JP2018021367A - Roller cutter for drilling machine, and drilling machine with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a roller cutter for drilling machine.SOLUTION: On a side face of a tip part 20b constituting a base substrate part 20 of a roller cutter RC that is mounted on a cutter head 2 of a drilling machine 1, super-hard alloy side chips 23 are welded at predetermined intervals along a full circumference of the roller cutter RC and on a side face of a tip part 20b around them, a hardened built-up welding part 22 is welded. Thus, wearing of the base substrate part 20 of the roller cutter RC with shield drilling can be suppressed or prevented and wearing, folding and dropping of a super-hard alloy main chip part 21 caused by wearing of the base substrate part 20 can be suppressed or prevented, thereby improving durability of the roller cutter RC.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a roller cutter for an excavator and an excavator provided with the same, for example, an abrasion resistance technique for a roller cutter for an excavator.

  A disc-shaped excavation plate called a cutter head is installed in a rotatable state at the front end of an excavator represented by a shield machine or the like. A plurality of excavator roller cutters are arranged in a rotatable state on the front surface (surface facing the face) of the cutter head. This roller cutter for excavator is an excavating part that cuts a natural ground, and a plurality of cemented carbide tip portions are fixed at predetermined intervals along the outer periphery of the tip of the outer peripheral cutting edge. Installed. In addition, about the structure of the roller cutter for excavators, patent document 1-3 has description, for example.

Japanese Patent Laid-Open No. 2006-61123 Japanese Patent Laid-Open No. 10-246093 Japanese Patent Laid-Open No. 10-246094

  By the way, in the roller cutter for excavators, the wear resistance of the base material portion of the roller cutter for excavator is improved by performing hard overlay welding on the side surface of the blade edge portion. However, the hardfacing welded portion is softer than the tip portion made of cemented carbide at the tip of the blade tip and cannot be made too thick. For this reason, while the amount of wear of the tip made of cemented carbide at the tip of the blade tip is small, the hardfacing welded portion wears, and further, the base material portion of the lower layer is also worn and cemented carbide at the tip of the blade tip The made chip part is exposed. As a result, there is a problem that the cemented carbide tip at the tip of the blade tip is worn, broken or dropped due to shield thrust, cutter head torque, or the like.

  The wear, breakage, and dropout of the tip of the cemented carbide alloy at the tip of the blade tip cause a decrease in the excavating capability of the excavator, so it is necessary to replace the roller cutter for the excavator. The excavation operation must be interrupted, and further auxiliary work such as ground improvement is required, leading to a delay in the excavation period and an increase in construction costs. In particular, as the excavation work becomes longer, wear of the excavator roller cutter increases, and the number of excavator roller cutter replacements increases, which increases the time and cost burden. For this reason, in excavation work, how to improve the durability of the roller cutter for excavators is an important issue.

  The present invention has been made from the above-described technical background, and an object of the present invention is to provide a technique capable of improving the durability of the roller cutter for excavators.

  In order to solve the above-mentioned problems, the roller cutter for an excavator according to the first aspect of the present invention is formed on the outer periphery of the main body formed in a disc shape so as to gradually become thinner from the center of the main body toward the outer periphery. A plurality of holes formed so as to extend from the tip of the blade edge part toward the center of the main body at predetermined intervals along the outer periphery of the main body at the tip of the blade edge part. In a roller cutter for excavator provided with a plurality of first carbide tip portions provided in a state of being fitted in each of the holes, it is predetermined along the outer periphery of the main body on the side surface of the blade edge portion. A plurality of grooves formed at every interval, a plurality of second cemented carbide tip parts welded to the main body in a state of being fitted to each of the plurality of grooves on the side surface of the cutting edge part, First carbide tip and A hardfacing welded portion welded to the main body so as to cover the side surface of the cutting edge portion excluding the second carbide tip portion, and the hardness of the second carbide tip portion is the first It is characterized in that it is lower than the cemented carbide tip part, and the thickness of the second cemented carbide tip part is thicker than that of the hardened welded part.

  According to a second aspect of the present invention, in the first aspect of the invention, the second carbide tip portion is disposed between adjacent ones of the plurality of first carbide tip portions. It is characterized by.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, at least a part of the upper surface of the second carbide tip portion is inclined so as to be along the side surface of the blade edge portion. It is characterized by.

  An excavator according to a fourth aspect of the present invention is characterized in that the roller cutter for excavator according to any one of the first to third aspects is installed in a cutter head.

  According to the first aspect of the present invention, the wear of the main body of the excavator roller cutter can be suppressed or prevented, and the wear, breakage, and dropping of the first carbide tip portion due to the wear of the main body can be suppressed or Therefore, the durability of the roller cutter for excavator can be improved.

  According to invention of Claim 2, while being able to arrange | position a 2nd carbide | carbonized_material tip part to the front end side vicinity which is easy to wear in the blade edge | tip part which comprises the main body of the roller cutter for excavators, it is 2nd carbide | carbonized_material. Since the total area of the tip portion can be increased, the protection capability of the main body by the second carbide tip portion can be improved.

  According to the invention described in claim 3, it is possible to suppress or prevent the second carbide tip portion from dropping off.

  According to the invention described in claim 4, since the durability of the roller cutter for excavator can be improved, the excavating capability of the excavator can be maintained over a long period of time.

It is the principal part block diagram which looked through the inside of the excavator which concerns on one embodiment of this invention from the side. It is a front view of the cutter head which comprises the excavator of FIG. (A) is a principal part side view of a roller cutter, (b) is a partially broken side view of the base material part of the roller cutter of FIG. 3 (a). 3A is a front view of the roller cutter of FIG. 3A, FIG. 3B is a cross-sectional view taken along line II in FIG. 3A, and FIG. 3C is a cross-sectional view taken along line II-II in FIG. FIG. (A) is a principal part perspective view of the roller cutter of Fig.3 (a), (b) is a principal part enlarged plan view of the blade edge | tip part of the roller cutter of Fig.5 (a). (A) is an expanded sectional view of the III-III line of FIG.5 (b), (b) is an expanded sectional view of the IV-IV line of FIG.5 (b). (A) is a principal part top view in the manufacturing process of a roller cutter, (b) is an expanded sectional view of the VV line of Fig.7 (a), (c) is manufacture of the roller cutter following Fig.7 (a). The principal part top view in a process, (d) is an expanded sectional view of the VV line of FIG.7 (c). 7A is a plan view of the main part of the roller cutter during the manufacturing process following FIG. 7C, FIG. 8B is an enlarged sectional view taken along the line V-V in FIG. 8A, and FIG. ) Is a main part plan view in the manufacturing process of the roller cutter following (), (d) is an enlarged cross-sectional view taken along line VV of FIG. 8 (c).

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  First, a configuration example of the excavator according to the present embodiment will be described with reference to FIG. FIG. 1 is a main part configuration diagram showing the inside of the excavator according to the present embodiment as seen through from the side.

  The excavator 1 according to the present embodiment is, for example, impervious and plastic fluidity generated by injecting an additive into the earth and sand excavated by the cutter head 2 and kneading (property that can be freely deformed and moved). Is excavated in a state in which the mud is filled in the chamber 4 between the cutter head 2 and the device body 3, thereby generating mud pressure against the earth pressure of the face and ensuring the stability of the face. It is a mud pressurizing shield machine that excavates in a state.

  The cutter head 2 is a cutter board for excavating the ground, and is installed on the front face of the tip head of the excavator 1 in a state of being rotatable in the forward and reverse directions along the circumferential direction of the device main body 3. Although not particularly limited, the diameter of the cutter head 2 is, for example, about 5360 mm, and the thickness of the cutter head 2 is, for example, 610 mm.

  A center cutter C, a roller cutter RC, a scraper tooth (not shown in FIG. 1), and the like are installed on the front surface (the surface facing the face) of the cutter head 2. The center cutter C and the roller cutter RC are excavation parts that mainly cut a natural ground, and the scraper tooth is a cutting part that mainly cuts a natural ground.

  A copy cutter CC is installed on the outer periphery of the cutter head 2. The copy cutter CC has a role of performing excavation at the time of sharp curve construction, attitude control of the excavator 1, and the like. A mixing blade 6 is provided on the back surface of the cutter head 2. The kneading blade 6 is formed of, for example, a cylindrical protruding member, and has a role of stirring and mixing the earth and sand in the chamber 4 and the additive when the cutter head 2 rotates. The cutter head 2 will be described later.

  The apparatus body 3 includes a front body plate (front body part) 3a, a rear body plate (rear body part) 3b behind the front body plate 3a, and a tail seal 3c behind the body body plate 3a.

  The front trunk plate 3a and the rear trunk plate 3b are formed of, for example, a cylindrical steel plate, and are components that form the outer shape of the device main body 3 and form a hollow space inside the device main body 3. The front body plate 3a and the rear body plate 3b are engaged with each other when the spherical bearing portion at the tip of the rear body plate 3b is in contact with the inner peripheral surface of the front body plate 3a on the rear end side of the front body plate 3a. Are combined.

  The tail seal 3c is a sealing member that prevents groundwater and the like from entering the apparatus main body 3 from the rear part of the apparatus main body 3 during excavation work, and the inner periphery of the rear cylinder plate 3b at the rear end of the rear cylinder plate 3b. It is installed in a frame shape along.

  On the front side of the front body plate 3a, a partition wall 7 is installed at a position retracted from the front surface to the inside of the device body 3. The partition wall 7 is a steel plate that divides the hollow space in the apparatus main body 3 into a face side and an inside of the machine, and the chamber 4 described above on the face side of the partition wall 7 (that is, between the cutter head 2 and the partition wall 7). Is provided. The earth and sand excavated by the cutter head 2 is taken into the cutter head 2 through a through hole (not shown in FIG. 1) that penetrates the front and back surfaces of the cutter head 2.

  On the other hand, inside the machine main body 3 of the excavator 1, there are a cutter driving body 8, a bent jack 9a, a shield jack 9b, a screw conveyor 10, an erector 11, an earth pressure detecting unit 12, and additive material injecting units 13a, 13b, 13c etc. are installed.

  The cutter driving body 8 is a motor (drive source) that rotates the cutter head 2 in the forward and reverse directions, and a plurality of cutter driving bodies 8 are installed in the vicinity of the outer periphery in the front of the cutter head 2 along the circumferential direction of the cutter head 2. Has been. Here, the outer periphery support driving method is illustrated as the cutter driving method.

  The middle-folded jack 9a is a device that corrects the propulsion direction and posture of the excavator 1, and the front trunk plate 3a and the rear trunk plate 3b are connected to the front trunk plate 3a and the rear trunk plate 3b in the equipment main body 3. Are installed side by side along the circumferential direction of the device body 3 in a state of straddling the boundary. When the excavator 1 is propelled in a state where pressure oil is supplied to the bent jack 9a and the front body plate 3a and the rear body plate 3b are refracted in a predetermined direction and angle, It is possible to control the posture.

  The shield jack 9b is a device that generates a propulsive force for advancing the excavator 1 by applying a reaction force to the segment SG installed behind the device main body 3, and the front trunk plate 3a and the rear A plurality of devices are installed side by side along the circumferential direction of the device body 3 in a state of straddling the boundary with the body plate 3b.

  The screw conveyor 10 is a device for discharging the earth and sand taken into the chamber 4 to the outside of the machine, and passes through the partition wall 7 at the bottom of the device body 3 from the earth and sand taking-in end portion 10 a disposed in the chamber 4. The device main body 3 is installed in a state of continuously extending obliquely upward toward the discharge end portion 10b disposed at a position slightly higher than the center of the device main body 3 in the height direction. Here, a ribbon screw conveyor is illustrated.

  The erector 11 is an assembly device that grips the segment SG, turns in the inner circumferential direction of the excavation mine, and transfers the segment SG to an assembly position in the inner circumferential direction of the excavation mine, and is driven by a hydraulic motor (not shown) for driving the erector. It is installed in the hollow of the back trunk plate 3b so as to be rotatable along the circumferential direction of the excavation mine.

  The earth pressure detection unit 12 is a sensor that detects the mud pressure in the chamber 4. The excavator 1 can dig while ensuring the stability of the face by managing the mud pressure in the chamber 4 detected by the earth pressure detector 12.

  The additive injection part 13 a is a pipe part for injecting the additive (mud clay material) into the chamber 4, and is installed in a state of penetrating the partition wall 7. The additive injection part 13b is a pipe part for injecting the additive (mud clay material) to the outer periphery and face of the excavator 1, and is installed at a plurality of locations along the circumferential direction of the front trunk plate 3a. . Furthermore, the additive injection part 13c is a pipe part for injecting the additive (mud clay material) to the outer periphery of the excavator 1, and is installed at a plurality of locations along the circumferential direction of the rear trunk plate 3b. .

  Next, a configuration example of the above-described cutter head 2 will be described with reference to FIG. FIG. 2 is a front view of a cutter head constituting the excavator of FIG.

  The cutter head 2 is composed of, for example, a disc-shaped spoke-type cutter head, and is installed at four positions between two spoke portions 2a and 2b assembled in a cross shape and adjacent to the spoke portions 2a and 2b. The cover portion 2c, the outer ring portion 2r that connects the tip portions of the spoke portions 2a and 2b, and the through hole 2h formed between these members.

  In the center of the front face of the cutter head 2, the center cutter C described above is installed. Instead of the center cutter C, another excavator cutter member such as a center bit or a cone head type roller bit may be installed.

  A plurality of roller cutters RC (RC1, RC2) are installed in a rotatable state in the front face of the cutter head 2. One roller cutter RC1 is installed in the center in the width direction (short direction) of the spoke portions 2a and 2b in a state of being arranged at predetermined intervals along the longitudinal direction of the spoke portions 2a and 2b. Instead of the roller cutter RC1, another excavator cutter member such as a leading bit may be installed. The other roller cutter RC2 is installed in a state of being arranged along the circumferential direction of the cutter head 2 by two for each cover portion 2c. In addition, the two roller cutters RC2 of each cover portion 2c are installed in a state where the inclination angle (installation angle) of each other is changed.

  In addition, a plurality of scraper teeth ST described above are installed along the longitudinal direction of the spoke portions 2a and 2b on both sides in the width direction (short direction) of the spoke portions 2a and 2b in the front of the cutter head 2. Has been.

  Further, a plurality of additive injections for injecting a mud material such as bentonite-based additive toward the front face of the cutter head 2 in the spoke portions 2a and 2b in the front of the cutter head 2 are performed. The parts 13d to 13f are installed. As the additive, a bubble material may be used instead of the bentonite-based additive, or both a bentonite-based additive and a bubble material may be used.

  Next, the configuration of the roller cutter RC2 as an example of the roller cutter RC will be described with reference to FIGS. 3A is a side view of the main part of the roller cutter, FIG. 3B is a partially cutaway side view of the base material portion of the roller cutter of FIG. 3A, and FIG. 4A is FIG. 4B is a cross-sectional view taken along the line II of FIG. 3A, FIG. 4C is a cross-sectional view taken along the line II-II of FIG. 3A, and FIG. 3A is a perspective view of the main part of the roller cutter of FIG. 3A, FIG. 5B is an enlarged plan view of the main part of the blade tip of the roller cutter of FIG. 5A, and FIG. FIG. 6B is an enlarged sectional view taken along line IV-IV in FIG. 5B. FIG. 6B is an enlarged sectional view taken along line III-III in FIG. 3A and 4A are not cross-sectional views, but the cemented carbide member is hatched to make the drawings easy to see. Further, FIG. 5B is a plan view, but in order to make the drawing easy to see, the hardfacing welded portion and the welded portion are hatched. In addition, the enlargement magnification is different between FIG. 6A and FIG.

  The roller cutter RC2 includes a base material portion (main body) 20, a main tip portion (first carbide tip portion) 21, a hardfacing welded portion 22, and a side tip portion (second carbide tip portion) 23. And the welding part 24 is provided. Although not particularly limited, the diameter of the roller cutter RC2 is, for example, 432 mm.

  The base material portion 20 of the roller cutter RC2 is a main body portion that forms the disk-shaped base of the roller cutter RC2, and is, for example, a chromium molybdenum steel material (SCM440H) that is easily available, has high toughness, and excellent mechanical workability. ) And the like. The hardness of the base material portion 20 is, for example, about HV500. Note that HV is one of hardness standards and indicates Picker hardness. However, the constituent material of the base material part 20 is not limited to the above-described material, and can be variously changed.

  This base material part 20 is integrally provided with a central shaft part 20a at the center in the radial direction and a cutting edge part 20b at the outer periphery thereof. The blade edge portion 20b is formed in a state in which both side surfaces of the blade edge portion 20b are inclined toward the thickness direction center of the blade edge portion 20b so as to become gradually thinner from the center of the roller cutter RC2 toward the outer periphery.

  As shown in FIGS. 3B and 4B, holes 20c are formed at the tip of the blade edge portion 20b at predetermined intervals along the outer periphery of the roller cutter RC2. The hole 20c extends from the tip of the blade edge portion 20b toward the center of the roller cutter RC2, and terminates at a midway position.

  As shown in FIGS. 3B and 6, grooves 20d are formed on both side surfaces of the blade edge portion 20b at predetermined intervals along the outer periphery of the roller cutter RC2. For example, the groove 20d is formed in a long groove shape in which the radial dimension of the roller cutter RC2 is longer than the circumferential dimension, and is formed so as to be positioned adjacent to the hole 20c.

  The main tip portion 21 is a blade body portion that mainly has a function of hitting and breaking a natural ground and disturbing it, and as shown in FIG. 4B, a state where the tip (blade edge) of the main tip portion 21 is exposed. And fitted into each of the plurality of holes 20c of the base material part 20. Although not particularly limited, the total number of main chip portions 21 is, for example, 24, and the interval between adjacent main chip portions 21 is, for example, 24 mm.

  The main tip portion 21 is formed of, for example, a cylindrical body whose tip is formed in a blade shape. By making the main tip portion 21 a cylindrical body, the stress applied to each main tip portion 21 during shield excavation can be distributed almost evenly, so that the strength of the main tip portion 21 can be improved. For this reason, it is possible to make it difficult for the main chip portion 21 to be broken or broken. Although not particularly limited, the diameter of the main chip portion 21 is, for example, 22 mm, and the length is, for example, 40 mm.

  Further, the main tip portion 21 is made of, for example, a JIS / E5 type alloy (E5 type alloy standardized by JIS) having a good balance between hardness and mine folding force (that is, difficult to wear and break), for example, Metal carbide particles such as tungsten carbide (WC), titanium carbide (TiC) or tantalum carbide (TaC) are bonded with a binder metal such as cobalt (Co), nickel (Ni) or iron (Fe). It is made of super hard alloy. The hardness of the main chip portion 21 is, for example, about HV940 that is harder than the base material portion 20.

  The hardfacing welded portion 22 has a function of fixing the side tip portion 23 in addition to a function as a protective member for suppressing or preventing wear of the base material portion 20, and constitutes the base material portion 20 of the roller cutter RC2. Welded so as to cover the surface (both side surfaces) of the cutting edge portion 20b.

  However, when the hardfacing welded portion 22 covers the main tip portion 21 and the side tip portion 23, the main tip portion 21 and the side tip portion 23 may break. Therefore, as shown in FIG. 5B, the hardfacing welded portion 22 is formed so as not to directly cover the main tip portion 21 and the side tip portion 23. That is, the hardfacing welded portion 22 is formed in a state separated from the outer periphery of the exposed portion of the main tip portion 21 by a predetermined distance. Further, the hardfacing welded portion 22 is formed in a state where it overlaps the surface of the welded portion 24 on the outer periphery of the side tip portion 23 but is separated from the outer periphery of the sidetip portion 23 by the amount of the welded portion 24.

  The hardfacing welded portion 22 is formed of, for example, a welding material for hardfacing (JIS Z 3326 YF3B-C-800) such as MT-HVC. Moreover, since the hardfacing welded part 22 will be cracked if it is too thick, the thickness is thinner than the side tip part 23, for example, about 2-3 mm. The hardness of the hardfacing welded portion 22 is, for example, HV800 (about HV780) that is harder than the base material portion 20 but softer than the main tip portion 21.

  By providing such a hardened welded portion 22, it is possible to suppress or prevent the wear of the base material portion 20, so that the wear, breakage, and dropout of the main tip portion 21 due to the wear of the base material portion 20 can be achieved. Can be suppressed or prevented. Therefore, durability (life) of the roller cutter RC2 can be improved.

  Further, by providing the hardfacing welded portion 22 so as to surround the outer periphery of the sidetip portion 23, the sidetip portion 23 can be firmly fixed by the hardfacing welded portion 22. Dropout can be suppressed or prevented.

  The side tip portion 23 is a protective member that mainly suppresses or prevents wear of the base material portion 20 and is fitted in each of the plurality of grooves 20d on both side surfaces of the cutting edge portion 20b constituting the base material portion 20. In the state, it is welded to the base material part 20 by the welding part 24. Although not particularly limited, the total number of side chip portions 23 is, for example, 48.

  The side tip portion 23 is formed in a plate shape, for example. Thereby, since the reduction | decrease of the volume of the base material part 20 can be made into the minimum, the support power fall of the main chip part 21 resulting from the reduction | decrease in the volume of the base material part 20 can be prevented. Further, since the side tip portion 23 is formed in a plate shape, the groove 20d into which the side tip portion 23 on the surface of the base material portion 20 is fitted can be shallow, so that the mechanical strength of the base material portion 20 itself can be secured. it can. Although not particularly limited, the side chip portion 23 has a width (short dimension) of, for example, 16 mm, a length (longitudinal dimension) of, for example, 40 mm, and a thickness of, for example, 6 mm.

  The side tip portion 23 is made of, for example, cemented carbide (metal carbide particles such as tungsten carbide (WC), molybdenum (Mo), etc.) such as cobalt (Co), nickel (Ni), or iron (Fe). Super hard alloy bonded with a binder metal). The hardness of the side tip portion 23 is, for example, about HV600 which is harder than the base material portion 20 but softer than the main tip portion 21 and the hardfacing welded portion 22.

  However, normally, the cemented carbide member is fixed by brazing, but if the side tip portion 23 is fixed by brazing, the brazing melts due to the welding heat during the construction of the hardfacing welded portion 22. Since the side tip portion 23 falls off, the side tip portion 23 is formed of a weldable cemented carbide, and the side tip portion 23 is fixed by welding. A forward taper (slope) is formed on the outer peripheral side surface of the side tip portion 23 so as to facilitate welding.

  Such a side tip portion 23 is made of a softer material than the hardfacing welded portion 22, but can be made thicker than the hardfacing welded portion 22 as shown in FIG. 6. For this reason, in addition to providing the hardfacing welded portions 22 on both side surfaces of the cutting edge portion 20b of the roller cutter RC2, by providing a plurality of side tip portions 23, the mother tip portion 23 is not provided. Wear of the material part 20 can be further suppressed or prevented. For this reason, compared with the case where there is no side tip portion 23, the wear, breakage, and dropout of the main tip portion 21 due to the wear of the base material portion 20 can be further suppressed or prevented, so the durability of the roller cutter RC2 (Life) can be further improved.

  Further, as shown in FIGS. 3A and 5, the side chip portion 23 is arranged between the main chip portion 21 in the circumferential direction of the roller cutter RC2 by arranging the side chip portion 23 between the main chip portions 21. The following effects can be obtained as compared with the case where it is disposed at the same position (the central shaft portion 20a side of the roller cutter RC2 from the exposed position of the main chip portion 21). That is, since the side tip portion 23 can be disposed up to the vicinity of the tip side that is likely to be worn at the cutting edge portion 20b, and the total area of the side tip portion 23 can be increased, the base material portion 20 of the side tip portion 23 can be increased. The protection ability can be improved.

  Further, since the hardfacing welded portions 22 and the side tip portions 23 are alternately arranged along the circumferential direction (rotational direction) of the roller cutter RC2, the impact resistance can be improved. Durability can be improved.

  Further, as shown in FIG. 6A, an inclined surface 23a that is inclined in accordance with the inclination of the side surface of the blade edge portion 20b is formed on a part of the top end side of the blade edge portion 20b on the upper surface of the side tip portion 23. Yes. Thereby, dropping of the side chip part 23 can be suppressed or prevented.

  The welded portion 24 is a member that joins the side tip portion 23 to the base material portion 20 and is formed so as to surround the entire circumference of the side tip portion 23. The welding material of the welding part 23 is formed of, for example, a welding material (JIS Z 3313 YFW24) such as SF-1.

  When the side tip portion 23 is joined by brazing, the side tip portion 23 falls off when the overlay welding is performed around the side tip portion 23 and the side tip portion 23 falls off. As a result of welding, it is possible to prevent the side tip portion 23 from falling off when overlay welding is performed around the side tip portion 23.

  The configuration of the roller cutter RC2 as described above is also applied to the roller cutter RC1. Thereby, since durability of all the roller cutters RC in the front surface of the cutter head 2 can be improved, the cutting capability of the roller cutters RC can be ensured. For this reason, the excavation capability of the excavator 1 can be maintained over a long period of time. Moreover, since the fall of the excavation speed of the excavator 1 can be suppressed, the amount of advance can be ensured.

  Further, since the number of times of exchanging the roller cutter RC can be reduced, it is possible to avoid a delay in the excavation work period and to reduce the construction cost even when excavating long distances. Furthermore, it is possible to flexibly cope with hard ground and low-speed excavation processes that are higher than expected.

  However, the above roller cutter configuration may be applied only to the roller cutter RC having a relatively long sliding distance from the outer peripheral side of the cutter head 2 to the midway position in the radial direction. Thereby, compared with the case where it applies to all the roller cutter RC in the surface of the cutter head 2, the cost of the excavator 1 can be reduced, without reducing the excavation capability of the excavator 1 significantly.

  In addition, when there are two cutting edge portions on the outer periphery of one base material portion 20 like the roller cutter RC1, the above-described cured build-up weld portion 22 and side tip portion 23 are provided only on the outer side surface of each cutting edge portion. May be.

  Next, an example of a method for manufacturing the roller cutter RC2 will be described with reference to FIGS.

  First, FIG. 7A is a plan view of the main part in the manufacturing process of the roller cutter, and FIG. 7B is an enlarged sectional view taken along line VV of FIG. 7A.

  Here, as shown in FIG. 7A, the main chip portion 21 is fitted and fixed in the hole 20c of the base material portion 20 for manufacturing the roller cutter by vacuum press-fitting or the like. As shown in FIGS. 7A and 7B, at this stage, the side tip portions 23 are not installed in the grooves 20d on both side surfaces of the blade edge portion 20b constituting the base material portion 20.

  Next, FIG. 7C is a plan view of the main part in the manufacturing process of the roller cutter following FIG. 7A, FIG. 7D is an enlarged sectional view taken along line VV of FIG. 7C, and FIG. ) Is a plan view of the main part in the manufacturing process of the roller cutter following FIG. 7C, and FIG. 8B is an enlarged sectional view taken along line VV of FIG. 8A. Although FIG. 8A is a plan view, the welded portion 24 is hatched to make the drawing easy to see.

  Here, as shown in FIGS. 7 (c) and 7 (d), the side tip portion 23 is fitted in the groove 20 d on the side surface of the cutting edge portion 20 b constituting the base material portion 20 for manufacturing the roller cutter. Thereafter, as shown in FIGS. 8A and 8B, the outer periphery (entire circumference) of the side tip portion 23 is formed by performing mag welding or the like on the outer circumference (full circumference) of the side tip portion 23 in the groove 20d. ) And the side tip portion 23 is welded to the base material portion 20.

  Next, FIG. 8C is a plan view of the main part in the manufacturing process of the roller cutter following FIG. 8A, and FIG. 8D is an enlarged sectional view taken along the line VV of FIG. 8C. Yes. Although FIG. 8C is a plan view, the hardfacing welded portion 22 and the welded portion 24 are hatched to make the drawing easy to see.

  Here, the hardfacing welded portion 22 is formed on the surface of the blade edge portion 20b by performing mag welding or the like on the surface of the blade edge portion 20b constituting the base material portion 20 for manufacturing the roller cutter. At this time, since the side tip portion 23 is welded, it is possible to prevent the side tip portion 23 from falling off during overlay welding. The hardfacing welded portion 22 is separated from the outer periphery of the main tip portion 21 and is also separated from the outer periphery of the side tip portion 23 by the width of the welded portion 24.

  In this way, a roller cutter RC2 having a plurality of main tip portions 21 on the outer periphery of the tip end of the blade edge portion 20b and having a hardened welded portion 22 and a plurality of side tip portions 23 on both side surfaces of the blade edge portion 20b is manufactured. To do.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. It is not a thing. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  For example, in the above-described embodiment, the case where the outer peripheral support drive type mud pressure shield machine is used has been described. However, the present invention is not limited to this, and other methods such as a center shaft drive method and an intermediate support drive method are used. You may use the mud pressure shield machine of the drive system.

  In the above description, the case where the present invention is applied to a mud pressure shield machine has been described. However, the present invention is not limited to this. For example, mud water is pumped into a mud chamber between a cutter head and an apparatus main body, It may be applied to a mud type shield machine that excavates the ground by pressing the cutter head against the face and rotating it while making the pressure of the muddy water in the room suitable for the earth pressure and groundwater pressure of the face and stabilizing the face. .

DESCRIPTION OF SYMBOLS 1 Excavator 2 Cutter head 3 Apparatus main body 4 Chamber 6 Mixing blade 7 Bulkhead 8 Cutter drive body 20 Base material part 20a Central axis part 20b Cutting edge part 20c Hole 20d Groove 21 Main tip part 22 Hardening weld part 23 Side tip part 23a Inclined surface 24 Welded part C Center cutter RC, RC1, RC2 Roller cutter CC Copy bit ST Scraper tooth

Claims (4)

The outer periphery of the main body formed in a disc shape is provided with a blade edge portion formed so as to become gradually thinner from the center of the main body toward the outer periphery, and is determined in advance along the outer periphery of the main body at the tip of the blade edge portion. A plurality of holes formed so as to extend from the tip of the blade edge portion toward the center of the main body at intervals, and a plurality of first carbide tips provided in a state of being fitted in the holes. In an excavator roller cutter comprising a portion,
A plurality of grooves formed at predetermined intervals along the outer periphery of the main body on the side surface of the cutting edge portion;
A plurality of second cemented carbide tip portions welded to the main body in a state of being fitted in each of the plurality of grooves on the side surface of the cutting edge portion;
A hardfacing welded portion welded to the main body so as to cover a side surface of the cutting edge portion excluding the first carbide tip portion and the second carbide tip portion;
With
Excavation characterized in that the hardness of the second cemented carbide tip is lower than that of the first cemented carbide tip, and the thickness of the second cemented carbide tip is thicker than that of the hardfacing weld. Roller cutter for machine.   The roller cutter for an excavator according to claim 1, wherein the second cemented carbide tip portion is disposed between adjacent ones of the plurality of first cemented carbide tip portions.   The roller cutter for an excavator according to claim 1 or 2, wherein at least a part of an upper surface of the second carbide tip portion is inclined along a side surface of the cutting edge portion.   An excavator comprising the excavator roller cutter according to claim 1 installed on a cutter head.

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