JP2002233197A - Control method for braking force of eddy-current reduction gear and actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a rise in temperature, even at continuous braking over a long time, without causing losses of a braking effect at braking over a short time. SOLUTION: In an eddy-current reduction gear, which switches on/off braking by moving a permanent magnet 1 from a non-braking position to a braking position, an actuator 5 constituting an on/off switch is used, of which the stroke is set to be St2 longer than a stroke St1 required for switching on/off braking, and the permanent magnet 1 is moved to a position where a braking force becomes strongest immediately after the starting of braking, and the braking force is then restrained by moving the permanent magnet 1 in the forward or backward direction. Accordingly, the stable braking effect independent of an elapsed time can be obtained by restraining the generated braking force from lowering after long braking, without increasing the initial braking force to be more than required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a braking force of an eddy current type reduction gear mounted on a large vehicle such as a bus or a truck as a braking assist device, and an actuator suitable for carrying out the method. In particular, it is possible to increase the fade rate of the braking force of the eddy current type speed reducer.

[0002]

2. Description of the Related Art In recent years, for large vehicles such as buses and trucks, the number of times a foot brake is used on a downhill road is reduced to prevent abnormal wear of a lining and a fade phenomenon, and to shorten a braking stop distance. For this purpose, eddy current type reduction gears have come to be mounted in addition to a foot brake which is a main brake and an exhaust brake which is an auxiliary brake. Recently, many eddy current type speed reducers which use a permanent magnet as a magnetic pole and do not need to be energized at the time of braking, as disclosed in Japanese Patent Application Laid-Open No. 1-298948, have been increasing.

[0003]

However, if the permanent magnet type eddy current type speed reducer is used for a long time, the temperature of the rotor rises, and the performance is deteriorated due to damage such as thermal deformation and generation of thermal cracks of the rotor. There is a fear. In particular, when the braking force is large, the amount of heat generated by the rotor due to braking is large, and the temperature of the rotor rises rapidly, so that the rotor becomes hot in a short time, and the braking must be interrupted even on a downhill. In some cases, there is a problem that the braking duration cannot be long. On the other hand, if the braking force is reduced in order to suppress the heat generation of the rotor, the braking torque at the time of frequent and short braking is reduced, and a sufficient braking effect cannot be obtained.

The present invention has been made in view of the above-mentioned problems of the conventional eddy current type speed reducer, and does not impair the braking effect at the time of short-time braking which is frequently used, and continuously operates for a long time. It is an object of the present invention to provide a braking force control method for an eddy current type reduction gear capable of suppressing a rise in temperature of a rotor even during braking and extending a braking duration, and an actuator suitable for implementing the braking force control method. The purpose is.

[0005]

In order to achieve the above object, according to the present invention, in an eddy current type speed reducer for switching ON / OFF of braking by moving a magnet from a non-braking position to a braking position, The stroke of the actuator constituting the -OFF switching device is, for example, ON-O for braking.
By using an actuator longer than the stroke required to switch the FF, the magnet is moved to the position where the braking force is maximized immediately after the start of braking, and thereafter the magnet is moved forward and backward to suppress the braking force. . By doing so, the braking effect during short-time braking that is frequently used is not impaired, and the temperature rise of the rotor can be suppressed even during long-time continuous braking, so that the braking duration can be extended. Become.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors move a magnet from a non-braking position to a braking position to turn on / off braking.
By changing the stroke of the actuator of the eddy current type reduction gear that changes the braking, we investigated the transition of the braking force with the elapsed braking time and the effect of extending the braking duration,
As shown in FIG. 8, the stroke St required to switch the stroke of the actuator between the ON and OFF states of the braking operation.
Even when the stop position of the magnet is moved further forward than the position where the braking force is greatest by setting it longer than St1 by St2, it is found that the braking force does not change much if the braking elapsed time is short. did. On the other hand, as shown in FIG. 9, the longer the stroke of the actuator is than the stroke St1 required to switch ON / OFF of the braking, that is, the longer the St2 is, the longer the braking duration is. It has been found.

The braking force control method for an eddy current type speed reducer according to the present invention is based on the above-mentioned knowledge of the present inventors, and the braking is performed by moving a magnet from a non-braking position to a braking position. In the eddy current type deceleration device that switches ON and OFF, the magnet is moved to a position where the braking force is maximized immediately after the braking is started, and thereafter the magnet is moved forward and backward to suppress the braking force. .

As in the braking force control method for an eddy current type reduction gear according to the present invention, the magnet is moved to a position where the braking force is maximized immediately after the braking is started, and thereafter the magnet is moved forward and backward. As described above, the braking effect during frequently used short-time braking is not impaired, and the rotor temperature can be suppressed even during long-time continuous braking, so that the braking duration can be extended. Become.

In implementing the method for controlling the braking force of the eddy current type reduction gear according to the present invention, the stroke of the actuator constituting the ON-OFF switching device is controlled by the ON-O of the braking.
Use a stroke longer than the stroke required to switch the FF. This is the actuator of the first eddy current type reduction gear according to the present invention.

In the actuator of the first eddy current type speed reducer according to the present invention, a spring is provided at the protruding end of the piston rod in the cylinder, and the natural length position and compression of the spring in the cylinder are reduced. A second piston is provided so as to be slidable between the limit positions, and a stroke necessary for switching ON / OFF of the braking is set at a natural length position of the spring from the retreat limit position of the piston rod. When the first piston is moved to the length of the piston, and the movement of the piston rod exceeding the stroke is obtained by compression of the spring,
After the magnet is moved to the position where the braking force is maximized, the magnet can be easily moved forward. This is the actuator of the second eddy current type reduction gear according to the present invention.

Further, in place of the actuator of the second eddy current type speed reducer according to the present invention, the stroke of the actuator is changed to only the stroke necessary for switching ON / OFF of braking, and is shown in FIG. Thus, the spring force is larger than the cylinder propulsion force at the piston rod protruding limit position, and the spring force is reduced inside the cylinder so that the spring force becomes smaller as the piston rod retreats and becomes smaller than the cylinder propulsion force. When it is arranged on the outside or as shown in FIG. 11, when the piston rod projects, both the compressive force and the tensile force are applied, and at a position before the piston rod reaches the projecting limit. Even if the spring is arranged inside or outside the cylinder so that the magnetic reaction force and the spring force are balanced, the position where the braking force becomes the largest is obtained. The retreating movement of the magnet after moving the stones so easily. This is the third aspect of the present invention.
4 is an actuator of the eddy current type speed reducer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An actuator of an eddy current type reduction gear according to the present invention will be described below with reference to the embodiments shown in FIGS. 1 to 7, and the braking force of the eddy current type reduction gear according to the present invention will be described using this actuator. A case where the control method is performed will be described. FIGS. 1A and 1B are diagrams illustrating the operation of an actuator according to the first embodiment of the present invention applied to a single-row turning type eddy current type reduction device together with the position of a magnet. FIG. ) Is an explanatory diagram when the maximum braking force is generated, (c) is an explanatory diagram when the braking force is suppressed from the maximum braking force, and FIG.
FIG. 3 is a diagram illustrating the operation of the actuator according to the present invention.
(A) is an explanatory diagram of the braking OFF, (b) is an explanatory diagram when switching from the braking OFF to the braking ON, (c) is an explanatory diagram of when the maximum braking force is generated, and (d) is a control that is more effective than the maximum braking force. FIGS. 3 and 4 are diagrams illustrating the operation of the actuator according to the third embodiment of the present invention when the power is suppressed. FIG.
(B) is an explanatory diagram of the protruding limit position, (c) is an explanatory diagram of retreating from the protruding limit position, (d) is an explanatory diagram of braking OFF, and FIGS. FIGS. 7A and 7B are diagrams for explaining the operation of the actuator according to the present invention, wherein FIG. 8A is an explanatory diagram at the time of braking ON, FIG. 7B is an explanatory diagram of a protruding limit position, FIG. d) is an explanatory diagram when braking is OFF,
FIG. 7 is an explanatory view of another method of controlling the braking force of the eddy current type reduction gear according to the present invention when the actuator according to the first present invention is used, and FIG. b)
Is an explanatory view of retreating from the protruding limit position, and FIG.
FIG.

In FIG. 1, reference numeral 1 denotes a rotor which is supported opposite to a rotor integrally mounted on a rotating shaft, and is rotatable by a required angle so that the directions of magnetic poles are opposite to each other along the circumferential direction of the rotor. A permanent magnet group arranged at a predetermined interval on a ferromagnetic support ring 2; and between the permanent magnet group 1 and the cylindrical portion 3 of the rotor, each permanent magnet group of the permanent magnet group 1 is provided. A group of ferromagnetic switch plates 4 is interposed at basically the same angular position as that of the switch plate 1.

In the single-row turning type eddy current type speed reducer having the above-described structure, as shown in FIG.
The actuator 5 is moved from a non-braking position in which one permanent magnet 1 overlaps the adjacent switch plate 4 by half each time to a braking position in which the permanent magnet 1 overlaps the switch plate 4 as shown in FIG. The ON / OFF of the braking is switched by, for example, projecting the piston rod 5a and turning the permanent magnet 1 to turn.

The actuator 5 according to the first aspect of the present invention, as shown in FIG. 1 (b), changes the stroke by St2 from the stroke St1 required to switch the braking ON / OFF. It has a longer configuration.

When switching ON / OFF of the braking by using the actuator 5 according to the first aspect of the present invention, first, immediately after the braking is started, the anti-piston state is changed from the non-braking state shown in FIG. By supplying compressed air into the cylinder 5b on the side of the rod 5a, the piston rod 5a of the actuator 5 is protruded and moved by the stroke St1.
The permanent magnet 1 is moved to the braking position where the braking force is maximized as shown in FIG.

Thereafter, the anti-piston rod 5a
Compressed air is further supplied into the cylinder 5b on the side of the cylinder, and the permanent magnet 1 is moved to the stroke S as shown in FIG.
The braking force is suppressed by moving forward within the range of t2. This is the braking force control method of the present invention using the first actuator 5 of the present invention.

According to the braking force control method of the present invention, it is possible to suppress a rise in the temperature of the rotor even during continuous braking for a long time without impairing the braking effect during frequently used short-time braking. It is possible to extend the duration.

However, when the actuator 5 whose stroke is simply extended by St2 is used, the permanent magnet 1 generates the maximum braking force immediately after the braking is started.
Since the vehicle passes through the position shown in (b) instantaneously, the braking effect for a short time may be insufficient.

Therefore, St2 having the structure as shown in FIG.
By employing the actuator 6 having only a longer stroke, there is no fear that the short-time braking effect described above becomes insufficient. That is, in FIG. 2, reference numeral 7 denotes a spring provided inside the protruding end of the piston rod 6a in the cylinder 6b of the actuator 6, and 6c denotes a natural length position of the spring 7 in the cylinder 6b (FIG.
(C)) and the compression limit position (see FIGS. 2 (a) and 2 (b))
This is a second piston provided so as to be slidable therebetween.

In the actuator 6 shown in FIG. 2, the stroke St1 required for switching ON / OFF of the braking is changed to the second piston 6c shown in FIG.
2B in which the second piston 6c is returned to the natural length position of the spring 7 by the reaction force of the spring 7 from the retreat limit position (braking OFF position) of the piston rod 6a in a state where the spring 7 is compressed. 2), the first piston 6d is moved to the second piston 6c located at the natural length position of the spring 7 shown in FIG. 2C, and the piston rod 5a exceeds the stroke St1. Figure 2
As shown in (d), the spring 7 is obtained by compression. This is the actuator of the second eddy current type reduction gear according to the present invention. In FIG. 2, 8 is a check valve, and 9 is a flow restrictor.

In the embodiment described above with reference to FIGS. 1 and 2, after the permanent magnet 1 is moved to the braking position where the braking force is maximized, the permanent magnet 1 is advanced and moved within the range of the stroke St2. The braking force may be suppressed by moving the permanent magnet 1 backward within the range of the stroke St2. These are shown in FIGS.
It is an Example shown in FIG.

That is, in the embodiment shown in FIGS. 3 and 4, instead of the actuator 6 of the second eddy current type speed reducer according to the present invention shown in FIG. In the embodiment shown in FIG. 3, only the stroke necessary for switching OFF is provided. The embodiment shown in FIG. 3 is provided at the protruding end of the piston rod 10 a in the cylinder 10 b. The embodiment shown in FIG.
A spring 11 is provided inside the protruding end of the piston rod 10a on the outside.

The spring 11 exerts a force greater than the propulsion force of the actuator 10 at the protruding limit position of the piston rod 10a in a state where the spring 11 is compressed as shown in FIGS. 3 and 4B. Between the natural length of the spring 11 shown in FIG. 3 and FIG. 4 (a) and the compressed state shown in FIG. 3 and FIG. 4 (b), the combined force of the biasing force of the spring 11 and the magnetic reaction force acts on the actuator. A counterbalance of ten propulsions is used. In addition, 1 in FIG. 3 and FIG.
2 indicates a 2-port valve.

When the actuator 10 configured as described above is employed, after the piston rod 10a reaches the protruding limit position (see FIG. 3 and FIG. 3 and 4 (c) of FIG.
By retracting the piston rod 10a as shown in (1), the magnet can be easily moved backward after the magnet is moved to the position where the braking force is maximized. This is the actuator of the third eddy current type reduction gear transmission according to the present invention.

Also, instead of the actuator 10 of the third eddy current type speed reducer according to the present invention, an actuator 13 shown in FIG. 5 is provided on the side of the piston rod 13a protruding outside the cylinder 13b, and shown in FIG. Actuator 1
Reference numeral 3 denotes a spring in which a spring 14 is disposed at an end of the cylinder 13b opposite to the piston rod.

When the piston rod 13a projects, both the compressive force and the tensile force act on the spring 14, and at a position before the piston rod 13a reaches the projecting limit, the spring 14 is larger than the magnetic reaction force. The ones on which the forces act are used.

When the actuator 13 configured as described above is employed, when the brake is ON, the piston rod 13a reaches the protruding limit position (see FIG. 5 and FIG. Actuator 1
When the thrust of 3 is turned off, the piston rod 1
Although FIG. 3A retreats, the spring 14 causes the spring 14 to move to FIG.
As shown in (2), the vehicle stops at a predetermined position. The stop position varies depending on the magnetic reaction force. The higher the rotation, the larger the magnetic reaction force and the larger the retreat amount. Therefore, the duration can be earned. This is the actuator of the fourth eddy current type reduction gear according to the present invention.

Also, when a three-port valve 15 is installed on the side of the compressed air supply to the actuator 5 according to the first aspect of the present invention, for example, on the side opposite to the piston rod 5a, as shown in FIG. The same braking force control as when the actuators 10, 13 of the third and fourth eddy current type reduction gears according to the present invention are used is possible.

That is, shortly after the braking ON operation shown in FIG. 7A, the three-port valve 15 is closed. By doing so, the compressed air is sealed in the cylinder 5b on the side opposite to the piston rod 5a, but the air gradually escapes from the throttle valve 16 which is provided in the middle of the pipe on the side of the three-port valve 15 and which is open to the end. Then, since the retreating force by the magnetic reaction force acts, the piston rod 5a gradually retreats.

In this embodiment, the present invention is applied to a single-row turning type eddy current type speed reducer. However, it goes without saying that the present invention is also applicable to a two-row turning type eddy current type speed reducer.

[0032]

As described above, according to the present invention,
Without increasing the initial braking force more than necessary, it is possible to suppress the reduction in the generated braking force after long-time braking, so that a stable braking effect can be obtained regardless of the elapsed time.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the operation of an actuator according to the present invention according to the first present invention, together with the position of a magnet;
FIG. 7 is an explanatory diagram of braking OFF, FIG. 7B is an explanatory diagram when a maximum braking force is generated, and FIG. 7C is an explanatory diagram when a braking force is suppressed from the maximum braking force.

FIGS. 2A and 2B are diagrams for explaining the operation of the actuator according to the second invention, wherein FIG. 2A is an explanatory diagram of braking OFF, FIG. 2B is an explanatory diagram of switching from braking OFF to braking ON, and FIG. FIG. 4 is an explanatory diagram when a maximum braking force is generated, and FIG. 4D is an explanatory diagram when a braking force is suppressed to be smaller than the maximum braking force.

3A and 3B are diagrams for explaining the operation of the actuator according to the third aspect of the present invention, wherein FIG. 3A is an explanatory diagram when braking is ON, FIG. 3B is an explanatory diagram of a protruding limit position, and FIG. FIG. 4D is an explanatory diagram when the vehicle is moving backward, and FIG.

FIGS. 4A and 4B are diagrams for explaining the operation of another embodiment of the actuator according to the third aspect of the present invention, wherein FIG. 4A is an explanatory diagram when braking is ON, FIG. FIG. 8 is an explanatory diagram when the vehicle is retracted from the protruding limit position, and FIG.

FIGS. 5A and 5B are diagrams for explaining the operation of the actuator according to the fourth invention, wherein FIG. 5A is an explanatory diagram when braking is ON, FIG. 5B is an explanatory diagram of a protruding limit position, and FIG. FIG. 4D is an explanatory diagram when the vehicle is moving backward, and FIG.

FIGS. 6A and 6B are diagrams for explaining the operation of another embodiment of the actuator according to the fourth invention, wherein FIG. 6A is an explanatory diagram when braking is ON, FIG. FIG. 8 is an explanatory diagram when the vehicle is retracted from the protruding limit position, and FIG.

FIG. 7 is an explanatory view of another method of controlling the braking force of the eddy current type reduction gear according to the present invention when the actuator according to the first present invention is used, and FIG. (B) is an explanatory diagram of when retracting from the protruding limit position,
(C) is an explanatory diagram at the time of braking OFF.

FIG. 8 investigates the transition of the braking force with the elapsed braking time by changing the stroke of the actuator of the eddy current type speed reducer that switches the braking ON / OFF by moving the magnet from the non-braking position to the braking position. FIG.

FIG. 9 is a diagram illustrating the effect of extending the braking duration by changing the stroke of the actuator of the eddy current type speed reducer that switches ON / OFF of the braking by moving the magnet from the non-braking position to the braking position.

FIG. 10 is a diagram illustrating a spring installed in an actuator according to the third invention.

FIG. 11 is a diagram illustrating a spring installed on an actuator according to a fourth invention.

[Explanation of symbols]

 Reference Signs List 1 permanent magnet 5 actuator 5a piston rod 5b cylinder 6 actuator 6a piston rod 6b cylinder 6c second piston 7 spring 10 actuator 10a piston rod 10b cylinder 11 spring 13 actuator 13a piston rod 13b cylinder 14 spring 15 3 port valve

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Saito 5-1-1109, Shimaya, Konohana-ku, Osaka-shi 5H649 AA03 BB03 GG09 GG18 HH04 HH18 JK03

Claims (5)

[Claims] In an eddy current type speed reduction device for switching ON / OFF of braking by moving a magnet from a non-braking position to a braking position, the magnet is moved to a position where the braking force becomes largest immediately after the start of braking, and thereafter, Is a braking force control method for an eddy current type reduction gear, wherein a braking force is suppressed by moving a magnet forward and backward. 2. An actuator constituting an ON-OFF switching device for implementing the method for controlling a braking force of an eddy current type reduction gear according to claim 1, wherein the stroke of the actuator is switched between ON and OFF of braking. An actuator for an eddy current type reduction gear, characterized in that the stroke is longer than a stroke required for the eddy current reduction gear. 3. An actuator for an eddy current type speed reducer according to claim 2, wherein a spring is provided at a protruding end of the piston rod in the cylinder, and a spring is provided between a natural length position and a compression limit position in the cylinder. A second piston is provided so as to be slidable, and a stroke required for switching ON / OFF of braking is set from the retreat limit position of the piston rod to the second piston located at the natural length position of the spring. An actuator for an eddy current type speed reducer, wherein a length of the first piston moves and a movement of the piston rod exceeding the stroke is obtained by compression of the spring. 4. An actuator for an eddy current type speed reducer according to claim 2, wherein a stroke of the actuator is only a stroke necessary for switching ON / OFF of braking, and a piston inside or outside the cylinder. A spring is disposed at the protruding end of the rod, and this spring exerts a force greater than the propulsion force of the cylinder at the protruding limit position of the piston rod in a state where the spring is compressed, and from the natural length of the spring to the compressed state In the meantime, the actuator of the eddy current type speed reduction device is characterized in that the resultant force of the spring and the magnetic reaction force is balanced with the propulsion force of the cylinder. 5. A spring in the actuator of the eddy current type speed reducer according to claim 4, wherein the spring is disposed at an end of the cylinder opposite to the piston rod side or at a side of the piston rod protruding outside the cylinder. Sometimes both compressive and tensile forces act,
An actuator for an eddy current type reduction gear, wherein a force larger than a magnetic reaction force acts at a position before the piston rod reaches a protruding limit.