JP2004250917A - Electric screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric screen high in reliability while reducing cost and assembly man-hours. <P>SOLUTION: A driving rotary shaft 5A of an electric motor 5 for rotationally operating a driving rotation body 4 is interlockingly connected to the driving rotation body 4 for winding the screen, and a pair of clamping members 9A, 9B for clamp-holding a motor body 5B of the electric motor 5 is pivoted in the state of being energized in a clamp-holding direction by a single energizing means 12. A single detecting means is provided for detecting the operation of the clamping members 9A, 9B in a separating direction due to the rotation of the motor body 5B in an opposite direction to the driving rotation body 4 caused by applying larger load than the energizing force of the energizing means 12 to the driving rotation body 4 under rotation, and the driving of the electric motor 5 is stopped by an output signal from the detecting means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, for example, the attitude can be freely changed by using a driving force of an electric motor between a storage attitude wound around a driving rotary body having a screen arranged in a casing and a use attitude fed out (extended) from the driving rotary body. The present invention relates to an electric screen configured as described above.
[0002]
[Prior art]
For example, when the screen is being fed or wound by an electric motor, a finger may be accidentally inserted into the casing. Further, when the screen in the use posture is being wound by the electric motor, the lower end of the screen may be caught by something, and the winding may be prevented.
When a large load is applied to the electric motor as described above, the electric motor may be damaged.Therefore, the electric motor and the output shaft for transmitting the power from the electric motor to the screen winding pipe are conventionally used. Provide a friction clutch mechanism with a pair of contact bodies between them, when the finger accidentally thrusts into the casing or the lower end of the screen is caught by something, and the output shaft side locks, The driving force of the electric motor is released while the body slips, so that damage to the electric motor can be avoided (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2-53496.
According to the configuration of the above-mentioned patent document, a space for disposing the two contact bodies must be provided in the casing, and there is a disadvantage that the entire electric screen is enlarged.
Moreover, not only is it difficult to adjust the contact pressure of both contact bodies, but also the contact pressure changes with use, so that maintenance must be performed periodically, which is troublesome.
As a solution to the above-mentioned inconvenience, there is a technique already proposed by the present inventor (Japanese Patent Application No. 2001-375377). This is achieved by providing a pair of coil springs for rotatably supporting the motor body of the electric motor and biasing the motor body to a predetermined neutral position, and when the motor body rotates against the biasing force of the coil spring. A contact member having two limit switches that come into contact with each other to be turned on and two contact portions that respectively contact the two limit switches is provided, and an electric signal is supplied by an ON signal from the limit switch. Driving stop means for stopping rotation of the motor is provided.
[0005]
[Problems to be solved by the invention]
According to the above configuration, not only a large number of components such as a contact member having two contact portions, two limit switches, and two coil springs are required, but also two limit switches and a control device. Must be connected to each other, which not only increases the cost but also increases the number of assembly steps.
In addition, it is not only difficult to urge the motor body to the neutral position using the two coil springs, but also the elastic force of the two coil springs changes with use, and the electric motor varies depending on the rotation direction. In some cases, the timing (sensitivity) at which the operation can be stopped is greatly different (delayed), and thus it is difficult to use.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has an object to solve the problem in providing a highly reliable electric screen while reducing costs and man-hours for assembly.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the electric screen of the present invention is configured such that a driving rotary shaft of an electric motor for rotating the driving rotary body is connected to a driving rotary body for winding the screen, and the motor main body of the electric motor is electrically connected to the electric rotating body. A pair of holding members for holding and holding a pair of holding members by holding the holding members in a direction perpendicular to the direction of the rotation axis of the motor are movable in a separation direction in which the holding and holding by the members are released, and a single bias is applied in the holding and holding direction. The motor main body is opposed to the driving rotator by applying a load greater than the urging force of the urging means to the driving rotator during rotation of the driving rotator. A single detecting means for detecting that the holding member has been operated in the separating direction by rotating in the direction, and stopping the driving of the electric motor based on an output signal from the detecting means. It is characterized in that a stop means.
The motor body of the electric motor rotates when the finger is accidentally inserted into the casing or the lower end of the screen is caught by something, and the drive shaft of the electric motor is stopped or decelerated. Will be. Thereby, the pair of holding members are operated in the separating direction against the urging force of the urging means, and by detecting this by the detecting means, the driving of the electric motor can be stopped by the driving stopping means. It is. Even if the motor body of the electric motor is rotated clockwise or counterclockwise as viewed in the direction of the axis of rotation of the electric motor, the pair of holding members are operated in the separating direction. It is sufficient to provide a single detecting means for detecting that the holding members have been separated from each other, and it is also possible to use only one urging means for urging the pair of holding members in the closing direction.
[0008]
The detection means, a limit switch attached to one of the pair of holding members, the ON state when the limit switch is in the holding state of the holding member, and the pair of A limit switch operating contact member attached to the other holding member so that the holding member is turned off when the holding member is separated.
[0009]
A pair of swinging members, wherein the pair of holding members are parallel to a driving rotation axis of the electric motor, and are swingably mounted around an axis positioned at the same end from the driving rotation axis. And a coil spring for connecting the other ends of the pair of swing arms opposite to the shaft centers and for biasing the pair of swing arms to a holding state. ing.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 and 2 show a part (right side) of an electric screen (size (size) may be other than that shown in the figures) 1 for displaying an image from a projector or the like. The electric screen 1 is long in the left-right direction, has a size in the front-rear direction such that a finger can enter a lower end thereof, and is formed in a casing 2 in which a horizontally long opening 2A having dimensions slightly smaller than both left and right ends is formed. And a rotatably supported cylindrical driving rotator 4 for winding up the screen 3, and an electric motor 5 for driving the driving rotator 4 to rotate. The electric motor 5 includes a motor main body 5B and a drive rotating shaft 5A protruding from the motor main body 5B. A protrusion 4A is formed at one location on the inner surface of the driving rotor 4 over the entire area in the left-right direction, and the rotor 6 provided with a recess 6A engaging with the projection 4A at one location on the outer peripheral surface is electrically driven. It is attached to the tip of the drive rotation shaft 5A of the motor 5 in an integrally rotating state. Therefore, by driving the drive rotating shaft 5A of the electric motor 5 to one side, the screen 3 wound around the drive rotating body 4 is fed downward through the opening 2A to project an image from, for example, a projector (not shown). The driving posture of the electric motor 5 can be changed in a direction opposite to the rotating direction, and the screen can be returned to the storage posture wound around the driving rotating body 4 by driving the driving rotating shaft 5A of the electric motor 5 in the opposite direction. 3 can be changed in posture. The rotation command signal to the electric motor 5 may be sent by any method such as being sent from a wired or wireless remote control, or being sent by ON-OFF operation of a switch provided in the casing 2. In addition, reference numeral 7 shown in FIG. 1 is fixed to one end of the screen 3 and serves as a weight for flattening the surface of the screen when the screen 3 is used, and a casing when the screen 3 is stored. Although the bar is engaged with the second opening 2A and covers the opening 2A, the bar may have a shape other than that shown in the drawing, or may be omitted. In FIG. 2, the rotating body 6 is fixed to the driving rotating shaft 5A of the electric motor 5, and the rotating body 6 and the driving rotating body 4 are engaged with each other. Although the body 4 is interlocked and connected, it is also possible to use a gear mechanism or the like to interlock and connect the two.
[0011]
As shown in FIGS. 3A and 3B, a square shaft body 8 having a square cross section is provided at an end of the electric motor 5 opposite to the drive rotation shaft 5A of the motor main body 5B. A control device C (see FIG. 2) for the electric motor 5 is provided with a pair of holding members 9A and 9B for holding the shaft body 8 in a direction perpendicular to the core direction of the drive rotation shaft 5A by bolt fixing. It is swingably attached to a box 10 composed of fixed side divided cases 10A and 10B. More specifically, as shown in FIGS. 3 to 5, a through hole 10 </ b> D into which the shaft body 8 can be inserted is formed in a divided case 10 </ b> A inside a box 10 fixed to one end of the casing 2, At the lower part of the inner wall 10a of the case 10A, a plate-shaped holding member (oscillating arm) 9A made of a substantially U-shaped metal (or a wooden or plastic material having substantially the same strength) may be used. 9B is pivotally connected to each other by screws 11. The swing arms 9A and 9B have upper and lower mating surfaces 9a, 9b, 9c and 9d, respectively, in a holding posture in which the shaft body 8 is sandwiched, and substantially hold the shaft body 8 between the upper and lower mating surfaces. It has V-shaped (an angle between the two surfaces is 90 degrees) sandwiching surfaces 9e and 9f, and is provided at a position on the same end side with respect to the shaft body 8 around a shaft center parallel to the shaft center 5X of the drive rotary shaft 5A. The screws 11, 11 are pivotally supported on the inner wall 10a of the divided case 10A by the screws 11, 11 so as to be swingable at X1, X2. Here, the fitting surfaces 9a, 9b, 9c, and 9d are substantially diagonally aligned with the rectangular inner wall 10a in order to efficiently store the electric screen in the inner wall 10a of the divided case 10A and suppress the enlargement of the electric screen. In FIG. 3A, the swing arms 9A and 9B are mounted in an inclined posture in which the upper ends are inclined leftward toward the left, but the mating surfaces 9a, 9b, 9c and 9d are in a vertical posture in which they are positioned vertically. You may. Further, although the holding surfaces 9e and 9f are located substantially at the center of the swing arms 9A and 9B in the longitudinal direction, they may be arranged on either one end or the other end of the swing arms 9A and 9B in the longitudinal direction.
[0012]
Then, one end of a coil spring 12 is fixed to one of the ends of the swing arms 9A and 9B on the surface opposite to the box 10 side on the side opposite to the pivotal support portion by screws 13. The other end of the coil spring 12 is fixed to the other end with a screw 13, and constitutes an urging means for urging the swing arms 9 </ b> A and 9 </ b> B to the holding posture by the pulling force of the coil spring 12. By arranging the coil spring 12 at a position furthest away from the pivot at one end in the longitudinal direction of the swing arms 9A, 9B, that is, at the other end in the longitudinal direction of the swing arms 9A, 9B, a required predetermined value is obtained. There is an advantage that the holding force can be exerted by the small coil spring 12 and the size of the electric screen can be further reduced. However, the coil spring 12 is arranged on the pivot portion side with respect to the pivot portion. The installation position of the coil spring 12 can be freely changed.
[0013]
When a load greater than the urging force of the coil spring 12 is applied to the driving rotator 4 during the rotation of the driving rotator 4, the motor main body 5B rotates in the opposite direction to the driving rotator 4 to swing the arm 9A. , 9B for detecting that the electric motor 5 has been operated in the separating direction, and a driving stop means (driving stop circuit) for stopping driving of the electric motor 5 based on an output signal from the detecting means 14. ) Is provided in the control device C (see FIG. 2).
The detecting means 14 includes a limit switch 14R attached via a screw 15 to a surface of one of the pair of swing arms 9A and 9B on the box 10 side, and a switch portion 14a of the limit switch 14R. Is in a state where the pair of swing arms 9A and 9B are sandwiched and held, the limit switch 14R is turned on, and the limit switch 14R is turned off by separating the pair of swing arms 9A and 9B. A substantially L-shaped limit switch operating contact member 14S attached via screws 16 to the surface of the other swing arm 9A on the box 10 side so as to be in a state. Here, by providing the contact type limit switch 14R, it is possible to make the switch inexpensive and highly reliable, but a non-contact photoelectric sensor or the like can also be used.
Therefore, as shown in FIG. 2, the finger H is accidentally inserted from the opening 2A of the casing 2 and the coil H is added to the driving rotating body 4 (during winding) rotating in the direction X in the drawing. When the motor main body 5B rotates in the direction Y (see FIG. 3A) opposite to the drive rotation shaft 5A by applying a load greater than the urging force (clamping force) by the spring 12, as shown in FIG. 3B. When the swing arm 9A, 9B swings to the side away from the holding position, the switch portion 14a of the limit switch 14R, which has been pushed in, returns to the initial position on the OFF side by the force of the internal spring. The switch 14R is turned off, and this OFF signal is input to the control device C. Then, the drive of the electric motor 5 is stopped by outputting a drive stop signal from the control device C to the electric motor 5. When the rotation direction of the electric motor 5 is the direction Y opposite to the direction X, the swing arm 9A, 9B is swung to the side separated from the holding posture by 4 as described above, and the limit is reached. The switch 14R is turned off, and a drive stop signal is output from the control device C to the electric motor 5 according to the OFF signal, so that the drive of the electric motor 5 is stopped. 3C and 4C are through holes formed in the inner wall 10a to allow the limit switch 14R and the limit switch operating contact member 14S to escape.
[0014]
【The invention's effect】
According to the first aspect of the present invention, only a single urging means for holding and holding the motor body and a single detecting means for detecting that the holding by the holding means is released are erroneously provided. An electric screen that can reliably stop the electric motor when a finger is inserted or a large load is applied to the drive of the electric motor can be configured, thereby reducing costs and reducing the number of assembly steps. Can also be configured to be highly reliable. Moreover, by using a mechanical configuration that effectively utilizes the movement of the motor body, not only can the control circuit be simplified, but also the number of required components can be reduced, which is advantageous in terms of cost. .
[0015]
According to the second aspect of the present invention, the detection means is constituted by a contact-type limit switch, so that the reliability can be improved as compared with the case where a non-contact-type sensor such as a photoelectric sensor is provided. It is also advantageous in terms of cost.
[0016]
According to the third aspect of the present invention, the pivot portions of the pair of clamping members are located on the same end side from the drive rotation axis, and the pair of swing arms are clamped and held at the other end farthest from the pivot portion. By attaching a coil spring to be urged, a large urging force can be exerted while using a small coil spring, and there is an advantage that the size of the electric screen can be further reduced. Further, by simply changing the coil spring to another coil spring having a different elastic biasing force, the timing (sensitivity) of stopping the drive of the electric motor can be adjusted, and there is an advantage that the design can be easily changed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one side (right side) of an electric screen.
FIG. 2 is a perspective view showing a state where a finger is put in a casing of the electric screen.
3A and 3B are explanatory views showing a state in which a pair of holding members are holding a shaft body, wherein FIG. 3A shows a holding state, and FIG. 3B shows a holding release state.
FIG. 4 is an exploded perspective view showing a mounting structure of a pair of holding members.
FIG. 5 is a perspective view showing a main part in which a pair of holding members are attached to a box.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric screen 2 Casing 2A opening 3 Screen 4 Drive rotating body 4A Convex part 5 Electric motor 5A Drive rotating shaft 5X Shaft core 6 Rotating body 6A Concave 7 Bar 8 Shaft 9A, 9B Clamping members 9a, 9b, 9c, 9d 9e, 9f Holding surface 10 Box 10A, 10B Dividing case 10D Through hole 10a Inner wall 10C Through hole 11 Screw 12 Coil spring 13 Screw 14 Detecting means 14R Limit switch 14a Switch section 14S Contact member 15, 16 Screw C Control device H Finger

Claims (3)

A driving rotating shaft for winding the screen is connected to a driving rotating shaft of an electric motor that rotates the driving rotating body, and the motor body of the electric motor is sandwiched and sandwiched from a direction orthogonal to the driving rotating shaft center of the electric motor. A pair of holding members to be held are movably provided in a separating direction in which the holding and holding by them is released, and provided in a state where the holding members are urged by a single urging means in the direction of holding and holding, and When a load greater than the urging force of the urging means is applied to the driving rotator during rotation, the motor body rotates in the opposite direction to the driving rotator, and the holding member is operated in the separating direction. An electric screen, comprising: a single detecting means for detecting the occurrence of a fault; and a drive stopping means for stopping driving of the electric motor based on an output signal from the detecting means. The detection means, a limit switch attached to one of the pair of holding members, the ON state when the limit switch is in the holding state of the holding member, and the pair of 2. The electric screen according to claim 1, further comprising a limit switch operating contact member attached to the other holding member so as to be turned off when the holding member is separated. A pair of swinging members, wherein the pair of holding members are parallel to a driving rotation axis of the electric motor, and are swingably mounted around an axis positioned at the same end from the driving rotation axis. And a coil spring for connecting the other ends of the pair of swing arms opposite to the shaft centers and for biasing the pair of swing arms to a holding state. The electric screen according to claim 1, wherein the electric screen comprises:

Images