JP6423218B2 - Roller cutter and manufacturing method thereof - Google Patents

Description

  The present invention relates to a roller cutter and a manufacturing method thereof, and more particularly, to a roller cutter excellent in durability and a manufacturing method thereof.

  Conventionally, various tunnel excavators such as shield machines have been used as machines for excavating tunnels for railways, roads, and the like. And as one of such tunnel excavators, at the front end, it rotates with the rotational drive of the cutter head, and is crushed so as to cut rock or the like with the cutting edge provided on the outer periphery One with a roller cutter is known.

  Further, as such a roller cutter, Japanese Laid-Open Patent Publication No. 11-200754 (Patent Document 1) clearly discloses a drilling blade (bit) formed by fixing a protective member in close contact with a side surface portion of a chip. Has been. There, a configuration is adopted in which a large number of chips made of cemented carbide are integrally attached to the outer peripheral surface of a cylindrical bit with some of the chips inserted into the main body of the bit. is there. In Patent Document 1, after covering the side surface of the chip with a protective member, the surface of the chip becomes brittle or denatured by casting molten metal into the mold and molding the bit body. In fact, it is described that the chip can be held firmly by cooling and contracting the bit body.

  By the way, in the bit (roller cutter) having such a structure, when excavating the tunnel, the entire bit body including the chip is cut into a rock or the like. As a result, the bit body is scraped and worn due to contact with the rock, and the tip embedded in the bit body falls off, reducing the excavation efficiency and lowering the durability of the bit. The problem of becoming shorter is inherent.

  Therefore, in order to solve such a problem, conventionally, a hard overlay made of a material having high hardness has been applied to the surface portion of the bit body. However, it is difficult to sufficiently improve the durability of the bit only by providing such a hardened buildup, and it takes more man-hours to form the hardened buildup, which increases the manufacturing cost of the bit. There is a problem that it ends up.

  It is also conceivable that the entire bit body is made of a highly wear-resistant material. However, in general, such a highly wear-resistant material is also highly brittle, and therefore, due to the difference in thermal expansion coefficient, cracks or the like are generated starting from the boundary with the chip, This may cause a problem that the bonding strength cannot be secured. Furthermore, since the bit body is a relatively large and thick member, stress is concentrated inside due to shrinkage during cooling, and cracking and the like are likely to occur, resulting in a decrease in the durability of the bit. And so on, new problems will arise.

Japanese Patent Laid-Open No. 11-200754

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is to prevent the carbide chip from falling off and to effectively suppress the occurrence of cracks and the like. It is an object of the present invention to provide a highly durable roller cutter having an improved structure so that it can be prevented, and to provide a method for advantageously manufacturing such a roller cutter.

And in the present invention, in order to solve the problems related to the roller cutter as described above, the cemented carbide tip made of cemented carbide has an outer circumferential surface on both side surfaces of the tip portion extending in the circumferential direction in the chevron cross-sectional shape. so as to expose the circumferential direction is buried at predetermined intervals an annular cutter cone, it is rotatably disposed on an outer peripheral portion, a roller cutter mounted to the front end of the tunnel boring machine The cutter cone is configured so as to form an annular shape as a whole by a plurality of cone segments that are formed by dividing the cutter cone at a plurality of locations in the circumferential direction. is constituted by cast wrapping ing is cast product of a metal in the form obtained by accommodating the chip buffer tube body, and the buffer cylinder is hardness lower than casting metal constituting the cone divided body Is a metallic material, which is integrated with their casting metal and the carbide inserts and shock absorbing cylinder body, further ultra-hard chips, as there is no gap between the said template material metal, the buffer tube Embedded in the casting through the body so that only both side surfaces of the chevron cross-sectional shape of the tip portion are exposed to the outer peripheral surface of the cone split body, and the casting metal, the carbide tip and the buffer The gist of the present invention is a roller cutter that is configured so as to exhibit a continuous circular contour at the end of each cylinder divided body on the outer peripheral side .

  In addition, according to one of the desirable aspects of the roller cutter according to the present invention, the cast metal constituting the cone divided body is C: 2.0 to 4.0%, Si: 0.00. 5 to 3.0%, Mn: 0.06 to 1.5%, V: 6.0 to 16.0%, Mg: 0.01 to 0.1%, and Ni: 1.0% or less The balance is composed of an alloy composition in which Fe and unavoidable impurities are included, and alloy white cast iron in which spheroidized V carbides are crystallized in the pearlite matrix by molten metal addition treatment. .

  Furthermore, in the present invention, it is desirable that the buffer cylinder is made of a steel material.

And in this invention, in order to solve the subject which concerns on the manufacturing method of an above-described roller cutter, the carbide | carbonized_material chip | tip which consists of a cemented carbide will carry out the outer periphery of the both sides | surfaces of the front-end | tip part extended in the circumferential direction in a mountain-shaped cross-sectional shape. so as to expose the surface, circumferentially embedded at predetermined intervals an annular cutter cone, it is rotatably disposed on an outer peripheral portion, the manufacture of the roller cutter which is attached to the front end of the tunnel boring machine (A) The cutter cone is configured so as to form an annular shape as a whole by a plurality of cone division bodies that are formed by dividing the cutter cone at a plurality of locations in the circumferential direction. A step of preparing a mold having a casting cavity for giving a divided body, (b) a molten metal for casting the cone divided body, a cemented carbide tip made of the cemented carbide, and the cemented carbide A buffer cylinder made of a metal material that has a cylindrical shape having an inner peripheral surface shape that is equal to or larger than the outer peripheral surface shape of the cup and that has a lower hardness than the material that gives the cone divided body is prepared. a step of, the hard tip and buffer cylindrical body which is prepared according (c), are accommodated ultra hard tip into the body the buffer tube Rutotomoni, remain in the body the shock absorbing cylinder in housing under ultra hard tip In the form in which the cavity portion is filled with sand, the step of disposing the mold at a predetermined position in the casting cavity of the mold, and (d) pouring the molten metal into the casting cavity, thereby a step of casting the cast wrapped by comprising casting intermediates in form consisting accommodated in the buffer tube body and remove the cast intermediate according (e) from the mold, removing the sand filled in the buffer tube body Then To, by allowed to remove the buffer cylinder portion projecting from the outer peripheral surface of said template material intermediate said cone divided bodies composed of casting their hard tip and a shock absorbing cylinder body is integrated with the casting metal A step of forming each of the plurality of cone cutters, and ( f ) a step of forming a cutter cone by combining a plurality of cone segments thus obtained in an annular shape, and a method for producing a roller cutter, Moreover, it is set as the summary.

  As described above, in the roller cutter according to the present invention, the cutter cone disposed on the outer peripheral portion of the roller cutter is divided into a plurality of cone division bodies that are formed at a plurality of locations in the circumferential direction. Since each of the cone divisions is made of a metal casting formed by casting a cemented carbide chip, it is arranged in a circumferential direction of internal stress generated during casting. Is advantageously suppressed, and the stress concentration inside the cast metal constituting the cone segment is reduced. As a result, cracks and the like are advantageously prevented from occurring in the cone divided body, and the stress remaining in the cone divided body is alleviated, so that the cone divided body is less likely to be damaged. As a result, the durability of the roller cutter can be advantageously improved.

  In addition, each of such cone divided bodies is constituted by a metal casting formed by casting in a form in which a cemented carbide chip is accommodated in the buffer cylinder, and the buffer cylinder constitutes the cone divided body. Since the cast metal is made of a metal material having a lower hardness than the cast metal, and the cast metal, the cemented carbide tip, and the buffer cylinder are integrated, the thermal expansion of the cemented carbide constituting the cemented carbide chip and the cone segment is performed. The stress generated by the difference in rate is buffered by the buffer cylinder. This advantageously prevents cracks and the like from occurring at the boundary between the cemented carbide chip and the cast metal that constitutes the cone, and relieves the residual stress at the boundary. This makes it difficult for the cemented carbide chip to fall off, so that the decrease in excavation efficiency is advantageously suppressed or prevented, and the durability of the cutter cone and thus the roller cutter can be advantageously improved. It is.

  Further, in the roller cutter according to the present invention, as described above, it is possible to prevent the cemented carbide chip from falling off and to suppress or prevent the occurrence of cracks. As a cast metal constituting the material, it is possible to use a material having relatively high brittleness but good wear resistance, which makes it possible to improve the durability of the roller cutter more advantageously. There is also an advantage of becoming.

  Then, according to the method for manufacturing a roller cutter according to the present invention, since molds having casting cavities for providing the respective cone segments are prepared, the molds for casting these cone segments are relatively small in size. Will be enough. Therefore, the cost concerning a casting_mold | template can be reduced and it becomes possible to reduce the manufacturing cost of a roller cutter advantageously.

  Further, by pouring a molten metal for casting the cone divided body into the casting cavity, the cemented carbide chip is cast in a form in which it is accommodated in the buffer cylinder, and the cemented carbide chip and the buffer cylinder are formed. Are formed to form a plurality of cone segments integrated with cast metal, eliminating the need for a process for embedding a cemented carbide tip, which advantageously reduces the manufacturing cost of the roller cutter. There is an advantage that can be. Furthermore, since the cemented carbide tip is more firmly held, the durability of the roller cutter can be advantageously improved by suppressing or preventing the cemented carbide chip from falling off.

It is side explanatory drawing which shows an example of the roller cutter according to this invention. It is AA cross-section explanatory drawing in FIG. It is the B section enlarged explanatory view in FIG. It is explanatory drawing which shows an example of the process employ | adopted when manufacturing the cone division | segmentation body which comprises the roller cutter shown by FIG. 1, Comprising: The state which has arrange | positioned the buffer cylinder body and the cemented carbide chip to the lower mold | type, It is plane explanatory drawing which omits and shows. It is end surface explanatory drawing in the CC cross section of FIG. FIG. 6 is an end surface explanatory view corresponding to FIG. 5, showing an example of a process performed subsequent to the process shown in FIG. 5, showing a state where the mold is clamped. FIG. 6 is an end surface explanatory view corresponding to FIG. 5, showing an example of a process performed subsequent to the process shown in FIG. 6, showing a state in which the molten metal is poured into the cavity. FIG. 8 is an enlarged cross-sectional explanatory view of a D part in FIG. 7 schematically showing a cemented carbide chip holding structure (a mode of forming a buffer cylinder part), in which (a) shows a state before cooling of the molten metal; b) has shown the state after cooling of a molten metal. It is explanatory drawing which shows an example of the process implemented following the process shown by FIG. 7, Comprising: It is a plane explanatory view which shows the state immediately after taking out a metal casting from a casting_mold | template. It is explanatory drawing which shows an example of the process implemented following the process shown by FIG. 9, Comprising: It is plane explanatory drawing which shows the state which removed a part of buffer cylinder and obtained the cone division body. It is side surface explanatory drawing which shows typically the form which comprised the cyclic | annular cutter cone using the plurality of cone division bodies shown by FIG. It is plane explanatory drawing which shows an example of the holder formed by connecting the some buffer cylinder which can be used when manufacturing a cone division body. FIG. 13 is an explanatory plan view corresponding to FIG. 4 when the holder shown in FIG. 12 is used. It is a cross-sectional explanatory drawing which shows another example of the roller cutter according to this invention in the cross-sectional form corresponding to FIG.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIGS. 1 and 2 show an example of a roller cutter having a structure according to the present invention in the form of a side view and a partial cross-sectional view, respectively. In this case, the roller cutter 10 is fixedly attached to the front end of the tunnel excavator, and a thin line arrow in FIG. 1 is attached to the support shaft member 12 via a bearing or the like (not shown). As shown in the figure, a rotation part 14 is provided that is externally fitted around a central axis P. The rotating portion 14 has a substantially cylindrical shape as a whole, and its central axis: P is coaxial with the central axis of the support shaft member 12 (hereinafter, in the present embodiment, this central axis: A direction parallel to P is referred to as an axial direction, and a central axis: a direction perpendicular to P is referred to as a radial direction).

  More specifically, as shown in FIG. 2, the rotating portion 14 is configured to include an annular cutter cone 18, a ring spacer 20, and a fixing ring 22 together with a substantially cylindrical rotating portion main body 16. As a whole, the cross section perpendicular to the circumferential direction has a chevron shape in which the central portion protrudes radially outward.

  Here, on the outer peripheral surface 24 of the rotating part main body 16, the annular cutter cone 18 disposed in the central portion in the axial direction includes inclined upper surfaces 26, 26 that form the outer peripheral surface, inclined side surfaces 28, 28, and inner surfaces. A cross section perpendicular to the circumferential direction has a circumferential surface 30 and expands toward the inner circumferential surface 30 side (inward in the radial direction), and the outer peripheral surface side central portion protrudes radially outward. It is configured to have a pentagonal shape. A plurality of known cemented carbide tips 32 made of cemented carbide are embedded in the cutter cone 18 at a predetermined interval in the circumferential direction so that the tip portion is exposed to the outer circumferential surface of the cutter cone 18. ing.

  Further, an engaging convex portion 34 is provided on one side (right side in FIG. 2) in the axial direction of the rotating portion main body 16 so as to protrude radially outward, and the cutter of the engaging convex portion 34 is provided. A side surface facing the cone 18 is an engagement inclined surface 36 corresponding to the inclined side surface 28. A male screw portion 38 whose outer peripheral surface shape is slightly smaller than the outer peripheral surface 24 is formed at the end on the other axial side of the rotating portion main body 16.

  Furthermore, in the ring spacer 20 that is fitted on the outer peripheral surface 24 of the rotating part main body 16 from the other axial side (the left side in FIG. 2), the side surface facing the cutter cone 18 corresponds to the inclined side surface 28. An inclined surface 40 is formed. Furthermore, the fixing ring 22 is screwed to the male screw portion 38 of the rotating portion main body 16 by a female screw portion 42 formed on the inner peripheral surface thereof.

  Then, the cutter cone 18 is disposed on the outer peripheral surface 24 of the rotating portion main body 16, and the fixing ring 22 is tightened via the ring spacer 20 fitted from the other side in the axial direction. The main part 16, the cutter cone 18, the ring spacer 20, and the fixing ring 22 are integrally coupled to constitute the rotating part 14. The inclined upper surfaces 26 and 26 of the cutter cone 18 are each formed with a bent portion in the middle so that the inclination of the portion on the inclined side surface 28 side with respect to the axial direction is slightly gentle, and the rotating portion main body 16. The outer peripheral surface of the engaging projection 34 formed on the outer periphery of the ring spacer 20 and the outer peripheral surface of the ring spacer 20 are smoothly continuous.

  That is, in the rotating portion 14, the inclined side surfaces 28, 28 formed on both sides of the cutter cone 18 in the axial direction are connected to the engaging inclined surface 36 of the engaging convex portion 34 provided on the rotating portion main body 16 and the ring spacer. When the pressing force by the screw mechanism provided between the fixing ring 22 and the rotating portion main body 16 is applied to the 20 inclined surfaces 40 in a surface contact state, the cutter cone 18 is While being strongly clamped from both sides, it is pressed against the outer peripheral surface 24 of the rotating part main body 16. As a result, the position of the cutter cone 18 on the outer peripheral surface 24 of the rotating part main body 16 is restricted so as not to move in the axial direction, and sliding movement in the circumferential direction is also prevented. The state in which the outer cone 24 is firmly fitted and fixed on the outer peripheral surface 24 is maintained, and the cutter cone 18 is configured to rotate integrally with the rotating portion main body 16. Thus, the annular cutter cone 18 is rotatably disposed on the outer peripheral portion of the roller cutter 10.

  By the way, as is apparent from FIG. 1, the cutter cone 18 according to the present embodiment has a plurality of (here, six) cone division bodies 44 a to 44 that are formed by dividing one cutter cone at a plurality of locations in the circumferential direction. 44f is combined to form a ring as a whole. Here, all of the cone division bodies 44a to 44f have the same configuration. For this reason, in the following, the cone division body 44a whose cross-sectional form is shown in FIG. 2 will be described, and a detailed description of the other cone division bodies 44b to 44f will be omitted. Further, in the cone divided bodies 44a to 44f, the portions corresponding to the structure of the cutter cone 18 described above are denoted by the same reference numerals, and the letters a to f are added to the end, whereby each of the cone divided bodies 44a to 44f. The detailed description will be omitted to indicate the corresponding parts.

  As shown in FIGS. 1 and 2, the cone divided body 44 a includes a main body portion 46 that is a cast metal portion, and a plurality (four in this case) of carbide chips embedded in the main body portion 46. 32, 32, 32, 32, and buffer cylinder portions 48, 48, 48, 48 disposed at the boundary portions between the main body portion 46 and the carbide tips 32, respectively, and the main body portions. 46, the carbide | carbonized_material chip | tip 32,32,32,32 and the buffer cylinder part 48,48,48,48 are comprised by the metal casting formed by integrating.

  Here, the main body 46 of the cone segment 44a is generally made of cast iron having high wear resistance. In particular, as such cast iron, C: 2.0 to 4.0%, Si: 0.5 to 3.0%, Mn: 0.06 to 1.5%, V: 6. 0 to 16.0%, Mg: 0.01 to 0.1%, and Ni: 1.0% or less, the balance is made of an alloy composition of Fe and inevitable impurities. An alloy white cast iron in which the spheroidized V carbide is crystallized in the pearlite matrix is advantageously used. This cast iron has a range of alloy compositions as described above, so that it has effective wear resistance on the cutter cone and V carbide, which is a compound of V (vanadium) and C (carbon), is spherical. Thus, the impact resistance (toughness) is advantageously improved. Such materials are described in detail in Japanese Patent Application Laid-Open No. 2002-275573, and are also commercially available from Okamoto Co., Ltd. as STARK (trade name). In the present embodiment, the main body 46 is made of this STARK material.

  Further, the cemented carbide tip 32 is a known one made of cemented carbide, and as shown in FIG. 3, the tip portion having the chevron shape is formed by two inclined upper surfaces 26 a and 26 a of the main body 46. It is embedded in the main body portion 46 so as to be exposed on the formed outer peripheral surface. In this case, a buffer cylinder body 48 is disposed around the side surface portion 50 of the cemented carbide chip 32 (a boundary part with the main body 46), and the cemented carbide chip 32 is provided with the buffer cylinder body 48. It is held (gripped) so as to be tightened by the main body 46 via

  In addition, such a buffer cylinder part 48 is comprised with the metal material whose hardness is lower than the cast metal which comprises the main-body part 46 of the cone division body 44a, and in this embodiment, it is mainly made of one steel material. It is composed of one chromium molybdenum steel (SCM). Here, the term “mainly” means that in the buffer cylinder portion 48, a part of the boundary portion between the buffer cylinder portion 48 and the main body portion 46 or the entire buffer cylinder portion 48 is the main body portion 46. The boundary between the main body 46 and the buffer cylinder 48 is ambiguous, as indicated by a two-dot chain line in FIGS. ing. In addition, such a structure is manifested by forming the cone divided body 44a by casting in a form in which the cemented carbide chip 32 is accommodated in a predetermined buffer cylinder (52), as will be exemplified later. Will be.

  Here, the buffer cylinder portion 48 is formed of a metal material having a lower hardness than the cast metal constituting the main body portion 46 while the carbide chip 32 is gripped on the inner peripheral surface side thereof. Accordingly, the reaction force (stress) that acts on the main body 46 caused by the main body 46 gripping the carbide chip 32 to be tightened is reduced on the outer peripheral surface side.

  Further, the roller cutter 10 having such a structure is advantageously manufactured according to the following method.

  Here, first, a cone split body 44a that is a constituent member of the target roller cutter 10 is formed. For this purpose, a molten metal (54) of STARK material for casting the main body 46 of the cone divided body 44a, four cemented carbide tips 32, 32, 32, 32 made of cemented carbide, Four buffer cylinders 52, 52, 52 made of cylindrical chrome molybdenum steel (SCM) having an inner peripheral surface shape substantially equal to the outer peripheral surface shape and a length sufficiently longer than the carbide tip 32. , 52 are prepared. In addition, a mold 58 having a casting cavity (56) for providing a cone split body 44a is prepared separately. The mold 58 includes a lower mold 60 and an upper mold 62 disposed to face the lower mold 60 so as to overlap the lower mold 60, and is configured by a sand mold.

  The prepared carbide tips 32, 32, 32, 32 and the buffer cylinders 52, 52, 52, 52 are respectively formed in the form in which the carbide tips 32 are accommodated in the buffer cylinder 52 in FIG. As shown in FIG. 5, the lower mold 60 is disposed in four lower holding recesses 64, 64, 64, 64 formed at predetermined positions. Further, the lower mold 60 communicates with the lower holding recesses 64, 64, 64, 64 so that a part of the outer shape of the main body 46 (here, the main body 46 is half in the axial center). A lower cavity forming recess 66 having an inner surface shape corresponding to the shape of the lower cavity forming recess 66 is formed, and each of the cemented carbide chips 32 is accommodated in the buffer cylinder 52 and is formed in the lower cavity forming recess. It is held at a predetermined position in 66, that is, a position to be embedded in the main body portion 46 to be formed. In the figure, reference numeral 68 denotes sand filled in a hollow portion in the buffer cylinder 52 in order to prevent displacement of the cemented carbide chip 32 in the buffer cylinder 52 during the casting operation.

  At this time, as shown in FIG. 5, the upper die 62 is disposed to face the lower die 60 at a predetermined distance above the lower die 60. The upper mold 62 can be moved in a vertical direction by a known moving device such as a crane, and the lower holding recesses 64, 64, 64, 64 and the lower cavity are formed in the lower mold 60. An upper holding recess 70, 70, 70, 70 and an upper cavity forming recess 72 having an inner shape corresponding to the recess 66 are formed so as to open on the lower surface thereof.

  Next, the upper mold 62 is moved closer to the lower mold 60 by a predetermined moving device, and the upper mold 62 and the lower mold 60 are closed with a predetermined pressure as shown in FIG. Thereby, in order to form the main body 46 of the target cone split body 44a at a portion surrounded by the upper cavity forming recess 72 of the upper mold 62 and the lower cavity forming recess 66 of the lower mold 60. The casting cavity 56 is formed. At this time, the buffer cylinder 52 in which the carbide chip 32 is accommodated is sandwiched and held between the upper holding recess 70 of the upper mold 62 and the lower holding recess 64 of the lower mold 60. Become.

  Then, as shown in FIG. 7, a predetermined metal melt 54 is poured into the casting cavity 56, so that the cemented carbide chip 32 is cast in a form that is accommodated in the buffer cylinder 52. The casting is to be cast. That is, the main body 46 is formed with a predetermined shape so as to be integrated with the cemented carbide chip 32 and the buffer cylinder 52, and the buffer cylinder part is formed in the casting cavity 56 of the buffer cylinder 52. 48 is formed, and the cemented carbide chip 32 is held in a state of being embedded in a predetermined position of the main body 46.

  More specifically, with respect to such a holding structure of the carbide tip 32 (formation mode of the buffer cylinder portion 48), as shown in FIG. 8A, the molten metal poured into the casting cavity 56. When 54 is in contact with the inner part of the casting cavity 56 of the buffer cylinder 52, at least a part or all of the buffer cylinder 52 covered on the side surface portion 50 of the cemented carbide chip 32 is melted by the heat. 54 is integrated (welded), or is not melted, but is diffused and alloyed with the molten metal 54 to be integrated (joined). Note that, as schematically shown in FIG. 8A, the portion of the buffer cylinder 52 in the casting cavity 56 is expanded by the heat of the molten metal 54.

  Then, the molten metal 54 is cooled in the casting cavity 56, and the casting operation of the main body 46 is completed. At this time, as shown in FIG. The side portion 50 of the cemented carbide chip 32 is tightened and firmly held by the portion 48 and the main body portion 46 [see the white arrow in FIG. 8B]. Such a holding force (clamping force) is generated due to a difference in thermal expansion coefficient between the main body portion 46 and the buffer cylinder portion 48 and the carbide tip 32. That is, the STRK material constituting the main body 46 and the thermal expansion coefficient of the SCM constituting the buffer cylinder 48 are about 10 to 13 ppm / K, whereas the cemented carbide constituting the carbide tip 32. Since the coefficient of thermal expansion is approximately 5 ppm / K, the buffer cylinder portion 48 and the main body portion 46 are greatly contracted as compared with the carbide tip 32 during cooling, so that such tightening force is reduced. It will occur. Further, here, the buffer cylinder portion 48 is made of a material having a relatively low hardness, and therefore, as schematically shown in FIG. The outer peripheral surface shape is deformed so as to be reduced, so that the stress (reaction force) acting on the main body portion 46 is relieved.

  Thereafter, the upper mold 62 and the lower mold 60 are opened, and a casting (intermediate body 74) as shown in FIG. 9 is taken out. In the intermediate body 74, a part of the buffer cylinder 52 remains so as to protrude from the main body portion 46. The sand 68 filled in the buffer cylinder 52 is removed from the intermediate body 74, and the protruding portion of the buffer cylinder 52 from the main body 46 is removed by a grinder or the like. The tip of the tip 32 is exposed on the outer peripheral surface of the main body 46. Thus, the target cone segment 44a having a structure in which the cemented carbide tip 32 and the buffer cylinder 52 are integrated with the main body 46 made of cast metal as shown in FIG. 10 is obtained. .

  Further, the above process is repeated five times to form five cone division bodies 44b to 44f. And the annular cutter cone 18 as shown in FIG. 11 is comprised by combining the six cone division bodies 44a-44f obtained in this way. Next, the cutter cone 18 composed of the cone divided bodies 44a to 44f is externally fitted to the separately prepared rotating body main body 16 that is rotatably attached to the support shaft member 12, and the ring spacer 20 is mounted. By being fastened by the fixing ring 22 via the, the fixing is performed. Thus, a roller cutter 10 as shown in FIG. 1 is obtained.

  As is clear from the above description, in the present embodiment, the cutter cone 18 is not constituted by an integral annular casting, but as a whole by a plurality of cone divided bodies 44a to 44f cast individually. Since each of the cone divided bodies 44a to 44f is made of a metal casting formed by casting the cemented carbide tip 32, it is particularly cooled during casting because it is configured to form an annular shape. Propagation in the circumferential direction of internal stress generated at the time of shrinkage is advantageously suppressed by using the divided body, and the stress concentration inside the main body 46 made of cast metal constituting the cone divided bodies 44a to 44f is effective. Will be alleviated. As a result, cracks and the like are advantageously prevented from occurring in the cone segments 44a to 44f, and stress remaining in the cone segments 44a to 44f is relieved, thereby reducing the cone segments 44a to 44f. As a result, the durability of the cutter cone 18 and thus the roller cutter 10 can be advantageously improved.

  Moreover, in the cutter cone 18 composed of such cone divided bodies 44a to 44f, when excavating the tunnel, an impact acting on the cutter cone 18 is caused by the divided portions of the cutter cone 18 (cone divided cone bodies adjacent to each other). 44a to 44f), and the cone cones 44a to 44f are less likely to be damaged. Therefore, the durability of the cutter cone 18 (roller cutter 10) is improved. It can be advantageously improved.

  Moreover, even if these cone division bodies 44a-44f generate | occur | produce the fall of the carbide | carbonized_material chip | tip 32, the damage | damage of the main-body part 46, etc. in the one part, the characteristics which do not need to replace | exchange the cutter cone 18 whole. is there. That is, since only the cone divided body 44 in which damage or the like has occurred can be repaired and replaced, there is an advantage that the repair cost of the roller cutter 10 can be advantageously reduced.

  Further, in the cone divided bodies 44a to 44f, the buffer cylinder 52 is made of a metal material whose hardness is lower than that of the cast metal constituting the cone divided bodies 44a to 44f, and the main body portion 46 and the cemented carbide chip made of the cast metal. 32 and the buffer cylinder 52 are integrated, in other words, the carbide chip 32 is embedded in the main body 46 via the buffer cylinder part 48 formed of such a buffer cylinder 52. Therefore, the stress generated by the difference in thermal expansion coefficient between the cemented carbide chip 32 and the main body part 46 is effectively relieved by the buffer cylinder part 48. Thereby, in the cone divided bodies 44a to 44f, it is advantageously prevented that a crack or the like is generated from the boundary portion between the cemented carbide chip 32 and the main body portion 46, and stress remaining in the boundary portion is relieved. This makes it difficult for the cemented carbide tip 32 to fall off, so that a decrease in excavation efficiency is advantageously suppressed or prevented, and the durability of the cutter cone 18 and thus the roller cutter 10 can be advantageously improved. It becomes.

  And in the roller cutter 10 of this embodiment, in the main-body part 46 which comprises each cone division body 44a-44f by the division structure of the cutter cone 18 as mentioned above, and the presence of the buffer cylinder part 48, it cracks. Since the occurrence of the above is advantageously suppressed or prevented, the cast metal constituting the cone divided bodies 44a to 44f is relatively high in brittleness including the exemplified STARK material, This makes it possible to use a material with good wear properties, and this has the advantage that the durability of the roller cutter 10 can be improved more advantageously.

  Here, the thermal expansion coefficient of the material of the buffer cylinder 52 and the cast metal constituting the main body 46 is higher than the thermal expansion coefficient of the cemented carbide tip 32 made of cemented carbide, Due to the shrinkage during cooling, a stress is generated that tightens the carbide tip 32, and the carbide tip 32 is more firmly held, so that the falling of the carbide tip 32 is more advantageously prevented. Yes.

  Further, when the roller cutter 10 is manufactured by such a method according to the present embodiment, a mold 58 having a casting cavity 56 is prepared as a mold for providing the respective cone divided bodies 44a to 44f. The size of 58 is relatively small compared to a mold for casting the entire cutter cone 18 at one time. Therefore, the cost for manufacturing the mold 58 can be reduced, and thus the manufacturing cost of the roller cutter 10 can be advantageously reduced.

  Furthermore, by casting a molten metal 54 for casting the cone divided bodies 44a to 44f in the casting cavity 56, the cemented carbide chip 32 is cast in a form in which it is accommodated in the buffer cylinder 52, Since the cemented carbide chips 32 and the buffer cylinders 52 are respectively formed with the cone divided bodies 44a to 44f formed by integrating with the main body 46 made of cast metal, the carbide chips 32 are formed into the main body. The process for embedding in 46 becomes unnecessary, Therefore The manufacturing cost of the roller cutter 10 can be reduced advantageously. In addition, since the carbide tip 32 is firmly held by the buffer cylinder 52 (buffer cylinder part 48) and the main body part 46, the falling of the carbide chip 32 is suppressed or prevented, and the roller The durability of the cutter 10 can be advantageously improved.

  The exemplary embodiments of the present invention have been described in detail above. However, the embodiments are merely examples, and the present invention is limited in any way by specific descriptions according to such embodiments. It should be understood that it is not interpreted.

  For example, in the previous embodiment, the buffer cylinder 52 has a sufficiently large length with respect to the cemented carbide chip 32. The buffer cylinder 52 is accommodated in the lower holding recess 64 and held at a predetermined position in the casting cavity 56, and is not limited to this. That is, the buffer cylinder 52 only needs to have a length that covers at least the side surface portion 50 of the cemented carbide chip 32. Furthermore, as shown in FIG. 12, it is also possible to use a connection holder 76 having a configuration in which four buffer cylinders 52, 52, 52, 52 having a length covering only the side surface portion 50 of the cemented carbide chip 32 are connected. Is possible. As a result, the four buffer cylinders 52, 52, 52, 52 can be arranged in the lower holding recesses 64, 64, 64, 64 of the lower mold 60 at a time. Note that the rod-shaped member extending radially inward from the connection holder 76 is a support member 78 to maintain the position of the connection holder 76 in the casting cavity 56 as shown in FIG. It is provided.

  Further, the inner peripheral surface shape (inner diameter) of the buffer cylinder 52 is not limited to the substantially same outer peripheral surface shape (outer diameter) of the cemented carbide chip 32, but may be a larger inner peripheral surface shape. Good. That is, there may be a certain amount of gap between the outer peripheral surface (side surface portion 50) of the cemented carbide chip 32 and the inner peripheral surface of the buffer cylinder 52. In that case, when the casting operation is performed, the poured molten metal 54 enters between the buffer cylinder 52 and the carbide tip 32, and as shown in FIG. A thin cast metal layer 80 is formed between the buffer 32 and the buffer cylinder 48. Even in such a case, the cemented carbide tip 32 is hardly melted or alloyed between the cemented carbide tip 32 and the molten metal 54, and the performance of the cemented carbide tip 32 is ensured. Further, in the cast metal layer 80 that has entered such a gap, there is no stress that causes cracking or the like.

  Further, the material of the buffer cylinder 52 is not limited to the exemplified chromium molybdenum steel (SCM), and various known materials having a hardness lower than that of the cast metal constituting the main body 46 are appropriately selected. Can be used. The material constituting the buffer cylinder 52 is preferably carbon steel (ordinary steel), alloy steel (special steel), nickel chrome steel, nickel chrome molybdenum steel, chrome molybdenum steel, chrome steel, manganese steel, or the like. Steel materials can be mentioned.

  In the roller cutter 10, in order to improve the overall strength and durability, adjacent members, that is, the rotating body 16 and the cutter cone 18, the cutter cone 18 and the ring spacer 20, the ring spacer 20 and the like. You may make it join by welding the boundary part etc. of the fixing ring 22. FIG.

  In addition, although not listed one by one, the present invention can be carried out in an embodiment to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Roller cutter 12 Support shaft member 14 Rotating part 16 Rotating part main body 18 Cutter cone 20 Ring spacer 22 Fixing ring 32 Carbide tip 44a-44f Cone division body 46 Main body part 48 Buffer cylinder part 52 Buffer cylinder body 54 Molten metal 56 Casting Cavity 58 mold

Claims (5)

Hard tip consisting of cemented carbide, so as to expose an outer peripheral surface of both side surfaces of the distal end portion extending in the circumferential direction in the chevron sectional shape, circumferentially embedded at predetermined intervals an annular cutter cone A roller cutter that is rotatably disposed on the outer periphery and is attached to the front end of the tunnel excavator,
The cutter cone is configured so as to form a ring as a whole by a plurality of cone division bodies that are formed by being divided at a plurality of locations in the circumferential direction.
Each of the cone divided body, wherein are composed of cast wrapped in ing cast product of a metal in the form of a hard tip consisting housed in a buffer tube body, and the buffer cylinder is, the cone divided body It is made of a metal material whose hardness is lower than that of the cast metal, and the cast metal, the cemented carbide tip, and the buffer cylinder are integrated, and the cemented carbide chip has a gap between the cast metal and the cast metal. It is embedded in the casting through the buffer cylinder so that it does not exist, and only the both side surfaces of the chevron cross-sectional shape of the tip are exposed to the outer peripheral surface of the cone split body, A roller cutter, characterized in that each of the cast metal, the cemented carbide tip, and the buffer cylinder is configured to have a continuous circular contour at each end of the outer periphery of the cone segment .   The cast metal constituting the cone segment is, on a mass basis, C: 2.0 to 4.0%, Si: 0.5 to 3.0%, Mn: 0.06 to 1.5%, V: Containing 6.0 to 16.0%, Mg: 0.01 to 0.1%, and Ni: 1.0% or less, with the balance being Fe and an inevitable impurity alloy composition, addition of molten Mg The roller cutter according to claim 1, wherein the roller cutter is made of an alloy white cast iron obtained by crystallizing a spheroidized V carbide into a pearlite matrix by treatment.   The roller cutter according to claim 1 or 2, wherein the buffer cylinder is made of a steel material. The cast metal that constitutes the cone segment and the metal material that constitutes the buffer cylinder each have a coefficient of thermal expansion greater than that of the cemented carbide that constitutes the cemented carbide tip. Item 4. The roller cutter according to any one of Items 3 to 4. Hard tip consisting of cemented carbide, so as to expose an outer peripheral surface of both side surfaces of the distal end portion extending in the circumferential direction in the chevron sectional shape, circumferentially embedded at predetermined intervals an annular cutter cone , A method of manufacturing a roller cutter that is rotatably disposed on the outer periphery and is attached to the front end of a tunnel excavator,
The cutter cone has a casting cavity that gives each cone segment by being configured so as to form an annular shape as a whole by a plurality of cone segments exhibiting a form divided at a plurality of locations in the circumferential direction. Preparing a mold; and
The molten metal for casting the cone segment, a cemented carbide tip made of the cemented carbide, and a cylindrical shape having an inner circumferential shape equal to or larger than the outer circumferential shape of the cemented carbide tip. And a buffer cylinder made of a metal material whose hardness is lower than the material for providing the cone divided body,
Such prepared hard tip and buffer cylindrical body, ultra-hard chip made to fill the sand into the cavity portion remaining in the body the shock absorbing cylinder in housing under the buffer tube is housed in the body Rutotomoni, ultra hard tip In the form of, the step of arranging at a predetermined position in the casting cavity of the mold,
Casting a cast intermediate formed by casting in a form in which the cemented carbide chip is accommodated in the buffer cylinder by pouring the molten metal into the casting cavity ;
By removing the casting intermediate from the mold and removing the sand filled in the buffer cylinder, and removing the buffer cylinder protruding from the outer peripheral surface of the casting intermediate , the carbide tips and A step of forming each of a plurality of the cone divided bodies formed of a casting in which the buffer cylinder is integrated with the casting metal;
A step of composing the cutter cone by combining a plurality of cone divisions thus obtained in an annular shape,
The manufacturing method of the roller cutter characterized by including.

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