JP2002285778A - Excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance assembling workability of an enlarged wing and enhance the durability of the attaching part of the enlarged wing. SOLUTION: Attaching grooves 21 are formed on the edge of a device 6 at regular circumferential intervals. The enlarged wings 23 capable of rotation in the radial direction are pivoted on the attaching grooves 21. A pivotally supported shaft 22 penetrates the enlarged wing 23, and engaging recess grooves 24 fitted to the pivotally supported shaft 22 are formed on the attaching grooves 21. The engaging recess grooves 24 are opened on the inner face of the device 6, and a pivotally supported shaft 22 is fitted to the engaging recess grooves 24 from the inner face side of the device 6. A bit device 15 is assembled on the inside of the device 6, and movement for the inside of the enlarged wing 23 supported pivotally on the engaging recess grooves 24 is regulated to hold slip stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator used for excavating a buried pipe in the ground for water wells, anchor work, prevention of landslides, etc., and particularly to a connecting hole formed at a tip of a device. The present invention relates to an excavator in which a connection shaft provided at a base end of a bit device is rotatably connected within a connection hole, and the bit device is rotated with respect to the device so as to increase a hole diameter of the bit device. .

[0002]

Conventionally, in the case of boring for embedding a buried pipe made of a steel pipe or the like, excavation is performed while rotating by giving an impact to a bit device provided at the tip of the buried pipe. In order to facilitate the insertion of the buried pipe into the ground, a bit device having a larger diameter than the buried pipe is used.

[0003] For example, in Japanese Patent Publication No. 2710192, a longitudinal connecting hole is formed at the tip of a device which receives the impact force and the rotational force of an air hammer, and the longitudinal end of the bit device is formed in the connecting hole. Is rotatably inserted and connected, and the device is rotated at a predetermined angle to one side in the circumferential direction with respect to the bit device to enlarge the perforation diameter of the bit device. In a drilling apparatus for drilling while rotating the bit device by directional rotation, there has been proposed a drilling apparatus in which the device pivotally supports a plurality of enlarged wings rotatable in a radial direction. In this excavator, when the device is advanced with respect to the bit device, the holding portion of the bit device contacts the enlarged wing, and the enlarged wing is enlarged. Thereby, the drilling diameter of the bit device is increased.

[0004] The mounting structure of the enlarged wing will be described. As shown in FIG. 13, three mounting grooves 102 are formed at equal circumferential intervals on the distal end surface of a device 101 for pivotally supporting the enlarged wing 100. From the outer peripheral surface of 101, the mounting groove 102
Is formed. In addition, the expanding wing 1
00, a through hole 104 is formed at the base, and the enlarged wing 100 is formed in the mounting groove 102.
With the base of the device inserted, the shaft hole 103 is
The enlarged wing 100 is pivotally supported in the radial direction with respect to the center of the bit device by passing the shaft 105 through the through hole 104 and the shaft 105. Thus, the mounting groove 102 and the enlarged wing 100
It is necessary to prevent the shaft 105 from dropping off in a structure in which the shaft 105 is formed so as to pivotally support the enlarged wing 100. To this end, a step 106 for positioning one end of the shaft 105 is formed at one end of the shaft hole 103, and an insertion hole 108 is formed at the other end of the shaft hole 103, and a lock pin 107 is inserted into the insertion hole 108. The other end of the shaft 105 is press-fitted and locked. This lock pin 1
Reference numeral 07 has a split groove (not shown) in the axial direction, and prevents it from falling out of the insertion hole 108 by elastic restoring force when inserted into the insertion hole 108.

As described above, in the conventional drilling rig, the device
In order to pivotally support the enlarged wing 100 on the 101, a mounting groove 102 formed in the device 101 is formed through a shaft hole 103 for inserting the shaft 105 in a horizontal direction, so that the strength of the device 101 is increased by the shaft hole 103. When the expanding wing 100 rotates, when a large force is applied to the shaft 105 that pivots the expanding wing 100,
There is a concern that the durability may decrease due to cracks generated from the shaft hole 103 portion. Further, since the shaft 105 for pivotally attaching the enlarged wing 100 is prevented from coming off by the lock pin 107 inserted into the insertion hole 108, when a large force is applied to the shaft 105 during rotation of the enlarged wing 100, the lock pin 107 is damaged. For example, there is a problem that the shaft 105 pivotally supporting the enlarged wing 100 falls out of the shaft hole 103. In this way, when the shaft 105 pivotally supporting the enlarged wing 100 falls off, it becomes difficult to excavate, and once stopped, the shaft 105 of the enlarged wing 100 is pivoted again with the lock pin 107.
Extremely complicated maintenance work is required, and there is a problem that efficient excavation work cannot be performed.

In this type of excavator, as shown in FIG. 14, a passage (not shown) communicating with an air hammer is formed in the device 101, and a compressed air passage 110 communicating with this passage is provided in a bit device. 111 is formed. And
A plurality of branch passages 110 </ b> A are communicated with the tip of the compression passage 110, and each of the branch passages 110 </ b> A is opened on the tip surface of the bit device 111. A first groove 112 is formed radially on the distal end surface of the bit device 111 so as to face the distal end opening of each of the branch passages 110A, and the body of the bit device 111 is connected to the first groove 112. A second groove 113 is provided vertically outside the peripheral surface, and a discharge groove 114 (shown in FIG. 13) is formed on the outer periphery of the device 101. Then, by injecting compressed air from a branch passage 110A opening at the tip of the bit device 111, soil and the like excavated by the bit device 111 are discharged from the first groove portion 112 to the second groove portion 113.
The gas is discharged from the discharge groove 114 of the 101 to the ground surface.

Incidentally, the tip of the bit device 111 has a tapered surface 111A and a body peripheral surface 111B continuous with the tapered surface.
The first groove 112 is formed on the tip end surface of the body peripheral surface 111B, and the second groove 113 is formed from the outer periphery of the body peripheral surface 111B to the tapered surface 111A. As shown in FIG. 2, in this type of excavator, the depth S of the first groove 112 and the second groove 113 formed on the tip end surface of the bit device 111 is relatively small, and The length L of the peripheral surface 111B and the tapered surface 111A
The length L1 of the second groove 113 formed over is relatively long. For this reason, during excavation,
When excavating a clay layer having viscosity such as silt clay, the first groove 112 formed on the tip end surface of the bit device 111 is easily clogged with earth and sand, and the total length L1 of the second groove 113 is long. The portion of the second groove 113 that is being discharged to the discharge groove 114 of the device 101 is also likely to be clogged with mud or earth and sand.
For this reason, there was a problem that excavated earth and sand could not be efficiently discharged.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an excavator capable of increasing the mounting strength of an expanding wing and maintaining the mounting of the expanding wing to a device stably for a long period of time. An object of the present invention is to provide a drilling device capable of discharging.

[0009]

According to a first aspect of the present invention, there is provided an excavator, wherein a bit device is provided at a tip of a device which receives an impact force and a rotational force so as to be able to move forward and backward, and a tip of the device is radially provided at the tip of the device. The device is provided with a mounting groove for pivotally supporting a plurality of rotatable magnifying wings and receiving the magnifying wing on the device side by retreating the device with respect to the bit device, and advancing the bit device of the device to the bit device. In an excavator for enlarging an enlarged wing and excavating the tip of a bit device and the enlarged wing from the tip of a buried pipe to perform excavation, a pivot shaft protruding from both sides of the enlarged wing is provided, and both ends of the pivot shaft are provided. And a pair of left and right engaging concave grooves for pivotally connecting the mounting groove are formed on opposite side wall surfaces of the mounting groove, and the engaging concave grooves are opened on the inner surface of the device.

According to the above configuration, the engaging groove for pivotally supporting the pivot axis of the enlarged wing is not provided on the outer surface of the device but is formed inside the device. Does not decrease. As a result, even when a large force is applied to the pivot axis for pivotally attaching the enlarged wing during rotation of the enlarged wing, no crack or the like is generated from the engagement groove, thereby increasing the durability. be able to. To assemble the enlarged wing, simply insert the pivot shaft provided on the enlarged wing from the inside of the device into the engagement groove and slide along the engagement groove to easily pivot the enlarged wing. By mounting the bit device inside the device with the pivot shaft fitted in the engagement groove, the inward movement of the enlarged wing is regulated by the bit device, and the enlarged wing is inserted into the engagement groove. On the other hand, the expansion wing is retained and retained.

According to a second aspect of the present invention, there is provided the excavator according to the first aspect, wherein a tip side of the pivot shaft is formed in a spherical shape, and the engaging groove engages with the pivot shaft. Is formed in a substantially semicircular cross section.

According to the above configuration, the pivot shaft and the engagement groove are fitted smoothly, and the movement of the enlarged wing is also smooth.

According to a third aspect of the present invention, a bit device is provided at a tip of a device receiving an impact force and a rotational force so as to be able to move forward and backward, and a plurality of radially rotatable devices are provided at the tip of the device. Pivoting the expanding wing, providing a mounting groove in the device for receiving the expanding wing on the device side by retracting the device with respect to the bit device, expanding the expanding wing by advancing the bit device of the device, In a drilling device that excavates by projecting the tip of the bit device and the enlarged wing from the tip of the buried pipe, and providing a compressed air passage that opens to the base end of the bit device and allows compressed air to pass to the tip of the bit device, A plurality of branch passages branching from the distal end of the compressed air passage and opening to the distal end surface of the bit device are provided, and the branch passages are provided at the distal end surface of the bit device. First grooves are formed radially from the periphery of the opening toward the outer periphery of the bit device, and a second groove communicating with the first groove is provided vertically outside the body peripheral surface of the bit device. And this second
A discharge groove is formed on the outer periphery of the device in correspondence with the groove of (1).

[0014] With the above structure, the earth and sand, clay and the like excavated by the bit device are discharged from the first groove portion formed in the tip end surface of the bit device to the second groove portion by blowing out the compressed air from the branch passage. Is discharged to the ground through a discharge groove formed on the outer peripheral surface of the.

According to a fourth aspect of the present invention, there is provided the excavator according to the third aspect, wherein the depth of the first groove portion is set to 7 to 15% of the diameter of the bit device, and the depth of the bit device is reduced. The length of the trunk surface is set to 30 to 40 mm.

According to the above configuration, when excavating a highly viscous layer such as a silt clayey layer, the first groove formed on the tip end surface of the bit device is deep and the second groove formed on the outer peripheral surface of the bit device. Since the total length of the groove is short, the soil and clay excavated by the bit device are unlikely to be clogged with the first and second grooves. As a result, the liquid is discharged from the first groove formed on the tip end surface of the bit device to the second groove, and further smoothly discharged to the ground via the discharge groove formed on the outer peripheral surface of the device.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 12 show an embodiment of the present invention. As shown in FIG. 1, a bit casing pipe 2 is welded to the tip of a buried pipe 1 made of a steel pipe or the like.
The casing pipe 2 has a thick portion 4 at the tip via an inner inner peripheral step 3. An air hammer 5 is inserted into the buried pipe 1, and a cylinder 7 at the base end of the device 6 is connected to the air hammer 5, and a spline groove 8 is integrally formed on the outer periphery of the cylinder 7. The spline groove 8 is fitted into the vertical groove 9 of the air hammer 5 so that the rotation of the air hammer 5 is transmitted to the device 6, and the air hammer 5 is powered by compressed air or the like. A hammer piston (not shown) serving as a source is built in, and the hammer piston strikes the cylindrical portion 7 to transmit an impact force. On the outer periphery of the device 6, three discharge grooves 10 for discharging earth and sand excavated along the axial direction of the device 6 above the buried pipe 1 are vertically provided at equal intervals,
An outer peripheral step portion 11 which engages with the inner peripheral step portion 3 of the bit casing pipe 2 is provided around. A connection hole 12 is formed on the distal end side of the device 6, and rotation transmitting pins 13, 13 are laterally provided facing the inner surface of the connection hole 12.
Are removably fixed to mounting holes 14, 14 pierced vertically in the device 6.

A connecting shaft 16 at the base end of the bit device 15 is rotatably and vertically slidably inserted into the connecting hole 12, and the outer periphery of the connecting shaft 16 is engaged with the rotation transmitting pins 13 Engaging grooves 17, 17 that allow the bit device 15 to rotate by a predetermined angle are formed vertically. The engagement grooves 17, 17 are provided so that the rotation transmitting pin 13 is substantially 90
One side engagement, which is a transmission engagement portion that transmits rotation of the device 6 in one direction R to the bit device 15 via the rotation transmission pin 13 on one side in the circumferential direction. Face 18 and
The other-side engaging surface 19, which is the other-side engaging portion for transmitting the rotation in the other direction to the bit device 15, is formed, and the engaging groove 17 is formed slightly larger than the diameter of the transmitting pin 13, and The other-side engaging surface 19 is provided above the other-side engaging surface 19 of the side engaging groove 17.
A sliding groove 20 having a flat surface that engages with the rotation transmitting pin 13 and that allows the bit device 15 to move back and forth and back in the longitudinal direction is formed.

At the distal end of the device 6, as shown in FIG. 5, three mounting grooves 21 are formed at equal intervals on the circumference so as to open on the distal end surface of the device 6. An enlarged wing 23 is pivotally supported via a pivot shaft 22. The pivot shaft 22 is located on the base side of the enlarged wing 23 and penetrates in the horizontal direction. Both ends of the pivot shaft 22 project from both side surfaces of the enlarged wing 23. Both ends of the pivot shaft 22 protruding from the enlarged wing 23 are formed as smooth spherical portions 22A. In addition, each of the mounting grooves
A pair of left and right engaging concave grooves 24 for pivotally supporting the pivot shaft 22 are formed on opposite side wall surfaces of the pair 21 respectively. The engagement groove 24 is open on the inner surface of the device 6. Further, the cross-sectional shape of the pivot shaft 22 is formed in a semicircular shape so as to be fitted to both ends of the pivot shaft 22. Then, both ends of the pivot shaft 22 attached to the enlarged wing 23 are inserted into the engagement groove 24 from inside the device 6 to support the shaft. In this way, the expanding wing 23 is mounted to be rotatable in the radial direction with respect to the center axis of the bit device 15.
At the base end of the enlarged wing 23, a flat shoulder surface 23A that is in contact with the inclined inner end surface 21A of the mounting groove 21 in an enlarged state of the enlarged wing 23 is formed, and is continuous with the shoulder surface 23A. Thus, a curved surface 25 centering on the pivot shaft 22 is formed. Also, wide portions 26, 26 are provided on the left and right sides on the distal end side of the enlarged wing 23, and the inclined surfaces 2 are provided on the left and right base end sides of the wide portions 26, 26.
7,27 are provided respectively. On the distal end side of the mounting groove 21, a wide groove portion 28 wider than the base end side and capable of storing the base end side of the wide portion 26 is formed, and in the wide groove portion 28, the enlarged wing 23 is in an expanded state. A receiving surface 29 with which the inclined surface 27 contacts is provided.

Further, the expanding wing 23 extends along the distal end side of the connecting shaft 16 of the bit device 15 in a contracted state, and can be inserted through the buried pipe 1 and the bit casing pipe 2. A tapered surface 32 and a body peripheral surface 32A continuous with the tapered surface 32 are formed at the tip of the bit device 15, and the tapered surface 32 is brought into contact with an inner side surface 23B of the enlarged wing 23 so that the enlarged blade 23
Is held in an enlarged state. Further, a plurality of chips 33 made of cemented carbide are provided on the distal end surfaces of the enlarged wing 23 and the bit device 15, and the distal end surface of the enlarged wing 23 has a substantially rectangular shape, and has an outer center and an inner side. The tip 33 is provided on the left and right, and a hard overlay portion 34 that is harder than the enlarged wing 23 is provided on the tip side in the rotation direction of the enlarged wing 23 by arc welding or the like.

In the device 6, a passage 41 communicating with the air hammer 5 is formed. A compressed air passage 42 communicating with the passage 41 is formed in the bit device 15, and three branches communicating with the tip of the compression passage 42. The passages 42A, 42A, 42A are open at the tip end of the body peripheral surface 32A of the bit device 15. And
Three first grooves 43, 4 facing the opening of each branch passage 42A
3 and 43 are from the center of the front end surface of the body peripheral surface 32A to the body peripheral surface 32A.
A is formed radially toward the outer peripheral edge of A. Also,
The trunk peripheral surface 3 is connected to these first grooves 43, 43, 43 so as to be continuous.
Second grooves 45, 45, 45 are formed on the outer peripheral surface of 2A at equal circumferential intervals, and a discharge groove 10 formed on the outer peripheral surface of the device 6 is connected to the second grooves 45, 45, 45. Has been established.
In this embodiment, the diameter D of the bit device 15 is 137 m.
m, the length L of the trunk surface 32A, that is, the length from the tip end surface of the bit device 15 to the tapered surface 32 is approximately 37 mm,
The length L1 of the second groove 45 formed from 32A to the tapered surface 32 is set to 47 mm. On the other hand, the depth S1 of the first groove 43 formed on the tip end surface of the body peripheral surface 32A and the depth S1 of the second groove 45 formed on the outer peripheral surface of the body peripheral surface 32A are determined by the bit device.
7 to 15% of the diameter D of 15, ie, approximately 9.6 to 20.5 m
m, 17.5 mm in this embodiment.

Further, the device 6 is provided with two compressed air passages 50 for injecting compressed air backward, at three places.
The compressed air passage 50 communicates with the passage 41 and is connected to the discharge groove.
Between 10 the openings are made in the shoulder 6A of the device 6.

Next, a method of using the above-mentioned excavator will be described. As shown in FIG. 8, after the pivot shaft 22 is passed through the enlarged wing 23, both ends of the pivot shaft 22 are attached from the inside of the device 6. It is inserted into the engagement groove 24 formed in the groove 21. Thereafter, the enlarged wing 23 is slid along the engagement groove 24 so that the pivot shaft 22 abuts against the end face of the engagement groove 24. As a result, the enlarged wing 23 is supported by the mounting groove 21, and
Reference numeral 23 is attached to the center axis of the bit device 15 so as to be rotatable in the radial direction. At this time, the pivot 22
Is merely slidably held along an engagement concave groove 24 opened inside the device 6, but is buried in a state in which the enlarged wing 23 is pivotally supported in the mounting groove 21 as shown in FIG. Tube 1
By locking the bit device 15 inserted into the upper end of the slide groove portion 20 by the rotation transmitting pin 13,
Is restricted from moving inward by the bit device 15 located inside. That is, the bit device 15 is the device 6
And the enlarged wings 23 can move inside the buried pipe 1 while being suspended along the connecting shaft 16. Then, when the bit device 15 is rotated in one direction R and grounded while applying an impact, the tip 33 at the tip of the bit device 15 is turned on.
Drilling is started by this
When the device 6 advances from the tip of the bit casing pipe 2 and the device 6 advances with respect to the grounded bit device 15, the rotation transmitting pin 13 advances to the front end of the slide groove 20. By this advance, the connecting shaft 16 retreats in the connecting hole 13, and as shown in FIG. 4, the tapered surface 32 of the bit device 15 contacts the inner side surface 23B of the expanding wing 23, and the expanding wing 23 is held in the expanded state. In addition, the shoulder surface 23A of the enlarged wing 23 is positioned in contact with the inner end surface 21A, and the drilling diameter P of the bit device 15 is enlarged.
At the same time, the rotation of the device 6 causes the rotation transmitting pins 13, 13 to rotate in one direction R of the engagement grooves 17, 17 to engage with the one-side engagement surfaces 18, 18, and to rotate in one direction R of the device 6. Is a bit device 15
Is transmitted to In this state, the outer peripheral step of the device 6
11 contacts the inner peripheral step 3 of the bit casing pipe 2,
The impact from the air hammer 5 is also transmitted to the bit casing pipe 2. In this way, with the expanding wing 23 expanded, for example, the bit device 15 is blown 1100 times per minute and rotated 20 times per minute, and the branch passages 42A, 42A, Excavation is performed by injecting compressed air from 42A. When the excavation at the predetermined depth is completed, the device 6 is rotated in the other direction. By this rotation, the rotation transmitting pins 13, 13 move to the slide groove 20 side, and when the device 6 is pulled up, the slide groove 20
The rotation transmission pins 13 and 13 move along, and the expanding wings 23 are stored in the bit casing pipe 2 while contracting, and the bit device 15 becomes movable in the buried pipe 1 and is raised to the ground. Can be.

Using such a device for expanding holes, for example,
When excavating a highly viscous layer such as silt clay, a first groove 43, 43, 43 formed on the tip end surface of the bit device 15 and a second groove 45, 45, 45 formed on the outer periphery of the bit device 15 are formed. If the depth is shallow, the excavated clay
No matter how much compressed air is injected from the branch passages 42A, 42A, 42A formed at the tip of the bit device 15, the excavated It is difficult to discharge the layer to the second groove portions 45, 45, 45 side. When the total length of the second grooves 45, 45, 45, that is, the length L of the body peripheral surface 32A of the bit device 15, is long, the first groove 4 formed on the distal end surface of the bit device 15 is formed.
Even if the clay is not clogged in the portion of 3, 43, 43, the bit device
The second groove portions 45, 45, 45 formed on the outer peripheral surface of the device 15 are clogged at the portion, and cannot be discharged to the discharge groove 10 side of the device 6. However, in this embodiment, the first groove 43 formed on the tip end surface of the bit device 15 is
The depth S, S1 of the second groove 45 formed on the outer peripheral surface of 32A is 1
The length L is set to 7.5 mm, and the length L of the body peripheral surface 32A of the bit device 15 is set to 30 to 40 mm.
m, and the length L1 of the second groove 45 formed from the trunk peripheral surface 32A to the tapered surface 32 is made 47 mm, which is shorter than that of a normal excavator.
Clogging of clay, earth and sand, etc. in the first groove portion 43 and the second groove portion 45 formed in 15 can be suppressed. For this reason, the excavated earth and sand or clay is transferred from the first groove 43 to the second groove 45 by the compressed air from the branch passages 42A, 42A, 42A opened to the first groove 43 formed in the bit device 15. Can be surely discharged to the discharge groove 10, and thus can be smoothly discharged from the discharge groove 10 to the ground.

As described above, in the present embodiment, the pivot shaft 22 penetrated by the enlarged wing 23 is slid into the engagement grooves 24 formed on both sides of the mounting groove 21 of the engagement groove 24 so that the device is Since the enlarged wing 23 is pivotally supported on the device 6, there is no possibility that the strength of the device 6 is reduced by the engagement groove 24. Therefore, even when a large force is applied to the pivot shaft 22 for pivotally attaching the enlarged wing 23 during rotation of the enlarged wing 23, no crack is generated from the engagement groove 24. Also, assembling of the enlarged wings 23,
Simply insert the pivot 22 attached to the enlarged wing 23 into the engagement groove 24 formed in the mounting groove 23 from inside the device 6, and
In order to prevent the pivot shaft 22 from slipping off by merely sliding the inner side along the engaging groove 24 (outward of the device 6).
Since a lock pin or the like is not required, the assembling work of the enlarged wing 23 is also easy. In this state, the expanded wing
Although the pivot shaft 22 of 23 is not positioned with respect to the engaging groove 24, the bit device 15 is mounted on the inner surface side of the enlarged wing 23 by the rotation transmitting pin 13 with the enlarged wing 23 attached to the mounting groove 23. When the wing 23 is assembled, the inward movement of the expanding wing 23 is regulated by the bit device 15, so that the pivot shaft 22 is
Is stopped. As a result, the enlarged wing 23 is retained and held against the device 6. Further, spherical portions 22A are formed at both ends of a pivot shaft 22 for pivotally mounting the enlarged wings 23, and the cross-sectional shape of the engaging concave groove 24 which supports the spherical portions 22A is semicircular so as to fit with the spherical portion 22A. With this configuration, the pivot shaft 22 and the engaging groove 24 fit smoothly, so that the movement of the expanding wing 23 interlocked with the bit device 15 is also smooth.

In this embodiment, three branch passages 42A, 42A, 42A communicating with the compressed air passage 42 of the bit device 15 are opened at the tip end surface of the bit device 15, and the branch passage 42A is provided.
Depth S of three first grooves 43, 43, 43 facing the opening of
And a second formed on the outer peripheral surface of the body peripheral surface 32A of the bit device 15.
The depth S1 of the groove 45 is 7 to 15 of the diameter D of the bit device 15.
%, In the present embodiment in which the diameter of the bit device 15 is formed to be 137 mm, the depth L is set to 17.5 mm, and the length L of the body peripheral surface 32A of the bit device 15 is 30 to 40 mm, which is as short as approximately 37 mm in the present embodiment. By forming the first groove 4
The length L1 of the second grooves 45, 45, 45 communicating with 3, 43, 43 is set to 4
By forming it as short as 7 mm, even when excavating a highly viscous layer such as silt clay,
Clay and earth and sand are hardly clogged in the portion of the first groove 43 and the second groove 45 which are formed in the first groove 43, and the clay and earth and sand excavated by the bit device 15 are removed from the first groove 43 and the second groove 45 and the device. 6 can be smoothly discharged to the ground along the discharge groove 10.

As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the present invention.
For example, in this embodiment, an example is shown in which both ends of the pivot shaft are formed in spherical shapes, but it is not always necessary to form them in spherical shapes. The shape and number of the first and second grooves formed on the tip end surface of the bit device may be appropriately selected.
Further, the device of the present invention can be used for excavation in a lateral direction, and various types of air hammers can be used.

[0028]

According to the first aspect of the present invention, a bit device is provided at the tip of a device that receives an impact force and a rotational force so as to be able to move forward and backward, and the tip of the device is pivoted in a radial direction. A mounting groove for pivotally supporting a plurality of possible expansion wings and receiving the expansion wing on the device side by retreating the device with respect to the bit device;
In a drilling device for expanding the enlarged wing by advancing the bit device of the device and projecting the tip of the bit device and the enlarged wing from the tip of a buried pipe to excavate, a pivot shaft protruding from both sides of the enlarged wing. And a pair of left and right engagement grooves for pivotally connecting both ends of the pivot shaft are formed on opposing side walls of the mounting groove, and the engagement grooves are opened on the inner surface of the device. Therefore, even when a large force is applied to the pivot shaft that pivotally connects the enlarged wing during rotation of the enlarged wing, no crack is generated from the engagement groove, so that the durability is improved. And the assembling work of the enlarged wing can be simplified.
Also, since the expanding wing assembled to the device is prevented from falling off by the bit device assembled inside,
The extended wing can be pivoted stably for a long time, and no maintenance work is required.

According to a second aspect of the present invention, in the excavating apparatus according to the first aspect, the distal end side of the pivot shaft is formed in a spherical shape, and the engaging portion engages with the pivot shaft. Since the cross-sectional shape of the concave groove is substantially semicircular, the pivot shaft and the engaging concave groove fit smoothly, and the movement of the enlarged wing is also smooth.

According to the third aspect of the present invention, the bit device is provided at the tip of the device receiving the impact force and the rotational force so as to be able to move forward and backward, and the tip of the device is rotatable in the radial direction. A mounting groove is provided in the device for pivotally supporting a plurality of enlarged wings and retracting the enlarged wing on the device side by retreating the device with respect to the bit device, and expanding the enlarged wing by advancing the bit device of the device. In a drilling device for excavating by projecting the tip of the bit device and the enlarged wing from the tip of the buried pipe, a compressed air passage is provided at the base end of the bit device and through which compressed air passes to the tip of the bit device. A plurality of branch passages that branch off from the distal end portion of the compressed air passage and open to the distal end surface of the bit device; The formed radially toward the outer periphery of each of the bit device from the peripheral edge of the opening of the passage 1
And a second groove communicating with the first groove is vertically provided on the outer peripheral surface of the body of the bit device, and a discharge groove is formed on the outer periphery of the device corresponding to the second groove. Since the compressed air is blown out from the first groove, the earth and sand excavated by the bit device is sent to the second groove formed from the first groove, and further discharged from the discharge groove formed on the outer peripheral surface of the device. Discharged smoothly to the ground.

According to a fourth aspect of the present invention, in the excavator of the third aspect, the depth of the first groove is set to 7 to 15% of the diameter of the bit device.
Since the length of the body peripheral surface of the bit device is set to 30 to 40 mm, even when excavating a highly viscous stratum such as a silt clayey layer, the first and second groove portions are formed. The soil and clay are hardly clogged, and the excavated soil and clay can be reliably discharged.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a device and a bit device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing one embodiment of the present invention.

FIG. 3 is a sectional view of a main part showing one embodiment of the present invention.

FIG. 4 is an enlarged sectional view of an enlarged wing showing one embodiment of the present invention.

FIG. 5 is a sectional view of a main part showing an attached state of an enlarged wing showing one embodiment of the present invention.

FIG. 6 is a plan view of an enlarged wing showing one embodiment of the present invention.

FIG. 7 is a front view of the enlarged wing, showing one embodiment of the present invention, as viewed from the tip side.

FIG. 8 is a sectional view around an enlarged wing showing one embodiment of the present invention.

FIG. 9 is a cross-sectional view around an enlarged wing showing one embodiment of the present invention, showing a state where the enlarged wing is enlarged.

FIG. 10 is a cross-sectional view showing a compressed air passage on the tip end side of a bit device according to an embodiment of the present invention.

FIG. 11 is a plan view of a bit device showing one embodiment of the present invention.

FIG. 12 is a sectional view showing a compressed air passage on the base end side of the bit device according to the embodiment of the present invention.

FIG. 13 is a cross-sectional view of a main part showing an attached state of an enlarged wing showing a conventional example.

FIG. 14 is a cross-sectional view showing a compressed air passage at the tip end side of a bit device showing a conventional example.

[Explanation of symbols]

 6 Device 10 Discharge groove 15 Bit device 21 Mounting groove 22 Pivot shaft 24 Pivot groove 22A Spherical portion 23 Enlarged wing 24 Engagement groove 32 Tapered surface 32A Body peripheral surface 42 Compressed air path 42A Branch passage 43 First groove 45 The second groove D The diameter of the bit L The length of the circumferential surface of the bit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomio Kato 285-3 Nakamura, Oaza, Niitsu, Niigata Prefecture Inside Wellman Co., Ltd. 72) Inventor Hiroki Matsuda 285, Nakamura, Niitsu-shi, Niigata F-term in Welmann Co., Ltd. (Reference) 2D029 DE01 EB01 PA02 PB02 PB03 PB05

Claims (4)

[Claims] 1. A bit device is provided at a tip of a device receiving an impact force and a rotational force so as to be able to move forward and backward, and a plurality of radially rotatable magnifying wings is pivotally supported at the tip of the device. A mounting groove for accommodating the expanding wing on the device side is provided in the device by retracting the device with respect to the bit device, and the expanding wing is expanded by advancing the bit device of the device, and the bit device is inserted from the tip of the buried pipe. In an excavating device for excavating the tip and the enlarged wing, a pivot shaft is provided to project from both sides of the enlarged wing, and a pair of right and left engagement grooves for pivotally coupling both ends of the pivot shaft is provided. An excavator, wherein the excavation groove is formed on an opposing side wall surface of the groove, and the engagement groove is opened on an inner surface of the device. 2. A front end side of the pivot shaft is formed in a spherical shape,
2. The excavator according to claim 1, wherein the cross-sectional shape of the engaging groove engaged with the pivot shaft is substantially semicircular. 3. A bit device is provided at a tip of a device receiving an impact force and a rotational force so as to be able to move forward and backward, and a plurality of radially rotatable expanding wings are pivotally supported at the tip of the device. A mounting groove for accommodating the expanding wing on the device side is provided in the device by retracting the device with respect to the bit device, and the expanding wing is expanded by advancing the bit device of the device, and the bit device is inserted from the tip of the buried pipe. In a drilling device that excavates by extruding the tip and the expanding wing, a compressed air passage that opens to the base end of the bit device and allows compressed air to pass to the distal end of the bit device is provided, and from the distal end of the compressed air passage. A plurality of branch passages that are branched and open at the distal end surface of the bit device are provided, and the distal end surface of the bit device is forwardly provided from the periphery of the opening of each branch passage. A first groove portion is formed radially toward the outer periphery of the bit device, and a second groove portion communicating with the first groove portion is vertically provided outside the body peripheral surface of the bit device. An excavator, wherein a discharge groove is formed on an outer periphery of the device corresponding to the groove of (1). 4. The method according to claim 1, wherein the depth of the first groove portion is set to 7 to 15% of the diameter of the bit device, and the length of the body peripheral surface of the bit device is set to 30 to 40 mm. An excavator according to claim 3.