Bosch Corporation

Yasuo Toyoshima

Yutaka Tanaka

Tomohiro Nakamura

Yoshihito Fujishiro

Katsumi Takatsu

Kan Cho

Shuichi Tsukahara

Yasushi Hiratsuka

A pressure-sensor-integrated glow plug which can increase reliability of a bonding portion between a ceramic heater and a metal-made outer sleeve while being manufactured with relatively simple manufacturing steps and, at the same time, can maintain airtightness over a long period, and a method of manufacturing such a pressure-sensor-integrated glow plug.

Pressure-sensor-integrated glow plug and manufacturing method thereof

Disclosed is a glow plug diagnosis method of being able to diagnose the aging or fault of a glow plug without being affected by cooling associated with air intake/exhaust or fuel injection, the method including: a step (S) of energizing a glow plugin a predetermined manner when a key switchof a vehicle is turned on; and a step (S) of measuring the resistance value of the glow plugwhen the energization of the glow plugis started, and the resistance value of the glow plug when the energization of the glow plugis started and then a change in the resistance value is saturated, and of calculating a change in the resistance value over time as a resistance value gradient, in which it is determined that the glow plugis normal when the resistance value gradient exceeds a predetermined first gradient reference value a, and it is determined that the glow plugis faulty, and a warning lamp or the like is lighted when the resistance value gradient is less than a predetermined second gradient reference value b (Sand S).

Glow plug diagnosis method and vehicle glow plug drive control apparatus

The presence or absence of degradation and abnormality is determined with high reliability by measuring a resistance value of a glow plug, which is in an operating state, as a latest resistance value. A method then determines whether or not the rate of the change of the latest resistance value with respect to an initial resistance value of the glow plug exceeds a first predetermined value. The method also determines whether or not the rate of the change of the latest resistance value with respect to a last resistance value that is a resistance value of the glow plug, which has been recently measured at the time of the acquisition of the latest resistance value, exceeds a second predetermined value when the rate of change of the latest resistance value with respect to the initial resistance value of the glow plug exceeds the first predetermined value. The method determines that the glow plug is in an abnormal degradation state when the rate of the change of the latest resistance value with respect to the last resistance value exceeds the second predetermined value.

Method of diagnosing glow plug and glow plug drive control device

A glow plug is provided that can be easily determined as to whether or not it is a new article. An additional circuit formed by connecting a diode, a fuse, and an adjusting resistor in series in this order is connected in parallel to a heating element of a glow plug. The diode is provided so as to have an anode located on the positive electrode side of the heating element and a cathode located on the fuse side. In the case of a unit inspection, by applying a positive voltage for test to a heating element negative electrode connecting portion, it is possible to determine whether or not the glow plug is normal without blowing the fuse before the glow plug is used in a vehicle.

Glow plug, new glow plug determination method, and glow plug driving control device

An arithmetic and control unit is configured to calculate a resistance value of a glow plug on the basis of an energization current of the glow plug and a voltage applied to the glow plug, perform a multiplication of the resistance value and a constant that has been determined beforehand on the basis of an electrical characteristic of the glow plug, input a predetermined heater reference point temperature, calculate an offset with a predetermined offset arithmetic expression from the heater reference point temperature, correct the multiplication result with that offset, and take the correction result as an estimated temperature of a tip of the glow plug.

Growing community of inventors

Saitama, Japan

Yasuo Toyoshima