JP3002075B2 - Excavator rope replacement alarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator for supporting an excavator for excavating underground with a rope wound up and fed out from the excavator body, such as an excavator using an earth drill or a crushed bucket. The present invention relates to an alarm device for generating an alarm before the rope is fatigued and cut.

[0002]

2. Description of the Related Art In this type of excavator, the rope for supporting the excavator needs to be replaced before the rope is cut due to fatigue. When the time reached a certain time, the rope was changed.

[0003] The present applicant has disclosed in Japanese Patent Application Laid-Open No. 5-51939.
In the publication, the rotation of the sheave on which the rope supporting the excavation tool is hung is detected by a sensor, the number of rotations of the sheave, that is, the total moving length of the rope is measured and integrated, and an alarm is issued when the integrated value reaches a predetermined value. Has proposed a rope change alarm device that emits an alarm.

[0004]

When the load applied to a rope is constant, as in an excavator using an earth drill or clamshell bucket, the life of the rope is determined by the number of times the rope is bent. Therefore, in the bench test, the rope is reciprocated at a constant pressure by the cylinders at both ends of the rope with one or two sheaves attached to the rope. It is determined that is attached. As described above, considering that the life of the rope is determined by the number of times of bending, as described above, judging the life of the rope based on the operating time and the total moving length of the rope requires accurately judging the life of the rope. Not be. This is because, depending on the site where the excavator is used, the rope extension length in one excavation differs between when excavating to a deep place and when it is shallow.
For these reasons, according to the above-described conventional technology, it is difficult to properly set the life of the rope, and there is a problem that the accuracy is lacking.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a rope replacement alarm device that can easily and accurately set the life of a rope.

[0006]

SUMMARY OF THE INVENTION The present invention considers that the fatigue of a rope is determined by the number of times of bending, and detects the degree of fatigue of the rope as the number of reversals of the vertical movement of the rope. That is, the present invention relates to an excavator that supports an excavating tool for excavating underground by a rope that is wound up from an excavator main body, a counting unit that counts the number of reversals of the vertical movement of the rope, and powers off the counted value. Storage means for storing data at times, and alarm generation means for issuing an alarm when the count value of the counting means exceeds a set value.

In the present invention, preferably, in the apparatus for detecting the excavation depth from the rotation of the sheave, a sensor for generating a pulse in accordance with the rotation of the sheave around which the rope is wound, and a drilling tool based on the output of the sensor. A depth counter pulse counter for counting while determining the depth of the rope, means for detecting the reversal of the movement direction of the rope from the output of the pulse counter or the sensor output, and the number of reversal of the vertical movement of the rope from the output of the reversal detection means. It is preferable that a counter for counting the number of reversals constitutes a means for counting the number of reversals of vertical movement.

Further, in the present invention, when the rope is inverted by the rope vertical inversion detecting means,
It is preferable to provide a dead zone setting unit that detects the amount of movement of the rope between the time of the next rope inversion and that does not count the number of rope inversions when the movement length is equal to or less than a predetermined length.

[0009]

Since the apparatus of the present invention has the above-described configuration, an alarm is issued when the number of repetitions of the vertical movement of the rope supporting the excavation tool exceeds a set number corresponding to the life of the rope.
The set number of the rope life is set by dividing the number of fatigue bending, which is the life of the rope obtained by a bench test or the like, by the safety factor. In the case of using the sheave rotation speed detecting sensor for the depth gauge and the pulse counter for the depth gauge, the inversion of the movement of the rope is detected by using any of these outputs. When the dead zone setting means is provided, for example, in the case of earth drilling, when the earth and sand in the bucket is discharged, slight vertical movement is not counted as the number of inversions.

[0010]

FIG. 1 is a side view of an earth drill which is an example of an excavator to which a rope replacement alarm device according to the present invention is applied. In this earth drill, a kelly rope (mainly wound rope) 3 wound up and fed by a main winding winch 2 installed on a main body 1 is wrapped around top sheaves 5 and 6 at the top of a boom 4, and the kelly rope 3 is For example, a kelly bar 7 formed of a multi-stage telescopic rod formed of a square rod is connected to the innermost inner rod of the kelly bar 7 through a swivel joint 8 to support the kelly bar 7, and an earth drill bucket 9 (opening and closing (Shown with respect to an enlarged bottom bucket in which a plurality of enlarged wings 9a are attached to the side opening) is detachably attached. The kerry bar 7 is inserted through a hole of a rotary drive plate of a kelly bar drive device 11 installed on a front frame 10 attached to a front portion of the main body 1 so as to be vertically movable and rotated by the drive plate.

The earth drill of this example is used for drilling.
A shaft excavation bucket is attached to the lower end of the inner rod of the kelly bar 7, the kelly rope 3 is paid out by the operation of the main winding winch 2, the bucket is lowered to the ground to be excavated, and the kerry bar driving device 11 rotates the bucket together with the kerry bar 7 to excavate. I do. In the case of this shaft digging bucket, the bottom of the hole is excavated by the cutter of the bottom cover of the bucket and introduced into the bucket, and when the excavated soil is filled in the bucket, the main winding winch 2 is operated to wind the kelly rope 3. By lifting the bucket, open the bottom lid on the ground and discharge the soil,
The work of excavating again as described above is repeated.

On the other hand, when the depth of the pit reaches a predetermined depth, an expanded bottom bucket 9 is attached to the lower end of the kelly bar 7 instead of the shaft digging bucket, and digging is performed while gradually expanding the openable wing 9a on the side surface. The work of excavating the bottom of the hole in an enlarged manner and raising and discharging the soil when the excavated soil has accumulated in the bucket to some extent is repeated.

As shown in the configuration diagram of FIG. 2 and the rear view of FIG. 3, this earth drill controls the free fall of the bucket 9 by obtaining the depth of the bucket 9 from the feeding length of the kelly rope 3. A depth gauge 12 as described below is provided. The depth gauge 12 has a large pulley 13 attached to a sheave 5 on which the kelly rope 3 is hung, a small pulley 15 attached to a frame 14 fixed to the boom 4, a belt 16 hung on both pulleys 13 and 15, and As shown in the partial cross-sectional view of FIG. 4A, a sensor (rotary encoder) 17 provided in the frame 14 and having the shaft of the small pulley 15 coupled to the rotor via a coupling 18,
The depth indicator 20 provided in the cab 19 as shown in FIG.
And a wire harness 21 for transmitting the output of the sensor 17 to the depth indicator 20.

As shown in FIG. 8 (A), the sensor 17 comprises a rotor 17d and a detector 17e made of a magnetic material, a magnet or a light reflector arranged at regular intervals on the rotor 17d.
The detection elements 17a to 17b for detecting these are arranged in a stationary part in opposition to the detection target 17e. In this example, 17a is an element for detecting the number of revolutions, 1
Reference numerals 7b and 17c denote elements for detecting the rotation direction.
When 7d rotates in the direction a (extending direction), FIG.
As shown in (B), when the detection output of the detection element 17b precedes and rotates in the direction b (winding direction), the detection element 1b
The detection elements 17b and 17c are set so that the detection output of 7c precedes.
The rotation direction is determined by arranging c and performing signal processing. Of course, the detection target 17e, the detection element 17a
17c and the direction in which the detection signal is used can be variously changed in addition to this example.

As shown in the block diagram of FIG. 5, for example, the depth indicator 20 includes a reversible counter 22 for adding and subtracting counts in consideration of a direction signal created from a pulse from the sensor 17.
It comprises direction discriminating means 23 added according to the present invention for discriminating the up-down direction of the kelly rope 3 from a signal related to the counter 22, computing means 24 for converting the output of the counter 22 into depth, and a depth display unit 25. .

Reference numeral 26 denotes a rope counter added according to the present invention for judging the service life of the rope and generating an alarm. The rope counter 26 is attached to the depth indicator 20 as shown in FIG. In FIG. 5, when a reversal detection output of the direction discriminating means 23 is obtained, a dead zone determining means 27 of the rope counter 26 counts a rope movement length from the reversal of the direction to the next reversal of the direction. If the value is equal to or less than a predetermined value, the number of rope inversions is omitted. The inversion number calculating means 28 counts the number of rope inversions other than those excluded by the dead zone determination means 27, and the storage means (memory) 29 retains the counted value even when the power is turned off. It has a function, and the held value is reset by reset means 30 such as a reset button. Inversion number display means 31
Represents the count value stored in the storage means 29, and is displayed on the display section 32 of the rope counter 26 as shown in FIG. The rope inversion number setting means 33 can arbitrarily set the set inversion number obtained by dividing the bending number obtained by the bench test by the safety factor. The rope inversion number set by the rope inversion number setting means 33 Number of times and storage means 2
9 is compared with the actually detected number of reversals of the vertical movement of the rope (counted once from the start of winding to the end of winding and one from the start of feeding to the end of feeding) stored in the comparator 32. When the set number of times is reached, an alarm is generated by an alarm generating means 34 such as a lamp or a buzzer (an alarm lamp is shown in the example of FIG. 4B).

FIG. 6 is a diagram for explaining the operation of the apparatus shown in FIG. 5 with respect to the vertical movement of the rope, and FIG. 7 is a flowchart for explaining the operation. The direction determining means 23 shown in FIG. 5 compares the previous value of the output of the reversible counter 22 for depth detection with the current value, and determines whether or not the output has been inverted (S1 in FIG. 7). Instead of comparing the value of the counter 22, the sensor 17
The inversion of the signal indicating the rotation direction obtained by the detection elements 17b and 17c may be monitored.

In the direction determination, while the direction is not reversed, the output pulses of the sensor 17 are continuously counted by a dead zone counter (not shown). On the other hand, when the inversion of the vertical movement of the rope is detected, the value of the dead zone counter, that is, the length of the feeding or winding rope after the previous inversion is less than a preset dead zone set length (for example, 1 m). It is determined whether or not this is the case (S2), and if it is less, the dead zone counter is reset (S6). On the other hand, if the value of the dead zone counter is equal to or greater than the set length, the inversion number calculation means 28 adds 1 to the value of the number of inversions stored in the storage means 29 (S3). Then, it is determined whether or not the number of reversals has reached the number of reversals set in the setting means 33 (S4). If the number of reversals has not reached the set number of reversals, the dead zone counter is reset (S6). The counting of the pulses from is started (S7). On the other hand, if the set number of reversals has been reached, an alarm is issued by the alarm generating means 34, and the process returns to the steps S3 and S7.

By such an operation, as shown in FIG. 6, the bucket is slightly lifted and freely dropped to cause the sediment adhering to the inner wall of the bucket to fall, as shown in FIG. A slight vertical movement such as raising and lowering the rope by an operation such as stepping on the brake 2 is not counted as the number of reversals. In this manner, by not counting the slight vertical movement of the rope as reversal, it is possible to set the exact number of reversals related to the life. Also, as in the present embodiment, by using the signal system of a depth gauge provided in an earth drill or the like,
The device can be configured easily and inexpensively. The number of inversions may be counted and compared with the set number of inversions by setting the number to a fraction.

[0020]

According to the first aspect of the present invention, the number of winding and unwinding of the rope supporting the excavation tool is detected, and the number is compared with the set number of inversions. As compared with the case where the life is determined, the life can be determined more accurately and accurately, and the life can be easily set. In addition, this makes it possible to reliably prevent a rope breakage accident, thereby improving safety and reducing waste as compared with the case where the rope use limit time is set shorter in consideration of safety.

According to the second aspect, since the apparatus is configured by utilizing a part of the signal system of the depth gauge, it can be implemented easily at low cost.

According to the third aspect of the present invention, since the dead zone for the vertical movement of the rope is provided, the vertical movement of the bucket at the time of earth removal, for example, in an earth drill, is not counted as the number of rope inversions, and the accurate number of inversions can be grasped. .

[Brief description of the drawings]

FIG. 1 is a side view of an earth drill which is an example of an excavator to which a rope replacement alarm device according to the present invention is applied.

FIG. 2 is a configuration diagram of a rope replacement alarm device of the embodiment.

FIG. 3 is a partial cross-sectional rear view of the sheave rotation detector of the embodiment.

FIG. 4A is a partial cross-sectional rear view showing a configuration of a portion attached to a boom of the depth gauge according to the embodiment, and FIG. 4B is a front view showing a display unit in the cab.

FIG. 5 is a block diagram illustrating a configuration of an alarm device according to the present embodiment.

6 is an explanatory diagram of vertical movement of a rope and counting of the number of times of bending including a dead zone, which are used for explaining the operation of FIG. 5;

FIG. 7 is a flowchart for explaining the operation of FIG. 5;

FIG. 8A is a diagram for explaining the configuration of a sensor in principle;
(B) is an explanatory diagram of the operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Excavator main body 2 Main winding winch 3 Kelly rope 4 Boom 5, 6 sheave 7 Kelly bar 9 Expanding bucket 12 Depth gauge 13 Large pulley 15 Small pulley 16 Belt 17 Sensor 17a-17c Detection element 17d Rotor 17e Detected object 20 Depth indicator 21 wire harness 26 rope counter

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) E21B 19/08 E21B 12/00-12/02 E21B 19/02

Claims (3)

(57) [Claims] An excavator for supporting an excavating tool for excavating underground by a rope wound up and out of an excavator body, a counting means for counting the number of reversals of the vertical movement of the rope,
A rope replacement alarm device for an excavator, comprising: storage means for storing the count value even when the power is turned off; and alarm generation means for issuing an alarm when the count value of the count means reaches a set value. 2. A depth sensor according to claim 1, wherein said counting means generates a pulse in accordance with rotation of said sheave around said rope, and counts the depth of said digging tool based on an output of said sensor. A measuring pulse counter, a means for detecting the reversal of the movement direction of the rope from the output of the pulse counter or the sensor output, and a counter for counting the number of reversals of the vertical movement of the rope from the output of the reversal detecting means. An excavator rope replacement alarm device. 3. The apparatus according to claim 2, wherein the moving length of the rope between the time of the rope reversal detected by the reversal detecting means of the vertical movement of the rope and the time of the next rope reversal is detected, and the length is detected. A rope replacement alarm device for an excavator, comprising: a dead zone setting unit that does not count the number of rope vertical movement reversals when the length is equal to or less than a predetermined length.