Linkage structure of outward lifting type panoramic sunroof
By using the linkage structure of the front slider and the rear slider in the panoramic sunroof, the problem of restricted opening of the traditional panoramic sunroof is solved, and a large opening and stable exterior flip-flop design is realized, reducing cost and weight.
Patent Information
- Application Number
- CN202422919546.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-11-28
AI Technical Summary
In the traditional panoramic sunroof system, the front glass is opened and the rear glass is fixed, and the opening is limited, so it cannot achieve a larger opening, and it is expensive and heavier.
The linkage structure of the outer flip-up panoramic sunroof is adopted. The front slider and rear slider symmetrically installed on the guide rails on both sides of the roof frame are used to realize the linkage between the front slider and the rear slider, which drives the front and rear robot arms to move, and realizes the outer flip-up opening of the sunroof.
The large opening function of the panoramic sunroof is realized, which is easy to operate, ensures the stability of the fastening position, reduces costs and reduces weight.
Smart Images
Figure CN223278870U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of automobile sunroofs, in particular to a linkage structure of an outward-folding panoramic sunroof. Background Art
[0002] Traditional panoramic sunroof systems use an opening front glass and a fixed rear glass. The opening of the sunroof glass is limited by the size of the sunroof. If you want a larger opening, you can only add a panoramic sunroof, which is expensive and heavier. Utility Model Content
[0003] In order to solve the above problems existing in the prior art, the utility model provides a linkage structure of an outward-opening panoramic sunroof.
[0004] The above-mentioned problem of the present invention is solved by the following technical solutions:
[0005] A linkage structure for a tilt-up panoramic sunroof comprises guide rails symmetrically mounted on both sides of a roof frame, wherein a front mechanical arm for mounting a front glass and a rear mechanical arm for mounting a rear glass are sequentially arranged on the guide rails; a front slider is arranged between the front mechanical arm and the guide rails, and a rear slider is arranged between the rear mechanical arm and the guide rails; the front slider is driven by a driving component controlled by a vehicle control system to slide backward along the guide rails (100), thereby driving the rear slider to slide backward together;
[0006] A first buckling structure is provided between the front slider and the rear slider. When the front slider moves backward, the front mechanical arm is driven to move. When the first buckling structure is buckled, the front slider pushes the rear slider to move backward together, thereby driving the rear mechanical arm to move backward and the sunroof is opened.
[0007] The above technical solution is further configured as follows: the first buckling structure includes a first buckling portion and a first guiding portion provided between the front slider and the rear slider;
[0008] The first guide portion is inserted into the first buckling portion, so that the front slider and the rear slider form a linkage.
[0009] The above technical solution is further configured as follows: the first fastening portion is a first fastening groove provided at the tail of the front slider; the first guide portion is a first guide portion provided at the front end of the rear slider and matching the first fastening groove.
[0010] The above technical solution is further configured as follows: an opening of the first buckling groove is provided on the lower end surface of the front slider, and a guide end surface is provided at the rear end of the front slider extending toward the first buckling groove.
[0011] The above technical solution is further configured as follows: the guide end surface is sequentially configured as a horizontal guide surface and an inclined guide surface along the sliding direction of the first guide portion; the inclined guide surface is the rear end surface of the first engaging groove;
[0012] The horizontal guide surface is not lower than the upper end surface of the first guide portion in the height direction.
[0013] The above technical solution is further configured as follows: an end surface on one side of the first engaging groove opposite to the inclined guide surface is configured as a stop surface, and a lower end of the stop surface is lower than the horizontal guide surface.
[0014] The above technical solution is further configured as follows: a tilting structure is further provided between the front robotic arm and the front slider, and the tilting structure is a tilting groove provided on the front robotic arm and a first guide shaft provided on the front slider;
[0015] The two ends of the warping groove are sequentially arranged as a warping first end and a warping second end along the opening direction of the skylight, and the warping first end is higher than the warping second end in the height direction.
[0016] The above technical solution is further configured as follows: a slider is provided between the front end of the front robotic arm and the guide rail, and the front slider is hinged to the slider.
[0017] The above technical solution is further configured as follows: a downward pressing structure is provided between the rear slider and the rear mechanical arm, and the downward pressing structure is a downward pressing groove provided on the rear mechanical arm and a second guide shaft provided on the rear slider;
[0018] The two ends of the downward pressing groove are sequentially arranged as a downward pressing first end and a downward pressing second end along the opening direction of the skylight, and the downward pressing first end is lower than the downward pressing second end in the height direction.
[0019] The above technical solution is further configured as follows: a limit seat is provided between the rear robotic arm and the guide rail, and a limit slot in the height direction is provided on the limit seat; and a limit block is provided on the rear robotic arm to cooperate with the limit slot.
[0020] Compared with the prior art, the beneficial effect of the present invention lies in: a first buckling structure is provided on the front slider and the rear slider, the front slider is driven to move by the front mechanical arm, and then the front slider and the rear slider are buckled together to push the rear slider to move, thereby realizing the outward-flipping opening process of the panoramic sunroof, ensuring the stability of the buckling position, and being able to smoothly realize the connection between the front slider and the rear slider, so that the sunroof can be opened smoothly, the operation is convenient, and the large opening function of the panoramic sunroof is realized. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the exploded structure of the present invention.
[0022] Figure 2 This is a schematic diagram of the structure when the sunroof is closed.
[0023] Figure 3 This is a schematic diagram of the structure when the front glass is opened.
[0024] Figure 4 This is a schematic diagram of the structure when the rear glass is opened.
[0025] Figure 5 This is a structural diagram of the separation of the first buckling structure.
[0026] Figure 6 It is a structural schematic diagram when the first buckling structure is buckled.
[0027] Figure 7 Schematic diagram of the warping structure.
[0028] Figure 8 Schematic diagram of the downward pressure structure.
[0029] Figure 9 Schematic diagram of the second buckling structure.
[0030] Marked on the accompanying drawings: 100, guide rail;
[0031] 200, front robotic arm; 201, lifting groove; 201.1, lifting first end; 201.2, lifting second end;
[0032] 300, rear robotic arm; 301, downward pressing slot; 301.1, downward pressing first end; 301.2, downward pressing second end;
[0033] 400, front slider; 401, first fastening groove; 410, fastening plate; 411, first sliding foot; 402, second fastening portion;
[0034] 500, rear slider; 510, guide block; 520, first guide portion; 530, second slide foot;
[0035] 600, limited seat;
[0036] 700, slider;
[0037] 800, control link; 810, second guide portion;
[0038] a. Horizontal guide surface; b. Inclined guide surface; c. Stop surface;
[0039] 1. First guide shaft; 2. Second guide shaft; 3. Limit block. DETAILED DESCRIPTION
[0040] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the following is a detailed description of the specific implementation method, structure, characteristics and effects of the present invention in combination with the accompanying drawings and preferred embodiments.
[0041] like Figure 1-8 As shown, this embodiment discloses a linkage structure of an outward-opening panoramic sunroof.
[0042] A linkage structure for a tilt-up panoramic sunroof comprises guide rails 100 symmetrically mounted on both sides of a roof frame, wherein a front mechanical arm 200 for mounting a front glass and a rear mechanical arm 300 for mounting a rear glass are sequentially arranged on the guide rails 100; a front slider 400 is arranged between the front mechanical arm 200 and the guide rails 100, and a rear slider 500 is arranged between the rear mechanical arm 300 and the guide rails 100; the front slider 400 is driven by a driving component controlled by a vehicle control system to slide backward along the guide rails (100), thereby driving the rear slider 500 to slide backward together;
[0043] A first locking structure is provided between the front slider 400 and the rear slider 500. When the front slider 400 moves backward, it drives the front robotic arm 200 to move. When the first locking structure is locked, the front slider 400 pushes the rear slider 500 to move backward together, thereby driving the rear robotic arm 300 to move backward and the sunroof opens.
[0044] The above is the basic solution of this embodiment.
[0045] Specific reference Figure 1 As shown, two sets of guide rails 100 can be fixedly installed on both sides of the car sunroof respectively, and each set of guide rails 100 includes two symmetrical guide rails 100, and each guide rail 100 is slidably provided with a front mechanical arm 200 and a rear mechanical arm 300, as well as a front slider 400 that drives the front mechanical arm 200 and a rear slider 500 that drives the rear mechanical arm 300. The front slider 400 and the rear slider 500 are provided with sliding feet that can slide on the guide rails 100 in a limited manner; the front glass is set between the two front mechanical arms 200, and the rear glass is set between the two rear mechanical arms 300. As the front mechanical arm 200 and the rear mechanical arm 300 slide, the opening and closing of the sunroof are realized.
[0046] The driving component is provided on the front slider 400 and is controlled by the vehicle control system to pull the front slider 400 backward, thereby pulling the front robot arm 200 connected to the front slider 400 backward;
[0047] Specific reference Figure 2-Figure 4As shown, the movement process of the front robotic arm 200 on the guide rail 100 has a first stroke and a second stroke; in the first stroke, the front slider 400 moves backward under the action of the driving component, and during the movement, the front robotic arm 200 is opened, so that the front glass is tilted upward; in the second stroke, the front slider 400 moves backward with the front robotic arm 200, and after being engaged with the rear slider 500, drives the rear slider 500 to slide backward together; in the second stroke, the rear slider 500 drives the rear robotic arm 300 to move while sliding, so that the rear glass is opened.
[0048] Preferably, in this embodiment, the first buckling structure includes a first buckling portion and a first guiding portion provided between the front slider 400 and the rear slider 500;
[0049] The first guide portion is inserted into the first engaging portion, so that the front slider 400 and the rear slider 500 form a linkage.
[0050] Compared with setting the first snap-fit structure between the front robotic arm 200 and the rear robotic arm 300, in this embodiment, it is set on the front slider 400 and the rear slider 500. The front slider 400 and the rear slider 500 both slide on the guide rail 100 through the sliding foot limiter, and their positions in the vertical direction are consistent. Setting the first snap-fit structure between the front slider 400 and the rear slider 500 makes the movement process more stable, which can ensure the smooth snap-fitting process of the first snap-fit structure.
[0051] In this embodiment, the first fastening portion is a first fastening groove 401 provided at the rear of the front slider 400 ; the first guiding portion is a first guiding portion 520 provided at the front end of the rear slider 500 and matching the first fastening groove 401 .
[0052] In other embodiments, the first locking groove 401 and the first guide portion 520 may also be arranged in reverse.
[0053] To ensure that the first guide portion 520 can slide smoothly into the guide groove, in this embodiment, the opening of the first snap-fit groove 401 is arranged on the lower end surface of the front slider 400, and the tail end of the front slider 400 extends toward the first snap-fit groove 401 to provide a guide end surface.
[0054] Specific reference Figure 5 and Figure 6 As shown, the first snap-fitting groove 401 is an inclined groove, with the rear end position lower than the front end position; the shape of the first guide portion 520 matches the first snap-fitting groove 401, and the first guide portion 520 slides along the guide end surface, slides into the groove from the opening part of the first snap-fitting groove 401, thereby forming a snap fit with the first snap-fitting groove 401.
[0055] Based on the above setting, when the first guide portion 520 slides into the first snap-fit groove 401 along the inclined direction, during the opening process, the front end face of the first snap-fit groove 401 generates a thrust on the first guide portion 520, and the direction of the thrust is horizontally backward, and its component force is upward along the inclined surface, so the first guide portion 520 cannot move downward, thereby ensuring that the first guide portion 520 cannot slide out of the first snap-fit groove 401.
[0056] Preferably, in this embodiment, in order to ensure the balance of the fastening position, in this embodiment, two first fastening grooves 401 are provided on each front slider 400, and by providing fastening plates 410 on both sides of the front slider 400, the first fastening grooves 401 are formed on the fastening plates 410;
[0057] At the same time, each rear slider 500 is provided with two first guide portions 520 , which are formed by providing a guide block 510 at the tail of the rear slider 500 and providing protrusions on both sides of the guide block 510 ;
[0058] In addition, in order to ensure the stable position of the guide block 510, in this embodiment, a first sliding foot 411 is provided at the position of the snap-fit plate 410 to ensure that the position of the first snap-fit groove 401 is consistent relative to the guide rail 100, and a second sliding foot 530 is provided on the rear slider 500 to ensure that the position of the first guide portion 520 is consistent relative to the guide rail 100.
[0059] It should be noted that a sliding groove is provided on the side or bottom of the guide rail 100. The function of the first sliding foot 411 and the second sliding foot 530 is to be inserted into the sliding groove and slide along the sliding groove, so that the front slider 400 and the rear slider 500 can be slidably connected to the guide rail 100 without separating from the guide rail 100.
[0060] In this embodiment, the specific implementation of the guide end surface is as follows: the guide end surface is sequentially provided with a horizontal guide surface a and an inclined guide surface b along the sliding direction of the guide block 510; the inclined guide surface b is the rear end surface of the first engaging groove 401;
[0061] The horizontal guide surface a is not lower than the upper end surface of the guide block 510 in the height direction.
[0062] Specific reference Figure 5 and Figure 6 As shown, when the first guide portion 520 slides along the guide end surface, the upper end surface of the first guide portion 520 first contacts the horizontal guide surface a, and the horizontal guide surface a guides the position of the first guide portion 520;
[0063] When sliding to the end of the horizontal guide surface a, the front end of the first guide portion 520 is stopped by the front end surface of the first locking groove 401, and then the first guide portion 520 slides into the first locking groove 401 along the inclined guide surface b, so that the first locking structure is locked and connected.
[0064] Preferably, in this embodiment, an end surface on one side of the first engaging groove 401 opposite to the inclined guide surface b is provided as a stop surface c, and a lower end of the stop surface c is lower than the horizontal guide surface a.
[0065] Based on the above arrangement, when the first guide portion 520 moves horizontally along the horizontal guide surface a, it is stopped when encountering the stop surface c and cannot continue to slide horizontally, thereby being able to slide in along the inclined guide surface b.
[0066] In this embodiment, the sunroof is opened in a tilting manner to maximize the opening of the sunroof when opened. The specific implementation is as follows: a tilting structure is further provided between the front robotic arm 200 and the front slider 400. The tilting structure is a tilting groove 201 provided on the front robotic arm 200 and a first guide shaft 1 provided on the front slider 400.
[0067] The two ends of the warping groove 201 are sequentially arranged as a warping first end 201.1 and a warping second end 201.2 along the opening direction of the skylight, and the warping first end 201.1 is higher than the warping second end 201.2 in the height direction.
[0068] Specific reference Figure 7 As shown, in this embodiment, the tilting groove 201 is set as an arc groove, at least a part of the path is set as an arc, the tilting first end 201.1 is the starting end, and the tilting second end 201.2 is the ending end; when the sunroof is closed, the first guide shaft 1 is located at the first end of the tilting groove 201. At this time, the front robotic arm 200 is in a closed state, that is, close to the position of the slide rod; when the front slider 400 moves backward under the action of the driving component, the front slider 400 moves backward relative to the front robotic arm 200. At this time, the first guide shaft 1 slides along the tilting groove 201, from the tilting first end 201.1 to the tilting second end 201.2. Since the position of the tilting second end 201.2 is lower than the position of the tilting first end 201.1, and the height of the first guide shaft 1 on the front slider 400 remains unchanged, the rear part of the front robotic arm 200 moves upward to form a tilting state.
[0069] At the same time, a slider 700 is provided between the front end of the front robotic arm 200 and the guide rail 100 , and the front slider 400 and the slider 700 are hinged.
[0070] The front end of the front slider 400 is hinged to the slider 700, and the slider 700 is limited on the guide rail 100. Therefore, the front end height of the front slider 400 remains unchanged and only moves backward. After the rear end of the front robot arm 200 is tilted, the entire front robot arm 200 is tilted. For details, refer to Figure 3 As shown, at this time, the rear end of the front glass is lifted.
[0071] In addition, in this embodiment, the driving component is connected to the front robotic arm 200 and is located behind the slider 700. When the driving component drives the front robotic arm 200 to move, the slider 700 moves therewith.
[0072] In this embodiment, the front robotic arm 200 and the front slider 400 are connected by a control link 800; the control link 800 includes a first end and a second end, and the first end is hinged to the front robotic arm 200, and the second end and the front slider 400 are connected by a second snap-fit structure; the second snap-fit structure includes a second guide portion 810 and a second snap-fit portion 402, and the specific implementation of the second guide portion 810 and the second snap-fit portion 402 is consistent with the first snap-fit structure, which will not be repeated here.
[0073] Specific reference Figure 2 and Figure 9 As shown, when the sunroof is closed, the second fastening structure is in a disengaged state, the second guide portion 810 and the second fastening portion 402 are separated and the second guide portion 810 is located in front of the second fastening portion 402; when the driving component drives the front slider 400 to move backward, the second fastening portion 402 on the front slider also moves backward, gradually approaching the second guide portion 810; the front slider 400 continues to move until the second fastening portion 402 and the second guide portion 810 are fastened and connected, as shown in FIG. Figure 3 shown.
[0074] When the sunroof is closed, the second buckling structure operates in the opposite manner to that described above, which will not be described in detail here.
[0075] In this embodiment, in order to store the sunroof and minimize the storage space, the front and rear window panels of the panoramic sunroof are configured to be superimposed, that is, the front window panel is tilted upward and the rear window panel is downward, so that the front and rear window panels are at least partially in an upper and lower state; the opening structure of the rear sunroof is specifically configured as follows: a downward pressing structure is provided between the rear slider 500 and the rear mechanical arm 300, and the downward pressing structure is composed of a downward pressing groove 301 provided on the rear mechanical arm 300 and a second guide shaft 2 provided on the rear slider 500;
[0076] The two ends of the downward pressing groove 301 are sequentially arranged as a downward pressing first end 301.1 and a downward pressing second end 301.2 along the opening direction of the skylight, and the downward pressing first end 301.1 is lower than the downward pressing second end 301.2 in the height direction.
[0077] Specific reference Figure 8 As shown, in this embodiment, the downward pressing groove 301 and the warping groove 201 structures are arranged in opposite directions, the downward pressing first end 301.1 is the starting end, and the downward pressing second end 301.2 is the ending end; in the closed state, the second guide shaft 2 is located at the downward pressing first end 301.1, at this time, the rear robotic arm 300 is arranged close to the rear slider 500; when the rear slider 500 moves backward under the drive of the front slider 400, when the second guide shaft 2 slides along the downward pressing groove 301 from the downward pressing first end 301.1 to the downward pressing second end 301.2, the position of the second guide shaft 2 remains unchanged, so that the position of the rear robotic arm 300 moves downward, thereby realizing the downward pressure on the rear robotic arm 300 and lowering the height of the rear glass.
[0078] In this embodiment, a limit seat 600 is provided between the rear robotic arm 300 and the guide rail 100 , and a limit groove in the height direction is provided on the limit seat 600 ; a limit block 3 cooperating with the limit groove is provided on the rear robotic arm 300 .
[0079] During the downward pressing process of the rear robotic arm 300, the rear robotic arm 300 and the window surface installed on the rear robotic arm 300 will not slide along the guide rail 100 under the action of the limit seat 600. When the rear robotic arm 300 is pressed down, the limit block 3 slides down to the bottom of the limit seat 600, that is, slides out of the limit groove. At this time, under the action of the driving component, the front robotic arm 200 continues to push the rear robotic arm 300 to move backward, thereby fully opening the sunroof.
[0080] When closing the sunroof, first pull back the front robotic arm 200 and the rear robotic arm 300 so that the limit block on the rear robotic arm 300 is aligned with the limit slot, and the rear robotic arm 300 is lifted under the action of the downward pressure structure. The lifting process is opposite to the downward pressure process, which will not be described here; after the rear robotic arm 300 is lifted, the front robotic arm 200 is disengaged from the first buckling structure on the rear robotic arm 300, and the front robotic arm 200 continues to move forward until the second buckling structure is disengaged; at this time, the front slider 400 continues to move, and the front robotic arm 200 no longer moves, but under the action of the tilting structure, the rear end of the front robotic arm 200 is pressed downward, and the downward pressure process is opposite to the tilting process, which will not be described here; after the downward pressure is completed, the driving component drives the front slider 400 back to the closed position.
[0081] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A linkage structure for a tilting panoramic sunroof, comprising guide rails (100) symmetrically mounted on both sides of a roof frame, wherein a front mechanical arm (200) for mounting a front glass and a rear mechanical arm (300) for mounting a rear glass are sequentially arranged on the guide rails (100); a front slider (400) is arranged between the front mechanical arm (200) and the guide rails (100), and a rear slider (500) is arranged between the rear mechanical arm (300) and the guide rails (100); the front slider (400) is driven by a driving component controlled by a vehicle control system to slide backward along the guide rails (100), thereby driving the rear slider (500) to slide backward together; Its characteristics are: A first buckling structure is provided between the front slider (400) and the rear slider (500), and when the front slider (400) moves backward, the front mechanical arm (200) is driven to move; the first buckling structure is buckled, so that the front slider (400) pushes the rear slider (500) to move backward together, thereby driving the rear mechanical arm (300) to move backward, and the sunroof is opened.
2. The linkage structure of the tilt-up panoramic sunroof according to claim 1, characterized in that: The first buckling structure comprises a first buckling portion and a first guiding portion arranged between the front slider (400) and the rear slider (500); The first guide portion is inserted into the first buckling portion, so that the front slider (400) and the rear slider (500) form a linkage.
3. The linkage structure of the tilt-up panoramic sunroof according to claim 2, characterized in that: The first fastening portion is a first fastening groove (401) provided at the rear of the front slider (400); the first guiding portion is a first guiding portion (520) provided at the front end of the rear slider (500) and matching the first fastening groove (401).
4. The linkage structure of the tilt-up panoramic sunroof according to claim 3, characterized in that: The opening of the first buckling groove (401) is provided on the lower end surface of the front slider (400), and the tail end of the front slider (400) is extended toward the first buckling groove (401) and provided with a guide end surface.
5. The linkage structure of the tilt-up panoramic sunroof according to claim 4, characterized in that: The guide end surface is sequentially arranged as a horizontal guide surface (a) and an inclined guide surface (b) along the sliding direction of the first guide portion (520); the inclined guide surface (b) is the rear end surface of the first buckling groove (401); The horizontal guide surface (a) is not lower than the upper end surface of the first guide portion (520) in the height direction.
6. The linkage structure of the tilt-up panoramic sunroof according to claim 5, characterized in that: An end surface on one side of the first locking groove (401) opposite to the inclined guide surface (b) is provided as a stop surface (c), and a lower end of the stop surface (c) is lower than the horizontal guide surface (a).
7. The linkage structure of the tilt-up panoramic sunroof according to claim 1, characterized in that: A tilting structure is further provided between the front mechanical arm (200) and the front slider (400), wherein the tilting structure comprises a tilting groove (201) provided on the front mechanical arm (200) and a first guide shaft (1) provided on the front slider (400); The two ends of the warping groove (201) are sequentially arranged as a warping first end (201.1) and a warping second end (201.2) along the skylight opening direction, and the warping first end (201.1) is higher than the warping second end (201.2) in the height direction.
8. The linkage structure of the tilt-up panoramic sunroof according to claim 7, characterized in that: A slider (700) is provided between the front end of the front mechanical arm (200) and the guide rail (100), and the front slider (400) and the slider (700) are hinged.
9. The linkage structure of the tilt-up panoramic sunroof according to claim 1, characterized in that: A downward pressing structure is provided between the rear slider (500) and the rear mechanical arm (300), wherein the downward pressing structure comprises a downward pressing groove (301) provided on the rear mechanical arm (300) and a second guide shaft (2) provided on the rear slider (500); The two ends of the downward pressing groove (301) are sequentially arranged as a downward pressing first end (301.1) and a downward pressing second end (301.2) along the skylight opening direction, and the downward pressing first end (301.1) is lower than the downward pressing second end (301.2) in the height direction.
10. The linkage structure of the tilt-up panoramic sunroof according to claim 1, characterized in that: A limiting seat (600) is provided between the rear mechanical arm (300) and the guide rail (100), and a limiting groove in the height direction is provided on the limiting seat (600); and a limiting block (3) is provided on the rear mechanical arm (300) to cooperate with the limiting groove.