JP2019167166A - Winch control method and winch system using the same - Google Patents

Abstract

To compensate for the generation of a descending phenomenon of suspended loads in a synthetic fiber rope.SOLUTION: A winch system 30 uses a synthetic fiber rope and comprises a winch operating lever 11, suspended load detection means 26 to detect the weight of the suspended load, suspended load height detection means 27 to detect height of the suspended load, winch means 8 to wind/rewind the synthetic rope, and a controller 31 to output a driving signal to the winch means 8 to which an operating signal is input from the winch operating lever 11 and to which a detected signal is input from the suspended load detection means 26 and from the suspended load height detection means 27. The controller performs a feedback control on the winding drive by the winch means 8 to maintain the suspended load at the same height using the detected signal from the suspended load height detection means 27 when the controller 31 determines that the winch control lever 11 is returned to neutral under a suspended condition of the suspended load by the operating signal from the winch operating lever 11 and by the detected signal from the suspended load detection means 26.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a winch system that automatically compensates for a "fall of suspended load with time" generated by using a synthetic fiber rope.

  Although it has the same strength as a wire rope but has a small weight per unit length, which helps to reduce the weight of the equipment, the use of synthetic fiber ropes as a hoisting rope for crane winches has been considered. It was.

  However, in a state where the suspended load is suspended in a suspended state and tension is applied to stop the rotation of the winch drum, the synthetic fiber rope is stretched, bitten by the winch drum, and crushed. For this reason, it has been pointed out that the suspended load falls and it takes time to stabilize until the suspended load stops.

  FIG. 5 is a graph showing the “relationship between the elapsed time in the synthetic fiber rope and the amount of descent of the suspended load” measured by the applicant. As can be seen from FIG. 5, the suspended load suspended in the air rapidly descends in the initial stage and then gradually decreases with the passage of time, while the amount of descent per hour gradually decreases, and falls several tens of millimeters in several minutes. . The graph shown in FIG. 5 shows an example of the characteristics of the synthetic fiber rope, and the synthetic fiber rope material, knitting method, length, diameter, tension, temperature, humidity, winding layer in the winch drum The characteristics vary greatly depending on the number and the like.

  As described above, since the suspended load drop phenomenon occurs in the synthetic fiber rope, it is difficult to align the suspended load in the bolt thread, which is a crane work after the winch drum is stopped in the suspended state. End up.

  By the way, in an elevator using a synthetic fiber rope for a main rope for suspending a car and a counterweight, a main rope elongation compensation device having an adjustment sheave movable between a drive sheave and a deflector is proposed. (Patent Document 1). By compensating for the elongation generated in the synthetic fiber rope by the elongation compensator described in Patent Document 1, it is possible to properly maintain the positional relationship between the car and the balance weight in accordance with the change in the length of the main rope. .

WO2002 / 038481

  However, the crane winch does not have a counterweight, and the entire configuration is completely different from an elevator, such as winding a hoisting rope around a winch drum. The compensation device cannot be applied.

  Therefore, after the crane operator returns the winch control lever to the neutral position, the present invention compensates the suspended load by feedback control of the winding drive by the winch drum based on the height signal detected by the suspended suspended load. Thus, a winch control method capable of keeping the suspended load height constant and a winch system using the same method are proposed.

A winch control method according to a first aspect of the present invention is a winch control method using a synthetic fiber rope, which detects the height of a suspended load in a suspended state and feeds back the winch winding drive using the detection signal. The suspended load is maintained at the same height by controlling.

The winch control method according to the first aspect of the invention automatically compensates for the "lift of suspended load over time" generated by using a synthetic fiber rope by performing feedback control of the winch winding drive based on the suspended load height signal. can do. That is, the suspended load in the suspended state can be maintained at the same height.

A winch system according to a second aspect of the invention is a winch system using a synthetic fiber rope, the winch operation lever, a suspension load detection means for detecting the weight of the suspension load, and the height of the suspension load. Suspended load height detection means, winch means for winding and unwinding the synthetic fiber rope, operation signals of the winch operation lever, detection signals from the suspended load detection means and the suspended load height detection means And a controller that outputs a drive signal to the winch means, and the controller winches the suspension load when the suspension load is suspended by an operation signal from the winch operation lever and a detection signal from the suspension load detection means. When it is determined that the operation lever has been returned to the neutral position, a detection signal from the suspended load height detecting means is used to maintain the suspended load at the same height. Wherein the feedback control of the winding drive by wrench means.

  In the winch system of the second invention, the controller controls the winding drive by the winch means using the detection signal from the suspended load height detecting means so that the suspended load is maintained at the same height. It can automatically compensate for the “falling of the suspended load over time” that occurs and keep the suspended load at the same height. Therefore, in the crane work such as bolt alignment in the construction work, the suspended load can be positioned in the height direction safely and efficiently.

The winch system according to a third aspect of the invention is characterized in that the winch means is a hydraulic winch.

  Even when a synthetic fiber rope is used for a hydraulic winch often used for a mobile crane, the same suspended load height can be maintained after the winch operating lever is returned to neutral while the suspended load is suspended in the air.

  The winch system according to a fourth aspect of the invention is characterized in that the suspended load height detecting means uses a non-contact type distance sensor.

  The winch system according to the fourth aspect of the invention can be applied to a mobile crane or the like having a lot of outdoor work by using a non-contact type distance sensor.

  According to the winch control method or winch system of the present invention, even if a synthetic fiber rope is used, after the crane operator returns the operation lever of the winch to neutral, the height signal detected by the suspended load in the suspended state is detected. Based on the above, the height of the suspended load can be kept constant by feedback controlling the winding drive by the winch drum and compensating for the suspended load drop. Therefore, in the crane work such as bolt alignment in the construction work, the suspended load can be positioned in the height direction safely and efficiently.

It is a rough terrain crane equipped with the winch system of the present invention. It is a block diagram of the winch system concerning an embodiment of the invention. It is a control flowchart of the winch system of FIG. It is a graph which shows the example of the suspended load height maintenance control by the winch system of this invention. It is a graph which shows the relationship between the elapsed time in a synthetic fiber rope, and the fall amount of a suspended load.

  FIG. 1 is a rough terrain crane 1 equipped with the winch system of the present invention. The rough terrain crane 1 is in a crane working posture in which the telescopic boom 4 is raised and extended after the outrigger 2 is grounded to the ground 3. The rough terrain crane 1 shown in FIG. 1 is equipped with a winch system that uses a synthetic fiber rope 7 as a suspended load rope. The swivel frame 5 is equipped with winch means 8 for winding and unwinding the synthetic fiber rope 7. A winch operation lever 11 is disposed in the cab 10 disposed on the revolving frame 5.

  As shown in FIG. 1, the synthetic fiber rope 7 fed out from the winch drum 12 of the winch means 8 is suspended from the boom head 14 via the back surface portion 13 of the telescopic boom 4. Further, after the synthetic fiber rope 7 is hung around the sheave 16 of the hanging load hook 15 and the sheave 17 of the boom head 14 as many times as necessary, the ends of the synthetic fiber rope 7 are locked to the boom head 14 or the hanging load hook 15. A suspended load 20 is suspended from a suspended load hook 15 shown in FIG.

A non-contact type distance sensor 21 that constitutes the suspended load height detection means 20 is suspended from the boom head 14. Specifically, a sensor using ultrasonic waves, a sensor using lasers, or the like is used as the distance sensor 21. Ultrasonic wave 23 or laser 24 is irradiated from the distance sensor 21 to the reflection plate 22 on the upper surface of the hanging hook 15 to measure the time until it is reflected and returned, and the distance is measured. In this case, the height of the hanging load hook 15 is accurately detected. Since the extension of the sling wire 18 connecting the suspended load 20 and the suspended load hook 15 can be ignored, the height of the suspended load is controlled in the present invention, but by detecting the height of the suspended load hook 15. It is possible to control the suspended load height.

  In the hoisting cylinder 25 interposed between the turning frame 5 and the telescopic boom 4, the hoisting cylinder axial force sensor constituting the suspended load detecting means 26 is arranged. The hoisting cylinder axial force sensor detects the axial force acting on the hoisting cylinder 25. The suspended load detection means 26 calculates the weight of the suspended load 20 from the detected undulation cylinder axial force and the length and undulation angle of the telescopic boom 4.

  FIG. 2 is a block diagram of the winch system 30 according to the embodiment of the present invention. The controller 31 receives an operation signal from the winch operation lever 11 (see FIG. 1). Specifically, an operation signal of the operation direction (winding and lowering) and the operation amount (winding and lowering speed) of the winch operation lever 11 is input to the controller 31.

A detection signal from the suspended load detection means 26 is input to the controller 31. The suspended load detection means 26 includes an undulating cylinder axial force sensor 32, a boom length sensor 33, a boom angle sensor 34, and a suspended load calculation unit 35. As the hoisting cylinder axial force sensor 32, specifically, a hydraulic sensor provided in the holding side oil chamber of the hoisting cylinder 25 (see FIG. 1) or a load cell provided in the rod is used. As the boom length sensor 33, specifically, a cord reel type length detector or the like that is disposed in communication between the proximal end portion and the distal end portion of the telescopic boom 4 (see FIG. 1) is used. Specifically, as the boom angle sensor 34, a potentiometer or the like that is disposed on the telescopic boom 4 pivotal support portion (see FIG. 1) of the revolving frame 5 and detects the relative angle between the two is used.

  Detection signals from the hoisting cylinder axial force sensor 32, the boom length sensor 33, and the boom angle sensor 34 are input to the suspension load calculation unit 35. The suspended load calculation unit 35 stores weight gravity center data of each part of the telescopic boom 4. The suspended load calculation unit 35 calculates the weight of the suspended load (see FIG. 1) from the input signal and the stored data, and outputs it to the controller 31.

  The suspended load height detection means 27 includes the distance sensor 21 (see FIG. 1) and the suspended load height calculation unit 36. A detection signal from the distance sensor 21 is input to the suspended load height calculation unit 36, and the suspended load height calculation unit 36 calculates the height of the suspended load hook 15 or the suspended load 20. A detection signal from the suspended load height detection means 27 is input to the controller 31. The suspended load height maintenance control switch 37 is a switch for selecting whether to perform suspended load height maintenance control, and is disposed in the vicinity of the winch operation lever 11 in the cab 10 (see FIG. 1). An operation signal of the suspended load height maintenance control switch 37 is input to the controller 31.

  In the winch means 8, the winch drum 12 around which the synthetic fiber rope is wound is rotationally driven by a hydraulic motor 42 via a speed reducer 41. Pressure oil discharged from the hydraulic pump 43 is supplied to the hydraulic motor 42 with its direction and flow rate being controlled by a pilot-type switching valve 44. The winding side electromagnetic proportional valve 45 generates a pilot pressure corresponding to the winding drive signal from the controller 31 and supplies the pilot pressure to the pilot type switching valve 44. The lowering-side electromagnetic proportional valve 46 generates a pilot pressure corresponding to the lowering drive signal from the controller 31 and supplies the pilot pressure to the pilot-type switching valve 44. The pilot-type switching valve 44 switches the pressure oil to the direction and flow rate according to the drive signal from the controller 31 and supplies it to the hydraulic motor 42. A counter balance valve 47 is interposed in the oil supply path to the hydraulic motor 42.

  FIG. 3 shows a control flowchart 50 of the winch system 30 shown in FIG. A winch operation lever signal is input from the winch operation lever 11 (see FIG. 2) to the controller 31 (step 1). A winch drive signal is output from the controller 31 to the winch means 8 (step 2). A suspension load signal is input from the suspension load detection means 26 to the controller 31 (step 3). The above is a flowchart of a normal winch operation.

  Next, it is determined whether or not the winch operation lever 11 (see FIG. 2) is neutral (step 4). If not neutral, the normal winch operation flowchart is continued. If neutral, it is determined that the winch operation has been stopped, and a change in the suspended load is determined (step 5). When the suspended loads are not the same, that is, when the suspended load 20 (see FIG. 1) that is suspended in the air is grounded, the control of the winch system 30 is finished (step 6). When the suspended load is the same, that is, when the winch operation is stopped while the suspended load 20 is suspended, the suspended load height Hs immediately after the lever is neutral is input to the controller 31 from the suspended load height detecting means 27 (see FIG. 2). (Step 7).

Next, it is determined whether or not the signal from the suspended load height maintenance control switch 37 is ON (step 8). When the suspended load height maintenance control is OFF, the control of the winch system 30 ends (step 6). When the suspended load height maintenance control is ON, it is determined whether or not the suspended load drop amount Hd is larger than the threshold value (step S9). When the suspended load drop amount Hd is larger than the threshold value, a winch minute hoisting drive signal is output from the controller 31 to the winch means 8 (S10). When the suspended load drop amount Hd is smaller than the threshold value, the controller 31 proceeds to the next step without outputting the winch minute hoisting drive signal to the winch means 8.

Next, the suspended load height Hc is input from the suspended load height detection means 27 (see FIG. 2) to the controller 31 (step 11). The suspended load drop amount Hd (Hd = Hs−Hc) is calculated by the controller 31 (step 12). Thereafter, feedback control (indicated by steps 8 to 12) for winding drive by the winch means 8 using a detection signal from the suspended load height detecting means 27 so as to maintain the suspended load 20 (see FIG. 1) at the same height. Is repeated.

FIG. 4 is a graph showing an example of the suspended load height maintenance control by the winch system 30 according to the embodiment. The suspended load height maintaining control starts when the suspended load 20 is suspended in the air (see FIG. 1) and the winch operation lever 11 (see FIG. 2) is returned to the neutral position. In the control example shown in FIG. 4, the control threshold is set to ΔZmm. As shown in FIG. 4, when the suspended load drop amount Hd reaches ΔZ mm, the synthetic fiber rope 7 is wound up by the winch means 8 so that the suspended load drop amount Hd becomes 0 mm. By repeating this minute winding, the suspended load 20 (see FIG. 1) is maintained at the same height. The winch control of the present invention is not limited to the example shown in FIG. Any control content can be adopted as long as the winding drive by the winch drum is feedback-controlled based on the height signal detected by the suspended load in the air.

  As shown in FIG. 5, the suspended load drop of the winch system 30 using the synthetic fiber rope 7 has a characteristic that the suspended load drop per unit time decreases with the passage of time. Therefore, the winding in the winch system 30 of the present invention tends to increase the interval time of operation along with the elapsed time. Note that various control factors are considered in setting the threshold value for the feedback control for maintaining the suspended load height of the present invention. For example, the minimum oil amount that can be supplied at one time of the hydraulic supply system (hydraulic pump 43, pilot switching valve 44), the minimum possible rotation angle of the hydraulic motor 42, the detection height resolution of the suspended load height detection means 27, etc. A comprehensively appropriate threshold value is set in consideration. At that time, the allowable change in the suspended load height during crane work such as bolt alignment is also considered.

  As described above, according to the winch control method or the winch system 30 of the present invention, even when the synthetic fiber rope is used, after the crane operator returns the winch operation lever 11 to the neutral position, the suspended load in the suspended state is detected. By carrying out feedback control of the winding drive by the winch drum based on the height signal and compensating for the suspended load drop, the suspended load height can be kept constant. Therefore, in the crane work such as bolt alignment in the construction work, the suspended load can be positioned in the height direction safely and efficiently.

7: synthetic fiber rope 8: winch means 11: winch operation lever 20: suspended load 21: distance sensor 26: suspended load detection means 27: suspended load height detection means 30: winch system 31: controller

Claims (4)

A method for controlling a winch using a synthetic rope,
A winch control method characterized by maintaining the suspended load at the same height by detecting the height of the suspended load in the suspended state and performing feedback control of the winding drive of the winch using the detection signal. A winch system using synthetic rope,
Winch control lever,
A suspended load detection means for detecting the weight of the suspended load;
A suspended load height detecting means for detecting the height of the suspended load;
Winch means for winding and unwinding the synthetic fiber rope;
A controller that receives an operation signal from the winch operation lever, a detection signal from the suspension load detection means and a detection signal from the suspension load height detection means, and outputs a drive signal to the winch means,
When the controller determines that the winch operation lever has been returned to neutral in the suspended state by the operation signal from the winch operation lever and the detection signal from the suspension load detection means, the controller removes the suspended load. A winch system in which a winding drive by the winch means is feedback-controlled using a detection signal from the suspended load height detection means so as to maintain the same height. The winch means is a hydraulic winch,
The winch system according to claim 2. The suspended load height detecting means uses a non-contact type distance sensor,
The winch system according to claim 2 or 3.

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