Battery pack

Abstract

A battery core module and a circuit board assembly are arranged in a bottom shell, an upper cover is combined with the bottom shell, the upper cover is provided with a switch base and an insertion block part, two switch openings are formed in the two sides of the switch base, and the insertion block part is provided with a plurality of insertion piece openings right opposite to a metal clamping piece set of the circuit board assembly; two guide grooves are formed in the two sides of the insertion block part, and each guide groove is provided with an insertion block opening. Two switches are arranged in the upper cover, each switch is provided with a switch button and an insertion block, the switch buttons and the insertion blocks penetrate out of the switch openings and the insertion block openings respectively, and springs for pushing the switches to reset are arranged in the upper cover; therefore, when the insertion block part is inserted into the socket of the electric tool, the insertion block is inserted into the groove of the socket, and the insertion piece group of the socket is inserted into the metal clamping piece group to be electrically connected, the insertion block can retract inwards to release the battery pack by pressing the two switch buttons, so that the technical effect that the battery pack is really positioned in the socket or detached from the socket is achieved.

Description

Technical Field

[0001] The utility model relates to a power supply device; in particular to a battery pack that can be detachably installed on a power tool. Background Art

[0002] In existing power tools, a rechargeable battery is disposed inside a handle, and a charging port for charging the battery is disposed at the bottom of the handle, so as to supply the power required for the operation of the power tool by the battery. Some power tools are provided with a socket in order to directly replace the battery with a new one and avoid wasting time waiting for the battery to be charged. A replaceable battery pack is disposed in the socket. By detachably combining different battery packs with the socket of the power tool, the effect of directly replacing a fully charged battery pack without waiting for the battery to be charged can be achieved.

[0003] Although the above power tool is more convenient to use by replacing different battery packs through the socket, however, since the existing battery pack is fixed to the socket of the power tool by a single buckle, the structure of positioning the battery pack by a unilateral buckle is relatively unstable, so that the battery pack cannot be firmly installed on the socket of the power tool, and it is necessary to improve the combination of the two to be more stable. Summary of the Utility Model

[0004] In view of this, the purpose of the present utility model is to provide a battery pack that can be used for a power tool. The battery pack has a plug portion for inserting into the socket of the power tool, and plugs that can be snapped into the grooves on both sides of the socket are provided on both sides of the plug portion. Switch buttons for driving the two plugs to move are provided on both sides of the upper cover of the battery pack, thereby achieving the technical effect of stably fixing the battery pack to the power tool or detaching it from the power tool.

[0005] To achieve the above purpose, the present utility model provides a battery pack, which includes a battery box, a battery core module, and a circuit board assembly. The battery box includes a bottom case, an upper cover, and two switches. A battery chamber is provided inside the bottom case; the upper cover is covered and combined with the bottom case to enclose the battery chamber; a switch seat and an upper cover surface are provided on opposite sides of the upper cover. Two switch ports are provided on opposite sides of the switch seat. An insertion block portion protrudes in the middle of the upper cover surface. A plurality of insertion piece ports are provided on the side of the insertion block portion facing away from the switch seat. Two guiding grooves are provided on both sides of the insertion block portion corresponding to the two switch ports. Each of the two guiding grooves has an insertion block port; a first groove and a second groove are respectively formed inside the upper cover between the switch seat and the insertion block portion. The first groove communicates with the two switch ports and has two spring seats. The second groove communicates with the two insertion block ports and the plurality of insertion piece ports, and the second groove has a first linear guiding portion.

[0006] The two switches are disposed within the upper cover and each has a switch button, a connecting rod, and an insertion block that are sequentially connected. A second linear guiding portion is formed on the connecting rod; each of the switch buttons passes through each of the switch openings, each of the insertion blocks passes through each of the insertion block openings, and each of the second linear guiding portions is slidably disposed in each of the first linear guiding portions; a spring is disposed between each of the spring seats and each of the switch buttons. The battery cell module is disposed in the battery chamber of the battery case. The circuit board assembly has a circuit board disposed on the battery cell module. The circuit board is electrically connected to the battery cell module. A metal clip group is disposed on the circuit board. The metal clip group is located in the second groove and has a plurality of metal clips. The plurality of metal clips face the plurality of insertion openings.

[0007] Preferably, the battery cell module has a battery cell holder. A plurality of battery slots are provided within the battery cell holder; a battery cell is respectively inserted into each of the plurality of battery slots. A first conductive sheet group is electrically connected to one end of each of the plurality of battery cells, and a second conductive sheet group is electrically connected to the other end of each of the plurality of battery cells. The first conductive sheet group and the second conductive sheet group are respectively electrically connected to the circuit board.

[0008] Preferably, a circuit board seat is formed on one side of the battery cell holder facing the upper cover, and the circuit board is fixed to the circuit board seat.

[0009] Preferably, at least one push switch is provided on one side of the circuit board corresponding to the switch seat; a panel is provided on the switch seat. The panel has at least one pressing portion. The at least one pressing portion is connected to a pressing rod. The pressing rod passes through the first groove and extends to abut on the at least one push switch.

[0010] Preferably, at least one light-emitting element is provided on one side of the circuit board corresponding to the switch seat; the panel further has at least one signal display portion. The at least one signal display portion is light-transmissive and is connected to a light guide tube around it. The light guide tube passes through the first groove and its free end is sleeved on the at least one light-emitting element.

[0011] Preferably, the at least one push switch includes a push switch, the at least one light-emitting element includes a plurality of light-emitting elements, and each light-emitting element is an LED bulb; the at least one pressing portion includes a pressing portion. The pressing portion has elasticity and is formed in the middle of the panel; the at least one signal display portion includes a plurality of signal display portions.

[0012] Preferably, at least one anti-fooling bump is formed on the upper cover surface. The at least one anti-fooling bump protrudes from the upper cover surface and is adjacent to one side of the insertion block portion having the plurality of insertion openings.

[0013] Preferably, the at least one fool-proofing protrusion includes two fool-proofing protrusions, and the two fool-proofing protrusions are respectively located on both sides of the plurality of inserting openings.

[0014] Preferably, the insert block portion has at least one fool-proof groove, and the at least one fool-proof groove is located on a side of the insert block portion away from the switch seat and on one side of the plurality of insert openings.

[0015] Preferably, the at least one fool-proof groove includes two fool-proof grooves, and the two fool-proof grooves are respectively located on both sides of the plurality of insert openings.

[0016] The effect of the utility model is that when the user inserts the plug-in block of the battery pack into the socket of an electric tool, the two plug-in blocks on both sides of the plug-in block can be inserted into the two grooves of the socket, and the two symmetrical plug-in blocks can be engaged with the two grooves to stably fix the battery pack to the socket of the electric tool. When the battery pack needs to be removed from the electric tool, the switch buttons on both sides can be pressed with one hand at the same time to drive the two plug-in blocks to retract into the two plug-in block openings, thereby releasing the battery pack. At this time, the battery pack can be smoothly removed from the electric tool, and the operation is very convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional diagram of a first preferred embodiment of the utility model.

[0018] Figure 2 It is a three-dimensional diagram from another angle of the above preferred embodiment of the utility model.

[0019] Figure 3 This is a three-dimensional diagram of the preferred embodiment of the utility model from another angle.

[0020] Figure 4 It is an exploded view of the above preferred embodiment of the utility model.

[0021] Figure 5 This is an exploded view of the preferred embodiment of the utility model with only the upper cover removed.

[0022] Figure 6 It is a front view of the above preferred embodiment of the utility model.

[0023] Figure 7 for Figure 6 Cross-sectional view in the direction of 7-7.

[0024] Figure 8 It is a right side view of the above preferred embodiment of the utility model.

[0025] Figure 9 for Figure 8 Sectional view in the 9-9 direction.

[0026] Figure 10 This is the rear view of the above preferred embodiment of the present utility model.

[0027] Figure 11 It is Figure 10 a sectional view taken along the direction 11-11 of

[0028] Figure 12 This is the top view of the above preferred embodiment of the present utility model.

[0029] Figure 13 It is Figure 12 a sectional view taken along the direction 13-13 of

[0030] Figure 14 This is the top view of a second preferred embodiment of the present utility model.

[0031] Explanation of reference numerals:

[0032] 100, 200: Battery pack

[0033] 10: Battery box

[0034] 12: Bottom case

[0035] 121: Battery chamber

[0036] 14: Upper cover

[0037] 141: Switch seat

[0038] 1411: Switch opening

[0039] 142: Upper cover surface

[0040] 1421: Anti-fooling bump

[0041] 143: Insert block part

[0042] 1431: Insert piece opening

[0043] 1432: Guide groove

[0044] 1433: Insert block opening

[0045] 1434: Anti-fooling groove

[0046] 144: First groove

[0047] 1441: Spring seat

[0048] 145: Second groove

[0049] 1451: First linear guide part

[0050] 1452: Rib

[0051] 16: Switch

[0052] 161: Switch button

[0053] 162: Connecting rod

[0054] 1621: Second linear guiding part

[0055] 1622: Slide block

[0056] 163: Insert block

[0057] 165: Spring

[0058] 18: Panel

[0059] 181: Pressing part

[0060] 182: Pressing rod

[0061] 183: Signal lamp display part

[0062] 184: Light guide tube

[0063] 20: Battery cell module

[0064] 22: Battery cell holder

[0065] 221: Circuit board seat

[0066] 222: Battery slot

[0067] 24: Battery cell

[0068] 26: First conductive sheet group

[0069] 28: Second conductive sheet group

[0070] 30: Circuit board assembly

[0071] 32: Circuit board

[0072] 34: Metal clip group

[0073] 341: Metal clip

[0074] 36: Push switch

[0075] 38: Light emitting element

[0076] L: Installation direction Detailed implementation manners

[0077] To more clearly illustrate the present utility model, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. Please refer to Figures 1 to 5As shown, it is a battery pack 100 of a first preferred embodiment of the present utility model. When in use, the battery pack 100 is inserted into a socket of a power tool along an installation direction L, whereby the battery pack 100 is detachably coupled to the power tool.

[0078] The battery pack 100 includes a battery case 10, a battery cell module 20, and a circuit board assembly 30, wherein:

[0079] The battery case 10 includes a bottom case 12, an upper cover 14, two switches 16, and a panel 18. The bottom case 12 is a rectangular box body with an opening facing the upper cover 14, and a battery chamber 121 is provided inside the bottom case 12. The upper cover 14 is a housing with a peripheral contour the same as that of the bottom case 12, and the upper cover 14 is covered and coupled to the upper cover 14 to enclose the battery chamber 121.

[0080] Please refer to Figure 1 、 Figure 2 and Figures 4 to 7 As shown, the upper cover 14 has a switch seat 141 and an upper cover surface 142 on opposite sides along the opposite direction of the installation direction L. The switch seat 141 protrudes in a direction away from the bottom case 12. The switch seat 141 has two switch openings 1411 on opposite sides perpendicular to the opposite direction of the installation direction L. The upper cover surface 142 is a flat surface, and a plug portion 143 protrudes in a direction away from the bottom case 12 in the middle of the upper cover surface 142. The plug portion 143 is generally a long rectangle. The side of the plug portion 143 away from the switch seat 141 has a plurality of tab openings 1431. The plug portion 143 is perpendicular to the opposite sides of the installation direction L, that is, the two sides of the plug portion 143 corresponding to the two switch openings 1411 have two guiding grooves 1432. The two guiding grooves 1432 respectively have a plug opening 1433 on the side close to the switch seat 141. At least one anti-fooling protrusion 1421 is formed on the upper cover surface 142. The anti-fooling protrusion 1421 protrudes from the upper cover surface 142 and is adjacent to the side of the plug portion 143 having the plurality of tab openings 1431. In one embodiment, the number of anti-fooling protrusions 1421 can also be multiple. For example, there are two anti-fooling protrusions 1421, and the two anti-fooling protrusions 1421 are respectively located on both sides of the plurality of tab openings 1431.

[0081] The upper cover 14 forms a first groove 144 and a second groove 145 on the inner sides of the switch base 141 and the plug portion 143 respectively; the space of the first groove 144 is larger than that of the second groove 145, and the first groove 144 communicates with the second groove 145. The first groove 144 communicates with the two switch openings 1411, and two spring seats 1441 are provided on two opposite sides of the first groove 144 opposite to the two switch openings 1411. The second groove 145 communicates with the plurality of blade openings 1431 and the two plug openings 1433, and the second groove 145 has a first linear guiding portion 1451, and the first linear guiding portion 1451 includes two convex ribs 1452, and the two convex ribs 1452 are formed on the inner wall of the second groove 145 and extend respectively in a direction perpendicular to the installation direction L.

[0082] The two switches 16 are arranged on opposite sides perpendicular to the installation direction L inside the bottom case 12, and the two switches 16 respectively have a switch button 161, a connecting rod 162 and a plug 163 which are sequentially connected in the direction from the switch base 141 to the plug portion 143. As Figure 1 shown, Figures 8 to 9 matching the two convex ribs 1452 of the first linear guiding portion 1451, a second linear guiding portion 1621 is formed on the connecting rod 162, and the second linear guiding portion 1621 includes two sliders 1622, and the two sliders 1622 are slidably combined with the two convex ribs 1452, so that each switch 16 can reciprocate in a direction perpendicular to the installation direction L. Please refer to Figure 1 、 Figure 2 and Figures 4 to 7 shown, the switch buttons 161 of each switch 16 pass through the respective switch openings 1411, and the plugs 163 pass through the respective plug openings 1433; a spring 165 is arranged between each spring seat 1441 and each switch button 161, and each spring 165 provides a restoring force for the switch button 161 of the switch 16 to be pressed inward by an external force, thereby driving the plug 163 to retract into the plug opening 1433 and then making the switch 16 return to its original position again.

[0083] Please refer to Figure 1 、 Figures 4 to 5 and Figures 10 to 11As shown, the panel 18 is disposed on the switch base 141 of the upper cover 14. There is a pressing portion 181 in the middle of the panel 18. The pressing portion 181 has elasticity and can return to its original position after being pressed. The pressing portion 181 is connected to a pressing rod 182, and the pressing rod 182 is inserted into the first groove 144. The panel 18 also has three signal lamp display portions 183. Each of the signal lamp display portions 183 is a light-transmissive plastic sheet body, and a light guide tube 184 is connected around each of the signal lamp display portions 183. The light guide tube 184 is inserted into the first groove 144.

[0084] The battery cell module 20 is disposed in the battery chamber 121 of the battery case 10. The battery cell module 20 has a battery cell holder 22. The battery cell holder 22 is disposed in the battery chamber 121, and a circuit board base 221 is formed on one side of the battery cell holder 22 facing the upper cover 14. The circuit board base 221 is a rectangular frame. There are a plurality of battery slots 222 inside the battery cell holder 22. The plurality of battery slots 222 are respectively cylindrical slots that penetrate both sides of the battery cell holder 22 perpendicular to the installation direction L. The battery cell module 20 has a plurality of battery cells 24, and the plurality of battery cells 24 are respectively inserted into the plurality of battery slots 222. At one end of the plurality of battery cells 24, a first conductive sheet group 26 is electrically connected, and at the other end of the plurality of battery cell holders 22, a second conductive sheet group 28 is electrically connected.

[0085] The circuit board assembly 30 fixedly embeds a circuit board 32 on the circuit board base 221 of the battery cell module 20, thereby disposing the circuit board 32 on the battery cell module 20. The circuit board 32 is electrically connected to the battery cell module 20. Specifically, the first conductive sheet group 26 and the second conductive sheet group 28 are respectively electrically connected to the circuit board 32. As Figure 1 As Figures 12 to 13 shown, in cooperation with the plurality of insertion openings 1431 of the battery case 10, a metal clip group 34 is disposed on the circuit board 32. The metal clip group 34 is located in the second groove 145 and has a plurality of metal clips 341. The plurality of metal clips 341 face the insertion openings 1431. When the battery pack 100 is detachably combined with the power tool, a plurality of inserts of the socket of the power tool are inserted into the plurality of metal clips 341 through the plurality of insertion openings 1431, thereby electrically connecting the battery pack 100 to the power tool, and supplying the power required for the operation of the power tool by the battery cell module 20.

[0086] Please refer to again Figure 1 、 Figures 4 to 5 and Figures 10 to 11As shown, on one side of the circuit board 32 corresponding to the switch base 141, there is a push switch 36 that matches the number of the pressing parts 181. The free end of the pressing rod 182 connected to the pressing part 181 extends and abuts on the push switch 36; in this way, when the user presses the pressing part 181, it will drive the pressing rod 182 to press the push switch 36, starting the circuit or chip on the circuit board 32 to execute a preset function, such as the function of power display. On the side of the circuit board 32 corresponding to the switch base 141, there are three light-emitting elements 38 that match the number of the signal display parts 183. In this preferred embodiment, each of the light-emitting elements 38 is an LED bulb; each light guide tube 184 connected to each of the signal display parts 183 has its free end sleeved on each of the light-emitting elements 38; in this way, when a certain light-emitting element 38 emits light, the light can pass through the light guide tube 184 sleeved on the light-emitting element 38 to make the signal display part 183 emit light outward. For example, when the circuit or chip on the above-mentioned circuit board 32 executes the function of power display, it displays the remaining power of the battery cell module 20 by driving the plurality of light-emitting elements 38 to emit light. When the number of the plurality of light-emitting elements 38 that emit light is more, it means that the remaining power of the power supply is more; when all the light-emitting elements 38 emit light, it means that the power of the battery cell module 20 is full. On the contrary, it means that the power of the battery cell module is insufficient.

[0087] In other preferred embodiments, the panel 18 may not only have one pressing part 181, but may be provided with two or more other numbers of pressing parts 181, and then the push switches 36 that match the positions and numbers of the plurality of pressing parts 181 are arranged on the circuit board 32, and the pressing rods 182 for pressing the respective push switches 36 are connected to the respective pressing parts 181. Similarly, the panel 18 may be provided with only one or a number of signal display parts 183 other than three, and then the light-emitting elements 38 that match the positions and numbers of the or the plurality of signal display parts 183 are arranged on the circuit board 32, and a light guide tube 184 is connected around each of the signal display parts 183, so that the free end of each light guide tube 184 is sleeved on the corresponding light-emitting element 38.

[0088] When the battery pack 100 of the above preferred embodiment of the present invention is in use, please refer to Figures 1 to 2 and Figure 4As shown, the battery box 10 is inserted into a socket of an electric tool along the installation direction L, and the two plug blocks 163 on both sides of the plug block 143 are inserted into the grooves on both sides of the socket for positioning. During the process, the multiple plugs for electrical connection in the socket are inserted into the multiple metal clips 341 through the multiple plug openings 1431, so that the electric tool is electrically connected to the battery pack 100, thereby the battery pack 100 supplies the power required for the operation of the electric tool. When the battery pack 100 needs to be removed from the electric tool, the two switch buttons 161 on both sides of the upper cover 14 can be pressed with one hand to drive the two plug blocks 163 on both sides of the plug block 143 to retract into the two plug openings 1433 to release the battery pack 100. At this time, the battery pack 100 can be removed from the socket of the electric tool.

[0089] In the above preferred embodiment, the battery cell module 20 disposed in the battery chamber 121 is a power source for supplying a voltage of 40V. The foolproof protrusion 1421 disposed in the upper cover 14 and located in front of the plurality of inserting ports 1431 can be used to identify the foolproof purpose of the voltage of the battery cell module 20; that is, with the setting of the foolproof protrusion 1421, a recess having a shape matching the foolproof protrusion 1421 is provided in the socket of the electric tool using a voltage of 40V to accommodate the foolproof protrusion 1421. In this way, the battery pack 100 can be prevented from being inserted into the socket of the electric tool with an inappropriate operating voltage. In other preferred embodiments, the battery cell module 20 of the battery pack 100 can also be set as a battery cell module for supplying other voltages such as 20V or 40V. In this case, the positions of the foolproof protrusions formed on the upper cover surface 142 are different. By changing the position of the foolproof protrusion or the upper cover surface 142 not having the foolproof protrusion, battery packs of different voltages can be distinguished. In addition, the foolproof protrusion 1421 can also be used for foolproof identification of different models of electric tools.

[0090] See also Figure 14 FIG. 2 shows a battery pack 200 according to a second preferred embodiment of the present invention, which has a structure substantially the same as that of the first embodiment, except that, in this embodiment, the inserting block 143 has at least one foolproof groove 1434, and the foolproof groove 1434 is located on the side of the inserting block 143 away from the switch seat 141 and on one side of the plurality of inserting openings 1431. In one embodiment, the number of foolproof grooves 1434 may also be multiple, for example, there are two foolproof grooves 1434, and the two foolproof grooves 1434 are respectively located on both sides of the plurality of inserting openings 1431.

[0091] Therefore, the anti-fooling groove 1434 can also be used for anti-fooling identification of the voltage of the battery cell module 20 and / or for anti-fooling identification of different models of power tools.

[0092] The above are only the preferred and feasible embodiments of the present invention. Any equivalent changes made by applying the description and claims of the present invention should be included within the scope of the patent of the present invention.

Claims

1. A battery pack, characterized in that: include: A battery box, comprising a bottom shell, an upper cover and two switches, wherein the bottom shell has a battery chamber; the upper cover is combined with the bottom shell and closes the battery chamber; the upper cover has a switch seat and an upper cover surface on opposite sides of the upper cover, the switch seat has two switch openings on opposite sides, the middle of the upper cover surface protrudes to form an insertion block part, the insertion block part has a plurality of insertion openings on the side away from the switch seat, the insertion block part has two guide grooves on both sides corresponding to the two switch openings, and the two guide grooves have an insertion block opening respectively; the upper cover forms a first groove and a second groove on the inner side of the switch seat and the insertion block part respectively a second slot, wherein the first slot is communicated with the two switch ports and has two spring seats, the second slot is communicated with the two plug-in ports and the plurality of plug-in ports, and the second slot has a first linear guide; the two switches are arranged in the upper cover and respectively have a switch button, a connecting rod and an inserting block connected in sequence, and a second linear guide is formed on the connecting rod; each of the switch buttons passes through each of the switch ports, and each of the inserting blocks passes through each of the inserting block ports, and each of the second linear guides is slidably arranged on each of the first linear guides; a spring is arranged between each of the spring seats and each of the switch buttons; a battery cell module, the battery cell module being disposed in the battery chamber of the battery box; as well as A circuit board assembly is provided on the battery cell module. The circuit board is electrically connected to the battery cell module. A metal clip group is provided on the circuit board. The metal clip group is located in the second groove and has a plurality of metal clips. The plurality of metal clips are directly opposite to the plurality of inserting openings.

2. The battery pack according to claim 1, characterized in that: The battery cell module has a battery cell frame, and the battery cell frame has multiple battery slots; a battery cell is respectively installed in the multiple battery slots, a first conductive sheet group is electrically connected to one end of the multiple battery cells, and a second conductive sheet group is electrically connected to the other end of the multiple battery cells, and the first conductive sheet group and the second conductive sheet group are respectively electrically connected to the circuit board.

3. The battery pack according to claim 2, characterized in that: A circuit board seat is formed on one side of the battery core frame facing the upper cover, and the circuit board is fixed to the circuit board seat.

4. The battery pack according to claim 1, wherein: The circuit board has at least one push switch on one side corresponding to the switch seat; a panel is arranged on the switch seat, the panel has at least one push portion, the at least one push portion is connected to a pressure rod, the pressure rod is inserted into the first slot and extends onto the at least one push switch.

5. The battery pack according to claim 4, characterized in that: The circuit board has at least one light-emitting element on one side corresponding to the switch seat; the panel also has at least one light signal display portion, which is light-transmissive and connected to a light guide around it. The light guide is inserted into the first groove and the free end is fitted on the at least one light-emitting element.

6. The battery pack according to claim 5, characterized in that: The at least one push switch includes a push switch, the at least one light-emitting element includes a plurality of light-emitting elements, and each light-emitting element is an LED bulb; the at least one pressing portion includes a pressing portion, the pressing portion is elastic and formed in the middle of the panel; the at least one light signal display portion includes a plurality of light signal display portions.

7. The battery pack according to claim 1, characterized in that: At least one fool-proofing protrusion is formed on the upper cover surface, and the at least one fool-proofing protrusion protrudes from the upper cover surface and is adjacent to a side of the inserting block portion having the plurality of inserting openings.

8. The battery pack according to claim 7, characterized in that: The at least one fool-proofing protrusion includes two fool-proofing protrusions, and the two fool-proofing protrusions are respectively located on both sides of the plurality of inserting openings.

9. The battery pack according to claim 1, characterized in that: The insert block part has at least one fool-proof groove, and the at least one fool-proof groove is located on a side of the insert block part away from the switch seat and on one side of the plurality of insert openings.

10. The battery pack according to claim 9, characterized in that: The at least one fool-proof groove includes two fool-proof grooves, and the two fool-proof grooves are respectively located on both sides of the plurality of inserting openings.

Images