Contact system and built-in switch

Abstract

The contact system and the built-in switch comprise at least two contact mechanisms and a linkage piece, each contact mechanism comprises a moving contact assembly and a static contact which are matched with each other, each moving contact assembly comprises a contact support and a moving contact connected to the contact support, and the linkage piece is arranged in a linear movement mode. Every two adjacent contact supports are rotationally assembled side by side at intervals in the moving track direction of the linkage piece, a linkage structure is arranged between the linkage piece and each contact support so that linear movement of the linkage piece can drive the contact supports of at least two contact mechanisms to rotate synchronously, and each linkage structure comprises a matching part and a matching groove which are connected in an inserted mode. And a space for the matching part to slide is reserved in the matching groove, the matching groove is arranged on the linkage piece or the contact support, and the matching part is arranged on the contact support or the linkage piece. In the utility model, each contact support is connected with the linkage piece, so that the action consistency of all contact mechanisms is ensured, the internal space is saved, and the overall volume is reduced.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, in particular to a contact system and a built-in switch. Background Art

[0002] The existing prepaid energy meter mainly controls the power consumption of the main line through a built-in relay or an external circuit breaker. Since the current carrying capacity of the built-in relay is low, it is easy to cause failures such as burning or welding, and the external circuit breaker is large in size and short in life. At present, the power consumption of the main line is controlled by configuring a built-in switch in the energy meter.

[0003] In the existing built-in switches, the contact mechanism is driven to open and close by the linear movement of the electromagnetic operating system. When the contact system includes multiple contact mechanisms, two adjacent contact mechanisms are connected by a linkage. However, since the electromagnetic operating system, the moving contact assembly and the static contact are usually arranged in the same direction, the moving direction of the linkage is perpendicular to the setting direction of the multiple contact mechanisms. Such a structure has the following defects: First, when the electromagnetic system is linked with one of the moving contact assemblies, the others are linked with the linkage, and the consistency of their movements is poor. Second, the electromagnetic operating system is linked with all the moving contact assemblies through the linkage. Since the moving trajectories of the electromagnetic operating system, the linkage and the moving contact assembly are all linear motions in the same direction, not only is the moving stroke long and occupies a large space, but also the requirements for the electromagnetic operating system are high. Summary of the invention

[0004] The utility model aims to overcome at least one defect of the prior art and provide a contact system and a built-in switch.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model provides a contact system, including at least two contact mechanisms and a linkage member, the contact mechanism including a movable contact assembly and a stationary contact that cooperate with each other, the movable contact assembly including a contact support and a movable contact connected to the contact support, the linkage member is arranged for linear movement, two adjacent contact supports are assembled for rotation side by side and at intervals along the moving trajectory direction of the linkage member, a linkage structure is provided between the linkage member and each contact support so that the linear movement of the linkage member drives the contact supports of the at least two contact mechanisms to rotate synchronously, the linkage structure includes a mating portion and a mating groove that are plugged into each other, and the mating groove reserves a space for the mating portion to slide, the mating groove is arranged on the linkage member or the contact support, and the mating portion is arranged on the contact support or the linkage member.

[0007] Furthermore, the matching portion is a convex shaft, the matching groove is a strip-shaped through groove, and the outer diameter of the matching portion is less than or equal to the minimum inner diameter of the matching groove.

[0008] Furthermore, the linkage member is in the shape of a strip, and is provided with at least two matching parts arranged side by side and at intervals along the direction of its moving track.

[0009] Furthermore, at least one strip groove serving as a guide groove is provided in the middle of the linkage member, and the guide groove is arranged in a direction parallel to the moving track of the linkage member.

[0010] Furthermore, a slot is provided at one end of the linkage member.

[0011] Furthermore, the contact support is provided with a transmission part, the transmission part and the moving contact are respectively located on two opposite sides of the rotation center of the contact support, and the transmission part is provided with a matching groove.

[0012] Furthermore, the contact support is provided with two transmission parts, and a gap is left between the two transmission parts for the linkage member to pass through, so that the matching parts arranged on the positive and negative sides of the same position of the linkage member are respectively linked and connected with the matching grooves of the two transmission parts.

[0013] The utility model also provides a built-in switch, comprising a shell, wherein an electromagnetic operating system is arranged in the shell, wherein the contact system as described above is also arranged in the shell, and the electromagnetic operating system is linked to a linkage member.

[0014] Preferably, the electromagnetic operating system includes a yoke, a coil assembly and a moving assembly, and the moving assembly is linked to a linkage member, and the yoke and the coil assembly cooperate to drive the moving assembly to move in a straight line, and the moving trajectory of the moving assembly is collinear with the moving trajectory of the linkage member.

[0015] Preferably, the moving assembly is provided with a snap-fitting portion, and the snap-fitting portion is plugged into a slot provided at one end of the linkage member.

[0016] The contact system and built-in switch of the utility model are assembled on the same plane by the contact supports rotating along the moving trajectory direction of the linkage part, and each contact support is connected to the linkage part, thereby ensuring the consistency of the actions of all contact mechanisms. At the same time, the matching part and the matching groove of the linkage structure slide relative to each other on the basis of plug-in matching, thereby converting the linear motion of the linkage part into driving the moving contact assembly to swing, thereby avoiding the situation where the moving trajectories of the linkage part and the moving contact assembly are both straight lines, which is beneficial to saving internal space and reducing the overall volume.

[0017] In addition, the matching groove is a strip-shaped through groove, and the matching part is a convex shaft, which has the advantages of simple structure and stable matching.

[0018] In addition, the linkage member is also provided with a guide groove to help limit its movement trajectory.

[0019] In addition, the linkage part is provided with a card slot, which is convenient for assembly in the built-in switch and linkage connection with the electromagnetic operating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the coordination between the contact system and the electromagnetic operating system in the utility model;

[0021] Figure 2 This is the front view of the contact system and arc operating system in the utility model;

[0022] Figure 3 It is a structural schematic diagram of the electromagnetic operating system in the utility model;

[0023] Figure 4 This is the front view of the electromagnetic operating system in the utility model;

[0024] Figure 5 It is a structural schematic diagram of the built-in switch of the utility model;

[0025] Reference numerals:

[0026] 1-housing, 2-electromagnetic operating system, 21-yoke, 22-coil assembly, 221-coil frame, 23-moving assembly, 232-push rod, 2321-clamping part, 233-linkage part, 2331-guide groove, 234-matching part, 235-clamping groove, 3-contact mechanism, 31-contact support, 312-transmission part, 314-matching groove, 32-moving contact, 33-static contact, 4-arc extinguishing chamber, 52-transformer, 6-connecting terminal. DETAILED DESCRIPTION

[0027] The following embodiments are combined with the accompanying drawings to further illustrate the specific implementation of the contact system and the built-in switch of the utility model. The contact system and the built-in switch of the utility model are not limited to the description of the following embodiments.

[0028] A built-in switch comprises a housing 1, an electromagnetic operating system 2 and at least two contact units, wherein the electromagnetic operating system 2 is arranged in the housing 1, and each contact unit generally comprises a pair of wiring terminals 6 and a contact mechanism 3. Generally, the pair of wiring terminals 6 are arranged outside the housing 1, and the contact mechanism 3 is arranged in the housing 1, and the contact mechanism 3 is connected between the pair of wiring terminals 6 for controlling the on and off of the main line in each contact unit, and the contact mechanism 3 comprises a movable contact assembly and a stationary contact 33 cooperating with each other, and the movable contact assembly comprises a contact support 31 and a movable contact 32, wherein the contact support 31 is linked to the electromagnetic operating system 2, and the movable contact 32 is connected to the contact support 31 for cooperating with the stationary contact 33, and the contact mechanisms 3 of two adjacent contact units are linked to each other, that is, a linkage member 233 is connected between the contact supports 31 of two adjacent contact mechanisms 3, and of course, all contact mechanisms 3 may be connected to the same linkage member 233, so that at least two contact mechanisms 3 and the linkage member 233 cooperate to form a contact system arranged in the housing 1.

[0029] like Figure 1 , 2 As shown, the improvement of the present application lies in that the linkage member 233 is arranged for linear movement, and two adjacent contact supports 31 are assembled on the same plane in a side-by-side and spaced rotational manner along the moving trajectory direction of the linkage member 233, and a linkage structure is provided between the linkage member 233 and each contact support 31 so that the linear movement of the linkage member 233 drives the contact supports 31 of the at least two contact mechanisms 3 to rotate synchronously, and the linkage structure includes a mating portion 234 and a mating groove 314 that are plugged into each other, and the mating groove 314 reserves a space for the mating portion 234 to slide, and the mating groove 314 is arranged on the linkage member 233 or the contact support 31, and the mating portion 234 is arranged on the contact support 31 or the linkage member 233.

[0030] In this way, the contact support 31 is assembled on the same plane by rotation along the moving trajectory of the linkage part 233, and each contact support 31 is connected to the linkage part 233, ensuring the consistency of the movement of all contact mechanisms. At the same time, the mating part 234 and the mating groove 314 of the linkage structure slide relative to each other on the basis of plug-in fit, converting the linear motion of the linkage part 233 into driving the moving contact assembly to swing, avoiding the situation where the moving trajectories of the linkage part 233 and the moving contact assembly are both straight lines, which is beneficial to saving internal space and reducing the overall volume.

[0031] It should be noted that in this embodiment, the linkage part 233 is driven to move linearly by the electromagnetic operating system 2, and the linkage part 233 is connected to the moving iron core 231 of the electromagnetic operating system 2. As other embodiments, the linkage part 233 can also be driven to move linearly by other electric mechanisms, such as a cylinder, a hydraulic mechanism, a motor mechanism, etc., and can also be driven manually by buttons or the like.

[0032] Specifically, the matching portion 234 is a convex shaft, the matching groove 314 is a strip-shaped through groove, and the outer diameter of the matching portion 234 is less than or equal to the minimum inner diameter of the matching groove 314, which has the advantages of simple structure and stable matching.

[0033] Furthermore, the contact support 31 is provided with a transmission part 312, and the transmission part 312 and the moving contact 32 are respectively located on opposite sides of the rotation center of the contact support 31, and the transmission part 312 is provided with a matching groove 314, and the linkage part 233 is correspondingly provided with a matching part 234, so as to avoid mutual interference between the linkage part 233 and the moving contact 32. Of course, the matching part 234 can also be set on the transmission part 312, and the matching groove 314 is correspondingly opened in the linkage part 233.

[0034] Combination Figure 1-5 A specific embodiment of a contact system is provided.

[0035] like Figure 1-4 As shown, the contact system includes a linkage 233 and three contact mechanisms 3, each contact mechanism 3 includes a moving contact assembly and a stationary contact 33 that cooperate with each other, the moving contact assembly includes a rotatably assembled contact support 31, and the moving contact 32 is rotatably connected to the contact support 31, and the three contact supports 31 are arranged side by side and spaced apart on the same plane of the built-in switch along the direction of the moving trajectory of the linkage 233, and the linkage 233 is driven by the electromagnetic operating system 2 of the built-in switch to move in a straight line, or the linkage 233 is a part of the electromagnetic operating system 2, and the moving trajectory of the linkage 233 is parallel to the line between two adjacent contact supports 31.

[0036] A linkage structure is provided between the linkage member 233 and the contact support 31. In the present embodiment, the linkage structure comprises a mating portion 234 provided on the linkage member 233 and a mating groove 314 provided on the contact support 31. The mating portion 234 and the mating groove 314 are slidably plugged into each other, and when the contact support 31 rotates, the mating portion 234 and the mating groove 314 slide relative to each other. Thus, the mating portion 234 and the mating groove 314 with a simple structure are slidably engaged with each other, and the moving contact assembly can be driven by moving a small distance, thereby shortening the moving stroke of the moving assembly 23 and reducing the requirements for the electromagnetic operating system 2.

[0037] like Figure 1-4 As shown, the linkage member 233 synchronously drives the three contact supports 31, and its length is relatively large. The linkage member 233 is a strip plate structure, and the linkage member 233 moves linearly along its length direction, that is, the linkage member 233 is arranged along the first direction, and the linkage member 233 is provided with three mating parts 234 arranged side by side and spaced in the first direction, and each mating part 234 is respectively linked and connected with a mating groove 314 of a contact support 31.

[0038] In this embodiment, the linkage member 233 is plugged into one end of the push rod 232. Preferably, a slot 235 is provided at one end of the linkage member 233, and a snap-fit ​​portion 2321 is provided at one end of the push rod 232. The snap-fit ​​portion 2321 and the slot 235 are plugged into each other, which has the advantages of convenient assembly and stable connection. Of course, when the push rod 232 is not provided, the snap-fit ​​portion 2321 can be directly provided at one end of the moving iron core 231. A strip groove is provided in the middle of the linkage member 233, which can be used as a guide groove 2331. The guide groove 2331 is provided at one end of the push rod 232. 331 is arranged along a moving trajectory parallel to the linkage member 233. In the present embodiment, at least two parallel guide grooves 2331 are arranged on the linkage member 233, and the guide grooves 2331 are through grooves with a certain length, which is also conducive to reducing its overall weight. When the contact system is assembled in the housing 1 of the built-in switch, a guide portion (not shown) can be arranged on the inner side wall of the housing 1, and the guide portion and the guide groove 2331 are slidably matched to limit the moving trajectory of the linkage member 233, thereby ensuring that the movement process thereof will not deviate.

[0039] In addition, in this embodiment, each mating portion 234 protrudes from the front and back sides of the same position of the linkage member 233. When the linkage member 233 passes through the gap between the two transmission portions 312, the two ends of each mating portion 234 are respectively connected to the mating grooves 314 of the two transmission portions 312 on the same contact support 31, thereby improving the driving stability between the linkage member 233 and the contact support 31.

[0040] like Figure 1 , 2 As shown in Figure 5, the structures of the three contact mechanisms 3 are the same. Each contact mechanism 3 includes a moving contact assembly and a stationary contact 33. The moving contact assembly includes a contact support 31, a moving contact 32 and a contact spring. The contact support 31 is rotatably arranged in the housing 1, and the contact support 31 is opposite to one end of the coil assembly 22 along the axial direction of the coil assembly 22. The moving assembly 23 moves along a straight line between the contact support 31 and the coil assembly 22. The moving trajectory of the moving assembly 23 is parallel to the axial direction of the coil assembly 22. The contact support 31 is driven to rotate by the moving assembly 23. At the same time, During the rotation of the support 31, relative sliding occurs between the contact support 31 and the moving component 23; one end of the moving contact 32 is rotatably connected to the contact support 31, and the other end is provided with a moving contact for cooperating with the static contact of the static contact 33. The contact spring is arranged between the contact support 31 and the moving contact 32, and the contact spring provides contact pressure for the moving contact 32. Preferably, the moving contact 32 and the contact spring are coaxially rotatably assembled on the contact support 31. In the present embodiment, the moving contact 32 and the contact spring are assembled on the positioning shaft, and the rotation of the moving contact 32 simultaneously drives the positioning shaft to rotate.

[0041] like Figure 1 , 2As shown in Figure 5, the contact support 31 is provided with a transmission part 312, and the transmission part 312 and the moving contact 32 are respectively located on the opposite sides of the rotation center of the contact support 31, and a matching groove 314 is provided on the transmission part 312. In the figure, the matching groove 314 is a strip-shaped through groove, and a matching part 234 is provided on the moving component 23. The matching part 234 is a convex shaft, and the outer diameter of the convex shaft is less than or equal to the minimum inner diameter of the matching groove 314. When the moving component 23 moves along a straight line, the matching part 234 first links with the matching groove 314 to drive the contact support 31 to rotate. During the rotation of the contact support 31, the matching part 234 slides in the matching groove 314, that is, the space reserved by the strip-shaped through groove in its length direction, thereby completing the driving of the moving contact component. In this way, the matching part 234 with a simple structure is slidably matched with the matching groove 314, and the moving contact component can be driven by moving a small distance, thereby shortening the moving stroke of the moving component 23 and reducing the requirements for the electromagnetic operating system 2.

[0042] Combination Figure 1 , 2 5 provides a structure of a contact support 31 used in this embodiment, the contact support 31 includes a circular shaft-shaped support body, a receiving cavity is provided in the middle of the support body, an opening is provided on the side of the receiving cavity corresponding to the support body, a notch is provided on one edge of the opening, connecting holes penetrating the receiving cavity are provided at both ends of the support body, a positioning shaft is provided in the connecting hole, so that the positioning shaft is penetrated and arranged in the receiving cavity, one end of the moving contact 32 is connected to the positioning shaft and the positioning shaft rotates with the moving contact 32, that is, one end of the moving contact 32 and the contact spring are arranged in the receiving cavity, and a transmission part 312 and a baffle are respectively provided on two opposite sides of the rotation center of the support body, Figure 1 In the figure, the transmission part 312 is a protruding boss structure, and the number of the transmission parts 312 is two, which correspond to the opposite ends of the accommodating cavity respectively. The transmission part 312 is provided with a strip through groove as a matching groove 314, and the penetration direction of the matching groove 314 is parallel to the axial direction of the supporting body. The same matching part 234 arranged on the linkage part 233 passes through the matching grooves 314 on the two transmission parts 312 on the same contact support 31. Of course, the interval left between the two transmissions 312 can also be used for the linkage part 233 to pass through, so that the matching parts 234 arranged on the positive and negative sides of the same position of the linkage part 233 are respectively matched with the matching grooves 314 of the two passing parts 312; the baffle is connected to the edge of the open side with a notch, and the baffle is formed by extending outward from the edge area of ​​the supporting body, and the middle part of the moving contact 32 extends out from the notch and matches with the baffle.

[0043] like Figure 1As shown, the moving contact 32 includes at least two moving contact pieces arranged in parallel, and two adjacent moving contact pieces are linked to ensure the consistency of movement. One end of each moving contact piece is rotatably connected to the positioning shaft, and the other end is provided with a moving contact for cooperating with the static contact of the static contact 33. By providing at least two moving contact pieces, the current carrying capacity is improved; of course, the moving contact 32 can also include only one moving contact piece, or the moving contact 32 and the static contact 33 cooperating with the moving contact 32 can also adopt the existing technology. Of course, when the contact support 31 is provided with only one transmission part 312, it can also be linked with the transmission member 233, but the stability may be slightly poor.

[0044] The contact spring includes two torsion springs, each torsion spring includes a twisted portion, the two twisted portions are assembled on the positioning shaft at intervals, and a connecting space for connecting the moving contact 32 is reserved between the two twisted portions, one end of each twisted portion extends outward to form a first elastic arm abutting the moving contact 32, and the other end of each twisted portion extends outward to form a second elastic arm abutting the contact support 31, and the first elastic arm and the second elastic arm are respectively parallel to the axial direction of the twisted portion. In this embodiment, the first elastic arms of the two torsion springs are connected to form a first abutting portion, and the second elastic arms of the two torsion springs are connected to form a second abutting portion, and the first abutting portion and the second abutting portion both span the connecting space.

[0045] In addition, a sleeve is provided outside the positioning shaft, and at least part of the sleeve is located between the contact spring and the outside of the positioning shaft to prevent the contact spring from locking the positioning shaft, so that the positioning shaft cannot rotate together with the moving contact 32 .

[0046] like Figure 5 As shown, the built-in switch includes a shell 1, in which the contact system of the above embodiment is arranged, and an electromagnetic operating system 2 is also arranged in the shell 1. The electromagnetic operating system 2 can adopt the existing technology. The electromagnetic operating system 2 includes a coil skeleton 221 and a yoke 21. The yoke 21 is surrounded and arranged on the outside of the coil skeleton 221, that is, the yoke 21 can be arranged outside the coil skeleton 221 as a whole in a frame structure. A moving iron core is slidably assembled in the middle of the coil skeleton 221, and a coil is wound on the outside of the middle of the coil skeleton 221. The coil and the yoke 21 cooperate to drive the moving iron core to slide along a straight line. A push rod 232 is connected to the moving iron core. One end of the push rod 232 passes through the yoke 21 and extends out of the coil skeleton 221 for connecting with the linkage 233. Preferably, a clamping portion 2321 is provided at the end of the push rod 232, and the clamping portion 2321 is clamped with the clamping slot 235, which has the advantages of easy assembly and stable connection, so that the moving trajectory of the moving component 23 is collinear with the moving trajectory of the linkage 233.

[0047] The built-in switch also includes an arc extinguishing chamber 4 and at least two pairs of terminals 6. The arc extinguishing chamber 4 is arranged on one side of the contact mechanism 3. Preferably, the number of arc extinguishing chambers 4 corresponds to the number of contact mechanisms 3, that is, all arc extinguishing chambers 4 are arranged side by side in the housing 1, and each contact mechanism 3 is electrically connected between a pair of terminals 6. Preferably, the terminals 6 are arranged outside the housing 1, and each terminal 6 is connected to a conductive plate, which extends into the housing 1 for electrical connection with the contact mechanism 3.

[0048] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate directions or positional relationships based on directions or positional relationships shown in the drawings, or directions or positional relationships that are usually placed when in use, and are only for the convenience of description, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions, and cannot be understood as indicating relative importance.

[0049] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A contact system, comprising at least two contact mechanisms (3) and a linkage member (233), wherein the contact mechanism (3) comprises a movable contact assembly and a stationary contact (33) that cooperate with each other, wherein the movable contact assembly comprises a contact support (31) and a movable contact (32) connected to the contact support (31), characterized in that: The linkage member (233) is arranged to move linearly, and two adjacent contact supports (31) are assembled to rotate side by side and at intervals along the moving track direction of the linkage member (233). A linkage structure is arranged between the linkage member (233) and each contact support (31) so that the linear movement of the linkage member (233) drives the contact supports (31) of the at least two contact mechanisms (3) to rotate synchronously. The linkage structure comprises a mating portion (234) and a mating groove (314) that are plugged into each other, and the mating groove (314) reserves a space for the mating portion (234) to slide. The mating groove (314) is arranged on the linkage member (233) or the contact support (31), and the mating portion (234) is arranged on the contact support (31) or the linkage member (233).

2. The contact system according to claim 1, characterized in that: The matching portion (234) is a convex shaft, the matching groove (314) is a strip-shaped through groove, and the outer diameter of the matching portion (234) is less than or equal to the minimum inner diameter of the matching groove (314).

3. The contact system according to claim 1 or 2, characterized in that: The linkage member (233) is in the shape of a strip, and the linkage member (233) is provided with at least two matching portions (234) arranged side by side and at intervals along the direction of its moving track.

4. The contact system according to claim 3, characterized in that: At least one strip groove serving as a guide groove (2331) is provided in the middle of the linkage member (233), and the guide groove (2331) is arranged in a direction parallel to the moving track of the linkage member (233).

5. The contact system according to claim 3, characterized in that: A clamping slot (235) is provided at one end of the linkage member (233).

6. The contact system according to claim 1 or 2, characterized in that: The contact support (31) is provided with a transmission part (312), the transmission part (312) and the moving contact (32) are respectively located on two opposite sides of the rotation center of the contact support (31), and the transmission part (312) is provided with a matching groove (314).

7. The contact system according to claim 6, characterized in that: The contact support (31) is provided with two transmission parts (312), and a gap is left between the two transmission parts (312) for the linkage member (233) to pass through, so that the matching parts (234) arranged on the positive and negative sides of the same position of the linkage member (233) are respectively connected in a linkage manner with the matching grooves (314) of the two transmission parts (312).

8. A built-in switch, comprising a housing (1), wherein an electromagnetic operating system (2) is arranged in the housing (1), characterized in that: The housing (1) is further provided with a contact system according to any one of claims 1 to 7, and the electromagnetic operating system (2) is linked to a linkage member (233).

9. The built-in switch according to claim 8, characterized in that: The electromagnetic operating system (2) comprises a yoke (21), a coil assembly (22) and a moving assembly (23); the moving assembly (23) is linked to a linkage member (233); the yoke (21) and the coil assembly (22) cooperate to drive the moving assembly (23) to move along a straight line, and the moving trajectory of the moving assembly (23) is collinear with the moving trajectory of the linkage member (233).

10. The built-in switch according to claim 9, characterized in that: The moving assembly (23) is provided with a snap-fitting portion (2321), and the snap-fitting portion (2321) is plugged into a snap-fitting slot (235) provided at one end of the linkage member (233).

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