摘要:
To permit machining of a workpiece into a highly accurate tapered configuration, a wire-cutting EDM including a numerical controller that reads programmed shape data is utilized. To precisely taper the workpiece, it is necessary to move the upper and lower guides of the wire so that they start and stop moving simultaneously. From the programmed shape data, the respective speeds of the upper and lower guides are computed. The upper guid is interpolated by the upper guide speed, and the lower guide is interpolated by the lower guide speed so that the guides can start and stop moving simultaneously.
摘要:
A method of automatically measuring the flexure value of a wire electrode 1 in a wire-cut electric discharge machine is disclosed.At a measurement point in the course of electric discharge machining, the electric discharge is temporarily stopped, and whether or not the wire electrode 1 and a workpiece 2 come into contact is sensed by a contact sensing device 107a. The wire electrode 1 and the workpiece 2 are moved relatively to advance or retreat in accordance with the sensed touch signal TS, and the distance .epsilon..sub.1 of movement until the contact state changes, is measured. The flexure value .epsilon. is obtained calculatively from the measured movement distance .epsilon..sub.1.
摘要:
A method of controlling a wire-cut electric discharge machine to prevent cutting errors when cutting a corner CN which are caused by flexing of a wire electrode 1 during electric discharge cutting of a workpiece. Electric discharge is stopped when a rectilinear slot is cut to measure an amount of flexing of the wire electrode 1, and then the measured amount of flexing is used to effect an arithmetic operation to calculate a commanded speed or an interval of time in which relative movement between the wire electrode and the workpiece is arrested at the corner CN. The corner CN is cut under the control of the calculated commanded speed or interval of time in which the relative movement is arrested.
摘要:
A cutting control method for reducing cutting errors at a corner due to flexing of a wire electrode in a wire-cut electric discharge machine in which a voltage is applied between the wire electrode and a workpiece to cut the latter with electric discharge energy while moving the workpiece relatively to the wire electrode based on cutting command data for cutting the workpiece to a predetermined shape. An amount of override (K) is determined by an override arithmetic unit (103b) using data (r) on the radius of curvature of a corner angle (.theta.) data which are given as the cutting command data from a paper tape (101). A relative speed (F) is derived by a relative speed arithmetic unit (103f) from the amount of override (K) and a commanded feeding speed (F.sub.0). Motors (MX, MY) are rotated by pulse distributors (105X, 105Y) and servo circuits (SVX, SVY), respectively, based on the relative speed (F) which is lower than the commanded feeding speed (F.sub.0) to move the workpiece with respect to the wire electrode for electric discharge cutting of the corner.
摘要:
A system for restoring a numerically controlled machine tool to its former condition after a power interruption, the numerical control system being of the type in which a position sensor senses the current position of a movable member or of a drive motor of the machine tool and generates a current position signal in accordance with said current position, the movable member being positioned on the basis of a commanded position signal and the current position signal. The positional control information which prevails immediately prior to an interruption in the electric power which is applied to the machine tool and to the numerical control device is stored in a non-volatile memory before the power interruption occurs. When the electric power is reintroduced, the positional control information is read out of the non-volatile memory, and the movable member is returned to the position which it occupied immediately prior to the power interruption, this being accomplished on the basis of the positional control information and the current position signal.
摘要:
A wire-cut electric discharge machining control method which enables the corner portion at the intersection of first and second tapered surfaces of a workpiece to be cut into a tapered surface of oblique cylindrical shape. With the present invention, the tapered surface of oblique cylindrical shape is formed between the first and second tapered surfaces by entering command data for the radius r of the oblique cylindrical tapered surface in addition to positional control information for cutting the first and second tapered surfaces, computing a pair of points Q and R where the oblique cylindrical tapered surface meets the first and second tapered surfaces from the positional control information and radius, and cutting the tapered surface of oblique cylindrical shape between the points Q and R.
摘要:
Soil cement slurry is produced by mixing blast-furnace slag fine particles with a specified fineness and Portland cement at a specified ratio to prepare blast-furnace slag cement and using a specified amount of slurry composition for ground improvement including this blast-furnace slag cement with water and an admixture per 1 m3 of ground. The admixture contains specified amounts of a hardening accelerator, a defoamer and a fluidizer.
摘要:
Concrete compositions including a binder, water, a fine aggregate, a coarse aggregate and an admixture are provided. The binder is formed with a blast-furnace slag composition including 100 mass parts of a mixture of 80-95 mass % of blast-furnace slag fine particles with fineness 3000-13000 cm2/g and 5-20 mass parts of gypsum for a total of 100 mass % and 0.5-1.5 mass parts or 5-45 mass parts of an alkaline stimulant. Such concrete compositions can maintain superior operability by reducing the discharged amount of carbon dioxide and the decrease with time in fluidity and air content of the prepared concrete compositions. They can also reduce the drying shrinkage of the obtained hardened objects and allow the obtained hardened objects to manifest necessary strength.
摘要:
Slurry composition for ground improvement is obtained from cement, water and an admixture. The slurry composition cement is of a kind prepared by using blast-furnace slag cement of a specified type as the cement at a water/blast-furnace slag cement mass ratio of 40-250% and contains the admixture in an amount of 0.1-5 mass parts for 100 mass parts of the blast-furnace slag cement. The blast-furnace slag cement of the specified type contains blast-furnace slag fine particles with fineness 3000-13000 cm2/g in an amount of 60-80 mass % and portland cement in an amount of 20-40 mass % for a total of 100 mass %.
摘要:
An ultra high-strength hydraulic cement composition contains a binder, fine aggregates, coarse aggregates, an antifoaming agent, water and a specified admixture and has a unit amount of the binder in the range of 480-1800 kg/m3. Water and the binder are contained at a ratio of 10-25% and the admixture is contained in the amount of 0.2-3.5 weight parts per 100 weight parts of the binder. The binder may be cement or a mixture of cement and a microscopic powder admixture. The admixture is one or more selected from reaction mixtures obtained by specified two processes and partially or completely neutralized substances obtained from such a reaction mixture through these two processes and also a specified third process. The specified two processes include initiating a radical copolymerization process of a radical polymerizable monomer mixture containing maleic anhydride and a monomer of a specified kind in a non-aqueous system in the presence of a non-aqueous radical initiator and stopping the radical copolymerization reaction in its midst while the inversion rate of polymerization is at a specified level by adding water to the reaction system to thereby obtain a reaction mixture. The specified third process is for partially or completely neutralizing the reaction mixture.