JPH059504Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention captures the state of ignition or combustion in the cylinder of an internal combustion engine as the presence or absence of combustion light, or the strength or weakness of combustion light, and then transmits this optical information via a photoelectric element. The present invention relates to a spark plug with a combustion light sensor that converts the signal into an electrical output signal and takes out the signal.

[Prior Art] Conventionally, sensors are used to send feedback control information to an automatic combustion control device to automatically determine the optimal timing, optimal injection amount, and optimal ignition timing for fuel injection in an internal combustion engine. Flame front sensors that capture the charged particles generated by knocking, and pressure sensors and vibration sensors that measure the increase in combustion gas pressure and vibration caused by the knocking phenomenon, have been used, but these all have problems with measurement accuracy, durability, etc. Recently, combustion light sensors that capture the brightness of combustion light inside a cylinder and convert it into an electrical signal have been attracting attention.

[Problems to be solved by the invention] The above-mentioned combustion light sensor can be used not only for the purpose of inputting a feedback control signal to the combustion automatic control device of an internal combustion engine that is operated on a daily basis, such as an automobile engine, but also for the purpose of, for example, prototyping. It can also be effectively used to obtain engine design data and check operating conditions. When using the sensor in this way, before inputting the sensor's electrical output signal to various display devices or recording devices,
It would be extremely convenient if the presence or absence of combustion light inside the cylinder and the strength of the light could be confirmed in advance by human eyes.

This invention allows the light-emitting surface of the light guide and the light-receiving surface of the photoelectric element to be easily and quickly separated from each other as needed, and the combustion light emitted from the light-emitting surface can be visually confirmed directly. To provide a spark plug with a combustion light sensor, which is equipped with a connector for engaging a light guide part of a combustion light sensor and a photoelectric element incorporating part, and which can easily and quickly restore the engaged state. The purpose is

[Means for Solving the Problems] The spark plug with a combustion light sensor of the present invention has the tip of the straight center electrode exposed from one end of the cylindrical insulator, and the axial center portion provided on the center electrode. A thin wire-like light guide is installed in the through hole so that one end surface of the thin wire light guide serves as a light-receiving surface at the tip of the center electrode, and a joining joint having a threaded portion for screwing is provided at the other end of the cylindrical insulator. , an ignition plug main body in which the other end surface of the thin wire light guide is exposed at the center of the joining joint; a screw that can be screwed into the threaded part of the joining joint; a photodetection chamber in which a photoelectric element is arranged; a window in the center of the screw for allowing the other end of the thin wire-shaped light guide to face the light receiving part of the photoelectric element; It consists of a photoelectric element storage case with a connected connector,
A configuration is adopted in which the spark plug main body and the photoelectric element storage case are screwed together.

[Operation and Effects of the Invention] The ignition plug with a combustion light sensor having the above-mentioned configuration can be used to check the engagement state between the photoelectric element storage case and the connection joint when it is desired to directly visually confirm the combustion light inside the internal combustion engine cylinder. can be released almost in a one-touch manner, so the combustion light emitted from the light emitting surface of the light guide inserted into the connection joint can be directly observed.

In addition, when you want to input the electrical output signal of the sensor to an automatic combustion control device or various measuring devices, you can return the disengaged state to the engaged state with a single touch, so you can easily connect the connector of the storage case to the connector of these devices. If the sensor is connected to the output terminal using a conduction cable, it can be immediately put into its original state of use as a sensor, making it extremely convenient to use.

[Example] The structure of the connector of the ignition plug with combustion light sensor according to the present invention will be specifically described below based on the example shown in the attached drawings.

FIG. 1 is a partial longitudinal sectional view of a connector as an embodiment, and numeral 1 indicates a photodiode as a photoelectric element, which may be replaced by a photovoltaic cell or the like.
Reference numeral 2 denotes a storage case for the photoelectric element 1, which is made of a cylindrical body made of metal such as aluminum. 3 is a connector for taking out the output of the photoelectric element 1 screwed onto the rear end of the storage case 2 (upper side in the figure); 3b is a screw for screwing the connector 3; 4 is a positive contact of the connector 3;
5 is the positive terminal 1a of the photoelectric element 1 and the connector 3
It is a lead wire for connection with the contactor 4 and is joined by soldering. 6 is an insulating tube, and 7 is an insulating retainer ring, which is made of Teflon and has a slit that runs through it in the axial direction.This is used to pass the lead wire 5 through when inserting it into the storage case 2, and to reduce the outer diameter. This is useful for holding down the photodiode in the axial direction and fixing it.

Reference numeral 8 denotes a joint for joining the fiber-shaped light guide 10 and the storage case 2 of the photoelectric element 1, and is adapted to be screwed or fitted into a screw 2b provided in the light receiving window 2a of the storage case 2. It has a shape similar to a plug body. 8a is a hole for inserting the light guide 10;
b is a screw for screwing into the inner circumferential surface of the light-receiving window 2a, and 9 is a protective tube for the light guide 10. Reference numeral 10b denotes a light emitting surface of the light guide 10, which is fixed in a position facing the light receiving section of the photoelectric element 1.

FIG. 2 is a partial axial cross-sectional view of the internal combustion engine spark plug 100 incorporating the light guide 10 with the connector shown in FIG. 1 connected to the light emitting side end. has its light-receiving side inserted into a shaft hole drilled through the center electrode 11, and the light-receiving surface 10
a is assembled so as to substantially coincide with the discharge side end surface of the center electrode 11.

12 is a center electrode 1 made of nickel-based alloy, etc.
It is a cylindrical insulator enclosing the cylindrical insulator 1, and is made of high alumina content porcelain, silicon nitride, or the like. 13
is a main metal fitting made of iron-based metal that is fitted onto the outside of the cylindrical insulator 12, and an outer electrode 14 is welded to the end face on the discharge side, and serves as a fitting for attachment to the engine cylinder wall. 16 is a packing for gas sealing, 17 is an adhesive for joining the light guide 10 and the cylindrical insulator 12,
18 is a gasket for installing a spark plug; 19 is a filler such as talc; 20 is a powdered filler; 21 is a packing; 22 is a cylindrical terminal for connecting a high-voltage power supply line 23;
24 is a heat-shrinkable tube made of silicone resin, 25
26 is a bakelite layer, 26 is a lock pin, 27 is silicone rubber, 28 is an input side terminal of the high voltage power supply line 23, and 33 is an insulation reinforcing tube.

Reference numeral 29 is a non-metallic outer cylindrical body for attaching the joint 8 for joining the ignition plug with combustion light sensor and the photoelectric element storage case 2 to the rear end of the ignition plug, and connects the high-voltage power supply line 23 to the ignition plug. It also functions as a protective cover for certain areas. The joining joint 8 is connected to this outer cylindrical body 2.
It is fitted or fixed to the rear end of 9 using an adhesive or the like. Other symbols in the figure are the same as those in FIG.

FIG. 3 is a partial axial cross-sectional view illustrating the overall structure of the light guide 10, in which 30 is a reinforcing silicone polymer layer covering the outer peripheral surface of the light guide 10;
31 is a PFA tube for further protecting the outer peripheral surface of the silicone polymer layer 30; 32 is a light guide 1;
A protective tube made of stainless steel is fitted onto the light emitting side end of the light guide 10 from which the polymer layer 30 has been removed, and is integrally fitted via an adhesive layer to the light guide 10 from which the polymer layer 30 has been removed. Reference numeral 11 indicates a center electrode in which the light guide 10 is inserted into the shaft hole, and 17 indicates a center electrode in which the light guide 10 is inserted into the shaft hole of the center electrode 11. It is a cementitious adhesive.

FIG. 4 is a partial axial cross-sectional view depicting a second embodiment of the structure of the light guide 10, in which the light receiving surface of the light guide 10 is a flat surface compared to the light receiving surface 10a of the first embodiment. Unlike the above, it has a feature in that it has a curved surface shape as indicated by the symbol 10c. For this reason, the light-receiving surface 10c has a light-gathering ability similar to a fisheye lens or a convex lens, which has the effect of greatly improving the sensitivity of the sensor compared to a light guide having a simply flat light-receiving surface 10a. Regarding the structure of the light receiving surface 10c, there is no difference from that of the first embodiment.

Next, a method of using the connector shown in the above embodiment will be explained below. As mentioned at the beginning,
For example, when a spark plug with a built-in combustion light sensor with the structure shown in Figure 2 is installed on the cylinder wall of an internal combustion engine and the performance of the spark plug or internal combustion engine is tested, the sensor's electrical output signal is If it is necessary to visually confirm the discharge state of the spark plug, the state of ignition, or the strength of the combustion light before inputting it to various recording devices such as an oscilloscope or data analysis device, photoelectric By rotating the element storage case 2 relative to the joint 8, the element storage case 2 can be stored from the joint 8 attached to the light emitting side end of the light guide 10 assembled to the spark plug side. Since the case 2 can be removed and removed, the combustion light and discharge light inside the cylinder can be directly observed by looking into the light emitting surface 10b of the light guide 10 protruding from the joining joint 8. become. When the purpose is achieved, the connection between the two is completed in one touch by lightly screwing the joining joint 8 into the light receiving window 2a of the storage case 2, so you can connect the output output connector 3 of the storage case 2 as desired. By connecting the cable to the input connector of the experimental equipment, the combustion light sensor can immediately be put into use.

In the above embodiment, the coupling joint 8 between the photoelectric element storage case 2 and the light guide 10 is configured to be engaged and separated by a combination of male and female screws, but of course other methods may also be used. As such, a known joint structure such as a fitting type joint with a tapered contact surface may be employed.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a spark plug with a combustion light sensor according to the present invention, and Fig. 2 shows a combustion light sensor of the type incorporated in a spark plug for an internal combustion engine using the connector shown in Fig. 1. FIGS. 3 and 4 are partial axial sectional views illustrating the structure of the light guide, respectively. In the figure, 1... photoelectric element, 2... photoelectric element storage case, 2a... window for light reception, 3... connector for taking out the output of the photoelectric element, 8... joint for joining, 10...
...Light guide, 10a, 10c...Light receiving surface, 10b...
...Light emitting surface, 11... Center electrode of spark plug, 100...
...Spark plug.

Claims (1)

[Claims for Utility Model Registration] The tip of the straight center electrode is exposed from one end of the cylindrical insulator, and one end surface of the thin wire light guide is inserted into the axial center through hole provided in the center electrode. is assembled so that the tip of the center electrode serves as a light-receiving surface, a joining joint having a threaded portion for screwing is provided at the other end of the cylindrical insulator, and the other end surface of the thin wire light guide is assembled into the joining joint. The main body of the ignition plug is exposed at the center of the joint, the screw is screwable to the threaded part of the joint, and a photodetection chamber is formed in which a photoelectric element is disposed. , a photoelectric element storage case having a window in the center of the screw for allowing the other end of the thin wire light guide to face the light receiving part of the photoelectric element, and a connector connected to the photoelectric element; An ignition plug with a combustion light sensor, wherein the ignition plug main body and the photoelectric element storage case are screwed together.