JPS5992894A - Preventive device for overload of joint type crane with multistage arm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an articulated crane having a multi-stage bending arm, a patent, and an overload protection device suitable for application when used as a hydraulic excavator crane.

BACKGROUND OF THE INVENTION Conventionally, cranes have been required by law to be equipped with a stopper in order to ensure work safety. This overload prevention device is
From the angle of the crane arm or boom, find out the operating radius at that position and the rated load, which is a load that is less than the ratio of the overturning moment of the crane, as shown in Figure 1 of the crane loading drawing. In the case of a crane with a single frame B, the working radius is 2L-
ABC7)7-), Via B, Oml. Since the elevation angle θ changes only in proportion to the change in the distance of the load point B1 at the tip of the boom B from the rotation center axis X7X of the main body, the force of the arm B; In a conventional crane, this can be calculated from the elevation angle θ of the boom B, and if the hanging load W' exceeds this, the crane will not operate.

That is, the overturning moment M at the position of the boom foot bin Bf is M=W'Jcosθ+ab-1°·cosθ. However, here, L: Overall length of boom B Gb: Weight of boom B Jc: Center of gravity B of boom B. is the length from its foot bin Bf. Also, if the cross section of boom B is uniform or vertically symmetrical, JG=:=//2)-, so M=(W's+t/2G1.kai,1-)codayθ becomes. In FIG. 1, D indicates the horizontal distance from the pivot axis X-x of the main body of the notebook bin Bf of the boom B.

However, cranes with multi-stage articulating arms,
For example, when using a hydraulic excavator as a crane, there is not a single boom, but as shown in Figure 2, there is an arm A in addition to the boom B, and both B and A rotate together. - Even at the same radius of attack, that is, the same load moment, there are infinite combinations of angles of boom B and arm A, and the center of gravity position B of boom B and arm A is determined according to each angle. , Ao change, so a single rated load *
i7;j It is difficult to simply determine the respective claw centers 1i B depending on the angles of the overload prevention poom B and arm A of the conventionally known crane. , Ao appears differently on the 7th day. For example, as shown in FIG. 2 (in this case, total load moment in position work) -w'x L+w; xa, +w', xa.

Total load moment at position ■) - w″X L + w', x a, '-4 - w × d2
'. However, here Wl: weight of boom B W2. Weight of arm A d,,a,': Center of gravity B of boom B. The horizontal distance a2. from the center of rotation mx-x at positions I and II of . a2': Similarly, it is the horizontal distance of arm A.

For this purpose, a crane with a multi-stage bending arm and a patented load rating display device suitable for displaying the rated load and preventing overload when used with a hydraulic excavator crane have already been developed. Non-appearance II: Proposed by Kaito, in this proposed device, the boom and arm are each provided with means for detecting their ground angles, and from both ground angles detected by these means, The safe rated load and working radius f: is displayed, and the bottom of the comb is designed to display a valley if the load exceeds the safe rated load for this working radius. It is.

An embodiment of this apparatus will now be described with reference to FIGS. 3 to 5.

In Fig. 3, l is the main body of the hydraulic excavator, λ is a section, and 1
3 is an arm that is rotatably attached to the main body l, and arm 3 is rotatably attached to the other end of the poomco. As a matter of fact, arm 3 is equipped with eight arm detectors S for measuring its angle with respect to the ground. Furthermore, a hook 7 is attached to the other end of the arm 3 via a load detector 6, so that when an object is hung from the hook 7, the load can be taken out by the load detector B. . g is a moment limit controller, which is installed in a part of the operator's cab 9.
The safe rated load and working radius corresponding to various ground angles of the boom and arm 3 are stored in advance, and the safe load rating and working radius corresponding to various ground angles of the boom and arm 3 are stored in advance. Then, the rated load and working radius of the tip of the arm 3 are calculated using pre-stored numerical values, and compared with the load of the load detector B. As shown in FIG. 4, the moment limiter fI device g connects these detectors 'I, ! through the terminal plate lθ. ;, is connected to A. In addition, in Fig. 3, ll is a load indicator, which is installed at the front of the operator's cab 9 and is used to display the load of the load detector O, which is connected to the moment limit controller. (See Figure 1). Furthermore, 1 is a boom cylinder for operating the boom control, 13 is an arm cylinder for making the arm 3 ib, and 11 is an information device installed at an appropriate location on the main body.

Here, - as an example, Poom - Length 11 = '7.2!
;m, length of arm 3 J! 2 = p, 2! rm hydraulic excavator, the safe rated load Wi&:, 7 for various ground angles θ1 and θ2 of the boomco and arm 3.
If the bottom of the comb 7 is drawn on rectangular coordinates with the vertical axis of the ground height H of point C and the horizontal axis of the work radius, it will be as shown in Fig. 3.The load W is the same for the same work. Also with respect to the radius, the angle from the ground θ.

It can be seen that different values are taken depending on the values of and θ2.

This device (4) has the above-mentioned configuration, and its function is as follows.

The position of the hook 7, which is the comb-lowering point of the load at the tip of the arm 3, can be changed four times as desired by changing the relative position of the boomco and the arm 3 with respect to the main body l due to the operation of the boom cylinder 12 and arm cylinder 13. But,
The primary load rating at the current position of the hook 7 is determined by its horizontal position and the angle of the boom co and arm 3 relative to the ground. Now, the length of Poom-〇, that is, the length from the connecting point (foot pin) with the main body 1 to the connecting point with Boo A3! 1. The angle from the ground at the connection point A with the main body L is θ.

Also, if the length of the arm 3, that is, the length from the connection point opening with the boomco to the lowering point C of the hook 7, is J-2, and its angle to the ground is 02, then the length of the boomco' and the arm 3 is From the total length in the horizontal direction, the working radius is determined by L=J, cos θ, -1-J-2cos θ2. However, in the above equation, the horizontal pressure i#D from the pivot axis X-X of the main body 1 at the connection point A with the main body 1 of the boomco is ignored.

On the other hand, Poom 2 is a factor that affects the stability of the aircraft.
and the combination of the postures of arm 3, that is, each 0. The single moment changes depending on the combination of each value of 02 corresponding to the value of .

That is, the overturning moment MI1. due to the dead weight of the boomco and arm 3. As shown in FIG.
B, lifting platform MB where arm 3 is represented by A = W',
, J, 'cosθ1''w2 ・(J, cosθ, +J
, 'cos θ2'). However, here w;, w', : own weight Bo, Ao of boom B and arm A
: Equivalent center of gravity position of Poom B and Arm A including their respective accessories 0.1: Ground angle θ of the straight line connecting Poom B's rotation fulcrum and Poom center of gravity Bo, ': Arm A's rotation fulcrum and arm The ground angle of the straight line connecting 〇 to the center of gravity! ,': Length from the rotational fulcrum of the poom B to its center of gravity Bo J2゛: Length from the rotational fulcrum of the arm A to its center of gravity Ao.In addition, V/,,W in this formula , and J,,′,12”
are determined by the specific shapes of boot B and arm A, respectively, and θ4. θ, ', and θ21 vary depending on the rotation angle of boom B and arm A. In other words, the overall rated load M that takes into account the truss load and own weight is the angle θ4 of the boom B and the arm A relative to the ground.
．． Horizontal distance p of the load lowering point due to changes in θ;
i# Load moment of change in L and center of gravity position B of boom B1 arm A. , and the self-weight moment due to changes in Ao, and these are determined by the ground angle θ of boom B (Y in Figure 3) and arm A (
It is calculated using a certain formula based on each combination of the ground angles θ, 3) in FIG. There are infinite combinations of θ2, so these angles θ
7. θ2f: The rated load is calculated based on the detected value.

In this way, as shown in FIG. 3, the boom angle θ1 from the ground is detected by the boom angle detector DA, and
When the arm 30 ground angle θ2 is detected by the arm angle 4 extractor 5, both 8 rough angles θ1 and θ2 are detected by the terminal plate I.
The working radius is calculated from the sum of the horizontal lengths of the boom co and the arm 3 from the numerical values sent to the moment limit controller g and pre-stored therein via the Based on θ and θ2,
Similarly, the safe load rating at this time is calculated from the stored numerical values, that is, the seven load ratings at the current seven positions are calculated and stored. On the other hand, the load on the comb 7 is detected by the load detector 6 and sent to the moment limit controller g via the terminal plate io. Therefore, the load of this comb load is compared in the moment limit controller g with the rated load stored in the moment limit controller g, and if this load exceeds the rated load, a notification is issued. No. 16 is sent to the alarm Lda, and by activating it, it is notified that (iijM is exceeded.) At the same time, No. 4a is sent from the moment limit controller g to the load indicator 1/, and the load 7L is displayed, so even if φIJ is within the rated load, the operator can know this and can work with peace of mind.

Previously proposed crane rated load display device 1゛L
has the above-mentioned structure and function, but in Book 4, the display of the load is based on the angle θ of the boomcoat and the arm 3 from the ground at regular intervals.

and θ, the rated loads for the eight limbs in the middle of these intervals were displayed as approximate values by the rated loads for the angles closest to them.

Therefore, the ratings for intermediate angles of these intervals 11.
will be displayed as an approximate load, and this approximate load Nf
J: To be accurate, angle θ,.

Since the interval of θ2 is very consultative, it is not necessary to store a large number of numerical values in the moment limit control.

Therefore, the present invention improves the previously proposed device and provides accurate and safe rated load display or overload prevention for any combination of boom and arm ground angle in an articulated crane having a multi-stage arm. The purpose is to obtain a device.

In order to achieve this purpose, the invention provides a boom whose proximal end is rotatably attached at all times, and an arm which is attached to the free end of the boom so that it can rotate near the proximal end. and a load suspension device rotatably attached to the free end of the boom, and an electrical angle detection device for measuring the ground angle # is attached to each of the boom and arm, and the load suspension device An electrical load detection device is installed to measure the load, and from the results of measuring the angle of the boom and arm to the ground, the working radius and allowable lifting limit are calculated to the power of the iris, that is, the safe rated load is calculated by q. (4-ki performance 3
1. In an overload prevention device 6 for an articulated crane, which has a device M and a comparison device that compares a value calculated by the ram and a lifting load 1 detected by the load detection device 1,
A storage device stores in advance the safe rated load p% 'tl for each ground angle of the boom and arm by adjusting the ground angles θ1 and θ2 at regular intervals, and stores these ground angles θ4 . It has a proportional calculation device that calculates the rated load for the intermediate angle of θ2 by a ratio 5.1 calculation from the most recent value of the rated load stored in the 1-unit storage device, and a comparison device that compares the angle, and further, if necessary, It is characterized by having a display that displays the lifting load, working radius, constant 4/6 load at that working radius, etc., as well as a warning and notification device for the rated load.

Hereinafter, the present invention will be explained based on the accompanying drawings 7 and 5 showing embodiments thereof.

The uninvented device is the previously proposed device shown in FIG.
The block diagram of its electric circuit is shown in FIG. Note that reference symbol 9 in FIG. j.

B, g, 10. // and /ll indicate the same elements as those in Figure 1, and other reference symbols indicate the following elements, respectively.

10. The angle of the boomco and arm 3 from the ground at regular intervals is 0. Working radius and rated load memory f! by combination of and θ2. - , 2/... A proportional calculation device 6 that calculates the rated load N by proportional calculation from the latest value of the rated load 22... A comparison device that compares the proportional meter n value with the actual crimp load.

The inventive device is constructed as described above and its general operation is similar to the previously proposed device shown in FIGS. 3-5, except that: In the previously proposed device α, the ground angles θ and θ2 of the boomco and arm 3 are only calculated by combining them at regular intervals, for example, at each loo (see Figure S). Safe load ratings for intermediate angles ``The weight had to depend on the safe load ratings corresponding to the ground angles at regular intervals immediately adjacent to those intermediate angles.
In the present invention, the safe rated loads for the respective ground angles 01 and 02 of the boom co and arm 3 are determined in advance at certain intervals, for example, at angles θ for each loo.
(see Figure 5), store the results in the rated load storage device 2o, and set the boom λ.
and the ground angle θ of the arm 3 other than the ground angle θ and θ stored in advance in these rated load storage devices. and (or n θ2゜ (see below and Figure 3)
Take these angles θ. , 020 f: When detected by boom angle detector q and arm angle detector S,
Proportional calculator, 2/ is these angles to the ground, θ. , θ2o
Based on these angles 0. . , the ground angle θ4. which is closest to θ2o. Rated load storage device for θ2, 20
These ground angles θ, by proportional calculation from the rated load stored in. ,θ,. The safe rated load N is calculated, and this calculated value is compared with the fruitful load Mr, w' detected by the load detector B by the comparing device 22, and the fruitful load W'' is displayed as the load? li'Y / /, and if it attempts to exceed or exceeds the safe rated load W, the alarm shall notify the crane operator of this fact. This is what I did.

Now, here, the rated load storage device 2o and the proportional meter 9 device 2
The process of proportional calculation according to No. 1 will be explained based on FIG. 3 as follows.

That is, the ground angle θ+a l of the boom 2 and arm 3 is stored in advance in the rated load storage device 20 at regular intervals.
Safety force rated load W, , W7. due to the combination of θ, b and θ2a lθ2b. When W and w4 are stored, the current ground angle of Boomco and Arm 3 is θ. and θ2°, the safe rated load WR of 2 at this time can be calculated by proportional meter 3=1 from these predetermined values as follows. That is, it should be noted that the rated 4I heavy storage 20 and proportional calculation device, 2/, etc. required for such an instrument can be easily constructed by any known 1L child circuit. .

As described above, the present invention is similar to the previously proposed device crane, and is applicable to e=I articulated cranes having multi-stage bending arms, for example, when a hydraulic excavator is used as a crane. An angle detector is attached to each of the boom and arm to detect the angle relative to the ground, and a moment limit controller is used to calculate the rated load and working radius.Furthermore, a load detector attached to the end of the arm detects the comb load sound.
These rated loads are compared with the comb load, and if the latter attempts to exceed or exceeds the former, a warning or traversal warning can be issued, and the comb load and work The radius, rated load, etc. can be displayed on the display, so the operation name has the effect of allowing you to drive safely with peace of mind. Because it can be rated,
The present invention provides an overload prevention device that is most suitable for applications requiring such a thing.

[Brief explanation of the drawing]

Figure 1 shows lI'! , Fig. 2 is an explanatory diagram of an overturning moment in a crane having a boom of -, Fig. 2 is an explanatory diagram of an overturning moment in an articulated crane having a multi-stage arm, and Fig. 3 is an illustration of an overturning moment in an articulated crane having a multi-stage arm. FIG. 1 is a block diagram of the previously proposed equipment u', t, and FIG. S is a front view of the hydraulic excavator proposed above. A line diagram showing an example of the relationship between θ and the rated load. Figure 6 is an explanatory diagram of how the weight of the boom and arm affects the overturning moment. Figure 7 is a block diagram of the uninvented device. Figure 3 is an explanatory diagram of the proportional calculation of the rated load using the rated load storage device and the proportional calculation device in the unexploded interlock (6). &...
Boom and arm angle detector; 6. Load detector; 7.
・Hook; 10... Terminal board; //... Display; L da...
2o... Storage device; 21... Proportional calculation device; Here... Comparison device. Bamboo
IL-111, Figure 1

Claims (1)

[Claims] l A boom whose base end is rotatably attached to the main body;
It consists of an arm that is rotatably attached to the free end of the boom near the base end, and a load suspension device that is rotatably attached to the free end of the arm, and the boom and arm each have a ground angle. An electrical angle detection device is attached to the load suspension device, and an electrical load detection device is attached to the load suspension device to measure the lifted load.Furthermore, the working radius and An electrical calculation device that calculates a safe rated comb lifting load,
In an overload prevention device for an articulated crane, which has a comparison device that compares this load calculation value with the load detection result of the load detection device, the working radius and safety for each ground rotation angle of the boom and arm are determined in advance. A storage device that stores the rated load for the combination of angles θ and θ at regular intervals, and
A proportional calculation device that calculates the rated load for the intermediate angle of 2 by proportional calculation from the most recent value of the rated load stored in a storage device, and a comparison device that compares the calculated value by the proportional calculation device with the actual crimp load by the load suspension device. An overload prevention device for an articulated crane, comprising: (e) The overload prevention device according to claim 1, which has a display that displays the working radius, rated load, etc. in addition to the actual load caused by the load suspension device. 3. The overload prevention device according to claim 1 or 2, which has an alarm for giving notice and warning of exceeding the rated load.