JPS6111878B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a hoisting device that rotates a winding drum using a commutator motor to perform hoisting and lowering operations.

[Conventional technology]

Conventional hoisting devices of this type use, for example, an induction motor as a drive source. By the way, when an induction motor is used as a drive source, the winding is driven with a predetermined torque during hoisting, and on the other hand,
When lowering, the vehicle is lowered while being braked by regenerative braking. In other words, the acceleration of the lowering speed during lowering is suppressed.

However, in the case where a commutator motor is used as a drive source, regenerative braking is not generated during lowering, and therefore acceleration tends to occur. Therefore, as a countermeasure against this problem, there is one shown in Japanese Utility Model Application Publication No. 51-99370. In other words, with this configuration, during lowering operation, the non-ferrous metal disk approaches the permanent magnet side and is braked, and during hoisting operation, the non-ferrous metal disk moves away from the permanent magnet and is released from the braking torque. Become.

A braking device is also provided on one of the rotating shafts of the electric motor, and this braking device performs braking when the motor is stopped.

[Problem that the invention seeks to solve]

In this way, since it utilizes the axial movement of the non-ferrous metal disc, it is not only necessary for the inner periphery of the non-ferrous metal disc to engage with the male thread of the shaft, but also the axial movement of the non-ferrous metal disc is required. Space is also required to allow movement, and on the other hand, a braking means for stopping is constructed on the rotating shaft separately from these braking means, which has the disadvantage of complicating the structure and increasing the size. Was.

The present invention has been made in order to eliminate such drawbacks, and an object of the present invention is to provide a hoisting device which can be simplified in structure and downsized.

[Means for solving the invention]

A hoisting device according to the present invention includes a commutator motor that rotationally drives a winding drum to perform hoisting and unwinding operations, and a commutator motor that is movable in the axial direction on a rotating shaft of the commutator motor and that rotates relative to the rotating shaft. A brake plate made of a magnetic material that is immovably engaged, one surface facing the brake plate and disposed so as to be non-rotatable and axially displaceable with respect to the frame of the commutator motor; A movable iron core having a thick wall part that faces each other and protrudes in the axial direction including a part, and a thin wall part that is concave in a direction away from the brake plate with respect to the thick wall part. an opposing fixed core; an excitation coil provided on the fixed core and energized when the commutator motor is energized; a spring that urges the movable core toward the brake plate; a spring provided on the rotating shaft and energized; a positioning member that separates the brake plate from the movable iron core when the coil is energized;
A resistor is connected in series to the excitation coil, and a short circuit is connected in parallel to the resistor to short-circuit the resistor. During the lowering operation, the resistor is short-circuited to directly energize the excitation coil. Also, during the winding operation, the excitation coil is energized via the resistor.

[Effect]

In this invention, during lowering operation, the resistor is short-circuited to directly energize the excitation coil, and the movable core is attracted to the fixed core by the magnetic flux from the stator core, and the brake plate is moved to a position separated from the movable core. When the brake plate is positioned and the leakage magnetic flux passes through the brake plate, the brake plate is braked by this eddy current.During hoisting operation, a resistor is connected to suppress the current flowing to the excitation coil, but this current flows through the movable iron core. Since the size is sufficient to isolate the brake plate from the brake plate, eddy currents generated in the brake plate when the brake plate is separated from the movable iron core are suppressed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In the figure, 1 is armature 1
A, a DC compound-wound commutator motor (hereinafter simply referred to as a motor) having a series winding coil 1b, and a shunt winding coil 1c, which receives power from a battery (not shown) and has a winding drum (not shown). It rotates and drives the load to hoist and lower the load. 2 is electric motor 1
A brake button is an electromagnetic brake that acts as a brake on the electric motor 1, and is fitted to the motor shaft 1d of the electric motor 1 so as to rotate integrally with the motor shaft 1d, and to be movable in the axial direction on the spline 1e of the motor shaft 1d. A magnetic brake plate 3 with an attached brake plate 3 and a movable iron core 5 arranged adjacent to the brake plate 3, which can freely move in the axial direction toward the brake plate 3 but are prevented from rotating by a pin 4. , a compression coil spring 6 and a coil 7a connected in parallel to the armature 1a constituting a means for pressing the brake butt 3a against the fixed part consisting of the frame 1f of the electric motor 1 via the movable iron core 5.
When the movable core 5 is energized, the movable core 5 is attracted to the fixed core 7b and the above-mentioned pressure is released, and the brake plate 3 is configured with an electromagnet 7 arranged so that the eddy current is braked. As shown, the brake butt 3a is prevented from coming into pressure contact with a fixed part such as the frame 1d. Note that the electromagnet 7 constitutes a fixed iron core. In other words, when energized, as shown in FIG.
The cross-sectional area of the thin wall portion 5a of the movable core 5 is set so as to be separated from the magnetic flux bypassed to the
The gap size between the brake plate 3 and the movable iron core 5 is determined. Reference numeral 8 denotes a shaft retaining ring installed on the motor shaft 1d, which is used to limit the brake plate 3 from being attracted by the electromagnet 7 and moving toward the electromagnet 7 to a predetermined amount when the electromagnet 7 is in its position. 9 is a push button switch for winding operation (hereinafter simply referred to as a switch) consisting of an A contact; 10 is an electromagnetic coil 10a connected in series with the switch 9; an A contact 10b and a B contact 10c that respond to the energization of the coil 10a; The electromagnetic relay for winding operation is composed of a C contact 10d, 11 is a push button switch for lowering operation (hereinafter simply referred to as a switch) consisting of an A contact, and 12 is an electromagnetic coil 12a connected in series with the switch 11.
and an a contact 12 that responds to the energization of the coil 12a.
The above-mentioned electromagnetic relay for lowering operation is composed of a contact b, b contact 12c, and a c contact 12d, 13 is a stop push button switch consisting of a b contact connected in series to the parallel circuit of switches 9 and 11, and 14 is a Contact 12
When the a contact 10b is on, the coil 7 is more active than when the b is on.
This is a resistor that reduces the value of current flowing through the circuit. Note that the a contact 12b constitutes a short circuit.

In the device configured in this way, when the switch 9 is turned on, the coil 10a is energized and the contact 10 is turned on.
It is clear from the circuit of FIG. 3 that contacts 12b, 10c, and 10d respond to perform the above-mentioned hoisting operation, and that when switch 11 is turned on, contacts 12b, 12c, and 12d respond to perform the above-mentioned lowering operation. By the way, during the lowering operation, the contact 12b
is closed, the resistor 10b is short-circuited, and the excitation current of the coil 7a increases. On the other hand, during winding operation, the contact 12b is opened and the contact 1
0b is closed, the resistor 14 is connected in series with the coil 7a, and the excitation current to the coil 7a is reduced compared to during the lowering operation. Therefore, during the above operation, the brake plate 3 is braked by eddy current due to the action of the electromagnet 7, but as mentioned above, the value of the current flowing through the coil 7a is smaller during the above-mentioned winding operation than during the above-mentioned lowering operation. Therefore, the braking torque of the eddy current braking is also smaller during the hoisting operation than during the hoisting operation. Furthermore, when the electric motor 1 is deenergized, the electromagnet 7 is also deenergized, so the coil spring 6 presses the brake pad 3a against the fixed part of the frame 1f via the movable iron core 5, so that the electric motor 1 is braked. .

〔Effect of the invention〕

As described above, the present invention provides a commutator motor that rotates a winding drum to perform winding and lowering operations;
A brake plate made of a magnetic material that is displaceable in the axial direction of the rotating shaft of the commutator motor and is engaged with the rotating shaft so that it cannot rotate relative to the rotating shaft, one surface of which faces the brake plate; arranged so as to be non-rotatable and displaceable in the axial direction with respect to the frame,
A movable iron core having a thick wall portion that includes a brake pad of the brake plate and protrudes in the axial direction, and a thin wall portion that is concave in a direction away from the brake plate with respect to the thick wall portion; A fixed core facing the other surface of the fixed core, provided on this fixed core,
an excitation coil that is energized when the commutator motor is energized; a spring that biases the movable iron core toward the brake plate; a positioning member for separating the brake plates; a resistor is connected in series to the excitation coil;
A short circuit is connected in parallel to this resistor to short-circuit the resistor, and during the lowering operation, the resistor is short-circuited to directly energize the exciting coil, and during the winding operation, the current is applied to the exciting coil via the resistor. Since it is energized, it is possible to generate eddy current braking on the brake plate in products using commutator motors that do not generate regenerative braking, which not only prevents acceleration during lowering, but also prevents eddy current braking from occurring during hoisting. In other words, the occurrence of functionally unnecessary eddy current braking during winding can be suppressed by connecting a resistor in series with the excitation coil and energizing the excitation coil via the resistor.
-The axial dimension can be made extremely small compared to the one disclosed in Publication No. 99370, in which a non-ferrous metal disk is separated from a permanent magnet, and the brake plate can also perform eddy current braking and stop braking. Similarly, as disclosed in Japanese Utility Model Application Publication No. 51-99370, one braking means is provided on one side of the rotor in the axial direction, and another is provided on the other side in the axial direction of the rotor. The axial dimension can be further reduced compared to the case where a single braking means is provided, and the device can be significantly downsized and the arrangement can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the embodiment, and FIG. 3 is a circuit diagram of the embodiment. In the figure, 1 is an electric motor, 3 is a magnetic brake plate, 3a is a brake pad, 5 is a movable iron core, 5a is a thin wall part, 5b is a thick wall part, 6 is a compression coil spring, 7 is an electromagnet, 7a is a coil, 7b is a fixed iron core, 12b is an a contact, and 14 is a resistor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A commutator motor that rotationally drives the winding drum to perform hoisting and lowering operations, and is engaged to the rotating shaft of the commutator motor such that it can be displaced in the axial direction and cannot rotate relative to the rotating shaft. A brake plate made of a magnetic material, one surface of which faces the brake plate, is arranged so as to be non-rotatable and axially displaceable with respect to the frame of the commutator motor, and includes the brake pads of the brake plate and faces the frame. a movable iron core having a thick wall portion projecting in the axial direction and a thin wall portion forming a concave shape in a direction away from the brake plate with respect to the thick wall portion;
a fixed iron core facing the other surface of the movable iron core; an excitation coil provided on the fixed iron core and energized when the commutator motor is energized; a spring that urges the movable iron core toward the brake plate; A positioning member is provided on the rotating shaft and separates the brake plate from the movable iron core when the exciting coil is energized, and a resistor is connected in series to the exciting coil and is connected in parallel to the resistor. A short-circuit circuit capable of short-circuiting the resistor is provided, and during the lowering operation, the resistor is short-circuited to directly energize the excitation coil, and during the winding operation, the excitation coil is energized via the resistor. A hoisting device featuring: