JP2015227604A - Shielding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shielding device that suppresses interruption in falling of a shielding material due to its own weight.SOLUTION: A shielding device of the present invention makes a shielding material fall due to its own weight, by rotating a winding shaft by the self-weight of the shielding material, and includes a speed adjustment part that adjusts the speed of falling of the shielding material due to its own weight. The speed adjustment part reduces the braking force exerted on the winding shaft, in response to the increase in fall rotation number of the winding shaft as the shielding material falls due to its own weight, thereby allowing the shielding material to reach the lower limit without being interrupted.

Description

  The present invention relates to a shielding device that lowers a shielding material by its own weight, such as a horizontal blind, a raised curtain, and a pleated screen.

  In the horizontal blind described in Patent Document 1, when the slat and the bottom rail are lowered by their own weight, a governor device is used to maintain the descent speed below a certain level. In this governor device, the governor weight is pressed against the governor drum by the centrifugal force generated by the rotation of the governor shaft, thereby generating a frictional force between the governor weight and the governor drum so as to suppress the rotation of the governor shaft to a certain speed or less. It is configured.

Japanese Patent No. 3140295

  In the horizontal blind using the governor device as in Patent Document 1, when the slat and the bottom rail are lowered by their own weight, the bottom rail is not lowered to the original lower limit position, and the lowering of the own weight is in progress. I noticed that it might stop at.

  This invention is made | formed in view of such a situation, and provides the shielding apparatus which can suppress the midway stop of the weight fall of a shielding material.

  According to the present invention, the shielding device is configured to lower the weight of the shielding material by rotating the winding shaft by the weight of the shielding material, and a speed adjusting unit that adjusts the speed of lowering the weight of the shielding material. The speed adjusting unit is set to a lower limit without stopping the shielding material due to a decrease in braking force applied to the winding shaft in accordance with an increase in the descending rotation speed of the winding shaft when the weight is lowered. A shielding device is provided that is configured to reach.

  The present inventors have analyzed the phenomenon that the weight drop of the shielding material stops in the middle, and when the shielding material falls to near the lower limit position, the rotational force applied to the winding shaft by the weight of the shielding material is very high. It has been found that this phenomenon is caused by the fact that the brake force applied to the take-up shaft by the governor device maintains a certain level of strength despite the fact that it becomes smaller. And based on such knowledge, the shielding material is used by using a speed adjusting unit configured to reduce the braking force applied to the winding shaft in accordance with the increase in the descent rotational speed of the winding shaft during the weight drop. As a result, the present invention has been completed. In the present specification, the “lowering rotation speed of the winding shaft” means the number of rotations of the winding shaft that accompanies the drop in the weight of the shielding material.

Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.
Preferably, the speed adjusting unit includes a housing that stores the viscous fluid, and a moving member that is accommodated in the housing and moves in accordance with the rotation of the winding shaft, and the movement of the moving member. The moving member is configured to change a resistance force received from the viscous fluid.
Preferably, the speed adjusting unit is configured such that the moving member is capable of reciprocating relative movement within a certain range in conjunction with the opening / closing range of the shielding material in the housing, and the moving member receives from the viscous fluid. The resistance force is configured to change depending on the position within the certain range.
Preferably, the speed adjusting unit is configured such that the lowest position of the driving torque in the opening / closing range of the shielding material is the lowest position of the resistance force within the certain range.
Preferably, the speed adjusting unit is configured such that the maximum position of the driving torque in the opening / closing range of the shielding material is the maximum position of the resistance force within the certain range.
Preferably, the speed adjusting unit may change a cross-sectional area of the flow path through which the viscous fluid can pass through the moving member as the moving member moves, bypass the larger flow path, or It is comprised so that the at least 1 elastic modulus of the member which comprises a flow path may change.
Preferably, when the moving member moves in the first direction when the shielding member is lowered by its own weight, the speed adjusting unit has a flow resistance of the viscous fluid in a second direction opposite to the first direction. It is comprised so that it may become larger than the distribution | circulation resistance of the said viscous fluid at the time of a movement.
Preferably, the speed adjusting unit is configured such that a moving distance of the moving member per unit rotation of the winding shaft becomes smaller as the moving member moves.
Preferably, the speed adjustment unit includes a non-moving region where the moving member does not move even when the winding shaft rotates in the descending direction of the shielding material, and the moving member is in the non-moving region. When the winding shaft rotates in the upward direction of the shielding member, the moving member moves with the rotation of the winding shaft.
Preferably, the speed adjusting unit includes a damper case and a damper shaft inserted into the damper case, and a damper device that attenuates a relative rotational speed between the damper case and the damper shaft, and rotation of the winding shaft Is transmitted to the damper device, and the rotation transmission unit stops the transmission of the rotation when the descending rotation speed reaches a predetermined number of times.
Preferably, the rotation transmission unit includes a moving member that moves as the winding shaft rotates, and transmission of rotation from the winding shaft to the damper device is stopped as the moving member moves. Configured as follows.
Preferably, the speed adjusting unit includes a damper case and a damper shaft inserted into the damper case, and a damper device that attenuates a relative rotational speed between the damper case and the damper shaft, and rotation of the winding shaft The transmission mechanism is configured to reduce a transmission ratio when rotation of the winding shaft is transmitted to the damper device in accordance with an increase in the descending rotation speed. Is done.
Preferably, the speed change mechanism includes a moving member that moves as the winding shaft rotates, and is configured such that the transmission ratio decreases as the moving member moves.
Preferably, the speed adjusting unit includes a linked state in which the rotation of the winding shaft and the movement of the moving member are linked, and an unlinked state in which the rotation of the winding shaft and the movement of the moving member are not linked. Are configured to be switchable.

It is a front view of the pleat screen of a 1st embodiment of the present invention. It is a right view of the pleat screen of FIG. The speed adjustment part 36 of 1st Embodiment of this invention is shown, (a) is the time of the descent | fall start of the bottom rail 5, (b) shows the state just before completion of the descent of the bottom rail 5. FIG. (C)-(e) shows the example of the axis orthogonal cross-section of the speed adjustment part 36. FIG. (A) is a graph which shows the relationship between the height position of the bottom rail 5 of a pleat screen, and the load added to the raising / lowering cord 7, (b) is the height position of the bottom rail 5 of a pleat screen, and speed adjustment. 7 is a graph showing the relationship between the braking force by the part 36, (c) is a graph showing the relationship between the descending rotation speed of the winding shaft 10 and the rotational force applied to the winding shaft 10, and (d) is a graph showing the relationship between the rotating force applied to the winding shaft 10. 4 is a graph showing the relationship between the descent speed of the spindle 10 and the braking force by the speed adjusting unit 36. The speed adjustment part 36 of 2nd Embodiment of this invention is shown, (a) shows the state at the time of the raising operation of the bottom rail 5, (b) shows the time of the bottom rail 5's own weight fall. The speed adjustment part 36 of 3rd Embodiment of this invention is shown, (a) is sectional drawing, (b)-(d) is an expanded view of the inner surface 37a of the housing 37 of the structural examples 1-3. It is a perspective view which shows the speed adjustment part 36 of 4th Embodiment of this invention. The speed adjustment part 36 of 5th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b) is a development view of the inner surface 37a of the housing 37, (c) is the moving member 39. Front view, (d) is a left side view of the moving member 39, (e) to (g) are cross-sectional views taken along line AA in (c), showing the state of the movable plate 39b at positions R, Q, and P. It is. (H) is a graph showing the relationship between the rotational speed and the braking force. The speed adjustment part 36 of 6th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b) is a front view of the moving member 39, (c) is the left side surface of the moving member 39. FIGS. 3D and 3E are cross-sectional views taken along line AA in FIG. 2B, showing the state of the movable projecting member 39k at positions Q and P. FIG. The speed adjustment part 36 of 7th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b) is a left view of the moving member 39. FIG. The speed adjustment part 36 of 8th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b)-(e) is AA sectional drawing, BB sectional drawing, respectively, CC sectional drawing, DD sectional drawing, (f) is sectional drawing corresponding to (a) which shows the state which the moving member 39 moved to position S, T, U. FIG. It is a perspective view which shows the speed adjustment part 36 of 9th Embodiment of this invention. The moving member 39 and the center axis | shaft 38 of the speed adjustment part 36 of 10th Embodiment of this invention are shown, (a) is a perspective view, (b) is sectional drawing. The speed adjustment part 36 of 11th Embodiment of this invention is shown, (a) is an expanded view of the inner surface 37a of the housing 37, (b) is a graph which shows the relationship between rotation speed and brake force. The speed adjustment part 36 of 12th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b) is AA sectional drawing. The speed adjustment part 36 of 13th Embodiment of this invention is shown, (a) is a front view (the housing 37 is sectional drawing), (b)-(g) is AA sectional drawing, BB sectional drawing, respectively, They are CC sectional drawing, DD sectional view, EE sectional view, and FF sectional view. In the speed adjustment part 36 of 13th Embodiment of this invention, it is a front view (housing 37 is sectional drawing) which shows the state after the moving member 39 moved with the fall of the bottom rail 5. FIG. It is a front view (housing 37 is sectional drawing) which shows the speed adjustment part 36 of 14th Embodiment of this invention. It is a schematic front view which shows the method of incorporating the speed adjustment part 36 of 14th Embodiment of this invention in the head box 1, (a) is the state in which the bottom rail 5 exists in an upper limit position, (b) is the bottom rail 5 The state in the lower limit position is shown. It is a schematic front view which shows the method of incorporating the speed adjustment part 36 of 14th Embodiment of this invention in the head box 1, and shows the state which raised the bottom rail 5 to the middle. The speed adjustment part 36 of 15th Embodiment of this invention is shown, (a) is a front view (The housing 64, damper case, and damper adapter 67f are sectional drawings), (b) is the AA cross section in (a). FIG. 4C is a diagram corresponding to FIG. 3A in a state where the rotation of the drive shaft 12 is not transmitted to the damper device 67 due to the movement of the moving member 69. The speed adjustment part 36 of 16th Embodiment of this invention is shown, (a) And (d) is a front view (the housing 83 is sectional drawing), (b) is a right view, (c) is AA sectional drawing. It is. (A) And (d) shows a state when the bottom rail 5 exists in an upper limit position and a lower limit position, respectively. 22 shows a damper device 82, in which (a) is a front view, (b) is a front view (a damper case 82d is a sectional view), and (c) to (d) are CC sectional views. (A)-(b) is a graph which respectively shows the relationship of the torque and brake force which are added to a winding shaft with respect to the winding shaft rotation speed in a horizontal blind. (A)-(b) is a graph which respectively shows the relationship of the torque and brake force which are added to a winding shaft with respect to the winding shaft rotation speed in a Roman shade.

  Hereinafter, embodiments of the present invention will be described. Various characteristic items shown in the following embodiments can be combined with each other. The invention is established independently for each feature.

<First Embodiment>
In the pleated screen according to the first embodiment of the present invention shown in FIGS. 1 to 2, the screen 4 is suspended and supported from the head box 1, and the bottom rail 5 is attached to the lower end of the screen 4. The screen 4 enables the fabric to be folded in a zigzag shape.

  Between the head box 1 and the bottom rail 5, a pitch holding cord 33 for holding the pitch of the folds of the screen 4 is provided. The pitch holding cord 33 is provided with a large number of annular holding portions 57 at equal intervals. After the holding portions 57 are inserted into the screen 4, the lifting cord 7 for raising and lowering the bottom rail 5 is held by the holding portion 57. The holding portion 57 is prevented from coming off from the screen 4 by being inserted into the screen 4, thereby enabling the pitch of the screen 4 to be held. The pitch holding cord 33 and the lifting / lowering cord 7 are arranged on opposite sides of the screen 4.

  A pitch holding cord holding member 56 that holds the pitch holding cord 33 and a lifting cord holding member 55 that holds the lifting cord 7 are attached to the bottom rail 5. The pitch holding cord 33 and the lifting / lowering cord 7 are attached to the bottom rail 5 by these holding members.

  The upper end of the lifting / lowering cord 7 is attached to the winding shaft 10. The winding shaft 10 rotates together with the drive shaft 12. The screen 4 can be folded or stretched by raising or lowering the bottom rail 5 by winding or rewinding the lifting / lowering cord around the winding shaft 10. At one end of the head box 1, an operation unit unit 23 including a ball chain 13, an operation pulley 11, and a transmission clutch 21 is provided. The ball chain 13 is hooked on the operation pulley 11, and the rotational force in the pulling direction of the bottom rail 5 (direction of arrow A in FIG. 1) applied to the operation pulley 11 by the ball chain 13 is transmitted via the transmission clutch 21. It is transmitted to the drive shaft 12. The transmission clutch 21 is configured to transmit the rotational force in the direction of arrow A in FIG. 1, but not to transmit the rotational force in the direction of arrow B in FIG.

  The drive shaft 12 is inserted through the stopper device 24 at the intermediate portion of the head box 1. When the ball chain 13 is released after the bottom rail 5 is lifted, the stopper device 24 stops the rotation of the drive shaft 12 and prevents the bottom rail 5 from dropping its own weight.

  As shown in FIG. 1, a speed adjustment unit 36 is disposed on the side of the stopper device 24. The speed adjustment unit 36 suppresses the rotation speed of the drive shaft 12 to be equal to or lower than a predetermined value without stopping the rotation of the drive shaft 12, and suppresses the lowering speed when the bottom rail 5 is lowered by its own weight.

  Here, the speed adjustment unit 36 will be described in detail. As shown in FIG. 3, the speed adjustment unit 36 includes a housing 37, a central shaft 38 inserted into the housing 37, and a moving member 39 accommodated in the housing 37. The central shaft 38 is connected to the drive shaft 12 so as not to rotate. Note that the drive shaft 12 itself may be inserted into the housing 37 through the central shaft 38. If the cross section of the central shaft 38 is rectangular and the penetrating portion of the drive shaft 12 has the same rectangular cross section, the shafts 38 can be connected so as not to rotate. The housing 37 is fixed to the head box 1 so as not to rotate directly or indirectly.

  A gap 41 is provided between the inner surface 37 a of the housing 37 and the moving member 39. The accommodation space 40 in the housing 37 is filled with oil. At least a part of the center shaft 38 in the housing 37 is a screw shaft, and the screw shaft is immersed in oil. The moving member 39 is screwed to the central shaft 38 and is engaged with the housing 37 so that relative sliding movement is possible and relative rotation is impossible. Specifically, as shown in FIG. 3C, an example in which the inner circumference of the inner surface 37 a is a circle and the outer circumference of the cross section of the moving member 39 is a circle with a gap 41 from the inner surface 37 a. Then, the convex portion 39v or the concave portion provided in the moving member 39 is engaged with the groove 37c or the convex strip provided on the inner surface of the housing 37 along the longitudinal direction of the central shaft 38. In this example, the moving member 39 and the housing 37 are only required to be relatively movable in the axial direction and cannot be relatively rotated. As shown in FIGS. 3D to 3E, the moving member 39 and the housing 37 are rectangular. -If it is an ellipse, a convex part or a recessed part is unnecessary, and in short, what is necessary is just to have a contact with a different distance from the center point. With such a configuration, the moving member 39 slides with the rotation of the central shaft 38. Specifically, the moving member 39 moves in the arrow X direction by the rotation in the arrow B direction in FIG. When the moving member 39 moves, the oil in the accommodation space 40 moves from the front (traveling direction) side of the moving member 39 to the rear side through the gap 41. The resistance received by the oil at this time is the oil flow resistance. The narrower the gap 41 and the higher the viscosity of the oil, the greater the oil flow resistance. As the oil flow resistance increases, the resistance force that the moving member 39 receives from the oil increases, and accordingly, the braking force applied to the central shaft 38 increases. Therefore, when the inner surface 37a is tapered, as shown in FIG. 4 (d), the braking force decreases with an increase in the descending rotation speed of the winding shaft. Further, the brake force applied to the central shaft 38 by the speed adjusting unit 36 can be easily adjusted by appropriately changing the size of the gap 41 and the viscosity of the oil.

  By the way, when the screen 4 is folded, almost the entire weight of the screen 4 and the bottom rail 5 is supported by the lifting / lowering cord 7, so that the load applied to the lifting / lowering cord 7 is large. Since the screen 4 is suspended and supported by the head box 1, the load applied to the elevating cord 7 decreases as the bottom rail 5 descends and the screen 4 is expanded. From the upper limit, the height position of the bottom rail 5 decreases in proportion to the increase in the rotational speed of the shaft. That is, the relationship between the height position of the bottom rail 5 and the load applied to the lifting / lowering cord 7 is as shown in FIG. Further, since the bottom rail 5 is lowered as the lowering rotational speed of the winding shaft 10 is increased and the rotational force (rotational torque) applied to the winding shaft 10 is reduced, the lowering rotational speed of the winding shaft 10 is reduced. The relationship of the rotational force applied to the winding shaft 10 is as shown in FIG.

  Since the bottom rail 5 tends to descend at a higher speed as the load applied to the lifting / lowering cord 7 is larger, a speed adjusting unit prevents the lowering speed of the bottom rail 5 from excessively increasing when the bottom rail 5 is lowered from a higher position. As shown in FIG. 4B, 36 is configured such that the braking force increases as the bottom rail 5 is at a higher position. That is, in the shielding device, the braking force changes so that the braking force is maximized when the bottom rail 5 is at the upper limit position and the braking force is minimized when the bottom rail 5 is at the lower limit position. In another expression, the speed adjusting unit 36 is configured so that the braking force applied to the take-up shaft 10 decreases as the descent speed of the take-up shaft 10 increases as shown in FIG. .

  In order to realize such characteristics, the inner surface 37a of the housing 37 of the speed adjusting unit 36 is tapered as shown in FIGS. 3A and 3B, and the moving member 39 moves in the direction of the arrow X. As the gap 41 gradually increases, the oil flow resistance gradually decreases. With such a configuration, the height position of the bottom rail 5 and the braking force by the speed adjusting unit 36 have the relationship shown in FIG. 4B, and the lowering speed of the bottom rail 5 can be prevented from becoming excessively large. Further, immediately before the bottom rail 5 is lowered, the braking force by the speed adjusting unit 36 can be made extremely small, so that the problem that the bottom rail 5 does not drop to the lower limit position can be prevented, and the bottom rail 5 The lifting / lowering cord can be rewound to the lowest limit without stopping just before completion of the descent. This is defined by the wide clearance 41 and the viscosity of the allowable minimum brake force that can rewind the lifting and lowering cord without stopping the bottom rail 5 to the lowest limit while receiving the sliding resistance of all rotating parts, Under such conditions, it can be realized by defining a narrow gap 41 at a high position near the upper limit of the blind height so that the descending speed of the blind is equal to or lower than a predetermined speed. By adopting such a blind configuration, the bottom rail 5 stops immediately before completion of the descent by properly defining the oil viscosity and the gap 41 even with shielding materials of any weight and specific gravity and shielding materials of any width / height ratio. It can be lowered to the lowest limit without any problem. The inclination direction of the graph of FIG. 4B needs to be the same as that of the graph of FIG. 4A, but the inclination angle of the graph of FIG. Even if the brake force is within an allowable range in which the lifting / lowering cord can be rewound without stopping the bottom rail from the lowering start position to the lowest limit while receiving the sliding resistance of all the rotating parts, FIG. It may be the same as or different from the graph of 4 (a). Further, the relationship between the height position of the bottom rail 5 or the rotating speed of the winding shaft 10 and the braking force by the speed adjusting unit 36 may not be a linear relationship as shown in FIG. 4B or 4D. Or a relationship represented by a curve or a broken line. The relationship between the height position or the descending rotation speed and the braking force can be easily changed by changing the shape of the inner surface of the housing 37.

  Here, the operation of the pleated screen will be described. When the interior portion of the ball chain 13 is pulled in the direction of arrow A in FIG. 2, the rotational force generated by the force is transmitted to the transmission clutch 21 via the operation pulley 11. Since the transmission clutch 21 is configured to transmit only the rotational force in the direction of arrow A in FIG. 1 to the drive shaft 12, the rotational force generated by pulling the ball chain 13 in the direction of arrow A in FIG. Is transmitted to the drive shaft 12, and the drive shaft 12 is rotated. As the drive shaft 12 rotates, the take-up shaft 10 rotatably supported by the support member 8 in the head box 1 rotates in the direction of arrow A in FIG. The bottom rail 5 attached to the tip of the cord 7 is raised.

  If the hand is released from the ball chain 13 in this state, the stopper device 24 is activated to prevent the bottom rail 5 from dropping its own weight. In this state, when the ball chain 13 is pulled again in the direction of arrow A in FIG. 2 and then released, the operation for preventing the weight of the stopper device 24 from dropping is released, and the lifting / lowering cord 7 is rewound from the winding shaft 10. The bottom rail 5 falls by its own weight.

  When the bottom rail 5 starts to descend, the moving member 39 is located at the position shown in FIG. For this reason, the braking force by the speed adjustment part 36 is large, and the descent speed of the bottom rail 5 does not become excessively large.

  As the bottom rail 5 descends, the moving member 39 moves in the direction of the arrow X in FIG. 3A, so that the gap 41 gradually increases. As a result, the oil flow resistance and the braking force by the speed adjusting unit 36 are increased. Gradually decreases. And immediately before completion of the lowering of the bottom rail 5, the speed adjustment part 36 will be in the state shown in FIG.3 (b). In this state, since the braking force by the speed adjusting unit 36 is very small, the occurrence of the problem that the bottom rail 5 does not fall by its own weight to the lower limit position is suppressed.

  From the state shown in FIG. 3B, by pulling the ball chain 13 again in the direction of arrow A in FIG. 2, the bottom rail 5 is raised and the moving member 39 is moved in the direction of arrow Y in FIG. Can be made. When the bottom rail 5 reaches the upper limit position, the moving member 39 moves to the position shown in FIG.

  Here, an example has been described in which the moving member 39 moves from the substantially left end to the substantially right end of the housing space 40 of the housing 37, but the moving member 39 is substantially the left end or the substantially right end of the housing space 40. It is not necessary to reach. When the common speed adjustment unit 36 is used for a plurality of types of pleated screens having different lengths of the lifting / lowering cord 7, the position of the moving member 39 when the bottom rail 5 is at the lower limit position is aligned. It is preferable to do. This is because it is important to appropriately define the braking force immediately before the bottom rail 5 is lowered.

The present invention can also be implemented in the following embodiments.
-In addition to the pleated screen, the present invention can also be applied to a shielding device having a reverse characteristic that lowers the shielding material by its own weight (for example, a horizontal blind or a lifting curtain). The shielding device having the reverse characteristic is window covering in which the torque applied to the winding shaft decreases as it is rewound. Further, the torque applied to the take-up shaft by the weight of the shielding material becomes the drive torque for driving the take-up shaft to rotate. In the case of a horizontal blind, the torque applied to the take-up shaft decreases each time the slats stacked on the bottom rail ride on the ladder cord one by one during the weight drop. Therefore, the relationship between the rotational speed of the winding shaft and the torque applied to the winding shaft by the weight of the shielding material is as shown in the graph of FIG. The lower clearance slat rides on the ladder cord, and the bottom rail extends between the lowermost slats until the warp of the ladder cord extends, and the lifting cord can be rewound without stopping until the lifting cord is rewound. In this condition, a narrow gap 41 is defined at a high position near the upper limit of the blind height so that the descending speed of the blind is equal to or less than a predetermined speed. As shown in FIG. The inner surface of the housing 37 may be tapered so that the number graph has an inclination that approximates the inclination of the torque-winding shaft rotation speed.

・ In the case of a roman shade, the torque applied to the take-up shaft decreases each time the rings (folds) stacked on the cord catch are separated one by one during the weight drop. Therefore, the relationship between the rotational speed of the winding shaft and the torque applied to the winding shaft by the weight of the shielding material is as shown in the graph of FIG. Then, as shown in FIG. 25 (b), the inner surface of the housing 37 is tapered so that the graph of braking force-winding shaft rotational speed has an inclination that approximates the inclination of torque-winding shaft rotational speed. What is necessary is the same as that of the horizontal blind.

-For the horizontal blind, the lowest limit means that the lifting / lowering cord is unwound and descends, the tension of the lifting / lowering cord decreases rapidly, and the warp thread of the ladder cord supports the bottom rail (the ladder between the bottom rail and the lowermost slat). In the state where the warp of the cord is stretched), in the case of a roman shade, the lifting cord is rewound and lowered and the head box supports the entire load of the screen. In the case of a pleated screen, the lifting cord is rewound and lowered and lowered. A state in which the entire load is supported directly by the headbox or directly supported by the pitch cord or supported by the headbox, or before reaching each of the above states, the lifting / lowering cord is unwound by a lower limit device etc. It is the limit that cannot be lowered any further. If the lower limit device is a device that locks by detecting the mechanical slack of the lifting / lowering cord that also functions as an obstacle stop device, it will be the lowest limit at almost the same timing as above, but with a lower limit device such as a screw feed mechanism In this blind, the user can freely determine the lower limit position. Therefore, in the case of a blind with a lower limit device such as a screw feed mechanism, the minimum brake force may be determined by setting the lower limit freely determined by the user as the lowest limit.

In the above embodiment, the central shaft 38 is rotated integrally with the drive shaft 12, but the central shaft 38 may be fixed to the head box 1 and the housing 37 may be rotated integrally with the drive shaft 12. Further, the rotation of the drive shaft 12 may be transmitted so that the central shaft 38 and the housing 37 rotate in opposite directions.

In the above embodiment, the moving member 39 is screwed to the central shaft 38 and is slidably engaged with the housing 37. However, the moving member 39 is screwed to the housing 37 and slid to the central shaft 38. You may engage so that movement is possible. In this case, for example, by changing the thickness of the central shaft 38 along the moving direction of the moving member 39, the size of the gap between the moving member 39 and the central shaft 38 is changed to change the oil flow resistance. be able to.
In the above embodiment, oil is used as the viscous fluid, but a viscous fluid other than oil can also be used.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and differs in that it has a one-way function (a damper torque is not generated or significantly reduced for rotation to a side where speed control is not performed). As a specific member, the main difference is that the moving member 39 includes an internal flow passage 43 and a valve member 44. Hereinafter, the difference will be mainly described.

  As shown in FIG. 5, the moving member 39 is provided with an internal flow passage 43 that penetrates the moving member 39 and a valve member 44 that can open and close the internal flow passage 43. When the bottom rail 5 is lowered by its own weight, the moving member 39 moves in the direction of the arrow X. At that time, the valve member 44 is pushed by the oil and moves to a position where the internal flow passage 43 is closed as shown in FIG. In this state, the oil can move from the front to the rear of the moving member 39 only through the gap 41, and the oil flow resistance is large, and therefore the braking force of the speed adjusting unit 36 is large.

  On the other hand, when the bottom rail 5 is raised, the moving member 39 moves in the direction of the arrow Y. At that time, the valve member 44 is pushed by oil and moves to a position where the internal flow passage 43 is opened as shown in FIG. To do. In this state, the oil can move from the front to the rear of the moving member 39 through both the gap 41 and the internal flow passage 43, and the oil flow resistance is small, so that the braking force of the speed adjusting unit 36 is large.

  As described above, in this embodiment, the speed adjustment unit 36 is obtained by using the valve member 44 to substantially change the cross-sectional area of the flow path through which the oil can pass through the moving member 39 according to the moving direction of the moving member 39. It is possible to change the braking force. Further, with such a configuration, when the bottom rail 5 is lowered by its own weight with a simple configuration, it is possible to suppress an excessive increase in the descending speed of the bottom rail 5 by appropriately applying a braking force, and the side where the speed is not controlled (bottom) When the rail 5 is lifted, the braking force is reduced to suppress an increase in operating force when the bottom rail 5 is lifted. In order to apply the present invention to a blind using an automatic winding mechanism using a stored energy such as a spring, the valve is opened by rotation to the side (down direction) where speed control is not performed. When it is applied to a self-closing device using a horizontal pulling window covering or a stored energy in a partition, the valve is opened by rotation to the side where the speed is not controlled (opening direction). When applied to a self-opening device, the valve is opened by rotation to the side where the speed is not controlled (closing direction).

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and the inner surface 37a of the housing 37 is not tapered, and the flow resistance of the oil can be changed by the movement of the moving member 39 by another means. This is the main difference. Hereinafter, the difference will be mainly described.

  In the configuration example 1 of the present embodiment, as shown in FIG. 6B, a large number of grooves 45 extending along the moving direction of the moving member 39 are provided on the inner surface 37 a of the housing 37. The oil in the accommodation space 40 moves from the front to the rear of the moving member 39 through the groove 45. As shown in FIG. 6B, the number of grooves 45 arranged around the moving member 39 increases as the moving member 39 moves in the arrow X direction. For this reason, the cross-sectional area of the oil flow passage increases stepwise, and the oil flow resistance is reduced. Although the braking force decreases stepwise by the movement of the moving member 39 in the arrow X direction, the amount of movement of the moving member—the inclination of the braking force may be adjusted to the height of the blind—the inclination of the load. If the increased pitch of each step is matched with the stepwise decrease of the shielding material, it is possible to further approximate the torque change accompanying the lowering of the shielding material. Although the number of grooves 45 is changed here, the width or depth of the grooves may change as the moving member 39 moves. That is, the cross-sectional area of the groove around the moving member 39 may be increased as the moving member 39 moves.

  In the configuration example 2 of the present embodiment, as shown in FIG. 6C, a large number of recesses 46 are provided on the inner surface 37 a of the housing 37. The oil in the accommodation space 40 moves from the front of the moving member 39 to the rear through the recess 46. As shown in FIG. 6C, as the moving member 39 moves in the arrow X direction, the number of concave portions 46 arranged around the moving member 39 increases. For this reason, the cross-sectional area of the oil flow passage increases, and the oil flow resistance is reduced. Although the number of recesses 46 is changed here, the size or depth of the recesses may change as the moving member 39 moves. In other words, the cross-sectional area of the recess around the moving member 39 may be increased as the moving member 39 moves.

  In the configuration example 3 of this embodiment, as shown in FIG. 6D, the elastic coefficient of the inner surface 37 a of the housing 37 is changed along the moving direction of the moving member 39. When the moving member 39 is not moving, there is substantially no gap between the housing 37 and the moving member 39 or the size of the gap between the housing 37 and the moving member 39 is in the moving direction of the moving member 39. However, when the moving member 39 moves in the direction of the arrow X, the oil elastically deforms the inner surface 37a of the housing 37 to form a flow passage, and moves from the front to the rear of the moving member. In this configuration example, as the moving member 39 moves, the elastic coefficient of the inner surface 37a becomes smaller, so that an oil flow passage is easily formed, and the oil flow resistance becomes smaller.

  As described above, even if the inner surface 37a of the housing 37 is not tapered, the inner surface 37a of the housing 37 is configured with a simple configuration as shown in the first to third configuration examples, whereby the moving member 39 is moved. By changing the oil flow resistance, the oil can be reliably opened and closed at a position where the weight is minimum or a position where the torque gap is minimum without stopping.

<Fourth embodiment>
A fourth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and the main difference is that the flow resistance of oil is changed using a tapered fixed shaft 49. Hereinafter, the difference will be mainly described.

  In the present embodiment, the difference between the inner periphery of the moving member 39 and the housing 37 is constant in the axial direction, and the gap is zero or very small. The through hole 50 is provided in the moving member 39, and the through hole 50 is provided. A taper-shaped fixed shaft 49 is inserted through the shaft. Since the cross-sectional area of the through hole 50 is larger than the cross-sectional area of the fixed shaft 49, a gap 51 is provided between the moving member 39 and the fixed shaft 49. When the moving member 39 moves, the oil moves from the front to the rear of the moving member 39 through the gap 51. As the moving member 39 moves in the direction of the arrow X, the gap 51 increases and the oil flow resistance decreases.

  In the first to third embodiments, the oil flow passage is provided between the housing 37 and the moving member 39. However, in this embodiment, the gap 51 between the moving member 39 and the fixed shaft 49 is the main oil. It becomes a flow passage. By changing the size of the gap 51 in accordance with the movement of the moving member 39, the oil flow resistance is changed, so that the braking force that does not stop at the position where the own weight is the minimum or the torque gap is the minimum can be opened and closed reliably. it can.

<Fifth Embodiment>
A fifth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and the main difference is that the flow resistance of oil is changed using the movable plate 39b. Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 8, the moving member 39 includes a main body 39a having a through hole 39d and a movable plate 39b that can open and close the through hole 39d. The movable plate 39 b has a protrusion 39 c, and the protrusion 39 c engages with a groove 53 provided on the inner surface 37 a of the housing 37. In this example, as shown in the development view of FIG. 8B, the groove 53 is provided on the inner surface 37a of the housing 37 with an oblique angle with respect to the axial direction. The main body portion 39a is provided with a female screw portion 39f and a groove 39e. The female screw portion 39f is screwed into a male screw portion 38a provided on the central shaft 38. Further, the ridge 52 provided on the inner surface 37 a of the housing 37 is engaged in the groove 39 e so that the moving member 39 is accommodated in a relatively non-rotatable manner with respect to the housing 37. With such a configuration, the moving member 39 slides along the axial direction of the central shaft 38 with relative rotation between the housing 37 and the central shaft 38.

  In this embodiment, when the moving member moves, the oil in the accommodation space 40 moves from the moving direction of the moving member to the separating direction through the through hole 39d of the main body 39a. When the moving member is at the position P, the through hole 39d is completely closed as shown in FIG. 8G, so that the oil flow resistance is large, and therefore the braking force by the speed adjusting unit 36 is also large. On the other hand, as the moving member 39 moves in the arrow X direction, the protrusion 39c moves along the groove 53, whereby the movable plate 39b rotates. As the movable plate 39b rotates, as shown in FIGS. 8E to 8F, the through hole 39d is gradually opened, the oil flow resistance is reduced, and the braking force is shown in FIG. 8H. To change. The shielding member can be reliably opened and closed by setting the moving member so that its own weight is minimized at a position slightly ahead of the maximum R of the through hole 39d and the opening and closing body does not stop halfway. Further, by setting the descent speed associated with the weight drop near P to a predetermined value or less, it is possible to achieve both reliable opening and closing of the shielding material and speed control for starting the weight drop.

<Sixth Embodiment>
A sixth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fifth embodiment, and the main difference is that the flow resistance of oil is changed using the movable projecting member 39k. Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 9, the moving member 39 includes a main body 39a having a through hole 39h, and a movable projecting member 39k that can open and close the through hole 39h. The movable projecting member 39k has a through hole 39j, and is biased by a biasing member (for example, a coil spring) 39i so that the tip 39g thereof is a main body portion 39a as shown in FIG. 9 (d). Protruding from. A groove 54 whose depth varies along the moving direction of the moving member 39 is provided on the inner surface 37a of the housing 37, and when the moving member 39 is housed in the housing space 40, the tip of the movable projecting member 39k. 39 g contacts the upper end in the groove 54.

  In the present embodiment, the oil in the accommodation space 40 moves from the accommodation space in the traveling direction to the accommodation space in the separation direction as the moving member moves through the through hole 39h of the main body 39a. When the moving member is at the position P, the end 39g of the movable projecting member 39k is pushed by the inner surface 37a of the housing 37, and the state shown in FIG. In this state, the position of the through hole 39h of the main body 39a and the position of the through hole 39j of the movable projecting member 39k do not match, so the through hole 39h is completely closed. For this reason, the flow resistance of oil is large, and therefore the braking force by the speed adjusting unit 36 is also large. On the other hand, the tip 39g moves along the groove 54 as the moving member 39 moves in the arrow X direction. As the groove 54 becomes deeper, the tip 39g protrudes as shown at the position Q, and at the position R, as shown in FIG. 9 (d), the protruding amount of the tip 39g further increases, and accordingly, the through hole 39h. And the through hole 39j overlap, the oil flow resistance is reduced and the braking force is reduced. With such a configuration, it is possible to both weaken the braking force near the position R and securely open and close the shielding material, and to reduce the descent speed associated with the weight drop near the position P to a predetermined value or less.

<Seventh embodiment>
A seventh embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fifth embodiment, and the main difference is that the flow resistance of oil is changed using magnetic force. Hereinafter, the difference will be mainly described.

In the present embodiment, as shown in FIG. 10, a magnet 57 is provided on the outer periphery of the moving member 39. Further, on the outer periphery of the housing 37, a magnetic body 55 such as an iron plate is provided in a part of the longitudinal direction in the brake force increasing region P. According to such a configuration, when the moving member 39 moves to the position where the magnetic body 55 is provided, the housing 37 is contracted by the attractive force between the magnet 57 and the magnetic body 55, thereby moving the moving member 39 and the housing. 37 is narrowed. Further, when the magnet 57 moves in the conductor 55, an eddy current is generated in the conductor 55 so as to prevent a change in the magnetic field, and a braking force in a direction that prevents the movement is applied to the magnet. For this reason, the area where the magnet 55 is provided becomes the brake force further increase area P, and the other area becomes the weak brake area R. In the present embodiment, the oil moves from the front to the rear of the moving member 39 through the gap 41. Therefore, the oil circulation is achieved by changing the size of the gap 41 with a simple configuration by the magnetic force as the moving member 39 moves. Resistance can be changed. Further, when the moving speed of the magnet is increased, the braking force is increased by the eddy current in the conductor 55. With such a configuration, it is possible to both weaken the braking force in the region R and securely open and close the shielding material, and to reduce the descent speed associated with the weight drop in the region P to a predetermined value or less.
The moving member 39 may be provided with a magnetic body, and the housing 37 may be provided with a magnet. Further, a magnet may be provided on both the moving member 39 and the housing 37. An attractive force or a repulsive force may be applied between the magnet of the moving member 39 and the magnet of the housing 37. When an attractive force is applied between them, the magnet of the housing 37 is disposed on the outer periphery of the housing 37. Further, when a repulsive force is applied between the magnet of the moving member 39 and the magnet of the housing 37, the magnet of the housing 37 is disposed on the inner surface of the housing 37. In this case, the housing 37 is expanded by the repulsive force, the gap 41 between the moving member 39 and the housing 37 is widened, and the oil flow resistance is reduced.

<Eighth Embodiment>
The eighth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fifth embodiment, and is mainly different in that the resistance force that the moving member 39 receives from the oil is changed using the oil flow passage 37d provided in the housing 37. Hereinafter, the difference will be mainly described.

  In the present embodiment, the moving member 39 is accommodated in the housing 37 so as to be relatively movable in the axial direction and not to be relatively rotatable. The center shaft 38 is screwed into the center of the moving member 39, and the moving member 39 moves in the axial direction as the center shaft 38 rotates. In the case of application to window covering with reverse characteristics such as a horizontal blind, when the central shaft 38 rotates based on the rotation of the drive shaft 12 in the descending direction, the moving member 39 moves toward the direction of arrow X in FIG. Configured to move. An oil flow passage 37 d is provided at the right end of the housing 37. The oil flow passage 37d includes a first opening 37e and a second opening 37f that are separated from each other in the moving direction of the moving member 39.

  When the bottom rail 5 is at a position away from the lower limit position, as shown in FIG. 11A, the oil flow passage 37d does not function because the moving member 39 is on the left side of the second opening 37f. The resistance force that the moving member 39 receives from the oil is large.

  When the bottom rail 5 falls by its own weight and reaches the vicinity of the lower limit position, the moving member 39 reaches the position T past the position S in FIG. In this state, the moving member 39 is located between the first opening 37e and the second opening 37f. When the moving member 39 moves from the position T toward the position U, oil on the moving direction side of the moving member 39 enters the oil flow passage 37d through the first opening 37e and moves through the second opening 37f. Therefore, the resistance force that the moving member 39 receives from the oil is small.

  Based on the above principle, according to the present embodiment, the resistance force that the moving member 39 receives from the oil while the moving member 39 moves from the position S to the position T is drastically reduced. Continue until position U is reached. Thus, the region R shown in FIG. 11A is the weak brake region. Therefore, by setting the moving member 39 to reach the position S when the bottom rail 5 reaches the vicinity of the lower limit position, the braking force in the vicinity of the lower limit position of the bottom rail 5 is reduced, It is possible to reliably reach the lower limit position.

<Ninth Embodiment>
A ninth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the first embodiment, and is mainly different in that the moving member 39 is fixed to the central shaft 38. Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 12, the moving member 39 is fixed to the central shaft 38. The central shaft 38 rotates in conjunction with the drive shaft 12 of the shielding device and applies a braking force to the drive shaft 12 as a reaction force of the rotational resistance. For example, a square shaft having a square cross section is inserted into a square hole provided on the central axis and having substantially the same shape as the outer shape of the rectangular shaft, so that the angular shaft and the central axis are not relatively rotatable and relatively movable. Engaged. The housing is fixed so as not to move relative to the head box in the axial direction and to prevent relative rotation. The central shaft 38 is screwed to a pedestal 59 fixed to the head box 1, and the central shaft 38 moves in the axial direction while rotating with respect to the pedestal 59 as the central shaft 38 rotates. At that time, the drive shaft 12 and the central shaft 38 move relative to each other. Further, as the central shaft 38 rotates and moves in the axial direction, the moving member 39 moves in the axial direction while rotating in the accommodation space 40 of the housing 37. There is a slight gap between the inner surface 37a and the outer peripheral surface of the moving member 39. As the moving member moves in the axial direction, the moving member moves from the receiving space in the moving direction toward the receiving space in the separating direction. Oil moves. Since the inner surface 37a of the housing 37 is tapered as shown in FIG. 12, the gap becomes narrower toward the right end of FIG. As the moving member 39 moves, the oil flow resistance changes. The blinds are assembled so that the right end is at the top and the left end is at the bottom. Accordingly, as the rewinding rotational speed increases so as to approximate the load characteristic of the blind, the braking force decreases, and the blind is rewound without stopping near the lower limit of the blind.

  In the present embodiment, the central shaft 38 does not penetrate the housing 37, but may be configured to penetrate the housing 37.

<Tenth Embodiment>
A tenth embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the ninth embodiment, and differs in that it has a one-way function (a damper torque is not generated or significantly reduced for rotation to a side where speed control is not performed). Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 13, the moving member 39 includes a main body 39a and a movable ring 39l. The main body 39a is fixed to the central shaft 38 by a fixing pin 39t. The tip of the central shaft 38 is inserted into the shaft hole 39r of the movable ring 39l. The main body 39a is disposed so that the engaging protrusion 39n provided in the main body 39a and protruding in the axial direction is accommodated between the engaging protrusions 39o and 39p provided in the movable ring 39l and protruding in the radial direction. In a state where the movable ring 39l is overlapped, the fixed ring 39s is attached to the front and back of the movable ring 39l so that the movable ring 39l is rotatably supported with respect to the main body 39a. When the bottom rail 5 is raised, the central shaft 38 rotates in the direction of arrow A, and the main body 39a and the movable ring 39l are in contact with the engaging convex 39n of the main body 39a abutting on the engaging convex 39o of the movable ring 39l. Rotate together. In this state, the through-hole 39m of the main body 39a and the through-hole 39q of the movable ring 39l are overlapped, and oil can flow through these through-holes, so the oil flow resistance is small. For this reason, the operation force required for the raising operation of the bottom rail 5 is small. On the other hand, when the weight of the bottom rail 5 is lowered, the central shaft 38 rotates in the direction of arrow B, and the main body 39a and the main body 39a are in contact with the engaging convex 39p of the movable ring 39l. The movable ring 39l rotates integrally. In this state, since the through hole 39m of the main body 39a and the through hole 39q of the movable ring 39l do not overlap, the oil flow resistance is large. For this reason, an appropriate braking force is generated when the bottom rail 5 is lowered by its own weight. In short, the valve is opened by rotation to the side where the speed control is not performed (in the raising direction). In window covering that automatically raises by the urging force, the valve is opened by rotation to the side where the speed is not controlled (down direction). When it is applied to a self-closing device using a horizontal pulling window covering or a stored energy in a partition, the valve is opened by rotation to the side where the speed is not controlled (opening direction). When applied to a self-opening device, the valve is opened by rotation to the side where the speed is not controlled (closing direction).

<Eleventh embodiment>
The eleventh embodiment of the present invention will be described with reference to FIG. This embodiment is similar to the fifth embodiment, and the main difference is that the shape of the groove 53 is different. Hereinafter, the difference will be mainly described.

  In the fifth embodiment, since the groove 53 is linear in the developed view shown in FIG. 8B, the through hole 39d of the main body 39a is gradually closed as the moving member 39 moves, so that the oil In the present embodiment, the groove 53 is formed in the moving direction of the moving member 39 in the range from the position S to the position T as shown in FIG. Since it is parallel, until the moving member 39 moves from the position S to the position T, the through hole 39d is kept closed as shown in FIG. The braking force by the speed adjustment unit 36 is large as shown in FIG. Then, since the inclination angle of the groove 53 is large in the range from the position T to the position U, the through hole 39d is opened while the moving member 39 moves in this range, and the state shown in FIG. The braking force by the part 36 is reduced. A weak braking force is maintained while the moving member 39 moves from the position U to the position V. Therefore, the weak brake region R is between the position T and the position V. With such a configuration, by setting the moving member 39 to reach the region R when the bottom rail 5 reaches the vicinity of the lower limit position, the braking force in the vicinity of the lower limit position of the bottom rail 5 is reduced, The bottom rail 5 can be reliably reached to the lower limit position. Thus, in this embodiment, in the dead weight solar radiation shielding device, the braking force is decreased from the lower limit by a predetermined multiple number of revolutions.

<Twelfth embodiment>
A twelfth embodiment of the present invention will be described with reference to FIG. The present embodiment is similar to the eighth embodiment, and the main point is that the resistance that the moving member 39 receives from the oil is changed by changing the moving speed of the moving member 39 as the moving member 39 moves. This is a major difference. Hereinafter, the difference will be mainly described.

  In the present embodiment, a moving member 39 that is movable as the bottom rail 5 is moved up and down is provided in a housing 37 filled with oil, and the oil is placed in the gap between the outer periphery of the moving member 39 and the inner peripheral surface 37a of the housing 38. The braking force is obtained by the moving resistance. The moving speed of the moving member 39 when the weight of the bottom rail 5 is lowered is changed by changing the feed angle of the central shaft 38 having the groove 38b within the moving range of the moving member 39 and changing the moving distance of the moving member 39 per unit rotation. And the braking force is changed according to the position of the bottom rail 5. When the bottom rail 5 is near the upper limit, the braking force is increased, and when the bottom rail 5 is near the lower limit, the braking force is decreased. Even in the region where the bottom rail 5 is lowered to near the lower limit and the difference between the downward force due to the weight of the bottom rail 5 and the screen 4 and the upward force due to the spring property of the screen 4 itself is small, the bottom rail 5 The braking force in this region is sufficiently reduced so that reaches the lower limit position.

  Hereinafter, the configuration of the present embodiment will be described more specifically. The moving member 39 is accommodated in the housing 37 so as to be relatively movable in the axial direction and not to be relatively rotatable. The central shaft 38 includes a spiral groove 38b, and the pitch of the spiral of the groove 38b becomes narrower as it goes to the right in FIG. The moving member 39 includes an engaging convex portion 39u that is engaged with the groove 39b.

  When the central shaft 38 rotates based on the rotation of the drive shaft 12 in the descending direction, the spiral groove 38b also rotates together, and the engaging convex portion 39u moves along the groove 39u, whereby the moving member 39 is moved to the arrow. Move in the X direction. The moving distance of the moving member 39 per unit rotation of the drive shaft 12 depends on the pitch of the spiral of the groove 39u, and the moving member 39 moves fast in the high-speed moving region where the pitch is relatively large. The resistance force received from is great. On the other hand, as the moving member 39 moves, the pitch of the spiral of the groove 39u becomes narrower, and accordingly, the moving distance of the moving member 39 per unit rotation of the drive shaft 12 (or the winding shaft 10) becomes smaller. The resistance force that the moving member 39 receives from the oil is reduced. For this reason, when the moving member 39 moves from the high-speed moving region to the medium-speed moving region to the low-speed moving region as the descending rotation speed increases, the resistance force received by the moving member 39 changes from large to medium to small, and the bottom rail 5 The braking force in the vicinity of the lower limit position becomes sufficiently small, and the bottom rail 5 reliably reaches the lower limit position. In the present embodiment, the pitch of the spiral of the groove 39u changes in three stages, but it may be changed in more stages, or may be changed continuously in a stepless manner.

<13th Embodiment>
A thirteenth embodiment of the present invention will be described with reference to FIG. The present embodiment is similar to the eighth embodiment, and the main difference is that the rotation of the drive shaft 12 is transmitted to the central shaft 38 via the switching member 62. Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 16B, the central shaft 38 has an opening 38d having a circular cross section, and the drive shaft 12 can idle in the opening 38d. A switching member 62 is provided adjacent to one end of the central shaft 38. The switching member 62 is configured so as not to rotate relative to the drive shaft 12 and to be relatively movable in the axial direction of the drive shaft 12. Engaging portions 38c and 62a that can be engaged with each other are provided at the respective ends of the central shaft 38 and the switching member 62 so as to face each other. As shown in FIGS. 16A and 16F, the engaging portion 62a is configured by alternately forming concave portions and convex portions in the circumferential direction. The engaging portion 38 c has a shape complementary to the engaging portion 62. As shown in FIG. 17, when the switching member 62 is slid in the direction approaching the central shaft 38 and the engaging portions 38 c and 62 a are engaged, the drive shaft 12 and the central shaft 38 are connected to each other so as to be integrally rotatable. . On the other hand, when the switching member 62 is slid in the direction away from the central shaft 38 to disengage the engaging portions 38c and 62a, the central shaft 38 is idled with respect to the drive shaft 12.

  According to such a configuration, even after the drive shaft 12 is inserted into the central shaft 38, the moving member can be rotated without rotating the drive shaft 12 by rotating the central shaft 38 in an unconnected state. 39 can be moved to a desired position. That is, the stroke end position of the moving member 39 can be adjusted in the assembled state. According to such a configuration, it is possible to adjust the position of the moving member 39 after the speed adjusting unit 36 is incorporated into the head box 1, and the assemblability is improved.

  Further, an upward force is exerted on the bottom rail 5 due to the spring property of the screen 4 itself. This upward force may become weaker as time elapses, and as a result, the bottom rail 5 descends. The speed may be higher than at the start of use. In the present embodiment, by rotating the central shaft 38 in the disconnected state, the position of the moving member 39 at the lower limit position and the upper limit position of the bottom rail 5 is changed from L1 and U1 to L2 and U2, as shown in FIG. It can easily be changed. By changing in this way, the timing at which the moving member 39 reaches the second opening 37 when the bottom rail 5 is lowered is delayed, and accordingly, the timing at which the braking force applied to the drive shaft 12 is reduced is delayed. The descending speed of the bottom rail 5 can be reduced.

  In another expression, in the present embodiment, the speed adjustment unit 36 includes a link state in which the rotation of the winding shaft 10 and the movement of the moving member 39 are linked, and the rotation of the winding shaft 10 and the moving member 39. It is configured to be switchable between an unlinked state in which movement is not linked. In the unlinked state, the moving member 39 can be moved independently of the rotation of the winding shaft 10. In other embodiments as well, the same effect can be obtained by enabling switching between a link state and a non-link state as in the present embodiment. If it demonstrates in 8th Embodiment, it will be illustrated that the drive shaft 12 is removable with respect to the center axis | shaft 38. FIG.

<Fourteenth embodiment>
A fourteenth embodiment of the present invention will be described with reference to FIGS. This embodiment is similar to the fifth embodiment, and is mainly different in that a portion (non-threaded portion) 38e having no male screw portion 38a is provided on the central shaft 38. Hereinafter, the difference will be mainly described.

  In the present embodiment, as shown in FIG. 18, the central shaft 38 is provided with a male screw portion 38 a over almost the entire portion except for a portion close to the left end of the accommodation space 40, and there is nothing at the left end of the accommodation space 40. A screw portion 38e is provided. When the bottom rail 5 is at a high position, the moving member 39 is screwed into the male screw portion 38a, and the central shaft 38 rotates as the bottom rail 5 is lowered by its own weight, so that the moving member 39 is moved in the arrow X direction. Moving. The inner surface 37a of the housing 37 is tapered as in the first embodiment, and the resistance force that the moving member 38 receives from the oil as the bottom rail 5 is lowered is reduced.

When the moving member 39 reaches the non-threaded portion 38e, the screwing between the moving member 39 and the male screw portion 38a is released. In this state, even if the central shaft 38 is further rotated in the descending direction of the bottom rail 5, the moving member 39 does not move.

  Since the moving member 39 is urged toward the male screw portion 38a by the urging member (e.g., coil spring) 58, when the central shaft 38 is rotated in the upward direction of the bottom rail 5, the moving member 39 is again turned on. It is screwed into the male screw portion 38a and moves toward the right end of the accommodation space 40 as the bottom rail 5 is raised.

  The speed adjustment unit 36 of the present embodiment is characterized in that it can be easily incorporated into the head box 1. Hereinafter, a method for incorporating the speed adjusting unit 36 into the head box 1 will be described with reference to FIGS. 19 to 20.

First, as shown in FIG. 19A, the speed adjusting unit 36 is attached in the head box 1 with the bottom rail 5 raised to the upper limit position. At this time, the moving member 39 is disposed in the screwless portion 38e.
Next, as shown in FIG. 19B, the bottom rail 5 is lowered to the lowest limit. At this time, the drive shaft 12 and the central shaft 38 rotate in the descending direction along with the rotation of the winding shaft 10. However, since the moving member 39 is already arranged in the screwless portion 38e, the central shaft 38 is rotated. However, the central axis is idle and the moving member 39 does not move.

  When the drive shaft 12 is rotated in the upward direction of the bottom rail 5 from the state of FIG. 19B, the central shaft 38 is also rotated in the same direction. Since the moving member 39 is urged by the urging member 58, when the central shaft 38 is rotated in the upward direction of the bottom rail 5, the moving member 39 is immediately screwed into the male screw portion 38a, and the bottom rail As 5 rises, it moves in the direction of arrow Y in FIG. Further, when the bottom rail 5 is lowered again, the moving member 39 moves in the direction of the arrow X in FIG. 18, and when the bottom rail 5 reaches the lowest limit, the moving member 39 reaches the screwless portion 38e.

  As described above, by providing the screwless portion 38e, the position of the moving member 39 when the bottom rail 5 is at the lowest limit even when the speed adjusting portion 36 is mounted in the head box 1 at the upper limit position of the bottom rail 5. Can be set easily. The speed adjusting unit 36 may be attached to the head box 1 at a position other than the upper limit position of the bottom rail 5. Further, the moving member 39 only needs to reach the unthreaded portion 38e until the bottom rail 5 reaches the lowest limit. Therefore, when the speed adjusting portion 36 is mounted in the head box 1, the moving member 39 is not necessarily placed on the unthreaded portion 38e. It may not be arranged. That is, when the speed adjusting unit 36 is attached to the head box 1, the moving member 39 is disposed on the male screw portion 38a, and the moving member 39 moves toward the non-threaded portion 38e as the bottom rail 5 is lowered. Thus, the moving member 39 may reach the non-threaded portion 38e until the bottom rail 5 reaches the lowest limit. Even in this case, the position of the moving member 39 when the bottom rail 5 is at the lowest limit can be easily set.

  In another expression, in the present embodiment, the speed adjustment unit 36 includes a non-moving region (no screw portion) in which the moving member 39 does not move even when the winding shaft 10 rotates in the descending direction of the bottom rail 5. When the winding shaft 10 rotates in the ascending direction of the bottom rail 5 while the moving member 39 is in the non-moving region, the moving member 39 moves with the rotation of the winding shaft 10. By configuring the speed adjusting unit 36 in this way, an effect is obtained that the position of the moving member 39 when the bottom rail 5 is at the lowest limit can be accurately set.

<Fifteenth embodiment>
A fifteenth embodiment of the present invention will be described with reference to FIG. In the first to fourteenth embodiments, the braking force applied to the take-up shaft 10 is reduced according to the increase in the descending rotation speed of the take-up shaft 10 by changing the resistance force that the moving member 39 receives from the oil. However, in this embodiment, by switching between transmission and non-transmission of rotation from the winding shaft 10 to the damper device 67, the braking force applied to the winding shaft 10 according to an increase in the descending rotational speed of the winding shaft 10 is applied. It is decreasing. Details will be described below.

  In the present embodiment, as shown in FIG. 21, the speed adjustment unit 36 includes a damper device 67 and a rotation transmission unit 71. The damper device 67 is fixed to the head box 1 via a damper adapter 67f. The rotation transmission unit 71 is accommodated in a housing 64 fixed to the head box 1. The damper device 67 includes a damper case 67a and a damper shaft 67b inserted into the damper case 67a. The accommodating space 67e in the damper case 67a is filled with oil. A fin 67d is provided on the damper shaft 67b. When the damper shaft 67b rotates relative to the damper case 67a, the fin 67d rotates while receiving the resistance of the oil, so that the relative rotational speed between the damper case 67a and the damper shaft 67b is attenuated. The damper device 67 may have a different configuration as long as it can attenuate the relative rotational speed between the damper case 67a and the damper shaft 67b.

  The rotation transmission unit 71 transmits the rotation of the winding shaft 10 to the damper device 67 through the drive shaft 12. Specifically, the rotation transmission unit 71 includes a moving member 69, a screw shaft 72 that is non-rotatably fixed to the housing 64, and a flat gear shaft 75 that is non-rotatably fixed to the damper shaft 67b. The moving member 69 includes a driving flat gear 73 having a flange 73 a and a transmission flat gear 74 that is screwed to the screw shaft 72 and meshes with the driving flat gear 73. The transmission spur gear 74 is also meshed with the spur gear shaft 75 and transmits the rotation of the driving spur gear 73 to the flat gear shaft 75. Since the drive spur gear 73 is supported so as not to rotate relative to the drive shaft 12 and to be slidable, the drive spur gear 73 rotates integrally with the drive shaft 12. When the transmission spur gear 74 is rotated with the rotation of the driving spur gear 73, the transmission spur gear 74 moves along the screw shaft 72. Since the transmission spur gear 74 is disposed between a pair of flanges 73 a provided on the driving spur gear 73, the driving spur gear 73 moves together with the transmission spur gear 74. The rotation of the transmission flat gear 74 is transmitted to the damper shaft 67b via the flat gear shaft 75. With the above configuration, the rotation of the winding shaft 10 is transmitted to the damper device 67.

  When the transmission spur gear 74 reaches the position F in FIG. 21C, the transmission spur gear 74 does not mesh with the spur gear shaft 75. In this state, transmission of rotation from the winding shaft 10 to the damper device 67 is stopped, so that the braking force by the damper device 67 does not act on the winding shaft 10 at all. For this reason, according to the present embodiment, the bottom rail 5 continues to descend even when the bottom rail 5 reaches its lower limit and the rotational force applied to the winding shaft 10 is reduced. It is suppressed that the weight drop of the rail 5 stops on the way.

  When the drive shaft 12 is rotated in the upward direction of the bottom rail 5 from the state where the transmission spur gear 74 is in the weak brake region R shown in FIG. 21C, the transmission spur gear 74 together with the drive spur gear 73 is shown in FIG. After moving toward the right direction of 21 (c) and passing the position F, the flat gear shaft 75 is engaged again. When the bottom rail 5 reaches the upper limit position, the transmission spur gear 74 and the drive spur gear 73 return to the predetermined upper limit position.

<Sixteenth Embodiment>
A sixteenth embodiment of the present invention will be described with reference to FIGS. This embodiment is similar to the fifteenth embodiment, and in this embodiment, the rotation of the drive shaft 12 is transmitted to the damper device 82 via the continuously variable transmission mechanism. Corresponding to the height position of the bottom rail 5, the continuously variable transmission mechanism is shifted by screw feed so that the high speed region is near the upper limit and the low speed region is near the lower limit.

  In the present embodiment, as shown in FIG. 22, the speed adjustment unit 36 includes a drive drum 81, a damper device 82, and a housing 83 that accommodates these. The drive drum 81 and the damper device 82 constitute a continuously variable transmission mechanism. The drive shaft 12 is inserted into the housing 83 through a bearing portion 83 a having a collar 83 b, and is inserted into the drive drum 81 in the housing 83. The drive drum 81 is configured so as not to rotate relative to the drive shaft 12 and to be slidable.

  The drive drum 81 includes a male screw part 81a and a transmission part 81b. The male screw portion 81 a is screwed into a female screw portion 83 c provided in the housing 83. When the drive shaft 12 rotates in the lowering direction of the bottom rail 5, the drive drum 81 and the transmission portion 81b move in the direction of arrow B in FIG.

  The damper device 82 includes a damper case 82d and a damper shaft 82a inserted into the damper case 82d. The damper shaft 82a is fixed to the housing 83, and the damper case 82d is supported so as to be rotatable relative to the damper shaft 82a. The transmission part 81b is in contact with the damper case 82d, and the rotation of the transmission part 81b is transmitted to the damper case 82d by a frictional force. The surface of the damper case 82d is roughened so that the rotation is easily transmitted by increasing the frictional force.

  Due to the rotation of the drive shaft 12, the damper case 82d rotates through the transmission portion 81b. As shown in FIG. 23, oil is filled in the accommodation space 82h of the sealed damper case 82d. Two fins 82f protrude from the damper case 82d toward the center. A damper shaft 82a is provided at the center, and the damper case 82d is divided into two chambers. There is a gap between the damper shaft 82a and the fin 82f, and when the damper case 82d rotates, a braking force is exhibited by viscous resistance. The braking force increases as the rotational speed of the damper case 82d increases.

  Further, the fin 82f is provided with a flow passage 82g capable of communicating the two chambers, and a leaf spring 82i closes one end of the flow passage 82g. A one-way opening / closing valve is constituted by the flow passage 82g and the leaf spring 82i. As shown in FIG. 23 (c), when the damper case 82d rotates in the braking direction when the bottom rail 5 is lowered, the one-way opening / closing valve is closed by the leaf spring 82i and a sufficient braking force is applied to the damper case 82d. On the other hand, as shown in FIG. 23 (d), when the damper case 82d rotates in the non-braking direction when the bottom rail 5 is raised, the leaf spring 82i of the one-way on-off valve is elastically deformed, the valve opens and the load is extremely low. In this state, the damper case 82d rotates. Therefore, the braking force works during automatic operation (down), and the bottom rail 5 can be raised with a light operating force during manual operation (up).

  The damper case 82d has a truncated cone shape. When the bottom rail 5 is near the upper limit, the transmission portion 81b is positioned at the small diameter portion 82b, and when the bottom rail 5 is near the lower limit, the transmission portion 81b becomes the large diameter portion 82c. To be located. The transmission ratio of rotation from the transmission part 81b to the damper case 82d (the outer peripheral length of the damper case 82d / the outer peripheral length of the transmission part 81b) decreases as the transmission part 81b moves from the small diameter part 82b to the large diameter part 82c. As the bottom rail 5 is lowered, the rotation angle of the damper case 82d per unit rotation of the transmission portion 81b decreases. For this reason, the braking force by the damper device 82 becomes smaller as the bottom rail 5 descends. Therefore, even if the load due to its own weight decreases near the lower limit of the bottom rail 5, the winding shaft 10 does not stop and the lifting / lowering cord 7 is rewound until the bottom rail 5 reaches the lower limit position. Descent. When the bottom rail 5 starts to rise, the drive drum 81 and the transmission portion 81b move in the direction opposite to the arrow B by screw feed, and when the bottom rail 5 reaches the upper limit position, it reaches the position shown in FIG. .

  In another expression, in the present embodiment, the speed adjustment unit 36 includes a damper case 82d and a damper shaft 82a inserted therein, and attenuates the relative rotational speed between the damper case 82d and the damper shaft 82a. And a transmission mechanism that transmits the rotation of the winding shaft 10 to the damper device 82, and the transmission mechanism is configured such that the rotation of the winding shaft 10 is a damper in response to an increase in the descending rotational speed of the winding shaft 10. It is comprised so that the transmission ratio at the time of transmitting to the apparatus 82 may fall. The speed change mechanism includes a moving member (transmission portion 81b) that moves as the winding shaft 10 rotates, and is configured such that the transmission ratio decreases as the moving member moves.

  In the above embodiment, a continuously variable transmission mechanism is used, but a multi-stage transmission mechanism may be used. Alternatively, the damper case 82d may be fixed to the housing 83, and the rotation of the transmission portion 81b may be input to the damper shaft 82a. In this case, it is possible to reduce the transmission ratio as the bottom rail 5 is lowered by providing a truncated cone-shaped portion on the damper shaft 82a and bringing the portion into contact with the transmission portion 81b. In this case, the fin 82f is rotated integrally with the damper shaft 82a. Further, a speed change mechanism having the same function as described above may be realized by a mechanism other than the mechanism shown here.

1: Head box 4: Screen 5: Bottom rail 7: Lifting cord 8: Support member 10: Winding shaft 11: Operation pulley 12: Drive shaft 13: Ball chain 21: Transmission clutch 24: Stopper device 33: Pitch holding cord 36 : Speed adjustment part 37: housing 38: central axis 39: moving member 40: accommodating space 41: gap

Claims (14)

A shielding apparatus configured to lower the weight of the shielding material by rotating the winding shaft by the weight of the shielding material;
A speed adjusting unit for adjusting the speed of descending the weight of the shielding material;
The speed adjusting unit is configured so that a braking force applied to the take-up shaft is reduced according to an increase in the descent speed of the take-up shaft when the weight is lowered, and the shielding material reaches the lowest limit without stopping. A shielding device composed of The speed adjusting unit includes a housing that contains the viscous fluid, and a moving member that is accommodated in the housing and moves as the winding shaft rotates, and the moving member moves as the moving member moves. The shielding apparatus according to claim 1, wherein a resistance force received from the viscous fluid is changed. The speed adjustment unit is configured such that the moving member is capable of reciprocating relative movement within a certain range in conjunction with the opening / closing range of the shielding material within the housing, and the resistance force that the moving member receives from the viscous fluid is The shielding apparatus according to claim 2, wherein the shielding apparatus is configured to change depending on a position within the certain range. The shielding apparatus according to claim 3, wherein the speed adjustment unit is configured such that a minimum position of driving torque in an opening / closing range of the shielding material is a minimum position of the resistance force within the certain range. The shielding according to claim 3 or 4, wherein the speed adjustment unit is configured such that a maximum position of a driving torque in an opening / closing range of the shielding material is a maximum position of the resistance force within the certain range. apparatus. The speed adjusting unit may change a cross-sectional area of the flow path through which the viscous fluid can pass through the moving member, detour from a larger flow path, or move the flow path through the movement member. The shielding apparatus according to any one of claims 2 to 5, wherein at least one elastic coefficient of a member to be configured is changed. When the moving member moves in the first direction when the shielding member is lowered by its own weight, the speed adjusting unit is configured such that the flow resistance of the viscous fluid moves in the second direction opposite to the first direction. The shielding device according to claim 2, wherein the shielding device is configured to be larger than a flow resistance of the viscous fluid. The speed adjustment unit is configured so that a moving distance of the moving member per unit rotation of the take-up shaft decreases as the moving member moves. The shielding apparatus as described in one. The speed adjusting unit includes a non-moving region where the moving member does not move even when the winding shaft rotates in the descending direction of the shielding material, and the winding shaft is in a state where the moving member is in the non-moving region. The shielding device according to any one of claims 2 to 8, wherein when the shield member rotates in a rising direction of the shield member, the moving member moves with the rotation of the winding shaft. The speed adjusting unit includes a damper case and a damper shaft inserted into the damper case, and a damper device that attenuates a relative rotational speed between the damper case and the damper shaft; and the rotation of the winding shaft is the damper. A rotation transmission unit for transmitting to the device,
The shielding apparatus according to claim 1, wherein the rotation transmission unit stops transmission of the rotation when the descending rotation speed reaches a predetermined number. The rotation transmission unit includes a moving member that moves as the winding shaft rotates, and is configured to stop transmission of rotation from the winding shaft to the damper device as the moving member moves. The shielding device according to claim 10. The speed adjusting unit includes a damper case and a damper shaft inserted into the damper case, and a damper device that attenuates a relative rotational speed between the damper case and the damper shaft; and the rotation of the winding shaft is the damper. A transmission mechanism for transmitting to the device;
2. The shielding device according to claim 1, wherein the speed change mechanism is configured such that a transmission ratio when rotation of the winding shaft is transmitted to the damper device is reduced in accordance with an increase in the descending rotation speed. 13. The shielding apparatus according to claim 12, wherein the speed change mechanism includes a moving member that moves as the winding shaft rotates, and the transmission ratio decreases as the moving member moves. The speed adjustment unit switches between a linked state in which the rotation of the winding shaft and the movement of the moving member are linked and an unlinked state in which the rotation of the winding shaft and the movement of the moving member are not linked. The shielding device according to any one of claims 1 to 8, 11, and 13, which is configured to be possible.