JP2003049446A - Alarm control device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alarm control device for a construction machine capable of appropriately issuing an alarm, when resulting in a state of causing breakage of an arm cylinder when crushing a reinforced frame in demolishing a building. SOLUTION: This alarm control device for the construction machine is provided with an angle sensor 80 detecting an angle between the lower surface of a hoisting boom 12 and an arm 14, a pressure sensor 76 detecting the dropping movement of the hoisting boom 12, and an alarm controller 78 issuing the alarm from a buzzer 82 or a lamp 84 to an operator based on the detection signal from the sensors 76 and 80, when the arm 14 is in a state of reaching full crowding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a warning control device for a construction machine used for various construction works such as a hydraulic excavator.

[0002]

2. Description of the Related Art For example, Japanese Patent Laid-Open No. 5-18122 shows an example in which a hydraulic excavator is used for dismantling work. In the hydraulic excavator of this publication, a hydraulic crushing tool is attached to the tip of its arm instead of an ordinary bucket, and the crushing tool can be used to dismantle a building or the like.

Further, the hydraulic excavator disclosed in the gazette is equipped with a warning device for issuing a warning when the crushing tool reaches a work posture in which the crushing tool deviates from its allowable work radius. This warning device is useful for safely performing dismantling work. It is believed that there is.

[0004]

By the way, since the warning device for the hydraulic excavator described above issues an alarm only when the crushing tool is out of the allowable working radius, the crushing tool stays within the allowable working radius. It doesn't work for a while. That is, the above warning device does not give a warning even if the arm of the hydraulic excavator is used in an undesired posture during the disassembling work within the allowable work radius.

Explaining this point in detail, a hydraulic excavator is used for crushing a reinforcing bar frame taken out from crushed concrete when a building is dismantled. Such crushing work is performed by an arm of the hydraulic excavator. In the cloud state, the hoisting boom is hoisted, and a crushing tool or a bucket at the end of the arm is struck against the reinforcing bar frame on the ground, whereby the volume occupied by the reinforcing bar frame can be reduced.

Since the arm is in a cloud state during such a crushing operation, when the reinforce frame is repeatedly hit, a pulling force acts on a hydraulic cylinder for rotating the arm, that is, a so-called piston rod of the arm cylinder. The rod gradually pulled out,
The hydraulic excavator operator may notice that the arm reaches the full cloud.

Then, in the full cloud state of the arm,
When the rebar frame is struck more and more times, in this case, the arm cylinder is already in the full stroke state, so that the pin connecting the arm cylinder and the arm is excessively added and the arm cylinder is damaged. May be caused. An object of the present invention is to appropriately warn the operator that the arm is in a state of reaching a full cloud in a situation where the above-described crushing work of the reinforcing bar frame is performed, and to cause damage to the arm cylinder. It is to provide a warning device for a construction machine capable of avoiding work.

[0008]

In order to achieve the above-mentioned object, a warning control device for a construction machine according to the present invention (claim 1) comprises:
Angle detecting means for detecting an angle formed between the lower surface of the hoisting boom and the arm, tilting detecting means for detecting a tilting operation of the hoisting boom, and work attitudes of the hoisting boom and the arm based on the detection results detected by the respective detecting means. A controller that determines whether or not the operation is permitted and outputs a warning signal based on the determination result and a warning device that issues a warning based on the warning signal are provided.

According to the above-mentioned warning control device, the controller is based on the combination of the angle detected by the angle detection means, that is, the cloud state of the arm and the receding boom of the hoisting boom detected by the recoil detecting means. It is determined whether or not the work posture and movement of the hoisting boom and arm are allowed, and if the determination result is no, the controller outputs a warning signal to generate a warning from the warning device and Alert the operator of.

Specifically, the controller outputs a warning signal when the angle detected by the angle detecting means is smaller than the threshold value and the fall motion of the undulating boom is detected by the fall motion detecting means. 2). In this case, the warning signal will not be output from the controller even if the detected angle becomes smaller than the threshold value, and the warning will be issued from the warning device when the hoisting boom is lowered, and the operator will Be able to recognize the situation properly.

Further, it is preferable that the controller includes a variable means for varying the output cycle of the warning signal based on the deviation between the angle and the threshold value when the angle is smaller than the threshold value ( Claim 3). In this case, the generation period of the warning from the warning device can be changed according to the degree of the cloud state in the arm, and the operator's attention can be more effectively called.

Specifically, the warning device comprises a buzzer that makes a sound (claim 4) or a lamp that lights up (claim 5) in the output cycle of the warning signal, and both of these buzzers and lamps. May be included (Claim 6).

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a hydraulic excavator as a construction machine. The hydraulic excavator includes a crawler-type lower traveling body 2 and an upper revolving body 4 rotatably provided on the lower traveling body 2, and the lower traveling body 2 and the upper revolving body 4 form a machine body of the hydraulic excavator. The upper swing body 4 is equipped with a front attachment 6 for performing construction work (including dismantling work) and a cab 8. The cab 8 enables operation of the machine body and operation of the front attachment 6. In addition, an engine room 10 accommodating an engine (not shown) is provided at a rear portion of the upper revolving structure 4, and the engine drives the lower traveling structure 2 or the upper revolving structure 4 and operates the front attachment 6. It is a drive source for hydraulic equipment.

The front attachment 6 is provided with a hoisting boom 12 extending from the machine body of the hydraulic excavator, that is, the upper revolving superstructure 4, and the hoisting boom 12 is pivotally supported at its base end to the front part of the upper revolving superstructure 4 so as to be hoistable. ing. Undulating boom 12
The arm 14 is rotatably connected to the tip of the
A work tool such as a bucket 16 as a work tool or a crushing tool can be attached to the tip of the arm 14.

On the other hand, a boom cylinder 18 is provided between the upper swing body 4 and the hoisting boom 12, between the hoisting boom 12 and the base end of the arm 14, and between the tip of the arm 14 and the bucket 16. An arm cylinder 20 and a bucket cylinder 22 are provided, and these cylinders 18, 20, 22 are hydraulic cylinders. The boom cylinder 18 raises and lowers the hoisting boom 12 by its expansion and contraction,
The arm cylinder 20 and the bucket cylinder 22 can rotate the arm 14 and the bucket 16 by expanding and contracting them.

The traveling of the lower traveling structure 2, the revolving of the upper revolving structure 4, and the expansion and contraction of each cylinder in the front attachment 6 can be controlled by an operating lever in the cab 8 via a hydraulic circuit. A part of the hydraulic circuit is shown in FIG. FIG. 2 shows a hydraulic circuit that controls expansion and contraction of the boom cylinder 18 and the arm cylinder 20, and the hydraulic circuit is a main pump 24 that is a variable displacement hydraulic pump.
Is equipped with. The main pump 24 is driven by the engine described above, and discharges the pressure oil sucked from the hydraulic tank 26 toward the main supply pipeline 28. Main supply line 2
8 is branched on its downstream side as branch supply pipes 30 and 32, and these branch supply pipes 30 and 32 are connected to the boom cylinder 1
8 and the arm cylinder 20, respectively.

A main return pipe 34 extends from the hydraulic tank 26, and the main return pipe 34 is branched on the upstream side into branch return pipes 36 and 38. These branch return pipes 36 and 38 are also boom cylinders. 18 and the arm cylinder 20 so as to form a pair with the corresponding branch supply lines 30 and 32. On the other hand, as is apparent from FIG. 2, the boom cylinder 18 and the arm cylinder 20 are
Are each a return type hydraulic cylinder, and a pair of boom pipe lines 40 and arm pipe lines 42 extend from the boom cylinder 18 and the arm cylinder 20, respectively.

A pair of boom conduits 40 is provided with a boom control valve 44.
Is connected to the branch supply line 30 and the branch return line 36 via the arm control valve 46, and the arm control valve 46 is also connected to the branch supply line 32 and the branch return line 38 via the arm control valve 46. Has been done. Here, the boom control valve 44
The arm control valve 46 is a pilot pressure operated type directional control valve, more specifically, a 4-port 3-position directional control valve.

When the boom control valve 44 is switched from the illustrated neutral position to one switching position, the branch supply line 30 is connected to one boom line 40 and the branch return line 36 is connected to the other boom line. As a result of being connected to the passage 40, pressure oil is supplied to one pressure chamber inside the boom cylinder 18, and the rod of the boom cylinder 18 expands or contracts. At this time, the pressure oil in the other pressure chamber of the boom cylinder 18 is the other one of the boom pipe 40 and the branch return pipe 38.
And is returned to the hydraulic tank 26 via the main return line 34.

In the arm cylinder 20, the rod is similarly extended or contracted by switching the arm control valve 46. The main supply line 28
The main return pipe 34 and the main return pipe 34 are connected by a relief pipe 48 near the discharge side of the main pump 24, and a relief valve 50 is inserted in the relief pipe 48. The relief valve 50 regulates the hydraulic pressure in the main supply line 28 to a predetermined pressure.

On the other hand, in order to operate the switching of the boom control valve 44 and the arm control valve 46 described above, the hydraulic circuit is provided with a pilot pump 52 which is a hydraulic pump, and a pilot pressure supply line 54 extends from the pilot pump 52. . The pilot pressure supply conduit 54 is branched and connected to the boom operation lever unit 56 and the arm operation lever unit 58, and the boom operation lever unit 56 and the arm operation lever unit 5 are connected.
A pair of pilot pressure lines 60 and 62 and a pair of branch return lines 64 respectively extend from 8.

The pair of pilot pressure lines 60 are connected to both pressure receiving portions 66 of the boom control valve 44, and the pair of pilot pressure lines 62 are connected to both pressure receiving portions 68 of the arm control valve 46. Further, the two branch return pipe lines 64 are joined to each other and then connected to the hydraulic tank 26 as a return pipe line 70. On the other hand, the boom operation lever unit 56 and the arm operation lever unit 58 each have a pressure reducing valve (not shown) for reducing the pilot primary pressure supplied from the pilot pump 52 according to the operation amount of each operation lever 56a, 58a. ing.

Therefore, the boom operation lever unit 5
6, the pilot pressure is supplied to the boom control valve 44 through one pilot pressure conduit 60 by operating the operation lever 56a, the boom control valve 44 is switched, and the pressure from the main pump 24 to the boom cylinder 18 is changed. The boom cylinder 18 can be expanded and contracted by supplying the oil.

Also in the arm operating lever unit 58, the arm cylinder 20 can be expanded and contracted in the same manner by operating the operating lever 58a. The pilot pressure supply pipe 54 is also provided with a relief pipe 72 extending from the vicinity of the discharge side of the pilot pump 52 toward the hydraulic tank 26, and the relief valve 74 inserted in the relief pipe 72 supplies the pilot pressure. The pilot pressure in the pipe 54 is adjusted to a predetermined pressure.

Further, a pressure sensor 76 is provided in one of the pilot pressure pipes 60 on the boom cylinder 18 side, and the pressure sensor 76 detects the pilot pressure in the pilot pressure pipe 60 and outputs a pressure signal to the alarm controller. Send to 78. Here, the pilot pressure pipe line 60 including the pressure sensor 76 includes a pressure receiving portion 66 on the side for switching the boom control valve 44 in a direction in which the boom cylinder 18 is contracted.
To supply pilot pressure to. That is, the pressure sensor 76 constitutes a backlash detection means for detecting the contraction of the boom cylinder 18, that is, the backing of the hoisting boom 12, by detecting the pilot pressure in the pilot pressure conduit 60.

In addition to the pressure sensor 76, a switch for detecting the operation of the operating lever 56a in the boom operating lever unit 56, an angle sensor for directly detecting the receding motion of the hoisting boom 12 itself, or the like may be used as the recoil detecting means. It may be. Further, in addition to the pressure sensor 76 described above, an angle sensor 80 is also connected to the input side of the warning controller 78, and the angle sensor 80 connects the tip of the hoisting boom 12 and the arm 14 as shown in FIG. The angle θ formed by the lower surface of the hoisting boom 12 and the arm 14 is mounted coaxially with the connecting pin, and the detected angle signal is transmitted to the warning controller 78.

On the other hand, a buzzer 82 and a lamp 84 as warning devices are electrically connected to the output side of the warning controller 78, and the buzzer 82 and the lamp 84 are arranged in the cab 8 near the driver's seat. ing. As shown in FIG. 2, the warning controller 78 includes a central processing unit (CPU) 86, a memory 88 such as ROM and RAM,
In addition, a driver 90 for the buzzer 82 and the lamp 84,
It is composed of a microcomputer including various peripheral devices such as 92, and issues an alarm to the operator of the hydraulic excavator via the buzzer 82 and the lamp 84 based on the pressure signal and the angle signal described above.

Specifically, the warning controller 78 repeatedly executes the warning routine shown in FIG. 3 every predetermined control cycle according to the program stored in the memory 88, that is, the ROM, and the buzzer 82 is extinguished. And controlling the blinking of the lamp 84.

Warning routine In the warning routine, first, based on the angle signal from the angle sensor 80, the angle θ between the hoisting boom 12 and the arm 14 is set.
Is read (step S1), and then step S2
The steps S4 to S4 and the steps S5 to S7 are executed in parallel.

In step S2, it is judged whether or not the read angle θ is smaller than a predetermined threshold value α (α <90 °). If the judgment result here is true (Yes), that is, the angle θ is In the cloud state of the arm 14 that is smaller than the threshold α, the deviation Δθα of the angle θ from the threshold α
(= Α−θ) is calculated (step S3), and the ringing cycle Tα of the buzzer 82 is calculated based on this deviation Δθα (step S4). Here, the ringing cycle Tα indicates a time interval when the buzzer 82 periodically rings as shown in FIG. More specifically, the tone cycle Tα is the deviation Δ
As θα increases, it is set shorter. The sounding time T _B of the buzzer 82 per time is constant.

On the other hand, in step S5, it is judged whether or not the angle θ is smaller than a predetermined threshold β (β <90 °),
If the determination result here is true (Yes), that is, in the cloud state of the arm 14 in which the angle θ is smaller than the threshold β, the deviation Δθβ (= β
−θ) is calculated (step S6), and the lighting cycle Tβ of the lamp 84 is calculated based on this deviation Δθβ (step S7). Here again, the lighting cycle Tβ indicates a time interval when the lamp 84 is cyclically lit as shown in FIG. 5, and the lighting cycle Tβ is set shorter as the deviation Δθβ increases, and the lighting per time is performed. The time T _L is constant. The thresholds α and β are stored in the memory 88 in advance.

Steps S4 to S7 are executed to step S8. Here, it is determined whether or not the hoisting boom 12 is to be recoiled based on the pressure signal from the pressure sensor 76 described above. If the result of the determination in step S8 is true, the warning controller 78 causes the hoisting boom 12 and the arm 14 to move.
It is determined that the work posture and the movement are not permitted, and the buzzer 82 is extinguished based on the calculated sounding cycle Tα (step S9), and at the same time, the lamp 84 blinks based on the calculated lighting cycle Tβ (step S10). That is, steps S9 and S10 are performed in parallel.

If the result of the determination in step S2 or S5 is false (No), only the angle θ is read in step S1 and the warning routine is not substantially executed. Even if the determination result of step S2 or S5 becomes true, the buzzer 82 is extinguished or the lamp 84 is turned off.
Blinking is not executed immediately, but the undulating boom 12
When is moved down, its extinction and lighting are performed.

By the way, the buzzer 82 is extinguished and the lamp 84 is turned off.
The work status of the hydraulic excavator in which the blinking of is executed may be the crushing work of the reinforcing bar frame accompanying the dismantling of the building as described above. In this crushing work, as shown in FIG. 1, the arm 14 is placed in the cloud state, and in this state, the hoisting operation of the hoisting boom 12 is repeated. That is, the undulating boom 1
2, the bucket 16 is moved up and down via the arm 14, so that the ground reinforcing bar frame F is crushed by the bucket 16.

During such a crushing operation, when the detected angle θ becomes smaller than the threshold value α or β, the hoisting boom 12 is lowered, that is, the bucket 16 is lowered, the magnitude of the deviation Δθα or Δθβ. Based on the above, the buzzer 82 is turned off or the lamp 84 is blinked. Therefore,
The operator of the hydraulic excavator can confirm that the hoisting boom 12 in the current working condition is displayed after the buzzer 82 is turned off or the lamp 84 is blinking.
It is possible to audibly or visually recognize that there is a possibility that the full cloud of the arm 14 will be caused if the bobbin motion of is repeated, and thus it is possible to reliably avoid such a bobber motion.

Therefore, during the crushing work, the operator does not notice and the arm 14 does not reach the full cloud, and the crushing work is executed while the arm 14 is in the full cloud state and the arm cylinder is operated. The arm cylinder 20 will not be damaged by applying an excessive load to the arm cylinder 20. Further, the ringing cycle Tα of the buzzer 82
Alternatively, each of the lighting periods Tβ of the lamp 84 has a deviation Δ
The larger θα or Δθβ becomes, that is, the shorter the arm 14 becomes closer to the full cloud, the shorter the alarm is given from the buzzer 82 or the lamp 84 to the operator, so that the operator can accurately recognize the current work situation. Can be made.

The present invention is not limited to the above-mentioned one embodiment, and various modifications can be made. For example, the warning device may be one of the buzzer 82 and the lamp 84. Further, when both the buzzer 82 and the lamp 84 are used as in one embodiment, the threshold values α and β may have different values or the same value. However, if the threshold value β is set to a value larger than the threshold value α, first, after the lamp 84 starts blinking, the buzzer 82
Is performed, which is preferable for calling the operator's attention.

Further, as the deviations Δθα and Δθβ increase, the ringing period Tα and the lighting period Tβ are shortened, and the ringing level of the buzzer 82 and the lamp 84 are increased.
If the light emission level is also increased, the warning to the operator becomes more effective. Furthermore, the crushing work described above
It is carried out with the crushing tool attached to the tip of the arm 14 instead of the bucket 16.
4 is in a cloud state that is more than the allowable level, and when the hoisting boom 12 is tilted, an alarm is similarly issued from the buzzer 82 and the lamp 84.

Furthermore, not only the crushing work, but also any work situation as long as an alarm should be issued,
Since an alarm is issued, various work can be safely performed.

[0040]

As described above, according to the warning control device for a construction machine of the present invention (Claim 1), the angle detecting means for detecting the cloud state of the arm and the fall motion detecting the fall motion of the hoisting boom. Based on the detection result from the means, it is determined whether the work posture and movement of the undulating boom and arm are allowed.If the determination result is no, the warning device issues a warning, so the operator can It is possible to perform an avoidance operation to avoid a full cloud of the arm, and work can be safely performed without damaging the hydraulic cylinder or the like.

Further, when the warning from the warning device is generated at the time when the oscillating boom boom is detected (Claim 2), the operator can be effectively alerted. Also,
When the output cycle of the warning signal emitted from the warning device is changed depending on the degree of cloud state in the arm (claim 3
5), the operator can be more appropriately warned.

[Brief description of drawings]

FIG. 1 is a diagram showing a hydraulic excavator as a construction machine.

FIG. 2 is a diagram showing a part of a hydraulic circuit including a warning control device according to an embodiment.

FIG. 3 is a flowchart showing a warning routine executed by the warning control device of FIG.

FIG. 4 is a graph showing a sound pattern of a buzzer as a warning device.

FIG. 5 is a graph showing a lighting pattern of a lamp as a warning device.

[Explanation of symbols]

12 ups and downs boom 14 arms 16 buckets 18 boom cylinder 20 arm cylinder 56 Boom control lever unit 76 Pressure sensor (falling motion detection means) 78 Warning Controller 80 Angle sensor (angle detection means) 82 Buzzer (warning device) 84 lamp (warning device)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mitsuhashi Makoto             Hitachi Construction Machinery Co., Ltd.             Ceremony Company Tsuchiura Factory (72) Inventor Yoichi Furuwatari             Hitachi Construction Machinery Co., Ltd.             Ceremony Company Tsuchiura Factory F-term (reference) 2D003 AA01 AB03 BA07 BB07 CA02                       DA03 DA04 DB04                 2D015 GB04 HA03                 2E176 AA01 DD64

Claims (6)

[Claims] 1. An arm is rotatably connected to the tip of a hoisting boom, and a work tool is provided at the tip of the arm, and the hoisting operation of the hoisting boom and the turning operation of the arm are respectively performed via hydraulic cylinders. In a construction machine that is performed, an angle detection unit that detects an angle formed by the lower surface of the hoisting boom and the arm, a backlash detection unit that detects a backing motion of the hoisting boom, and a detection result detected by each of the detection units. A controller that determines whether or not the work posture and motion of the undulating boom and the arm are allowed, and outputs a warning signal based on the determination result; and a warning device that issues a warning based on the warning signal. A warning control device for a construction machine, comprising: 2. The controller, when the angle detected by the angle detection means is smaller than a threshold value, and when the tilt motion of the hoisting boom is detected by the tilt motion detection means,
The warning control device for a construction machine according to claim 1, wherein the warning signal is output. 3. The controller includes variable means for varying an output cycle of the warning signal based on a deviation between the angle and the threshold value when the angle is smaller than the threshold value. The warning control device for a construction machine according to claim 2, wherein 4. The warning control device for a construction machine according to claim 3, wherein the warning device is a buzzer that sounds based on an output cycle of the warning signal. 5. The warning control device for a construction machine according to claim 3, wherein the warning device is a lamp that lights up based on an output cycle of the warning signal. 6. The warning control device for a construction machine according to claim 3, wherein the warning device includes a buzzer and a lamp that sound and light based on an output cycle of the warning signal.