JPH08104496A - Overload state recording device of moving-type crane - Google Patents

Abstract

PURPOSE: To achieve reliability of a recorded value by limiting recording of a load factor in switching operation in the operating state of a crane. CONSTITUTION: A load factor is calculated by a load factor calculating means C on the basis of the actual value calculated by an actual value calculating means A and a limit value calculated by a limit value calculating means B. This load factor and the recorded load factor I are compared with each other by an overload information outputting means D, and the load factor information is outputted to an overload state recording means E when the load factor exceeds the recorded load factor I. In the overload state recording means E, in principle, a peak value of the load factor is recorded together with the date and time each time the overload information is received. When the operational parameter is inputted by manual switching of an operational parameter manual inputting means F, a recording operation prohibiting signal is outputted from a recording operation prohibiting signal outputting means G, the recording operation in the overload state recording means E is prohibited, and the peak value of the load factor in that time is not recorded. Accordingly, reliability of the recorded overload data is improved in comparison with the case where the overload state under the specific condition is uniformly recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload state recording apparatus for a mobile crane, which records the load state at the time when an overload state occurs in the mobile crane.

[0002]

2. Description of the Related Art Generally, a mobile crane is equipped with an overload prevention device in order to ensure work safety.
During crane work, the actual load condition (actual value) and the limit load condition (limit value) allowed in the crane's operating condition at that time (boom length, boom hoisting angle, boom turning angle, etc.) are constantly monitored, When the load factor specified by the ratio of the actual value to the limit value reaches the preset alarm load factor, a predetermined alarm is issued to alert the operator and the crane operation to the side where the load factor increases (Boom extension operation, boom fall operation, etc.) are automatically prohibited.

On the other hand, in a mobile crane equipped with such an overload prevention device, if a fault occurs in the crane for some reason, especially when a fault occurs due to overload work, the cause of the fault is determined. It is necessary to investigate and take effective measures against this. For that purpose, it is important to sufficiently analyze and examine the crane state when a failure occurs. For the purpose of collecting data related to the crane condition necessary for such analysis work, an overload condition recording device was installed, and the load factor associated with the crane work was set to a value greater than the above alarm load factor by a specified value. Whenever the rate is exceeded, the peak value of the load rate is recorded together with the work date and time so as to be useful for analysis in the event of a failure.

[0004]

By the way, the limit value serving as a calculation standard of the load factor is given as a function of a plurality of operating parameters such as a boom hoisting angle and a boom length which are input corresponding to the operating state of the crane. However, not all of these operating parameters are automatically input in response to actual operation, but some of them are manually input by the operator.

That is, the operation parameters to be automatically input are, for example, the operation parameters related to the boom length, the boom hoisting angle and the like. Since these boom lengths and the like are constantly detected by the boom length detecting means, the boom hoisting angle detecting means, etc., each of which is composed of a sensor, the detected values are automatically used as they are as operating parameters on the overload prevention device side. This is because it is easy to enter.

On the other hand, the operating parameters that are input by the operator's manual switching operation are operating parameters related to the working mode of the crane. For example, the work form of crane work is, for example, a double rope hanging work using a main winding winch (so-called boom work) and a single rope hanging work using a supplementary winch (single top work using a single top. (There is a jib work using a jib) and a double rope hanging work, a single rope hanging work, and even a single rope hanging work between a single top work and a jib work. Since the load condition of the crane device is completely different, it is necessary to switch the performance of the overload prevention operation corresponding to each of these three work modes.However, the operator selects the work selection switch to switch the performance of the overload prevention operation. This is because it is performed by switching operation with.

However, when there is an operation parameter input by a manual switching operation by the operator as described above, the load factor based on the actual value and the limit value is uniformly applied regardless of the presence or absence of the switching operation. When the load state recording device is operated, for example, when the work selection switch is operated in a direction to decrease the limit value (for example, when the work condition is switched from boom work to jib work), the change operation Immediately after that, the load factor suddenly changes in the increasing direction and exceeds the recording load factor, and as a result,
The peak value of the load factor at that time is recorded as overload data.

In this case, if the jib work is actually performed, it is necessary to record the peak value of the load factor at that time.
For example, although boom work is currently being performed, it is often the case that the operator performs a test switching operation to confirm whether or not work can be performed safely even if this is switched to jib work. In this case, if all peak values of the load factor at that time are uniformly recorded as overload data, this reliability may be questioned when it is used for analysis of the crane condition at a later date. Become.

In view of the above, the present invention provides an overload state recording apparatus for a mobile crane, in which the recording of the load factor during the switching operation of the operating state is prohibited to ensure the reliability of the recorded value as the overload data. It was made as a proposal.

[0010]

According to the present invention, as a specific means for solving such a problem, a swivel base is mounted on a vehicle equipped with an outrigger so that the swivel base can turn freely, and the telescopic boom can move up and down on the swivel base. In the mobile crane with the attached, as shown in the claim correspondence diagram of FIG. 1, according to the actual value calculation means A for calculating the actual value of the load acting on the telescopic boom and the actual condition of the operation of the mobile crane. Limit value calculation means B for calculating the limit value of the load allowable in the current operating state of the crane based on the input operation parameters H, the actual value input from the actual value calculation means A, and the above-mentioned limit value A load factor calculating unit C that compares the limit value input from the calculating unit B and calculates the ratio of the actual value to the limit value as a load factor, and a negative value from the load factor calculating unit C. An overload information output means D for comparing the rate with a preset recording load rate I and outputting overload information when the load rate exceeds the recording load rate I; and an overload from the overload information output means D. Every time the information is received, the peak value of the load factor at that time is recorded together with the date and time.
And an operation parameter manual input means F for inputting at least one operation parameter among the operation parameters H by a manual switching operation, and an operation parameter switching signal when the operation parameter switching signal is input from the operation parameter manual input means F. A recording operation prohibition signal output means G for outputting a recording operation prohibition signal to the overload state recording means E to prohibit the recording operation is provided.

[0011]

According to the present invention, the following actions and effects can be obtained with such a configuration. That is, the actual value calculation means A calculates the actual value of the load acting on the telescopic boom, while the limit value calculation means B calculates each operation parameter H.
Based on the above, the load limit value in the current operating state of the crane is calculated. Then, in the load factor calculating means C, the actual value input from the actual value calculating means A and the limit value input from the limit value calculating means B are compared to determine the ratio of the actual value to the limit value. Calculate as a load factor.

Further, in the overload information output means D, the load factor from the load factor calculation means C is compared with a preset recording load factor I, and when the load factor exceeds the recording load factor I, the overload information is exceeded. The load information is output to the overload state recording means E.

In this case, in principle, the overload state recording means E records the peak value of the load factor at that time together with the date and time every time the above-mentioned overload information is received. When at least one operation parameter of the parameters H is input by a manual switching operation, a recording operation prohibition signal is input from the recording operation prohibition signal output means G and the recording operation is prohibited. Is not recorded.

Therefore, the overload state recording means E does not record the overload state under a special situation where the operating state of the crane is changed by the switching operation of the operating parameter manual input means F, and the operating parameter manual input is performed. Since only the overload state in the normal state in which the operation state is not switched by the means F is recorded as the overload data, for example, compared with the case where the overload state under a special situation is also recorded uniformly. The recorded overload data is highly reliable, and a more accurate analysis result can be obtained by analyzing the crane state based on this overload data.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An overload state recording apparatus for a mobile crane according to the present invention will be specifically described below with reference to the accompanying drawings.

First Embodiment FIG. 2 shows a mobile crane Z equipped with an overload condition recording apparatus according to a first embodiment of the present invention. In the figure, reference numeral 1 is an outrigger 2, 2 ,. And a swivel base 3 is rotatably mounted on the vehicle 1, and a telescopic boom 4 is movably attached to the swivel base 3. The telescopic boom 4 is the swivel base 3 described above. It is driven up and down by an up-and-down cylinder 8 arranged between the and. Further, a main hook 11 is hung on a double rope and a jib 6 and a single top 7 are detachably attachable to a boom head 5 provided at the tip of the telescopic boom 4. Then, the jib 6 and the single top 7 are selectively attached to the auxiliary hook 1 which is selectively attached as necessary.
It is multiplied by 2. Therefore, the mobile crane Z performs boom work for hanging a load using the main hook 11 and jib work or single top work for hanging a load using the auxiliary hook 12 depending on working conditions. Can be selected. Here, since the load condition on the crane is greatly different between the boom work using the main hook 11 and the jib work or the single top work using the auxiliary hook 12, when the work condition is changed, the load condition is changed accordingly. It is necessary to change the performance of the overload prevention device, and the change of the performance of the overload prevention device due to the change of the work state is performed by the work state setting means 19 composed of a selection switch manually switched by the operator. Be seen. Therefore, in this embodiment, the work state setting means 19 corresponds to the operation parameter manual input means F in the claims, and is one of the components of the overload state recording device described later. In addition to providing an overload prevention device that issues a predetermined alarm and prohibits crane operation to the dangerous side, when an overload state recording device that is the gist of the present invention is incorporated into this overload prevention device, an overload state is generated. The peak value of the load factor at that time is recorded together with the date and time of occurrence so that it can be used as overload data during later analysis.

Further, in order to provide the overload prevention device and the overload state recording device with operation parameters corresponding to the actual operation of the mobile crane Z, moment detection for detecting the moment value applied to the telescopic boom 4 is performed. Means 20
A boom hoisting angle detecting means 21, a boom turning angle detecting means 22, and a boom length detecting means 23 are provided.
These detection means 20 to 23 correspond to the operating parameter H in the claims, and the detection signals of the detection means 20 to 23 and the work state setting means 19 are set.
Both switching signals are input to a control unit 15, which will be described later, which constitutes an overload prevention device and an overload state recording device. Then, in the control unit 15, when the working condition of the mobile crane Z becomes an overload condition, a predetermined alarm is issued by the alarm means 16 and this is displayed on the display means 18 to alert the operator. The mobile crane Z with the control means 17
Prohibit operations on the dangerous side of. In addition, the load factor in the overloaded state is recorded under a certain condition (described later), which is used as analysis data at a later date and is displayed on the display means 18 as needed. Hereinafter, the specific configuration and control of the control unit 15 that constitutes the overload prevention device and the overload state recording device will be described with reference to FIGS. 3 and 4.

First, referring to FIG. 3, the specific configuration of the control unit 15 will be described. In the control unit 15, the moment amplification circuit 31, the actual load calculation circuit 32, the rated load calculation circuit 33, and the load factor calculation circuit 3 are included.
4, a comparison circuit 35, a determination circuit 36, and a storage circuit 37. Here, the contents of each of these constituent circuits will be described individually. First, the moment amplification circuit 31 receives the current value of the moment applied to the telescopic boom 4 input from the moment detection means 20 and amplifies it. It is output as a moment signal to an actual load calculating circuit 32 described later.

The actual load calculating circuit 32 corresponds to the actual value calculating means A in the claims and calculates the load applied to the telescopic boom 4 at present as a load value and calculates the actual load (patented). It corresponds to the actual value in the claim) and outputs it. That is, in addition to the moment signal from the moment detecting means 20, the actual load calculating circuit 32
A boom hoisting angle signal from the boom hoisting angle detecting means 21, a boom turning angle signal from the boom turning angle detecting means 22, a boom length signal from the boom length detecting means 23, and a work state signal from the work state setting means 19 ( In this embodiment, signals indicating boom work, jib work, or single top work) are input. Then, in the actual load calculation circuit 32, the actual load is calculated based on each of these input signals, and this is output to the load factor calculation circuit 34 described later as an actual load signal.

The rated load calculating circuit 33 corresponds to the limit value calculating means B in the claims, and the allowable load in the current crane state (the limit value in the claims is Applicable) is calculated. That is, the rated load calculation circuit 33 receives the boom hoisting angle signal from the boom hoisting angle detecting means 21, the boom turning angle signal from the boom turning angle detecting means 22, and the boom length signal from the boom length detecting means 23. The work status signals from the work status setting means 19 are input respectively. Then, the rated load calculation circuit 33 calculates the rated load in the current crane state based on each of these input signals and outputs it to the load factor calculation circuit 34 described later.

The load factor calculation circuit 34 corresponds to the load factor calculation means C in the claims, and the actual load input from the actual load calculation circuit 32 and the rated load calculation circuit 33 are input. The input load rating is compared, the current load state is calculated as a load factor which is the ratio of the actual load to the rated load, and this load factor is output to the comparison circuit 35 and the determination circuit 36, which will be described later.

The comparison circuit 35 compares the current load factor input from the load factor calculation circuit 34 with an alarm load factor 41 which is a reference for issuing a preset alarm, and the calculated load factor is the alarm load factor 41. When exceeding the threshold, alarm signals are output to the alarm means 16, the control means 17, and the display means 18, respectively.
The alarm means 16 issues a predetermined alarm and the display means 18 displays the alarm status to call the operator's attention, and the control means 17 controls the operation of the mobile crane Z to the dangerous side (that is, (Operation in the direction in which the load factor further increases) can be restricted, and thus the risk of the mobile crane Z tipping over can be avoided.

The determination circuit 36 includes the overload information output means D and the recording operation prohibition signal output means G in the claims.
And a signal corresponding to the current load factor from the load factor calculating circuit 34, and a switching signal corresponding to this when the work condition switching means 19 performs a work condition switching operation. I am supposed to receive it. Then, in principle, in the determination circuit 36, the above-mentioned load factor and a preset recording load factor 42 (that is, the load factor to be recorded as overload data, which is the recording load factor I in the claims) If the calculated load factor exceeds the recording load factor 42, the memory circuit 37 stores the load factor of that case. The peak value is recorded together with the date and time of occurrence of the overload condition (that is, in this embodiment, the memory circuit 37 corresponds to the overload condition recording means E in the claims). However, even if the calculated load factor exceeds the recording load factor 42, when the switching signal is input from the work state setting means 19, the output to the storage circuit 37 is prohibited and the load factor is changed. Stop recording.

Therefore, even if the mobile crane Z is overloaded, the memory circuit 37 does not record the overload data under the special condition in which the working state is switched, and the working state switching operation is performed. Overload data will be recorded only during normal times when it is not done, and as a result,
The reliability of the recorded overload data can be improved, and more accurate analysis can be performed, as compared with the case of uniformly recording the overload data even under special conditions.

The possible data stored in the storage circuit 37 can be confirmed on the display means 18 as needed.

Next, the control in the control unit 15 as described above will be explained concretely with reference to the flow chart shown in FIG. 4. After the control is started, first, in step S1, based on the operation parameter output from each detecting means. To read the current work status. Next, in step S2, the current actual load is calculated, and step S
In 3, calculate the rated load corresponding to the current crane state. Then, in step S4, the current load factor (δ) is calculated from the actual load and the rated load.

Next, in step S5, the load factor (δ) is compared with the alarm load factor (α), and if (δ> α), it is determined that an overload condition exists, and in step S6. A predetermined alarm and display are performed, and the operation of the mobile crane Z toward the dangerous side is limited to ensure the safety of the mobile crane Z.

Further, in step S7, the load factor (δ) is compared with the recording load factor (β, β> α),
If (δ> β), as a general rule, the peak value of the load factor at this time is recorded as overload data together with the date and time of occurrence (step S9). When the switching is executed (step S8), the load factor is not recorded from the viewpoint of ensuring the reliability of the overload data.

Second Embodiment FIG. 5 shows a control unit 15 which constitutes an overload state recording apparatus according to the second embodiment of the present invention. In this embodiment, the load factor is calculated as a load value in the first embodiment, whereas the load factor is calculated as a moment value. Therefore, this embodiment is provided with an actual moment calculation circuit 38 and a rated moment calculation circuit 39 in place of the actual load calculation circuit 32 and the rated load calculation circuit 33 in the first embodiment. Also in the case of this embodiment including the control unit 15 having such a configuration, the first
As a matter of course, the same effect as that of the embodiment can be obtained.

In each of the above embodiments, the work mode is switched by a manual switching operation by the operator, and the recording operation of the overload data is prohibited or permitted depending on the presence or absence of the operation. However, the present invention is not limited to this, and the prohibition or permission of the recording of the overload data can be performed by an operation parameter other than the work mode switching, for example, another operation parameter such as the outrigger overhang amount. Further, in the above embodiment, the peak value of the load factor is recorded as the overload data together with the date and time of occurrence, but the present invention is not limited to this, and the load factor at that time is overload data. Needless to say, each operation parameter (for example, boom length, boom hoisting angle, outrigger extension amount, etc.) may be recorded together with the peak value.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is an overall system diagram of an overload condition recording device in a mobile crane according to a first embodiment of the present invention.

3 is a functional block diagram of the overload state recording device shown in FIG. 1. FIG.

FIG. 4 is a control flowchart of the overload state recording device shown in FIG.

FIG. 5 is a functional block diagram of an overload state recording device in a mobile crane according to a second embodiment of the present invention.

[Explanation of symbols]

1 is a vehicle, 2 is an outrigger, 3 is a swivel base, 4 is a telescopic boom, 5 is a boom head, 6 is a jib, 7 is a single top, 8 is a hoisting cylinder, 11 is a main hook, 12 is an auxiliary hook, and 15 is a control. Unit, 16 is alarm means,
Reference numeral 17 is a control means, 18 is a display means, 19 is a work state setting means, 20 is a moment detecting means, 21 is a boom hoisting angle detecting means, 22 is a boom turning angle detecting means, 23 is a boom length detecting means, and 31 is a moment. Amplifier circuit, 32 is an actual load calculation circuit, 33 is a rated load calculation circuit, 34 is a load factor calculation circuit, 35 is a comparison circuit, 36 is a determination circuit, 37 is a memory circuit, 38 is an actual moment calculation circuit, and 39 is a rated moment. Calculation circuit, A is actual value calculation means, B is limit value calculation means, C is load factor calculation means, D is overload information output means, E is overload state recording means, F is operating parameter manual input means, and Z is It is a mobile crane.

Claims (1)

[Claims] 1. A mobile crane in which a swivel base is rotatably mounted on a vehicle equipped with an outrigger, and a telescopic boom is mounted on the swivel base so that the telescopic boom is movable up and down. And an actual value calculating means for calculating the actual load, and a limit value calculating means for calculating the limit value of the load allowable in the current operating state of the crane based on each operating parameter input according to the actual state of operation of the mobile crane. Load factor calculation means for comparing the actual value input from the actual value calculation means with a limit value input from the limit value calculation means to calculate the ratio of the actual value to the limit value as a load rate, Overload information output means for comparing the load factor from the load factor calculation means with a preset recording load factor and outputting overload information when the load factor exceeds the recording load factor; Each time the overload information is received from the load information output means, the peak value of the load factor at that time is recorded together with the date and time, and at least one of the above operating parameters is manually switched. A recording operation for inputting the operation parameter and a recording operation for prohibiting the recording operation by outputting the recording operation prohibition signal to the overload state recording means when the operation parameter switching signal is inputted from the operation parameter manual input means. An overload state recording device in a mobile crane, comprising: a prohibition signal output means.