A milling machine for road surface construction and its operating method

Abstract

The application relates to the technical field of milling and planing machines, in particular to a milling and planing machine for road pavement construction and an operation method, which comprises a vehicle body and a milling and planing mechanism installed on the vehicle body, wherein the milling and planing mechanism comprises a walled milling and planing frame, a milling and planing drum installed in the milling and planing frame, a crushing groove and a back-throwing mechanism; the milling and planing frame is a five-surface enclosure structure which is composed of side plates, a top plate, a rear end plate and a front end plate, a milling and planing opening is reserved at the bottom, height-adjustable baffles are arranged on the side plates, movable counterweight push plates are arranged on the baffles, the front end plate and the rear end plate; a discharging structure is arranged on the front end plate and connected with the crushing groove, a zigzag channel is formed in the crushing groove through an inclined plate, a screen and a crushing roller group synchronously driven by the milling and planing drum are further arranged; the back-throwing mechanism comprises a back-throwing frame rotatably installed on the side wall of the crushing groove close to the screen, a base is arranged at the bottom end of the back-throwing frame, and fixed throwing rods and movable throwing rods are arranged on the base; the application achieves the purpose of improving the material recycling efficiency in the construction process of the milling and planing machine.

Description

Technical Field

[0001] This invention relates to the field of milling machine technology, specifically to a milling machine for road surface construction and its operating method. Background Technology

[0002] Milling machines are key pieces of equipment in road construction and maintenance, primarily used to remove old pavement layers, repair pavement defects, or adjust road elevation. Their working principle involves using a high-speed rotating milling drum to cut the pavement, and the resulting waste material is recycled. With accelerating urbanization and increasing environmental protection requirements, milling machines are playing an increasingly important role in the recycling of asphalt concrete and cement concrete pavements.

[0003] Traditional milling machines typically consist of a chassis, a milling drum, a conveying system, and a power unit. The milling drum, mounted at the bottom of the machine, rotates via hydraulic or mechanical transmission to cut the road material. The cut material is then transported by conveyor belt to a hopper and finally transferred to a recycling or processing site. However, existing technology still has many shortcomings in practical applications:

[0004] First, traditional milling machines are prone to bouncing during operation due to the reaction force of the milling drum, affecting the stability of the milling depth and causing material splashing, thus reducing the recycling rate. Although some equipment uses counterweight design to suppress vibration, the effect is limited and it increases the weight and energy consumption of the equipment. Second, the material recovery system of existing milling machines is relatively simple, usually relying solely on the conveyor belt to directly collect the debris. Because the size of the milled material is uneven, larger particles may clog the conveyor system or reduce the quality of the recycled material, which is not conducive to subsequent recycling. Summary of the Invention

[0005] The purpose of this invention is to provide a milling machine and its operating method for road surface construction, so as to improve the material recovery efficiency during the milling process and solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a milling machine for road surface construction, comprising a vehicle body and a milling mechanism mounted on the vehicle body, the milling mechanism comprising a wall-type milling frame, a milling drum, a breaking trough and a return throwing mechanism mounted inside the milling frame;

[0007] The milling frame is a five-sided enclosure structure, consisting of side plates, top plate, rear end plate and front end plate. The bottom has a milling opening. The side plates are equipped with height-adjustable baffles. The baffles, front end plate and rear end plate are all equipped with movable counterweight push plates. The counterweight push plates can fit into the ground under the action of gravity.

[0008] The front end plate is equipped with a discharge structure connected to the crushing trough. The crushing trough is formed by inclined plates to form a tortuous channel. It is also equipped with a screen and a crushing roller group driven synchronously by a milling drum. The crushing roller group is located between the inclined plates, and the screen is connected to the bottom of the inclined plates.

[0009] The throw mechanism includes a throw frame rotatably mounted on the side wall of the crushing trough near the screen. The bottom of the throw frame is equipped with a base, on which there are fixed throw rods and movable throw rods. The movable throw rods are movably mounted by adjusting the slider and, together with the spring push rod and the magnetic block, form an adjustable spacing structure driven by magnetic force. The top of the throw frame is pressed down by the extension rod of the counterweight push plate when the vehicle body throws the throw frame, which drives the fixed throw rods and the movable throw rods to throw the residual material on the screen back to the crushing roller group.

[0010] The side plates, top plate, rear plate, and front plate of the milling frame are connected to each other by bolt assemblies, and there are two side plates symmetrically arranged.

[0011] It also includes a drive unit installed on the vehicle body, and a first support and a second support are connected to the side plate near the drive unit.

[0012] The first support is equipped with a belt pulley drive pair, which connects the drive shaft and the milling shaft. The drive shaft is connected to the drive device, and the two ends of the milling shaft are connected between the two side plates and connected to the milling drum.

[0013] The baffle is height-adjustable via a cylinder, with the two ends of the cylinder mounted on the side plate and the baffle, respectively.

[0014] The movable structure of the counterweight push plate includes a bracket connected to both sides of the baffle, the front plate and the rear plate. The bracket is provided with a sliding groove, and the counterweight push plate is limited and installed in the sliding groove.

[0015] The discharge structure of the front end plate includes an end groove connected in the middle, an upwardly inclined guide plate connected at the opening of the end groove, and a crushing trough fixedly connected to the front end plate by a bottom support.

[0016] The inclined plates in the crushing trough include a first inclined plate and a second inclined plate arranged in an alternating manner. The first inclined plate is located on top of the second inclined plate, and the two are located on opposite sides of the crushing trough.

[0017] The drive structure of the crushing roller assembly includes a main shaft and a secondary shaft in the crushing trough. The main shaft is connected to the milling shaft through a belt pulley drive pair in the second support. The main shaft and the secondary shaft are connected by a gear set to achieve reverse rotation.

[0018] The crushing roller assembly consists of spiral crushing rollers connected to the main shaft and the auxiliary shaft respectively.

[0019] The bottom of the crushing trough below the screen is equipped with a ramp, and the bottom outlet of the crushing trough is connected to an inclined discharge chute.

[0020] The return thrower has a J-shaped structure and is rotatably installed in the side wall groove of the crushing trough near the screen. The bottom end of the return thrower is located inside the crushing trough, and the top end is located outside the crushing trough.

[0021] The extension rod is mounted on the counterweight push plate of the front end plate, and a pressure head is provided at the top of the extension rod, which is located above the top of the return throw frame.

[0022] In the magnetically driven adjustable spacing structure, the base is provided with a sliding cavity, the adjusting slider is located in the sliding cavity, and the movable throwing rod passes through the through groove on the base and is connected to the adjusting slider.

[0023] One end of the spring push rod is connected to the adjusting slider, and the other end is equipped with a first magnetic block;

[0024] A support rod is provided at the end of the main shaft away from the second support, and a second magnetic block is provided on the support rod. The second magnetic block intermittently generates a magnetic repulsion force on the first magnetic block as the main shaft rotates.

[0025] A method for operating a milling machine used for road surface construction includes the following steps:

[0026] S1. Move the milling machine to the road surface to be constructed, adjust the height of the machine body so that the bottom opening of the milling frame contacts the road surface, and ensure that the milling drum is in contact with the road surface;

[0027] S2, start the vehicle drive unit to drive the milling shaft to rotate, so that the milling drum rotates at high speed to cut and destroy the road surface, and the road surface material produced by cutting is confined within the milling frame;

[0028] S3, the road material enters the crushing trough through the discharge structure on the front end plate, falls through the tortuous channel formed by the inclined plate, and is initially crushed by the crushing roller group;

[0029] S4, the crushed material falls onto the screen, and the material that meets the size requirements passes through the screen into the bottom of the crushing tank, and finally enters the belt conveyor mechanism for recycling through the discharge chute;

[0030] S5, when the milling frame bounces due to the reaction force, the counterweight push plate is pressed back to the top of the throwing frame through the extension rod to make it rotate, which drives the fixed throwing rod and the movable throwing rod to throw the material that did not pass through the screen back to the top of the crushing roller group for secondary crushing;

[0031] S6, After milling is completed, raise the vehicle body and stop the drive unit.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. The milling machine of the present invention adopts a unique enclosed milling frame structure, combined with an adjustable height baffle design, which can be flexibly adjusted according to different milling depths, effectively preventing the material splashing and loss problems common in traditional milling operations. This enclosed working environment not only significantly improves the material recycling rate, but also reduces dust pollution at the construction site, making it more conducive to the recycling of road materials.

[0034] 2. The present invention features a multi-stage crushing trough structure. Through staggered inclined plate channels and bidirectional rotating crushing rollers, the material undergoes multiple collisions and shearing during its descent, achieving a more uniform and thorough crushing effect. It is suitable for processing road materials with different hardness and particle size, ensuring the quality of subsequent recycling. The transmission design enables synchronous drive of the milling shaft to the crushing mechanism. The integrated power distribution scheme not only saves on additional power sources but also improves energy utilization efficiency.

[0035] 3. The magnetic drive return throwing mechanism of the present invention can automatically throw materials that do not meet the size requirements back to the crushing zone for secondary processing. It utilizes the unavoidable vehicle body jumping phenomenon in milling operations and converts this mechanical vibration into the power to drive the return throwing frame through the counterweight push plate and movable scraper structure, thus realizing the recycling of energy.

[0036] 4. This invention adopts an adjustable spacing throwing bar assembly design, which can intermittently adjust the gap during use, ensuring rapid material passage most of the time and greatly improving screening efficiency. When back-throwing is required, the gap of the throwing bar assembly is reduced to ensure that large-sized materials can be back-thrown. Attached Figure Description

[0037] Figure 1 This is a first schematic diagram of the overall structure of the present invention.

[0038] Figure 2 This is a second schematic diagram of the overall structure of the present invention.

[0039] Figure 3 This is a schematic diagram of the side plate and four-axis structure of the present invention.

[0040] Figure 4 This is a schematic diagram of the side plate and telescopic baffle structure of the present invention.

[0041] Figure 5 This is a first schematic diagram of the milling drum and crushing groove structure of the present invention.

[0042] Figure 6 This is a second schematic diagram of the milling drum and crushing groove structure of the present invention.

[0043] Figure 7 This is a schematic diagram of the front-end board structure of the present invention.

[0044] Figure 8 This is a schematic diagram showing the positions of the main shaft and secondary shaft structures of the present invention.

[0045] Figure 9 This is a schematic diagram of the crushing trough structure of the present invention.

[0046] Figure 10 This is a schematic diagram of the internal structure of the crushing tank of the present invention.

[0047] Figure 11 This is a schematic diagram of the screen and return throwing frame structure of the present invention.

[0048] Figure 12 This is a schematic diagram of the installation of the movable throwing rod structure of the present invention.

[0049] In the diagram: 1. Side plate; 2. Top plate; 3. Rear end plate; 4. Front end plate; 5. First support; 6. Second support; 7. Drive shaft; 8. Milling shaft; 9. Milling drum; 10. Cylinder; 11. Baffle; 12. Hanger; 13. Counterweight push plate; 14. End slot; 15. Guide plate; 16. Base support; 17. Crushing trough; 18. First inclined plate; 19. Second inclined plate; 20. Screen; 21. Ramp; 22. Discharge chute; 23. Main shaft; 24. Sub-shaft; 25. Gear set; 26. Crushing roller set; 27. Return throw frame; 28. Base; 29. ​​Fixed throw bar; 30. Adjusting slider; 31. Movable throw bar; 32. Through slot; 33. Spring push rod; 34. First magnetic block; 35. Support rod; 36. Second magnetic block; 37. Extension rod; 38. Pressure head. Detailed Implementation

[0050] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] Please see Figures 1 to 12 The present invention provides a technical solution: a milling machine for road surface construction. The milling machine is a heavy-duty vehicle-mounted structure. The milling mechanism is installed at the bottom of the vehicle, and the vehicle adopts a lifting structure. By lowering the vehicle body, the milling mechanism is brought into contact with the bottom surface, which can destroy the road surface and recycle the road surface material.

[0052] The milling machine includes a wall-type milling frame installed at the bottom of the vehicle body. The milling frame is a five-sided enclosure structure, consisting of two side plates 1 connected by bolt assemblies, a top plate 2, a rear end plate 3, and a front end plate 4. A milling opening is left at the bottom, and the vehicle body is equipped with a drive unit, which typically uses a motor with a frequency converter. A first support 5 and a second support 6 are welded and installed on the side plate 1 near the drive unit. Both the first support 5 and the second support 6 are equipped with pulley drive pairs. The pulley drive pair of the first support 5 is used to connect the drive shaft 7 and the milling shaft 8. The drive shaft 7 and the milling shaft 8 are both horizontally installed in the first support 5 through bearings. The drive shaft 7 is connected to the drive unit in the vehicle body, while the milling shaft 8 is connected between the two side plates 1. A milling drum 9 is installed on it by flange bolts. Therefore, the milling drum 9 is located in the middle of the milling frame. After the vehicle body is lowered, the milling drum 9 can contact the road surface from the bottom opening of the milling frame and damage it.

[0053] The front plate 4 is positioned in the forward direction of the vehicle compared to the rear plate 3, and a belt conveyor mechanism is provided at the front of the vehicle body to lift the road material and put it into a separate hopper.

[0054] When the road surface is broken into fine road surface material by the milling drum 9, the road surface material is confined within the milling frame, thereby guiding the road surface material to be recovered from the corresponding discharge position on the front plate 4. The front plate 4 and the rear plate 3 are located on the cutting line, and their heights are usually set according to the size of the milling drum 9 to ensure that when the milling drum 9 cuts the road surface to a certain depth, the front plate 4 and the rear plate 3 can respectively fit the road surface before and after cutting. The side plate 1 is equipped with a telescopic baffle 11 by a cylinder 10. The two ends of the cylinder 10 are respectively bolted to the side plate 1 and the baffle 11. The height of the baffle 11 can be freely adjusted. According to the road surface cutting depth, the cylinder 10 controls the baffle 11 to fit it on both sides of the cut road surface to prevent the loss of road surface material.

[0055] When the road surface is cut and damaged by the milling drum 9, the reaction force generated by the road surface on the milling drum 9 will cause the vehicle body and milling frame to bounce, causing the milling frame to detach from the ground and resulting in the loss of road material. As an embodiment of the present invention, the baffle 11 and the front plate 4 and the rear plate 3 are all provided with a movable scraper structure. The movable scraper structure includes a bracket 12 welded to both sides of the baffle 11, the front plate 4 and the rear plate 3. The bracket 12 is provided with a groove, and a counterweight push plate 13 is limited and installed in the groove. The counterweight push plate 13 is in contact with the ground under the action of gravity. When bouncing occurs, the counterweight push plate 13 can be relatively displaced with the baffle 11, the front plate 4 and the rear plate 3, so as not to cause bouncing but to keep in contact with the ground as much as possible to scrape the road material.

[0056] Furthermore, the front end plate 4 is provided with a discharge structure. An end groove 14 is welded in the middle of the front end plate 4, and an upwardly inclined guide plate 15 is welded at the opening of the end groove 14. At the same time, a bottom support 16 is fixed to the front end plate 4 by bolts, and a crushing trough 17 is fixed to the bottom support 16 by bolts. The accumulated road material can fall into the crushing trough 17 from the guide plate 15. The crushing trough 17 serves as a transition structure to pre-crush road material larger than a certain size before it enters the belt conveyor mechanism to facilitate subsequent recycling.

[0057] The crushing trough 17 is welded with a first inclined plate 18 and a second inclined plate 19 arranged in an alternating manner. The first inclined plate 18 is located on top of the second inclined plate 19, and the two are located on both sides of the crushing trough 17, forming a tortuous recycling channel in the crushing trough 17. A screen 20 is installed in the crushing trough 17 by screws. The screen 20 is connected to the bottom of the second inclined plate 19. After the material is screened by the screen 20, only the material that meets the size requirements will fall to the bottom of the crushing trough 17.

[0058] Furthermore, a ramp 21 is provided at the bottom of the crushing trough 17, and an inclined discharge chute 22 is welded to the bottom outlet of the crushing trough 17, so that the material eventually enters the belt conveyor mechanism from the discharge chute 22.

[0059] The crushing trough 17 is equipped with a material crushing structure that is synchronously driven by the milling shaft 8. The crushing trough 17 is equipped with a main shaft 23 and a secondary shaft 24 through bearings. The main shaft 23 is connected to the second support 6. The main shaft 23 is connected to the milling shaft 8 through the belt pulley transmission pair in the second support 6. The main shaft 23 can be driven by the milling shaft 8.

[0060] In one embodiment of the present invention, the main shaft 23 and the secondary shaft 24 are connected by a gear set 25, so the secondary shaft 24 can rotate in the opposite direction to the main shaft 23. A crushing roller set 26 is connected to the main shaft 23 and the secondary shaft 24, which consists of two spiral crushing rollers respectively connected to the main shaft 23 and the secondary shaft 24. The crushing roller set 26 is located between the first inclined plate 18 and the second inclined plate 19. The road material passes through the crushing roller set 26 and can be crushed by it, and then falls into the screen 20 for screening.

[0061] Furthermore, considering that the material passing through the crushing roller group 26 may have flattened and large-sized residues due to the angle of passage, a throw-back structure is set on the screen 20 to throw large-sized materials back to the top of the crushing roller group 26.

[0062] As an embodiment of the present invention, the return throwing structure includes a return throwing frame 27 rotatably mounted on the crushing trough 17 via a rotating shaft. The return throwing frame 27 has a J-shaped structure and is installed in the side wall groove 32 of the crushing trough 17 near the screen 20. The bottom end of the return throwing frame 27 is inside the crushing trough 17, and a base 28 is mounted on it by screws. The top end of the return throwing frame 27 is outside the crushing trough 17. Multiple sets of fixed throwing rods 29 and movable throwing rods 31 are arranged on the base 28. The fixed throwing rods 29 and movable throwing rods 31 fall on the screen 20. When the top end of the return throwing frame 27 is pressed, the return throwing frame 27 can rotate, and the material is tilted upward and thrown into the top of the crushing roller group 26 through the fixed throwing rods 29 and movable throwing rods 31.

[0063] The fixed throwing rod 29 is welded to the base 28, while the movable throwing rod 31 is movably installed via the adjusting slider 30. The base 28 has a sliding cavity, in which the adjusting slider 30 is located. The base 28 also has a through groove 32, through which the movable throwing rod 31 passes and connects to the adjusting slider 30. The end of the adjusting slider 30 is connected to a spring push rod 33, which passes through the side wall of the base 28. The end of the spring push rod 33 has a first magnetic block 34, and the two ends of the spring on it are connected to the first magnetic block 34 and the outer wall of the base 28, respectively. Through the elastic force generated by the spring, the adjusting slider 30 can be moved to the end position of the base 28, so that the movable throwing rod 31 is close to the fixed throwing rod 29. Therefore, there is a large gap between adjacent throwing rod groups, which allows most of the crushed material to pass through the screen 20 quickly without being affected by the throwing rod group. A groove is also provided on the side wall of the crushing trough 17 to accommodate the movement of the spring push rod 33.

[0064] Furthermore, the end of the main shaft 23 away from the second support 6 is set through the crushing groove 17, and a support rod 35 is installed at its end by screws. A second magnetic block 36 is embedded in the support rod 35. The second magnetic block 36 can rotate under the drive of the support rod 35, and the first magnetic block 34 is located on the side of the rotation path of the second magnetic block 36. Through the relative arrangement of the magnetic poles, the first magnetic block 34 can be subjected to the magnetic repulsion force of the second magnetic block 36. Therefore, when the second magnetic block 36 intermittently approaches the first magnetic block 34, the spring push rod 33 can overcome the elastic force of the spring and drive the adjusting slider 30 to move, so that the movable throwing rod 31 and the fixed throwing rod 29 are separated, reducing the gap of the throwing rod group. This allows the throwing rod group to throw the road material that has not passed through the screen 20 back into the crushing roller group 26 when it rotates with the return throwing frame 27.

[0065] The return throw frame 27 is driven by the throwing motion of the milling frame. The counterweight push plate 13 installed on the front end plate 4 is equipped with an extension rod 37 by screws. The top of the extension rod 37 is integrally formed with a pressure head 38, which is located above the top of the return throw frame 27. When the milling frame throws due to the reaction force, there is a relative displacement between the front end plate 4 and the counterweight push plate 13. The crushing trough 17 drives the return throw frame 27 to rise, while the extension rod 37 remains in place with the counterweight push plate 13. The extension rod 37 can press down the top of the return throw frame 27, causing the return throw frame 27 to rotate and use the throwing rod assembly on it to throw and crush large-sized materials.

[0066] In use, the milling machine is first moved to the road surface to be constructed. The height of the machine is adjusted so that the bottom opening of the milling frame contacts the road surface, ensuring that the milling drum 9 is in close contact with the road surface. The machine drive device is started to drive the milling shaft 8 to rotate, and the milling drum 9 rotates at high speed to cut and destroy the road surface. The road surface material produced by cutting is confined within the milling frame and enters the crushing trough 17 through the guide plate 15 on the front end plate 4. The material falls through the tortuous channel formed by the inclined plates in the crushing trough 17 and is initially crushed by the crushing roller group 26. The crushed material falls onto the screen 20. Material that meets the size requirements passes through the screen 20 and enters the discharge trough 22 for collection by the belt conveyor mechanism. Large-sized material that does not pass through the screen 20 is handled by the return throw frame 27. When the milling frame throws the material, the counterweight push plate 13 presses down on the top of the return throw frame 27 through the extension rod 37 to make it rotate. The throw rod throws the material back to the top of the crushing roller group 26 for secondary crushing. During milling, the counterweight pusher plate 13 remains in contact with the ground under gravity to reduce vehicle bounce. The baffle plate 11 and the movable scraper structure continuously scrape the road material to ensure a high recovery rate. After milling, the vehicle body is raised and the drive device is stopped. This invention achieves multiple crushing and screening of materials through the synergistic action of the crushing trough 17 and the return throwing frame 27. The dynamically adjustable throwing rod group and magnetic drive design optimize the return throwing effect. The design of the counterweight pusher plate 13 and the baffle plate 11 effectively suppresses vehicle bounce, ensuring operational stability and ensuring efficient and stable completion of road construction tasks and refined material recovery.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A milling machine for road pavement construction comprising a vehicle body and a milling mechanism mounted on the vehicle body, characterized by: The milling mechanism comprises a walled milling frame, a milling drum installed in the milling frame, a crushing groove and a back-throwing mechanism; The milling frame is a five-sided enclosure composed of side plates, a top plate, a rear end plate and a front end plate, with a milling opening left at the bottom, height-adjustable baffles provided on the side plates, movable counterweight push plates provided on the baffles, the front end plate and the rear end plate, and the counterweight push plates capable of adhering to the ground under the action of gravity; The front end plate is provided with a discharging structure connected with the crushing groove, the crushing groove is provided with a zigzag channel formed by inclined plates, a screen and a crushing roller set synchronously driven by the milling drum, the crushing roller set is located between the inclined plates, and the screen is connected to the bottom of the inclined plates; The back-throwing mechanism comprises a back-throwing frame rotatably installed on the side wall of the crushing groove near the screen, a base provided at the bottom end of the back-throwing frame, fixed and movable throwing rods provided on the base, and a magnetic force driven adjustable spacing structure formed by the movable throwing rod, an adjusting slide block and a spring push rod and a magnetic block; The top end of the back-throwing frame is pressed down by an extension rod of the counterweight push plate when the vehicle body is thrown, thereby driving the fixed and movable throwing rods to throw the residual materials on the screen to the crushing roller set. The milling mechanism further comprises a driving device installed on the vehicle body, a first support and a second support connected to the side plate near the driving device; A belt wheel transmission pair is provided in the first support, the transmission pair is connected to a driving shaft and a milling shaft, the driving shaft is connected to the driving device, and the milling shaft is connected between the two side plates and connected to the milling drum; The driving structure of the crushing roller set comprises a main shaft and a secondary shaft in the crushing groove, the main shaft is connected to the milling shaft through a belt wheel transmission pair in the second support, and the main shaft and the secondary shaft are connected through a gear set to realize reverse rotation; The back-throwing frame is in a J-shaped structure, rotatably installed in a side wall through groove of the crushing groove near the screen, with the bottom end located in the crushing groove and the top end located outside the crushing groove; The extension rod is installed on the counterweight push plate of the front end plate, and a pressing head is provided at the top end of the extension rod; In the magnetic force driven adjustable spacing structure, a sliding cavity is provided in the base, the adjusting slide block is located in the sliding cavity, and the movable throwing rod is connected to the adjusting slide block through a through groove in the base; One end of the spring push rod is connected to the adjusting slide block, and the other end is provided with a first magnetic block; 2. A milling machine for road pavement construction according to claim 1, characterized in that: One end of the main shaft away from the second support is provided with a support rod, and a second magnetic block is provided on the support rod, which generates a magnetic repulsion force on the first magnetic block in an intermittent manner with the rotation of the main shaft.

3. A milling machine for road surfacing construction according to claim 2, characterized in that: The side plates, the top plate, the rear end plate and the front end plate of the milling frame are connected to each other through bolt assemblies, and two side plates are symmetrically provided.

4. A milling machine for road surfacing construction according to claim 3, characterized in that: The height of the baffles is adjusted by a pneumatic cylinder, and the two ends of the pneumatic cylinder are installed on the side plate and the baffle respectively.

5. A milling machine for road surfacing according to claim 4, characterised in that: The movable structure of the counterweight push plate comprises a hanging seat connected to the two sides of the baffle, the front end plate and the rear end plate, a sliding groove is provided in the hanging seat, and the counterweight push plate is limitingly installed in the sliding groove.

6. A milling machine for road surfacing according to claim 5, characterised in that: The discharging structure of the front end plate comprises an end groove connected to the middle part, an upward inclined guide plate connected to the slot opening of the end groove, and the crushing groove fixedly connected to the front end plate through a bottom support. The inclined plates in the crushing groove comprise first and second inclined plates arranged alternately, the first inclined plate is located at the top of the second inclined plate, and the two are respectively located on the two sides of the crushing groove.

7. The milling machine according to claim 6, characterized in that: The crushing roller set is composed of spiral crushing rollers connected to the main shaft and the secondary shaft respectively.

8. A milling machine for road surfacing according to claim 7, characterised in that: The bottom of the crushing groove under the screen is provided with a ramp, and the bottom outlet of the crushing groove is connected with an inclined discharge chute.

9. A method of operating a road planing machine as claimed in claim 8, characterised in that: The method comprises the following steps: S1, moving the milling machine to the road surface to be constructed, adjusting the height of the vehicle body to make the bottom opening of the milling frame contact with the road surface, and ensuring that the milling drum is attached to the road surface; S2, starting the vehicle body driving device to drive the milling shaft to rotate, so that the milling drum rotates at high speed to cut and damage the road surface, and the road surface material generated by cutting is limited in the milling frame; S3, the road surface material enters the crushing groove through the discharge structure on the front end plate, falls through the zigzag channel composed of the inclined plate, and is preliminarily crushed by the crushing roller set; S4, the crushed material falls onto the screen, the material meeting the size requirement passes through the screen into the bottom of the crushing groove, and finally enters the belt conveying mechanism through the discharge chute for recycling; S5, when the milling frame jumps due to the reaction force, the counterweight push plate lowers the top end of the return frame through the extension rod to make it rotate, drives the fixed throw rod and the movable throw rod to return the material on the screen that does not pass to the top of the crushing roller set for secondary crushing; S6, after the milling is completed, the vehicle body is raised and the driving device is stopped.

Images