JPH10227190A - Excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably protrude the edge of a bit device outward to maintain and exactly perform excavation by providing a recess part communicating with the bottom face of two bit devices in the case where the device is rotated and one end of both the bit devices is protruded outward only in a prescribed excavation amount from the outer peripheral face of the device. SOLUTION: Bit devices 52a, 52b are rotated by rotation of a hammer cylinder 30, and force of excavation advancement is received to protrude one end thereof in a prescribed amount from the outer periphery of a pipe 46 to excavate soil. At the time, the partial contact face of the linear end faces of both the bit devices 52a, 52b becomes a stopper and rotation is stopped. In the state, the bit devices 52a, 52b receive rotation force of the hammer cylinder 30 to perform excavation, half-circular recess parts provided on the bottom face communicate with both the bit devices 52a, 52b, and the center thereof is a circular recess part 58 positioned on the rotation shaft of a device 36. In hard ground, rock enters a recess part 58, in soft and weak ground, clay enters the recess part 58, dislocation of the linear end faces of the bit devices 52a, 52b is prevented, and rotation can be not performed at a half-way rotation position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a drilling rig having a bit device.

[0002]

2. Description of the Related Art As an excavator for excavating the ground, there is provided a bit device which is attached to the bottom surface of a device which receives the impact force of a hammer and the rotational force of a hammer cylinder, rotates and excavates earth and sand, etc. There is known a drilling device as disclosed in Japanese Patent Application Laid-Open Publication No. H11-146,873. The conventional excavator will be described with reference to FIGS. 10 is a device. The device 10 has a spline groove 15 provided on an inner peripheral wall of a screw cylinder (cylindrical body) 13 screwed and fixed in a lower part of a hammer cylinder 18 of an air hammer device 11.
, It is vertically movable and engages with the screw cylinder 13 in a non-rotation state, and is rotated together with the hammer cylinder 18 by the rotation of the hammer cylinder 18 about an axis by a driving device (not shown). You.

A collar 19 (retaining portion) is fitted to the upper end of the device 10 located in the hammer cylinder 18 to prevent the device 10 from being removed. The device 10 discharges the air discharged from the air hammer device 11 from the inside of the hammer cylinder 18 to the outside.
8 is provided with an air vent hole 23 that communicates the inside and outside.
Reference numerals 12a and 12b denote bit portions each having a substantially semicircular shape. Eccentric shafts 14a and 14b provided on the upper surface
The device 10 is rotatably inserted and fixed in a shaft hole provided at a point symmetrical position with respect to the center of the circular bottom surface.
Attached to. A sufficient number of bits 16 made of cemented carbide are fixed to the bottom surfaces of both bit portions 12a and 12b.

[0004] Reference numeral 17 denotes a pipe. As the excavation progresses, a pressing portion 21 provided on a large diameter portion of the device 10 comes into contact with a step 22 provided on a lower portion of the inner periphery of the pipe 17, so that the device 10 becomes They are drawn into the digging hole. Both bit sections 12a and 12b are shown in FIG.
When the two peripheral surfaces are circular as viewed from the bottom side, the straight end surfaces are opposed to each other with an appropriate interval 15, and the diameter of the circle formed by both bit portions is smaller than the inner diameter of the pipe 17. . Then, as shown in FIG.
When b rotates around the eccentric shafts 14a and 14b and the straight end faces abut, the ends of both bit parts 12a and 12b protrude outward from the pipe 17 to excavate earth and sand.

When the hammer cylinder 18 and the device 10 rotate in the direction of the arrow A, the bit portions 12a and 12b receiving resistance from earth and sand also rotate about the eccentric shafts 14a and 14b, respectively, as shown in FIG. The end faces are in contact. Thereafter, the straight end surfaces act as stopper surfaces for each other, and the two bit portions 12a and 12b rotate with their ends protruding outward from the pipe 17, and are hit by the hammer 25 of the air hammer device 11. While excavating earth and sand. The excavated earth and sand is discharged to the outside by the high pressure discharge air from the air hammer device 11 through the discharge groove 24 provided on the outer periphery of the device 10 and between the hammer cylinder 18 and the pipe 17.

Since the borehole is larger than the diameter of the pipe 17, the pipe 17 is drawn with the device 10 into the borehole. At the time of excavation, both bit portions 12a and 12b rotate stably because their straight end faces abut. At the end of the excavation, the hammer cylinder 18 and the device 1
0 is rotated slightly in the opposite direction. Thereby, both bit portions 1
As 2a and 12b return to the state of FIG. 6 and the diameter decreases,
The bit devices 12a and 12b can be collected upward through the pipe 17 together with the device 10 and the like while the pipe 17 remains in the ground.

[0007]

The conventional bit device 12
According to the excavator provided with the a and 12b, the wide straight end surfaces of both bit devices 12a and 12b abut against each other and act as stoppers during excavation, so that a strong rotational force from the device 10 can be received. However, where the ground is hard such as a bedrock, both bit devices 12a and 12b are rotated in a state where their straight end faces do not come into contact with each other due to a reaction force from the earth and sand due to strong resistance from hard earth and sand. On the other hand, when excavating soft ground, the resistance from the ground is rather small, and the two bit devices 12a and 12b do not rotate while the straight end faces are in contact with each other. As a result, a drilled hole having a desired diameter cannot be drilled, resulting in a variation in the diameter of the drilled hole, and a situation in which the entry of the pipe 17 is hindered.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problem, and an object of the present invention is to excavate an excavation capable of excavating an accurate hole by stably maintaining the tip of the bit device in an outwardly protruding position during excavation. It is to provide a device.

[0009]

The present invention has the following arrangement to achieve the above object. That is, according to the excavator according to the present invention, a bit device that is attached to the bottom surface of the device that receives the impact force of the hammer and the rotational force of the hammer cylinder, rotates, and excavates earth and sand, etc., is provided on the bottom surface of the device. A shaft hole is provided at a point symmetrical position with respect to the axis of the device, and the bit device has a substantially cylindrical shape when the end surfaces are arranged to face each other, and at least two bits each having a bit attached to the bottom surface. Formed into equipment,
An eccentric shaft is erected on the upper surface of the two bit devices, and the end surfaces of the two bit devices are opposed to each other. The eccentric shaft is rotatably provided on the bottom surface, and the position of the eccentric shaft is narrowed to become a columnar shape having substantially the same diameter as the device when the two bit devices are located with their end faces facing each other. When the device is rotated in the digging direction, one end of each of the two bit devices is deviated from the center of the device so as to rotate to a position in which both end portions project outward by a predetermined digging amount from the outer peripheral surface of the device. In the drilling device provided with the center, the device rotates on the bottom surface of the both bit devices, and one end of each of the two bit devices protrudes outward by a predetermined excavation amount from the outer peripheral surface of the device. if you did this It is characterized in that a recess Oite communicate with each other. When this configuration is adopted, rocks and the like enter into the concave portion that connects the end surfaces of both bit devices in contact with each other to the concave portion when the ground is hard, and clay and the like enter into the concave portion when the ground is soft. To prevent misalignment. For this reason, both bit devices can be prevented from rotating at a halfway rotation position without bothering. Further, since the center of the concave portion is provided on the axis of the device, the resistance from the ground at the time of excavation can be equally received by both bit devices, and the rotation of both bit devices can be performed smoothly. Furthermore, by making the concave portion circular, the resistance from the ground at the time of excavation can be reduced, and the rotation of both bit devices can be performed smoothly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an excavator according to the present invention will be described below in detail with reference to the accompanying drawings.
In FIG. 1, reference numeral 30 denotes a hammer cylinder, which has a suitable hammer 32 built therein and rotates about its axis by a suitable power source (not shown). An internal thread is cut on the inner wall of the lower end of the hammer cylinder 30,
The fixture 34 is screwed. The fixture 34 is hollow and has a projection 34a provided inside. 36 is a device in which a spline groove 38 is integrally formed on the upper part,
Further, a cylindrical body 40 is fixed to the upper part, and the cylindrical body 4 is fixed.
The collar 42 is fixed to the body part of No. 0.

To mount the device 36 on the hammer cylinder 30, the fixture 34 is fitted to the device 36 so that the projection 34 a on the inner surface thereof engages with the spline groove 38.
Next, the collar 42 is fixed to the columnar body 40 and screwed to the lower part of the hammer cylinder 30 by the fixing tool 34. The device 36 is prevented from coming off because the collar 42 abuts against the fixture 34, and rotates integrally with the hammer cylinder 30 because it engages with the spline groove 38 and the projection 34a. The hammer 32 strikes the top of the cylinder 40. Device 36
A pressing portion 44 is provided at a large diameter portion of the first portion, and is engaged with a step 48 provided in a pipe 46. Further, the device 36 is provided with an appropriate discharge groove 50 for discharging earth and sand.

Reference numerals 52a and 52b denote bit devices having a semicircular shape, each having one eccentric shaft 54a, 54b, and a point symmetrical with respect to the center of the bottom surface of the device 36 on the circular bottom surface of the device 36. Shaft hole provided at position (not shown)
The device 36 is attached to the device 36 by being rotatably fixed to the device 36. In this fixing method, grooves 56a, 56b are provided on the outer periphery of the eccentric shafts 54a, 54b, and inserted into the shaft holes.
By inserting a pin into a concave groove 56a, 56b with a pin through a hole (not shown) provided on a side surface of the device 36 corresponding to the device a, 56b, the pin is rotatably fixed to the device 36. I have. The bottom surfaces of the bit devices 52a and 52b are provided with semicircular recesses 58 at respective straight end surfaces.
a, 58b are formed. The recesses 58a, 58b are
Before the bit devices 52a and 52b rotate, they are shifted without communication, but when the bit device 52a and 52b rotate and their straight end faces come into contact with each other, on the rotation axis of the device 36, It is formed so that the center may be located in a circular shape. However, before the bit devices 52a and 52b rotate, the recesses 58a and 58b need not be displaced without communicating at all, and may be partially communicating. Also, recesses 58a on the bottom surfaces of both bit devices 52a, 52b,
A sufficient number of bits 60 made of cemented carbide are fixed to portions other than 58b. Further, both bit devices 52
When the a and 52b are rotated, the bottom surface of the end protruding outward from the pipe 46 has tapered surfaces 62a and 6a in which the diameter of the bit device is reduced from the side surface to the bottom surface of the bit device.
2b is formed. Therefore, the tapered surfaces 62a, 62
When the bit 60 is provided in 2b, the bit 60 protrudes outward, and the ground located on the side of the bit device 52a, 52b is excavated, so that wear of the bit device 52a, 52b can be prevented.

Next, the operation of the excavator will be described. When the hammer cylinder 30 receives power and rotates in the direction of arrow A, the device 36 and the bit devices 52a and 52b also rotate in the same direction as a unit. Further, when the hammer 32 arranged in the hammer cylinder 30 applies an impact force to the top of the cylindrical body 40 from above, the bit devices 52a and 52b advance into the ground, and the bit 60 excavates the earth and sand by the rotational force. When the hammer cylinder 30 rotates, the bit device 5
2a and 52b are rotatably attached to the eccentric shafts 54a and 54b, and further have a gap 63 so that they rotate in the direction of arrow A by rotation. Double bit device 52
4a and 4b receive the force of the excavation advance from the hammer 32, and one end protrudes from the outer periphery of the pipe 46 by a predetermined amount as shown in FIG.
Drill at 0. At this time, some surfaces of the straight end surfaces of both bit devices 52a and 52b contact each other. The contacting surface serves as a stopper, and the rotation of the bit devices 52a and 52b stops. Therefore, in this state, the bit device 52
A and 52b excavate by receiving the rotational force of the hammer cylinder 30. At this time, the semicircular recesses 58a, 58b provided on the bottom surfaces of both bit devices 52a, 52b communicate with both bit devices 52a, 52b and become a circular recess 58 whose center is located on the rotation axis of the device 36. . In the case of excavating hard ground, rocks and the like that have entered the recess 58 prevent the straight end faces of the bit devices 52a and 52b from shifting, so that both bit devices are not cut off and are incomplete. It can be prevented from rotating in the pivot position. Further, even when excavating soft ground, the bit device 52 may be subjected to shear stress of clay or the like that has entered the recess 58.
Since the straight end faces of a and 52b are prevented from shifting, it is possible to prevent the two bit devices from rotating at a halfway rotation position without being blocked. The shape of the recess is preferably circular, but is not limited to a circle.

Further, the impact force of the hammer 32 is applied,
When the excavator advances underground, the pressing portion 44 provided on the large-diameter portion of the device 36 and the step 48 of the pipe 46 are hung, so that the bit devices 52a, 52b and the device 36 advance, The pipe 46 can also move forward. Excavated earth or the like is provided on the bottom surface of the device 36 and is connected to an air hole 64 connected to a hole provided on the top of the cylindrical body 40.
When the hammer 32 drops from the inside of the hammer cylinder 30 that is blown out from the a and 64b, the hammer 32 is removed by compressed air and sent out through the discharge groove 50 provided in the device 36 into the pipe 46. Therefore, earth and sand etc. may be
2b or the like can be prevented from being clogged. After the excavation is completed, the bit devices 52a, 52b and the like are pulled out of the pipe 46. At this time, since the earth and sand clogged in the concave portion 58 formed in communication with both the bit devices 52a, 52b must be removed, The entire excavator is slightly lifted so that the tip of the bit device does not contact the ground, and an impact force is applied to both bit devices 52a and 52b by the hammer 21. Next, the hammer cylinder 30 is rotated in the reverse direction to the time of excavation. Then, the bit devices 52a and 52b are in the state shown in FIG. 3 and the diameter is equal to or smaller than the lower end of the device 36, and the bit devices 52a and 52b are slidable in the pipe 46. Therefore, if the hammer cylinder 30 is pulled out, the entire device can be pulled out. At this time, since the upper end of the fixture 34 engages with the collar 42, the device 36 and the bit devices 52a and 52b are also connected to the pipe 4.
6 can be pulled out.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0016]

According to the excavator according to the present invention, the device is rotated on the bottom surface of both bit devices so that one end of each of both bit devices is outside the outer peripheral surface of the device by a predetermined excavation amount. In the case of excavating hard ground, the rocks and the like that enter the recess prevent the end faces of both bit devices from shifting, so that the two bit devices are prevented from shifting when excavating hard ground. The device can be prevented from rotating in a halfway pivot position without squeezing. In addition, even when excavating soft ground, the end faces of both bit devices are prevented from shifting due to shear stress of clay or the like that has entered the concave portion, so that the two bit devices are not half-closed and a halfway rotation position. To prevent rotation. Further, since the center of the concave portion is provided on the axis of the device, the resistance from the ground at the time of excavation can be equally received by both bit devices, and the rotation of both bit devices can be performed smoothly. Furthermore, by making the concave portion circular, the resistance from the ground at the time of excavation can be reduced, and the rotation of both bit devices can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a sectional view of an excavator according to the present invention.

FIG. 2 is a perspective view of a bit device.

FIG. 3 is a bottom view of the excavator at rest.

FIG. 4 is a bottom view of the excavator rotated in the excavation direction.

FIG. 5 is a sectional view of a conventional excavator.

FIG. 6 is a bottom view of a state where the conventional excavator is stopped.

FIG. 7 is a bottom view of the conventional excavator rotated in the excavation direction.

[Explanation of symbols]

 A Excavation direction 30 Hammer cylinder 32 Hammer 34 Fixture 34a Projection 36 Device 38 Spline groove 40 Cylindrical body 42 Collar 44 Pressing part 46 Pipe 48 Step 50 Discharge groove 52a, 52b Bit device 54a, 54b Eccentric shaft 56a, 56b Concave groove 58a, 58b recess 60 bit 62a, 62b tapered surface 63 gap 64a, 64b air hole

Claims (3)

[Claims] 1. A bit device which is attached to a bottom surface of a device which receives an impact force of a hammer and a rotation force of a hammer cylinder, rotates and excavates earth and sand, etc., and has a point on the bottom surface of the device with respect to an axis of the device. A shaft hole is provided at a symmetrical position, and the bit device is formed in two bit devices having a substantially columnar shape when the end faces are opposed to each other and having a bit attached to at least the bottom surface. An eccentric shaft is erected on the upper surface of each of the bit devices, and the two eccentric shafts are inserted into the shaft holes on the bottom surface of the device with the end surfaces of the bit devices facing each other. The position of the eccentric shaft is narrowed to become a columnar shape having substantially the same diameter as the device when the two bit devices are positioned with their end faces facing each other. When the device is rotated in the digging direction, one end of each of the two bit devices is deviated from the center of the device so as to rotate to a position in which both end portions project outward by a predetermined digging amount from the outer peripheral surface of the device. In the drilling device provided in the center, the device rotates on the bottom surface of the both bit devices, and one end of each of the two bit devices protrudes outward by a predetermined excavation amount from the outer peripheral surface of the device. An excavator, wherein recesses communicating with each other are provided when the excavation is performed. 2. The excavator according to claim 1, wherein a center of the recess is provided on an axis of the device. 3. The excavator according to claim 1, wherein the recess is circular.