A milling machine

Abstract

The present invention relates to a milling machine, belonging to the technical field of special road machinery and equipment; the milling machine comprises a frame, a seat rotatably and adjustably connected to the frame, an armrest rotatably and adjustably connected to the frame, and a ladder rotatably and adjustably elastically connected to the frame, wherein the armrest and the ladder are arranged on the outer side of the frame, the armrest can be rotated inwardly for storage, the ladder can be rotated downwardly for extension, and the ladder can be rotated upwardly for folding and storage; the present invention provides a milling machine, wherein the armrest, the ladder, and the seat can all be retracted inwardly, and after being retracted, the requirements for edge milling and transportation width of the whole machine can be met, thereby facilitating construction and making transportation safer.

Description

Technical Field

[0001] The invention relates to a milling machine, belonging to the technical field of special mechanical equipment for roads. Background Art

[0002] Pavement milling machines are special machinery and equipment for highway and urban road maintenance operations. They are mainly used in the excavation and renovation of asphalt concrete surface layers in highways, airports, docks, parking lots, etc., the removal of pavement diseases such as rutting, cracking, carbuncles, road markings on asphalt roads, and the milling of roughened cement roads and surface misalignment. During construction, large milling machines need to see the front track and side panels of the milling room due to vision requirements, and the right-side handrail, ladder, pedal, and seat need to extend out of the frame. Currently, the right-side handrail, ladder, etc. are fixed on the frame. When milling along the edge or transporting long distances, the whole machine is extra-wide, which affects edge milling and long-distance transportation. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a milling machine whose handrails, ladders, and seats can all be retracted inwards. After retraction, the requirements for edge milling and whole machine transportation can be met, thereby facilitating construction and making transportation safer.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A milling machine comprises a frame, a seat rotatably and adjustably connected to the frame, an armrest rotatably and adjustably connected to the frame, and a ladder rotatably and adjustably elastically connected to the frame, wherein the armrest and the ladder are arranged on the outside of the frame, the armrest can be rotated inwardly for storage, the ladder can be rotated downwardly for extension, and the ladder can be rotated upwardly for folding and storage.

[0006] Furthermore, the seat includes a base arranged on the frame, a rotating shaft rotatably connected to the base, and a seat cushion arranged on the rotating shaft, the rotating shaft can be inserted in the base and rotated, the seat cushion and the rotating shaft are connected via a seat cushion bottom plate, the seat cushion bottom plate is arranged under the seat cushion, an electrical cabinet is provided on the frame, and the seat cushion can be rotated to the bottom of the electrical cabinet.

[0007] Furthermore, a self-lubricating graphite copper sleeve is provided between the base and the rotating shaft, an inwardly concave limiting ring groove is provided on the outer circumference of the rotating shaft, and a limiting bolt is threadedly connected on the outer circumference of the base, and the limiting bolt can pass into the base and be clamped in the limiting ring groove;

[0008] The base is provided with a protruding supporting circular plate on the outer periphery, and a clamp is provided above the supporting circular plate. The clamp is sleeved on the outer periphery of the base, and the clamp is connected to the seat cushion bottom plate through a seat connecting rod. One end of the seat connecting rod is hinged to the seat cushion bottom plate, and the other end of the seat connecting rod is connected to the clamp through a handle screw.

[0009] Furthermore, the handrail includes a front handrail rotatably connected to the frame, a rear handrail rotatably connected to the frame, a guardrail rotatably connected to the front handrail, and a revolving door rotatably connected to the rear handrail.

[0010] Furthermore, the front armrest can slide relative to the frame, the guardrail can slide relative to the front armrest, the rear armrest can slide relative to the frame, and the revolving door can slide relative to the rear armrest; a rotation limiting device is provided between the front armrest and the frame, between the front armrest and the guardrail, between the frame and the rear armrest, and between the rear armrest and the revolving door, and the rotation limiting device includes a rotation limiting seat, a plurality of limiting grooves arranged around the rotation limiting seat, and a rotation limiting plate that can be inserted into the limiting grooves.

[0011] Furthermore, a main pedal is provided on the frame, and the ladder includes an outer pedal rotatably connected to the main pedal, a secondary ladder rotatably connected to the outer pedal, and a primary ladder rotatably connected to the secondary ladder, the upper end of the secondary ladder is rotatably connected to the outer lower end of the outer pedal, and a ladder connecting rod is further provided between the secondary ladder and the frame, one end of the ladder connecting rod is rotatably connected to the frame, and the other end of the ladder connecting rod is rotatably connected to the secondary ladder.

[0012] Furthermore, an elastic driving device is provided between the outer pedal and the frame, and the outer pedal can be rotated and folded inwards under the action of the elastic driving device, and drive the secondary ladder to fold inwards.

[0013] Furthermore, the elastic force driving device is a pneumatic spring, one end of the pneumatic spring is rotatably hinged to the outer pedal, the other end of the pneumatic spring is rotatably hinged to the frame, and the elastic force driving device is arranged on the inner side of the secondary ladder.

[0014] Furthermore, the secondary ladder is provided with a ladder rotation positioning seat plate, and the first ladder is correspondingly provided with a ladder rotation positioning hole. When the first ladder is flipped and folded upward to fit tightly with the secondary ladder, the pin shaft can pass through the rotation positioning hole and the positioning seat plate to fix the first ladder and the second ladder.

[0015] Furthermore, a pedal limit plate is also provided on the main pedal, and when the outer pedal is rotated to a horizontal state, the lower part can be pressed against the upper part of the pedal limit plate; the outer pedal is a hollow structure and is provided with a plurality of resistance-increasing racks.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The ladder, seat and handrail of the technical solution can be rotated and adjusted, which is convenient for quick and flexible switching under different usage requirements. It is more convenient to use and can meet the needs of edge milling and long-distance transportation after folding and storage;

[0018] The seats of the technical solution can be stored under the electrical cabinet, making full use of the space, making the structure more compact after folding and storing, and improving the space utilization rate;

[0019] The present invention provides a rotation limiter between the armrest and the frame and between the various components of the armrest, which can easily adjust the various components of the armrest to the required angle and then lock and fix them, making it more convenient and stable to use.

[0020] The seat of the technical solution is also provided with a limiting ring groove and a limiting bolt, which can limit the axial relative movement of the base and the rotating shaft without interfering with the relative rotation of the base and the rotating shaft, and is safer to use;

[0021] The ladder of the technical solution is provided with an elastic driving device, which can save more effort and be more convenient to use when folding and storing the ladder;

[0022] The first-level ladder of the technical solution can be folded upward and can be fixed with the second-level ladder. After folding, it occupies less space and is more convenient to store;

[0023] The outer pedal of the technical solution is provided with a resistance-increasing rack, which can increase friction and prevent slipping, and can ensure the operating safety of the operator.

[0024] The outer pedal of the present technical solution is hollowed out, and the hollow structure can facilitate the operator to observe the operating status of the milling chamber side panel and other components below, making it more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The three-dimensional structure diagram of a milling machine provided by an embodiment of the present invention is Figure 1 (handrails, ladder and seat are extended);

[0026] Figure 2 The schematic diagram of the partial structure of a milling machine provided by the embodiment of the present invention is shown in the front view Figure 1 (handrails, ladder and seat are extended);

[0027] Figure 3 The schematic diagram of the local structure of a milling machine provided by the embodiment of the present invention is shown in a top view Figure 1 (handrails, ladder and seat are extended);

[0028] Figure 4 The three-dimensional structure diagram of a milling machine provided by an embodiment of the present invention is Figure 2 (When the handrails, ladder and seat are folded and stored);

[0029] Figure 5 The schematic diagram of the partial structure of a milling machine provided by the embodiment of the present invention is shown in the front view Figure 2(When the handrails, ladder and seat are folded and stored);

[0030] Figure 6 The schematic diagram of the local structure of a milling machine provided by the embodiment of the present invention is shown in a top view Figure 2 (When the handrails, ladder and seat are folded and stored);

[0031] Figure 7 It is a side view structural diagram of a seat structure of a milling machine provided by an embodiment of the present invention;

[0032] Figure 8 It is a schematic diagram of the main structure of a seat structure of a milling machine provided by an embodiment of the present invention;

[0033] Fig. 9 It is a schematic diagram of a top view of a seat structure of a milling machine provided by an embodiment of the present invention;

[0034] Fig.10 is a side structural schematic diagram of a ladder structure of a milling machine provided by an embodiment of the present invention (when extended);

[0035] Fig.11 is a schematic diagram of the three-dimensional structure of an armrest of a milling machine provided by an embodiment of the present invention (when extended);

[0036] Fig.12 It is a partial structural schematic diagram of a ladder of a milling machine provided by an embodiment of the present invention (when extended).

[0037] Explanation of reference numbers: 1-frame, 2-seat, 3-armrest, 4-ladder, 5-base, 6-rotating shaft, 7-seat cushion, 8-seat cushion bottom plate, 9-electrical cabinet, 10-self-lubricating graphite copper sleeve, 11-limiting ring groove, 12-limiting bolt, 13-supporting circular plate, 14-clamp, 15-seat connecting rod, 16-handle screw, 17-front armrest, 18-rear armrest, 19-guardrail, 20-revolving door, 21-rotation limiting device, 22-rotation limiting seat, 23-limiting groove, 24-rotation limiting plate, 25-main pedal, 26-outer pedal, 27-secondary ladder, 28-first ladder, 29-ladder connecting rod, 30-elastic drive device, 31-ladder rotation positioning seat plate, 32-ladder rotation positioning hole, 33-pedal limiting plate, 34-resistance increasing rack. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] A milling machine as shown in the accompanying drawings comprises a frame 1, a seat 2 rotatably connected to the frame, an armrest 3 rotatably connected to the frame, and a ladder 4 rotatably and elastically connected to the frame, wherein the armrest and the ladder are arranged on the outside of the frame, the armrest can be rotated inwardly for storage, the ladder can be rotated downwardly for extension, and the ladder can be rotated upwardly for folding and storage;

[0042] When in use, the seat, handrails and ladder can be rotated to the desired position for personnel to use. After use, they can also be rotated and folded for storage to reduce space occupancy and reduce the size of the entire milling machine in the width direction, making it convenient for the milling machine to perform edge milling operations and long-distance transportation.

[0043] More specifically, the seat includes a base 5 arranged on the frame, a rotating shaft 6 rotatably connected to the base, and a seat cushion 7 arranged on the rotating shaft, the rotating shaft can be inserted in the base and rotated, the seat cushion and the rotating shaft are connected through a seat cushion bottom plate 8, the seat cushion bottom plate is arranged below the seat cushion, an electrical cabinet 9 is arranged on the frame, and the seat cushion can be rotated to the bottom of the electrical cabinet;

[0044] The base is similar to a sleeve structure, with a hollow center, which provides support and orientation for the entire seat. The rotating shaft can be inserted in the sleeve and rotated. The seat cushion is installed on one side of the rotating shaft through the seat cushion bottom plate. The seat cushion is horizontal and can rotate in the horizontal plane with the rotating shaft as the axis. When it is not needed for operation, it can be rotated under the electrical cabinet to save space, which is safe and convenient. When it is needed, it can be rotated out to provide support and convenience for people to sit and rest;

[0045] In one embodiment, a self-lubricating graphite copper sleeve 10 is further provided between the base and the rotating shaft, an inwardly concave limiting ring groove 11 is provided on the outer circumference of the rotating shaft, and a limiting bolt 12 is threadedly connected on the outer circumference of the base, and the limiting bolt can be passed into the base and clamped in the limiting ring groove;

[0046] The self-lubricating graphite copper sleeve can reduce the friction between the base and the rotating shaft, reduce wear and heat, and ensure safe use and service life. The cooperation between the limit bolt and the limit ring groove can avoid the axial relative movement of the rotating shaft and the base without affecting the relative rotation of the rotating shaft and the base, ensuring safe use. When it is necessary to disassemble and assemble the rotating shaft and the base, first unscrew the limit bolt, and the rotating shaft can be smoothly pulled out upward along the base or smoothly inserted into the base. During specific use, the depth of the limit bolt screwed into the inner wall of the base should be sufficient to not affect the rotation between the rotating shaft and the base, and to hinder the axial movement of the rotating shaft.

[0047] More specifically, a protruding support circular plate 13 is provided on the outer periphery of the base, a clamp 14 is provided above the support circular plate, the clamp is sleeved on the outer periphery of the base, the clamp is connected to the seat cushion bottom plate through a seat connecting rod 15, one end of the seat connecting rod is hinged to the seat cushion bottom plate, and the other end of the seat connecting rod is connected to the clamp through a handle screw 16;

[0048] The seat cushion bottom plate horizontally supports the seat cushion, and is generally installed at a vertical angle to the base and the rotation axis. In order to ensure structural strength and avoid deformation, a seat connecting rod is obliquely provided between the seat cushion bottom plate and the base. At the same time, in order to facilitate the adjustment of the seat cushion so that it can be locked and fixed after being rotated to an appropriate angle, a clamp is also provided and connected to the seat connecting rod through a handle bolt. When the rotation angle of the seat cushion needs to be adjusted, the handle bolt is loosened, the gap between the clamp and the outer periphery of the base becomes larger, and the friction resistance becomes smaller, so the rotation angle can be conveniently adjusted. After adjusting to the appropriate position, the handle bolt is tightened so that the clamp is tightly clamped to the outer periphery of the base, and the seat cushion bottom plate and the base can be locked and fixed, making it difficult for relative rotation to occur. The supporting circular plate can provide support to the clamp from below to prevent it from axial movement relative to the base.

[0049] In one embodiment, the handrail includes a front handrail 17 rotatably connected to the frame, a rear handrail 18 rotatably connected to the frame, a guardrail 19 rotatably connected to the front handrail, and a revolving door 20 rotatably connected to the rear handrail;

[0050] More specifically, the front handrail can slide relative to the frame, the guardrail can slide relative to the front handrail, the rear handrail can slide relative to the frame, and the revolving door can slide relative to the rear handrail; a rotation limiting device 21 is provided between the front handrail and the frame, between the front handrail and the guardrail, between the frame and the rear handrail, and between the rear handrail and the revolving door, and the rotation limiting device includes a rotation limiting seat 22, a plurality of limiting grooves 23 arranged around the rotation limiting seat, and a rotation limiting plate 24 that can be inserted into the limiting grooves;

[0051] The handrail is used to provide support for people who need to enter or evacuate the workstation, making it easier to enter or evacuate the workstation. It can also provide enclosure protection for operators working in the workstation, making it more convenient and safer to use. The handrail is divided into multiple parts, which are rotatably connected to each other. When needed, it can be rotated and unfolded, and when not needed, it can be rotated and folded for storage, reducing space occupation and facilitating long-distance transportation and edge milling operations.

[0052] A rotation limiter is used between the armrest and the frame and between adjacent armrest parts to achieve adjustable rotation connection. The following uses the armrest and the frame as an example to illustrate the working process of the rotation limiter;

[0053] When it is necessary to rotate and adjust the angle of the front armrest, first lift the front armrest upwards to disengage the rotation limit plate from the rotation limit seat, then rotate the front armrest to rotate the rotation limit plate to just above the limit groove that needs to be engaged. At this time, lower the front armrest to insert the rotation limit plate into the corresponding limit groove to complete the position adjustment. Due to its own gravity, the rotation limit plate on the front armrest can be tightly engaged in the limit groove. After the rotation limit plate is engaged in the limit groove, it can prevent the front armrest from rotating, thereby playing a role of limiting and fixing. Regarding the number and position of the limit grooves, it can be determined according to the different rotation angles corresponding to different working states of the front armrest during actual use.

[0054] In one embodiment, a main pedal 25 is provided on the vehicle frame, and the ladder includes an outer pedal 26 rotatably connected to the main pedal, a secondary ladder 27 rotatably connected to the outer pedal, and a primary ladder 28 rotatably connected to the secondary ladder, the upper end of the secondary ladder is rotatably connected to the outer lower end of the outer pedal, and a ladder connecting rod 29 is further provided between the secondary ladder and the vehicle frame, one end of the ladder connecting rod is rotatably connected to the vehicle frame, and the other end of the ladder connecting rod is rotatably connected to the secondary ladder;

[0055] When the operator needs to enter the operating station, he / she first extends the first-level ladder, the second-level ladder and the outer pedal. The operator can then enter the outer pedal through the first-level ladder and the second-level ladder in turn, thereby entering the operating station and sitting on the seat to perform construction work. In the process of entering the work station through the first-level ladder and the second-level ladder, the handrail can provide additional support for the operator to climb. The operator can grasp the handrail with his / her palm to assist in climbing, which is more convenient and safer.

[0056] In one embodiment, an elastic driving device 30 is further provided between the outer pedal and the frame, and the outer pedal can be rotated and folded inwardly under the action of the elastic driving device, and drive the secondary ladder to fold inwardly; more specifically, the elastic driving device is a pneumatic spring, one end of the pneumatic spring is rotatably hinged to the outer pedal, and the other end of the pneumatic spring is rotatably hinged to the frame, and the elastic driving device is arranged on the inner side of the secondary ladder;

[0057] During actual production and use, the rotating connection points of the outer pedal and the main pedal, the rotating connection points of the outer pedal and the secondary ladder, the rotating connection points of the secondary ladder and the ladder connecting rod, and the rotating connection points of the ladder connecting rod and the frame form a parallelogram, which can enable the outer pedal, the secondary ladder, and the ladder connecting rod to always remain linked during the rotation and stacking process to ensure structural stability; after the outer pedal, the secondary ladder and the primary ladder are extended to the specified position, the pneumatic spring is in a compressed state. At this time, the elastic force of the pneumatic spring is not enough to drive the outer pedal, the secondary ladder, the primary ladder and the ladder connecting rod to rotate and fold upward for storage; when the outer pedal, the secondary ladder, the primary ladder and the ladder connecting rod need to be rotated and folded upward for storage, the outer pedal or the secondary ladder is first lifted to a certain height by manpower, and then the elastic force of the pneumatic spring can provide part of the driving force, so as to continue to rotate and store the entire ladder, thereby providing convenience for the folding and storage of the ladder.

[0058] In one embodiment, a ladder rotation positioning seat plate 31 is provided on the secondary ladder, and a ladder rotation positioning hole 32 is correspondingly provided on the primary ladder. When the primary ladder is flipped upward and folded to fit tightly with the secondary ladder, the pin shaft can pass through the rotation positioning hole and the positioning seat plate to fix the primary ladder and the secondary ladder;

[0059] In actual use, the operating position of the milling machine is high from the ground, and in order to ensure the safety of the operation, the ladder needs to have a certain structural strength and deformation resistance. If a single ladder is used, the required length is long and it is not convenient to fold and store. Therefore, the ladder in this embodiment is divided into a secondary ladder and a primary ladder, and the two are rotatably connected. When the ladder needs to be used for climbing operations, the free end of the primary ladder is rotated and extended to the bottom. At this time, the free end of the ladder is closest to the ground, and the primary ladder is in front of the secondary ladder; the ladder needs to be folded and stored. When the first ladder is rotated upward by nearly 180 degrees, its free end is rotated upward and still fits tightly with the second ladder. At this time, the locating hole corresponds to the locating seat. The locating seat is originally provided with a through hole. At this time, components such as pins or bolts can pass through the locating holes and the locating seat to lock and fix the first ladder and the second ladder. This can prevent the two from moving relative to each other during edge milling operations or long-distance transportation, causing safety hazards or component damage. The pneumatic spring is located on the inner side of the second ladder to avoid affecting the operator's climbing up and down the ladder and sitting operation.

[0060] More specifically, a pedal limit plate 33 is also provided on the main pedal, and when the outer pedal is rotated to a horizontal state, the lower part can abut against the upper part of the pedal limit plate; the outer pedal is a hollow structure and is provided with a plurality of resistance-increasing racks 34;

[0061] The pedal limit plate can provide limit and support for the outer pedal after it is rotated to a horizontal position; the resistance-enhancing rack can increase friction and prevent slipping, thereby ensuring the operator's operating safety; the hollow structure enables the operator to observe the operating status of the milling chamber side panel and other components below, making it more convenient to use.

[0062] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A milling machine, characterized in that: The vehicle comprises a frame (1), a seat (2) connected to the frame in a rotatable and adjustable manner, an armrest (3) connected to the frame in a rotatable and adjustable manner, and a ladder (4) connected to the frame in a rotatable and adjustable elastic manner, wherein the armrest and the ladder are arranged on the outside of the frame, the armrest can be rotated inwardly for storage, the ladder can be rotated downwardly for extension, and the ladder can be rotated upwardly for folding and storage; The seat comprises a base (5) arranged on a vehicle frame, a rotating shaft (6) rotatably connected to the base, and a seat cushion (7) arranged on the rotating shaft, the rotating shaft being insertable and rotatable in the base, the seat cushion and the rotating shaft being connected via a seat cushion bottom plate (8), the seat cushion bottom plate being arranged below the seat cushion, an electrical cabinet (9) being arranged on the vehicle frame, and the seat cushion being rotatable to below the electrical cabinet; A self-lubricating graphite copper sleeve (10) is further provided between the base and the rotating shaft, an inwardly concave limiting ring groove (11) is provided on the outer circumference of the rotating shaft, and a limiting bolt (12) is threadedly connected on the outer circumference of the base, and the limiting bolt can be passed into the base and clamped in the limiting ring groove; A protruding supporting circular plate (13) is provided on the outer periphery of the base, a clamp (14) is provided above the supporting circular plate, the clamp is sleeved on the outer periphery of the base, the clamp is connected to the seat cushion bottom plate via a seat connecting rod (15), one end of the seat connecting rod is hinged to the seat cushion bottom plate, and the other end of the seat connecting rod is connected to the clamp via a handle screw (16); The handrail comprises a front handrail (17) rotatably connected to the vehicle frame, a rear handrail (18) rotatably connected to the vehicle frame, a guardrail (19) rotatably connected to the front handrail, and a revolving door (20) rotatably connected to the rear handrail. The front armrest can slide relative to the frame, the guardrail can slide relative to the front armrest, the rear armrest can slide relative to the frame, and the swing door can slide relative to the rear armrest; a rotation limiting device (21) is provided between the front armrest and the frame, between the front armrest and the guardrail, between the frame and the rear armrest, and between the rear armrest and the swing door, and the rotation limiting device comprises a rotation limiting seat (22), a plurality of limiting grooves (23) arranged around the rotation limiting seat, and a rotation limiting plate (24) capable of being inserted into the limiting grooves.

2. A milling machine according to claim 1, characterized in that: The frame is provided with a main pedal (25), the ladder comprises an outer pedal (26) rotatably connected to the main pedal, a secondary ladder (27) rotatably connected to the outer pedal, and a primary ladder (28) rotatably connected to the secondary ladder, the upper end of the secondary ladder is rotatably connected to the outer lower end of the outer pedal, and a ladder connecting rod (29) is provided between the secondary ladder and the frame, one end of the ladder connecting rod is rotatably connected to the frame, and the other end of the ladder connecting rod is rotatably connected to the secondary ladder.

3. A milling machine according to claim 2, characterized in that: An elastic driving device (30) is also provided between the outer pedal and the vehicle frame. The outer pedal can be rotated and folded inwards under the action of the elastic driving device, and can drive the secondary ladder to fold inwards.

4. A milling machine according to claim 3, characterized in that: The elastic force driving device is a pneumatic spring, one end of the pneumatic spring is rotatably hinged to the outer pedal, the other end of the pneumatic spring is rotatably hinged to the frame, and the elastic force driving device is arranged on the inner side of the secondary ladder.

5. A milling machine according to claim 2, characterized in that: The secondary ladder is provided with a ladder rotation positioning seat plate (31), and the primary ladder is correspondingly provided with a ladder rotation positioning hole (32). When the primary ladder is flipped and folded upward to fit tightly with the secondary ladder, the pin shaft can pass through the rotation positioning hole and the positioning seat plate to fix the primary ladder and the secondary ladder.

6. A milling machine according to claim 2, characterized in that: The main pedal is also provided with a pedal limit plate (33), and when the outer pedal is rotated to a horizontal state, the lower part can abut against the upper part of the pedal limit plate; the outer pedal is a hollow structure and is provided with a plurality of resistance-increasing racks (34).

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