CN219822920U - Glass cover plate transmission mechanism - Google Patents

Abstract

The utility model provides a glass cover plate transmission mechanism, which belongs to the technical field of conveying mechanisms, and comprises: the frame, the translation assembly and the lifting assembly are connected; the translation assembly comprises a cover plate placing station, and the cover plate placing station is parallel to the horizontal plane; the lifting component is arranged below the translation component and is connected with the translation component through a connecting frame. According to the scheme provided by the utility model, long-span movement of the glass cover plate can be realized, compared with a mode of pushing by using an air cylinder alone in the prior art, the long-span transmission can be effectively ensured by the structure of the air cylinder and the movable cam, the whole plane of the glass cover plate always maintains the lifting and the translation of the same horizontal plane, and the damage of the glass cover plate caused by inclined falling is effectively avoided; the transmission mechanism is simple in structure, low in cost, stable in operation and high in reliability.

Description

Glass cover plate transmission mechanism

Technical Field

The utility model relates to the technical field of conveying mechanisms, in particular to a glass cover plate conveying mechanism.

Background

With the development of touch screen technology, current electronic devices such as smart phones and tablet computers generally adopt a touch screen as a display screen. In order to prevent the touch screen from being damaged due to friction of hard objects, a glass cover plate is universally arranged on the touch screen, the glass cover plate plays a role in protecting the touch screen, on the one hand, different colors, patterns and marks can be printed on the other hand, and the effect of decorating and beautifying products is achieved, so that the appearance quality of the glass cover plate directly influences the appearance and the usability of the electronic product.

The glass cover plate is in a rectangular plate shape, and the shape of the glass cover plate of different products is different mainly from the two long sides and the two short sides of the glass cover plate. In the process of processing and producing the glass cover plate, glass raw materials can be produced into the glass cover plate meeting expected requirements after a plurality of working procedures such as cutting, computer digital control precision machining, light sweeping, flat grinding, tempering, screen printing inspection and the like. In order to realize automatic processing, before each procedure processing, the glass cover plate is transported to a processing station through a transmission mechanism, but during transmission, the stations of different procedures may have high and low fall, and the glass cover plate needs to be lifted and horizontally transported to complete butt joint. Because the glass cover plate is of a planar structure and has fragile characteristics, the glass cover plate needs to be ensured not to incline when being lifted and translated for transportation.

At present, a power cylinder is commonly used for lifting and translating a glass cover plate, the lower end of the glass cover plate is generally provided with the power cylinder, the glass cover plate is pushed by the power cylinder, and accordingly the whole glass cover plate is driven to lift and translate, in the process, if the cylinder is arranged in the middle of the glass cover plate, in the transmission process of the glass cover plate, the two ends of the glass cover plate cannot be ensured to be positioned on the same horizontal plane, the glass cover plate can be inclined, the risk of falling and damaging exists, if the cylinder is arranged at the two ends of the glass cover plate, the occupied space of the cylinders is relatively large, the power of the cylinders cannot be ensured to be output consistently, and the risk of falling obliquely exists.

Therefore, the design of the glass cover plate conveying mechanism is urgently needed, when the glass cover plate is conveyed, the whole plane of the glass cover plate can be guaranteed to be positioned on the same horizontal plane, damage caused by inclined falling of the glass cover plate is effectively avoided, and the glass cover plate conveying mechanism is simple in structure and good in stability.

Disclosure of Invention

In order to overcome the problems in the related art, the utility model provides the glass cover plate conveying mechanism, which can ensure that the whole plane of the glass cover plate is positioned on the same horizontal plane when the glass cover plate is conveyed, effectively avoids the damage of the glass cover plate caused by inclined falling, and has the advantages of simple structure, low cost, stable operation and high reliability.

One of the objects of the present utility model is to provide a glass cover plate transport mechanism comprising: the frame, the translation assembly and the lifting assembly are connected; the translation assembly comprises a cover plate placing station, and the cover plate placing station is parallel to the horizontal plane; the lifting component is arranged below the translation component and is connected with the translation component through a connecting frame.

In a preferred technical scheme of the utility model, the lifting assembly comprises a driving part and a moving cam; the driving part is connected with the movable cam and used for driving the movable cam to move; the movable cam is connected with the connecting frame.

In the preferred technical scheme of the utility model, the driving part comprises a driving cylinder, a linear sliding rail and a sliding rail connecting plate; the movable push plate of the driving cylinder is connected with the slide rail connecting plate, and the pushing direction of the movable push plate faces the extending direction of the linear slide rail; the slide rail connecting plate is connected with the sliding block of the linear slide rail.

In the preferred technical scheme of the utility model, the movable cam comprises a lifting cam block and a movable roller; the lifting cam block is fixed on the slide rail connecting plate; the movable roller is connected with the connecting frame and is abutted with the upper surface of the lifting cam block.

In a preferred technical scheme of the utility model, the translation assembly comprises a driving motor and a cover plate conveyor belt; the driving motor is arranged on the connecting frame and used for driving the cover plate conveyor belt to run; the cover plate conveyor belt is arranged above the connecting frame, and the conveying direction of the cover plate conveyor belt is consistent with the extending direction of the linear sliding rail.

In the preferred technical scheme of the utility model, the lifting assembly further comprises a lifting clamping plate and a lifting guide shaft; the movable roller is fixed on the lifting clamping plate through a bearing seat screw; the lower end of the lifting guide shaft is connected with the lifting clamping plate, and the upper end of the lifting guide shaft is connected with the connecting frame.

In the preferred technical scheme of the utility model, the utility model also comprises a fixed base and a tension spring; the linear sliding rail is fixed on the fixed base; the upper end of the tension spring is connected with the lifting clamp plate, and the lower end of the tension spring is connected with the fixed base.

In the preferred technical scheme of the utility model, the utility model also comprises a support column; the support column comprises a first support column and a second support column; the two ends of the first support column are respectively connected with the tension spring and the lifting clamp plate; and two ends of the second support column are respectively connected with the tension spring and the fixed base.

In a preferred technical scheme of the utility model, the translation assembly further comprises a rotating shaft and a driving wheel; the driving wheel comprises a driving wheel and a driven wheel; the rotating shaft is respectively connected with the driving motor and the driving wheel; the driving wheel is connected with the driven wheel through the cover plate conveyor belt.

In the preferred technical scheme of the utility model, the lifting cam block is provided with a through hole; the sliding rail connecting plate is provided with a threaded hole; and the lifting cam block is fixed on the slide rail connecting plate through the through hole by a screw matched with the threaded hole.

The beneficial effects of the utility model are as follows:

(1) The utility model provides a glass cover plate transmission mechanism which comprises a connecting frame, a translation assembly and a lifting assembly, wherein the translation assembly is arranged above the connecting frame, and the lifting assembly is arranged below the connecting frame; when the glass cover plate is required to be transmitted so as to finish the butt joint of transmission lines with different heights, the lifting transmission of the connecting rack and the translation assembly is realized through the lifting assembly, the translation assembly realizes the translation transmission of the glass cover plate, and particularly, the long-span transmission of the glass cover plate is realized through the arrangement of the driving cylinder and the moving cam; the transmission mechanism is simple in structure, low in cost, stable in operation and high in reliability.

(2) According to the utility model, by arranging the tension spring, when the lifting assembly lifts or descends the connecting frame and the translation assembly, the connecting frame and the translation assembly can be stably lifted and descended through the buffer function by the reaction force formed by the extension or contraction of the tension spring.

Drawings

FIG. 1 is a schematic view of a glass cover plate conveying mechanism provided by the utility model;

FIG. 2 is a schematic view of another construction of the glass cover plate transport mechanism provided by the present utility model;

fig. 3 is a schematic cross-sectional view of a glass cover plate conveying mechanism provided by the utility model.

Reference numerals:

1. the connecting frame; 11. a U-shaped plate; 111. a bottom plate; 112. a side plate; 113. a strip-shaped chute; 12. a long rod; 21. a driving section; 211. the cylinder, 212 and the linear slide rail are driven; 213. a slide rail connecting plate; 22. moving the cam; 221. lifting the cam block; 222. moving the roller; 23. lifting splints; 24. a lifting guide shaft; 31. a driving motor; 32. a cover plate conveyor belt; 33. a rotating shaft; 34. a driving wheel; 35. driven wheel; 351. a first driven wheel; 352. a second driven wheel; 4. a fixed base; 5. a tension spring; 6. a support column; 61. a first support column; 62. a second support; 7. a glass cover plate.

Detailed Description

Preferred embodiments of the present utility model will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present utility model are shown in the drawings, it should be understood that the present utility model may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the utility model to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the utility model. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

At present, a power cylinder is commonly used for conveying a glass cover plate, and is generally arranged at the lower end of the glass cover plate, the glass cover plate is pushed by the power cylinder, so that the whole glass cover plate is driven to be conveyed, and in the process, the glass cover plate can be inclined due to the fact that two ends of the glass cover plate cannot be ensured to be positioned on the same horizontal plane, and the risk of falling damage exists.

In view of the above problems, the embodiment of the utility model provides a glass cover plate conveying mechanism, which can ensure that the whole plane of the glass cover plate is positioned on the same horizontal plane when the glass cover plate is conveyed, and effectively avoid damage to the glass cover plate caused by inclined falling.

The following describes the technical scheme of the embodiment of the present utility model in detail with reference to the accompanying drawings.

Examples

As shown in fig. 1 to 3, the glass cover plate conveying mechanism provided by the present utility model includes: the frame 1, the translation component and the lifting component are connected; the translation assembly comprises a cover plate placing station, wherein the cover plate placing station is parallel to the horizontal plane, so that the glass cover plate 7 can be horizontally placed on the cover plate placing station; the lifting component is arranged below the translation component and connected with the translation component through the connecting frame 1 and used for driving the whole connecting frame 1 to perform lifting motion with the translation component.

Specifically, the connection rack 1 comprises a U-shaped plate 11 and a long rod 12, and the U-shaped plate 11 and the long rod 12 are integrally formed; the U-shaped plate 11 comprises a bottom plate 111 and side plates 112, the number of the U-shaped plates 11 is 2, the U-shaped plates are symmetrically arranged, the two long rods 12 are arranged on the side plates 112 in parallel, and through the arrangement of the structure, the stability in the transmission process is improved under the condition of effectively reducing the weight.

The lifting assembly comprises a driving part 21 and a moving cam 22; the driving part 21 is connected with the moving cam 22 and is used for driving the moving cam 22 to move; the movable cam 22 is connected to the connection frame 1.

Specifically, the driving part 21 includes a driving cylinder 211, a linear rail 212, and a rail connecting plate 213; the movable push plate of the driving cylinder 211 is connected with the slide rail connecting plate 213, and the pushing direction of the movable push plate faces the extending direction of the linear slide rail 212, and the slide rail connecting plate 213 is connected with the slider of the linear slide rail 212. More specifically, the driving cylinder 211 is disposed on one side of the linear sliding rail 212, the linear sliding rail 212 includes a linear rail and a slider, the slider is movably disposed on the linear rail, the bottom surface of the sliding rail connecting plate 213 is connected to the slider, and one end of the sliding rail connecting plate 213 is connected to a movable push rod of the driving cylinder 211; the driving cylinder 211 drives the slide rail connecting plate 213 to reciprocate linearly on the linear slide rail 212.

The moving cam 22 includes a lifting cam block 221 and a moving roller 222; the lifting cam block 221 is fixed on the slide rail connecting plate 213, and the upper surfaces of the lifting cam block 221 are not on the same horizontal plane; specifically, the lifting cam block 221 is provided with a through hole; the sliding rail connecting plate 213 is provided with a threaded hole; the lifting cam block 221 is fixed on the slide connection plate 213 through the through hole by a screw matched with the threaded hole. The movable roller 222 is connected with the connection rack 1 and is abutted against the upper surface of the lifting cam block 221, so that when the lifting cam block 221 is driven by the slide rail connection plate 213 to do horizontal linear reciprocating motion, the horizontal linear reciprocating motion is converted into lifting linear motion in the vertical direction through the movement of the movable roller 222 on the lifting projection, and the lifting transmission of the glass cover plate 7 is completed, so that the butt joint of glass cover plate transmission lines with different heights is facilitated.

The lifting assembly further comprises a lifting clamping plate 23 and a lifting guide shaft 24; the movable roller 222 is fixed on the lifting clamp plate 23 through a bearing seat screw; the lower end of the lifting guide shaft 24 is connected with the lifting clamping plate 23, and the upper end is connected with the connecting frame 1. Specifically, the extending direction of the lifting guide shaft 24 is perpendicular to the extending direction of the linear sliding rail 212, the lifting clamping plate 23 is disposed at the lower end of the lifting guide shaft 24 in a clamping manner, and the upper end of the lifting guide shaft 24 is connected with the bottom plate 111 of the U-shaped board 11.

The translation assembly comprises a drive motor 31 and a cover plate conveyor belt 32; the driving motor 31 is arranged on the connecting frame 1 and is used for driving the cover plate conveyor belt 32 to run; the cover plate conveyor belt 32 is disposed above the connection frame 1, and the conveying direction of the cover plate conveyor belt 32 is consistent with the extending direction of the linear slide rail 212. Specifically, the driving motor 31 is disposed on the bottom plate 111 of the U-shaped board 11, the cover plate conveyor 32 is disposed on the long rod 12 of the connection frame 1, and the conveying direction of the cover plate conveyor 32 is consistent with the extending direction of the long rod 12.

In order to realize synchronous conveying of the cover plate conveying belt 32, the translation assembly further comprises a rotating shaft 33 and a driving wheel, wherein the driving wheel comprises a driving wheel 34 and a driven wheel 35, the rotating shaft 33 is respectively connected with the driving motor 31 and the driving wheel 34, and the driving wheel 34 is connected with the driven wheel 35 through the cover plate conveying belt 32. When the driving motor 31 drives the rotating shaft 33 to rotate, the driving wheel 34 is driven to synchronously rotate, and the driven wheel 35 is synchronously driven to rotate by the cover plate conveying belt 32, so that the translation transmission of the glass cover plate 7 is completed.

Specifically, the driving wheel 34 is parallel to the driving motor 31 and is connected with the driving motor through a rotating shaft 33, and the driving wheel 34 and the driven wheel 35 are both disposed on the side plate 112 of the U-shaped plate 11 and are disposed in a V-like shape. In order to facilitate adjusting the tensioning degree of the cover plate conveyor belt 32, the side plate 112 is provided with a strip-shaped chute 113, the extending direction of the strip-shaped chute 113 is perpendicular to the extending direction of the linear sliding rail 212, and the driven wheel 35 is movably arranged in the strip-shaped chute 113. Illustratively, the driven wheel 35 includes a first driven wheel 351 and a second driven wheel 352, the first driven wheel 351 and the second driven wheel 352 are disposed in a V shape, a strip-shaped chute 113 is disposed between the first driven wheels 351, the second driven wheel 352 is disposed in the strip-shaped chute 113, and when the cover conveyer 32 is loose, the cover conveyer 32 can be tensioned by only adjusting the second driven wheel 352 in a direction away from the first driven wheel 351.

In a preferred embodiment, since the driving motor 31 has a certain weight, in order to further improve the stability of the cover plate conveyor belt 32, the glass cover plate conveying mechanism provided by the utility model further comprises a fixed base 4 and a tension spring 5; the linear slide rail 212 is fixed on the fixed base 4, and specifically, the linear slide rail 212 is fixed on the base 4 through a screw; the upper end of the tension spring 5 is connected with the lifting clamp plate 23, and the lower end is connected with the fixed base 4. Further, in order to improve the stretching effect of the tension spring 5 and simultaneously facilitate replacement of the tension spring, the glass cover plate conveying mechanism further comprises a support column 6; the support column 6 comprises a first support column 61 and a second support column 62; both ends of the first support post 61 are respectively connected with the tension spring 5 and the lifting clamp plate 23; the two ends of the second support post 62 are respectively connected with the tension spring 5 and the fixed base 4, that is, the tension spring 5 is arranged between the first support post 61 and the second support post 62. When the connecting frame 1 is lifted up, the tension spring 5 is stretched, giving a downward reaction force; when the connecting frame 1 descends, the tension springs 5 are compressed, so that an upward reaction force is given, and the stability of the glass cover plate transmission mechanism in the process of transmitting the glass cover plate can be further improved through the buffer and shock absorption of the tension springs 5.

The specific implementation process is as follows:

taking the example that the former process transmission belt is lower than the latter process transmission belt:

when the glass cover plate 7 reaches a specified position, if the glass cover plate 7 is conveyed to a cover plate placing station from a previous process conveying belt, the driving cylinder 211 is driven to do extending movement, and the sliding rail connecting plate 213 moves along the extending direction of the linear guide rail under the pushing of the movable push rod of the driving cylinder 211 to drive the lifting cam block 221 to synchronously move along the extending direction of the linear guide rail; at this time, the moving roller 222 abutting against the upper surface of the lifting cam block 221 rolls to convert the horizontal linear reciprocating motion into the lifting linear motion in the vertical direction, the lifting guide shaft 24 pushes the connecting frame 1 and the translation assembly integrally upwards, the tension spring 5 is pulled up, the whole connecting frame 1 and the translation assembly can stably rise until the height of the translation assembly is consistent with that of the conveying belt in the subsequent process, at this time, the driving motor 31 is started to drive the cover plate conveying belt 32 to move, so that the glass cover plate 7 can be translated and conveyed onto the conveying belt in the subsequent process, and the smooth conveying of the glass cover plate 7 is completed.

After the transmission is completed, all actions are opposite to the actions, so that the glass cover plate transmission mechanism can recover the initial position, and the description is omitted here.

The glass cover plate conveying mechanism of the present utility model can convey not only glass cover plates but also articles such as process plates or boxes with planar bottom surfaces, and is not limited herein.

In the embodiment of the utility model, the glass cover plate transmission mechanism comprises a connecting frame, a translation assembly and a lifting assembly, wherein the translation assembly is arranged above the connecting frame, and the lifting assembly is arranged below the connecting frame; when the glass cover plate is required to be transmitted so as to finish the butt joint of transmission lines with different heights, the lifting transmission of the connecting rack and the translation assembly is realized through the lifting assembly, the translation assembly realizes the translation transmission of the glass cover plate, and particularly, the long-span transmission of the glass cover plate is realized through the arrangement of the driving cylinder and the moving cam; the transmission mechanism is simple in structure, low in cost, stable in operation and high in reliability.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures. In the description of the present utility model, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present utility model.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (7)

1. A glass cover plate transfer mechanism, comprising: the device comprises a connecting frame (1), a translation assembly and a lifting assembly;

the translation assembly comprises a cover plate placing station, and the cover plate placing station is parallel to the horizontal plane;

the lifting assembly is arranged below the translation assembly and is connected with the translation assembly through a connecting frame (1);

the lifting assembly comprises a driving part (21) and a moving cam (22);

the driving part (21) is connected with the moving cam (22) and is used for driving the moving cam to move;

the movable cam (22) is connected with the connecting frame (1);

the driving part (21) comprises a driving cylinder (211), a linear sliding rail (212) and a sliding rail connecting plate (213);

the movable push plate of the driving cylinder (211) is connected with the slide rail connecting plate (213), and the pushing direction of the movable push plate faces the extending direction of the linear slide rail (212);

the slide rail connecting plate (213) is connected with the sliding block of the linear slide rail (212);

the moving cam (22) comprises a lifting cam block (221) and a moving roller (222);

the lifting cam block (221) is fixed on the sliding rail connecting plate (213);

the movable roller (222) is connected with the connecting frame (1) and is abutted against the upper surface of the lifting cam block (221).

2. The glass cover conveying mechanism according to claim 1, wherein,

the translation assembly comprises a driving motor (31) and a cover plate conveyor belt (32);

the driving motor (31) is arranged on the connecting frame (1) and is used for driving the cover plate conveyor belt (32) to run;

the cover plate conveyor belt (32) is arranged above the connecting frame (1), and the conveying direction of the cover plate conveyor belt (32) is consistent with the extending direction of the linear sliding rail (212).

3. The glass cover conveying mechanism according to claim 1, wherein,

the lifting assembly further comprises a lifting clamping plate (23) and a lifting guide shaft (24);

the movable roller (222) is fixed on the lifting clamp plate (23) through a bearing seat screw;

the lower end of the lifting guide shaft (24) is connected with the lifting clamping plate (23), and the upper end of the lifting guide shaft is connected with the connecting frame (1).

4. A glass cover plate transmission mechanism according to claim 3, further comprising a fixed base (4) and a tension spring (5);

the linear slide rail (212) is fixed on the fixed base (4);

the upper end of the tension spring (5) is connected with the lifting clamp plate (23), and the lower end is connected with the fixed base (4).

5. Glass cover plate transport mechanism according to claim 4, further comprising support columns (6);

the support column (6) comprises a first support column (61) and a second support column (62);

two ends of the first support column (61) are respectively connected with the tension spring (5) and the lifting clamp plate (23);

two ends of the second support column (62) are respectively connected with the tension spring (5) and the fixed base (4).

6. The glass cover conveying mechanism according to claim 2, wherein,

the translation assembly further comprises a rotating shaft (33) and a driving wheel;

the driving wheel comprises a driving wheel (34) and a driven wheel (35);

the rotating shaft (33) is respectively connected with the driving motor (31) and the driving wheel (34);

the driving wheel (34) is connected with the driven wheel (35) through the cover plate conveyor belt (32).

7. The glass cover conveying mechanism according to claim 1, wherein,

the lifting cam block (221) is provided with a through hole;

the sliding rail connecting plate (213) is provided with a threaded hole;

the lifting cam block (221) is fixed on the sliding rail connecting plate (213) through the through hole by a screw matched with the threaded hole.