JP4104359B2 - Overwinding prevention device for hoisting machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
It relates to an overwinding prevention device in a hoisting tractor equipped with a load sheave and a chain having a hook wound on the load sheave, and a sensor for preventing overwinding of the chain. As an overwinding prevention device, a magnetic sensor and The present invention relates to an overwinding prevention device in a hoisting tractor provided with a magnetomotive member.
[0002]
[Prior art]
Conventionally, the following four means have been mainly used as overwinding prevention means of a hoisting machine. The first means is to attach a rubber damper to the hook part and the chain end part so as to absorb the impact at the time of the collision between the hook part and chain end part and the hoisting and pulling machine main body. The second means uses an eddy current proximity switch, which has a coil on the electric chain block main body side, and detects the approach of the iron piece provided on the hook part by the change in current flowing in the coil due to the eddy current flowing in the iron piece. It is what you do. According to a third means, the electric chain block main body is provided with a switch and a switch lever interlocking with the switch, and the switch lever transmits an operation of raising the hook to the upper limit to detect the upper limit. . The fourth means is provided with a pulse encoder or the like in the chain drive part and the rotating part, measures the chain winding length by replacing the number of pulses generated by the encoder, and uses an output signal from an electronic counter, etc. It is designed to stop at a position.
[0003]
[Problems to be solved by the invention]
In the above-described prior art, the one provided with the rubber damper as the first means damages the drive unit, the mechanism unit, the chain, etc. due to the impact at the time of collision, and this operation is repeated, It also becomes a factor in causing fatigue failure. Further, the means using the eddy current proximity switch, which is the second means, has low detection sensitivity, and in order to achieve high sensitivity, the coil diameter of the detection portion must be increased, and the installation location is limited. Have the problem of receiving. Further, the means using the mechanical limit switch, which is the third means, has a problem that the mechanism for operating the limit switch is complicated and the life is short because of the mechanical contact. In addition, since the fourth means, which uses a pulse encoder, does not detect the absolute position, it must obtain the apex signal by some method, and by some method at the time of power failure or non-energization. The current position must be stored, these storage devices are required, and the device becomes complicated. In addition, it is also known that a magnetic sensor is provided inside the hoisting body and overwinding prevention is performed by a magnet generator that is attached to the belt with the direction of the magnetic force line sideways, but this means is applicable to chain hoisting machines. It is not possible. For example, if a magnetism is attached to the chain, the magnetism cannot pass through the chain guide hole inside the hoisting body where the magnetic sensor is provided, and even if the magnetic sensor is provided outside the hoisting body, Since the conventional magnetism generator is provided in the chain so that the direction of the lines of magnetic force is horizontal, there is a problem that the magnetism sensor cannot reliably detect the magnetism generator due to a chain swing or the like.
[0004]
[Means for Solving the Problems]
The present invention solves the above-described problems, and includes a magnetic detection sensor provided with an overwinding prevention device for a hoisting tractor on the hoisting tractor body, a hook side and a no-load side of the chain, It is characterized by comprising magnetizing means whose direction is the vertical direction.
[0005]
According to the present invention, since the sensor unit for preventing overwinding is a non-contact type, it has a longer life than a contact type using a mechanical contact, and the magnetism attached to the chain unit has a strong magnetic strength. By changing the length or changing the threshold of the sensor switching unit, it is possible to easily adjust the operating distance until detection, and since a magnetic sensor is used, it is necessary to enlarge the detection unit when increasing sensitivity There are no restrictions on the mounting location, and the polarity of the magnets installed at the unloaded side end of the hook and chain is set to different polarities, and the position of the two magnets is detected by one magnetic sensor. By performing the above, it becomes possible to share the sensor, and therefore, a novel hoisting machine that is not limited by the sensor mounting portion can be provided.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention is wound around the load sheave and the load sheave, a chain with a hook on the end, in the over-winding prevention apparatus in hoisting and pulling machine with excessive winding prevention sensor chain there are, over-winding prevention apparatus provided by changing the respective magnetic poles on the chain hook and chain unloaded portion end, a Hatsu磁body direction of the magnetic lines of force is the vertical direction, the threshold value for detecting the approach of the calling magnetized member , Ri Tona a magnetic sensor for detecting magnetic by greater threshold than the threshold value for detecting the separating of magnetism generation body, the winding, characterized in that to detect the different poles of the chain hook and chain unloaded part ends with a magnetic sensor in the over-winding prevention apparatus in traction machine, the sensor because it is a non-contact method of detecting the magnetic lines of Hatsu磁means are compared long life contact method using a mechanical contact, also the chain portion The operating distance of detection can be easily adjusted by changing the magnetic strength of the attached generator and changing the threshold value of the sensor switching unit, and the direction of the magnetic force lines of the generator is vertical. Even if the chain is swung, it can be detected reliably, and since a magnetic sensor is used, it is not necessary to enlarge the detection part to increase sensitivity, and it is not limited by the installation location It has the effect | action which can provide an apparatus. Moreover, it has the effect | action which can detect stably with respect to the runout of a chain. In addition, it is possible to detect the position of two generators with one magnetic sensor, and when using two sensors corresponding to the chain hook part and the unloaded side chain end part, Each magnetic sensor has an action that can be provided close to each other.
[0007]
The invention according to claim 2, Hatsu磁body, by stacking the plate-like onset magnet body characterized in that the tabular onset magnetized body is a magnetism generation body formed by laminating polymerizing heteropolar, magnetism generation body It has the effect | action which can make a process and manufacture easy.
[0008]
The invention according to claim 3 is characterized in that the magnetomotive member is fitted in a non-magnetic case, the magnetic lines of force of the magnetic material can be output to the outside of the non-magnetic case, and the magnetic material is protected. In addition, it has an effect of facilitating the attachment of the magnetic body to the chain.
[0011]
The invention according to claim 4 is characterized in that the hook-side magnet generator is a magnet generator having an insertion slot for inserting the chain in the pole direction of the magnet generator. Can be easily attached, and the attachment position to the chain can be easily changed.
[0012]
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
FIG. 1 is a conceptual diagram showing an overwinding prevention device of the present invention, FIG. 2 is an enlarged exploded view showing a magnetizing portion provided on the hook side, and FIG. 3 is an enlarged exploded view showing a magnetizing portion provided on the no-load side. FIG. 4 is a front view showing the upper limit of hoisting of the chain in the hoisting and pulling machine. In the embodiment shown in FIGS. 1 and 2, 1 is a hoisting tractor, 2 is a load sheave, 3 is a chain wound around the load sheave 2, 4 is a magnetomotive member attached to the chain 3, and on the hook side And a magnetic generator 4b attached to the no-load side which is the other side end. The magnetism generator 4 is formed by laminating a plurality of plate-like magnetism generators 4c, and each magnetism generator 4c is laminated by superposing different polarities in the polar direction of the magnetism generator, and upwards the magnetism generator. Are aligned so that the magnetic field lines are evenly distributed along the circumference. Further, the flat plate-like magnetic body 4c of the magnetic body 4a has a chain fitting insertion hole 4d in the polar direction of the magnetic body. Reference numeral 5 denotes a main body case of the hoisting and pulling machine, and 5a denotes a chain guide disposed below the load sheave 2 and is provided with a chain guide hole 5b. 6 is provided in the vicinity of the chain guide hole 5b, and includes a coil (not shown) that changes the magnetic flux density according to the approaching distance of the magnet generator 4, and converts the amount of change of the magnetic flux density into a voltage to convert it into a sensor switching circuit. 10 is protected by a protective cover 6a formed of a nonmagnetic material such as synthetic resin. 7a is a lower hook, 7b is an upper hook, 8 is a chain storage unit, 9 is a motor for driving a load sheave, 10 is operated by a magnetic sensor 6, and the output value of the magnetic sensor 6 is constantly detected, a certain output value Sensor switching circuit that outputs an ON-OFF signal to the motor control circuit 11, 11 is a motor control circuit controlled by the sensor switching circuit 10 and a switching box 12 having a push button, and 13 loads the rotation of the motor 9. A reduction gear 14 for transmitting to the sheave 2 is an overload prevention clutch.
[0014]
In the present embodiment, as shown in FIG. 2, the magnet generator 4a is formed by laminating a plurality of flat magnet generators 4c, and the magnet generator 4a is fitted in a magnet generator case 15 made of a non-magnetic material such as aluminum. Has been. Further, a bottom plate 15b made of a non-magnetic material is fitted in the lower part above and below the magnet generator, and an upper plate 15a fixed to the magnet case 15 is provided in the upper part. Is fitted with a retaining ring 17 to form a magnetic body 4a. In this way, the flat magnet generator 4c is fitted to the non-magnetic magnet generator case 15 so as to superimpose different polarities to strengthen the magnetic force, thereby protecting the magnet generator 4 and directing it upward. Further, since the magnetic lines of force appear uniformly along the circumference of the case 15, the magnetic sensor 6 can detect the magnetic generator by the approach of the magnetic generator, and an accident occurs where the magnetic sensor 6 does not detect the magnetic generator 4. Therefore, stable detection can be performed, and the production and processing of the magnetomotive member are easy. Further, by making the threshold value of the magnetic sensor 6 that the sensor 6 detects the approach of the magnet generator 4 larger than the threshold value that detects the separation of the magnet generator 4, it is possible to stably detect the chain shake. It becomes. More specifically, in order to transmit the OFF signal for stopping the motor to the motor control circuit when the magnetic generator 4 approaches the upper limit position with respect to the magnetic sensor 6, the output of the magnetic sensor 6 set in advance in the sensor switching circuit 11 is used. This is performed when a certain threshold value is exceeded due to the approach of the magnet generator 4, and the winding operation is stopped. Further, the magnet generator 4 is kept in the upper limit position by continuously pressing the switching box 12, and the magnet generator 4 When the operation of moving away from the magnetic sensor 6 is performed, the output value of the magnetic sensor 6 falls below the threshold value for turning off the motor described above, but the output of the signal for turning the motor on again when the magnetism generator 4 is separated from the upper limit position is Since the threshold value is set to be smaller than the threshold value for turning off the motor, chattering of the upper limit position of the magnetomotive member due to chain swing is prevented. It can be, it is possible to detect the over-winding of the chain stably. Further, the magnet generator 4 is provided on the chain hook portion side magnet generator 4a and the stopper side magnet generator 4b by changing the magnetic poles, and by providing a magnetic sensor for detecting different magnetic poles of the magnet generator 4a and the magnet generator 4b. Two sensors 6 respectively corresponding to the magnetic bodies 4a and 4b can be provided close to each other. FIG. 3 shows a no-load-side magnetism generator 4b. The basic configuration is the same as that of FIG. 2, but the flat magnetism generator 4c does not have a chain through hole 4d. 3 is provided with a hole 18 into which the end of 3 is inserted, a stop pin 19 and a stop clip 20 for engaging the end of the chain 3 with the magnet case 15.
[0015]
【The invention's effect】
The overwinding prevention device of the present invention includes a magnetic detection sensor provided in the hoisting traction machine main body, and a magnetizing means provided on the hook side and the no-load side of the chain, and the direction of the line of magnetic force is the vertical direction. Since the sensor part is a non-contact type, it has a longer life than the contact type using a mechanical contact, and the magnetic strength of the magnet generator attached to the chain part can be changed. By changing the threshold value of the sensor circuit switching unit, the operating distance of detection can be easily adjusted, and since the magnetic sensor is used, it is not necessary to enlarge the detection unit when increasing the sensitivity. Because the direction of the magnetic force line of the magnetizing means is up and down, it can be detected reliably even when the chain swings, and it is installed at the hook and the unloaded side end of the chain. Then By making the polarities of the magnet generators different from each other and detecting the position of two magnet generators with a single magnetic sensor, it becomes possible to share the sensor, so there is no space limitation on the sensor mounting part. In addition, by laminating the flat plate-like magnetophores, it is possible to facilitate the processing and production of the magnetism and have an effect.
[0016]
In addition, by protecting the magnetic body by fitting it in a non-magnetic case, it is possible to output the magnetic lines of magnetic force to the outside of the case, and the threshold at which the magnetic sensor detects the approach of the magnetic generator, By making it larger than the threshold value for detecting the separation of the magnetic generator, it is possible to stably detect the vibration of the chain, and further, the magnet generating means and the magnetic sensor are connected to the chain hook portion and the no-load side chain end portion. It is possible to detect the position of two generators with one magnetic sensor by providing a magnetic sensor to detect the magnetic pole of each magnetizing means at each chain hook part and no load side chain end part. If two magnetic sensors corresponding to the chain hook and the no-load side chain end are used, they can be installed close to each other. Having that effect.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an overwinding prevention device of the present invention.
FIG. 2 is an enlarged exploded view showing a hook-side magnetism generating portion.
FIG. 3 is an enlarged exploded view showing a no-load side magnetizing portion.
FIG. 4 is a front view showing the upper limit of winding of the chain.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hoisting traction machine 2 Load sheave 3 Chain 4 Magnet body 4a Hook side magnet body 4b Stopper side magnet body 5 Case 5a Chain guide 5b Chain guide hole 6 Magnetic sensor 6a Sensor cover 7a Lower hook 7b Upper hook 8 Storage part 9 Motor 10 Sensor circuit / switching circuit 11 Motor control circuit 12 Switch box 13 Reduction gear 14 Overload prevention clutch 15a Top plate 15b Bottom plate 16 Cushion rubber 17 Retaining ring 18 Hole 19 Retaining pin 20 Retaining clip

Claims (4)

An overwinding prevention device in a hoisting tractor equipped with a load sheave and a chain wound around the load sheave and having a hook at an end, and a sensor for preventing overwinding of the chain. and provided by changing the respective pole to the chain unloading unit end, a Hatsu磁body direction of the magnetic lines of force is the vertical direction, the threshold value for detecting the approach of the onset magnetized member, greater threshold than the threshold value for detecting the separating of magnetism generation body magnetic sensor and Tona is, over-winding prevention apparatus in hoisting and pulling machine and detecting the different magnetic poles of the chain hook and chain unloaded part ends in a magnetic sensor for detecting magnetic by. Hatsu磁body, over-winding prevention apparatus in hoisting and pulling device according to claim 1, characterized in that the magnetism generation body formed by laminating by polymerizing different poles.   3. The overwinding prevention device for a hoisting traction machine according to claim 1 or 2, wherein the magnetism member is fitted in a non-magnetic case. The overwinding prevention in the hoisting traction machine according to any one of claims 1 to 3, wherein the hook-side magnetism generator is a magnetism generator having an insertion slot for inserting a chain in the pole direction of the magnetism generator. apparatus.

Images