JPS61282294A - Boom lateral load limit signal generator for working machinewith boom - 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 (Industrial Application Field) The present invention is used for a working machine having a boom, such as a mobile crane or an aerial work vehicle, and is used to reduce the load that acts on the boom orthogonally to the up-and-down direction of the boom. In other words, it relates to a boom lateral load limit signal generator for a work machine having a boom that outputs a boom lateral load limit signal to warn or stop the movement of the work machine when the boom lateral load reaches its limit. .

(Prior Art) A work machine having a boom includes a base, a boom whose base end is pivotally connected to the base via a hoisting fulcrum pin and can be hoisted about the hoisting fulcrum pin, and a connection between the base and the boom. It is equipped with a boom hoisting drive device that is interposed between appropriate places and drives the boom to hoist it up and down. The load is suspended from the tip of the boom, or the load is set at the tip of the boom, and a worker rides on top of the boom, and the boom is raised and lowered to perform crane work or work at high places. A relatively large longitudinal load that tends to bend the boom along its undulation trajectory plane and a lateral load that tends to bend the boom in a direction perpendicular to its undulation trajectory plane act on the boom. That is, the longitudinal load is generated by the boom's own weight, the own weight component of the load carried at the tip of the boom, and the force generated in the direction of the boom locus due to the influence of wind acting on the boom. Forces generated in a direction perpendicular to the boom hoisting trajectory plane due to the influence of wind acting on the boom; Forces generated in a direction perpendicular to the boom hoisting trajectory plane due to swinging of the load carried at the tip of the boom; In the case of a boom, the boom is generated by the boom's own weight and a force generated in a direction perpendicular to the boom loft trajectory plane as a component of the load carried at the boom tip.

The limits of the above-mentioned longitudinal and lateral loads are determined based on the strength of the boom or the stability of the work equipment. It is necessary to work hard not to exceed a predetermined limit value.

Conventionally, various boom longitudinal load limit signal generators have been proposed and put into practical use, which output an alarm or a signal to stop the work equipment when the longitudinal load acting on the boom reaches its limit value. However, there is an accurate boom lateral load limit signal generator that outputs an alarm or a signal to stop the movement of the work equipment when the lateral load acting on the boom reaches its limit value. Shinakatsu friend.

A conventional boom lateral load limit signal generator is disclosed in Japanese Patent Laid-Open No. 58-135095, which outputs an alarm or a signal to stop the work equipment when the lateral load acting on the boom reaches a predetermined limit value. Although the basic structure of such a boom lateral load limit signal generating device is shown, there is no proposal as to what the predetermined limit value of the lateral load should be. However, JP-A-58-1
The basic configuration of the boom lateral load limit signal generating device am disclosed in US Pat. By collecting the techniques of (2), it is easy to imagine that it would be a good idea to change the limit value of the lateral load according to the boom's heave angle.

(Problems with the prior art) However, it is not possible to obtain an accurate lateral load limit value for the reasons described below, and it is difficult to obtain an accurate boom lateral load limit signal generator ft-. It has the disadvantage of not being possible.

In other words, as mentioned above, relatively large longitudinal loads and lateral loads act on the boom of work equipment having a boom, but the lateral loads necessary to destroy the boom are the ones that act on the boom. It varies depending on the magnitude of the longitudinal load being applied. This means that when the boom is subjected to a longitudinal load close to the longitudinal load limit, the boom will fail with an extremely small lateral load, and that the boom will be subject to almost no longitudinal load. It will be appreciated that when not, the boom withstands large lateral loads. In addition, the force that tends to cause the work equipment to fall laterally due to the boom lateral load on a working machine with a boom increases when the boom is upright, so the limit value of the lateral load is: It also varies depending on the magnitude of the undulation angle of the boom. In this way, the limit value of the lateral load acting on the boom varies not only depending on the boom heave angle, but also depending on the magnitude of the longitudinal load acting on the boom.

Therefore, in the boom lateral load limit signal generating device as described above, which is obtained by simply varying the lateral load limit value as a function of the luffing angle of the boom, it is difficult to accurately generate the boom lateral load limit signal. It is not possible to utter it.

(Problems to be Solved by the Present Invention) The present invention improves the above-mentioned drawbacks of the conventional boom lateral load limit signal generator, that is, it is inaccurate, and provides accurate boom lateral load limit signal generation devices. The present invention attempts to provide a signal generator.

(Next Means for Solving the Problem) The boom lateral load limit signal generator for a working machine having a boom according to the present invention detects the lateral load limit with which the actual value of the lateral load acting on the boom is to be compared. The system is characterized in that the value is determined as a function of the boom undulation angle and the actual value of the longitudinal load acting on the boom, and specifically, it is constructed as follows. That is, a base, a boom whose base end is pivotally connected to the base via a hoisting fulcrum pin and can be hoisted about the hoisting fulcrum pin;
and a boom lateral load limit signal of a mobile crane or a working machine having a boom, such as an aerial work vehicle, which is equipped with a tilt device that is interposed between the base and the boom at a suitable location to drive the boom up and down. A generator, which is a heave angle detector that detects the actual value of the heave angle of the boom; and a longitudinal load detector that detects the actual value of the load acting on the boom, which is a longitudinal load that acts in the heave direction of the boom. , a lateral load detector for detecting the actual value of a lateral load acting on the boom perpendicular to the boom's heave direction; and Based on each actual value signal, the limit value of the lateral load at the actual boom heave angle and the actual longitudinal load is determined, and this limit value of the lateral load is compared with the actual value measured from the lateral load detector. , an arithmetic processing unit that outputs a companion boom lateral load limit signal that causes an alarm or stops the work equipment when the latter value reaches the former ′ value.

It is characterized by being composed of the following.

(Function) The boom lateral load limit signal generating device for a working machine having a boom according to the present invention having the above configuration is configured to detect the lateral load limit with which the lateral load acting on the boom is compared, the boom heave angle, and the boom lateral load limit signal generator. By obtaining the limit value as a function of the longitudinal load acting on the boom, it is possible to accurately obtain the limit value of the lateral load that fluctuates with changes in the boom heave angle and the longitudinal load, and as a result, the limit value of the boom lateral load can be obtained with high accuracy. It is possible to generate signals with high precision.

(Example) The present invention will be described below with reference to the drawings regarding an example in which the present invention is implemented in a boom lateral load limit signal generator for a truck crane.

FIG. 1 shows a truck crane as a working machine having a boom. In FIG. 1, reference numeral 1 denotes a base mounted on a vehicle V so as to be rotatable. 2f'i, the proximal end is connected to the base l via the erecting fulcrum pin 3, and the boom is pivoted. Reference numeral 4 denotes a sophisticated boom hoisting drive device that is interposed between the base 1 and the boom 3 at a proper location and drives the boom 3 to hoist it up and down. 5 is a heave angle detector located at the ninth heave fulcrum V of the boom 2 for detecting the actual value of the heave angle of the boom 2. 6 is a longitudinal load detector for detecting the actual value of the longitudinal load acting on the boom 2, particularly in the up-and-down direction of the boom 2. In the case of this embodiment, the vertical load detector 6 is constructed of a load cell inserted into the piston rod of a hydraulic cylinder that extends over the boom hoisting drive length. It may be configured with a pressure-electrical converter that converts the hydraulic pressure in the boom moment carrying side oil chamber of the hydraulic cylinder that is the drive device m14 into an electric signal, or it can be configured with strain gauges attached to the upper and lower walls of the boom 2. Furthermore, this vertical load detector 6 may be constructed of a boom hoisting drive device like a mechanical crane, or a guy rope stretched between the tip of the boom and the base, and a winch that operates the guy rope. In some cases, it may consist of a load cell that measures the tension of the guy rope.7
is a companion lateral load detector that detects the actual value of the lateral load acting perpendicularly to the up-and-down direction of the boom 2 among the loads acting on the boom 2. The lateral load detector 7 includes strain gauges attached to both the left and right sides of the boom 2, and calculates the lateral load acting on the boom 2 by calculating the difference in output between the left and right strain gauges. I'm trying to detect it.

The heave angle detector 5, longitudinal load detector 6, and lateral load detector 7 are part of a boom lateral load limit signal generating device for a working machine having a boom according to the present invention, which will be explained based on FIG. It is what constitutes wo.

As shown in FIG. 2, the boom lateral load limit signal generating device for a working machine having a boom according to the present invention includes the boom heave angle detector 5, the longitudinal load detector 6, the lateral load detector 7, and an arithmetic processing section 8. Based on the actual value signals from the heave angle detector 5 and the longitudinal load detector 6, the arithmetic processing unit 8 calculates the allowable lateral load on the boom 2 under the actual boom heave angle and the longitudinal load. The limit lateral load output unit 9 calculates the limit value, and the limit value of the lateral load generated by the limit lateral load output unit 9 is compared with the actual value of the lateral load detector 7, and the latter value is determined. The truck crane is equipped with a comparator unit 10 which outputs an alarm or a boom lateral load limit signal to stop the movement of the truck crane when the former value is reached.

Regarding the calculation method of the limit value of the lateral load in the limit lateral load output section 9, some examples are given below.

(1) As shown in FIG. 3, the limit lateral load output section 9 is provided with a memory 11 that stores the limit value of the lateral load corresponding to the actual value of each longitudinal load for each boom lifting angle. Then, the corresponding limit value of the lateral load is read out from the memory 11 using the actual value signals from the heave angle detector 5 and the longitudinal load detector 6 as index signals.

(2) As shown in Fig. 4, the limit value of the lateral load when no longitudinal load is acting on the boom 2 is set in the limit lateral load output section 9 (hereinafter this is referred to as the limit value without considering the longitudinal load). A memo IJ-12k is provided to store the limit value of the lateral load for each boom lifting angle, and the actual boom lifting angle is stored in the memory 12 using the actual value signal from the lifting angle detector 5 as an index signal. The limit value corresponding to (the limit value of the lateral load when the longitudinal load is not considered) is read out, and the read limit value is converted into the actual value signal from the longitudinal load detector 6 by the arithmetic circuit 13. Based on this, when the vertical load acting on the boom 2 is large, it is reduced, and the result is taken as the limit value of the lateral load.

(8) As shown in FIG. 5, the limit lateral load output unit 9 is provided with a memory 14 that stores the limit value of the longitudinal load for each boom heave angle, and Using the actual value signal as an index signal, Memo IJ-
14, read out the limit value of the longitudinal load corresponding to the actual boom heave angle, and calculate the limit value of the longitudinal load that has been read out and the vertical and horizontal strength ratio of the boom 2 (this is unique to the boom 2 and is a constant). ), the arithmetic circuit 15 calculates the limit value of the lateral load without considering the longitudinal load, and the arithmetic circuit 16 calculates the limit value of the lateral load when the longitudinal load is not considered. When the lateral load acting on the boom 2 is large, it is reduced based on the actual value signal from 6, and the result is taken as the limit value of the lateral load.

The limit lateral load output section 9 in the arithmetic processing section 8 is capable of determining the limit value of the lateral load at the actual boom heave angle and the actual lateral load based on various methods as described above. be.

In the above embodiment, the arithmetic processing section 8 is explained to be composed of a limit lateral load output section 9 and a comparison arithmetic section 10, and it is as if these are individually present in the arithmetic processing section 8. As described above, the arithmetic processing section 8 may be configured with a microcomputer that sequentially and periodically performs the arithmetic processing of the above-mentioned limit lateral load output section 9 and the arithmetic processing of the comparison arithmetic section 10. , the limit lateral load output section 9 and the comparison calculation section 10 are mixedly present in this microcomputer. In short, based on the actual value signals from the arithmetic processing unit 8Vi, the heave angle detector 5, and the longitudinal load detector 6, find the limit value of the lateral load at the actual boom heave angle and the actual longitudinal load. , this lateral load limit value is compared with the actual value from the lateral load detector 7, and when the latter value reaches the former value, a boom lateral load limit signal is generated to issue an alarm or stop the movement of the implement. Anything that outputs or performs arithmetic processing is fine.

Next, the effect will be explained. In the arithmetic processing section 8, the limit lateral load to be compared with the actual measured value of the lateral load from the lateral load detector 7 (the output signal of the limit lateral load output section 9 in the above embodiment) is determined by the heave angle detector. 5 and the longitudinal load detector 6, that is, obtained as a function of the actual boom heave angle and the actual boom longitudinal load, these functional relationships are set appropriately. This makes it possible to extremely accurately obtain the limit value of the lateral load, which varies with the boom lifting angle and the magnitude of the longitudinal load acting on the boom. Therefore, the accurate lateral load obtained in this way and the lateral load detector 7
The boom lateral load detector compares the actual measured value signal from the When the lateral load on the boom 2 of the truck crane (truck crane) reaches its limit, an output is generated in exact proportion to this. The boom lateral load limit signal output from the arithmetic processing unit 8 is used as a signal to activate an alarm to alert the operator of the work equipment (truck crane) that the lateral load acting on the boom has reached its limit. It is used as a signal to notify or actuate the control device of the work equipment (truck crane) to stop the movement of the work equipment, and to stop the movement of the work equipment (truck crane) when the lateral load acting on the boom reaches its limit. It is something that makes you

Next, an example of the development of the boom lateral load limit signal generating device for a working machine having a boom according to the present invention will be described. In the above embodiment, the boom 2 of the 7 tl-rack crane was explained as a working machine and was explained as being not retractable at all, but as shown by the imaginary line in Fig. 1, the boom 2 is telescopic and its length , the limit value of the lateral load acting on the boom 2 varies as a function of the boom luffing angle and the longitudinal load acting on the boom, as well as as a function of the boom length. When implementing the present invention in such a work machine whose boom length fluctuates, a boom length detector 17 (indicated by a dashed line in FIGS. 1 to 5) is provided, and the boom length detected by this detector 17 is installed. The actual value signal is input to the arithmetic processing section 8, and in the arithmetic processing section 8, the undulation angle detector 5,
Based on the actual value signals from the longitudinal load detector 6 and the boom length detector 17, the limit values of the actual boom heave angle, the actual longitudinal load, and the lateral load at the actual boom length are determined. A companion boom lateral load that compares the limit value of the directional load with the actual value from the lateral load detector 7 and issues an alarm or stops the movement of the implement (truck crane) when the latter value reaches the former value. This is to output a limit signal. In this case, the calculation methods for calculating the limit values of the three types of lateral loads in the limit lateral load output section 9 described in the above embodiment with reference to FIGS. 3 to 5 are as follows.

(1) As shown in Fig. 3, the limit lateral load output unit 9 stores the limit value of the lateral load corresponding to the actual value for each boom lifting angle, each longitudinal load, and each boom length. The limit value of the corresponding lateral load is read out from the memory 11 using each actual value signal from the heave angle detector 5, longitudinal load detector 6 and boom length detector 17 as an index signal. Do it like this.

(2) As shown in Fig. 4, the limit lateral load output unit 9 has a memory that stores the limit value of the lateral load without considering the longitudinal load for each boom heave angle and each boom length. 12't, and using the actual value signals from the heave angle detector 5 and the boom length detector 17 as index signals, limit values (longitudinal load) corresponding to the actual boom heave angle and the actual boom length are stored in the memory 12. Read out the limit value of lateral load (without considering
This readout limit value is reduced by the arithmetic circuit 13 based on the actual value signal from the longitudinal load detector 6 when the longitudinal load is large, and the result is used as the limit value of the lateral load.

(81,! As shown in Figure 5, the limit lateral load output section 9
Inside, a memo IJ-14 is provided to store the limit value of the longitudinal load for each boom heave angle and for each boom length, and the actual value signals from the heave angle detector 5 and the boom length detector 17 are indexed. As a signal, read out the limit value of the vertical load corresponding to the actual boom heave angle and the actual boom length from memo IJ-14, and compare the read limit value of the vertical load with the vertical and horizontal strength ratio of boom 2 (this is boom 2
The calculation circuit 15 calculates the limit value of the lateral load when the longitudinal load is not considered.
Therefore, when the longitudinal load acting on the boom 2 is large, it is reduced based on the actual signal from the longitudinal load detector 6.
The result is taken as the limit value of the lateral load.

In the case of this developed example, the limit lateral load (output signal of the limit lateral load output section 9) to be compared with the actual value of the lateral load on the lateral portion of the lateral load detector 7 is undulating as in the above embodiment. Based on the actual value signals from the angle detector 5 and the longitudinal load detector 6, 'ii! In addition to being obtained as a function of the boom heave angle of M and the actual longitudinal load, the actual boom length from the boom length detector 17 (itiL (!) is obtained as a function of the actual boom length. This development example is
High-precision boom lateral load limit signal generator IF'i used for telescopic boom-type work equipment (truck cranes)
We can provide it.

The above embodiments and development examples are explained as examples in which the present invention is applied to a truck crane. Of course.

In addition, in the case of a work machine having a boom, there is generally a boom direction load limit signal generator, that is, a boom operating condition (boom hoisting angle, if the boom is a telescoping boom, boom hoisting angle and boom length). Limit of longitudinal load for each t
＠ is stored in the memory, and from this memory, the limit value of the longitudinal load corresponding to the actual boom operating state is read out using the actual value signals from the boom heave angle detector and the boom length detector as index signals. This is compared with the actual value signal from the longitudinal load detector, and the boom longitudinal load limit signal is equipped with a boom longitudinal load limit signal generator. The boom angle detector, longitudinal load detector, boom length detector, and boom longitudinal load limit signal in the directional load limit signal generation v7crIt are used in implementing the boom lateral load limit signal generation device of the present invention. Of course it's true.

(Effects) The boom lateral load limit signal generating device for a work machine having a boom according to the present invention, which is constructed and operates as described above, detects a problem until the boom lateral load of a work machine having a boom reaches its limit.
It can be detected well and has a great effect on the safe operation of the work equipment.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a truck crane as a working machine having a boom, and FIGS. 2 to 5 are explanatory diagrams of a boom lateral self-confidence limit signal generating device for a working machine having a boom according to the present invention. Base; 1, Boom; 2, Hoisting fulcrum pin; 3, Hoisting drive device; 4, Hoisting angle detector; 5, Vertical load detector; 6, Lateral load detector; 7, Arithmetic processing unit; 8, Atsushi 1gA v number 21!1 Figure 5

Claims (1)

[Scope of Claims] A base; a boom whose base end is pivotally connected to the base via a hoisting fulcrum pin and can be hoisted about the hoisting fulcrum pin;
and a boom lateral load limit signal generator for a work machine having a boom, such as a mobile crane or an aerial work vehicle, which is interposed between the base and the boom at a suitable location and is equipped with a boom hoisting drive device for hoisting the boom. A heave angle detector for detecting the actual value of the heave angle of the boom; a longitudinal load detector for detecting the actual value of a longitudinal load acting on the boom in the boom's heave direction; a lateral load detector for detecting the actual value of a lateral load acting perpendicular to the heave direction of the boom, and respective actual values from said heave angle detector and said longitudinal load detector; Based on the signal, determine the lateral load limit value at the actual boom heave angle and the actual longitudinal load, compare this lateral load limit value with the actual value from the lateral load detector, and determine the latter. An arithmetic processing unit that outputs a boom lateral load limit signal to warn or stop the work equipment when the value reaches the former value. A boom lateral load limit signal generating device for a working machine having a boom, characterized in that it is comprised of: