CN102706499B - Cable tension measurement method and device thereof for vertically downward unwinding type winch - Google Patents

Abstract

The invention discloses a method and a device for measuring the cable tension of a vertically downward pulling winch, belonging to the field of winches. The method includes measuring the length Lc of the cable released when the winch actually works; according to the length Lc and the amount of stored rope L on the winch, it is judged which layer the force-measuring point of the cable is located on the drum, and the distance between the force-measuring point of the cable and the center of the drum is determined. Rg; calculate the cable tension F according to the moment balance equation. The device includes a roller and a bracket. The two ends of the roller are installed on the bracket. Sensors are respectively pressed on the bottom of the two ends of the roller. and the sensor are respectively electrically connected to the main control unit. The real-time detection of the actual distance between the force measuring point of the cable and the center of the drum is realized through the additional opening meter and the main control unit, and the real-time tension of the cable can be accurately obtained through the calculation of the main control unit, the measurement result is more accurate, and the structure Simple. Suitable for winches.

Description

A method and device for measuring cable tension of a vertically downward-drawing winch

technical field

The invention relates to the field of winches, in particular to a method and a device for measuring the cable tension of a vertically downward pulling winch.

Background technique

At present, in ship engineering and ocean engineering, the working load requirements of the winch are getting higher and higher, which leads to the increasing weight and volume of the winch, and the installation layout is gradually transferred to the open upper deck, which requires the direction of the winch to be is vertically downward.

At present, there are generally two methods for measuring the tension of the winch cable:

One is a direct contact measurement method, the direct contact measurement method is to directly attach the measuring element to the cable, relying on the extrusion of the cable to the sensitive element to measure the tension of the cable; the other is the indirect contact measurement method, the indirect The contact measurement method is to measure the parts related to the drum, and then convert the measured data into the cable tension.

In the process of realizing the present invention, the inventor found that the prior art has at least the following problems:

The first method is mostly used for cables made of steel wire, but it is not applicable to cables made of other soft materials, and its versatility is poor; the second method converts the measured data into cable tension. The distance to the center of the drum is taken as a fixed value. In this way, when the winch retracts and unwinds the cable for a long distance, due to the large change in the distance from the force measuring point of the cable to the center of the drum during use, there is a large error in the measurement results. The measurement is not accurate.

Contents of the invention

In order to accurately measure the cable tension of the winch and improve the versatility of the measurement, an embodiment of the present invention provides a method and a device for measuring the cable tension of a vertically downward-drawing winch. Described technical scheme is as follows:

A method for measuring the tension of a cable of a vertically downward-drawing winch, comprising:

Measure the length Lc of the cable when the winch is actually working;

According to the length Lc and the amount of stored rope L on the winch, determine which layer the force-measuring point of the cable is located on which layer of the drum, and determine the distance Rg between the force-measuring point of the cable and the center of the drum;

The cable tension F is calculated according to the moment balance equation.

Specifically, the judging on which layer the force-measuring point of the cable is located on the drum, and determining the distance Rg between the force-measuring point of the cable and the center of the drum includes:

According to the formula Ln=(B/d)2πdn, calculate the total length Ln of the rope that can be wound on the nth layer of the drum, wherein, B represents the width of the drum, d represents the diameter of the cable, and dn represents the distance between the center of the cable of the nth layer and the center of the drum distance;

Calculate the cable length Lg=L-Lc wound on the drum;

When 0≤Lg<L1, the force-measuring point of the cable is located on the first layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d1; when L1≤Lg<L1+ When L2, the force-measuring point of the cable is located on the second layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d2; when L1+L2≤Lg<L1+L2+L3 , the force-measuring point of the cable is located on the third layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d3; when L1+L2+...+Ln-1≤Lg<L1 When +L2+...+Ln-1+Ln, the force-measuring point of the cable is located on the nth layer of the drum, and the distance between the force-measuring point of the cable and the center of the drum is Rg=dn.

More specifically, said dn=[D+(2n-1)d]/2, wherein D represents the diameter of the drum and d represents the diameter of the cable.

Further, the calculation of the cable tension F according to the moment balance equation includes:

Calculate the cable tension F according to the formula F=(F2-F1)Rf/Rg, wherein, F1 represents the total pressure caused by the tension of the cable at the left end of the two supports of the drum, and F2 represents the force at the right end of the two supports of the drum due to the tension of the cable. The total pressure caused by the tension, Rf represents the distance from the F1 and F2 to the center of the drum.

A cable tension measuring device for a vertically downward-extracting rope winch, comprising: a drum and a bracket, the two ends of the drum are installed on the bracket, the bottoms of the two ends of the drum are respectively press-fitted with sensors, and a main control unit is also included. The rotating shaft of the drum is provided with an opening meter for real-time detection of the stroke of the drum, and the opening meter and the sensor are respectively electrically connected to the main control unit.

Specifically, the main control unit includes a programmable logic controller.

Specifically, the sensor is a load sensor.

The beneficial effects brought by the technical solution provided by the embodiment of the present invention are: by real-time detection and calculation of the actual distance between the force measuring point of the cable and the center of the drum, the accuracy of cable tension measurement is effectively improved; And the main control unit realizes the real-time detection of the actual distance between the force measuring point of the cable and the center of the drum, and the real-time tension of the cable can be accurately obtained through the operation of the main control unit, the measurement result is more accurate, the structure is simple, and it is easy to use.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a flow chart of a method for measuring the cable tension of a vertically downward cable-out type winch provided in Embodiment 1 of the present invention;

Fig. 2 is a structural schematic diagram of a cable tension measuring device of a vertically downward-extracting rope winch provided in Embodiment 2 of the present invention;

FIG. 3 is a simplified schematic diagram of the side view of FIG. 1 .

Among them, the bracket 1, the drum 2, the main control unit 3, the sensor 4, the opening meter 5, and the cable 6.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Example 1

An embodiment of the present invention provides a method for measuring the cable tension of a vertically downward-drawing winch, as shown in FIG. 1 , the method includes:

Step 101: Calculate the distance between the center of the cable on the nth layer of the drum and the center of the drum: dn=[D+(2n-1)d]/2, where D represents the diameter of the drum and d represents the diameter of the cable.

Step 102: According to the formula Ln=(B/d)2πdn, calculate the total length Ln of the cable that can be wound on the nth layer of the drum, where B represents the width of the drum.

Step 103: Measure the length Lc of the unwound cable when the winch is working in real time.

Specifically, an opening meter can be used for measurement.

Step 104: According to the measured length Lc and the amount of stored rope L on the winch, determine which layer the force-measuring point of the cable is located on the drum, and determine the distance Rg between the force-measuring point of the cable and the center of the drum.

Specifically, this step includes:

Calculate the cable length Lg=L-Lc wound on the drum;

When 0≤Lg<L1, the force-measuring point of the cable is located on the first layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d1; when L1≤Lg<L1+ When L2, the force-measuring point of the cable is located on the second layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d2; when L1+L2≤Lg<L1+L2+L3 , the force-measuring point of the cable is located on the third layer of the drum, then the distance between the force-measuring point of the cable and the center of the drum is Rg=d3; when L1+L2+...+Ln-1≤Lg<L1 When +L2+...+Ln-1+Ln, the force-measuring point of the cable is located on the nth layer of the drum, and the distance between the force-measuring point of the cable and the center of the drum is Rg=dn.

Step 105: Calculate the cable tension F according to the moment balance equation.

Specifically, this step includes:

Calculate the real-time tension F of the cable according to the formula F=(F2-F1)Rf/Rg, where F1 represents the total pressure caused by the tension of the cable at the left end of the two supports of the drum, and F2 represents the total pressure caused by the tension of the cable at the right end of the two supports of the drum , Rf represents the distance from F1 and F2 to the center of the drum.

It should be noted that step 101 and step 102 can be performed simultaneously with step 103 or step 104, and the sequence is not limited here, and they can also be pre-calculated and configured in the main control unit according to the actual situation (see embodiment 2) .

The embodiment of the present invention effectively improves the accuracy of cable tension measurement by detecting and calculating the actual distance between the force-measuring point of the cable and the center of the drum in real time.

Example 2

The embodiment of the present invention provides a cable tension measuring device for a vertically downward pulling-out winch, see Figures 2 to 3, the device includes: a bracket 1, a drum 2 and a main control unit 3, and the two ends of the drum 2 are installed on the bracket 1, the bottom of both ends of the drum 2 are respectively press-fitted with sensors 4, and the rotating shaft of the drum 2 is provided with an opening meter 5 for real-time detection of the stroke of the drum 2, and the opening meter 5 and the sensor 4 are respectively electrically connected to the main control unit 3 . The main control unit 3 includes a programmable logic controller for performing all the above calculations and judgments. The sensor 4 is a load sensor, which is used to respectively detect the total pressure (F1 and F2) at both ends of the two supports of the drum 2 due to the tension of the cable 6.

When in specific use: first, input the parameters such as the diameter of the drum 2, the width of the drum 2, and the diameter of the cable 6 into the main control unit 3; then, measure in real time according to actual needs, and the opening meter 5 will release the length of the cable 6 measured in real time when the winch is working Lc is transmitted to the main control unit 3, and at the same time, the sensor 4 transmits the real-time measured total pressure (F1 and F2) caused by the tension of the cable 6 at both ends of the drum 2 to the main control unit 3; finally, the main control unit 3 passes The calculation displays the real-time tension of the cable 6.

The embodiment of the present invention realizes the real-time detection of the actual distance between the force-measuring point of the cable 6 and the center of the drum 2 through the additional opening meter 5 and the main control unit 3, and can accurately obtain the distance between the cable 6 and the center of the drum 2 through the operation of the main control unit 3. Real-time tension, more accurate measurement results, simple structure, easy to use.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention Inside.

Claims (5)

1. a cable tension measuring method for the winch of rope stretching formula vertically downward, is characterized in that, comprising:

While measuring winch real work, emit the length L c of hawser;

According to the storage rope amount L on described length L c and described winch, judge that the force-detecting position of described hawser is positioned on which layer of cylinder, and determine the force-detecting position of described hawser and the distance R g between described centre of the drum;

According to torque equilibrium equation, calculate described cable tension F;

The force-detecting position that judges described hawser is positioned on which layer of described cylinder, and determines the force-detecting position of described hawser and the distance R g between described centre of the drum, comprising:

The reelable hawser overall length of the n layer Ln that calculates described cylinder according to formula Ln=(B/d) 2 π dn, wherein, B represents cylinder width, and d represents cable diameter, and dn represents the hawser center of n layer and the distance between centre of the drum;

Described dn=[D+ (2n-1) d]/2, wherein, D represents diameter of cylinder, d represents cable diameter;

Calculate the cable length Lg=L-Lc being wound around on described cylinder;

When 0≤Lg < L1, the force-detecting position of described hawser is positioned at the ground floor of described cylinder, the distance R g=d1 between the force-detecting position of described hawser and described centre of the drum; When L1≤Lg < L1+L2, the force-detecting position of described hawser is positioned at the second layer of described cylinder, the distance R g=d2 between the force-detecting position of described hawser and described centre of the drum; When L1+L2≤Lg < L1+L2+L3, the force-detecting position of described hawser is positioned at the 3rd layer of described cylinder, the distance R g=d3 between the force-detecting position of described hawser and described centre of the drum; Work as L1+L2+ ... + Ln-1≤Lg < L1+L2+ ... during+Ln-1+Ln, the force-detecting position of described hawser is positioned at the n layer of described cylinder, the distance R g=dn between the force-detecting position of described hawser and described centre of the drum.

2. measuring method as claimed in claim 1, is characterized in that, describedly according to torque equilibrium equation, calculates described cable tension F, comprising:

According to formula F=(F2-F1) Rf/Rg calculates cable tension F, wherein, F1 represents the general pressure that described cylinder two stands left end causes due to described cable tension, F2 represents the general pressure that described cylinder two stands right-hand member causes due to described cable tension, and Rf represents the distance of described F1HeF2Dao centre of the drum.

3. a device of realizing method described in claim 1, comprise: cylinder and support, described cylinder two ends are rack-mount, bottom, described cylinder two ends is pressed with respectively sensor, it is characterized in that, also comprise main control unit, the rotating shaft of described cylinder is provided with for detecting in real time the aperture instrument of cylinder stroke, and this aperture instrument and described sensor are electrically connected to described main control unit respectively.

4. device as claimed in claim 3, is characterized in that, described main control unit comprises programmable logic controller (PLC).

5. device as claimed in claim 3, is characterized in that, described sensor is load sensor.

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