JP2000219489A - Safety device for mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device capable of warning or previously preventing crane work in the working form beyond the safety ensuring ability of a conventional safety device computing partial constitution to the conventional safety device computing critical load without adding a parameter related to whether or not to use a main hook and a sub-hook. SOLUTION: This safety device is provided with a main winch operation detecting means 14 for detecting the operation of a main winch operating means, a sub-winch operation detecting means 15 for detecting the operation of a sub- winch operating means, and an inappropriate work detecting means 16 receiving detection signals from the operation detecting means 14, 15 and a jib extension yes/no signal from a jib extension yes/no setting means 10 to monitor the inappropriately combined state of crane work using a main hook and a sub-hook and a jib extension state beyond the safety ensuring ability of a conventional safety device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a mobile crane having a detachable jib which is used by being added to the tip of a telescopic boom.

[0002]

2. Description of the Related Art As shown in FIG. 3, a mobile crane having a detachable jib which is used at the tip of a telescopic boom is mounted on a vehicle 1 having outriggers 1a, 1a,. A swivel 2, a telescopic boom 4 attached to the swivel 2 so as to be able to move up and down by an up-and-down drive means 3, a detachable jib 5 to be used by adding to a tip end of the telescopic boom 4,
A main winch 6 arranged on a swivel 2 for driving a main hook 6a suspended at the end of the telescopic boom 4 to lift and lower;
And a sub-winch 7a disposed on the swivel 2 for driving a sub-hook 7a suspended from the end of the jib 5 attached to the end of the telescopic boom 4 to raise and lower.

[0003] Such a mobile crane is provided with outriggers 1a, 1a,...
Turntable 2 without or with additional
For turning the telescopic boom 4, raising and lowering the telescopic boom 4, driving the main hook 6a suspended from the distal end of the telescopic boom 4 by the main winch 6, or driving the telescopic boom 4 to lower the telescopic boom 4; The crane operation is performed by driving the sub-hook 7a suspended at the tip of the sub-unit to lift and lower.

[0004] In order to ensure the safety of crane operation, this type of mobile crane is required to confirm that the load acting on the hoisting drive means 3 has reached a limit load at which the mobile crane may fall or break down. A safety device configured to detect and regulate operation of the mobile crane is installed.

As shown in FIG. 3, the conventional safety device includes an overhang state setting means 8 for setting the overhang state of the outriggers 1a, 1a,... It comprises detection means 11, limit signal output means 12, and crane operation restriction means 13.

The overhang state setting means 8 includes an outrigger 1
a, 1a... are set, and the actual overhang lengths of the outriggers 1a, 1a... are set artificially or overhang length detection means arranged at each outrigger 1a, 1a. (Not shown) to set automatically. The overhang state setting means 8 outputs an outrigger overhang state setting signal related to the setting.

The boom attitude detecting means 9 includes a turning angle detector 9a for detecting the actual turning angle of the swivel 2 and an undulating angle detector 9 for detecting the actual undulating angle of the telescopic boom 4.
b, and a length detector 9c for detecting the actual length of the telescopic boom 4, and these detectors 9a, 9b, 9c
Is used to detect the operating posture of the telescopic boom 4.
The boom posture detection means 9 outputs a boom posture detection signal relating to the detection.

The jib replenishment setting means 10 is for setting the resilience of the jib 5 to the end of the telescopic boom 4 and for determining the resilience of the jib 5, that is, the jib 5.
Is automatically or artificially or automatically set by a suitable detecting means (not shown). The jib replenishment setting means 10 outputs a jib replenishment setting signal relating to the setting.

The limit signal output means 12 includes an outrigger extension state setting signal from the extension state setting means 8, a boom attitude detection signal from the boom attitude detection means 9, and a jib extension setting state from the jib extension setting means 10. A signal and an actual load from the actual load value detecting means 11 are received, and a limit load as a limit value of a load that can be applied to the undulating drive means 3 is a function of an outrigger extension state, a boom posture, and a jib extension state. On the other hand, the actual load from the actual load value detecting means 11 is compared with the limit load according to the calculation, and when the former value reaches the latter value, a limit signal indicating a limit state of crane work is output. It is.

The crane operation restricting means 13 operates by receiving a limit signal from the limit signal output means 12 to restrict the operation of the crane. Specifically, the operation of changing the attitude of the telescopic boom 4 in a direction (dangerous side) in which the actual load acting on the undulating drive means 3 exceeds the limit load is restricted.

In the conventional safety device constructed as described above, the actual load acting on the undulating drive means 3 is reduced by the outrigger 1a,
1a, the overhang state, the boom posture (the operating angle of the telescopic boom 4 determined by the swivel angle of the swivel base 2, the undulation angle of the telescopic boom 4 and the length of the telescopic boom 4), and the jib 5 to the tip of the telescopic boom 4 When the limit load calculated using the presence or absence of the extension as a parameter is reached, the operation of changing the posture of the telescopic boom 4 to the dangerous side is automatically regulated to ensure the safety of the crane operation.

In the above-mentioned conventional safety device, the limit load calculated by the limit signal output means 12 to compare with the actual load is as follows for each extension state of the jib 5 to the tip of the telescopic boom 4. Have been prepared.

1) The limit load when the crane work is performed by driving the main hook 6a up and down by the main winch 6 in a state where the jib 5 is not added to the tip of the telescopic boom 4; Outrigger overhang state,
And a limit load calculated using the boom posture from the boom posture detection means 9 as a parameter.

2) The limit load when crane work is performed by driving the sub-hook 7a up and down by the sub-winch 7 with the jib 5 added to the end of the telescopic boom 4, and the outrigger from the overhang state setting means 8 Overhang state,
And a limit load calculated using the boom posture from the boom posture detection means 9 as a parameter.

[0015] From the two groups of limit loads prepared as described above, a corresponding limit load is selected and calculated based on a jib replenishment setting signal from the jib replenishment setting means.

[0016]

However, the mobile crane described above has a problem in that the actual load acting on the up-and-down driving means 3, the overhang state of the outriggers 1a, 1a,. (The operating posture of the telescopic boom 4 determined by the angle of the boom 4 and the length of the telescopic boom 4) and the limit load calculated by using the extension of the jib 5 at the tip of the telescopic boom 4 as a parameter. In the device, there are the following usage modes in which the safety of the crane operation cannot be ensured.

A) A main hook 6a suspended from the end of the telescopic boom 4 with the jib 5 added to the end of the telescopic boom 4.
A form of crane work.

B) The main hook 6 suspended from the end of the telescopic boom 4 with the jib 5 added to the end of the telescopic boom 4
a, and a crane operation using a sub hook 7a suspended at the tip of the jib 5.

When a mobile crane is used in such a usage form, the safety device described above may not be able to ensure the safety of the crane operation. In other words, in the mobile crane described above, the parameters for determining the limit load include the outriggers 1a, 1a,..., The posture of the telescopic boom 4, the presence or absence of the extension of the jib 5, and the addition of the main hook 6a. There is a presence / absence of use (whether the main winch 6 is used) and a use of the sub hook 7a (whether the sub winch 7 is used). In the conventional safety device, the use of the main hook 6a and the sub hook 7a is not available. The missing parameter is missing. However, it is not practical to calculate the limit load in consideration of the parameters related to the use of the main hook 6a and the sub hook 7a, because the calculation becomes complicated and the storage amount of data used for the calculation increases. .

According to the present invention, by adding a part of the configuration to the conventional safety device which does not calculate the limit load in consideration of the parameter relating to the use of the main hook 6a and the sub hook 7a, the safety of the conventional safety device is improved. An object of the present invention is to provide a safety device capable of preventing or issuing a warning of a crane operation in the above-mentioned use form that cannot be secured.

[0021]

The safety device for a mobile crane according to the present invention is different from the conventional safety device described above in that the main winch operation detecting means for detecting the operation of the operating means of the main winch 6 and the sub winch 7 are provided. The sub winch operation detecting means for detecting the operation of the operating means, and the detection signal from these operation detecting means and the jib replenishment setting signal from the jib replenishment setting means 10 are received, and the safety device cannot guarantee the safety. Non-conforming work detecting means for monitoring an improper combination state of the jib replenishment state and the crane operation by the main winch 6 or the sub winch 7; and when the non-conforming work detecting means detects the improper combination state, the crane operation restricting means is provided. 13 is configured to output an operation signal or an alarm signal for operating an alarm unit.

The safety device for a mobile crane according to the present invention having the above-described structure is used in the same manner as the above-mentioned mobile crane in which the conventional safety device cannot ensure safety. Then, the added nonconforming work detecting means detects this and activates the crane operation restricting means 13 or the alarm means. For this reason, the use form of the incompatible mobile crane can be automatically restricted, or can be prevented beforehand according to the intention of the alerted operator.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIG. The safety device of the present invention
As described above, a part of the configuration of the conventional safety device is added to the conventional safety device, and the description of the components of the conventional safety device shown in FIG. 3 is omitted. The following description is made only for the added components. Shall be explained.

In FIG. 1, part A is a conventional safety device, and part B is an embodiment according to the present invention in which part B is added. The added embodiment part B includes a main winch operation detecting means 14 for detecting operation of the operating means of the main winch 6, a sub winch operation detecting means 15 for detecting operation of the operating means of the sub winch 7, and these operation detecting means. 14,15
And the jib extension setting signal from the jib extension setting means 10 to receive the jib extension state and the main winch 6 where the safety device cannot guarantee the safety.
Or a non-conforming work detecting means 16 for monitoring a non-conforming combination state of the crane operation by the sub winch 7. If the nonconforming work detecting means 16 detects an improper combination state, an operation signal is output to the crane operation restricting means 13 or a warning means 17 is output.
To output an alarm signal.

The main winch operation detecting means 14 comprises a limit switch (not shown) for detecting the operation of an operation lever (not shown) for controlling the drive of the main winch 6. The sub winch operation detecting means 15 is provided with an operation lever (not shown) for controlling driving of the sub winch 7.
And a limit switch (not shown) for detecting the operation of.

The incompatible work detecting means 16 comprises a main winch operation detecting means 14 and a sub winch operation detecting means 1.
5 and the jib extension setting signal from the jib extension setting means 10, and the non-conforming operation state in which the safety of the crane operation cannot be ensured depending on the conventional safety device A, that is, for example, Boom 4
A crane operation with the main hook 6a suspended at the tip of the telescopic boom 4 with the jib 5 added to the tip, and "a tip of the telescopic boom 4 with the jib 5 added to the tip of the telescopic boom 4". Operating state to the crane operation restricting means 13 or the alarm means 17 and the like, and the operation signal is sent to the crane operation restricting means 13 or the alarm means 17. Output.

The nonconforming work monitored by the nonconforming work detecting means 16 is monitored based on the nonconforming work monitoring information stored in the nonconforming work detecting means 16 in advance. Whether to perform the work can be arbitrarily set for each mobile crane.

It is needless to say that the nonconforming work detecting means 16 may be provided inside the conventional safety device A.

[0029]

According to the safety device for a mobile crane according to the present invention having the above-described structure, the non-conforming work detecting means detects the use form of the mobile crane, which cannot be secured by the conventional safety device, and detects the use of the crane. Since the operation is regulated or alarmed, the non-conforming work of the mobile crane can be prevented automatically or in advance by the attention of the alerted operator.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a safety device for a mobile crane according to the present invention.

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

FIG. 3 is an explanatory view of a conventional safety device for a mobile crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Vehicle, 1a; Outrigger, 2; Swivel base, 3; Up-and-down drive means, 4; Telescopic boom, 5; Jib, 6;
6a; main hook, 7; sub winch, 7a; sub hook, 8; overhang state setting means, 9; boom posture detecting means,
9a: turning angle detector, 9b; undulation angle detector, 9c;
Length detector, 10; Jib extension setting means, 11;
Load actual value detection means, 12; limit signal output means, 13;
Crane operation restricting means, 14; main winch operation detecting means, 15; sub winch operation detecting means, 16; incompatible work detecting means, 17; alarm means,

Claims (1)

[Claims] 1. A swivel rotatably mounted on a vehicle provided with an outrigger, a telescopic boom mounted to the rotatable so as to be able to raise and lower by a raising and lowering drive means, a detachable jib which is used by being added to a tip end of the telescopic boom, A main winch for raising and lowering a main hook suspended at a distal end of the telescopic boom, and a sub winch for raising and lowering a subhook suspended at a distal end of a jib added to the distal end of the telescopic boom. A safety device for a mobile crane, comprising: an outrigger state setting means for setting an outrigger state of an outrigger; a swivel angle detector for detecting a swivel angle of the swivel base; and detecting an up / down angle of the telescopic boom. Boom posture detection means including an elevation angle detector and a length detector for detecting the length of the telescopic boom, and a jib extension setting means for setting the presence or absence of a jib extension Load actual value detection means for detecting an actual load as an actual value of the load acting on the undulation drive means; outrigger extension state setting signal from the extension state setting means; boom attitude detection signal from boom attitude detection means. Receiving the actual load from the actual load value detection means and the jib replenishment setting signal from the jib replenishment presence / absence setting means, and setting the limit load as the limit value of the load that can be applied to the undulation drive means to the outrigger extension state. While calculating as a function of the jib replenishment state and the actual boom attitude,
Limit signal output means for comparing the actual load from the actual load value detection means with the limit load according to the calculation, and outputting a limit signal indicating a limit state of crane operation when the former value reaches the latter value; and A crane operation restricting means for receiving the limit signal from the signal output means and operating to restrict the operation of the crane; and a safety device for a mobile crane, comprising: Means, a sub winch operation detecting means for detecting an operation of the operating means of the sub winch, and a detection signal from these operation detecting means and a jib extension setting signal from the jib extension setting means are received, and the safety device is secured. Monitoring of the jib replenishment condition and the improper combination condition of the crane operation by the main winch or sub-winch Non-conforming work detecting means, and when the non-conforming work detecting means detects the non-conforming combination state, an operation signal or an alarm signal for activating the alarm means is output to the crane operation restricting means. And mobile crane safety equipment.