JPH05278993A - Slewing motion braking start signal generator for moving type crane - Google Patents

Abstract

PURPOSE:To simplify an operation circuit by outputting a threshold value corresponding to a slewing position advanced by a necessary control angle in the slewing stand slewing direction to a present slewing position, and outputting a slewing motion braking start signal when an actual value by means of a load detector reaches the threshold value. CONSTITUTION:Respective detecting means 4-7 are provided to detect a boom posture to a slewing stand of a moving type crane, a slewing angle of the slewing stand, the slewing direction and a load acted on a boom, and these detected signals are inputted to an operation part 8. According to the boom posture and the slewing angle, a threshold position of a load capble of acting on a boom is outputted from a threshold value output means 8a, and this threshold value and the detected load (actual value) are compared with each other by means of a comparing means 8b, and when the actual value reaches the threshold value, a slewing motion braking start signal is outputted. At this time, a signal of a braking angle necessary from a braking start of slewing motion to a stoppage is outputted from an output means 8c, and an advance signal obtained by a calculating means 8d according to the output is used as a read signal of the threshold value output signal 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing braking start signal generator for a mobile crane.

[0002]

2. Description of the Related Art As shown in FIG. 2, a mobile crane comprises a swivel base 2 mounted on a vehicle 1 so as to be swivel-driving, and a boom 3 mounted on the swivel base 2 so that its posture can be changed.
It is configured to lift a load from the tip of the boom 3. In this type of mobile crane, the limit value of the load acting on the boom 3 changes as a function of the swivel position of the swivel base 2 and the attitude of the boom. In addition to automatically stopping the attitude changing operation of the boom 2, it is necessary to automatically stop the swing motion of the swivel base 2.

By the way, when the turning motion of the swivel base 2 is automatically stopped in the working limit state of the mobile crane,
If the mobile crane is suddenly stopped at the limit turning position where the swing operation causes the limit work state, not only the suspended load suspended from the tip of the boom 3 swings greatly but also the inertia moment of the boom 3 and the suspended load Since an excessive lateral force may be applied to the boom 3 due to the runout and the boom 3 may be damaged, a required braking angle is set before the limit turning position to eliminate the fear, and the actual turning position is set to this required position. When the braking angle is reached, it is necessary to operate the swing braking means for hydraulically braking the swing drive hydraulic motor of the swivel base 3.

According to the present invention, a swing braking start signal generator for a mobile crane that outputs a braking start signal to a swing braking means when the swing position of the swivel base 2 reaches a required braking angle set before the limit swing position. It is about.

Therefore, Japanese Patent Laid-Open No. 3-177299 discloses the following type of turning braking start signal generating device of this type. Working radius detection means for detecting the working radius of the boom, turning angle detection means for detecting the turning position (turning angle), and limit work area setting for setting the limit work area of the boom according to the suspension load and the stability of the vehicle Means, a remaining angle calculation means for calculating a remaining angle at which the vehicle can turn until it exceeds the set limit work area, a required braking angle calculation means for calculating a required braking angle, the calculated required braking angle and the remaining angle. Comparing means for comparing the above, and a swing braking start signal generating device for a mobile crane configured to output a swing braking start signal when the remaining angle reaches a required braking angle.

That is, in the device disclosed in Japanese Patent Laid-Open No. 3-177299, the limit turning position at which the mobile crane is brought to the limit working state by the turning motion is defined as the limit working area set as a function of the suspension load and the stability of the vehicle. Calculated from the actual working radius of the boom. Find the remaining angle until the actual turning angle reaches this limit turning position. When the remaining angle reaches the required braking angle, a turning braking stop signal is output. The turning braking start signal is obtained through the calculation process.

[0007]

[Patent Document 1] Japanese Patent Application Laid-Open No. 3-17729
In the device of Japanese Patent Publication No. 9, the turning braking start signal is obtained through the above calculation processes (1) to (4). In this calculation process, the limit work area which is a function of the suspension load and the stability of the vehicle is set. There is a problem that the calculation for obtaining the limit turning position becomes complicated due to the complexity of setting and the relationship between the limit work area and the actual work radius. The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a turning braking start signal generator capable of obtaining a turning braking start signal based on a simple configuration and calculation.

[0008]

In order to achieve the above object, the swing braking start signal generator for a mobile crane according to the present invention is constructed as follows. A mobile crane having a swivel base 2 mounted on a vehicle 1 so as to be swivel-driving, and a boom 3 attached to the swivel base 2 so that its posture can be changed, and configured to lift a load from the tip of the boom 3. In particular, the limit value of the load that can be applied to the boom 3 changes as a function of the swing position of the swivel base 2 and the attitude of the boom 3, and is a swing braking start signal generator for a mobile crane. Boom posture detecting means for detecting the posture of the boom 3, swing angle detecting means for detecting the swing angle of the swivel base 2, swing direction detecting means for detecting the swing direction of the swivel base 2, and load for detecting the load acting on the boom 3. Detection means,
The calculation unit receives a detection signal from each of the detection means and calculates a braking start position of the swing motion of the swivel base 2, and the arithmetic unit reads information about the attitude of the boom 3 and the swing angle of the swivel base 2. Limit value output means for outputting a limit value of a load that can act on the boom 3 at a boom posture and a turning angle corresponding to the read signal, and a limit value from the limit value output means and the load detection means. Comparing means for comparing the signal of the latter, when the value of the latter reaches the value of the former, a comparison means for outputting a turning braking start signal, a required braking angle signal output means for outputting a signal of a required braking angle required from the start of braking of the turning to the stop, The signals from the turning angle detecting means, the turning direction detecting means, and the required braking angle signal outputting means are received, and the position is set to the turning direction related to the detection of the turning direction detecting means with respect to the present turning angle. An advancing angle calculating means for calculating a turning angle advanced by the braking angle, and a detection signal of the boom posture detecting means and a calculation of the advancing angle calculating means as the read signal of the limit value output means. A swing braking start signal generator for a mobile crane, which is configured to use a signal.

[0009]

In the swing braking start signal generating device of the present invention constructed as described above, information relating to the posture of the boom 3 and the swing angle of the swivel base 2 is used as a read signal, and the boom posture and swing angle corresponding to the read signal are used. To the limit value output means for outputting the limit value of the load that can be applied to the boom 3, the information of the actual boom posture and the information obtained by adding the required braking angle to the actual turning angle are input as a read signal. Load detection means for reading a limit value (a limit value that can act on the boom 3) at a turning position advanced by a required braking angle in the turning direction from the actual turning position of the platform 2 and detecting a load acting on the boom 3. When the actual value from 1 reaches the read limit value, a turning braking start signal is output. Therefore, it is not necessary to set a limit working area which is a function of the suspension load and the stability of the vehicle and to determine a limit turning position unlike the conventional one.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a turning braking start signal generator according to the present invention. In FIG. 1, reference numeral 4 denotes a boom attitude detecting means for detecting the attitude of the boom with respect to the swivel base 2. The boom posture detecting means 4 detects the hoisting angle of the boom 3 when the boom 3 is telescopic.
And a boom length detector 4b for detecting the length of the boom 3. Reference numeral 5 is a turning angle detecting means for detecting a turning angle of the turntable 2. Reference numeral 6 denotes a turning direction detecting means for detecting a turning direction of the turning base, and an operation lever (not shown) for operating a control device for controlling the drive of a turning drive hydraulic motor (not shown) of the turning base 2. It is composed of a detection switch for detecting the operation direction of (the right turning direction or the left turning direction). Reference numeral 7 is a load detecting means for detecting a load acting on the boom, and is a boom hoisting drive device (not shown).
It is composed of a detector that detects the load acting on. The boom hoisting drive device corresponds to a boom hoisting hydraulic cylinder in the case of a hydraulic crane, and the boom hoisting winch in the case of a mechanical crane having a lattice boom.

Reference numeral 8 is a calculation unit for receiving the detection signals from the detection means 4 to 7 and calculating the braking start position of the turning motion of the swivel base 2. This calculation unit is provided with the limit value output means 8
a, a comparison means 8b, a required braking angle signal output means 8c, and an advance angle calculation means 8d. The limit value output means 8a uses the boom posture and the swing angle corresponding to the read signal as information about the posture of the boom 3 (function of the boom hoisting angle and length) and the swing angle of the swivel base 2. It outputs the limit value of the load that can act on the boom. Further, the comparison means 8b is
A limit value output from the limit value output means 8a is compared with a signal from the load detection means 7, and when the latter value reaches the former value, a turning braking start signal is output. The required braking angle signal output means 8c outputs a signal related to the required braking angle required from the start to the stop of the turning motion of the swivel base 2. This required braking angle signal output means 8
c may be configured to always output a signal of a constant required braking angle, or may be configured as follows, for example. As a function of the turning speed of the swivel base 2 at the start of braking, the faster the turning speed is, the larger the signal of the required braking angle is output. In this case, an appropriate turning speed detecting means for detecting the turning speed of the turning base 2 is attached, and the signal of the required braking angle is output using the detection signal of the turning speed detecting means. Outputs the required braking angle as a function of the hanging distance of the suspended load and the swing speed at the start of swing braking, so that the swing of the suspended load does not remain when the swing motion stops. In this case, appropriate turning speed detecting means and hanging load hanging distance detecting means are provided, and the signal of the required braking angle is output using the detection signals of these both detecting means.

The advance angle calculating means 8d receives signals from the turning angle detecting means 5, the turning direction detecting means 6 and the required braking angle signal outputting means 8c, and receives the present turning angle (turning angle detecting means 5). (Corresponding to the output signal of the required braking angle signal output means 8c) in the turning direction according to the detection of the turning direction detection means 6).
This is the calculation of the turning angle advanced by only. To the limit value output means 8a, a detection signal of the boom posture detecting means 4 and a turning angle signal related to the calculation of the advance angle calculating means 8d are inputted as a read signal of the limit value.

The turning braking start signal output from the comparison means 8b is used as an output signal of the turning braking start signal generator according to the present invention and as a braking start signal of the turning braking means 9. The swing braking means 9 brakes the swing drive hydraulic motor so that the swing angle required from the start to the stop of braking becomes the required braking angle. Specifically, it is configured by a variable flow rate control valve provided in the drive hydraulic circuit of the swing drive hydraulic motor and a control signal generating section for outputting a control signal to the variable flow rate control valve. Various turning braking means are disclosed in Japanese Patent Application Laid-Open No. 4-7295 and are already known.

The swing braking start signal output device for a mobile crane according to the present invention having the above-described structure allows the required braking angle from the limit value output means 8a in the computing unit 8 in the swivel direction of the swivel base 2 with respect to the present swiveling position. The limit value (the limit value of the load that can act on the boom 3) corresponding to the turning position advanced by only is output, and the limit value related to this output and the actual value from the load detector 7 (the load value that acts on the boom 3 When the latter value reaches the former value, the turning braking start signal is output.

[0015]

As described above, the swing braking start signal generator for a mobile crane according to the present invention constructed and operated as described above sets a limit working area which is a function of suspension load and vehicle stability. This has an effect that it is not necessary and that it is not particularly necessary to calculate and calculate the limit turning position.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a swing braking start signal generator for a mobile crane according to the present invention.

FIG. 2 is an explanatory diagram of a mobile crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Vehicle, 2; Revolving base, 3; Boom, 4; Boom attitude detecting means, 4a; Boom hoisting angle detector, 4b; Boom length detector, 5; Turning angle detecting means, 6; Turning direction detecting means,
7: load detection means, 8: computing section, 8a; limit value output means, 8b; comparison means, 8c; required braking angle signal output means, 8d; advance angle calculation means, 9: turning braking means,

Claims (1)

[Claims] 1. A swivel base 2 mounted on a vehicle 1 so as to be swivel-driving, and a boom 3 mounted on the swivel base 2 so that the posture of the swivel base 2 can be changed, and a load is lifted from the tip of the boom 3. A mobile braking crane, in particular, a swing braking start signal generator used in a mobile crane in which a limit value of a load that can act on the boom 3 changes as a function of a swing position of the swivel base 2 and a posture of the boom 3. Boom position detecting means 4 for detecting the attitude of the boom 3 with respect to the swivel 2, swivel angle detecting means 5 for detecting the swivel angle of the swivel 2, swivel direction detecting means 6 for detecting the swivel direction of the swivel 2, boom 3 A load detection means 7 for detecting a load acting on the vehicle, and a calculation portion 8 for receiving a detection signal from each of the detection means 4 to 7 and calculating a braking start position of the swing motion of the swivel base 2. Is Limit value output means 8a that outputs, as a read signal, information about the posture of the boom 3 and the swing angle of the swivel base 2 and the limit value of the load that can act on the boom 3 at the boom posture and swing angle corresponding to the read signal. Comparing means 8b that compares the limit value from the limit value output means 8a with the signal from the load detecting means 7 and outputs a turning braking start signal when the latter value reaches the former value, The signals from the required braking angle signal output means 8c for outputting the required braking angle signal, the turning angle detection means 5, the turning direction detection means 6 and the required braking angle signal output means 8c are received and And a lead angle calculating means 8d for calculating a turning angle advanced by the required braking angle in the turning direction detected by the turning direction detecting means 6 with respect to the turning angle. As the readout signal of stage 8a, the detection signal of the boom attitude detection section 4, and the advance angle angle calculating means 8d
A swing braking start signal generation device for a mobile crane, characterized in that the calculation signal is used.