JPS5938395B2 - Rotary lock bit and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ground drilling technology, and more particularly to a row relock bit made from a number of image-side segments joined together using energy beams and a method of manufacturing the same. Pertains to.

Row drill lock bits typically include a main bit body that is adapted to be connected to a row drill string.

A cutter means connected to the main bit body contacts the formation during the drilling operation to form the desired hole.

The present invention provides a row relock bit that is made up of separate, independent segments.

The segments are joined together using energy beams.

Rokelock bits must operate under extremely harsh ambient conditions and must effectively drill through very hard formations to form the desired hole.

The gauge dimensions of the bit must be precise.

In the prior art, non-uniform gauge dimensions of bits have been a problem.

In some operations, the bit must pass through the casing with minimal gaps.

In other operations, the bit needs to pass through a hole and drill a hole that is within a few tenths of an inch of the gauge size of the bit.

If the dage size of the bit changes during the manufacturing process, the bit will experience various problems during drilling operations.

The conventional method of making rotary lock bits is as follows:
A filler must be used to size the bit to the appropriate gauge size.

According to the present invention, bits can be made with accurate and uniform gauge dimensions without using fillers.

During the manufacture of rotary lock bits according to the prior art, significant amounts of heat are generated when the individual segments of the bit are welded together.

Conventional bits require cooling power to prevent tempering of the steel components and to prevent thermal failure of the rubber components.

Excessive heat risks causing uneven hardening of the metal in the rock bit, thereby causing premature failure of the metal during drilling operations, as rock bits often have rubber or synthetic resin parts. , excessive heating in the vicinity of those parts can weaken or damage them.

Dowels must be used between segments of conventional bits to properly align them.

A conventional method of manufacturing a rotary lock bit consists of forming a weld groove between adjacent segments of the bit and filling the weld groove with deposited metal through a welding process.

Although the surfaces joining the segments are in an abutting relationship, the surfaces are joined together and the joining of the segments is effected only by the deposited metal.

The cross-sectional shape of the weld according to the prior art is an irregular polygon.

During welding of conventional bits, excess weld metal is created and the excess weld metal results in distortion of the bit body.

The excess weld metal can cause damage to the lubrication system and the bearing system is contaminated by debris from the welding process during the manufacturing process.

The welded metal is not very stiff in the main body, which causes fatigue problems.

When the individual segments of the bit body are joined together,
They must be precisely positioned during the welding process.

If the individual segments are not properly positioned, the gauge dimensions of the bit cannot be accurate.

When an energy line is used to join individual segments of the bit, the individual segments must be precisely aligned with the energy line during the welding process.

By joining the individual segments of the bit body in accordance with the present invention, the gauge dimensions of the bit are accurate.

The problems encountered in prior art manufacturing processes are explained with reference to rotary cone lock bits.

A low recone locking bit includes at least one rotatable cutter mounted on a support pin extending from the main bit body.

Bearings are provided between the cutter and the support pin to facilitate rotation of the cutter, and the outer surface of the cutter is provided with a bit and means for excavating the formation when the cutter is rotated and moved through the formation. ing.

A sufficient amount of lubricant must be supplied to the bearings during the life of the bit.

Lubricant is kept within the bearing area by a flexible rubber seal between the cutter and the support pin.

Excessive heat on the bit damages the rubber seals and/or lubricant.

If the bit body is not made to precise gauge dimensions, difficulties will be encountered when the bit is moved through a casing with minimal clearance or through a hole with minimal clearance.

Excess weld metal can result in distorted bits and inaccurate gauge dimensions.

W, H patented on September 24, 1957.

Re1fschnider U.S. Patent No. 2,807,4
No. 44, a rotary drilling drill is shown in which the bit head is made of a plurality of arcuate segments, each segment being asymmetrical and having a downwardly extending leg and a downwardly extending leg. The bit head has a body portion having a parallel hollow boss with a passage communicating between the interior of the bit head and the hole in the boss.

G, R patented on April 22, 1958.

In U.S. Pat. No. 2,831,661 to Brown, a drill bit is shown consisting of three sub-elements which are adapted to be joined together to form a bit.

After forging, the sub-elements are machined to provide precisely matching surfaces when the elements are assembled together.

The edges that match the segments provide a chamfer to provide a weld groove.

The three partial elements are assembled in a jig and welding is carried out along the grooves.

W, H patented on January 22, 1957.

Schneider U.S. Pat. No. 2,778,9
No. 26, a method is shown for welding and soldering by bombarding the mating surfaces of two parts to be joined with electrons.

The method presented therein shows a system for soldering, welding, or sintering suitable materials by heating the parts to be joined using an electron beam.

The assembly of the row relock bit in the present invention is performed by electron beam welding.

An electron gun used for electron beam welding consists of a hot cathode and an electron lens system having a first lens for intersecting emitted electrons and a 21st lens for focusing the electrons.

Welding using this method is usually carried out in an empty chamber, which is, for example, a rectangular iron chamber that maintains an adjustable vacuum level.

Within the vacuum chamber there is equipment for transporting each segment to be assembled to the welding area, and equipment for manipulating and holding it in its final welding position.

These facilities are usually operated from the outside by means such as numerical control devices.

The segments are brought into a vacuum chamber and held in welding position on a table, and once a predetermined vacuum is achieved, an electron beam is emitted to create a seam between the individual segments.

During welding, the segments undergo pre-arranged movements, including, for example, rotation of the table mentioned above, to complete the required seam and are removed from the vacuum chamber once welding is complete.

The beam intensity and radiation time in electron beam welding are:
Although it depends on the depth of the seam to be welded, by using this method for assembling the lock bit, there is no problem caused by heating as in conventional methods.

It is therefore an object of the present invention to create a %zQ screw bit that will not be damaged or altered by excessive heat during the manufacturing process.

Another object of the present invention is to provide a method for manufacturing rock bits in which the bits are made with accurate gauge orthogonality.

Still another object of the present invention is to provide a strong and durable rock bit without melting zones between segments.

Yet another object of the present invention is to provide a method for manufacturing a rock bit that has substantially 100% bonding with segments that do not have a steep hardness gradient across the heat affected zone.

Still another object of the present invention is to provide a method for manufacturing a ceramic rock bit that is simple in the manufacturing process.

Yet another object of the present invention is to provide more reliability and reliable repeatability in the manufacture of the Rokryokubi.

Yet another object of the present invention is to precisely control welding parameters during welding of a row relock bit.

Embodiments of the present invention will be explained with reference to the drawings.

In FIG. 1, 11. of the lock bit is shown. The individual segments of the bits that make up /3 are shown expanded.

The segment is indicated generally by the reference numeral 10.

Each segment 10 constitutes one arm of a three-cone rotary lock bit.

A central passageway 11 is disposed in the rock bit to permit passage of cutting fluid through the rock bit to the bottom of the wellbore for removing chips and cooling the bit.

Cutting fluid is routed through the central feeder 11 and exits the bit through a nozzle.

One such nozzle 12 is shown in FIG.

The bit is adapted to be connected to the rotating trill string by a threaded connection, which threaded connection is provided by threading the outer surface 13.

The segment 10 of the bit is provided with an art 14 terminating in a support pin 15.

A rotatable gastric cutter 16 is arranged on the support pin 15 and is rotatable there.

A bearing (not specifically shown) between support pin 15 and cutter 16 facilitates rotation of cutter 16.

The bearing comprises a series of ball bearings placed within the ball bearing race 17 of the support pin 15.

After the cone cutter 16 is in place on the support pin 15, the ball bearing is inserted between the inner ball bearing race (not shown) of the cutter 16 and the ball bearing race 17 of the holding pin 15 on the arm 14. through the hole 18.

Once the ball bearing is packed and the cone cutter 16 is locked to the support pin 15J-, the hole 18 is filled with a plug to prevent the ball bearing from becoming loose during operation of the bit.

A number of inserts 19 are placed outwardly of the cutter 16 for drilling the formation as the bit is rotated and moved through the formation.

To increase the life of the bearing, a lubricant is placed in the area between the cutter 16 and the bearing 15.

A rubber seal 20 is placed between arm 14 and cutter 16 to keep lubricant within the bearing area.

In FIG. 2, segment 10 is shown arranged with other 31J (solid segments 21 and 22).

One segment is positioned in fixture 23, with segments 10, 21 and 22 placed in the appropriate position relative to the final bit.

This fixture allows the apertures 24 between each individual segment of the lock bit to be placed in the proper position for the joining or welding process.

A high velocity electron beam or electron beam is directed at the seams between the individual segments of the rock bit, melting the segments together and creating a fully integrated rock bit.

The electron beam is generated by the electron beam gun 30, and the electron beam 29 is transmitted between the segments l-10, 2L22 and the electron beam gun 3.
0 is moved in the plane of the seam.

Because the electron beam (10 KW/myl) is very strong and the capacity of the electron beam is large (60 KW), the width of the area between the segments is much narrower than in prior art lock bits.

In addition, the electron beam gun generates an electron beam that penetrates substantially the entire area to be bonded.

The energy from the electron beam is applied rapidly, thereby preventing a rise in temperature of parts of the lock bit and reducing the risk of damage to parts of the lock bit that are less heat resistant, such as the rubber seal 20 and lubricant. ing.

Segments 10° 21 and 22 of the lock bit are mated together and have a square butt (5qua
re-butt) forming a junction.

The electron beam does not add material that increases the deposited metal along the seam, and there is very little, if any, strain.

In FIG. 1, surfaces 25 and 26 are planar and are adapted to be placed in contact with the other segments making up the locking bit.

Edges 27 and 28 of faces 25 and 26, respectively, are substantially square and are not chamfered and beveled as in conventional lock bits.

The method of the invention provides a sufficiently large area to be joined;
This gives the bit greater strength and hardness.

A comparison is made between the welded areas on the individual segments used in the construction of rock bits according to the method of the invention and the welded areas on the individual segments used in the construction of rock bits according to typical conventional methods. .

The measured area corresponds to the part to be joined.

The following table shows that substantially large areas can be joined by the method of the invention.

In FIG. 3, the dimensions of adjacent segments 36 joined by the method of the present invention are shown.

The surface 25 shown in FIG.
1, placed in contact with the adjacent surface.

Substantially the entire surface area is bonded by the method of the invention.

External line 32 indicates the area to be joined in the method of the invention.

The area that is not joined is area 33.

Substantially the entire area of the contact surface is bonded by the method of the invention.

In FIG. 4, the weld area of a prior art lock bit is shown.

An outline 34 indicates the area of welding.

A weld groove is formed between adjacent segments and is filled with deposited metal by the welding process.

The resulting weld is only in the area indicated by outline 34.

Area 35 is the area that will not be welded.

It is understood that substantially large areas can be welded according to the invention.

The method of the present invention prevents fouling of the bit's bearings and lubrication system during the manufacturing process.

Spatter during welding using conventional methods can contaminate bearings and lubrication systems.

Because prior art methods create a significant amount of weld metal, some of the weld metal contaminates the bearing and lubrication system.

In FIG. 5, a horizontal cross-sectional view of a prior art weld is shown.

Segment 36 is located adjacent segment 37.

Surface 38 on segment 36 is opposite surface 39 on segment 37.

Dowel 40 connects hole 41 of segment 36 and segment 3
1 dowel 40 extending into the 7 hole 42 is used to align the segments of the bit in the proper position for welding.

Segment 36 includes a portion 43 which, when joined with contacting portion 44 of segment 37, forms a weld groove.

As previously explained, the bit must have an accurate gauge diameter.

To size the bit to the appropriate gauge diameter, face 3
A shim 45 is placed between 8 and 39.

Various numbers of shims are required to adjust the bit to the proper gauge size.

The weld groove formed by portions 43 and 44 is filled with deposited metal 46.

Surfaces 38 and 39 are not joined by welding, and segments 36 and 37 are joined only by weld metal 46.

The cross section of the weld metal 46 is an irregular polygon.

This weld geometry is subject to complex stresses and the fatigue life is shorter than that of the weld of the present invention.

The deposited metal is shorter than segments 36 and 37.

For example, the hardness of weld metal 46 is approximately in the range of 10 to 20 Rockwell C, while the hardness of segments 36 and 37 is in the range of 25 to 350 Rockwell C.

The soft weld metal is therefore not as strong as adjacent segments 36 and 37.

In FIG. 6 a horizontal sectional view of a weld according to the invention is shown.

Segment 4γ is arranged next to segment 480.

Surface 49 on segment 47 is surface 50 on segment 48
is in contact with

Segments 47 and 48 are joined over substantially the entire surfaces 49 and 50, as described above, and solids 52 and 53 are formed on segments 47 and 48, respectively, by the flash left by the forging of segments 47 and 48. .

No shims are used to size the bit to the proper gauge.

To position segments 47 and 48 (instead of using dowels, segments 47 and 48 are moved relative to each other to bring the bit to the appropriate gauge size.

For example, the upper portions of segments 47 and 48 are moved slightly outward.

Portion 51 of face 50 is exposed by sliding of faces 49 and 50 when the bit is sized to the appropriate gauge.

Preferably, surfaces 49 and 50 are precisely abutted to each other near the lower threaded end of the bit, with slight sliding of surfaces 50 and 51 occurring near the upper portion of the body of the bit.

That is, in order to ensure accurate gage alignment of the bit being formed, both sides of adjacent segments are welded with slight misalignment.

There is a small heat affected zone on each side of surfaces 49 and 50, which is even harder than segments 47 and 48.

For example, this heat affected zone or weld zone is 35 to 45
It has a hardness within the range of 0 Tsukwell C.

This can be compared to segments 47 and 48 having a hardness in the range of approximately 25-350 Tsukwell C.

It is therefore clear that bits made according to the present invention are substantially stronger than bits according to the prior art.

The difference in hardness between the weld area and the segment of the bit of the present invention is small compared to the difference in hardness between the weld and the segment of the bit of the present invention.

The welds of the present invention have less knurling effects than prior art welds.

The present invention is very reliable and repeatable, as compared to the prior art, significantly more manufacturing operations can be performed by machines.

[Brief explanation of the drawing]

1 shows the individual segments of a rotary lock bit, FIG. 2 shows three individual segments of a rotary lock bit placed together for seam welding, and FIG. 3 shows the method of the invention. FIG. 4 is a diagram showing the welding area of a prior art rotary lock bit; FIG. 5 is a horizontal cross-section of a prior art weld; FIG. 6 is a horizontal cross-section of a weld of the present invention. FIG. 10.21, 22: segment, 13: outer surface, 14: arm, 15: support pin, 16: cutter, 25.26: surface, 47, 48: segment, 49° 50: surface.

Claims (1)

[Scope of Claims] 1. A tricone roke locking bit comprising three segments each having a cone cutter on top and each having a pair of substantially planar surfaces, wherein said planar surface abuts one of the planar surfaces of an adjacent segment, and although these abutting surfaces are not exactly aligned, the gauge diameter of the roke relock bit is exactly dimensioned. A rotary locking bit in which the abutting surfaces are welded by electron beam welding. 2. A method for manufacturing a tricone rokelock bit, comprising: preparing three segments each having a cone cutter at the top and having a pair of substantially planar face openings; Collecting two segments together such that each planar surface abuts one of the surfaces of the adjacent segment, the abutting segments can be cut by a cone cutter to obtain a precise gauge diameter. but the abutting surfaces are left unaligned, and the seam between the abutting surfaces is welded by a process comprising the steps of: 1) electron beam welding the seam; 11) directing the electron beam to the eyepiece; 111) causing relative motion between the beam and the eyepiece of the individual segment in the plane of the electron beam; Method.