Method for designing milling drum cutter head distribution based on full regeneration requirement of regenerated material gradation

Abstract

This invention belongs to the field of road repair technology, specifically relating to a method for milling drum cutter head distribution based on the gradation design of recycled materials according to full recycling requirements, including the following steps: Step 1: Determine the target gradation X according to design requirements; Step 2: Determine the gradation of recycled materials produced by milling drums with different cutter head densities. Step 3: Based on the target gradation X, divide the milling drum surface into different milling regions and determine the cutter density of each milling region; then determine the recycled material gradation corresponding to each milling region. Step 4: Combine formula (1) to determine the proportion of different milling areas on the milling drum. Step 5: Design the arrangement of different milling zones on the milling drum. This invention calculates the gradation of recycled material under different milling drum cutter head densities, sets milling zones with different cutter head densities on the same milling drum, and mixes the recycled materials produced by different milling zones during the milling process to obtain high-performance recycled material that meets the requirements of full recycling.

Description

A method for designing milling drum cutter head distribution based on the gradation of recycled materials according to the requirement of full recycling. Technical Field

[0001] This invention belongs to the field of road repair technology, specifically relating to a method for milling drum cutter head distribution based on the gradation design of recycled materials according to the requirements of full recycling. Background Technology

[0002] As time goes by, the area of ​​roads requiring maintenance and repair continues to increase. With the popularization of road construction mechanization, milling machines have become one of the main pieces of equipment for road maintenance and repair, and as the maintenance tasks continue to increase, they are attracting more and more attention from road owners and construction units.

[0003] The main working device of a road milling machine is the milling drum, which is equipped with milling components arranged in a symmetrical spiral pattern. During operation, the road material is crushed into granules by the impact and compression of the milling drum cutters, and then collected for use as recycled material. Traditional milling machines are designed to remove existing road material quickly, economically, and effectively. Based on the number of milling components, they are divided into rough milling and fine milling. The former produces recycled material with a particle size mainly of 10mm-30mm, but also includes a significant amount of oversized recycled material larger than 30mm, making it unsuitable for direct road recycling. The latter produces recycled material... The material is mainly composed of particles smaller than 10mm, lacking recycled materials with a particle size of 10mm-25mm, and is not suitable for direct recycling of road surfaces. Because a certain number of milling components are evenly distributed on the milling drum in a spiral pattern, the resulting recycled material is either too coarse or too fine overall, as shown in Figure 1. It cannot be directly recycled in its entirety, and the recycled material generally needs to be screened and adjusted. Common methods include secondary crushing or adding new aggregates to adjust the gradation. These additional technical measures and equipment requirements increase the cost of existing technologies, reduce the utilization rate of recycled materials, and reduce the efficiency of process implementation.

[0004] The gradation quality of milled material directly determines whether it can be 100% reused. The particle size of recycled material required for recycling should be appropriately fine; recycled material that is too coarse cannot be used in road recycling; recycled material that is too fine will result in insufficient high-temperature performance of the recycled mixture, causing plastic deformation and increasing the demand for binder materials, thus incurring additional costs; a lack of fine particles in the recycled material will lead to insufficient strength and overall low road performance indicators. Road surfaces paved with unsuitable recycled material will be damaged, affecting their service life and failing to meet actual usage requirements.

[0005] When the milling machine travel speed and milling drum rotation speed are constant, and the cutter head density on the milling drum surface is fixed, the recycled material obtained by milling, while meeting the maximum nominal particle size, cannot meet the ideal content of fine powder within the recycled material. This mismatch increases as the milling cutter head density decreases. Furthermore, since the effects of equipment and processes are often intertwined and jointly influence the final RAP (recycled material), some experimental data are simplified and categorized, as shown in Table 1.

[0006] Table 1 Comparison of recycled materials obtained by precision milling and standard climb milling

[0007]

[0008] By summarizing the recycled material data in Table 1 above, a regional map of RAP technical indicators with different numbers of cutters can be drawn (as shown in Figure 1). Combined with Figure 1, it can be clearly seen that it cannot directly reuse all the recycled material. While meeting the maximum nominal particle size of the recycled material, there is insufficient fine powder, which cannot meet the ideal fine powder content in the recycled material.

[0009] There are roughly two solutions: one is to reduce the working speed of the milling machine, which can compensate for the fine powder to some extent, but this will reduce the maximum nominal particle size of the milled material and affect the work efficiency of on-site construction; the other is to increase the number of standard milling machine cutters, which can balance milling efficiency and fine powder content at a reasonable working speed, but will significantly reduce the maximum nominal particle size of RAP, which will have an adverse effect when dealing with thicker paving thicknesses. Summary of the Invention

[0010] This invention addresses the problem that recycled materials produced by existing milling processes are either too coarse or too fine, making them unsuitable for direct full reuse. Specifically, existing milling drums, while meeting the maximum nominal particle size of the recycled material, cannot achieve the desired fine powder content. The invention provides a method for designing the distribution of milling drum cutter heads based on the requirement of full recycling. By calculating the recycled material gradation under different milling drum cutter head densities, milling zones with different cutter head densities are set on the same milling drum. Then, during the milling process, the recycled materials produced from different milling zones are mixed to obtain high-performance recycled materials that meet the requirements of full recycling.

[0011] To achieve the above objectives, the technical solution of the present invention is as follows:

[0012] A method for designing the milling drum cutter head distribution based on the gradation of recycled materials according to the requirement of full recycling includes the following steps:

[0013] Step 1: Determine the target gradation X of the required recycled material according to the design requirements:

[0014] Step 2: Detect and calculate the gradation of recycled material obtained from milling drums with different cutter densities, and obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the gradation;

[0015] Step 3: Based on the target gradation X, obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the target gradation X, as well as the passing rate of different sieve aperture sizes corresponding to the target gradation X. Divide the milling drum surface into different milling areas and determine the cutter density of the different milling areas.

[0016] Subsequently, the recycled material gradation corresponding to different milling zones was determined based on the cutter density and type of milling zone. ;

[0017] Step 4: Combine Formula (I) to determine the proportion of different milling areas on the milling drum. Perform calculations;

[0018] X (one)

[0019] in, —Target gradation of recycled material produced by milling drum;

[0020] — Milling material throughput for different milling zones and different sieve openings, %

[0021] —The percentage of different milling areas on the milling drum, %

[0022] —Sieve aperture size, taken as 0.075, 0.15, 0.3, 0.6…31.5 mm;

[0023] n—the partition corresponding to different cutter head densities on the milling drum, taking the values ​​1, 2, 3, ...;

[0024] Step 5: Design the layout of different milling areas on the milling drum based on the proportion of different milling areas on the milling drum.

[0025] Preferably, the milling area in step three includes a rough milling area, a medium milling area, and a fine milling area, with different milling areas producing recycled materials of different gradations.

[0026] Preferably, a plurality of bases are fixedly arranged on the surface of the milling drum, and a tool holder is sleeved inside the base, with each tool holder corresponding to one of the bases, and a tool head is installed on the tool holder.

[0027] Preferably, the base is unevenly welded to the outer wall of the milling drum, taking into account the proportion of different milling areas on the surface of the milling drum. The number of cutter heads is consistent with the number of bases. The uneven arrangement of the bases achieves the uneven arrangement of the cutter heads on the surface of the milling drum.

[0028] Preferably, the base is uniformly and symmetrically installed on the surface of the milling drum. Based on the proportion of different milling areas on the surface of the milling drum, the cutter heads are uniformly or unevenly installed on the corresponding cutter holders. The uneven arrangement of the cutter heads achieves the arrangement of different milling areas on the surface of the milling drum.

[0029] Preferably, the cutter heads are evenly and symmetrically mounted on the corresponding cutter holders, taking into account the proportion of different milling areas on the surface of the milling drum. The number of cutter heads may be the same as or different from the number of bases, and the cutter head density at different positions can be changed by changing the number of cutter heads.

[0030] Preferably, based on the proportion of different milling areas on the surface of the milling drum, the cutter heads are unevenly distributed along the axial direction of the milling drum and installed on the corresponding cutter holders, and the cutter heads are symmetrically distributed along the longitudinal section of the middle part of the milling drum.

[0031] Preferably, based on the proportion of different milling areas on the surface of the milling drum, the cutter heads are unevenly distributed along the circumference of the milling drum and installed on the corresponding cutter holders, and the cutter heads are symmetrically distributed along the central cross-section of the milling drum.

[0032] Preferably, the cutter heads are unevenly and asymmetrically distributed and installed on the corresponding cutter holders, taking into account the proportion of different milling areas on the surface of the milling drum.

[0033] Preferably, depending on the proportion of different milling areas on the surface of the milling drum, the cutter heads are arranged in a spiral pattern with unequal density along the surface of the milling drum, or in a diamond pattern, straight line pattern, wavy line pattern, or sawtooth pattern with unequal density.

[0034] The beneficial effects of the present invention through the above technical solution are as follows:

[0035] 1. This invention determines the target gradation of the recycled material to be obtained, and then, in combination with the situation that different gradations of recycled material are produced under different cutter head densities, calculates the proportion of different milling areas on the surface of the milling drum using formula (I), thereby achieving the production of recycled material that meets the required target gradation and realizing the full recycling of recycled material.

[0036] 2. This invention achieves the simultaneous production of recycled materials of different grades by arranging the cutter heads on the surface of the milling drum, and mixes them during the milling process, thereby achieving the requirement of full recycling of recycled materials.

[0037] 3. This invention allows for convenient adjustment of the cutter head arrangement on the milling drum surface through various arrangement methods, enabling adaptation to different working environments or equipment conditions.

[0038] 4. Through reasonable steps and methods, this invention achieves the goal of obtaining a fine powder content in recycled material that meets the requirements of full recycling while satisfying the maximum nominal particle size of the recycled material. Attached Figure Description

[0039] Figure 1 shows the regional map of technical indicators of recycled materials obtained from milling drums with different numbers of cutter heads.

[0040] Figure 2 shows the relationship between the number of milling drum cutters, the maximum nominal particle size of recycled material, and the passing rate of recycled material through a 0.3mm sieve.

[0041] Figure 3 is a schematic diagram of the asymmetrical axial arrangement of the milling drum cutter heads.

[0042] Figure 4 is a schematic diagram of the asymmetrical axial arrangement of the milling drum cutter heads.

[0043] Figure 5 is a schematic diagram of the axially symmetrical arrangement of the milling drum cutter heads and their composite gradation curve.

[0044] Figure 6 shows the gradation curves of the target gradation and multiple synthetic gradations.

[0045] Figure 7 is a schematic diagram of the structure of a milling drum of the present invention, in which milling areas are unevenly distributed according to different cutter head densities.

[0046] Figure 8 is a graph showing the target gradation and its range in an application embodiment of the present invention.

[0047] Figure 9 shows the gradation curves corresponding to different milling areas in an application embodiment of the present invention.

[0048] Figure 10 is a graph showing the ratio of production gradation to target gradation in an application embodiment of the present invention.

[0049] Figure 11 shows the range curve of RAP obtained by rough milling.

[0050] Figure 12 shows the range curve of RAP obtained by milling.

[0051] Figure 13 shows the range curve of RAP obtained by fine milling.

[0052] The numbers in the attached diagram are: 1 for milling drum, 2 for base, 3 for tool holder, and 4 for tool head. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0054] As shown in Figure 2, the relationship between the number of milling drum cutters, the maximum nominal particle size, and the fine powder content is summarized. It can be clearly seen that the number of cutters (the number of cutters is the number of milling cutters when the milling drum is fully installed) has a nearly linear relationship with the nominal maximum particle size and the fine powder content (0.3mm throughput). The required number of milling drum cutters for the maximum nominal particle size of the recycled material is obtained. Then, the corresponding 0.3mm fine powder throughput is calculated as a verification of the recycled material gradation optimization. The results are shown in Table 2 below:

[0055] Table 2 Relationship between maximum nominal particle size, number of cutter heads, and fine powder

[0056]

[0057] Under normal processes, the content of fine powder obtained is positively correlated with the number of cutter heads; that is, the denser the number of cutter heads, the higher the content of fine powder. Based on this fundamental principle, the above problem cannot be solved by simply changing the number of cutter heads on the milling drum (by uniformly distributing them in a spiral pattern). Therefore, the problem becomes: how to achieve the corresponding fine powder content on the same milling drum while meeting the maximum nominal particle size of the recycled material through a non-uniform distribution of cutter heads, ultimately ensuring that the gradation of the milled material meets the gradation design requirements for full recycling?

[0058] Following the principle of in-situ cold recycling, this application redesigns the milling drum to alter the size and mass of recycled material particles during a single milling pass. To achieve this goal while maintaining the stability of the recycled material gradation, this is achieved by changing the number of milling cutters per unit area. This change can be along the longitudinal direction of the milling drum, the transverse direction, or both. The ultimate goal is to obtain recycled material with different particle sizes and corresponding required proportions for each rotation of the milling drum.

[0059] Figure 3-4 shows a schematic diagram of dividing the milling drum surface into two different milling regions. The milling drum surface is divided into a coarse milling region (low cutter density) and a fine milling region (high cutter density). In the region with higher cutter density, the recycled material obtained by milling has a smaller particle size and more fine powder, and vice versa. By "synthesizing" recycled material through milling in different density regions, the final recycled material is obtained. In this way, by flexibly designing the number of milling drum cutters, the maximum nominal particle size and fine powder content of the final RAP (recycled material) gradation can be met as much as possible, and the gradation of the milled material can meet the gradation design requirements of the whole life.

[0060] In actual milling operations, factors affecting the gradation of recycled materials include not only the cutter head arrangement, but also the milling drum speed and the milling equipment travel speed. In the process of milling recycled materials with the corresponding gradation, the optimal milling speed and travel speed are selected, and then the cutter head arrangement and cutter head density are designed in combination with the above steps to obtain the milled recycled materials with the required gradation.

[0061] The milling material gradation is determined by three factors: the milling machine travel speed, the milling drum speed, and the number of cutter heads. Let the milling material gradation be X, the milling machine travel speed be v, the milling drum speed be r, and the number of cutter heads be t. The relationship is as follows:

[0062] X = f(v, r, t)

[0063] The gradation ranges obtained for the three milling drums (coarse, medium, and fine) are shown in Figures 11-13.

[0064] Furthermore, by employing a non-uniform arrangement, the milling cutter heads are placed on the milling drum in different arrangements. Since the same milling machine and the same milling drum are used, the milling machine travel speed v and the milling drum rotation speed r are both fixed values. The only adjustable value is the number of cutter heads t. Therefore, under the required milling machine travel speed and milling drum rotation speed, the required graded recycled material can be obtained by adjusting the number of milling cutter heads per unit area in different regions.

[0065] Therefore, a method for designing the milling drum cutter head distribution based on the requirement of full recycling is obtained. First, the corresponding milling machine travel speed and milling drum rotation speed are determined, and then the following steps are performed:

[0066] Step 1: Determine the target gradation X of the required recycled material.

[0067] Step 2: Detect and calculate the gradation of recycled material obtained from milling drums with different cutter densities, and obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the gradation.

[0068] Step 3: In order to achieve the target gradation X, considering the maximum nominal particle size and fine powder content of the recycled material corresponding to the target gradation X, and combining the results of Step 1, the surface of the milling drum is divided into different milling areas and the cutter head density of the different milling areas is determined.

[0069] Subsequently, the recycled material gradation corresponding to different milling zones was determined based on the cutter density and the number of milling zones in different milling zones. .

[0070] As shown in Figure 2, the maximum nominal particle size and fine powder content of recycled material corresponding to the number of cutter heads (i.e., cutter head density) per unit area can be calculated. Then, the number of milling regions and the cutter head density in each milling region can be determined by combining the target gradation X. The milling regions include coarse milling regions and fine milling regions.

[0071] Step 4: Combine Formula (I) to determine the proportion of different milling areas on the milling drum. Perform calculations;

[0072] X (one)

[0073] in, —Target gradation of recycled material produced by milling drum;

[0074] — Milling material throughput for different milling zones and different sieve openings, %

[0075] —The percentage of different milling areas on the milling drum, %

[0076] —Sieve aperture size, taken as 0.075, 0.15, 0.3, 0.6…31.5 mm;

[0077] n—Divisions corresponding to different cutter densities on the milling drum, taken as 1, 2, 3…

[0078] As shown in Figure 6, draw the gradation curve diagram and plot the gradation curve of the target gradation X in the figure;

[0079] Several were initially selected The values ​​of a1 + a2 + a3 + ... + a i =1), and combined with the gradation of the recycled material obtained from milling drums with different cutter densities in step two, substitute it into formula (I) to obtain a new gradation value X1. Plot the corresponding gradation curve based on X1, and compare the gradation curve corresponding to X1 with the gradation curve of X. Analyze the relationship between the particle size distribution of the recycled material corresponding to X1 and the proportioning. Adjustments are made (i.e., when the coarse-grained gradation curve is higher than the target gradation curve, while the fine-grained gradation curve is lower than the target gradation curve, the proportion corresponding to the rough milling area is reduced). Increase the proportion of the fine milling area. Then, through multiple iterative calculations, the gradation curve corresponding to the gradation curve that coincides with the target gradation curve is obtained. The values ​​are then used to determine the proportion of different milling areas on the surface of the milling drum.

[0080] Step 5: Design the layout of different milling areas on the milling drum based on the proportion of different milling areas on the milling drum.

[0081] This allows for the production of recycled materials with different gradations in different milling areas, and the different recycled materials are "synthesized" during the milling and conveying process to obtain the desired target gradation of recycled material that meets the requirements of full recycling.

[0082] By designing the arrangement of milling zones with different cutter densities on the surface of the milling drum, high-performance recycled material that meets full recycling requirements can be directly produced during the milling process. The gradation range of this recycled material is higher than the technical specifications for recycled material given in current recycling technical standards, effectively expanding the application scenarios of recycled material. The specific arrangement of milling zones with different cutter densities on the surface of the milling drum is as follows:

[0083] As shown in Figure 7, this embodiment also provides a milling drum with unevenly distributed milling areas according to different cutter head densities. Multiple bases 2 are fixedly arranged on the surface of the milling drum 1. A cutter holder 3 is sleeved inside the base 2 and the cutter holder 3 corresponds one-to-one with the base 2. A cutter head 4 is installed on the cutter holder 3.

[0084] Based on the proportion of different milling areas on the surface of the milling drum 1, the base 2 is unevenly welded to the outer wall of the milling drum 1, and the number of cutter heads 4 is consistent with the number of base 2, as shown in Figure 5. When the base 2 is symmetrically installed on the surface of the milling drum 1 along the axial direction of the milling drum 1, and the cutter heads 4 are correspondingly installed on the cutter holder 3, different particle sizes of recycled material are produced by setting regions of different densities in the axial direction of the milling drum 1. As shown in Figures 3-4, when the base 2 is asymmetrically installed on the surface of the milling drum 1 along the axial direction, and the cutter heads 4 are correspondingly installed on the cutter holder 3, different particle sizes of recycled material are produced by setting regions of different cutter head densities in the tangential direction.

[0085] Meanwhile, as one possible implementation, depending on the proportion of different milling areas on the surface of the milling drum 1, the base 2 is arranged in a spiral pattern with unequal density along the surface of the milling drum 1, or in a diamond pattern, straight line pattern, wavy line pattern, or sawtooth pattern (not shown in the figure), and the cutter head 4 is correspondingly mounted on the cutter holder 3.

[0086] The above-mentioned milling area layouts can all produce both coarse and fine recycled materials, and through the "synthesis" of the milling process, produce recycled materials with a more reasonable gradation to achieve the requirements of full recycling. The difference lies in the different equipment requirements of different layout methods. For example, a milling drum with axially symmetrical cutter heads will cause fluctuations in the load of the milling machine motor in the direction of travel, that is, the load is small in the area with low cutter head density and large in the area with high cutter head density; while a milling drum with axially asymmetrical cutter heads may cause uneven stress on the milling drum due to the inconsistent cutter head density on the left and right sides in the axial direction. Therefore, the choice should be made based on the specific application and requirements.

[0087] The above-mentioned arrangement of the base 2 according to the different proportions of the milling area on the surface of the milling drum 1 is suitable for working environments that produce the same type of recycled material for a long time. It reduces the number of welding installations of the base 1 and can effectively reduce the equipment production cost.

[0088] When it is necessary to produce recycled materials with different gradations, another implementation method is adopted, as follows:

[0089] Based on the proportion of different milling areas on the surface of the milling drum 1, the base 2 is uniformly welded to the outer wall of the milling drum 1. The base 2 is arranged according to the distribution density of fine milling (not shown in the figure). The cutter heads 4 are unevenly arranged. The cutter heads 4 are symmetrically installed along the axial direction of the milling drum 1 or asymmetrically installed along the axial direction, or arranged in a spiral shape with unequal density along the surface of the milling drum 1, or arranged in a diamond shape, straight line, wavy line, or sawtooth shape with unequal density.

[0090] By flexibly designing various ways to install the cutter head 4 on the milling drum 1, the same milling drum can be used to produce recycled materials with different gradation requirements, increasing the flexibility of milling to produce recycled materials.

[0091] Application Examples:

[0092] Step 1: Based on the original asphalt pavement upper and middle layers that need to be repaired, with a total surface layer thickness of 7cm, the target gradation X of the recycled material for repair is shown in Table 3 below;

[0093] Table 3 Target Gradation X and Range Values

[0094]

[0095] Summarizing the data in Table 3 above, we obtain the target gradation and range curve shown in Figure 8.

[0096] Step 2: Detect and calculate the gradation of the recycled material obtained from milling drums with different cutter head densities, and obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the gradation. Table 3 shows that the maximum nominal particle size of the recycled material corresponding to target gradation X is 16 mm, and the fine powder content (<0.3 mm) of the recycled material corresponding to target gradation X is 12.

[0097] Step 3: Based on the relationship between the existing milling cutter head density and the maximum nominal particle size and fine powder content, the milling density region corresponding to a milling drum with 180 cutters can be determined; based on the fine powder content (<0.3mm) of the recycled material corresponding to the target gradation X, the milling density region corresponding to a milling drum with 500 cutters can be determined; the remaining part of the gradation is determined based on the particle size distribution corresponding to the target gradation, and the milling density region corresponding to a milling drum with 330 cutters is comprehensively determined.

[0098] Furthermore, the milling drum surface was divided into three regions: a coarse milling region (the milling density region corresponding to a milling drum with 180 cutter heads), a medium milling region (the milling density region corresponding to a milling drum with 330 cutter heads), and a fine milling region (the milling density region corresponding to a milling drum with 500 cutter heads). The gradation X corresponding to each milling region was also determined. i The values ​​are shown in Table 4 below:

[0099] Table 4 Gradation corresponding to different milling zones

[0100]

[0101] Summarizing the data in Table 4 above, we obtain the gradation curves corresponding to different milling areas as shown in Figure 9 (the number of cutter heads is the number of milling cutter heads when the complete milling drum is laid out, i.e., the number of cutter heads - 180 corresponds to the rough milling area, the number of cutter heads - 330 corresponds to the medium milling area, and the number of cutter heads - 500 corresponds to the fine milling area).

[0102] Step 4: Combine formula (1) to determine the proportion 'a' of different milling areas on the milling drum. i Perform calculations;

[0103] The following calculation formula can be obtained:

[0104] 1) X1(95)=88*a1+100*a2+100*a3;

[0105] 2) X2(85)=68*a1+85*a2+100*a3;

[0106] ...

[0107] 10) X 10 (6) = 3*a1 + 5*a2 + 8*a3;

[0108] Multiple a's were initially selected i The values ​​of a1 + a2 + a3 + ... + a i =1), then substitute it into the above calculation formula, and according to the different gradation values ​​obtained (such as X1, X2...X... 10 Plot the corresponding gradation curve and compare it with the gradation curve of the target gradation X. Compare the particle size distribution of the recycled material corresponding to X1 with the proportioning. Adjustments are made (i.e., when the coarse-grained gradation curve is higher than the target gradation curve, while the fine-grained gradation curve is lower than the target gradation curve, the proportion 'a' corresponding to the rough milling area is reduced). i Increase the proportion of the fine milling area (a) i Through multiple calculations, the data shown in Table 5 were obtained:

[0109] Table 5. Percentage of different milling areas

[0110]

[0111] The comparison between the calculated production gradation value and the target gradation value based on the above proportions is shown in Table 6:

[0112] Table 6 Comparison of Production Gradient and Target Gradient X

[0113]

[0114] The data in Table 4 above are summarized, and the production gradation and target gradation curves are shown in Figure 10. The curves basically coincide with the target gradation curves. The fluctuation rate of some sieve aperture sizes is ≤1%, which is much smaller than the requirements of industry standards and international standards (for new road surfaces, my country generally uses ±2%-±5%, the United States uses ±2%-±7%, my country's recycling standard is ±3%-±10% for plant-mixed hot recycling and ±2%-±7% for on-site hot recycling, and the specific values ​​are different depending on the sieve aperture).

[0115] Step 5: Based on the proportion of different milling areas on the milling drum (36% for rough milling area; 25% for medium milling area; and 39% for fine milling area), design the layout of different milling areas on the milling drum.

[0116] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included within the scope of the present invention.

Claims

1. A method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to the requirement of full recycling, characterized in that, Includes the following steps: Step 1: Determine the target gradation X of the recycled material according to the design requirements; Step 2: Detect and calculate the gradation of the recycled material obtained from milling drums with different cutter head densities, and obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the gradation; Step 3: Based on the target gradation X, obtain the maximum nominal particle size and fine powder content of the recycled material corresponding to the target gradation X, as well as the passing rate of different sieve aperture sizes corresponding to the target gradation X, divide the surface of the milling drum into different milling areas, and determine the cutter head density of the different milling areas; Subsequently, the recycled material gradation corresponding to different milling zones was determined based on the cutter density and type of milling zone. Step 4: Combine formula (1) to determine the proportion of different milling areas on the milling drum. Perform calculations; X (a) Among them, —Target gradation of recycled material produced by milling drum; — Milling material throughput for different milling zones and different sieve openings, % —The percentage of different milling areas on the milling drum, % —Sieve aperture size; n—Divisions corresponding to different cutter densities on the milling drum, take 1, 2, 3...; Step 5: Design the arrangement of different milling areas on the milling drum based on the proportion of different milling areas on the milling drum.

2. The method for designing the milling drum cutter head distribution based on the gradation of recycled materials according to claim 1, characterized in that, The milling area in step three includes a rough milling area, a medium milling area, and a fine milling area.

3. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 1, characterized in that, The milling drum (1) has multiple bases (2) fixedly arranged on its surface. Each base (2) has a tool holder (3) sleeved inside it, and the tool holder (3) corresponds to each base (2). A tool head (4) is installed on the tool holder (3).

4. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 3, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the base (2) is unevenly welded to the outer wall of the milling drum (1), and the number of cutter heads (4) is consistent with the number of bases (2).

5. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 3, characterized in that, The base (2) is evenly and symmetrically installed on the surface of the milling drum (1). Depending on the proportion of different milling areas on the surface of the milling drum (1), the cutter head (4) is evenly or unevenly installed on the corresponding cutter holder (3).

6. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 5, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the cutter heads (4) are evenly and symmetrically installed on the corresponding cutter holders (3), and the number of cutter heads (4) is the same as or different from the number of bases (2).

7. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 5, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the cutter heads (4) are unevenly distributed along the axial direction of the milling drum (1) and installed on the corresponding cutter holders (3), and the cutter heads (4) are symmetrically distributed along the longitudinal section of the middle part of the milling drum (1).

8. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 5, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the cutter heads (4) are unevenly distributed along the circumference of the milling drum (1) and installed on the corresponding cutter holders (3), and the cutter heads (4) are symmetrically distributed along the cross-section of the middle part of the milling drum (1).

9. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 5, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the cutter heads (4) are unevenly and asymmetrically distributed and installed on the corresponding cutter holders (3).

10. The method for designing the distribution of milling drum cutter heads based on the gradation of recycled materials according to claim 6, characterized in that, Based on the proportion of different milling areas on the surface of the milling drum (1), the cutter head (4) is arranged in a spiral pattern with unequal density along the surface of the milling drum (1), or in a diamond pattern, straight line pattern, wavy line pattern, or sawtooth pattern with unequal density.

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