CN214896145U

CN214896145U - Light shield

Info

Publication number: CN214896145U
Application number: CN202121124548.9U
Authority: CN
Inventors: 唐唯; 张健磊
Original assignee: Shenzhen Leqi Network Technology Co Ltd
Current assignee: Shenzhen Leqi Network Technology Co Ltd
Priority date: 2021-05-24
Filing date: 2021-05-24
Publication date: 2021-11-26
Anticipated expiration: 2031-05-24

Abstract

The utility model discloses a light shield, light shield is including the cover body and flag, the first side of flag with the top side of the cover body sets up relatively and is articulated, just the flag is relative the cover body pivoted axis with the length direction of the top side of the cover body is unanimous. In this application, the first side of flag with the top side of the cover body is articulated in order to adjust the position of flag to realize better effect of hiding the light, easy operation, convenient and fast.

Description

Light shield

Technical Field

The utility model relates to a photographic goods technical field especially relates to a lens hood.

Background

In order to change or improve the photographing effect, a photographing enthusiast usually installs a light shield in front of the lens of a camera or a video camera.

In view of this, the present application is specifically made.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a lens hood, the position of flag, easy operation, convenient and fast are adjusted to the top side hinge of the flag of lens hood and the cover body.

The light shield comprises a shield body and a flag, wherein a first side of the flag is opposite to and hinged with the top side of the shield body, and the flag rotates relative to the shield body along an axis which is consistent with the length direction of the top side of the shield body.

Optionally, the first side of the flag is hinged to the top side of the cover through a rotating assembly, the rotating assembly includes a first connecting piece arranged on the first side of the flag and a second connecting piece arranged on the top side of the cover, and the first connecting piece and the second connecting piece are rotatably connected.

Optionally, the first connecting piece includes a transfer rod, the second connecting piece is provided with a transfer groove connected with the transfer rod, and the transfer rod is rotatably inserted into the transfer groove.

Optionally, the second connecting piece includes a connecting seat, the connecting seat is installed on the top side of the cover body, the adapter groove is arranged on the connecting seat, and a resistance adjusting piece for adjusting the resistance of the adapter rod to the rotation of the adapter groove is arranged on the connecting seat.

Optionally, be equipped with on the lateral wall of switching pole rather than coaxial ring channel, be equipped with on the connecting seat and run through the regulation screw of the inner wall in switching groove, resistance adjusting part including the spiro union in adjust screw first adjusting screw, the inner of first adjusting screw support and hold the diapire of ring channel.

Optionally, a notch is formed in the outer side wall of the transfer groove and penetrates through the inside of the transfer groove, the notch extends from one end of the transfer groove to the other end of the transfer groove, the resistance adjusting piece comprises a second adjusting screw, and one end of the second adjusting screw penetrates through one side wall of the notch and is connected with the other side wall of the notch to adjust the size of the notch.

Optionally, a damping shaft sleeve coaxial with the transfer groove is arranged in the transfer groove, the outer side wall of the damping shaft sleeve is attached to the inner side wall of the transfer groove, and the damping shaft sleeve is sleeved on the transfer rod; the outer side wall of the damping shaft sleeve comprises at least one positioning plane extending from one end to the other end of the damping shaft sleeve, and the area of the inner side wall of the transfer groove, which is opposite to the positioning plane, is a plane.

Optionally, the connecting base is slidably fitted with the top side of the cover in the front-rear direction of the cover.

Optionally, a sliding groove is formed in the top side of the cover body, the connecting seat is slidably arranged in the sliding groove, and limiting portions for preventing the connecting seat from being disengaged from the sliding groove are oppositely extended from two sides of the opening of the sliding groove.

Optionally, at least one of the limiting portions is provided with a plug connector, one surface of the connecting seat facing the limiting portion is correspondingly provided with a plurality of positioning holes for the plug connector to be inserted into, and the positioning holes are distributed at intervals along the sliding direction of the connecting seat.

Optionally, the positioning hole is arranged in an inclined manner, a vertical plane passing through an axis of the positioning hole is parallel to an axis of the switching groove, the plug connector penetrates through the limiting portion and is inserted into the limiting portion, and the plug connector and the positioning hole are arranged coaxially.

The utility model discloses a light shield, light shield are including the cover body and flag, the first side of flag with the top side of the cover body sets up relatively and is articulated, just the flag is relative the cover body pivoted axis with the length direction of the top side of the cover body is unanimous. In this application, the first side of flag with the top side of the cover body is articulated in order to adjust the position of flag to realize better effect of hiding the light, easy operation, convenient and fast.

Drawings

Fig. 1 is a schematic view of the overall structure of a first embodiment of the light shield of the present invention;

fig. 2 is a schematic view of the whole structure of the first embodiment of the light-shielding cover of the present invention at another angle;

fig. 3 is a partially exploded view of a first embodiment of the light shield of the present invention;

fig. 4 is a schematic view of the overall structure of a second embodiment of the light shield of the present invention;

fig. 5 is a schematic view of another angle of the second embodiment of the light-shielding cover of the present invention;

fig. 6 is a partially exploded view of a second embodiment of the light shield of the present invention.

Reference numerals:

a cover body 1; a mounting port 11; a third threaded hole 12;

a flag plate 2; an adapter lever 21; an annular groove 22; a damping bush 23;

a connecting seat 3; a transfer groove 31; the notches 32; positioning holes 33;

a first adjusting screw 41; a second adjusting screw 42;

an external rubbing plate 5; a chute 51; a second threaded hole 52;

and a plug-in unit 6.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention, and all other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

In order to block and absorb unnecessary light during photographing of a camera, a light shield is generally used, and a flag is mounted on the light shield to block the unnecessary light.

The utility model provides a light shield, light shield are including the cover body and flag, and the first side of flag sets up and is articulated relatively with the top side of the cover body, and the flag covers the length direction unanimous of body pivoted axis and the top side of the cover body relatively. In this application, the first side of flag and the top side of the cover body are articulated in order to adjust the position of flag to realize better effect of hiding the light, easy operation, convenient and fast. The method comprises the following specific steps:

referring to fig. 1 and 4, the present invention provides a first embodiment of a light shield, which comprises a cover body 1 and a flag 2, wherein the first side of the flag 2 is hinged to the top side of the cover body 1 via a rotation component, the rotation component comprises a first connecting piece disposed on the first side of the flag 2 and a second connecting piece disposed on the top side of the cover body 1, and the first connecting piece and the second connecting piece are rotatably connected to facilitate operation.

Specifically, the first connecting piece includes the changeover lever 21, is equipped with the switching groove 31 with changeover lever 21 on the second connecting piece, and changeover lever 21 rotates to peg graft in switching groove 31. The second connecting piece comprises a connecting seat 3, the connecting seat 3 is installed on the top side of the cover body 1, the adapter groove 31 is formed in the connecting seat 3, and a resistance adjusting piece used for adjusting the rotating resistance of the adapter rod 21 relative to the adapter groove 31 is arranged on the connecting seat 3. The resistance adjusting piece enables the adapter rod 21 to rotate relative to the connecting seat 3, and the adapter rod is even in stress, slow in adjustment and convenient to position.

Wherein, the bottom wall of the cover body 1 is provided with a mounting port 11, and the mounting port 11 is used for being sleeved on the camera lens; one side of the connecting base 3 is provided with an adapter groove 31, and the adapter rod 21 is rotatably accommodated in the adapter groove 31; the connecting seat 3 shares the bearing capacity of the cover body 1, so that the bearing capacity is uniformly distributed on the cover body 1, and the service life of the cover body 1 is prolonged.

In this embodiment, the cover body 1 may be made of plastic, so that the weight is light and the production is convenient. The cover body 1 includes the last, left, lower, right side wall that connect gradually, and the diapire, and last, left, lower, right side wall, and diapire can be trapezoidal for along the diapire to the 1 cross-sectional area grow gradually of open-ended direction cover body. The cover body 1 may be integrally injection molded, or may be provided separately. The mounting opening 11 may be circular to match the shape of the outer peripheral wall of the camera lens. The utility model discloses in, confirm the upper and lower left and right sides position of the cover body 1 when just to the opening of the cover body 1. The flag 2 can be rectangular, the adapter rod 21 can be cylindrical, and the adapter groove 31 corresponds to a circle matched with the adapter rod 21 in shape; the connecting seat 3 may be a metal member.

As shown in fig. 2 and 3, in order to facilitate the operation of locking or unlocking the adapting rod 21, an annular groove 22 is formed on the outer wall of the adapting rod 21, the annular groove 22 coaxial with the adapting rod 21 is formed on the outer side wall of the adapting rod 21, an adjusting screw hole penetrating through the inner wall of the adapting groove 31 is formed on the connecting seat 3, the resistance adjusting member includes a first adjusting screw 41 screwed in the adjusting screw hole, and the inner end of the first adjusting screw 41 abuts against the bottom wall of the annular groove 22. The first adjusting screw 41 is used for locking or unlocking the adapter rod 21, when the adapter rod is locked, the flag 2 cannot rotate relative to the cover body 1, and when the adapter rod is unlocked, the flag 2 can rotate up and down relative to the cover body 1.

During unlocking, the adapter rod 21 of the flag board 2 can rotate in the adapter groove 31, the installation angle of the flag board 2 is adjusted to assist shooting, and during locking, the adapter rod 21 is locked in the adapter groove 31 and cannot rotate, so that the position of the flag board 2 is fixed, the adjustment is convenient, and the whole structure is compact.

In this embodiment, the axis of the annular groove 22 extends along the length direction of the cover 1, the inner end of the first adjusting screw 41 may be a pressing portion of the first adjusting screw 41, and the pressing portion of the first adjusting screw 41 can penetrate through the groove wall of the transfer groove 31 and press against the bottom wall of the annular groove 22, or the pressing portion releases the bottom wall of the annular groove 22. Specifically. The adapter rod 21 is locked in the adapter groove 31 by the first adjusting screw 41, a first limiting part and a second limiting part are encircled on the outer wall of the adapter rod 21, an annular groove 22 is formed between the first limiting part and the second limiting part, and the first adjusting screw 41 is screwed on the groove wall of the adapter groove 31. The first limiting part and the second limiting part can be convexly arranged in an annular shape and surround the periphery of the adapter rod 21, the bottom wall of the annular groove 22 can be higher than or lower than the outer wall of the adapter rod 21, and when the first adjusting screw 41 is screwed into the groove wall of the adapter groove 31, the pressing part gradually approaches and is pressed against the bottom wall of the annular groove 22, so that the adapter rod 21 is tightly clamped on the pressing part and the groove wall of the adapter groove 31, the adapter rod 21 cannot rotate, and the flag 2 is fixed; when the angle of the flag 2 needs to be adjusted, the first adjusting screw 41 is rotated to gradually unscrew the groove wall of the adapting groove 31, so that the pressing part loosens the bottom wall of the annular groove 22, the flag 2 can be adjusted, and the adapting rod 21 rotates in the adapting groove 31. Of course, the adapter rod 21 can be cylindrical, the cylindrical outer wall is concavely provided with an annular groove, and lubricating oil is coated between the cylindrical outer wall and the inner wall of the adapter groove to reduce friction force.

In order to enhance the integrity of the flag 2, a damping shaft sleeve 23 coaxial with the switching groove 31 is arranged in the switching groove 31, the outer side wall of the damping shaft sleeve 23 is attached to the inner side wall of the switching groove 31, and the damping shaft sleeve 23 is sleeved on the switching rod 21; the outer side wall of the damping shaft sleeve 23 comprises at least one positioning plane extending from one end to the other end, and the area of the inner side wall of the transfer groove 31 facing the positioning plane is a plane.

The damping shaft sleeve 23 may be integrally formed or may be formed by a plurality of gaskets, and the damping shaft sleeve 23 is formed by a plurality of gaskets, and the adapter rod 21 is fixed with a limiting member and sleeved with a plurality of gaskets, the plurality of gaskets are accommodated in the adapter groove 31, the second limiting member is located between the first limiting member and the limiting member, and the plurality of gaskets are sequentially compressed between the limiting member and the second limiting member.

In this embodiment, the in-process of changeover lever 21 internal rotation in switching groove 31, a plurality of gaskets make torsion even, and unblock changeover lever 21 back, flagboard 2 can not turn down at once yet, makes it in suitable position through manually pulling flagboard 2, loosens the first adjusting screw 41 of knob after hand, improves experience effect. The spacers may be resilient spacers having a load bearing capacity therebetween, and the number of resilient spacers may be 4, 5, 6, or more.

In order to prevent the damping bush 23 from rotating during the rotation of the adapter rod 21 in the adapter groove 31, the periphery of the washer is formed with inclined edges, and the inclined edges form a positioning plane. The inner wall of the transfer groove 31 is correspondingly provided with a plane, and the bevel edge of the gasket is abutted on the plane of the inner side wall of the transfer groove 31 to block the rotation of the gasket.

In some embodiments, the damping sleeve 23 may also be provided with a protruding limiting portion, the inner wall of the adapting groove 31 is provided with a concave groove, and the limiting portion of the damping sleeve 23 is received in the concave groove of the inner wall of the adapting groove 31 to prevent the damping sleeve 23 from rotating relative to the inner wall of the adapting groove 31.

In order to prevent the first adjusting screw 41 from being excessively screwed and prevent the compressing portion from excessively compressing the adapter rod 21 to be damaged, the first adjusting screw 41 has a blocking portion, a first threaded hole penetrates through the wall of the adapter groove 31, the first adjusting screw 41 is in threaded connection with the inner wall of the first threaded hole, the blocking portion is located on one side of the first threaded hole, which is far away from the adapter groove 31, and the diameter size of the blocking portion is larger than that of the first threaded hole. The blocking part has the function of pinching and screwing by the hand of a user.

In this embodiment, the first adjusting screw 41 is screwed into the first threaded hole until the blocking portion abuts on the opening of the first threaded hole, and the user can stop rotating the first adjusting screw 41.

As shown in fig. 4 to 6, the present invention provides a second embodiment of a light shielding cover, which is mainly different from the following, a notch 32 is formed on an outer sidewall of the adapting groove 31, the notch 32 is communicated with an inside of the adapting groove 31, the notch 32 is extended from one end of the adapting groove 31 to the other end, the resistance adjusting member includes a second adjusting screw 42, and one end of the second adjusting screw 42 passes through a side wall of the notch 32 and is connected to another side wall of the notch 32 to adjust the size of the notch 32. The adapter groove 31 is opened with a notch 32 along the axial direction, and one end of the second adjusting screw 42 passes through one side wall of the notch 32 to be screwed with the other side wall of the notch 32, so that the two side walls of the notch 32 can be close to or far away from each other.

The second adjusting screw 42 locks the adapter rod 21 in the adapter groove 31, and a notch 32 penetrates through a groove wall of the adapter groove 31 along the length direction, and one end of the second adjusting screw 42 penetrates through one side wall of the notch 32 and is in threaded connection with the other side wall of the notch 32 to lock or unlock the adapter rod 21.

In this embodiment, one end of the connecting base 3 is bent inward to form a switching groove 31, a side wall of the switching groove 31 is made of a metal material, and when the second adjusting screw 42 is rotated forward, the second adjusting screw 42 pushes a side wall of the notch 32 to gradually approach to another side wall of the notch 32, so that the inner side wall of the switching groove 31 gradually approaches to and covers the outer wall of the switching rod 21, and the switching rod 21 is locked in the switching groove 31 and can not rotate, thereby fixing the position of the flag plate 2; when the second adjusting screw 42 is rotated reversely, in the process that the second adjusting screw 42 is gradually screwed out of the other side wall of the slot 32, one side wall of the slot 32 is gradually far away from the other side wall of the slot 32, so that the adapter rod 21 is released, the adapter rod 21 can rotate in the adapter groove 31, and the position of the flag 2 is adjusted.

In order to adjust the flag 2 to a proper position, the connecting seat 3 is slidably fitted with the top side of the cover 1 in the front-rear direction of the cover 1. The top side of the cover body 1 is provided with a sliding groove 51, the connecting seat 3 is slidably arranged in the sliding groove 51, and two sides of a notch of the sliding groove 51 extend oppositely to form a limiting part for preventing the connecting seat 3 from being separated from the notch of the sliding groove 51.

At least one be equipped with plug connector 6 in the spacing portion, connecting seat 3 towards the one side of spacing portion corresponds is equipped with the confession a plurality of locating holes 33 of plug connector 6 male, each locating hole 33 is followed the sliding direction interval distribution of connecting seat 3.

Specifically, in order to make the bearing capacity born by the cover body even, the light shield further comprises an outer rubbing plate 5 and a plug connector 6 which are positioned at the top end of the cover body 1, a sliding groove 51 is formed in the upper surface of the outer rubbing plate 5, the connecting seat 3 is slidably accommodated in the sliding groove 51, and the plug connector 6 locks the connecting seat 3 in the sliding groove 51. Of course, the sliding groove 51 may be directly formed at the top end of the cover body 1, and the groove wall of the sliding groove 51 and the cover body 1 may be integrally formed.

In this embodiment, during unlocking, the connecting seat 3 can slide back and forth along the sliding groove 51 to adjust the position of the flag 2, a protrusion is convexly arranged at the top end of the inner wall of the sliding groove 51, the connecting seat 3 is located between the protrusion and the bottom wall of the sliding groove 51 to prevent the connecting seat 3 from separating from the sliding groove 51, and openings are formed in both sides of the sliding groove 51 in the front-back direction.

Specifically, the positioning hole 33 is obliquely arranged, a vertical plane passing through an axis of the positioning hole 33 is parallel to an axis of the transfer groove 31, the plug connector 6 penetrates through the limiting portion and is inserted into the limiting portion, and the plug connector 6 and the positioning hole 33 are coaxially arranged.

In this embodiment, the minimum distance that the connecting seat 3 slides back and forth each time is the minimum distance between the adjacent positioning holes 33, and the number of the positioning holes 33 may be 3, 4, 5, 6, 7, or more. When the plug connector 6 is screwed into the side wall of the sliding groove 51, the plug-in part is driven to gradually extend into the sliding groove 51, so that the plug-in part is inserted into the positioning hole 33 corresponding to the plug-in part, and the extending direction of the plug-in part is parallel to the extending direction of the positioning hole 33, thereby preventing the connecting seat 3 from moving back and forth. The insertion part can be arranged along the horizontal extending direction or in an inclined way.

Specifically, in order to facilitate screwing the plug-in connector 6, the central axis of the positioning hole 33 is obliquely arranged in a vertical plane, the insertion part extends in a direction parallel to the central axis of the positioning hole 33, and the plug-in connector 6 is screwed with the side wall of the sliding groove 51 to drive the insertion part to be inserted into or separated from the positioning hole 33.

In this embodiment, an included angle between the central axis of the positioning hole 33 and the connecting seat 3 may be 30 °, 45 ° or 60 °, and of course, other angles may also be used, which are not limited herein. Of course, the inserting member 6 is rotatably installed on the side wall of the sliding groove 51, and the inserting portion is screwed with the positioning hole 33.

In some embodiments, the first connecting member and the second connecting member may be rotatably connected by other structures, such as a gear engagement rotation connection, a threaded structure screw connection, a sleeve structure rotation connection, a hook structure rotation connection, and the like.

In other embodiments, the central axes of the positioning holes 33 are perpendicular to the connecting seat 3, the positioning holes 33 penetrate the connecting seat 3 in the vertical direction, and the insertion portion of the insertion piece 6 passes through the positioning holes 33 to be screwed with the bottom wall of the sliding slot 51, so that the insertion piece 6 locks the connecting seat 3 in the sliding slot 51.

In other embodiments, the plug-in unit 6 is installed on the connecting seat 3, the bottom wall of the sliding slot 51 is concavely provided with a plurality of positioning holes 33, the plurality of positioning holes 33 extend along the length direction of the sliding slot 51, and the plug-in part of the plug-in unit 6 penetrates through the connecting seat 3 to be screwed with the positioning holes 33 on the connecting seat 3.

In other embodiments, the adapter rod of the flag is in damping connection with the inner side wall of the adapter groove, the flag is positioned at the position of the flag relative to the cover body through damping acting force, a user can move the other end of the flag up and down at any time to rotate in the up-and-down direction so as to adjust the position of the flag, the flag can be directly loosened after adjustment, and the flag can be directly covered at the front end of the opening of the cover body when not in use.

In other embodiments, the transition slot may be formed in a surface of the top end of the cover, and an outer wall of the transition slot may be integrally formed with the cover.

The utility model discloses in, in order to lock the camera lens, the lens hood still includes locking Assembly, and locking Assembly centers on set up around installing port 11 with locking or unblock camera lens.

For external connection of photographic accessories, such as a magic hand with a threaded interface, a hard disk bracket and the like. The top end of the cover body 1 is also provided with an external rubbing plate 5, and the external rubbing plate 5 is provided with a plurality of second threaded holes 52.

In order to mount the cover body 1 on a photographic accessory such as a double-tube kit, a tripod and the like, the bottom end of the cover body 1 is further provided with an external rubbing port for externally connecting the photographic accessory, and the external rubbing port can be a third threaded hole 12, a cold boot groove and the like. The front end of the housing body 1 may also be constructed with at least one filter mounting groove. The left side and the right side of the cover body 1 can also be provided with a clamping component for clamping the filter.

What just go up be the utility model discloses a part or preferred embodiment, no matter be characters or the drawing can not consequently restrict the utility model discloses the scope of protection, all with the utility model discloses a holistic thought down, utilize the equivalent structure transform that the contents of the description and the drawing do, or direct/indirect application all includes in other relevant technical field the utility model discloses the within range of protection.

Claims

1. A light shield, comprising:

a cover body; and

the first side of the flag plate is opposite to and hinged with the top side of the cover body, and the axis of the flag plate rotating relative to the cover body is consistent with the length direction of the top side of the cover body.

2. The light shield of claim 1, wherein the first side of the flag is hingedly coupled to the top side of the shield body via a pivot assembly, the pivot assembly including a first connector disposed on the first side of the flag and a second connector disposed on the top side of the shield body, the first connector and the second connector being pivotally coupled.

3. The light shield of claim 2, wherein the first connector comprises an adapter rod, the second connector is provided with an adapter groove for the adapter rod, and the adapter rod is rotatably inserted into the adapter groove.

4. The light shield of claim 3, wherein the second connecting member comprises a connecting base, the connecting base is mounted on the top side of the light shield body, the adapter slot is disposed on the connecting base, and a resistance adjusting member is disposed on the connecting base for adjusting the amount of resistance of the adapter rod to rotate relative to the adapter slot.

5. The light shield according to claim 4, wherein an annular groove coaxial with the adapter rod is formed on an outer side wall of the adapter rod, an adjusting screw hole penetrating through an inner wall of the adapter groove is formed on the connecting seat, the resistance adjusting member comprises a first adjusting screw screwed in the adjusting screw hole, and an inner end of the first adjusting screw abuts against a bottom wall of the annular groove.

6. The light shield of claim 4, wherein a slot is formed on an outer side wall of the adapting groove, the slot communicating with the inside of the adapting groove, the slot extends from one end of the adapting groove to the other end of the adapting groove, the resistance adjusting member comprises a second adjusting screw, and one end of the second adjusting screw passes through one side wall of the slot and is connected with the other side wall of the slot to adjust the size of the slot.

7. The light shield according to any one of claims 3 to 6, wherein a damping bushing coaxial with the adapter groove is arranged in the adapter groove, an outer side wall of the damping bushing is attached to an inner side wall of the adapter groove, and the damping bushing is sleeved on the adapter rod; the outer side wall of the damping shaft sleeve comprises at least one positioning plane extending from one end to the other end of the damping shaft sleeve, and the area of the inner side wall of the transfer groove, which is opposite to the positioning plane, is a plane.

8. The light shield according to any one of claims 4 to 6, wherein the connecting base is slidably fitted with the top side of the shield body in the front-rear direction of the shield body.

9. The light shield according to claim 8, wherein the top side of the light shield body is provided with a sliding groove, the connecting seat is slidably disposed in the sliding groove, and two sides of the notch of the sliding groove extend oppositely to form a limiting portion for preventing the connecting seat from being released from the notch of the sliding groove.

10. The light shield of claim 9, wherein at least one of the position-limiting portions is provided with a plug connector, and a plurality of positioning holes for the plug connector to be inserted are correspondingly formed on a surface of the connecting base facing the position-limiting portion, and the positioning holes are spaced along a sliding direction of the connecting base.

11. The light shield of claim 10, wherein the positioning hole is disposed obliquely, and a vertical plane passing through an axis of the positioning hole is parallel to an axis of the switching groove, the plug member is inserted through the limiting portion and is inserted into the limiting portion, and the plug member is disposed coaxially with the positioning hole.