Patent Application
20100236831
The present invention relates to an excavation tool used for excavating the ground and/or soil; in works, for example, various anchor constructions, various well drilling constructions, and/or various foundation constructions.
Generally, as excavation tools which excavate a ground, the ground, and/or soil, a so-called diameter-enlarged type excavation tool (for example, refer to Patent Document 1) is provided.
This tool includes a device which rotates on a central axis and a bit head, namely, bit wing, rotatable on a rotational axis eccentric from the central axis.
Also, this tool has a structure in which the bit head protrudes radially outward when the device is rotating in one direction, and the bit head retracts radially inward when the device is rotating in the other direction.
Specifically, an attaching hole which is open into the tip face of the device and extends parallel to the central axis, is bored in a position eccentric from the central axis.
A pin hole; which is open into the outer peripheral surface of the device, and passes through a part of the inner peripheral surface of the attaching hole; is formed in the attaching hole. A locking pin is embedded in the pin hole.
The bit head includes
The attaching shaft of the bit head is inserted into the attaching hole of the device, and also the locking pin is inserted into the pin hole from the outer peripheral surface of the device. Thus, the locking pin and the groove of the attaching shaft are engaged with each other.
Therefore, the bit head is retained at the tip of the rotational axis.
Additionally, the bit head has a structure; in which, when the bottom surface in the groove and the outer peripheral surface of the locking pin slide along each other, this sliding movement can make the bit head rotate on the axis of the attaching hole (and attaching shaft) as its rotational axis.
In such an excavation tool, when excavation is performed, the device is rotated in one direction (forward direction). This rotation generates a force of friction among the device, the bit head, an object to be excavated (a mountain, the ground, etc.) and/or a casing top, namely, casing shoe. Also, the force of friction makes the bit head protrude radially outward, and then an excavated hole can be formed.
After the formation of the excavated hole has been completed, the device is rotated in the other direction (backward direction). This rotation generates a force of friction with the object to be excavated and/or a casing top. Also, the force of friction makes the bit head retract radially inward, and then the excavation tool can be withdrawn through the excavated hole.
If the locking pin comes off during an excavation work, the bit head may detach from the device and may remain inside the excavated hole; and then the excavating work will be suspended or stopped. Or a further excavation work is required to be performed again. Accordingly, it is necessary to provide a retaining means so that the locking pin does not come off from the device. As such a retaining means for the locking pin, for example, the use of an elastic member has been suggested as disclosed in Patent Documents 2 to 4.
[Patent Document 1] Japanese Unexamined Patent Application No. H05-065787
[Patent Document 2] Japanese Unexamined Patent Application No. H06-074222
[Patent Document 3] Japanese Unexamined Patent Application No. H08-295268
[Patent Document 4] Japanese Unexamined Patent Application No. H08-295269
Meanwhile, in a case where the retaining means disclosed in Patent Documents 2 to 4 is adapted for the locking pin provided in the aforementioned excavation tool, since the locking pin presses the elastic member to elastically deform the elastic member due to an impact or repulsion during excavation, there is a possibility that the locking pin may not be firmly fixed.
Additionally, if the attaching shaft of the bit head and the locking pin come into contact with each other when the bit head has been rotated on the rotational axis, there is a problem in that the locking pin is pushed out in the insertion/removal direction.
The invention was made in view of the aforementioned situation, and the object thereof is to provide an excavation tool which can firmly fix a locking pin so that the locking pin does not move even in the case of an impact during excavation and/or the locking pin being pushed out in the insertion/removal direction.
In order to solve such a problem and achieve the above object,
an excavation tool of the invention includes
In the excavation tool of this construction, the fixing member which is made of a rigid body, and abuts on the end face of the locking pin to fix the locking pin; is embedded in the opening of the pin hole formed in the tool body. Thus, it is possible to firmly fix the locking pin without a large elastic deformation of the fixing member caused by an impact or the like during excavation.
Additionally, since the locking portion which locks and fixes the fixing member in the extension direction of the pin hole (the insertion/removal direction of the locking pin) is provided, the locking pin is prevented from moving in the insertion/removal direction of the locking pin, so that the coming-off of the locking pin can be reliably prevented.
Here, an auxiliary member, which maintains an engagement state between the fixing member and the locking portion, may be embedded in the tool body.
In this case, since the engagement state between the fixing member and the locking portion is maintained by the auxiliary member, the fixing member can be prevented from coming out of the locking portion due to an impact or the like during excavation, and the coming-off of the locking pin can be reliably prevented.
Additionally, the auxiliary member may be made of an elastic material.
In this case, the engagement state between the fixing member and the locking portion can be maintained by using the elastic force of the elastic material, and the moving of the fixing member can be prevented. In addition, since the locking pin does not directly contact with the auxiliary member made of the elastic material, the locking pin can be firmly fixed without any elastic deformation of the auxiliary member caused by the pressing force from the locking pin.
Moreover, the tool body: wherein
a sliding groove, along which
Additionally,
the tool body may be used as a device which is rotatable on a central axis, and
the attaching hole may be formed so as to be open into the tip of the device.
The attaching member may be used as a bit head having a bit excavating portion to which a tip made of a hard material is fixed, the attaching shaft may be integrally connected to the bit excavating portion.
The outer peripheral surface of the attaching shaft may be provided with a groove which crosses the extension direction of the attaching shaft and also extends in a peripheral direction.
According to the invention; an excavation tool, which can firmly fix the locking pin so that the locking pin does not move, can be provided; even in the case of an impact during excavation and/or the locking pin being pushed out in the insertion/removal direction.
An excavation tool that is a first embodiment of the invention will be described below in reference to the accompanying drawings.
The excavation tool 10, as shown in
The casing top 11
The device 20 has
Additionally, a fluid supply passage 24 which; extends along the center axis O, goes to the device body 21, and is open into the rear end face of the small diameter portion 23; is provided inside the device 20.
A connecting passage 25, which extends towards a direction (radially outward) perpendicular to the center axis O, is connected to a tip portion of the fluid supply passage 24. Also, a communicating hole 26; which extends parallel to the center axis O from the connecting passage 25, and is open into the bottom surface of the attaching hole 32 which will be described later; is provided. The attaching hole 32 which will be described later.
Moreover, a fluid discharge hole 27, which gradually goes radially outward in the direction of the tip, is connected to the tip portion of the fluid supply passage 24.
The tip face of the device body 21 is provided with a housing recess 30, which is concave radially inward and toward the rear end.
In this embodiment,
Thereby the portion of the tip face of the device body 21 except the housing recess 30, is substantially H-shaped in the view from the tip face, and protrudes towards the tip.
A plurality of tips 15 made of a hard material, such as cemented carbide, is implanted in the substantially H-shaped portion, and is used as a device excavating portion 29 which excavates an object to be excavated.
Specifically, the device excavating portion 29 includes
Additionally, an inclined surface portion 31 is formed at a forward portion in a rotational direction R1 on the inner surface facing to the tip of the housing recess 30. The inclined surface portion 31 gradually retracts radially outward in the direction of the rear end. The aforementioned fluid discharge hole 27 is open into the inclined surface portion 31.
Additionally, as shown in
Two attaching holes 32 are formed respectively at backward portions in the rotational direction R1 on the inner surface facing to the tip of the housing recess 30. The attaching holes 32 are eccentric from the central axis O, and also are point-symmetrical with respect to the central axis O as shown in
Additionally, a pin hole 33; which
One end (lower side in
A loading recess 35; which is open into the outer peripheral surface of the device body 21, and has a circular shape in a cross sectional view; is formed at the rear end of the sliding groove 34 in the direction of the central axis O. A ring-shaped groove 36 is formed between the bottom portion and inner peripheral surface of the loading recess 35.
Additionally, the tip of the loading recess 35 in the direction of the central axis O is provided with a locking groove 37 which extends with a width smaller than the diameter of the loading recess 35.
In this embodiment, as shown in
An opening of the pin hole 33 is embedded in the tip of the sliding groove 34 in the central axis O.
Next, the bit head 40 will be described.
As shown in
The attaching shaft 45 has a structure of fitting into the attaching hole 32 which is open into the tip face of the device 20; and also the axis of the attaching shaft 45 is same as the rotational axes P1 and/or P2.
A groove 46; which is perpendicular to the axis (the rotational axes P1 and/or P2), and extends along the peripheral surface of the attaching shaft 45; is formed at the attaching shaft 45.
In this embodiment, as shown in
In addition, the groove 46 is formed on the side opposite to the side where the tapered portion 43 and the tier portion 44 of the bit excavating portion 41 are provided, as a view from the direction of the axis (the rotational axes P1 and/or P2) of the attaching shaft 45.
Next, a fixing member 50 embedded in the sliding groove 34, and an auxiliary member 53 will be described. As shown in
The auxiliary member 53, as shown in
Next, a method of connecting the bit head 40 and the device 20 will be described in reference to
First, the attaching shaft 45 of the bit head 40 is inserted into the attaching hole 32 which is open into the tip face of the device 20.
At this time, the bit head 40 is arranged that the portion of the pin hole 33 and the groove 46 face each other. The pin hole 33 passes through a portion of the attaching hole 32, and the groove 46 is formed in the outer peripheral surface of the attaching shaft 45.
In this state, inserting the cylindrical locking pin 56 into the pin hole 33 which is open into the sliding groove 34 (
The fixing member 50 is loaded into the sliding groove 34 from the loading recess 35 of the sliding groove 34 so that the flange portion 51 faces radially inward. Then the fixing member 50 is slidingly moved into the locking groove 37 (
Then, the auxiliary member 53, which is elastically deformable, is press-fitted into the loading recess 35 (
At this time, the claw 54 provided in the auxiliary member 53 is engaged with the ring-shaped groove 36 formed in the inner peripheral surface of the loading recess 35; whereby the auxiliary member 53 is fixed.
Additionally, since the outer peripheral surface of the auxiliary member 53 presses the outer peripheral surface of the fixing member 50, this pressure prevents the fixing member 50 from moving within the sliding groove 34.
In this way, the device 20 and the bit head 40 are connected with each other. Since the groove 46 formed in the outer peripheral surface of the attaching shaft 45 is locked to the locking pin 56, the bit head 40 is retained at the tip in the direction of the rotational axes P1 and/or P2.
In the excavation tool 10 constructed in this way;
rotating the device 20 in the rotational direction RI shown in
On the other hand,
when rotating the device 20 in the rotational direction R2 shown in
The excavation tool 10 is driven by a striking device provided in an excavation machine (not shown); and then a rotary force, a striking power, and a thrust are transmitted to the excavation tool 10.
Whereby the device excavating portion 29 and the bit head 40, which are formed at the tip of the excavation tool 10, will break and excavate an object to be excavated, such as a base rock.
In this excavation operation, the fluid supply passage 24 supplies a fluid, such as air, to break an object to be excavated; and then the excavation debris generated in this operation is discharged towards the rear end of the excavation tool 10 via the cutout groove 28.
When an excavation is in operation, the rotation of the device 20 in the rotational direction R1 makes the bit head 40 protrude radially outward, and then a large-diameter excavated hole is bored.
Further, a thrust is transmitted to the casing top 11 to bury the casing pipe 13.
After the excavation of boring an excavated hole has been completed, the rotation of the device 20 in the rotational direction R2 makes the bit head 40 retract into the housing recess 30. Thus, the excavation tool 10 becomes smaller than the internal diameter of the casing pipe 13.
By pulling out the excavation tool 10 in this state, the excavation tool 10 is withdrawn through the inside of the buried casing pipe 13.
In the excavation tool 10 that is the present embodiment, the fixing member 50 made of a rigid body, such as steel, is embedded in the opening of the pin hole 33 into which the locking pin 56 is inserted. The locking pin 56 locks the device 20 and the bit head 40. Thus, it is possible to firmly fix the locking pin 56 without a large elastic deformation of the fixing member 50 caused by an impact or the like during excavation.
Additionally, the locking groove 37, which locks and fixes the fixing member 50 in the extension direction of the pin hole 33 (the insertion direction of the locking pin 56), is provided to prevent the locking pin 56 from moving in the extension direction of the pin hole 33 (the insertion direction of the locking pin 56). Therefore, the coming-off of the locking pin 56 can be reliably prevented.
Additionally, the auxiliary member 53, which maintains the engagement state between the fixing member 50 and the locking groove 37, is embedded therein.
While an excavation is in operation, this auxiliary member 53 can prevent an accident, in which the fixing member 50 comes off the locking groove 37, caused by an impact or the like during excavation. Thus the coming-off of the locking pin 56 can be reliably prevented.
Additionally, the auxiliary member 53 made of an elastic material can maintain the engagement state between the fixing member 50 and the locking groove 37 by using the elastic force of the elastic material; and then the positional deviation of the fixing member 50 can be prevented.
In addition, since the locking pin 56 does not directly contact with the auxiliary member 53 made of the elastic material, the locking pin 56 can be firmly fixed without any elastic deformation of the auxiliary member 53 caused by the pressing force from the locking pin 56.
The sliding groove 34, along which the fixing member 50 slidingly moves, is formed on the outer peripheral surface of the device 20. The loading recess 35 for loading the fixing member 50 into the sliding groove 34 is formed at the rear end of the sliding groove 34. The locking groove 37 is formed at the tip of the loading recess 35.
Thus, inserting the fixing member 50 along the sliding groove 34 from the loading recess 35, and also moving slidingly the fixing member 50; the fixing member 50 is embedded in the opening of the pin hole 33, and can be locked and fixed there by the locking groove 37.
Therefore, the fixing member 50 can be embedded by a simple operation of firmly fixing the locking pin 56.
Next, an excavation tool that is a second embodiment of the invention will be described. The excavation tool that is the second embodiment of the invention is shown in
Additionally, an inclined surface portion 131 is formed at a forward portion in a rotational direction R1 on the inner surface facing to the tip of the housing recess 130. The inclined surface portion 131 gradually retracts radially outward in the direction of the rear end. A fluid discharge hole 127 is open into the inclined surface portion 131. A cutout groove 128 is formed on a side surface of the device 120 which is integrally connected to a radial outer end of the inclined surface portion 131. The cutout groove 128 retreats into one step radially inward, and also extends parallel to the central axis O. Moreover, in this embodiment, a fluid supply passage 124, which extends to a portion nearer to the tip than the bottom surface of an attaching hole 132 described later, is provided. The fluid discharge hole 127; which is connected to a fluid supply passage 124, and is open into the inclined surface portion 131; is provided.
Three attaching holes 132 are formed respectively at backward portions in the rotational direction R1 on the inner surface facing to the tip of the housing recess 130. The attaching holes 132 are eccentric from the central axis O, and also are point-symmetrical with respect to the central axis O as shown in
Pin holes 133; which
The bit head 140 mounted on the attaching hole 132 includes, as shown in
The attaching shafts 145 of the bit heads 140 are respectively inserted into the three attaching holes 132 which are open into the tip face of the device 120.
Also, three cylindrical locking pins 156 are respectively inserted into the three pin holes 133 which are open into the sliding grooves 134.
A fixing member 150 is loaded into the sliding groove 134 from the loading recess 135 of the sliding groove 134 so that a flange portion 151 faces radially inward. Then the fixing member 150 is slidingly moved along a locking groove 137.
The fixing member 150 abuts on the end face of the locking pin 156, and the flange portion 151 is engaged with the locking groove 137.
Then, the auxiliary member 153, which is elastically deformable, is press-fitted into the loading recess 135. Thus, the fixing member 150 is fixed so as not to move within the sliding groove 134.
In the excavation tool 110 constructed in this way;
rotating the device 120 in the rotational direction R1 shown in
On the other hand,
rotating the device 120 in the rotational direction R2 shown in
In the excavation tool 110 that is the embodiment constructed in this way, three bit heads 140 are provided for excavation. Thus, for example, even if a large-diameter excavated hole is excavated, a large number of the tips 115 provided in the radial outer portion enable the tool to perform the excavation efficiently.
The fluid supply hole 127 extends to the tip of the device body 121. Thus, supplying a fluid, such as air, to the inside of an excavated hole through the fluid supply hole 127 helps to discharge the excavation debris; and then the excavation operation can be smoothly performed.
Although the excavation tool that is the embodiment of the invention has been described hitherto, the invention is not limited thereto, and can be suitably changed without departing from the technical idea thereof.
The number or arrangement of bit excavating portions and tips to be implanted in each device excavating portion is not particularly limited, and will preferably be appropriately set in consideration of excavation conditions or the like.
Additionally, although the auxiliary member made of an elastic material has been described as one which is press-fitted into the loading recess, the invention is not limited thereto, and auxiliary members of other constructions may be used. For example, as shown in
Additionally, for example, as shown in
Moreover, although it has been described that a device excavating portion is provided by implanting tips in the tip face of a device, the invention is not limited thereto. For example, as shown in
Additionally, although it has been described in this embodiment that the tool body is used as a device, and the attaching member is used as a bit head, the invention is not limited thereto. For example, as shown in
Moreover, an attaching hole 662 which is open towards the rear end of the tool body 660 may be provided, an adapter 680 serving as an attaching member to be mounted on the attaching hole 662 may be detachably mounted, and the locking pin 656 and the fixing member 650 may be utilized for the fixation of the tool body 660 and the adapter 680. Additionally, the attaching shaft and the attaching hole may not be limited to the circular cross-sectional shape, but may have a polygonal cross-sectional shape, such as a regular hexagon as shown in
Provided is an excavation tool which can firmly fix a locking pin so that the locking pin does not move even in the case of an impact during excavation and/or the locking pin being pushed out in the insertion/removal direction.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-204174 | Aug 2007 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/063499 | 7/28/2008 | WO | 00 | 2/5/2010 |
