Abstract: Conventionally, as screw tightening axial force control, there is a control method such as a torque control method. The torque control method requires estimation of a torque coefficient, and has a problem that a calculated axial force value is an estimated value. An object of the present invention is to provide a method for directly controlling an axial force by calculating the axial force generated by an impact force by using an impact wrench. A 45-degree slant line is set from an origin O of orthogonal coordinate axes to be used for screw tightening axial force control, an impact progress point Hi generated by an i-th impact is detected on the 45-degree slant line, a length HSi of a line segment OHi is read, and an axial force value Fi after the i-th impact occurs is calculated by using the formula Fi=HSi×cos 45°. Another method for controlling the axial force by using impact information is also disclosed.

Abstract: A hand-held powered screw tightening tool has a detecting device to detect a rotation angle of a rotary member in a clockwise direction and a counterclockwise direction. In screw tightening, an angle obtained by subtracting a cumulative total of the rotation angle of the rotary member with rebound, if any, in a counterclockwise direction from a cumulative total of the rotation angle of the rotary member in the clockwise direction is detected and accumulated as a total rotation angle (P) and a rotation angle formed during the deceleration at the hammering is detected as &Dgr;H and accumulated, and a preset design angle Pd for hammering is accumulated. A wobbling angle is calculated from Equation: A wobbling angle=P−a cumulative total of Pd−a cumulative total of &Dgr;H (where Pd is a design value of the impact wrench, indicating an angle corresponding to 360°/m for the case of the m number of hammerings per rotation of the rotary member).

Abstract: A die casting method and a casting that is obtained through use of the die casting method. The die casting method can solve problems such as air catching occurring at the time of injection into the cavity of a die and molten metal run defect, thereby enabling efficient production of defect-free perfect castings. Via a mouth piece 7 and a molten-metal feed port 4, molten metal from a molten metal feeder flows into a casting sleeve 2 while undergoing laminar flow. When the molten metal reaches a predetermined level, a plunger tip 5 is moved upward within the casting sleeve 2 and stops at a position where the side surface of the plunger tip 5 closes the molten-metal feed port 4. The molten metal that has flowed into the casting sleeve 2 is cooled by a cooling medium flowing through passages 2b formed within the casting sleeve 2 so that said molten metal forms primary crystals. Simultaneously, through use of a high frequency coil 6, the molten metal is subjected to electromagnetic agitation.

Abstract: A hand-held powered screw tightening tool is provided with a detecting means to detect a rotation angle of a rotary member in a clockwise direction and a counterclockwise direction. In screw tightening, an angle obtained by subtracting a cumulative total of the rotation angle of the rotary member with rebound, if any, in a counterclockwise direction from a cumulative total of the rotation angle of the same in the clockwise direction is detected and accumulated as a total rotation angle (P) and a rotation angle formed in the middle of the deceleration at the hammering is detected as &Dgr;H and accumulated, and a preset design angle Pd for hammering is accumulated. A wobbling angle is calculated from Equation: A wobbling angle=P−a cumulative total of Pd−a cumulative total of &Dgr;H (where Pd is a design value of the powered wrench, indicating an angle corresponding to 360°/m for the case of the m number of hammerings per rotation of the rotary member).

Abstract: The present invention relates to a die casting method in order to obtain aluminum alloy having high quality and excellent mechanical characteristics. Further, the present invention relates to a die casting method to produce such an aluminum alloy casting, wherein primary crystal of molten metal is substantially granulated in a casting sleeve so as to form a semi-molten status, and then filled under pressure into a die cavity and solidified, so that molten metal flow becomes laminar flow, thus making less air mixing, and casting can be made without oxides and solidified matter being filled into die cavity.

Abstract: A high toughness and high strength casting of an aluminum alloy, has comparatively thick portions with a thickness of 20 mm or more, 4-6% Si, 0.2-0.6% Mg, less than 0.15% Fe, not more than 0.4% Mn, by weight, residual aluminum and unavoidable impurities; Si(%).times.Mg(%) having a value of 1.2-2.8. In forming the casting, the aluminum alloy is under an atmosphere of more than atmospheric pressure during solidification and subsequently a T6 heat treatment is applied to casting.

Abstract: A die casting method and a die casting machine of the invention is provided. The method comprises the steps of forming a casting sleeve comprising an inner cylinder and an outer cylinder, having a conductor material, and disposing an induction coil on the outer periphery of the outer cylinder. The conductor material may be in the form of a plurality of conductors uncontinuously disposed about the cylinder or it may be in the form of a single conducting material having a plurality of slits. A material to be cast in the casting sleeve may be heated, maintained a constant temperature and stirred by electromagnetic induction. The material may be substantially separated from the wall face of the casting sleeve by an electromagnetic force generated between the conductor and the material and the temperature drop of the material may be suppressed.

Abstract: A heat roll for electrophotography of a surface heating type having a heating resistor is arranged such that a bonding layer, an insulating layer, a resistance layer, and a surface insulating layer are consecutively provided on an outer surface of a hollow cylindrical core, and a bearing member for fitting with a bearing is fitted at each opposite end of the heat roll. A pipe or a round bar formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like which has a greater coefficient of thermal conductivity than that of mild steel is disposed inside the core to permit a uniform distribution of the temperature. In addition, a gap of 0.2 mm or more is provided between the inner surface of the core and an outer peripheral surface of the member formed of the high-temperature conductive material.

Abstract: The resistive layer of an electrically heated toner fixing roll includes a Fe-Cr-Al metal alloy phase and a ceramic substrate phase thermally sprayed onto the surface of a thermally and electrically insulated metal roll. The ceramic substrate can be Al.sub.2 O.sub.3 and the alloy can be 64-89 wt % Fe; 10-30 wt % Cr; and 2-10 wt % Al. Al.sub.2 O.sub.3 can be the insulating layer, and the metal roll can be iron, or an iron-based alloy.

Abstract: The roller has a roller body having a small electrical resistivity, a bonding layer formed substantially uniformly on the outer peripheral surface of the roller body, a lower insulating layer provided on the bonding layer; a heat generating layer provided on the lower insulating layer and a ceramic matrix and a metallic resistance layer, constituted by a metal dispersed in the ceramic matrix, the metallic resistance layer extending substantially continuously in the lengthwise direction of the roller, a heat generating layer, an upper insulating layer provided on the heat generating layer, a protective layer formed on the upper insulating layer so as to prevent offset of the toner images, an electrode layer formed on each end of the roller and adapted to connect the heat generating layer to an external power source; and side protective layers covering at least the side surface of the heat generating layer, and the side surfaces and the axially outside surfaces of the lower insulating layer.

Abstract: The roller has a roller body having a small heat capacity, a bonding layer formed substantially uniformaly on the outer peripheral surface of the roller body, a lower insulating layer provided on the bonding layer; a heat generating layer provided on the lower insulating layer and having a ceramic matrix and a metallic resistance layer constituted by a metal dispersed in the ceramic matrix, the metallic resistance layer extending substantially continuously in the lengthwise direction of the roller, the heat generating layer having a thermal expansion coefficient substantially the same that of the lower insulating layer, an upper insulating layer provided on the heat generating layer, a protective layer formed on the upper insulating layer so as to prevent offset of the toner images, and an electrode layer formed on each end of the roller and adapted to connect the heat generating layer to an external power source.

Abstract: An impact wrench for using fastening or unfastening fasteners comprises a cylindrical rotor coupled to a motor shaft, said cylindrical rotor including a projection on its inner surface, the projection having a circumferential width and an axial length; an anvil coupled to said cylindrical rotor, the anvil including a hammer member capable of rocking therein, the hammer member being engageable with said projection; a springloaded pusher for urging said hammer member towards said projection, wherein a spring support slides either on a deep cam face or a shallow cam face both produced on said inner surface of the cylindrical rotor, thereby allowing said spring to become compressed or relaxed against said hammer member.

Abstract: An impact wrench includes a hammer, an anvil and a rotor driven by a motor, the hammer being swingeable in either direction with respect to the rotary axis of the rotor, the hammer resting on the anvil in a spring-loaded state so as to enable the hammer to line up with the axis of the anvil, the hammer including means for engaging itself with the inside surface of the rotor, whereby the hammer produces impacts at fixed intervals and transmits the same to the anvil.