Abstract: This invention relates to a helical intake port for an internal combustion engine comprising a straight passage, a swirl passage connected to the straight passage and formed in a spiral around the center of an intake valve, and a cylindrical throat connected to the swirl passage via an opening over the whole area of the swirl passage. The cross-sectional area S of the swirl passage is determined by the following equation: ##EQU1## where: .beta.=swirl angle from swirl start position,.beta.0=whole swirl angle from swirl start position to swirl end position of swirl passage,S0=cross-sectional area of swirl passage at swirl start position.As a result, swirl can be enhanced and a high flow coefficient of the intake port can be realized.

Abstract: A magnetic tape data management method and apparatus is described that reduces the access time for updating and referring to directory data. At the time of accessing data on a magnetic tape loaded in a magnetic tape subsystem, directory data for the magnetic tape is, in response to the completion of the processing of data, recorded in a region located near the place at which the magnetic tape head is positioned at that time, said region constituting a directory data region (DDR). Further, a directory data memory for recording directory data from the magnetic tape is provided in the magnetic tape subsystem, remote from the tape. At the time of accessing data on the magnetic tape loaded in the magnetic tape subsystem, directory data for the magnetic tape processing is, in response to completion of the processing of data, recorded in the directory data memory in the magnetic tape subsystem.

Abstract: A magnetic recording control apparatus includes conventional magnetic recording media, a large capacity type magnetic recording medium having a memory capacity corresponding to the sum of the capacities of a plurality of conventional magnetic recording media, recording unit for recording data of a plurality of conventional magnetic recording media to the large capacity type magnetic recording medium using a virtual volume corresponding to the recording capacity of one conventional magnetic recording medium and control data relating to the virtual volume as one recording unit, and/or division unit for dividing a data buffer for temporarily storing the data of the large capacity type magnetic recording medium into logical devices corresponding to the conventional magnetic recording media.

Abstract: In an information processing system having an upper rank apparatus and an external storage device which performs transmission and reception of data between the storage device and the upper rank apparatus, at least one of encryption and decryption of the data by use of an algorithm controlled by a desired data key is performed in the external storage device, while generation, encryption and decryption of the data key are performed on the upper rank apparatus side. By this configuration, the burden of the upper rank apparatus is largely reduced and the secrecy of data stored in the external storage device can be surely kept without spoiling the throughput of the whole system.

Abstract: When invormation is recorded on a magnetic tape, a plurality of first data blocks which have been separately transferred from a higher rank apparatus are combined with each other while adding thereto control information for identifying each of the first data blocks, and are recorded on the magnetic tape as a continuous second data block. During a reproducing operation, either the first data blocks which have been separated based upon the control information, or the second data block containing the control information, are transferred to the higher rank apparatus.

Abstract: An I/O control system includes an I/O control unit, a plurality of I/O devices, the start process prior to a data transfer process of the I/O device being off-line processed from the I/O control unit, and a data transfer path for data transferring to the I/O device, the data transfer being performed for one I/O device at a time. The I/O control unit controls an I/O device in such a way that the start process of the I/O device completes at the time when another I/O device under data transfer completes its data transfer, thus improving the utilization of a data transfer path.

Abstract: First and second cam members are engageable in a fuel injection pump. A first device urges the first cam member toward the second cam member to obtain engagement between them. The first cam member reciprocates as it moves relative to the second cam member when the first and second cam members are in engagement. A plunger connected to the first cam member reciprocates with the first cam member. The plunger defines at least part of a pumping chamber which contracts and expands as the plunger reciprocates. As the pumping chamber expands in a fuel intake stroke, fuel moves into the pumping chamber. As the pumping chamber contracts in a fuel compression stroke, the fuel moves out of the pumping chamber. A second device resists movement of the plunger in the fuel compression stroke.

Abstract: A hydraulic reservoir in a tandem master cylinder includes a main portion defining a fluid reservoir chamber for reserving brake fluid, two fluid supply portions defining fluid paths under the main portion, the fluid supply portions being contiguous with the main portion and an opening formed at the top, the two fluid supply portions being connected to two fluid connection portions of a tandem master cylinder body.

Abstract: A plurality of sequentially occuring information signals are stored in a memory by considering past record of the information signals. The number of times the same information occurs is counted, and when the information changes, the current count and the newly generated information are stored in the memory. The method of the invention thus enables much information to be stored in a small-capacity memory.

Abstract: A vibration sensor for detecting the magnitude of engine vibration and for generating an electric signal corresponding to the vibration incorporates a piezoelectric vibration element. The vibration sensor is used, for example, for detecting the knocking condition of an internal combustion engine. The piezoelectric element is secured onto an internal boss of a sensor housing by a threaded fastener. The fastener effectively secures the piezoelectric element onto the sensor boss so that the connection therebetween is not affected by vibration which could otherwise impair the electrical contact.

Abstract: A vibration sensor for an automotive vehicle including a piezoelectric vibrator of cantilever type for detecting mechanical vibrations, such as knocking, from an engine body. The vibration sensor prevents the vibrator from being deformed by thermal stress even if temperature near the sensor rises sharply, so that a stable resonant frequency will be maintained when detecting the vibration of an engine body.

Abstract: The air-fuel ratio for an internal combustion engine is controlled at the three stages: (A) when the engine temperature is lower than a first predetermined value, the air-fuel ratio is controlled only by a choke valve, (B) when the engine is at a temperature of the first predetermined value to a second predetermined value, the air-fuel ratio is controlled according to the output signals of engine temperature detecting means, and (C) when the engine temperature is higher than the second predetermined value, the air-fuel ratio is controlled according to the signals from air-fuel ratio detecting means.

Abstract: A sufficient amount of secondary air is supplied to the exhaust gases without requiring numerous supply tubes. The supply tubes are connected to the longest branch of the exhaust manifold or the exhaust port passage to which the longest branch is connected where the inertial flow of the exhaust gases is greatest. A mass of the exhaust gases recirculated to the intake through a recirculation tube is prevented from being admixed with the secondary air. The recirculation tube is connected to the branches of the manifold exclusive of the longest branch.