JPS63277193A - Balance weight operating device for counter balance crane - 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 a mobile crane in which an upper rotating body including a boom and a mast is rotatably mounted on a lower traveling body. This invention relates to a balance weight actuating device for a counterbalance crane, which is equipped with a balance weight suspended from the tip of the mast in addition to a main body weight attached to the rear of the crane.

[Prior Art] A mobile crane includes an upper revolving body equipped with a boom and a mast that is rotatably mounted on a lower traveling body.
A counterbalance crane is known which includes a main body weight attached to the rear of an upper revolving structure and a balance weight suspended from the tip of a mast. (For example, see Japanese Patent Application Laid-Open No. 62-41192.) In this type of known counterbalance crane,
In addition to the main body weight, the decision as to whether or not to operate the counterbalance weight was entirely up to the driver.

Therefore, the operator reads the load meter while operating the crane, recognizes the size of the load to be lifted, determines whether or not a balance weight is necessary, and immediately lifts the balance weight when it is determined that it is necessary to use the balance weight. I had to perform the above operation.

[Problems to be Solved by the Invention] As described above, when operating a counterbalance crane, the judgment as to whether or not it is necessary to operate the balance weight and its operation are left to the operator, and are all done manually. Therefore, when working with a crane, the operator must perform hoisting operations, boom hoisting operations, mast hoisting operations, and lifting operations of balance way 1~ at the same time or alternately in a well-timed manner. This caused problems in terms of operability and safety.

This invention was made with the aim of eliminating the problems caused by the above-mentioned human judgment and operation, and it detects the tension of the elevating rope that occurs when lifting a load, and automatically uses the detected signal to automatically Determine whether or not balance weight operation is necessary! This makes it possible to automatically lift the balance ways 1 to 1 in a well-timed manner as required.

[Means for Solving the Problems] The present invention aims to provide a means for solving the above problems, and is directed to providing a means for solving the above-mentioned problems. A boom (3) and a mast (/1) are pivotally connected so that they can be raised and raised, and the tip of the mast (A), a mast support pendant (20), and a mast elevation rope (17) are connected to each other.
The main mast (8), balance weight support pendant (26) and hydraulic lifting device (25) connected by
In a counterbalance crane equipped with a balance weight (24) connected via a counterbalance crane, a means (30) for detecting the tension of the mast elevation rope (17) is provided,
When the tension of the elevating rope (17) detected by the detection means exceeds a predetermined upper limit, the hydraulic lifting device (25) is operated in the contraction direction to suspend the balance weight (24).
The object of the present invention is to provide a balance weight actuating device for a counterbalance crane, which is characterized in that the tension of the mast elevation rope (17) is detected by the means (30) for detecting the tension of the mast elevation rope (17). Rope (17
) is below the predetermined lower limit, the hydraulic lifting device (
25) is preferably operated in the extension direction, when the value is above a predetermined upper limit value, it is operated in the reduction direction, and when it is an intermediate value between the two, it is stopped.

[Example] The refinement of the present invention will be explained with reference to an example shown in the drawings.

FIG. 1 shows an outline of a counterbalance crane to which the present invention is applied.

In the figure, reference numeral 1 denotes an upper revolving body which is rotatably mounted on a lower traveling body 2.

A boom 3 and a mast 4 are pivotally attached to the front part of the upper revolving structure 1 so as to be able to move up and down, and a hoisting winch 5. A mast elevation winch 6 and a boom elevation winch 7 are provided, and a main mast 8 is attached near the rear end. Also,
A main body weight 9 is attached to the rear thereof.

The hoisting row 110 paid out from the hoisting winch 5 is hooked onto the sheave of the hook block 12 via a sheave 11.11° attached to the tip of the boom 3, and then connected to the tip of the boom 3. ing.

The mast elevating rope 17 paid out from the mast elevating winch 6 is connected to the mast pail 1 which is pivotally connected to the main mast 8.
8 and one end of which is hooked to the mast priddle 19 attached to the other end of the mast support pendant 20 attached to the tip of the mast 4, and then connected to the elevating rope tension detection device 30 attached to the main mast 8. connected.

This elevation rope tension detection device 30 is shown in FIGS. 3 to 6.
As shown in the figure, an outer cylinder 30a, a spring 30b, a rod 30c, a lug 30d, a spring retainer 30e, 30
f, and limit switches 31a, 31. It consists of b, etc.

One end of the outer cylinder 30a is pivotally connected to the main mast 8 by a pin 34, and a rod 30c whose one end is connected to the mast elevation rope 17 via a socket 32 and a pin 33 is inserted inside the outer cylinder 30a. A spring 30b is installed between the rod 30c and the inner wall of the outer cylinder 30a.

Suspension ring retainers 30e and 30f are attached to the other ends of the rod 30c and the outer cylinder 30a, respectively, and are fixed by nuts 30g and bolts 30h, respectively.

A lug 3 is attached to the spring retainer 30e at the tip of the rod 30c.
0d is fixed, and the outer cylinder is fixed so that the spring retainer 30e compresses the spring 30b by the tension of the mast elevation rope 17, and the lug 30d can move in the load direction of the rope tension detection device 30 in accordance with the deflection of the spring 30b. A notch (slit) is provided in the longitudinal direction of 30a.

Reference numerals 31a and 31b are limit switches operated by the lug 30d, and when the detected value of the rope tension detection device 30, which is a means for detecting the tension of the elevation row 117, is below a predetermined lower limit value, 31b is a limit switch operated by the lug 30d. When this occurs, 31a is activated.

When the lower limit switch 31b is activated as shown in the figure, the upper limit switch 31a moves the hydraulic lifting device 25 for lifting a balance weight, which will be described later, in the extending direction.
When activated, they expand and contract in the contraction direction.

A boom elevating rope 13 extending from the boom elevating winch 7 is attached to a boom pail 14 pivotally attached to the tip of the mast 4 and a boom elevating pendant 16 whose one end is attached to the boom tip. After the plydle 15 is rotated, it is connected to the boom pail 14.

A balance weight truck 22 equipped with tire-type wheels 23 as shown in FIG. 2 is provided on the ground behind the lower traveling body 2 so as to be movable in the turning direction. The truck 22 and the rear end of the revolving upper structure 1 are connected by a pin via a connecting stay 21 so that the truck 22 can pivot upwardly.

The upper end of a balance weight support pendant 26 is connected to the tip of the mast 4, and the lower end of the balance weight support pendant 26 is connected via links 27 and 28 to the piston rod side of the lifting cylinder that constitutes the balance weight lifting bag M25. The tip part is connected, and the lifting cylinder 2
The bottom side of 5 is connected to a link 29 attached to a balance weight truck 22.

[Operation] The operation of the present invention will be explained with reference to the above embodiments.

When a load is suspended, a tensile force acts on the mast support pendant 20 and the mass L-elevation rope 17 connected to the mast support pendant 20 via the mast priddle 19, and the rope tension detection device 30 is proportional to the magnitude of this tension. The spring 30b is bent, the lug 30d fixed to the spring retainer 30e moves in the direction of the load, and the limit switch 31a is moved.

31b is actuated, and an electromagnetic valve (not shown) is actuated based on the output signal, thereby extending and contracting the lifting cylinder of the balance weight hydraulic lifting device 25.

That is, when no load is suspended, no tension is generated in the mast elevation rope 17, so the rope tension detection device 3
The spring 30b at 0 does not bend, and the lug 30d keeps the lower limit switch 31b activated.
Pressure oil from a hydraulic pump (not shown) is supplied to a hydraulic lifting device 25.
The tire-type wheels 23 of the balance way) and truck 22 remain in contact with the ground, and no tension is generated in the balance weight support pendant 26, rather it becomes loose and the mast 4 The gravity of the balance weight 24 is not applied at all.

Next, when a load is suspended, tension is generated in the mast elevation rope 17, but when the tension is less than a predetermined lower limit value, that is, while the lifting load is small, the spring 30b hardly bends, and the lower limit switch 31b remains in operation.

Therefore, in the case of no load or a small load, the gravity of the balance weight 24 is not inadvertently applied to the mast 4, thereby preventing the inconvenience of causing the aircraft to become unbalanced.

When the suspended load exceeds a certain load, the spring 30b begins to bend and the lower limit switch 31b is deactivated, the supply of pressure oil to the hydraulic lifting device 25 is cut off, and the lifting device 25 is stopped and fixed in that state. During this period, the wheels 23 of the balance weight truck 22 remain in contact with the ground.

Therefore, in this state, the gravity of the balance weight 24 is not acting on the mast 4 yet, but if the load of the suspended load increases and a situation occurs where the weight of the main body weight 9 alone is insufficient, the gravity of the balance weight 24 will be applied immediately. This means that changes in load can be dealt with quickly.

Furthermore, when the lifting load is increased, the mast elevation rope 1
Since the tension of the row 117 also increases, the amount of deflection of the spring 30b also increases, and when the tension of the row 117 exceeds a predetermined upper limit value, the upper limit switch 31a is activated. Then,
The pressure oil acts in the direction of contracting the rod of the hydraulic lifting device 25, lifts the truck 22 onto the balance way 1 via the two links, and the wheels 23 are grounded.

As a result of the grounding, when the weight of the balance weight 24 acts on the tip of the mast 4, the weight moves Ω in a direction that balances the weight of the suspended load - the suspension, and the tension of the mast elevation rope 17 decreases by the corresponding amount η. and returns from the upper limit value to the intermediate value. Therefore, the amount of deflection of the spring 30b is also slightly reduced, and the lug 30d moves away from the upper limit switch 31a, taking an intermediate position between the upper and lower limit switches 31a and 31b. Then, the supply of pressure oil to the hydraulic lifting device 25 is cut off,
Since the lifting device 25 is stopped and fixed at that position, stable operation is possible without lifting the balance weight 24 more than necessary.

In this way, the lifting load increases and the mast elevation rope 17
When the tension exceeds a predetermined upper limit, the hydraulic lifting device 25 automatically operates in the contraction direction, lifting the balance weight 24 and applying its weight to the balance weight 24, thereby increasing the stabilizing moment.

"Effects" According to the present invention, a means for detecting the tension of the mast elevation rope is provided, and when the tension of the mast elevation rope detected by the detection means exceeds a predetermined upper limit value, the hydraulic lifting device is operated in the contraction direction. By lifting balance ways 1 to 1, the necessity and operation of balance weights can be determined without relying on human judgment and operation when operating a counterbalance crane, and the elevation rope that occurs when lifting a load can be easily determined. By detecting the tension and automatically determining whether or not to operate the balance weight based on the detection signal, it is possible to automatically lift the Balance Way I in a timely manner as necessary, reducing operator fatigue. This has the effect of significantly improving work safety and operability.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the counterbalance crane of the present invention, Fig. 2 is a rear view of the balance weight portion, Fig. 3 is a side view showing the tension detection means of the elevating rope, Fig. 4 is a plan view thereof, and Fig. 4 is a plan view thereof. Figure 5 is an enlarged view of the tension detection means for the elevation rope.
! ! J sectional view and FIG. 6 are its plan views. Upper revolving body 4: Mast 6: Mast elevation winch 8: Main mast 17: Mast elevation rope 24: Balance ways 1 to 25: Balance weight hydraulic lifting device 26: Balance weight support pendant 30: Elevation rope tension detection device 30a: Outside Cylinder 30b = Spring 30C: Lot 31: Limit switch

Claims (1)

[Claims] 1) An upper rotating body (1) mounted on the lower traveling body (2).
) to which a boom (3) and a mast (4) are pivotally mounted so that they can be lifted up and down, and the tip of the mast (4) and the mast support pendant (
20) and a counterbalance crane with a main mast (8) connected by a mast elevation rope (17) and a balance weight (24) connected via a balance weight support pendant (26) and a hydraulic lifting device (25). , the mast elevation rope (17)
A means (30) for detecting the tension of the elevating rope (17) is provided, and when the tension of the elevating rope (17) detected by the detecting means exceeds a predetermined upper limit value, the hydraulic lifting device (25) is operated in the contraction direction to balance the elevating rope (17). Balance weight actuating device for a counterbalance crane, characterized in that the weight (24) is lifted 2) Means for detecting the tension of the mast elevation rope (17) (
When the tension of the elevating rope (17) detected in step 30) is below a predetermined lower limit, the hydraulic lifting device (25) is operated in the extension direction, and when it is above the predetermined upper limit, it is operated in the contraction direction. A balance weight actuating device for a counterbalance crane according to claim 1, which is configured to stop in the case of