A wear-resistant optimization layout design method for the front cutting tools of a shield spoke cutterhead

Abstract

The present invention discloses a wear-resistant optimization layout design method for the front cutting tools of a shield spoke cutter disc, including: selecting the cutter disc form: the cutter disc adopts an eight-spoke cutter disc with four main spokes + four auxiliary spokes; designing the layout level of the tearing cutter: the tearing cutter is designed in n levels along the direction from small to large radius; arranging the tearing cutter: only one high tearing cutter B is arranged on each radius path of the cutter disc; designing the layout level of the cutting cutter: the cutting cutter is designed in k levels along the direction from small to large radius; arranging the cutting cutter: the cutting cutter and the tearing cutter are arranged in different radius paths, that is, the cutting cutter and the tearing cutter do not exist at the same time on the same radius path of the same cutter beam. The present invention abandons the traditional cutter disc tool arrangement concept of "the longer the cutting path, the more cutting tools are arranged", and the cutting cutter arrangement is less, and the configuration is more concise, so as to achieve a lower wear effect with less cutting tool configuration, thereby realizing long-distance shield without changing cutting cutters, saving construction time, and reducing construction costs.

Description

Technical Field

[0001] The invention relates to the technical field of shield construction equipment, in particular to the design of shield cutterhead tools, in particular to a wear-resistant optimized arrangement design method of shield spoke cutterhead front tools. Background Art

[0002] When shield tunneling is in the strata with poor gradation of sand and gravel, pebble and boulder layers, high quartz content and strong abrasiveness, the cutterhead and tool are very easy to wear, and even the tool may collapse and fall off, leading to serious situations such as cutterhead failure. In typical sand and gravel strata such as Beijing, Shenyang and Chengdu, the construction of earth pressure balance shield generally adopts a spoke cutterhead with an opening rate greater than 60%, and the correctness of this cutterhead selection has been proved after long-term engineering application and on-site evaluation. However, the facts show that the wear of the tool is still very serious, the damage of the cutterhead often occurs, and the economic losses caused by the waste of construction time for opening the cabin and changing the tool are also huge. Through long-term and extensive engineering practice, the engineering effect after the modification of the cutterhead or tool shows that the serious engineering accident caused by excessive wear of the tool can be completely avoided by reasonable cutterhead design and tool configuration. Therefore, it is urgent to design the cutterhead reasonably, select and design the tools reasonably and optimize the layout. Summary of the invention

[0003] To solve the above problems, the purpose of the present invention is to propose a wear-resistant optimization layout design method for the front cutting tools of a shield spoke cutter disc, so as to solve the problem of high wear or conservative configuration of conventional selection and configuration of cutting tools.

[0004] The present invention is achieved in that:

[0005] A wear-resistant optimization layout design method for front cutters of a shield spoke cutter disc, wherein the front cutters include tearing cutters and cutting cutters, the tearing cutters include high tearing cutters B and low tearing cutters b, and the cutting cutters include front cutting cutters M and outer cutting cutters m; the wear-resistant optimization layout design method includes the following steps:

[0006] Step 1: Select the blade type: the blade adopts an eight-spoke blade with four main spokes and four auxiliary spokes. The blade is divided into eight blocks between adjacent spokes.

[0007] Step 2, design the layout level of the tearing knife: the tearing knife is designed in n levels along the direction from small to large radius;

[0008] Step 3: Arrange the tearing knives: the 1st to (n-2)th levels are all arranged on the spokes, the (n-1th)th level is arranged on the inner side of the outer edge of the knife disc, the nth level is arranged on the outer side of the outer edge of the knife disc, and only one high tearing knife B is arranged on each radial path of the knife disc;

[0009] Step 4: Design the layout level of the cutter: the cutter is designed in k levels from small to large radius;

[0010] Step 5, arrange the cutters: the 1st to (k-1)th level front cutters M1~M(k-1) are all arranged on the spokes, the kth level outer cutter m(k) is arranged on the outer edge of the cutter disc, and the cutters and tearing knives are arranged in different radial paths, that is, the cutters and tearing knives do not exist at the same radial path of the same knife beam at the same time.

[0011] Preferably, in step 3, the 1st to (n-2)th level high tearing knives B1 to B(n-2) are arranged as follows:

[0012] Within the radius of 1.5 m of the cutter disc, the 1st to 4th level high tearing knives B1 to B4 are arranged in a staggered manner along the first path;

[0013] Outside the radius of 1.5 m of the cutter disc, the 5th to (n-2)th level high tearing knives B5 to B(n-2) are arranged clockwise along the spiral line direction in the order of radius from small to large along the second path.

[0014] Preferably, in step 3, the first to (n-2) level low tearing knives b1 to b(n-2) are arranged as follows:

[0015] Within the radius of 1.5m of the cutter disc, low tearing knives b1 to b4 are not arranged;

[0016] Outside the radius of 1.5 m of the cutter disc, the 5th to (n-2)th level low-tearing cutters b5 to b(n-2) are arranged clockwise along the spiral line direction in the order of radius from small to large along the third path.

[0017] Preferably, in step 3, the (n-1)th level tearing knife is arranged as follows:

[0018] A tearing knife is arranged in each block in the order of 1 to 8 blocks on the inner side of the outer edge of the knife disc, and the high tearing knife B (n-1) and the low tearing knife b (n-1) are arranged alternately.

[0019] Preferably, in step 3, the n-th level tearing knife is arranged as follows:

[0020] Two tearing knives are arranged in each block along the outer side of the outer edge of the knife disc in the order of 1 to 8 blocks, namely a high tearing knife B(n) and a low tearing knife b(n). Similarly, the high tearing knife B(n) and the low tearing knife b(n) are arranged alternately.

[0021] Preferably, the tearing knives are arranged at a certain inclination angle in levels, the inclination angle of the tearing knives of the 1st to (n-1) levels is 0°, that is, not inclined, and the nth level tearing knife is arranged inclined, and the inclination angle of the tearing knife is the angle between the tearing knife axis and the vertical line of the spoke.

[0022] Preferably, the inclination angle of the nth tearing knife is 20° to 30°.

[0023] Preferably, in step 5, the 1st to kth level cutters are arranged as follows:

[0024] Along the fourth path, M1 to m(k) are arranged clockwise along the spiral line in the order of small to large radius;

[0025] Along the fifth path, M5 to M(k-1) are arranged clockwise along the spiral line in the order of small to large radius.

[0026] Preferably, the cutters are arranged in levels at a certain inclination angle, and the inclination angle of the cutters decreases in levels along the radius from small to large. The inclination angle of the cutter is the angle between the width direction of the cutter and the tangent of the cutter disc radius at its position on the cutter disc plane, that is, the angle rotated counterclockwise with the centroid of the cutter disc as the center.

[0027] Preferably, the inclination angles of the 1st to 6th level cutters M1-M6 are 20°, the inclination angles of the 7th to (k-1)th level cutters M7-M(k-1) are reduced to 10°, and the inclination angle of the kth level cutter m(k) is set to 0°.

[0028] Compared with the prior art, the present invention has the following beneficial effects: the present invention aims at the phenomenon that the front cutter of the cutter disc wears quickly, studies the wear mechanism of the front cutter, abandons the traditional concept of front cutter arrangement, and adopts a new design concept and configuration method, with fewer cutters arranged and a simpler configuration, so as to achieve a lower wear effect with fewer cutter configurations, thereby achieving long-distance shield tunneling without changing cutters, saving construction time and reducing construction costs. Specifically:

[0029] (1) Only one leading knife (high tearing knife) is arranged on each radial path. This arrangement is different from the general spoke-type cutter head tearing knife arrangement. Generally speaking, theoretically, the larger the cutting radius of the cutter, the longer the cutting path, the more severe the cutter wear, and the more tearing knives need to be arranged on the longer path. The present invention abandons the traditional concept of leading tearing knife arrangement. In the sand and gravel formation, only one tearing knife is arranged on each path, and the number of cutters arranged is even smaller. However, from the final construction effect of the project, the wear of the cutter is very small, which has obvious advantages over the effect of other shield cutter head arrangements in nearby projects.

[0030] (2) The cutter and tearing knife are arranged at different radii, that is, there is no tearing knife and cutter on the same blade beam and the same path. Most cutter disc designs tend to arrange tearing knives and cutters on the same cutting path to improve the scraping effect of the cutter, which easily leads to dense arrangement of knives and cannot play a good coordination role between the knives. The present invention arranges fewer knives, and it can be seen from the construction effect that the cutters arranged in this way basically do not have severe wear and tear, and the shield construction parameters are normal.

[0031] (3) All the front tearing knives on the inner side of the outer edge of the cutter disc are not tilted, and the outer side of the outer edge of the cutter disc is tilted, which helps to take into account the cutting effect of the front side of the cutter disc and the soil around the cutter disc, and at the same time can reduce the wear of the knives on the edge of the cutter disc. This design is reasonable.

[0032] (4) The cutters are arranged with a certain inclination angle, strictly following the principle of gradually decreasing the inclination angle of the cutters along the radial direction, which can better cater to the cutting path. At the same time, the paired cutters are tilted inwards towards the side close to the center and are symmetrically distributed, which can ensure that the cutters on both sides can play their role separately when the cutter disc rotates forward and reverse.

[0033] (5) The tool arrangement path is more reasonable, which can maximize the cutting efficiency. The tool configuration structure of the present invention meets the normal wear requirements, and even has less tool wear than the conventional configuration method. At the same time, the tool configuration is simpler than the traditional concept, and the tool arrangement is less, so that the tool configuration can achieve lower wear effect with less tool configuration, thereby realizing long-distance shield without tool change, saving construction time and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0035] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment in size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0036] Figure 1 is a schematic diagram of the cutting mode of the tool;

[0037] Figure 2 This is a diagram showing the wear of a heavy-duty tearing knife;

[0038] Figure 3 This is a schematic diagram of the heavy-duty tearing knife structure design;

[0039] Figure 4 Schematic diagram of the Archimedean spiral layout;

[0040] Figure 5 It is a schematic diagram of the double helix arrangement of the cutter;

[0041] Figure 6 A schematic diagram of the arrangement of cutter heads in a cutter head according to an embodiment of the present invention;

[0042] Figure 7 A diagram showing the arrangement paths of the high tearing knives within the outer edge of the knife disc (the first and second paths) according to an embodiment of the present invention;

[0043] Figure 8 A diagram showing the arrangement path of the low tearing knives within the outer edge of the knife disc (third path) according to an embodiment of the present invention;

[0044] Fig. 9 A diagram showing the arrangement path of the tearing knives at the outer edge of the knife disc according to an embodiment of the present invention;

[0045] Fig.10 A cutter arrangement path diagram (fourth and fifth paths) of an embodiment of the present invention;

[0046] Fig.11 This is a schematic diagram of the relative positions of the tearing knife and the cutting knife according to an embodiment of the present invention;

[0047] Fig.12 A schematic diagram of a complete tool path arrangement according to an embodiment of the present invention;

[0048] Fig.13 It is an overall layout diagram of a cutter head according to an embodiment of the present invention;

[0049] Fig.14 A schematic diagram of the inclined arrangement of the tearing knife according to an embodiment of the present invention;

[0050] Fig.15 A schematic diagram of the inclined arrangement of a cutter according to an embodiment of the present invention;

[0051] Fig.16 This is a schematic diagram of actual wear of the cutter when the cutter disc is leaving a hole according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0053] In the description of the present invention, the terms "include / comprise", "consist of..." or any other variations thereof are intended to cover non-exclusive inclusion, so that a product, device, process or method including a series of elements includes not only those elements, but also other elements not explicitly listed when necessary, or also includes elements inherent to such product, device, process or method. In the absence of further restrictions, the elements defined by the sentences "include / comprise...", "consist of..." do not exclude the presence of other identical elements in the product, device, process or method including the elements.

[0054] It should be understood that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, any suitable setting method, fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium, internal connection between two elements or interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] It should also be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", and "center" to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the device, component or structure referred to must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0056] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0057] The implementation of the present invention is described in detail below in conjunction with preferred embodiments.

[0058] In subway shield construction, the cutter selection and action mechanism are:

[0059] The subway tunnel sections in Beijing, Chengdu, Shenyang and other cities and the Nanjing Cross-River Tunnel are all typical gravel formations. The gravel has a large particle size and a high quartz content. The wear and impact cracking of the tool are serious. The single cutting mode of the cutting tool cannot meet the needs of the project. The shell-type pre-excavation tool is used, and the roller cutter is used in the cemented gravel formation. Tool cutting is divided into four types according to the principle: ① water-type cutting; ② shear-type cutting; ③ fracture-type cutting; ④ peeling-type cutting, such as Figure 1 The cutting mode corresponding to the sand and gravel formation should be peeling cutting.

[0060] In gravel and sand formations, the following types of cutters are mainly used:

[0061] ① Pioneer cutter. Pioneer cutters are generally divided into two types according to the cutting state: tearing cutters and roller cutters (rolling cutters are less commonly used in general, and the main function of roller cutters is to crush pebbles with larger particle sizes). As the name implies, this type of cutter has a higher blade height and will cut the stratum first. The pioneer cutter is generally installed in the cutter box in the middle of the spokes. It is back-mounted and can be replaced from the soil compartment. The pioneer cutter is arranged ahead of the cutting cutter, so that the pioneer cutter cuts ahead of the stratum, thereby protecting the cutter and avoiding it from cutting gravel or rock strata first. The tearing type pioneer cutter is mainly divided into three forms according to its shape: shell cutters, toothed cutters and heavy tearing cutters, such as Figure 2 . The advance knife loosens the ground before the cutter contacts the ground, especially the harder ground. The cutting width is generally narrow, so that the advance knife has higher cutting efficiency in harder ground such as gravel ground. In addition to loosening the dense soil layer first, the advance tearing knife also plays the role of crushing sand and gravel. The advance knife can also extend the life of the cutter. The advance knife is designed according to the two-way rotation of the cutter disc. The tooth knife and tearing knife can be installed in a specially designed knife box, allowing appropriate micro-movement according to the rotation direction of the cutter disc. This design is mainly used to reduce the wear on the side of the lead knife. The heavy-duty tearing knife head is generally arranged with a highly wear-resistant alloy block, such as Figure 3 The wear index is also determined based on the wear height of the wear-resistant alloy block.

[0062] ② Cutter. Also called scraper, it is usually arranged on the spokes of the cutter disc or the edge of the cutter disc panel. Its height is lower than that of the leading knife (tearing knife). Therefore, it is different from the tearing knife in that it does not cut the slag, but is used to scrape the slag cut by the tearing knife into the soil compartment.

[0063] ③ Auxiliary tools such as center cutter, diameter protection cutter, super digging cutter, etc.

[0064] The center cutter is a cutter arranged in the center of the cutterhead. Since the opening and excavation path at the center of the shield cutterhead are small, the center cutter is generally set in a continuous type, such as a center fishtail cutter.

[0065] As the name suggests, the diameter-maintaining cutter is the tool on the outermost circle of the shield cutter head used to ensure the excavation diameter. The characteristic of this tool is that it is generally not arranged perpendicular to the excavation surface, but is arranged at a certain inclination angle to the excavation surface and obliquely upward. And because its cutting path is the longest, it is often severely worn, and the tool even often falls off.

[0066] The super excavation cutter is a special cutter with telescopic function set on the outermost path of the cutter disc. Its main function is to assist in increasing the outer diameter of the excavation and increase the excavation gap so that the shield can turn smoothly. Generally, there is only one cutter disc set, and it is not used unless in special circumstances, so its wear and tear is generally not considered.

[0067] About the arrangement of tools:

[0068] At present, there are three main types of tool configurations for shield cutterheads in gravel and sandstone formations: ① front scraper + peripheral scraper combination, which is used in Beijing Metro and Shenyang Metro projects; ② front scraper + peripheral scraper + roller cutter combination, which is widely used in Chengdu Metro and Beijing Metro. The purpose of setting roller cutters is mainly to crush large-size pebbles in the formation, but in fact, according to the slag discharge conditions of many projects, this crushing effect is actually not ideal for gravel and sandstone formations; ③ front scraper + peripheral shell cutter + lead cutter or front scraper + peripheral shell cutter + center fishtail cutter + lead cutter combination, which takes into account the advantages and disadvantages of the first two and is widely used in Beijing Metro. Engineering applications show that the engineering effects of the first and second types of tool configurations are poor and the tool wear is serious. In loose gravel and sandstone formations, the configuration of shell-shaped lead cutters has become an important reference for shield tool configuration. For gravel formations, the incompatibility of cutterhead tool design with formation conditions is the main factor leading to serious engineering consequences.

[0069] The tearing knife is the first tool to contact and cut the soil layer when the cutter disc is used for excavation. Its layout is generally arranged according to the Archimedean spiral, such as Figure 4 This ensures that the excavation surface soil can be cut evenly as the cutter rotates.

[0070] The shape and position of the cutter are designed to facilitate scraping the soil into the soil compartment, and there are usually multiple cutters working simultaneously on the same track. The width of the cutter makes the cutting tracks of each cutter overlap to a certain extent. Due to the positive and negative rotation of the shield cutter head, the cutters should be arranged in positive and negative symmetry. Moreover, the running distance of the cutters on the same cutter head is proportional to their distribution radius, that is, within the same running time, the running distance of the peripheral cutters is longer than that of the inner cutters, and their wear is greater. According to the equal wear arrangement principle, the arrangement spacing of the peripheral cutters is generally smaller than that of the inner cutters. For example, a single spiral arrangement is used within 1 / 2 of the cutting diameter, and a double spiral arrangement is used for the rest of the periphery. Figure 5This tool arrangement, which is mainly based on cutting tools and supplemented by central fishtail tools, peripheral scrapers and super-excavation tools, is more common in foreign shield machines and is suitable for soft soil layers such as clay and sand.

[0071] The existing tool selection and tool arrangement methods have become relatively solidified after long-term use. Although great progress has been made in overcoming wear, they basically continue to use the existing selection and arrangement methods, with limited improvement in wear resistance, or the tool configuration is conservative, resulting in material waste. Through long-term and extensive engineering practice, the engineering results after the modification of the cutterhead or tool show that serious engineering accidents caused by excessive tool wear can be completely avoided by reasonable cutterhead design, tool selection and tool configuration.

[0072] In view of this, the present invention provides a wear-resistant optimization arrangement design method for the front cutter of the spoke-type cutter disc of a shield machine, and studies the tearing cutter and the cutting cutter on the front of the cutter disc, without paying attention to the side cutters such as the super-digging cutter. The front cutter includes a tearing cutter and a cutting cutter, the tearing cutter has a high tearing cutter B and a low tearing cutter b, and the cutting cutter has a front cutting cutter M and an outer cutting cutter m. The present invention takes a 6m-diameter shield machine as an example, the tearing cutter level n is 19, and the cutting cutter level k is 17, that is, the tearing cutter is arranged in 19 levels, and the cutting cutter is arranged in 17 levels. It should be understood that the values ​​of n and k are not unique, and there will be a reasonable level design according to the cutter disc diameter and the formation conditions. For example, for a 6m-diameter cutter disc, 16 to 20 levels can be set for excavation in the sand layer, and even more than 20 levels can be set in special cases, and 10 levels of tearing cutters are set in the clay layer, or even within 10 levels or basically no tearing cutters are arranged, and only cutting cutters are sufficient to cut the clay.

[0073] In addition, the layout of the cutter is completely different from that of the tearing knife. The layout principle of the cutter must be "full path layout". As the name suggests, at least one cutter can be found on any circular path. This can ensure that the cutter can effectively scrape off the soil in every area of ​​the excavation surface during the rotation of the cutter disc.

[0074] Based on the above principles, the wear-resistant optimization layout design method of the present invention is as follows:

[0075] Step 1: Select the blade type: the blade adopts an eight-spoke blade with four main spokes and four auxiliary spokes. The blade is divided into eight blocks between every two spokes.

[0076] Step 2: Design the layout level of the tearing knife: the tearing knife is designed in 19 levels from small to large radius;

[0077] Step 3, arranging tearing knives: the 1st to 17th levels are all arranged on the spokes, the 18th level is arranged on the inner side of the outer edge of the knife disc, the 19th level is arranged on the outer side of the outer edge of the knife disc, and only one high tearing knife B is arranged on each radial path of the knife disc;

[0078] Step 4: Design the layout level of the cutter: the cutter is designed in 17 levels from small to large radius;

[0079] Step 5, arrange the cutters: the 1st to 16th level front cutters M1 to M16 are all arranged on the spokes, the 17th level outer cutter m17 is arranged on the outer edge of the cutter disc, and the cutters and tearing knives are arranged in different radial paths, that is, the cutters and tearing knives do not exist at the same radial path of the same knife beam at the same time.

[0080] Specifically, Figure 6 As shown, a 6m-class diameter shield cutterhead of the present invention has an excavation diameter of 6640mm. It is a spoke-type cutterhead with a heavy-duty tearing knife combined with a cutting knife. The cutterhead is composed of two long spokes and four short spokes, that is, four main spokes + four auxiliary spokes, a total of 8 cutter beams, and the cutter beams are numbered in a clockwise direction: cutter beams 1 to 8. The heavy-duty tearing knife uses a shell-shaped tearing knife, which is divided into two types: a high tearing knife (denoted by B) and a low tearing knife (denoted by b), and the cutting knife is divided into two types: a front cutting knife (denoted by M) and an outer cutting knife (denoted by m).

[0081] The specific configurations of various tools are shown in Tables 1 and 2.

[0082] Table 1 Details of the arrangement of tearing knife along the trajectory

[0083]

[0084] Table 2 Details of scraper arrangement along the track

[0085] List Track radius Knife beam 1 Knife beam 2 Knife beam 3 Knife beam 4 Knife beam 5 Knife beam 6 Knife beam 7 Knife beam 8 Tilt Angle 1 700 MM 20° 2 850 MM 20° 3 1000 MM 20° 4 1150 MM 20° 5 1300 MM 20° 6 1450 MM 20° 7 1600 MM 10° 8 1750 MM 10° 9 1900 MM MM 10° 10 2050 MM MM 10° 11 2200 MM MM 10° 12 2350 MM MM 10° 13 2500 MM MM 10° 14 2650 MM MM 10° 15 2800 MM MM 10° 16 2950 MM MM 10° 17 3320 mm mm mm mm mm mm mm mm 0°

[0086] The optimization design concept of the present invention is described in detail below with reference to the accompanying drawings.

[0087] 1. About tool layout path:

[0088] The present invention arranges the tearing knives in a hierarchical manner when designing them, and designs 19 levels of tearing knives along the direction from small to large radius, that is, high tearing knives B1-B19 and low tearing knives b1-b19 are arranged on the front of the knife disc, such as Figure 6 .

[0089] When the tearing knives are arranged in the present invention, the first to seventeenth levels are all arranged on the spokes, the eighteenth level is arranged on the inner side of the outer edge of the knife disc, and the nineteenth level is arranged on the outer side of the outer edge of the knife disc.

[0090] Specifically, the 1st to 17th level high tearing knives B1 to B17 within the outer edge of the knife disc are all arranged on the spokes, and can be arranged in two areas: within a radius of less than 1.5m, in order to avoid the knives at adjacent radial positions being too close and too dense, the 1st to 4th level high tearing knives B1 to B4 are arranged in a staggered manner along the first path. Figure 7 , the first path is: starting from the 1st level of blade beam 7 and ending at the 4th level of blade beam 5, arranged from left to right, up, and then down. Between the radius greater than 1.5m and the outermost edge of the cutter disc, along the second path, the 5th to 17th level high tearing cutters B5~B17 are arranged clockwise along the spiral direction in the order from low to high along the radius. The second path is: starting from the 5th level of blade beam 7 and ending at the 17th level of blade beam 3, arranged along the clockwise spiral rotation path. The present invention is arranged in this way because the high tearing cutter B is the highest cutter in the entire cutter disc, that is, the cutter that contacts the soil of the face for the first time. The spiral arrangement is divided into two areas, which can match the direction of the cutter rotation and play the role of efficiently cutting the soil. At the same time, the cutters are evenly distributed, so as not to clamp the soil, resulting in "some cutters are too close to maximize the efficiency, and some cutters are too far away, resulting in poor cutting effect".

[0091] See also Figure 8 , the same as the high tearing knife B, the 1st to 17th level low tearing knives b1 to b17 within the outer edge of the knife disc are all arranged on the spokes, and the specific design is also divided into two areas: within the radius of 1.5m of the knife disc, no low tearing knives b1 to b4 are arranged; outside the radius of 1.5m of the knife disc, along the third path, the 5th to 17th level low tearing knives b5 to b17 are arranged clockwise along the spiral direction in the order from small to large radius. The third path is: starting from the 5th level of knife beam 3 and ending at the 17th level of knife beam 7, arranged along the clockwise spiral rotation path. Fig.12 , it can be found that the arrangement trajectory of this low tearing knife just complements Figure 7 The residual space in the arrangement of the medium and high tearing knives is also arranged in a clockwise spiral line to maximize the cutting efficiency of the tearing knives.

[0092] Continue to see Fig. 9 The outer edge of the knife disc has a certain thickness and is divided into inner and outer sides. The 18th tearing knife on the inner side is arranged as follows: a tearing knife is arranged in each block along the order of 1 to 8 blocks on the inner side of the outer edge of the knife disc, and the high tearing knife B18 and the low tearing knife b18 are arranged alternately.

[0093] In addition, the 19th-level tearing knife is arranged as follows: two tearing knives are arranged in each block in the order of 1 to 8 blocks along the outer side of the outer edge of the knife disc, namely, a high tearing knife B19 and a low tearing knife b19. Similarly, the high tearing knife B19 and the low tearing knife b19 are arranged alternately.

[0094] The reason why the tearing knives on the outer edge of the cutter disc are arranged in the above manner is that the outer edge of the cutter disc is a solid shell. Different from the arrangement of the knives on the spokes, the outer edge knives need to be arranged more densely, that is, they need to be arranged more densely, which helps to protect the outer periphery of the cutter disc.

[0095] It should also be noted that the present invention only arranges one high tearing knife B on each radial path of the cutter disc, as shown in Table 1, that is, on the cutter beams 1 to 8, there is one and only one high tearing knife B on each radial path (700 to 3100 mm). This arrangement subverts the general spoke-type cutter disc tearing knife arrangement rules, because theoretically speaking, the larger the cutting radius of the tool and the longer the cutting path, the more tools are needed to cut simultaneously on the same path. The present invention abandons this traditional concept of arranging tearing knives in advance, and fewer tools are arranged. However, from the final construction effect of the project (detailedly shown in the following text), the wear of the tool is very small, which has obvious advantages over the effects of other shield cutter disc arrangements in adjacent projects.

[0096] When designing the cutter, the present invention designs 17 levels of cutters along the radius from small to large, including the 1st to 16th level front cutters M1 to M16, and the 17th level outer cutter m17. Figure 6 .

[0097] When arranging the cutters, the 1st to 16th level front cutters M1 to M16 are all arranged on the spokes, and the 17th level outer cutter m17 is arranged on the outer edge of the cutter disc.

[0098] Specifically, Fig.10 , arrange the 1st to 17th level cutters as follows:

[0099] Along the fourth path, M1 to m17 are arranged clockwise along the spiral line in the order of small to large radius. The fourth path starts from the first level of blade beam 1 and ends at the 17th level of blade beam 8, and is arranged along the spiral line rotating path in the clockwise direction;

[0100] Along the fifth path, M5 to M16 are arranged clockwise along the spiral line in the order of radius from small to large. The fifth path starts from the 5th level of blade beam 1 and ends at the 16th level of blade beam 4, and is arranged along the spiral line rotating path in the clockwise direction.

[0101] The two paths of the cutting knife distribution are similar to the two paths of the high tearing knife B and the low tearing knife b, and their advantages are also similar to the arrangement of the tearing knives along the line.

[0102] It should also be noted that the cutting knife and the tearing knife are arranged in different radial paths, that is, the cutting knife and the tearing knife do not exist at the same time on the same radial path of the same knife beam, such as Fig.11As shown in Table 1 and Table 2, it can be seen that on the blade beams 1 to 8, on each radial path (700 to 2950 mm), there is no cutting knife M at the location where there is a high tearing knife B or a low tearing knife b, and there is no high tearing knife B or low tearing knife b at the location where there is a cutting knife M. This arrangement also subverts the general spoke-type cutter head cutter arrangement rule: as mentioned above, the tearing knife is a leading tool with a relatively high knife height, and its main function is to first contact the excavation surface and cut the soil, while the cutting knife height is lower than the leading knife (tearing knife) height, and its function is to assist the tearing knife and scrape the slag cut by the tearing knife into the soil compartment. Under the traditional configuration, the cutting knife and the tearing knife are usually mixed and arranged together on the same track, that is, the tearing knife and the cutting knife are usually arranged on the same cutting path. In order to facilitate the scraping of the cut soil into the soil compartment, there are generally multiple cutting knives working at the same time on the same track to improve the chip cutting and peeling effect, which easily leads to dense arrangement of the tools and cannot play a good role in the coordination between the tools. However, this is not the case with the present invention. The present invention separates the cutting paths of all adjacent tearing knives and scrapers, that is, they are not arranged on the same path. It can be seen from the construction effect (detailed description will be given later) that the cutters arranged in this way basically do not have severe wear, and the shield construction parameters are normal, and the effect of each tool can be better exerted.

[0103] The tearing knife and the scraper of the present invention are not on the same path, which is a special design different from the conventional design concept. In fact, it can provide enough space for the scraper to move the soil. If it is arranged on the same path as the tearing knife, the distance between the knives is too close, which will lead to poor soil moving effect.

[0104] For a complete arrangement of ripping and cutting knives, see Fig.13 ,Depend on Fig.13 It can be seen that on the front side of the entire cutter disc, the tearing knives and cutting knives are arranged relatively evenly and reasonably, neither too densely in a certain position nor leaving a large residual space, and during the chip cutting process, they will not produce more serious wear effects than conventional arrangements.

[0105] 2. About the layout angle of the tool:

[0106] In some embodiments, see Fig.14 The present invention also designs that the tearing knife is arranged at a certain inclination angle, and the inclination angle of the tearing knife is the angle between the axis of the tearing knife and the vertical line of the spoke.

[0107] Specifically, the inclination angle of the tearing knives of the 1st to 18th levels is 0°, that is, the axis of the tearing knives is in line with the vertical line of the spokes, and the inclination angle of the tearing knives of the 19th level is 20° to 30°, and the preferred angle of the present invention is 25°. In this arrangement, the inclined tearing knives are all on the outer edge of the cutter disc, because in fact, not all the soil cut by the cutter disc is the front soil, and the surrounding soil must also be cut. Therefore, the outer edge is inclined by 25° to help take into account the cutting effect of the front and surrounding soil of the cutter disc, and this design is reasonable.

[0108] In some embodiments, see Fig.15 The present invention also designs the cutters to be arranged at a certain inclination angle, and the inclination angle of the cutters decreases in stages along the radius from small to large. The inclination angle of the cutters is the angle between the width direction of the cutters and the tangent of the cutter disc radius at its position on the cutter disc plane, that is, the angle rotated counterclockwise with the centroid of the cutter disc as the center.

[0109] Specifically, the inclination angle of the 1st to 6th level cutters M1-M6 is 20°, that is, the cutter rotates 20° counterclockwise with the centroid of the cutter disc as the center, the inclination angle of the 7th to 16th level cutters M7-M16 is reduced to 10°, the cutter rotates 10° counterclockwise with the centroid of the cutter disc as the center, and the inclination angle of the 17th level cutter m17 is set to 0°, and the cutter does not rotate. Because the closer to the center, the shorter the tool cutting path and the greater the curvature, in order to cope with the tool cutting path with large curvature, the present invention increases the rotation of the cutter from 0° to 10° and finally to 20° from the edge to the center, which can better cater to the cutting path.

[0110] In order to verify the engineering application effect of the new tool selection and arrangement method adopted in the present invention, in the shield construction in a certain sand and gravel stratum, the shield cutter disc tools adopted the above-mentioned new selection and arrangement type, and the final measured wear conditions of the tearing knife and cutting knife are shown in Tables 3 and 4 below.

[0111] Table 3 Wear of tearing knife

[0112]

[0113]

[0114] Table 4 Cutter wear

[0115]

[0116]

[0117]

[0118] From the measured wear conditions of the tearing knives and cutting knives in Tables 3 and 4, it can be seen that in the shield construction in the sand and gravel strata, the wear effect of the tool selection and arrangement type of the present invention is not severe. The entire shield project has a continuous shield excavation of 2 km without changing the knife, and the technical and economic effects are good.

[0119] The wear of the entire tool when the cutter head comes out of the hole is as follows: Fig.16 As shown, from the actual wear effect, it can be seen that the entire tool basically has no major wear, which shows that the tool arrangement of the present invention is reasonable, the tool wear is very small, it is practical and suitable for engineering applications.

[0120] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wear-resistant optimization layout design method for the front cutters of a shield spoke cutter disc, wherein the front cutters include tearing cutters and cutting cutters, the tearing cutters include high tearing cutters B and low tearing cutters b, and the cutting cutters include front cutting cutters M and outer cutting cutters m; characterized in that: The wear-resistant optimization layout design method comprises the following steps: Step 1: Select the blade type: the blade adopts an eight-spoke blade with four main spokes and four auxiliary spokes. The blade is divided into eight blocks between adjacent spokes. Step 2, design the layout level of the tearing knife: the tearing knife is designed in n levels along the direction from small to large radius; Step 3: Arrange the tearing knives: the 1st to (n-2)th levels are all arranged on the spokes, the (n-1)th level is arranged on the inner side of the outer edge of the knife disc, and the nth level is arranged on the outer side of the outer edge of the knife disc, and only one high tearing knife B is arranged on each radial path of the knife disc; Step 4: Design the layout level of the cutter: the cutter is designed in k levels from small to large radius; Step 5, arrange the cutters: the 1st to (k-1)th level front cutters M1~M(k-1) are all arranged on the spokes, the kth level outer cutter m(k) is arranged on the outer edge of the cutter disc, and the cutters and tearing knives are arranged in different radial paths, that is, the cutters and tearing knives do not exist at the same radial path of the same knife beam at the same time.

2. The wear-resistant optimization layout design method according to claim 1 is characterized in that: In step 3, the 1st to (n-2)th level high tearing knives B1 to B(n-2) are arranged as follows: Within the radius of 1.5 m of the cutter disc, the 1st to 4th level high tearing knives B1 to B4 are arranged in a staggered manner along the first path; Outside the radius of 1.5 m of the cutter disc, the 5th to (n-2)th level high tearing cutters B5 to B(n-2) are arranged clockwise along the spiral line direction in the order of radius from small to large along the second path.

3. The wear-resistant optimization layout design method according to claim 1 is characterized in that: In step 3, the 1st to (n-2)th level low tearing knives b1 to b(n-2) are arranged as follows: Within the radius of 1.5m of the cutter disc, low tearing knives b1~b4 are not arranged; Outside the radius of 1.5 m of the cutter disc, the 5th to (n-2)th level low-tearing cutters b5 to b (n-2) are arranged clockwise along the spiral line in the order of radius from small to large along the third path.

4. The wear-resistant optimization layout design method according to claim 1 is characterized in that: In step 3, the (n-1)th tearing knife is arranged as follows: A tearing knife is arranged in each block in the order of 1 to 8 blocks on the inner side of the outer edge of the knife disc, and the high tearing knife B (n-1) and the low tearing knife b (n-1) are arranged alternately.

5. The wear-resistant optimization layout design method according to claim 1 is characterized in that: In step 3, the n-th level tearing knife is arranged as follows: Two tearing knives are arranged in each block along the outer side of the outer edge of the knife disc in the order of 1 to 8 blocks, namely a high tearing knife B (n) and a low tearing knife b (n). Similarly, the high tearing knife B (n) and the low tearing knife b (n) are arranged alternately.

6. The wear-resistant optimization layout design method according to any one of claims 1 to 5, characterized in that: The tearing knives are arranged at a certain inclination angle in levels. The inclination angle of the 1st to (n-1)th tearing knives is 0°, that is, not inclined. The nth tearing knives are arranged inclined, and the inclination angle of the tearing knives is the angle between the axis of the tearing knife and the vertical line of the spoke.

7. The wear-resistant optimization layout design method according to claim 6 is characterized in that: The inclination angle of the nth-stage tearing knife is 20°~30°.

8. The wear-resistant optimization layout design method according to any one of claims 1 to 5, characterized in that: In step 5, the 1st to kth level cutters are arranged as follows: Along the fourth path, M1~m(k) are arranged clockwise along the spiral line in the order of small to large radius; Along the fifth path, M5~M(k-1) are arranged clockwise along the spiral line in the order of small to large radius.

9. The wear-resistant optimization layout design method according to any one of claims 1 to 5, characterized in that: The cutters are arranged at a certain inclination angle in levels, and the inclination angle of the cutters decreases from small to large radius in levels. The inclination angle of the cutter is the angle between the width direction of the cutter and the tangent of the cutter disc radius at its position on the cutter disc plane, that is, the angle rotated counterclockwise with the centroid of the cutter disc as the center.

10. The wear-resistant optimization layout design method according to claim 9, characterized in that: The inclination angles of the 1st to 6th level cutters M1~M6 are 20°, the inclination angles of the 7th to (k-1) level cutters M7~M(k-1) are reduced to 10°, and the inclination angle of the kth level cutter m(k) is set to 0°.

Images