JP3971558B2 - lift device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an elevating device for a load such as a lighting fixture mounted at a high place, and more particularly to an elevating device using a DC motor as a driving means for elevating the load and a control circuit for the DC motor.
[0002]
[Prior art]
Conventionally, in a large structure with a relatively high ceiling, such as a concert hall, a gymnasium, a convention hall, etc., an elevating device for the luminaire has been used in order to facilitate maintenance of the luminaire mounted on the ceiling. The elevating device mainly includes an elevating part to which a lighting fixture is connected, a suspension member for suspending the elevating part, a driving means for raising / lowering the elevating part via the suspension material, and the driving means on the ceiling. It consists of a fixed part to be fixed.
As the driving means, a winding drum to which one end of the suspension material is connected and an AC motor that rotates the winding drum to wind the suspension material are used. With the lifting device having such a configuration, the lifting unit is moved between the uppermost position near the ceiling where the lighting fixture is used and the lowest position lowered near the floor in order to perform maintenance of the lighting fixture. It becomes possible.
[0003]
[Problems to be solved by the invention]
However, when an AC motor is used, if it is attempted to increase the moving speed of the elevating unit, the reduction ratio of the speed reducer must be reduced, and a relatively large AC motor having a large rotational force must be used. .
[0004]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, it is an object without using a large-sized driving means, along with easily adjustable lifting speed of the load, the entire device An object of the present invention is to provide a lifting device capable of reducing the cost .
[0005]
That is, the lifting device according to claim 1 of the present invention is fixed to at least one suspension member, a lifting unit to which a load can be connected, and a ceiling of a structure, and is connected to the lifting unit via the suspension member. A lifting part to which one end of the suspension member is connected, and a DC motor that rotates the take-up drum to take up the suspension member. A lifting and lowering device comprising: a driving means configured to: and a control circuit for the DC motor ,
However, the control circuit includes a single relay that operates in response to either a rising or falling power supply, and a rising diode bridge that is used to power the DC motor via a relay contact. And a diode bridge on the descending side used for applying power to the DC motor via a relay contact that opens and closes opposite to the relay contact on the ascending side .
[0006]
According to a second aspect of the present invention, in the first aspect of the invention, the control circuit has a rising terminal, a lowering terminal, and a common terminal, and the relay is provided between the rising terminal or the lowering terminal and the common terminal, An ascending diode bridge and a descending diode bridge are provided between the ascending terminal and the common terminal and between the descending terminal and the common terminal, respectively .
[0007]
According to a third aspect of the present invention, in the second aspect of the present invention, a relay is provided between the rising terminal and the common terminal, and both output ends of the rising-side diode bridge are the first and second normally-opened relays. It is connected to a DC motor via a contact, and both output ends of the descending diode bridge are connected to the DC motor via normally closed third and fourth contacts of the relay .
[0008]
According to a fourth aspect of the present invention, in the second or third aspect of the present invention, an elevating limit switch that opens when the elevating unit reaches the uppermost position is interposed between the elevating terminal and the elevating diode bridge, and the elevating unit A lower limit switch that opens when the position reaches the lowest position is interposed between the lower terminal and the lower diode bridge .
[0009]
According to a fifth aspect of the present invention, in the first aspect of the invention, the control circuit includes an ascending side circuit that functions when the ascending / descending portion ascends and a descending side circuit that functions when the ascending / descending portion descends, and the ascending side circuit has an ascent end limit switch. It is characterized by.
[0010]
According to a sixth aspect of the present invention, in the first or fifth aspect of the present invention, the control circuit includes an ascending side circuit that functions when the ascending / descending portion ascends and a descending side circuit that functions when the ascending / descending portion descends. It is characterized by having.
[0011]
The invention according to claim 7 is the invention according to any one of claims 1, 5 and 6 , wherein the control circuit includes an ascending side circuit which functions when the ascending / descending portion is raised and a descending side circuit which functions when the ascending / descending portion is lowered, Each descending circuit has a surge absorber and a fuse for lightning surge countermeasures.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
With reference to the attached drawings, a preferred embodiment of the lifting device of the present invention will be described in detail below. Although it is not particularly limited as a load, it is used by being placed at a high place (near the ceiling) and needs to be lowered to the ground (floor surface) in order to perform its maintenance, for example, lighting equipment, security camera, Examples include fire detectors and banners.
[0013]
In FIG. 1, the external appearance of the raising / lowering apparatus of the lighting fixture based on a present Example is shown. The lifting device includes, as main components, a suspension member 2 composed of a pair of strips, a lifting unit 3 to which a lighting fixture can be connected at the lower portion, and a ceiling of the structure. The fixed part 1 to be connected is included.
[0014]
The suspension member 2 is preferably made of a rigid metal material or the like. The number of the suspension members is not particularly limited. However, when the number of the suspension members is two or more, even if one of them is broken, the lift part 3 can be held with the remaining one, which is preferable in terms of safety.
[0015]
The fixed part 1 has a case 10 having a concave part 13 that can accommodate the elevating part 3 on the lower surface, and a drive unit that allows the elevating part to be raised and lowered using the suspension member 2 is disposed therein. . The case 10 includes a base 12 fixed to the ceiling of the structure and a cover 14 that is detachably attached to the base.
[0016]
As shown in FIG. 2, the drive unit includes a pair of winding drums 20 to which one end of the suspension member is connected to wind up each suspension member 2, a permanent magnet and a rectifying brush for rotating the winding drum. And a reduction gear 26 for reducing the rotation of the drive shaft of the motor and transmitting it to the winding drum. In FIG. 2, a predetermined electric circuit including a control circuit for the DC motor is arranged in an area denoted by reference numeral 7.
[0017]
As shown in FIG. 3, the suspension member 2 having one end connected to the take-up drum 20 extends vertically downward toward the elevating unit 3 via the pulley 5. At this time, the pair of suspension members 2 extend so as to be substantially parallel and so that the mutual planes of the strips are substantially in the same direction. The rotation of the drive shaft of the DC motor 22 is transmitted via a reduction gear 26 to a spur gear 24 provided at one end of the main shaft 21 that is a rotation shaft of the pair of winding drums 20. Thereby, a pair of winding drum 20 can be rotated simultaneously and in the same direction.
[0018]
In the configuration described above, by driving the DC motor 22, the lifting / lowering unit 3 is fixed by completely unraveling the suspension member 2 from the winding drum 20 and the uppermost position where the lifting / lowering unit 3 is accommodated in the recess 13 of the case 10 of the fixing unit 1. The raising / lowering part 3 can be raised / lowered between the lowest position where the distance between the part 1 and the raising / lowering part 3 becomes the maximum.
[0019]
Next, a control circuit for the DC motor 22 in the lifting device of the present invention will be described.
[0020]
As shown in FIG. 4, the control circuit is provided with a rising terminal a, a falling terminal b, and a common terminal c. When the lifting unit 3 is lifted, an alternating current is connected between the rising terminal a and the common terminal c. When the commercial power source P is applied and the elevating unit 3 is lowered, the alternating commercial power source P is applied between the descending terminal b and the common terminal c. In addition, when a plurality of lifting devices (A, B) are installed as shown in FIG. 4, the commercial power supply P is applied by connecting the rising terminal a, the falling terminal b, and the common terminal c in parallel.
[0021]
One embodiment of the control circuit is shown in FIG. The control circuit includes a first relay R1 having relay contacts R11 to R13 between the rising terminal a and the common terminal c, and a second relay R2 having relay contacts R21 to R23 between the lowering terminal b and the common terminal c. Is provided. The rising terminal a is connected to the input terminal of the diode bridge DB1 via the contact R11 of the first relay R1, and the falling terminal b is connected to the same input terminal of the diode bridge DB1 via the contact R21 of the second relay R2. The The common terminal c is connected to the other input terminal of the diode bridge DB1 and is connected to the AC commercial power applied between the rising terminal a and the common terminal c, or between the falling terminal b and the common terminal c. The applied AC commercial power supply is full-wave rectified.
[0022]
On the other hand, the output of the diode bridge DB1 is output to the brush 22a of the DC motor 22 via the contact R12 and the contact R13 of the first relay R1 provided at both output ends so that the DC motor 22 is reversed in the positive and negative directions. A power source is applied to the brush 22a of the DC motor 22 through the contact R22 and the contact R23 of the second relay R2 provided at the end. The operation state of this circuit is shown in FIG. 6 (a) when the AC commercial power is applied between the rising terminal a and the common terminal c. FIG. 6B shows the operation of the control circuit (bold line) when an AC commercial power supply is applied to the common terminal c. Here, the contacts R11 and R21 of the first relay R1 and the second relay R2 are provided with a plurality of lifting devices, and prevent current from flowing when each of them is connected in parallel.
[0023]
In the control circuit of FIG. 5, two relays are used. However, as shown in FIG. 7, a single relay can be used. That is, a relay R1 having contacts R11 to R14 is provided between the rising terminal a and the common terminal c, the rising terminal a is connected to the input terminal of the diode bridge DB1 via the normally open contact R11, and the falling terminal b is normally closed. Are connected to the same input terminal of the diode bridge DB1 through the contact R12. In addition, switching contacts R13 and R14 are provided so that the DC motor 22 can reverse the polarity of the output of the diode bridge DB1. The relay is provided between the rising terminal a and the common terminal c, but may be provided between the lowering terminal b and the common terminal c.
[0024]
Furthermore, there is a control circuit shown in FIG. 8 as an embodiment of a control circuit constituted by normally open and normally closed contacts without using a switching contact with a single relay. The control circuit includes a relay R1 between the rising terminal a and the common terminal c, and the first and second diode bridges DB1 between the rising terminal a and the common terminal c and between the lowering terminal b and the common terminal c, respectively. By providing DB2, the AC commercial power applied between the rising terminal a and the common terminal c or the AC commercial power applied between the descending terminal b and the common terminal c is full-wave rectified respectively. ing.
[0025]
The output of the first diode bridge DB1 is provided with the normally open first and second contacts R11 and R12 of the relay R1 at both output ends, and the brush 22a of the DC motor 22 is connected to the output of the second diode bridge DB2. Is connected to the brush 22a of the DC motor 22 by providing normally closed third and fourth contacts R13, R14 of the relay R1 at both output ends. The operation state (bold line) of this control circuit when an AC commercial power supply is applied between the rising terminal a and the common terminal c is shown in FIG. FIG. 9B shows an operation state (thick line) of the control circuit when an AC commercial power supply is applied. The relay R1 is provided between the rising terminal a and the common terminal c, but may be provided between the lowering terminal b and the common terminal c.
[0026]
Further, as shown in FIG. 10, an ascending limit limit switch LS1 that opens when the elevating part 3 reaches the uppermost position is interposed in series with the ascending terminal a, and as shown in FIG. When the elevating unit 3 reaches the uppermost position or the lowermost position, a power supply to the DC motor 22 is provided by interposing a descending limit switch LS2 opened in series when the elevating part 3 reaches the lowest position. Can be shut off automatically.
[0027]
Further, as shown in FIG. 12, surge absorbers ZNR1 and ZNR2 that allow current to pass when a large voltage such as a lightning surge is superimposed between the rising terminal a and the common terminal c and between the falling terminal b and the common terminal c. In addition, when a fuse H that interrupts the circuit when a current of a predetermined level or more flows on the common terminal c side, the diode bridges DB1 and DB2 and the contacts R11, R12, R13, and R14 are caused by a large voltage such as a lightning surge. Damage or the like can be prevented.
[0028]
【The invention's effect】
In the past, as a result of reducing the reduction ratio of the reducer in order to increase the rotation speed of the winding drum, that is, the raising / lowering speed of the raising / lowering part, it was necessary to use a large AC motor. Since a DC motor is used as the driving means, the apparatus can be reduced in size and the load elevating speed can be easily adjusted as compared with the case where an AC motor is used.
[0029]
Furthermore, if the DC motor control circuit is configured using two relatively inexpensive diode bridges and a single relay, the overall cost of the device can be reduced, and the number of relay contacts can be reduced to reduce the circuit connection cost. Can be lowered.
[0030]
The lifting device of the present invention is particularly suitable for use in large structures with relatively high ceilings such as concert halls, gymnasiums, convention halls, etc., and efficiently performs maintenance work of loads such as lighting fixtures arranged at high places. Yes.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the appearance of a lifting device for a lighting fixture according to an embodiment of the present invention.
FIG. 2 is a schematic top view showing an internal configuration of a fixing part of the lifting device same as above.
FIG. 3 is a schematic cross-sectional view showing the internal configuration of the fixed part of the above.
FIG. 4 is a diagram showing a feed wiring when a plurality of lifting devices are installed.
FIG. 5 is a diagram illustrating a first embodiment of a control circuit of a driving unit.
6A is a diagram illustrating the operation of the control circuit when an AC commercial power supply is applied between the rising terminal a and the common terminal c in FIG. 5, and FIG. It is a figure which shows the operation | movement of a control circuit when alternating current commercial power is applied between the descent | fall terminal b and the common terminal c.
FIG. 7 is a diagram showing a second embodiment of the control circuit of the driving means.
FIG. 8 is a diagram showing a third embodiment of the control circuit of the driving means.
9A is a diagram illustrating the operation of the control circuit when an AC commercial power supply is applied between the rising terminal a and the common terminal c in FIG. 8, and FIG. 9B is a diagram illustrating the operation of the control circuit. It is a figure which shows operation | movement of a control circuit when alternating current commercial power is applied between the descent | fall terminal b and the common terminal c.
FIG. 10 is a diagram illustrating an example of a control circuit when an ascent limit switch is provided.
FIG. 11 is a diagram illustrating an example of a control circuit when a lower limit switch is provided.
FIG. 12 is a diagram illustrating an example of a control circuit when a lightning surge countermeasure circuit is provided.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed part 2 Suspension material 3 Elevating part 5 Pulley 10 Case 12 Base 14 Cover 20 Winding drum 22 DC motor

Claims (7)

At least one suspension;
A lifting part to which a load can be connected;
A fixed part fixed to the ceiling of the structure and connected to the elevating part via the suspension member;
A driving means that includes a winding drum to which one end of the suspension material is connected and a DC motor that rotates the winding drum to wind up the suspension material, and that allows the elevating unit to be moved up and down by using the suspension material; ,
A lifting device comprising a control circuit for the DC motor ,
However, the control circuit includes a single relay that operates in response to either a rising or falling power supply, and a rising diode bridge that is used to power the DC motor via a relay contact. And a descending diode bridge used to apply power to the DC motor via a relay contact that opens and closes opposite to the ascending relay contact . The control circuit has an ascending terminal, a descending terminal, and a common terminal, and the relay is provided between the ascending terminal or the descending terminal and the common terminal, and between the ascending terminal and the common terminal and the descending terminal. The elevating device according to claim 1, wherein the ascending diode bridge and the descending diode bridge are provided between the common terminal and the ascending diode bridge, respectively . The relay is provided between the ascending terminal and the common terminal, and both output ends of the ascending diode bridge are connected to the DC motor via the normally open first and second contacts of the relay, and the descending side The lifting device according to claim 2, wherein both output ends of the diode bridge are connected to the DC motor via normally closed third and fourth contacts of the relay . An ascending limit switch that opens when the ascending / descending part reaches the uppermost position is interposed between the ascending terminal and the ascending-side diode bridge, and an ascending limit limit switch that opens when the ascending / descending part reaches the lowest position 4. The lifting device according to claim 2, wherein the lifting device is interposed between the descending terminal and the descending diode bridge . The control circuit includes a lowering side circuit functioning during raising and lowering side circuit functioning at elevated elevating part, lifting apparatus according to claim 1, wherein the rising-side circuit and having an ascent limit limit switch . The control circuit includes a lowering side circuit functioning during raising and lowering side circuit functioning at elevated elevating part, according to claim 1 or 5 wherein the descending side circuit and having a lowermost limit switch lift device. The control circuit includes an ascending side circuit that functions when the ascending / descending portion ascends and a descending side circuit that functions when the ascending / descending portion descends, and each of the ascending side circuit and the descending side circuit has a surge absorber and a fuse for lightning surge countermeasures. The lifting device according to any one of claims 1, 5, and 6 .

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