JPH07372Y2 - Safety equipment for work machines - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a safety device for a working machine such as a construction machine or an aerial work vehicle.

[Conventional technology]

Some work machines provided with a work member such as a boom can ensure the stability of the vehicle body by grounding the outrigger jack during the work. But,
Even in such a working machine, if the driver neglects to ground the outrigger jack or if the jack rises due to land subsidence, etc., the stability will be impaired, so a safety device that warns against such an abnormal situation. Are generally provided.

This safety device is generally equipped with a detector that detects grounding or non-grounding of the outrigger jack, and when the detector outputs a non-grounding state detection signal, it performs a warning operation such as forcibly stopping the working member. Is. However, if the warning operation is performed too sensitively to the detection of grounding or non-grounding, the safety is particularly affected, for example, when the outrigger jack floats instantaneously due to the load fluctuation of the working member or the dynamic inertia. Even when there is no work, the work is stopped each time, and the work efficiency is significantly reduced.

Therefore, in Japanese Utility Model Laid-Open No. 59-32548, a delay circuit for delaying the output of the non-grounded state detection signal is provided in the output circuit of the above detector, so that a state with a long ascent time causing a fall may occur. It has been disclosed that the warning operation is performed only when the above occurs.

[Problems to be Solved by the Invention]

If the operation performed based on the output of the non-grounding detection signal is merely an alarm, for example, the alarm is only continuously issued until the outrigger jack is grounded in the work preparation stage. However, it is impossible to positively prevent an erroneous operation in which the driver accidentally operates the work member before operating the outrigger jack. Such an erroneous operation can be prevented by forcibly stopping the operation of the work member based on the output of the non-ground detection signal, but in this case, especially in a crane or an aerial work vehicle,
There is no problem in safety due to its rigidity, load, ground contact, etc. during work of the work member, but when only one outrigger jack is constantly floating, the work member's operation stops and work efficiency is improved. Inconvenience of remarkably lowering is brought about.

Further, in this device, if the driver mistakenly operates the outrigger jack during work, an alarm operation is started after a delay time has elapsed since the outrigger jack was brought into a non-grounded state, so that a fall or the like may occur. The probability is rather high.

In view of such circumstances, the present invention provides a safety device capable of reliably preventing an erroneous operation before and after the start of work and accurately ensuring safety without impairing work efficiency. With the goal.

[Means for Solving the Problems]

As shown in FIG. 1, the present invention provides a working member 12 that can be switched between a stored state and a working state, and an outrigger jack.
In a working machine provided with 10, a working state detecting means 14 for detecting whether the working member 12 is in a retracted state or a working state, and an outrigger for detecting whether or not each outrigger jack 10 is in a grounded state. Jack detection means 16 and outrigger jack switching means for forcibly stopping the operation of the outrigger jack 10 when the working member 12 is in the working state.
18, a warning means 20 for giving a warning at about the same time that it is detected that at least one outrigger jack 10 is not grounded in the working state, and the working member 12 is in the retracted state and at least one outrigger. Work member switching means (22) for forcibly stopping the operation of the work member (12) only when the jack (10) is not grounded.

[Action]

According to the above configuration, the work member switching means 22 forcibly stops the operation of the work member 12 until the outrigger jack 10 is completely grounded, so the work member 12 is erroneously operated before the work preparation is completed. Never.

On the other hand, after the working member 12 is activated and is in the working state, the outrigger jack switching means 18 forcibly stops the operation of the outrigger jack 10, so that the outrigger jack 10 malfunctions during work and is not grounded. It never goes into a state.

Further, when the outrigger jack 10 is brought into a non-grounded state due to the movement of the work member 12 during work, a warning is issued by the warning means 20 almost at the same time.
12 remains operational.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS.

The aerial work vehicle (work machine) shown in FIG. 2 is equipped with a boom (work member) 26 having a bucket 24 at its tip. This boom 26 is a boom rest 28 that is erected on the work vehicle body.
It is installed in a position where it can be stored above. A boom rest limit switch (working state detecting means) 30 as shown in FIG. 3 is arranged on the boom rest 28, and by turning the boom rest limit switch 30 on and off, the boom 26 is placed on the boom rest 28. The stored state of being stored and the working state of moving away from the boom rest 28 are detected.

On the other hand, outrigger jacks 10 are provided at a total of four places on the left and right of the work vehicle body. As shown in FIG. 4, each outrigger jack 10 comprises a horizontal member 101 housed in a cover 32 on the side of the work vehicle main body, and a jack portion 102 provided at a side end of the horizontal member 101. On the upper wall of the cover 32, an outrigger jack limit switch (outrigger jack detecting means) 34 is arranged at a position facing the horizontal member 101 side (lower side). In this structure, when the jack portion 102 is not extended, the outrigger jack 10
There is some play in the horizontal member 101 due to its own weight.
, The outrigger jack limit switch 34 and the horizontal member 101 are separated from each other (state shown by the solid line in FIG. 4), but when the jack portion 102 is extended and grounded,
The horizontal member 101 rises slightly and comes into contact with the outrigger jack limit switch 34 (state indicated by a chain double-dashed line in the figure). Therefore, the outrigger jack limit switch 34 detects the grounding or non-grounding of each outrigger jack 10.

FIG. 5 shows a circuit of a safety device provided in this work vehicle.

In the figure, the four outrigger jack limit switches 34 and the relay (solenoid) 36 are arranged in series with each other, and the normally closed contact 38b and the buzzer (warning means) 40 of the relay 36 are arranged in series. Relay 36 normally open contact 38
a is the normally closed contact 30b of the boom rest limit switch 30
An electromagnetic valve (working member switching means) 42 such as a boom is arranged in parallel with the above. This boom etc. solenoid valve
Reference numeral 42 is for switching the boom 26 to an operable state in the energized state.

Also, the normally open contact of the boom rest limit switch 30 above.
An outrigger jack solenoid valve (outrigger jack switching means) 44 is arranged in series with 30a. This outrigger jack solenoid valve 44 is designed for each outrigger jack 10 when energized.
Is switched to an operable state.

Then, the relay 36, the buzzer 40, the boom solenoid valve 42,
Also, the outrigger jack solenoid valves 44 are arranged in parallel, and the voltage V is applied between both electrodes at the stage of starting the work preparation.

Next, the operation of this safety device will be described with reference to the flowchart of FIG.

First, when the work vehicle is stopped and switched to the work preparation state, the voltage V is applied to the relay circuit of FIG. 5 and the safety device is activated.

Boom 26 is not yet actuated, the state stored in the boom rest 28, since the state of the boom rest limit switch 30 is "contact" by the abutment of the boom 26 (YES in Step S _1), closed normally open contact 30a of the switch 30 is, thereby being energized outrigger jacks solenoid valve 44, the outriggers 10 becomes operable state (step S _2).

When these outrigger jacks 10 are not completely grounded, that is, when some or all of the outrigger jack limit switches 34 are not closed (step S ₃
In NO), the relay 36 is not energized (Step S _4), since it remains its normally closed contact 38b is closed, the buzzer 40 is energized (step S _5), the alarm to the outside is generated. On the other hand, since open normally open contact 38a of the relay 36, the boom such as an electromagnetic valve 42 is not energized, the boom 26 can not be operated (Step S _6).

In contrast, to operate the outriggers 10, when fully grounded respectively (YES in Step S _3), the relay 36 is energized by the full outrigger jacks limit switch 34 is closed (step S _7). Thereby, the normally closed contact 38b of the relay the buzzer 40 becomes non-energized state to open (Step S _8), together with the alarm is stopped, the normally open contact 38a boom such as electromagnetic valve 42 is energized to close The boom 26 is ready for operation (step
S ₉ ).

If you activate the boom 26 from this state and enter the working state,
The boom 26 boom rest limit switch 30 by away from the boom rest 28 is switched to the "cross" (NO in Step S _1). Therefore, the normally-open contact 30a of the boom rest limit switch 30 is opened, and the outrigger jack solenoid valve 44 is switched to the non-energized state (step
S ₁₀ ). Therefore, in this state, each outrigger jack 10 cannot operate.

These outriggers 10, because of all the grounded state as described above, are all outriggers limit switch 34 is "contact" (YES in step S _11),
Therefore buzzer 40 as in the state it does not operate (step S _7, S _8). On the other hand, one or more outrigger jacks 10 float due to the influence of the load fluctuation of the boom 26 and the dynamic inertial force.
One or more outriggers limit switch 34 becomes the "cross" (at step S ₁₁ NO), the relay 36 is de-energized (step S _12), so that the normally closed contact 38b is closed, the buzzer 40 is energized alarm is performed Te (step S _13). On the other hand, since the normally closed contact 30b of the boom rest limit switch 30 remains closed, the boom solenoid valve 42
Remains energized, continue to operate without the boom 26 is stopped (step S _9).

As described above, this safety device forcibly stops the operation of the boom 26 after the work preparation state until the outrigger jack 10 is completely grounded, so the boom 26 is grounded before the outrigger jack 10 is grounded. Operation mistakes such as activation are surely prevented.

Conversely, ground the outrigger jack 10 and
Since the operation of the outrigger jack 10 is forcibly stopped after activating, the erroneous operation of pulling up the outrigger jack 10 during the operation of the boom 26 is reliably prevented. In addition, during operation of the boom 26, if some of the outrigger jacks 10 float due to the influence of the dynamic inertia force,
The buzzer 40 gives an alarm to the outside to call attention, but since the boom 26 is not stopped, the work efficiency is not affected.

Moreover, in the case of this embodiment, there is an advantage that the above excellent effects can be realized by an extremely simple circuit as shown in FIG.

Next, a second embodiment will be described with reference to FIGS. 7 and 8.

In this embodiment, as shown in FIG. 7, four outrigger jack limit switches 34 and a boom rest limit switch 30 arranged in series are connected to a microcomputer 46, respectively. Valve 42, outrigger jack solenoid valve 4
4, and the energization of the buzzer 40 is controlled.

Regarding the control contents of the microcomputer 46, as shown in the flow chart of FIG. 8, the same operation as that of the relay circuit of the above embodiment may be performed.
That is, if the boom rest limit switch 30 the boom 26 is not stored is on YE in (Step S ₂₁
S), to turn on the outrigger jacks solenoid valve 44 (step S _22), together with the outriggers 10 into operation, each outrigger jack 10 is fully grounded until all outriggers limit switch 34 becomes "contact" It is a warning (step NO at S _23), forcibly stops the operation of the turn off the boom such as an electromagnetic valve 42 (step S ₂₄₎ the boom 26, and turn on the buzzer 40 (step S _25). Then, each outrigger jack 10 is completely grounded, and all outrigger jack limit switches 34 "contact".
When it becomes a (YES in step S _23), the boom such as an electromagnetic valve
42 is turned on (step S ₂₆ ) to switch the boom 26 to an operable state, and the buzzer 40 is turned off (step S ₂₇ ) to stop the warning.

When the boom 26 operates from this state and the boom rest limit switch 30 is switched to "contact" (step S
₍ NO in ₂₁ ), the outrigger jack solenoid valve 44 is turned off, the operation of the outrigger jack 10 is forcibly stopped, and the boom solenoid valve 42 is kept on and the operation is continued (step S ₂₈ ). For buzzer 40, the states of all the outrigger jacks limit switch 34 is "contact" but keep the (YES in step S ₂₉₎ off (step S
_27), if the state of even one "cross" (at step S ₂₉ N
O) Switch on and give a warning. However, the boom solenoid valve 42 is left on and the boom 26 continues to operate.

In the present invention, regardless of the number and specific structure of the outrigger jacks, the means for detecting the ground contact may be the one suitable for the structure of the outrigger jacks. Also,
Regardless of the type of working member, the present invention can be applied to various things provided in each working machine in addition to the boom described above. As the warning means, other than the buzzer 40, for example, an appropriate lamp such as a display lamp may be used.

In the above-described embodiment, the work preparation state (outrigger jack
The alarm is activated when the outrigger jack 10 floats in both the condition (until the 10 is completely grounded) and the working condition (the condition in which the boom 26 is activated). In the case of the apparatus, since the boom (working member) 26 is not always activated in the work preparation state, the purpose can be achieved by performing the alarm operation at least in the work state.

[Effect of the Invention] As described above, the present invention detects the state of the working member and the grounding or non-grounding of each outrigger jack, and forcibly stops the operation of the outrigger jack when the working member is in the working state. , At least at the same time when it is detected that one or more outrigger jacks are not grounded in the working state, a warning is issued almost at the same time, the working member is in the retracted state, and at least one outrigger jack is not grounded. Since only the working member is forcibly stopped, it is necessary to reliably prevent erroneous operation such as operating the working member before grounding the outrigger jack or pulling up the outrigger jack while the working member is operating. In addition, it can alert you when the outrigger jack floats during work by giving an immediate warning. It Moreover, in this case, since the working member can continue the operation, it does not affect the working efficiency.

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of a safety device of the present invention, FIG. 2 is a schematic side view of an aerial work vehicle according to a first embodiment of the present invention, and FIG. 3 is a boom of the aerial work vehicle. Fig. 4 is a front view showing the mounting position of the rest limit switch, Fig. 4 is a partial sectional front view showing the mounting position of the outrigger jack limit switch of the same aerial work vehicle, and Fig. 5 is the safety provided for the aerial work vehicle. FIG. 6 is a relay circuit diagram of the device, FIG. 6 is a flowchart showing the operation of the relay circuit, FIG. 7 is a hardware configuration diagram of the safety device in the second embodiment, and FIG. 8 is a control content of a microcomputer in the safety device. It is a flowchart. 10 …… Outrigger jack, 12 …… Working member, 14 …… Working state detecting means, 16 …… Outrigger jack detecting means,
18 …… Outrigger jack switching means, 20 …… Warning means,
22 …… Working member switching means, 26 …… Boom (working member),
28 …… Boom rest, 30 …… Boom rest limit switch (working state detection means), 34 …… Outrigger jack limit switch (outrigger jack detection means), 40
...... Buzzer (warning means), 42 ...... boom solenoid valve (working member switching means), 44 ...... outrigger jack solenoid valve (outrigger jack switching means), 46 ...... microcomputer.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area B66F 11/04

Claims (1)

[Scope of utility model registration request] 1. A work machine equipped with a working member that can be switched between a stored state and a working state and an outrigger jack, and a working state detecting means for detecting whether the working member is in the stored state or the working state. , Outrigger jack detection means for detecting whether or not each outrigger jack is in the grounded state, outrigger jack switching means for forcibly stopping the operation of the outrigger jack when the working member is in the working state, and at least in the working state Only when the one or more outrigger jacks are detected not to be grounded, a warning means is provided almost at the same time, and the working member is in the retracted state, and at least one outrigger jack is not grounded. A safety device for a working machine, comprising: a work member switching means for forcibly stopping the operation of the member.