JP3280238B2 - Drum winding layer detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a winding layer of a rope wound on a drum such as a crane.

[0002]

2. Description of the Related Art In order to detect how much rope is wound around a drum used in a winch device of a crane, various devices for detecting a winding layer of the rope in the drum have been proposed. FIG. 8 is a diagram showing a configuration of a conventional winding layer detecting device. As shown in FIG. 8, the wound layer detecting device has an ultrasonic sensor 30 that emits ultrasonic waves toward the drum 32 in the vicinity of the drum 32. Then, a distance L1 from the rotation axis of the drum 32 to the ultrasonic sensor 30 is measured in advance, and ultrasonic waves are emitted from the ultrasonic sensor 30 toward the rope winding surface of the drum 32, and reflected on the rope winding surface. The detected ultrasonic wave is detected to detect a distance S1 from the ultrasonic sensor to the rope winding surface. Then, the winding radius R1 of the drum 32 is obtained by subtracting the distance S1 from the distance L1, and the winding amount of the rope is obtained based on the winding radius R1.

[0003] A winding layer detecting device shown in FIG. 9 has also been proposed. The device shown in FIG. 9 is configured such that a potentiometer 40 is provided near a drum 42 and a link 41 protruding from the potentiometer 40 is biased toward the rotation center of the drum 42. Accordingly, when the rope 45 is wound around the drum 42 and the winding radius changes, the link 41 moves in a direction away from the center of the drum 42 and the link angle ψ changes. Then, based on the previously measured length L3 of the link 41, the distance L2 from the center of the drum 42 to the center of rotation of the link 42, and the link angle ψ, the winding radius R2 of the rope 45 is calculated by the following equation. Based on the winding radius R2 of the rope 45, the rope 4
5 can be obtained. R2 = √ ((L2-L3cosψ ) 2 + (L3sin
ψ) ² )

[0004]

However, in the apparatus shown in FIG. 8, since an ultrasonic sensor is used, an environment in which mud or the like adheres to the rope as in the case of outdoor work under poor environmental conditions. Below, when ultrasonic waves are irregularly reflected by this mud, etc., the reflected wave cannot be received by the ultrasonic sensor, and the distance to the rope reflection surface can not be measured, and as a result, the winding amount of the rope is measured Can not. A part of the irregularly reflected ultrasonic waves may be received, but in such a case, the measurement is not accurate. Further, if mud adheres to the ultrasonic emission surface or the reception surface of the sensor, the measurement cannot be performed at all.

In the apparatus shown in FIG. 9, since the link of the potentiometer is in contact with the rope,
When the rope is wound at a high speed, the rope is damaged or the link is broken, and as a result, the wound layer cannot be detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drum winding layer capable of accurately detecting a rope winding wound or unwound on a drum even when the drum is rotated at a high speed or in a work site where environmental conditions are poor. A detection device is provided.

[0007]

FIG. 1 shows an embodiment of the present invention.
The invention of claim 1 is applied to an apparatus for detecting a winding layer of a rope 5 wound or unwound on a drum 4.

A rope speed detecting means 7 for detecting the speed of the rope 5, a drum rotation speed detecting means 6 for detecting the rotation speed of the drum 4, and a rope 5 on the drum 4 based on the rope speed and the rotation speed of the drum. Radius calculation means 10 for calculating the radius R of the feeding, and the calculated radius R
Exceeds the upper limit value and the lower limit value defined from the minimum winding layer and the maximum winding layer, respectively.
And a table in which a feeding radius R and a winding layer corresponding to the feeding radius R are associated with each other, and the table and the feeding radius calculation means 10
And a winding radius calculating means 10 for obtaining a winding layer of the rope 5 from the feeding radius R calculated by the following formula or the feeding radius R restricted by the restricting means. The above-described object is achieved by calculating the five winding layers and performing a correction process so that the most calculated winding layer in the series of calculated winding layers is the final winding layer.

According to the first aspect of the present invention, the rope speed detecting means detects the speed of the rope wound or wound on the drum, and the drum speed detecting means detects the rotational speed of the drum. . Then, the feeding radius R of the drum 4 is calculated based on the rope speed detected by the rope speed detecting means 7 and the drum rotation speed detected by the drum rotation speed detecting means 6, and the rope 5 is calculated based on the feeding radius R. Is calculated by the winding layer calculating means 10.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used for easy understanding of the present invention. However, the present invention is not limited to this.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a crane equipped with a drum winding layer detecting device according to the present invention. As shown in FIG. 1, a boom 1 is mounted on a crane body (not shown) so as to be able to move up and down, and sheaves 2A and 2B are rotatably mounted on the tip of the boom 1. One end of a rope 5 is connected to the end of the boom 1, and the other end of the rope 5 is wound around a hook 9 for lifting a load 8 and sheaves 2 </ b> A, 2 </ b> B and driven by a motor 3. The suspended load 8 suspended or wound by the drum 4 by the drum 4
Goes up and down. A rotation detector 6 such as a rotary encoder for detecting the rotation speed of the winding drum 4 is provided in the vicinity of the winding drum 4, and a sheave 2A for detecting the rotation speed of the sheave 2A. A rotation detector 7 is provided. The rotation detectors 6, 7 are connected to the control device 10.

FIG. 2 is a flowchart showing a winding layer detection process performed in the control device 10. As shown in FIG. 2, first, V = Ws × based on the rotation speed Ws of the sheave 2A detected by the rotation detector 7 and the diameter d of the sheave 2A.
The winding or unwinding speed V of the rope 5 is calculated by calculating d × π. Next, in step S2, the delivery radius R is calculated by dividing the speed V calculated in step S1 by the product of the drum rotation speed Wd detected by the rotation detector 6 and 2π (R = V / 2πW).
d). In the next step S3, it is determined whether or not the payout radius R calculated in step S2 is between the upper limit value and the lower limit value. If step S3 is denied, in step S4, the payout radius R is determined. Perform processing to limit to the upper limit or lower limit.

This is because, for example, when the rotation speed of the drum 4 is very small, the equation (R = V / 2πW
If the payout radius R calculated according to d) becomes very large and, on the contrary, the rope speed V is very small,
This is to prevent the feeding radius R from becoming much smaller than the actual value. On the other hand, when step S3 is affirmed, the process proceeds to the next step S5 without performing the process of step S4.

In step S5, a process for obtaining the winding layer based on the value of the payout radius R is performed with reference to the table shown in FIG. In addition,
In the table shown in FIG. 3, a certain range is set for the payout radius R with the theoretical payout radius as an intermediate value,
The feeding radius R and the winding layer are related so that the winding layer is constant within the range. This is because the delivery radius R does not actually change unless the winding layer changes, but even if the rotation speed of the drum 3 is constant, the sheave 2A due to the swing of the suspended load or the like.
May not be constant, and in this case, the rope speed V, the feeding radius R, and the winding layer are not constant. In order to prevent the fluctuation of the winding layer, a table as shown in FIG. 3 is used so that a constant winding layer can be obtained even if the feeding radius R changes to some extent from the theoretical value.

When the winding layer is obtained in step S5 in this way, the correction processing of the winding layer is performed in step S6. This correction process is performed to remove the influence of the fluctuation of the rope speed V and the like due to the swing of the suspended load described above. First, the processing between the above-described steps S1 to S5 is performed three times to obtain three winding layer values. Of the three winding layer values, two or three winding layers having the same winding layer value are actually used. This is the value of the winding layer. For example, the integer part n of the average value of the values of the three winding layers is compared with the value of the three winding layers, and if there are two winding layer values larger than the integer part n, n
+1 is a true value, and the value of the winding layer larger than the integer part n is 1
If there is no or one, a correction process can be performed such that n is a true value. Then, in step S7,
The value of the winding layer is output, and the process ends.

As described above, according to the winding layer detecting device of the present invention, as compared with the conventional winding layer detecting device shown in FIG.
Even if mud or the like adheres to the rope, the rotation detectors 6 and 7 detect the rotation speed of the drum 3 and the rotation speed of the sheave 2A,
Since the wound layer can be detected, the wound layer can be accurately detected regardless of the use conditions of the crane. Also,
Compared with the conventional wound layer detecting device shown in FIG. 9, even if the drum is rotated at a high speed, the rotation detectors 6, 7 and the like are not damaged, and the position of the link does not need to be adjusted. In addition, the maintenance of the device becomes easy.

In the above-described embodiment, the actual rope speed may be reduced due to the swing of the suspended load, the elongation of the rope, etc.
Vibrates as shown in FIG. 4 and the payout radius detected by the vibration also fluctuates. On the other hand, if the rope speed is relatively high, this vibration does not cause much problem. However, if the rope payout speed is very low, about 3 to 180 cm / min, as shown in FIG. As a result, a situation occurs where the rope speed becomes zero even though the rope speed is not actually zero. Therefore, when performing motor rotation control or the like based on the rope speed, accurate control cannot be performed based on the rope speed detected by the rotation detector 7.

In such a case, as shown in the flowchart of FIG. 6, based on the winding layer detected in step S7, the actual drawing radius Rr is calculated backward with reference to the table shown in FIG. S11), Step S1
2, V = Rr × 2πW based on the feeding radius Rr
Calculate the rope speed from d and calculate this rope speed in step S
13 and may be used for controlling the rotation of the motor. Thereby, accurate control of the number of rotations of the motor or the like can be performed based on the accurate rope speed.

In the correspondence between the above-described embodiment and the claims, the rotation detector 6 constitutes a drum rotation number detecting means, the rotation detector 7 constitutes a rope rotation number detecting means, and the control device 10 constitutes a winding layer calculating means. I do.

[0020]

As described above in detail, according to the first aspect of the present invention, the winding layer of the rope wound on the drum is calculated based on the rope speed and the rotation speed of the drum. Even if mud or the like adheres to the surface, the wound layer can be detected without affecting the detection accuracy. In addition, there is no possibility of breakage even at high speed, and a highly reliable wound layer detecting device can be provided. Since the feeding radius is limited by the upper and lower limits defined by the minimum winding layer and the maximum winding layer, respectively, when the rotation speed of the drum is very small, the feeding radius exceeds the actual value and becomes very large. In addition, when the rope speed is very small, the feeding radius is prevented from being much smaller than the actual value. Furthermore, among the winding layers detected continuously for a predetermined number of times, the winding layer calculated most often is set as the final winding layer, so that the accuracy of the detected winding layer can be further improved.

According to the second aspect of the present invention, the feeding radius is limited by the upper limit value and the lower limit value defined by the minimum winding layer and the maximum winding layer, respectively. The feeding radius is prevented from becoming very large beyond the actual value, and the feeding radius is prevented from becoming much smaller than the actual value when the rope speed is very low. According to the third aspect of the present invention, among the winding layers detected a predetermined number of times in succession, the most calculated winding layer is used as the final winding layer, so that the accuracy of the detected winding layers is further improved. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a crane equipped with a wound layer detection device according to the present embodiment.

FIG. 2 is a flowchart showing processing performed in the control device according to the present embodiment;

FIG. 3 is a table showing a relationship between a feeding radius and a winding layer.

FIG. 4 is a graph showing a state in which the rope speed oscillates.

FIG. 5 is a graph showing a state in which the rope speed oscillates.

FIG. 6 is a flowchart showing processing performed by the control device when the rope speed is very low.

FIG. 7 is a table showing a relationship between a feeding radius and a winding layer;

FIG. 8 is a diagram showing a configuration of a conventional wound layer detection device.

FIG. 9 is a diagram showing a configuration of a conventional wound layer detection device.

[Explanation of symbols]

 Reference Signs List 1 boom 2A, 2B sheave 3 motor 4 drum 6, 7 rotation detector 8 suspended load 9 hook 10 controller

Claims (1)

(57) [Claims] 1. An apparatus for detecting a winding layer of a rope wound or unwound on a drum, comprising: a rope speed detecting means for detecting a speed of the rope; and a drum rotation number detecting means for detecting a rotation number of the drum. A delivery radius calculating means for calculating a delivery radius of a rope in the drum based on the rope speed and the rotation speed of the drum; and wherein the calculated delivery radius is calculated from a minimum winding layer and a maximum winding layer.
Exceeding the upper and lower limits specified respectively
In addition, the calculated payout radius is the upper limit or the lower
The limiting means for limiting to the limit value, the feeding radius and the winding layer corresponding to the feeding radius are related.
Table and the calculation of the dispensing radius
The feeding radius calculated by the means, or the limiting means
The winding radius of the rope is determined from the feeding radius restricted by
And a winding layer calculating means for calculating the winding number of the rope.
Calculate the number of layers and calculate the most
Correction processing is performed so that the released winding layer becomes the final winding layer.
Cormorant be wound layer detecting apparatus of the drum according to claim.