, a ferromagnetic material (pole piece) is provided. This is because the permanent magnet has a strong temperature dependence, and when the temperature exceeds a certain temperature, the magnetic force decreases and the braking torque decreases. Therefore, in order to suppress the temperature rise of the permanent magnet, the permanent magnet is placed between the permanent magnet and the braking disk as the heat source. By providing an appropriate distance. That is, as these distances increase, the braking torque decreases, so that a ferromagnetic material (ball piece) is interposed between them to minimize the gap on the magnetic circuit.
[0019]
However, in comparison with the drum type in which the guide cylinder is covered with a drum, the disc type can have a structure in which the guide cylinder is exposed to the outside of the brake disk, which is a heat generating portion. Therefore, even if the heat input to the guide tube is the same, the disc type guide tube can be in direct contact with the outside air, and the area that can be cooled can be increased. Can be suppressed.
[0020]
Furthermore, by making the structure of the device a disk type, it becomes easier to attach cooling fins than the drum type, and the heat dissipation capability of the brake disk, which is a heat source, can be increased. Therefore, the temperature rise of the permanent magnet can be suppressed during braking, and in addition, the heat itself transmitted from the braking disk can be reduced, so that the distance between the permanent magnet and the braking disk can be extremely reduced.
[0021]
As a result, the permanent magnet can be made sufficiently close to the braking disk, and a sufficient braking torque can be secured even if the magnetic circuit is configured without using a ferromagnetic material (pole piece). Based on such knowledge, a “magnet pole face facing type” eddy current reduction device that does not use another ferromagnetic material (pole piece) has been studied.
[0022]
Although FIG not shown, in the eddy current reduction apparatus is the action of the basic structure and members the same as the eddy current reduction apparatus "magnet poles face opposite method" shown in FIGS. 1 and 2, The guide tube 3 is made of a non-magnetic material without placing a ferromagnetic material (pole piece) on the end surface facing the brake disk.
[0023]
In addition, this type of eddy current reduction device can add the magnetic lines of force from the permanent magnet directly to the braking disk with a short magnetic path length without providing a ferromagnetic material (pole piece). Can be improved.
[0024]
As described above, the eddy current reduction device in which the permanent magnet is disposed so as to face the braking disk is excellent in magnetic efficiency during braking, can have a simple structure, and is excellent in economy. However, as future demands diversify, new issues to be addressed include dealing with further miniaturization and weight reduction.
[0025]
In these eddy current reduction devices, when the permanent magnet is brought close to the braking disk from the non-braking position away from the braking disk and switched to the braking position, the permanent magnet and the ferromagnetic braking disk are attracted. Therefore, little power is required to switch the permanent magnet. However, when the permanent magnet is separated from the braking disk and switched to the non-braking position, a great amount of power is required to overcome the attractive force generated in the permanent magnet and the braking disk. For this reason, a device that generates a large amount of power is required to move the permanent magnet and switch from the braking position to the non-braking position, which causes an increase in the size and weight of the device.
[0026]
In order to solve the above-mentioned problems, the present inventors have focused on the attractive force generated in the brake disk and the permanent magnet, and have examined the downsizing and weight reduction of the eddy current reduction device in more detail. (A) to (e) were obtained.
(a) As described above, in order to pull the permanent magnet away from the braking position where the permanent magnet is brought close to the braking disk made of a ferromagnetic material and switch it to the non-braking position, the attractive force generated in the braking disk and the permanent magnet is reduced. A great deal of power is needed to overcome it. Therefore, a device that generates a large amount of power is required for switching the permanent magnet.
[0027]
For example, as shown in FIG. 1 to FIG. 2, if the system moves the permanent magnet with a cylinder, it is necessary to increase the diameter of the cylinder or increase the number of cylinders to be arranged. And the mountability to the vehicle becomes worse.
[0028]
For this reason, it is possible to reduce the necessary power by switching the permanent magnet to the non-braking position and releasing the braking at a stage where the attractive force generated in the braking disk and the permanent magnet is relatively low. As a result, since the power generation device such as the cylinder can be of a small capacity, the device can be reduced in size and weight.
(b) When a permanent magnet is brought close to a rotating braking disk made of ferromagnetic material and a magnetic force is applied, an eddy current is generated near the surface of the braking disk. Although the braking force acts on the brake disk by the action of the eddy current and the magnetic force, a repulsive magnetic field is generated at the same time by the action of the eddy current and the rotating braking disk. Since the direction of the magnetic force of the repulsive magnetic field is opposite to the direction of the line of magnetic force of the permanent magnet, a part of the magnetic force from the magnet acting on the braking disk is offset by the repulsive magnetic force, and the magnetic force acting on the braking disk apparently decreases. .
[0029]
The higher the number of revolutions of the brake disk, the greater the eddy current generated, and the stronger the repulsive magnetic force. That is, the higher the number of revolutions of the brake disk, the lower the apparent magnetic force acting on the brake disk and the lower the attractive force generated on the brake disk and the permanent magnet.
(c) From the knowledge of (a) and (b) above, when the permanent magnet is brought close to the braking disk, the attraction force generated on the braking disk and the permanent magnet is maximum when the braking disk is stationary, and the rotational speed is It can be seen that the suction force decreases with each increase. The power required to switch the permanent magnet from the braking position to the non-braking position must exceed the attractive force generated in the braking disk and the permanent magnet. Therefore, the lower the number of revolutions of the braking disk, the more necessary the switching is. Power increases.
[0030]
Therefore, when the number of rotations of the brake disk becomes a predetermined value or less, the necessary power can be reduced by switching the permanent magnet to the non-braking position and releasing the braking. As a result, the power generation device such as a cylinder necessary for switching can be reduced in capacity, so that the device can be reduced in size and weight.
(D) Normally, the braking disk is fixed to the rotating shaft of the vehicle, and the low rotational speed of the braking disk corresponds to the vehicle traveling at a low speed. Since the braking force required by the vehicle is low during this low speed traveling, there is a reserve in brakes other than the eddy current reduction device, such as a foot brake, an engine brake, an exhaust brake, and the like. Therefore, when the rotational speed of the brake disk is low and the vehicle is traveling at a low speed, the vehicle does not have insufficient braking force even if the eddy current reduction device is in the non-braking state.
(E) As means for directly detecting the attractive force generated in the brake disk and the permanent magnet, a rotation meter for measuring the rotation speed of the brake disk and a displacement amount of a support plate attached to a vehicle on which the device is mounted are measured. It may be a displacement meter or a load meter (load cell) provided on the piston rod. Furthermore, a vehicle speed sensor that detects the vehicle speed of a vehicle equipped with the device can be used as a means for indirectly detecting the suction force. Any detection means can directly or indirectly detect the attractive force generated in the brake disk and the permanent magnet.
[0031]
In the eddy current reduction device of the present invention, means for detecting the attractive force generated in the braking disk and the permanent magnet is provided, and when the permanent magnet is in the braking position and the attractive force exceeds the set value, the permanent magnet is brought into the non-braking position. By switching and releasing the braking, it is possible to reduce the size and weight of the device without requiring excessive power and without impairing the braking performance of the vehicle.
[0032]
As a means for detecting the attractive force generated in the brake disk and the permanent magnet, a tachometer for measuring the rotation speed of the brake disk can be used. Usually, the braking disk is fixed to the rotating shaft of the vehicle, and the rotating shaft is integrally connected. Therefore, either the rotational speed of the braking disk or the rotational speed of the rotating shaft may be measured. In some cases, a speed increasing rotation mechanism is provided between the rotating shaft of the vehicle and the braking disk. In this case, the speed of the braking disk may be detected by converting the speed increasing ratio. The tachometer used for measurement may be a contact type or a non-contact type.
[0033]
Furthermore, using a displacement meter as means for detecting the suction force, the amount of displacement detected at a specific site can be used as a reference set value. For example, the attracting force generated in the brake disk and the permanent magnet can be detected by attaching a support plate for the guide cylinder that houses the permanent magnet to the fixed portion of the vehicle body and measuring the amount of displacement with a displacement meter.
[0034]
When an attractive force is generated in the brake disk and the permanent magnet, the guide cylinder and the support plate that accommodate the permanent magnet are attracted to the brake disk and deformed, but the amount of displacement depends on the attractive force. Therefore, if this displacement amount is measured, the suction force generated based on the measured result can be detected. As an example, the case where a displacement meter is attached to the support plate of the guide cylinder is shown, but the present invention is not limited to this part, and the displacement amount of any part is detected as long as it is a fixed part of the eddy current type speed reducer It may be.
[0035]
A vehicle speed sensor can be used as means for indirectly detecting the suction force, and braking can be released based on the detected vehicle speed. Since the rotational speed of the rotating shaft of the vehicle and the vehicle speed have a relative relationship, as described above, the attractive force generated in the brake disk and the permanent magnet can be predicted based on the detected vehicle speed.
[0036]
Further, a load meter (load cell) interposed between the holding ring and the piston rod can be used as means for detecting the attractive force generated in the brake disk and the permanent magnet. The load is measured from the amount of piston rod strain generated due to the suction force, and braking is released when the output value exceeds a predetermined value.
[0037]
【Example】
Hereinafter, a specific configuration example of the eddy current reduction device of the present invention and an example of applicable control will be described based on Examples 1 to 2.
Example 1
1 and 2 are diagrams illustrating the configuration of the eddy current reduction device used in the first embodiment. The brake disc 2 is integrally attached to the rotating shaft 1 of the vehicle. On the other hand, the guide cylinder 3 is supported by a support plate 10 attached to a vehicle body, for example, a rear cover of a transmission, and is disposed on the side of the brake disk 2. At this time, the guide tube 3 is arranged so that a predetermined gap is secured between the brake disk 2 and the end surface of the guide tube.
[0038]
A holding ring 4 capable of moving back and forth in the vertical direction with respect to the brake disk 2 is accommodated in the guide tube 3, and a plurality of permanent magnets 7 are circumferentially arranged on the side surface of the holding ring 4 facing the brake disk 2. Is arranged. The direction of the magnetic poles of the permanent magnet 7 is opposed to the braking surface of the braking disk 2, and the magnetic poles of the adjacent permanent magnets are arranged in opposite directions. A plurality of ferromagnetic materials (pole pieces) 8 are arranged in the circumferential direction on the end face of the guide cylinder 3 facing the brake disk so as to face the magnetic pole face of each permanent magnet 7.
[0039]
Further, the guide cylinder 3 is provided with a cylinder 5 necessary for moving the holding ring 4 forward and backward, and a piston rod 6 fitted to the cylinder 5 penetrates the outer end wall of the guide cylinder 3 to the holding ring 4. Are connected. By the operation of the cylinder 5 and switching thereof, the permanent magnet 7 can freely move forward and backward along the rotational axis direction between the braking position and the non-braking position.
[0040]
Using the eddy current reduction device shown in FIGS. 1 and 2, the relationship between the rotational speed of the braking disk and the power required for switching from braking to non-braking was tested. The brake disk 2 used was made of CrMo-based low alloy steel and had an outer diameter of 450 mm and a thickness of 10 mm. The opposing guide tube 3 is made of an aluminum alloy and has an outer diameter of 450 mm, an inner diameter of 260 mm, and a thickness of 10 mm. Sixteen permanent magnets 7 are arranged on the side circumference of the retaining ring 4. The support plate 10 that supports the guide tube is made of cast steel and has a thickness of 7 mm, and a tachometer 11 for measurement is attached to the rotating shaft.
[0041]
During the test, the braking torque was adjusted to 70 kgm when the rotational speed of the braking disk 2 was 2000 rpm. The rotational speed of the brake disk 2 is measured with the tachometer 11 attached to the rotary shaft 1, and the power required for switching from braking to non-braking at each rotational speed is measured by changing to 0 rpm, 600 rpm, 1000 rpm, 1600 rpm and 2000 rpm. did. The power required for switching from braking to non-braking was measured by connecting a load meter (not shown) to the intermediate portion of the piston rod, assuming that it is equivalent to the attractive force generated in the braking disk 2 and the permanent magnet 7.
[0042]
FIG. 3 is a diagram showing the relationship between the rotation speed of the brake disk and the power required for switching from braking to non-braking. As is clear from the results of FIG. 3, the lower the rotational speed of the brake disk 2, the greater the attractive force generated in the brake disk 2 and the permanent magnet 7, so that the permanent magnet 7 is switched from the braking position to the non-braking position. The power required for is increased. From this result, the power required for switching can be reduced by switching from braking to non-braking when the number of rotations of the braking disk falls below a predetermined value based on the detection value of the tachometer, and consequently the device It can be seen that the size and weight can be reduced.
(Example 2)
FIG. 5 is a diagram illustrating the configuration of the eddy current reduction device used in the second embodiment. In the eddy current reduction device used in the second embodiment, the displacement meter 12 is arranged on the support plate 10 in addition to attaching the tachometer 11 to the rotary shaft 1, but the other is the eddy current used in the first embodiment. The configuration of the reduction gear is the same. The displacement meter 12 is arranged at a position 130 mm in the radial direction from the center of the rotary shaft 1 so as to measure the amount of displacement of the support plate on the surface opposite to the side on which the braking disk 2 is arranged.
[0043]
Using the eddy current reduction device shown in FIG. 5 , the relationship between the rotational speed of the brake disk and the displacement of the support plate was tested. During the test, as in Example 1, the braking torque was adjusted to 70 kgm when the rotational speed of the braking disk 2 was 2000 rpm. The rotation speed of the braking disk 2 was measured with a tachometer 11 attached to the rotary shaft 1 and changed to 0 rpm, 600 rpm, 1000 rpm, 1600 rpm, and 2000 rpm. The displacement amount of the support plate 10 at this time was measured with a displacement meter 12.
[0044]
FIG. 4 is a diagram showing the relationship between the rotation speed of the brake disk and the displacement amount of the support plate. The lower the rotation speed of the brake disk 2, the greater the displacement of the support plate. This is because the attractive force generated in the brake disk 2 and the permanent magnet 7 is larger as the rotation speed of the brake disk 2 is lower from the result of FIG. For this reason, since the displacement amount of the support plate is substantially proportional to the attractive force generated in the braking disk and the permanent magnet, if the relationship between the two is obtained in advance, when the displacement amount of the support plate becomes a predetermined value or more, It can be seen that the power required for switching can be reduced by switching from braking to non-braking.
[0045]
In addition, if the amount of displacement of the support plate is originally larger than the value set separately, the extra switching operation is maintained by maintaining the non-braking state even when a signal for switching the braking state is input. You can avoid it.
[0046]
FIG. 6 is a diagram illustrating an example of a schematic configuration that can be applied to the switching control between braking and non-braking that can be applied in the eddy current reduction device of the present invention. The eddy current reduction device includes a braking disk 2 that is directly connected to the rotating shaft 1 and a guide cylinder 3 that houses a holding ring 4 and a permanent magnet 7. As a drive mechanism for the permanent magnet 7, a cylinder 5 is disposed on the outer end wall of the guide cylinder 3, and a piston rod 6 fitted to the cylinder 5 passes through the outer end wall of the guide cylinder 3 and is coupled to the holding ring 4. Yes.
[0047]
Due to the action of the electromagnetic switching valve 14, one of the two end chambers 5a and 5b of the cylinder 5 communicates with the air source 13, and the other communicates with the atmosphere. When the electromagnetic switching valve 14 excites the electromagnetic coil, the valve body moves to the illustrated braking position. When the electromagnetic switching valve 14 demagnetizes the electromagnetic coil, the valve body receives a spring force and moves to the left, the pressurized air from the air source 13 is supplied to the end chamber 5b of the cylinder 5, and the end chamber 5a of the cylinder 5 Released to the atmosphere. Then, the permanent magnet 7 moves to the left together with the piston rod 6 and switches to the non-braking position.
[0048]
The electromagnetic switching valve 14 is energized through a release switch 15 that is opened and closed by the output of the electronic control device 16. The release switch 15 is connected to the power battery 17. The electronic control device 16 for controlling the eddy current reduction device includes a reduction device ON / OFF command based on input signals from a deceleration switch, an accelerator sensor, a clutch sensor, and the like, a detection value from the attraction force detection means 11, and this electronic control. A braking condition is determined from a command (ON or OFF) issued by the device 16 itself according to a flowchart shown in FIG. 7 to be described later, and an output signal is generated, whereby the release switch 15 is opened or closed.
[0049]
FIG. 7 is a diagram showing an example of a braking and non-braking switching control flowchart applicable to the eddy current reduction device of the present invention. In the drawing, Fs: suction force detection value, F1: first set value (“braking release” set value during braking), and F2: second set value (“braking release” set value during non-braking) Each is shown.
[0050]
First, when the suction force Fs is larger than F1, the release switch 15 is opened, that is, if it is in a braking state at that time, it is switched to a non-braking state. However, at that time, the non-braking state is maintained if it is in the non-braking state.
[0051]
Next, when the suction force Fs is smaller than F1, if the deceleration device ON / OFF command such as the accelerator is OFF (no deceleration), the release switch 15 is opened (non-braking state), and the deceleration device ON / OFF If the command is ON (decelerates), the determination is made based on the braking state at that time. If the state at that time is a braking state, the release switch remains closed and the braking state is maintained. If the state at that time is a non-braking state, the suction forces Fs and F2 are compared. If the suction force Fs is smaller than F2, the non-braking state is switched to the braking state, and the suction force Fs is greater than F2. If it is larger, the non-braking state is maintained.
[0052]
And by repeating the procedure shown in this flowchart periodically, efficient control can be performed while always monitoring the state.
[0053]
For example, when the suction force Fs is smaller than F1, the deceleration device ON / OFF command is ON (decelerates), and the release switch 15 is open (non-braking state), and the suction force Fs is greater than F2. The electronic control device 16 issues a signal for opening the release switch 15, and the pressurized air from the air source 13 is continuously supplied to the end chamber 5b of the cylinder 5. As a result, the permanent magnet 7 remains moved to the left, and the non-braking state is maintained.
[0054]
【The invention's effect】
According to the eddy current reduction device of the present invention, the magnetic efficiency at the time of braking is excellent and the structure is simple, the power required for switching the permanent magnet from the braking position to the non-braking position is reduced, and the size and weight are reduced. Can be achieved. Thereby, it becomes possible to remarkably improve the mountability to the vehicle.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a configuration example during braking of an eddy current reduction device of a “magnet pole face facing type” as an example of the present invention.
FIG. 2 is a diagram for explaining a configuration example of the “magnet pole face facing type” eddy current reduction device at the time of non-braking as an example of the present invention;
FIG. 3 is a diagram showing the relationship between the number of rotations of a brake disk and the power required for switching from braking to non-braking.
FIG. 4 is a diagram showing a configuration of another eddy current reduction device as an example of the present invention.
FIG. 5 is a diagram showing the relationship between the number of rotations of the brake disk and the amount of displacement of the support plate.
FIG. 6 is a diagram showing an example of a schematic configuration of switching control between braking and non-braking that can be applied in the eddy current reduction device of the present invention.
FIG. 7 is a diagram showing an example of a braking and non-braking switching control flowchart applicable to the eddy current reduction device of the present invention.
[Explanation of symbols]
1: rotating shaft, 2: braking disk 2a: support end, 3: guide tube 4: holding ring, 5: cylinder 6: piston rod, 7: permanent magnet 8: ferromagnetic material, pole piece 10: support plate, 11: Detection means, tachometer 12: displacement meter 13: air source 14: electromagnetic switching valve 15: release switch 16: electronic control unit 17: power supply battery

Claims (7)

A brake disc attached to the rotating shaft of the vehicle ;
A guide cylinder that is supported by a non-rotating part via a support plate and is arranged on the side of the braking disk;
A holding ring that is accommodated in the guide cylinder and is movable in the direction of the rotation axis of the brake disc;
A plurality of permanent magnets that are opposed to the brake disk in the circumferential direction of the retaining ring and in which adjacent magnetic poles are arranged in opposite directions, and
An eddy current reduction device capable of moving the permanent magnet back and forth in the rotational axis direction between a braking position and a non-braking position,
An attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet;
When the permanent magnet is in the braking position ,
The eddy current reduction device according to claim 1, wherein the permanent magnet moves to a non-braking position when a value detected by the attractive force detection means is equal to or greater than a first set value. A brake disc attached to the rotating shaft of the vehicle ;
A guide cylinder that is supported by a non-rotating part via a support plate and is arranged on the side of the braking disk;
A holding ring that is accommodated in the guide cylinder and is movable in the direction of the rotation axis of the brake disc;
A plurality of permanent magnets that are opposed to the brake disk in the circumferential direction of the retaining ring and in which adjacent magnetic poles are arranged in opposite directions, and
An eddy current reduction device capable of moving the permanent magnet back and forth in the rotational axis direction between a braking position and a non-braking position,
An attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet;
When the permanent magnet is in the non-braking position,
The eddy current reduction device, wherein the permanent magnet holds a non-braking position when a value detected by the attraction force detecting means is equal to or greater than a second set value. A brake disc attached to the rotating shaft of the vehicle ;
A guide cylinder that is supported by a non-rotating part via a support plate and is arranged on the side of the braking disk;
A holding ring that is accommodated in the guide cylinder and is movable in the direction of the rotation axis of the brake disc;
A plurality of permanent magnets that are opposed to the brake disk in the circumferential direction of the retaining ring and in which adjacent magnetic poles are arranged in opposite directions, and
An eddy current reduction device capable of moving the permanent magnet back and forth in the rotational axis direction between a braking position and a non-braking position,
An attraction force detecting means for detecting an attraction force generated between the braking disk and the permanent magnet;
When the permanent magnet is in the braking position,
When the detection value by the attraction force detection means is equal to or greater than a first set value, the permanent magnet moves to the non-braking position,
When the permanent magnet is in the non-braking position,
The eddy current reduction device, wherein the permanent magnet holds a non-braking position when a value detected by the attraction force detecting means is equal to or greater than a second set value. 4. The eddy current reduction device according to claim 1, wherein the attraction force detecting means is a displacement meter for measuring a displacement amount of a support plate attached to a vehicle on which the device is mounted . 4. The eddy current reduction device according to claim 1, wherein the attraction force detecting means is a vehicle speed sensor that detects a vehicle speed of a vehicle equipped with the device.   The eddy current according to any one of claims 1 to 3, wherein the attraction force detecting means is a load cell (load cell) interposed between the holding ring and means for moving the holding ring in the direction of the rotation axis. Reducer.   4. The eddy current reduction device according to claim 1, wherein the attraction force detecting means is a tachometer that measures the number of rotations of the brake disk.

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