JPH1050130A - lift device - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a lifting device capable of simplifying a structure for urging a pulley and preventing an error in timing of turning on and off a detection switch. A lifting device that stops the operation of a drive unit provided on a fixed part when a slack detection mechanism provided on a fixed part on a ceiling side detects looseness of a wire rope. I do. The detection mechanism 13 includes a mechanism frame 21 and a rope 18
A guide shaft 22 extending in the direction in which the tension is applied to the frame 21, a pulley support 23 movably mounted on the shaft 22 along the axial direction, and a rotatable support Pulley 24 to be attached and rope 18 to be hung
A single spring 25 interposed between the frame 21 and the pulley support 23 to urge the pulley support 23 in a direction against the tension of the rope 18, and to move the pulley support 23 attached to the mechanism frame 21. And a detection switch 26 that is turned on and off in conjunction with the detection switch 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting apparatus which is installed on a high ceiling of a gymnasium or the like and which raises and lowers a lighting fixture or the like by winding and rewinding a wire rope. The present invention relates to an elevating device with an improved slack detection mechanism for detecting a slack.

[0002]

2. Description of the Related Art A slack detection mechanism of a lifting device detects a slack of a rope when a lighting device suspended on a wire rope via a lifting unit reaches a floor surface during maintenance or the like. It is used to automatically stop the operation of the winding / rewinding drive unit.

As the slack detection mechanism, an arm type and a pulley movable type are known. Among them, the arm type which detects the slack of the wire rope by the circular motion of the arm, the arm gives a movement against the winding direction of the wire rope to the wire rope to disturb the movement of the wire rope. Therefore, it tends to be difficult to stably wind and rewind the wire rope with respect to the rope drum.

On the other hand, a pulley-movable slack detection mechanism for detecting slackness of a wire rope by moving a pulley on which the wire rope is hung does not have the disadvantages of the arm type described above. Since it is possible to exhibit a stable elevating performance without disturbing the rewinding operation, it is excellent in that it follows the wire rope well and its slack can be accurately detected.

FIG. 2 and FIG. 3 of Japanese Utility Model Publication No. 59-21461 show a conventional pulley movable slack detection mechanism. This mechanism is arranged on a fixed part together with a driving part for raising and lowering the elevating part by a wire rope, and its basic configuration is that both ends of a shaft of a pulley on which a wire rope is hung are disposed on both sides of the pulley. A pulley is disposed in the fixed portion by being inserted into a horizontal elongated hole formed in a pair of mounting plates so as to be movable, and one end of a tension spring is connected to both ends of the shaft to oppose the tension of the wire rope. A detection switch is provided near the pulley for urging the pulley and detecting the movement of the pulley.

In this slack detection mechanism, when only the tension due to the weight of the wire rope is applied to the pulley,
Since the pulley retreats along the elongated hole due to the spring force of the pair of tension springs, the detection switch is turned on in conjunction therewith, and the operation of the drive unit for winding and rewinding the wire rope in the fixed unit is continued. Further, when the tension of the wire rope to which the weight of the elevating section is added is applied to the pulley, the pulley advances along the elongated hole against the spring force. The operation of the driving unit can be stopped.

[0007]

However, the slack detection mechanism described in the above publication requires two tension springs to urge the pulley in a direction against the tension of the wire rope. There is a problem that there are many. In addition, since the spring characteristics of the tension coil springs are not the same but vary, the use of two such springs is necessary when the support shaft of the pulley moves using the two long holes of the mounting plate as guides. In addition, it is difficult to move the support shaft for turning the switch on and off in parallel. Therefore, switch on
There is a high possibility that an error will occur in the timing of turning off the wire, which may cause the wire rope to be excessively slack, which may come off the pulley, or may protrude from the rope drum of the driving unit, thereby hindering the subsequent winding operation. Can be

Accordingly, a first object of the present invention is to provide a lifting device capable of simplifying a structure for biasing a pulley and preventing an error in timing of turning on and off a detection switch. .

A second object of the present invention is to provide a lifting device capable of preventing the wire rope hung on the pulley from coming off the pulley while solving the first problem. .

[0010]

According to the present invention, a driving portion for winding and rewinding a wire rope is provided on a fixed portion disposed at a high position on the ceiling side, and a slack detecting mechanism for detecting a slack of the wire rope. Further, it is assumed that the lifting unit raises and lowers the lifting unit suspended from the wire rope by the driving unit, and stops the operation of the driving unit when the slack detection mechanism detects the slack of the wire rope.

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that the slack detecting mechanism comprises a mechanism frame fixed to the fixing part and a frame extending in a direction in which the tension of the wire rope is applied. A guide shaft attached to the pulley, a pulley support movably attached to the guide shaft along the axial direction thereof, and a pulley rotatably attached to the pulley support and on which the wire rope is hung. A single spring interposed between the mechanism frame and the pulley support to urge the pulley support in a direction against the tension of the wire rope; and a single spring attached to the mechanism frame for movement of the pulley support. A detection switch that is turned on / off in conjunction with the detection switch.

According to the first aspect of the present invention, the pulley support that supports the pulley extends in the direction in which the tension of the wire rope hung on the pulley is applied to one guide shaft attached to the mechanism frame, and the axial direction thereof , And is urged by the spring force of a single spring interposed between the support and the mechanism frame.

Therefore, when only the tension due to the weight of the wire rope is applied to the pulley, for example, when the lifting section is lowered to the floor, the pulley is supported by the spring force and the pulley is supported at one end of the guide shaft. , The detection switch is turned off in conjunction therewith, and the operation of the drive unit that winds and rewinds the wire rope in the fixed unit is stopped. In addition, during the elevating operation, the tension of the wire rope with the weight of the elevating part is applied to the pulley, so that the pulley moves toward the other end of the guide shaft together with the pulley support against the urging force of the spring. Then, the detection switch is turned on in conjunction with the operation, and the operation of the driving unit is continued.

Since a single spring is used in such an operation, the number of springs used can be minimized. In addition, since the pulley support supporting the pulley is moved in the axial direction as described above along the guide shaft only according to the spring characteristics of the single spring, the pulley support is interlocked with the axial movement of the pulley support. The variation in spring characteristics does not affect the on / off timing of the detection switch as in the related art using a plurality of springs.

According to a second aspect of the present invention, the pulley support has a pair of side wall portions provided on both sides of the pulley with the pulley interposed therebetween. The side wall portion is arranged close to the pulley.

According to the second aspect of the present invention, since the pair of side walls provided on the pulley support are disposed on both sides of the pulley so as to sandwich the pulley, the wire rope hung on the pulley can be pulled. From falling off.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing a partial configuration of the lifting device according to the first embodiment, and FIG.
(A) is a diagram schematically showing the lighting device suspended by the lifting device on the floor, and FIG. 6 (A) raises and lowers the lighting device suspended by the lifting device. It is a figure which shows roughly in the state on the way, and 11 in these figures is a fixed part arrange | positioned at ceiling side high places, such as a gymnasium. A drive unit 12, a slack detection mechanism 13, a first pulley 14, a lifting / lowering unit holding mechanism (not shown), various electric components, and the like are attached to the fixing unit 11, respectively.

As shown in FIG. 1, the drive unit 12 includes a drive motor 15 capable of rotating forward and backward, a gear reducer 16 connected to a rotating shaft of the motor 15, and an output shaft of the reducer 16. And a rope drum 17 rotated integrally with the shaft.

One end of a wire rope 18 is fixed to the rope drum 17, and a rope end 18a attached to the other end of the rope 18 is connected to a rope fixing part (not shown) in the fixing part 11 via fixing means. Fixed. The wire rope 18 is wound on or unwound from the rope drum 17 by rotating the drive motor 15 of the drive unit 12 forward or backward.

The wire rope 18 in the fixed portion 11
The first pulley 14 is provided vertically through the slack detection mechanism 13 as described later and with the roller shaft being horizontal.
Have been routed through. First of the wire rope 18
A lifting section 19 is suspended from a rope portion extending from the pulley 14 to the rope end 18a. The elevating unit 19 has a pair of pulleys (not shown) inside thereof, and the wire rope 18 can enter and exit from the upper surface of the elevating unit 19 via these pulleys.

As shown in FIGS. 5 (A) and 6 (A), the elevating unit 19 has an electric device such as the lighting fixture 2 on the lower surface thereof.
0 is attached. The elevating part 19 is at least in the ascending position where the upper part is inserted into the fixed part 11,
In order to prevent the weight of the lighting device 20 and the elevating unit 19 from being added to the wire rope 18, the wire rope 18 is mechanically detachably held by the elevating unit holding mechanism (not shown) and is fixed by detachable electrical connection means (not shown). It is configured to be electrically connected to the unit 11 side.

Next, the configuration of the slack detecting mechanism 13 will be described with reference to FIGS. The mechanism 13 includes a mechanism frame 21, one guide shaft 22, a pulley support 23, a second
It is formed with a pulley 24, a single spring 25, and a detection switch 26.

The mechanism frame 21 has a bottom plate 31 and side plates 32, 33 bent upward at right angles from both ends by bending a steel plate into a U-shape, and the distal ends of these side plates 32, 33 are formed. The attachment pieces 34a and 34b are formed by bending the attachment pieces 34a and 34b in a direction away from each other. The mechanism frame 21 has its mounting pieces 34a, 3
It is fixed to the fixing part 11 via a screw 35 passing through 4b (only one screw is shown in FIGS. 1, 5A and 6A). This fixing is performed by connecting one side plate portion 32 to the rope drum 1.
7 is performed. This one side plate portion 32 is
A narrow portion 32a having a width smaller than the diameter of the second pulley 24 is provided at the center in the width direction.

The metal guide shaft 22 is formed, for example, in a columnar shape, and extends across the side plate portions 32 and 33 to the bottom plate portion 31.
It is laid in parallel with. Thereby, this guide shaft 2
2 is provided to extend in a direction in which the tension of the wire rope 18 is applied to the slack detection mechanism 13. Reference numeral 36 shown in FIG. 4 and the like denotes a mounting screw with a washer that is inserted into the side plate 32 or 33 and screwed to the end of the guide shaft 22.

The pulley support 23 is formed by bending a steel plate so as to be shorter than the bottom plate portion 31, and has a pulley storage box portion 37 and a pair of mounting legs 38, 39. The pulley housing box portion 37 includes an upper wall portion 37a and a lower wall portion 37b which are horizontal and parallel to each other, and both of the wall portions 37a and 37a.
7b, a pair of left and right side plates 37c, 3
7d forms a tetrahedral square box structure. At both ends of the opening of the storage box portion 37, mounting legs 38 and 39 are bent from a lower wall portion 37b in a direction opposite to the upper wall portion 37a. Each of these mounting legs 38 and 39 is flat and has a fitting hole 40 formed therein.

The pulley support 23 has its fitting hole 40 slidably fitted to the guide shaft 22 and is attached to the guide shaft 22 so as to be movable in the axial direction. A switch operating projection 38a is integrally formed at the tip of one of the mounting legs 38 of the pulley support 23, and the projection 38a passes through a rectangular through hole 31a opened in the bottom plate portion 31 and extends downward. It is projected to. The through hole 31a is formed in a size that does not hinder the movement of the pulley support 23 along the guide shaft 22. The width of the through hole 31a and the width of the switch operation projection 38a are substantially the same so that the switch operation projection 38a slides along the hole edge of the through hole 31a. This configuration is excellent in that the pulley support 23 can be prevented from freely rotating around the axis of the guide shaft 22, whereby the state in which the pulley support 23 holds a predetermined posture can be moved along the guide shaft 22. You can move smoothly.

The second pulley 24 includes upper and lower walls 37a, 37
It is rotatably supported by a pulley shaft 41 which is vertically mounted between the central portions of b. Therefore, this pulley 24
Is mounted in the pulley housing box 37 in a horizontal posture. The second pulley 24 is hung with a wire rope 18 that is horizontally routed in the fixed portion 11.
The parallel portions of the rope 18 are the pulley supports 2
3 and pass through both sides of the narrow portion 32a.

The two side walls 37c and 37d of the pulley housing box 37 located on both sides of the second pulley 24 are spaced apart from the second pulley 24 by a distance smaller than the diameter of the wire rope 18.
It is arranged close to. In addition, the configuration in which the pulley support 23 has the upper wall portion 37a can support the pulley shaft 41 at both ends between the pulley support 41 and the lower wall portion 37b.
Even if the wire rope 18 comes off from the cable, the rope 18 can be prevented from coming off by the pulley shaft 41, which is extremely excellent in safety. However, in a configuration in which the side walls 37c and 37d are brought close to both sides of the second pulley 24 to prevent the wire rope 18 from coming off as in the first embodiment, the upper wall 37a is omitted. You can also.

The coil spring 25 is interposed between the side plate portion 32 of the mechanism frame 21 and the mounting leg 38 of the pulley support 23. In the first embodiment, the structure for supporting the coil spring 25 is simplified. For this purpose, it is wound and held around its outer circumference using the guide shaft 22. This coil spring 2
5 urges the pulley support 23 in a direction against the tension of the wire rope 18 hung on the second pulley 24. Therefore, in a normal state, as shown in FIG. The mounting leg 39 is pressed against the side plate 33 of the mechanism frame 21.

As the detection switch 26, a micro switch having a normally open contact structure is used. The switch 26 is screwed to the outer surface of the bottom plate 31 of the mechanism frame 21. The actuator lever 26a of the detection switch 26 is provided so as to cross the through hole 31a in the width direction, and the switch operation protrusion 38a is brought into contact with and separated from the through hole 31a. Thus, the detection switch 26 is turned on / off in conjunction with the movement of the pulley support 23. The detection switch 26 is inserted in a lower drive circuit of the drive motor 15 of the drive unit 12. When the detection switch 26 is on, the drive motor 15
When the detection switch 26 is turned off, the power supply to the drive motor 15 is cut off.

In the lifting device provided with the slack detecting mechanism 13 having the above-described structure, to release the holding of the lifting portion 19 with respect to the fixed portion 11, first, a current is supplied to the lifting-side drive circuit in which the detection switch 26 is not inserted. Then, since the wire rope 18 is wound, the lifting part 19 is not mechanically held, and at the same time, the weight of the lifting part 19 and the lighting equipment 20 supported by the lifting part 19 is applied to the wire rope 18.

As a result, as shown in FIG. 6B, in the slackness detection mechanism 13, the pulley support 23 moves along the guide shaft 22 toward the side wall 32 of the mechanism frame 21 while compressing the coil spring 25. Since it is moved, the actuator lever 26a of the detection switch 26 is pushed by the switch operation projection 38a, and the detection switch 26 is turned on.

Therefore, the wire rope 18 is rewound from the rope drum 17 by switching the driving motor 15 in the reverse direction by switching to the descending side drive circuit. 20 can be lowered to the floor side. This lowering state is shown in FIG. 6A, and during this period, the detection switch 26 of the looseness detection mechanism 13 is kept in the ON state. This state is shown in FIG.

When the lighting fixture 20 descends and reaches the floor surface as shown in FIG.
8 is loosened from the weight of the device. Then, in the slack detection mechanism 13, the pulley support 23 that supports the second pulley 24 on which the wire rope 18 is hung is moved to the guide shaft 22 while the compressed coil spring 25 extends.
Is pushed toward the side plate 32 side of the mechanism frame 21 along with the switch operation protrusion 38a.
6, the detection switch 26 is turned off. This state is shown in FIG.
It is shown in (B). Then, the reverse rotation operation of the drive motor 15 of the drive unit 12 is stopped, so that the wire rope 18 is not further extended.

In order to raise the luminaire 20 that has reached the floor surface and has undergone maintenance, it is switched to the ascending side drive circuit and the drive motor 15 is rotated forward to rotate the wire rope 18. Since the taking operation is performed, the lighting fixture 20 can be raised to the ceiling side together with the elevating unit 19.
At this time, since the weight of the lifting unit 19 and the lighting fixture 20 supported by the lifting unit 19 is applied to the wire rope 18, the looseness detection mechanism 13 is in the state shown in FIG. 6B, and the detection switch 26 is turned on. maintain.

The elevating part 19 is fixed to the fixed part 11 on the ceiling side.
When it enters, the elevating unit 19 is mechanically held by the fixing unit 11 by the elevating unit holding mechanism of the fixing unit 11 (not shown), and the lighting unit 20 is electrically connected to the lighting unit 20 so that it can be turned on. It becomes.

By the way, in the slack detection mechanism 13 for detecting the slack of the wire rope 18 as described above, the pulley support 23 which is moved while supporting the second pulley 24 on which the wire rope 18 is hung is connected to the wire rope. The coil spring 25 used for biasing in the direction against the tension of 18,
Because it is single, the number of springs can be minimized,
The structure for urging the second pulley 24 can be simplified.

In addition, the pulley support 23 supporting the second pulley 24 is moved in the axial direction as described above along one guide shaft 22 according to the spring characteristics of the single coil spring 25 only. Therefore, the variation in the spring characteristics does not affect the axial movement of the pulley support 23 as in the related art using a plurality of springs.

For this reason, it is possible to prevent an error in the timing of turning off the detection switch 26 when the lighting fixture 20 is lowered, and as the lighting fixture 20 reaches the floor surface,
The timing of stopping the drive unit 12 is not delayed, so that the wire rope 18 is not excessively slackened. Thus, the risk that the wire rope 18 comes off from the second pulley 24 or protrudes from the rope drum 17 of the drive unit 12 and hinders the subsequent winding operation can be eliminated.

Further, the pulley support 23 has side walls 37a and 37b approaching both sides of the second pulley 24 supported by the pulley support 23, and the second pulley 24 is hung on the second pulley 24 using these as stoppers. Wire rope 18 is a pulley 24
Is prevented from coming off. Therefore, when the wire rope 18 breaks in the rope drum 17, or when the lighting fixture 20 is once caught on something during the ascent / descent operation, or when the wire rope 18 is wound / unwound during the ascent / descent operation. When the behavior of the wire rope 18 is not stable, for example, when the wire rope 18 changes suddenly, the rope 18 can be prevented from coming off the second pulley 24.

[0041]

The present invention is embodied in the form described above and has the following effects.

According to the first aspect of the present invention, since a single spring is used to bias the pulley support supporting the pulley in a direction against the tension of the wire rope, the number of springs used is minimized. The structure for biasing the pulley can be simplified, and the variation in spring characteristics does not affect the axial movement in the axial movement of the pulley support supporting the pulley along the guide shaft. , An error in the timing of turning on / off the detection switch linked to.

According to the second aspect of the present invention, the pair of side walls provided on the pulley support allows the wire hung on the pulley even when there is a sudden change during the winding and rewinding operations of the wire rope. The rope can be prevented from coming off the pulley, and can be used more safely.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a partial configuration of a lifting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a slack detection mechanism included in the elevating device according to the first embodiment.

FIG. 3 is a perspective view showing a structure around a pulley support provided in the slack detection mechanism shown in FIG. 2;

FIG. 4 is an exploded perspective view showing a configuration of a slack detection mechanism shown in FIG. 2;

FIG. 5A is a diagram schematically showing the lifting device according to the first embodiment in a state where a lighting fixture suspended by the lifting device is lowered on a floor surface. FIG. 5B shows the configuration of the slack detection mechanism in FIG.
FIG.

FIG. 6A is a diagram schematically showing the lifting device according to the first embodiment in a state in which the lighting fixture suspended by the lifting device is being lifted and lowered. FIG. 7B is a side view showing the configuration of the slack detection mechanism with a part cut away in the state of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Fixed part, 12 ... Drive part, 13 ... Looseness detection mechanism, 18 ... Wire rope, 19 ... Elevating part, 21 ... Mechanism frame, 22 ... Guide shaft, 23 ... Pulley support, 24 ... 2nd pulley (pulley), 25: coil spring (spring) 26: detection switch 37a, 37b: side wall of pulley support

Claims (2)

[Claims] A drive unit for winding and rewinding a wire rope and a slack detection mechanism for detecting slack of the wire rope are provided on a fixed unit arranged at a high position on the ceiling side, and the slack detection mechanism for detecting slack of the wire rope is provided. A lifting device that raises and lowers the lifting unit suspended in the lifting device, and stops the operation of the driving unit when the looseness detection mechanism detects the looseness of the wire rope. The looseness detection mechanism is fixed to the fixing unit. A guide shaft extending in a direction in which the tension of the wire rope is applied and attached to the frame; a pulley support movably attached to the guide shaft along the axial direction; A pulley rotatably attached to the pulley support and on which the wire rope is hung; and a pulley supported between the mechanism frame and the pulley support. A single spring biasing in a direction against the tension of the wire rope; and a detection switch attached to the mechanism frame and turned on / off in conjunction with movement of the pulley support. apparatus. 2. The pulley support has a pair of side walls provided on both sides of the pulley with the pulley interposed therebetween, and the side walls are arranged close to the pulley. The elevating device according to item 1.