JPS647959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mast raising device using a wire rope in a climbing crane of the above ground type.

(Background Art) An example of a ground-lifting type climbing crane having a mast-lifting device using a wire rope will be described with reference to FIGS. 1 to 7. As shown in FIG. 1, the mast 1 on which the crane body 10 is mounted includes a plurality of unit masts 1a to 1.
It is constructed by adding n using the mast raising device 11 on the ground. As shown in FIGS. 2 and 3, the mast raising device 11 includes a support mast 2 and a guide rail 1 provided on the support mast 2.
The lift frame 4 has a guide rail 13 that rolls along the lift frame 2. As shown in FIG. 4, the elevating device for the elevating frame 4 includes a sheave block 14 on which a wire rope 5, which is wound and let out by a climbing winch 3, is attached to an upper frame 2A at the top of the support mast 2. , 16 and sheave blocks 15, 17 attached to the lifting frame 4.
It is constructed by passing it between Fifth
As shown in FIGS. 7 to 7, the bolt pin 6 attached to the lifting frame 4 is
The mast 1 can be fixed to the lifting frame 4 by inserting it into the bolt hole 18 provided in the.

The rise of mast 1 is the lowest unit mast 1
The mast 1 is fixed to the lifting frame 4 by inserting the bolt pin 6 into the bolt hole 18 of i, and the mast 1 is raised together with the lifting frame 4 by winding the wire rope 5 with the climbing winch 3. As shown in FIGS. 2 and 3, the lifting frame 4
When the unit mast 1j rises enough to create a space under the mast 1 for the additional unit mast 1j, the unit mast 1j
is inserted and connected to the unit mast 1i fixed to the lifting frame 4. When the next unit mast 1j is connected in this way and the crane body 10 is supported by the mast 1, the bolt pin 6 is pulled out to separate the mast 1 and the lifting frame 4. Next, the lifting frame 4 is lowered with no load, and when it reaches the lowest point, the bolt pin 6 is again inserted into the bolt hole of the next unit mast. Continue climbing by repeating this motion.

In such a mast raising device 11, as a climbing winch 3, a conventional climbing winch 3 is used.
The fastest one is used. Therefore, even when the mast 1 is raised, that is, when it is loaded,
After completing the raising of mast 1, Figures 2 and 3
Even when the lifting frame 4 is being lowered to attach the next unit mast 1j shown in the figure, that is, when it is unloaded, the climbing winch 3 can only be operated at the same speed, and the time required to raise (climb) the mast is shorter. There was a problem with the length of time. Furthermore, if a one-speed climbing winch 3 is used to shorten the climbing time, the capacity of the motor for driving the climbing winch 3 must be increased, which is uneconomical.

On the other hand, looking at the output status of the climbing winch 3, when the mast 1 is fixed to the lifting frame 4 (when loaded), the output is close to the rated output, but when the mast 1 is fixed to the lifting frame 4, the output is close to the rated output. When it is not working, it is doing far less work than its rated output and is inefficient.

(Object of the present invention) In view of the above-mentioned problems, the object of the present invention is to provide a climbing crane having a structure capable of shortening the time required for climbing and reducing the capacity of the driving motor of the climbing winch. The purpose of the present invention is to provide a mast raising device.

(Summary of the Invention) In order to achieve this object, the mast raising device for a climbing crane according to the present invention is equipped with an induction motor whose rotational speed can be changed by inverter control as a driving device for the climbing winch, and an induction motor for setting the frequency of the inverter. The lifting frame for lifting the mast has a plurality of potentiometers, and the lifting frame for lifting the mast is provided with a status detection switch for detecting whether or not the mast is fixed to the lifting frame, and the status detection switch is connected to the operation circuit of the induction motor. If the built-in state detection switch detects that the mast is fixed to the lifting frame, it is only possible to raise and lower at the low speed set on the low speed setting potentiometer, and on the other hand, it detects the unfixed state. The circuit is characterized in that the circuit is configured so that it is possible to select the high speed or low speed set by the high speed or low speed setting potentiometer.

(Example) The present invention will be explained below with reference to an example shown in FIGS. 8 to 10. Reference numeral 7 denotes a limit switch attached to the lifting frame 4 according to the present invention, and as shown by the solid line in FIG. The lifting frame 4
If the limit switch 7 is fixed to
The actuating rod 7a is in an inoperative state, and the contact of the limit switch 7 is open, while the bolt pin 6 is pulled out and the mast 1 is closed, as shown by the phantom line.
When the limit switch 7 is not fixed to the lifting frame 4, the operating rod 7a of the limit switch 7 is pushed by the bolt pin 6 into the operating state, and the contact point of the limit switch 7 is configured to close.

FIG. 10 shows an operating circuit for an electric motor 9 for driving the climbing winch 3 incorporating the limit switch 7, and the electric motor 9 is an induction motor whose rotational speed can be changed by inverter control.
The inverter device 9A once rectifies the three-phase alternating current input from the input terminals R, S, and T, and outputs a variable frequency alternating current output to the electric motor 9 from the output terminals U, V, and W, and E is grounded. Terminals, f and g are power supply terminals for control, d and e are input terminals for rotation direction command, b is frequency setting signal input terminal, a is start signal self-holding relay terminal, c is remote control terminal for control circuit, h is start This is a signal input terminal.

Reference numeral 8 denotes an operation switch, which controls the electric motor 9 in the winding direction and the unwinding direction of the wire rope 5 (that is, in the ascending direction and descending direction of the elevating frame 4, respectively).
Operation switch for commanding rotation to
It consists of PB1, PB2, and operation switches PB3, PB4 for commanding high speed rotation and low speed rotation, respectively. CF, CR, CH, and CL are relays; the letters with a or b added to the alphanumeric lowercase letters are the contacts of each relay; PM1 and PM2 are high-speed potentiometers and low-speed potentiometers, respectively. .

In this circuit, when the mast 1 is raised by inserting the bolt pin 6 and fixing the mast 1 to the lifting frame 4, the operating rod 7a of the limit switch 7 is in an inoperative state, and the contact point of the limit switch 7 is is open, so the relay
CH is not excited regardless of the operation for high-speed rotation command, its a contact cha remains open, and b
Contact chb remains closed. In this state, when the low speed rotation command operation switch PB4 is operated, the relay CL is energized and excited via the b contact chb, so the a contact cla of the relay CL is closed, and the low speed potentiometer PM2 is An output frequency corresponding to the set voltage is set. If operation switch PB1 or PB2 is operated in this state, relay CF or CR will be energized and these a
Contact cfa or cra is closed, a signal is applied to the rotation direction command input terminal d or e to command the rotation direction, and an operation signal is applied to the start signal input terminal h and the start signal self-holding relay terminal a. The electric motor 9 rotates at low speed in the wire rope winding or unwinding direction. That is, the mast 1 is attached to the lifting frame 4.
If it is fixed, the elevating frame 4 can only be moved up and down at low speed.

On the other hand, when the bolt pin 6 is pulled out, the operating rod 7a of the limit switch 7 is in an operating state, and the contact of the limit switch 7 is closed. In this state, press the operation switch for low speed rotation command.
The operation when operating PB4 and operating the ascending or descending operating switch PB1 or PB2 is as described above. Operation switch for high-speed rotation command
When PB3 is operated, relay CH is energized, its a contact cha is closed, and high-speed potentiometer PM
The output frequency corresponding to the voltage set to 2 is set. Therefore, if operating switch PB1 or PB2 is operated in this state, electric motor 9 will rotate at high speed. That is, when the mast 1 is not fixed to the lifting frame 4, that is, when there is no cargo, either high speed or low speed can be selected.

Therefore, during the lowering operation of the unloaded lifting frame 4, the climbing winch 3 can be operated at high speed to shorten the climbing time, and the capacity of the electric motor 9 for driving the climbing winch for this purpose can be reduced to the necessary minimum. You can choose only. When the crane is lowered by sequentially separating and pulling out the unit masts, the operation is just the opposite, and the time required for hoisting the empty load of the lifting frame 4 can be shortened. Also, potentiometer PM1,
Since the rotational speed of the electric motor 9 can be set arbitrarily by PM2, a speed preferable in terms of work efficiency can be selected whether the motor is loaded or unloaded.

Note that the state detection switch for detecting whether or not the mast 1 is fixed to the lifting frame 4 is not limited to the limit switch mentioned above, but also other types such as magnetic type, electromagnetic type, photoelectric type, electrostatic induction type, etc. It is also possible to use one. In addition, in the embodiment, two potentiometers are provided and the height is 2.
The speed selection range can be further expanded by increasing the potentiometer. Also,
When performing speed control using inverter control, not only the output frequency to the motor but also the peak value of the output voltage may be changed. In addition, in FIG. 10, for example, the low speed rotation command operation switch PB4
and b contact of relay CL connected to relay CH
If you eliminate clb and short-circuit the parts where these were provided, you only need to press the operation switch PB3 when you want to perform high-speed ascent and descent, and you do not need to press the operation switch for speed selection when you want to do low-speed ascent and descent. It goes without saying that the configuration of the specific operating circuit can be changed in various ways without departing from the gist of the present invention.

(Effects of the Present Invention) According to the present invention, since high-speed lifting and lowering can be performed when the lifting frame is in an empty state, the climbing time and the time for lowering the empty load can be shortened. In addition, in the present invention, high-speed lifting is possible only in an unloaded state, and the electric motor for driving the climbing winch can be operated with high efficiency at all times, so the capacity of the electric motor is kept to the minimum necessary. Capacity is sufficient. Further, according to the present invention, since the rotation speed of the electric motor for driving the climbing winch can be arbitrarily set using the potentiometer, the load,
In either case, a speed suitable for work efficiency can be selected.

[Brief explanation of the drawing]

Figure 1 is an overall view showing an example of a ground climbing crane, Figure 2 is a front view showing the mast lifting device of the crane in Figure 1, and Figure 3 is a view taken along arrow A-A in Figure 2. , FIG. 4 is a diagram showing an example of the wiring of the mast raising device, FIG. 5 is a plan view showing the connection structure between the lifting frame of the mast raising device and the mast, and FIG. 6 is a diagram showing B of FIG. 5. -B
7 is a sectional view taken along the line C--C in FIG. 6, FIG. 8 is a diagram showing an example of the mounting structure of the state detection switch according to the present invention, and FIG. 9 is a view taken along the line D--D in FIG. 8. 10 are diagrams showing an example of an operating circuit for a climbing winch driving electric motor according to the present invention. 1...Mast, 2...Support mast, 3...Climbing winch, 4...Elevating frame, 5...Wire rope, 6...Lock pin, 7...Limit switch, 8...Operation switch, 9...Induction motor for driving climbing winch, 9A...Inverter Device,
PM1, PM2...Potentiometer.

Claims (1)

[Claims] 1. A climbing crane mast raising device in which a lifting frame that is lifted and lowered by a climbing winch via a wire rope is attached to a support mast installed on the ground, and the mast of the climbing crane is fixed to the lifting frame to raise the mast. The climbing winch is equipped with an induction motor whose rotational speed can be changed by inverter control as a driving device, as well as multiple potentiometers for setting the frequency of the inverter. If a state detection switch is provided to detect whether or not the mast is fixed, and the state detection switch is incorporated into the operation circuit of the induction motor, and the state detection switch detects the state in which the mast is fixed to the lifting frame, It is only possible to move up and down at the low speed set on the low speed setting potentiometer; on the other hand, if a non-fixed state is detected, it is possible to select high speed or low speed set on the low speed setting potentiometer. A mast raising device for a climbing crane characterized by having a circuit configuration such that.