Hitachi Construction Machinery Co., Ltd.

Nippon Telegraph and Telephone Public Corporation

Hitachi, Ltd.

Naoki Miyanagi

Shigeyuki Sakurai

Yoshiaki Shimomura

Kojiro Ogata

Nobuhiko Tada

Yoshinari Nagano

Shinya Okumura

Kiyoshi Tsuchiya

Masao Suda

Osamu Ae

Yoshiyuki Iwai

Shuichi Satoh

Tsuyoshi Inoue

Kozo Ono

Yutaka Takano

Hikaru Yamamoto

Nobuyuki Tobita

Toru Takatani

Manabu Nakano

Minoru Shiozaki

Takashi Moro

Yasushi Minomoto

Keiji Morimoto

Manabu Hirakawa

A welding method is disclosed for butt welding a first base materialand a second base materialwith each other. To also permit stable and efficient formation of a bead in the form of a fillet weld on a back side of a groove by conducting arc welding from the side of the groove without arranging a bead beforehand on the back side of the groove, the first memberon which a root faceand a single groove facehave been formed, is brought at its root faceinto contact with a flat surfaceof the second base materialA welding wireis arranged facing on the groove formed by the contact between the first base materialand the second base materialThe first base materialand the second materialare caused to fuse at an area of contact between them by an arc from the welding wireA melt, which has been formed by the fusion at the area of contact and the like, is forced out to the back side of the groove to form a bead Bin the form of a fillet weld on the back side of the groove.

Welding method, welding device, welded joint, and welded structure

In an arc welding method and apparatus, a plasma ( ) is generated at a welding intended position on a base material ( ) by a laser ( ) irradiated to the base material ( ). When a discharge electrode ( ) is at a minus potential, an arc discharge ( ) takes place in the direction of the plasma ( ) and is induced at a position irradiated with the laser ( ). When the electrode ( ) is at a plus potential, arc electrons are generated from a laser irradiated point and discharged to the electrode ( ). When a voltage applied between the electrode ( ) and the base material ( ) is alternating, the polarities of the electrode ( ) and the base material ( ) alternately change so that the foregoing phenomena alternately occur. When the base material ( ) is at a minus potential, an arc discharge ( ) takes place from a laser spot. Also, in regard to the arc discharge ( ), since the plasma ( ) is generated by the laser ( ), a stable arc discharge ( ) can be generated irrespective of the state of the base material ( ) or the state of the electrode ( ).

Method for guiding arc by laser, and arc guiding welding and device by the method

An optical deflection angle measuring apparatus which, upon optically measuring a deflection angle, does not require an operation for directing a light onto a position detecting element and makes it possible to obtain measurement results without being affected by external force such as vibrations. A detector is constructed with a common lens for converging diffuse lights from light sources . Position detecting elements - - receive the thus-converged lights from the light sources and detect received positions of the converged lights. Reflecting prisms - - allow the diffuse lights from the light sources to be transmitted and guided so that the diffuse lights from the light sources , are converged, by the lens , onto the position detecting elements - - . The respective position detecting elements are arranged so as not to interfere with the convergence of the lights by the lens . The deflection angle &PHgr; can then be measured by computation.

Position measuring apparatus and optical deflection angle measuring apparatus for underground excavators

Laser processing apparatus, laser processing method and dam bar

Dam bar cutting apparatus and dam bar cutting method

Lead frame fabricating method and lead frame fabricating apparatus

Metal plate processing method, lead frame processing method, lead frame,

In a method for forming a lead frame (1) from a metallic plate, a metallic plate (11) is first etched to form outer leads (4) and outer portions (3b) of inner leads of the lead frame (1). Inner portions (3a) of the inner leads (3) are then laser-cut under the condition that a joint portion (7) is left so as to interconnect the inner leads (3) at their distal ends. Mechanical surface treatment and chemical surface treatment are then carried out to remove dross (10), spatters (9) and oxide films deposited during the laser cutting. Inner areas of the inner leads (3) connected to respective terminals of a semiconductor chip are then plated with gold to form plated terminal portions (3A). Subsequently, the region of the lead frame other than the outer leads (4) is coated with a protective film for solder plating and the outer leads (4) are plated with solder. The joint portion (7) left at the distal ends of the inner leads (3) is then cut off by laser cutting so that the inner leads (3) are separated from one another, thereby forming a final lead frame pattern. The protective film for solder plating is then removed, followed by washing and drying. The inner leads (3) are prevented from being curved due to thermal deformations with the laser cutting, resulting in highly accurate processing.

Lead frame processing method

A vibration generating apparatus including a support body having a first center axis, a first spherical joint element provided at a forward end of the support body and having the center of a sphere located on the first center axis, a vibrating body having a second center axis passing through the sphere center, a second spherical joint element provided on the vibrating body and concentric complementary with the first spherical joint element to cooperate therewith to allow the vibrating body to be supported on the support member for universal movement, a rotary shaft coaxially rotatably supported within the vibrating body, a pair of eccentric weights mounted on the rotary shaft with a phase deviation of 180 degrees and in a manner symmetrical with respect to the sphere center, and a drive motor connected to the rotary shaft for driving same for rotation whereby the pair of eccentric weights are rotated about the second center axis to cause the vibrating body to move in conical motion vibration such that the second center axis describes a circular cone having a vertex located at the sphere center about the first center axis.

Vibration generating apparatus

A pipe laying apparatus having an excavator for performing excavation in the earth to form a substantially horizontally extending hole, with the excavator having connected to its trailing end a leading end of at least one underground pipe at least partially located in the horizontally extending hole, an injector for injecting a viscosity imparting liquid into the earth in which excavation is being performed by the excavator to produce viscosity imparting liquid containing soil particles. A propelling device positioned against a trailing end of the pipe and is located in a starting pit. The viscosity imparting liquid containing soil particles produced by the excavator and injector are conveyed rearwardly of the excavator past an outer periphery thereof and filled in an annular gap defined between the horizontally extending hole and the pipe while the excavator and pipe are advanced by the propelling device. A soil particle discharging device is located between the trailing end of the excavator and the leading end of the pipe and within the pipe for introducing into the pipe the viscosity imparting liquid conveyed rearwardly of the excavator past the outer periphery thereof and discharging the soil particles into the starting pit through the pipe.

Pipe laying apparatus

A pipe laying apparatus including an excavator propulsion unit located in a starting pit. The excavator includes an excavator body having a first axis, an excavating tool having a second axis and located at a forward end portion of the excavator body, and injection ports formed in the excavating tool for injecting a viscosity imparting liquid into soil as excavated. The excavator body has a rearward portion thereof disposed adjacent pipes to be laid each having an outer diameter smaller than the outer diameter of the excavating tool and positioned at a rearward end thereof against the propulsion means, and is operative to excavate the earth to form a hole therein while the viscosity imparting liquid is being injected through the injection ports into the soil as excavated to thereby produce a viscosity imparting liquid containing soil which is conveyed rearwardly through an outer periphery of the excavator body while being filled in an annular clearance defined between the hole formed in the earth and the pipes to be laid, so that the pipes can be successively laid as the excavator body and the pipes are propelled forwardly by the propulsion unit.

A method of and a system for laying a pipe underground wherein a head attached to the leading end of the pipe to be laid underground is caused to move in vibratory movement while a propelling force is exerted on the rear end of the pipe to obtain penetration of the earth by the pipe. While the head is forced to move ahead by the propelling force exerted on the rear end of the pipe, the vibration of the head is measured. When the vibration drops in magnitude, the propelling force is decreased to reduce the speed at which the head is forced to move ahead; so as to cause restoration of the vibration to the original level, and when the vibration rises, the propelling force is increased to increase the speed at which the head is forced to move ahead.

Method of laying pipe underground and system therefor

Growing community of inventors

Ibaraki-ken, Japan

Naoki Miyanagi