Coal collecting device of scraper conveyer at rear part of top coal caving hydraulic support

Abstract

The utility model discloses a top coal caving hydraulic support rear scraper conveyor coal collecting device which comprises a blocking piece, a driving piece and a protection piece, the blocking piece is arranged on the side, close to a hydraulic support, of a rear scraper conveyor, the blocking piece is provided with a first position and a second position, and the blocking piece can rotate between the first position and the second position. An included angle a is formed between the first position and the second position, the value range of the included angle a is 0 < = a < = 90 degrees, one end of the driving part is rotatably connected with the blocking part and used for driving the blocking part to rotate between the first position and the second position, the protection part is arranged around the driving part by a circle, and when the blocking part is located at the first position, the blocking part covers the protection part; when located at the second position, the blocking piece is far away from the protection piece. The top coal caving hydraulic support rear scraper conveyor coal collecting device has the advantages of being flexible in structure, convenient to use and high in working efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mining and transportation machinery, and in particular to a coal collecting device of a scraper conveyor at the rear of a top coal caving hydraulic support. Background Art

[0002] In the top coal caving mining process, top coal caving hydraulic supports are often used for support. A scraper conveyor is laid in front and behind the hydraulic support. When the top coal caving hydraulic support moves forward, the hydraulic support swings the tail beam and retracts the tail beam plug, the coal on the top of the support will fall directly onto the middle trough of the rear scraper conveyor.

[0003] In actual mining work, most of the coal on the top of the support will fall around the rear scraper conveyor. Therefore, in order to reduce the waste of coal, a recovery device is set on the side of the rear scraper conveyor away from the hydraulic support. However, the coal that falls in front of the rear scraper conveyor is rarely recovered, resulting in a waste of resources. Utility Model Content

[0004] The present utility model is based on the discovery and recognition of the following facts and problems by the utility model inventor:

[0005] When coal is spilled, it will not only spill behind the rear scraper conveyor, but also in front of the scraper conveyor. The coal spilled in front of the rear scraper conveyor will prevent the rear scraper conveyor from being pulled forward, causing it to gradually "go uphill" and tilt backward, and be unevenly placed; secondly, it will make it impossible for the rear scraper conveyor to be pulled to the designed relative position with the hydraulic support, causing the released coal to not fall accurately into the middle trough of the rear scraper conveyor, and the accumulation of floating coal will squeeze and damage the pulling mechanism.

[0006] The utility model aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the embodiment of the utility model proposes a coal collecting device for a scraper conveyor at the rear of a top coal caving hydraulic support, which has the advantages of flexible structure, convenient use and high working efficiency.

[0007] The coal collecting device of the scraper conveyor at the rear of the top coal caving hydraulic support of the utility model embodiment comprises:

[0008] A stopper, the stopper is arranged on a side of the rear scraper conveyor close to the hydraulic support, the stopper has a first position and a second position, the stopper can rotate between the first position and the second position, an angle a is formed between the first position and the second position, and the value range of the angle a is: 0≤a≤90°;

[0009] a driving member, one end of which is rotatably connected to the blocking member and is used to drive the blocking member to move between the first position and the second position;

[0010] The protective member is arranged around the driving member. When the blocking member is located at the first position, the blocking member cover is arranged on the protective member. When the blocking member is located at the second position, the blocking member is away from the protective member.

[0011] In the coal collecting device of the rear scraper conveyor of the hydraulic support for top coal caving of the utility model, a driving member drives the baffle to move between a first position and a second position to adjust the baffle so that the coal can fall onto the rear scraper conveyor along the extension direction of the baffle, thereby reducing coal waste and not affecting the movement of the rear scraper conveyor, thereby ensuring that the rear scraper conveyor is placed flat. The rear scraper conveyor can maintain a relative position with the hydraulic support so that the coal can accurately fall into the middle groove of the rear scraper conveyor when it falls, thereby further reducing coal waste and being simple and convenient to operate. When caving coal, the baffle can be adjusted so that the baffle will not block the worker's line of sight when observing the coal caving situation, thereby improving work efficiency. The protective member is used to protect the driving member from being damaged by falling rocks or coal, thereby ensuring the service life of the driving member.

[0012] In some embodiments, in the first position, the top surface of the stopper is substantially flush with the horizontal direction, and in the second position, the top surface of the stopper is substantially flush with the vertical direction.

[0013] In some embodiments, one side of the blocking member is rotatably connected to the scraper conveyor, the other side of the blocking member is rotatable between the first position and the second position, and the other side of the blocking member is bent toward the protective member.

[0014] In some embodiments, one side edge of the blocking member is bent toward the protective member.

[0015] In some embodiments, the distance between the inner wall surface of the protective element and the outer wall surface of the scraper conveyor in the first direction is smaller than the dimension of the blocking element in the first direction, and the first direction is orthogonal to the extension direction of the scraper conveyor.

[0016] In some embodiments, the coal collecting device of the scraper conveyor at the rear of the top coal caving hydraulic support also includes a shovel plate, which is located on the side of the scraper conveyor close to the hydraulic support and extends along the extension direction of the scraper conveyor, and the driving member and the protective member are arranged on the top surface of the shovel plate.

[0017] In some embodiments, the other end of the driving member is rotatably connected to the shovel plate.

[0018] In some embodiments, the guard includes a first connecting plate, a first support rod and a second support rod, the first connecting plate extends in the up-down direction, the lower end of the first connecting plate is connected to the shovel plate, the first support rod and the second support rod are arranged at intervals along the up-down direction on the side of the first connecting plate adjacent to the rear scraper conveyor, there are two first support rods, the two first support rods are arranged at intervals along the second direction, the second direction is orthogonal to the up-down direction, there are two second support rods, the two second support rods are arranged at intervals along the second direction.

[0019] In some embodiments, there are multiple blocking members, which are arranged at intervals along the extension direction of the scraper conveyor, there are multiple driving members, which correspond one-to-one to the multiple blocking members, and there are multiple protective members, which correspond one-to-one to the multiple driving members. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a blocking member of a coal collecting device of a scraper conveyor at the rear of a top coal caving hydraulic support in a first position according to an embodiment of the utility model.

[0021] Figure 2 It is a schematic diagram of a blocking member of a coal collecting device of a scraper conveyor at the rear of a top coal caving hydraulic support in a second position according to an embodiment of the utility model.

[0022] Figure 3 It is a top view of the protective component of the coal collecting device of the scraper conveyor at the rear of the top coal caving hydraulic support according to the embodiment of the utility model.

[0023] Figure 4 It is a front view of the protective component of the coal collecting device of the scraper conveyor at the rear of the top coal caving hydraulic support according to the embodiment of the utility model.

[0024] Figure numerals: 1. stopper; 2. driving member; 3. protective member; 31. first connecting plate; 32. first support rod; 33. second support rod; 41. first position; 42. second position; 5. hinged ear; 6. shovel plate; 7. scraper conveyor. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0026] like Figure 1-4As shown, the coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support of the utility model embodiment comprises a blocking member 1, a driving member 2 and a protective member 3. The blocking member 1 is arranged on the side of the rear scraper conveyor 7 close to the hydraulic support (not shown), and the blocking member 1 has a first position 41 and a second position 42. The blocking member 1 can rotate between the first position 41 and the second position 42. There is an angle a between the first position 41 and the second position 42, and the value range of the angle a is: 0≤a≤90°.

[0027] One end of the driving member 2 (such as Figure 1 The upper end of the driving member 2 shown in the figure is rotatably connected to the blocking member 1, and is used to drive the blocking member 1 to move between the first position 41 and the second position 42. Specifically, the driving member 2 is a jack. The protection member 3 is arranged around the driving member 2. When the blocking member 1 is in the first position 41, the blocking member 1 covers the protection member 3 to protect the driving member 2. When the blocking member 1 is in the second position 42, the blocking member 1 is away from the protection member 3, and the blocking member 1 is arranged in an inclined manner, so that the coal falls on the scraper conveyor 7 along the top surface of the blocking member 1.

[0028] Specifically, when the hydraulic support retracts the plug plate and the tail beam swings down, the blocking member 1 is tilted by adjusting the driving member 2 to receive the coal that has escaped to the front of the rear scraper conveyor 7, so that the coal slides along the blocking member 1 into the middle groove of the rear scraper conveyor 7. When the coal is discharged, the tail beam of the hydraulic support returns to its position, and the blocking member 1 is moved to the second position 42 by adjusting the driving member 2, so that all the coal received by the blocking member 1 can fall into the middle groove of the rear scraper conveyor 7, and finally the blocking member is returned to the first position 41 by the driving member 2.

[0029] In the coal collecting device of the rear scraper conveyor of the hydraulic support for top coal caving of the utility model, the driving member 2 drives the blocking member 1 to move between the first position 41 and the second position 42 to adjust the blocking member 1 so that the coal can fall onto the rear scraper conveyor 7 along the extension direction of the blocking member 1, thereby reducing the waste of coal and not affecting the movement of the rear scraper conveyor 7, thereby ensuring that the rear scraper conveyor 7 is placed flat. The rear scraper conveyor 7 can be kept in a relative position by the hydraulic support so that the coal can accurately fall into the middle groove of the rear scraper conveyor 7 when it falls, thereby further reducing the waste of coal. Moreover, the operation is simple and convenient. When caving coal through the blocking member 1, the blocking member 1 can be adjusted so that the blocking member 1 does not block the worker's line of sight for observing the coal caving situation, thereby improving the work efficiency. The protective member 3 protects the driving member 2 from being damaged by falling rocks or coal and prevents the coal and stones in front and other equipment from squeezing the driving member 2, thereby ensuring the service life of the driving member 2.

[0030] In some embodiments, the angle of the baffle 1 is flexibly adjusted. When in use, it is not easy to interfere with or collide with the tail beam and the plug plate of the hydraulic support. It can also be linked with the tail beam and the plug plate of the hydraulic support to set the best action sequence and coordination angle based on experience to improve work efficiency.

[0031] In some embodiments, in the first position 41, the top surface of the blocking member 1 is substantially flush with the horizontal direction. In the second position 42, the top surface of the blocking member 1 is substantially flush with the vertical direction. Preferably, 30°≤a≤60°, so that the inclination of the blocking member 1 is convenient for the coal to move and slide onto the scraper conveyor 7, and it is not too steep, so that only a small part of the orthographic projection of the blocking member 1 in the vertical direction falls on the protective member 3, so that the falling rocks or coal can easily fall into the protective member 3 and damage the driving member 2, and can also prevent the coal and stones in front, as well as other equipment from squeezing the driving member 2.

[0032] In some embodiments, one side of the blocking member 1 is rotatably connected to the scraper conveyor 7 , and the other side of the blocking member 1 is rotatable between a first position 41 and a second position 42 .

[0033] Specifically, the coal collecting device of the scraper conveyor at the rear of the top coal hydraulic support further includes a hinge ear 5. A hinge ear 5 is provided on one side of the baffle 1 and the upper surface of the trough of the scraper conveyor 7, and the baffle and the scraper conveyor 7 are hinged through the hinge ear 5 to realize rotatable connection.

[0034] Specifically, two hinged ears 5 are provided on the upper surface of the trough side of the scraper conveyor 7, and the two hinged ears 5 are arranged at intervals along the extension direction of the scraper conveyor 7. A hinged ear 5 is provided on one side of the stopper 1. The hinged ear 5 on one side of the stopper 1 is inserted between the two hinged ears 5 on the scraper conveyor 7 and hinged, and the connection method is simple and flexible. Alternatively, a hinged ear 5 is provided on the upper surface of the trough side of the scraper conveyor 7, and two hinged ears 5 are provided on one side of the stopper 1.

[0035] One side of the blocking member 1 is bent toward the direction of the protective member 3, and the other side of the blocking member 1 is also bent toward the direction of the protective member 3. Specifically, both side edges of the blocking member 1 are bent toward the bottom surface of the blocking member 1, which reduces the gap between the blocking member 1 and the protective member 3, making it difficult for falling rocks or coal to fall into the protective member 3 and to get stuck between the side edge of the blocking member 1 and the protective member 3, but to slide along the bending part of the side edge of the blocking member 1, and also enhancing the structural strength of the blocking member 1, making it difficult for falling rocks or coal to damage the side edge of the blocking member 1.

[0036] In some embodiments, the distance between the inner wall surface of the protective element 3 and the outer wall surface of the scraper conveyor 7 in the first direction is smaller than the dimension of the blocking element 1 in the first direction, and the first direction is orthogonal to the extension direction of the scraper conveyor 7 .

[0037] Specifically, the cross-sectional area of ​​the blocking member 1 is greater than the cross-sectional area of ​​the protective member 3 , thereby improving the protection of the protective member 3 by the blocking member 1 , ensuring that falling rocks or coal are not likely to fall into the protective member 3 , thereby improving the safety of the driving member 2 .

[0038] In some embodiments, the scraper conveyor coal collecting device at the rear of the top coal caving hydraulic support further includes a shovel board 6, which is located on the side of the scraper conveyor 7 close to the hydraulic support and extends along the extension direction of the scraper conveyor 7, and the driving member 2 and the protective member 3 are arranged on the top surface of the shovel board 6. Specifically, the shovel board 6 is integrally formed with the lower end of the trough side of the scraper conveyor 7, ensuring the firmness of the installation of the shovel board 6 and the stability of the overall structure.

[0039] In some embodiments, the other end of the driving member 2 (eg Figure 1 The lower end of the driving member 2 shown is rotatably connected to the shovel plate 6.

[0040] Specifically, a hinged ear 5 is provided at the lower end of the driving member 2, and two hinged ears 5 are provided on the upper surface of the shovel plate 6. The driving member 2 and the shovel plate 6 are hinged through the hinged ears 5 to achieve a rotatable connection between the driving member 2 and the shovel plate 6. Alternatively, two hinged ears 5 are provided at the lower end of the driving member 2, and a hinged ear 5 is provided on the upper surface of the shovel plate 6.

[0041] In some embodiments, the guard 3 includes a first connecting plate 31, a first support rod 32, and a second support rod 33. The first connecting plate 31 extends in the up-down direction, and the lower end of the first connecting plate 31 is connected to the shovel plate 6. The first support rod 32 and the second support rod 33 are arranged at intervals and opposite to each other on the side of the first connecting plate adjacent to the rear scraper conveyor 7 in the up-down direction. There are two first support rods 32, and the two first support rods 32 are arranged at intervals in the second direction, and the second direction, the first direction, and the up-down direction are orthogonal to each other. There are two second support rods, and the two second support rods are arranged at intervals in the second direction.

[0042] Specifically, the top view of the protective member 3 is U-shaped, and the driving member 2 is arranged in the space surrounded by the protective member 3. The gap between the first support rod 32 and the second support rod 33 can be used to pass the pipeline connected to the driving member 2, and the gap is also convenient for removing the accumulated coal. The protective member 3 has a simple structure, is easy to manufacture, and saves costs.

[0043] In some embodiments, there are multiple blocking members 1, which are arranged at intervals along the extension direction of the scraper conveyor 7, so that collision between adjacent blocking members 1 can be avoided when the scraper conveyor 7 is bent. There are multiple driving members 2, which correspond to the multiple blocking members 1 one by one, and there are multiple guarding members 3, which correspond to the multiple driving members 2 one by one, so as to improve the coal collecting efficiency of the scraper conveyor coal collecting device at the rear of the top coal caving hydraulic support.

[0044] In addition, it should be noted that:

[0045] Optionally, different specifications of jacks (diameter, thickness, length, working pressure) are all designed to adapt to different specifications of hydraulic supports, different specifications of rear scraper conveyors 7, different working conditions and different "two-machine" matching space dimensions, all of which comply with the design of this patent.

[0046] Optionally, different specifications of the baffle 1 (width, length, thickness, material, etc.) are all designed to accommodate different specifications of hydraulic supports, different specifications of rear scraper conveyors 7, different working conditions and different "two-machine" matching space dimensions, all of which comply with the design of this patent.

[0047] Optionally, the connection method of the jack's inlet and return liquid pipelines, the layout method of the pipelines along the line, and the connection method of the pipelines with the hydraulic support tail beam and the plug plate hydraulic pipelines are different, as long as the linkage effect is achieved, they all comply with the design of this patent.

[0048] Optionally, the connection method of the jack's inlet and return liquid pipelines, the layout method of the pipelines along the line, and the connection method of the pipelines with the hydraulic support tail beam and the plug plate hydraulic pipelines are different, as long as the linkage effect is achieved, they all comply with the design of this patent.

[0049] Optionally, the control method in the device is to change the manual hydraulic control valve into a pilot control, or into an electro-hydraulic control, both of which are improvement schemes of the utility model patent.

[0050] Optionally, the linkage between the jack and the tail beam and the plug plate of the hydraulic support is not connected through hydraulic pipelines, but the electro-hydraulic controller of the device is connected to the controller of the tail beam and the plug plate through a cable, or is connected to the controller of the tail beam and the plug plate through wireless communication, or the tail beam and the plug plate and the device are connected to the remote control through wireless communication and controlled by the same button on the remote control, or are all controlled in linkage by a program in the upper computer. As long as the linkage effect is achieved, it complies with the design of this patent and is an improvement scheme of the utility model patent.

[0051] Optionally, the connection method between the jack and the stopper 1, in addition to the pin-articulated type, can be other such as the snap-on type, and different pin fixing methods, such as dovetail snap-on type, U-shaped snap-on type, cotter pin, etc., as long as the jack and the stopper 1 have rotational freedom, they are in line with the design of this patent.

[0052] Optionally, the connection methods between the jack and the shovel plate 6 of the scraper conveyor 7 are different, except for the pin-articulated type, other methods such as column socket type, snap-on type, and different pin fixing methods such as dovetail clip type, U-shaped clip type, cotter pin, etc., as long as the jack and the coal shovel plate have rotational freedom, they are in line with the design of this patent.

[0053] Optionally, the baffle 1 adopts an edge bending structure or a straight plate or other shapes, or the baffle 1 adopts other embossed horizontal lines, diagonal lines, corrugated lines or is coated with other materials, all of which are improved structures of the present utility model.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships described in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0056] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0058] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0059] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are illustrative and cannot be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A coal collecting device for the rear scraper conveyor of a top coal caving hydraulic support, characterized in that: include: A blocking member (1), the blocking member (1) being arranged on a side of the rear scraper conveyor (7) close to the hydraulic support, the blocking member (1) having a first position (41) and a second position (42), the blocking member (1) being rotatable between the first position (41) and the second position (42), an angle a being provided between the first position (41) and the second position (42), the value range of the angle a being 0≤a≤90°; a driving member (2), one end of which is rotatably connected to the blocking member (1) and is used to drive the blocking member (1) to move between the first position (41) and the second position (42); A protective member (3), wherein the protective member (3) is arranged around the driving member (2); when the blocking member (1) is located at the first position (41), the blocking member (1) covers the protective member (3); and when the blocking member (1) is located at the second position (42), the blocking member (1) is away from the protective member (3).

2. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 1 is characterized in that: In the first position (41), the top surface of the blocking member (1) is substantially flush with the horizontal direction, and in the second position (42), the top surface of the blocking member (1) is substantially flush with the vertical direction.

3. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 1 is characterized in that: One side of the baffle (1) is rotatably connected to the scraper conveyor (7), and the other side of the baffle (1) is rotatable between the first position (41) and the second position (42), and the other side of the baffle (1) is bent toward the protective member (3).

4. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 3 is characterized in that: One side edge of the blocking member (1) is bent towards the protective member (3).

5. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 4 is characterized in that: The distance between the inner wall surface of the protective element (3) and the outer wall surface of the scraper conveyor (7) in the first direction is smaller than the dimension of the blocking element (1) in the first direction, and the first direction is orthogonal to the extension direction of the scraper conveyor (7).

6. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 1 is characterized in that: It also includes a shovel plate (6), which is located on a side of the scraper conveyor (7) close to the hydraulic support and extends along the extension direction of the scraper conveyor (7), and the driving member (2) and the protective member (3) are arranged on the top surface of the shovel plate (6).

7. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 6 is characterized in that: The other end of the driving member (2) is rotatably connected to the shovel plate (6).

8. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 6, characterized in that: The protective member (3) comprises a first connecting plate (31), a first support rod (32) and a second support rod (33), wherein the first connecting plate (31) extends in the up-down direction, the lower end of the first connecting plate (31) is connected to the shovel plate (6), the first support rod (32) and the second support rod (33) are arranged at intervals along the up-down direction on the side of the first connecting plate (31) adjacent to the rear scraper conveyor (7), there are two first support rods (32), the two first support rods (32) are arranged at intervals along the second direction, the second direction is orthogonal to the up-down direction, there are two second support rods (33), the two second support rods (33) are arranged at intervals along the second direction.

9. The coal collecting device of the rear scraper conveyor of the top coal caving hydraulic support according to claim 1, characterized in that: There are a plurality of blocking members (1), and the plurality of blocking members (1) are arranged at intervals along the extension direction of the scraper conveyor (7); there are a plurality of driving members (2), and the plurality of driving members (2) correspond one-to-one to the plurality of blocking members (1); there are a plurality of protective members (3), and the plurality of protective members (3) correspond one-to-one to the plurality of driving members (2).

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