Connector with variable cavity and locking mechanism used in connector

Abstract

The present invention relates to the technical field of rod connection, and discloses a connecting piece with a variable cavity and a locking mechanism used in the connecting piece, comprising an upper cavity and a lower cavity, wherein a guide piece is installed on the inner wall of the upper cavity, a guide groove is provided on the top of the lower cavity, the guide groove is adapted to the guide piece, a positioning tube is fixedly installed on the bottom of the lower cavity, and also comprises a support piece, wherein the support piece is installed in the lower cavity, a locking device is provided on the support piece, the locking device comprises a locking head and a pressure pad, an open groove is provided on the locking head, the pressure pad is movably plugged into the open groove, and a reset device is provided at the bottom of the locking device; the present invention connects the rod piece by providing an upper cavity and a lower cavity, and locks the rod piece by the locking mechanism through the relative rotation of the upper cavity and the lower cavity, the operation is simple, and the rod piece can be unlocked by only rotating the upper cavity and the lower cavity in the opposite direction, and the connection of the rod piece can be achieved without disassembling and assembling some parts.

Description

Technical Field

[0001] The invention belongs to the technical field of rod connection, and in particular relates to a connecting piece with a variable cavity and a locking mechanism used in the connecting piece. Background Art

[0002] At present, there are various ways to connect the rod bodies of hand tools. In order to facilitate storage and transportation, telescopic or detachable and assembleable rod bodies are becoming more and more popular among consumers. Such tool rod bodies occupy a small area and are easy to assemble and replace. However, among the numerous assembleable tool rod bodies, in order to ensure their stability and use strength, the connection between most of the rod bodies needs to be connected and fixed by additional connecting parts such as bolts. During the assembly process, the user also needs to operate the additional connecting parts such as bolts on the spot. If the user is a female or a person with less strength, this connection method still cannot achieve the purpose of quick installation and easy assembly. During unloading, the operation sequence of loosening the fastening sleeve and loosening the rod body is often confused, which damages the connecting parts, thereby affecting the assembly and use of the tool. Therefore, a connection structure that can realize the assembly of the rod body without additional connecting parts has become a new solution that tool manufacturers have been studying and exploring.

[0003] A Chinese patent with authorization announcement number CN214367090U discloses a displacement rod quick connection structure, which includes a docking female head and a docking male head. The docking female head includes a female head seat, a ferrule nut and a locating pin. One end of the locating pin is connected to the female head seat, and the other end is plugged into the docking male head. The ferrule nut can be rotatably sleeved on the outside of the locating pin and connected to the docking male head. The outer ends of the female head seat and the docking male head are both used for fixed connection with the pipe fitting. A limiting step surface is provided in the middle of the locating pin. The inner wall of one end of the ferrule nut abuts and clamps against the limiting step surface. The docking male head is provided with an external thread, and the ferrule nut is provided with an internal thread. The ferrule nut is threadedly connected to the docking male head. The female head seat is provided with an inserting cavity. The locating pin and the female head seat are plugged and connected through the inserting cavity. The female head seat at the inserting cavity is provided with a locking The hole and the locating pin are provided with a card slot. After the locating pin is connected with the female head seat, the position of the locking hole and the card slot corresponds to each other. The locking piece passes through the locking hole and is fixed in the card slot. The female head seat is provided with a circular boss. The locking hole is provided on the circular boss. The connecting channel is provided with a stop cavity. The stop cavity has at least one plane. The locating pin is provided with a stop column matched with the shape of the stop cavity. The stop column is inserted in the stop cavity. One end of the female head seat and the docking male head are both plug-in columns. The end of the plug-in column is a conical cone. The plug-in column is used for plugging with a hollow pipe. A boss is provided between the pipe connecting section of the male head and the connecting section of the ferrule nut. Anti-slip surfaces are provided on both sides of the ferrule nut, which solves the installation problem of long rod parts on the engineering site. Through the quick-connection structure, the long rod parts can be installed quickly and efficiently, which reduces the difficulty of on-site construction and improves the efficiency of engineering installation.

[0004] However, this technical solution still has at least the following defects: multiple latches are required to fix the various parts, there are many small parts, there is a risk of falling, and it is not easy to be found. At the same time, when the displacement rod quick connection structure is connected to the solid pipe, the male or female connector of the structure needs to be replaced, which is a cumbersome operation. In view of this, the present invention is proposed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a connecting piece with a variable cavity and a locking mechanism applied in the connecting piece. The rod is connected by setting an upper cavity and a lower cavity, and the locking mechanism locks the rod through the relative rotation of the upper cavity and the lower cavity. The operation is simple, and the rod can be unlocked by only rotating the upper cavity and the lower cavity in opposite directions. The connection of the rod can be achieved without disassembling and assembling some parts. The rod is connected by inserting the connecting piece, which can be applied to solid rods or hollow rods without replacing parts.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A connector with a variable cavity comprises an upper cavity and a lower cavity, wherein a guide is installed on the inner wall of the upper cavity, a guide groove is opened on the top of the lower cavity, the guide groove is adapted to the guide, and a positioning tube is fixedly installed on the bottom of the lower cavity.

[0008] The guide groove limits the guide member so that the rotation angle of the upper cavity and the lower cavity is limited to prevent them from rotating too far. The guide member abuts against the two ends of the guide groove to determine whether the upper cavity and the lower cavity have rotated to the right position.

[0009] The outer side of the upper cavity is provided with anti-slip grooves to facilitate twisting of the upper cavity and the lower cavity.

[0010] As a preferred embodiment of the present invention, an installation groove is opened on the side of the lower cavity, and a fastener is installed on the inner wall of the lower cavity. The installation groove is used to install the reset device, wherein the upper connecting frame, the lower connecting frame and the slide plate all pass through the installation groove, and the fastener is used to fix the support member and the lower cavity by screws.

[0011] The locking mechanism includes a support member, which is installed in a lower cavity. A locking device is arranged on the support member, and the locking device includes a locking head and a pressure pad. An open groove is provided on the locking head, and the pressure pad is movably plugged into the open groove. A reset device is arranged at the bottom of the locking device, and the reset device is used to reset the locking device.

[0012] There are four groups of interlocking devices, which are evenly spaced around the support to avoid uneven force caused by single-point contact of the inner tube. At the same time, multi-directional interlocking devices fix the rods, greatly improving the firmness of the connection.

[0013] As a preferred embodiment of the present invention, fixed blocks are fixedly installed on both sides of the lock, and the fixed blocks are movably inserted in the top of the support member. An insertion rod is fixedly installed on the bottom of the lock, and the bottom of the insertion rod movably passes through the bottom of the support member and extends to the outside. A slot is provided on one side of the insertion rod, and the fixed blocks are close to the inner wall of the support member, so that the lock and the pressure pad can be offset toward the rod, and the insertion rod is used to lift up when rising.

[0014] As a preferred embodiment of the present invention, the reset device includes a lower connecting frame, a slide plate is fixedly installed on the top of the lower connecting frame, an upper connecting frame is movably sleeved on the slide plate, the bottom of the upper connecting frame and the top of the lower connecting frame are both embedded and connected with magnets, and the magnets are close to each other on one side and repel each other with the same charge, the repulsive force of the magnets pushes the upper connecting frame to move upward along the slide plate, and the upper connecting frame drives the insertion rod to move upward through the card plate and the card slot.

[0015] As a preferred embodiment of the present invention, a card plate is fixedly installed on one side of the upper connecting frame, and the card plate is adapted to the card slot. A mounting plate is fixedly installed on one side of the lower connecting frame, and one side of the mounting plate is fixedly connected to the top of the skateboard, and the mounting plate is not connected to the upper connecting frame. Both sides of the mounting plate are fixedly connected to the lower cavity, and the mounting plate and the lower cavity are connected by screws. The detachable connection method enables the resetting device to be disassembled, and the embedded connection of the magnet enables it to be replaced when the magnetic force decays, thereby extending the overall service life of the connecting part.

[0016] As a preferred embodiment of the present invention, it also includes an inner tube body, which is fixedly installed inside the upper cavity, and a first plane section is provided at one end of the inner tube body, a slope section is provided at one end of the first plane section, and a second plane section is provided at one end of the slope section. There is a height difference between the first plane section and the second plane section, and the height difference causes the lock head to move when it contacts the first plane section or the second plane section. The slope section is used to connect the first plane section and the second plane section, so that the lock head can move between the first plane section or the second plane section.

[0017] As a preferred embodiment of the present invention, a slot is provided on one side of the lock, an insert block is installed on one side of the pressure pad, the insert block is adapted to the slot, an elastic extrusion component is provided on one side of the pressure pad, the elastic extrusion component is used to squeeze the pressure pad and move the pressure pad relative to the lock, the insert block and the slot are used to link the lock and the pressure pad, so that when the lock moves, the pressure pad can follow the movement.

[0018] As a preferred embodiment of the present invention, the elastic extrusion assembly includes a slope block, a groove is provided on one side of the pressure pad, one end of the slope block is fixedly connected to one end of the groove, a spring is installed on one side of the slope block, one end of the spring is fixedly installed on one side of the inner wall of the groove, a stopper is provided on one side of the slope block, and one side of the stopper is fixedly installed on the inner wall of the lower cavity. During the descending process of the pressure pad, the slope block is driven to descend, the slope block descends and resists the stopper, so that it squeezes the spring itself, and the elastic force of the spring acts on the pressure pad, so that the pressure pad can squeeze the side wall of the rod to fix the rod, and when the slope block moves upward, the slope block and the stopper are staggered, so that the spring is in a relaxed state, and the pressure pad no longer squeezes the rod, and the rod can be taken out.

[0019] As a preferred embodiment of the present invention, a limiting groove is provided on the side of the support member, the limiting groove is adapted to the fastener, the limiting groove is used to position the fastener, and the cross-sectional shape of the limiting groove is an arc shape adapted to the fastener. When installing the support member and the lower cavity, the fastener is aligned with the limiting groove to prevent installation misalignment.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention connects the rod by setting an upper cavity and a lower cavity, and the locking mechanism locks the rod by relative rotation of the upper cavity and the lower cavity. The operation is simple, and the rod can be unlocked by only rotating the upper cavity and the lower cavity in opposite directions, and the connection of the rod can be achieved without disassembling and assembling some parts.

[0022] The rods in the present invention are connected by inserting the connecting piece, and can be applied to solid rods or hollow rods without replacing parts;

[0023] The present invention provides a detachable mounting plate so that the mounting plate can be disassembled, which is convenient for replacement when the magnetic force of the magnet decays, so as to avoid the reset device being unable to work when the magnetic force is insufficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of a connector with a variable cavity;

[0025] Figure 2 It is a schematic diagram of the locking mechanism structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the internal structure of the upper cavity of the present invention;

[0027] Figure 4 It is a structural schematic diagram of the guide member and the guide groove of the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of the reset device of the present invention;

[0029] Figure 6 This is a schematic diagram of the lock structure of the present invention;

[0030] Figure 7 This is a schematic diagram of the lower cavity structure of the present invention;

[0031] Figure 8 It is a structural schematic diagram of the support member of the present invention;

[0032] Fig. 9 This is a schematic diagram of the structure of the lock head and the pressure pad in the separated state of the present invention;

[0033] Fig.10 It is a structural schematic diagram of the slope block of the present invention.

[0034] 10. The axial direction of the present invention is as follows: 100. The upper cavity; 101. The inner tube; 102. The first plane section; 103. The inclined plane section; 104. The second plane section; 105. The guide member; 106. The lower cavity; 107. The guide groove; 108. The lock head; 109. The fixing block; 110. The open groove; 111. The slot; 112. The pressure pad; 113. The plug block; 114. The groove; 115. The slope block; 116. The spring; 117. The stopper; 118. The plug rod; 119. The slot; 120. The support member; 121. The limit groove; 122. The positioning tube; 123. The mounting groove; 124. The mounting plate; 125. The lower connecting frame; 126. The slide plate; 127. The upper connecting frame; 128. The clamping plate; 129. The magnet; 130. The fastener. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention.

[0036] Example 1

[0037] like Figures 1 to 4 As shown, the connector with a variable cavity includes an upper cavity 100 and a lower cavity 106. A guide member 105 is installed on the inner wall of the upper cavity 100. A guide groove 107 is opened on the top of the lower cavity 106. The guide groove 107 is adapted to the guide member 105. A positioning tube 122 is fixedly installed on the bottom of the lower cavity 106.

[0038] The guide groove 107 limits the position of the guide member 105 so that the rotation angle of the upper cavity 100 and the lower cavity 106 is limited to prevent them from rotating too far. The guide member 105 abuts against the two ends of the guide groove 107 to determine whether the upper cavity 100 and the lower cavity 106 are rotated in place.

[0039] The outer side of the upper cavity 100 is provided with anti-slip grooves to facilitate twisting of the upper cavity 100 and the lower cavity 106 .

[0040] like Figure 1 , Figure 2 , Figure 7 As shown, in a specific embodiment, a mounting groove 123 is provided on the side of the lower cavity 106, and a fastener 130 is installed on the inner wall of the lower cavity 106. In this configuration, the mounting groove 123 is used to install the reset device, wherein the upper connecting frame 127, the lower connecting frame 125 and the slide plate 126 all pass through the mounting groove 123, and the fastener 130 is used to fix the support member 120 and the lower cavity 106 by screws.

[0041] Example 2

[0042] like Figure 2 , Figure 4 , Figure 6 As shown, the locking mechanism includes a support member 120, which is installed in the lower cavity 106. A locking device is arranged on the support member 120, and the locking device includes a locking head 108 and a pressure pad 112. An open groove 110 is opened on the locking head 108, and the pressure pad 112 is movably inserted in the open groove 110. A reset device is arranged at the bottom of the locking device, and the reset device drives the insertion rod 118 to rise through the magnetic force of two magnets 129, thereby resetting the locking device.

[0043] Among them, there are four groups of interlocking devices, which are evenly distributed around the support member 120 to avoid uneven force caused by single-point contact of the inner tube body 101. At the same time, the multi-directional interlocking devices fix the rods, greatly improving the firmness of the connection.

[0044] like Figure 2 , Figure 6 , Figure 8 , Fig. 9 As shown, in a specific embodiment, fixed blocks 109 are fixedly installed on both sides of the lock head 108, and the fixed blocks 109 are movably inserted at the top of the support member 120. A plug rod 118 is fixedly installed at the bottom of the lock head 108. The bottom of the plug rod 118 movably passes through the bottom of the support member 120 and extends to the outside, and a slot 119 is opened on one side of the plug rod 118. In this configuration, the fixed blocks 109 are close to the inner wall of the support member 120, so that the lock head 108 and the pressure pad 112 can be offset toward the rod, and the plug rod 118 is used to lift the lock head 108 when rising.

[0045] like Figure 5As shown, further, the reset device includes a lower connecting frame 125, a slide plate 126 is fixedly installed on the top of the lower connecting frame 125, an upper connecting frame 127 is movably sleeved on the slide plate 126, and magnets 129 are embedded and connected to the bottom of the upper connecting frame 127 and the top of the lower connecting frame 125, and the magnets 129 are close to each other and repel each other. In this setting, the repulsive force of the magnet 129 pushes the upper connecting frame 127 to move up along the slide plate 126, and the upper connecting frame 127 drives the insertion rod 118 to move up through the clamping plate 128 and the clamping slot 119.

[0046] like Figure 1 , Figure 2 , Figure 5 , Figure 7 As shown, in a specific embodiment, a card plate 128 is fixedly installed on one side of the upper connecting frame 127, and the card plate 128 is adapted to the card slot 119. A mounting plate 124 is fixedly installed on one side of the lower connecting frame 125. One side of the mounting plate 124 is fixedly connected to the top of the slide plate 126, and the mounting plate 124 is not connected to the upper connecting frame 127. Both sides of the mounting plate 124 are fixedly connected to the lower cavity 106. In this setting, the mounting plate 124 is connected to the lower cavity 106 by screws, and its detachable connection mode enables the reset device to be disassembled. At the same time, the embedded connection of the magnet 129 enables it to be replaced when the magnetic force decays, thereby extending the overall service life of the connection.

[0047] like Figure 3 , Figure 4 As shown, further, the locking mechanism also includes an inner tube body 101, the inner tube body 101 is fixedly installed inside the upper cavity 100, a first plane section 102 is provided at one end of the inner tube body 101, a slope section 103 is provided at one end of the first plane section 102, and a second plane section 104 is provided at one end of the slope section 103. In this setting, there is a height difference between the first plane section 102 and the second plane section 104, and the height difference causes the lock head 108 to move when it contacts the first plane section 102 or the second plane section 104, and the slope section 103 is used to connect the first plane section 102 and the second plane section 104, so that the lock head 108 can move between the first plane section 102 or the second plane section 104.

[0048] Example 3

[0049] like Fig. 9 As shown, further, a slot 111 is provided on one side of the lock head 108, an insert block 113 is installed on one side of the pressure pad 112, the insert block 113 is adapted to the slot 111, and an elastic extrusion component is provided on one side of the pressure pad 112, the elastic extrusion component is used to squeeze the pressure pad 112, and the pressure pad 112 moves relative to the lock head 108. In this configuration, the insert block 113 and the slot 111 are used to link the lock head 108 and the pressure pad 112, so that when the lock head 108 moves, the pressure pad 112 can follow the movement.

[0050] like Figure 6 , Fig.10 As shown, further, the elastic extrusion assembly includes a slope block 115, a groove 114 is provided on one side of the pressure pad 112, one end of the slope block 115 is fixedly connected to one end of the groove 114, a spring 116 is installed on one side of the slope block 115, one end of the spring 116 is fixedly installed on one side of the inner wall of the groove 114, a stopper 117 is provided on one side of the slope block 115, and one side of the stopper 117 is fixedly installed on the inner wall of the lower cavity 106. In this configuration, the slope block 115 is driven to descend during the descent of the pressure pad 112, and the slope block 115 descends and abuts against the stopper 117, so that it squeezes the spring 116, and the elastic force of the spring 116 acts on the pressure pad 112, so that the pressure pad 112 can squeeze the side wall of the rod to fix the rod, and when the slope block 115 moves upward, the slope block 115 and the stopper 117 are staggered, so that the spring 116 is in a relaxed state, and at this time, the pressure pad 112 no longer squeezes the rod, and the rod can be taken out.

[0051] like Figure 7 , Figure 8 As shown, further, a limiting groove 121 is provided on the side of the support member 120, and the limiting groove 121 is adapted to the fastener 130, and the limiting groove 121 is used to position the fastener 130. In this configuration, the cross-sectional shape of the limiting groove 121 is an arc shape adapted to the fastener 130, and when the support member 120 and the lower cavity 106 are installed, the fastener 130 is aligned with the limiting groove 121 to prevent installation misalignment.

[0052] The implementation principle of the connector with a variable cavity and the locking mechanism used in the connector of this embodiment is as follows: when in use, a rod can be fixed on the positioning tube 122 by a screw, one end of the rod to be connected is inserted from the upper cavity 100, and the upper cavity 100 and the lower cavity 106 are screwed to rotate the upper cavity 100 relative to the lower cavity 106. When the upper cavity 100 rotates, it drives the inner tube 101 to rotate, and the inner tube 101 drives the first flat section 102 and the inclined surface 106 at the bottom to rotate. The first section 103 and the second plane section 104 rotate and push against the lock head 108 to drive it to move downward. The lock head 108 moves downward and drives the pressure pad 112 to move downward. The pressure pad 112 moves downward and drives the slope block 115 to move downward. The slope block 115 moves downward and pushes against the stopper 117, so that it squeezes the spring 116. The elastic force of the spring 116 acts on the pressure pad 112, so that the pressure pad 112 can squeeze the side wall of the rod, fix the rod, and connect the two rods.

[0053] When disassembling, the upper cavity 100 is twisted in the opposite direction to rotate relative to the lower cavity 106. At this time, the inner tube 101 rotates in the opposite direction and releases the lock 108. The repulsive force of the magnet 129 pushes the upper connecting frame 127 upward. The upper connecting frame 127 drives the insertion rod 118 upward through the clamping plate 128 and the clamping groove 119. The insertion rod 118 drives the lock 108 upward and drives the slope block 115 upward. The slope block 115 is staggered from the stopper 117, so that the spring 116 is in a relaxed state. At this time, the pressure pad 112 no longer squeezes the rod, and the rod can be taken out.

[0054] In this embodiment, the rod member can be a solid rod or a hollow rod, which has a wider range of uses. In addition, during normal connection and use, all parts are contained inside the upper cavity 100 and the lower cavity 106 to avoid exposure of the parts.

[0055] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A locking mechanism for a connector with a variable cavity, applied to a connector with a variable cavity, the connector comprising an upper cavity (100) and a lower cavity (106), the inner wall of the upper cavity (100) being provided with a guide member (105), the top of the lower cavity (106) being provided with a guide groove (107), the guide groove (107) being adapted to the guide member (105), the bottom of the lower cavity (106) being fixedly provided with a positioning tube (122), the side of the lower cavity (106) being provided with a mounting groove (123), the inner wall of the lower cavity (106) being provided with a fastener (130), characterized in that: The locking mechanism comprises a support member (120), the support member (120) being mounted in the lower cavity (106), a locking device being arranged on the support member (120), the locking device comprising a locking head (108) and a pressure pad (112), an open groove (110) being provided on the locking head (108), the pressure pad (112) being movably plugged into the open groove (110), and a resetting device being arranged at the bottom of the locking device, the resetting device being used to reset the locking device; A slot (111) is provided on one side of the lock head (108); an insert block (113) is installed on one side of the pressure pad (112); the insert block (113) is adapted to fit the slot (111); an elastic extrusion component is provided on one side of the pressure pad (112); the elastic extrusion component is used to squeeze the pressure pad (112) and move the pressure pad (112) relative to the lock head (108); The elastic extrusion assembly comprises a slope block (115), a groove (114) is provided on one side of the pressure pad (112), one end of the slope block (115) is fixedly connected to one end of the groove (114), a spring (116) is installed on one side of the slope block (115), one end of the spring (116) is fixedly installed on one side of the inner wall of the groove (114), a stopper (117) is provided on one side of the slope block (115), and one side of the stopper (117) is fixedly installed on the inner wall of the lower cavity (106); Fixed blocks (109) are fixedly mounted on both sides of the lock head (108), the fixed blocks (109) are movably plugged into the top of the support member (120), an insertion rod (118) is fixedly mounted on the bottom of the lock head (108), the bottom of the insertion rod (118) movably passes through the bottom of the support member (120) and extends to the outside, and a slot (119) is provided on one side of the insertion rod (118); It also comprises an inner tube body (101), the inner tube body (101) being fixedly mounted inside the upper cavity (100), a first plane section (102) being provided at one end of the inner tube body (101), an inclined section (103) being provided at one end of the first plane section (102), and a second plane section (104) being provided at one end of the inclined section (103).

2. The locking mechanism of the connector with a variable cavity according to claim 1, characterized in that: The resetting device comprises a lower connecting frame (125), a slide plate (126) is fixedly mounted on the top of the lower connecting frame (125), an upper connecting frame (127) is movably sleeved on the slide plate (126), magnets (129) are embedded and connected to the bottom of the upper connecting frame (127) and the top of the lower connecting frame (125), and the magnets (129) repel each other when they are close to each other.

3. The locking mechanism of the connector with a variable cavity according to claim 2, characterized in that: A clamping plate (128) is fixedly mounted on one side of the upper connecting frame (127), and the clamping plate (128) is adapted to the clamping slot (119). A mounting plate (124) is fixedly mounted on one side of the lower connecting frame (125), and one side of the mounting plate (124) is fixedly connected to the top of the slide plate (126), and the mounting plate (124) is not connected to the upper connecting frame (127). Both sides of the mounting plate (124) are fixedly connected to the lower cavity (106).

4. The locking mechanism of the connector with a variable cavity according to claim 3, characterized in that: A limiting groove (121) is provided on the side of the support member (120), the limiting groove (121) is adapted to the fastener (130), and the limiting groove (121) is used to position the fastener (130).

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