JPS61197393A - Electric winding machine - 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] [Industrial application field] The present invention relates to an electric climbing machine.

[Conventional technology and its problems]

With conventional electric hoisting machines, speed changes are rapid when starting and stopping, creating a shock. Furthermore, there was a problem in that inching □ raising and lowering operations of minute dimensions was difficult. In addition, if only the brake device was released and the power to the electric motor (drive source) was cut off, an accident would occur in which a suspended object would fall.

[Means for solving problems]

The present invention aims to solve the above problems, and therefore includes an induction motor as a drive source, an inverter device for changing the speed of the induction motor by frequency conversion, and an output section of the inverter device. A DC converter is provided to convert the signal extracted from the DC converter into DC, and the DC output side of the DC converter is connected to a solid state relay, and the solid state relay is configured to control opening and closing of the brake device. .

[Effect]

The frequency is converted by an inverter device, and the speed of the induction motor is gradually accelerated and decelerated when starting and stopping, respectively.

Furthermore, since the signal from the output section of the inverter device can always be taken out when the induction motor is rotating, the solid state relay can control the brake device so that it is released only during this rotation.

〔Example〕

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 1 and FIG. 2 show an example of the entire electric hoist. 11
is the casing body, various gears and load sheave 1
4. Contains various shafts, brake devices, etc. An induction motor IM is attached to the side position, an upper hook 12 is provided upwardly, and a load sheave 14 is provided downwardly.
A cargo chain 13 suspended from the front is installed vertically, and an electric control box 15 is attached to the front. Induction electric l#lIM
The driving force rotates the load sheave 14 via a reduction gear to wind up or unwind the load chain 13. Reference numeral 16 denotes an operation panel, which is vertically disposed from the casing body 11 and includes push button switches 8a and 8b for winding up and lowering, respectively.

Therefore, in Fig. 3, the induction motor I as the drive source
An inverter device 1 is provided so that the rotational speed of M is determined by frequency conversion.

This induction motor IM is for Sanwa AC, and is connected as shown in the figure (to the power source on the left side of the figure) via an inverter device 1.

5 is a DC converter that converts the signal (AC output) taken out from the output section 17 of the inverter device 1 into DC.

The DC output side of this DC converter 5 is connected to the solid state relay 4. 3 indicates a brake device, and the two are connected so that the brake solenoid 3a is controlled to open and close by the solid state relay 4.

The inverter device 1 is provided with a frequency setting volume 2 for setting the final output frequency, and a contact 18 of the forward rotation (hoisting) relay R1 and a contact 19 of the reverse rotation (lowering) relay R2 are provided. attached.

Both relays R1 and R2 are connected as shown in the lower part of FIG. 3, respectively. That is, in one relay R1, the soil rolling push button switch 8a, the upper limit switch 6, and the contact 20 of the other relay R2 are connected in series. In the other relay R2, the lowering pushbutton switch 8b, the lower limit switch 7, and the contact 21 of the relay R1 are connected in series. The circuits of both relays R1 and R2 are interconnected in parallel to form an interlock.

Note that Sl and S2 represent spark killers. In addition, the limit switches 6 and 7 are hoisted by the respective loaders 13 at the same time.
It operates by mechanically detecting the lowered position. And the brake device 3 is the inverter device 1
The output section 17 is configured to be in an open state only when there is AC power, and performs a braking operation when there is no AC output.

The operation will be explained below. When the push button switch 8a for rolling soil is pressed by hand, the relay R1 is turned on, the contact 18 is connected, and a low voltage, low frequency AC output is output from the output section 17 of the inverter device 1. The induction motor IM is about to start rotating. At this time, the AC output is immediately taken out as a signal, converted to DC by the DC converter 5, and then the solid state relay 4 turns on the power to the brake solenoid 3a to open the brake device 3.

The induction motor IM, which has started rotating, gradually increases its rotational speed as the voltage and frequency of the AC output from the inverter device 1 gradually increases over a period of several seconds. Constant speed rotation is reached at the final frequency set.

After that, if you release your hand from the soil rolling push button switch 8a,
Relay R1 is turned OFF, contact 18 is disconnected, and the voltage and frequency of the AC output from output section 17 of inverter device 1 are gradually reduced.

The solid state relay 4 is reversely switched via the DC converter 5, turning off the power to the brake solenoid 3a and applying the brake.

Similarly, the lowering pushbutton switch 8b starts and stops slowly, and the brake is switched between the released and activated states.

〔Effect of the invention〕

With the above configuration, the present invention exhibits the following significant effects.

■ Frequency conversion is performed using an inverter device to gently accelerate and decelerate the induction motor, so there is less shock at startup and stop, allowing for smooth hoisting and lowering operations.

(2) Therefore, it is also possible to easily raise or lower the dimensions (so-called inching).

- Since the brake device 3 is released only when power is being supplied to the induction motor IM, it is possible to reliably prevent a suspended load from falling, resulting in high safety.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a control circuit diagram. IM...Induction motor, 1...Inverter device, 3.
...Brake device, 4...Solid state relay,
5... DC converter, 17... Output section.

Claims (1)

[Claims] 1. An induction motor IM is provided as a drive source, an inverter device 1 is attached to convert the speed of the induction motor IM by frequency conversion, and a direct current converter is used to convert the signal taken out from the output section 17 of the inverter device 1 into direct current. An electric hoist characterized in that a converter 5 is provided, the DC output side of the DC converter 5 is connected to a solid state relay 4, and the solid state relay 4 controls opening and closing of the brake device 3. Machine.