JPS58125597A - Hoisting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a No. 1 hoist with a two-stage "overload protection for the motive" for hoisting.

A conventional device of this type will be explained with reference to FIGS. 1 and 2. In the figure, r%s1t is a three-phase AC source 1-L, 8.
The power supply cable connected to each phase of T, M is supplied via a reversible Vt electromagnetic contactor described later (cable/r, s%t). It has a closing auxiliary contact and a coil OUo. TR1 and TRg constitute a voltage detector that outputs a lit source voltage. Transformer OT> is a current detector that detects the current in cable t, and CCI is a As detailed in Fig. 2, a power detector 8, pI, which detects power by voltage input from transformer TRg and current input from CT+;
a comparator H1 that comparatively detects that the output of the force generator Sp1 has reached a calibrated overload state above a predetermined tiu;
A control circuit formed on a substrate consisting of a holding circuit that maintains that the output of the power detector Sp+ has reached a predetermined value or more based on the output of the comparator H1, and a contact 0Da4.
When the circuit is closed, the heat is reset to the holding circuit. In general, the holding circuit is energized (holding) at 1.
This is a relay that is energized when this occurs, and has a normally closed contact RYb. Bu is a push-button switch for hoisting, and Bd is a push-button switch for hoisting. In this structure, when the switch Bu is turned on, OUo is energized and the contact O is turned on.
Since Ua+, OUag%C[Ja s is closed,
The electric motor M performs hoisting operation, and when the switch Bu is turned off, the hoisting operation is stopped. Also, when switch Bd is turned on, ODc is energized and contacts CDa t, ODa t, C
Since Dam is closed, '(movement #!!M performs lowering operation, and when switch Bd is turned off, the lowering operation is accompanied. Also, if an overload operation gc occurs during hoisting operation) relay 1
1LY is energized, contact Ryb is opened, and the hoisting operation is continued, and when the contact CDa a is closed during the subsequent hoisting operation, the holding circuit KPM is reset and the next hoisting operation t is prepared.

However, since the reset contact CDa a is required, a contactor with many auxiliary contacts is required, and the wiring is complicated, resulting in high cost and poor productivity.

This invention has been made to solve the above-mentioned conventional drawbacks, and one embodiment of the invention will be described below with reference to FIGS. 8 and 4. In the figure, CTg is N motion 11! M's W phase' (current detector that detects current, 0
As detailed in Fig. 4, 0s is a power detector Bpz that detects the voltage by the voltage input from the single transformer TR and the current input from the CTg, and the detected power of the power detector Spg is set to a predetermined value. A comparator H*l that compares and detects that an overload condition exceeding a value has been reached - a holding circuit Km that maintains that the output of the power detector 8 ps has reached a predetermined value or more by the output of the comparator H2; This is a control circuit formed on the board, which is composed of a seven-tit circuit Rs that detects the output of the power detector SP! and causes the holding circuit to turn eight during the lowering operation of the motive M. Note that the explanations of other symbols are the same as those of FIGS. 1 and 2, and will therefore be omitted.

In the device configured in this way, the control circuit CC!
Since the reset circuit Rs is provided in the
(Reset contact of magnetic contactor (Fig. 1) normally open contact C shown in Fig. 1)
Da4) becomes unnecessary. In addition, the control circuit CC! It goes without saying that the specific configuration is not limited to the 5N embodiment described above.

Since all of these questions are structured as described above, the number of auxiliary contacts of the electromagnetic contactor can be reduced compared to conventional methods, and the wiring can be reduced.
1, it is possible to provide an excellent hoisting device that is cheaper and more productive than the conventional one.

[Brief explanation of the drawing]

1 and 2 are circuits of a conventional hoisting device, where FIG. 1 is an overall diagram and FIG. 2 is a detailed diagram of a control circuit. In the actual circuit diagram, Fig. 8 is an overall diagram and Fig. 4 is a detailed diagram of the control circuit. In the figure 8, M is a 1t @ machine for hoisting, CU is a magnetic contactor, CUa>, OUag, OUa s are normally open contacts,
OUb is a normally closed contact, CD is a magnetic contactor, CDa +, C
rDts 2, CDas1CDa4 are normally open contacts6. ．． O.D.
b C Normally closed m point, T movement, TRg is voltage detector 1, CT
2 is a current detector, CC1 control circuit, 8pg is a power detector, mouth 2 is a comparator, K2 is a holding circuit, intuition is a reset circuit,
ay is a normally closed contact for relay RYb, a push button switch for Btlfi upper, and Bd is a push button switch for lower value I. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] A three-phase induction electric motor for hoisting, a contactor for the P-type inverter that operates in response to the first and second rotation of the motor, and a contactor for this I4.
i. One 'source side of the magnetic contactor is connected, an operation switch for controlling the winding and current operation of the electric motor X4, one 'It source side of the magnetic contactor is connected, and the '1 news source'; [An IE detector that detects the pressure, and an IE detector that detects the pressure flowing to the load side of the contactor.]
<71 @11 Flow detector, above '(
``Detect the peeking force'' by the output of the pressure detector and the output of the above-mentioned ``*detector''. A hoisting device comprising: a means for holding the electric motor in place when the motor is hoisting the motor; .