JPH0550437B2 - - Google Patents

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. That is, the present invention relates to a boom lateral load limit signal generating device for a working machine having a boom that outputs a boom lateral load limit signal for warning or stopping the movement of the working 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. A load is suspended from the tip of the boom, or a worker rides on a bucket installed at the tip of the boom, and then 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 are applied to the boom. That is, the longitudinal load is generated by the boom's own weight, the dead weight component of the load carried at the tip of the boom, and the force generated in the direction of the boom's locus of the boom due to the influence of wind acting on the boom.
The lateral load is a force generated in a direction perpendicular to the boom hoisting trajectory plane due to the influence of wind acting on the boom, a force generated in a direction perpendicular to the boom hoisting trajectory plane due to swinging of the load carried at the tip of the boom, If the base is tilted laterally, this is caused by the boom's own weight and a force generated in a direction perpendicular to the boom locus plane as a component of the load carried at the tip of the boom.

And the above longitudinal load and lateral load are:
The limit values are determined based on the strength of the boom or the stability of the work equipment, so care must be taken to ensure that the vertical and lateral loads acting on the boom do not exceed the specified limit values at all times when working with the work equipment. be.

Conventionally, various boom vertical load limit signal generators have been proposed and put into practical use, which output an alarm or a signal to stop the movement of the work equipment when the vertical load acting on the boom reaches its limit value. However, there is no 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. Nakatsuta.

A conventional boom lateral load limit signal generator is disclosed in Japanese Patent Application 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, the basic configuration of the boom lateral load limit signal generator disclosed in Japanese Patent Application Laid-Open No. 58-135095, as well as the conventionally known boom longitudinal load limit signal generator (which detects the limit value of the vertical load) It is possible to easily imagine that the limit value of the lateral load can be made to vary according to the angle of the boom. .

(Problems with the prior art) However, this has the disadvantage that it is not possible to obtain an accurate lateral load limit value for the reasons shown below, and therefore it is not possible to obtain an accurate boom lateral load limit signal generator. have.

In other words, as mentioned above, relatively large longitudinal and lateral loads act on the boom of a working machine having a boom, but the lateral load necessary to destroy the boom does not act on the boom. It varies depending on the magnitude of the longitudinal load applied. This means that when the boom is subjected to a longitudinal load close to the longitudinal load limit, the boom will be destroyed by an extremely small lateral load;
It will be appreciated that when there is little longitudinal load acting on the boom, the boom will withstand large lateral loads. In addition, the force that tends to cause the work equipment to fall laterally due to the boom lateral load on work equipment with a boom increases as the boom is raised, so the limit value of the lateral load is , which also varies depending on the magnitude of the boom's undulation angle. 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 case of the boom lateral load limit signal generating device which is obtained by simply varying the lateral load limit value as a function of the boom heave angle as described above, the boom lateral load limit signal is It cannot be uttered accurately.

(Problems to be Solved by the Present Invention) The present invention improves the above-mentioned drawback 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.

(Means for Solving the Problems) The boom lateral load limit signal generating device for a working machine having a boom according to the present invention provides a lateral load limit signal generator with which the actual value of the lateral load acting on the boom is to be compared. is determined as a function of the actual value of the boom undulation angle and the longitudinal load acting on the boom. 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 which is interposed between the base and the boom at an appropriate position and which is able to hoist the boom. A boom lateral load limit signal generator for a working machine having a boom such as a mobile crane or an aerial work vehicle equipped with a boom hoisting drive device for driving the hoisting device for detecting the actual value of the boom hoisting angle. angle detector, a longitudinal load detector that detects the actual value of the longitudinal load acting on the boom in the direction of boom heave; a lateral load detector for detecting the actual value of the applied lateral load; and, based on the respective actual value signals from the heave angle detector and the longitudinal load detector, the actual boom heave angle and the actual longitudinal direction. The limit value of the lateral load at the load is determined, and this limit value of the lateral load is compared with the actual value measured from the lateral load detector, and when the latter value reaches the former value, an alarm is issued or the work equipment is stopped. A processing unit that outputs a boom lateral load limit signal to

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-mentioned configuration determines the limit value of the lateral load to which the lateral load acting on the boom is compared, based on the boom's heave angle and the boom lateral load limit signal generator. Since it was obtained 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 changes with the fluctuation of the boom heave angle and the longitudinal load, and as a result, it is possible to generate the boom lateral load limit signal with high accuracy.

(Example) The present invention will be described below with reference to the drawings with reference to an example in which the present invention is applied to 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. 2 is
It is a boom whose base end is pivotally connected to a base 1 via a fulcrum pin 3 and can be raised and lowered about the fulcrum pin. Reference numeral 4 denotes a 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. Reference numeral 5 denotes a luffing angle detector provided at the luffing fulcrum of the boom 2 in order to detect the actual value of the luffing 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, this longitudinal load detector 6 is constituted by a load cell inserted into the piston rod of a hydraulic cylinder that is the boom hoisting drive device 4; It may be configured with a pressure-to-electrical converter that converts the hydraulic pressure in the boom moment carrying side oil chamber of the four hydraulic cylinders into an electric signal, or it may be configured with strain gauges attached to the upper and lower walls of the boom 2. good. Furthermore, this vertical load detector 6
For mechanical cranes where the boom hoisting drive device consists of a guy rope stretched between the boom tip and the base and a winch that operates this guy rope, it consists of a load cell that measures the tension of the guy rope. can do. 7 is boom 2
This is a lateral load detector for detecting the actual value of the lateral load that acts perpendicularly to the up-and-down direction of the boom 2 among the loads that act 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 constitutes.

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 determines the limit of the lateral load allowed to the boom 2 under the actual boom heave angle and the longitudinal load. Limit lateral load output section 9 that calculates the value
Then, the limit value of the lateral load generated by the limit lateral load output section 9 is compared with the actual value measured by the lateral load detector 7, and when the latter value reaches the former value, an alarm is issued or the movement of the truck crane is stopped. and a comparison calculation unit 10 that outputs a boom lateral load limit signal for increasing the load.

Some examples of methods for calculating the limit value of the lateral load in the limit lateral load output section 9 are as follows.

(1) As shown in Figure 3, the limit lateral load output section 9
The inside is provided with a memory 11 for storing the limit value of the lateral load corresponding to the actual value of each longitudinal load for each boom hoisting angle. Each actual value signal is used as an index signal to read out the corresponding limit value of the lateral load from the memory 11.

(2) As shown in FIG. A memory 12 is provided for storing the limit value of the lateral load in each boom lifting angle, and the lifting angle detector 5
Using the actual value signal from as the index signal,
The limit value corresponding to the actual boom heave angle (the limit value of the lateral load when the longitudinal load is not taken into consideration) is read out from the memory 12, and the read limit value is used in the arithmetic circuit 13 to detect the vertical load detector. Based on the actual value signal from 6, the larger the vertical load acting on the boom 2 is, the more it is reduced, and the result is taken as the limit value of the lateral load.

(3) As shown in FIG. 5, the limit lateral load output unit 9 is provided with a memory 14 for storing the limit value of the longitudinal load for each boom hoisting angle, and Using the actual value signal as an index signal, the limit value of the longitudinal load corresponding to the actual boom heave angle is read out from the memory 14. ) is used in the arithmetic circuit 15 to find the limit value of the lateral load when the longitudinal load is not taken into account, and the limit value found here is used in the arithmetic circuit 16. Based on the actual value signal from the longitudinal load detector 6, the larger the lateral load acting on the boom 2, the more it is reduced, and the result is taken as the limit value of the lateral load.

Limit lateral load output section 9 in the calculation processing section 8
As mentioned above, it is possible to determine the limit value of the lateral load at the actual boom lifting angle and the actual lateral load based on various methods.

In the above embodiment, the arithmetic processing section 8 is explained as being constituted by the limit lateral load output section 9 and the comparison arithmetic section 10, which are the arithmetic processing section 8.
Although the calculation processing section 8 has been described as being separately present in the microcomputer, it is composed of a microcomputer that sequentially and periodically performs the calculation processing of the above-mentioned limit lateral load output section 9 and the calculation processing of the comparison calculation section 10. In that case, the limit lateral load output section 9 and the comparison calculation section 10 will exist in this microcomputer as a single unit. In short, the arithmetic processing unit 8 calculates the limit value of the lateral load at the actual boom heave angle and the actual longitudinal load based on the actual value signals from the heave angle detector 5 and the longitudinal load detector 6. 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 is set to issue an alarm or stop the movement of the implement. Any device that outputs a signal or performs arithmetic processing is sufficient.

Next, the effect will be explained. In the arithmetic processing section 8,
The limit lateral load (in the above embodiment, the output signal of the limit lateral load output section 9) with which the actual measured value of the lateral load from the lateral load detector 7 is compared is determined by the heave angle detector 5 and the longitudinal load detector. Based on each actual value signal from the device 6, that is, obtained as a function of the actual boom heave angle and the actual boom longitudinal load, by appropriately setting these functional relationships, the boom heave angle can be adjusted. In addition, the limit value of the lateral load, which varies with the magnitude of the longitudinal load acting on the boom, can be obtained very accurately. Therefore, the accurate lateral load obtained in this way is compared with the actual measured value signal from the lateral load detector 7, and when the latter value reaches the former value, an alarm or work equipment ( In this case, the boom lateral load limit signal that stops the movement of the truck crane is the boom 2 of the work equipment (truck crane).
When the lateral load of the vehicle reaches its limit, the output is output exactly in accordance with this. The boom lateral load limit signal output from the processing unit 8 is used as a signal to activate an alarm to notify the operator of the work equipment (truck crane) that the lateral load acting on the boom has reached its limit. When the lateral load acting on the boom reaches the limit, the movement of the work equipment (truck crane) is stopped by using it as a signal to notify or actuate the control device of the work equipment (truck crane) to stop the movement of the work equipment. 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 truck crane described as a working machine was explained as being non-extendable, but as shown by the imaginary line in Fig. 1, the boom 2 is retractable and its length is variable. In this case, 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 the boom length detector 17 is The actual value signal is input to the arithmetic processing unit 8, and the arithmetic processing unit 8 calculates the actual boom heave based on the actual value signals from the heave angle detector 5, longitudinal load detector 6, and boom length detector 17. Find the limit value of the lateral load at the angle, the actual longitudinal load and the actual boom length, compare this lateral load limit value with the actual value from the lateral load detector 7, and compare the latter value with the former. When this value is reached, an alarm or a boom lateral load limit signal is output to stop the movement of the work equipment (truck crane). In this case, the method for calculating the limit values of the three types of lateral loads in the limit lateral load output section 9 explained based on FIGS. 3 to 5 in the above embodiment is as follows:
They are as follows.

(1) As shown in Figure 3, the limit lateral load output section 9
The inside is provided with a memory 11 for storing the limit value of the lateral load corresponding to the actual value for each boom hoisting angle, for each longitudinal load, and for each boom length. The respective actual value signals from the detector 6 and the boom length detector 17 are used as index signals to read out the corresponding limit value of the lateral load from the memory 11.

(2) As shown in Fig. 4, the limit lateral load output section 9 has a memory that stores the limit value of lateral load without considering longitudinal load for each boom heave angle and each boom length. 12, a luffing angle detector 5 and a boom length detector 1.
Using the actual value signal from 7 as an index signal, the limit value corresponding to the actual boom heave angle and the actual boom length (the limit value of the lateral load when the longitudinal load is not considered) is read out from the memory 12. The calculated limit value is reduced by the arithmetic circuit 13 based on the actual value signal from the longitudinal load detector 6 as the longitudinal load increases, and the result is taken as the limit value of the lateral load.

(3) As shown in Fig. 5, in the limit lateral load output section 9, there is a memory 1 that stores the limit value of the longitudinal load for each boom hoisting angle and for each boom length.
4, and using the actual value signals from the heave angle detector 5 and the boom length detector 17 as index signals, the limit value of the longitudinal load corresponding to the actual boom heave angle and the actual boom length is stored from the memory 14. The arithmetic circuit 15 uses the read limit value of the vertical load and the vertical/horizontal strength ratio of the boom 2 (this is a constant and is unique to the boom 2) to determine the case where the vertical load is not considered. Find the limit value of the lateral load at
The limit value obtained here is reduced as the longitudinal load acting on the boom 2 is larger based on the actual signal from the longitudinal load detector 6 using the arithmetic circuit 16, and the result is used as the limit value of the lateral load. shall be.

In the case of this development, the limit lateral load (output signal of the limit lateral load output 9) with which the actual value of the lateral load detected by the lateral load detector 7 is to be compared
is obtained as a function of the actual boom heave angle and the actual longitudinal load based on the actual value signals from the heave angle detector 5 and the longitudinal load detector 6 as in the above embodiment. as a function of the actual boom length. Therefore, this developed example can provide a highly accurate boom lateral load limit signal generating device for use in a telescopic boom type work machine (truck crane).

Although the above embodiments and developed examples have been explained as examples in which the present invention is applied to a truck crane, the present invention can also be adopted to a stationary crane, an aerial work vehicle, a stationary aerial work machine, etc. Of course.

In addition, in the case of a work machine having a boom, generally a boom longitudinal load limit signal generator, that is,
The vertical load limit value for each boom operating condition (boom hoisting angle, boom hoisting angle and boom length if the boom is a telescopic boom) is stored in memory, and from this memory, the boom hoisting angle detector Then, the actual value signal from the boom length detector is used as an index signal to read out the limit value of the longitudinal load corresponding to the actual boom operating state, and this is compared with the actual value signal from the longitudinal load detector, and the comparison is made. A boom longitudinal load limit signal generator configured to obtain a boom longitudinal load limit signal according to the result is equipped, and the boom angle detector, longitudinal load detector, and boom length in this longitudinal load limit signal generator are Of course, the detector and the boom longitudinal load limit signal can be used in implementing the boom lateral load limit signal generating device of the present invention.

(Effects) The boom lateral load limit signal generating device for a working machine having a boom according to the present invention, which is configured and operated as described above, can accurately detect that the boom lateral load of a working machine having a boom has reached its limit. This has a great effect on the safe operation of work equipment.

[Brief explanation of drawings]

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 negative limit signal generating device for a working machine having a boom according to the present invention. Base; 1. Boom; 2; Lifting fulcrum pin; 3; Lifting drive device; 4; Lifting angle detector; 5; Vertical load detector; 6; Lateral load detector; 7; Arithmetic processing unit; 8.

Claims (1)

[Scope of Claims] 1. 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 interposed between the base and the boom at an appropriate position. A boom lateral load limit signal generator for a working machine having a boom, such as a mobile crane or an aerial work vehicle, which is equipped with a boom hoisting drive device for hoisting and driving the boom, and which detects the actual hoisting angle of the boom. A vertical load detector that detects the actual value of the vertical load that acts on the boom in the direction of the boom. A vertical load detector that detects the actual value of the load that acts on the boom in the direction of the boom. a lateral load detector for detecting the actual value of a lateral load acting orthogonally to the boom; The limit value of the lateral load under 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, and when the latter value reaches the former value, an alarm is issued. A calculation processing unit that outputs a boom lateral load limit signal to stop the work equipment. A boom lateral load limit signal generating device for a working machine having a boom, characterized in that it is comprised of: