JPS6340097A - Tricone bit in underground excavator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a tricone bit for excavation, particularly to a tricone bit for use in underground drilling equipment.

(Prior Art) Conventionally, when burying 51111?1 etc. underground, an underground excavation device has been used which buries a pipe while excavating a horizontal hole underground.

In this case, if the ground where the pipe is buried is in a stratum containing gravel, one or more recon bits are arranged in a ring at the tip of the excavation rig, and these recon bits are driven to revolve to create a narrow path underground. Even if it is a gravel layer, it can be crushed and excavated.

(Problems to be solved by the invention) However, in the conventional drilling equipment using a tricone bit,
Inside the tip of the leading pipe of the casing provided inside the buried pipe are a plurality of outer tricone bits whose axes face toward the center of the forward position of the leading pipe, and whose axes face outward. ! Two inner 1-recombinant bits are arranged in a ring.

With such a structure, since the outer 1-recon bits 1~ circle 2 is not parallel to the conical surface of the inner tricone bit, the tip side of the outer tricone bit 1~ and the inner 1-recon bit There is a high possibility that the same lump of gravel will come into contact with the MQF+i side of the bit. In such a case, the blade on the distal end constantly contacts and excavates at the same location, resulting in severe wear, and even if the blade on the proximal end is not worn that much, the number of replacements due to wear is increased.

As a countermeasure to this problem, the apex of the cone that forms the outer helicon pit is aligned with the axis of the tip of the tip i4 tube, and the length of the bit is kept the same as before, but the tip side is made with a point. Instead, we devised a surface with a gentle cone angle, but even though this solved the problem of j〒 bending,
As the surface area of the bit increases, the drilling resistance increases.
New problems arose, including the inability to rotate effectively.

In view of this, the present invention aims to provide a tricom pit for underground excavation equipment which prevents heeling and smoothes the rotation, thereby eliminating the drawbacks of the prior art.
It is what was done.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of pipes whose axes are directed toward the center of the front position of the leading pipe of the casing inserted into the inside of the buried pipe. In an underground cutting machine with a tricone bit arranged in a ring, the tricone bit, which has a substantially conical shape, is separated in a direction perpendicular to its axis and divided into two parts: a large base bit and a small tip 1~, The apexes of Dl'fA of these large and small bits were formed in a shape that approximately coincides with the center of the front position of the leading pipe, and a support member was interposed in the casing between the small bits to rotatably support the guide pipe. [In underground excavation equipment]・Reconbit is characterized.

[For production]

By adopting this configuration, it is possible to reduce abnormal wear only in local parts when the tricone bit rotates, and also to reduce the
Dividing the single bit into two parts, a large bit and a small bit, prevents the rotation from stopping at the same time when excavation resistance is large, allowing smooth excavation.

〔Example〕

The present invention will be described below with reference to embodiments shown in FIGS. 1 to 6.

As shown in the cross section of FIG. 1, the hollow type underground excavation machine to which the present invention is applied has a buried pipe 3 placed in a base 2 installed in a pilot hole 1, and a buried pipe 3 placed in the base 2 with the front end A casing 4 in which a conduit 5 is disposed is supported by a plurality of rollers 6 so as to be rotatable within the buried pipe 3 and slidable in the front-rear direction.

The driving source for digging through the buried pipe 3 and the casing 4 is a gear motor 7 that transmits power to a propulsion jack 8 via a chain (not shown), etc., and horizontal excavation is performed by the operation of this propulsion jack 8. There is.

There is a cutting edge 9 provided around the leading pipe 5 on the front surface of the buried pipe 3, and a plurality of supporting members 1 are provided in the leading pipe 5.
One end of the o is rotatably mounted, and the other end is provided with an outer bit 11, respectively.

Note that the inner bit that is actually provided in FIG. 1 is omitted because it is a schematic diagram.

The cutting edge 9, the outer bit 11 and the inner bit 1-
(See FIG. 1 (not shown)) The excavated earth and sand are discharged from a leading pipe 5, through a casing 4, and from an outlet (not shown).

In the figure, 12 is a cutting hose, 13 is a main power kissep tie pulling 7 cord, and 14 is a cutting hydraulic hose.

As shown in FIGS. 2 and 3, the tricone bit 15 of the underground excavation equipment according to the present invention has a large base bit 16.
, a small tip bit 17, a support member 18 provided therebetween, a shaft 19 spanning the three, and bearings 20, 2 provided in the large base bit 16 and small tip bit 17.
It is composed of 0, etc.

The large base bit 16 and the small tip 17 are integral tricone bits having a substantially conical shape, with the axis 2
1, and 114 points of the conical generatrix 22.22 of the large base bit 16 and the small tip bit 17 are located at the center of the forward position of the leading pipe 5. It is formed in a shape that substantially matches the shape shown in Figure 4).

The large base bit 16 and the small tip bit 17 have a conical shape with a protrusion 25 such as a blade embedded in a conical main body 23.24. There is a support portion 26 of the support member 18 between
is provided.

A shaft 19 is fixed to the support portion 26, and the large base bit 16 and small tip bit 17 are rotatably supported at both ends of the shaft 19 via bearings 20 and 20, respectively.

Figures 4 to 6 show an embodiment of underground excavation equipment using the tricone bit according to the present invention, and the same parts as in Figure 1 are designated by the same reference numerals and dimensions. , the casing 4 inserted into the buried pipe 3, and the leading pipe 5 of the casing 4, with the axis facing the front center of the leading pipe 5? !
Two (four in the illustration) outer tricon pits 1 of the present invention
~15+ 15+... and a plurality of (4 in the illustration) located between each of these outer tricone bits 15.15...
The inner helicon pits 1 to 27, 27, and so on are arranged in a ring shape.

The support member 18 is attached to the outer recombinants 1 to 15.
The support member 18 is provided with a first J3 and a second
Behind and in front of the annular members 28 and 29, a stopper portion 30 and a push-back means 31 are provided on the first annular member 28, and a bearing portion 32 is provided on the second annular member 29, respectively.

In the illustrated embodiment, the support member 18 is formed with a twisted portion 33 inclined at an angle of about 35° from the support portion 26, and a flat portion 34 is further formed from the terminal end of this twisted portion 33.

Therefore, the surface of the support portion 26 and the flat portion 34 are formed at an angle that is twisted by the amount of the twisted portion 33.

One side 35 of the flat part 34 can come into contact with the stopper part 3o, and the end 36 of the flat part 34 can contact the stopper part 3o.
is adapted to be engaged with the bearing portion 32.

The first annular member 28 is provided with an angled guide hole 37 extending from the vicinity of the outer periphery to the vicinity of the circumference.
When the flat part 34 of the support member 18 is inserted into the guide hole 37, it can be fitted loosely in the width direction J3, and one end in the width direction is formed in the stopper part 30.

Further, the first annular portion 28 is provided with a push-back means 31 (a spring in the fifth figure) such as a spring, a damper, or a similar elastic body, which constantly presses the other side of the support member 18. It is taken as such.

The second annular member 29 has an end portion 36 of the flat portion 34.
A bearing portion 32 is provided which engages with the forked portion.

In this case, the hole 3 in the end 36 of the flat part 34 of the support member 18
8 is pivotally supported by a pin 39 in a bearing portion 32 of the second annular member 29, so that the support member 18 can swing around the pin 39.

When the other side of the flat part 34 is pressed by the push-back means 31 and the one side 35 comes into contact with the stopper part 30, the three forming the outer tricon pits 1 to 15
The A section bit 16a3 and the small tip 1-17 are rotated and protrude outward from the outer diameter of the buried pipe 5 to be in the digging state.

In addition, in FIG. 5, a plurality of cutting edges 9 are provided protruding from the outer periphery of the leading pipe 5, and the bolt 40 is in a protruding state during excavation.
However, when the leading pipe 5 is retracted, the bolt 40 can be loosened and folded so that it does not approach the outer circumferential surface. Figure 41 is a di-India flange.

Next, the effect will be explained.

First, at 1iFr when excavation is started, the outer 1-recombiner bit 15 is placed in a state where it protrudes beyond the outer diameter of the buried pipe 3, that is, one side 35 of the J5 support member 18 is placed at the stopper section. 30, and when the casing 4 is rotated, for example, clockwise by a drive device (not shown), the leading pipe 5 rotates together, and both the outer and inner tricon pits 1 to 30 are rotated.
15.27 revolves. These tricone bits 15.2
7 crushes underground gravel, and the crushed gravel is taken into the casing 4, carried rearward by a spiral wing (not shown), and discharged to the ground.

The outer and inner tricone bits 15°27 in contact with the gravel rotate about the support part 18 and the center of the axis between them and a support part (not shown), and especially in the outer tricone bits 1 to 15, the base large bit 16 The small tip bit 17 rotates separately and independently, and when the resistance is large, it is slow and when the resistance is small, it is ♀, and the tip part makes point contact with the gravel -C
Crush the gravel while maintaining point contact.

In this case, the outer tricone bit 15 is pressurized by earth pressure in the direction of protruding outward from the buried pipe 5 when rotated forward (for example, clockwise), and when rotated in reverse (for example, left) Pressure is applied in the direction of inward diameter reduction. When the earth pressure disappears, the support member 1 is pushed back by the push-back means 31.
8 is pressed and it becomes possible to quickly return to the digging position.

Therefore, when the outer tricone bit 15 is replaced due to wear or the like, the leading pipe 5 is moved backward, and when it reaches the rear end of the buried pipe 3, the bearing part 32 to which the support member 18 is connected is
After removing the pin 39 from the guide hole 37 of the first annular member 28, the first annular member 28 can be pulled out. In order to install a new 1-recombiner bit 15 or a repaired tricone bit 15, this procedure can be reversed.

In addition, in the example, the case where the twist angle is 35° was explained for the support member having a twisted part, but the twisted part is not essential, and even if there is a twisted part, it is necessarily limited to b35°. =(・No.

(Effects of the Invention) As explained above, the present invention provides +11 inside the buried pipe;
In an underground excavator in which a plurality of tricone bits are arranged in a ring with the axis facing toward the center of the front position of the leading pipe of the casing to be inserted, the tricone bit, which has a substantially conical shape, is arranged in a direction perpendicular to the axis of the tricone bit. Separate it into a large base bit and a small tip bit, and form the apex of the generatrix of these small bits into a shape that approximately coincides with the center of the front position of the leading pipe. Since the bits are rotatably supported by interposing a supporting member to support the casing between the bits, even the small tip bit is different from the conventional one in which only the cutting edge at the circle Slu Il'J comes into contact with gravel and wears abnormally. The problem is gone and F
The protrusions on the entire surface of the I Kit come into contact with gravel, eliminating local wear. In addition, to solve the problem of not being able to rotate effectively due to contact with the protrusions on the entire conical surface, in the present invention, the tricone bit is divided into two parts, a large base bit and a small tip bit, so both bits can be used independently of each other. It becomes possible to rotate. As a result, wear of the blades of the recombiners 1 to 1 is reduced, and excavation efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a side view showing an outline of an underground excavator to which the present invention is applied, FIG. 2 is a front view of an embodiment of the tricone bit according to the present invention, and FIG. 3 is a side view of FIG. Figure 4 shows the underground excavation equipment to which the tricone bit is applied. front view of l,
FIG. 5 is a side view of the 41st embodiment, and FIG. 6 is a perspective view of the 41st embodiment showing the relationship between the tricone bit and the support member of the present invention. 3... Buried pipe, 4... Casing, 5... Leading pipe, 15... Tricompit 1~. 16... Base large bit, 17... Tip small bit, 18... Support member, 1
One...shaft, 20...bearing, 21...axis line, 22...
...Bus bar, ○...center of leading pipe. Applicant's agent Mr. Sato Figure 4

Claims (1)

[Claims] In an underground excavator that has a plurality of tricone bits arranged in a ring with the axis facing toward the center of the forward position of the leading pipe of the casing that is inserted into the inside of the buried pipe, a tricone bit having a substantially conical shape is aligned with the axis of the tricone bit. The guide tube is separated in a direction orthogonal to the guide pipe and divided into two parts, a large base bit and a small tip bit, and the apexes of the generatrix of these large and small bits are formed into a shape that approximately coincides with the center of the front position of the leading pipe. A tricone bit for an underground excavation equipment, characterized in that the small bit is rotatably supported with a support member interposed between the small bits to support the casing.