Abstract: An acceleration detector including an acceleration transducer assembly including a piezoelectric element, an output terminal and an inertial weight. The transducer assembly is secured on a threaded bushing by a substantially ring-shaped, thread-engaging stop nut thread-engaging to the threaded bushing. The stop nut has an internal thread in its inner circumferential surface and a pair of axially extending engagement grooves formed in its outer circumferential surface at equal intervals for receiving a tool for rotating the stop nut about the bushing. The output terminal may have a ring-shaped portion, a connecting tab radially outwardly extending from the ring-shaped portion for an external connection, and a transition fillet provided at a transition area between the ring-shaped portion and the tab for moderating the concentration of stress on the transition area.

Abstract: An ignition timing control apparatus for an internal-combustion engine comprises a knock sensor for detecting engine knocking information, a knock discriminator for selecting a knock signal produced in the engine, from the output of the knock sensor, a controller for generating a control signal in accordance with a knock signal, a signal generator for generating an ignition signal, an ignition timing controller for controlling the ignition signal in accordance with the control signal, a switch for controlling power supply to the ignition coil, and a failure detector which generates a fail signal in case of a malfunction of any of the knock detecting components, the ignition timing controller being adapted to generate the control signal from the controller within the range in which no knocking control is performed.

Abstract: An acceleration detector comprising a housing and an acceleration transducer assembly including a piezoelectric element, an inertial weight and an output terminal. A thread-engaging fastener on the bushing, for securing the transducer assembly in the housing, and an electrically insulating washer is provided, and a resilient filler material is applied around the acceleration transducer assembly in the housing so that the movement of the inertial weight relative to the housing is allowed when an acceleration is applied. An electrically insulating, low-friction washer made of a plastic material selected from a group consisting of polyester, polyethylene terephtalate and polyphenylene sulfite is disposed between the thread-engaging fastener and the output terminal of the transducer assembly.

Abstract: A control apparatus for an internal combustion engine has a vibration sensor which senses engine vibrations and a low-pass filter which passes a low-frequency component of the output of the vibration sensor. A comparator detects misfiring when the level of the low-frequency component exceeds a prescribed reference level. When misfiring is detected, a microcomputer identifies the misfiring cylinder and stops the supply of fuel to the misfiring cylinder. The control apparatus may also include a knocking suppression device responsive to a component of the output signal of the vibration sensor.

Abstract: An ignition timing control apparatus for an internal-combustion engine comprises a resonance-type acceleration sensor for detecting vibration acceleration, a discriminating means for eliminating noise signal components from the output of the acceleration sensor and selecting knocking signal components, a reference ignition timing signal generating means for generating a reference ignition timing signal, a phase shifting means for shifting the phase of the reference ignition timing signal in accordance with the output of the discriminating means, a switching means for interrupting power supply to an ignition coil corresponding to the output of the phase shifting means; and an operating condition detecting means for applying a specific voltage to the acceleration sensor, and for verifying the operating condition of the acceleration sensor and the integrity of a connection between the output side of the acceleration sensor and the input side of the discriminating means from the responsiveness of the acceleration

Abstract: A knock suppression apparatus for an engine includes a knock sensor for sensing an engine operating parameter representative of an occurrence of knocking and a knock unit for detecting knock signals in the output signal of the knock sensor and controlling the ignition timing of the engine to suppress the knocking. The knock sensor is connected with the knock unit by wiring that is disposed in the proximity of wiring for a component of the vehicle that can induce electrical noise in the knock sensor wiring large enough to be mistaken for a knock signal substantially only when the engine load is low or decreasing. In a preferred embodiment, the knock sensor wiring is in a wiring harness for an antilock brake control system.

Abstract: A control apparatus for internal combustion engine which controls running of an internal combustion engine by use of a microcomputer, and which is provided with a signal processing circuit with a higher operating voltage than that of the microcomputer and a control circuit which invalidates an output of the signal processing circuit or lowers the control level in response to this output when the voltage of the signal processing circuit becomes to have a predetermined low value. Even if the voltage of the signal processing circuit becomes so low that a wrong signal should be outputted, there occurs no disadvantage in running control of the internal combustion engine.

Abstract: A knocking suppression apparatus for a multi-cylinder engine has a knock sensor mounted on a bracket which is secured to the engine in at least two locations. Engine vibrations are transmitted from the engine to the knock sensor by the bracket. The knock sensor generates an electrical signal, on the basis of which a knocking suppression circuit controls an engine operating parameter, such as the ignition timing, so as to suppress knocking.

Abstract: An acceleration detector comprising transducer including a pair of ring-shaped piezoelectric elements, a terminal having a ring-shaped eye portion for taking out an output from the piezoelectric elements and a weight for applying a stress to the piezoelectric elements in response to an acceleration applied to the detector. The transducer is mounted on a base having a threaded hole by a screw having a threaded portion thread-engaged with the threaded hole of the base. The axial length of the threaded portion of the screw is selected such that its substantially entire length engages the threaded hole in order not to damage an electrically insulating tube placed over the screw by the thread on the screw. The threaded hole in the base may have a counter sink for providing a predetermined dimensional allowance in the relationship between the axial length of the threaded portion and the depth of the thread hole.

Abstract: An acceleration or knocking detector for a vehicle engine includes an electrically conductive bushing 24 mounted to the engine, and an acceleration transducer assembly disposed on the bushing and including a piezoelectric element 31, an inertial weight 34, an output electrode 31a, and a ground electrode 31b in contact with the bushing. An output terminal 29a is connected to the output electrode of the transducer assembly and extends through the housing for external connection to a grounded control unit 38, and a ground terminal 29b electrically connected to the ground electrode of the transducer assembly also extends through the housing for connection to the control unit, thus establishing parallel ground paths. An electrical conduction maintaining element such as a bonding agent, tape, washer or grease is disposed between the bushing and the engine to establish and maintain good conduction therebetween for a prolonged time.

Abstract: The vibration detector comprises a tube-like portion provided with a threaded bolt hole and a threaded portion defined on the outer periphery of the top of the tube-like portion and is secured integrally to the object the vibration of which is to be detected by means of a bolt inserted in the threaded bolt hole and a nut engaged with the bolt. The outer diameter of the portion of the tube-like portion apart from the threaded portion is equal to or smaller than the minimum diameter of the threaded portion. Thus the compression stress caused by the bolt inserted in the threaded bolt hole against clamping force can be fully secured because the strength of the tube-like portion depends on the minimum diameter of the threaded portion.

Abstract: An ignition timing control apparatus has an acceleration sensor having a flat detection characteristic in a frequency region of 10 KHz-20 KHz and a frequency filter having its central frequency in the region of 10 KHz-20 KHz.

Abstract: An ignition timing control device for internal-combustion engines which is provided in an internal-combustion engine to control the ignition timing of the internal-combustion engine, such as a gasoline engine and a diesel engine mounted as an automotive engine, and to control what is called a knocking phenomenon including abnormal sound and abnormal vibration resulting from abnormal combustion in the combustion chamber, and includes a knocking sensor which senses knocking information of the internal-combustion engine, a knocking discriminator which discriminates the knocking phenomenon in each cylinder of the engine sensed by the knocking sensor, a processing device which performs specific processing in accordance with the knocking phenomenon thus discriminated, a phase shifter which performs the phase shift control of an ignition signal by the output of this processing device, and a switching circuit which turns on and off the ignition coil by the output of this phase shifter; the processing device including