JP3379410B2 - Roller cutter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller cutter mounted on the tip of a shield excavator or the like for excavating the ground or the like.

[0002]

2. Description of the Related Art As a roller cutter of this type, a roller rotatably supporting a steel ring has hitherto been mainly used for hard rock excavation, but recently, as a soft rock excavator, for example, As shown in FIGS. 4 to 6, a plurality of chips 2 made of a hard material such as cemented carbide is planted on the outer periphery of the cutter body 1 rotatably supported.
The so-called chip insert type is being widely used. Here, the tip insert type roller cutters shown in these figures are provided on the outer circumference of the shaft 4 fixed to the excavation surface of the shield excavator or the like via the attachment member 3,
The cutter body 1 having an annular shape is mounted so as to be rotatable about its axis O via bearings 5 and 5 and seal members 6 and 6.

On the outer periphery of the cutter body 1, a pair of ring-shaped portions 7 having a mountain-shaped cross section in the illustrated example are formed around the axis O so as to be aligned in the direction of the axis O.
A large number of concave portions 8 are formed at equal intervals in the circumferential direction on the ridge line portion projecting to the outer peripheral side of the ring-shaped portions 7, 7, and the chips 2 ... It is inserted and fixed by tight fitting such as fitting. However, according to such a roller cutter,
By rotating the excavation surface of the shield excavator or the like while pressing the ring-shaped portions 7, 7 of the cutter body 1 against the natural ground or the like with a predetermined thrust, the cutter body accompanying the rotation of the thrust and the excavation surface Excavate rocks etc. by interaction with rotation of 1.

[0004]

By the way, in the tip insert type roller cutter having the above-mentioned structure, the tip 2 is fitted into the recess 8 by interference fitting such as shrink fitting as described above. Is pressed against the inner peripheral surface of the recess 8 so as to be clamped and fixed to the cutter body 1. On the other hand, as the pressing force for clamping the chip 2 acts, the cutter body 1 On the contrary, a tensile stress that tends to pull the cutter body 1 toward the center of the concave portion 8 acts. However, such a tensile stress acts in a direction that causes peeling or cracking of the surface of the cutter body 1, and if an excessive excavating load is applied during excavation, the cutter works together with the tensile stress. The main body 1 may be damaged.

Further, recently, in such a tip insert type roller cutter, the cutter body is formed into a cylindrical hub member on the inner peripheral side and a ring shape which is attached to the outer periphery thereof to form the ring-shaped portion. An exchange ring type constituted by a member has also been proposed, but in such an exchange ring type roller cutter, when attaching a ring-shaped member to the outer periphery of the hub member,
Usually, the hub member is tightened by shrink fitting such as shrinkage fitting to fix the ring-shaped member.Therefore, conversely to the ring-shaped member, tensile stress is applied in the direction of pulling the ring-shaped member toward the inner peripheral side. Will work. For this reason, in such an exchange ring type roller cutter, the tensile stress may be combined with the tensile stress generated when the chip is fixed, and the damage of the cutter body may be further promoted.

The present invention has been made under such a background, and in the chip insert type roller cutter as described above, the tensile stress generated for fixing the chip is reduced to prevent the damage of the cutter body. An object is to provide a roller cutter that can be prevented.

[0007]

In order to solve the above-mentioned problems and to achieve such an object, the present invention provides an outer periphery of an annular cutter body rotatably supported around a central axis,
In a roller cutter in which a plurality of chips made of a hard material are planted at intervals in the circumferential direction of the cutter body, the chips are fitted into a recess formed in the outer peripheral surface of the cutter body by an interference fit. Along with planting
The concave portion of at least the outer peripheral surface of the cutter body
It is characterized by carburizing and quenching the part except the inner surface . However, by performing such carburizing and quenching, residual compressive stress is induced in the cutter body, and the tensile stress is offset by the residual compressive stress. Can be reduced.

[0008] Among such roller cutters, in particular, the cutter body is constructed by fitting a ring-shaped member, in which the tip is planted, on the outer periphery of a substantially cylindrical hub member by interference fit. In the above-mentioned exchange ring type roller cutter, the ring-shaped member is formed by carburizing and quenching the outer peripheral surface of the ring-shaped member excluding the recess and the inner peripheral surface of the ring-shaped member. It is also possible to reduce the tensile stress when fixing the steel to the hub member by the residual compressive stress due to carburizing and quenching. Furthermore, the carburizing depth of these carburizing quenches is 0.5 mm.
It is desirable to set it within a range of up to 2.0 mm. If the carburizing depth is shallower than this, the effect of reducing the tensile stress may not be sufficiently obtained, but even if the carburizing depth is deeper than this, the effect will not be obtained. Can no longer be expected to improve.

[0009]

1 to 3 show an embodiment of a roller cutter according to the present invention. The roller cutter according to the present embodiment includes a pair of mounting wall portions 11A and 11A of a mounting member 11 mounted on an excavation surface of a shield excavator or the like.
Shaft 13 is fixed between A and via end caps 12, 12 by mounting bolts 14, and an annular cutter body 15 is provided on the outer periphery of shaft 13 with bearing 1
The cutter body 15 is attached via 6 and 16 and is rotatably supported around the central axis O thereof.
Both ends of the bearings 16 and 16 are formed so as to cover the outer peripheries of the end caps 12 and 12.
Of the end caps 12, 12 on the outer peripheral side of the
A floating seal 17 is interposed between the cutter body 15 and the surface facing inward.

Here, the cutter body 15 in the present embodiment is of the ring exchange type described above, that is, the substantially cylindrical hub member 18 is attached to the outer circumference of the bearings 16 and 16, and the axis line. While being rotatably supported around O, the outer periphery of the hub member 18 is
A mounting surface 18B having a circular cross section is formed on one end side (left side in FIG. 3) of a positioning protrusion 18A. From the other end side (right side in FIG. 3) of the hub member 18, the mounting surface 18B is formed. , A pair of ring-shaped members 19, 19 made of steel material are fitted by interference fitting such as shrink fitting, aligned in the direction of the axis O, and fixed, and further, a groove formed on the other end side of the mounting surface 18B. A retainer ring 20 is attached to 18C to prevent it from coming off. Therefore, the hub member 18 and the ring-shaped member 19,
This ring-shaped member 19 is separate from 19
If the ring wears, only the ring-shaped member 19 can be replaced.

As shown in FIG. 3, the ring-shaped member 19 has a substantially mountain-shaped cross section, and the mountain-shaped ridge has a circular cross-section recessed in the radial direction of the axis O. A large number of recesses (round holes) 19A are formed at equal intervals in the circumferential direction, and in these recesses 19A, a substantially cylindrical tip 21 made of a hard material such as cemented carbide is formed, and its tip is a ring-shaped member. It is inserted so as to face the outer periphery of 19, and is fixed and implanted by shrink fitting such as shrink fitting. However, the tip ends of these chips 21 are formed in a mountain shape over the diameter direction of the chips 21 so as to be substantially flush with the outer peripheral surface of the ring-shaped member 19.

In the present embodiment, the hub member 18 is attached to the entire surface of the ring-shaped members 19, 19 excluding the inner surfaces of the recesses 19A before the tips 21 are implanted. Before attaching to surface 18B,
Carburized and quenched. The carburizing depth of this carburizing and quenching is 0.5 mm to 2.0 mm in this embodiment.
Is set in the range.

In the roller cutter thus constructed, however, the surface of the ring-shaped member 19 of the cutter body 15 is carburized and quenched, so that the surface of the ring-shaped member 19 is compressed and retained in advance. Since the stress is induced, the concave portions 19A formed on the outer peripheral surface of the concave portion 19A ...
When the chips 21 ... Are fitted into and mounted by interference fitting such as shrink fitting, the tensile stress generated by this interference fitting can be offset and relaxed by the compressive residual stress. Therefore, according to the roller cutter having the above configuration,
Even when an excessive excavating load is applied during excavation, the excavating load and the tensile stress are combined to make the ring-shaped member 1
It is possible to prevent peeling or cracking from occurring on the surface of the roller 9, thereby preventing the cutter body 15 from being damaged and extending the life of the roller cutter.

Further, since the carburizing and quenching is a treatment method for hardening the surface of the steel material in the first place, the surface of the ring-shaped member 19 is subjected to such surface treatment so as to prevent the ring-shaped member 19 from being worn by sand and the like. The wear resistance can be improved, and this can also promote the extension of the life of the roller cutter.

Further, in this embodiment, the cutter body 15 is a ring exchange type as described above, and the ring-shaped members 19, 19 are attached to the attachment surface 18B of the hub member 18 by shrink fitting such as shrink fitting. On the other hand, the carburizing and quenching is performed on the entire surface of the ring-shaped member 19 excluding the inner surfaces of the recesses 19A ...
That is, it is also applied to the inner peripheral surface of the ring-shaped member 19.
Therefore, the tensile stress generated by the interference fit when the ring-shaped members 19, 19 are attached to the hub member 18 is also
Since the compressive residual stress induced by the carburizing quenching cancels and is relaxed, according to the present embodiment, even in such a ring replaceable roller cutter, the damage of the cutter body 15 can be more reliably prevented. Therefore, it is possible to further extend the life.

In addition, in the present embodiment, the carburizing depth of the carburizing and quenching is set in the range of 0.5 mm to 2.0 mm, which allows more reliable quenching while avoiding excessive quenching. The tensile stress due to the interference fit can be reduced. That is, if the carburizing depth is smaller than 0.5 mm, the effect of reducing the tensile stress due to the residual compressive stress may not be sufficiently exerted. On the other hand, even if the carburizing depth is larger than 2.0 mm, the carburizing depth may be large. However, further improvement of the effect cannot be achieved and becomes inefficient.

In this embodiment, in the ring-replaceable roller cutter, the entire surface of the ring-shaped member 19 excluding the recess 19A in which the chip 21 is planted is carburized and quenched. However, for example, in FIG.
As shown in FIG. 6 to FIG. 6, a roller cutter having a cutter body integrally formed with a ring-shaped portion in which a chip is implanted and a hub portion attached to the outer periphery of a bearing is a cutter except the inner surface of the recess. Carburizing and quenching may be applied only to the outer peripheral surface (ring-shaped portion) of the main body.

[0018]

As described above, according to the present invention,
Carburizing and quenching the surface of the cutter body except for the inner surface of the recess where the chip is implanted induces compressive residual stress on the surface of the cutter body. The tensile stress that occurs when mounted in the recess can be offset and reduced by the compressive residual stress. Therefore, even if an excessive excavation load acts on the cutter body during excavation, it is possible to prevent the cutter body from being damaged due to the combination of the excavation load and the tensile stress. It becomes possible to provide a roller cutter with a long life.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment shown in FIG.

3 is a sectional view taken along line YY in FIG.

FIG. 4 is a side view showing a conventional roller cutter.

5 is a plan view of the conventional example shown in FIG.

6 is a ZZ cross-sectional view in FIG.

[Explanation of symbols]

11 Mounting member 12 End cap 13 shaft 15 cutter body 16 bearings 17 Floating seal 18 Hub member 18A mounting surface 19 Ring-shaped member 19A recess 20 retainer ring 21 chips O Cutter body 15 center axis

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Fujimawa 1528 Nakanishi, Yokoi, Kobe, Anpachi-gun, Gifu Prefecture Mitsubishi Materials Corporation Gifu Manufacturing (56) References JP 63-125797 (JP, Sho, JP A) JP 8-21191 (JP, A) JP 59-67364 (JP, A) JP 7-158372 (JP, A) JP 8-4481 (JP, A) JP 8 -291695 (JP, A) Actual development Sho 62-185784 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21B 10/50 E21B 10/10

Claims (3)

(57) [Claims] 1. A roller cutter in which a plurality of chips made of a hard material are planted on the outer periphery of an annular cutter body rotatably supported around a central axis at intervals in the circumferential direction of the cutter body. , The tip is fitted and implanted in a recess formed in the outer peripheral surface of the cutter body by interference fitting, and at least a portion of the outer peripheral surface of the cutter body excluding the inner surface of the recess is A roller cutter characterized by being carburized and quenched. 2. The cutter body comprises a ring-shaped member, in which the tip is planted, mounted by interference fit on the outer periphery of a substantially cylindrical hub member, and the outer peripheral surface of the ring-shaped member is The roller cutter according to claim 1, wherein a portion of the ring-shaped member excluding the recess is carburized and quenched. 3. The carburizing depth of the carburizing and quenching is 0.
The roller cutter according to claim 1 or 2, wherein the roller cutter is set in a range of 5 mm to 2.0 mm.