JP2002115729A - Clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch device capable of biting-in a clutch spring to a joint part between two shafts constituting a clutch device without increasing the number of parts. SOLUTION: The clutch device has an input shaft 24 and a clutch shaft 25 relative-rotatably provided concentrically along an axial direction in parallel; and a clutch spring 30 laid and wound on these two shafts and selectively switching a connection and a disconnection of the two shafts unitizing a tightening and a relaxing of the clutch spring 30. A rib 25a radially and axially projected toward the input shaft 24 is formed on an end of the clutch shaft 25 at a border end between the clutch shaft 25 and the input shaft 24 and a cutout part 25b is further formed on the rib 25a. A part of the clutch spring 30 passing through a border line of the input shaft 24 and the clutch shaft 25 is only forcedly passed through a part of the cutout part 25 by the rib 25a and is passed so as to obliquely cross the border line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch device for use in a device such as a blind for switching between connection and disconnection of two shafts.

[0002]

2. Description of the Related Art In a conventional device such as a blind, various clutch devices for selectively switching connection / disconnection between a driving side shaft and a non-driving side shaft are used. For example, one example is described in Japanese Patent Application Laid-Open No. 4-149390. The clutch device shown here is
One end of the screen is provided at one end of a take-up shaft that is windably and unwoundly mounted, and a first shaft that is rotatably supported adjacent to the spring shaft and supported by the support bracket. Spring drum, a second spring drum, a clutch spring provided over these two spring drums, and an intermediate portion thereof rotatably supported by the first spring drum and rotated by rotation of a pulley. A possible clutch arm. One end of the clutch spring is locked to the first spring drum, and the other end is locked to the tip of the clutch arm. The first spring drum is rotatable by a pulley, and
The second spring drum is connected to the winding shaft.
When the pulley is rotated in a certain direction, the first spring drum follows and rotates in that direction, and the clutch spring tightens the first and second spring drums. Rotate in the unwinding direction of the screen. When the pulley is rotated in the opposite direction, the distal end of the clutch arm rotates in a predetermined direction to relax the clutch spring and reduce the frictional force between the clutch spring and the second spring drum. Can idle.

However, in the case of the above-described clutch device using a clutch spring, when a large torque is momentarily applied when the clutch spring tightens both drums, the diameter of the clutch spring instantaneously exceeds a predetermined amount. To shrink,
There is a problem that the clutch spring may bite into a joint at the boundary between the two drums, causing malfunction.

[0004] As means for solving such a problem, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 7-233684 has been proposed. In this publication, a clutch adapter and a clutch spring receiver are provided so as to be rotatable relative to each other and concentrically along the axial direction, and the winding is performed between the clutch adapter and the clutch spring receiver. And a clutch having a cam surface which can be engaged with the clutch adapter. The clutch is rotatable at a predetermined angle with respect to the clutch spring receiver, and the clutch cam surface is provided by the clutch. The adapter can be pushed out toward the clutch spring receiver. When rotation in the screen winding direction from the screen acts on the clutch, the pressing force from the cam surface of the clutch to the clutch adapter and the instantaneous application of rotational force make the boundary line between the clutch adapter and the clutch spring receiver. The clutch spring is tightened without the clutch spring digging into the joint at which the clutch adapter is engaged, and the clutch adapter is connected to the clutch spring receiver.

[0005]

However, the configuration of the latter publication can prevent the clutch spring from biting, but has the problem of increasing the number of parts.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and it is possible to prevent a clutch spring from cutting into a joint between two shafts constituting a clutch device without increasing the number of parts. Its purpose is to provide a device.

[0007]

In order to achieve the above-mentioned object, the present invention is directed to a driving-side shaft and a non-driving-side shaft which are arranged rotatably and concentrically along the axial direction. A clutch device having a shaft and a clutch spring wound around these two shafts, and selectively switching between connection and non-connection of the two shafts by using the tightening and relaxation of the clutch spring. Forcibly inclining means for forcibly inclining a portion of the clutch spring passing through a boundary between the driving side shaft and the non-driving side axis with respect to at least one of the driving side shaft and the non-driving side shaft. It is characterized by being provided. The forced inclining means allows the clutch spring to pass through the boundary between the two axes while being inclined, so that it is possible to prevent the clutch spring from digging into the boundary line.

According to a second aspect of the present invention, the forcible inclining means according to the first aspect is formed on a rib formed at at least one boundary end of the driving side shaft or the non-driving side shaft and on the rib. Wherein the rib is disposed so as to straddle a boundary line, and the clutch spring portion passes through the notch of the rib. The forced inclining means can be configured with a simple configuration of the rib and the notch.

According to a third aspect of the present invention, in the rib of the second aspect, an inclined surface inclined with respect to a boundary line is formed adjacent to the notch, and the inclined surface is formed by the clutch spring. Is guided toward the notch. The inclined surface can smoothly guide the clutch spring toward the notch.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of a clutch device according to the present invention.

In this embodiment, a clutch device used for a blind is taken as an example, and the blind can be applied to any blind such as a horizontal blind, a Roman shade, and a roll screen.
In this embodiment, the other end of the lifting / lowering cord, one end of which is attached to the lower portion of the shielding member, is wound around a winding drum, and is mounted so as to be able to be unwound, so that the winding drum rotates integrally with the winding shaft 10. The linked one is taken as an example. When the shielding material rises, the winding shaft 10 rotates in a predetermined direction, whereby the winding drum rotates integrally, the lifting cord is wound on the winding drum, and the shielding material rises. Conversely, when the shielding material is lowered, the lifting cord is unwound from the winding drum, and the winding drum and the winding shaft 10 rotate in the opposite direction. As described above, the winding shaft 10 rotates in conjunction with the raising and lowering of the shielding material when the shielding material is raised and lowered, and the clutch device 20 having the stopper mechanism is connected to the winding shaft 10. Further, the speed reducer 40 is connected via the clutch device 20. Of course, the present invention is not limited to this example. For example, in the case of a roll screen, one end of the shielding material can be wound, and the clutch device 20 can be connected to a winding pipe that is unwound. It is.

The clutch device 20 includes a case 22, an input shaft 24 through which the winding shaft 10 penetrates and rotates integrally with the winding shaft 10, and a bearing portion 24a which is reduced in diameter from one end of the input shaft 24 and extends. And a clutch shaft 25 which is fitted to the outer peripheral side so as to be relatively rotatable. Therefore, the input shaft 24 and the clutch shaft 25 are concentrically arranged along the axial direction so as to be relatively rotatable, and have the same outer diameter on the outer peripheral surface. A coil-shaped clutch spring 30 extends over the outer peripheral surfaces of the input shaft 24 and the clutch shaft 25.
Is wound. One end of the clutch spring 30 is inserted into a cam drum 26 that is integral with the clutch shaft 25 and has a diameter larger than that of the clutch shaft. The other end of the clutch spring 30 is on the outer peripheral surface of the input shaft 24. At the end of the boundary between the clutch shaft 25 and the input shaft 24, a rib 25a is formed at the end of the clutch shaft 25 so as to protrude toward the input shaft 24 in the radial direction and the axial direction. 25a
Is formed with a notch 25b (see FIG. 4). An inclined surface 25c that is inclined toward the notch 25b is formed on an end surface of the rib 25a adjacent to the notch 25b. When the bearing portion 24a of the input shaft 24 is inserted into the clutch shaft 25, the rib 25a is disposed across the respective outer peripheral surfaces of the clutch shaft 25 and the input shaft 24. The portion of the clutch spring 30 that passes through the boundary between the input shaft 24 and the clutch shaft 25 is forcibly passed only by the notch 25b by the rib 25a.
It crosses the border diagonally. By setting the dimension of the rib 25a in the axial direction to some extent, the clutch spring 30 can be inclined more greatly with respect to the boundary line. Further, the ribs 25a are guided so as to cross the boundary line reliably and smoothly obliquely by the inclined surface 25c.

A guide groove 26a is formed on the outer peripheral surface of the cam drum 26 integrated with the clutch shaft 25, and the guide groove 26a is formed within the vertical groove 22a formed on the inner peripheral surface of the case 22 by the shaft. Ball 2 that slides in the direction
8 is slidable. The cam drum 26 and the ball 28 constitute a stopper mechanism. As shown in FIG. 3, the guide groove 26a includes an endless loop 26b extending endlessly in the circumferential direction of the cam drum 26, and a branch loop 26c branched from the endless loop 26b.
A first locking portion 26d and a second locking portion 26e are formed in the branch loop 26c.

An input shaft of a speed reducer 40 is connected to a side of the cam drum 26 opposite to the clutch shaft 25 so as to rotate integrally with the cam drum 26.

The operation of the clutch device configured as described above will be described. First, when the winding shaft 10 is rotated in the lowering direction of the shielding material, the input shaft 24 rotates together, the clutch spring 30 is tightened, the input shaft 24 and the clutch shaft 25 are connected, and the cam drum 26 is also rotated. Rotate. At this time, the cam drum 26 rotates so that the ball 28 that cannot be rotated with respect to the case 22 moves relative to the endless loop 26b of the guide groove 26a from the top to the bottom as indicated by the solid arrow in FIG. The rotation of the cam drum 26 is transmitted to the brake device 40 to apply a brake to the rotation. Therefore, the shielding member performs a descending operation while being decelerated.

Next, when the rotation of the take-up shaft 10 is changed to the rotation of the shielding material in the ascending direction, the input shaft 24 rotates in the opposite direction, and the clutch shaft 25 rotates in the same direction as the input shaft 24. In the cam drum 26, the ball 28 relatively moves from the endless loop 26b to the branch loop 26c as shown by the one-dot chain line arrow in FIG. 3, and reaches the first locking portion 26d. Therefore, thereafter, the cam drum 26 cannot rotate in that direction, so that the clutch spring 30
Is loosened, the input shaft 24 and the clutch shaft 25 are disconnected, and the input shaft 24 idles with respect to the clutch shaft 25. Therefore, the shielding member performs an ascending operation without being decelerated by being separated from the brake device 40.

Next, when the rotation of the wind-up shaft 10 in the direction in which the shielding material rises is stopped, the wind-up shaft 1 is driven by its own weight.
When 0 rotates in the shielding material lowering direction and this rotation is input to the input shaft 24, the clutch spring 30 is tightened, and the input shaft 24 and the clutch shaft 25 are connected. For this reason, the cam drum 26 also rotates together with the input shaft 24, and the ball 28
Relatively move from the first locking portion 26d to the second locking portion 26e as shown by the two-dot chain line arrow in FIG.
Thereafter, since the cam drum 26 cannot rotate in that direction, the rotation of the input shaft 24 and the winding shaft 10 connected by the clutch spring 30 is stopped. Thus, the shield stops at that level.

In this state, when the winding shaft 10 is rotated in the ascending direction of the shielding member, the rotation is transmitted to the input shaft 24, the clutch shaft 25 and the cam drum 26, and the ball 28 is relatively endlessly moved from the branch loop 26c. Returning to the loop 26b,
The winding shaft 10 can be rotated either in the shielding material descending direction or the shielding material ascending direction.

In the above series of operations, as the operation immediately before the shielding member is stopped, when the winding shaft 10 is switched from the rotation in the shielding member rising direction to the rotation in the shielding member descending direction, the clutch spring is moved. 30 is changed from the relaxed state to the tightened state, a large torque is instantaneously applied, and the clutch spring 3
The diameter of 0 tries to shrink to a predetermined amount or more. However,
At the boundary between the input shaft 24 and the clutch shaft 25, the rib 25 a and the notch 25 b allow the clutch spring 30 to cross the boundary line at an angle. It is possible to prevent the clutch spring from digging into the joint of the boundary line.

Thus, by inclining the portion of the clutch spring 30 passing through the boundary between the input shaft 24 and the clutch shaft 25, it is possible to prevent the clutch spring 30 from being damaged with a simple structure. In order to pass the boundary line obliquely, it is conceivable to use a coil spring having a large pitch and a large lead angle by partially changing the pitch of the clutch spring 30 itself. Although it is difficult to make an adjustment so that the coil spring always passes through the boundary line, in the present embodiment, it is possible to surely obliquely force the coil spring in a portion passing through the boundary line. In addition, as the forcible inclining means for forcibly passing the clutch spring 30, the rib 25a and the notch 25b provided integrally with the clutch shaft 25 are used, so that the structure is simple and the number of parts is not increased. , Can be implemented.

In the above embodiment, the input shaft 24 and the clutch shaft 25 are taken as an example of the drive-side shaft and the non-drive-side shaft. However, the present invention is not limited to this. It goes without saying that it can be applied to two axes. For example, in this example, the input shaft 24 and the clutch shaft 25 are connected when the shielding material is lowered, and the input shaft 24 and the clutch shaft 25 are not connected when the shielding material is raised. Alternatively, the two shafts may be connected when the shield is raised, and the two shafts may be disconnected when the shield is lowered.

Further, in the present embodiment, the ribs and the notches are provided on the clutch shaft 25, but they may be provided on the input shaft 24 or on both the input shaft 24 and the clutch shaft 25. The means for forcibly passing the clutch spring 30 is not limited to the means using the ribs and the cutouts, and any means can be used.

[0023]

As described above, according to the present invention, it is possible to prevent the clutch spring from cutting into the joint between two shafts constituting the clutch device without increasing the number of parts.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a clutch device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the clutch device of FIG.

FIG. 3 is a development view of the cam drum of FIG.

FIG. 4 is a view seen from an end surface of a clutch shaft.

[Explanation of symbols]

 Reference Signs List 24 Input shaft (drive-side shaft) 25 Clutch shaft (non-drive-side shaft) 25a Rib (forced tilting means) 25b Notch (forced tilting means) 25c Inclined surface 30 Clutch spring

Claims (3)

[Claims] 1. A driving side shaft (24) and a non-driving side shaft (2) which are relatively rotatably and concentrically arranged along an axial direction.
5) and a clutch spring (30) wound around these two shafts (24, 25).
0) using the tightening and loosening of the two shafts (2).
4, 25), wherein at least one of the driving side shaft (24) and the non-driving side shaft (25) is provided with a driving side shaft (24) and a non-driving side shaft (25). Forcibly tilting means (25a, 25a) forcibly inclining the portion of the clutch spring (30) passing through the boundary between
5b). A clutch device comprising: 2. The forcible inclining means (25a, 25b).
Is a rib (25a) formed on at least one boundary end of the driving side shaft (24) or the non-driving side shaft (25).
And a notch (25b) formed in the rib (25a). The rib (25a) is disposed so as to straddle a boundary line, and the clutch spring (30) is a rib (25a).
The clutch device according to claim 1, wherein the clutch device passes through the notch (25b). 3. The notch (25) is formed in the rib (25a).
b) an inclined surface adjacent to the boundary line (25)
3. The clutch device according to claim 2, wherein c) is formed, and the inclined surface (25c) guides the portion of the clutch spring (30) toward the notch (25b).