JPS6218476B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention connects the base end of a boom to a crane base via a fulcrum, and the boom has a predetermined position at its tip with respect to the axis of the boom. The working radius of a crane is attached to the base end of a supplementary boom with a pulley at its tip for lifting a hook at an offset angle. This refers to the horizontal distance to the tip pulley).

(Prior art) The conventional method for determining the working radius is as follows:
No. 32578 and JP-A-50-132643 are known. These conventional examples will be explained based on FIG. 1.

In FIG. 1, the base end of a boom A is connected to a crane base (not shown) via a fulcrum, and the boom A has its tip at a predetermined offset angle α with respect to the axis of the boom A. A crane is shown equipped with the base end of a supplementary boom B, which is equipped with a pulley at the end of the crane for lifting a hook.

Here, as shown in Fig. 1, the boom end pulley, which is equipped to suspend the lifting equipment from the boom end and perform lifting work, is moved from the boom A
The boom A is placed on a straight line extending parallel to the axis of the boom A toward the tip of the boom A. Therefore, the length of the boom A is indicated by the straight-line distance L between the hoisting fulcrum and the boom tip pulley, and the length of the supplementary boom B is indicated by the linear distance I between the boom tip pulley and the supplementary boom tip pulley. . If the angle of the boom A relative to the ground is θ, then in the above cited publication, the working radius R is L.
A technique for obtaining cos θ+I cos (θ−α) has been disclosed.

(Problems to be Solved by the Present Invention) However, when attempting to determine the working radius as described above, there were the following disadvantages.

That is, when a load is suspended from the pulley at the end of the replenishment boom B, the boom A and the replenishment boom B are bent. Therefore, in order to obtain an accurate working radius R, it is necessary to correct the working radius R due to the deflection. In the conventional device described above, a technique for determining the working radius R by correcting the deflection is not disclosed. Furthermore, even if correction is to be made, the method for determining the working radius R described above requires individual correction of both the boom A and the supplementary boom B, making the calculation extremely complicated. That is, it requires the deflection angles for each of the boom A and the supplementary boom B for the above-mentioned load, and it is necessary to memorize these separately in advance and calculate the deflection angles from these memorized values during actual crane work. .

(Means for Solving the Problems) In order to solve the above-mentioned problems, the method of determining the working radius of a crane according to the present invention is to connect the base end of the boom to the crane base via a luffing fulcrum, and A method for determining the working radius of a crane in which the base end of the boom is equipped with a supplementary boom having an end pulley for lifting a hook at the end of the boom at a predetermined offset angle with respect to the axis of the boom, the method comprising: The straight line connecting the fulcrum and the tip pulley is taken as the reference straight line, and the standard straight distance, which is the distance between these two points, is calculated from the value responsive to the length of the boom, the value responsive to the additional boom length, and the offset angle. and obtain the deviation angle between the reference straight line and the axis of the boom at the hoisting fulcrum, and furthermore, determine the displacement position of the tip pulley based on the deflection that occurs in the boom and the additional boom when a predetermined load is lifted from the tip pulley. An angle formed by a straight line connecting the hoisting fulcrum of the boom and the reference straight line is a deflection angle, and the relationship between this deflection angle and the load is stored in advance as a memory value for each recorded angle,
During actual crane work, calculate the actual deflection angle during this work based on the memorized value and the actual load, subtract the deflection angle and the actual deflection angle from the value that responds to the boom heave angle, and calculate the reduced angle. The working radius of the crane is obtained by multiplying the cosine of the angle value by the reference linear distance.

(Function) The method of determining the working radius of the crane of the present invention having the above configuration is to add the reference linear distance to the boom length, calculate the horizontal distance of this reference linear distance from the boom length and offset angle, and calculate the working radius. The deflection angle of the reference straight line that occurs when a load is suspended from the pulley at the end of the supplementary boom is calculated based on the memorized value and the actual load. An accurate working radius is obtained by simply calculating the horizontal distance of the standard straight distance. Therefore, there is no need to calculate the horizontal distance between the boom and the supplementary boom, unlike in the prior art, and the angle of deflection of both is not required when correcting the working radius due to deflection. Therefore, the storage capacity for the deflection angle can be reduced.

(Example) An example of the method for determining the working radius of a crane according to the present invention will be described below with reference to FIG.

In FIG. 2, 1 is a crane base mounted on a truck 2 via a swing bearing 3;
is a boom whose base end is pivotally connected to the crane base 1 via a pin 4. 5 is a luffing cylinder inserted between boom A and crane base 1;
By extending and contracting the hoisting cylinder 5, the boom A moves up and down using the pin 4 as a hoisting fulcrum. Reference numeral 8 denotes a pulley at the end of the boom A, which is used when lifting a load by suspending a hoist from the end of the boom A. This tip pulley 8 is connected to the pin 4
Boom A toward the tip of boom A from (the hoisting fulcrum)
It is arranged so that it is located on a straight line extending parallel to the axis of. 6 is a boom length detector;
The length of the cord 7, whose base end is wound around a drum (not shown) so that it can be freely unwound and whose tip end is fixed to the tip of the boom A, is continuously detected via, for example, a potentiometer, and the cord 7 is connected to the boom A. The boom length L, that is, the distance between the pin 4 and the end pulley 8 of the boom A can be obtained. 9 is a boom luffing angle detector, and boom A
The angle θ from the ground is detected by using the movement of a weight or the movement of the boom A relative to the crane base 1, for example, by changing the output voltage of a potentiometer. Reference numeral B is a supplementary boom having a tip pulley 10 for suspending a hook at the tip of the boom A at a predetermined offset angle α with respect to the axis of the boom A. l ₀ indicates the distance from the tip pulley 8 to the tip pulley 10 of the supplementary boom B. l indicates the length of the shadow formed when the line segments 8 and 10 are projected perpendicularly onto the extended line connecting the pin 4 and the distal pulley 10. d indicates the distance between the tip pulley 10 and the location where the tip pulley is projected.
K is a straight line connecting the pin 4 (the fulcrum) and the tip pulley 10, that is, a reference straight line, and M is a reference straight line distance indicating the distance between these two points. β is a deviation angle, which is an angle formed between the reference straight line K and the axis of the boom A (here, the straight line connecting the pin 4 and the tip pulley 8).

When each code is set in this way, the working radius R can be calculated as follows.

Since the standard straight line distance M is M=L+l/cosβ, the working radius R is: R=M×cos(θ-β)=L+l/cosβ×cos(θ-β)......Here, tanβ=d /L+l β=tan ^-1 d/L+l={d/L+l-1/3(d/L+l) ³ +1/5(d/L+l) ⁵ ...}×180°/
π… For example, when d/L+l=0.2, d/L+l×
180°/π≒ 11.4°, 1/3 (d/L+l) ³ ×180°/π≒0.15
As is clear from the fact that d/L+l is used in a small range, β=tan ^-1 d/L+l≒d/L+l
It may be approximated as ×180°/π.

Therefore, in the above equation, l and d are constants, and the length of the additional boom B and the offset angle α
From this, L can be found from the boom length detector 6, and θ can be found from the heave angle detector 9, respectively.

Next, in the above formula, the end pulley 1 of the replenishing boom B
If the deflection of boom A and supplementary boom B that occurs when a load is lifted from zero is not taken into consideration, then take it into consideration as follows. As shown in FIG. 4, the straight line connecting the pin 4 and the tip pulley 10 when the tip pulley 10 is displaced to the position 20 due to flexure (reference straight line K passing over the reference numeral 20) and the reference line If the angle formed by K (a straight line passing over code 10) is the deflection angle △θ, then the working radius R is R≒L+l/cosβcos(θ−β−△θ)……
It is expressed as

This deflection angle Δθ is determined by the technique disclosed in Japanese Patent Application No. 53-150675, that is, the deflection of the tip pulley 10 based on the deflection that occurs in the boom A and the supplementary boom B when a predetermined load is suspended from the tip pulley 10. The angle formed by the straight line connecting the displacement position and the fulcrum of the boom A with the reference straight line K is defined as a deflection angle, and the relationship between this deflection angle and the load is stored in advance as a memory value for each heave angle, During actual crane work, the actual deflection angle Δθ may be calculated based on the stored value and the actual load.

Next, the calculation means will be explained using the block diagram shown in FIG.

Boom length signal L from boom length detector 6
is sent to the first calculation unit 11, the first calculation unit 11 calculates β by calculating the above equation. When this angle signal β is sent to the second calculation section 12,
This second calculation unit 12 is connected to the third calculation unit 13.
In addition to sending the cos β signal, this second calculation unit 12
is the heave angle signal θ from the heave angle detector 9 and the actual deflection angle signal Δ from the generator 15 which calculates the actual deflection angle Δθ and generates this signal as described above.
Upon receiving θ, the third calculation unit 13 calculates cos(θ
−β−△θ) signal is sent. and third calculation unit 1
3, each of these signals cosβ, cos(θ−β−△
θ) and the boom length signal L from the boom length detector 6 as input signals, the above equation is calculated, and the working radius R is output and displayed on the display 14.

In the above embodiment, the boom tip pulley 8 was placed on a straight line extending from the pin 4 (boom hoisting fulcrum) in parallel with the axis of the boom A toward the tip of the boom A, but if it is not located on this straight line, the following You can do it like this. That is, find the orthogonal point between a straight line that is perpendicular to the boom axis and passes over the tip pulley 8, and a straight line that extends from the pin 4 (the up-and-down fulcrum) parallel to the boom A axis toward the tip of the boom A. The straight line distance between the pins 4 (the up-and-down fulcrums) may be taken as the boom length, and the straight line distance between this orthogonal point and the tip pulley 10 may be added to make the boom length.

In addition, the working radius of a crane usually refers to the distance from the center of rotation of the crane, and refers to the value R subtracted by r in Figure 2 from the above R.
Since this r is a constant, the working radius of the crane described above has been explained as the working radius of the crane excluding this constant r.

(Effects of the Invention) As described above, the present invention is capable of determining an accurate working radius in consideration of the deflection that occurs in the boom and the replenishment boom when lifting the load from the pulley at the end of the replenishment boom. . That is, the horizontal distance of the reference straight line distance is determined, and the horizontal distance is corrected based on the deflection angle of the reference straight line, thereby making it possible to obtain an accurate working radius taking the deflection into consideration. Therefore, there is no need to determine the horizontal distances of the boom and the supplementary boom as in the prior art, and the angle of deflection of both is not required when correcting the working radius due to deflection. Therefore, the storage capacity of the deflection angle is small because only the deflection angle of the reference straight line needs to be stored.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional method for determining the working radius of a crane, FIG. 2 is a schematic diagram of a crane for explaining the present invention, and FIG. 3 is a block diagram for explaining the present invention. FIG. 4 is an explanatory diagram for explaining the relationship between the deflection of the boom and the additional boom and the present invention. 1: Crane base, A: Boom, α: Offset angle, 10: Tip pulley, B: Additional boom,
4: Up-and-down fulcrum, K: Reference straight line, M: Reference straight line distance, β: Deviation angle, Δθ: Deflection angle, R: Working radius.

Claims (1)

[Scope of Claims] 1. The base end of a boom is connected to a crane base via a fulcrum, and the boom is provided with a hook at its tip at a predetermined offset angle with respect to the axis of the boom. A method for determining the working radius of a crane equipped with the base end of a supplementary boom equipped with a tip pulley, wherein the straight line connecting the hoisting fulcrum and the tip pulley is taken as a reference straight line, and the reference line is the distance between these two points. Obtaining a straight line distance from a value responsive to the length of the boom, a value responsive to the length of the supplementary boom, and the offset angle, and obtaining a declination angle between the reference straight line and the axis of the boom at the hoisting fulcrum; The angle between the reference straight line and the straight line connecting the shifting position of the tip pulley based on the deflection that occurs in the boom and additional boom when a predetermined load is lifted from the tip pulley and the boom's uphill fulcrum is defined as the deflection angle. The relationship between the deflection angle and the load is stored in advance as a memory value for each undulation angle,
During actual crane work, calculate the actual deflection angle during this work based on the memorized value and the actual load, subtract the deflection angle and the actual deflection angle from the value that responds to the boom heave angle, and calculate the reduced angle. A method of calculating the working radius of the crane by multiplying the cosine of the angle value by the reference straight line distance.