Electric control pull rod mechanism, tractor chassis and tractor

Abstract

The utility model belongs to the technical field of tractor chassis, and particularly relates to an electric control pull rod mechanism, a tractor chassis and a tractor. The driving assembly is mounted on the mounting frame; the first end of the push rod is in driving connection with the driving assembly, and the driving assembly is used for driving the push rod to extend or retract under the condition that the control signal is received; the first end of the connecting arm is hinged to the second end of the push rod, the second end of the connecting arm is connected with a shifting fork assembly of the tractor, and the connecting arm swings relative to the push rod to drive the shifting fork assembly to act, so that the tractor is switched between a rear drive mode and a four-wheel drive mode. By the adoption of the electric control pull rod mechanism, the labor intensity of operators can be relieved, and the braking effect and driving safety of the tractor under the road condition that braking is difficult are improved.

Description

Technical Field

[0001] This utility model belongs to the field of tractor chassis technology, specifically relating to an electronically controlled tie rod mechanism, a tractor chassis, and a tractor. Background Technology

[0002] Tractors have their center of gravity at the rear, so they typically use rear-wheel drive and braking. In most road conditions, the braking force of the rear wheels is usually sufficient for practical needs, and the rear-wheel braking system is relatively simple in structure, easy to maintain, and inexpensive.

[0003] However, tractors need faster and more effective braking to cope with various emergencies on muddy, slippery, or rough and uneven roads. In existing technology, switching a tractor from rear-wheel drive to four-wheel drive requires manually pulling a lever. The lever engages the front-wheel drive linkage with the output gear to put the tractor into four-wheel drive mode. However, this structure requires the operator to apply significant pushing and pulling force to the lever. Utility Model Content

[0004] The purpose of this utility model is to provide an electronically controlled tie rod mechanism, a tractor chassis, and a tractor to solve the technical problem of difficulty in pushing the tie rod in the prior art.

[0005] To achieve the above objectives, this utility model provides an electrically controlled tie rod mechanism for use in tractors, comprising:

[0006] Mounting rack;

[0007] The drive component is mounted on the mounting bracket;

[0008] The push rod has its first end connected to a drive assembly, which is used to extend or retract the push rod upon receiving a control signal.

[0009] The connecting arm has its first end hinged to the second end of the push rod, and the second end of the connecting arm is connected to the tractor's shift fork assembly. The swinging of the connecting arm relative to the push rod can drive the shift fork assembly to move, so that the tractor can switch between rear-wheel drive mode and four-wheel drive mode.

[0010] In some embodiments, the mounting bracket includes: a base plate; two side plates respectively disposed on both sides of the base plate, the base plate and the two side plates forming an accommodating space; a support rod located in the accommodating space and disposed near the end, the two ends of the support rod passing through the two side plates respectively, and the end of the drive assembly opposite to the connecting arm being mounted on the support rod.

[0011] In some embodiments, the drive assembly includes a housing and a drive member mounted on one end of the housing near the connecting arm. The end of the housing is provided with a mounting hole, through which a support rod passes. The three side walls of the housing abut against the base plate and two side plates, respectively.

[0012] In some embodiments, the second end of the push rod has two connecting portions extending along the axial direction of the push rod, the two extension portions being arranged in parallel and spaced apart, and one end of the connecting arm being inserted between the two extension portions and hinged to both extension portions.

[0013] In some embodiments, the driving component is a rotary driving component, and the electrically controlled pull rod mechanism further includes: a rotary lead screw, which is drivenly connected to the rotary driving component, and a lead screw nut is helically fitted on the rotary lead screw, and the first end of the push rod is installed on the outer periphery of the lead screw nut.

[0014] The second aspect of this utility model provides a tractor chassis, which includes a main support frame and the aforementioned electronically controlled tie rod mechanism, wherein the mounting frame is detachably connected to the main support frame.

[0015] In some embodiments, the tractor chassis further includes a transfer case mounted on the main support frame and having an output shaft; and disposed within the transfer case: an output gear, sleeved on the output shaft and used to drive the tractor's rear travel wheels; a front drive coupling assembly, arranged side-by-side with the output gear along the axial direction of the output shaft, the front drive coupling assembly being sleeved on the output shaft and used to drive the tractor's front travel wheels; and a shift fork assembly, with a shift fork portion and a connecting shaft portion at each end, the shift fork portion being drivably connected to the front drive coupling assembly, the connecting shaft portion being connected to a connecting arm, the action of the shift fork assembly being used to push the front drive coupling assembly to move and engage with the output gear to enter four-wheel drive mode, or to disengage the front drive coupling assembly from the output gear to enter rear drive mode.

[0016] In some embodiments, a through hole is provided on the side wall of the transfer case, and a connecting cylinder is provided at the second end of the connecting arm. The connecting cylinder passes through the through hole and is rotatably engaged with the inner wall of the through hole. The connecting shaft of the shift fork assembly is fixedly inserted into the connecting cylinder.

[0017] In some embodiments, the tractor chassis further includes a human-machine interface component, which is communicatively connected to the drive component and used to control the drive component to extend or retract a drive rod.

[0018] The second aspect of this utility model provides a tractor, including the tractor chassis described above.

[0019] The above-described technical solution provides an electronically controlled lever mechanism for use in tractors. This mechanism includes a mounting bracket, a drive assembly, a push rod, and a connecting arm. The drive assembly is mounted on the mounting bracket and drivenly connected to the first end of the push rod, enabling it to extend or retract. The connecting arm is hinged to the second end of the push rod, and the second end of the connecting arm is connected to the tractor's shift fork assembly. When the drive assembly receives a control signal, it drives the push rod to extend or retract, which in turn causes the connecting arm to swing. The swinging of the connecting arm further drives the shift fork assembly. The movement of the shift fork assembly enables switching between rear-wheel drive and four-wheel drive modes. This electronically controlled lever mechanism design significantly reduces the operator's workload and improves the tractor's braking performance and driving safety under different road conditions.

[0020] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of the electrically controlled pull rod mechanism provided according to an embodiment of the present utility model;

[0023] Figure 2 This is a schematic diagram of the structure of a tractor chassis according to an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the transfer case and the electronically controlled tie rod mechanism in the rear-drive state according to an embodiment of the present utility model;

[0025] Figure 4 This is a cross-sectional schematic diagram of the transfer case and the electronically controlled linkage mechanism in the rear-drive state according to an embodiment of the present utility model;

[0026] Figure 5 This is a schematic diagram of the transfer case and the electronically controlled linkage mechanism in four-wheel drive mode according to an embodiment of the present invention;

[0027] Figure 6 This is a cross-sectional schematic diagram of the transfer case and the electronically controlled linkage mechanism in four-wheel drive mode according to an embodiment of the present utility model;

[0028] Figure 7This is a schematic diagram showing the cooperation between the shift fork assembly and the front drive connection assembly according to an embodiment of the present utility model.

[0029] Explanation of reference numerals in the attached figures

[0030] 10. Electrically controlled tie rod mechanism

[0031] 11 Mounting rack

[0032] 111 base plate

[0033] 112 Side Panel

[0034] 113 Support rod

[0035] 12 Driver Components

[0036] 121 Casing

[0037] 122 Drive components

[0038] 13 Putter

[0039] 131 Connecting part

[0040] 14 Connecting Arm

[0041] 141 Connecting cylinder

[0042] 20 Main support frame

[0043] 30 transfer case

[0044] 31 Output gear

[0045] 32 Front drive connection assembly

[0046] 321 Groove

[0047] 33 Shift Fork Assembly

[0048] 331 Shift fork section

[0049] 332 Connecting shaft

[0050] 333 Shift Fork Connector Block

[0051] 40 Output shaft Detailed Implementation

[0052] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0053] The electrically controlled pull rod mechanism 10 according to the present invention is described below with reference to the accompanying drawings.

[0054] like Figure 1The diagram shown is a structural schematic of the electrically controlled pull rod mechanism 10 provided according to an embodiment of the present invention. The electrically controlled pull rod mechanism 10 is used in a tractor and includes:

[0055] Mounting bracket 11;

[0056] Drive component 12 is mounted on mounting bracket 11;

[0057] The push rod 13 has its first end connected to the drive assembly 12, which is used to drive the push rod 13 to extend or retract when a control signal is received.

[0058] The connecting arm 14 has its first end hinged to the second end of the push rod 13. The second end of the connecting arm 14 is connected to the shift fork assembly 33 of the tractor. The swing of the connecting arm 14 relative to the push rod 13 can drive the shift fork assembly 33 to move, so that the tractor can switch between rear-wheel drive mode and four-wheel drive mode.

[0059] In existing technology, if the tractor's drive mode is changed from rear-wheel drive to four-wheel drive, the operator usually needs to manually pull a lever. The lever then engages the front-wheel drive connection assembly 32 with the output gear 31, allowing the tractor to enter four-wheel drive mode. However, this manual operation method has many inconveniences. The operator needs to apply a large pushing and pulling force to the lever, which not only increases the operator's labor intensity but also may not be able to quickly complete the mode switch in an emergency, thus affecting the tractor's braking effect and driving safety.

[0060] To address the aforementioned problems in the prior art, the electrically controlled lever mechanism 10 of this invention employs an electric drive. Specifically, the electrically controlled lever mechanism 10 includes a mounting frame 11, a drive assembly 12, a push rod 13, and a connecting arm 14. The drive assembly 12 is mounted on the mounting frame 11 and is drivenly connected to the first end of the push rod 13. When the drive assembly 12 receives a control signal, it drives the push rod 13 to extend or retract. The connecting arm 14 is hinged to the second end of the push rod 13, and the second end of the connecting arm 14 is connected to the tractor's shift fork assembly 33. Therefore, the extension or retraction of the push rod 13 causes the connecting arm 14 to swing, and the swing of the connecting arm 14 further drives the shift fork assembly 33 to move. The movement of the shift fork assembly 33 can change the meshing state between the front-drive connecting assembly 32 and the output gear 31 on the tractor chassis, thereby enabling rapid switching between rear-drive and four-wheel drive modes for the tractor.

[0061] The design of this electronically controlled linkage mechanism 10 not only greatly reduces the labor intensity of operators but also improves the braking effect and driving safety of the tractor in difficult braking conditions. Furthermore, due to its electric drive, the electronically controlled linkage mechanism 10 can also achieve remote and automated control, further enhancing the tractor's level of intelligence.

[0062] In one embodiment, such as Figure 1 As shown, the mounting frame 11 includes a base plate 111, two side plates 112, and a support rod 113. The two side plates 112 are respectively disposed on both sides of the base plate 111, forming an accommodating space. The support rod 113 is located within the accommodating space and positioned near its end. Both ends of the support rod 113 penetrate the two side plates 112 respectively. The end of the drive assembly 12 facing away from the connecting arm 14 is mounted on the support rod 113. Using the aforementioned mounting frame 11, the drive assembly 12 can be stably supported, ensuring a stable and reliable connection between the drive assembly 12 and the push rod 13. Furthermore, the mounting frame 11 has a simple and reasonable structural design, facilitating manufacturing and installation, and reducing production costs. In addition, the detachable connection between the mounting frame 11 and the main support frame 20 allows for convenient installation and disassembly of the electrically controlled pull rod mechanism 10, facilitating maintenance and replacement.

[0063] In one embodiment, such as Figure 1 As shown, the drive assembly 12 includes a housing 121 and a drive member 122 mounted on one end of the housing 121 near the connecting arm 14. The end of the housing 121 has a mounting hole through which a support rod 113 passes. The three side walls of the housing 121 abut against the base plate 111 and the two side plates 112, respectively. Using the aforementioned drive assembly 12 ensures a stable and reliable connection between the drive assembly 12 and the mounting bracket 11, while also facilitating the installation and disassembly of the drive assembly 12. Furthermore, the housing 121 stabilizes and supports the drive member 122, ensuring stable output during drive operations. The selection of the drive member 122 can be flexibly adjusted according to actual needs; for example, a motor or hydraulic motor can be used to meet the requirements of different scenarios.

[0064] In one embodiment, such as Figure 1 As shown, the second end of the push rod 13 has two connecting portions 131 extending along the axial direction of the push rod 13. The two extensions are arranged in parallel and spaced apart. One end of the connecting arm 14 is inserted between the two extensions and hinged to both extensions. By using the push rod 13 described above, the connection between the connecting arm 14 and the push rod 13 is more stable and can withstand greater forces and torques, thereby ensuring the stability and reliability of the electrically controlled pull rod mechanism 10 during long-term use.

[0065] In one embodiment, the drive element 122 is a rotary drive element, such as a motor. The electronically controlled lever mechanism 10 also includes a rotary lead screw, which is driven by the rotary drive element 122. A lead screw nut is helically fitted on the rotary lead screw, and the first end of the push rod 13 is mounted on the outer periphery of the lead screw nut. The rotary lead screw is a transmission element that can convert rotary motion into linear motion. When the rotary drive element 122 drives the rotary lead screw to rotate, the lead screw nut will move linearly along the axial direction of the rotary lead screw. The first end of the push rod 13 is mounted on the outer periphery of the lead screw nut, and the linear motion of the lead screw nut will drive the push rod 13 to extend and retract. This transmission method has the advantages of simple structure, smooth transmission, and strong load-bearing capacity, and can meet the requirements of the electronically controlled lever mechanism 10 for transmission accuracy and stability. At the same time, by adjusting the rotation speed and direction of the rotary drive element 122, the extension and retraction speed and direction of the push rod 13 can be easily controlled, thereby achieving precise control of the tractor drive mode.

[0066] In one embodiment, such as Figure 2 The diagram shown is a structural schematic of a tractor chassis according to an embodiment of the present invention. The tractor chassis includes a main support frame 20 and the aforementioned electronically controlled tie rod mechanism 10. The mounting frame 11 is detachably connected to the main support frame 20. Using this tractor chassis, the tractor can easily switch between rear-wheel drive and four-wheel drive modes, improving its adaptability and flexibility. Furthermore, because the electronically controlled tie rod mechanism 10 is detachably connected to the main support frame 20, the tractor chassis structure is more modular, facilitating maintenance and upgrades.

[0067] In one embodiment, such as Figure 3 The diagram shown is a structural schematic of the transfer case 30 and the electrically controlled linkage mechanism 10 in the rear-drive state according to an embodiment of the present invention; Figure 4 The diagram shown is a cross-sectional view of the transfer case 30 and the electronically controlled linkage mechanism 10 in rear-drive mode according to an embodiment of the present invention; Figure 5 The diagram shown is a structural schematic of the transfer case 30 and the electronically controlled linkage mechanism 10 in four-wheel drive mode according to an embodiment of the present invention; Figure 6The diagram shown is a cross-sectional view of the transfer case 30 and the electronically controlled linkage mechanism 10 in four-wheel drive mode according to an embodiment of the present invention. The tractor chassis also includes a transfer case 30 mounted on the main support frame 20 and having an output shaft 40, and within the transfer case 30: an output gear 31, a front-drive connection assembly 32, and a shift fork assembly 33. The output gear 31 is sleeved on the output shaft 40 and is used to drive the tractor's rear wheels. The front-drive connection assembly 32 and the output gear 31 are arranged side-by-side along the axial direction of the output shaft 40. The front-drive connection assembly 32 is sleeved on the output shaft 40 and is used to drive the tractor's front wheels. The shift fork assembly 33 has a shift fork portion 331 and a connecting shaft portion 332 at its two ends. The shift fork portion 331 is driven to connect to the front drive connecting assembly 32. The connecting shaft portion 332 of the shift fork assembly 33 is connected to the connecting arm 14. The action of the shift fork assembly 33 is used to push the front drive connecting assembly 32 to move and engage with the output gear 31 to enter the four-wheel drive mode, or to separate the front drive connecting assembly 32 from the output gear 31 to enter the rear drive mode.

[0068] Specifically, Figure 3 and Figure 4 The figures shown are a schematic diagram and a cross-sectional view of the tractor in rear-wheel drive mode. In this mode, the tractor is in rear-wheel drive, the front-wheel drive connection assembly 32 is disengaged from the output gear 31, and the tractor's power is supplied solely by the rear wheels. Figure 5 and Figure 6 The diagrams shown are a schematic diagram and a cross-sectional view of the tractor in four-wheel drive mode. When switching to four-wheel drive mode, the drive assembly 12 receives a control signal, causing the drive push rod 13 to extend. The extension of the push rod 13 causes the connecting arm 14 to swing, and the swing of the connecting arm 14 further drives the shift fork assembly 33. The shift fork portion 331 of the shift fork assembly 33 pushes the front drive connecting assembly 32 to move, so that the front drive connecting assembly 32 meshes with the output gear 31, thereby realizing the switching of the tractor from rear-wheel drive mode to four-wheel drive mode. In four-wheel drive mode, the tractor's power is provided by both the rear and front wheels, improving the tractor's driving capability and braking effect. When switching back from four-wheel drive mode to rear-wheel drive mode, the drive assembly 12 receives a control signal again, but this time the drive push rod 13 shortens. The shortening of the push rod 13 also causes the connecting arm 14 to swing, but the direction of the swing is opposite to the direction of extension. The swing of the connecting arm 14 further drives the shift fork assembly 33 to move in the opposite direction. The shift fork portion 331 of the shift fork assembly 33 pulls the front drive connecting assembly 32 to move, causing the front drive connecting assembly 32 to separate from the output gear 31, thereby realizing the switching of the tractor from four-wheel drive mode to rear drive mode.

[0069] This design allows the tractor to flexibly switch between rear-wheel drive and four-wheel drive modes according to road conditions and driving needs, improving the tractor's passability and driving stability. In summary, the electronically controlled linkage mechanism 10, tractor chassis, and tractor provided by this invention, through the use of electric drive, achieve rapid switching between rear-wheel drive and four-wheel drive modes, not only reducing the operator's workload but also improving the tractor's braking effect and driving safety in difficult braking conditions. The use of the electronically controlled linkage mechanism 10 facilitates improved tractor intelligence and also simplifies the layout of the tractor chassis space.

[0070] In one embodiment, a through hole is provided on the side wall of the transfer case 30, and a connecting cylinder 141 is provided at the second end of the connecting arm 14. The connecting cylinder 141 passes through the through hole and is rotatably engaged with the inner wall of the through hole. The connecting shaft portion 332 of the shift fork assembly 33 is fixedly inserted into the connecting cylinder 141. This design makes the connection between the connecting arm 14 and the transfer case 30 more flexible and can adapt to the movement requirements of the shift fork assembly 33 when switching drive modes. At the same time, the rotatable engagement between the connecting cylinder 141 and the inner wall of the through hole limits the movement of the connecting cylinder 141, improving the reliability of the movement of the connecting arm 14. In addition, the fixed insertion of the connecting shaft portion 332 of the shift fork assembly 33 into the connecting cylinder 141 ensures that the connection between the shift fork assembly 33 and the connecting arm 14 is stable and reliable, avoiding loosening or detachment when switching drive modes, and further improving the driving safety of the tractor.

[0071] In a specific embodiment, such as Figure 7The diagram shows the engagement of the shift fork assembly 33 and the front drive connecting assembly 32 according to an embodiment of the present invention. The front drive connecting assembly 32 is a front drive connecting sleeve. The shift fork assembly 33 includes a shift fork portion 331 and a connecting shaft portion 332. A shift fork connecting block 333 is provided at the end of the shift fork portion 331. A groove 321 is formed circumferentially on the outer side wall of the front drive connecting sleeve, and teeth are formed circumferentially on the inner side wall of the front drive connecting sleeve. The shift fork connecting block 333 is movably embedded in the groove 321. Further, the front drive connecting sleeve includes a large-diameter portion and a small-diameter portion coaxially connected in sequence. The inner circumferential wall of the small-diameter portion contacts the output shaft 40. When the shift fork assembly 33 rotates, the shift fork connecting block 333 applies a force along the axial direction of the output shaft 40 to the front drive connecting sleeve, causing the teeth on the inner side wall of the large-diameter portion of the front drive connecting sleeve to mesh or separate from the output gear 31. The shift fork connecting block 333 is movably embedded in the groove 321 of the front drive connecting sleeve. This structure ensures that the shift fork assembly 33 remains stably embedded in the groove 321 during rotation, and also guarantees that the shift fork assembly 33 can accurately push or pull the front drive connecting sleeve when switching drive modes, thereby achieving reliable switching between rear drive and four drive modes for the tractor. Simultaneously, it prevents excessive friction on the front drive connecting sleeve during rotation.

[0072] In one embodiment, the tractor chassis further includes a human-machine interface component, which is communicatively connected to the drive assembly 12 and used to control the drive assembly 12 to extend or retract the drive push rod 13. Using the aforementioned human-machine interface component, it is possible to accept control commands input by the user to adjust the engine's drive state based on the control commands.

[0073] In one embodiment, a tractor is provided, including the tractor chassis described above.

[0074] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0075] In this utility model, unless otherwise explicitly 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0076] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electrically controlled pull rod mechanism, characterized by, The electric control pull rod mechanism (10) is used for a tractor, and the electric control pull rod mechanism (10) comprises: a mounting frame (11); a driving assembly (12) mounted on the mounting frame (11); a push rod (13) having a first end drivingly connected with the driving assembly (12), the driving assembly (12) being configured to drive the push rod (13) to extend or shorten when receiving a control signal; a connecting arm (14) having a first end hingedly connected with a second end of the push rod (13) and a second end connected with a shift fork assembly (33) of the tractor, the connecting arm (14) being configured to drive the shift fork assembly (33) to act to switch the tractor between a rear-wheel drive mode and an all-wheel drive mode in response to an oscillation of the connecting arm (14) relative to the push rod (13).

2. The electrically controlled tensioning rod mechanism according to claim 1, characterized in that The mounting frame (11) comprises: a bottom plate (111); two side plates (112) respectively arranged on two sides of the bottom plate (111), the bottom plate (111) and the two side plates (112) forming a containing space; a support rod (113) located in the containing space and arranged close to an end portion, both ends of the support rod (113) penetrating through the two side plates (112) respectively, and the driving assembly (12) being mounted on the support rod (113) at an end thereof away from the connecting arm (14).

3. The electrically controlled tensioning rod mechanism of claim 2, wherein, The driving assembly (12) comprises a housing (121) and a driving member (122) mounted on the housing (121) at an end thereof close to the connecting arm (14), an end portion of the housing (121) being provided with a mounting hole through which the support rod (113) penetrates, and three side walls of the housing (121) being respectively in abutment with the bottom plate (111) and the two side plates (112).

4. The electrically controlled tensioning rod mechanism of claim 1, wherein, The second end of the push rod (13) has two connecting portions (131) extending in an axial direction of the push rod (13), the two connecting portions being arranged in parallel and at intervals, and one end of the connecting arm (14) being inserted between and hingedly connected with the two connecting portions.

5. The electrically controlled pull rod mechanism of claim 3, wherein The driving member (122) is a rotary driving member (122), and the electric control pull rod mechanism (10) further comprises: a rotary screw rod drivingly connected with the rotary driving member (122), and a screw nut being helically sleeved on the rotary screw rod, and the first end of the push rod (13) being mounted on an outer periphery of the screw nut.

6. A tractor chassis characterised in that, The tractor chassis comprises a main support frame (20) and the electric control pull rod mechanism (10) according to any one of claims 1 to 5, the mounting frame (11) being detachably connected with the main support frame (20).

7. A tractor chassis according to claim 6, characterised in that, The tractor chassis further comprises a transfer case (30) mounted on the main support frame (20) and having an output shaft (40), and an output gear (31) provided in the transfer case (30) and sleeved on the output shaft (40) and configured to drive rear traveling wheels of the tractor. The tractor chassis further comprises a transfer case (30) mounted on the main support frame (20) and having an output shaft (40), and an output gear (31) provided in the transfer case (30) and sleeved on the output shaft (40) and configured to drive rear traveling wheels of the tractor. A front drive connecting assembly (32) is disposed along the output shaft (40) in parallel with the output gear (31) in the axial direction, is sleeved on the output shaft (40) and is used to drive the front walking wheels of the tractor to walk; A shift fork assembly (33) has a shift fork part (331) and a connecting shaft part (332) at two ends, the shift fork part (331) is drivingly connected with the front drive connecting assembly (32), the connecting shaft part (332) is connected with the connecting arm (14), and the shift fork assembly (33) is used to push the front drive connecting assembly (32) to move and engage with the output gear (31) to enter the four-wheel drive mode or separate the front drive connecting assembly (32) from the output gear (31) to enter the rear-wheel drive mode.

8. A tractor chassis according to claim 7, characterised in that, A through hole is formed in the side wall of the transfer box (30), a connecting barrel (141) is arranged at the second end of the connecting arm (14), the connecting barrel (141) penetrates through the through hole and is rotatably matched with the inner wall of the through hole, and the connecting shaft part (332) of the shift fork assembly (33) is fixedly inserted into the connecting barrel (141).

9. A tractor chassis according to claim 8, characterised in that, The tractor chassis further comprises: A human-computer interaction assembly is in communication connection with the driving assembly (12) and is used to control the driving assembly (12) to drive the push rod (13) to elongate or shorten.

10. A tractor characterised in that, The tractor chassis comprises any one of claims 7 to 9. The tractor chassis comprises any one of claims 7 to 9.

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