JPH109303A - Duplex retarder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve moderate braking stop having a slight shock, and retain certain stationary by a large braking force after rotation is stopped, by immediately shutting off the operating coil current of a first electromagnetic brake after the stop command to a braked rotating machine, and momentarily retaining the operating coil current of a second electromagnetic brake. SOLUTION: When a command to stop a motor is transmitted, the exciting current of an electromagnetic brake 10 is immediately made to be zero and braking having a little delay time starts to operate, however, effect of braking force is loose because of residual magnetism, and the rotational speed of the motor is gradually lowered, and finally stopped. Although electric power supply to an electromagnetic brake 50 is disconnected afterward, momentary current is continued to flow by the self-holding energy of the electromagnetic brake 50 and the residual energy of the motor while rotating, and timing when the braking force of the electromagnetic brake 50 is exhibited is further delayed, thereby braking force can be generated for the first time after a while after the motor is stopped. After this time, the motor braking force is kept applying to both electromagnetic brakes 10 and 50, to retain the motor in its static condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound brake system provided with two types of brakes having different functions.

[0002]

2. Description of the Related Art A braking device is used to apply a brake to stop a rotating rotating machine or to hold a stopped rotating machine in a stopped state. Here, the rotating machine may be a drive motor in an elevator such as an elevator or an escalator, or may be a motor other than an electric motor. The conventional braking device used for this type of application is a single type, and applies or releases braking by, for example, exciting or turning off the operating coil. In that case, the braking is applied when the operation coil is excited and the braking is released when the operation coil is de-energized.
There is a non-excitation brake system in which braking is released when excited. The present invention relates to the latter non-excitation brake type braking device.

A conventional braking device of this kind has a single function, and releases or applies braking by turning on / off excitation of an operation coil. As described above, the braking device has the function of stopping the rotating machine by stopping the rotating machine by applying a brake when trying to stop the rotating machine. It also has the function of doing. TECHNICAL FIELD The present invention relates to a braking device that skillfully combines both functions.

[0004]

SUMMARY OF THE INVENTION In a conventional braking device,
Since the above two functions are not combined, measures have been taken such as designing with emphasis on either function or designing to fully consider both functions to achieve both functions. Was. However, the former often does not satisfy any of the functions, while the latter is structurally large and expensive.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a double braking system which can be controlled by a simple control circuit for braking a rotating rotating machine to stop the rotating machine and for surely holding a stopped rotating machine in a stopped state. It is to provide a device.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a dual braking device according to the present invention is configured such that when a power supply to an operating coil is turned off, braking starts to take effect after a relatively short period of time, and a relatively gentle braking is applied to the rotating machine to be braked. A first electromagnetic brake for applying an appropriate braking, and a second electromagnetic brake for additionally applying a relatively strong braking to the braked rotary machine after a relatively long time when the power supply of the operating coil is cut off, After the stop command of the braked rotating machine, the operating coil current of the first electromagnetic brake is immediately cut off, and the second electromagnetic brake is operated based on the energy held by the operating coil of the second electromagnetic brake and the energy held by the braked rotating machine. Circuit means for maintaining the operating coil current for a while.

[0007] The first electromagnetic brake can be activated immediately after the power supply to the operating coil is turned off, and the second electromagnetic brake can be activated after the braked rotary machine is almost stopped.

For this purpose, the second electromagnetic brake preferably has a larger residual magnetic flux than the first electromagnetic brake.

It is preferable that the operation coil of the second electromagnetic brake is relatively thin and has a larger number of turns than the operation coil of the first electromagnetic brake.

The first electromagnetic brake shuts off the power source of the operation coil at the same time as shutting off the drive source of the rotating machine to be braked.
In order to keep the current flowing even after the drive source of the rotating machine to be braked is shut off, a freewheeling diode can be connected in parallel with the operation coil.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a compound brake system according to the present invention. This dual braking device is used to apply braking to a shaft 2 of a rotating machine to be braked, for example, an electric motor 80 (see FIG. 2), and includes a first electromagnetic brake 10 and a second electromagnetic brake 50. First
The electromagnetic brake 10 is a single-plate type brake and is used for gentle braking stop immediately after the motor power is turned off.
The electromagnetic brake 50 is a double-disc type brake having a large braking ability, and is used for surely holding the stationary state after the motor stops. The free end of the shaft 2 is formed in a three-stage type having a gradually decreasing diameter. The first electromagnetic brake 10 is disposed on the small diameter side of the shaft end, and the second electromagnetic brake 50 is disposed on the large diameter side.
Is arranged. Both of the electromagnetic brakes 10 and 50 are of a flat plate type, that is, a disk type, in which the movable portion moves in the axial direction.

A fixed iron core 12 of the first electromagnetic brake 10 is provided so as to extend over a middle diameter portion and a small diameter portion of the shaft 2 and at a predetermined interval in a radial direction from the shaft 2. The movable iron core 14 of the electromagnetic brake 10 is the shaft 2
Is located on the free end side of the. An operation coil 16 is mounted on the fixed iron core 12, and braking springs 18 that exert a braking action by pressing the movable iron core 14 in a separating direction are arranged at a plurality of locations in the circumferential direction. The braking spring 18 presses the movable iron core 14 in a direction away from the fixed iron core 12 to exhibit a braking action.
For example, they are distributed at about 10 locations. A brake lining 20 is adhered to the end of the movable iron core 14 opposite to the suction side. The fixed iron core 12 is fixed to the fixed iron core 52 at a plurality of locations on the periphery by bolts 22 with holes that are screwed into the fixed iron core 52 through through holes formed in the movable iron core 54 of the second electromagnetic brake 50 at a plurality of locations on the circumference. . The rotation of the brake lining 20 and the movable core 14 is prevented by a screw 24 screwed into the fixed core 12 through the movable core 14. The operation coil 16 of the electromagnetic brake 10 is used to speed up the response of the brake operation when the excitation is stopped.
In comparison with the corresponding part of the second electromagnetic brake 50,
A small magnetic gap is formed between the fixed iron core 12 and the movable iron core 14 at the time of attraction so as to reduce the residual magnetism when the excitation is cut off and speed up the response. Designed to form.

A boss 26 is fixedly attached to the shaft 2 in a circumferential direction at a small diameter portion at a free end of the shaft 2 by a key 28 engaging with a key groove as a means for attaching a rotating member of the first electromagnetic brake 10. At the same time, it is fixed by screwing a set screw 32 having a stop plate 30 into the shaft 2 from the shaft end side, and further, by screwing a set screw 34 through the stop plate 32 into the boss 26 at a plurality of locations on the periphery. The boss 26 and the shaft 2 are integrally connected to each other. A brake plate 38 is provided on the boss 26 via a rib 36.
Is mounted so as to face the brake lining 20. The electromagnetic brake 10 is located on the shaft end side of the illustrated braking device, and has good heat radiation efficiency, and can effectively reduce the heat generated by the brake until the rotating motor 80, which is to be stopped by cutting off the drive source, is stopped. Can be dissipated.

The fixed core 52 of the second electromagnetic brake 50 disposed on the large diameter side of the shaft 2 and the movable core 54 axially opposed to the shaft 2 with a slight gap therebetween have a relatively large gap with respect to the shaft 2. It is located with. The fixed iron core 52 is not shown in the figure.
It is fixed to the fixing portion 0) at a plurality of locations on the circumference by bolts 56 with holes. On the other hand, the movable iron core 54 penetrates the bolts 22 with holes for fixing the first electromagnetic brake 10, and is not rotatable in the circumferential direction but is slightly movable in the axial direction. A braking spring 58 and an operation coil 60 are mounted on the fixed iron core 52. The braking spring 58 exerts a braking action by pressing the movable core 54 in a direction away from the fixed core 52, and, like the first electromagnetic brake 10, is equally distributed in a circumferential direction at a plurality of locations. Will be arranged. The electromagnetic brake 50 is of a double-plate type and is powerful, but in order to intentionally delay the response of the braking operation when the excitation is cut off, the operation coil 60 is more thick than the corresponding part of the electromagnetic brake 10 in comparison with the corresponding part of the electromagnetic brake 10. And the magnetic gap between the fixed iron core 52 and the movable iron core 54 at the time of attraction is designed to be substantially zero so as to increase the residual magnetism when the excitation is cut off. The through holes or the screw holes for passing the bolts 22 and the bolts 56 are provided in the fixed iron core 52 so as to be alternately arranged in the circumferential direction. The rotating operation of the movable iron core 54 is prevented by the bolt 22 penetrating therethrough.

A brake hub is provided at the middle end of the free end of the shaft 2 so as to rotate integrally with the shaft 2 by means of a key 4 engaging with a keyway and to slide slightly in the axial direction in connection with the braking operation. 62 are provided. A large diameter side of the shaft of the brake hub 62 is formed as a flange portion 64, and a brake plate 66 on an outer peripheral surface of the brake hub 62 cannot rotate relative to the brake hub 62 in the circumferential direction, but slides slightly in the axial direction. It is arranged via a gear 68 to obtain it. Brake linings 70 and 72 are adhered to both sides of the edge of the brake plate 66 to form a double-plate brake. The brake lining 70 faces the movable iron core 54, and the brake lining 7
2 faces the fixed iron core 12 of the first electromagnetic brake 10. The disc spring 6 and the spring washer 8 are interposed between the brake hub 62 and the boss 26, and press the brake hub 62 toward the large diameter side of the shaft 2 by the spring force.

The operation of the individual electromagnetic brakes 10, 50 in the braking device shown in FIG. 1 will be described.

The electromagnetic brakes 10, 50 are of the non-excitation brake type, and when the operation coils 16, 60 are not excited, the shafts 2 are braked by the braking springs 18, 58 to excite the operation coils 16, 60. As a result, the braking by the braking springs 18, 58 is released, and the shaft 2 is released. Hereinafter, this operation mode will be described in more detail.

First, the first electromagnetic brake 10 will be described. When the operation coil 16 is de-energized, the first electromagnetic brake 10 presses the movable iron core 14 in a direction away from the fixed iron core 12 by the spring force of the braking spring 18, and as a result, the brake lining 20 and the brake plate 3
8, a braking action occurs. When the operation coil 16 is excited, the movable iron core 14 is attracted to the fixed iron core 12 against the spring force of the brake spring 18, and as a result, the movable core 14 is pushed between the brake lining 20 attached to the movable iron core 14 and the brake plate 38. The pressure, ie the braking force, no longer acts.

The second electromagnetic brake 50 includes the operating coil 6
By deenergizing 0, the movable iron core 54 is pressed in a direction away from the fixed iron core 52 by the spring force of the braking spring 58, and as a result, between the brake lining 70 and the movable iron core 54, and between the brake lining 72 and A braking action occurs between the first electromagnetic brake 10 and the fixed iron core 12. By exciting the operating coil 60, the movable core 5
4 is attracted to the fixed iron core 52 side against the spring force of the braking spring 58, and as a result, the braking action between the brake linings 70, 72 and the opposed fixing portions is released.

The braking device according to the present invention, as described below,
A major feature is that the timing at which the braking action starts to be effective when the excitation power supply is turned off while the operation coils 16 and 60 of the electromagnetic brakes 10 and 50 are being excited is different.

FIG. 2 shows an operation circuit for operating the two electromagnetic brakes 10, 50. Here, a motor 80 is shown as the rotating machine to be braked. The motor 80 is supplied with driving power from an AC power supply via an electromagnetic contactor 82.
The electromagnetic brakes 10 and 50 are of a DC drive type, and are driven by DC power obtained from the load side of the electromagnetic contactor 82 via a rectifier circuit. In the figure, a single-phase half-wave rectifier circuit composed of one diode 84 is shown as an example of the simplest rectifier circuit. Of course, it can be replaced by a dual-phase rectifier circuit or the like. Surge absorbing elements 86, 88, and 90 are connected in parallel to the input side of the diode 84, the input side of (the operation coil 16 of) the electromagnetic brake 10, and the input side of the (operation coil 60) of the electromagnetic brake 50, respectively. . Further, a diode 84 and a surge absorbing element 88
And a freewheeling diode 92 is connected in antiparallel to the DC output of the diode 84. The first electromagnetic brake 10 is excited by the output direct current of the diode 84 via the auxiliary contact 94 of the electromagnetic contactor 82, and the second electromagnetic brake 50 is directly excited by the output direct current of the diode 84.

Next, referring to FIG. 3, the operation of the braking device shown in FIG. 1 operated by using the operation circuit shown in FIG. 2 will be described.

When the main contact and the auxiliary contact 94 of the electromagnetic contactor 82 are closed at time t1, drive power is supplied to the motor 80 and DC excitation power is supplied to the electromagnetic brakes 10 and 50 via the diode 84. At time t2 with a slight delay, the electromagnetic brakes 10,
The braking of 50 is released, the motor 80 starts, and the rotation speed N gradually increases to reach the steady rotation speed. By the way, at time t3
Suppose that a stop command is sent to stop the motor 80, and the main contact and the auxiliary contact 94 of the electromagnetic contactor 82 are opened. At this time, the exciting current of the electromagnetic brake 10 is immediately reduced to zero by the auxiliary contact 94, and immediately starts to operate at time t4 with a slight delay time. However, the effect of the braking force is gradual due to residual magnetism, and the motor has a low impact. The rotation speed N at 80 gradually decreases and reaches zero at time t5. After this, the brake of the electromagnetic brake 50 is still effective. After the electromagnetic contactor 82 is opened, the electromagnetic brake 5
Although the power supply from the power source side to the electromagnetic brake 50 is cut off, current continues to flow for a while through the freewheeling diode 92 due to its own energy in the electromagnetic brake 50, and furthermore, due to residual energy during rotation of the motor 80. The current continues to flow through the diode 84. Therefore, the timing at which the electromagnetic brake 50 starts exerting the braking force is further delayed than the time t5, and the braking force is generated only at the time t6 after a short time after the motor 80 stops. After the time t6, the braking forces of the two electromagnetic brakes 10, 50 act together, and the motor 8
0 can be reliably kept still.

[0025]

As described in detail above, according to the present invention,
Two types of non-excitation type electromagnetic brakes are used in combination, the characteristics of each electromagnetic brake are utilized, a simple control circuit is used to achieve gentle braking with little impact, and after rotation is stopped, a large braking force is used to ensure static stopping. Retention can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a compound braking device according to the present invention.

FIG. 2 is a connection diagram showing an operation circuit of both electromagnetic brakes in the compound braking device of FIG. 1;

FIG. 3 is a time chart for explaining operation timings of both electromagnetic brakes in the compound braking device of FIG. 1;

[Explanation of symbols]

 2 rotating machine shaft 10 first electromagnetic brake 12 fixed iron core 14 movable iron core 16 operation coil 18 brake spring 20 brake lining 26 boss 36 rib 38 brake plate 50 second electromagnetic brake 52 fixed iron core 54 movable iron core 58 brake spring 60 operation coil 62 Brake hub 66 Brake plate 70, 72 Brake lining 80 Motor 82 Magnetic contactor 84, 92 Diode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F16D 55/28 F16D 55/28 B

Claims (5)

[Claims] A first electromagnetic brake for applying a relatively gentle braking to the braked rotary machine after a relatively short period of time when the power to the operating coil is turned off; A second electromagnetic brake for applying a relatively strong braking to the braked rotating machine after braking starts to take effect after a relatively long time; and operating the first electromagnetic brake after a stop command of the braked rotating machine. Circuit means for immediately interrupting the coil current and temporarily maintaining the operating coil current of the second electromagnetic brake based on the energy held by the operating coil of the second electromagnetic brake and the energy held by the braked rotating machine. Double braking device. 2. The dual type as claimed in claim 1, wherein the first electromagnetic brake starts to operate immediately when the power supply to the operating coil is turned off, and the second electromagnetic brake starts to operate after the braked rotary machine stops. Braking device. 3. The dual braking device according to claim 1, wherein said second electromagnetic brake has a larger residual magnetic flux than said first electromagnetic brake. 4. The double braking device according to claim 3, wherein the operation coil of the second electromagnetic brake is relatively thin and has a larger number of turns than the operation coil of the first electromagnetic brake. 5. The first electromagnetic brake shuts off a drive source of the rotating machine to be braked, and at the same time shuts off a power supply of an operation coil. The second electromagnetic brake shuts off a drive source of the rotating machine to be braked. 3. The double braking device according to claim 1, wherein a freewheeling diode is connected in anti-parallel to the operating coil so as to continue flowing current thereafter.