JP2007138437A - Roller cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller cutter capable of being put on a cutter plate of a tunnel excavator, displaying strong resistance force against torsional force acting on each cemented carbide chip put on the end section of an edge of the roller cutter in the case of excavation and efficiently excavating the ground over a long period of time without changing the direction of the end section of the edge for the cemented carbide chip. <P>SOLUTION: Conical interlocking projections 4 having a plurality of sharp front ends are projected to the outer circumferential surface section of the basic end face of the cemented carbide chip 3, press-fit and fittedness of the cemented carbide chip 3 can be made to a chip mounting hole 2 bored in the end section of the edge of a roller cutter body 1 to make each interlocking projection 4 encroached on the bottom of the chip mounting hole 2, and the roller cutter is so constituted that the strong resistance force against torsional force acting in the case of excavation can be displayed by interlocking force thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a roller cutter that is mounted on a cutter plate of a tunnel excavator and excavates the ground in front by rotating the cutter plate.

  Conventionally, as an excavator for excavating a tunnel in a natural ground such as a rock mass or a composite ground of a rock mass and an earth and sand ground, a large number of roller cutters that can excavate while crushing the rock mass are attached to the cutter plate. Tunnel excavator is used. The roller cutter body has a Soroban ball shape whose outer peripheral part is formed as a chevron-shaped cutting edge part, and the tip part of the cutting edge part has the same cross section as the roller cutter body cutting edge part at small intervals in the circumferential direction. A roller cutter is configured by mounting a cylindrical carbide tip formed on a chevron-shaped cutting edge.

In such a roller cutter structure, in order to mount the cylindrical carbide tip on the cutting edge of the roller cutter body, for example, as described in Patent Documents 1 and 2, the outer peripheral portion of the roller cutter body A chip mounting hole having a circular cross section with a constant depth is drilled at a small interval toward the center of the roller cutter body, and the carbide chip is press-fitted into the chip mounting hole so that a flat base end surface of the carbide chip is formed. Is brought into contact with the bottom surface of the chip mounting hole, and the blade edge portion is fitted to the blade edge portion of the roller cutter body so as to be embedded in the circumferential direction.
Japanese Unexamined Patent Publication No. 63-125797 Japanese Patent Laid-Open No. 10-246093

  The roller cutter configured as described above has a state in which the center axis of rotation is directed to the cutter plate in the radial direction of the cutter plate, that is, the rotation direction of the blade edge protruding from the front surface of the cutter plate is the rotation direction of the cutter plate. In the state of being tangentially directed to the surface, it is supported so that it can rotate freely, and it is pressed against the face ground during excavation. At that time, as described above, since the rotation direction of the cutting edge portion of the roller cutter protruding from the cutter plate is directed tangential to the rotation direction of the cutter plate, the cutting edge is placed on the cutting ground. When the cutter plate is rotated with the part biting in, a large pressing force from the face ground acts from the inner peripheral side to the outer peripheral side of the cutter plate on the biting start end side of the cutting edge, and this pressing The roller cutter pressed in a state embedded in the edge portion of the main body, hard tip of cylindrical shape and is fitted is subject to torsional forces about its center by.

  This torsional force becomes larger as the roller cutter arranged on the inner peripheral side of the cutter plate, and the cemented carbide chip press-fitted and fitted into the mounting hole formed in the blade tip of the roller cutter body is Twist around the center against the fitting force with the mounting hole by the torsional force, and as shown in FIGS. 11 and 12, the direction of the tip edge 22 of the cemented carbide tip 21 is set on the roller cutter body 11. There is a problem in that it becomes a state of being deflected in the direction of the blade edge portion 12, that is, in a direction crossing the circumferential direction, and it becomes difficult to excavate the natural ground before the roller cutter body 11 reaches the service life.

  The present invention has been made in view of such problems. The object of the present invention is to firmly press-fit and fit a cemented carbide tip into a roller cutter body with a simple structure. It is an object of the present invention to provide a roller cutter that can prevent twisting and deformation even when a large torsional force is applied to a hard tip.

  In order to achieve the above object, the roller cutter of the present invention is provided with a tip mounting hole having a circular cross section at regular intervals in the circumferential direction at the blade edge portion of the roller cutter body, as described in claim 1. In a roller cutter formed by press-fitting and fitting a cylindrical carbide tip whose tip is formed into a cutting edge having a chevron cross section, a plurality of latches are provided on the outer peripheral portion of the base end surface of the carbide tip. A protrusion is provided so that the locking protrusion is bitten into the bottom surface of the chip mounting hole and locked.

  In the roller cutter configured as described above, in the invention according to claim 2, the locking protrusion protruding from the base end surface of the cemented carbide tip is formed in a small-diameter conical shape with the protruding end being a sharp end. In addition, three or more of the locking projections are protruded from the outer peripheral portion of the base end surface of the cemented carbide chip at regular intervals in the circumferential direction.

  According to the first aspect of the present invention, since the plurality of locking projections are projected from the outer peripheral portion of the base end surface of the cylindrical carbide tip having the tip portion formed at the blade edge portion, this carbide tip. Since the locking projection protrudes from the base end face of the cemented carbide tip in the press-fitting direction when it is press-fitted and fitted into the tip mounting hole having a circular cross section provided on the blade tip of the roller cutter body. This locking projection can be easily and surely cut into the bottom surface of the mounting hole.

  In this way, a plurality of roller cutters equipped with a plurality of cemented carbide tips are rotated on the cutter plate with the rotation direction of the cutting edge protruding from the cutter plate being tangential to the rotation direction of the cutter plate. When excavating ground such as rock with a tunnel excavator equipped with this cutter plate, the cutting edge of the roller cutter body cuts into the cutting blade ground in a direction tangential to the rotation direction of the cutter plate. Cut the face ground. When cutting this face ground, as described above, the force to twist the carbide tip around the center acts on the cutting edge of the carbide tip from the excavation ground side, but the base end surface of the carbide tip Since the locking protrusion protruding from the outer periphery bites into the bottom surface of the chip mounting hole, the locking force due to the biting acts as a large resistance against the twisting direction, and the carbide tip is twisted. Can be firmly prevented.

  Therefore, reliable and efficient drilling is possible over a long period of time while maintaining the state in which the length direction of the cutting edge portion of the carbide tip in the carbide tip is accurately continued to the circumferential cutting edge portion of the roller cutter body. Can be. In addition, the carbide chip has a simple structure in which a plurality of locking protrusions are provided on the outer peripheral portion of the base end surface of the carbide chip, and the locking protrusions are inserted into the bottom surface of the chip mounting hole of the roller cutter body. It is possible to easily obtain a roller cutter that exerts a large resistance against the twisting direction of the roller cutter body.

  As a preferable shape of the locking protrusion protruding from the base end surface of the cemented carbide tip, as described in claim 2, if the protruding end is formed into a small-diameter conical shape having a sharp end, the roller cutter body It is possible to provide a locking structure in which the locking protrusion is easily and firmly cut into the bottom surface of the chip mounting hole. The number of the locking protrusions is not particularly limited, but two or less is not preferable because the locking force with the bottom surface of the chip mounting hole becomes weak.

  Next, a specific embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 4, the roller cutter A is formed by forming an outer peripheral portion into a blade edge portion 1a having a cross-sectional chevron shape over the entire periphery. A abacus ball-shaped roller cutter body 1 made of a hard metal material and press-fitted into a tip mounting hole 2 having a circular cross section formed in the blade edge portion 1a of the roller cutter body 1 at regular intervals in the circumferential direction. The cemented carbide tip 3 is fitted.

  As shown in FIG. 4, the tip mounting hole 2 having a circular cross section formed in the blade edge portion 1a of the roller cutter body 1 is provided to a certain depth from the top surface of the blade edge portion 1a toward the center. The diameter of the carbide tip 3 is slightly smaller than the diameter of the carbide tip 3, that is, the carbide tip 3 is formed with a tolerance dimension that can be press-fitted into the hole, and the carbide tip 3 is hydraulically inserted into the tip mounting hole 2. The cemented carbide chip 3 is press-fitted with a jack or the like, and the outer peripheral surface of the cemented carbide chip 3 is fitted to the hole wall surface of the chip mounting hole 2. When the cemented carbide chip 3 is press-fitted into the chip mounting hole 2, the roller cutter body 1 is heated to increase the diameter of the chip mounting hole 2 and press-fit the cemented carbide chip 3. You may wear it.

  The cemented carbide chip 3 is formed in a cylindrical shape having a fixed diameter and a fixed length by press-fitting and fitting the base part excluding the tip part thereof into the chip mounting hole 2 of the roller cutter body 1, and the tip part is It is formed on a blade edge portion 3a having the same cross-sectional shape as the blade edge portion 1a of the roller cutter body 1, and the length direction of the top surface 3a1 of the blade edge portion 3a is set to the top surface 1a1 of the blade edge portion 1a of the roller cutter body 1. Each cemented carbide tip 3 is press-fitted and fitted into the tip mounting hole 2 of the roller cutter body 1 in a state of being directed in the length direction.

  Accordingly, the top surface 3a1 of the cutting edge portion 3a of the cemented carbide tip 3 is continuous with the top surface 1a1 of the cutting edge portion 1a of the roller cutter body 1 in the circumferential direction of the roller cutter body 1, and the base side from the top surface 3a1. Both side inclined surfaces 3a2 and 3a3, which are inclined in a direction gradually widening toward the edge, are gradually widened from the top surface 1a1 of the blade edge portion 1a of the roller cutter body 1 toward both sides of the roller cutter body 1. The two side inclined surfaces 3a2 and 3a3 of the blade edge portion 3a are exposed to the outside from the two side inclined surfaces 1a2 and 1a3 of the roller cutter body 1 that are continuous in the circumferential direction with the two side inclined surfaces 1a2 and 1a3 inclined to is doing.

  Further, a plurality of (four in FIG. 5 and six in FIG. 6) locking projections 4, 4,... Are provided on the outer peripheral portion of the base end surface 3a4 of the carbide tip 3 at regular intervals in the circumferential direction. When the cemented carbide tip 3 is press-fitted and fitted into the tip mounting hole 2 provided in the blade edge portion 1a of the roller cutter body 1 as described above, these locking projections 4 are shown in FIG. As shown in FIG. 3, the base surface 3a4 is entirely pressed against and received by the bottom surface 2a of the chip mounting hole 2 so as to be pushed into the bottom surface 2a of the chip mounting hole 2 of the roller cutter body 1 and locked. ing. Further, these locking projections 4 are formed in a conical shape having a small diameter with a protruding end (tip) being a sharp end. If the number of the protrusions 3 is 2 or less, the engaging force with the bottom surface 2a of the tip mounting hole 2 when a twisting force around the center acts on the tip mounting hole 2 as will be described later. Since it becomes weak, three or more, preferably 4-8, are provided in a protruding manner.

  As described above, the roller cutter A in which the cemented carbide chip 3 is press-fitted and fitted into each chip mounting hole 2 formed in the blade edge portion 1a of the roller cutter body 1 at regular intervals in the circumferential direction is well known. Thus, shaft bodies 5 and 5 are projected from the center of both side surfaces, and the shaft bodies 5 and 5 are rotatably supported by the side support members 6 and 6. As shown in FIGS. 7 and 8, the roller cutter main body 1 can be rotated freely at predetermined intervals from the central portion toward the outer peripheral end from the central portion. The side support members 6 and 6 that are pivotally supported are fixed to the cutter plate 7. Note that the roller cutter A is not limited to one, but two or three roller cutters A, which are integrated in a parallel state, are combined and mounted on the cutter plate 7.

  At this time, all the roller cutters A are oriented so that the shafts 5 and 5 that are the rotation center axes of the roller cutter main body 1 are directed in the radial direction of the cutter plate 7 and the front peripheral portion of the roller cutter main body 1 is the cutter plate. It is attached in a state of protruding forward from 1. Therefore, the blade edge portion 1 a of the roller cutter body 1 projecting from the front surface of the cutter plate 7 is configured to rotate in a tangential direction with respect to the rotation direction of the cutter plate 7. A plurality of roller cutters A arranged in a row from the center of the cutter plate 7 toward the outer periphery are arranged in a plurality of rows and radially on the cutter plate 7 and between adjacent roller cutter rows. The earth and sand intake 8 is provided.

  The cutter plate 7 configured as described above is rotatably disposed at the front end opening of the cylindrical body 11 of the tunnel excavator 10, and the tunnel excavator 10 is propelled while rotating the cutter plate 7. Excavate the face ground. At this time, the roller cutter A attached to the cutter plate 7 cuts the cemented carbide chip 3 attached to the blade edge portion 1a protruding from the cutter plate 7 in the roller cutter body 1 into the face ground while cutting the carbide chip 3 into the face ground. However, since the cutting edge 1a of the roller cutter body 1 protruding from the front surface of the cutter plate 7 is directed in a tangential direction with respect to the rotation direction of the cutter plate 7, the cutter plate 7 The cutting start end portion of the cutting edge portion 1a of the cemented carbide chip 3 to be cut into the face ground according to the rotation of the carbide chip 3 cuts the face ground while operating in the direction of scraping the face ground toward the inside of the cutter plate 7.

  Therefore, a large pressing force from the inner peripheral side to the outer peripheral side of the cutter plate 7 acts on the cutting start end portion of the cutting edge 1a of the carbide tip 3 as a reaction force from the face ground side. It acts as a torsional force to rotate the hard tip 3 around its center. The carbide tip 3 has a cylindrical base outer peripheral surface fitted to the hole wall of the tip attachment hole 2 provided in the cutting edge portion 1a of the roller cutter body 1. Since it acts in the circumferential direction of the wall, the outer peripheral surface of the cemented carbide tip 3 slips against the hole wall of the cemented carbide tip 2 against the fitting force, and the cemented carbide tip 3 rotates around the center. The ridge line direction of the blade edge part 3a is inclined and deflected in the direction of the ridge line direction of the blade edge part 1a of the roller cutter body 1, that is, the direction intersecting the circumferential direction of the roller cutter body 1. Since the plurality of locking projections 4 protruding from the outer peripheral portion of the base end surface are engaged with the bottom surface of the chip mounting hole 2 and locked, the locking force of the locking projection 4 is applied to the above-described screw. Acts as a large resistance against the rotational force, and firmly prevents the carbide tip 3 from being deflected. Until the useful life of the cutter A, it is those that can be subjected to drilling working face ground.

  Next, Table 1 shows the experimental results comparing the resistance force to the torsional force between the above-mentioned cemented carbide tip of the present invention and the conventional cemented carbide tip. In this experiment, a cemented carbide tip with the same structure having a square shaft protruding at the center of the distal end surface, and a carbide tip having four locking projections on the outer peripheral portion of the proximal end surface was implemented. As shown in FIGS. 9 and 10, the carbide tip provided with 6 locking projections is set as Example 2 and the cemented carbide tip provided with no locking projection is used as a comparative example as shown in FIGS. 9 and 10. After the cemented carbide chip is press-fitted and fitted into the chip mounting hole C provided in the base B, the square axis D protruding from the test fixed base B is applied to the square axis D while applying a load of 6 tons with a press. A rotational torque around the center of the chip was applied, and the torque when the carbide chip was rotated against the fitting force with the chip mounting hole C was measured.

  As can be seen from Table 1 above, the rotational torque (resistance force) of the cemented carbide chip with the locking projection protruding from the base end surface is increased compared to the carbide chip without the locking projection. The excavation efficiency of the face ground can be improved.

The perspective view of a roller cutter. The front view of the state supported rotatably by the supporting member. The side view. The enlarged vertical front view of the part which press-fits and inserts the cemented carbide chip. The perspective view of the cemented carbide tip which has provided four latching protrusions. The perspective view of the cemented carbide chip which has provided six latching protrusions. A simplified longitudinal side view of a tunnel excavator. The front view of the cutter board. The simplified front view of the state which is testing the locking force. The plan view. The longitudinal cross-sectional front view of a part of roller cutter which has mounted the conventional carbide tip. The longitudinal cross-sectional front view of the state in which the cemented carbide tip was twisted.

Explanation of symbols

A Roller cutter 1 Roller cutter body
1a Cutting edge 2 Insert mounting hole 3 Carbide insert
3a Cutting edge 4 Locking protrusion

Claims (2)

  The tip of the roller cutter body is provided with tip mounting holes with a circular cross-section at regular intervals in the circumferential direction, and a cylindrical carbide tip whose tip is formed into a chevron-shaped cutting edge is press-fitted into the tip mounting hole. In the fitted roller cutter, a plurality of locking projections are provided on the outer peripheral portion of the base end surface of the cemented carbide tip, and the locking projections are bitten into the bottom surface of the chip mounting hole to lock. Roller cutter, characterized in that   The locking projections are formed in a small-diameter conical shape with a sharpened end, and three or more locking projections are provided on the outer peripheral portion of the base end surface of the cemented carbide tip at regular intervals in the circumferential direction. The roller cutter according to claim 1, wherein the roller cutter is provided.

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