JP4847158B2 - Shutter abnormal drop prevention device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a shutter abnormal drop prevention device capable of accurately and reliably preventing an abnormal drop of a shutter curtain in the event of an abnormality such as a broken chain or a broken chain in a shutter having an opening / closing device having a braking mechanism. .

  In a shutter equipped with an opening / closing device having a braking mechanism, if the roller chain for transmitting the rotation of the rotation shaft of the opening / closing device to the winding shaft of the shutter curtain is broken or disconnected for some reason, the shutter curtain Since it falls uncontrollable by its own weight, it is necessary to provide a mechanism for preventing an abnormal drop at the time of the abnormality. In the following Patent Documents 1 and 2, a conventional device for preventing the abnormal drop is disclosed as a fall prevention device.

  The fall prevention device of Patent Document 1 includes a ratchet tooth that is coaxially attached to a sprocket that is coupled to a winding shaft, and one end pivotally supported by a bracket that supports the winding shaft, and a biasing means. The ratchet pawl urged in the ratchet teeth direction by the ratchet and the tip of the arm integrated with the ratchet pawl on the shaft side are pivotally attached, and rotate in mesh with the roller chain wound around the sprocket The chain is connected to the motor side, and a tension is constantly applied to the chain, so that the ratchet pawl is held away from the ratchet teeth against the biasing force of the biasing means.

  According to this structure, when the chain is cut for some reason and the tension is removed, the ratchet pawl engages with the ratchet teeth by the biasing pressure to stop the rotation of the winding shaft, and the shutter curtain is in the gravitational direction. Prevent abnormal drop to the closed side.

The fall prevention device of Patent Document 2 is provided with a governor coaxially with the take-up shaft. When the rotation speed of the take-up shaft becomes higher than a predetermined speed, the weight portion of the governor opens in the radial direction, and the governor casing friction It contacts the surface and brakes the rotation of the drive shaft by the braking effect.
Japanese Utility Model Application Publication No. 2-105494 Japanese Utility Model Publication No. 7-26600

  However, in the technique described in Patent Document 1, when a sudden abnormal lowering operation due to chain cutting occurs, if the engagement of the ratchet pawl is accidentally shallow and insufficient, the ratchet teeth are caused by the rotational inertia of the winding shaft. There is a possibility that the ratchet claw will be momentarily bounced, and the rotation of the take-up shaft may not stop instantaneously, and if the battering phenomenon occurs repeatedly, the engagement portion of the ratchet claw may be damaged by impact.

  Further, with the technique described in Patent Document 2, although the descent speed can be slowed, the descent itself cannot be prevented, and a sufficient braking effect can be obtained if the descent inertia is large with respect to the braking force. I couldn't.

  Regardless of the abnormal descent prevention device, the descent stop or braking action depends on the weight of the entire shutter curtain, and even if it fits to some extent with a small and light shutter curtain, it is a large and heavy shutter. It is considered unsuitable as a curtain descent prevention device, and as a guideline, it is about 1.2 tons in weight, and it cannot be handled any more.

  Therefore, the present invention solves the above-described problems, and has a simple structure and is capable of reliably stopping abnormal descent even when a sudden descent operation occurs, and is suitable for a large and large shutter curtain. A descent prevention device is provided.

  In order to achieve the above object, the invention of claim 1 is directed to a rotary shaft of a switch having a driven sprocket 4 provided at a shaft end of a winding shaft 2 that is supported by a bracket 3 and winds up a shutter curtain, and a braking mechanism. In the shutter in which the roller chain 8 is wound between the drive sprockets 7 provided at the shaft ends of the shaft 6, and the rotation of the rotary shaft 6 of the switch and the rotation of the winding shaft 2 are linked by chain conduction. A stopper rod 10 which is located at an intermediate position between the sprockets and is rotatably disposed on the bracket 3 via a support shaft 9 so that one end portion thereof faces the board surface direction of the driven sprocket 4; An idler 11 disposed at the other end and rotatably engaged with the roller chain 8 to separate the stopper rod 10 from the surface of the driven sprocket 7; When the idler 11 is detached from the roller chain 8 when the roller chain 8 is cut, the stopper rod 10 is rotated and its one end is in a position facing the board surface of the driven sprocket 4. Is positioned between the positioning portion 14 and the positioning portion 14 which protrudes from the board surface of the driven sprocket 4 and abuts against one end portion of the stopper rod 10. A stopper portion 12 for stopping the free rotation of the driven sprocket 4 by holding one end portion of the stopper rod 10 is provided.

  The invention of claim 2 is characterized in that a plurality of the stopper portions 12 are formed on the surface of the driven sprocket 4 by pins protruding in the circumferential direction at substantially equal intervals.

  According to the invention of claim 3, the stopper portion 12 protrudes from the bracket 3, and the positioning portion 14 is positioned radially inward of the driven sprocket 7 from the stopper portion 12. It is characterized by a more protruding arrangement.

  The invention of claim 4 is characterized in that a shutter lock detecting means 16 for detecting the rotation stop position of the stopper rod 10 is provided.

  According to the apparatus for preventing abnormal lowering of the shutter according to claim 1, since the stopper rod surely stops at the contact position with the stopper portion and is sandwiched between the positioning portion, the rotational inertia of the winding shaft is large. Both can stop rotation reliably and stop the descent of the shutter curtain.

  According to the apparatus for preventing an abnormal drop of the shutter according to claim 2, since there are a plurality of stopper portions, even if the stopper rod does not rotate immediately due to an impact caused by a chain breakage or the like, the driven sprocket rotates during the entire circumference. The rotation can be reliably stopped within any rotation angle range.

  According to the apparatus for preventing an abnormal drop of the shutter according to claim 3, the one end portion of the stopper rod is held between the positioning portion and the stopper portion at the time of contact with the stopper rod, and the positioning portion and the power point which are fulcrums are used. Since the distance to a certain stopper portion is short, the impulse acting on the stopper rod is small and there is no risk of breakage.

  According to the apparatus for preventing an abnormal drop of the shutter according to the fourth aspect of the present invention, it is possible to perform control operations such as generating an alarm and stopping the switch, according to the detection by the detection means.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view showing a partial configuration of the uppermost part of a shutter device provided with a stopper device according to the present invention, and FIG. 2 is a front view thereof. In the drawing, a case 1 for winding and collecting a shutter curtain (not shown) is provided at the top of the shutter device, and a stationary end for bearing the winding shaft 2 of the shutter curtain is provided at a side end of the case 1. Side bracket 3 is arranged.

  A large-diameter driven sprocket 4 is pivotally supported at the projecting end of the take-up shaft 2 from the outer side of the bracket 3, and is fixed to the inner side of the bracket 3 at a position away from the driven sprocket 4. A rotary shaft 6 that is an output shaft of the opening / closing machine 5 is supported by a bearing, and a small-diameter drive sprocket 7 is pivotally supported at a projecting end of the rotary shaft 6 from the bracket 3.

  A roller chain 8 is wound between the sprockets 4 and 7, and the rotation of the rotary shaft 6 of the opening / closing machine 5 and the rotation of the winding shaft 2 are linked via the sprockets 4 and 7 and the chain 8. The shutter curtain wound around the winding shaft 2 is braked in accordance with braking by a braking mechanism (not shown) provided in the opening / closing device 5, such as a speed reducer. Further, when the opening / closing machine 5 has a structure including a motor, the shutter curtain wound around the winding shaft 2 is wound and fed out in accordance with forward / reverse rotation of the opening / closing machine 5. The rotation direction of the both sprockets 4 and 7 when the shutter curtain is wound up is the clockwise direction (counter arrow a direction) in the illustration of FIG. 1, and the rotation direction of the shutter curtain when it is extended is the opposite direction in the illustration of FIG. It is a clockwise direction (arrow a direction).

  At a substantially intermediate position between the two sprockets 4 and 7, a support shaft 9 protrudes from an outer portion of the bracket 3 at an inner position surrounded by the chain 8, and a stopper rod 10 rotates on the support shaft 9. Bearing is possible.

  The stopper rod 10 is made of a steel material having a rectangular arm shape that is shallow and substantially in the shape of a square or a substantially U shape with the support shaft 9 as the center, and the lower end of the stopper rod 10 has a wedge shape as a contact portion 10 a facing the driven sprocket 4. And is positioned within the disk surface of the driven sprocket 4 at a position close to the outer surface of the bracket 3 in a rotating state.

  On the other hand, the upper portion of the stopper rod 10 protrudes toward the upper side of the chain 8, and an idler (idle sprocket) 11 that is rotatably engaged with the chain 8 is supported by a bearing at the protruding end. By the meshing, the stopper rod 10 is prevented from rotating toward the board surface. The weight balance between the contact portion 10a side of the stopper rod 10 and the idler 11 side compared with the support shaft 9 as a reference is set so that the idler 11 side is heavier.

  A total of eight stopper portions 12 are provided on the periphery of the surface of the driven sprocket 7 facing the outside of the bracket 3 on the concentric circle with the driven sprocket at intervals of 45 ° in the circumferential direction. . The number and interval of each stopper portion 12 shall be determined as appropriate. In addition, the stopper part 12 should just be at least one.

  On the other hand, the bracket 3 abuts against the abutting portion 10a of the driven sprocket 7 at the inner peripheral position of the stopper portion 12 in a rotating state of the stopper rod 10 and fixes the stopper rod 10 at that position. A positioning portion 14 for projecting is provided.

Further, a check portion 15 for preventing the stopper rod 10 from rotating to the opposite side protrudes from the side surface of the bracket 3, and a micro switch 16 for detecting the tilt position of the stopper rod 10. Is arranged.
In this embodiment, each of the stopper portion 12, the positioning portion 14, and the check portion 15 has a pin shape, for example. In addition, the stopper part 12, the positioning part 14, and the non-return part 15 can be formed by protrusions other than the said pin shape.

  In the above, when chain conduction from the opening / closing machine 5 to the take-up shaft 2 is performed in the normal state, the idler 11 rotates while meshing with it in a substantially fixed position due to the tension of the chain 8 in FIG. As shown by the solid line, the inclination of the stopper rod 10 is constant, and the contact portion 10a is kept away from the stopper portion 12.

  When the chain 8 is cut due to metal fatigue or the like from this state, as a result of the removal of the tension, the stopper rod 10 rotates in the clockwise direction in FIG. Thus, the abutting portion 10a at the tip abuts against the positioning portion 14 and stops rotating.

  At this time, the suspension weight of the shutter curtain is applied to the take-up shaft 2, and when the driven sprocket 4 freely rotates in the downward direction indicated by the arrow in FIG. Collide, and the contact portion 10a is sandwiched between the positioning portion 14 and the contact portion 10a. As a result, the driven sprocket 4 stops rotating, and the shutter curtain is stopped from being lowered.

  At the same time, the upper end surface of the stopper rod 10 comes into contact with the micro switch 16 and generates a warning for confirming the shutter lock according to the detection signal, and also stops the driving of the switch 5 by operating a governor device (not shown). Control can also be performed.

  Even when the idler 11 is lifted by an impact at the time of cutting the chain and the stopper rod 10 is temporarily applied with a force that rotates in a direction opposite to the rotation stop direction, the idler 11 is brought into contact with the check portion 15 and rotated. Since the movement is stopped, it is reliably rotated in the rotation stop direction.

  In the present embodiment, the above stopping operation is performed in the rotation range of at least 0 to 45 ° of the driven sprocket 4 immediately after the stopper rod 10 is rotated. The rotation stopping operation is performed in a state where the abutting portion 10a is sandwiched between the positioning portion 14 as a fulcrum and the stopper portion 12 as a power point, and the distance between the both portions 12 and 14 is extremely large. Since it is short, its impulse is small, and this can prevent breakage of the stopper rod 10 itself due to impact.

  In the above-described embodiment, the stopper rod 10 is prevented from rotating in the reverse direction only by the check portion 15, but in addition to this, it can be urged to rotate in the forward direction by a tension spring or the like. . In this case, the idler 11 can also function as a tension pulley and can always hold the chain 8 at a constant tension. However, in the case of this configuration, a force for inclining the contact portion 10a in the rotation stop direction is applied particularly during winding, but even if the contact portion 10a comes into contact with the stopper portion 12, the contact portion 10a is immediately separated. What is necessary is just to determine arrangement | positioning of the stopper rod 10 by target arrangement.

The side view which shows the partial structure of the uppermost part of the shutter apparatus provided with the stopper apparatus which concerns on this invention. It is the same front view

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Winding shaft 3 Bracket 4 Driven sprocket 5 Opening and closing machine 6 Rotating shaft 7 Drive sprocket 8 Roller chain 9 Support shaft 10 Stopper rod 11 Idler 12 Stopper part 14 Positioning part 15 Checking part 16 Micro switch as detection means

Claims (4)

A roller chain is wound between a driven sprocket that is supported by the bracket and provided at the shaft end of the take-up shaft that winds up the shutter curtain, and a drive sprocket that is provided at the shaft end of the rotary shaft of the switch having a braking mechanism. In the shutter that is adapted to link the rotation of the rotary shaft of the switch and the rotation of the winding shaft by chain conduction,
A stopper rod that is located at an intermediate position between the sprockets, and is rotatably disposed on the bracket via a support shaft so that one end portion thereof is directed to the surface direction of the driven sprocket;
An idler that is disposed at the other end of the stopper rod, meshes rotatably with the roller chain, and separates the stopper rod from the surface of the driven sprocket;
When the idler is detached from the roller chain along with the cutting of the roller chain, the stopper rod is rotated, and the stopper rod is rotated and stopped in a state where one end of the stopper rod faces the disk surface of the driven sprocket. A positioning part projecting from the bracket,
Projecting on the disk surface of the driven sprocket, for contacting the one end portion of the stopper rod and holding the one end portion of the stopper rod between the positioning portion, to stop the free rotation of the driven sprocket And an abnormal drop prevention device for a shutter.   2. The apparatus for preventing abnormal lowering of a shutter according to claim 1, wherein the stopper portion is formed by a plurality of pins projecting at substantially equal intervals in the circumferential direction on the surface of the driven sprocket.   The stopper portion projects from the bracket, and the positioning portion protrudes from the bracket at a radially inner position of the driven sprocket from the stopper portion. The apparatus for preventing abnormal lowering of a shutter according to 1 or 2.   4. The apparatus for preventing abnormal lowering of a shutter according to claim 1, further comprising a shutter lock detecting unit that detects a rotation stop position of the stopper rod. 5.

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