JPH0352790Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mast hoisting device using a wire rope in a ground-lifting type climbing crane.

(Prior art) Ground climbing cranes that have a lifting device that raises and lowers a mast lifting frame via a wire rope wound by a climbing winch usually use a single-speed climbing winch. . Therefore, both when the mast is raised, i.e., loaded, and when the mast has been raised and the lifting frame is lowered to install the next supplementary unit mast, i.e., unloaded. The problem was that the climbing winch could only be operated at the same speed, which increased the time required to raise the mast. Further, if an attempt is made to shorten the climbing time in this state, a motor with a large capacity capable of raising and lowering the mast at high speed must be used as the motor for driving the climbing winch, which is uneconomical.

On the other hand, looking at the output status of the climbing winch, when the mast is fixed to the lifting frame (when loaded), the output is close to the rated output.
When the mast is not fixed to the lifting frame, the work is much less than the rated output, and the efficiency is poor.

For this reason, the vehicle of the present invention uses a motor capable of switching between high and low speeds as the electric motor for operating the climbing winch, and uses a limit switch to detect the position of the mast fixing bolt pin of the lifting frame to determine whether it is in a loaded state. The control circuit for the climbing winch motor was constructed so that it could operate at high speed when it was not loaded, but the limit switch was configured so that the operating rod of the limit switch was pressed by the head of the outer end of the bolt pin. In particular, since the limit switch is configured to operate, there is a problem that when the mast is hung, there is a risk that the mast will collide with the limit switch and be damaged.

(Problems to be solved by the invention) In view of the above-mentioned problems, the purpose of the invention is to be able to raise and lower the lifting frame at high speed in an unloaded state, thereby shortening the time required for climbing. To provide a mast hoisting device for a climbing crane, which is capable of reducing the capacity of a driving motor of a climbing winch, and has a structure in which a load detection switch such as a limit switch is not damaged by mast collision. The purpose is to

(Means for Solving the Problem) In order to achieve this purpose, the present invention has a lifting frame that is lifted and lowered by a climbing winch attached to a support mast installed on the ground, and is inserted into a boss provided on the lifting frame. In a mast raising device for a climbing crane, which has a structure for removably fixing the mast of a climbing crane with a bolt pin, and is equipped with an electric motor capable of switching between high and low speeds as a driving device for the climbing winch, A stepped portion is provided on the outer periphery of the intermediate portion so that the tip side has a smaller diameter, a hole is provided in the intermediate portion of the boss, one end of the rod is inserted into the hole, and the end of the rod is attached to the bolt pin by a spring. pressing, attaching to the other end of the rod an operating body for a pin protrusion/retraction state detection switch attached to the elevating frame;
When the bolt pin is pulled out or inserted, the tips of the rods come into contact with the small diameter portion and the large diameter portion of the bolt pin, respectively, and the rod is pulled out by the force of the spring or against the force of the spring. The pin protrusion/retraction state detection switch has a configuration in which the pin protrusion/retraction state detection switch is moved inward or outward from the boss, and the operating body is accordingly displaced to activate or deactivate the pin protrusion/retraction state detection switch. It is characterized in that it is incorporated into the control circuit of the electric motor so that high-speed operation of the electric motor is prohibited when the bolt pin is inserted, and high-speed operation is allowed when the bolt pin is pulled out.

(Embodiment) First, the overall configuration of an embodiment of the present invention will be explained with reference to FIGS. 4 to 10. As shown in FIG. 4, the mast 1 on which the crane main body 10 is mounted is constructed by connecting a plurality of unit masts 1a to 1n using a mast hoisting device 11 on the ground. As shown in FIGS. 5 and 6, the mast raising device 11 includes a support mast 2 and a support mast 2.
The lift frame 4 has a lift frame 4 having a guide roller 13 that rolls along a guide rail 12 provided at the top. As shown in FIGS. 5 and 7, 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. As shown in FIGS. 8 to 10, the mast 1 can be fixed to the lifting frame 4 by inserting the bolt pin 6 attached to the lifting frame 4 into the bolt hole 18 provided in the unit mast 1i. .

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. 5 and 6, 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 descends to the lowest end, the bolt pin 6 is again inserted into the bolt hole 18 of the next unit mast. Repeat this action to continue climbing.

Next, the main parts of the present invention will be explained with reference to the embodiment shown in FIGS. 1 to 3. The bolt pin 6 has a small diameter portion 6 on the outer periphery of the middle portion thereof.
a, and the outer end side having the flange 6d is the large diameter portion 6.
A step portion 6c is provided as shown in FIG. The large diameter portion 18a at one end of the rod 18 is slidably inserted. Reference numeral 21 denotes a U-shaped bracket fixed to the lower end of the boss 4a with a bolt 25, and the rod 18 is slidably inserted into a hole 24 provided at the center of the bracket, and the bracket 21 of the rod 18 and the large diameter portion 18a are connected to each other. By installing a pressure spring 20 between the rod 18
The end of the bolt is pressed against the bolt pin 6. In addition, in this embodiment, in order for the rod 18 to smoothly follow the forward and backward movement and rotation of the bolt pin 6, a concave portion 26 having a hemispherical surface is provided on the distal end surface of the large diameter portion 18a. A ball 22 that contacts and rolls on the outer peripheral surface of the bolt pin 6 is rotatably fitted into the bolt 26.

A limit switch 7 as a pin protrusion/retraction state detection switch is attached to the lower part 4b of the boss 4a attachment part of the lifting frame 4, and the outer end of the rod 18 is operated by pressing against the operating rod 7a of the outer limit switch 7. A striker 19 as a body is attached. As shown by the solid line in FIG. The ball 22 faces and contacts the large diameter portion 6b of the bolt pin 6, and the spring 2
The rod 18 is moved outward from the boss 4a (downward in this example) against the force of 0, and the limit switch 7 is in an inoperative state.

On the other hand, when the bolt pin 6 is pulled out and the lifting frame 4 is separated from the mast 1 as shown by the arrow a in FIG. The rod 18 is pushed up as shown by arrow b, and the ball 22 at its tip faces and contacts the small diameter portion 6a, and the rod 1
8 moves inward (in the illustrated example, upward) of the boss 4a, and the striker 19 pushes up the operating rod 7a of the limit switch 7 as shown by the arrow c to bring it into the operating state.

This limit switch 7 is connected to a control circuit of, for example, a pole change type electric motor 9 that can be operated by switching between high and low speeds of the climbing winch 3 shown in FIG.
When the bolt pin 6 is in the inserted state (loaded state), high-speed operation of the electric motor 9 is prohibited;
It is built in such a way that high-speed operation is permitted in the unloaded state (unloaded state). In Figure 3, 8
(PB1 to PB4) are push button switches operated by the operator, 7 is the limit switch,
In this embodiment, a normally open type is used.
Also, C1, CX, CF1, CR1, CF, CR,
CFX and CRX are relays. Those with a or b attached to lowercase letters are their respective a or b contacts. cf, cr, cfx, crx on the power line connected to motor 9 are each relay CF, CR, CFX, CRX. It is a point of contact.

Now, bolt pin 6 is inserted (loaded state)
, the operating rod 7a is not moved by the striker 19 and the contact point of the limit switch 7 is open, so the relay CX is not energized regardless of whether the push-button switch PB3 for high-speed rotation command is operated. Since the a contact cxa remains open,
The high-speed ascent and high-speed descent relays CFX and CRX are not excited, and the motor 9 cannot be rotated at high speed.

On the other hand, by operating the low speed rotation command operation switch PB4, the relay C1 is set to
Since it is energized and excited via contact cxb, contact cla of relay C1 is closed, and if operation switch PB1 or PB2 is operated in this state, the relay is activated.
When CF1 or CR1 is energized, these a contacts
Since cfla or crla is closed, relay CF or CR is energized, and contact cf or cr is closed, motor 9 rotates at low speed in the direction of raising or lowering lifting frame 4. That is, in a loaded state in which 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 load is empty, that is, when the bolt pin 6 is pulled out, the rod 18 is pushed up by the force of the spring 20, and the striker 19 pushes up the operating rod 7a of the limit switch 7, so that the contact of the limit switch 7 is closed. becomes. In this state, operate the operation switch PB4 for low speed rotation command, and also operate the operation switch for raising or lowering.
The operation when operating PB1 or PB2 is as described above. Operation switch PB3 for high-speed rotation command
When operated, relay CX is energized and its a contact cxa is closed. If operating switch PB1 or PB2 is operated in this state, relay CF1 or CR is activated.
1 is energized to close these A contacts cfla or crla, and relay CFX or CRX is energized to close the contacts.
Since cfx or crx is closed, the motor 9 rotates at high speed in the upward or downward direction of the 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 cargo on the lifting frame 4 can be shortened.

In addition, in Fig. 3, for example, if the low-speed rotation command operation switch PB4 and the b contact c1b of the relay C1 connected to the relay CX are removed and the part where these were provided is shortened, high-speed vertical movement can be performed. Just press the operation switch PB3 only when
It is understood that the configuration of the specific operating circuit can be modified in various ways without departing from the gist of the present invention, such as eliminating the need to press the operating switch for speed selection in the case of low-speed ascending and descending. Needless to say. Further, as a switch for detecting the presence or absence of a load, in addition to a limit switch that operates a contact point mechanically, it is also possible to use a switch that operates a contact point or a switching element magnetically or optically.

(Effects of the Invention) According to the present invention, high-speed lifting and lowering can be performed when the lifting frame is in an empty state, so that the climbing time and the time for hoisting the empty load can be shortened. In addition, in this invention, high-speed lifting is possible only when the load is empty, so there is no need to increase the capacity of the climbing winch drive motor.
Only the minimum required capacity is required.

Furthermore, in the present invention, the switch for detecting the presence or absence of a load can be installed near the boss rather than outside the boss, so there is no risk of the mast colliding with the switch and damaging it.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is a side cross-sectional view showing an example of the mounting structure of the limit switch in the present invention, Fig. 2 is a partially enlarged view of Fig. 1, and Fig. 3 is an embodiment of the limit switch in the present invention. An example of a control circuit for an electric motor for driving a climbing winch; FIG. 4 is an overall view of an example of a ground-lifting climbing crane; FIG. 5 is a front view of a mast-lifting device for the crane shown in FIG. Figure 6 is A of Figure 5.
-A view, FIG. 7 is a diagram showing an example of the wiring of the mast raising device, FIG. 8 is a plan view showing the connection structure between the lifting frame of the mast raising device and the mast, and FIG. 9 is a diagram showing an example of the wiring of the mast raising device. BB arrow view in Figure 8,
FIG. 10 is an enlarged sectional view taken along the line CC in FIG. 9.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A lifting frame that is raised and lowered by a climbing winch is attached to a support mast installed on the ground, and the mast of a climbing crane is detachably fixed by a bolt inserted into a boss provided on the lifting frame. In addition to having a structure that
In the mast raising device for a climbing crane, which is equipped with an electric motor capable of switching between high and low speeds as a driving device for the climbing winch, a stepped portion is provided on the outer periphery of the intermediate portion of the bolt pin so that the tip side has a smaller diameter, A hole is provided in the middle part of the boss, one end of the rod is inserted into the hole, the end of the rod is pressed against the bolt pin by a spring, and the other end of the rod is attached to the lifting frame. When the operating body of the pin protruding/retracting state detection switch is attached and the bolt pin is pulled out or inserted, the tips of the rods face-to-face contact with the small diameter portion and the large diameter portion of the bolt pin, respectively, and the force of the spring causes the rod to be pulled out or inserted. The rod moves inward or outward from the boss against the force of a spring, and the operating body is accordingly displaced to activate or deactivate the pin protrusion state detection switch. and the pin protruding/retracting state detection switch prohibits high-speed operation of the electric motor when the bolt pin is inserted;
1. A mast raising device for a climbing crane, characterized in that the device is incorporated into a control circuit of the electric motor so that high-speed operation is permitted in a pulled-out state. 2. The mast raising device for a climbing crane according to claim 1, characterized in that a ball that contacts and rolls on the bolt pin is attached to the tip of the rod.