JPH10331560A - Excavating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excavate an accurate hole by stably keeping the ends of bit devices at outwardly projected positions during excavation. SOLUTION: The eccentric shafts of both of bit devices 52a, 52b are lockingly and freely rotationally fitted into a shaft hole, one bit device 52a is provided in such a way as to freely move to and away from a device 36 by a predetermined distance along the direction of its axis, a projecting piece 55 projecting toward the other bit device 52b is provided on the end face of the bit device 52a, and the other bit device 52b is provided with a notched part into which the projecting piece 55 can enter. When the bit device 52a is at a position away from the device 36, the projecting piece 55 of one bit device 52a extends around the lower surface of the other bit device 52b, so that the bit devices 52a, 52b can be constricted into an almost circular shape on plan view. During excavation, the ends of the bit devices 52a, 52b project outward from the outer peripheral surface of the device 36 by a predetermined amount of excavation, and at a position where the projecting piece 55 coincides with the notched part, the bit device 52a approaches the device 36, with the projecting piece 55 entering the notched part.

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
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 arrow A, the bit portions 12a and 12b receiving resistance from earth and sand also rotate about the eccentric shafts 14a and 14b, respectively, and 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
2a and 12b return to the state of FIG. 7 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, the excavator receives the impact force of the hammer and the rotational force of the hammer cylinder, and is attached to the bottom surface of a device provided so as to be movable a predetermined distance in the axial direction of the hammer cylinder, rotates, and rotates. In a drilling device having a bit device for drilling, etc., a shaft hole is provided on a bottom surface of the device at a point symmetrical position with respect to an axis of the device, and the bit device has at least two bits with bits attached to the bottom surface. An eccentric shaft is erected on the upper surface of the two bit devices, and the eccentric shafts of the two bit devices are locked in the shaft holes so as to be rotatably fitted. A protruding piece is provided on the end face of the one bit device so as to protrude toward the other bit device, and is provided so as to be able to freely contact and separate a predetermined distance in the axial direction with respect to the device. A winding device, wherein the protrusion is provided with a notch capable of entering, at a position where the one bit device releases contact from the device,
When the protruding piece of one bit device goes around the lower surface side of the other bit device, both bit devices can be narrowed so as to be substantially circular in a plan view. When rotating, the two bit devices rotate in the initial direction of rotation about the eccentric axis with respect to the rotation direction of the device in the direction opposite to the rotation direction of the device due to ground resistance or the like. Both ends of the device protrude outward by a predetermined excavation amount from the outer peripheral surface of the device, and the one bit device is relatively approached to the device at a position where the protruding piece coincides with the notch. Then, the projecting piece enters into the notch portion, and thereafter, both bit devices receive rotation force from the device and rotate in the same direction as the device to perform excavation through the contact portion of both bit devices. Features There. When this configuration is employed, the projecting piece and the notch contact each other to act as a stopper, so that when excavating a hard ground or a soft ground, the turning in the direction in which the two bit devices are about to contract is difficult. Blocked,
Both bit devices can be prevented from rotating in a halfway rotation position.

[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.

In FIGS. 2 and 3, 52a, 52b
Is a bit device, and the eccentric shafts 54a, 5
4b is provided upright, and at least a suitable number of bits 60 are attached to the lower surface. A concave groove 56a is formed on the outer periphery of one eccentric shaft 54a, and a concave groove 56b whose width in the vertical direction is smaller than that of one concave groove 56a is formed on the outer periphery of the other eccentric shaft 54b. On the other hand, the circular bottom of the device 36 has a shaft hole 6 at a point symmetrical position with respect to the center of the bottom.
8a and 68b are provided. The eccentric shaft 54a has the shaft hole 6
The bit device 52a is attached to the device 36 so as to be rotatable about the eccentric shaft 54a by the pin 70a fitted into the device 8a and penetrating the device 36 entering the concave groove 56a of the eccentric shaft 54a. Note that the pin 70 has a smaller width than the width of the groove 56a.
a is set smaller, and the bit device 52a
Is configured to be able to approach and separate from the device 36 in the axial direction of the eccentric shaft 54a. Similarly, the eccentric shaft 54b is
The bit device 52b is attached to the device 36 so as to be rotatable about the eccentric shaft 54b by the pin 70b fitted into the device b and penetrating the device 36 entering the concave groove 56b. Since the width of the concave groove 56b and the diameter of the pin 70b are substantially the same, the eccentric shaft 54b does not move in the axial direction.

One bit device 52a has a substantially semicircular outer shape in plan view, and a projecting piece 55 projecting toward the bit device 52b is provided substantially at the center and lower side of the straight end surface 72a.
Is provided. The protruding piece 55 has a stopper surface 74a,
It is formed substantially perpendicular to the straight end face 72a. The bottom surface of the projecting piece 55 is flush with the bottom surface of one of the bit devices 52a, and the bit 60 is also attached to the bottom surface. The other bit device 52b also has a substantially semicircular outer shape in plan view, and has a device 3
6 rotates the bit devices 52a, 52b about the eccentric shafts 54a, 54b, and the notch 57 into which the projecting piece 55 can enter when each end protrudes outward from the pipe 46. Is provided. The notch 57 also has a stopper surface 74b formed substantially perpendicular to the straight end surface 72b. At the position where the bit device 52a descends due to its own weight and stops farthest from the device 36, the upper surface of the projecting piece 55 is set to be lower than the bottom surface of the bit device 52b. Device 5
2b, and in this state, both bit devices 52a and 52b can be narrowed to form a circle having substantially the same diameter as the diameter of the device 36 (FIG. 4). At this time, a constant gap 63 is generated between the two straight end faces 72a and 72b.

A sufficient number of bits 60 made of cemented carbide are fixed to the bottom surfaces of both bit devices 52a and 52b. The notch 57 is not provided with a bit because the projecting piece 55 enters. When the bit devices 52a and 52b rotate, the bottom surface of the end protruding outward from the pipe 46 has a tapered surface 62a in which the diameter of the bit device is reduced from the side surface to the bottom surface of the bit device. 62b are formed. Further, when both bit devices 52a and 52b rotate, the upper surface of the end protruding outward from the pipe 46 also has a tapered surface 65a in which the diameter of the bit device is reduced from the side surface to the upper surface of the bit device. 65b are formed.

Next, the operation of the excavator will be described. When the hammer cylinder 30 receives power from a drive source (not shown) and rotates in the direction of arrow A in FIG.
6 also rotates in the same direction, but since the bit devices 52a and 52b are grounded, the bit devices 52a and 52b rotate around the eccentric shafts 54a and 54b, respectively, in the direction opposite to the arrow A, and each end is outward. To protrude. The projecting piece 55 enters the notch 57 at a position where the projecting piece 55 coincides with the notch 57. Specifically, the bit device 52b descends together with the device 36.
At this point, the straight end faces 72 of both bit devices 52a, 52b
a, 72b are in contact with each other, and both stopper surfaces 74a, 74b
The two bit devices 52a, 52b receive rotational force from the device 36 via their straight end faces 72a, 72b and rotate in the same direction as the device 36. 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 device 5
Bits 2a and 52b penetrate into the ground, and the bit 60 excavates earth and sand by the rotational force. Both bit devices 52a, 52b
Receives the force of the digging advance from the hammer 32, so that one end of the pipe 46 is formed by the digging resistance as shown in FIG.
The earth and the like are excavated by the bit 60 by projecting a predetermined amount from the outer periphery of the work.

At this time, in addition to the above-mentioned straight end face, the stopper face 74a of the projecting piece 55 and the stopper face 74 of the notch 57 are provided.
b and abut against each other to act as a stopper, so that when excavating hard ground or excavating soft ground, both bit devices 52a and 52b are prevented from rotating in the direction in which they are about to contract, The bit device can be prevented from rotating at a halfway rotation position. Further, when the impact force of the hammer 32 is applied and the excavator advances underground, the pressing portion 4 provided on the large-diameter portion of the device 36 is pressed.
Since the step 48 between the 4 and the pipe 46 is hung, as the bit devices 52a, 52b and the device 36 advance,
The pipe 46 can also move forward. Excavated soil and the like are provided on the bottom surface of the device 36, and are removed by compressed air when the hammer 32 falls in the hammer cylinder 30 that blows out from the air hole 64 connected to the hole provided on the top of the cylindrical body 40. Through the discharge groove 50 provided in the pipe 46. Therefore, it is possible to prevent earth and sand from clogging the bit devices 52a and 52b. Also, tapered surfaces 62a and 62b are formed on the bottom surfaces of the ends of both bit devices 52a and 52b from the side surface to the bottom surface of the bit device so that the diameter of the bit device is reduced. Is provided, bit 6
0 protrudes outward and excavates the ground located beside the bit devices 52a, 52b, so that the bit devices 52a,
52b can be prevented from being worn.

After the excavation is completed, the bit devices 52a, 52b
And the like are pulled out of the pipe 46. At this time, the entire excavator is pulled up, and the bit device 52a is lowered by its own weight. When the bit device 52a descends, the protruding piece 55 comes off the notch portion 57, and the upper surface of the protruding piece 55 is located below the bottom surface of the other bit device 52b. In this state, the hammer cylinder 30 is rotated in the direction opposite to the excavation. Then, the bit devices 52a and 52b are in the state shown in FIG. 4, and the diameter is equal to or smaller than the lower end of the device 36, and the bit devices 52a and 52b can slide 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. Bit device 5
When the 2a and 52b are to be pulled upward, the taper surfaces 65a and 65b provided on the upper surfaces of the end portions of the bit devices 52a and 52b are pressed by earth and sand or the like so that the bit devices 52a and 52b are narrowed. Tapered surfaces 65a, 65b
Is preferably set.

As described above, various preferred embodiments of the present invention have been described. However, 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.

[0019]

According to the excavator of the present invention, one of the bit devices is provided so as to be able to freely contact with and separate from the device by a predetermined distance in the axial direction, and the end device of one of the bit devices is directed toward the other bit device. A protruding protruding piece is provided, and a cutout portion into which the protruding piece can enter is provided in the other bit device, and at a position where one bit device is separated from or separated from the device, the protruding piece of one bit device is connected to the other bit device By turning around the lower surface side of the two bit devices, both bit devices can be narrowed so as to be substantially circular in a plan view. Due to resistance etc., it rotates in the opposite direction relative to the rotation direction of the device around the eccentric axis with respect to the rotation direction of the device,
Both ends of both bit devices protrude outward by a predetermined excavation amount from the outer peripheral surface of the device, and one bit device relatively approaches the device at a position where the protruding piece coincides with the notch. Then, the projecting piece entered the notch, and thereafter, both bit devices received rotational force from the device via the contact portion of both bit devices, so that they were rotated in the same direction as the device and excavated. The projecting piece and the notch contact each other to act as a stopper, and when excavating hard ground or soft ground, rotation of both bit devices in the direction in which the bit device is about to be closed is prevented, and both bit devices are halfway It can be prevented from rotating at an appropriate rotation position. For this reason, the tip of the bit device is stably maintained at a position protruding outward, and an accurate hole can be excavated.

[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 an explanatory diagram illustrating a situation in which a bit device approaches and separates in an axial direction of a device.

FIG. 4 is a bottom view of the excavator at rest.

FIG. 5 is a bottom view of the excavator when the protruding piece rotates into the excavation direction and enters the notch.

FIG. 6 is a sectional view of a conventional excavator.

FIG. 7 is a bottom view of a state where a conventional excavator is stopped.

FIG. 8 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 55 Projection piece 56a, 56b concave Groove 57 Notch 60 Bit 62a, 62b Tapered surface 63 Gap 64 Air hole 65a, 65b Tapered surface 68a, 68b Shaft hole 70a, 70b Pin 72a, 72b Straight end surface 74a, 74b Stopper surface

Claims (1)

[Claims] A bit device that receives the impact force of a hammer and the rotational force of a hammer cylinder, and is attached to the bottom surface of a device that is provided to be movable a predetermined distance in the axial direction of the hammer cylinder, rotates, and excavates earth and sand. An excavating device having: a shaft hole provided at a point symmetrical position with respect to an axis of the device on a bottom surface of the device; wherein the bit device is formed into at least two bit devices having bits attached to the bottom surface; An eccentric shaft is erected on the upper surface of each of the bit devices, and the eccentric shafts of the two bit devices are locked in the shaft holes so as to be rotatable, and one of the bit devices is axially inserted into the device. A protruding piece is provided on the end face of the one bit device so as to be freely contactable with and separated from the other bit device, and the protruding piece advances to the other bit device. In the position where the one bit device is separated from the device, the projecting piece of one bit device goes around the lower surface side of the other bit device, so that both bit devices are flat. When drilling, when the device rotates in the direction of excavation, at the initial stage of rotation, the two bit devices are rotated with respect to the direction of rotation of the device by ground resistance or the like. Rotating in a direction opposite to the rotation direction of the device about the eccentric axis, both ends of both bit devices project outward from the outer peripheral surface of the device by a predetermined excavation amount, and At the position where the piece coincides with the notch, the one bit device is relatively approached to the device, and the protruding piece enters the notch, and thereafter, the two bit devices are brought into contact with each other through the contact portions of both bit devices. Bit Device excavating device and performs drilling by rotating the device in the same direction by receiving the rotational force from the device.