Method for calculating height of lifting hook of boom crane

Abstract

The invention discloses a method for calculating the height of a lifting hook of a boom crane. The method comprises the steps that an encoder is arranged on a motor of a lifting winch, an angle sensor is arranged on a cargo boom, the cargo boom is controlled to fall to the minimum working angle, a lifting hook is lifted to the highest point, and the numerical value of the encoder at the moment, the total layer number of steel wire ropes on the lifting winch at the moment and the number of turns of the steel wire ropes on the outermost layer at the moment are recorded; calculating the maximum height of the lifting hook from the ground when the cargo boom is at the maximum working angle; during use, the angle of the cargo boom and the numerical value of the encoder are collected in real time, and the total rope outlet length is calculated according to the numerical value of the encoder; and finally calculating the height of the lifting hook. The maximum height from the lifting hook to the ground and the rope outlet length are calculated according to the numerical value change of the encoder, the outer end height change amount caused by the angle change of the cargo boom is calculated, then the real-time height of the lifting hook can be accurately calculated, auxiliary lifting operation is facilitated, and safety is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cranes, and in particular to a method for calculating the hook height of a jib crane. Background Art

[0002] With the continuous increase of large and high-rise buildings, the number of cranes is also increasing. Small jib cranes usually do not accurately calculate the height of the hook from the ground, and only use mechanical travel limiters to limit the upper and lower positions of the lifting. In this way, the driver can only observe the hook position by visual inspection, which is not convenient for lifting operations and has certain safety hazards. Summary of the invention

[0003] The purpose of the present invention is to provide a method for calculating the hook height of a jib crane in view of the shortcomings of the prior art.

[0004] To achieve the above object, the present invention provides a method for calculating the hook height of a jib crane, comprising:

[0005] An encoder is installed on the motor of the hoisting winch, and an angle sensor is installed on the boom to control the boom to drop to the minimum working angle α and the hook to rise to the highest point. The encoder value a, the total number of wire rope layers n0 on the hoisting winch and the number of outermost wire rope circles r are recorded. m ;

[0006] Calculate the maximum height c of the hook from the ground when the boom is at the maximum working angle β;

[0007] During use, the angle j of the crane arm and the encoder value b are collected in real time, and the total length of the rope s is calculated according to the encoder value b;

[0008] Calculate the height H of the hook:

[0009] H=cf*(sinβ-sinj)-s

[0010] Where f is the length of the boom.

[0011] Furthermore, the total outgoing rope length s is calculated as follows:

[0012] Calculate the current number of rope turns r according to the encoder value b n =|ba| / (k*i), where k is the resolution of the encoder and i is the reduction ratio of the reducer of the hoisting winch;

[0013] Determine the current number of rope loops r n Number of turns of the outermost wire rope r m The size relationship of

[0014] If the current number of rope turns rn <Number of outermost wire rope turns r m , then calculate the diameter d of the circle where the initial outermost wire rope is located 末 =[(n0-1)*√3+1]*d+D, where √ is the square root symbol, d is the diameter of the wire rope, and D is the diameter of the hoisting drum;

[0015] Then calculate the total rope length s = π*n0*d 末 ;

[0016] If the current number of rope turns r n ≥Number of outermost wire rope turns r m , then calculate r z =INT[(r n -r m ) / r], where INT[.] is a rounding function, r is the maximum number of wire rope turns per layer of the hoisting winch drum, and then the current number of wire rope layers n is calculated. 当 =n0-r z -1. The number of turns of the current outermost wire rope r 当 =[(r n -r m ) / rr z ]*r and the diameter d of the circle where the current outermost wire rope is located 当 =[(n 当 -1)*√3+1]*d+D, and then calculate the current length s of the outermost wire rope 当 =π*r 当 *d 当 ;

[0017] Calculate the sum of the diameters of the middle layer d 中 for:

[0018] d 中 =(n0-n 当 -1)*(d*√3+d 当 )+(n0-n 当 -2)*0.5*d*√3

[0019] Calculate the rope length s of the middle layer 中 =π*r*d 中 ;

[0020] Calculate the initial outermost wire rope length s 末 =π*r m *d 末 ;

[0021] Finally, calculate the total rope length s = s 当 +s 中 +s 末 .

[0022] Furthermore, the maximum height c of the hook from the ground is calculated by the following method:

[0023] Control the crane arm to lift to the maximum working angle β and lower the hook to the ground, record the encoder value e at this time, and then calculate the maximum height c of the hook from the ground based on the encoder value e and the encoder value a and the above-mentioned calculation method of the total rope length.

[0024] Furthermore, the minimum working angle α is 20°, and the maximum working angle β is 85°.

[0025] Furthermore, the calculation is implemented based on a programmable controller.

[0026] Beneficial effect: The present invention calculates the maximum height of the hook from the ground and the length of the rope according to the changes in the encoder value, and calculates the change in the outer end height of the boom caused by the angle change, thereby accurately calculating the real-time height of the hook, facilitating auxiliary lifting operations and improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a method for calculating the hook height of a jib crane according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0029] An embodiment of the present invention provides a method for calculating the hook height of a boom crane. The above-mentioned crane specifically includes a slewing mechanism 1, a boom 2 hinged at the front end of the slewing mechanism 1, a balance arm 3 fixed at the rear end of the slewing mechanism 1, a bracket 4 arranged between the slewing mechanism 1 and the upper end of the balance arm 3, a lifting winch 5 and a variable-length winch for controlling the angle of the boom 2, etc. The lifting winch 5 specifically includes a motor, a reducer connected to the motor, a drum connected to the reducer and a steel cable wound on the drum, etc. The outer end of the steel cable on the drum is fixedly connected to the hook 6 after passing through the bracket 4 and the fixed pulley at the front end of the boom 2 in sequence, and its structural part is not repeated here.

[0030] The method for calculating the height of the hook 6 includes:

[0031] An encoder 7 is set on the motor of the hoisting winch 5, and an angle sensor 8 is set on the boom 2 to control the boom 2 to fall to the minimum working angle α and the hook 6 to rise to the highest point. The encoder value a of the encoder 7 at this time, the total number of wire rope layers n0 on the hoisting winch 5 at this time, and the number of outermost wire rope circles r at this time are recorded.m The model of the encoder 7 is preferably RH190N-OHAK1R61N-1024. The working angle of the boom 2 refers to the angle between the central axis of the boom 2 and the horizontal plane where the hinge center of the boom 2 is located. The working angle of the boom 2 is controlled by the luffing winch. The minimum working angle α and the maximum working angle β of cranes of different manufacturers and models may be different. Figure 1 Taking the crane shown in the figure as an example, the minimum working angle α of the boom 2 is 20°, and the maximum working angle β is 85°.

[0032] Calculate the maximum height c of the hook 6 from the ground when the boom 2 is at the maximum working angle β.

[0033] During use, the angle j of the crane arm 2 and the encoder value b are collected in real time, and the total outgoing rope length s is calculated according to the encoder value b. Specifically, the total outgoing rope length s is calculated as follows:

[0034] Calculate the current number of rope turns r according to the encoder value b n =|ba| / (k*i), where k is the resolution of the encoder 7 and i is the reduction ratio of the reducer of the hoisting winch 5. Determine the current number of rope turns r n Number of turns of the outermost wire rope r m If the current number of rope loops is r n <Number of outermost wire rope turns r m , then calculate the diameter d of the circle where the initial outermost wire rope is located 末 =[(n0-1)*√3+1]*d+D, where √ is the square root symbol, d is the diameter of the wire rope, and D is the diameter of the drum of the hoisting winch 5. Then calculate the total rope length s=π*n0*d 末 .

[0035] If the current number of rope turns r n ≥Number of outermost wire rope turns r m , then calculate r z =INT[(r n -r m ) / r], where INT[.] is a rounding function, r is the maximum number of wire rope turns per layer of the hoisting winch 5, and then the current number of wire rope layers n is calculated. 当 =n0-r z -1. The number of turns of the current outermost wire rope r 当

[0036] =[(r n -r m ) / rr z ]*r and the diameter d of the circle where the current outermost wire rope is located 当 =[(n当 -1)*√3+1]*d+D, and then calculate the current length s of the outermost wire rope 当 =π*r 当 *d 当 .

[0037] Then calculate the sum of the diameters of the middle layer d 中 for:

[0038] d 中 =(n0-n 当 -1)*(d*√3+d 当 )+(n0-n 当 -2)*0.5*d*√3.

[0039] Then calculate the rope length s of the middle layer 中 =π*r*d 中 .

[0040] Calculate the initial outermost wire rope length s 末 =π*r m *d 末 .

[0041] Finally, calculate the total rope length s = s 当 +s 中 +s 末 .

[0042] Calculate the height H of the hook 6 as:

[0043] H=cf*(sinβ-sinj)-s

[0044] Wherein, f is the arm length of the crane arm 2.

[0045] The maximum height c of the hook 6 from the ground can be obtained by manual measurement, and more preferably calculated by the following method:

[0046] Control the crane arm 2 to lift to the maximum working angle β, lower the hook 6 to the ground, record the encoder value e at this time, and then calculate the maximum height c of the hook 6 from the ground based on the encoder value e and the encoder value a and the above-mentioned calculation method of the total outgoing rope length. Specifically, first calculate the number of rope turns r based on the encoder value e n’ =|ea| / (k*i), the number of loops r n’ It must be greater than the number of turns of the outermost wire rope r m Then directly use the above-mentioned total rope length calculation method to calculate the rope length at this time as the maximum height c of the hook 6 from the ground.

[0047] In the specific implementation, the angle sensor 8 is preferably installed at the lower end of the boom 2. The model of the angle sensor 8 is preferably JD-180. The pre-collected minimum working angle α and maximum working angle β can be sent to the controller through the transmitter as setting parameters. The model of the transmitter is preferably LCT6-JPA0101, and the controller preferably adopts PLC (programmable controller). In addition, the parameters such as pi, the diameter d of the outer edge of the steel cable on the drum of the hoisting winch 5, the resolution k of the encoder 7, the reduction ratio i of the reducer of the hoisting winch, and the maximum number of wire rope turns r per layer of the drum need to be input into the controller as setting parameters. A display screen can be set in the cab of the crane. The model is preferably MT4523TE. The display screen is connected to the above-mentioned controller, and the display screen is used to display the current height H of the hook 6, so that the driver can understand the current height of the hook 6 and assist the lifting operation. A sound and light alarm can also be provided, and the model is preferably ND16-22FS. The sound and light alarm is connected to the controller. When the distance h of the hook 6 relative to the highest point is less than the set upper threshold, the controller controls the sound and light alarm to send a corresponding alarm signal, prompting the driver to drive carefully, and prohibiting the hook 5 from continuing to move upward; when the distance h of the hook 6 relative to the highest point is less than the set upper threshold, the controller controls the sound and light alarm to send a corresponding alarm signal, prompting the driver to drive carefully, and prohibiting the hook 5 from continuing to move upward; when the current height H of the hook 6 is less than the set lower threshold, the controller controls the sound and light alarm to send a corresponding alarm signal, prompting the driver to drive carefully, and prohibiting the hook 5 from continuing to move downward. The upper threshold and lower threshold set above are preferably set to 2 meters.

[0048] The above is only a preferred embodiment of the present invention. It should be noted that for ordinary technicians in this technical field, other parts not specifically described belong to the prior art or common knowledge. Several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A method for calculating the hook height of a boom crane. It is characterized in that include: An encoder is installed on the motor of the hoisting winch, and an angle sensor is installed on the boom to control the boom to drop to the minimum working angle α and the hook to rise to the highest point. The encoder value a and the total number of wire rope layers n on the hoisting winch are recorded. 0 And the number of outermost wire rope turns r m ; Calculate the maximum height c of the hook from the ground when the boom is at the maximum working angle β; During use, the angle j of the crane arm and the encoder value b are collected in real time, and the total length of the rope s is calculated according to the encoder value b; Calculate the height H of the hook as: H=cf*(sinβ-sinj)-s Where f is the length of the boom.

2. A method for calculating the hook height of a jib crane according to claim 1, It is characterized in that The total outgoing rope length s is calculated as follows: Calculate the current number of rope turns r according to the encoder value b n =|ba| / (k*i), where k is the resolution of the encoder and i is the reduction ratio of the reducer of the hoisting winch; Determine the current number of rope loops r n Number of turns of the outermost wire rope r m The size relationship of If the current number of rope turns r n <Number of outermost wire rope turns r m , then calculate the diameter d of the circle where the initial outermost wire rope is located 末 =[(n 0 -1)*√3+1]*d+D, where √ is the square root symbol, d is the diameter of the wire rope, and D is the diameter of the hoisting drum; Then calculate the total rope length s = π*n 0 *d 末 ; If the current number of rope turns r n ≥Number of outermost wire rope turns r m , then calculate r z =INT[(r n -r m ) / r], where INT[.] is a rounding function, r is the maximum number of wire rope turns per layer of the hoisting winch drum, and then the current number of wire rope layers n is calculated. 当 =n 0 -r z -1. The number of turns of the current outermost wire rope r 当 =[(r n -r m ) / rr z ]*r and the diameter d of the circle where the current outermost wire rope is located 当 =[(n 当 -1)*√3+1]*d+D, and then calculate the current length s of the outermost wire rope 当 =π*r 当 *d 当 ; Calculate the sum of the diameters of the middle layer d 中 for: d 中 =(n 0 -n 当 -1)*(d*√3+d 当 )+(n 0 -n 当 -2)*0.5*d*√3 Calculate the rope length s of the middle layer 中 =π*r*d 中 ; Calculate the initial outermost wire rope length s 末 =π*r m *d 末 ; Finally, calculate the total rope length s = s 当 +s 中 +s 末 .

3. A method for calculating the hook height of a jib crane according to claim 2, It is characterized in that The maximum height c of the hook from the ground is calculated in the following way: Control the crane arm to lift to the maximum working angle β and lower the hook to the ground, record the encoder value e at this time, and then calculate the maximum height c of the hook from the ground based on the encoder value e and the encoder value a and the above-mentioned calculation method of the total rope length.

4. A method for calculating the hook height of a jib crane according to claim 1, It is characterized in that The minimum working angle α is 20°, and the maximum working angle β is 85°.

5. A method for calculating the hook height of a jib crane according to claim 1, It is characterized in that The calculation is implemented based on a programmable controller.

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