A scroll spring for driving curtains and a forming method thereof

Abstract

The present invention provides a spiral spring for driving curtains and a forming method thereof, belonging to the technical field of springs. It solves the technical problem that the existing spiral spring for driving curtains has poor applicability. The spiral spring for driving curtains comprises a spring leaf wound in a spiral shape, characterized in that when the spring leaf is stretched and opened, the two edges of the pulled-out part of the spring leaf are bent to one side and tilted to form a torque-adjusting warping edge, and the tilting height of the torque-adjusting warping edge gradually changes along the length direction of the spring leaf and gradually changes the torque at different positions of the pulled-out part. The spiral spring for driving curtains has a high degree of design freedom and better applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of springs and relates to a scroll spring for driving curtains and a molding method thereof. Background Art

[0002] Cordless curtains have become the main development direction of curtain products. In cordless curtains, the cord connected to the curtain is wound on a reel, which can be rotated under the drive of a driving mechanism, so that the cord is wound around the reel or released from the reel, thereby realizing the lifting and lowering of the curtain. A common driving mechanism is a plane scroll spring, which is also called a spring spring. It is a spring with one end fixed and the other end acting on a torque. Under the action of the torque, the spring leaf produces a bending elastic deformation, causing the spring to twist in the plane, and the size of the deformation angle is proportional to the torque. When the traditional plane scroll spring is formed, the radius of curvature of the spring leaf after bending and forming gradually increases from the inner circle to the outer circle, and the smaller the radius of curvature of the spring leaf, the greater the torque that can be provided. Therefore, the torque provided by the traditional plane scroll spring gradually decreases from the inner circle to the outer circle.

[0003] When driving the curtain, the outer end of the plane scroll spring is wound and fixed on the rotating shaft parallel to the central axis of the plane scroll spring itself. The rotating shaft is connected to the winding wheel transmission. When the rotating shaft rotates, it will drive the winding wheel to rotate, and vice versa. When the curtain needs to be lowered, the curtain can be manually pulled down, and the pull rope will drive the winding wheel to rotate forward, thereby driving the rotating shaft to rotate forward, and the reed of the plane scroll spring is wound around the rotating shaft circle by circle; when the curtain needs to be raised, the curtain only needs to be slightly pulled down, and the plane scroll spring will drive the rotating shaft to rotate in the opposite direction under the action of its own elastic force. At the same time, the reed will gradually withdraw from the rotating shaft circle by circle and retract and wind, and the rotating shaft drives the winding wheel to rotate in the opposite direction to retract the pull rope, thereby driving the curtain to rise.

[0004] In the existing rope-free curtain structure, when the curtain drops to a lower position, the weight that needs to be supported by the driving mechanism is relatively small. At this time, most of the spring leaves of the planar scroll spring are wound on the rotating shaft. At this time, the spring leaves on the outer ring of the rotating shaft have a smaller radius of curvature, which can provide a larger torque, and it is easy to cause the rotating shaft to rotate in the opposite direction, resulting in unnecessary rise of the curtain. On the contrary, when the curtain rises to a higher position, the weight that needs to be supported by the driving mechanism is relatively large. At this time, most of the spring leaves of the planar scroll spring have been withdrawn from the rotating shaft and retracted and wound. At this time, the spring leaves on the outer ring of the rotating shaft have a larger radius of curvature, which can only provide a smaller torque and may not be able to effectively support the weight of the curtain, resulting in unnecessary falling of the curtain due to gravity.

[0005] To solve the above problems, a Chinese patent with authorization announcement number CN206889541U discloses a planar scroll spring for a curtain drive device, which is formed by reverse winding of a traditional planar scroll spring made by conventional technology, and the forming curvature radius of the pulled-out part of the spring leaf of the planar scroll spring gradually changes from the outer circle to the inner circle.

[0006] The above-mentioned scroll spring structure is more suitable for the lifting and lowering drive of curtains, but the scroll spring is difficult to maintain stable state under natural conditions after reverse winding, and it is easy to release its own energy before installation, which increases the workload. To solve the above-mentioned problem, ordinary technicians in this field can easily consider: after the plane scroll spring is reversely wound, use a lock structure to keep its state stable to avoid self-release, and unlock it after the installation is completed. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention provides a scroll spring for driving curtains. The technical problem to be solved by the present invention is that the prior scroll spring has poor applicability and is inconvenient to install.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A spiral spring for driving a curtain comprises a spring sheet wound in a spiral shape, characterized in that when the spring sheet is stretched and opened, the two edges of the pulled-out portion of the spring sheet are bent to one side and lifted up to form a torque-adjusting warp edge, and the lifted height of the torque-adjusting warp edge gradually changes along the length direction of the spring sheet and causes the torque at different positions of the pulled-out portion to gradually change.

[0010] By arranging the spring leaf of the scroll spring to form raised torque-adjusting warping edges on both sides of the pull-out part in the width direction when it is opened, the pull-out part of the spring leaf can release the potential energy accumulated in the winding state when it is opened under force to supplement the force required to drive the pull-out part to open, thereby reducing the torque requirement for the pull-out part to open, and further arranging the warping degrees of the torque-adjusting warping edges to be different in different sections, so that the torque of each pull-out part of the entire scroll spring can be adjusted by the warping degree of the torque-adjusting warping edges to meet the use requirements of different torques at different stages of the product, such as the requirements of cordless blinds. The degree of warping of the torque-adjustable warping edge in the lower design gradually increases from the outer circle to the inner circle, so that the torque of the outer circle with a large curvature radius decreases less, while the torque of the inner circle with a small curvature radius decreases significantly. Ultimately, the formed spiral spring can achieve in a stable state that although the outer circle has a large curvature radius, the torque is greater when opened, and the inner circle has a small curvature radius and its torque is smaller, thereby better meeting the force requirements of the curtain's retraction and extension drive, so as to meet the gravity generated by the gradual change of the curtain's own weight at different positions during the curtain's retraction process and balance it, and no additional locking structure is required to ensure easy installation.

[0011] In the above-mentioned spiral spring, the warping direction of the torque-adjusting warping edge and the winding direction of the spring leaf are respectively toward the two sides of the spring leaf. The winding direction of the spring leaf is toward the inner side of the spiral spring, and by setting the torque-adjusting warping edge to warp toward the outer side of the spiral spring along the thickness direction, it is beneficial for the spring leaf whose inner circle has been reset to abut against the lower part of the middle part of the spring leaf to be reset when the spring leaf is rewound and reset, so as to promote its deformation to a nearly flat state or a nearly flat state.

[0012] In the above-mentioned spiral spring, the cross section of the pull-out portion is arc-shaped. By setting the cross section of the pull-out portion to be arc-shaped, the width range of the torque-adjusting warping edge is maximized, which is conducive to keeping the warping height of the torque-adjusting warping edge within a suitable range while satisfying its regulating effect on the torque of the pull-out portion.

[0013] As another solution, the cross section of the pull-out portion is U-shaped, the torque-adjusting warping edge is arc-shaped, and the pull-out portion between the two torque-adjusting warping edges is flat-plate-shaped. By setting the torque-adjusting warping edge to be arc-shaped and the pull-out portion between the two torque-adjusting warping edges to be flat-plate-shaped, the processing difficulty of the spiral spring forming can be reduced, and the flat-plate-shaped pull-out portion is conducive to smooth transportation during the manufacturing process, reducing the process difficulty.

[0014] In the above spiral spring, the torque-adjusting warping edge on the spring leaf is reset in the reeled state and is flush with the spring leaf portion between the torque-adjusting warping edges on both sides in the width direction. In this way, the spring leaf can absorb energy after reeling and reset to prepare for the torque change of the subsequent pulling-out portion.

[0015] In the above-mentioned spiral spring, the spring leaf is a stainless steel strip or a beryllium bronze strip. Both stainless steel and beryllium bronze have good elasticity and fatigue resistance, which ensure the mechanical properties of the spiral spring.

[0016] A method for forming a scroll spring for driving a curtain comprises the following steps:

[0017] a. Pass the flat spring steel strip horizontally between the vertically opposed V-shaped rollers, drive the V-shaped rollers to rotate and control the flat spring steel strip to synchronously feed at a low speed, perform preliminary bending processing on the flat spring steel strip, and make the two sides of the flat spring steel strip initially warp;

[0018] b. Pass the initially processed spring steel strip horizontally between the second V-shaped rollers with a greater bending degree. While driving the spring steel strip to feed at a low speed, gradually reduce the clamping force between the V-shaped rollers to gradually reduce the degree of warping on both sides of the spring steel strip. After processing the unit length, the V-shaped rollers are reset to the high pressure state and gradually reduce it;

[0019] c. The processed spring steel strip continues to be fed and begins to abut against the forming cutter head and bend and wind. During the winding process, the forming cutter head gradually moves outward to complete the winding of the spiral spring;

[0020] d. The punch cutter cuts off the excess of the spring steel strip, and the formed scroll spring is collected in the receiving box to complete the processing.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] The volute spring is provided with a spring leaf of the volute spring so that when it is opened, the two sides of the pull-out part in the width direction can form a raised torque-adjusting edge, so that when the pull-out part of the spring leaf is opened under force, the potential energy accumulated in the winding state can be released to supplement the force required for driving the pull-out part to open, thereby reducing the torque requirement for the pull-out part to open, and further providing a setting so that the degree of the tilting of the torque-adjusting edge gradually increases from the outer ring to the inner ring, so that the torque of the outer ring with a large curvature radius is reduced less, while the torque of the inner ring with a small curvature radius is significantly reduced, and finally the formed volute spring can realize in a stable state that the outer ring has a large curvature radius but has a larger torque when opened, and the inner ring has a small curvature radius but has a smaller torque, thereby better meeting the driving force requirements of the curtain, and no additional locking structure is required to ensure convenient installation. Therefore, the curvature of the spring leaf can be changed at any point within the length range of the volute spring according to the requirements of the use occasion, so as to obtain a variable torque value, so that when in use, the curtain can be retracted and pulled to get a more comfortable feel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view structural schematic diagram of the spiral spring in the first embodiment.

[0024] Figure 2 yes Figure 1 Enlarged view of part A in .

[0025] Figure 3 It is a schematic diagram of the side structure of the spiral spring in the first embodiment.

[0026] Figure 4 It is a schematic cross-sectional view of the pulled-out portion in the first embodiment.

[0027] Figure 5 It is a schematic cross-sectional view of the pull-out portion in the second embodiment.

[0028] In the figure, 1. reed; 2. pull-out part; 3. torque adjustment warping edge. DETAILED DESCRIPTION

[0029] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0030] Embodiment 1:

[0031] like Figure 1-4As shown, the scroll spring for driving the curtain comprises a spring leaf 1 wound in a scroll shape. When the spring leaf 1 is not opened, it is similar to the state of a conventional plane scroll spring. When the spring leaf 1 is stretched and opened, the two edges of the pull-out portion 2 of the spring leaf 1 along the width direction form torque-adjusting warping edges 3 that are raised along the thickness direction of the pull-out portion 2. The warping height of the torque-adjusting warping edges 3 gradually increases from the outer ring to the inner ring of the scroll spring, so that the torque of the pull-out portion 2 of the spring leaf 1 when stretched and opened gradually decreases from the outer ring to the inner ring, and the cross-section of the pull-out portion 2 is arc-shaped. By setting the spring leaf 1 of the spiral spring to form a raised torque-adjusting edge 3 on both sides of the pull-out part 2 in the width direction when it is opened, the pull-out part 2 of the spring leaf 1 can release the potential energy accumulated in the winding state to supplement the force required to drive the pull-out part 2 to open when it is forced to open, thereby reducing the torque requirement for the pull-out part 2 to open, and further setting the tilting degree of the torque-adjusting edge 3 to gradually increase from the outer ring to the inner ring, so that the torque of the outer ring with a large curvature radius is reduced less, while the torque of the inner ring with a small curvature radius is significantly reduced, and finally the formed spiral spring can achieve in a stable state that the outer ring has a larger curvature radius but a larger torque when it is opened, and the inner ring has a smaller curvature radius but a smaller torque, thereby better meeting the force requirements of the curtain retraction and release drive, and no additional locking structure is required to ensure convenient installation. Further, the torque-adjusting edge 3 is tilted toward the outside of the spiral spring along the thickness direction. By setting the torque adjustment warping edge 3 to warp toward the outside of the spiral spring, when the spring 1 is rolled and reset, the inner ring of the spring 1 that has been reset can be pressed against the lower part of the middle of the spring 1 to be reset to promote its deformation to a near-plane state or a near-plane state, so as to prepare for the next drive. Preferably, the spring 1 is a stainless steel strip. Stainless steel strips have good elastic properties and fatigue resistance, which ensure the mechanical properties of the spiral spring.

[0032] The above-mentioned scroll spring forming method comprises the following steps:

[0033] a. Pass the flat spring steel strip horizontally between the vertically opposed V-shaped rollers, drive the arc V-shaped rotation and control the flat spring steel strip to feed synchronously at a low speed, perform preliminary bending processing on the flat spring steel strip, and make the two sides of the flat spring steel strip initially warp;

[0034] b. Pass the initially processed spring steel strip horizontally between the second V-shaped rollers with a greater bending degree. While driving the spring steel strip to feed at a low speed, gradually reduce the clamping force between the V-shaped rollers to gradually reduce the degree of warping on both sides of the spring steel strip. After processing the unit length, the V-shaped rollers are reset to the high pressure state and gradually reduce it;

[0035] c. The processed spring steel strip continues to be fed and begins to abut against the forming cutter head and bend and wind. During the winding process, the forming cutter head gradually moves outward to complete the winding of the spiral spring.

[0036] d. The punch cutter cuts off the excess of the spring steel strip, and the formed scroll spring is collected in the receiving box to complete the processing.

[0037] Embodiment 2:

[0038] like Figure 5 As shown, this embodiment is basically the same as the first embodiment, except that: the cross section of the pull-out portion 2 is U-shaped, the torque-adjusting warping edge 3 is arc-shaped, and the pull-out portion 2 between the two torque-adjusting warping edges 3 is flat. By setting the torque-adjusting warping edge 3 to be arc-shaped and the pull-out portion 3 between the two torque-adjusting warping edges to be flat, the processing difficulty of the spiral spring forming can be reduced, and the flat-plate-shaped pull-out portion 2 is conducive to smooth transportation during the manufacturing process, reducing the process difficulty.

[0039] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A spiral spring for driving a curtain, comprising a spirally wound reed leaf (1), characterized in that: When the spring leaf (1) is stretched and opened, the two edges of the pulled-out portion (2) of the spring leaf (1) are bent and raised to one side to form a torque-adjusting edge (3), and the raised height of the torque-adjusting edge (3) gradually changes along the length direction of the spring leaf (1) so that the torque at different positions of the pulled-out portion (2) gradually changes; the raised direction of the torque-adjusting edge (3) and the winding direction of the spring leaf (1) are respectively oriented toward the two sides of the spring leaf (1), and the raised degree of the torque-adjusting edge (3) gradually increases from the outer circle to the inner circle; in the wound state, the torque-adjusting edge (3) on the spring leaf (1) is reset and is flush with the portion of the spring leaf (1) between the two sides of the torque-adjusting edge (3) along the width direction.

2. The spiral spring for driving a curtain according to claim 1, characterized in that: The cross section of the pulled-out portion (2) of the reed leaf (1) is arc-shaped.

3. The spiral spring for driving a curtain according to claim 1, characterized in that: The cross section of the pull-out portion (2) is U-shaped, the torque-adjusting warping edge (3) is arc-shaped, and the pull-out portion (2) between the two torque-adjusting warping edges (3) is flat.

4. The spiral spring for driving a curtain according to claim 1, 2 or 3, characterized in that: The reed (1) is a stainless steel strip or a beryllium bronze strip.

5. A method for forming a scroll spring for driving a curtain according to claim 1, characterized in that: The steps include: a. Pass the flat spring steel strip horizontally between the vertically opposed V-shaped rollers, drive the V-shaped rollers to rotate and control the flat spring steel strip to feed synchronously at a low speed, perform preliminary bending processing on the flat spring steel strip, and make the two sides of the flat spring steel strip initially warp; b. Pass the initially processed spring steel strip horizontally between the second V-shaped rollers with a greater bending degree. While driving the spring steel strip to feed at a low speed, gradually reduce the clamping force between the V-shaped rollers to gradually reduce the degree of warping on both sides of the spring steel strip. After processing the unit length, the V-shaped rollers are reset to the high pressure state and gradually reduce it; c. The processed spring steel strip continues to be fed and begins to abut against the forming cutter head and bend and wind. During the winding process, the forming cutter head gradually moves outward to complete the winding of the spiral spring; d. The punch cutter cuts off the excess of the spring steel strip, and the formed scroll spring is collected in the receiving box to complete the processing.

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