JP2003119832A - Hydraulic backhoe with hook - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy of an operation monitor or the like to enhance reliability by permitting crane operation only when a bucket and a hook assume predetermined states. SOLUTION: When a bucket cylinder 13 is held in a state in which it is most extended and a hook 21 is taken out of a storage position inside a bucket link 16, these states are detected by a hydraulic sensor 22 and a proximity switch 23 and a crane monitor 24 is held in an operable state by a controller 25. Otherwise, the crane monitor 24 is stopped and the crane operation is restricted. Thus, the bucket 10 can be held in a reference attitude such that it is most crowded toward the crane body, and the attitude of a front 7 and the weight of suspended load of the like can be accurately displayed by the crane monitor 24. Normal crane operation using the hook 21 can also be carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic excavator with a hook, which is preferably used to perform a lifting work (crane work) or the like with a hook provided at the front.

[0002]

2. Description of the Related Art Generally, as a hydraulic excavator, a hook is provided on the front end side for excavating work such as earth and sand, and the hook is configured to be capable of carrying a relatively light load such as a load. An attached hydraulic excavator is known (for example, Japanese Patent Laid-Open No. 2000-87395).

In this type of conventional hydraulic excavator with a hook, the front is attached to the front side of the vehicle body so that the front can be raised and lowered. And the front is the boom, arm and bucket, the boom cylinder that operates them,
It is configured to include an arm cylinder and a bucket cylinder.

Further, the bucket cylinder is connected to the bucket via a bucket link, and the hook is rotatably attached to the bucket link.

When excavating earth and sand with a hydraulic excavator, the hook is fixed to the bucket link and the front is operated in this state to perform the excavating operation. Further, when the crane operation is performed, the hook is released from the fixed state and the hook can be rotated with respect to the bucket link, and the load is hung by the hook.

In this case, at the time of crane work, first, the bucket cylinder is extended to the maximum extent, and the bucket link is exposed to the ground by making a large swing (cloud) so that the bucket is folded toward the vehicle body at the tip end side of the arm. Hold in position. Then, the fixed state of the hook fixed to the bucket link is released, and the crane work is performed by suspending the luggage and the like on the tip end side and operating the boom, the arm and the like.

Further, during crane work, for example, if the suspended load is too heavy or the front is in an unnatural posture,
Since the vehicle body may become unstable, the hydraulic excavator is provided with an alarm device for issuing an alarm to an operator during crane work.

In this case, the alarm device stores in advance various constants including, for example, the weight of the vehicle body, the position of the center of gravity, the maximum allowable value of the moment applied to the vehicle body, the weight of the suspended load, the boom and the arm. Various sensors are connected to detect the operating angle and the like. Then, the alarm device uses the detection result of the sensor and various constants to calculate the rated load of the suspended load and the stability of the vehicle body according to the posture of the front, and the actual load and the stability of the vehicle body are calculated. When it becomes inappropriate,
It gives an alarm to the operator.

[0009]

By the way, in the above-mentioned prior art, when carrying out a crane operation, a state in which the bucket is most clouded on the vehicle body side is set as a reference posture, and the luggage is hung on the hook in this reference posture. It is assumed that. For this reason, the alarm device is preset with various constants and the contents of the arithmetic program so that an accurate alarm operation is performed when the bucket is held in the reference posture.

However, at an actual work site or the like, the operator may not pay enough attention to the posture of the bucket when performing the crane work, and the bucket may be rotated (dumped) forward from the reference posture. , Luggage may be hung on the hook.

Therefore, if the bucket deviates from the standard posture during the crane work, even if the alarm device calculates the rated load of the suspended load and the stability of the vehicle body according to the front posture, the Since an error is likely to occur in the calculation result of, there is a possibility that an alarm to the operator may be inaccurate, and there is a problem that reliability is reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to prevent the crane work from being performed with the bucket deviating from the standard posture, and to improve the reliability. To provide a hydraulic excavator with a hook.

[0013]

In order to solve the above-mentioned problems, the present invention comprises a self-propelled vehicle body and a front attached to the vehicle body, the front being a boom attached to the vehicle body. An arm provided on the tip side of the arm, a bucket attached to the tip side of the arm and rotated by a bucket cylinder via a bucket link, and a hook provided on a connecting portion between the bucket and the bucket link. Applies to hydraulic excavators with hooks.

The feature of the configuration adopted by the invention of claim 1 is that the bucket cylinder extended state detecting means for detecting that the bucket cylinder is in the extended state, and the bucket cylinder extended state detecting means for making the bucket cylinder substantially extend. The crane work permitting means for permitting the crane work using the hook only when the maximum extension is detected is provided.

With this construction, when the crane work is performed by the hydraulic excavator, the bucket cylinder is extended to the maximum extent, and the bucket is in the standard posture in which the bucket is rotated most toward the vehicle body (cloud). Whether or not it can be detected by the bucket cylinder extension state detecting means. Then, the crane work permission means, according to the detection result of the bucket cylinder extension state detection means,
The crane work can be permitted when the bucket is in the standard posture, and the crane work can be stopped when the bucket cylinder is contracted from the maximum extension state and the bucket is out of the standard posture.

According to the second aspect of the present invention, the bucket cylinder extension state detecting means for detecting that the bucket cylinder is in the extension state, and whether or not the hook is in the storage position fixed to the bucket link are detected. The hook storage state detection means and the bucket cylinder extension state detection means detect that the bucket cylinder is extended to the maximum extent, and the hook storage state detection means detects that the hook is at a position deviated from the storage position. Crane work permitting means for permitting crane work using the hook only when is detected.

Thus, during crane work, it is possible to detect whether or not the bucket cylinder is extended to the maximum extent by the bucket cylinder extension state detecting means, and
Whether or not the hook is taken out from the storage position can be detected by the hook storage state detecting means. Then, the crane work permission means can permit the crane work according to the detection results of these detection means when the bucket is in the reference posture and the hook is taken out to the position for crane work. On the other hand, when the bucket is out of the standard posture or the hook is stored, the crane work can be stopped.

According to the third aspect of the invention, the vehicle body is provided with a crane monitor for monitoring the state of the work when the crane work is performed using the hook.

Thus, during crane work, for example, the rated load of the suspended load and the stability of the vehicle body according to the posture of the front can be displayed on the crane monitor and the operator can be notified of them.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A hydraulic excavator with a hook according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In the figure, 1 is a lower traveling body of a hydraulic excavator, 2
Is an upper revolving structure that is rotatably mounted on the lower traveling structure 1. The upper revolving structure 2 includes a revolving frame 3 that constitutes the lower side thereof, a cab 4 provided on the revolving frame 3, and a building cover. 5, and a counter weight 6 are included.

A front 7 is provided on the front side of the upper revolving superstructure 2 so as to be able to move up and down. The front 7 has a boom 8 attached to the revolving frame 3 so that it can be moved up and down, and the boom 8 9 rotatably attached to the tip side of the
A bucket 10 rotatably attached to the tip side of the arm 9, a boom cylinder 11 provided between the revolving frame 3 and the boom 8 to lift and lower the boom 8, a boom 8 and an arm 9. And an arm cylinder 12 for rotating the arm 9, a bucket cylinder 13 for rotating (dumping, clouding) the bucket 10, and bucket links 16 and 17, which will be described later, and a hook 21. ing.

Here, as shown in FIGS. 2 and 3, the bucket 10 includes two brackets 10 which are separated in the left and right directions.
A and 10A are provided. And bucket 10
Is rotatably supported on the tip side of the arm 9 via an arm bucket connecting pin 14 inserted between the brackets 10A.

Further, the bucket cylinder 13 is provided with a tube 13A whose base end side is rotatably attached to the arm 9 side through a bottom side connecting pin 15, and a tube 13A which is extendably inserted into the tube 13A. Bucket link 1 on the side
And a rod 13B that is rotatably connected to the bucket 10 via 6 or the like.

Reference numeral 16 is a bucket 10 and a bucket cylinder 1.
The bucket link 16 is provided between the third rod 13B and the third rod 13B, and the bucket link 16 has elongated link plates 16A and 16B that are separated in the left and right directions.
One of the lengthwise ends of A and 16B is the bucket cylinder 13
It is rotatably connected to the rod 13B and is also connected to the arm 9 via another bucket link 17.
The other ends of the link plates 16A and 16B are connected to the bucket 1
It is rotatably connected between 0 brackets 10A.

In this case, the rod 13B of the bucket cylinder 13, the link plates 16A and 16B, and the bucket link 17 are connected using the rod-side connecting pin 18, and the link plates 16A and 16B and the bracket 10A of the bucket 10 are connected.
Are connected to each other using a bucket-side connecting pin 19.
Further, the bucket link 17 and the arm 9 are connected using an arm side connecting pin 20.

Reference numeral 21 denotes a hook mounted on the bucket link 16. The hook 21 is a boss 21A for a hook rotatably fitted to the outer peripheral side of the bucket side connecting pin 19 as shown in FIGS. A universal joint portion 21B pin-connected to the hook boss 21A, and a hook portion 21C rotatably connected to the hook boss 21A via the universal joint portion 21B and having a tip end bent into a hook shape. It is configured.

When excavating earth and sand with a hydraulic excavator, for example, the hook 21 is housed between the left and right link plates 16A and 16B as shown in FIG. 6, which will be described later. For example, it is fixed to a predetermined storage position by a fixing pin 21D or the like provided on the link plate 16A.

When carrying out the crane work, FIG.
As shown in, the hook 21 is taken out to the working position by removing the hook 21 from the fixing pin 21D and rotating it downward. The operator of the hydraulic excavator operates the crane monitor 24, which will be described later, and confirms the displayed contents, while performing the hanging work using the hook 21.

Next, referring to FIG. 5, the configuration relating to the crane monitor 24 will be described. First, 22 is a hydraulic pressure sensor as a bucket cylinder extension state detecting means, and the hydraulic pressure sensor 22 is shown in FIG. As described above, for example, it is provided in a hydraulic pipe (not shown) for supplying / discharging pressure oil to / from the bucket cylinder 13. Then, the oil pressure sensor 22 is
When the rod 13B is most extended from the tube 13A, the maximum extension state of the bucket cylinder 13 is detected by the hydraulic pressure in the tube 13A, and the controller 2 described later is used.
The detection signal is output to 5.

Reference numeral 23 denotes a proximity switch as hook storing state detecting means provided on the link plate 16A of the bucket link 16, for example, and the proximity switch 23 is, for example, a non-contact type magnetic pickup or the like as shown in FIG. , The magnetic field changes when the universal joint portion 21B of the hook 21 moves toward and away from the proximity switch 23,
Is to detect which of the storage position and the work position is in.

A crane monitor 24 is provided in the cab 4. As shown in FIG. 4, the crane monitor 24 includes a crane mode switch 24A operated by an operator or the like when starting a crane operation, and a crane monitor 24. The power supply lamp 24B is turned on when the power is turned on, and the display unit 24C that displays the output content of the controller 25 is included.

When the crane operation is performed by the hydraulic excavator, if the operator or the like closes the crane mode switch 24A, the crane monitor 2 is excluded unless the controller 25 prohibits the crane operation.
4 is activated and the crane work is ready. As a result, the power lamp 24B is turned on and the display section 24C displays
The controller 25 displays various work states according to the weight of the suspended load, the posture of the front 7, and the like.

Further, when the crane work is prohibited by the controller 25, the crane monitor 24 is stopped by the controller 25 even if an operator or the like closes the crane mode switch 24A, whereby the crane work is prohibited. It is configured to.

Reference numeral 25 is a controller mounted on a hydraulic excavator and serving as a crane work permission means.
The proximity switch 23 and the crane mode switch 24A of the crane monitor 24 are connected, and an angle sensor for individually detecting the rotation angle of the boom 8 and the arm 9 and a load sensor for detecting the weight of the load suspended on the hook 21. (Both not shown) and the like are connected. A power lamp 24B (power circuit) of the crane monitor 24, a display unit 24C, and a fall prevention valve 26 described later are connected to the output side of the controller 25. Further, the controller 25 stores in advance various constants including, for example, the vehicle body weight of the hydraulic excavator, the position of the center of gravity, and the like.

Then, the controller 25 detects that the bucket cylinder 13 is in the maximum extension state as shown in FIG. 2 by the hydraulic pressure sensor 22 and that the hook 21 is taken out to the working position. Allows crane work to be carried out when detected by
When the crane mode switch 24A is closed in this state, the operation of the crane monitor 24 is started. As a result, the controller 25 uses the detection signals input from the angle sensor, the load sensor, and the like and various constants to calculate, for example, the rated load of the suspended load and the stability of the vehicle body according to the posture of the front 7. The operation results can be displayed on the display unit 24C of the crane monitor 24 so that the operator can monitor the working condition.

Here, these constants and the contents of the arithmetic processing are based on the state where the bucket cylinder 13 is extended to the maximum as shown in FIG. 2 (that is, the posture in which the bucket 10 is most clouded toward the vehicle body side). It is set in advance, and when carrying out a crane operation while holding the bucket 10 in a standard posture, the display on the crane monitor 24 has accurate contents corresponding to the actual operation state.

On the other hand, as shown in FIG. 6, the bucket cylinder 1
When 3 is smaller than the maximum extension state or when the hook 21 is in the retracted position, the monitor display and the crane work itself cannot be properly performed, so even if the operator closes the crane mode switch 24A. The controller 25 stops the crane monitor 24.

26 is a fall prevention valve controlled by the controller 25. The fall prevention valve 26 is, as shown in FIG.
For example, it is provided between the boom cylinder 11 and a hydraulic pipe (not shown) for supplying / discharging pressure oil to / from the boom cylinder 11, and between the arm cylinder 12 and a hydraulic pipe (not shown) for supplying / discharging pressure oil to / from the arm cylinder 12. The controller 25 is operated and stopped in conjunction with the crane monitor 24.

When the hydraulic pipe or the like is damaged during crane work, for example, the hydraulic oil leaks from the damaged portion, so that the boom 8, arm 9 loses the driving force, and the suspended load is prevented. It prevents it from falling.

The hydraulic excavator with a hook according to this embodiment has the above-mentioned structure. Next, the control process of the controller 25 will be described with reference to FIG.

First, in step 1, the detection signal input from the oil pressure sensor 22 is read, and in step 2, it is determined whether or not the bucket cylinder 13 is in the maximum extension state using this detection signal.

When the determination in step 2 is "NO", the bucket 10 is not held in the standard posture corresponding to the crane work. Therefore, in step 3, the crane monitor 24 is stopped, and in step 13 which will be described later. To return.

When it is determined to be "YES" in step 2, the detection signal input from the proximity switch 23 is read in step 4, and in step 5, the hook 21 is moved from the retracted position to the working position by using this detection signal. Determine whether it has been taken out.

When it is determined to be "NO" in step 5, the hook 21 is stored, so the crane monitor 24 is stopped in step 3. Therefore, when it is determined to be "NO" in any one of steps 2 and 5,
Even if the operator closes the crane mode switch 24A to perform crane work, the crane monitor 2
4 does not work.

When it is determined to be "YES" in step 5, the operation of the crane monitor 24 is permitted in step 6, and in step 7, the crane mode switch 24A is activated.
Read the signal input from.

Then, in step 8, it is determined whether or not the crane mode switch 24A is closed (ON), and if "YES" is determined, the operation of the crane monitor 24 is started in step 9, and step 10 Then, after activating the fall prevention valve 26, the process returns in step 13.

Therefore, when the crane work is performed by the hydraulic excavator, first, the bucket cylinder 13 is extended to the maximum extent to hold the bucket 10 in the reference posture, the hook 21 is taken out from the retracted position, and then the crane mode switch 24A is turned on. Crane monitor 2 by closing
4 can be activated. And the operator
By suspending a load on the hook 21 and operating the boom 8, the arm 9 and the like while monitoring and confirming the display of the crane monitor 24, the suspended load work can be smoothly performed.

When it is judged "NO" in step 8, the crane mode switch 24A is opened (OF).
F) state is maintained, and it is a case where a normal excavation work or the like is performed by, for example, a hydraulic excavator, so step 11
Then, the crane monitor 24 is stopped at step 12, the fall prevention valve 26 is stopped at step 12, and then the routine returns at step 13. As a result, the operator expands and contracts the cylinders 11, 12, and 13 with the hook 21 stored, and operates the boom 8, the arm 9, and the bucket 10.
Can excavate earth and sand.

Thus, according to the present embodiment, the controller 25 detects that the bucket cylinder 13 is in the maximum extension state by the hydraulic pressure sensor 22, and the hook 21 is taken out from the storage position by the proximity switch 23. When it is detected that there is a crane, the crane monitor 24 is activated.

As a result, the operator can carry out the crane work by the regular suspension method using the hook 21, and can prevent the crane work from being carried out by using a portion other than the hook 21, for example.

Further, since the bucket 10 can always be held in the standard posture during the crane work, the crane monitor 24 can accurately display the state of the front 7, the suspended load, etc., and it is possible to prevent an error in the displayed contents. At the same time, it is possible to avoid contact between the dumped bucket 10 and the suspended load as shown in FIG. 6, for example, so that safety and reliability can be further improved.

When the bucket 10 is out of the standard posture or the hook 21 is stored, the crane monitor 24 can be held in a stopped state even if the operator closes the crane mode switch 24A. Crane work in such a state can be reliably regulated, the posture of the bucket 10 can be corrected, and the hook 2
The operator can be prompted to take out 1.

In the above embodiment, the operation of the crane monitor 24 is started when the bucket cylinder 13 is in the maximum extension state and the hook 21 is taken out from the retracted position. Not limited to this,
For example, the proximity switch 23 is omitted and the bucket cylinder 1
It is also possible to detect only whether or not No. 3 is in the maximum extension state and operate the crane monitor 24 according to the detection result.

In the embodiment, the oil pressure sensor 22 is used as the bucket cylinder extension state detecting means. However, the present invention is not limited to this, and the bucket cylinder 13 is rotated at the position of the bottom side connecting pin 15, for example. A rotation angle sensor that detects the angle or a rotation angle sensor that detects the rotation angle of the bucket link 17 at the position of the arm-side connecting pin 20 is provided, and when these detection angles reach a predetermined rotation angle. The state may be detected as the maximum extension state of the bucket cylinder 13.

Similarly, the rotation angle sensor is used to detect the rotation angle of the bucket 10 at the position of the connecting pin 14, and the bucket link 16 is detected at the position of the connecting pins 18 and 19.
By detecting the rotation angle of the bucket cylinder 1
The maximum extension state of No. 3 may be detected.

Further, as the bucket cylinder extension state detecting means, for example, the rod 13 of the bucket cylinder 13 is used.
A stroke sensor that detects the displacement (stroke) of B,
Alternatively, a limit switch or the like that is closed when the rod 13B extends to the maximum position may be used.

In the embodiment, the proximity switch 23 is used as the hook storage state detecting means,
The present invention is not limited to this, and may be configured to use, for example, a limit switch closed when the hook 21 is stored, or an optical pickup such as a photocoupler.

Further, in the embodiment, the controller 2
5 is arranged outside the crane monitor 24, but the present invention is not limited to this, and a calculation circuit or the like serving as a controller may be arranged inside the crane monitor.

[0060]

As described in detail above, according to the invention of claim 1, the crane work permitting means is configured to permit the crane work only when the bucket cylinder is in the maximum extension / contraction state. The bucket can be held in the most clouded reference posture toward the vehicle body side, and the crane work by the operator can be stopped when the bucket deviates from the reference posture. As a result, contact between the bucket and the suspended load can be avoided, and the crane work can be performed smoothly, while ensuring safety and
The reliability can be increased.

According to the second aspect of the invention, the crane work permitting means permits the crane work only when the bucket cylinder is in the maximum extension / contraction state and the hook is out of the retracted position. The operator
Crane work can be performed by a regular suspension method using hooks, and at this time the bucket can be held in the reference posture, and for example, the bucket is out of the reference posture,
The crane operation can be stopped when the hook is in the retracted position. As a result, for example, it is possible to prevent crane work from being performed using a part other than the hook,
Crane work can be performed smoothly, and safety and reliability can be improved.

Further, according to the invention of claim 3, since the crane monitor is provided on the vehicle body, during crane work, for example, the rated load of the suspended load and the stability of the vehicle body depending on the posture of the front can be used. The information can be displayed on the monitor and can be notified to the operator, and the safety and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing a hydraulic excavator with a hook according to an embodiment of the present invention.

FIG. 2 is an enlarged front view of the front tip side showing a state in which the bucket cylinder is extended to the maximum extent and the hook is taken out from the retracted position.

FIG. 3 is a partially enlarged bottom view of the front viewed from the arrow III-III direction in FIG.

FIG. 4 is a front view showing a crane monitor arranged in a cab.

[Fig. 5] Oil pressure sensor, proximity switch, crane monitor,
It is a whole block diagram which shows a controller etc.

FIG. 6 is an enlarged front view of a front portion showing a state in which the bucket cylinder is contracted and the hook is retracted.

FIG. 7 is a flowchart showing control processing by the controller.

[Explanation of symbols]

1 Lower Traveling Body (Vehicle) 2 Upper Revolving Body (Vehicle) 3 Revolving Frame 4 Cab 6 Counterweight 7 Front 8 Boom 9 Arm 10 Bucket 10A Bracket 11 Boom Cylinder 12 Arm Cylinder 13 Bucket Cylinder 13A Tube 13B Rods 14, 15, 18 , 19, 20 Connection pin 16, 17 Bucket link 16A, 16B Link plate 21 Hook 21D Fixed pin 22 Oil pressure sensor (bucket cylinder extension state detection means) 23 Proximity switch (hook storage state detection means) 24 Crane monitor 24A Crane mode switch 25 Controller (crane work permission means) 26 Fall prevention valve

Continued front page    F-term (reference) 2D012 DA03                 2D015 GA03 GB05                 3F004 AG00 AG09 EA35 NA01 NA07                       PA01 PC07

Claims (3)

[Claims] 1. A self-propelled vehicle body and a front attached to the vehicle body, wherein the front is provided with an arm provided on a tip side of a boom attached to the vehicle body, and an arm provided on a tip side of the arm. In a hydraulic excavator with a hook including a bucket attached and rotated by a bucket cylinder via a bucket link, and a hook provided at a connecting portion between the bucket and the bucket link, the bucket cylinder is in an extended state. Bucket cylinder extension state detecting means for detecting, and crane work permission means for permitting crane work using the hook only when the bucket cylinder extension state detecting means detects that the bucket cylinder is extended to the maximum extent. A hydraulic excavator with a hook characterized by being configured. 2. A self-propelled vehicle body and a front attached to the vehicle body, wherein the front is an arm provided on a tip side of a boom attached to the vehicle body and a front side of the arm. In a hydraulic excavator with a hook including a bucket attached and rotated by a bucket cylinder via a bucket link, and a hook provided at a connecting portion between the bucket and the bucket link, the bucket cylinder is in an extended state. Bucket cylinder extension state detection means for detecting, hook storage state detection means for detecting whether or not the hook is in the storage position stored in the bucket link, and bucket cylinder extension state detection means for detecting the bucket cylinder It is detected that the hook is extended to the maximum, and the hook storage state detecting means detects the hook. A hydraulic excavator with a hook, characterized in that it is provided with crane work permission means for permitting crane work using the hook only when it is detected that the hook is out of the storage position. 3. The hydraulic excavator with a hook according to claim 1, wherein the vehicle body is provided with a crane monitor for monitoring a working state when performing a crane work using the hook.