JP3124700B2 - Excavator direction control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a drilling direction of a drilling device such as an oil well or gas well drilling machine.

[0002]

2. Description of the Related Art Drilling rigs for drilling holes underground for the purpose of collecting underground resources or civil engineering work, especially for collecting underground fluid resources such as oil, natural gas, geothermal steam, etc. A rotary drilling rig, a typical drilling rig that efficiently drills a well, requires a drilling direction control device that changes the direction of drilling in order to continue drilling work by bypassing hard rock. is there. In addition, when the excavation direction is misaligned for some reason during excavation, an excavation direction control device is required to correct the excavation direction to a target direction.

Conventionally, as an excavation direction control device for a rotary excavator, Japanese Patent Application Laid-Open Nos. 57-21695, 57-100290, and 58-21030 have been disclosed.
No. 0 publication proposes various excavation direction control mechanisms. However, Japanese Patent Application Laid-Open Nos.
The excavation direction control mechanism disclosed in Japanese Patent Application Laid-Open No. 7-100290 and Japanese Patent Application Laid-Open No. 58-210300 not only cannot control the excavation direction in all directions but also has a problem that the mechanism is complicated. And was not fully satisfactory.

Recently, a plurality of hollow harmonic gear reducers and an eccentric hollow portion connected to each output element of the hollow harmonic gear reducer and eccentrically rotating with respect to each corresponding reducer rotating shaft. A plurality of eccentric rotating members comprising: a hollow shaft of the excavator drill mounted so as to penetrate through the hollow portion of the hollow type harmonic gear reducer and the eccentric hollow portion of the eccentric rotating member. A device in which a portion of the rotating shaft is displaced in a direction substantially perpendicular to a shaft central axis by an inner peripheral surface of the rotating eccentric hollow portion (Japanese Patent Laid-Open No. 4-76183), A first and a second hollow-type harmonic gear reducer arranged at a first annular member arranged coaxially with the first hollow-type harmonic gear reducer and rotated by the reducer; A second annular member arranged coaxially with the second hollow-type harmonic transmission and rotated by the transmission, wherein the first and second annular members are relatively rotatable. The annular end faces are superimposed on each other in a state, and the superposed end faces are set as inclined surfaces inclined by a fixed angle with respect to the center axis direction, and the first and second circles are set. A rotating shaft of a drilling drill is arranged in a state penetrating the hollow portion of the annular member, and the first and second annular members are relatively rotated to bend the rotating shaft in a predetermined direction. As shown in FIG. 7, a cylindrical housing 101 and a cylindrical housing 101 are rotatably supported on a circular inner peripheral surface of the cylindrical housing 101. A first annular member 102 having an eccentric circular inner peripheral surface; and a first annular member 102 rotatably supported on the circular inner peripheral surface of the first annular member 102 and having a circular inner peripheral surface. A second annular member 103 having a circular inner peripheral surface eccentric with respect to the first annular member 103;
And cylindrical hollow gear reducers 104 and 105 for relatively rotating the second annular members 102 and 103 around the centers of the members.
1 and the amount of eccentricity of the circular inner peripheral surface of the first annular member 102 with respect to the first annular member 102 is equal to the amount of eccentricity of the circular inner peripheral surface of the second annular member 103 with respect to the first annular member 102. And the second annular member 10
And a rotating shaft 107 having a drill bit 106 at the end thereof so as to move integrally with the center of the circular inner peripheral surface of the third annular member 103 to the second annular member 103. A device for positioning the rotary shaft 107 with a fulcrum bearing 108 as a fulcrum by relatively rotating the shafts 102 and 103 (Japanese Patent Laid-Open No. 5-202689).
No. Gazette).

[0005]

The excavation direction control devices disclosed in Japanese Patent Application Laid-Open Nos. 4-76183, 5-49079 and 5-202689 have the following problems. are doing. (A) The thrust bearing receiving the bit load is the rotary shaft holding mechanism on the upper part of the excavation direction control device, and the bit load acts on the rotary shaft up to this position. (B) The direction and amount of deflection of the rotary shaft are determined by the rotational angle positions of the first and second annular members.Pulse counting methods such as conventional optical sensors and eddy current sensors that detect this rotational angle position are used. It is difficult to maintain the origin with a position detection sensor, and it can be adjusted on the ground, but it is almost impossible to accurately detect it under high temperature and high pressure environment of several hundreds or thousands of meters underground such as oil drilling. (C) The fulcrum of the rotation of the rotating shaft is the shaft holding mechanism on the upper part of the excavation direction control device, and the distance from the fulcrum to the lower seal mechanism becomes longer. As a result, the structure of the sealing mechanism becomes complicated and the design becomes difficult, so that the bending angle of the rotating shaft cannot be made large due to the limitation in the sealing mechanism. (D) The rotary shaft is supported immediately above the drill bit by the double eccentric mechanism, and the vibration during drilling is immediately transmitted to the eccentric mechanism, which has a problem in strength. Therefore, in actual excavation, the excavation direction is controlled using the lateral load of the drill bit.
Since the rigidity of the rotary shaft is weak, the bit lateral load greatly fluctuates due to the bit load, and in some cases, the bit lateral load changes to a force in a direction opposite to the direction to be changed.

SUMMARY OF THE INVENTION It is an object of the present invention to accurately detect the rotational angle positions of the first and second annular members in a high temperature and high pressure environment at the bottom of a shaft, and to displace the rotational shaft in the lower seal portion in a direction perpendicular to the axis. Provided is an excavating direction control device for an excavator capable of minimizing the amount, suppressing the bit load and vibration during excavation from acting on an eccentric mechanism having low strength, and increasing the rigidity of a rotating shaft above the bit. It is in.

[0007]

Means for Solving the Problems The present inventors have intensively studied and studied to achieve the above object. As a result, placing the fulcrum bearing intermediate the drill bit and the double eccentric mechanism section, while a flexible joint for absorbing axis-perpendicular direction displacement of the rotational shaft at the top of the double eccentric mechanism the upper bearing By disposing the fulcrum bearing, the fulcrum bearing not only functions as a thrust bearing that receives the bit load, but also becomes the rotation center when the rotating shaft is displaced in the direction perpendicular to the axis of the double eccentric mechanism, and displaces the drill bit in the opposite direction. The lower seal can be arranged adjacent to the fulcrum bearing to act, the displacement of the lower shaft in the direction perpendicular to the axis of the rotating shaft is small, and the seal structure is simpler. Was absorbed by the flexible joint, and it was found that excessive bending stress on the rotating shaft could be prevented, and the present invention was reached.

That is, the present invention provides a cylindrical housing and an upper seal disposed at upper and lower ends of the cylindrical housing.
Le and the lower seal, with is rotatably supported on a circular inner peripheral surface of the circular tubular housing, a first annular member having a circular inner peripheral surface that is eccentric with respect to the cylindrical housing, the first annular member of the fitted rotatably on a circular inner peripheral surface Rutotomoni, and a second annular member having a circular inner peripheral surface that is eccentric with respect to the circular inner peripheral surface
A hollow harmony gear reducer comprising a double eccentric mechanism for relatively rotating the first and second annular members around the center of the members, the first to the cylindrical housing being The amount of eccentricity of the circular inner peripheral surface of the annular member is set to be equal to the amount of eccentricity of the circular inner peripheral surface of the second annular member with respect to the first annular member. The rotary shaft of the excavator drill is incorporated into the second annular member so as to move integrally with the center of the circular inner peripheral surface of the second annular member, and the first and second annular members are separately used. In the excavation direction control device of the excavator for positioning the rotary shaft by rotating, the first
And a resolver for detecting the rotation angle position of the first and second annular members is disposed between the second annular member and the hollow type harmonic gear reducer, and a drill bit and the first and second
A fulcrum bearing of the rotating shaft is arranged in the middle of the annular member, and a rotating shaft is provided above the double eccentric mechanism.
Flexible joy to absorb displacement perpendicular to axis
The bearing is located between the bearing and the upper bearing.
A drilling direction control device of the arranged Drilling machine lower seal Te.

[0009]

In the present invention, the first and second annular members are provided between the first and second annular members and the hollow harmonic gear reducer.
By disposing the resolver for detecting the rotation angle position of the annular member, the absolute amount of the rotation angle position of the first and second annular members can be accurately detected, and accurate and stable control of the excavation direction is performed. be able to. In addition, the rotor of the resolver can also serve as a power transmission member that transmits the output rotation of each harmonic reduction gear to the first and second annular members, and can have a compact structure.

Further, in the present invention, the fulcrum bearing of the rotary shaft is disposed between the drill bit and the first and second annular members, so that the fulcrum bearing functions as a thrust bearing for receiving a bit load. Not only that, the double eccentric mechanism comprising the first and second annular members serves as a rotation center when the rotating shaft is displaced in a direction perpendicular to the axis, and displaces the drill bit in the opposite direction. It works and has the following advantages: (A) A lower seal portion between the cylindrical housing and the rotary shaft can be installed adjacent to the fulcrum bearing, the amount of displacement of the rotary shaft in the lower seal portion in the direction perpendicular to the axis is small, and the seal structure is simplified. (B) bit load, to be transmitted to the cylindrical housing is received by the fulcrum bearing, does not act immediately bit load from the rotating shaft to the double eccentric mechanism section, a strength weak parts two
The heavy eccentric mechanism can be protected. (C) Since the fulcrum bearing and the lower seal portion are close to each other, the inclination angle of the rotary shaft with respect to the amount of displacement of the rotary shaft in the direction perpendicular to the axis at the lower seal portion can be increased. (D) The distance between the drill bit and the fulcrum bearing can be reduced, and since there is no double eccentric mechanism between them, the diameter of the rotating shaft can be increased, and the rigidity of the rotating shaft can be increased and drilling can be performed. A large bit lateral load during direction control can be obtained.

Further, according to the present invention, a double eccentric machine is provided.
Absorbs the amount of displacement of the rotating shaft perpendicular to the shaft at the top of the structure
Flexible joint between the upper bearing and
By arranging the lower seal adjacent to the fulcrum bearing, the bending force due to the displacement in the direction perpendicular to the axis given to the rotating shaft by the double eccentric mechanism can be absorbed by the flexible joint, and the rotating shaft due to the displacement in the direction perpendicular to the axis can be absorbed. Can be prevented from generating excessive bending stress.

The flexible joint in the present invention is not particularly limited as long as it can absorb the bending force due to the displacement in the direction perpendicular to the axis given to the rotary shaft by the double eccentric mechanism and can prevent the outflow of the muddy water flowing inside the rotary shaft. However, a hollow universal joint in which a seal tube is inserted into the connection between the hollow yoke, the hollow center shaft and the cross pin to seal both ends, or a screw-connected hollow flexible tube using a titanium material with a low Young's modulus, etc. Can be used.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic overall configuration diagram of an excavation direction control device of the present invention, FIG. 2 is a schematic overall configuration diagram of a state in which a rotary shaft is decentered by the excavation direction control device of the present invention, and FIG. 3 is a detailed cross section of an excavation direction control unit. FIG. 4
Is a detailed horizontal sectional view of the double eccentric mechanism, FIG. 5 is an explanatory view showing the operation of the excavation direction control device of the present invention, and FIG. 6 is a schematic block diagram showing a control system of the excavation direction control device. 1 to 6, reference numeral 1 denotes an upper rotary shaft of a rotary excavator, and reference numeral 2 denotes a lower rotary shaft, which is connected to the upper rotary shaft 1 by a flexible joint 3.
Reference numeral 4 denotes a drill collar coaxially connected to the tip of the lower rotary shaft 2, and reference numeral 5 denotes a drill bit fixed to the tip of the drill collar 4, and the upper rotary shaft 1 is connected to a rotation drive mechanism (not shown). Reference numeral 6 denotes a cylindrical housing arranged so as to surround the outer periphery of the upper and lower rotary shafts 1 and 2 above the drill collar 4, and a lower seal 7 is provided between the tip of the cylindrical housing 6 and the lower rotary shaft 2. ing.

Reference numeral 8 denotes a drill bit 5 provided between the cylindrical housing 6 above the lower seal 7 and the lower rotary shaft 2.
3 is a double eccentric mechanism provided between the cylindrical housing 6 above the fulcrum bearing 8 and the lower rotary shaft 2, and as shown in FIG.
Cylindrical member 10 fixedly supported on the inner peripheral surface of
The first annular member 11 rotatably mounted inside the first annular member 11
And a second rotatably mounted inside the annular member 11.
Of the annular member 12. 13 is a first harmonic reduction gear for rotating the first annular member 11 provided immediately above the double eccentric mechanism 9, and 14 is the second circle provided immediately below the double eccentric mechanism 9. This is a second harmonic reduction gear for rotating the annular member 12. Reference numeral 15 denotes a bearing that supports the lower part of the upper rotary shaft 1, and reference numeral 16 denotes a cylindrical housing 6.
Is an upper seal between the upper part of the shaft and the upper rotating shaft 1.

As shown in FIG. 3, the first harmonic gear reducer 13 has a ring-shaped first and second rigid internal gear 2.
1 and 22, an annular external gear 23 disposed inside thereof, and an elliptical wave generator disposed inside thereof. The wave generator includes an elliptical rigid cam plate 24 and a bearing 25 inserted between the outer periphery of the rigid cam plate 24 and the surrounding external gear 23.
A hollow part 26 is formed at the center of the elliptical rigid cam plate 24, and the lower rotary shaft 2 penetrates with play. The first rigid gear 21 is fixedly supported on the inner peripheral surface of the cylindrical housing 6. One end of a hollow rotor 28 of the resolver 27 is connected to the second rigid gear 22, and the other end of the hollow rotor 28 is directly connected to the first annular member 11. 29 is fixed to the inner peripheral surface of the cylindrical housing 6, and includes the second rigid gear 22, the hollow rotor 28 and the first annular member 11
Are designed to rotate together. The wave generator is connected to the lower rotating shaft 2 via the electromagnetic clutch brake mechanism 30 and the first Oldham coupling 31, and operates the electromagnetic clutch brake mechanism 30 to rotate the lower rotating shaft 2. Is transmitted to the first harmonic reduction gear 13, the first harmonic reduction gear 13 reduces the speed to a predetermined reduction ratio, and then the first annular member 11 through the hollow rotor 28 of the resolver 27. Is configured to rotate.

The second harmonic gear reducer 14 includes annular first and second rigid internal gears 41 and 42, an annular circumscribing external gear 43 disposed inside thereof, and an internal , And an elliptical wave generator arranged at the center.
The wave generator includes an elliptical rigid cam plate 44 and a bearing 45 inserted between the outer periphery of the rigid cam plate 44 and the external gear 43.
A hollow portion 46 is formed at the center of 4, and the lower rotary shaft 2 penetrates with play. The first rigid internal gear 41 is fixedly supported on the inner peripheral surface of the cylindrical housing 6. One end of a hollow rotor 48 of a resolver 47 is connected to the second rigid internal gear 42, and the other end of the hollow rotor 48 is connected to the second annular member 12 via an Oldham type alignment mechanism 49. The stator 50 of the resolver 47 is fixed to the inner peripheral surface of the cylindrical housing 6,
The second rigid internal gear 42, the hollow rotor 48, and the second annular member 12 are integrally rotated via an Oldham type alignment mechanism 49. Also, the wave generator
Electromagnetic clutch brake mechanism 51, second Oldham coupling 5
2 and connected to the lower rotating shaft 2 side,
If the torque of the lower rotary shaft 2 is transmitted to the second harmonic gear reducer 14 by operating the electromagnetic clutch brake mechanism 51, the second harmonic gear reducer 14 reduces the speed to a predetermined reduction ratio, and then the resolver 47. The second annular member 12 is configured to rotate via the hollow rotor 48 and the Oldham type alignment mechanism 49.

The outermost cylindrical member 10 of the double eccentric mechanism 9 has a circular center surface defined by the fulcrum bearing 8, that is, a circular inner peripheral surface having a center on the shaft rotation axis A as shown in FIG. A circular outer peripheral surface 63 of the first annular member 11 is rotatably supported via a roller bearing 62. First annular member 1
1 has a circular inner peripheral surface 64 centered on a position B eccentric to the shaft rotation axis A by a distance e, and a circular outer peripheral surface 66 of the second annular member 12 via a roller bearing 65. It is rotatably supported. The second annular member 12 has a circular inner peripheral surface 67 centered on a position C eccentric by the same distance e with respect to the center B of the circular outer peripheral surface 66, and the outer peripheral surface of the lower rotary shaft 2 is a roller. It is rotatably supported via a bearing 68.

The double eccentric mechanism 9 supports the lower rotary shaft 2 by controlling the rotation angle positions and the relative rotation amounts of the first and second annular members 11 and 12. The center C of the circular inner peripheral surface 67 of the annular member 12 can be moved by a predetermined distance in an arbitrary direction. That is, as shown in FIG. 5, since the center B of the circular inner peripheral surface 64 of the first annular member 11 is eccentric with respect to the shaft rotation center A by the distance e, the center B is centered on the shaft rotation center A. A circle having a radius e is a movement locus.
Since the center C of the circular inner peripheral surface 67 of the second annular member 12 is eccentric by a distance e with respect to the center B describing the movement trajectory, a circle having a radius e centered on the center B forms a movement trajectory. It is. Therefore, the center C of the circular inner peripheral surface 67 of the second annular member 12 is the same as that of the first and second annular members 11,
By controlling the rotation angle of 12 and the relative rotation amount,
The portion of the lower rotary shaft 2 supported in the double eccentric mechanism 9 can be moved to an arbitrary position within a circle having a radius 2e around the shaft rotation axis A, and is orthogonal to the rotation axis. It is configured such that it can be displaced in any direction on the plane by a distance of up to 2e.

The center of the lower position of the lower rotating shaft 2 is held by a shaft rotating shaft A by a fulcrum bearing 8. Therefore, the tip side of the lower rotary shaft 2 is shown in FIG.
, The center A of the fulcrum bearing 8 and the double eccentric mechanism 9
In the direction along the line segment L connecting the center C of the circular inner peripheral surface 67 of the second annular member 12 with the traveling direction (excavation direction)
Is changed. In this case, since the lower rotary shaft 2 and the upper rotary shaft 1 are connected via the flexible joint 3, bending stress due to displacement of the lower rotary shaft 2 in a direction perpendicular to the axis is absorbed, and the upper rotary shaft 1 and the lower rotary shaft 1 are rotated. No deflection occurs in the shaft 2. In this embodiment, since the eccentric amounts of the centers B and C of the circular inner peripheral surfaces 64 and 67 formed on the first and second annular members 11 and 12 are both e, the excavation direction is controlled. If it is not necessary, control is performed so that the center C of the portion of the lower rotary shaft 2 penetrating the double eccentric mechanism 9 is located on the shaft rotary axis A.

In FIG. 6, reference numeral 71 denotes a host computer which controls the entire driving of the excavator, and 72 denotes a controller of the excavation direction control device. The host computer 71 receives an azimuth and angle command signal 73 for defining the excavation direction. You. The controller 72 controls the first and second annular members 11, based on the azimuth and angle command signals 73 that define the digging direction input from the host computer 71,
Target rotation position calculation unit 74 for calculating the twelve target rotation positions
have. The controller 72 also includes a resolver 2 interposed between the first and second annular members 11 and 12 and the first and second harmonic reduction gears 13 and 14.
Based on the angle detection signals 75 and 76 from 7 and 47, the first
And an actual rotation position calculation unit 77 that calculates the actual rotation position of the second annular members 11 and 12. further,
The controller 72 includes the first and second annular members 1.
A drive signal instructing section 79 for outputting a drive control signal 78 for controlling the drive of the first and second harmonic reduction gears 13 and 14 such that the actual rotational positions of the first and second 12 become the target rotational positions. ing. The drive control signal 78 output from the drive signal command unit 79 is output to the drive control units 80, 81 of the first and second harmonic reduction gears 13, 14. The drive control units 80 and 81 include the drive signal command unit 7
9, when the drive control signal 78 is input, the electromagnetic clutch brake mechanisms 30, 51 connected to the first and second Oldham couplings 31, 52 are operated to reduce the rotational force of the lower rotary shaft 2 to the first. After transmitting to the second harmonic reduction gears 13 and 14 and reducing the gears to a predetermined reduction ratio, the first and second annular members 11 and 12 are passed through the hollow rotors 28 and 48 of the resolvers 27 and 47, respectively. It is configured to rotate and hold 12 to a target rotational position. Such first and second annular members 11, 12
Is achieved by executing a control program stored in the host computer 71 in advance.

With the above configuration, when the excavating direction of the excavator is changed, the host computer 71 outputs to the controller 72 an azimuth and angle command signal 73 that defines the excavating direction.
2 is the first rotation position calculation unit 74 based on the azimuth and angle command signal 73 that defines the input digging direction.
And the target rotational positions of the second annular members 11 and 12 are calculated and output to the drive signal command unit 79. On the other hand, the actual rotation position calculation unit 77 includes the first and second annular members 11, 1
2 and the first and second annular members 1 based on angle detection signals 75 and 76 from resolvers 27 and 47 interposed between the first and second harmonic reduction gears 13 and 14, respectively.
Calculate the actual rotational positions of the drive signals 1 and 12 and calculate the drive signal
9 is output. When the target rotation positions of the first and second annular members 11 and 12 are input from the target rotation position calculation unit 74, the drive signal command unit 79 outputs a drive command to the drive control units 80 and 81, Actual rotation position calculator 7
7 and the first and second annular members 11, 1
Drive control of the first and second harmonic reduction gears 13 and 14 based on the actual rotational position of the first and second annular members 11 and 12 such that the actual rotational position of the first and second annular members 11 and 12 becomes the target rotational position. A drive control signal 78 is output to the drive control units 80 and 81.

When a drive command is input from the drive signal command unit 79, the drive control units 80 and 81 control the electromagnetic clutch brake mechanisms 30 and 51 to control the electromagnetic clutch brake mechanisms 30 and 51 via the first and second Oldham couplings 31 and 52. The rotational force of the lower rotary shaft 2 is transmitted to the first and second harmonic reduction gears 13 and 14, and the first and second toroids are formed based on a drive control signal 77 input from a drive signal command unit 79. Member 1
After changing the rotation angle positions and the relative rotation amounts of the first and second annular members 11 and 12, the rotation positions of the first and second annular members 11 and 12 are reduced to a predetermined reduction ratio so as to become the target rotation position, and then the resolvers 27 and 47 are rotated. Through the hollow rotors 28, 48 of the first
And the second annular members 11 and 12 are rotated and held to a target rotational position. By the above operation, the lower rotary shaft 2 penetrating through the circular inner peripheral surface 67 of the second annular member 12 is inclined by a predetermined amount in an arbitrary direction on a plane orthogonal to the rotation axis around the fulcrum bearing 8. The excavation direction can be changed to any direction. In this case, the bending stress between the upper rotary shafts 1 due to the displacement in the direction perpendicular to the axis about the fulcrum bearing 8 of the lower rotary shaft 2 is absorbed by the flexible joint 3, and the radius of the upper rotary shaft 1 and the lower rotary shaft 2 is reduced. It is greatly reduced, and the rotating shaft can be used for a long time.

In this embodiment, the resolvers 27 and 47
Between the first and second harmonic gear reducers 13 and 14 and the first and second annular members 11 and 12, The absolute amount of the rotation angle position can be detected with high accuracy, and accurate and stable control of the excavation direction can be performed. The resolvers 27 and 47 directly connect the first and second harmonic reduction gears 13 and 14 and the first and second annular members 11 and 12 with hollow rotors 28 and 48, respectively. Since it also serves as a power transmission member for transmitting the output rotation of the second harmonic gear reducers 13 and 14 to the first and second annular members 11 and 12, a compact structure can be achieved. Further, in the present invention, the fulcrum bearing 8 is connected to the drill bit 5
And between the double eccentric mechanism 9 and
The fulcrum bearing 8 functions as a thrust bearing for receiving the load of the drill bit 5 and serves as a rotation center when the lower rotary shaft 2 is displaced in a direction perpendicular to the axis, so that the drill bit 5 is oriented in a direction opposite to the inclination direction of the double eccentric mechanism. To be displaced.

In the present invention, the lower seal 7 is provided between the drill bit 5 and the fulcrum bearing 8, so that the displacement of the lower rotary shaft 2 in the direction perpendicular to the axis at the lower seal 7 is small, and the seal structure can be simplified. And the inclination angle of the lower rotary shaft 2 at the lower seal 7 can be made large. Also, the lower seal 7
The diameter of the lower rotary shaft 2 between the drill shaft 4 and the drill collar 4 can be increased, the rigidity can be increased, and a large lateral load on the bit can be obtained when the drilling direction is controlled.

[0025]

As described above, the excavation direction control apparatus according to the present invention uses the resolver for detecting the eccentric angle of the double eccentric mechanism to accurately determine the absolute amount of the rotational angular position of the two annular members. Detection can be performed well, and accurate and stable stepless control of the excavation direction can be performed. In addition, by disposing the fulcrum bearing between the double eccentric mechanism and the drill bit, the lower seal can be arranged adjacent to the fulcrum bearing, and the displacement of the rotating shaft in the lower seal portion in the direction perpendicular to the axis is small. Not only the structure is simplified, but also the hit load is received by the fulcrum bearing and transmitted to the cylindrical housing, so the bit load is not immediately applied to the double eccentric mechanism from the rotating shaft, and the double eccentricity is weak in terms of strength. The mechanism is protected. Furthermore, since the fulcrum bearing and the lower seal are close, the inclination angle of the rotating shaft at the lower seal can be increased, and
The diameter of the rotating shaft can be increased. Furthermore, by arranging the flexible joint above the double eccentric mechanism, bending of the rotating shaft can be prevented by the flexible joint, and generation of excessive bending stress can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an excavation direction control device of the present invention.

FIG. 2 is a schematic overall configuration diagram showing a state in which a rotary shaft is decentered by the excavation direction control device of the present invention.

FIG. 3 is a detailed vertical sectional view of an excavation direction control unit of the excavation direction control device of the present invention.

FIG. 4 is a detailed horizontal sectional view of a double eccentric mechanism of the excavation direction control device of the present invention.

FIG. 5 is an explanatory diagram showing an operation of the excavation direction control device of the present invention.

FIG. 6 is a schematic block diagram showing a control system of the excavation direction control device of the present invention.

FIG. 7 is a schematic explanatory view of a drilling direction control device of an oil well drilling machine disclosed in Japanese Patent Application Laid-Open No. 5-202689.

[Explanation of symbols]

 Reference Signs List 1 upper rotating shaft 2 lower rotating shaft 3 flexible joint 4 drill collar 5, 106 drill bit 6, 101 cylindrical housing 7 lower seal 8, 108 fulcrum bearing 9 double eccentric mechanism 10 cylindrical member 11, 102 first annular Member 12, 103 Second annular member 13 First harmonic gear reducer 14 Second harmonic gear reducer 15 Bearing 16 Upper seal 21, 41 First rigid internal gear 22, 42 Second rigid internal gear Gears 23, 43 Surroundable external gears 24, 44 Rigid cam plates 25, 45, 62, 65, 68 Roller bearings 26, 46 Hollow portions 27, 47 Resolvers 28, 48 Hollow rotors 29, 50 Stator 30, 51 electromagnetic clutch brake mechanism 31 first Oldham coupling 49 Oldham type alignment mechanism 52 second Oldham coupling 61 64, 67 Circular inner peripheral surface 63, 66 Circular outer peripheral surface 71 Host computer 72 Controller 73 Command signal 74 Target rotation position calculation unit 75, 76 Angle detection signal 77 Actual rotation position calculation unit 78 Drive control signal 79 Drive signal command unit 80, 81 Drive control unit 104, 105 Harmonic gear reducer 107 Rotary shaft

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21B 7/08 E21B 17/04 E21B 44/00

Claims (1)

(57) [Claims] 1. A and cylindrical housing, said cylindrical type Haujin
Upper and lower seals disposed on the upper and lower ends of the cylindrical housing, rotatably supported on a circular inner peripheral surface of the cylindrical housing, and having a circular inner eccentric with respect to the cylindrical housing. a first annular member having a peripheral surface, the first annular member rotatably mating Rutotomoni on the circular inner peripheral surface, a circular inner peripheral surface that is eccentric with respect to the circular inner peripheral surface And a double-type eccentric mechanism comprising a second annular member having a hollow-type harmonic gear reducer that relatively rotates the first and second annular members around the center of the members. Having an eccentric amount of the circular inner peripheral surface of the first annular member with respect to the cylindrical housing, and an eccentric amount of the circular inner peripheral surface of the second annular member with respect to the first annular member. Are set to be equal to each other, and coincide with the center of the circular inner peripheral surface of the second annular member. Embedded rotation shaft of the excavator drill to move in manner to the second annular member,
In the excavation direction control device of the excavator that positions the rotary shaft by independently rotating the first and second annular members, the first and second annular members and the hollow harmonic gear A resolver that detects the rotation angle position of the first and second annular members is arranged between the reducer and the first and second annular members,
With placing fulcrum bearing of the rotating shaft in the middle of the drill bit and the first and second annular members, said double
Absorbs the displacement of the rotating shaft in the direction perpendicular to the axis above the eccentric mechanism.
Between the upper bearing and the flexible joint
And the lower seal is arranged adjacent to the fulcrum bearing.
Drilling direction control device of the drilling machine.