JPS60173285A - Rock drilling bit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

Figures 1, 2, and 3 show cutters for conventional drilling 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 with a cutter mount,
It is equipped with a cutter blade 3 to which a carbide tip 4 is brazed. Then, the axial direction Y-Y of the cutter blade edge 6a and the shank 2
A rake angle α is provided between the plane y/ and the plane parallel to y/,
A plane X- that is perpendicular to the cutter blade edge 6a and the plane y/y/
A relief angle β is provided between X and X. However, no relief angle is provided on both sides of the cutter blade 6.

Therefore, the conventional cutter for excavation bits is capable of digging in the direction of pushing the cutter edge 3a forward, in the direction of arrow a in FIG. Although it is possible, the cutter blade 6 can be moved in other directions, as shown by arrow C in FIG.
It was not possible to excavate in the direction in which the side surface of the cutter blade 3 was moved parallel to the crocodile, and in the direction in which the side surface of the cutter blade 3 was rotated in the crocodile direction as shown by the arrow d in FIG. 4 for the following reasons.

In other words, since the cutter blade 3 does not have a clearance angle on both sides, α) the excavation resistance is large, (B) the excavation efficiency is poor, (C) the uneven wear on the sides of the cutter blade 5 is large, and ■) the cutter and There were problems such as excessive digging reaction force acting on the entire drilling bit.

1. Due to the synergistic effect of the above problems, there were also problems such as chatter υ vibration occurring throughout the drilling bit.

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

The object 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 cutter blade rotates around the side surface of the cutter blade. To provide a rock excavation bit capable of excavating even when a cutter blade is oscillated.

The features of the present invention include a rake angle formed between the cutter blade edge and a surface parallel to the axial direction of the shank for the cutter mounting plate, and a rake angle formed between the cutter blade edge and a surface perpendicular to said surface. A plurality of cutters each having a relief angle formed on the cutter blade and relief angles formed on both sides of the cutter blade are attached to the bit body, and this configuration reliably achieves the above purpose. It is.

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

FIG. 6 shows a pit 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. 8 to 10 show the cutter of the rock drilling bit of the present invention. A first embodiment is shown, and FIG. 11 shows the structure of the cutter attachment.

The pit excavator shown in FIG. 6 includes a tower device 10 and 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 lobe 12, a rotary table 14 installed in the tower device 10, a hydraulic unit 15, and a drill string connected to the swivel joint 13. 18 and this drill) A rock excavation bit 26 connected to the lower end of the IJ ring 18, a rocking cylinder 42 for this rock excavation bit, a casing vibe 49 pre-driven into the excavation position, and a casing vibrator 49 installed on the ground. A suction pump unit 51, a sedimentation tank 55, etc. are provided.

In FIG. 6, 100 indicates a rock mass as a rigid body, 1o3 indicates an excavated hole, and 104 indicates circulating water.

The rotary table 14 includes a rotary drive motor, a speed reducer, and a Kelly bar rotary table (none of which are shown) for the drill string 18, and applies rotational force to the drill string 18 through a Kelly bar 19, which will be described later. ing.

The hydraulic unit 15 supplies pressure oil for the swing cylinder 42 through the swivel joint 13 through the hydraulic hose 16, and also supplies pressure oil to the rotary table 14 through the hydraulic hose 17, and is connected to the swivel joint 16. Pressure oil is supplied to the swing cylinder 42 through a hydraulic hose 48.

As shown in FIG. 6, the drill string 18 includes a kely bar 19, a drill pipe 20, and a drill collar 21.
and a stabilizer 22 are connected to each other. The kely bar 19 is connected to the swivel joint 13 and inserted through the rotary table 14 so as to apply rotational force to the drill string 18. 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 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 50, a cutter mounting block 62, and a cutter 35 attached thereto. The bit body 24 is formed hollow and has a suction port 29 at the bottom for a mixture of circulating water and cuttings. In addition, the bit body 24 is attached to the drill string 1
The pit mounting p provided at the lower end of 8 is for frame 25
It is swingably attached to the housing via brackets 26 and 27 and a connecting pin 28. The suction pipe 60 is fixed to the center of the bit body 24, has a lower end facing the suction port 29, and an upper end connected to the lower end of the drill string 18 with the flexible pipe 31 in between. hand,
It is designed to suck up a mixture of circulating water and excavated debris.

The cutter mounting block 32 is attached to the bit body 24.
A plurality of them are arranged and fixed on the outer peripheral surface and the bottom surface. The structure of the cutter 35 and its attachment will be described in detail later.

As shown in FIGS. 6 and 7, the swing cylinder 42 is attached to the bit mounting frame 25 via a bracket 44 and a connecting pin 45. The piston rod 45 fitted into the bit body 24 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 connected to the rock excavation bit 2 through a piston rod 43.
5 can be swung.

The casing pipe 49 is inserted to prevent the inner wall of the excavated hole 106 from collapsing, especially to prevent the topsoil from collapsing near the ground.

The suction pump unit 51 includes a pump driving motor or engine, a speed reduction device, and a water pump (none of which are shown). The suction pump unit 51 also includes a suction hose 5 as shown in FIG.
0 to the swivel joint 13.

This suction pump unit 51 is connected to a suction port 29 provided in the bit body 24 → a suction pipe 60
→ Drills) IJ ring 18 - swivel joint 16
→The mixture of circulating water and excavated pieces is sucked up through the suction hose 50.

The settling tank 53 receives a mixture of circulating water and excavated pieces from the suction pump unit 51 via a discharge pipe 52, as shown in FIG. Further, this settling tank 56 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 106 as necessary.

The cutter 36 of the rock excavation bit 23 is shown in FIG.

As shown in FIGS. 9 and 10, it has a cutter body 34, a shank 35, and a cutter blade 38 to which a carbide tip 69 is brazed. The shank 35 is provided with a roughly semicircular bolt passage groove 66.

A rake face 3 is provided between the cutter body 34 and the shank 35.
A seat 57a is provided on the reaction force receiver protruding to the side opposite to 8b. The cutter blade 38 has, as shown in FIG.
Rake angle α (g) formed between the cutter cutting edge 38a and the plane y/y/ parallel to the axial direction Y-Y of the shank 65
In addition, there are (-) rake angles α' and α' between the plane Y-Y'' parallel to Y-Y shown in FIG. 10, and the cutter blade edge 38m and the plane Y /y/ and the plane X-X that is perpendicular to γ is provided.

In this embodiment, the rake angle α is 30 mm on the (G) side.
The rake angle α″ is (→
The clearance angles β and γ are each set in a range of (-1-)5° to (→5D°).

As shown in FIG. 11, the cutter 66 is fixed to the bit body 24 by inserting the shank 35 into the cutting block 62, and by inserting the cutter into the cutting hole formed in the cutting block 62. A shim 40 is interposed between the shanks 35, and for attaching the cutter, a bolt 41 is inserted through a bolt through hole formed in the block 32 into a bolt through groove 36 formed in the shank 35, and then a nut (not shown) is inserted. The cutter mounting block 32 is attached to the cutter mounting block 32 via a structure for tightening and fixing the cutter.

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

Now, when excavating a vertical hole as shown in FIG. 6, the cutter 65 attached to the bottom of the bit body 24 corresponds to the excavation direction shown by arrow a in FIG. The rake angle α and relief angle β of the cutter 56 effectively work to perform digging, and the cutter 36 attached to the outer peripheral surface of the bit body 24 corresponds to the digging direction shown by arrow C in FIG. However, the rake angle α' and relief angle γ of the cutter 33 work effectively to perform excavation. As a result, during this vertical excavation, there are no problems such as excavation resistance, excavation efficiency, uneven wear on the side of the cutter, excavation reaction force of each cutter 36 and the entire rock excavation bit 23, chatter vibration of the rock excavation bit 25, etc., and the performance is good. can be excavated.

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. 4, and the rake angle α' and clearance angle γ of the cutter 36 correspond to The cutter '55 attached to the outer circumferential surface of the bit body 24
corresponds to the excavation direction indicated by the arrow in Fig. 5, and the rake angle α and relief angle β of the cutter 35 work effectively.
Excavation takes place.

Therefore, even when excavating in this rotational direction, the above-mentioned problem does not occur and the excavation can be performed satisfactorily.

Furthermore, when the swing cylinder 42 is operated to swing the rock excavation bit 23 for excavation, the cutter 35 attached to the bottom and outer peripheral surface of the bit body 24 has a rake angle α and a rake angle The relief angle β and the relief angle γ work effectively at the same time, and excavation is performed. As a result, even in the case of the rocking direction, the above-mentioned problem does not occur and excavation can be performed.

In this example, as a result of experiments, the rake angles α and α' were less than (-) 5 degrees ((-) 6 degrees, (-) 7 degrees).
... etc.), the desired effect cannot be obtained, and (→3o
When it exceeds 0, there is a problem that the strength of the cutting edge is extremely reduced. In addition, both clearance angles β and γ are less than 0-5° ((+
) 4°, (+) 3°, etc.), the desired effect could not be obtained, and when it exceeded (+) 30', there was a problem in that the strength of the cutting edge 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 36 of this embodiment has a reaction force receiver between the cutter body 34 and the shank 35 that protrudes on the side opposite to the rake surface 58b of the cutter blade 68. The receiver is provided with a seat surface 37b, and the reaction force receiver protruding from both sides of the cutter blade 38 is provided with a seat surface 37e.
This embodiment is the same as the first embodiment except that the rigidity against the reaction force during excavation is strengthened.

151, FIGS. 16 and 17 show a sixth embodiment of the cutter of the rock excavation bit of the present invention.

In the cutter 3'5 of this embodiment, (-) rake angles α' and α' are formed in the cutter blade 68. The rake angles α' and α' are set between 0 and (-)5''.

In this example, even if the rake angles α' and α' are ←), the clearance angle β of ←) and the clearance angle γ of ←) cooperate with each other. In addition to excavation in the directions shown and the directions indicated by arrows in FIG. 5, it is also possible to excavate in the directions indicated 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 degrees (←) 6 degrees, ←) 7 degrees.
・・・・・・etc.), the desired effect cannot be obtained, and (-)s
If it exceeds oo, there is a problem that the cutter does not penetrate sufficiently.

The structure 2 of the cutter in this second embodiment is similar to that 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, the cutter blade edge and the cutter attachment are formed between the rake angle formed between the cutter blade edge and a plane parallel to the axial direction of the shank, and the gap between the cutter blade edge and a plane perpendicular to the plane. By attaching multiple cutters to the bit body, each with a clearance angle formed on the top and a clearance angle formed on both sides of the cutter blade, the cutter blade can be pushed forward and excavated even in hard rock. Any of the directions in which the cutter blade is moved parallel to the side surface, the direction in which the cutter blade is rotated in the side direction, and the direction in which the cutter blade is swung have the effect of allowing the cutter blade to be excavated without problems.

[Brief explanation of drawings]

Figures 1 to 6 show a conventional cutter for drilling bits. Figure 1 is a front view, Figure 2 is a side view, Figure 3 is a sectional view taken along the line ■-■ in Figure 1, and Figure 4 is a cross-sectional view taken along the line 5 and 5 are respectively explanatory diagrams showing the excavation directions necessary for this kind of excavation bit, and FIG. 6 is an explanatory diagram showing an example of a pit excavator to which the rock excavation bit of the present invention is applied, and the state in which it is used. 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 show a first embodiment of the cutter of the rock excavation bit of the present invention, and FIG. 8 is a front view. Figure 9 is a side view, Figure 10 is a sectional view taken along the line X-X in Figure 9, Figure 11 is a side view of the installation state, and Figures 12 to 14 are the second side view 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 C-■ in Fig. 16, and Figs. 15 is a front view, FIG. 16 is a side view,
FIG. 17 is a sectional view taken along the line ■--■ in FIG. 16. 23...Rock excavation bit, 24...Bit body, 3
2...Cutter removal block, filter 6...cutter, 34...cutter body, 65...shank, 37g
, 37b, 37c...The reaction force receiver is the seat surface, 38.
...Cutter blade, 68a...Cutter blade tip, 38b...
rake face, α...(+) rake angle, α'...(-
) rake angle, β, γ... relief angle. Patent applicant Taisei Corporation Hitachi Construction Machinery Co., Ltd. Agent Patent attorney Tadashi Akimoto Figure 1 Figure 2 B Figure 3 Figure 6// Figure 7 Figure 10 Figure 11

Claims (1)

[Claims] 1. The cutter blade edge and the cutter attachment are formed by a rake angle formed between the cutter blade edge and a plane parallel to the axial direction of the shank, and between the cutter blade edge and a plane perpendicular to the plane. A rock excavation bit characterized in that a cutter having a relief angle formed therein and relief angles formed on both sides of the cutter blade is attached to a bit body with a plurality of cutters. 2. The rock excavation bit according to claim 1, wherein the rake angle is up to 5 degrees on the (-) side and up to 6 (f) on the (g) side. 3. Each of the reliefs The rock excavation bit according to claim 1, characterized in that the angle is (g) 5° to (g) 30°.