Crane hoisting weight calculation method, force limiter system and crane

Abstract

The invention discloses a crane lifting weight calculation method, a force limiter system and a crane. The method comprises the steps that S1, the pressure N borne by a luffing cylinder, the length Lw of a suspension arm, the elevation angle alpha of the suspension arm and the elevation angle beta of the luffing cylinder are obtained; and S2, calculating through a mathematical model G = f (N pressure, Lw, alpha, beta) to obtain the actual hoisting weight G of the crane. The actual hoisting weight of the crane can be accurately calculated.

Description

Technical Field

[0001] The invention relates to a crane, and in particular to a crane hoisting weight calculation method, a force limiter system and a crane. Background Art

[0002] During the operation of mobile cranes, it is necessary to collect information such as lifting weight, arm length, and amplitude. Through the real-time collected information, it is calculated whether the overturning torque of the vehicle exceeds the safety value to avoid safety accidents. At present, the lifting weight of automobile cranes is mainly obtained by measuring the oil pressure of the variable-luffing cylinder. Affected by the friction of the cylinder, the variable-luffing oil pressure fluctuates, and the cylinder length fluctuates due to the settlement of the cylinder, and the weight of the oil in the cylinder changes, which causes the force limiter to calculate the weight deviation. At present, with the continuous development of new energy technologies, hydraulic control components are gradually being replaced by electric components. At this time, the oil pressure can no longer be used to convert the lifting weight; in some technologies, the wire rope tension is measured by a three-pulley sensor or a side pressure sensor, and the lifting weight is converted in combination with the wire rope ratio. However, for most mobile cranes, two sets of force measuring devices, the main reel and the auxiliary reel, are required, which are costly. At the same time, the additional cycle extrusion reduces the service life of the rope. Therefore, it is urgent to find a new measurement method to meet the needs of new energy cranes to obtain the actual lifting weight of the main machine in real time.

[0003] In the prior art, patent CN 117416866 A "A crane force limiter system and weight calculation method" uses two oil pressure sensors to measure the pressure of the large and small chambers of the variable-length oil cylinder, and combines the mathematical model with the boom length, boom elevation angle and other parameters to obtain the current lifting weight. This technology uses the variable-length oil cylinder oil pressure for conversion. Affected by the friction of the oil cylinder, the variable-length oil pressure fluctuates. In addition, due to the fluctuation of the oil cylinder length caused by the settlement of the oil cylinder, and the weight change of the oil in the oil cylinder, the force limiter calculates the weight with deviations, and the measurement accuracy, especially the measurement accuracy under small loads, is low.

[0004] Patent CN 117811287 A "A two-stage electric cylinder with integrated two-dimensional force sensor" discloses a two-stage electric cylinder with integrated two-dimensional force sensor, which integrates the two-dimensional force sensor into the internal components of the electric cylinder to measure the axial force and driving torque of the electric cylinder. The two-dimensional force sensor is integrated into the electric cylinder of this technology, and the structure is complex. The size of the two-dimensional sensor affects the size of the electric cylinder. Summary of the invention

[0005] In order to overcome the shortcomings of the above background technology, the present invention provides a crane hoisting weight calculation method, a force limiter system and a crane.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for calculating the crane hoisting weight based on a variable-luffing cylinder force measuring mechanism comprises the following steps:

[0008] S1: Get the pressure N of the luffing cylinder 压力 , boom length Lw, boom elevation angle α, luffing cylinder elevation angle β;

[0009] S2: Through the mathematical model G = f (N 压力 , Lw, α, β) to calculate the actual lifting weight G of the crane.

[0010] Further,

[0011] in, GC is the weight of the boom, L4 is the distance from the rear hinge point of the main boom to the center line of the main boom, GU is the weight of the luffing cylinder, AM is the vertical distance from the rear hinge point of the main boom to the wire rope, A0 is the distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder, R is the distance from the rear hinge point of the main boom to the lifting weight, I is the wire rope ratio, and C is the vertical distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder.

[0012] Furthermore, the pressure N on the luffing cylinder 压力 The pressure is measured by arranging a pressure sensor between the luffing cylinder and the lower hinge point of the luffing cylinder.

[0013] The present invention also provides a force limiter system based on a variable amplitude cylinder force measuring mechanism, comprising:

[0014] The length sensor is provided on the crane boom and is used to detect the elongated length Lw of the boom;

[0015] A plurality of angle sensors are respectively arranged on the crane boom and the luffing cylinder, for detecting the elevation angle α of the boom and the elevation angle β of the luffing cylinder;

[0016] The pressure sensor is located between the luffing cylinder and the lower hinge point of the luffing cylinder to detect the pressure N on the luffing cylinder. 压力 ;

[0017] The force limiter host is respectively connected with the length sensor, multiple angle sensors and pressure sensor signals to obtain corresponding detection information and execute the crane lifting weight calculation method based on the variable amplitude cylinder force measuring mechanism.

[0018] Furthermore, a crane comprises:

[0019] boom;

[0020] Luffing cylinder, the lower hinge point of the luffing cylinder is connected to the hinge point bracket on the turntable through a hinge point pin;

[0021] It also includes a force limiter system based on a variable amplitude cylinder force measuring mechanism.

[0022] Beneficial Effects

[0023] The calculation model of the present invention is based on the inherent structural parameters of the crane, and the measurement accuracy is only related to the measurement accuracy of the sensor, with high measurement accuracy, and can realize dynamic and static measurement functions. It solves the problem that the traditional variable-luffing oil cylinder is affected by the friction of the oil cylinder, the variable-luffing oil pressure fluctuates, and the cylinder length fluctuates due to the settlement of the oil cylinder, and the weight of the oil in the oil cylinder changes, which causes the force limiter to calculate the weight deviation.

[0024] A pressure sensor is used between the luffing cylinder and the lower hinge point of the luffing cylinder to directly measure the pressure on the luffing cylinder. It is easy to install, simple in structure and has high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the crane according to an embodiment of the present application.

[0026] Figure 2 for Figure 1 The partial schematic diagram of the crane shown is used to illustrate the pressure sensor arranged between the luffing cylinder and the lower hinge point of the luffing cylinder.

[0027] Figure 3 A force measurement analysis model diagram of an embodiment of the present application.

[0028] In the figure: Ⅰ-length sensor; Ⅱ-angle sensor; Ⅲ-force limiter host; 1-electric luffing cylinder; 1-1-pressure sensor; 1-2-lower hinge point of luffing cylinder; 2-turntable; 2-1-hinge bracket; 3-jib; 4-hinge pin. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0030] See also Figure 1 and Figure 2 The embodiment of the present invention discloses a crane. The crane includes a main body and a force limiter system. The main body can adopt a common design in the industry.

[0031] The main part includes:

[0032] Boom 3;

[0033] The luffing cylinder 1, the lower hinge point 1-2 of the luffing cylinder is connected with the hinge point bracket 2-1 of the turntable 2 through the hinge point pin 4.

[0034] In this embodiment, the crane adopts an electric luffing cylinder 1, but is not limited thereto. In other embodiments, a hydraulic cylinder may also be adopted.

[0035] Force limiter system, including:

[0036] Length sensor I, provided on the crane boom 3, for detecting the elongated length Lw of the boom 3;

[0037] A plurality of angle sensors II are respectively arranged on the crane boom 3 and the luffing cylinder 1, and are used to detect the elevation angle α of the boom 3 and the elevation angle β of the luffing cylinder 1;

[0038] The pressure sensor 1-1 is provided between the luffing cylinder 1 and the lower hinge point 1-2 of the luffing cylinder, and is used to detect the pressure N pressure exerted on the luffing cylinder 1;

[0039] The force limiter host III is respectively connected with the length sensor, multiple angle sensors and pressure sensor signals to obtain corresponding detection information and calculate the crane weight through the crane weight calculation method based on the variable amplitude cylinder force measuring mechanism.

[0040] The pressure sensor 1-1 is disposed between the luffing cylinder 1 and the lower hinge point 1-2 of the luffing cylinder. That is, the pressure sensor 1-1 connects the luffing cylinder 1 and the lower hinge point 1-2 of the luffing cylinder. Therefore, the pressure sensor 1-1 can accurately detect the pressure of the luffing cylinder 1.

[0041] The pressure sensor 1-1 is preferably a weighing sensor, a stress strain sensor, or the like.

[0042] The method for calculating the crane hoisting weight based on the luffing cylinder force measuring mechanism comprises the following steps:

[0043] S1: Get the pressure N of the luffing cylinder 压力 , boom length Lw, boom elevation angle α, luffing cylinder elevation angle β;

[0044] S2: Through the mathematical model G = f (N 压力 , Lw, α, β) to calculate the actual lifting weight G of the crane.

[0045] Further, in, GC is the weight of the boom, L4 is the distance from the rear hinge point of the main boom to the center line of the main boom, GU is the weight of the luffing cylinder, AM is the vertical distance from the rear hinge point of the main boom to the wire rope, A0 is the distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder, R is the distance from the rear hinge point of the main boom to the lifting weight, I is the wire rope ratio, and C is the vertical distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder.

[0046] like Figure 3 As shown, force analysis is performed. According to the static equilibrium condition, the moment of the rear hinge of the boom is taken, and point A is the origin of the coordinate system. Then ∑M=0, that is:

[0047] F×AM-GC(Lw×cosα-L4×sinα)+(N 压力 -GUsinβ)×AO×sin(π-λ-β)-G×R=0

[0048]

[0049] N+GU sinβ=N 压力

[0050] Where:

[0051] Wire rope ratio: I

[0052] Wire rope tension: F

[0053] Boom weight: GC

[0054] Weight of luffing cylinder: GU

[0055] Hanging weight: G

[0056] Main boom elevation angle: α

[0057] Luffing cylinder elevation angle: β

[0058] Vertical distance from the rear hinge point of the main arm to the lower hinge point of the luffing cylinder: C

[0059] Distance from rear hinge point of main arm to lower hinge point of luffing cylinder: AO

[0060] Vertical distance from rear hinge point of main arm to wire rope: AM

[0061] Distance from rear hinge point of main arm to hoisting weight: R

[0062] Distance from rear hinge point of main arm to center of gravity of boom: Lw

[0063] Distance from rear hinge point of main arm to center line of main arm: L4

[0064] Can be obtained:

[0065]

[0066] We get G = f(N 压力 , Lw, α, β) mathematical model, through the measured amplitude cylinder pressure sensor pressure N 压力 , boom length Lw, boom elevation angle α, luffing cylinder elevation angle β and other fixed parameter values, the actual lifting weight of the crane can be calculated through the force limiter system.

[0067] The calculation model is based on the inherent structural parameters of the crane. The measurement accuracy is only related to the measurement accuracy of the sensor. It has high measurement accuracy and can realize dynamic and static measurement functions. It solves the problem that the traditional variable-luffing oil cylinder is affected by the friction of the oil cylinder, the variable-luffing oil pressure fluctuates, and the cylinder length fluctuates due to the settlement of the oil cylinder, and the weight of the oil in the oil cylinder changes, which causes the force limiter to calculate the weight deviation.

[0068] The above description is only an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A crane lifting weight calculation method based on a variable-luffing cylinder force measuring mechanism, characterized in that: Includes steps: S1: Get the pressure N of the luffing cylinder 压力 , boom length Lw, boom elevation angle α, luffing cylinder elevation angle β; S2: Through the mathematical model G = f (N 压力 , Lw, α, β) to calculate the actual lifting weight G of the crane.

2. The crane lifting weight calculation method based on the luffing cylinder force measuring mechanism according to claim 1 is characterized in that: In step S2: in, GC is the weight of the boom, L4 is the distance from the rear hinge point of the main boom to the center line of the main boom, GU is the weight of the luffing cylinder, AM is the vertical distance from the rear hinge point of the main boom to the wire rope, A0 is the distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder, R is the distance from the rear hinge point of the main boom to the lifting weight, I is the wire rope ratio, and C is the vertical distance from the rear hinge point of the main boom to the lower hinge point of the luffing cylinder.

3. The crane lifting weight calculation method based on the luffing cylinder force measuring mechanism according to claim 1 or 2 is characterized in that: Pressure on the luffing cylinder N 压力 The pressure is measured by arranging a pressure sensor between the luffing cylinder and the lower hinge point of the luffing cylinder.

4. A force limiter system based on a variable amplitude cylinder force measuring mechanism, characterized in that: include: The length sensor is provided on the crane boom and is used to detect the elongated length Lw of the boom; A plurality of angle sensors are respectively arranged on the crane boom and the luffing cylinder, for detecting the elevation angle α of the boom and the elevation angle β of the luffing cylinder; The pressure sensor is located between the luffing cylinder and the lower hinge point of the luffing cylinder to detect the pressure N on the luffing cylinder. 压力 ; The force limiter host is respectively connected to the length sensor, multiple angle sensors and pressure sensor signals to obtain corresponding detection information and calculate the crane weight through the crane weight calculation method based on the variable amplitude cylinder force measuring mechanism as claimed in claim 1.

5. A crane comprising: boom; Luffing cylinder, the lower hinge point of the luffing cylinder is connected to the hinge point bracket on the turntable through a hinge point pin; It is characterized in that it also includes a force limiter system based on the variable amplitude cylinder force measuring mechanism as described in claim 4.

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