TWM648233U - Flexible screen shaft structure - Google Patents

Abstract

The invention is a flexible screen rotating shaft structure, in which two first arc-shaped parts of a base are respectively pivotally connected to two rotating shaft modules. The two rotating shaft modules are connected to a moving component and a torsional positioning component through at least one shaft. One end of the rotating member of any rotating shaft module is connected to the first arc part, and the rotating member has at least one receiving groove in the middle position to accommodate at least one cam member; one end of a door panel connecting rod is pivotally connected to one end of at least one cam member, The other end of at least one cam member is pivotally connected to the rotating member; one end of a connecting rod is pivotally connected to the rotating member and the other end of the door panel connecting rod, and the other end of the connecting rod has a guide rail; and one end of the moving member is At least one shaft is connected in a synchronous rotation manner, and the sliding part at the other end of the synchronous moving part is connected to the guide rail for relative movement.

Description

Flexible screen hinge structure

The invention relates to a hinge, in particular to a flexible screen hinge structure of a foldable electronic device.

Traditional foldable electronic devices, such as the monitor and base of a notebook computer, mainly connect the sides of the monitor and the base through single-axis hinges to form a pivot, so that the display can be flipped, opened or closed relative to the base. In addition to traditional notebook computers, especially for existing dual-touch screen computers, the current design direction of folding devices is mainly to improve the shortcomings of dual-touch screen computers so that dual screens can be used in During the opening and closing process, they can be close to each other and reduce the gap between each other to prevent the internal structure of the hinge or pivot joint from being exposed.

In existing "flexible screen foldable devices", different shaft structure designs are required according to the curvature of the flexible screen after folding in or out, so as to avoid hindering the folding action of the flexible screen and causing pulling. The opening and closing action of the foldable device that folds inside the flexible screen mainly follows the traditional folding device. After folding, the flexible screen can be protected inside, and it is closer to the user's habits and is easier to accept. However, in this type of product , the structural design of its rotating shaft structure will be limited by the type of flexible screen used, and it must also be considered that the curved part of the flexible screen after folding in will appear in either a water drop shape or a horseshoe shape, resulting in differences. Among them, for the water-drop-shaped rotating shaft structure, the components that need to be considered and the connection relationships and actions between them are key factors that affect whether the flexible screen is easy to be damaged and its service life; and because of the required components There are many, and manufacturing and assembly are even more challenging issues.

For the water-drop-shaped rotating shaft structure, as shown in the patent cases CN110630625B, CN109469680B, CN109654113B and CN209959699U, various structural designs are mainly tried with flexible screens to achieve both thinness and overall beauty. Considering the existing manufacturing process and cost, in order to achieve the effect of thinning, it is better to form a virtual rotation center when the rotating shaft structure is folded. For example, the drawings of the CN110630625B and CN209959699U patents disclose " Single virtual rotation center". However, in order to make the overall mechanism action closer to the water drop shape after the flexible screen is folded in to reduce damage, it has been continuously developed into "double virtual rotation centers" with "single, The structure of the "double crank connecting rod mechanism", but the manufacturing and assembly of the "crank connecting rod mechanism" is more complex than the previous "teardrop shaped rotating shaft structure", and has higher specifications and quality requirements, for example: As for the assembly of various parts of the crank-link mechanism, since the structural shape of the "link mechanism" is not conventional, its assembly angle will be quite special, making the assembly requirements stricter and more difficult.

In view of this, in order to provide a structure that is different from the conventional technology and improve the above-mentioned shortcomings, the creator has accumulated many years of experience and continuous research and development and improvement, and thus came into being this creation.

One of the purposes of this creation is to provide a flexible screen rotating shaft structure that can solve the problem of the conventional linkage mechanism having a complex structure and shape that is not easy to assemble. It can be designed to be detachable through the improvement of the shape and structural dispersion of each linkage mechanism. And the composite structure improves the convenience during assembly, makes the relative sliding between connecting rods stable and smooth, and helps to reduce the impact of abnormal noise.

In order to achieve the purpose of the above creation, the flexible screen rotating shaft structure set up in this invention includes a base and two rotating shaft modules in opposite directions. The base has a first side and a second side that are spaced and juxtaposed. The first side and the second side There are two first arc-shaped parts in opposite directions between the sides; one end of the two rotating shaft modules is connected to a moving component and a torsion positioning component through at least one shaft, and one end of the two rotating shaft modules is respectively pivotally connected to the two second An arc-shaped portion is used for two rotating shaft modules to rotate relative to open and close; each rotating shaft module includes a rotating part, a door panel connecting rod, at least one cam part, a housing connecting rod and a moving part. One end of the rotating part has a first guide part, and the first guide part is connected to the first arc part in a relatively arc-shaped swing. The rotating part has at least one receiving groove in the middle position; the top end of the door panel connecting rod is connected to a first arc-shaped part. The door panel is used to support a flexible screen upward. One end of the door panel connecting rod is pivotally connected to one end of at least one cam member. The at least one cam member is accommodated in at least one receiving groove. The other end of the at least one cam member is pivotally connected to the rotating member; the connecting shell The bottom end of the connecting rod is connected to a casing, one end of the connecting rod is pivoted to the other end of the rotating member with a first straight rod, and one end of the connecting rod is pivoted to the other end of the door panel connecting rod with a second straight rod. , the other end of the housing connecting rod has a guide rail; one end of the co-moving part is connected to at least one shaft rod in a synchronous rotation manner, and the other end of the co-moving part has a sliding part, and the sliding part is connected to the guide rail in a relatively moving manner.

When implemented, the invention further includes a support base, the support base has a limit slot for accommodating the limit co-moving component; one end of the support base is connected to one end of the base, and the other end of the support base has two fins and at least one shaft. It includes a first shaft and a second shaft. The first shaft and the second shaft pass through the two fins and the torsional positioning component of the support base in sequence, and are respectively connected with a first end seal and a first The two end seals are locked to the first shaft and the second shaft for fixing the compression torsion positioning assembly.

During implementation, the guide rail is a guide post, and the other end of the housing connecting rod has a first protruding part and a second protruding part that are parallel to each other, and there is a guide between the first protruding part and the second protruding part. The guide groove has a guide rail in the guide groove; the sliding part has a first convex block and a second convex block that are parallel to each other. The first convex block and the second convex block are coaxially sleeved with the guide rail for the sliding part to move relative to each other. It is limited to the guide groove of the connecting rod of the housing.

During implementation, one end of the connecting rod has a lug, and the other end of the connecting rod has a plate parallel to the lug; the lug and one side of the plate position the two ends of the first straight rod and the second straight rod respectively. ; The first straight rod is pivoted to a first pivot hole at the other end of the rotating member for relative rotation of the housing connecting rod and the rotating member; the second straight rod is pivoted to a second pivot hole at the other end of the door panel connecting rod for relative rotation The housing connecting rod and the door panel connecting rod rotate relatively; the top surface of the plate of the housing connecting rod has a guide groove.

When implemented, the invention further includes an elastic positioning member connected to the bottom of the base. At least one end of the elastic positioning member has at least one arc-shaped piece for elastically pressing the first guide portion upward.

During implementation, the first arcuate part includes two parallel and spaced arcuate blocks, the first guide part is provided with two spaced arcuate grooves, and the two arcuate grooves are located on opposite sides of the first guide part. To respectively butt the two arc-shaped blocks of the first arc-shaped part.

During implementation, at least one third pivot hole is provided in at least one receiving groove of the rotating member, at least one third straight rod is provided at the other end of at least one cam member, and at least one third straight rod is pivotally connected to the third pivot hole of the rotating member. For at least one cam member and the rotating member to rotate relative to each other.

During implementation, at least one receiving groove includes a first receiving groove and a second receiving groove. The first receiving groove and the second receiving groove are respectively located on both sides of the middle position of the rotating member. At least one cam member includes a first cam member. and a second cam member, the first cam member is received in the first receiving groove, and the second cam member is received in the second receiving groove.

In order to facilitate a deeper understanding of this creation, it is described in detail below:

The flexible screen rotating shaft structure of this invention mainly includes a base and two rotating shaft modules in opposite directions. Both sides of the base have first arc-shaped parts in opposite directions; one end of the two rotating shaft modules is connected together through at least one shaft. A moving component and a torsion positioning component. One end of the two rotating shaft modules is respectively pivotally connected to two first arc-shaped parts for relative rotation opening and closing of the two rotating shaft modules. Each rotating shaft module mainly includes a rotating part and a door panel. A connecting rod, at least one cam member, a connecting rod and a moving member. One end of the rotating member has a first guide part. The first guide part is connected to the first arc part in a relatively arc-shaped swing. There is at least one receiving groove in the middle position of the component; the top end of the door panel connecting rod is connected to a door panel to upwardly support a flexible screen, one end of the door panel connecting rod is pivotally connected to one end of at least one cam member, and the at least one cam member is accommodated in at least one receiving groove , and the other end of at least one cam member is pivotally connected to the rotating member; the bottom end of the connecting rod is connected to a casing, and one end of the connecting rod is pivotally connected to the other end of the rotating member; one end of the connecting rod is pivotally connected to the door panel. The other end of the rod and the other end of the housing connecting rod have a guide rail; one end of the co-moving part is connected to at least one shaft rod in a synchronous rotation manner, and the other end of the co-moving part has a sliding part, and the sliding part is connected in a relatively moving manner. rails.

Please refer to Figure 1 to Figure 12, which is a preferred embodiment of the flexible screen rotating shaft structure 1 of the present invention. It mainly includes a base 2, two rotating shaft modules (3, 3'), a supporting base 4, and a moving shaft structure 1. Component 5 and a twist positioning component 6. The top of the base 2 has two opposite first arc portions (21, 21’), and each first arc portion (21, 21’) includes two parallel and spaced arc blocks 22.

The two rotating shaft modules (3, 3') have the same appearance and structure, and are arranged on two parallel sides of the base 2 in opposite directions. The two rotating shaft modules (3, 3') are respectively pivotally connected to the two first arcs. parts (21, 21'), thereby driving the two halves of the flexible screen 9 to flip open and close relative to each other. Taking one of the two rotating shaft modules (3, 3') 3 as an example, it mainly includes a rotating member 31, a door panel connecting rod 32, at least one cam member 33, a connecting rod 34 and a connecting rod 34. Moving parts 35.

A first guide portion 311 is provided at one end of the rotating member 31. The first guide portion 311 includes two spaced arcuate grooves 312 and two parallel and spaced arcuate slots 313. Two arc-shaped grooves 312 are located on opposite sides of the first guide part 311, and are respectively connected with the two arc-shaped blocks 22 of the first arc-shaped part 21. Two arc-shaped slots 313 are located between the first guide part 311. Arc-shaped bottom surface, and between two arc-shaped grooves 312. The first guide portion 311 is connected to the first arc portion 21 of the base 2, thereby allowing the rotating member 31 to swing in an arc relative to the base 2. The other end of the rotating member 31 has a first pivot hole 314. There are two through grooves 315 between the first pivot hole 314 and the first guide portion 311 for respectively connecting the two arc-shaped slots 313; There is at least one receiving groove in the middle position. During implementation, the at least one receiving groove includes a first receiving groove 316 and a second receiving groove 317. The first receiving groove 316 and the second receiving groove 317 are respectively located at two middle positions of the rotating member 31. side, and there is a third pivot hole 318 in the first receiving groove 316 and the second receiving groove 317 respectively.

The bottom of the base 2 has an elastic positioning member 319. The middle region of the elastic positioning member 319 is a flat plate for upwardly locking the bottom of the base 2. The two ends of the flat plate have two upwardly curved arc-shaped pieces 310. During the swing process of the rotating member 31, the two arc-shaped pieces 310 respectively elastically press upward along the two arc-shaped slots 313 against the arc-shaped bottom surface of the first guide part 311; one end of the two arc-shaped pieces 310 respectively It is positioned in the two through grooves 315 to clamp the rotating member 31 and prevent the rotating member 31 from rotating out of the base 2 and causing loosening during the arc swing.

The door panel connecting rod 32 is a U-shaped block, and the top surface of the door panel connecting rod 32 is upwardly locked to one of the two door panels (91, 91'), door panel 91, thereby supporting one half of the two halves of the flexible screen 9. One end of the door panel connecting rod 32 is provided with two spaced and parallel elongated blocks (321, 322). The two elongated blocks (321, 322) have two coaxial screw holes (323, 324). The other end of the door panel connecting rod 32 is One end has a second pivot hole 325.

At least one cam member 33 includes a first cam member 331 and a second cam member 332. The first cam member 331 and the second cam member 332 have relatively symmetrical shapes, and the first cam member 331 is received in the first receiving groove 316. Inside, the second cam member 332 is received in the second receiving groove 317 . One end of the first cam member 331 and the second cam member 332 respectively has a pivot hole (333, 334). After a headed screw 335 is screwed into the screw hole 323 of the elongated block 321, it then penetrates into the pivot hole 333, and the other headed screw 335 is threaded into the pivot hole 333. After the screw rod 336 is screwed into the screw hole 324 of the other elongated block 322, it then penetrates into the other pivot hole 334, so that one end of the door panel connecting rod 32 is pivotally connected to one end of at least one cam member 33. In addition, the other ends of the first cam member 331 and the second cam member 332 respectively have a third straight rod (337, 338), and the two third straight rods (337, 338) are respectively pivotally connected to the third pivot holes 318 on both sides of the rotating member 31. , thereby allowing at least one cam member 33 and the rotating member 31 to rotate relative to each other.

The housing connecting rod 34 is a rectangular plate. The bottom surface of the housing connecting rod 34 is locked with one of the two casings (92, 92') 92. One end of the housing connecting rod 34 has a lug 341. The other end of the shell connecting rod 34 has a plate 342 with parallel lugs 341; the lugs 341 and one side of the plate 342 respectively position the two ends of a first straight rod 343 and a second straight rod 344; the first straight rod 344 is The rod 343 is pivotally connected to the first pivot hole 314 of the rotating member 31 to allow the housing connecting rod 34 and the rotating member 31 to rotate relative to each other; the second straight rod 344 is pivotally connected to the second pivot hole 325 of the door panel connecting rod 32 to allow the housing to be connected. The connecting rod 34 and the door panel connecting rod 32 rotate relatively. In addition, the plate 342 has a first protruding portion 345 and a second protruding portion 346 that are parallel to each other. There is a rectangular groove between the first protruding portion 345 and the second protruding portion 346. The rectangular groove As guide groove 347. There is a guide post in the guide groove 347, which serves as a guide rail 348; one end of the guide rail 348 is locked with the first protruding portion 345, and the other end of the guide rail 348 passes through the second protruding portion 346. During implementation, the first straight rod 343, the second straight rod 344 and the guide rail 348 are respectively straight round rods. One end of the straight round rod has a stop head and an adjacent external thread section, so that the external thread section can be aligned with the corresponding The perforated internal thread can form a quick locking effect to facilitate adjustment and assembly.

The co-moving member 35 is a long connecting rod. One end of the co-moving member 35 in the long direction has an axis hole 351. The axis hole 351 has two parallel surfaces for connecting one of the first shaft rods 7 of the two shaft rods. After that, the co-moving member 35 and the first shaft 7 are rotated synchronously; the other end of the co-moving member 35 in the longitudinal direction has a sliding part 352, and the sliding part 352 includes a first protrusion 353 and a second protrusion parallel to each other. 354. The first protrusion 353 and the second protrusion 354 have two coaxial through-holes 355, so that after the guide pillar passes through the two through-holes 355 and the second protrusion 346, the sliding part 352 is limited to the connecting shell. The guide groove 347 of the rod 34 allows the co-moving member 35 and the connecting rod 34 to move stably relative to each other.

The support base 4 is a long plate. One end of the support base 4 has an extended convex plate 41. The extended convex plate 41 overlaps and locks one end of the base 2; the other end of the support base 4 has two opposite fins ( 42, 42'), there is a limiting groove 43 between the two ends of the support base 4 for accommodating the limiting and moving component 5. In this embodiment, the co-moving component 5 is a gear set, including a first gear 51 in adjacent meshing, an intermediate gear set 52 and a second gear 53. The first gear 51 is axially connected to the first shaft. The rod 7 and the second gear 53 are connected to one of the two shafts, the second shaft 71, so that the two co-moving parts (35, 35') can rotate synchronously with the first shaft 7 and the second shaft 71 respectively. , and let the two co-moving parts (35, 35') rotate in opposite directions to open and close. In addition, the first shaft 7 and the second shaft 71 pass through the two fins (42, 42') of the support base 4 in sequence, then pass through a torsion positioning component 6, and are sealed with a first end respectively. The component 61 and a second end seal 62 are locked to the first shaft 7 and the second shaft 71 to fix the compression and twist positioning component 6, thereby allowing the two halves of the relatively bent flexible screen 9 to be flipped to closed or completely During the unfolding process, it can rotate stably and freely stop at a certain angle during rotation.

In summary, this invention not only allows the co-moving parts and the housing connecting rod to move back and forth stably relative to each other through the connection of the guide rails, thereby increasing the smoothness during use, reducing the impact of abnormal noise, and extending the service life of the components. The parts of the first straight rod, the second straight rod and the guide pillar are modularized to form a quick locking effect and facilitate adjustment and assembly. After the appearance of each linkage mechanism is improved and the structure is dispersed, the convenience of assembly can be improved. The door panel connecting rod and the housing connecting rod have a first rotation axis, the housing connecting rod and the rotating member have another rotating axis, at least one cam member and the rotating member have a second rotating axis, and at least one cam member and the door panel The connecting rod has a fixed fulcrum, which can form two fixed force arms, so that the fixed fulcrum is at the intersection of the two rotation circles formed by the first rotation axis and the second rotation axis at each angle of the connecting rod. Move it upward and allow the door panel connecting rod to have a fixed position to support the flexible screen. Furthermore, when the two halves of the flexible screen are flattened and closed, the transitional connection through at least one cam member can provide an avoidance space for the length difference, allowing the door panel connecting rod and the rotating member to smoothly bend at an angle.

Although this invention discloses preferred specific embodiments to achieve the above objectives, they are not intended to limit the structural features of this invention. Any person with ordinary knowledge in the technical field should know that within the technical spirit of this invention, any easily imagined Any changes or modifications are possible and are covered by the patentable scope of this invention.

1: Flexible screen shaft structure

2: Base

21,21’: first arc part

22:Arc block

3,3’: Rotary shaft module

31: Rotating parts

311:First Guidance Department

312:Arc groove

313: Arc-shaped gully

314:First pivot hole

315: Groove

316: First receiving tank

317: Second receiving slot

318:The third pivot hole

319: Elastic positioning parts

310: Curved piece

32: Door panel connecting rod

321,322: long block

323,324: Screw hole

325:Second pivot hole

33:Cam piece

331: First cam member

332: Second cam member

333,334: Pivot hole

335, 336: Headed screw

337,338: The third straight pole

34: Connecting rod with shell

341:Lug

342:Plate

343:First straight shot

344:Second straight bar

345: First protrusion

346:Second protrusion

347:Guide slot

348: Guide rail

35,35’: co-moving parts

351: Shaft hole

352:Sliding part

353: first bump

354: Second bump

355:Perforation

4: Support base

41:convex plate

42,42’: Wings

43:Limit slot

5: Synchronous components

51:First gear

52: Intermediate gear set

53:Second gear

6: Torsion positioning component

61: First end seal

62: Second end seal

7:First shaft

71:Second shaft

9: Soft screen

91,91’:Door panel

92,92’: Chassis

(Figure 1) is a schematic diagram of the three-dimensional appearance of the preferred embodiment of this invention installed between a flexible screen and two casings. (Figure 2) is a schematic diagram of the three-dimensional appearance of the preferred embodiment of this invention. ﹝Figure 3﹞is an exploded view of the preferred embodiment of this invention. (Figure 4) is a top view of the preferred embodiment of this invention when it is unfolded. ﹝Figure 5﹞is the A-A’ cross-sectional view of Figure 4. ﹝Figure 6﹞is the B-B’ cross-sectional view of Figure 4. ﹝Figure 7﹞is a schematic cross-sectional view of the A-A’ section of the preferred embodiment of the present invention when it is half folded. [Figure 8] is a schematic cross-sectional view of the B-B' section of the preferred embodiment of the present invention when it is half folded. (Figure 9) is a schematic diagram of the three-dimensional appearance of the preferred embodiment of this invention when it is half-folded. ﹝Figure 10﹞is a schematic cross-sectional view of the A-A’ section of the preferred embodiment of the present invention when folded and closed. ﹝Figure 11﹞is a schematic cross-sectional view of the B-B' section of the preferred embodiment of the present invention when folded and closed. (Figure 12) is a schematic diagram of the three-dimensional appearance of the preferred embodiment of the present invention when folded and closed.

1: Flexible screen shaft structure

2: Base

3,3’: Rotary shaft module

31: Rotating parts

32: Door panel connecting rod

33:Cam piece

331: First cam member

332: Second cam member

335:Headed screw

34: Connecting rod with shell

343:First straight shot

344:Second straight bar

35: Simultaneous moving parts

4: Support base

5: Synchronous components

6: Torsion positioning component

91,91’:Door panel

Claims (8)

A flexible screen rotating shaft structure, which includes a base and two rotating shaft modules in opposite directions. The base has a first side and a second side spaced side by side. There is an opposite direction between the first side and the second side. Two first arc-shaped parts; one end of the two rotating shaft modules is connected to a moving component and a torsional positioning component through at least one shaft, and the ends of the two rotating shaft modules are respectively pivotally connected to the two first arcs The shaped part is used for the relative rotation opening and closing of the two rotating shaft modules; the rotating shaft module includes: A rotating member has a first guide portion at one end, and the first guide portion is connected to the first arc-shaped portion in a relatively arcuate swing manner. The rotating member has at least one receiving groove in its middle position; A door panel connecting rod, the top end of which is connected to a door panel for upwardly supporting a flexible screen. One end of the door panel connecting rod is pivotally connected to one end of at least one cam member. The at least one cam member is accommodated in the at least one receiving groove. The other end of the cam member is pivotally connected to the rotating member; A connecting rod with a bottom end connected to a casing. One end of the connecting rod is pivotally connected to the other end of the rotating member with a first straight rod; one end of the connecting rod is connected with a second straight rod. The other end of the door panel connecting rod is pivotally connected, and the other end of the housing connecting rod has a guide rail; and One end of the co-moving part is connected to the at least one shaft in a synchronous rotation manner, and the other end of the co-moving part has a sliding part, and the sliding part is connected to the guide rail in a relatively moving manner. The flexible screen rotating shaft structure of claim 1 further includes a support base with a limiting slot for accommodating and limiting the co-moving component; one end of the support base is connected to one end of the base, and the support base is connected to an end of the base. The other end has two wings. The at least one shaft includes a first shaft and a second shaft. The first shaft and the second shaft pass through the two wings of the support base in sequence. The torsional positioning component is respectively locked with the first shaft and the second shaft with a first end seal and a second end seal for fixing and compressing the torsional positioning component. The flexible screen rotating shaft structure of claim 1, wherein the guide rail is a guide post, and the other end of the connecting rod has a first protrusion and a second protrusion that are parallel to each other, and the first protrusion There is a guide groove between the part and the second protruding part, and the guide rail is provided in the guide groove; the sliding part has a first protrusion and a second protrusion that are parallel to each other, and the first protrusion and The second protrusion is coaxially sleeved with the guide rail, so that the sliding part is limited in the guide groove of the housing connecting rod in a relative movement manner. The flexible screen hinge structure of claim 3, wherein one end of the connecting rod has a lug, and the other end of the connecting rod has a plate parallel to the lug; one of the lug and the plate Position the two ends of the first straight rod and the second straight rod respectively on the side; the first straight rod is pivotally connected to a first pivot hole at the other end of the rotating member for the housing connecting rod and the rotating member to face each other Rotate; the second straight rod is pivotally connected to a second pivot hole at the other end of the door panel connecting rod for relative rotation of the housing connecting rod and the door panel connecting rod; the top surface of the plate of the housing connecting rod has the Guide groove. The flexible screen rotating shaft structure of claim 1 further includes an elastic positioning member connected to the bottom of the base, and at least one end of the elastic positioning member has at least one arc-shaped piece for elastically pressing upward against the first Guidance Department. The flexible screen hinge structure of claim 1, wherein the first arc-shaped portion includes two parallel and spaced arc-shaped blocks, the first guide portion is provided with two spaced arc-shaped grooves, and the two arc-shaped The grooves are located on opposite sides of the first guide part to respectively butt the two arc-shaped blocks of the first arc-shaped part. The flexible screen rotating shaft structure of claim 1, wherein the at least one receiving groove of the rotating member has at least a third pivot hole, the other end of the at least one cam member has at least a third straight rod, and the at least one first Three straight rods are pivotally connected to the third pivot hole of the rotating member for relative rotation of the at least one cam member and the rotating member. The flexible screen rotating shaft structure of any one of claims 1 to 7, wherein the at least one receiving groove includes a first receiving groove and a second receiving groove, and the first receiving groove and the second receiving groove are respectively located on the rotating shaft. On both sides of the middle position of the member, the at least one cam member includes a first cam member and a second cam member. The first cam member is accommodated in the first receiving groove, and the second cam member is accommodated in the second in the receiving tank.

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