Technical Field
[0001] The present invention relates to a step tube rod and a boring machine using the step
tube rod as a drill rod.
Background Art
[0002] A boring machine such as a hydraulic crawler drill and a fan cut drill is provided
with a rock drill mounted on a. guide shell. A drill rod is insertedly mounted in
the rock drill, and a bit is installed at the tip end of the drill rod. Thereby, a
blow and rotation are transmitted from the rock drill to the bit via the drill rod,
and the rock drill is fed, whereby a rock-bed is bored.
[0003] For example, in the case where the boring machine is a hydraulic crawler drill 11
as shown in Figure 8, a boom 14 is provided on a carriage 13 provided with a track
frame 12 so as to be turnable and tiltable. At the distal end of the boom 14 is supported
a guide shell 16 mounted with a rock drill 15 so as to be capable of tilting and swinging.
The rock drill 15 is insertedly mounted with a drill rod 1 connected by a sleeve 2,
and at the tip end of the drill rod 1 is installed a bit 3 having an outside diameter
approximately equal to a bore diameter Dh.
[0004] The rock drill 15 has a blowing mechanism, a rotating mechanism, and a flushing mechanism
(not shown). The rock drill 15 is moved longitudinally by a feed force given by a
feed motor 17 provided on the guide shell 16, and transmits a blow and rotation to
the bit 3 via the drill rod 1, whereby a rock-bed R is bored. Also, the flushing mechanism
supplies compressed air to the tip end of the drill rod 1 to discharge cuttings. In
the tip end portion of the guide shell 16, a hood 18 is provided to cover the bore
and to collect cuttings.
[0005] In the case where the bore length is great, a plurality of drill rods 1 are connected
successively at the time of boring work. The supply and connection of the drill rods
1 and the separation and recovery of the drill rods 1 after the boring work is finished
are carried out mechanically by using a rod changer 19.
[0006] In the case where the connection and recovery of the drill rod 1 are carried out,
the drill rod 1 must be clamped so that the central axis of the drill rod 1 is fixed
when the drill rod 1 is connected or separated, so that a rod clamping device 4 is
provided in the vicinity of the tip end portion of the guide shell 16.
[0007] The general drill rod 1 used for the above-described hydraulic crawler drill 11 has
a hexagonal or circular external shape and has a predetermined size of 51 mm, 45 mm,
38 mm, etc. in outside diameter according to the size of connecting screw (T51 screw,
T45 screw, T38 screw, etc.). This outside diameter is considerably smaller than the
bore diameter Dh.
[0008] The drill rod 1 is available in two types: an MM rod 1A provided with external threads
MS at both ends as shown in Figure 9(a), and an MF rod 1B which is provided with external
threads MS at one end and the other end of which has a larger diameter and is provided
with internal threads FS on the inside as shown in Figure 9(b). When the MM rod 1A
is used, it is connected via a sleeve 2, and when the MF rod 1B is used, the external
threads MS and the internal threads FS are engaged directly with each other.
[0009] As shown in Figures 10 and 11, the rod clamping device 4 is constructed so that the
drill rod 1 having a particular diameter is clamped by a pair of clamps 5 pivotally
supported by pins 6 so as to be capable of being opened and closed. On the internal
surface of the clamp 5, a large-diameter portion 5L and a small-diameter portion 5S
are formed. When the MM rod 1A is used, the large-diameter portion 5L holds a portion
of the sleeve 2, and when the MF rod 1B is used, the large-diameter portion 5L holds
an internally threaded portion 1BL having a larger diameter.
[0010] This rod clamping device 4 not only clamps the sleeve 2 so as to prevent the rotation
of the sleeve 2, but also easily positions the drill rod 1 by a diameter difference
between the large-diameter portion 5L and the small-diameter portion 5S of the clamp
5.
[0011] Also, for a fan cut drill, a down-the-hole drill, and the like, a tube rod 1C as
shown in Figure 9 (c) has been devised and used. This tube rod 1C is provided with
external threads MS at one end and internal threads FS at the other end, and has a
larger outside diameter than the MM rod 1A and the MF rod 1B, and the outside diameter
of the tube rod 1C is approximately equal to the bore diameter. Therefore, a bore
bend at the time when a long hole is bored is reduced, and the cuttings discharge
efficiency can be improved.
[0012] When such a tube rod 1C is used, a rod clamping device 40 as shown in Figures 12
and 13 is provided for the fan cut drill, and a double clamp type rod clamping device
50 as shown in Figures 14 and 15 is provided for the down-the-hole drill.
[0013] The rod clamping device 40 shown in Figures 12 and 13 is constructed so that the
drill rod 1 having a particular diameter is clamped by a pair of clamps 45 pivotally
supported by pins 46 so as to be capable of being opened and closed. The inside diameter
of the clamp 45 is constant, and there is formed no diameter difference.
[0014] The rod clamping device 50 shown in Figures 14 and 15 is constructed so that clamps
55 are opened and closed by right and left clamping cylinders 56, by which the drill
rod 1 having a particular diameter is clamped. The inside diameter of the clamp 55
is constant, and there is formed no diameter difference.
[0015] If the tube rod 1C is used as the drill rod 1 to reduce a bore bend, since a rod
clamping device of a type such that the clamp 45, 55 has no diameter difference as
in the rod clamping device 40 shown in Figure 12 and the rod clamping device 50 shown
in Figure 14 is used, the positioning of the drill rod 1 is unstable, so that the
work time increases significantly, and also danger in the connection and recovery
work for drill rod increases.
[0016] Further, for the hydraulic crawler drill 11, if the tube rod 1C is used as the drill
rod 1, the rod clamping device 4 shown in Figure 10 cannot be used as it is, and the
function of the generally mounted rod changer 19 cannot be fulfilled.
[0017] The present invention has been made to solve the above problems with a boring machine,
and accordingly an object thereof is to provide a step tube rod which can reduce a
bore bend and in which the conventional rod clamping device and rod changer can be
used as they are, and the positioning of drill rod is easy to perform, so that connection
and recovery work can be performed efficiently and safely, and a boring machine using
this step tube rod.
Disclosure of Invention
[0018] A step tube rod in accordance with the present invention is constructed so that in
a drill rod for a boring machine, a rod outside diameter is large so as to be approximately
equal to a bore diameter, external threads are provided at one end and internal threads
are provided at the other end, and at least one small-diameter portion is formed near
an internally threaded portion.
[0019] The step tube rod may also be constructed so that a rod outside diameter is large
so as to be approximately equal to a bore diameter, external threads are provided
at both ends so that the rods are connected via a sleeve, and at least one small-diameter
portion is formed near an externally threaded portion.
[0020] The above-described step tube rod can reduce a bore bend at the time of boring because
the outside diameter thereof is large so as to be approximately equal to the bore
diameter.
[0021] Also, the small-diameter portion is formed near the internally threaded portion for
the step tube rod provided with the external threads at one end and the internal threads
at the other end or near the externally threaded portion for the step tube rod provided
with the external threads at both ends and connected via the sleeve. Therefore, for
the boring machine, the step tube rod can be used as a drill rod merely by slightly
modifying the conventional rod clamping device.
[0022] For the boring machine using the step tube rod as a drill rod, the drill rod can
be positioned easily, so that the connection and recovery work can be performed efficiently
and safely.
[0023] Feigned striking for loosening a screw of the connected step tube rod is performed
after the completion of boring. However, when screw loosening is insufficient, feigned
striking is performed in a state in which the step tube rod is fixed to the rod clamping
device.
[0024] Therefore, for the step tube rodprovidedwith the external threads at one end and
the internal threads at the other end, it is preferable that the small-diameter portion
has an outside diameter which is 90% or less of the rod outside diameter and has a
length which is 50% or more of the rod outside diameter.
[0025] Also, for the step tube rod provided with the external threads at both ends and connected
via the sleeve, it is preferable that the small-diameter portion has an outside diameter
which is 90% or less of the sleeve outside diameter and has a length which is 50%
or more of the sleeve outside diameter.
[0026] For the boring machine, in addition to the case where the step tube rod is used for
all drill rods, the step tube rod may be used only for the tip-end drill rod. Even
in the case where the step tube rod is used only for the tip-end drill rod, a bore
bend at the time of boring can be reduced as compared with the case where the conventional
drill rod is used.
Brief Description of Drawings
[0027]
Figure 1 is a side view of a hydraulic crawler drill using a step tube rod in accordance
with the present invention as a drill rod;
Figure 2 is a construction view of a step tube rod in accordance with one embodiment
of the present invention;
Figure 3 is an explanatory view showing a state in which a step tube rod is guided
by a rod guide;
Figure 4 is an explanatory view showing a state in which a step tube rod is clamped
by a rod clamping device;
Figure 5 is a construction view of a step tube rod in accordance with another embodiment
of the present invention;
Figure 6 is an explanatory view showing a state in which a step tube rod is clamped
by a rod clamping device;
Figure 7 is a construction view of a step tube rod in accordance with other embodiments
of the present invention;
Figure 8 is a side view of a hydraulic crawler drill using a conventional drill rod;
Figure 9 is a construction view of conventional drill rods;
Figure 10 is a construction view of a rod clamping device for a conventional hydraulic
crawler drill;
Figure 11 is an explanatory view showing a state in which a conventional drill rod
is clamped by a rod clamping device;
Figure 12 is a construction view of a rod clamping device for a conventional fan cut
drill;
Figure 13 is a sectional view taken along the line A-A of Figure 12;
Figure 14 is a construction view of a rod clamping device for a conventional down-the-hole
drill; and
Figure 15 is a sectional view taken along the line B-B of Figure 14.
Best Mode for Carrying out the Invention
[0028] Figure 1 is a side view of a hydraulic crawler drill using a step tube rod in accordance
with the present invention as a drill rod, Figure 2 is a construction view of a step
tube rod in accordance with one embodiment of the present invention, Figure 3 is an
explanatory view showing a state in which the step tube rod is guided by a rod guide,
and Figure 4 is an explanatory view showing a state in which the step tube rod is
clamped by a rod clamping device.
[0029] The construction of a hydraulic crawler drill 10 shown in Figure 1 is basically the
same as that of the conventional hydraulic crawler drill 11 shown in Figure 8. Therefore,
description is given by applying the same reference numeral to the same element.
[0030] In this hydraulic crawler drill 10 as well, a boom 14 is provided on a carriage 13
provided with a track frame 12 so as to be turnable and tiltable. At the distal end
of the boom 14 is supported a guide shell 16 mounted with a rock drill 15 so as to
be capable of tilting and swinging. The rock drill 15 is insertedly mounted with a
connected step tube rod 7 as a drill rod, and at the tip end of the step tube rod
7 is installed a bit 3 having an outside diameter approximately equal to a bore diameter
Dh.
[0031] The rock drill 15 has a blowing mechanism, a rotating mechanism, and a flushing mechanism
(not shown). The rock drill 15 is moved longitudinally by a feed force given by a
feed motor 17 provided on the guide shell 16, and transmits a blow and rotation to
the bit 3 via the step tube rod 7, whereby a rock-bed R is bored. Also, the flushing
mechanism supplies compressed air to the tip end of the step tube rod 7 to discharge
cuttings. In the tip end portion of the guide shell 16, a hood 18 is provided to cover
the bore and to collect cuttings.
[0032] In the case where the bore length is great, a plurality of step tube rods 7 are connected
successively at the time of boring work. The supply and connection of the step tube
rods 7 and the separation and recovery of the step tube rods 7 after the boringwork
is finished are carriedoutmechanically by using a rod changer 19.
[0033] In the case where the connection and recovery of the step tube rod 7 are carried
out, the step tube rod 7 must be clamped so that the central axis of the step tube
rod 7 is fixed when the step tube rod 7 is connected or separated, so that a rod clamping
device 4 is provided in the vicinity of the tip end portion of the guide shell 16.
[0034] Also, in front of the rod clamping device 4, there is provided a rod guide 9 which
holds the step tube rod 7 in the center to guide it when clamping by the rod clamping
device 4 is released and boring is performed.
[0035] The step tube rod 7 has a large rod outside diameter D that is approximately equal
to the bore diameter Dh, and is provided with external threads MS at one end and internal
threads FS at the other end. The step tube rods 7 are connected by directly engaging
the external threads MS with the internal threads FS. Also, a small-diameter portion
8 is formed near an internally threaded portion.
[0036] The small-diameter portion 8 is formed so that the outside diameter d thereof is
90% or less of the rod outside diameter D and the length L thereof is 50% or more
of the rod outside diameter D, that is,

and

[0037] When boring is performed, as shown in Figure 3, the step tube rod 7 is guided by
the rod guide 9 and is held in the center of the guide shell 16.
[0038] At the time of connection and recovery work, as shown in Figure 4, the step tube
rod 7 is clamped by the rod clamping device 4 provided on the guide shell 16 of the
hydraulic crawler drill 10.
[0039] The rod clamping device 4 is provided with a pair of clamps 5 pivotally supported
by pins 6 so as to be capable of being opened and closed. On the internal surface
of the clamp 5, a large-diameter portion 5L and a small-diameter portion 5S are formed,
and the large-diameter portion 5L holds the internally threaded portion of the step
tube rod 7.
[0040] Therefore, the step tube rod 7 is clamped by the rod clamping device 4 so as to be
prevented from rotating, and is positioned by a diameter difference between the large-diameter
portion 5L and the small-diameter portion 5S of the clamp 5.
[0041] Since the step tube rod 7 has the large outside diameter D approximately equal to
the bore diameter Dh, a bore bend occurring at the time of boring is reduced. Also,
since the small-diameter portion 8 is formed at the outer periphery near the internally
threaded portion, for the hydraulic crawler drill 10, the step tube rod 7 can be used
as a drill rod merely by slightly modifying the conventional rod clamping device.
[0042] For the hydraulic crawler drill 10 using the step tube rod 7 as a drill rod, the
step tube rod 7 can be positioned easily, so that the connection and recovery work
can be performed efficiently and safely.
[0043] Since the outside diameter d of the small-diameter portion 8 is 90% or less of the
rod outside diameter D and the length L thereof is 50% or more of the rod outside
diameter D, when screw loosening is insufficient, feigned striking can be performed
without trouble in a state in which the step tube rod 7 is fixed to the rod clamping
device 4.
[0044] Figure 5 is a construction view of a step tube rod in accordance with another embodiment
of the present invention, and Figure 6 is an explanatory view showing a state in which
the step tube rod is clamped by a rod clamping device.
[0045] This step tube rod 7 has a large rod outside diameter D that is approximately equal
to the bore diameter Dh, and is provided with external threads MS at both ends. The
step tube rods 7 are connected via a sleeve 2 provided with internal threads FS on
the inside. The outside diameter Ds of the sleeve 2 is equal to the rod outside diameter
D.
[0046] Also, a small-diameter portion 8 is formed near an externally threaded portion. The
small-diameter portion 8 is formed so that the outside diameter d thereof is 90% or
less of the sleeve outside diameter Ds and the length L thereof is 50% or more of
the sleeve outside diameter Ds, that is,

and

[0047] The step tube rod 7 can be formed into shapes shown in Figures 7(a) and 7(b).
[0048] At the time of connection and recovery work, as shown in Figure 6, the step tube
rod 7 is clamped by a rod clamping device 4 provided on a guide shell 16 of the hydraulic
crawler drill 10.
[0049] The rod clamping device 4 is providedwith a pair of clamps 5 pivotally supported
by pins 6 so as to be capable of being opened and closed. On the internal surface
of the clamp 5, a large-diameter portion 5L and a small-diameter portion 5S are formed,
and the large-diameter portion 5L holds a portion of the sleeve 2.
[0050] Therefore, the step tube rod 7 and the sleeve 2 are clamped by the rod clamping device
4 so as to be prevented from rotating, and are positioned by a diameter difference
between the large-diameter portion 5L and the small-diameter portion 5S of the clamp
5.
[0051] Since the step tube rod 7 has the large outside diameter D approximately equal to
the bore diameter Dh, a bore bend occurring at the time of boring is reduced. Also,
since the small-diameter portion 8 is formed near an externally threaded portion,
for the hydraulic crawler drill 10, the step tube rod 7 can be used as a drill rod
merely by slightly modifying the conventional rod clamping device.
[0052] For the hydraulic crawler drill 10 using the step tube rod 7 as a drill rod, the
step tube rod 7 can be positioned easily, so that the connection and recovery work
can be performed efficiently and safely.
[0053] Since the outsidediameterdof the small-diameterportion 8 is 90% or less of the sleeve
outside diameter Ds and the length L thereof is 50% or more of the sleeve outside
diameter Ds, when screw loosening is insufficient, feigned striking can be performed
without trouble in a state in which the step tube rod 7 is fixed to the rod clamping
device 4.
[0054] For the hydraulic crawler drill 10, in addition to the case where the step tube rod
7 is used for all drill rods, the step tube rod 7 may be used only for the tip-end
drill rod. Even in the case where the step tube rod 7 is used only for the tip-end
drill rod, a bore bend at the time of boring can be reduced as compared with the case
where the conventional drill rod 1 is used.
Industrial Applicability
[0055] As described above, for the step tube rod in accordance with the present invention,
a bore bend at the time of boring can be reduced. Also, the small-diameter portion
is formed near the internally threaded portion for the step tube rod provided with
the external threads at one end and the internal threads at the other end or near
the externally threaded portion for the step tube rod provided with the external threads
at both ends and connected via the sleeve. Therefore, for this boring machine, the
step tube rod can be used as a drill rod merely by slightly modifying the conventional
rod clamping device.
[0056] For the boring machine using the step tube rod as a drill rod, the drill rod can
be positioned easily, so that the connection and recovery work can be performed efficiently
and safely.