JPH11117222A - Excavating end mill and excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavating end mill and excavator in which a bending force is not applied to the end mill, and also unnecessary vibration is not caused, in the excavator by which excavating work is carried out by the end mill equipped at the end of the arm of a hydraulic work machine. SOLUTION: An end mill 10 fitted to the end of the arm of a hydraulic work machine body is made up of a connecting shaft 11 to be connected to the motor shaft of a hydraulic motor, a shaft part 12A extended from the connecting shaft 11, and a taper part 12B on the end side of the shaft part 12A. Then, a drilling bit 13 is provided on the end surface of the taper part 12, and also the diameter of the shaft part 12A is made to be smaller than that of the taper part 12B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavating end mill for excavating a pavement surface or the like on a road or the like and an improvement of an excavating apparatus.

[0002]

2. Description of the Related Art In the construction of roads and the burial of water and sewage pipes, power pipes, communication pipes, gas pipes, etc., it is sometimes necessary to dig the already paved ground. An excavator used in such construction is proposed in, for example, Japanese Patent Application No. 8-258896 filed by the present applicant.

FIGS. 10 and 11 show this excavator.

[0004] As shown in the figure, in this excavator, a hydraulic motor 3 is detachably mounted on a holder 5 at the tip of an arm 2 of a hydraulic working machine body 1 such as a power shovel. Then, an end mill 104 for excavating and cutting the pavement surface is coaxially attached to the motor shaft 3A of the hydraulic motor 3.

[0005] The arm 2 is an arm 2 connected to each other.
A, 2B, a plurality of hydraulic cylinders 6A, 6
B and 6C bend at an arbitrary angle by the expansion and contraction operation. The hydraulic motor 3 is fixed to the holder 5 by bolts or the like fastened to the flange portion 3B, and is operated together with the hydraulic cylinders 6A, 6B, 6C and the like from a hydraulic source (not shown) provided in the hydraulic working machine body 1. Upon receiving the supply of oil, the end mill 104 is driven to rotate. The supply of hydraulic oil to the hydraulic motor 3 is controlled by a control valve (not shown).

[0006] The end mill 104 has a motor shaft 3A.
The end mill main body 107 is provided below a coupling shaft portion (not shown) that fits into the end mill main body 107. And this end mill body 10
7 have two types of drill bits 1
21A and 121B, and the outer peripheral side surface (cutting surface) 112 are provided with cutting bits 122 each forming a bit train.

With such a configuration, when excavating (piercing) a pavement surface, the end mill 104 is set vertically on the pavement surface on which the excavation operation is to be performed by operating the arm 2, and the end mill 104 is rotated in the vertical direction as it is. When pushed in, the digging hole can be dug by the digging bits 121A and 121B. When the end mill 104 is held vertically and moved parallel to the pavement surface by operating the arm 2, the pavement surface can be cut or cut with a predetermined depth and width by the cutting bit 122 of the cutting surface 112. .

[0008]

However, in the excavating operation using such an excavating apparatus, it is difficult to continuously send out the end mill 104 by operating the arm 2 in a direction completely perpendicular to the pavement surface. For this reason, in this excavator, as shown in FIG. 12, the end mill 104 is inclined with respect to the excavated hole 100 dug substantially vertically, and the outer peripheral side surface 112 of the end mill main body 107 and the cutting bit 122 are inclined. Contacts the inner circumference near the upper end of the.

As a result, torque is applied to the rotation of the end mill 104 to generate torque loss, and a bending force is applied to the end mill main body 107 to cause the end mill 104 to rotate.
Will be damaged earlier.

The cutting bit 1 is provided on the outer peripheral side surface 112.
Since the 22 bit trains are intermittently provided along the outer circumferential direction, the end mill 104 is liable to generate vibrations due to the rotation of the end mill 104 due to the unevenness of the outer circumferential side surface 112 due to the bit trains. This may cause the operability to deteriorate.

On the other hand, as an excavating apparatus and a cutting tool provided with a feeding mechanism for feeding an excavating tool linearly at a constant angle with respect to a pavement surface so as to prevent such an inclination of the excavating tool, for example, FIG. 13 and FIG. 14 are known.

[0013] Of these, the one shown in Fig. 13 is provided in a concrete crusher 130, and has a cutting tool 1 at the tip end surface.
The rotary drilling machine 132 with the
Fixed to The holding bracket 133 is fed straight inside the machine body 136 along the rotating screw shaft 135 by the rotation of the rotating screw shaft 135 by operating the handle 134. As a result, the rotary drilling machine 132 keeps feeding a straight line at a constant angle with respect to the pavement surface.
However, in such an excavator, the rotary drill 1
A complicated feed mechanism including the holding bracket 133 for sending out the screw 32, the rotary screw shaft 135, and the like is required, and the simplicity and the high degree of freedom as in the above-described arm-operated excavator cannot be obtained.

Further, as shown in FIG. 14, there is also known a drilling device having a so-called core drill 140 having an annular drilling tool 142 at the tip of a cylindrical drill body 141. However, this excavator also requires a feed mechanism (not shown). Further, after the excavation work, excavation debris 101 (shown in a lattice pattern in the figure) corresponding to the hollow portion of the core drill 140 remains inside the excavation hole 100, and it is necessary to remove the excavation debris, which lowers the work efficiency. .

The present invention has been made in view of such a problem, and in a drilling apparatus for performing a drilling operation by an end mill provided at an end of an arm of a hydraulic working machine, a bending force is not applied to the end mill. It is another object of the present invention to provide a digging end mill and a digging apparatus in which unnecessary vibration is not generated in the end mill.

[0015]

According to a first aspect of the present invention, an end mill for digging having a digging bit on a distal end surface while being connected to a driving means at a connecting shaft portion on a base end side and driven to rotate about a central axis. In the above, the diameter of the shaft portion between the coupling shaft portion and the distal end surface is smaller than the diameter of the distal end surface.

In the second invention, at least one cutting bit array is provided on the outer peripheral side surface of the shaft portion.
The height of the cutting bit row was set sufficiently low so that it did not protrude outside the outer periphery of the end face with respect to the axis of the end mill.

In a third aspect, at least one of the cutting bits is provided in parallel with the central axis.

In the fourth aspect, at least one of the cutting bits is provided in a spiral shape around the central axis.

According to a fifth aspect of the present invention, there is provided a discharge passage which is open to the front end face, is inclined at a predetermined angle with respect to the central axis, and opens to a side surface of the shaft portion.

In a sixth aspect of the present invention, the discharge passage opens on the central axis in a gap surrounded by the excavation bit, and the diameter of the discharge passage is larger than the diameter of the gap.

In the seventh invention, the excavating bit has a vertex for positioning on the central axis.

According to an eighth aspect of the present invention, in a drilling end mill having a drilling bit on a distal end surface thereof, the coupling shaft portion and the distal end surface are connected to a driving means at a proximal end side coupling shaft portion and driven to rotate. A part of the shaft portion in the axial direction between them was a joint made of a flexible material.

In the ninth aspect, the hydraulic working machine main body driven hydraulically, an arm provided on the hydraulic working machine main body,
A hydraulic motor removably mounted on a holder of the arm; and a means for supplying a hydraulic pressure from a hydraulic source of a hydraulic working machine main body to the hydraulic motor, and any one of the first to eighth inventions. Two excavating end mills are driven to rotate using the hydraulic motor as the driving means.

[0024]

According to the first aspect of the present invention, the end mill for excavation is driven to rotate by the driving means and excavates the excavation surface with the excavation bit provided on the tip end surface. Since the diameter is smaller than the tip surface provided, there is sufficient room between the outer circumference of the shaft and the inner circumference of the excavated hole, and the center axis of the end mill for excavation is slightly Even if it is tilted, the shaft does not contact the end of the borehole or the inner circumference.

Accordingly, the rotation of the end mill for excavation does not receive any resistance due to the contact with the excavation hole, and no torcross occurs. Further, the bending force is not applied to the excavation end mill due to the contact with the excavation hole, and the durability of the excavation end mill is improved. Also,
The drilling end mill does not vibrate due to contact with the drilling hole.

In the second to fourth inventions, the cutting bit row provided on the outer periphery of the shaft portion has a sufficiently low height, so that even if the excavating end mill is slightly inclined, it does not come into contact with the inner periphery of the excavating hole. However, while not providing support for excavation work, when the inclination angle of the end mill becomes larger than the margin between the outer periphery of the shaft portion and the inner periphery of the excavation hole, the cutting bit row cuts the inner periphery of the excavation hole, and the shaft portion has No excessive force is applied.

Further, if the cutting bit array is provided spirally as in the fourth invention, the cutting bits are continuously arranged in the outer circumferential direction of the end mill for excavation. Contact is not intermittent and no significant vibrations occur in the drilling end mill. Further, since the cutting chips can be ejected upward by the spiral cutting bit array, the discharge property of the cutting chips is improved.

According to the fifth and sixth aspects of the present invention, as the excavation proceeds, the excavation waste is sent into the discharge passage, hits the inner peripheral surface of the discharge passage, is finely pulverized, and is discharged from the opening on the side surface of the shaft portion. Further, the excavated chips are further finely pulverized by a cutting bit array provided on the shaft portion, and then discharged to the outside of the excavated hole. Therefore, according to the present invention, the excavation waste is efficiently discharged, and the work efficiency of the excavation work is improved.

Further, when the diameter of the discharge passage is made larger than the diameter of the gap as in the sixth invention, the dischargeability of excavated chips can be further improved.

In the seventh aspect, at the start of the excavation operation, the excavation end mill is reliably positioned in the horizontal direction with respect to the excavation surface by the vertex. As a result, the reaction force received from the pavement surface at the start of drilling with the drill bit
The end mill does not shift from side to side, and the working efficiency is significantly improved.

According to the eighth aspect of the present invention, since a part of the shaft of the excavating end mill is a flexible joint, even if the end mill is tilted due to an operation error or the like, the load applied to the end mill is absorbed by the joint. Thus, damage to the shaft portion, the drill bit, the cutting bit and the like can be prevented.
Further, since the shaft portion of the end mill bends at the joint to absorb this inclination, the portion of the end mill ahead of the joint can face the excavation direction straight, and the excavation work can be continued as it is. Further, vibration generated in the end mill during the excavation work is absorbed by the joint and is not transmitted to other components of the excavator, so that the operability of the excavator is improved.

According to the ninth aspect, since the excavating end mill can be operated by the arm of the hydraulic working machine, the end mill can be controlled in any posture and direction, and excavating work with a high degree of freedom can be performed. It is difficult to keep the end mill straight in the direction of excavation. However, in the present invention, since the end mill for excavation of the first to seventh inventions is used, even if the end mill is inclined with respect to the excavation direction, the shaft portion of the end mill comes into contact with the excavation hole. Never. Therefore, the rotation of the excavation end mill does not receive any resistance due to the contact with the excavation hole, and no torque loss occurs.
Further, the bending force is not applied to the excavation end mill due to the contact with the excavation hole, and the durability of the excavation end mill is improved. Moreover, the end mill for excavation does not vibrate due to contact with the excavation hole.

[0033]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In each of the following embodiments, the entire configuration of the excavator is the same as that shown in FIG. 10, for example. Therefore, the following description focuses on the configuration of the end mill that is a feature of the present invention.

1 to 3 show an end mill 10 according to a first embodiment of the present invention.

As shown in the figure, the substantially cylindrical end mill 10 has a connecting shaft 11 on the base end side, and extends integrally from the connecting shaft 11 so that a bit as a cutting tool for excavation or cutting is formed. An end mill main body 12 is provided. The end mill 10 is integrally connected to a motor shaft 3A of the hydraulic motor 3 by a fastening means such as a spline or a screw at a connecting shaft portion 11, so that the rotation of the motor shaft 3A is transmitted to the end mill 10.

The end mill body 12 has a small outer diameter shaft portion 12A extending integrally from the coupling shaft portion 11 side.
The end mill 10 includes a tapered portion 12B which expands in a tapered shape from the shaft portion 12A. The end face of the end mill 10 is an end face perpendicular to the end mill axis of the tapered portion 12B, and a plurality of excavation bits 13 are attached to the end face.

As shown in FIG. 2, the drill bits 13 have a substantially sectorial cross section, and are separated by a discharge groove 14 extending in the radial direction of the end face of the end mill. The excavation bit 13 is not limited to such a bit having a fan-shaped cross section, and a bit having an arbitrary shape can be appropriately used.

Further, on the outer peripheral side surface of the shaft portion 12A,
A plurality of cutting bit arrays 1 extending in the axial direction of the end mill 10
5 are provided. These cutting bit arrays 15 are formed by fixing a plurality of cutting bits made of a high-hardness material such as diamond particles and cemented metal particles to the outer periphery of the shaft portion 12A by means such as welding.

The height of the cutting bit row 15 is sufficiently low.
The end mill should be located inside (outer end of the end mill) than the outer circumference of the end face. 1 and 2, the detailed illustration of each of these cutting bits is omitted, and the cutting bit train 1
Only the outer shape (arrangement position) of No. 5 is shown.

Next, the operation will be described.

When excavating a pavement surface, first, the arm 2 is operated by extending and retracting the hydraulic cylinders 6A, 6B and 6C, and the end mill 10 is moved to a predetermined excavation site. Subsequently, the end mill 10 is set vertically on the pavement surface, rotated by the hydraulic motor 3 and pushed in the vertical direction as it is, so that the excavation work is performed by the excavation bit 13.

As described above, the excavation hole 100 is dug with the substantially vertical direction as the excavation direction. However, as shown in FIG. 4, the end mill 10 may be inclined with respect to the vertical direction during this excavation operation. .

However, in the present invention, the end mill body 1
Most of the entire length of the end mill 2
Since the shaft portion 12A has an outer diameter smaller than the outer diameter of the shaft portion 12A, there is a sufficient margin between the outer periphery of the shaft portion 12A and the inner periphery of the excavation hole 100. Therefore, even if the end mill 10 is slightly inclined, the shaft portion 12 </ b> A does not come into contact with the inner periphery on the upper end side of the excavation hole 100.

Therefore, no resistance is applied to the rotation of the end mill 10, and no torque loss occurs. Further, the end mill body 12 is not subjected to a bending force, and the end mill 10 has improved durability. Further, the end mill 10 does not vibrate due to intermittent contact with the excavation hole 100.

Since the cutting bit array 15 on the outer periphery of the shaft portion 12A has a sufficiently low height, even if the end mill 10 is slightly inclined, it does not come into contact with the inner periphery of the excavation hole 100. On the other hand, when the inclination angle of the end mill 10 has become larger than the margin between the outer periphery of the shaft portion 12A and the inner periphery of the excavation hole 100, the cutting bit train 15
However, since the inner periphery of the excavation hole 100 is cut, an excessive force is not applied to the shaft portion 12A.

FIG. 5 shows a second embodiment of the present invention.

In this embodiment, in addition to the basic structure of the first embodiment, there is provided a discharge passage 16 for discharging cutting chips. From the discharge passage 16, the uncut portion left in the gap portion 17 on the central axis of the end mill 10 surrounded by the plurality of excavation bits 13 is discharged.

More specifically, the discharge passage 16
Extends above the gap portion 17 at a predetermined angle θ with respect to the axis of the end mill 10, penetrates the side surface of the shaft portion 12 </ b> A, and opens widely. As a result, the uncut portion left in the middle gap 17 of the drill bit 13 is
As the excavation proceeds, it reaches the discharge passage 16. And it crushes finely on the inner peripheral surface of the discharge passage 16,
It is discharged from the opening on the side surface of the shaft portion 12A so as to be pushed out by the lower uncut portion. The drilling waste discharged in this way is further finely ground by a cutting bit array 15 provided on the shaft portion 12A,
It is discharged out of 0. The diameter φB of the discharge passage 16
Is larger than the diameter φA of the gap portion 17, it is possible to further enhance the dischargeability of excavation debris.

As described above, in the present embodiment, the uncut portion left between the excavation bits 13 is automatically discharged from the discharge passage 16, so that the operation of removing the uncut portion becomes unnecessary, and the excavation work is performed. Efficiency is increased.

FIG. 6 shows a third embodiment of the present invention.

As shown, in this embodiment,
The cutting bit train 15 in the basic configuration of the first or second embodiment is replaced with a spiral cutting bit train 18.

By arranging the cutting bit array 18 in a spiral shape in this way, even if the cutting bit array 18
00, even if it comes into contact with the inner peripheral surface, since the cutting bits constituting the cutting bit row 18 are continuously present on the outer periphery of the shaft portion 12A, this contact is not intermittent and may cause the end mill 10 to vibrate. There is no.

Also, as shown in FIG.
If the side surface of the cutting bit row 18 in the direction of rotation of the cutting bit 18 is directed obliquely upward, the cutting chips are repelled upward by the cutting bit row 18 with the rotation of the end mill 10, so that the discharge property of the cutting chips is enhanced.

The number of cutting bit strings 18 need not be one as in this embodiment, but may be a plurality of cutting bit strings 18.
May be provided to further enhance the cutting property and the discharge property of the cutting chips.

FIGS. 7 and 8 show a fourth embodiment of the present invention.

As shown, in this embodiment,
In the basic configuration of the first embodiment, a plurality of digging bits 13 are replaced with a plurality of digging bits 20.

These excavating bits 20 are disposed along the radial direction of the end face of the end mill 10 (the end face of the tapered portion 12B) with the sharp edge of the triangular cross-section blade facing downward. In this embodiment, the number of the excavating bits 20 is four, and they are arranged at an interval of 90 degrees from each other.

Further, these drill bits 20 are inclined at a predetermined angle toward the central axis of the end mill 10 to form a cone as a whole, and form a vertex 21 on the central axis of the end mill 10. . Thereby, the end mill 1
0, end mill 1 at vertex 21
Zero positioning can be performed. That is, when the contact between the excavation bit and the excavation surface is a surface contact, the end mill 10 is easily shifted left and right at the start of excavation. Since the point contact is made at 21, the end mill 10 can be positioned easily and reliably, and the working efficiency is significantly improved.

In this embodiment, the tapered portion 12
A discharge groove 22 extending in a direction along the axis of the end mill 10 is formed on the outer peripheral side surface of the B so as to be alternate with the arrangement of the drill bit 20, thereby improving the discharge property of the cutting waste. .

Further, as described above, in the present embodiment, the drill bits 20 having a triangular cross section are arranged at intervals of 90 degrees, but the present invention is not limited to such an embodiment. Alternatively, a shape other than a triangular cross section may be used as the blade shape of the drill bit 20, and the interval between the drill bits 20 may be an angle other than 90 degrees.

FIG. 9 shows a fifth embodiment of the present invention.

As shown in the figure, in the end mill 30 of this embodiment, a part of an end mill body 31 made of a rigid body in the axial direction is connected to a joint 32 made of a material having flexibility (elasticity) such as rubber. Has become. The end mill 30 is attached to the motor shaft 3A of the hydraulic motor 3 at the coupling shaft portion 34 on the base end side, as in the above embodiments.

With such a configuration, the hydraulic working machine body 1
When the end mill 30 is tilted due to an operation error or the like when the end mill 30 is operated by the arm 2, even if a large load is likely to be applied to the end mill 30,
Since this load is absorbed by the joint 32, the end mill body 31 and the drill bit 33 at the end of the end mill 30 are removed.
Also, it is possible to prevent breakage of a cutting bit row (not shown) disposed on the outer peripheral surface of the end mill main body 31.

Even when the motor shaft 3A is inclined with respect to the excavation direction, the end mill 30 bends at the joint 32 to absorb this inclination. And continue straight along the drill hole,
Excavation work can be continued as it is.

Further, the vibration generated in the end mill 30 during the excavation operation is absorbed by the joint 32 and is not transmitted to other components of the excavation device.
It does not decrease due to the vibration of the end mill 30.

[Brief description of the drawings]

FIG. 1 is an external view showing an end mill according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a development view of a shaft portion.

FIG. 4 is an explanatory view showing the operation of the present invention.

FIG. 5 is a sectional view showing an end mill according to a second embodiment of the present invention.

FIG. 6 is a developed view of a shaft portion according to a third embodiment of the present invention.

FIG. 7 is a side view showing an end mill according to a fourth embodiment of the present invention.

FIG. 8 is a bottom view of the same.

FIG. 9 is a partial sectional view showing an end mill according to a fifth embodiment of the present invention.

FIG. 10 is a side view showing the entire configuration of the excavator.

FIG. 11 is a side view showing a state in which a conventional end mill is mounted on a hydraulic motor.

FIG. 12 is an explanatory diagram showing a problem of a conventional example.

FIG. 13 is a sectional view showing a conventional excavator.

FIG. 14 is a sectional view showing a conventional excavator.

FIG. 15 is an explanatory diagram showing a problem of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic working machine main body 2 Arm 3 Hydraulic motor 3A Motor shaft 10 End mill 11 Coupling shaft part 12 End mill main body 12A Shaft part 12B Taper part 13 Drilling bit 14 Drain groove 15 Cutting bit row 16 Drain passage 17 Gap part 18 Cutting bit row 20 Drilling bit 21 Apex 22 discharge groove 30 end mill 31 end mill body 32 joint 33 drill bit 34 coupling shaft part 100 drill hole

Continuing on the front page (72) Inventor Hideaki Shinohara 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Jun Kushituma 2-4-2 Hamamatsucho, Minato-ku, Tokyo No. 1 Inside the World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Masami Ochiai 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Shuji Ohira 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.

Claims (9)

[Claims] 1. A drilling end mill having a drill bit on a distal end surface, wherein the coupling shaft portion and the distal end surface are coupled with driving means at a proximal end coupling shaft portion and driven to rotate around a central axis. A diameter of a shaft portion between the end mill and the end portion is smaller than a diameter of the tip end surface. 2. An at least one outer peripheral side surface of the shaft portion.
2. The end mill for excavation according to claim 1, further comprising: a plurality of cutting bit arrays, wherein a height of the cutting bit arrays is sufficiently lower than an outer periphery of the tip end face so as not to protrude outside the axis of the end mill. . 3. The end mill for excavation according to claim 2, wherein at least one of the cutting bits is provided in parallel with the central axis. 4. The excavating end mill according to claim 2, wherein at least one of the cutting bits is provided spirally around the central axis. 5. A discharge passage which is open to the front end surface, is inclined at a predetermined angle with respect to the central axis, and is open to a side surface of the shaft portion.
The end mill for excavation according to any one of claims 1 to 4. 6. The discharge passage opens on a gap surrounded by the drill bit on the central axis, and the diameter of the discharge passage is larger than the diameter of the gap. 5. The end mill for excavation according to 5. 7. The end mill for excavation according to claim 1, wherein the excavation bit has a vertex for positioning on the central axis. 8. A digging end mill having a digging bit on a tip end surface thereof, the shaft being connected to a driving means at a base end side connection shaft portion, wherein the shaft between the connection shaft portion and the tip end surface is provided. An end mill for drilling, characterized in that a part of the portion in the axial direction is a joint made of a flexible material. 9. A hydraulic working machine main body driven hydraulically, an arm provided on the hydraulic working machine main body, a hydraulic motor detachably mounted on a holder of the arm, and a hydraulic source of the hydraulic working machine main body. Means for supplying the hydraulic pressure to the hydraulic motor, and the excavating end mill according to any one of claims 1 to 8 is rotationally driven using the hydraulic motor as the driving means. Drilling rig.