JP2000289985A - Excessive winding detection device for crane with hook storage mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a system configuration by dispensing with a function holding an output condition of an excessive winding detection signal in an excessive winding detection device for a crane with hook storage mechanism. SOLUTION: This excessive winding detection device for a crane with a hook storage mechanism is provided with an ultrasonic sensor 31 detecting an excessive winding condition when an interval between a hook 53 and a tip part 51 of a boom 50 becomes below predetermined excessive winding detection distance L, an optical sensor 32 detecting an excessive winding condition in a dead zone of the ultrasonic sensor 31, a contact detection switch 62 detecting an excessive winding condition when the hook 53 comes into contact with a hook guide member 63 of the hook storage mechanism, and an excessive winding signal output means outputting an excessive winding detection signal due to the excessive winding condition detection of any one detector of the ultrasonic sensor 31, the optical sensor 32, and the contact detection switch 62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane provided with a hook storage mechanism, which can reliably detect a winding state even when the hook is at any position. The present invention relates to a detection device.

[0002]

2. Description of the Related Art In a crane, a hook is hung from a tip end of a boom with a wire rope, and a loaded hook is hoisted.
When the hook is lifted, the hook is lifted to prevent damage to the hook, boom, wire rope, etc. And a winding detection device for detecting a so-called winding state in which the distance between the hook and the tip of the boom is less than or equal to a predetermined distance. When the winding detection device detects the winding state, an alarm is issued and the operation to the hook rising side is stopped.

In a crane provided with a hook storing mechanism, when storing the hook, the winch is lowered at a low pressure even when the hook is in a winding state, and the hook is further wound up. If the hook continues to be wound after the hook comes into contact with the hook guide member provided at the end of the boom, the hook is guided by the hook guide member and retracted sideways. As shown in FIG. 9, the conventional winding detection device is provided with a winding detection switch 54 at the tip end 51 of a boom 50, and a winding weight 57 is suspended from a switch lever 55 via a winding wire rope 56. are doing. In the normal state, the switch lever 55 is pulled down by the winding weight 57 so that the winding detection switch 54 is turned off.
It has become. The hook 53 rises and the winding weight 57
When the winding weight 57 is lifted, the switch lever 55 rotates upward (clockwise in the drawing), the winding detection switch 54 is turned on, and the winding state is detected.

When the hook is stored by a crane equipped with a hook storage mechanism, the hook 53 is wound up until it comes into contact with the tip end portion 51 of the boom 50 even if the hook is in a winding state.
The winding wire rope 56 becomes slack, and the hook 53 or the boom 50
May be caught between the pulley and the hook guide member 63 at the distal end portion 51 of the vehicle. Therefore, in order to avoid interference between the winding detection device and the hook storage mechanism, as shown in FIG. 10, an ultrasonic sensor or an optical sensor for detecting the distance between the hook 53 and the tip end 51 of the boom 50 is used. A controller 92 that is provided with a non-contact type distance detector 91 to detect a winding state and that maintains an output state of a winding detection signal even when the position of the hook 53 deviates from the detection range of the distance detector 91. Thus, even if an erroneous operation on the hook rising side is performed during the storage of the hook, a winding detection device (refer to Japanese Patent Application Laid-Open No. 10-109890) capable of preventing the collision of the hook 53 with the tip end portion 51 of the boom 50 is provided. Proposed.

[0005]

However, since this winding detection device holds the output state of the winding detection signal, the memory for holding or not holding the signal when the power is turned off, and the signal is released. Condition processing etc.
The system configuration was complicated. Also, for example, when the crane is turned and the tip 51 of the boom 50 erroneously hits a branch of a tree or the like and the branch enters the lower part of the tip 51 of the boom 50, the winding state is not reached. There is also a problem that the output state of the winding detection signal is held erroneously, and the output state of the winding detection signal is maintained even when the vehicle is turned back.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem in a winding detection device for a crane with a hook storage mechanism, and does not require a function of holding an output state of a winding detection signal during storage of a hook, thereby simplifying the system configuration. It is an object of the present invention to provide a winding detection device that does not maintain the output state of a winding detection signal due to erroneous detection.

[0007]

According to the present invention, there is provided an apparatus for detecting winding over of a crane with a hook storing mechanism, comprising: an ultrasonic detector for detecting a winding state when an interval between a hook and a tip end of a boom is less than a predetermined distance; An optical detector that detects a winding state in a dead zone of an ultrasonic detector, and a contact detector that detects a winding state when a hook abuts a hook guide member of a hook storage mechanism,
The above problem is solved by providing a winding signal output unit that outputs a winding detection signal by detecting a winding state of any one of the ultrasonic detector, the photodetector, and the contact detector. .

In the winding detection device for a crane with a hook storage mechanism according to the present invention, if the distance between the hook and the tip of the boom becomes less than a predetermined distance during the operation of raising the hook, the ultrasonic detector detects the winding state. Then, a winding detection signal is output from the winding signal output means. Since the ultrasonic detector has a wide measurement field of view, it is possible to detect the winding state even when the hook swings. However, since the ultrasonic detector has a dead zone in the close distance, the winding state cannot be detected if the hook keeps rising during storage and the distance from the tip of the boom becomes small.

At this time, the photodetector having almost no dead zone even at a short distance detects the winding state, and outputs a winding detection signal from the winding signal output means. The photodetector has a narrow measurement field of view, but since the distance between the hook and the tip of the boom has already been reduced, the deflection of the hook is small, and there is no problem in detecting the winding state. After the hook further rises and comes into contact with the hook guide member of the hook storage mechanism, the hook changes its direction and is stored laterally, so that the hook deviates from the measurement field of view of the photodetector and the winding state cannot be detected.

At this time, since the hook has already contacted the hook guide member, the contact detector detects the winding state and outputs a winding detection signal from the winding signal output means. As described above, the winding detection device for the crane with the hook storage mechanism of the present invention uses the ultrasonic detector and the optical detector until the hook reaches the storage position after the interval between the hook and the tip of the boom becomes equal to or less than a predetermined distance. Since the detector and the contact detector sequentially detect the winding state, the function of holding the output state of the winding detection signal while the hook is stored is unnecessary, and the system configuration can be simplified.

Since the output state of the winding detection signal is not held, the output of the winding detection signal does not continue in a normal state due to erroneous detection.

[0012]

FIG. 1 is a longitudinal sectional view of the tip of a boom of a crane with a hook storage mechanism provided with a winding detection device according to an embodiment of the present invention, and FIG. FIG. 3 is an explanatory diagram of a detection range of the photodetector, FIG. 3 is an explanatory diagram of a detection state by the ultrasonic detector, FIG. 4 is an explanatory diagram of a detection state by the photodetector, and FIG. 5 is detection by the photodetector and the contact detector. FIG. 6 is an explanatory diagram of a state detected by a contact detector, FIG. 7 is an electric circuit diagram of a winding detection device, and FIG. 8 is a hydraulic circuit diagram of a crane with a hook storage mechanism.

The crane has a front end 51 of a boom 50.
A hook 53 is hung by a wire rope 52 from above.
Further, a sensor support 33 to which an ultrasonic sensor 31 and an optical sensor 32 are attached at a lower end is provided at a distal end portion 51 of the boom 50. The ultrasonic sensor 31 is a distance detector that detects a winding state in an ultrasonic sensor detection range S in which the distance between the hook 53 and the tip end portion 51 of the boom 50 is equal to or less than a predetermined winding detection distance L using ultrasonic waves. It is. As shown in FIG. 2, the ultrasonic sensor 31 has a wide measurement field of view, but has a dead zone in the proximity distance, which makes it difficult to measure the proximity distance.

The optical sensor 32 is a detector that detects a winding state in the optical sensor detection range P using light. Optical sensor 3
In No. 2, since the measurement visual field is narrow, there is almost no dead zone even at a short distance, so that the winding state can be detected even when the hook 53 is in the dead zone of the ultrasonic sensor 31. A distance detector using light can perform precise measurement, but is complicated and expensive. However, since the optical sensor 32 is in charge of the detection in the dead zone after the ultrasonic sensor 31 has once detected the winding state, it is not necessary to detect the distance, and the hook 53 exists there. Since it suffices if it is only necessary to detect whether or not to do so, a cheap one can be used.

A hook guide member 63 for storing a hook is provided at the distal end portion 51 of the boom 50. The hook guide member 63 is rotatably attached to a support pin 65 which is connected and fixed to a base end of a bracket 64 provided at the base end upper part of the middle of the end part 51 of the boom 50. A detection pin 66 is fixed to the upper end of the hook guide member 63.

At the tip end of the bracket 64, a detection pin 6 is provided.
A concave portion 64A for receiving the detection pin 6 is formed.
The movement range of 6 is restricted by the recess 64A. A spring 67 is provided between the bracket 64 and the hook guide member 63, and the spring 67 constantly urges the detection pin 66 to contact the lower edge of the recess 64A.

Also, a recess 64 on the tip side of the bracket 64
Above A, a contact detection switch 62 is provided. The contact detection switch 62 is a normally closed limit switch and is always on. As shown in FIG. 5, the hook 53 is wound up and abuts on the hook guide member 63, and the hook guide member 63 is pushed up and the detection pin 66 is pressed. Is configured to be turned off when moved upward, and the contact of the hook 53 with the hook guide member 63 can be detected.

The electric circuit of the winding detecting device is as shown in FIG. That is, the power supply 22 is connected to the relay 34 serving as a winding detection signal output unit. A contact detection switch 62, an optical sensor 32, and an ultrasonic sensor 31 are connected in series to the coil of the relay. The contact detection switch 62, the optical sensor 32, and the ultrasonic sensor 31 are all on when normally closed and do not detect the winding state, and are off when the winding state is detected.

Therefore, when none of the contact detection switch 62, the optical sensor 32, and the ultrasonic sensor 31 detect the winding state, the coil of the relay 34 is energized. When any one of the contact detection switch 62, the optical sensor 32, and the ultrasonic sensor 31 detects the winding state, the excitation of the coil of the relay 34 is released, the relay 34 is turned on, and the winding detection signal is output.

This crane with a hook storage mechanism is shown in FIG.
As shown in FIG. 1, a hydraulic actuator includes a boom raising / lowering cylinder 1, a winch motor 2, a boom extension / retraction cylinder 3, a swing motor 4, and left and right vertical outrigger cylinders 5L and 5R. In these hydraulic actuators, the boom raising / lowering cylinder 1 is used for raising / lowering the hydraulic switching valve 1.
1. Winch motor 2 is a winch hydraulic switching valve 12, boom extension and contraction cylinder 3 is an expansion and contraction hydraulic switching valve 13, turning motor 4 is a turning hydraulic switching valve 14, and vertical outrigger cylinders 5L and 5R are outrigger hydraulic switching valves 15L. , 15R, are connected to a working oil passage 7 of a crane to which working hydraulic oil is supplied from a hydraulic pump 6 serving as a hydraulic pressure source, and a return oil passage 9 to a tank 8. The hydraulic pump 6 is driven by operating a PTO (not shown) and sends pressure oil to the working oil passage 7 side of the crane.

These hydraulic switching valves 11, 12, 13, 1
Reference numerals 4, 15L, and 15R denote three-position manual operation switching valves, which are manually operated by an operator to cause a boom raising / lowering cylinder 1, a winch motor 2, a boom extending / retracting cylinder 3, a swing motor 4, a right / left Of the vertical outrigger cylinders 5L, 5R can be operated. In the neutral position, the working oil passage 7 is communicated with the return oil passage 9.

A main relief valve 10 and an unload valve 20 are provided in parallel between the working oil passage 7 and the return oil passage 9. An electromagnetic valve 21 for the unload valve is provided between the vent of the unload valve 20 and the return oil passage 9.
Is provided. This unload valve solenoid valve 21
Operates, the unload valve 20 operates to unload the pressure oil from the pump 6.

The winch motor 2 includes a low pressure hoisting switching valve 1
The winch 2 can be wound in the low pressure state set by the low pressure relief valve 17 by switching the low pressure hoisting switching valve 16. When the hook 53 is stored, the hook 53 is wound up in a low pressure state.
3 is brought into contact with a hook guide member 63 provided at the distal end portion 51 of the boom 50.
Are stored laterally while being guided by the hook guide member 63.

The turning motor 4 has a turning motor lock cylinder 18. The turning motor lock cylinder 18 is connected to a back pressure valve 19 provided in the hydraulic oil passage 7. When the pressure oil is supplied to the passage 7, the lock of the swing motor 4 is released by the back pressure generated by the back pressure valve 19. In the crane operation, the hook 53 is lifted and the distance between the tip portion 51 of the boom 50 and the hook 53 is reduced when the winch is wound up, the boom is erected, and the boom is extended.
The hook 53 rises during the operation to move the hook upward, and as shown in FIG.
The ultrasonic sensor 31 detects the winding state when the distance between the solenoid valve 21 and the solenoid 21 of the solenoid valve 21 for the unload valve is detected.
Output to S.

Then, the solenoid 21S of the unload valve solenoid valve 21 is excited to operate the unload valve solenoid valve 21. Accordingly, the unload valve 20 is activated, the hydraulic oil passage 7 is returned to the return oil passage 9, and the crane automatically stops. Since the ultrasonic sensor 31 has a wide measurement field of view, it is possible to detect the winding state even when the hook 53 swings.

When the hook 53 is stored, the winch 2 is wound in the low-pressure state set by the low-pressure relief valve 17 by switching the low-pressure hoisting switching valve 16, and the hook 53 is moved to the distal end 51 of the boom 50. It is brought into contact with the hook guide member 63 provided. When the winding is further continued, the hook 53 is guided by the hook guide member 63 and is stored horizontally as shown in FIG.

During the storage of the hook 53, the hydraulic switching valve 11 for undulation and the hydraulic switching valve 1 for winch are mistakenly inserted.
2. If the expansion / contraction hydraulic switching valve 13 is operated to the hook rising side, the hook 53 collides with the tip portion 51 of the boom 50, and the boom 50, the hook 53, the wire rope 52, and the like may be damaged. There is. Therefore, the detection of the winding state by the winding detection device must be continued even during the storage of the hook 53.

However, since the ultrasonic sensor 31 has a dead zone at a close distance, the hook 53 continues to move upward and the boom 5 continues.
If the distance between the zero and the leading end 51 becomes small, the winding state cannot be detected. At this time, as shown in FIG. 4, the optical sensor 32 having almost no dead zone even at a short distance detects the winding state, and the relay 34 outputs a winding detection signal. Although the optical sensor 32 has a narrow measurement field of view, the hook 53 and the boom 5
Since the distance from the leading end 51 of the hook 53 is small, the deflection of the hook 53 is small, and there is no problem in detecting the winding state.

After the hook 53 further rises and comes into contact with the hook guide member 63 of the hook storage mechanism as shown in FIG. 5, the hook 53 changes its direction and is stored laterally as shown in FIG. The sensor 32 deviates from the measurement field of view and the winding state cannot be detected. At this time, since the hook 53 has already contacted the hook guide member 63, the contact detection switch 62 detects the winding state, and the relay 34 outputs a winding detection signal.

As described above, the winding detection device includes the hook 53
The ultrasonic sensor 31, the optical sensor 32, and the contact detection switch 62 are successively wound until the distance between the boom 50 and the tip 51 of the boom 50 becomes equal to or less than the predetermined winding detection distance L and until the hook 53 reaches the storage position. Since the state is detected, the function of maintaining the output state of the winding detection signal is not required, and the system configuration can be simplified and inexpensive.

Since the output state of the winding detection signal is not held, the output of the winding detection signal does not continue in a normal state due to erroneous detection. Since the ultrasonic sensor 31, the optical sensor 32, and the contact detection switch 62 share winding detection, the winding state can be detected even if one of them fails, and safety is improved.

[0032]

As described above, the winding detection device for a crane with a hook storage mechanism according to the present invention does not require a function of maintaining the output state of a winding detection signal while the hook is stored, thereby simplifying the system configuration. be able to. The output state of the winding detection signal due to erroneous detection is not held.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tip of a boom of a crane with a hook storage mechanism provided with a winding detection device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of detection ranges of an ultrasonic detector and a photodetector.

FIG. 3 is an explanatory diagram of a detection state by an ultrasonic detector.

FIG. 4 is an explanatory diagram of a detection state by a photodetector.

FIG. 5 is an explanatory diagram of a detection state by a photodetector and a contact detector.

FIG. 6 is an explanatory diagram of a detection state by a contact detector.

FIG. 7 is an electric circuit diagram of the winding detection device.

FIG. 8 is a hydraulic circuit diagram of a crane with a hook storage mechanism.

FIG. 9 is an explanatory diagram of a conventional winding detection device.

FIG. 10 is an explanatory diagram of a winding detection device using a conventional non-contact type distance detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boom raising / lowering cylinder 2 Winch motor 3 Boom expansion / contraction cylinder 4 Swing motor 6 Hydraulic pump 7 Working oil passage 8 Tank 9 Return oil passage 10 Main relief valve 11 Undulation hydraulic switching valve 12 Winch hydraulic switching valve 13 Extension hydraulic switching Valve 14 Hydraulic switching valve for turning 20 Unload valve 21 Solenoid valve for unload valve 21S solenoid 22 Power supply 31 Ultrasonic sensor 32 Optical sensor 33 Sensor support 34 Relay 50 Boom 51 Tip 52 Wire rope 53 Hook 62 Relay 63 Hook guide Member 64 Bracket 64A Recess 65 Support pin 66 Detection pin 67 Spring

Claims (1)

[Claims] 1. A winding detection device for a crane with a hook storage mechanism, comprising: an ultrasonic detector for detecting a winding state when an interval between a hook and a tip end of a boom is equal to or less than a predetermined distance;
An optical detector that detects a winding state in a dead zone of the ultrasonic detector, a contact detector that detects a winding state when the hook contacts the hook guide member of the hook storage mechanism, an ultrasonic detector,
And a winding signal output means for outputting a winding detection signal by detecting a winding state of one of the photodetector and the contact detector. Detection device.