JPH074559U - Work machine with telescopic arm - Google Patents

Abstract

(57) [Summary] [Purpose] In a telescopic arm in which arms are telescopically connected via a connecting wire, it is possible to accurately know the appropriate time for replacing the connecting wire. When a counter 26 for counting the number of telescopic arm expansion / contraction operations is provided, and the counted number of times reaches a preset number of times of operation that is a proper number of operations for replacing the connecting wire. And buzzer 2
A work machine with a telescopic arm that is configured to notify by means of 8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a working machine with a telescopic arm mounted as a front attachment of a construction machine such as a hydraulic shovel.

[0002]

[Problems to be Solved by Prior Art and Invention]

 Generally, this type of working machine is equipped with a telescopic arm in which a plurality of arm members assembled in a nesting joint shape are telescopically connected via a cord connecting body such as a connecting wire or a connecting chain. For example, there are those that perform work such as vertical deep hole digging work. By the way, in this structure, the cord-linking body gradually wears or fatigues as the telescopic arm expands and contracts. Judgment was made in accordance with the above, and the connection of cords was exchanged if necessary. However, there are some places where the cord connection body is not exposed to the outside, and it is troublesome and complicated to inspect such a place by disassembling the telescopic arm. Since it is difficult to judge the degree of damage to the cord connection, it is necessary to replace the cords earlier than necessary so as not to miss the replacement time, and there was the problem of poor maintainability. .

[0003]

[Means for Solving the Problems]

 The present invention was devised with the object of providing a working machine with a telescopic arm capable of eliminating these drawbacks in view of the above-mentioned circumstances, and a plurality of arms assembled in a telescopic joint shape. A working machine equipped with a telescopic arm formed by connecting the comrades to each other via a string connecting body in a telescopic manner is provided with a counter means for counting the number of times the telescopic arm expands and contracts. Is. Further, the present invention provides a working machine equipped with a telescopic arm in which a plurality of arms assembled in the form of a telescopic joint are telescopically connected to each other via a line connecting body. The counter means for counting the number of times of expansion and contraction operation of the vehicle, and the number of times of expansion and contraction operation counted by the count means have reached a preset number of times of operation which is preset as an appropriate number of times of operation for exchanging the rope connection body. It is characterized by providing an informing means for informing.

According to the present invention, the present invention makes it possible to accurately know the proper time to replace the connecting wire.

[0005]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 is a main body of a construction machine. The main body 1 is composed of members such as an upper revolving superstructure 2 and a lower traveling structure 3, and the front part of the upper revolving superstructure 2 is used for vertical deep hole digging. As a front attachment of the above, a working machine composed of members such as a boom 4, a boom cylinder 5, an arm cylinder 6, a telescopic arm 7, a grab bucket 8 and the like is mounted. Is also the same as before.

The telescopic arm 7 has three tubes (corresponding to the arm of the present invention), which are an outer tube 9, a middle tube 10, and an inner tube 11, which are telescopically assembled into a telescopic joint. The outer tube 9 which is installed on the outermost side is swingably supported by the boom 4 and the arm cylinder 6 extending from the main body 1 side through the bracket 12, and the inner tube which is installed on the innermost side. A grab bucket 8 is attached to the tip (lower end) of 11 via a joint 13.

Further, the telescopic arm 7 expansion / contraction mechanism is configured as follows. In other words, 14 is a hydraulic telescopic arm working cylinder interposed between the outer tube 9 and the middle tube 10, and the base end of the cylinder tube 14a constituting the working cylinder 14 is the outer tube. 9 and the tip end of the piston rod 14b is fixed to the upper end of the middle tube 10, respectively. Then, based on the expansion and contraction operation of the operating cylinder 14, the middle tube 10 is expanded and contracted vertically with respect to the outer tube 9.

Reference numeral 15 is a first connecting wire, one end of which is fixed to the lower end of the outer tube 9 and the other end of which is connected to the upper end of the middle tube 10. The first wire sheave 16 provided is suspended and fixed to the upper end of the inner tube 11. On the other hand, 17 is a second connecting wire, one end of the second connecting wire 17 being fixed to the lower end of the outer tube 9 and the other end being a second connecting wire provided at the lower end of the middle tube 10. The wire sheave 18 is suspended and fixed to the upper end of the inner tube 11. When the middle tube 10 expands and contracts in the vertical direction based on the expansion and contraction operation of the operating cylinder 14, the first and second wire sheaves 16 and 18 move up and down together with the middle tube 10, and accordingly By the pulling up and pulling down action of the first and second connecting wires 15 and 17, the inner tube 11 expands and contracts by an amount corresponding to twice the moving amount of the middle tube 10 with respect to the outer tube 9. Reference numeral 19 is a liner interposed between the outer peripheral surface portion and the inner peripheral surface portion of each of the tubes 9, 10 and 11.

Further, 20 is a pressure switch provided in the hydraulic circuit of the working cylinder 14, and the pressure switch 20 is incorporated in the circuit A from the reduction side operation valve 21 to the control valve 22 in the embodiment. ing. The pressure switch 20 is opened when the pressure of the circuit A from the reduction side operation valve 21 to the control valve 22 becomes a certain pressure or more when the working cylinder 14 is reduced, and the control for counting is performed. It is set to output a signal to the unit 23. In addition, 21a is an extension side operation valve.

On the other hand, when the signal from the pressure switch 20 is input, the count controller 23 outputs the signal to the AND circuit 25 and starts the timer 24. The timer 24 outputs a signal to the AND circuit 25 after a predetermined time (in the embodiment, the time required for the first and second wire sheaves 16 and 18 to make a half turn), and The AND circuit 25 is adapted to output a signal to the counter 26 when both the signal from the pressure switch and the signal from the timer 24 are input, whereby the actuation cylinder 14 is activated. The number of times the reduction operation is performed is configured to be counted. Further, 27 is a comparator, which compares the number of operations of the working cylinder 14 counted by the counter 26 with a preset number of operations, and It is set to output an actuation signal to a buzzer (corresponding to the notification means of the present invention) 28 when the actuation number of the actuation cylinder 14 reaches the set actuation number. The comparator 27 is adapted to be held when the number of operations of the operating cylinder 14 reaches the set number of operations. In the figure, 29 is a pilot pump, 30 is a main hydraulic pump, 31 is an oil tank, and 32 is a throttle valve.

Incidentally, the setting of the set number of times of operation is performed by previously measuring the relationship between the number of times of operation of the working cylinder 14 and the degree of damage to the connecting wires 15 and 17 by a strength test or the like, and connecting based on this. The number of actuations of the actuating cylinder 14 appropriate for exchanging the wire is obtained, and this is set as the set number of actuations. However, the set number of actuations can ensure sufficient safety in consideration of various conditions. Needless to say, it is set based on the safety factor set in this way.

In the embodiment of the present invention configured as described, each tube 9, 10, 11 of the telescopic arm 7 is connected to each other via the working cylinder 14 and the first and second connecting wires 15, 17. It is linked and linked, and it expands and contracts based on the expansion and contraction operation of the operating cylinder 14. In this case, the number of times of operation of the operating cylinder 14 on the contraction side is counted by the counter 26 and is counted. When the number of times of operation reaches a preset number of times of operation, which is set as an appropriate number of times of operation for exchanging the connecting wires 15 and 17, the buzzer 28 gives a notification. As a result, the worker can know the proper time to replace the connecting wires 15 and 17 by using the buzzer 28, and visually check the damage to the connecting wires 15 and 17 as in the conventional case. Perhaps there is no need to make a judgment, or because it is difficult to visually judge the degree of damage, there is no waste of exchanging the connecting wires 15 and 17 earlier than necessary, and the connecting wire 15 is always at an appropriate time. , 17 can be replaced, which greatly improves the maintainability.

It should be noted that the present invention is not limited to the above embodiment, but in the embodiment, the pressure switch is provided in the hydraulic circuit on the contracting side of the telescopic cylinder, but it is provided on the hydraulic circuit on the expanding side. Of course, it may be provided in both the reduction side circuit and the expansion side circuit. Further, as the notification means, a warning lamp may be turned on, and further, the number of expansion / contraction operations of the working cylinder counted by the counter is sequentially integrated, and this is displayed by an appropriate indicator (counter or meter). Displaying at will have the advantage that the work can be performed while predicting the proper replacement time of the rope connection body in advance.

[0014]

[Operation effect]

 In short, since the present invention is constructed as described above, each arm of the telescopic arm is telescopically connected by the cord connecting body, but in this case, the counter means is used. When the number of telescopic arm expansion / contraction operations is counted, and the counted number of operations reaches a preset number of operations that is a proper number of operations for exchanging the rope connection, a notification is given. It will be notified by means. As a result, the operator can easily and accurately know the proper replacement time of the connecting wire, and does not need to visually judge the damage degree of the connecting wire as in the conventional case. On the other hand, there is no waste of replacing the connecting wires too soon, and the connecting wires can always be replaced at an appropriate time, greatly improving maintainability.

[Brief description of drawings]

FIG. 1 is a schematic side view of a construction machine.

FIG. 2 is a sectional view of a telescopic arm.

FIG. 3 is a hydraulic circuit diagram of an operating cylinder.

FIG. 4 is a circuit diagram of a control unit.

[Explanation of symbols]

 7 Telescopic arm 9 Outer tube 10 Middle tube 11 Inner tube 14 Working cylinder 15 First connecting wire 17 Second connecting wire 26 Counter 28 Buzzer

Claims (3)

[Scope of utility model registration request] 1. A working machine equipped with a telescopic arm in which a plurality of arms assembled in a telescopic joint shape are connected to each other via a line connecting body so as to extend and contract. A working machine with a telescopic arm, characterized in that it is provided with a counter means for counting the number of stretching operations. 2. A working machine provided with a telescopic arm in which a plurality of arms assembled in a telescopic joint shape are connected to each other via a line connecting body so that the telescopic arm of the telescopic arm is provided. Informing that the counter means for counting the number of expansion and contraction operations and the number of expansion and contraction operations counted by the counting means have reached a preset operation number that is a proper operation number for exchanging the rope connection body A working machine with a telescopic arm, characterized by being provided with an informing means. 3. A counter means for counting the number of telescopic arm expansion / contraction operations according to claim 1 or 2, wherein the counter means is provided in a hydraulic circuit of an operating cylinder for expanding / contracting the telescopic arm. A work machine with a telescopic arm.