Description
Title of Invention: BIT REPLACING DEVICE FOR EXCAVATING
MACHINE
Technical Field
[0001]
The present invention relates to a device for
replacing an excavating bit in which a roller bit (disk
cutter) abraded by crushing rocks and pebbles during
excavation can be replaced from a workspace provided in a
cutter head of an excavating machine such as a shield
machine.
Background Art
[0002]
As a technique for a bit replacing device which
replaces the abraded roller bit for another roller bit
from the workspace formed in the cutter head during
excavation, for example, Patent Literature 1 and Patent
Literature 2 have been proposed. The bit replacing
devices each include a rotor having an opening and
disposed on the front surface of a cutter spoke. A roller
bit is disposed in the opening of the rotor. When
replacing the roller bit, the rotor is turned by 90° or
18 0° to cause the opening of the rotor to face an opening
for replacement provided on the side surface side or rear
surface side of the opening of the rotor. Thus, the
roller bit is removed out from the opening of the rotor
into the workspace via the opening for replacement.
Citation List
Patent Literatures
[0003]
Patent Literature 1: Japanese Patent No. 3139749
Patent Literature 2: Japanese Patent No. 4163965
Summary of Invention
Technical Problem
[0004]
In the conventional literatures, however, the rotor
is disposed on the front surface of the cutter head
(cutter spoke), and a sliding gap between the rotor and
its supporting member is exposed so as to face the front
surface of the cutter head. Thus, during excavation,
muddy water pressure may be directly applied to the
sliding gap or fragments of pebbles and the like may
enter the gap. Accordingly, a sealing material provided
at the sliding gap may be easily broken to impede the
rotation of the rotor.
[0005]
The present invention has been devised to solve the
above problem. An object of the present invention is to
provide a bit replacing device for an excavating machine
which can improve sealing properties at the sliding gap
of a rotor including a roller bit and replace the roller
bit by smoothly rotating the rotor during excavation.
Solution to Problem
[0006]
In order to solve the problem, the invention of a
first aspect is a bit replacing unit for an excavating
machine, in which the excavating machine includes, in the
front part thereof, a cutter head rotatably supported
about an excavating machine axial center, a roller bit
for crushing rocks and pebbles, the roller bit being
disposed qn the front surface of the cutter head, and a
workspace in which the abraded roller bit can be replaced,
the workspace being formed inside the cutter head,
wherein a housing is disposed in the front part of the
cutter head, a bit containing path is formed in the
housing along an in-and-out axis along which the roller
bit is extended and retracted, a bit containing portion
which opens at the front surface of the cutter head and a
valve containing portion which is formed behind the bit
containing portion are provided on the bit containing
path, an opening for replacement is formed in the
direction of an insertion-and-removal axis at a
predetermined angle with relative to the in-and-out axis
in the housing, the opening for replacement communicating
with the valve containing portion and the workspace, a
rotary valve is provided in the valve containing portion,
the rotary valve being rotatable about a rotary axis
substantially perpendicular to the in-and-out axis and
the insertion-and-removal axis, an attachment/detachment
path communicating with the bit containing portion is
formed in the rotary valve, a bit case containing the
roller bit is removably inserted into the
attachment/detachment path, the rotary valve is turned at
a predetermined angle to cause the attachment/detachment
path to communicate with the opening for replacement, so
that the bit case is movable between the
attachment/detachment path and the workspace, a bit
extending/retracting mechanism for extending and
retracting the bit case between the attachment/detachment
path and the bit containing portion is provided on the
rotary valve, a first sealing material is provided for
sealing at a gap between the bit case and the valve
containing portion, and a second sealing material is
provided for sealing at a gap between the periphery of
the opening of the attachment/detachment path and the
inner surface of the valve containing portion on the
outer peripheral surface of the rotary valve.
[0007]
The invention of a second aspect is the bit replacing
unit for an excavating machine according to the first
aspect wherein a reactive force support block is provided
on the rear surface side of the bit case in the
attachment/detachment path of the rotary valve, the
reactive force support block transferring the excavating
reactive force of the roller bit to the housing, and a
cotter for transferring the excavating reactive force is
removably fitted between the bit case and the reactive
force support block in the valve containing portion.
[0008]
The invention of a third aspect is the bit replacing
unit for an excavating machine according to the first or
second aspect, wherein the bit containing path penetrates
through the cutter head, the attachment/detachment path
penetrates through the rotary valve, the reactive force
support block is removably inserted into the
attachment/detachment path, and the reactive force
support block is removably inserted into the workspace
from the rear opening of the attachment/detachment path
of the rotary valve via the opening for replacement.
[0009]
The invention of a fourth aspect is the bit replacing
unit for an excavating machine according to the third
aspect, wherein a first soil removal path containing the
roller bit penetrates through the bit case in the
direction of the in-and-out axis, a second soil removal
path communicating with the first soil removal path
penetrates through the reactive force support block in
the direction of the in-and-out axis, and soil excavated
by the roller bit can be discharged from the first soil
removal path to the rear surface side of the cutter head
via the second soil removal path.
Advantageous Effects of Invention
[0010]
According to the configuration of the first aspect,
the valve containing portion containing the rotary valve
is formed behind the bit containing portion which opens
at the front surface of the cutter head, and the bit case
including the roller bit is moved from the
attachment/detachment path of the rotary valve so as to
protrude into the bit containing portion. Thus, a sliding
gap between the rotary valve and the valve containing
portion is covered by the bit case and is not exposed to
the front surface of the cutter head. Further, the first
sealing material stops water at a gap between the bit
containing portion and the bit case, and muddy water
pressure is supported by the first sealing material
during excavation. Thus, fragments of pebbles and the
like do not enter the gap between the rotary valve and
the valve containing portion together with muddy water
and muddy water pressure is not directly applied to the
second sealing material during excavation. Hence, the
sliding gap between the rotary valve and the valve
containing portion can be favorably sealed, so that the
rotary valve can be smoothly rotated when replacing the
abraded roller bit.
[0011]
According to the configuration of the second aspect,
the excavating reactive force transferred from the bit
case via the cotter can be supported by the housing via
the reactive force support block on the rear surface side
of the attachment/detachment path. Thus, a large
excavating reactive force can be effectively supported.
[0012]
According to the configuration of the third aspect,
the reactive force support block is first removed from
the attachment/detachment path, and then the bit case is
removed from the attachment/detachment path, so that the
roller bit can be easily replaced. Further, options for
the rotation direction of the rotary valve can be
increased.
[0013]
According to the configuration of the fourth aspect,
soil excavated by the roller bit can be smoothly
discharged from the first soil removal path to the rear
surface side of the cutter head via the second soil
removal path, so that rocks and pebbles can be favorably
crushed.
Brief Description of Drawings
[0014]
[FIG. 1] FIG. 1 is a cross-sectional view of a main
cutter spoke illustrating a first embodiment of a bit
replacing unit according to the present invention.
[FIG. 2] FIG. 2 is a central cross-sectional view of the
bit replacing unit.
[FIG. 3] FIG. 3 is a cross-sectional view taken along the
arrows A-A of FIG. 1.
[FIG. 4] FIG. 4 is an enlarged view of the major part of
FIG. 3.
[FIG. 5] FIG. 5 is a partially cutaway perspective view
of the main cutter spoke illustrating the bit replacing
unit.
[FIG. 6] FIG. 6 is a front view illustrating the bit
replacing unit.
[FIG. 7] FIG. 7 is a cross-sectional view taken along the
arrows B-B of FIG. 1.
[FIG. 8] FIG. 8 is an exploded longitudinal sectional
view illustrating a state in which a bit case and a
reactive force support block are removed from a rotary
valve.
[FIG. 9] FIG. 9 is an exploded perspective view
illustrating the bit case and the reactive force
supporting block.
[FIG. 10] FIG. 10 is a perspective view illustrating
sealing materials.
[FIG. 11] FIG. 11 is a front view illustrating a cutter
head of a shield machine having bit replacing units.
[FIG. 12] FIG. 12 is a central longitudinal sectional
view illustrating the shield machine having the bit
replacing units.
[FIG. 13] FIG. 13 is a central cross-sectional view of
the bit replacing unit illustrating the retraction
position of the bit case in the replacement of a roller
bit.
[FIG. 14] FIG. 14 is a central longitudinal sectional
view of the bit replacing unit illustrating the
retraction position of the bit case in the replacement of
the roller bit.
[FIG. 15] FIG. 15 is a central cross-sectional view of
the bit replacing unit illustrating the replacement
position of the rotary valve in the replacement of the
roller bit.
[FIG. 16] FIG. 16 is a central cross-sectional view of
the bit replacing unit illustrating a state in which the
bit case and the reactive force support block are removed
out in the replacement of the roller bit.
[FIG. 17] FIG. 17 is a central cross-sectional view of
the bit replacing unit illustrating a state in which the
bit case is removed out in the replacement of the roller
bit according to a modified example of the first
embodiment.
[FIG. 18],FIG. 18 is a front view of a main cutter spoke
illustrating the arrangement of bit replacing units
according to a second embodiment of the present invention.
[FIG. 19] FIG. 19 is a longitudinal sectional view of the
main cutter spoke.
[FIG. 20] FIG. 20 is a cross-sectional view taken along
the arrows C-C of FIG. 18.
[FIG. 21A] FIG. 21A is a central longitudinal sectional
view of the bit replacing unit illustrating the
excavation position of a roller bit.
[FIG. 21B] FIG. 21B is a central longitudinal sectional
view of the bit replacing unit illustrating the
retraction position of a bit case.
[FIG. 21C] FIG. 21C is a central longitudinal sectional
view of the bit replacing unit illustrating a state in
which the bit case is removed out.
Description of Embodiments
[0015]
Embodiments of the present invention will be
described.
[First Embodiment]
The following will describe an embodiment of a bit
replacing unit which is a bit replacing device for a
shield machine {excavating, machine) according to the
present invention.
First Embodiment
[0016]
A first embodiment will be described with reference
to FIGS. 1 to 16.
[0017]
[Shield Machine]
As shown in FIG. 12, a pressure bulkhead 12 keeping a
face colluvium pressure is provided in the front part of
a cylindrically-shaped shield body (excavating machine
body) 11, and a rotary ring body 14 is supported by the
pressure bulkhead 12 via a rotary bearing 13 so as to
rotate about shield axial center 0 (excavating machine
axial center). A circular cutter head 16 is supported at
the front ends of a plurality of support legs 15
projecting forward from the rotary ring body 14. An
atmospheric pressure chamber 19 kept at atmospheric
pressure is provided behind the pressure bulkhead 12. A
cutter drive device 17 for rotationally driving the
cutter head 16 is provided in the atmospheric pressure
chamber 19. The cutter drive device 17 includes a ring
gear 17a provided on the backside of the rotary ring body
14, a plurality of drive pinions 17b engaged with the
ring gear 17a, and a plurality of rotation drive devices
(hydraulic or electric motors) 17c for rotationally
driving the drive pinions 17b. A screw conveyor for soil
removal 18 is provided on the pressure bulkhead 12 to
discharge soil excavated by the cutter head 16 from the
front part of the pressure bulkhead 12 toward the
atmospheric pressure chamber 19 while keeping the face
colluvium pressure.
[0018]
As shown in FIG. 11, the cutter head 16 includes a
plurality of main spoke members 21 extended along a
radial direction from a center member 20 disposed on the
shield axial center O, a plurality of sectorial
intermediate face plates 22 disposed between the main
spoke members 21, and an intermediate ring member 23 and
an outer peripheral ring member 24 which are placed in a
circumferential direction centered about the shield axial
center O to connect the main spoke members 21 and the
intermediate face plates 22. Soil inlets 25 for
introducing excavated soil are formed between the members
21 to 24.
[0019]
A plurality of bit replacing units 30 according to
the present invention are arranged on the main spoke
member 21. A roller bit 31 for crushing rocks and pebbles
is provided on each bit replacing unit 30 so as to be
rotatable about an axis in a radial direction of the
shield body 11. The roller bits 31 on all the bit
replacing units 30 are positioned such that the turning
radii from the shield axial center O are different from
each other. Thus, the roller bits 31 can excavate and
crush different turning regions. A center roller bit is
provided on the center member 20, and a plurality of
fixed bits 26 are provided on two sides of each main
spoke member 21.
[0020]
As shown in FIG. 12, a manhole 27 is provided behind
the center member 20 so as to face the atmospheric
pressure chamber 19. The manhole 27 passes through the
pressure bulkhead 12 and communicates with a workspace 2 8
in the main spoke member 21 from the atmospheric pressure
chamber 19, so that an operator can enter and exit the
workspace 28 through the manhole 27.
[0021]
[First embodiment of bit replacing unit]
A first embodiment of the bit replacing unit will be
described with reference to FIGS. 1 to 10 and 13 to 16.
[0022]
As shown in FIG. 1, the main spoke member 21 is a
hollow member with a front surface plate 21F, a rear
surface plate 21B, and left and right side surface plates
21L and 21R. The main spoke member 12 has a substantially
trapezoidal cross-section in which the rear parts of the
left and right sides surface plates 21L and 21R are
inclined inward. The bit replacing unit 30 is disposed at
a predetermined distance from the center of the main
spoke member 21 on one side in the width direction
thereof, and the workspace 28 is formed on the other side
in the width direction of the main spoke member 21, when
the main spoke member 21 is viewed from the front.
[0023]
As shown in FIGS. 2 to 4, the bit replacing unit 3 0
includes a housing 32 connecting a mounting opening 21a
formed on the front surface plate 21F and a duct for soil
removal 21D penetrating through the rear surface plate
21B. A bit containing passage 33, which communicates with
the duct for soil removal 21D, penetrates through the
housing 32 along an in-and-out axis OP parallel to the
shield axial center O and perpendicular to the front
surface of the cutter head 16. On the bit containing
passage 33, there are formed a bit containing portion 34
which opens at the front surface of the main spoke member
21, a cylindrical valve containing portion 35 formed
around the radial axis (an axis of rotation which will be
described later) OR behind the bit containing portion 34,
and a plug containing portion 3 6 formed behind the valve
containing portion 35 with a reactive force support plug
32E fitted and fixed to the plug containing portion 36.
The housing 32 includes an opening for replacement 37
which communicates with the varve containing portion 35
and the workspace 28, the opening for replacement 3 7
being formed along a tangent axis (an insertion-and-
removal axis which will be described later) OE
intersecting with the in-and-out axis OP and the radial
axis Ok extended along the radial direction of the cutter
head 16. A door for replacement 37a is attached to the
opening for replacement 37 via a hinge so as to be
openable and closable.
[0024]
In the present embodiment, the in-and-out axis OP is
parallel to the shield axial center 0. The cutter head on
which the roller bit 31 is provided has a front surface
plate. The outer peripheral side of the front surface
plate may be inclined or curved rearward. Further, the
roller bit is provided so as to extend and retract
substantially perpendicular (for example, 85° to 95°) to
the front surface plate of the cutter head. Alternatively,
the roller bit is provided so as to extend and retract
while being tilted at a predetermined angle of, for
example, about 45° to 85° relative to the front surface
of the cutter head. In such cases, even when the in-and-
out axis OP of the roller bit is positioned substantially
perpendicular to the front surface plate of the cutter
head, the in-and-out axis OP of the roller bit is not
parallel to the shield axial center 0 but tilted at a
predetermined angle relative to the shield axial center 0.
[0025]
Moreover, the opening for replacement 37 is formed in
the direction of the tangent axis OE perpendicularly
intersecting with the in-and-out axis OP and the radial
axis OR. The opening for replacement 37 may be inclined
at a predetermined angle relative to the tangent axis OE,
for example, in a range of 15° forward to 60° rearward,
as long as the roller bit 31 and a reactive force support
block 44 can be extended and retracted/ which will be
described later, and the roller bit 31 and the reactive
force support block 44 can be contained in the space of
the main cutter spoke 21.
[0026]
A cylindrical rotary valve 39 is placed in the valve
containing portion 35 so as to freely rotate about the
radial axis OR. The rotary valve 3 9 includes a
cylindrical outer peripheral plate 39a and an expanding
cylinder 39b which penetrates through the outer
peripheral plate 39a in the diameter direction thereof to
form an attachment/detachment path 38. The
attachment/detachment path 38 has an elliptical cross-
section whose longer diameter is formed along the tangent
axis OE, and has a front surface opening communicated
with the bit containing portion 34. Further, the
attachment/detachment path 3 8 has a larger diameter than
that of a soil removal path 49 of the reactive force
support plug 32E. The rotary valve 39 is rotated to turn
the attachment/detachment path 38 by 90° from a use
position, so that the attachment/detachment path 38 can
be communicated with the opening for replacement 3 7 while
taking up a replacement position along the tangent axis
OE.
[0027]
Furthermore, in the present embodiment, the radial
axis OR as the rotation center of the rotary valve 3 9
perpendicularly intersects with the in-and-out axis OP
and the tangent axis OE. However, the radial axis OR may
intersect with the shield axial center O and the tangent
axis OE at about 90° (for example, 85° to 95°) to rotate
the rotary valve 39.
[0028]
(Bit case and reactive force support block)
As shown in FIG. 8, a bit case 41 containing the
roller bit 31 and the reactive force support block 44 are
removably inserted into the attachment/detachment path 38.
The reactive force support block 44 causes the housing 32
to support excavating reactive force applied from the
roller bit 31 via the bit case 41, from the reactive
force support plug 32E.
[0029]
As shown in FIGS. 7 and 9, the bit case 41 is
cylindrically-shaped to have an elliptical cross-section,
a soil removal path 42 having an elliptical cross-section
penetrates through the bit case 41 along the in-and-out
axis OP, and the roller bit 31 is rotatably supported by
the front part of the soil removal path 42 via an axial
portion 31a parallel to the radial axis OR. A pair of cam
rollers 43 shown in FIG. 4 is detachably provided so as
to protrude at the symmetric positions of the radial axis
OR on the rear part of the bit case 41.
[0030]
The reactive support block 44 includes a block body
45 with a large diameter which is fitted into the
attachment/detachment path 38, and a guide cylinder 4 6
with a small diameter which protrudes from a reactive
force receiving surface 45a on the front surface of the
block body 45 and is slidably fitted into the soil
removal path 42 of the bit case 41. The block body 45 and
the guide cylinder 46 are cylindrically-shaped to have an
elliptical cross-section, and a soil removal path 47
having an elliptical cross-section along the in-and-out
axis OP penetrates through the block body 45 and the
guide cylinder 46. Further, an arc-like reactive force
transmission surface 45b is formed along the outer
peripheral surface of the rotary valve 3 9 on the rear end
surface of the block body 45.
[0031]
-Thus, as shown in FIG. 13, the attachment/detachrr.ent
path 38 in the use position parallel to the shield axial
center O is aligned with the bit containing portion 34,
the bit case 41, the reactive force support block 44, and
the reactive force support plug 32E of the housing 32.
The soil removal path 42, the soil removal path 47, the
soil removal path 49, and the duct for soil removal 21D
linearly communicate with each other. In the replacement
position of FIG. 15 in which the rotary valve 39 is
turned by 90° about the radial axis OR in the arrow
direction of FIG. 13, the bit case 41 and the reactive
force support block 44 are inserted or removed for
replacement between the attachment/detachment path 3 8
communicated with the opening for replacement 37 and the
workspace 2 8.
[0032]
Reference numeral 48 in FIG. 7 denotes a pair of left
and right cotters interposed between the bit case 41
protruding into the bit containing portion 34 and the
reactive force receiving surface 45a of the block body 45.
The cotters 48 are interposed between the rear surface of
the bit case 41 and the reactive force receiving surface
45a of the block body 45 in an excavation position where
the bit case 41 is moved so as to protrude into the bit
containing portion 34 to fix the bit case 41. The cotters
48 are removably fitted into cotter inserting holes 40
which are formed in the direction of the short diameter
of the attachment/detachment path 38. The cotter
inserting holes 40 penetrate through the expanding
cylinder 39b in the direction of the radial axis OR. The
cotters 48 transfer the excavating reactive force of the
roller bit 31 from the bit case 41 to the reactive force
support block 44. Further, the excavating reactive force
is transferred from the reactive force transmission
surface 45b of the reactive force support block 44 to the
reactive force support plug 32E of the housing 32.
[0033]
(Valve rotating mechanism and bit extending/retracting
mechanism)
As shown in FIGS. 1, 5, and 7, the bit replacing unit
30 includes: a valve rotating mechanism 51 provided in
the housing 32 to turn the rotary valve 39 between the
use position and the replacement position; and a bit
extending/retracting mechanism 55 provided on the rotary
valve 3 9 to extend and retract the bit case 41 between an
excavation position and a retraction position in the
attachment/detachment path 38.
[0034]
The valve rotating mecnanism 51 includes: an arc-like
internal gear rack 52 attached to the inner surface of
the outer peripheral plate 3 9a of the rotary valve 3 9
within a predetermined range; a pinion 53 rotatably
supported by the housing 32 via a supporting member and
engaged with the internal gear rack 52; and a valve
rotating handle 54 for rotating the pinion 53 via a
driving mechanism with a wrapping connector 54a composed
of a chain and a sprocket.
[0035]
The bit extending/retracting mechanism 55 includes:
the pair of cam rollers 43 protruding in the symmetric
position of the bit case 41; guide holes 56 formed in an
extending/retracting direction on the expanding cylinder
39b of the rotary valve 39 to guide the bases of the cam
rollers 43; a pair of cam axes 57 for
extension/retraction which is supported on the outer
surface of the expanding cylinder 3 9b so as to freely
rotate about an axis parallel to the in-and-out axis OP
and has cam grooves 57a formed on the outer peripheral
surfaces thereof, the cam grooves 57a being engaged with
the leading ends of the cam rollers 43; and bit
extending/retracting handles 58 for rotating the
extending/retracting cam axes 57 via worm gears 58a,
driving shafts 58b, and driving mechanisms with wrapping
connectors 58c.
[0036]
The bit extending/retracting mechanism 55 may be
composed of a linear drive device such as a feed screw
mechanism, a hydraulic cylinder, or an electric jack.
[0037]
(Seal structure)
As shown in FIGS. 4 and 10, in the bit replacing unit
30, a plurality of sealing materials stop water to
prevent water leakage into the workspace 28.
[0038]
Specifically, a first sealing material 61 is provided
on the outer periphery of the front end of the bit case
41. The first sealing material 61 stops water at a gap
between the inner surface of the bit containing portion
34 of the housing 32 and the outer peripheral surface of
the bit case 41 in an excavation position.
[0039]
Second sealing materials 62A and 62B and third
sealing materials 63A and 63B are provided on the rotary-
valve 39. The second sealing materials 62A and 62B are
provided on the inner circumferential surface of the
valve containing portion 35 so as to surround the opening
surface and the rear opening surface of the valve
containing portion 35 to seal a sliding gap between the
inner circumferential surface of the valve containing
portion 35 and the outer peripheral plate 39a of the
rotary valve 39. The third sealing materials 63A and 63B
are provided over the peripheries around two end surfaces
of the outer peripheral plate 3 9a of the rotary valve 3 9
to seal the sliding gap between the outer peripheral
plate 3 9a.of the rotary valve 3 9 and the inner
circumferential surface or the valve containing portion
35. Further, as shown in FIG. 9, a fourth sealing
material 64 is attached over the outer peripheral surface
of the block body 45 in the reactive force support block
44 to seal a gap between the reactive force support block
44 and the attachment/detachment path 38. A fifth sealing
material 65 is attached over the outer periphery of the
front end of the guide cylinder 4 6 to seal a gap between
the guide cylinder 46 in the reactive force support block
44 and the soil removal path 42.
[0040]
Thus, when the bit case 41 is located at an
excavation position, muddy water and pebbles with a small
diameter, which are about to flow into the gap between
the rotary valve 39 and the valve containing portion 35,
are prevented by the first sealing material 61 from
flowing into the bit containing portion 34. Moreover, the
second sealing materials 62A and 62B and the third
sealing materials 63A and 63B prevent water leakage into
the workspace 28.
[0041]
In the retraction position of the bit case 41, the
first sealing material 61 seals a gap between the inner
surface of the attachment/detachment path 3 8 and the bit
case 41. The second sealing materials 62A and 62B and the
third sealing materials 63A and 63B prevent water leakage
from the gap between the rotary valve 3 9 and the valve
containing portion 35 into the workspace 28. Even when
the rotary valve 39 is turned by 90° from the use
position to the replacement position, the second sealing
materials 62A and 62B, the third sealing materials 63A
and 63B, the fourth sealing material 64, and the fifth
sealing material 65 prevent water leakage into the
workspace 28.
[0042]
(Replacement of roller bit)
The procedure for replacing the roller bit 31 in the
above configuration will be described.
[0043]
1) When the abraded roller bit 31 is replaced at an
excavation position where the bit case 41 is contained in
the bit containing portion 34, the cutter head 16 is
stopped at a predetermined position, operators enter the
workspace 28 in the main spoke member 21 from the manhole
27 to replace the roller bit 31.
[0044]
2) After the pair of cotters 48 is removed from the
cotter inserting holes 40, the bit extending/retracting
handle 58 is operated to rotate the extending/retracting
cam axis 57, so that the bit case 41 is retracted from
the excavation position to the retraction position of the
attachment/detachment path 38 via the cam rollers 43.
[0045]
3) The valve rotating handle 54 is operated to turn
the rotary valve 39 by 90° from the use position to the
replacement position, thereby causing the rear opening of
the attachment/detachment path 3 8 to face the opening for
replacement 3 7.
[0046]
4) The door for replacement 37a is opened, and an
operating tool such as a jack is used to draw out the
reactive force support block 44 in the direction of the
tangent axis OE from the attachment/detachment path 3 8 to
the workspace 28 via the opening for replacement 37. Next,
the bit case 41 is retracted to the rear opening side,
the cam rollers 43 are detached from the bit case 41 and
removed from the guide holes 5 6, and then the bit case 41
is drawn out from the attachment/detachment path 3 8 to
the workspace 28 through the opening for replacement 37.
[0047]
5) The bit case 41 with another roller bit 31 mounted
thereon is inserted into the attachment/detachment path
3 8 from the opening for replacement 37, the cam rollers
43 are attached to the bit case 41 and pushed into the
inner side of the attachment/detachment path 38, and the
cam rollers 43 are fitted into the guide holes 56 and
engaged with the cam grooves 57a of the
extending/retracting cam axes 57. Further, the reactive
force support block 44 is fitted from the workspace 28
into the attachment/detachment path 3 8 via the opening
for replacement 37.
[0048]
6) After the door for replacement 37a is closed, the
valve rotating handle 54 is operated to turn the rotary
valve 39 by 9C° from the replacement position to the use
position to align the front opening of the
attachment/detachment path 38 with the bit containing
portion 34.
[00< 9]
7) The bit extending/retracting handle 58 is operated
to rotate the extending/retracting cam axes 57, the bit
case 41 is moved from the retraction position of the
attachment/detachment path 3 8 in the direction of the in-
and-out axis OP via the cam rollers 43 so as to protrude
into the bit containing portion 34, and stops at the
excavation position. Further, the cotters 48 are inserted
from the cotter inserting holes 40 and fitted between the
rear surface of the bit case 41 and the reactive force
receiving surface 45a of the reactive force support block
44 to fix the bit case 41.
[00501
According to the first embodiment, the bit case 41
contained in the attachment/detachment path 3 8 of the
rotary valve 3 9 is moved so as to protrude into the bit
containing portion 34 which opens at the front surface of
the main cutter spoke 21, and is fixed to excavate soil.
Thus, the sliding gap of the rotary valve 39 in the valve
containing portion 35 is closed by the bit case 41, is
not exposed to the front surface of the main cutter spoke
21, and is not directly subjected to the muddy water
pressure of an excavated portion.
[0051]
The first sealing material 61 surrounding the bit
case 41 and the second sealing material 62A surrounding
the front opening of the valve containing portion 3 5
favorably stop water at the sliding gaps. Thus, muddy
water pressure is not directly applied to the sliding gap
of the rotary valve 39 and fragments do not flow into the
sliding gap. This enables the sliding gap between the
rotary valve 39 and the valve containing portion 35 to be
favorably sealed, thereby increasing sealing properties.
Hence, the rotary valve 3 9 can be smoothly rotated.
[0052]
The excavating reactive force transferred from the
bit case 41 to the rear surface of the
attachment/detachment path 38 via the cotters 48 can be
supported by the reactive force support plug 32E of the
housing 32 via the reactive force support block 44. Thus,
a large excavating reactive force applied to the roller
bit 31 can be effectively supported.
[0053]
The reactive force support block 44 is removed from
the attachment/detachment path 38 and the bit case 41 is
then removed from the attachment/detachment path 38, so
that the roller bit 31 can be easily replaced.
[0054]
Soil excavated by the roller bit 31 can be smoothly
discharged from the soil removal path 42 to the duct for
soil removal 21D via the soil removal path 47 and the
soil removal path 49, so that rocks and pebbles can be
favorably crushed.
[0055]
[Modified example of first embodiment]
FIG. 17 shows that the rotary valve 3 9 is turned by
90° in an opposite direction to the turning direction of
the rotary valve 39 in the first example. Only the bit
case 41 can be first removed. The cam rollers 43 obstruct
the replacement of the bit case 41. However, this problem
can be solved by detaching the cam rollers 43 after the
extending/retracting cam axes 57 of the bit
extending/retracting mechanism 55 are detached. In this
modified example, the reactive force support block 44 can
be fixed to the rotary valve 39 or the reactive support
block 44 and the rotary valve 39 can be integrated.
[0056]
According to the modified example of the first
embodiment, in addition to the effects of the first
embodiment, the roller bit 31 can be further easily-
replaced only by removing the bit case 41.
[0057]
[Second Embodiment]
A second embodiment of the bit replacing unit will be
described with reference to FIGS. 18 to 20. The same
members as those in the first embodiment are indicated by
the same reference numerals, and an explanation thereof
is omitted.
[0058]
Bit replacing units 70 are disposed on left and right
sides of a main cutter spoke 21, and a rotary valve 75
contained in a housing 71 is rotated about a tangent axis
(rotary axis) OE to replace a roller bit 31 from above or
below.
[0059]
As shown in FIG. 18, for shifting the excavation
position and keeping a workspace 28 inside the main
cutter spoke 21, the bit replacing units 70 are disposed
at interval L in the direction of a radial axis
(insertion-and-removal axis) OR and at interval W in the
direction of the tangent axis OE, and when the main
cutter spoke 21 is viewed from the front, the roller bits
31 on the left and right are displaced in the radial
direction in a zigzag pattern.
[0060]
As shown in FIGS. 20 and 21, a bit containing portion
34 and a valve containing portion 35 are formed, in this
order from the front surface of the housing 71, on a bit
containing path 33 penetrating through the housing 71. A
reactive force support portion 72 is formed integrally
with the housing 71 on the rear surface side of the valve
containing portion 35. A soil removal path 73 is formed
on the axial center portion of the reactive force support
potion 72. A reactive force receiving portion 76 is
integrally formed on the rear surface side of an
attachment/detachment path 38 of the rotary valve 75 to
prevent a reactive force support block 44 from being
removed. A communicating soil removal path 77 is formed
on the axial center portion of the reactive force
receiving portion 76. Thus, an excavating reactive force
applied to the roller bit 31 can be entirely supported by
the rotary valve 75 via the bit case 41, the reactive
force support block 44, and the reactive force receiving
portion 76. Moreover, the excavating reactive force can
be supported by the housing 71 from the rotary valve 75
via the reactive force support portion 72.
[0061]
An opening for replacement 76 having an
opening/closing door 76a is formed on one side in the
direction of the radial axis OR (on the outer peripheral
surface) [or on the other side (on the surface on the
shield axial center o side)] of the housing 71.
[0062]
As shown in FIG. 19, the bit replacing unit 70
includes a valve rotating mechanism 51 for rotating the
rotary valve 75 about the tangent axis OE and a bit
extending/retracting mechanism 54 for extending and
retracting the roller bit 31 between an excavation
position and a retraction position, the valve rotating
mechanism 51 and the bit extending/retracting mechanism
54 having the same structures as those in the first
embodiment.
[0063]
In the above configuration, as shown in FIGS. 21A to
21C, the bit extending/retracting mechanism 54 retracts
the rotary valve 75 from the bit containing portion 34 in
the excavation position into the attachment/detachment
path 38 in the retraction position. The valve rotating
mechanism 51 rotates the rotary valve 75 by 90° about the
tangent axis OE, thereby causing the front surface of the
attachment/detachment path 3 8 to face the opening for
replacement 76. Thus, as in the modified example of the
first embodiment, the bit case 41 can be removed out from
the opening for replacement 76 into the workspace 28.
[0064]
According to the second embodiment, the same effects
as the first embodiment and the modified example can be
produced. Further, multiple bit replacing units 70 can be
disposed on the main cutter spoke 21, which is preferable
to a large excavating machine.
We Claim:
[Claim 1]
A bit replacing unit for an excavating machine, in
which the excavating machine includes, in a front part
thereof, a cutter head rotatably supported about an
excavating machine axial center, a roller bit for
crushing rocks and pebbles, the roller bit being disposed
on a front surface of the cutter head, and a workspace in
which the. abraded roller bit can be replaced, the
workspace being formed inside the cutter head, wherein
a housing is disposed in a front part of the cutter
head,
a bit containing path is formed in the housing along
an in-and-out axis along which the roller bit is extended
and retracted,
a bit containing portion which opens at the front
surface of the cutter head and a valve containing portion
which is formed behind the bit containing portion are
provided on the bit containing path,
an opening for replacement is formed in a direction
of an insertion-and-removal axis at a predetermined angle
with relative to the in-and-out axis in the housing, the
opening for replacement communicating with the valve
containing portion and the workspace,
a rotary valve is provided in the valve containing
portion, the rotary valve being rotatable about a rotary
axis substantially perpendicular to the in-and-out axis
and the insertion-and-removal axis,
an attachment/detachment path communicating with the
bit containing portion is formed in the rotary valve,
a bit case containing the roller bit is removably
inserted into the attachment/detachment path,
the rotary valve is turned at a predetermined angle
to cause the attachment/detachment path to communicate
with the opening for replacement, so that the bit case is
movable between the attachment/detachment path and the
workspace,
a bit extending/retracting mechanism for extending
and retracting the bit case between the
attachment/detachment path and the bit containing portion
is provided on the rotary valve,
a first sealing material is provided for sealing at a
gap between the bit case and the valve containing portion,
and
a second sealing material is provided for sealing at
a gap between a periphery of an opening of the
attachment/detachment path and an inner surface of the
valve containing portion on an outer peripheral surface
of the rotary valve.
[Claim 2]
The bit replacing unit for an excavating machine
according to claim 1, wherein
a reactive force support block is provided on a rear
surface side of the bit case in the attachment/detachment
path of the rotary valve, the reactive force support
block transferring an excavating reactive force of the
roller bit to the housing, and
a cotter for transferring the excavating reactive
force is removably fitted between the bit case and the
reactive force support block in the valve containing
portion.
[Claim 3]
The bit replacing unit for an excavating machine
according to claim 1 or 2, wherein
the bit containing path penetrates through the cutter
head,
the attachment/detachment path penetrates through the
rotary valve,
the reactive force support block is removably
inserted into the attachment/detachment path, and
the reactive force support block is removably
inserted into the workspace from a rear opening of the
attachment/detachment path of the rotary valve via the
opening for replacement.
[Claim 4]
The bit replacing unit for an excavating machine
according to claim 3, wherein
a first soil removal path containing the roller bit
penetrates through the bit case in a direction of the in-
and-out axis,
a second soil removal path communicating with the
first soil removal path penetrates through the reactive
force support block in the direction of the in-and-out
axis, and
soil excavated by the roller bit can be discharged
from the first soil removal path to a rear surface side
of the cutter head via the second soil removal path.

ABSTRACT

A valve containing portion (35) is formed behind a
bit containing portion (34) which opens at the front
surface of a main cutter spoke (21). A rotary valve (39)
is rotatably disposed in the valve containing portion
(35). A bit case (41) containing a roller bit (31) is
moved so as to protrude from an attachment/detachment
path (39) formed in a rotary valve (38) into the bit
containing portion (34), and is fixed by a cotter (38) to
support an excavating reactive force. Thus, the sliding
gap of the rotary valve (39) is disposed in the bit
containing portion (34) and the valve containing portion
(35) to be covered with the bit case (41).