Asphalt pavement shaving apparatus

Abstract

The application discloses a kind of asphalt pavement spud equipment, belong to pavement maintenance equipment technical field, including the vehicle body with travelling mechanism and the spud of being located at the bottom of vehicle body, spud is driven by hydraulic impact device to asphalt pavement carries out high-frequency vibration spud, the spud depth of spud is controlled by leveling mechanism, guarantee the flatness of road surface after spud;High-frequency impact spud front is equipped with roll brush and conveying device, can be stripped asphalt debris to conveying device on the delivery and send out.Process of vehicle body travelling high-frequency impact spud to asphalt pavement carries out high-frequency vibration spud, can be stripped out flat lower layer surface, then utilize the roll brush in front and strip asphalt debris to the conveying belt of conveying device on, and be delivered by conveying belt and send out.The application utilizes high-frequency vibration cutting technology, can realize the purpose of broken asphalt mixture while realizing asphalt pavement overall stripping, convenient delivery and reduce subsequent recovery processing workload.

Description

Technical Field

[0001] This invention belongs to the technical field of road maintenance equipment, and particularly relates to an asphalt pavement scraping device. Background Technology

[0002] Currently, there are two main methods for breaking up asphalt pavements: milling and loosening.

[0003] (1) Milling and crushing involves using a road milling machine to mill the road surface. However, the uneven surface of the underlying layer after milling makes subsequent repairs difficult and generates many large pieces of material, which are not only difficult to transport but also inconvenient for subsequent recycling. Given that the gradation curve of the recycled material obtained by milling is severely damaged, the recycling rate can only reach about 20%.

[0004] (2) Loosening and crushing is mainly achieved by excavator breakers and bulldozer rippers. Through the squeezing of the drill bit and the tilling of the ripper, the road material is squeezed and deformed, resulting in cracks. The crushed road material is then loaded onto trucks by loaders and other machinery. Compared with milling and crushing, the aggregate crushing is reduced. However, the crushing thickness and the smoothness of the crushed road surface cannot be precisely controlled, and it is only suitable for overall road surface crushing.

[0005] Therefore, it is necessary to develop a new type of asphalt pavement scraping equipment that can crush asphalt mixtures during the overall stripping process to improve the recycling rate. Summary of the Invention

[0006] The purpose of this invention is to provide an asphalt pavement cutting device, which aims to solve the technical problems of uneven pavement and low recycling rate after pavement milling and loosening in the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] An asphalt pavement scraping device includes a vehicle body with a traveling mechanism and a scraper blade disposed at the bottom of the vehicle body. The scraper blade is located in the lower middle part of the vehicle body and is driven by a hydraulic impact device inside the vehicle body to drive the scraper blade to perform high-frequency vibration scraping of the asphalt pavement. A roller brush and a conveying device are provided in front of the scraper blade to push the stripped asphalt fragments onto the conveying device for conveying out. Leveling mechanisms are provided on both sides of the scraper blade to control the scraping depth on both sides of the scraper blade.

[0009] Preferably, the roller brush is driven by a drive device inside the vehicle body, and the roller surface of the roller brush is provided with a plurality of material-pushing teeth for pushing asphalt fragments onto the conveyor belt of the conveying device.

[0010] Preferably, the feeding teeth are axially divided into several segments, and the several segments of feeding teeth are arranged circumferentially and alternately on the surface of the roller.

[0011] Preferably, the walking mechanism includes a walking motor and four sets of tracks. The four sets of tracks are driven forward by the walking motor and are located at the bottom of the four corners of the vehicle body. The top of the front and rear sets of tracks is equipped with counterweights. The blade is located in the lower middle part of the vehicle body through a height adjustment mechanism, and the angle between the bottom surface of the blade and the road surface is an acute angle of 5-30°.

[0012] Preferably, the hydraulic impact device includes an impact component and a rebound absorption assembly. The impact component includes a hydraulic pump, a cylinder, an impact piston, a reversing valve, and a first accumulator. The hydraulic pump is connected to the inner cavity of the cylinder via a pipeline. The reversing valve is located on the pipeline. The impact piston is located inside the cylinder. The first accumulator is located on the outer wall of the cylinder. The rebound absorption assembly includes a body, a buffer piston, and a buffer bushing. The handle of the shovel is located inside the body. The buffer bushing is fitted onto the end of the handle. The buffer piston is fitted onto the end of the piston rod of the hydraulic impact device. The buffer bushing abuts against the end face of the buffer piston. A buffer cavity is provided between the buffer piston and the end face of the cylinder of the hydraulic impact device. The buffer cavity and the first accumulator are connected through a first channel inside the side wall of the cylinder.

[0013] Preferably, the leveling mechanism includes side slides disposed on both sides of the walking mechanism, and the bottom of the vehicle body is provided with a groove for guiding the side slides. The side slides are connected to the vehicle body through a leveling hydraulic cylinder. A pull rope sensor that is linked to the leveling hydraulic cylinder is provided between the side slides and the vehicle body to control the side slides on both sides to always be in contact with the ground.

[0014] Preferably, the conveyor belt of the conveying device is inclinedly arranged at the front of the vehicle body, the feed end of the conveyor belt is located in front of the roller brush, the discharge end of the conveyor belt is located at the front of the vehicle body, and the conveying device is connected to the vehicle body through a support frame.

[0015] Preferably, a spray pipe is provided above the feed end of the conveyor belt, and a nozzle for spraying water onto the asphalt aggregate below is provided at the bottom of the spray pipe.

[0016] Preferably, the shovel, roller brush, and conveyor belt feed end of the conveyor device are equipped with dust covers.

[0017] Furthermore, the operating parameters of the asphalt pavement scraping equipment include scraping speed, blade service life, and travel propulsion force; the impact frequency of the blade is 60-100HZ, and the single impact energy is 400-650J.

[0018] Shovel speed From formula (1), we can obtain:

[0019] (1)

[0020] In the formula: -Cutting speed, mm / s;

[0021] - Impact cutting efficiency refers to the ratio of energy required to cut and remove road surfaces to impact energy, which is measured by test and is taken as 80%.

[0022] - Impact power of the hydraulic impact device, in W;

[0023] - The impact energy of a single impact by the shovel blade, in J;

[0024] -Impact frequency, Hz;

[0025] - The cross-sectional area of ​​the blade of the shovel;

[0026] C P - Impact crushing energy of road surface, J / mm3;

[0027] The service life T of the shovel blade can be obtained from formula (2):

[0028] (2)

[0029] In the formula:

[0030] C, m - material constants;

[0031] - Impact frequency, Hz;

[0032] d - The fluctuating inertia of the cutting tool;

[0033] R h -The undulating inertia of the impact piston;

[0034] - Tool elastic modulus; c- Wave velocity;

[0035] - The speed at which the impact piston impacts the tool holder;

[0036] - The impact kinetic energy of the impact piston;

[0037] - The mass of the impact piston;

[0038] Walking propulsion R u From formula (3), we can obtain:

[0039]

[0040] In the formula:

[0041] - Road surface modulus, ;

[0042] -Impact frequency, Hz;

[0043] - Stroke-time ratio, generally taken as ;

[0044] - The impact kinetic energy of the impact piston; - The mass of the impact piston.

[0045] The beneficial effects of adopting the above technical solution are as follows: Compared with the prior art, this invention, by installing a shovel at the bottom of the vehicle body, allows the vehicle body, driven by the traveling mechanism, to use the shovel at the bottom to perform high-frequency vibration shoveling on the asphalt pavement during travel. A leveling mechanism controls the shoveling depth, enabling the removal of a smooth underlying layer compared to a milling machine. It also crushes the asphalt pavement after shoveling, and then uses a front roller brush to push the crushed asphalt onto a conveyor device, which then transports it out via a conveyor belt. The entire process is streamlined and automated, allowing for simultaneous crushing and loading, resulting in continuous and efficient operations. Furthermore, the leveling mechanisms on both sides ensure the smoothness of the pavement after shoveling. This invention utilizes high-frequency vibration cutting technology to achieve the simultaneous removal of the asphalt pavement and crushing of the asphalt mixture, facilitating transportation and reducing the workload of subsequent recycling, thereby improving the recycling rate. Attached Figure Description

[0046] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0047] Figure 1 This is a schematic diagram of the structure of an asphalt pavement scraping device provided in an embodiment of the present invention;

[0048] Figure 2 yes Figure 1 A schematic diagram of the feeding teeth on the roller surface of the medium roller brush;

[0049] Figure 3 This is a schematic diagram of the asphalt pavement stripping principle of the present invention;

[0050] Figure 4 This is a schematic diagram of the leveling mechanism in an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the connection between the knife handle and the rebound absorption component in an embodiment of the present invention;

[0052] Figure 6 This is a workflow diagram under the normal working mode;

[0053] Figure 7 This is a workflow diagram for a fast-paced work mode;

[0054] In the diagram: 00-Asphalt pavement; 1-Vehicle body, 2-Shovel blade, 3-Roller brush, 30-Roller, 31-Pulling teeth; 4-Conveying device, 5-Cab, 6-Crawler, 7-Counterweight, 8-Support frame, 9-Spray pipe; 10-Asphalt stripped from the surface; 11-Side plate, 12-Slide groove, 13-Leveling hydraulic cylinder, 14-Rope sensor; 15-Shovel handle, 16-Wear-resistant sleeve, 17-Machine body, 18-Buffer chamber, 19-Buffer bushing, 20-Buffer piston, 21-Piston rod, 22-Cylinder body, 23-First accumulator, 24-Second accumulator, 25-First channel, 26-Impact piston, 27-Second channel, 28-Nitrogen chamber. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0056] Please refer to Figure 1 This invention provides an asphalt pavement scraping device, comprising a vehicle body 1 with a traveling mechanism and a scraper 2 located at the bottom of the vehicle body 1. The scraper 2 is positioned below the center of the vehicle body 1 and is driven by a hydraulic impact device within the vehicle body 1 to perform high-frequency vibration scraping of the asphalt pavement. A roller brush 3 and a conveying device 4, driven by a power unit within the vehicle body, are located in front of the scraper 2 to transfer the stripped asphalt fragments onto the conveying device 4 for transport. Leveling mechanisms are located on both sides of the scraper 2 to control the scraping depth, ensuring the smoothness of the pavement after scraping. The high-frequency vibration scraping of the asphalt pavement by the hydraulic impact device breaks up the stripped asphalt, facilitating the roller brush to collect the scraped asphalt fragments onto the conveyor belt of the conveying device for transport, reducing the workload of subsequent cleaning and recycling. Furthermore, a driver's cab 5 is located in the upper center of the vehicle body, allowing the driver to control the starting and stopping of the traveling mechanism, scraper, roller brush, and conveying device from within the cab, facilitating operation and preventing the driver from being exposed to air pollution caused by the scraping process.

[0057] Using a scraper to perform high-frequency impact scraping on asphalt pavement can optimize the gradation curve of recycled materials for the following reasons: As the deformation rate of a material increases, its fracture toughness decreases. Therefore, high-speed shearing rapidly accumulates scraping stress, ensuring that the entire piece of asphalt concrete is removed before the scraper blade cracks extend, without damaging the aggregate outside the cut, resulting in a smooth scraped surface. Simultaneously, the energy required for asphalt mixture crushing is directly proportional to the failure strain of the asphalt concrete and the duration of external force application. The higher the shear rate of the asphalt mixture, the smaller the local shear strain and the shorter the shearing time. Therefore, high-speed impact shearing can significantly reduce construction energy consumption.

[0058] In one specific embodiment of the present invention, such as Figure 2 As shown, the roller brush 3 is driven by a drive device inside the vehicle body 1. The roller brush 3 has several material-pushing teeth 31 on its roller 30 surface, used to push asphalt fragments onto the conveyor device 4. Specifically, the material-pushing teeth 31 are axially divided into several segments, and these segments are arranged circumferentially in a staggered pattern on the roller 30 surface. To facilitate the driver's control of the roller brush's start and stop, a control lever for the drive device is installed in the driver's cab. Simultaneously, the material-pushing teeth are mounted on the roller via torsion springs to prevent damage when the roller brush impacts harder asphalt fragments or stones. The staggered material-pushing teeth on the roller surface can push the scraped asphalt fragments onto the conveyor belt of the conveyor device.

[0059] As a preferred option, such as Figure 1 As shown, the traveling mechanism includes a traveling motor and four sets of tracks 6. The four sets of tracks 6 are driven forward by the traveling motor and are located at the bottom of the four corners of the vehicle body 1. A counterweight 7 is located on top of the front and rear sets of tracks 6. The blade 2 is positioned below the center of the vehicle body 1 via a height adjustment mechanism. The angle between the bottom surface of the blade 2 and the road surface is an acute angle of 5-30°. Before construction, the height adjustment mechanism is used to adjust the blade's vertical swing to the required cutting depth. The counterweight provides a downward force to the high-frequency impact blade, while the tracks provide a forward force to the high-frequency impact blade during vehicle movement, driving the blade to vibrate and cut away the asphalt pavement to a certain depth.

[0060] In addition, a hydraulic cylinder is installed between the base of the blade and the vehicle body to adjust the blade's angle to meet the construction requirements of different working conditions. In practice, the impact frequency of the blade 2 is 60-100Hz, and the single impact energy is 400-650J. This asphalt pavement scraping equipment weighs 190KG. Using these parameters, the high-frequency impact blade can scrape and recover the smoothed pavement while simultaneously crushing the stripped asphalt mixture.

[0061] In one specific embodiment of the present invention, such as Figure 4 As shown, the leveling mechanism includes side slide plates 11 disposed on both sides of the traveling mechanism. The bottom of the vehicle body 1 is provided with a groove 12 for guiding the side slide plates 11. The side slide plates 11 are connected to the vehicle body 1 via a leveling hydraulic cylinder 13, and the side slide plates 11 can slide up and down along the groove 12. A pull rope sensor 14, linked to the leveling hydraulic cylinder 13, is provided between the side slide plates 11 and the vehicle body 1 to control the side slide plates 11 to always be in contact with the ground. Both the pull rope sensor and the leveling hydraulic cylinder are electrically connected to the leveling controller. During installation, one end of the pull rope sensor is fixed to the side slide plate. The side slide plates are installed on the left and right sides of the blade and can move freely up and down along the groove. Under the action of the leveling hydraulic cylinder and its own weight, the side slide plates are always in contact with the ground. During the scraping process, the pull rope sensor transmits the detected road elevation change signal to the leveling controller, which then sends an action command to the leveling hydraulic cylinder, driving the side slide plates to always maintain close contact with the ground. The specific leveling principle is as follows:

[0062] When the road surface is uneven, the vertical movement of the vehicle body and sideplates of the traveling mechanism will be inconsistent, manifesting as the sideplates moving up and down relative to the vehicle body. To enhance the contact between the sideplates and the road surface, a hydraulic cylinder can be used to apply a constant clamping force to the sideplates. When changes in road elevation cause changes in the relative position between the sideplates and the vehicle body, the elongation of the pull rope will change. This change is transmitted to the leveling controller via a pulse signal generated by the encoder inside the pull rope sensor. The leveling controller measures the change in pull rope length by counting pulses. Upon receiving the output signal from the pull rope sensor, the leveling controller calculates and outputs a control signal to control the opening of the leveling hydraulic valve, thereby changing the flow rate and direction of the hydraulic oil input to the leveling hydraulic cylinder, adjusting the elongation of the front outrigger leveling hydraulic cylinder, i.e., the cutting depth, to compensate for changes in the cutting depth of the blade caused by changes in road elevation, thus ensuring the smoothness of the road surface after cutting.

[0063] The specific application process is as follows:

[0064] ① The rear track of the traveling mechanism travels on the shoveled road surface, while the front track travels on the unshoveled old road surface. The elevation difference between the two determines the shoveling depth. When the road surface elevation at the front track position increases, it causes the vehicle body to rotate counterclockwise, raising the blade and reducing the shoveling depth. At the same time, the opposite side plate of the vehicle body rises, increasing the elongation of the pull rope sensor; conversely, the elongation of the pull rope sensor decreases.

[0065] ② The side slide plate always slides on the old road surface, keeping in line with the elevation change of the asphalt road surface. When the road elevation at the side slide plate increases, the side slide plate rises accordingly, the vehicle body remains parallel, but the vehicle body descends relative to the side slide plate, and the extension of the pull rope sensor shortens; conversely, the extension of the pull rope sensor increases.

[0066] In one specific embodiment of the present invention, such as Figure 1 As shown, the conveyor belt of the conveying device 4 is inclinedly arranged at the front of the vehicle body 1. The feed end of the conveyor belt is located in front of the roller brush 3, and the discharge end of the conveyor belt is located at the front of the vehicle body 1. The conveyor belt is connected to the vehicle body 1 through a support frame 8. The support frame is not limited to the structure shown in the figure; other support frame structures can also be used to install the conveyor belt on the vehicle body.

[0067] Further optimize the above technical solutions, such as Figure 1 As shown, a spray pipe 9 is provided above the feed end of the conveyor belt, and a nozzle for spraying water onto the asphalt aggregate below is provided at the bottom of the spray pipe 9. During the asphalt aggregate scraping process, a large amount of dust is generated by the sweeping of the machine roller brush. Water is sprayed onto the aggregate through the nozzle to suppress the dust. The asphalt mixture after dust suppression is output with the conveyor belt, preventing dust from flying around.

[0068] In addition, dust covers (not shown in the figure) are provided around the feed end of the shovel 2, the roller brush 3, and the conveyor belt. The dust covers can further prevent dust from flying around during the shoveling process and reduce the impact of dust on the surrounding workers.

[0069] The working principle of this invention is as follows: Figure 3 As shown, this is a cutting method that applies regular, controllable vibrations with a certain frequency and amplitude to the scraper. High-frequency vibration scraping involves applying reciprocating linear high-frequency vibrations to the tool in the scraping direction, resulting in periodic high-frequency pulse scraping. High-frequency impact scrapers, under the action of a hydraulic impact device, use high-frequency vibration to impact and scrape asphalt pavement, vibrating the asphalt mixture into fragments. These fragments are then easily swept by a roller brush to the feed end of the conveyor belt. As the conveyor belt moves, the asphalt fragments are transported to the discharge end. A receiving hopper for a transfer vehicle can be installed below the discharge end of the conveyor belt to facilitate the transfer of the asphalt fragments to a recycling and processing site, meeting the requirements of modern, assembly-line construction.

[0070] During the impact shoveling process, the blade will rebound. If the blade rebounds and directly contacts the cylinder of the hydraulic impact device, it will cause fatigue damage to the cylinder and the blade handle. Therefore, a rebound absorption component is installed to fully absorb the rebound energy of the blade, effectively improving work efficiency and extending the service life of components. Specifically, the hydraulic impact device includes an impact component and a rebound absorption component. The impact component includes a hydraulic pump, a cylinder 22, an impact piston 26, a reversing valve, and a first accumulator 23. The hydraulic pump is connected to the inner cavity of the cylinder 22 via a pipeline. The reversing valve is located on the pipeline. The impact piston 26 is located inside the cylinder 22, and the first accumulator 23 is located on the outer wall of the cylinder 22. Figure 5As shown, the rebound absorption assembly includes a body 17, a buffer piston 20, and a buffer bushing 19. The handle 15 of the blade 2 is disposed inside the body 17. The buffer bushing 19 is fitted onto the end of the handle 15. The buffer piston 20 is fitted onto the end of the piston rod 21 of the hydraulic impact device. The buffer bushing 19 abuts against the end face of the buffer piston 20. A buffer chamber 18 is provided between the buffer piston 20 and the end face of the cylinder 22 of the hydraulic impact device. The buffer chamber 18 and the first accumulator 23 are connected through a first channel 25 in the side wall of the cylinder 22. A second accumulator 24 is also provided on the cylinder 22. The right cavity of the impact piston 26 is connected to the second accumulator 24 through a second channel 27 in the side wall of the cylinder 22. The working process of the hydraulic impact device is as follows:

[0071] When the hydraulic pump supplies pressurized oil to the cylinder, the reversing valve controls the impact piston to reciprocate within the cylinder, impacting the blade handle at the piston's end. This converts the hydraulic pressure energy into impact energy, which strikes the blade handle. The impact energy is then transmitted to the road surface as a stress wave through the blade, removing the road surface. The impact force is adjusted using a gear shifting plug, while the cylinder is sealed using a sealing assembly.

[0072] When the impact piston completes its impact and begins its return stroke, the rebound force of the blade is transmitted to the buffer piston. The buffer piston rebounds, and under the action of the pressure oil in the buffer chamber, it absorbs the rebound energy, causing the buffer piston to decelerate. Therefore, the rebound absorption component plays a role in protecting the impact components.

[0073] In specific manufacturing, a wear-resistant sleeve 16 is installed between the inner hole of the tool holder 15 and the body 17; both the buffer bushing 19 and the buffer piston 20 are disc-shaped structures with frustoconical shapes. The end face of the body 17 has a stepped groove consistent with the shape of the buffer bushing 19. The end face of the cylinder 22 has a groove matching the frustoconical shape of the buffer piston 20 and an annular protrusion for limiting the position of the buffer piston 20. The outer diameter of the buffer piston 20 is larger than the outer diameter of the protrusion. The opening of the first channel 25 is located on the end face of the cylinder 22 outside the protrusion. The first accumulator 23 is located in the middle of the cylinder 22, and the second accumulator 24 is located on the rear outer wall of the cylinder 22. The specific working principle of the rebound absorption assembly is as follows:

[0074] During the impact shovel cutting process, when the blade handle rebounds, it pushes the buffer bushing and buffer piston to the right, and impacts the piston rod and impact piston to the right. The oil in the buffer chamber is compressed, and the oil pressure in the first accumulator continuously increases. The oil in the right chamber of the impact piston is compressed, which drives the oil pressure in the second accumulator to increase until the blade handle rebounds to zero. The rebound energy of the blade handle is converted into the oil pressure energy of the first accumulator.

[0075] After the rebound process is completed, the hydraulic pressure of the two accumulators drives the buffer piston and the blade handle to move to the left. Under the combined action of the overall propulsion force (travel propulsion force) and the hydraulic pressure of the buffer chamber, the blade presses back against the road surface, and at the same time, the energy of the accumulators is released.

[0076] In the specific design, the working parameters of the asphalt pavement shaving equipment include shaving speed, blade service life, and travel propulsion force.

[0077] I. Shoveling speed refers to the length of road surface shoveled per unit time, which is affected by factors such as impact energy, impact frequency, road surface properties, and cutter type. Once the road surface properties and cutter type are determined, the shoveling speed is proportional to the impact energy and impact frequency of the hydraulic impact device, as can be obtained from formula (1):

[0078] (1)

[0079] In the formula: -Cutting speed, mm / s;

[0080] - Impact cutting efficiency refers to the ratio of energy required to cut and remove road surfaces to impact energy, which is measured by test and is taken as 80%.

[0081] - Impact power of the hydraulic impact device, in W;

[0082] - The impact energy of a single impact by the shovel blade, in J;

[0083] -Impact frequency, Hz;

[0084] - The cross-sectional area of ​​the blade of the shovel;

[0085] C P - Impact crushing energy of road surface, J / mm 3 ;

[0086] II. Service life of the scraper

[0087] During impact cutting, the scraper is subjected to high-frequency compressive and tensile stresses. These two types of high-frequency stresses, which appear as stress waves, are the main factors causing tool fatigue failure. Using Miner's linear cumulative damage theory, the fatigue life of the tool under variable amplitude stress can be calculated. The calculation process for the scraper's service life is as follows:

[0088]

[0089] In the formula:

[0090] C, m - material constants;

[0091] -Impact frequency, Hz;

[0092] - Maximum stress amplitude, ;

[0093] - The ratio of the undulating inertia of the cutting tool to that of the impact piston. ;

[0094] d - The fluctuating inertia of the cutting tool;

[0095] R h -The undulating inertia of the impact piston;

[0096] - Tool elastic modulus; c- Wave velocity;

[0097] - The speed at which the impact piston impacts the tool holder.

[0098] During operation, the maximum stress amplitude generated by the impact piston is a key factor determining tool life. As the impact energy increases, the final velocity of the impact piston increases, generating a larger stress amplitude and causing a rapid decrease in tool life. The higher the peak value of the incident stress wave, the faster the tool will be damaged and fail.

[0099] After simplification, we obtain the formula for the service life of the shovel blade:

[0100] (2)

[0101] In the formula: -Impact frequency, Hz;

[0102] C, m - material constants;

[0103] d - The fluctuating inertia of the cutting tool;

[0104] R h -The undulating inertia of the impact piston;

[0105] - Tool elastic modulus; c- Wave velocity;

[0106] - The speed at which the impact piston impacts the tool holder;

[0107] - The impact kinetic energy of the impact piston;

[0108] - The mass of the impact piston;

[0109] Therefore, the fatigue life of the shovel blade is inversely proportional to the impact energy and impact frequency of the hydraulic impact device.

[0110] III. Propulsion for Walking

[0111] During operation, the propulsive force generated by the travel motor drives the impact blade to press against the road surface, achieving impact shaving. If the propulsive force is too large, it increases the impact resistance and causes the blade to wear too quickly; if the propulsive force is too small, the blade cannot make good contact with the road surface, and when the incident wave reaches the blade edge, the impact energy cannot be effectively transferred to the road surface, reducing shaving efficiency. Therefore, the optimal propulsive force must be obtained by adjusting the working pressure of the travel drive motor.

[0112] The optimal thrust depends not only on the operating parameters of the impact device but also on the properties of the road surface being cut. Therefore, there exists an optimal axial thrust for different road surface conditions.

[0113] Based on the rated thrust, the optimal thrust calculation formula can be obtained.

[0114] Rated thrust formula:

[0115]

[0116] In the formula:

[0117] -Impact frequency, Hz;

[0118] - Stroke-time ratio, generally taken as ;

[0119] - The impact kinetic energy of the impact piston; - The mass of the impact piston.

[0120] The optimal propulsion force Ru can be obtained from formula (3):

[0121]

[0122] In the formula:

[0123] - Road surface modulus, .

[0124] During the process of an impact cutter cutting the road surface, the rebound speed of the piston rod depends on the final impact velocity of the piston rod and the road surface modulus. The larger the road surface modulus, the greater the rebound speed of the piston rod; conversely, the smaller the road surface modulus, the smaller the rebound speed of the piston rod, or even no rebound occurs. Since the final impact velocity of the piston rod is constant during operation, the road surface modulus is determined by measuring the rebound speed of the piston rod.

[0125] The rebound speed of the piston rod is obtained by measuring the pressure change in the nitrogen chamber and using a mathematical conversion formula. For example... Figure 5 As shown, a nitrogen chamber 28 is provided at the other end of the piston rod 21. Based on the principle of indirect pressure measurement, the real-time collected nitrogen chamber pressure is converted into the displacement of the piston rod. The sampling time interval of the nitrogen chamber pressure is known. Using the "three-point method" piston rod velocity calculation formula, the velocity change of the piston rod at each sampling point can be calculated. Considering both the data acquisition card's conversion speed and data buffer capacity, a smaller sampling time interval should be selected. The nitrogen chamber pressure parameter is converted into the velocity value of the impact piston rod through mathematical processing; this is existing technology and will not be elaborated upon here.

[0126] Because the working speed and blade life of asphalt pavement scraping equipment cannot be simultaneously optimized, different working parameters need to be selected for different working modes. The following is an explanation of the normal working mode and the fast working mode.

[0127] In the normal working mode, it is necessary to select the optimal working parameters to improve the working speed while ensuring that the blade is within its normal service life, thereby obtaining better economic benefits.

[0128] like Figure 6 As shown, before the work begins, the impact crushing specific energy of the road surface material is measured through experiments and input into the automatic control program. The program runs automatically, following these steps:

[0129] (1) Using a multi-objective optimization algorithm, the optimal solutions for working speed and expected blade life are obtained. , ), and at this time, the impact energy of the impact component. and impact frequency .

[0130] (2) Based on work speed It automatically adjusts the matching speed of the walking motor.

[0131] (3) At the same time, the road modulus is determined in real time by measuring the rebound speed of the piston rod of the impact component. .

[0132] (4) Based on the road surface modulus Impact energy of impact device and impact frequency The optimal thrust was calculated. .

[0133] (5) Based on the optimal propulsion force It automatically adjusts the matching torque of the walking motor.

[0134] The impact energy of the impact component is automatically determined through the above control program. Impact frequency Matching speed with the travel motor, and adjusting the matching torque of the travel motor in real time.

[0135] II. Fast Working Mode

[0136] When rushing to meet deadlines, a fast working mode is required, in which the impact energy and impact frequency of the impact components are at their maximum values.

[0137] like Figure 7 As shown, before the work begins, the impact crushing specific energy of the road surface material is measured through experiments and input into the automatic control program. The fast working mode runs automatically, as follows:

[0138] (1) Based on the impact energy of the impact component and impact frequency The maximum working speed and the expected lifespan of the blade are obtained by solving the problem. , ).

[0139] (2) Based on the maximum working speed It automatically adjusts the matching speed of the walking motor.

[0140] (3) At the same time, the road modulus is determined in real time by measuring the rebound speed of the piston rod of the impact component. .

[0141] (4) Based on the road surface modulus Impact energy of impact components and impact frequency The optimal thrust was calculated. .

[0142] (5) Based on the optimal propulsion force It automatically adjusts the matching torque of the walking motor.

[0143] The above control program automatically determines the matching speed of the travel motor and adjusts its matching torque in real time. In this operating mode, the blade may experience abnormal damage, resulting in an actual lifespan shorter than the predicted lifespan. Therefore, an ultrasonic flaw detection device is needed to monitor the blade's condition so that damage can be detected and replaced promptly.

[0144] The specific application examples of the conventional working mode are as follows:

[0145] Before starting work, input the automatic control program parameters, including:

[0146] (1) Road surface performance parameters: Impact crushing specific energy = 0.028 J / mm 3

[0147] (2) Blade parameters: wave velocity = 5100 m / s, density = 7800 kg / m³ 3 Elastic modulus = 2.03 × 10 11 C = 1.5 × 10 9 m=8.9, cross-sectional area of ​​the blade edge = 4500mm 2 ,

[0148] (3) Impact component parameters: Impact piston mass = 6kg

[0149] The program runs automatically, following these steps:

[0150] (1) Using a multi-objective optimization algorithm, the optimal solutions for working speed and expected blade life are obtained. , ), and at this time, the impact energy of the impact component. and impact frequency .

[0151] (2) Based on work speed It automatically adjusts the matching speed of the walking motor.

[0152] (3) At the same time, the road modulus is determined in real time by measuring the rebound speed of the piston rod of the impact component. .

[0153] (4) Based on the road surface modulus Impact energy of impact components and impact frequency The calculated rated thrust is 4777 N, and the optimal thrust is... =4777N~6210N.

[0154] (5) Based on the optimal propulsion force It automatically adjusts the matching torque of the walking motor.

[0155] The impact energy of the impact component is automatically determined through the above control program. Impact frequency Matching speed with the travel motor, and adjusting the matching torque of the travel motor in real time.

[0156] This invention utilizes high-frequency vibration cutting technology to peel and recycle asphalt pavements of any thickness. It offers the following advantages:

[0157] ① Construction equipment: An integrated machine is used to scrape off the asphalt pavement surface material and then convey it to the next process via a conveyor belt.

[0158] ② In terms of construction benefits: By controlling the program, the working parameters are automatically adjusted, which improves the working speed while ensuring that the cutting tools are within the normal range of use, thereby achieving better economic benefits.

[0159] ③ In terms of construction effect: It can optimize the gradation curve of recycled materials and use the vibration of high-frequency impact shovel to quickly accumulate shovel stress. Before the crack in the shovel head extends, the entire piece of asphalt concrete material has been removed without damaging the stone material outside the cut, resulting in a smooth shovel surface.

[0160] ④ Construction energy consumption: The energy required for the crushing process of asphalt mixture is directly proportional to the failure strain of asphalt concrete and the time of external force application.

[0161] The higher the shear rate of asphalt mixture, the smaller the local shear strain and the shorter the shear time. Therefore, this application adopts high-speed impact shearing, which can significantly reduce construction energy consumption.

[0162] In summary, this invention is easy to operate. By adjusting the angle and height of the blade, it can meet the requirements of different cutting depths. The high-frequency impact blade applies high-frequency vibration impact to the asphalt pavement, resulting in a smooth underlying surface after cutting. The stripped asphalt is vibrated and formed into fragments, facilitating subsequent processing and achieving the goal of recycling. Simultaneously, the asphalt mixture is transported to a transfer vehicle via a roller brush and conveyor belt during the cutting process, achieving a fully automated and streamlined process. Crushing and loading can be carried out simultaneously, resulting in continuous and efficient operations. The use of nozzles and dust covers reduces dust at the work site, minimizes surrounding air pollution, and protects the personal safety of workers.

[0163] Many specific details have been set forth in the foregoing description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed above.

Claims

1. An asphalt pavement scraping device, characterized in that: The device includes a vehicle body with a walking mechanism and a blade located at the bottom of the vehicle body. The blade is positioned below the middle of the vehicle body and is driven by a hydraulic impact device inside the vehicle body to perform high-frequency vibration scraping of the asphalt pavement. A roller brush and conveying device are provided in front of the blade to push the stripped asphalt fragments onto the conveying device for transport. Leveling mechanisms are provided on both sides of the blade to control the scraping depth. The hydraulic impact device includes an impact component and a rebound absorption assembly. The impact component includes a hydraulic pump, a cylinder, an impact piston, a reversing valve, and a first accumulator. The hydraulic pump is connected to the inner cavity of the cylinder through a pipeline. The reversing valve is located on the pipeline. The impact piston is located inside the cylinder. The first accumulator is located on the outer wall of the cylinder. The rebound absorption assembly includes a body, a buffer piston, and a buffer bushing. The handle of the shovel is located inside the body, the buffer bushing is fitted onto the end of the handle, and the buffer piston is fitted onto the end of the piston rod of the hydraulic impact device. The buffer bushing abuts against the end face of the buffer piston. A buffer chamber is provided between the buffer piston and the cylinder end face of the hydraulic impact device. The buffer chamber and the first accumulator are connected through a first channel in the side wall of the cylinder. A second accumulator is also provided on the cylinder. The right side cavity of the impact piston is connected to the second accumulator through a second channel in the side wall of the cylinder. The operating parameters of the asphalt pavement scraping equipment include scraping speed, scraper life, and travel propulsion force; Shovel speed From formula (1), we can obtain: (1) In the formula: -Shovel cutting speed, mm / s; - Impact cutting efficiency, measured through experiments, is taken as 80%; - Impact power of the hydraulic impact device, in W; - The impact energy of a single impact by the shovel blade, in J; -Impact frequency, Hz; - The cross-sectional area of ​​the blade of the shovel; C P - Impact crushing energy of road surface, J / mm3; The service life T of the shovel blade can be obtained from formula (2): （2） In the formula: C, m - material constants; -Impact frequency, Hz; d - The fluctuating inertia of the cutting tool; R h - the fluctuation inertia of the impact piston; - Tool elastic modulus; c- Wave velocity; - The speed at which the impact piston impacts the tool holder; - The impact kinetic energy of the impact piston; - The mass of the impact piston; Walking propulsion force R u From equation (3), we have: （3） In the formula: - Road surface modulus, ; -Impact frequency, Hz; - Stroke-time ratio, take .

2. The asphalt pavement scraping equipment according to claim 1, characterized in that: The roller brush is driven by a drive device inside the vehicle body. The roller brush has several material-pushing teeth on its roller surface, which are used to push the asphalt fragments onto the conveyor belt of the conveying device.

3. The asphalt pavement scraping equipment according to claim 2, characterized in that: The feeding teeth are axially divided into several segments, and these segments are arranged circumferentially on the surface of the roller.

4. The asphalt pavement scraping equipment according to claim 1, characterized in that: The walking mechanism includes a walking motor and four sets of tracks. The four sets of tracks are driven forward by the walking motor and are located at the bottom of the four corners of the vehicle body. The top of the front and rear sets of tracks is equipped with counterweights. The blade is located in the lower middle part of the vehicle body through a height adjustment mechanism. The angle between the bottom surface of the blade and the road surface is an acute angle of 5-30°.

5. The asphalt pavement scraping equipment according to claim 1, characterized in that: The leveling mechanism includes side slides disposed on both sides of the walking mechanism. The bottom of the vehicle body is provided with a groove for guiding the side slides. The side slides are connected to the vehicle body through a leveling hydraulic cylinder. A pull rope sensor that is linked to the leveling hydraulic cylinder is provided between the side slides and the vehicle body to control the side slides on both sides to always be in contact with the ground.

6. The asphalt pavement scraping equipment according to claim 1, characterized in that: The conveyor belt of the conveying device is inclinedly arranged at the front of the vehicle body. The feed end of the conveyor belt is located in front of the roller brush, and the discharge end of the conveyor belt is located at the front of the vehicle body. The conveyor belt of the conveying device is connected to the vehicle body through a support frame.

7. The asphalt pavement scraping equipment according to claim 6, characterized in that: A spray pipe is provided above the feed end of the conveyor belt, and a nozzle for spraying water onto the asphalt aggregate below is provided at the bottom of the spray pipe.

8. The asphalt pavement scraping equipment according to claim 6, characterized in that: The feed end of the shovel, roller brush, and conveyor belt is equipped with dust covers.

Images