JPS6350510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rock excavation bit used in a vertical hole excavator, an underground wall excavator, a tunnel excavator, and the like.

Figures 1, 2, and 3 show cutters for conventional digging bits, Figure 4 shows the digging direction required for this type of cutter, and Figure 5 shows the digging direction of the conventional cutter. .

The conventional cutter shown in FIGS. 1, 2, and 3 includes a cutter body 1, a shank 2 for attaching the cutter, and a cutter blade 3 to which a carbide tip 4 is brazed. Then, the cutter blade edge 3a
and the axial direction Y of shank 2 - plane parallel to Y' -
A rake angle α is provided between the cutting edge 3a and the plane XX, which is perpendicular to the plane Y'-Y'. However, no relief angle is provided on both sides of the cutter blade 3.

Therefore, the cutter for conventional drilling bits is
Although it is possible to excavate in the direction of pushing the cutting edge 3a, that is, the direction of arrow a in FIG. 4, and in the direction of turning the rake face 3b, that is, the direction of arrow b in FIG. Shaving body 1
00, the cutter blade 3a is pushed forward and excavated in the direction in which the cutter blade 3 is moved parallel to the side surface as shown by the arrow c in FIG. It was not possible to excavate in the direction in which the sides were rotated for the following reasons.

In other words, since the cutter blade 3 does not have relief angles on both sides, (A) digging resistance is large, (B) digging efficiency is poor, (C) uneven wear on the sides of the cutter blade 3 is large, (D) There were problems such as excessive digging reaction force acting on the entire cutter and drilling bit.

In addition, due to the synergistic effect of the above problems, there were also problems such as chatter vibration occurring throughout the drilling bit.

In addition, 102 in FIG. 5 indicates an excavation trace.

The purpose of the present invention is to move the cutter blade in a direction parallel to the side surface of the cutter blade from the excavated state by pushing it forward, even in hard rock, and in a direction in which the side surface of the cutter blade turns in the direction of the other side. To provide a rock excavation bit capable of excavating even when swinging a cutter blade.

The present invention is characterized by a rake angle formed between the cutter cutting edge and a surface parallel to the axial direction of the shank for attaching the cutter, and a relief formed between the cutter cutting edge and a surface perpendicular to the said surface. A plurality of cutters each having a corner and relief angles formed on both sides of the cutter blade are attached to the bit body, and with this configuration, the above object can be reliably achieved.

Hereinafter, the present invention will be explained based on the drawings.

Fig. 6 shows a vertical hole excavator to which the rock drilling bit of the present invention is applied, Fig. 7 shows an embodiment of the rock drilling bit of the present invention, and Figs. A first example is shown,
FIG. 11 shows the structure for attaching the cutter.

The shaft excavator shown in Fig. 6 is the tower equipment 1.
0, a winch device 11 attached to the top of the tower device 10, a swivel joint 13 suspended from the winch device 11 via a wire rope 12, and a rotary table 14 installed inside the tower device 10. , hydraulic unit 15,
A drill string 18 connected to a swivel joint 13, a rock drilling bit 23 connected to the lower end of this drill string 18, a swing cylinder 42 for this rock drilling bit, and a casing driven in advance at the drilling position. A pipe 49, a suction pump unit 51, a sedimentation tank 53, etc. installed on the ground are provided.

In addition, 100 in Fig. 6 is the rock mass as the workpiece,
103 indicates an excavated hole, and 104 indicates circulating water.

The rotary table 14 has a rotary drive motor, a speed reducer, and a Kerry bar rotary table for the drill string 18 (none of which are shown),
Drill string 1 through Kerryba 19 (described later)
It is designed to give rotational force to 8.

The hydraulic unit 15 supplies pressure oil for the swing cylinder 42 through a hydraulic hose 16 and a swivel joint 13, and also supplies pressure oil to the rotary table 14 through a hydraulic hose 17, and is connected to the swivel joint 13. Hydraulic hose 4
8, pressure oil is supplied to the swing cylinder 42.

As shown in FIG. 6, the drill string 18 is constructed by connecting a kely bar 19, a drill pipe 20, a drill collar 21, and a stabilizer 22. The kely bar 19 is connected to the swivel joint 13 and inserted through the rotary table 14, and is connected to the drill string 1.
It is designed to give rotational force to 8. The drill pipe 20 has a Kerry bar 1 corresponding to the drilling depth.
9 one after the other to pump up a mixture of circulating water and cuttings. The drill collar 21 is provided to apply thrust to the drill string 18. The stabilizer 22 is
This is designed to prevent the drill string 18 from swinging laterally.

As shown in FIG. 7, the rock excavation bit 23 includes a bit body 24, a suction pipe 30, a cutter attachment block 32, and a cutter 33 attached thereto. The bit body 2
4 is formed hollow, and a suction port 29 for a mixture of circulating water and excavated pieces is provided at the bottom. The bit body 24 also has a bit mounting frame 25 provided at the lower end of the drill string 18.
It is swingably attached via brackets 26, 27 and a connecting pin 28. The suction pipe 30 is fixed to the center of the bit body 24, with a lower end facing the suction port 29 and an upper end connecting the drill string 1 with a flexible pipe 31 in between.
8 and is adapted to suck up the mixture of circulating water and cuttings. A plurality of the cutter attachment blocks 32 are arranged and fixed on the outer peripheral surface and the bottom surface of the bit body 24. The cutter 33 and the structure for attaching the cutter 33 will be described in detail later.

The swing cylinder 42 is attached to the bit mounting frame 25 via a bracket 44 and a connecting pin 45, as shown in FIGS. The piston rod 43 is connected to the bit body 24 via a bracket 46 and a connecting pin 47. Further, the swing cylinder 42 is connected to the hydraulic unit 15 through a hydraulic hose 48, and is configured to swing the rock excavation bit 23 via a piston rod 43.

The casing pipe 49 is inserted to prevent the inner wall of the excavated hole 103 from collapsing, particularly to prevent the topsoil near the ground surface from collapsing.

The suction pump unit 51 includes a pump driving motor or engine, a reduction gear, and a water pump (none of which are shown). Further, the suction pump unit 51 is connected to the swivel joint 13 through a suction hose 50, as shown in FIG. This suction pump unit 51 is connected to the bit main body 2.
Suction port 29 provided in 4 → Suction pipe 30
→ Drill string 18 → Swivel joint 1
3->The mixture of circulating water and excavated pieces is sucked up through the suction hose 50.

The settling tank 53 is adapted to receive a mixture of circulating water and cuttings from the suction pump unit 51 via a discharge pipe 52, as shown in FIG. Further, this sedimentation tank 53 separates the mixture sucked up by the suction pump unit 51 into circulating water and excavated pieces, and the circulating water is returned to the excavated hole 103 if necessary.

The cutter 33 of the rock excavation bit 23 is the eighth
9 and 10, it has a cutter body 34, a shank 35, and a cutter blade 38 to which a carbide tip 39 is brazed. The shank 35 has an approximately semicircular bolt passage groove 3.
6 is provided. A reaction force receiving seat 37a is provided between the cutter main body 34 and the shank 35 and projects on the side opposite to the rake face 38b. As shown in FIG. 9, the cutter blade 38 has a (+) rake angle α formed between the cutter cutting edge 38a and a plane Y'-Y' parallel to the axial direction YY of the shank 35. Also, the plane parallel to Y-Y shown in Figure 10
As shown in FIG. 9, there is a (-) rake angle α′, α″ between
As shown in FIG. 10, the (+) clearance angle β formed between Y′-Y′ and the plane
A (+) clearance angle γ is formed on both side surfaces of the cutter blade 38. In this embodiment, the rake angle α is provided in a range of up to 30° on the (+) side, the rake angle α″ is provided in a range of up to 5° on the (−) side, and the clearance angle β, γ is set in the range of (+)5° to (+)30°, respectively.

As shown in FIG. 11, the cutter 33 is assembled by inserting a shank 35 into a cutter attachment block 32 fixed to the bit body 24, and inserting a shim 40 between the attachment hole formed in the cutter attachment block 32 and the shank 35. Through a mounting structure in which a bolt 41 is inserted through a bolt passage hole formed in a cutter attachment block 32 into a bolt passage groove 36 formed in a shank 35, and a nut (not shown) is tightened and fixed. It is attached to the cutter attachment block 32.

The rock excavation bit of the above embodiment operates as follows.

Now, when excavating a vertical hole as shown in FIG. 6, the cutter 33 attached to the bottom of the bit body 24 corresponds to the excavation direction shown by arrow a in FIG. 3
The rake angle α and clearance angle β of 3 work effectively to perform excavation, and the cutter 33 attached to the outer peripheral surface of the bit body 24 corresponds to the excavation direction shown by arrow c in FIG. The rake angle α″ and relief angle γ of 33 work effectively to perform excavation.
As a result, during this vertical excavation, the excavation resistance,
Good excavation can be achieved without problems such as poor excavation efficiency, uneven wear on the sides of the cutters, excavation reaction force of each cutter 33 and the entire rock excavation bit 23, and chatter vibration of the rock excavation bit 23.

Furthermore, when excavating in the rotational direction, the cutter 33 attached to the bottom of the bit body 24 corresponds to the excavation direction shown by arrow d in FIG.
The rake angle α'' and clearance angle γ of the cutter 33 effectively work to perform excavation, and the cutter 33 attached to the outer peripheral surface of the bit body 24 has a fifth
This corresponds to the excavation direction shown by the arrow b in the figure, and the rake angle α and relief angle β of the cutter 33 work effectively to perform excavation. Therefore, even when excavating in this rotational direction, the above-mentioned problem does not occur and the excavation can be performed satisfactorily.

Furthermore, when excavating by operating the rocking cylinder 42 and rocking the rock excavation bit 23, both the cutter 33 attached to the bottom and outer peripheral surface of the bit body 24 have a rake angle α and a rake angle α″. , clearance angle β and clearance angle γ work effectively at the same time,
Excavation takes place. As a result, even in this swing direction, the above-mentioned problem does not occur and excavation can be performed.

In this example, as a result of experiments, rake angles α and α″ were less than (-)5° ((-)6°, (-)
7°...etc.), the desired effect could not be obtained, and when it exceeded (+)30°, there was a problem in which the strength of the cutting edge was extremely reduced. In addition, for both relief angles β and γ, if it is less than (+) 5° ((+) 4°, (+) 3°, etc.), the desired effect cannot be obtained, and if it exceeds (+) 30°, the cutting edge There was a problem where the strength was extremely reduced.

Next, FIGS. 12, 13 and 14 show a second embodiment of the cutter of the rock excavation bit of the present invention.

The cutter 33 of this embodiment has a rake surface 38 of the cutter blade 38 between the cutter body 34 and the shank 35.
A reaction force receiving seat surface 37b protrudes toward the rake surface side outside of the reaction force receiving seat surface 37a protruding to the side opposite to b.
This embodiment is the same as the first embodiment except that a reaction force receiving seat surface 37c protruding from both sides of the cutter blade 38 is provided, and the rigidity against the reaction force during excavation is strengthened.

Next, FIGS. 15, 16, and 17 are
A third embodiment of the cutter of the rock excavation bit of the present invention is shown.

In the cutter 33 of this embodiment, the cutter blade 38 is formed with (-) rake angles α' and α''.
The rake angles α' and α'' are set at 0 to (-)5 degrees.

In this example, even if the (-) rake angles α' and α'' are present, due to the cooperation of the (+) clearance angle β and the (+) clearance angle γ, the In addition to excavation in the direction shown by a and the direction shown by arrow b in FIG. 5, it is also possible to excavate in the directions shown by arrows c and d in FIG. 4 without any problem.

In addition, in this example, as a result of experiments, the rake angles α′ and α″ were less than (-)5° ((-)6°,
(-)7°...etc.), the desired effect cannot be obtained,
(-) If the angle exceeds 30°, there was a problem where the cutter did not penetrate sufficiently.

The structure and operation of the cutter in this second embodiment are the same as those in the second embodiment.

Furthermore, it goes without saying that the rock excavation bit according to the present invention can be applied not only to the above-mentioned vertical hole excavator, but also to a trench excavator for underground continuous walls, a tunnel excavator, and the like.

According to the present invention described above, a rake angle is formed between the cutter cutting edge and a surface parallel to the axial direction of the cutter attachment shank, and a rake angle is formed between the cutter cutting edge and a surface perpendicular to the surface. and the relief angle
By attaching multiple cutters with clearance angles formed on both sides of the cutter blade to the bit body, even in hard rock, the sides of the cutter blade can be easily removed from the excavated state by pushing the cutter blade forward. Any of the directions in which the cutter blade is moved in parallel to the cutter blade, the direction in which the side surface of the cutter blade is rotated, and the direction in which the cutter blade is swung have the effect of allowing excavation to be carried out without problems.

[Brief explanation of drawings]

Figures 1 to 3 show conventional cutting bits for drilling bits, with Figure 1 being a front view, Figure 2 being a side view, and Figure 2 being a side view.
Fig. 3 is a sectional view taken along the line - - of Fig. 1, Figs. 4 and 5 are explanatory diagrams showing the excavation directions required for this type of excavation bit, and Fig. 6 is a vertical hole excavation to which the rock excavation bit of the present invention is applied. Fig. 7 is a longitudinal sectional front view showing an example of the rock excavation bit of the present invention, and Figs. 8 to 11 are illustrations of the cutter of the rock excavation bit of the present invention. 1
Fig. 8 is a front view, Fig. 9 is a side view, Fig. 10 is a sectional view taken along the line - - in Fig. 9, Fig. 11 is a side view of the installed state, and Figs. Fig. 14 shows a second embodiment of the cutter, Fig. 12 is a front view, Fig. 13 is a side view, Fig. 14 is a sectional view taken along the line - - of Fig. 13,
15 to 17 show a third embodiment of the cutter, in which FIG. 15 is a front view, FIG. 16 is a side view, and FIG. 17 is a sectional view taken along the line -- in FIG. 16. 23...Rock excavation bit, 24...Bit body, 3
2...Cut mounting block, 33...Cut,
34...Cut body, 35...Shank, 37a, 3
7b, 37c... Reaction force receiving seat surface, 38... Katsuta blade,
38a...cutting edge, 38b...rake face, α...
(+) rake angle, α′...(-) rake angle, β,
γ... Relief angle.

Claims (1)

[Claims] 1. A rake angle formed between the cutter cutting edge and a surface parallel to the axial direction of the shank for attaching the cutter, and a rake angle formed between the cutter cutting edge and a surface perpendicular to the said surface. A rock excavation bit characterized in that a plurality of cutters each having a relief angle and relief angles formed on both sides of the cutter blade are attached to the bit body. 2. The rock excavation bit according to claim 1, wherein the rake angle is up to 5 degrees on the (-) side and up to 30 degrees on the (+) side. 3. The rock excavation bit according to claim 1, wherein each of the clearance angles is from (+)5 degrees to (+)30 degrees.