JPH0718979A - Excavator cutter bit and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] Since a cutting speed equivalent to the outer peripheral part of the cutter wheel can be created on the entire surface of the cutter wheel, uniform cutting can be realized in the entire cutting cross section, and high-speed rotary type It does not occur, and has excellent durability and wear resistance, and it can expand the range of application of cut objects. [Structure] A thin polyhedral superalloy chip 32 is fixed to an end of a ring-shaped shank material 31 by a weld metal 33 or a sintered metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter bit for an excavator for excavating the ground such as a shield excavator, a civil excavator for civil engineering, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, cutter bits used when excavating the ground with a tunnel excavator or shield excavator, select an excavation shape according to excavation soil conditions,
It is mounted on a disc-shaped cutter wheel in a suitable arrangement so that the desired cross section can now be excavated.

There are various types of such cutter bits, such as a flat chisel-shaped cemented carbide, a rectangular cemented rod-shaped cemented carbide, and a bar-shaped cemented carbide. However, when this is rotated at a high speed by a disc-shaped cutter wheel, vibration occurs due to structural problems, and the cutter bit is easily damaged. Further, such damage or wear occurs for each individual cutter bit, and it is difficult to maintain uniform cutting ability.

Further, in the cutter mechanism of an excavator using such a disc-shaped cutter wheel, the rotational angular velocities at the outermost peripheral portion and the central portion are greatly different, and the outer peripheral portion has the maximum cutting speed, but the central portion It becomes the minimum as it gets closer, and the excavation efficiency in the central part is extremely poor, which causes an increase in excavation resistance, which becomes a problem during construction of curved parts. This is because the front surface resistance increases due to the decrease in excavation performance.

Further, since the excavation performance deteriorates at the central portion as described above, it is impossible to cut hard materials such as rocks, reinforced concrete, and steel materials. For example, when excavating a highway as a branch road from an existing shield. It is not possible to use an excavator to perform the work of breaking the steel segment or the reinforced concrete segment of the existing shield, or the work of breaking the sheet pile, the steel sheet pile, or any other obstacle in the ground.

On the other hand, there is a diamond cutter which can cut a hard object, but since it is expensive, it is usually used only for a boring excavator or the like having a small bore diameter. Not suitable for road excavation.

[0007]

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example and to produce a cutting speed equivalent to the outer peripheral portion of the cutter wheel on the entire surface of the cutter wheel. Cutting can be realized, high speed rotation type does not cause expansion, and durability,
An object of the present invention is to provide a cutter bit for an excavator that is rich in abrasion resistance and that can expand the range of application of the material to be excavated, and a method for manufacturing the same.

[0008]

In order to achieve the above object, the present invention provides a cutter bit for an excavator, in which a small polyhedral superalloy tip is welded or sintered to the end of a ring-shaped shank material. As a method of manufacturing such a cutter bit, the shank material of the cutter bit is incorporated into the formwork base, and the inner and outer formwork, in which the superalloy chip of the small polyhedron is set on the formwork base, And while spreading in the groove portion surrounded by the shank material, the molten metal is poured onto it, and the superalloy chip of the small polyhedron is fixed to the end portion of the shank material to form the gist. is there.

[0009]

According to the present invention as set forth in claim 1, the thin and polyhedral superalloy chip itself has a large number of blade surface portions,
Moreover, the fixing directions are not uniform. Although the cutting amount per one blade surface is very small, the cutting amount is increased by the high speed rotary cutting, and the cutting amount equivalent to that of the conventional cutter bit can be secured. In addition, if the superalloy tip wears or falls off during cutting, a new blade surface is formed with another superalloy tip.In this way, the blade surface is self-developed and digging is continued. Stable digging and cutting can be performed on the end face and the inner and outer side faces.

According to the second aspect of the present invention, in addition to the above-mentioned action, the width, height, diameter, etc. of the shape of the cutter bit itself can be freely selected by the laminated welding structure of the superalloy tips of the small and small polyhedrons. It can be molded and can be manufactured at low cost.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 4 are perspective views showing the first to fourth embodiments of the cutter bit of the excavator of the present invention, in which 31 is a shank material, which is ring-shaped.

On the end of the shank material 31, a fine polyhedral superalloy chip 32 was fixed by a sintered metal or a welded metal 33.

FIGS. 5 and 6 show a method for manufacturing a cutter bit according to the present invention. A shank material 31 of the cutter bit is incorporated in a mold stand 35, and a mold stand is provided so as to surround the upper end of the shank material 31. The inner mold 36 and the outer mold 37 are set in 35.

Although not shown in the drawings, the mold base 35 is assembled on a turntable, and while the mold base 35 is rotated by the turntable, the thin and polyhedral superalloy chips 32 are inserted into the inner mold 36. The molten metal 33 is poured onto the outer frame 37 and the groove portion surrounded by the shank material 31 while being spread.

When the mold base 35, the inner mold 36, and the outer mold 37 are demolded when the weld metal 33 is solidified in this way, the end portion of the shank material 31 is placed through the weld metal 33. A cutter wheel 38 to which the thin polyhedral superalloy chips 32 are fixed is obtained.

In the formed cutter bit of the present invention, as shown in FIG. 1, when the ring-shaped formed body is provided with the concave portions 34 in a zigzag pattern in the circumferential direction, the inner and outer surfaces are formed as shown in FIG. In the case where the bald portions 34 are provided in pairs at an interval, when the lateral width of the bald portions 34 of the inner and outer pairs is narrow as shown in FIG. 3, and when the bald portion 34 as in FIG. 4 is not provided. There are various shapes. Since it is molded by the mold frame in this way, it is possible to freely mold by selecting the width, height, diameter, etc. of the shape of the cutter bit itself.

The cutter bit of the present invention may be formed by forming the shank material 31 into a coupling shape at once in case of a small diameter, but in the case of a large diameter, it is formed into a segment block shape. It is also conceivable to assemble them in a ring shape by connecting them together.

FIGS. 7 and 8 show one example of use.
The main shield excavator 1 is composed of an excavator body 2 and an excavation head 3 located in front of the excavator main body 2. Further, the excavation head 3 revolves around an outer peripheral cutter 5 and a free cutter 6, which is disposed inside thereof. It consists of 7.

The cutter bit of the present invention is used as the cutter bit of the outer peripheral cutter 5 and the cutter bits 6a and 7a of the universal cutters 6 and 7.

A drive motor 11 which is a hydraulic motor is disposed in the excavator main body 2, and a pinion gear 13 provided on the shaft of the drive motor 11 meshes with a drive gear 12 provided on the drive shaft of the outer peripheral cutter 5, The drive motor 11 drives the outer cutter 5 to rotate.

A cutter base 4 is provided inside the outer peripheral cutter 5, and a drive gear 14 provided on a drive shaft of the cutter base 4 also meshes with the pinion gear 13. In this case, the cutter base 4 rotates in the opposite direction with respect to the outer peripheral cutter 5.

Free cutters 6 and 7 are arranged on the base surface of the cutter base 4, and the free cutters 6 and 7 are provided.
Is a cutter bit 6a, 7a as its own drive mechanism
It has a drive motor 10 for rotating.

In the figure, 21, 22, 23 and 24 are roller bearings, 25 and 26 are ball bearings, and 27 is a rotary valve for supplying hydraulic oil to the drive motor 10. Further, in the case of the present invention, a mud pressure method is adopted, and the ends of the mud discharge pipe 8 and the mud feed pipe 9 located therein are exposed to the surface of the cutter base 4.

In the main shield excavator 1, the outer peripheral cutter 5 is rotationally driven by the drive motor 11 via the pinion gear 13 and the drive gear 12, and the circular cutter bit makes it possible to perform the same excavation as the main shield excavator 1. The diameter is secured, and core collecting type excavation cutting is performed by the outer peripheral portion of the excavation head 3 and the thickness of the cutter bit.

At the same time, inside the outer peripheral cutter 5, a ring-shaped cutter bit 6 of free cutters 6 and 7 is provided.
The a and 7a rotate independently by the drive motor 10, and the cutter bits 6a and 7a perform digging and cutting, and the universal cutters 6 and 7 have the cutter base 4 in the opposite direction to the outer peripheral cutter 5 at substantially the same speed. Since it rotates, excavation is performed such that the ring diameter becomes the excavation width according to the movement of the cutter base 4.

At this time, if the rotation directions of the cutter bits 6a and 7a are the same as the rotation direction of the cutter base 4,
The cutting speed is the rotation of the cutter base 4 plus the rotation of the cutter bits 6a and 7a.

However, it is not necessary that all of the cutter bits 6a and 7a be in the same direction as the rotation of the cutter base 4,
A part may be reversely rotated. That is, the rotational speeds, rotational torques, and rotational directions of the cutter bits 6a and 7a can be freely set. By appropriately increasing or decreasing these, the setting can be freely performed within the range suitable for the material to be cut. it can.

Further, the iron powder and the concrete scraps excavated and cut are sent to the muddy water plant by muddy water through the drainage pipe 8 arranged in the central portion of the main shield excavator 1.

When biting occurs inside the outer peripheral cutter 5, the rotating directions of the universal cutters 6 and 7 are made to coincide with the rotating direction of the outer cutter 5, or the height of the cutter base 4 is higher than that of the outer cutter 5. The height of the cutter bits 6a and 7a of the universal cutters 6 and 7 may be lowered accordingly.

In the cutter bit of the present invention, the thin and polyhedral superalloy tip 32 itself has a large number of blade surface portions,
Moreover, the fixing directions are not uniform. For example, a segment made by cutting a thin rod-shaped superalloy has a hexahedral shape.

Further, although the length of the blade edge formed by a large number of blade surface portions is minute, since it is cut at high speed,
The occurrence of expansion cutting is prevented, and the cutting amount per cutting edge surface is minute, but the cutting amount is increased by high-speed rotation cutting, and the cutting amount equivalent to that of the conventional cutter bit can be secured. If the superalloy tip 32 is worn or dropped during cutting, the weld metal
Since 33 is properly worn and a new blade surface is formed, it is possible to continue cutting without lowering the sharpness.

The digging and cutting of reinforced concrete is a composite cutting, but the concrete portion acts as an abrasive to abrade the welded metal 33 portion and form a new blade surface to effectively cut the reinforcing steel portion. be able to.

Further, since the melting point of the welding metal 33 for fixing the superalloy chip 32 is low during uncooled excavation and is melted by the frictional heat caused by excavation, as a preventive measure, cooling should be performed with fresh water, muddy water, and mud. To do. Optimum cutting can be achieved by using the muddy water shield excavator as described above.

In addition, the method of discharging the excavated earth and sand by the fluid has a cooling effect on the cutter bit, and is also useful for removing the superalloy chips 32 that have fallen off, so that the self-destruction of the cutter bit can be prevented.

When excavating downward, it is necessary to promptly remove the fallen cemented carbide chips 32 from the excavation portion, but generally, for excavation to a deep layer, burial of steel material or the like is performed. It is possible to avoid it in advance, and the friction of the cutter bit in ordinary excavation is considered to be minute from the viewpoint of the structure, so it can be performed without much difference from ordinary excavation management.

[0036]

As described above, according to the cutter bit of the excavator and the manufacturing method thereof of the present invention, a cutting speed equivalent to that of the outer peripheral portion of the cutter wheel can be created on the entire surface of the cutter wheel. Even cutting can be realized, high-speed rotation does not cause expansion, and it has excellent durability and wear resistance, and it can expand the range of application of cut objects.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a cutter bit of an excavator according to the present invention.

FIG. 2 is a perspective view showing a second embodiment of the cutter bit of the excavator of the present invention.

FIG. 3 is a perspective view showing a third embodiment of the cutter bit of the excavator of the present invention.

FIG. 4 is a perspective view showing a fourth embodiment of the cutter bit of the excavator of the present invention.

FIG. 5 is a vertical cross-sectional side view showing an embodiment of the method for manufacturing the cutter bit of the excavator of the present invention.

FIG. 6 is a partially cutaway plan view showing an embodiment of a method for manufacturing a cutter bit of an excavator according to the present invention.

FIG. 7 is a vertical sectional side view showing an example of a shield excavator including the cutter bit of the excavator of the present invention.

FIG. 8 is a plan view showing an example of a shield excavator provided with the cutter bit of the excavator of the present invention.

[Explanation of symbols]

1 ... Main shield excavator 2 ... Excavator body 3 ... Excavation head 4 ... Cutter base 5 ... Outer cutter 6,7 ... Free cutter 6a, 7a ... Cutter bit 8 ... Mud pipe 9 ... Mud pipe 10, 11 ... Drive Motor 12, 14… Drive gear 13… Pinion gear 21, 22, 23, 24… Roller bearing 25, 26… Ball bearing 27… Rotary valve 31… Shank material 32… Superalloy tip 33… Weld metal 34… Bare part 35 … Formwork base 36… Inner formwork 37… Outer formwork 38… Cutter wheel

Front Page Continuation (72) Inventor Kyobayashi Kyotsugu 1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Naomichi Sawada 1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihonhon Telegraph and Telephone Corporation (72) Inventor Minoru Nagashima 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Koji Akiyama 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihonhon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A cutter bit for an excavator, characterized in that a thin polyhedral superalloy chip is fixed to an end of a ring-shaped shank material by a weld metal or a sintered metal. 2. A shank material for a cutter bit is incorporated into a formwork stand, and a thin and polyhedral superalloy chip is set on the formwork stand, and an inner formwork, an outer formwork, and a groove portion surrounded by the shank material are spread. A method for manufacturing a cutter bit for an excavator, characterized in that the molten metal is poured onto the shank material, and the superalloy chip of the small polyhedron is fixed to the end portion of the shank material for molding.