A vehicle frame assembly and tractor

Abstract

The utility model provides a kind of frame assembly and tractor, frame assembly includes frame main body, seat framework, two support arms and two locking components.Frame main body is equipped with the middle installation site for installing engine, middle installation site is close to the middle part of frame main body.Seat framework can slide along the longitudinal direction of frame main body, and can rotate towards the head of frame main body.Two support arms are telescopic on seat framework along vertical direction, and locking component is used to lock support arm.Through the middle installation site for installing engine designed on frame main body, engine middle can make the gravity center of tractor more close to the geometric center of vehicle, so that tractor realizes better front and rear axle load distribution in driving and operation process, improves control stability.In the case where engine is middle, without overall removing seat framework, it is convenient to maintain, overhaul operation to engine, so as to effectively shorten maintenance time, improve maintenance efficiency.

Description

Technical Field

[0001] This utility model relates to the field of tractor frame technology, specifically to a frame assembly and a tractor. Background Technology

[0002] In hilly or mountainous areas (such as Southeast Asia), such as forest farms, tea plantations, and coffee plantations, transportation equipment is needed to move products. The road conditions in these areas are typically complex, and cargo tricycles lack off-road capabilities and cannot adapt to these conditions. While ATVs or ATVs can be modified to add cargo beds, their load-bearing capacity is poor and generally cannot meet cargo-carrying requirements. Therefore, four-wheeled tractors have become the core transportation equipment in these areas.

[0003] Currently, most four-wheel tractors on the market use a front-mounted engine layout. This front-mounted engine directly leads to excessive load on the front axle, requiring the driver to overcome a greater load when turning, especially when cornering, necessitating greater effort to turn the steering wheel. Simultaneously, a front-mounted engine occupies a significant amount of space in the front of the tractor, reducing the space utilization of the chassis. Therefore, the tractor's chassis assembly directly determines the overall handling, stability, and ease of maintenance of the machine.

[0004] Therefore, how to better distribute the front and rear axle loads by changing the engine's installation position, improve handling stability, and facilitate engine maintenance and repair after optimizing the engine's installation position are problems that urgently need to be solved by those skilled in the art. Utility Model Content

[0005] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a chassis assembly and tractor to solve or at least alleviate one or more of the above-mentioned technical problems or other problems existing in the prior art.

[0006] To achieve the above objectives, this utility model provides a vehicle frame assembly, including a vehicle frame body, and a central mounting position for mounting an engine. The central mounting position is located near the center of the vehicle frame body. The vehicle frame body is also provided with two connecting parts, which are respectively arranged on both sides of the central mounting position.

[0007] A seat frame is disposed on the main body of the vehicle frame. The seat frame can slide longitudinally along the main body of the vehicle frame and can rotate toward the head of the main body of the vehicle frame. The seat frame has a first state and a second state. In the first state, the seat frame is located above the center mounting position. In the second state, the seat frame is exposed above the center mounting position.

[0008] Two support arms extend and retract vertically onto the seat frame, and are arranged on both sides of the seat frame. The support arms can connect to corresponding connecting parts to maintain the seat frame in the first state; and

[0009] Two locking components, each corresponding to one of the two support arms, are provided. In the second state, the support arms can extend and abut against the frame body. The locking components are used to lock the support arms to prevent them from extending or retracting, or to release the locking state.

[0010] Preferably, the main body of the frame includes two first longitudinal beams, multiple first transverse beams, and two second longitudinal beams. The multiple first transverse beams are arranged between the two first longitudinal beams, and each second longitudinal beam is arranged below a corresponding first longitudinal beam. The two ends of the second longitudinal beams are bent upwards and connected to the corresponding first longitudinal beams. The seat frame is mounted on the two first longitudinal beams. The first longitudinal beams have protrusions along the lateral direction. The two protrusions and the two second longitudinal beams together form the central mounting position.

[0011] Preferably, it further includes a mounting bracket, which is disposed on the two second longitudinal beams and located within the central mounting position.

[0012] Preferably, the seat frame includes two opposing main arms, each main arm having a receiving cavity, a clearance hole and a first limiting hole, the clearance hole and the first limiting hole respectively communicating with the receiving cavity, and the support arm telescopically cooperating within the receiving cavity and extending out of the main arm;

[0013] The locking assembly includes: an inner tube fixed to the support arm and extending out of the clearance hole; a limiting pin movably inserted into the inner tube, one end of the limiting pin extending out of the support arm and the other end extending out of the inner tube, wherein in the second state, the limiting pin can be inserted into the first limiting hole to lock the support arm; an outer tube movably sleeved outside the inner tube, the outer tube being connected to a pin extending out of the inner tube from the limiting pin; and an elastic reset member disposed within the inner tube, the elastic reset member being used to apply an outwardly extending elastic force to the limiting pin.

[0014] Preferably, the limiting pin includes a first pin and a second pin that are coaxial and connected. The outer diameter of the first pin is larger than the outer diameter of the second pin. The first pin can be inserted into the first limiting hole. The second pin is located in the inner tube. The elastic reset member is sleeved on the outside of the second pin. The two ends of the elastic reset member abut against the end wall of the inner tube and the end wall of the first pin, respectively. The second pin extends out of the inner tube and the outer tube. The second pin is provided with a retaining spring to prevent the outer tube from falling off.

[0015] Preferably, the protrusion is provided with a support base, and the connecting part is a plug hole. The plug hole is provided on the support base. In the first state, the support arm is inserted into the corresponding plug hole. The support base is provided with a limiting groove, which is used to make the support arm slide only longitudinally.

[0016] Preferably, the main arm is provided with a second limiting hole communicating with the receiving cavity, and the limiting pin can be inserted into the second limiting hole. In the first state, the support arm is inserted into the insertion hole, and the limiting pin can be inserted into the second limiting hole to lock the support arm.

[0017] Preferably, the main arm is provided with a third limiting hole communicating with the receiving cavity, and the limiting pin can be inserted into the third limiting hole. When the support arm is completely disengaged from the insertion hole, the limiting pin can be inserted into the third limiting hole to lock the support arm.

[0018] Preferably, the first longitudinal beam is provided with a base, the base is provided with a guide hole, and the bottom of the seat frame is provided with two cylindrical sliding rods, each of the sliding rods being slidably and rotatably fitted into the corresponding guide hole.

[0019] This utility model also provides a tractor, including the above-described frame assembly.

[0020] The beneficial effects of this utility model are:

[0021] This utility model discloses a chassis assembly and tractor. By designing a centrally mounted engine position on the chassis body, the engine's center of gravity is brought closer to the vehicle's geometric center, resulting in better front-rear axle load distribution during driving and operation, thus improving handling stability. Furthermore, the centrally mounted engine provides more possibilities for utilizing space in other areas of the chassis body, allowing for a more compact and rational internal space layout, thereby enhancing the tractor's functionality and practicality.

[0022] Meanwhile, with the engine in a mid-mounted configuration, there is no need to completely remove the seat frame. By switching the seat frame to the second position, the mid-mounted mounting position can be quickly exposed, enabling rapid engine exposure and facilitating engine maintenance and repair operations. This effectively shortens maintenance time and improves maintenance efficiency.

[0023] The support arms engage with the connecting parts on the frame body to maintain the seat frame in its first state, ensuring its stability. In the second state, by extending the support arms and locking them with the locking assembly, the two support arms can support the rotated seat frame, maintaining it in the second state and ensuring safety during maintenance. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0025] Figure 1 This is a schematic diagram of the frame assembly provided in one embodiment of the present utility model;

[0026] Figure 2 This is a structural schematic diagram of the main body of the vehicle frame;

[0027] Figure 3 This is a structural diagram of the seat frame;

[0028] Figure 4 This is a schematic diagram of the support arm structure;

[0029] Figure 5 This is a cross-sectional view of the locking component;

[0030] Figure 6 A cross-sectional view showing the locking of another state of the component;

[0031] Figure 7 for Figure 2 Partial schematic diagram at point A in the middle;

[0032] Figure 8 A cross-sectional view of the support arm inserted into the socket;

[0033] Figure 9 A schematic diagram of the structure for the support arm to exit the socket;

[0034] Figure 10 This is a schematic diagram of the seat frame after it slides forward.

[0035] Figure 11This is a structural schematic diagram of the seat frame in the second state;

[0036] Figure label:

[0037] 10. Frame body; 11. Central mounting position; 12. First longitudinal beam; 121. Protrusion; 13. First crossbeam; 14. Second longitudinal beam; 15. Support seat; 151. Insertion hole; 152. Limiting groove; 16. Base; 161. Guide hole; 20. Seat frame; 21. Main arm; 211. Receiving cavity; 212. Clearance hole; 213. First limiting hole; 214. Second limiting hole; 215. Third limiting hole; 22. Slide rod; 30. Support arm; 40. Locking assembly; 41. Inner tube; 42. Limiting pin; 43. Outer tube; 44. Elastic reset component; 45. Snap ring; 50. Mounting bracket. Detailed Implementation

[0038] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0039] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0040] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0041] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0042] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] like Figure 1-11 As shown, in one embodiment of this utility model, a frame assembly is provided, including a frame body 10, a seat frame 20, two support arms 30, and two locking components 40. The frame body 10 has a central mounting position 11 for mounting the engine, located near the center of the frame body 10. The frame body 10 also has two connecting portions, respectively arranged on both sides of the central mounting position 11. The seat frame 20 is mounted on the frame body 10 and can slide along the longitudinal direction (i.e., the length direction of the frame body 10) of the frame body 10, and can rotate towards the head of the frame body 10. The seat frame 20 has a first state and a second state. In the first state, the seat frame 20 is located above the central mounting position 11. (Refer to...) Figure 1 In the second state, the seat frame 20 exposes the central mounting position 11, see reference. Figure 11 At this time, the seat frame 20 slides forward and rotates at a certain angle toward the head of the frame body 10.

[0045] Two support arms 30 extend and retract vertically onto the seat frame 20. The two support arms 30 are positioned on both sides of the seat frame 20 and can connect to corresponding connecting parts to maintain the seat frame 20 in a first state. Two locking components 40 correspond to the two support arms 30 respectively. In the second state, the support arms 30 extend and abut against the frame body 10. The locking components 40 are used to lock the support arms 30 to prevent their extension and retraction, or to release their locking.

[0046] This embodiment discloses a chassis assembly with a seat frame 20. By designing a centrally located engine mounting position 11 on the chassis body 10, the engine's center of gravity is closer to the vehicle's geometric center, resulting in better front-rear axle load distribution during driving and operation, thus improving handling stability. Furthermore, the central engine placement provides more possibilities for utilizing space in other areas of the chassis body 10, making the internal space layout of the chassis body 10 more compact and rational, thereby improving the tractor's functionality and practicality.

[0047] Meanwhile, with the engine in a mid-mounted configuration, there is no need to completely remove the seat frame 20. By switching the seat frame 20 to the second state, the mid-mounted mounting position 11 can be quickly exposed, enabling rapid exposure of the engine. This facilitates engine maintenance and repair operations, effectively shortening maintenance time and improving maintenance efficiency.

[0048] The support arm 30 can cooperate with the connecting part on the frame body 10 to keep the seat frame 20 in the first state, ensuring the stability of the seat frame 20. In the second state, by extending the support arm 30 and locking it with the locking component 40, the two support arms 30 can support the rotated seat frame 20, keeping the seat frame 20 in the second state and ensuring safety during maintenance.

[0049] In one embodiment, the frame body 10 includes two first longitudinal beams 12, multiple first crossbeams 13, and two second longitudinal beams 14. The multiple first crossbeams 13 are fixed between the two first longitudinal beams 12, and each second longitudinal beam 14 is arranged below a corresponding first longitudinal beam 12. The two ends of the second longitudinal beam 14 are bent upwards and fixedly connected to the corresponding first longitudinal beam 12. The seat frame 20 is mounted on the two first longitudinal beams 12. The first longitudinal beams 12 have protrusions 121 extending laterally outwards. The two protrusions 121 and the two second longitudinal beams 14 together form a central mounting position 11. The first longitudinal beams 12 and the first crossbeams 13 constitute the main load-bearing frame of the frame body 10, while the design of the second longitudinal beams 14 can improve the overall torsional strength of the frame body 10 and also protect the engine. The structural design of the protrusions 121 can effectively increase the space of the central mounting position 11, thereby better meeting the installation requirements of the engine and other components.

[0050] In one embodiment, in order to achieve a slidable and rotatable structure for the seat frame 20, a base 16 is fixed on the first longitudinal beam 12, the base 16 has a guide hole 161, and the bottom of the seat frame 20 is provided with two cylindrical sliding rods 22, each sliding rod 22 being slidably and rotatably fitted into the corresponding guide hole 161.

[0051] In one embodiment, the frame assembly further includes a mounting bracket 50, which is fixed to the two second longitudinal beams 14 and located within a central mounting position 11. The engine is fixed within the central mounting position 11 by the mounting bracket 50, which is designed to adapt to the shape of the engine block, facilitating stable support for the engine in multiple directions.

[0052] In one embodiment, the seat frame 20 includes two main arms 21 arranged opposite to each other. The main arms 21 are provided with a receiving cavity 211, a clearance hole 212 and a first limiting hole 213. The receiving cavity 211 extends through the bottom of the main arm 21. The clearance hole 212 and the first limiting hole 213 are respectively connected to the receiving cavity 211. The support arm 30 is telescopically fitted inside the receiving cavity 211 and extends out of the main arm 21.

[0053] The locking assembly 40 includes an inner tube 41, a limiting pin 42, an outer tube 43, and a resilient reset member 44. The inner tube 41 is fixed (e.g., welded) to the support arm 30 and extends out of the clearance hole 212. The limiting pin 42 is movably inserted into the inner tube 41, with one end extending out of the support arm 30 and the other end extending out of the inner tube 41. In a second state, the limiting pin 42 can be inserted into the first limiting hole 213 to lock the support arm 30. The outer tube 43 is movably sleeved outside the inner tube 41 and is connected to the pin of the limiting pin 42 extending out of the inner tube 41. The resilient reset member 44 is disposed inside the inner tube 41 and is used to apply an outward elastic force to the limiting pin 42.

[0054] Specifically, the limiting pin 42 includes a first pin and a second pin that are coaxial and connected. The outer diameter of the first pin is larger than that of the second pin. The first pin can be inserted into the first limiting hole 213. The second pin is located in the inner tube 41. An elastic reset member 44 is sleeved on the second pin. The two ends of the elastic reset member 44 abut against the end wall of the inner tube 41 and the end wall of the first pin, respectively. The elastic reset member 44 is a spring. The second pin extends out of the inner tube 41 and the outer tube 43. A retaining ring 45 is fixed on the second pin to prevent the outer tube 43 from falling off.

[0055] After sliding the seat frame 20 forward and rotating it at a certain angle toward the head of the frame body 10, the operator can extend the support arm 30 by pulling the outer tube 43. When the first pin is aligned with the first limiting hole 213, the elastic reset member 44 will quickly push the first pin to insert it into the first limiting hole 213. In this way, the support arm 30 can be locked on the main arm 21, and the support arm 30 will not extend or retract. After the two support arms 30 are abutted against the first longitudinal beam 12, the seat frame 20 can be kept in the second state, and the seat frame 20 will no longer rotate, thus ensuring safety during the maintenance process.

[0056] When it is necessary to release the locking state of the support arm 30, the operator pulls the outer tube 43 outward, which pushes against the retaining spring 45, thereby causing the first pin to exit the first limiting hole 213. In this way, the support arm 30 can be slid to adjust its extension length. During the sliding of the support arm 30, the first pin will abut against the cavity wall of the receiving cavity 211 under the action of the elastic reset member 44.

[0057] In one embodiment, a support base 15 is fixed to the protrusion 121, and the connecting part is an insertion hole 151. The insertion hole 151 is provided on the support base 15. In the first state, the support arm 30 is inserted into the corresponding insertion hole 151. The support base 15 is provided with a U-shaped limiting groove 152, which is used to ensure that the support arm 30 can only slide longitudinally. When the support arm 30 is inserted into the insertion hole 151, the seat frame 20 can be held in the first state by the cooperation of the slide rod 22 and the guide hole 161.

[0058] In one embodiment, the main arm 21 is provided with a second limiting hole 214 communicating with the receiving cavity 211. The limiting pin 42 can be inserted into the second limiting hole 214. In the first state, the support arm 30 is inserted into the insertion hole 151, and the limiting pin 42 can be inserted into the second limiting hole 214 to lock the support arm 30. By designing the second limiting hole 214 to cooperate with the limiting pin 42, the support arm 30 can be locked after it is inserted into the insertion hole 151, thereby preventing the support arm 30 from exiting the insertion hole 151 and keeping the seat frame 20 in the first state.

[0059] In one embodiment, the main arm 21 is provided with a third limiting hole 215 communicating with the receiving cavity 211. The limiting pin 42 can be inserted into the third limiting hole 215. When the support arm 30 is completely disengaged from the insertion hole 151, the limiting pin 42 can be inserted into the third limiting hole 215 to lock the support arm 30. By designing the third limiting hole 215 to cooperate with the limiting pin 42, the support arm 30 can be locked after it is completely disengaged from the insertion hole 151. This makes it convenient for the operator to operate the two support arms 30 separately, avoiding the support arms 30 from being reinserted into the insertion hole 151 under gravity, thus facilitating the switching of the seat frame 20 to the second state.

[0060] This embodiment also provides a tractor, including the aforementioned frame assembly. Because it uses the aforementioned frame assembly, it has the same working principle and technical effects as the frame assembly in the above embodiments, and will not be described again here.

[0061] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A vehicle frame assembly, characterized in that, include: The frame body (10) is provided with a central mounting position (11) for mounting the engine. The central mounting position (11) is close to the middle of the frame body (10). The frame body (10) is also provided with two connecting parts, which are respectively arranged on both sides of the central mounting position (11). A seat frame (20) is disposed on the frame body (10). The seat frame (20) can slide longitudinally along the frame body (10) and can rotate toward the head of the frame body (10). The seat frame (20) has a first state and a second state. In the first state, the seat frame (20) is located above the center mounting position (11). In the second state, the seat frame (20) exposes the center mounting position (11). Two support arms (30) extend and retract vertically on the seat frame (20). The two support arms (30) are arranged on both sides of the seat frame (20). The support arms (30) can be connected to the corresponding connecting parts so that the seat frame (20) is kept in the first state. as well as Two locking components (40) are respectively corresponding to the two support arms (30). In the second state, the support arms (30) can extend and abut against the frame body (10). The locking components (40) are used to lock the support arms (30) to prevent them from extending or retracting, or to release the locking state.

2. The frame assembly according to claim 1, characterized in that, The frame body (10) includes two first longitudinal beams (12), multiple first crossbeams (13) and two second longitudinal beams (14). The multiple first crossbeams (13) are arranged between the two first longitudinal beams (12), and each second longitudinal beam (14) is arranged below a corresponding first longitudinal beam (12). The two ends of the second longitudinal beam (14) are bent upward and connected to the corresponding first longitudinal beam (12). The seat frame (20) is mounted on two first longitudinal beams (12), and the first longitudinal beams (12) have protrusions (121) extending outward in the transverse direction. The two protrusions (121) and the two second longitudinal beams (14) together form the central mounting position (11).

3. The frame assembly according to claim 2, characterized in that, It also includes a mounting bracket (50), which is mounted on the two second longitudinal beams (14) and located in the central mounting position (11).

4. The frame assembly according to claim 2, characterized in that, The seat frame (20) includes two main arms (21) arranged opposite to each other. The main arms (21) are provided with a receiving cavity (211), a clearance hole (212) and a first limiting hole (213). The clearance hole (212) and the first limiting hole (213) are respectively connected to the receiving cavity (211). The support arm (30) is telescopically engaged in the receiving cavity (211) and extends out of the main arms (21). The locking component (40) includes: The inner tube (41) is fixed on the support arm (30) and extends out of the relief hole (212); A limiting pin (42) is movably inserted into the inner tube (41). One end of the limiting pin (42) extends out of the support arm (30), and the other end of the limiting pin (42) extends out of the inner tube (41). In the second state, the limiting pin (42) can be inserted into the first limiting hole (213) to lock the support arm (30). An outer tube (43) is movably fitted outside the inner tube (41), and the outer tube (43) is connected to a pin (42) extending out of the inner tube (41); and An elastic reset member (44) is provided inside the inner tube (41), and the elastic reset member (44) is used to apply an outwardly extending elastic force to the limiting pin (42).

5. The frame assembly according to claim 4, characterized in that, The limiting pin (42) includes a first pin and a second pin that are coaxial and connected. The outer diameter of the first pin is larger than the outer diameter of the second pin. The first pin can be inserted into the first limiting hole (213). The second pin is located in the inner tube (41). The elastic reset member (44) is sleeved on the second pin. The two ends of the elastic reset member (44) abut against the end wall of the inner tube (41) and the end wall of the first pin, respectively. The second pin extends out of the inner tube (41) and the outer tube (43), and the second pin is provided with a retaining ring (45) to prevent the outer tube (43) from falling off.

6. The frame assembly according to claim 4, characterized in that, The protrusion (121) is provided with a support base (15), and the connecting part is a plug hole (151). The plug hole (151) is provided on the support base (15). In the first state, the support arm (30) is inserted into the corresponding plug hole (151). The support base (15) is provided with a limiting groove (152). The limiting groove (152) is used to make the support arm (30) slide only in the longitudinal direction.

7. The frame assembly according to claim 6, characterized in that, The main arm (21) is provided with a second limiting hole (214) communicating with the receiving cavity (211). The limiting pin (42) can be inserted into the second limiting hole (214). In the first state, the support arm (30) is inserted into the insertion hole (151), and the limiting pin (42) can be inserted into the second limiting hole (214) to lock the support arm (30).

8. The frame assembly according to claim 6, characterized in that, The main arm (21) is provided with a third limiting hole (215) communicating with the receiving cavity (211). The limiting pin (42) can be inserted into the third limiting hole (215). When the support arm (30) is completely disengaged from the insertion hole (151), the limiting pin (42) can be inserted into the third limiting hole (215) to lock the support arm (30).

9. The frame assembly according to claim 2, characterized in that, The first longitudinal beam (12) is provided with a base (16), the base (16) is provided with a guide hole (161), and the bottom of the seat frame (20) is provided with two cylindrical sliding rods (22), each of the sliding rods (22) is slidably and rotatably fitted in the corresponding guide hole (161).

10. A tractor, characterized in that, The frame assembly includes any one of claims 1-9.

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