JP2015098913A - Brake apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake apparatus capable of reliably releasing an armature when a brake is released without performing highly accurate control using an expensive control part.SOLUTION: A brake apparatus 1 includes: a coil storage body 2 unrotatably provided on a vehicle body 10 side; an armature 5 disposed on a wheel 12 side so as to be opposed to the coil storage body 2; energization means for energizing the armature 5 in a direction separated from the coil storage body 2; a braking coil 3 and a releasing coil 4 stored in the coil storage body 2; and a power supply part 7. The power supply part 7 includes a single constant voltage source and means for switching the coil to be energized by the constant voltage source. When the power supply part 7 energizes the braking coil 3, the armature 5 is attracted to the coil storage body 2 side against energization force Fa of the energization means, and when the power supply part 7 energizes the releasing coil 4, current in a direction reversed from current energizing the braking coil 3 is allowed to flow into the releasing coil 4.

Description

  The present invention relates to a brake device that operates an armature by exciting a coil to brake a wheel.

  As a conventional brake device, for example, Patent Document 1 discloses a brake device including a brake main body including a brake movable member (armature) and a coil, and a permanent magnet. In this brake device, when the coil is not excited, the permanent magnet restrains the armature to generate a braking force (the brake is applied). On the other hand, in this brake device, when the coil is excited, the magnetic field by the electromagnet is weakened and the brake is released.

  FIG. 4 shows another conventional brake device. The brake device 20 brakes the rotation of the wheel 12 rotatably provided on the axle 11 protruding from the vehicle body 10. As shown in the figure, the brake device 20 includes a coil housing 21 that is non-rotatably fixed to the vehicle body 10 by bolts and the like, and an armature 5 that is provided on the wheel 12 side so as to face the coil housing 21. An urging means (not shown) for urging the armature 5 in a direction away from the coil housing body 21, a braking / release coil 22 housed in the coil housing body 21, and a braking / release coil 22 are arranged. And a power supply unit 23 to be energized.

  As illustrated in FIG. 5, the power supply unit 23 includes a constant voltage source E and four switches SWa to SWd that form an H bridge. The braking / release coil 22 is connected between the midpoint of the two switches SWa and SWb connected in series and the midpoint of the switches SWc and SWd. The four switches SWa to SWd are turned off (open) or on (closed) by a control unit (not shown).

  When all of the four switches SWa to SWd are in the OFF state, no current flows through the braking / release coil 22. In this case, since only the urging force Fa of the urging means acts on the armature 5, k is generated between the armature 5 and the coil housing body 21, and the brake is released (see times t0 to t1 in FIG. 6). On the other hand, when the switches SWa and SWd are in the ON state and the others are in the OFF state, the braking / release coil 22 is excited by a current flowing in the direction of the switch SWa → the braking / release coil 22 → the switch SWd. The In this case, in addition to the urging force Fa, an opposite force Fb larger than the urging force Fa acts on the armature 5, so that the armature 5 is attracted toward the coil housing body 21 against the urging force Fa. And a brake is applied because the space | gap between the armature 5 and the coil accommodating body 21 is lose | eliminated (refer time t1-t2 of FIG. 6).

  Further, the brake device 20 sets the switches SWb and SWc to the ON state and the others to the OFF state for a certain time immediately after releasing the brake, so that the switch SWc → the brake is applied to the braking / release coil 22. / The coil 22 for release → The current in the direction of the switch SWb is supplied to excite in the reverse direction, and the magnetic flux density remaining in the armature 5 is returned to 0 (see times t2 to t3 in FIG. 6). According to the brake device 20, by providing a period for reversely exciting the brake / release coil 22, the armature 5 is surely returned (released) to the original position after the brake is released, and the armature 5 and the coil are accommodated. It is possible to prevent the body 21 from rubbing against each other.

JP 2002-130342 A

  However, the conventional brake device 20 has a problem that an expensive control unit (for example, an LSI) is required to accurately and synchronously control the four switches SWa to SWd. Further, in the conventional brake device 20, when the armature 5 is released by reversely exciting the braking / release coil 22, a strong magnetic field whose direction is different from that during braking is generated around the braking / release coil 22. Therefore, it is difficult to control the period (see times t2 to t3 in FIG. 6) during which the braking / release coil 22 is reversely excited so that the magnetic flux density remaining in the armature 5 becomes exactly zero.

  The present invention has been made in view of the above circumstances, and the problem is that the armature can be reliably released when the brake is released without performing high-precision control using an expensive control unit. An object of the present invention is to provide a brake device that can be used.

  In order to solve the above problems, a brake device according to the present invention is a brake device that brakes the rotation of a wheel that is rotatably provided on an axle that protrudes from a vehicle body, and is a coil that is provided on the vehicle body side so as not to rotate. A housing, an armature provided on a wheel side so as to face the coil housing, a biasing means for biasing the armature in a direction away from the coil housing, a braking coil housed in the coil housing, and a release And a power source for energizing the braking coil and the release coil, and the braking coil and the release coil have a ring shape centering on the axle and are arranged along the protruding direction of the axle. The power supply unit has a single constant voltage source and means for switching a coil energized by the constant voltage source, and when the power source unit energizes the braking coil, the energizing unit The armature is drawn toward the coil housing body against the urging force, and when the power supply unit energizes the release coil, a current in the direction opposite to that when the brake coil is energized flows through the release coil. .

  In the brake device, it is preferable that the braking coil is disposed closer to the armature than the release coil.

  In addition, in the above brake device, the number of turns of the release coil is preferably smaller than the number of turns of the brake coil, and further, the release coil has a resistance value equal to or greater than the resistance value of the brake coil. It is preferable that the wire diameter is set.

  ADVANTAGE OF THE INVENTION According to this invention, even if it does not perform highly accurate control using an expensive control part, the brake device which can release an armature reliably at the time of brake release can be provided.

It is sectional drawing of the brake device which concerns on this invention, and the wheel with which this device was equipped. It is a circuit diagram of the power supply part with which the brake device shown in FIG. 1 was equipped. It is a timing chart which shows operation | movement of the brake device shown in FIG. It is sectional drawing of the wheel provided with the conventional brake device and this apparatus. It is a circuit diagram of the power supply part with which the brake device shown in FIG. 4 was equipped. It is a timing chart which shows operation | movement of the brake device shown in FIG.

  Hereinafter, embodiments of a brake device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a brake device according to the present invention. The brake device 1 brakes the rotation of a wheel 12 that is rotatably provided on an axle 11 protruding from a vehicle body 10. As shown in the figure, the brake device 1 includes a coil housing 2 fixed to the vehicle body 10 by a bolt or the like so as not to rotate, and an armature 5 provided on the wheel 12 side so as to face the coil housing 2. , An urging means (not shown) for urging the armature 5 in a direction away from the coil housing 2, a braking coil 3 and a release coil 4 housed in the coil housing 2, and a braking coil 3 And a power supply unit 7 for energizing the release coil 4.

  The coil housing 2 is a ring-shaped member having a hollow portion through which the axle 11 is passed, and two ring-shaped housing spaces are provided therein. As shown in FIG. 1, these two accommodation spaces are provided side by side along the protruding direction of the axle 11, the braking coil 3 is accommodated in the accommodation space closer to the armature 5, and the release coil is located on the other side. 4 is housed. The two housing spaces may be partitioned by an appropriate partition or may be continuous.

  The armature 5 is a ring-shaped member having a hollow portion through which the axle 11 is passed, and is made of a magnetic material such as iron. The diameter of the armature 5 is approximately equal to the diameter of the coil housing 2.

  The armature 5 has a plurality of protrusions 5 a arranged at equal angular intervals on a circle centered on the axle 11. The wheel 12 has a plurality of through holes 12 a arranged at equal angular intervals on a circle centered on the axle 11. As shown in FIG. 1, each protrusion 5 is inserted into the through hole 12a, and when the wheel 12 rotates, the armature 5 also rotates. In other words, when the rotation of the armature 5 is stopped, the rotation of the wheel 12 is also stopped.

  As described above, the armature 5 is constantly urged in a direction away from the coil housing 2 by urging means (spring or the like) (not shown). For this reason, the armature 5 remains attached to the wheel 12 as long as no other force acts on the armature 5. At this time, a slight gap 6 is generated between the armature 5 and the coil housing 2.

  The braking coil 3 is wound so as to draw a circle around the axle 11 in the above-described accommodation space. The release coil 4 is also wound so as to draw a circle around the axle 11 in the above-described accommodation space. However, the release coil 4 is wound in the opposite direction to the braking coil 3.

  The braking coil 3 needs to generate a stronger magnetic field than the release coil 4. For this reason, the number of turns of the brake coil 3 is larger than the number of turns of the release coil 4. The release coil 4 has a smaller wire diameter than the brake coil 3 in consideration of the fact that the number of turns is smaller than that of the brake coil 3. As a result, the resistance value of the release coil 4 is equal to or greater than the resistance value of the braking coil 3. The reason for this configuration will be described later.

  As shown in FIG. 2, the power supply unit 7 has a single constant voltage source E and two switches SW1 and SW2. The braking coil 3 is connected between the constant voltage source E and the switch SW1, and the release coil 4 is connected between the constant voltage source E and the switch SW2. The switches SW1 and SW2 are turned off (open) or on (closed) by a control unit (not shown). At least one of the switches SW1 and SW2 is turned off. In other words, in the present invention, the switches SW1 and SW2 are not simultaneously turned on.

  When the switches SW1 and SW2 are in the OFF state, no current flows through the braking coil 3 and the release coil 4. In this case, since only the urging force Fa of the urging means acts on the armature 5, a gap 6 is generated between the armature 5 and the coil housing 2 and the brake is released (see time t0 to t1 in FIG. 3). .

  When the switch SW1 is in the ON state and the switch SW2 is in the OFF state, the braking coil 3 is excited by a current that flows in the direction of the braking coil 3 → the switch SW1. In this case, in addition to the urging force Fa, an opposite force Fb larger than the urging force Fa acts on the armature 5, so that the armature 5 is drawn toward the coil housing body 2 against the urging force Fa. And since the space | gap 6 between the armature 5 and the coil container 2 is lose | eliminated, a brake will apply (refer time t1-t2 of FIG. 3).

  When the switch SW2 is turned on and the switch SW1 is turned off, the release coil 4 is excited by a current flowing in the direction of the release coil 4 → switch SW2 (see times t2 to t3 in FIG. 3). ). As described above, the winding direction of the braking coil 3 and the release coil 4 are opposite. For this reason, the direction of the magnetic field generated by exciting the release coil 4 is opposite to the direction of the magnetic field generated by exciting the braking coil 3. The magnetic field generated by the release coil 4 returns the magnetic flux density remaining in the armature 5 to zero.

  Here, the number of turns of the release coil 4 is less than the number of turns of the brake coil 3 because the armature 5 is pulled toward the coil housing 2 against the biasing force Fa when the armature 5 is released. This is because a strong magnetic field is not required. Reducing the number of turns is advantageous in terms of member cost and weight.

  Also, the reason why the wire diameter of the release coil 4 is made smaller than the wire diameter of the brake coil 3 is to compensate for the resistance reduced by reducing the number of turns, so that the resistance value of the release coil 4 is reduced. It is for making it more than the resistance value of. By doing so, it is possible to prevent the release coil 4 from burning due to an overcurrent flowing. The constant voltage source E is divided into a constant voltage source E1 for the braking coil 3 and a constant voltage source E2 for the release coil 4, and the output voltage of the constant voltage source E2 is lower than the output voltage of the constant voltage source E1. Even if set, burning of the release coil 4 is prevented. However, it is not preferable to provide the power supply unit 7 with the two constant voltage sources E1 and E2 because the cost increases.

  As described above, in the brake device 1 according to the present invention, since the number of switches to be synchronously controlled is smaller than that of the conventional brake device 20, an expensive control unit is not required. Further, in the brake device 1 according to the present invention, the armature 5 is released by a relatively weak magnetic field generated by exciting the release coil 4 having a small number of turns, so that the magnetic flux density remaining in the armature 5 is set to just zero. Easy to do.

  Needless to say, the present invention is not limited to the above-described embodiment, and various modifications exist.

DESCRIPTION OF SYMBOLS 1 Brake device 2 Coil container 3 Braking coil 4 Release coil 5 Armature 5a Protrusion 6 Gap 7 Power source 10 Car body 11 Axle 12 Wheel 12a Through hole

When all of the four switches SWa to SWd are in the OFF state, no current flows through the braking / release coil 22. In this case, since only the urging force Fa of the urging means acts on the armature 5, a gap is generated between the armature 5 and the coil housing body 21, and the brake is released (see times t0 to t1 in FIG. 6). On the other hand, when the switches SWa and SWd are in the ON state and the others are in the OFF state, the braking / release coil 22 is excited by a current flowing in the direction of the switch SWa → the braking / release coil 22 → the switch SWd. The In this case, in addition to the urging force Fa, an opposite force Fb larger than the urging force Fa acts on the armature 5, so that the armature 5 is attracted toward the coil housing body 21 against the urging force Fa. And a brake is applied because the space | gap between the armature 5 and the coil accommodating body 21 is lose | eliminated (refer time t1-t2 of FIG. 6).

In order to solve the above problems, a brake device according to the present invention is a brake device that brakes the rotation of a wheel that is rotatably provided on an axle that protrudes from a vehicle body, and is a coil that is provided on the vehicle body side so as not to rotate. A housing, an armature provided on a wheel side so as to face the coil housing, a biasing means for biasing the armature in a direction away from the coil housing, a braking coil housed in the coil housing, and a release And a power source for energizing the braking coil and the release coil, and the braking coil and the release coil have a ring shape centering on the axle and are arranged along the protruding direction of the axle. The power supply unit has a single constant voltage source and means for switching a coil energized by the constant voltage source, and when the power source unit energizes the braking coil, the energizing unit Armature is attracted to the coil housing side against the biasing force, when the power supply unit to energize the release coil, a current in the opposite direction flows in the release coil and when to energize the brake coil, the brake coil field in the opposite direction of weakening the magnetic field due to the residual magnetic flux is characterized Rukoto occur.

Claims (4)

A brake device for braking the rotation of a wheel rotatably provided on an axle protruding from a vehicle body,
A coil housing provided in a non-rotatable manner on the vehicle body side;
An armature provided on the wheel side so as to face the coil container;
Biasing means for biasing the armature in a direction away from the coil housing;
A braking coil and a release coil housed in the coil housing body;
A power supply for energizing the brake coil and the release coil;
With
The brake coil and the release coil have a ring shape centered on the axle, and are arranged side by side along the protruding direction of the axle,
The power supply unit has a single constant voltage source and means for switching a coil energized by the constant voltage source,
When the power supply unit energizes the braking coil, the armature is drawn toward the coil housing body against the urging force of the urging means, and when the power supply unit energizes the release coil, A brake device, wherein a current in a direction opposite to that when a coil is energized flows through the release coil.   2. The brake device according to claim 1, wherein the braking coil is disposed closer to the armature than the release coil. 3.   The brake device according to claim 1 or 2, wherein the number of turns of the release coil is smaller than the number of turns of the brake coil.   The brake device according to claim 3, wherein a wire diameter of the release coil is set so that a resistance value of the release coil is equal to or greater than a resistance value of the brake coil.

Images