JP2507622Y2 - Hydraulic grab bucket - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial application] The present invention relates to a hydraulic grab bucket that is suspended from a crane or the like at a harbor or a construction site, opens and closes the grab bucket with hydraulic pressure, grabs an object to be gripped, and handles cargo. More specifically, the present invention relates to a hydraulic grab bucket in which various detecting devices and control means for processing a detection signal of the detecting device to control opening / closing driving of the grab bucket are integrally provided in a glove bucket body.

[0002]

2. Description of the Related Art Generally, in order to perform cargo handling work using a hydraulic grab bucket, as shown in FIG. 3, the grab bucket 5 is hung on a crane 6 or the like by a cable 6a.
The suspended load B is gripped by opening and closing the glove bucket 5 by hydraulic pressure from a drive source 5b such as an electric motor placed on the upper portion of the glove bucket body 5a. The opening / closing drive of the grab bucket 5 and the operation of the crane 6 are performed by an operator on the ground by operating the controller 8 installed on the ground. The controller 8 and the glove bucket 5 are connected via a control panel 9 by a cabtire cable 6b.

Such a hydraulic grab bucket 5 has a grab bucket 5 in order to avoid a danger due to a malfunction of the grab bucket 5 and damage to the grab bucket 5.
It is common to install a detection device such as an opening / closing sensor for detecting the opening / closing driving limit of the above and an oil temperature sensor for detecting the oil temperature of the operating oil for opening / closing the grab bucket 5.

[0004]

However, the conventional grab bucket has a cab tire that is installed on the ground and has a control panel that incorporates a control circuit that processes a detection signal from the detection device and a glove bucket detection device. I had to connect with a cable. Therefore, when adding or installing detection devices such as the open / close sensor and the oil temperature sensor described above to the grab bucket,
A cabtyre cable had to be added to connect to the control board. In addition, the manufacturer of the detection device such as the open / close sensor and the oil temperature sensor may be different from the manufacturer of the operation panel, which may make attachment difficult and may cause malfunction due to inconvenience in control. The present invention has been made in view of the above problems, and an object of the present invention is to provide a control means for controlling a glove bucket opening / closing drive by processing a detection signal of a detection device in a glove bucket body. Thus, a hydraulic grab bucket in which various detection devices can be easily attached is obtained.

[0005]

In order to solve the above problems, the grab bucket of the present invention is a hydraulic grab bucket that grabs an object to be grabbed by opening and closing the grab bucket with hydraulic pressure to grab and load. In, a detection device for detecting the drive limit of the grab bucket, and the opening and closing of the grab bucket by stopping the supply of hydraulic oil to the hydraulic drive device that opens and closes the glove bucket when the detection device detects the drive limit. The grab bucket main body is provided with a control means for stopping the drive and stopping the supply of hydraulic oil to the hydraulic drive device until the drive limit is released to prohibit the re-driving of the grab bucket. And

[0006]

Since the hydraulic bucket of the present invention is constructed as described above, when the detection device attached to the grab bucket detects a drive limit due to, for example, an increase in hydraulic oil temperature or an increase in hydraulic oil pressure, this The detection signal is processed by the control means provided in the glove bucket body. The control means shuts off the hydraulic drive circuit for opening and closing the grab bucket to stop the opening and closing drive of the grab bucket. Further, the control means keeps the hydraulic drive circuit in the shut-off state until the drive limit is released, and prohibits the re-driving of the grab bucket due to a malfunction of an operator.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of a control circuit provided in the main body of the hydraulic grab bucket of the present invention, and FIG. 2 is a schematic diagram of a hydraulic drive circuit of the grab bucket 5.

As shown in FIG. 2, the hydraulic drive circuit of the grab bucket 5 (see FIG. 3) has a constant capacity for sending the hydraulic oil in the oil tank 16 to the oil passage 11 side by a drive source such as an electric motor E. Shaped hydraulic pump 10 and solenoid operation a,
A switching valve 14 of a center bypass type three-position four-way valve for switching the oil passage by b, and an oil passage 1 from this switching valve 14 to a two-way passage.
It is composed of left and right hydraulic cylinders (not shown) for opening and closing the grab bucket 5 connected by branching 8 and 18, and the pressure is controlled in the oil passage 11 between the hydraulic pump 10 and the switching valve 14. The relief valve 12 is provided via an oil passage 15. Reference numeral 11a in the figure is a flexible tube such as a rubber hose. The grab bucket 5 is operated by the operator while the hydraulic pump 10 is being driven (see FIG. 3).
To operate the solenoid a or b side of the switching valve 14,
Opening and closing is performed by supplying hydraulic oil to the hydraulic cylinders via the oil passages 18, 18. The opening / closing drive of the grab bucket 5 is performed by operating the controller 8
Can be stopped by switching to the neutral position.

In FIG. 1, the control means provided in the glove bucket body 5a of the present invention is a control circuit 1, 2, 3 corresponding to various detection devices attached to the glove bucket body 5a.
.., and these control circuits 1, 2, 3 ... Are circuits 1a, 2a, 3a for electrically connecting the electromagnetic relay STP or the timers TC, TO when the detection device detects the drive limit of the grab bucket 5. And self-holding circuits 1b, 2b, 3b for holding the electromagnetic relay STP and the timers TC and TO in a conductive state when the electromagnetic relay STP or the timers TC and TO are brought into conduction.

In the following, in the first embodiment of the present invention, a case will be described in which an oil temperature sensor (detection device) for detecting the temperature of the hydraulic oil that drives the glove bucket 5 to open and close is attached. When the oil temperature sensor 7 attached to the grab bucket body 5a detects the upper limit temperature (driving limit) of the hydraulic oil,
The switch TH is turned on by the detection signal of the oil temperature sensor 7.
The circuit 1a of the control circuit 1 is closed by operating N, and the electromagnetic relay S
TP becomes conductive. When the grab bucket 5 is being driven to open and close, the switch of the controller 8 that drives the glove bucket 5 to be opened and closed is in an ON state, so that the self-holding circuit 1b is closed by conduction of the electromagnetic relay STP. Therefore, the electromagnetic relay STP is always held in the conductive state via the self-holding circuit 1b even when the hydraulic oil temperature is lowered and the switch TH is turned off.

When the electromagnetic relay STP is turned on, the grab bucket opening / closing drive control circuit 4 for activating the switching valve 14 is cut off to switch the switching valve 14 to the neutral position and stop the opening / closing of the grab bucket 5. To re-drive the grab bucket 5 after the hydraulic oil temperature has dropped, the controller 8
Is operated to turn off the switch 8 ′ once to shut off the self-holding circuit 1b, and after the operator confirms the safety, the controller 8 is operated again to turn on the switch 8 ′. The circuit 4 is turned on again, the switching valve 14 is switched, and the grab bucket 5 restarts the opening / closing drive.

The control circuits 2 and 3 include timers TC and TO.
The delay means is provided. Hereinafter, in the second embodiment of the present invention, a case will be described in which a detection device for detecting the open / close drive limit of the grab bucket 5 is attached. Pressure switch P for detecting the open / close drive limit of the grab bucket 5
The S (detection device) is provided at one end of the oil passage 13 branched from the oil passage 11. For example, when the opening drive of the glove bucket 5 reaches a limit, the glove bucket 5 is actuated by the action of a stopper (not shown) provided in the glove bucket body 5a.
The open drive of stops. The oil pressure in the oil passage 11 rises because the hydraulic pump 10 continues to supply the hydraulic oil even when the opening / closing drive of the grab bucket 5 is stopped. The hydraulic oil pressure in the oil passage 11 is transmitted to the pressure switch PS via the oil passage 13, and when the oil pressure exceeds a predetermined pressure (driving limit), the pressure switch PS is turned on. This pressure switch PS
The circuit 2b is closed and the timer TC is turned on to start the operation. When the ON state of the pressure switch PS is not released even after the set time of the timer TC has passed, the circuit 2c is closed, the self-holding relay RC is turned on, and the self-holding circuit 2b is closed. Therefore, the timer TC maintains the conductive state even after the set time has elapsed.

On the other hand, when the set time of the timer TC has elapsed, the opening / closing drive control circuit 4 of the switching valve 14 is shut off to switch the switching valve 14 to the neutral position, and the opening / closing drive of the grab bucket 5 is stopped. Also in this case, as in the first embodiment, the pressure of the hydraulic oil in the oil passage 11 is reduced and the pressure switch P
Even if S is turned off, the self-holding circuit 2b of the timer TC is not shut off and the grab bucket 5 cannot be re-driven unless the controller 8 is operated to switch the switch 8'to the off state. In addition, the control circuit 3
Is a control circuit for preventing the object to be gripped with a force of a predetermined pressure or more when the grab bucket 5 is closed and grips the object to be gripped. There is no difference from the example, so a detailed description is omitted.

In the above-mentioned first and second embodiments, the case where the oil temperature sensor 6 and the pressure switch PS are provided has been described, but the present invention is not limited to this, and the above-mentioned control is performed by another detection device. It goes without saying that the circuits 1, 2, 3, ... May be switched.
Further, by providing a large number of control circuits 1, 2, 3, ... And connecting various detection devices to each of the control circuits 1, 2, 3, .. Further, in the above-described embodiment, the control circuits 1, 2,
Although 3 ... has been described as a circuit including a mechanical relay and a timer, it is needless to say that the circuit is not limited to this and may be a sequence circuit according to a system program.

[0015]

The hydraulic grab bucket of the present invention operates to a detection device for detecting the drive limit of the grab bucket and a hydraulic drive device for opening and closing the grab bucket when the detection device detects the drive limit. Control that stops the supply of oil to stop the opening and closing drive of the grab bucket, and stops the supply of hydraulic oil to the hydraulic drive device until the drive limit is released to prohibit re-driving of the grab bucket. Since the means is provided in the glove bucket main body, it is attached to the glove bucket main body, and various detecting devices for detecting the open / close limit of the grab bucket and the upper limit temperature of hydraulic oil temperature and the cab tile cable are connected to the ground operation panel. It is not only necessary to connect with, and it is possible not only to suspend the load without trouble, but also to add and install various detection devices easily. That. Further, since it has a control means independent of the operation panel on the ground, there is no fear of malfunction due to incompatibility between the operation panel and the detection device, and work efficiency and safety can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a control circuit provided in a hydraulic grab bucket of the present invention.

FIG. 2 is a schematic diagram of a hydraulic drive circuit of a grab bucket.

FIG. 3 is a diagram showing an outline of a hydraulic grab bucket.

[Explanation of symbols]

 1, 2, 3 Control circuit 4 Open / close drive control circuit 5 Grab bucket 6 Crane 6a Cable 6b Cabtyre cable 7 Oil temperature sensor 8 Controller 9 Control panel 10 Hydraulic pump 11, 13, 15, 18 Oil passage 12 Relief valve 14 Switching valve 16 Oil tank 17 Flexible pipe

Claims (1)

(57) [Scope of utility model registration request] 1. A hydraulic grab bucket that opens and closes a grab bucket by hydraulic pressure to grab an object to be gripped and performs a cargo handling operation, and a detecting device for detecting a drive limit of the grab bucket, and the detecting device. When the drive limit is detected, the supply of hydraulic oil to the hydraulic drive that opens and closes the grab bucket is stopped to stop the opening and closing drive of the grab bucket, and the hydraulic drive is connected until the drive limit is released. And a control means for prohibiting the re-driving of the glove bucket by stopping the supply of the hydraulic oil, the hydraulic glove bucket.