JP3972819B2 - Engine with temperature sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine with a temperature sensor having a temperature sensor for measuring the temperature of the engine .
[0002]
[Prior art]
A temperature sensor mounted on an engine and used for engine control is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-43220 (Patent Document 1).
[0003]
FIG. 2 is a cross-sectional view of the temperature sensor disclosed in Patent Document 1. As shown in FIG. A temperature sensor 10 in FIG. 2 is a thermistor temperature sensor, and is mounted in the housing portion 40 to measure the temperature of engine coolant or exhaust gas that is the fluid to be measured 80.
[0004]
The temperature sensor 10 includes a metal tube 11 whose tip is closed, and a thermo unit 20 that is arranged close to the front end 11t of the metal tube 11. The thermo unit 20 includes an insulating tube 21 through which the lead wire 14 is inserted, and a thermistor element 22 fixed to the front end portion of the insulating tube 21. The front portion of the thermo unit 20 is embedded and fixed in the cement 30 in the metal pipe 11. In FIG. 2, reference numeral 15 is a lead wire, reference numeral 16 is a rubber bush, and reference numeral 18 is a protective tube.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-43220 [0006]
[Problems to be solved by the invention]
In the automobile field, with the recent tightening of exhaust gas regulations, there is an increasing demand for combustion control using EFI even in small engines used in motorcycles and the like. In order to apply combustion control using EFI to a small engine, precise temperature measurement around the engine is indispensable. However, many small engines are air-cooled, and when the temperature sensor 10 of FIG. 2 is applied to an air-cooled engine, there are the following problems.
[0007]
Since an air-cooled engine does not use cooling water, when measuring the temperature of the engine, it is necessary to measure the temperature by reliably contacting the tip 11t of the temperature sensor 10 of FIG. 2 with the engine body. However, such contact is generally difficult, and the contact state deteriorates due to a difference in thermal expansion between the engine main body and the tip portion 11t or engine vibration, so that accurate temperature measurement gradually becomes impossible. In addition, since the contact area between the engine body and the tip portion 11t is small, the heat capacity of the tip portion 11t of the temperature sensor 10 cannot be ignored, and there is a problem that the responsiveness of the temperature sensor 10 is deteriorated.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide an engine with a temperature sensor having a temperature sensor that has high responsiveness and is capable of suppressing temperature change accuracy over time.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is an engine with a temperature sensor having a temperature sensor for measuring the temperature of the engine , wherein the temperature sensor is arranged to face the surface of the engine. When made and a cylindrical housing for accommodating the infrared sensor therein, the surface of the engine, it is formed with previously closed bore, the bore, the distal end portion of the cylindrical housing is inserted Te, wherein the temperature sensor is made is secured to the engine, by the infrared sensor detects infrared rays emitted from the surface of the engine, it is characterized in that the temperature of the surface of the engine is measured.
[0010]
Temperature engine with sensor of the present invention is to directly detect radiation heat radiated as an infrared from the surface of the engine at the infrared sensor measures the temperature of the surface of the engine. Accordingly, the tip of the temperature sensor is brought into contact with the engine body, unlike the conventional temperature engine with sensor comprising a temperature sensor such as a thermistor for detecting the temperature of the surface of the engine by conductive heat, the infrared sensor surface may be a non-contact of the engine. Thus, it is released from the deterioration problem of contact due to differential thermal expansion and engine vibration between the engine body and the temperature sensor tip caused by the contact type conventional temperature engine with sensor comprising a temperature sensor, accurate Temperature measurement without change over time becomes possible. Moreover, in the temperature sensor of the engine with a temperature sensor of the present invention that directly detects radiant heat, the heat capacity around the infrared sensor is hardly a problem, so that it can be a responsive temperature sensor.
[0012]
Further, according to the temperature sensor of the engine with the temperature sensor, when processing the housing, it is possible to process the cylindrical tip portion which is a simple shape at a low cost. Further, since the front end portion of the tubular housing is secured to the engine, it is possible to cut off the infrared ray entering from outside other than the surface of the engine, so that accurate temperature measurements.
[0014]
In particular, the temperature sensor of the engine with the temperature sensor has an infrared ray incident from the outside because the tip of the cylindrical housing is inserted into a closed hole formed on the surface of the engine and fixed to the engine. Is completely cut off. Further, since the temperature of the tip portion approaches the temperature of the surface of the engine, thereby enabling more accurate temperature measurement.
[0015]
According to a second aspect of the invention, into an inner surface of the outer peripheral surface and the hole in the front end portion of the cylindrical housing, the screw portion is formed, the distal end portion of the cylindrical housing is threaded into the bore by, it is characterized in Rukoto a is fixed to the engine.
[0016]
Thereby, the temperature sensor can be firmly attached to the engine. Further, the heat transfer from the surface of the engine through the threaded portion, since the temperature of the tip portion of the cylindrical housing approaches the temperature of more surface of the engine, it is possible to more accurate temperature measurement.
[0017]
The invention according to claim 3, the engine will comprise a sealing member interposed between the tip and the surface of the engine of the cylindrical housing, the tubular housing distal end portion is inserted into the bore inside, it is characterized in Rukoto a is sealed by the sealing member.
[0018]
According to this, by the sealing member interposed between the tip and the surface of the engine of the cylindrical housing, ingress of water or the like can be prevented between the cylindrical housing and the surface of the engine , adverse effects to the infrared sensor can be prevented.
[0019]
The invention according to claim 4, wherein the infrared sensor is characterized Rukoto such is enclosed in a case where at least one surface is made of an infrared transmitting filter.
[0020]
In the infrared sensor, it can be infrared light emitted from the surface of the engine is incident through the infrared transmission filter, for detecting the radiation heat in the infrared sensor. On the other hand, the infrared sensor, since that is the sealing structure by infrared transmission filter and the case, adverse effects due to intrusion or the like of water or the like is prevented.
[0021]
As set forth in claim 5, the engine with the temperature sensor is particularly effective when the engine is air-cooled engine.
[0022]
The water-cooled type engine uses cooling water, and the engine cooling water can be used for engine temperature measurement. In this case, even with a conventional temperature sensor such as a thermistor element that detects the temperature by conduction heat, the temperature measuring unit can be brought into good contact with the engine cooling water, and accurate and responsive temperature measurement is possible. is there. On the other hand, air-cooled engines do not use cooling water, and there is no good heat medium in the temperature measurement path . For this reason, the engine with the temperature sensor having the temperature sensor released from the problem of the contact state as described above is particularly effective.
[0023]
Further, as described in claim 6, in the engine with the temperature sensor, the tip portion of the cylindrical housing, is particularly effective when it is fixed to the cylinder head of the engine ing.
[0024]
By fixing the tip of the cylindrical housing to the cylinder head portion close to the combustion chamber of the engine, more precise engine control can be performed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0026]
Fig.1 (a) is sectional drawing of the temperature sensor 100 for engine temperature measurement of this invention.
[0027]
In the temperature sensor 100 for measuring engine temperature shown in FIG. 1A, the distal end portion 2c of the housing 2 has a cylindrical shape, and the infrared sensor 1e is accommodated in the cylinder of the distal end portion 2c with the distal end 2t open. . The infrared sensor 1e has a structure enclosed in a case 1c in which an infrared transmission filter 1f is attached to the opening of the head. Since the infrared sensor 1e is sealed by the infrared transmission filter 1f and the case 1c, adverse effects due to water intrusion and the like are prevented. The space between the case 1c and the tip 2c of the housing 2 is also sealed with a brazing material or the like. In FIG. 1A, reference numeral 3 denotes a connector resin, which is fixed to the rear end portion of the housing 2 by “caulking” with the packing 4 interposed therebetween. In addition, a metal terminal 5 is molded on the connector resin 3, and the infrared sensor 1 and the terminal 5 are connected via leads 6.
[0028]
The tip portion 2c can be processed at low cost by making the tip portion 2c into a simple cylindrical shape. In addition, by accommodating the infrared sensor 1e in the tube of the tip 2c, infrared rays incident from the outside other than the engine surface can be blocked, and accurate temperature measurement is possible.
[0029]
In the temperature sensor 100 for measuring engine temperature in FIG. 1A, the tip 2t of the tip 2c is open, and the infrared sensor 1e is disposed so as to face the engine surface via the infrared transmission filter 1f. . In addition, the infrared sensor 1e of FIG. 1A is disposed at a position retracted from the tip 2t of the tip 2c so as to block infrared rays incident from other than the opposed engine surface at the tip 2c of the housing 2. . The front end portion 2c of the housing 2 has a screw portion 2n on the outer peripheral surface, whereby the engine temperature measuring temperature sensor 100 is fixed to the engine.
[0030]
As described above, the distal end portion 2c of the housing 2 in which the infrared sensor 1e shown in FIG. 1A is accommodated serves to fix the infrared sensor 1e to the engine and to block infrared rays incident from outside the engine surface. Have both.
[0031]
FIG. 1B is an external view of the engine temperature measuring temperature sensor 100 shown in FIG. 1A, and also shows a state where the engine is mounted on the engine (cross section) 9.
[0032]
In FIG. 1B, a closed hole 9h is formed in the surface of the engine 9, and the engine temperature measuring temperature sensor 100 is fixed by inserting the tip 2c into the hole 9h. In this way, by inserting the cylindrical tip 2c in which the infrared sensor 1e is accommodated into the hole 9h of the engine 9, infrared rays incident from the outside are completely blocked. Moreover, since the temperature of the front-end | tip part 2c approaches the temperature of the surface of the engine 9, accurate temperature measurement is attained by this.
[0033]
The engine temperature measurement temperature sensor 100 is fixed to the engine 9 with screws, and the screw portion 2n of the engine temperature measurement temperature sensor 100 is screwed into the screw portion 9n formed on the inner peripheral surface of the hole 9h. Thereby, the engine temperature measuring temperature sensor 100 is firmly fixed to the engine 9. Moreover, since the temperature of the front-end | tip part 2c approaches the temperature of an engine surface more by the heat transfer from the surface of the engine 9 which passed the screw parts 9n and 2n, an accurate temperature measurement is attained also by this.
[0034]
The engine temperature measuring temperature sensor 100 shown in FIG. 1B has a seal member 8 interposed between the tip 2c of the cylindrical housing 2 and the engine 9, and the inside of the cylindrical housing 2 is sealed by the seal member 8. It has a structure. As the seal member 8, an O-ring or a metal gasket is used. Thereby, it is possible to prevent water from entering the hole 9h and the tip 2c between the surface of the engine 9 and the housing 2, and to prevent adverse effects on the infrared sensor 1e.
[0035]
In the engine temperature measuring temperature sensor 100 shown in FIGS. 1 (a) and 1 (b), the infrared rays indicated by the arrows in FIG. 1 (b) emitted from the surface of the engine 9 are transmitted through the infrared transmission filter shown in FIG. 1 (a). The light passes through If and enters the infrared sensor 1e, where radiant heat is detected. As described above, the engine temperature measuring temperature sensor 100 directly detects the radiant heat by the infrared sensor 1e disposed at the tip 2c and measures the temperature of the engine surface. Therefore, unlike a temperature sensor such as a thermistor element that detects the temperature of the engine surface by conduction heat by bringing the tip of the temperature sensor into contact with the engine body, the infrared sensor 1e that is a temperature measuring element is not connected to the surface of the engine 9. It may be a contact. This frees the problem of deterioration of the contact state caused by the difference in thermal expansion between the engine main body and the temperature sensor tip caused by the contact-type temperature sensor and the vibration of the engine, and enables accurate temperature measurement without change over time. Further, in the temperature sensor 100 for measuring the engine temperature shown in FIGS. 1A and 1B in which the radiant heat is directly detected by the infrared sensor 1e, the heat capacity around the infrared sensor 1e is hardly a problem. It can be.
[0036]
The engine temperature measuring temperature sensor 100 shown in FIGS. 1A and 1B is particularly effective when mounted on an air-cooled engine. The water-cooled type engine uses cooling water, and the engine cooling water can be used for engine temperature measurement. In this case, as shown in FIG. 2, even the temperature sensor 10 such as the thermistor element 22 that detects the temperature by conduction heat, the temperature measuring unit can be brought into good contact with the engine coolant 80, and it is accurate. Temperature measurement with good response is possible. On the other hand, the cooling water is not used in the air-cooled type engine, and there is no good heat medium in the temperature measurement path, so that the problem of the contact state as described above is eliminated as shown in FIGS. The engine temperature measuring temperature sensor 100 is particularly effective.
[0037]
Further, the engine temperature measuring temperature sensor 100 shown in FIGS. 1A and 1B is particularly effective when mounted on the cylinder head. By mounting the engine temperature measuring temperature sensor 100 shown in FIGS. 1A and 1B on the cylinder head portion close to the combustion chamber of the engine, more precise engine control becomes possible.
[0038]
As described above, the engine temperature measurement temperature sensor 100 shown in FIGS. 1A and 1B is a temperature sensor that has high responsiveness and suppresses a change in temperature measurement accuracy with time. Therefore, by using the engine temperature measuring temperature sensor 100, combustion control using EFI can be performed even in a small air-cooled engine used in a two-wheeled vehicle or the like, and the exhaust gas regulations can be strengthened.
[0039]
(Other embodiments)
The engine temperature measuring temperature sensor 100 shown in FIGS. 1A and 1B has screw portions 2n and 9n formed on the outer peripheral surface of the tip 2c and the inner peripheral surface of the hole 9h of the engine 9, and this screw portion 2n. , 9n to the engine 9. The engine temperature measuring temperature sensor is not limited to being fixed to the engine, and a bolt fixing hole may be formed in the housing 2 and fixed to the engine with a bolt.
[0040]
In the engine temperature measuring temperature sensor 100 shown in FIGS. 1 (a) and 1 (b), a closed hole 9h is formed in the engine 9, and a cylindrical tip portion 2c of the housing 2 is inserted into the hole 9h. And fixed to the engine. The arrangement of the engine temperature measuring temperature sensor in the engine is not limited to this. For example, a hook may be attached to the tip 2t of the engine temperature measuring temperature sensor 100 shown in FIG. In this case, it is not necessary to form the tip 9 hole 9h in the engine 9. Further, the infrared sensor 1e may be fixed to a place other than the engine and disposed opposite to the engine surface without taking the structure of fixing the infrared sensor 1e to the engine.
[0041]
The temperature sensor 100 for measuring engine temperature shown in FIGS. 1A and 1B has a structure in which an infrared sensor 1e is enclosed in a case 1c in which an infrared transmission filter 1f is attached to the opening of the head. Without being limited to this, without using the case 1c of FIG. 1 (a), the infrared transmission filter 1f is arranged in the opening of the tip 2t of the housing 2, and the infrared sensor 1e is arranged directly in the cylinder of the tip 2c. It may be.
[0042]
Even the engine temperature measurement temperature sensor having the above-described configuration can be a temperature sensor for engine temperature measurement that has high responsiveness and that suppresses a change with time in temperature measurement accuracy.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view of an engine temperature measurement temperature sensor of the present invention, and FIG. 1B is an external view of the engine temperature measurement temperature sensor of the present invention. The wearing state is also shown.
FIG. 2 is a cross-sectional view of a conventional temperature sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Temperature sensor 100 Engine temperature measuring temperature sensor 1e Infrared sensor 1f Infrared transmission filter 1c Case 2 Housing 2c Tip part 2t Tip 2n Screw part 8 Seal member 9 Engine 9h (Closed) hole 9n Screw part

Claims (6)

An engine with a temperature sensor having a temperature sensor for measuring the temperature of the engine ,
The temperature sensor is
It comprises an infrared sensor arranged opposite to the surface of the engine, and a cylindrical housing for accommodating the infrared sensor therein,
A closed hole is formed on the surface of the engine,
The tip of the cylindrical housing is inserted into the hole, and the temperature sensor is fixed to the engine.
Wherein the infrared sensor detects infrared rays emitted from the surface of the engine, the temperature engine with sensors, wherein the temperature of the surface of the engine is measured. A threaded portion is formed on the outer peripheral surface of the tip of the cylindrical housing and the inner peripheral surface of the hole,
The engine with a temperature sensor according to claim 1 , wherein a tip end portion of the cylindrical housing is fixed to the engine by being screwed into the hole . The engine
A seal member interposed between the tip of the cylindrical housing and the surface of the engine;
3. The engine with a temperature sensor according to claim 1 , wherein an inside of a cylindrical housing having a tip portion inserted into the hole is sealed by the seal member . The infrared sensor is
The engine with a temperature sensor according to any one of claims 1 to 3 , wherein at least one surface is enclosed in a case made of an infrared transmission filter . The engine with a temperature sensor according to any one of claims 1 to 4 , wherein the engine is an air-cooled engine . The tip of the cylindrical housing is
The engine with a temperature sensor according to any one of claims 1 to 5, wherein the engine is fixed to a cylinder head portion of the engine .

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