Apparatus for controlling underground excavator

• US 4,984,289 A
• Filed: 01/30/1989
• Issued: 01/08/1991
• Est. Priority Date: 07/31/1986
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Original Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Inventors: Arakawa, Shuji, Mimura, Tatsuo
• Primary Examiner(s): Taylor, Dennis L.
• Application Number:
  US07/309,726
• Time in Patent Office: 708 Days
• Field of Search: 405/184, 405/154, 405/303, 175/45, 175/61, 175/62, 175/73, 175/19, 299/1
• US Class Current: 405/184
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 7/06 Deflecting the direction of boreholes
• CPC Class Codes: E21B 7/064 specially adapted drill bits therefor

Abstract

With respect to correcting of a forward movement course of the underground excavator, the control apparatus is so constructed that a positional deviation of the pilot head (20) relative to an excavation planned value is obtained on the basis of detecting of the existent position assumed by the pilot head (20) and the excavation angle correcting means (S1, S2, 21, 23, 41, 71, 72, 73, 80) is provided for automatically correcting an excavating angle of the excavating head (10) on the basis of the positional deviation so as to allow controlling to be achieved automatically. With respect to controlling of start and stop of excavating operation to be performed by the underground excavator, an arrangement is made such that controlling is semiautomatically achieved using the commanding means (74) disposed in the start pit (SH) to issue commands indicative of start and stop of propelling operation of the propelling jack (40) in response to proper manual handling performed by an operator (M) staying on the bottom of the start pit (SH).

Claims

1. An apparatus for controlling an underground excavator of which excavating head connected to the fore end of a rod pipe and of which pilot head are propelled by actuating a propelling jack in such a manner as to follow an excavation planned line extending over the ground surface while a plurality of rod pipes having a predetermined length are successively connected to one after another so that a tunnel is excavated between a start pit and a target pit along said excavation planned line, wherein said apparatus comprises:

a magnetic field generating cable laid on the ground surface corresponding to the excavating planned line, having a going line and a returning line maintained at an equal distance from said excavation planned line, to generate a predetermined intensity of magnetic field by causing a properly determined intensity of electric current to flow therethrough;

excavating angle correcting means adapted to obtain a positional deviation of the existent position assumed by said pilot head relative to an excavation planned value of the pilot head when the generated magnetic field is detected and then automatically correct an excavating angle of said excavating head on the basis of said positional deviation, said excavating angle correcting means comprising;

a first magnetic field detecting element immovably supported in the pilot head for detecting a magnetic field generated by the magnetic field generating cable utilizing an electromotive voltage induced by the magnetic field in such a manner that the direction of detecting of the magnetic field is inclined by a predetermined angle from a perpendicularly extending axis as viewed from the front side in the direction of propelling of the pilot head;

a second magnetic field detecting element immovably supported in the pilot head for detecting a magnetic field generated by the magnetic field generating cable utilizing an electromotive voltage induced by the magnetic field in such a manner that a direction of detecting of the magnetic field relative to said second magnetic field detecting element intersects the direction of detecting of the magnetic field relative to said first magnetic field detecting element at a predetermined angle in a linear symmetrical relationship with respect to the perpendicularly extending axis as viewed from the front side in the direction of propelling of the pilot head;

first calculating means for obtaining a positional deviation relative to the excavation planned line as viewed in the transverse direction as an amount of deviation from a balanced point in the magnetic field generated by the going line and the returning line of the magnetic field generating cable on the basis of a ratio of the value of a magnetic field detected by said first magnetic field detecting element to the value of a magnetic field generated by said second magnetic field detecting element;

inclination detecting means accommodated in the pilot head for detecting an inclination of the pilot head relative to the horizontally extending plane;

propelled distance detecting means for detecting a propelled distance of the pilot head from the start pit on the basis of the number of used rod pipes;

second calculating means for obtaining a positional deviation of the pilot head as viewed in the vertical direction relative to the depth planned value preset from the ground surface on the basis of a detected value of said inclination detecting means and a detected value of said propelled distance detecting means;

whereby an excavating angle of said excavating head is automatically corrected on the basis of positional deviations obtained by said first and second calculating means; and

commanding means disposed in said start pit as a remote actuating unit to issue commands indicative of start and stop of propelling operation to be performed by said propelling jack by manually handling said commanding means in a suitable manner.

2. An apparatus for controlling an underground excavator as claimed in claim 1, wherein said predetermined angle formed by the first and second magnetic field detecting elements relative to the perpendicularly extending axis as viewed from the front side in the direction of propelling of the pilot head is 45 degrees.