Abstract: A hydraulic circuit, having a four-position closed-center valve (6) controlled by a proportional control valve (22), can facilitate the vertical position control and operating speed control of a blade with a simple structure, while providing that the floating condition of the blade can be precisely recognized by the position of a control lever (20a). The spool (41) of the four-position selector valve (6) has a "hold" position which is given by the closed-center position. Opposite ends of the spool (41) receive a pilot pressure from the pressure proportional control valve (22), one position being obtained by applying pilot pressure to a first end of the spool (41), and two positions being obtained by applying pilot pressure to the second end of the spool (41). One of the latter two positions is a "floating" position, while the other two positions are the "up" position and the "down" position.

Abstract: A cabin heating apparatus in accordance with the present invention is provided with a central duct (3) extended to one side of an operator's seat through a front-to-rear changeover damper (2) connected to an air conditioner unit (1), a rear duct (4) extended to the rear of the operator's seat through the front-to-rear changeover damper 2 and outlets (9) formed at an extreme end part of the rear duct (4). The cabin heating apparatus is further provided with a lower outlet (6) for supplying an air flow along a floor through an above-to-below changeover damper (5) connected to an extreme end part of the central duct (3), a front duct (7) rising from the above-to-below changeover damper 6 and a front outlet (8) provided at an extreme end part of the front duct (7). An appropriate air flow distribution ratio is set by these changeover dampers (2, 5).

Abstract: An expert system for retrieving molding conditions, in which a statistical technique is added to the functions of the conventional expert system, causes of defects are inferred from the records of countermeasures taken and inputted defect occurrence situation, conditions for temporary molding are obtained while repeating test molding, qualitative defects are extracted from defects occurred, a boundary of a region in which defects occur is determined with decision analysis of qualitative defects extracted with the use of the record of countermeasures as above, a condition for molding to eliminate the qualitative defects is determined on the basis of the boundary of region of defects occurrence, quantitative defects are extracted from defects occurred, and molding conditions for eliminating the quantitative defects are determined by performing analysis of variance depending on design of experiment with the quantitative defects extracted from the record of countermeasures, whereby the frequency of experiment is

Abstract: A panel bender which can remarkably improve productivity in a bending process, and can feed in and out works having different widths with a single conveyer without causing interference between a main body and the conveyer has a construction in which a plurality of main bodies (1) are provided at opposite positions across a conveyer (16) for feeding the work (A) to a working position within the panel bender, each of the main bodies being movable in a back and forth direction with respect to the other by a back and force feeding device (13). The conveyer (16) disposed between the main bodies is adapted to expand and contract in the width direction in cooperation with back and forth movement of the main bodies.

Abstract: A displacement control device of a variable-displacement hydraulic pump which increases the response speed when the pump discharge pressure is low and suppresses increase of the response speed when the pump discharge pressure is high. The displacement control device has a variable-displacement piston 3 which activates a displacement control member 2 of the variable displacement hydraulic pump 1, a circuit 10 which provides a communication between a large-diameter pressure chamber 6 on the variable-displacement piston 3 and an output port 9 of the control valve 7, and a variable restriction valve 11 which is provided in the circuit 10. The restriction valve 11 increases and decreases its opening area when the pump discharge pressure is low and high, respectively.

Abstract: The object of the present invention is to provide a die-cushion apparatus of a press machine capable of performing a preliminary acceleration imparted to a die-cushion pad following the lowering of a slide with an exact timing and high precision and being improved so as to eliminate a pressure deviation between an actual pressure in a hydraulic cylinder and a preliminarily set aimed value at a portion near a lower dead point of the slide stroke.

Abstract: A thermal cutting machine, capable of providing a high cutting quality and of avoiding any interference between a cut product and the machining nozzle, comprises a workpiece table (4) for supporting a workpiece (5) to be cut, the workpiece table (4) being capable of moving the workpiece in the X-axis direction, and a machining nozzle (2a) for emitting a heat source to cut the workpiece, said machining nozzle (2a) being movable in the Y-axis direction. The workpiece table (4) is provided with a chain conveyer (6) having a plurality of grid elements (11) laterally spanning the chains (10) of the conveyer (6). A retracting means is provided for retracting downwardly at least one grid element (11) which is in the conveyor position corresponding to the cutting path for the machining nozzle, by depressing the portion of the chains (10) which support that grid element.

Abstract: A molding apparatus with die-clamping and alignment devices has a stationary die plate for holding a stationary die, a movable die plate for holding a movable die, a device for moving forwardly/rearwardly the movable die plate with respect to the stationary die plate, a fastening device for fastening the movable die plate and the tie bar to each other by hydraulic force when the stationary die and the movable die have been approached to predetermined positions, and a tie bar for clamping the movable die and the stationary die by die-clamping force generated by a die-clamping cylinder, and a primary alignment mechanism provided for at least one junction among junctions between a piston of a die-clamping hydraulic cylinder and the tie bar, between a support plate and the tie bar, and between the movable die plate and a movable die plate support member, in order to permit the two dies to be aligned to each other by a secondary position alignment function, such as a guide pie for aligning the two dies at the time

Abstract: A disaster relief robot can be prevented from falling over a precipice or the like while safety for the operator can be ensured during outdoor field transportation of relief supplies such as rescue apparatus and materials, medicines or food stuffs in the case of a wide-area disaster caused by an earthquake, a heavy rainfall, a landslide or the like. Accordingly, track frames (16) for crawlers (12) are pivotably attached to a robot body (10), respectively, at its front and rear ends, the distance L between the pivot shafts of the front and rear crawlers (12F, 12R) is set so that maximum pivoting loci (CF, CR) of the crawlers do not interfere with each other, and further, the gravitational center (G) of the robot body is set at a position intermediate of the distance (L) between the pivot shafts of the front and rear crawlers. Several kinds of operation controllers are also provided.

Abstract: The present invention relates to a method for controlling a power output of an engine of a crawler vehicle; such as, large sized bulldozers, at a time when shoe slip of such crawler vehicle occurs in operation, the crawler vehicle being provided with working equipments; such as, dozing units or blades, ripping units or rippers or the like. More particularly, the present invention relates to an adaptive engine power output mode setting method for automatically keeping the engine of the crawler vehicle in an optimum power output condition according to rates of the shoe slip or shoe slip rates of the crawler vehicle.

Abstract: A traveling speed changeover device for a hydraulic excavator which can optimize the traveling speed in accordance with the road conditions and which enables a working machine of the excavator to be operated during traveling without impairing the simultaneous operation characteristic. To this end, the traveling speed changeover device has a spring set force adjusting device which includes: a traveling speed changeover switch (5); a controller (7) for computing a signal set by the traveling speed changeover switch; a solenoid actuated control pressure changeover valve (6) which operates in accordance with a command given by the controller; and a spring force adjusting cylinder (9) for adjusting the set force of a differential pressure setting spring (11a) of a load sensing valve (11) in accordance with the operation of the solenoid actuated control pressure changeover valve.

Abstract: The present invention discloses a system and a method for transmitting data in a shield machine and for calculating the filling amount of a void by detecting the distance to the natural ground. The system and the method are capable of transmitting analogue signals or signals of relatively high frequencies with reliability, enabling an unskilled operator to accurately detect buried articles and accurately carry out the back-filling work. Therefore, an optical rotary joint (100) is disposed between a rotary cutter head (10) and a non-rotary shield body (2) to count time taken to detect the peak value of a reflected signal larger than a standard value or time taken to detect the zero cross position present prior to the peak value. In accordance with the counted time, the distance between the antenna and the natural ground is calculated and displayed. Then, the void volume is calculated in accordance with the distance so that a target value of the back-filling amount is set.

Abstract: This invention relates to an apparatus for mounting fingers for transfer bars for use in a transfer feeder wherein each of the fingers serving as workpiece gripping means can be moved without causing any interference of the finger with an adjoining finger or upright. This apparatus comprises moving plates located on end bars arranged, respectively, behind the left and right uprights on the front side of the press body and which are each connected to a two-stage tandem cylinder mounted on each of the central bars adapted to be taken out of the press body together with the moving bolster so that the moving plates may be moved freely in the longitudinal direction of the transfer bars which are dividable into a plurality of segments by means of the cylinder, and fingers mounted on the moving plates. Each of the fingers has a misgrip detector. Further, transmission couplers and access switches are provided to transmit a signal generated by the misgrip detector in non-contact state.

Abstract: An operator compartment protecting device (12) for construction vehicles is located to the rear and above an operator compartment (11) on a vehicle body (10) in order to protect the operator compartment (11). The operator compartment protecting device (12) includes: a gate-shaped support (15) including a pair of vertical members (13), and a connecting horizontal member (14) extending between and fixed by welding to a side surface of an upper end portion of one of the pair of vertical members (13) and a side surface of an upper end portion of the other of said pair of vertical members (13); a pair of beam members (16) each fixed by welding to the front surface of the upper end portion of each of the pair of vertical members (13) in such a manner that they are directed in a forward direction, and a ceiling plate (17) placed over and releasably secured, e.g.

Abstract: A steering control system for a tracked vehicle having a left track and a right track, e.g., a bulldozer, assures smooth turning performance in a normal steering operation, provides a comfortable ride, and is durable. Power is transmitted to the right and left tracks via right and left drive sprockets having right and left driving shafts, with the right driving shaft being coupled to an output shaft of a speed change gear via a right clutch and a right brake, and the left driving shaft being coupled to the output shaft via a left clutch and a left brake.

Abstract: The present invention discloses a standoff control method and an apparatus for a plasma cutting machine capable of quickly correcting a deviation of the standoff with respect to a set value, keeping constant the standoff even if the cutting speed changes, preventing deterioration of the working efficiency even if a double-arc is generated, and properly detecting the use limit of the electrode. Standoff correction computing device (28) includes a reference voltage computation setter (36) for outputting a reference voltage between a workpiece to be cut and an electrode or a nozzle with respect to a predetermined standoff, an error computing device (37) for calculating the deviation of said detected voltage with respect to the reference voltage, and a correction quantity computing device (38) for outputting a vertical repositioning speed signal for the torch in accordance with the degree of the deviation.

Abstract: A punch press includes an upper main shaft (3) vertically movable by means of a hydraulic driving means (2.sub.1, 2.sub.2, 3a) and rotatable for indexing by means of a rotary driving means (7, 8, 9), a lower main shaft (30) positioned below the upper main shaft and rotatable in synchronism with the upper main shaft for indexing, upper and lower dies (23, 45) detachably mounted on the upper and lower main shafts in opposition to each other, and upper and lower clamping devices for clamping the upper and lower dies on the upper and lower main shafts (3, 30) with positioning in phase.

Abstract: The present invention relates to an apparatus for controlling the running speed of a hydraulic motor. A hydraulic motor employable for a construction machine such as a power shovel or the like as a driving power source is constructed such that its rotational speed can be changed to assume either a high speed (low torque) or a low speed (high torque) so as to cope with differences in the running state of the construction machine. The apparatus of the subject invention assures that the running state of the construction machine is determined by not only the running load of a hydraulic motor but also its rotational speed, whereby the construction machine can run smoothly at all times.

Abstract: An air cleaner for a cooling device in a driving system mounted on a large-size dump truck capable of separating and removing dust and rain water contained the air flow flowing in through an air intake portion from the air with a high efficiency. This air cleaner for cooling comprises a plurality of strata tubes (12) horizontally spanning between front and rear walls (1a, 1b) of a rectangular parallelepiped shape intake portion (1), a net pasted over the entire surface of the front of the intake portion, and a cover disposed in front of the net.

Abstract: A process for examining the appearance of an examination object has the steps of taking an image of the object to obtain image data and processing the image data by an image processing apparatus. A mask is formed to determine, in the image data to be processed, a non-examination region of various configurations and, when the position of the examination object is deviated from the correct position, the position of the mask also is shifted correspondingly to enable appearance examination in varying conditions. To this end, a brightness threshold value is set in the input multi-value image data so as to define the non-examination region to be excluded from said examination region, thereby forming said mask, and the pixels having gradation levels not higher or lower than the threshold value are excluded from the examination region.