JPS647958B2 - - 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 ground raising 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 the raising of mast 1 is completed, Figures 2 and 3
Even when the lifting frame 4 is 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 present invention) In order to achieve this object, the mast raising device for a climbing crane according to the present invention is equipped with a pole number changing motor as a driving device of the climbing winch, and the lifting frame for lifting the mast is equipped with a pole number changing motor. 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 pole number conversion motor, and the state detection switch detects a state in which the mast is fixed to the lifting frame. The circuit is configured in such a way that only low-speed elevation is possible when the vehicle is in the fixed state, and on the other hand, it is possible to select between high and low speeds when the non-fixed state is detected.

(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 of an electric motor 9 for driving the climbing winch 3 incorporating the limit switch 7, and the electric motor 9 is a pole number changing motor whose speed can be switched between high speed and low speed by changing the number of poles. In the figure, reference numeral 8 denotes an operation switch, which controls the motor 9 in the winding direction and unwinding direction of the wire rope 5 (that is, in the ascending direction of the lifting frame 4, respectively).
Operation switches PB1 and PB2 are used to command rotation in the downward direction), high-speed rotation,
Operation switch PB3 for commanding low speed rotation,
Consists of PB4. CF1, CR1, CX, C1,
CF, CR, CFX, CRX are relays, their lowercase alphanumeric characters and a
Or, the symbol with b indicates the contact point of each relay.

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 limit switch 7 Since the contact of is open, the relay
CX is not energized regardless of the operation for high-speed rotation command, and its a contact cxa remains open. Rotation is not possible. On the other hand, the relay C1 is energized and energized via the b contact cxb of the relay CX by operating the low-speed rotation command operation switch PB4, so the a contact cla of the relay C1 is closed, and in this state, the operation switch is When PB1 or PB2 is operated, relay CF1 or CR1 is energized, these a contacts cfla or crla close, and the relay
Since CF or CR is excited and the contact cf or cr is closed, the motor 9 rotates at low speed in the direction of raising or lowering the lifting frame 4. That is, when the mast 1 is fixed to the lifting frame 4, the lifting frame 4 can only be moved up and down at a 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 CX is energized and its a contact cxa is closed, and in this state, operating switch PB is
If you operate 1 or PB2, relay CF1 or
CR1 is energized and these A contacts cfla or crla
is closed, relay CFX or CRX is energized and contact cfx or crx is closed, so motor 9 rotates at high speed in the direction of raising or lowering lifting frame 4. 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 climbing winch drive motor 9 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.

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 described above, but may also be of other types such as magnetic type, electromagnetic type, photoelectric type, electrostatic induction type, etc. It is also possible to use one. In addition, in FIG. 10, for example, the operation switch for low speed rotation command is
PB4 and b of relay C1 connected to relay CX
If you eliminate the contact point clb and short-circuit the parts where these were provided, you only need to press the operating switch PB3 for high-speed lifting and lowering, and you do not need to press the operating switch for speed selection for low-speed lifting. It goes without saying that the specific configuration of the 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, since high-speed lifting is possible only in an unloaded state, there is no need to increase the capacity of the climbing winch drive motor.
Only the minimum required capacity is required.

[Brief explanation of drawings]

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 drive motor according to the present invention. 1... Mast, 2... Support mast, 3... Climbing winch, 4... Lifting frame, 5... Wire rope, 6... Bolt pin, 7... Limit switch, 8... Operation switch, 9... Climbing winch drive motor.

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 a motor that changes the number of poles as a driving device, and the elevating frame for lifting the mast is equipped with a status detection switch that detects whether the mast is fixed to the elevating frame.
If the state detection switch is incorporated into the operation circuit of the pole number conversion motor, and the state detection switch detects that the mast is fixed to the lifting frame, only low-speed lifting is possible; conversely, the mast is not fixed. A climbing crane mast raising device characterized by having a circuit configuration that allows selection of high speed or low speed when detecting