JPS6288924A - Sensor and internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to fluid monitoring equipment, and more particularly to lubricating oil monitors for internal combustion engines.

BACKGROUND OF THE INVENTION Internal combustion engines require the presence of lubricating oil to properly lubricate pistons, piston and crankshaft bearings, etc. For proper lubrication, the amount of lubricant (oil) in the crankcase sump must be kept to a minimum. Most internal combustion engines have an oil dipstick removably attached to the engine block and inserted downward into the oil sump. The user can easily check the oil level in the oil sump by pulling out the dipstick and visually inspecting the area of oil adhering to the dipstick. In pressurized lubrication systems, a pressure sensitive switch is conventionally installed in the lubricating oil circulation system. The pressure level decreases when the oil decreases below a predetermined safe operating level. The switch is connected to a suitable indicator system, such as a gauge, warning light, etc., to display a reading or generate a warning to the user when the oil level falls below a minimum level. Small internal combustion engines do not use pumps and associated pressurization systems. Rather, a splash lubrication system is used in such engines, in which an oil hook arm member on the crank unit moves through oil in a sump, throwing the oil onto the moving parts (
) provides lubrication. Conventional pressure sensitive protection systems are therefore not applicable to such lubrication systems.

Small internal combustion engines are used in relatively small equipment such as lawn mowers and lawn tractors. The operation of such equipment often neglects to properly maintain the necessary oil in the sump. If an engine is operated with an inadequate oil supply, even a relatively short period of operation can cause significant, if not catastrophic, damage to the engine. In the past, sensing systems have been proposed to replace manual oil level inspection with dipsticks. Automatic protection systems have also been proposed in the past that are mounted on engine sumps or oil tanks to shut down the engine or generate a visual and/or audible warning signal if the oil level drops to an inappropriate level. .

Mechanical sensing systems have also been proposed for such splash systems. Various electrical sensing means have also been proposed. In general, such conventional technology uses various float switches, G-switches, intermittent thermometers, spark gap units, etc. to provide an electrical output signal when the oil level falls below a predetermined minimum level in the crankcase. Change is coming.

In a spark gap system, a pair of electrodes is immersed in oil, which is a relatively poor conductor of electricity, and remains immersed in the oil as long as the oil level is above a predetermined safe level. be made into This electrode is connected to the ignition system as a voltage source. On the other hand, if the oil drops below a safe level, the electrodes are exposed to the air and conduction occurs.

Nos. 2.123.460 and 2.1, both issued to Berkshire on July 12, 1938.
No. 23,400 discloses a sensor introduced into an oil supply pipe, where the sensor is introduced into a dipstick pipe for testing the oil level of an engine. The sensor is
Includes a spark gap device mounted within the corresponding dipstick and grounded to the engine block. For example, a single sensing electrode is mounted insulated within a tubular dipstick that is grounded to the engine and forms a sensing electrode of opposite polarity. This sensing electrode is connected to the ignition system and
A high enough voltage is applied to cause an electrical discharge through the air between the electrode and the tubular test tube, and the electrical discharge causes a current to flow. When the oil level is above a selected safe level minimum, oil is present between the outer tube and the inner sensor electrode. By the way, oil is a relatively good electrical insulator, so in this state, discharge in the gap is blocked and no current flows. When the oil level falls below a predetermined level, the applied high voltage causes current to flow, which shorts the ignition circuit and immediately stops engine operation.

U.S. Patent No. 4, 25, issued March 17, 1981
No. 6.069 discloses a float-operated system in which a magnetic float is used that moves in a sump to follow the oil level in the sump relative to a relatively hermetically enclosed reed switch. . When the oil level is at a minimum, the float is lifted, closing the switch and allowing ignition. On the other hand, if the oil level drops below that level, the switch is opened and ignition is prevented. This detected temperature is enclosed in a special housing in the engine's oil sump and shielded from the influence of the oil spatula.

U.S. Pat. No. 2,529,775, issued to Maddox on January 20, 1948, discloses a pressure responsive electrical switch having a pair of spaced apart electrodes. A floating ball made of conductive material is forced by gravity to engage the electrode and close the circuit. When the engine is started and the oil level is above a predetermined minimum safe level, oil pressure increases and lifts the ball from its normal circuit-closing position, which opens the circuit and prevents normal ignition. become able to. However, when the oil level drops, the ball returns to its normal seated position, closing the circuit. In response to this, the engine operation is stopped. U.S. Pat. No. 4.203. issued May 20, 1980 to Janagschild et al.
No. 408 discloses another pressure sensitive unit operating a special diaphragm type actuator. Such systems cannot be used in conventional "splash" lubrication systems.

PROBLEM SOLVED BY THE INVENTION The above and similar proposals can be used for automatic monitoring of oil levels. However, such systems have not found widespread use in engines using commercially available splash lubrication systems. Of course, the costs associated with automatic sensing are often reasonable, but the accuracy and reliability of the available sensors, as well as their malfunctions, prevent commercial applications, especially for "splash" lubrication systems. This is noticeable when using small herring.

Additionally, when the engine is stopped and at rest, an accurate indication of whether the oil supply is adequate or not can only be obtained from the oil level if the engine is at the proper level and the position of the oil level relative to the dipstick is correctly determined. Obtainable. The oil dipstick is usually inserted from the side of the engine. If the engine is tilted significantly vertically or horizontally with respect to the oil dipstick position, the oil in the oil sump will flow to a lower position accordingly. This changes the apparent level on the dipstick. Therefore, in the tilted position, the oil level clearly indicates an inappropriate level. in general,
The user is instructed to check the oil level with the engine in the correct horizontal position. On the other hand, when an automatic sensor is inserted into a system having an oil test unit, there is a problem in that an erroneous display may occur when the engine in use is tilted, for example, when the vehicle moves on an inclined surface.

When the engine is mounted on a lawn mower or other moving vehicle, the oil tank is constantly moving as a result of the vehicle's motion and the motion of the shovel. This vehicle motion imparts an internal motion that creates waves in the oil tank in the sump.

Vibrations associated with engine motion also cause some oil movement. Furthermore, in the splash-type 'II+'t system, the oil paddle fixed to the engine crank acts to move oil from the oil sump to each part of the engine for lubrication, which further increases the disturbance of the oil. Moved violently.

In this way, even if the oil level in the engine is within normal safe limits when measured, for example, by a dipstick, it can be detected as a result of oil movement relative to an automatic sensor, especially in "splash" type lubricated engines. Temporary low-level conditions often occur around the organ.

Although such conditions occur only for relatively short periods of time, the sensor often provides a false indication in response. If the sensor is simply connected to a visual display device, no complications arise and such operation can be tolerated. However, it is desirable in the prior art that the sensor be connected to automatically shut down the engine. In most systems, the shutoff unit automatically restarts when the oil is reset to the sensor.

On the other hand, automatic shutoff may require manual activation by the operator. In any case, sensor malfunction is not only a nuisance to the operator, but is also economically undesirable when the engine is installed for commercial gain. Therefore, engine malfunctions in response to such conditions are almost generally unacceptable.

The inventors have noted that a fundamental problem with the prior art stems from the fact that while measuring the oil level on the one hand, a measurement must actually be made of m of oil in the engine. Also, when monitoring the amount of oil,
It is highly desirable to accurately monitor relatively small oil volume changes, especially before and after safe oil j, which allows for the desired minimum lubrication of the engine. The undulations and "splash" lubrication effects associated with the oil reservoir during operation of the system create problems, particularly when attempting to use oil level as a reference or to measure the amount of oil present.

Sensors having switches connected to high voltage ignition systems create another practical problem. This means that when connecting one electrode to a high-voltage system, a reliable electrical connection can be achieved even in environments subject to the severe vibrations associated with engines, and in the presence of foreign substances arriving from the surrounding air. must be able to be maintained. For this reason, the connection must be physically robust. Additionally, the connection must be able to accommodate the effects of foreign material build-up on the external surface of the electrode mounting portion that would act to bypass the electrode directly to engine ground. Additionally, the system must be capable of providing optimal system operation and providing accurate and repeatable oil supply indications under normal engine operating conditions, regardless of the physical position of the engine. Thus, whether it is a vehicle, a lawnmower, or any other type of ground-based device, such sensing devices will give the same reading as long as the device using them is properly engaged with the ground. However, on the other hand, it is preferable that the engine be automatically stopped, for example if the engine falls to one side or both sides.

Furthermore, the cost of the system must be kept at a reasonable level, especially for relatively small "splash" lubrication engines that are produced in high volumes.

In particular, it is an object of the present invention to provide an electrically responsive oil or lubricant sensor that effectively senses the amount of lubricant used to lubricate an engine.

SUMMARY OF THE INVENTION In accordance with the teachings of the present invention, electrically responsive sensing means are mounted in a sump in a special flow control enclosure that communicates with the lubricating oil sump. The enclosure is particularly configured to create a controlled flow to create controlled entry and exit of lubricant between the reservoir and the electrically responsive sensing means. The enclosure is particularly configured to maintain said electrically responsive means submerged in lubricant in the enclosure when an appropriate amount of lubricant is present as desired for engine lubrication. The entry and exit of lubricant between the enclosure and the sump is controlled so that the sensor operates reliably in environments conventionally found in "splash" type engines.

In the configuration of the present invention, undulating motions, moving motions, and rapid splashing motions in the sump have no effect on the accurate and reproducible sensing of the minimum effective amount of lubricant in the sump. Does not occur.

In particular, in accordance with the present teachings, a spark gap electrode unit, preferably having spaced apart electrodes forming a spark gap, is secured to the mounting member. Preferably, both electrodes are supported in an insulating support member. One of the electrodes is a high voltage electrode and is connected to the high voltage side of the ignition system. The other electrode is the common side and may be connected directly to the ground side of the engine or via a suitable display or reading device. The mounting may also be such that the electrically insulating enclosure or enclosure forms one wall of the enclosure and is secured to the member. The housing is provided with a plurality of vertically spaced openings spaced apart from the electrodes. The openings include at least one opening at substantially the same vertical level as the sensor gap and operative to introduce oil or lubricant between the enclosures and from such inlet openings. Also included is at least one further opening located on the underside for providing restricted flow or outflow of the IA lubricant exiting the enclosure. For most efficient and responsive operation, a third opening is preferably provided above the inlet opening to prevent air or other fumes from becoming trapped within the enclosure. Such a sensor fills rapidly with lubricant under normal system operating conditions and also fills during initial start-up. If the enclosure is filled with oil, the spark gap will be immersed in oil and conduction will be prevented. When the system is in operation, the wave motion and splashing of lubricant that occurs in the sump tends to erroneously change the flow of oil supplied through the inlet opening into the enclosure. However, Applicants have discovered that by controlling the flow of oil into and out of small isolated enclosures, a very accurate and reliable determination of the supply of lubricant available to the engine can be made.

If the oil base falls below the minimum design value, the difference between the supply of oil to the enclosure and the controlled and constrained discharge of oil from the enclosure causes the oil level in the enclosure to fall below the level at the gap location and automatically A discharge occurs and current flows through the spark gap, closing the circuit. Even if a relatively small amount of oil remains in the enclosure, there is no substantial disturbance due to waves, vibrations, splashes, etc., and the oil in the enclosure is relatively stable and the electrode is in a normal state. It's soaked in oil.

In an optimal configuration according to the invention, the inventor should also further provide in the enclosure a baffle plate that prevents the oil in the sump from moving directly from the inlet opening to the area where the gap is provided. I found out. That is, under some operating conditions, a situation arises in which rapidly moving oil from a central opening in the enclosure enters the enclosure and temporarily covers the ends of the spark gap of the sensor. Then, because the sensor responds quickly, the engine automatically reignites.
Engine operation is temporarily restarted. The inventors of the present application have found a simple and reliable solution that allows an optimal operating configuration. In this solution a baffle unit is introduced between the spark gap and the inlet opening of the enclosure. The baffle unit acts to prevent the incoming oil from moving directly towards the spark gap, effectively shaping the response to the oil level in the enclosure.
The oil level in the enclosure will then be 5, which accurately reflects the oil level in the engine sump.

In a preferred arrangement, the baffle unit is a solid plate that corresponds to the internal shape of the enclosure around the spark gap. The plate includes small edge notches on the side edges that are generally aligned with the spark gap and the inlet opening. The baffle unit forms a barrier to the flow of oil straight into the inlet opening and acts to prevent oil from flowing laterally around the baffle unit. The flow opening is formed by a notch in the edge, so that the flow of oil entering the enclosure toward the spark gap is split on both sides of the spark gap and does not impinge directly on the spark gap.

In a typical configuration, the outer housing has a width slightly larger than the electrode thickness and a vertical height slightly larger than the electrode spacing. The housing is removably secured to the support member to form a small enclosure. The enclosure then has a depth substantially greater than its width corresponding to the location and arrangement of the electrodes, forming a relatively narrow and deep reservoir, and extending towards both sides of the spark gap.

Three vertically spaced openings are formed at the outer edge of the enclosure, of which the central opening forms the oil inlet, the smaller bottom opening is a restricted drainage opening, and the top opening forms the oil inlet. The opening is an air release opening. A baffle plate is fixed within the housing between the electrode and the outside of the enclosure housing. A baffle plate defines an intermediate chamber adjacent the outer edge of the enclosure.

The baffle plate has a notch in its side edge, and the lower edge of the notch is aligned with the inlet opening to allow free flow of oil around the baffle plate. The lower end of the baffle plate is formed with a small exhaust opening aligned with the exhaust opening in the enclosure. The small exhaust openings in this baffle plate are made slightly smaller so that the flow through the baffle plate openings is smaller to ensure a properly responsive oil level in the sensing chamber.

When the engine is in the proper operating position at rest, the oil level in the enclosure corresponds to the desired oil level in the sump. Therefore, the present invention also provides an oil level sensor and an oil level sensor in an operating state.

An oil sensor suitable for small internal combustion engines containing splash lubrication systems, the sensor has an insulated mounting adapted for removably securing within an engine crankcase side wall opening, such as a molded plastic support member. or a supporting member. The spark gap electrode is a rod-shaped electrode embedded in the molded support member and extending across the support member. The inner ends of the electrodes are bent close to each other. The end of the upper electrode is connected to the high voltage side electrode and is formed to have a substantially sharp point. The opposing lower electrode is connected to a common line or return electrode and has a relatively rounded end. The mounting member is specifically configured to cooperate with the crankcase opening to orient the nepacer vertically, with the pointed electrode becoming the upper electrode and the rounded electrode becoming the lower electrode. It will be done like this. The inventors have discovered that such an electrode tip configuration can minimize malfunctions due to oil trapped between the electrodes as a result of surface tension. Such tip configuration provides a substantially instantaneous effective response if the oil level in the isolated enclosure drops below a safe ceiling.

Additionally, the housing electrode support member is formed into an integral tower extending outwardly around the high voltage electrode. The tower has a plurality of adjacent annular radial projections that significantly increase the surface creep path between the high voltage side electrode and the engine crankcase. This increased surface path minimizes the probability of parasitic currents from the high voltage electrode to the electrical ground level consisting of the engine crankcase and block.

The configuration of the support member and crankcase opening is such that the spark gap is located at a position corresponding to a predetermined minimum safe oil level in the center of the sump. The system according to the invention can monitor the adequacy of the oil and at the same time respond if the engine has fallen out of its normal operating condition or operating environment.

Additionally, in vehicle ignition systems that use a magneto as the power supply, the sensor is connected to the output of the magneto by tapping a spark plug cable or via a separate high voltage sensor wire connected to the coil. . When connecting a connector to a spark plug cable, the connector must be constructed to prevent moisture from entering the connection. Ingress of moisture will seriously impede engine operation. Using a separate connection wire is less likely to introduce moisture into the ignition system than tapping the spark plug cable.

The invention makes it possible to obtain a highly accurate, reliable and reproducible response of changes in the liquid level in the sump, which response accurately reflects the effective amount of oil in the sump. This allows effective lubrication of the internal combustion engine.

Additionally, the presence of water or other electrically conductive substances in the lubricant can have a detrimental effect on lltI sliding properties. Although generally considered to be of minor importance in lubricant monitoring for internal combustion engines, serious problems can arise in applications such as the lower unit of outboard motors that drive underwater propellers. In such a device, the propeller is submerged together with the lower unit, and the propeller shaft is coupled to the engine output shaft by a gear drive VJ mechanism in the lower unit. The lower unit is filled with a suitable lubricant to extend the life of the gear drive arrangement. Water often enters the lubricant space during operations in marine applications that are configured under water.

Significant accumulation of water will result in loss of lubrication and damage and destruction of the lower unit gears. The sensor according to the present invention can be easily attached to such a lower unit, and the presence of water in the lubricant can be continuously monitored by utilizing the difference in conductivity between the lubricant and water. Similarly, the sensor according to the present invention can be applied to transmissions and the like.

Sensing devices according to the present invention can be easily constructed with existing technology and can be quickly produced in high quality products at reasonable commercial prices. The present invention has the advantage that it can appropriately determine whether m of a lubricant for internal combustion engines, etc. is correct, and can also be used to monitor the presence of foreign conductive substances such as moisture and water in the lubricant. Can be used.

EMBODIMENTS The best embodiments of the present invention will now be described with reference to the drawings.

1 and 2 show a small internal combustion engine with a vertical drive shaft. The engine is a typical engine and includes a block and a head 2, in which a reciprocating piston 3 and a crank 4 are operatively mounted. It is pivotally supported by a crankshaft 5 which is rotatably mounted.

The bottom of the engine block 2 is closed with a crankcase or oil cover 6, forming an oil sump or oil chamber. Oil 7 fills the sump to a predetermined minimum level. Although not shown, an oil paddle is attached to the lower end of the crank 3, and is moved through the oil 7 to support the bearings.
The screws and cooperating parts are splash-lubricated in response to the rotational movement of the crankshaft and crank. A spark plug 9 is fixed to the head of the engine block head.

A high voltage lead 10 connects the spark plug 9 to a high voltage source such as a magneto coil. The ignition magnets 1 to 12 include a magnetic core unit 13 coupled to a magneto driven by the engine, and supply high voltage to the spark plug 9 at appropriate timing each time the piston reciprocates. The ignition system may be of any known configuration. Although all such configurations are known and various modifications thereof can be used, in the present invention, the magneto unit 12 is assumed to be in the block shape shown in the figure for illustrative purposes.

The amount of oil 7 in the oil sump must be maintained at a predetermined minimum level for proper lubrication of the engine. Its level varies with the configuration of the individual internal combustion engine. The level can be checked manually using a dipstick unit, which is not shown but is removably fixed to the block.
It extends downward into the oil 7 in the oil sump. In the illustrated embodiment of the invention, a sensor unit 14 constructed according to the invention is fixed to the lower end of the motor, and in the illustrated example a cover 6
mounted on. The sensor unit 14 projects inwardly into the oil sump, and its inner end is located approximately at the center of the horizontal position of the oil 7 when the engine is on a horizontal plane. Below, the second
As will be explained in more detail with reference to FIGS.
and 16 in the outer enclosure 17. ±Pole tip 18
and 19 are separated from each other to form a spark gap 20. A plurality of openings 21 , 22 and 23 control the flow of oil 7 into and out of enclosure 17 . Tip of electrode 18.
Once 19 is covered with oil 7, a high resistance path is formed between the electrodes, preventing conduction under normal operating conditions. On the other hand, if the oil 7 is not present and the electrode tips 18-19 are exposed, the ignition voltage of the unit 12 is large enough to discharge the gap 20, a conductive atmosphere is formed in the gap, and the voltage Vi15 A conductive path is formed that connects and 16 through the gap 20.

The electrode 15 is connected by a high voltage lead 24 to a high voltage lead 10 for the spark plug 9.

Electrode 16 is connected to ignition unit 12 by a further return connection lead 25 . The circuit formed by leads 24 and 25 is configured to effectively ground/short circuit spark plug 9 when conduction occurs between electrodes 15 and 16. As a result, the engine automatically stops operating in response to the conduction of the sensor unit 14.

The invention particularly relates to the construction of a sensor unit 14 for monitoring the presence of oil 7 available in the engine 1. The engine and other parts may be of any configuration, and therefore, the engine itself will not be described unnecessarily in describing the illustrated embodiments of the invention. Below, the configuration of unit 14,
Please refer to the drawings for the physical installation of the unit into the engine as part of the engine and the electrical connections that make up the electrical system that allows accurate, reliable and repeatable monitoring of available lubricating oil supply. This will be explained in detail.

In particular, FIGS. 2 and 3 clearly illustrate the sensor unit 14 of the present invention, which includes a molded plastic mounting block or support block 27 with sensing electrodes embedded therein. Recognize. Block 27 includes a cylindrical member or portion corresponding to an opening 28 in the side wall of crankcase cover 6 and is fastened into crankcase cover 6 by a fastening bracket 29 to seal the opening. The electrodes 15 and 16 are rod-shaped electrodes that protrude from the block 27 and have an internal sensing electrode end 18 and 19 at the tip.
are formed and integral external connectors or terminals 30 and 31
has.

The inner end of each electrode is formed into an L-shaped member and defines a pair of vertically spaced opposing tips 18 and one. The length of the spark gap 20 is selected depending on the circuit connection including the spark plug 9, and is selected such that a high-pressure discharge occurs through the air between the gaps in the absence of insulating oil 7 filling the gap. Conversely, if oil 7 is present filling the gap between the electrode tips, the circuit between the terminals is essentially opened. The gap 20 may be, for example, slightly smaller than the spark plug gap, although it has been found that the system will operate correctly even if the gap 20 is as large as the spark plug gap.

The enclosure 17 is fixed to the inner end of the support block 27 and the electrode 15
and a cup-shaped housing 27 surrounding the inner parts and tips of the electrodes 15 and 16, the cup-shaped barrel 27 and the block inner part 27 together forming an enclosure 17, which enclosure 17 in particular the opposite tips 18 of the electrodes 15 and 16. and 19 and a relatively small isolated chamber closely surrounding the spark gap 20.

The outer end wall 33 of the housing is provided with three vertically spaced openings 21, 22 and 23, in the example shown in the central part, for directing the oil 7 in the sump to the inside of the enclosure. An inlet or introduction opening 22 is included for introduction into the sensing chamber of the sensor.

The lower opening 21 forms a restricted discharge or outflow path forming a controlled flow of oil 7 out of the sensing chamber.

In addition, the upper opening 23 shown in the figure is the inlet opening 2 for oil.
2 and/or provide an outlet for air to freely escape from the sensing chamber upon entering the chamber through the exhaust opening 21. If the oil is full, the opening 23t3 will be immersed in the oil again, but even in that case, the air will rise due to its nature and come out of the opening 23, so the sensing chamber will be filled with oil1.The air is removed. is important. That is, the air in the palm of the hand expands at operating temperatures, forming large bubbles, and when these bubbles enter the gap, electrical conduction occurs, causing an erroneous stopping operation. In this way, the opening creates a controlled flow between the sump and the sensing chamber.

Additionally, the flow of oil from the oil sump to the sensing chamber within enclosure 17 is varied by a baffle plate 34 mounted within the sensing chamber. Baffle unit 34 connects inlet opening 22
and the spark gap 20 to prevent the four coils 7 from flowing straight from the opening 22 into the sensing gap. The illustrated baffle unit 34 has openings 35 in the side edges to allow oil to move laterally as it flows around the baffle wall and into the sensing chamber containing the sensing electrodes.

The openings 21-23 and the baffle unit 34 are configured such that the movement of oil 7 from the sump to the sensing chamber causes the tips 18 and 19 of the electrodes 15 and 16 to be immersed in oil during normal operation of the engine.

However, the baffle structure or baffle unit 34 prevents malfunctions due to the rapid flow of oil in the crankcase into the sensing chamber. That is, the oil rapidly flowing into the sensing chamber hits the baffle plate 34, so that first the small chamber between the outer wall and the baffle unit is filled. The oil is then removed from the staggered openings 35 and 36.
There is free flow through the sensing chamber and into the electrodes 15 and 16 and into the spark gap 20. The spark gap 20 has a high resistance when there is a minimum amount of oil required for proper lubrication in normal operation;
Prevents conduction through the gap. If the oil drop drops below a predetermined minimum safe level, the amount of lubricating oil in the sensing chamber will also be insufficient to drop below the level of the lower electrode tip 19 and the high voltage signal will be lowered to the high voltage lead 10. and to the connecting lead wire 24, conduction occurs. Although the present invention relies on the flow of liquid into and out of the sensing chamber, viscosity and efflux will vary with individual operating conditions and will generally require a tailored design for individual operating conditions.

For example, the state of the oil 7 in an engine changes significantly when the engine starts operating and its temperature rises. In internal combustion engines, the sensing unit is designed to respond to warm-up conditions that are reached 10 to 15 minutes after the engine has started running.

Accurate and reproducible measurement of oil quantity by using a special small sensing chamber defined by an enclosure closely surrounding the electrode and the gap and configured to suitably control the entry and exit of oil from the sump. It was discovered that it is possible to perform some sensing. When the engine is stopped, the oil level is selected such that the sensing unit 24 is covered, and the oil quickly fills the sensing chamber. In this way, the sensor of the present invention can be used as an oil level sensor in a stopped state.
act.

Further, by locating the sensor 14 at a substantially central position in the normal horizontal plane of the oil sump, accurate detection can be achieved substantially independently of the engine attitude within the normally permissible inclination range of the engine from the horizontal plane. Capable of 5 level sensing. If the engine completely topples from its normal horizontal position, tilts significantly, or falls on its side, whether this occurs while the engine is stopped or while running, the oil 7 moves to one side of the oil sump and sparks. Gap 20 is exposed to air and the engine is immediately shut down.

It has been found that in a preferred embodiment of the present invention, a means is provided for accurately sensing small changes in oil level at the end of a specifically selected safety level or between. This system is substantially unaffected by environmental conditions, vibrations associated with engine operation, and undulating motion of oil, etc., which can cause errors in splash lubrication systems. A highly reproducible response is obtained under various operating conditions and within the normal life of the engine and sensor unit.

Furthermore, the present system and components are based on today's technology and allow for economical and substantial fabrication of the sensor.

The insulated high voltage lead 24 and the insulated return lead 25 are specifically configured to allow connection of auxiliary components or display devices to the output of the sensor. Therefore, if desired, a lighting unit 37 as shown in FIG. 1 or the like can be connected in series to the return lead wire 25. The system is spark gap 2
Although a high voltage is applied around where 0 is connected to the high voltage source, the current level is small so that a small inexpensive lighting unit, such as a light emitting diode, can easily be inserted into the return lead circuit.

Specifically, in the illustrated embodiment of the invention, support block 27 is an internally molded plastic cylindrical member having an internal protrusion 32 . The rod-shaped electrodes 15 and 16 are molded into the block 27 and extend axially through the mounting block 27 and the inner projection. The cylindrical block 27 fits into a receiving opening 28 in the wall of the crankcase cover 6. An O-ring seal 39 is provided on the outer periphery of the molded support member 27,
Forms a reliable liquid-tight seal of the opening in the assembled state. The outer end of the support block 27 is formed with a flange 40 adapted to abut the outside of the crankcase cover 6 for positioning the electrodes. A fastening plate or bracket 29 is removably fixed to the outside of the crankcase by fastening bolts 41 or the like, and extends over the support block 27 to seal the sensor unit 14 to the crankcase.

Support member 27 forms complementary keyed portions that allow the sensor unit to be inserted only in a single orientation so that electrode tips 18 and 19 are positioned within the crankcase on a normal horizontal working plane. It is preferable to arrange them vertically. The illustrated key portions are a pair of recesses 42 of different shapes provided diametrically opposite each other on the support member 27. The bracket 29 is provided with a pair of arms having end protrusions 43 corresponding to the shape of the recess 41, and the bracket can be used when the support member 27 is oriented correctly and the electrodes in the support member are arranged in the correct direction. Attachment to the support member 27 is possible only in this case. Of course, other suitable key means may also be used.

Furthermore, when the direction is determined by the above key, the electrode with the sharp tip becomes the upper electrode.

Therefore, one rounded electrode becomes the lower electrode. Preferably, this rounded electrode tip actually has a flat cylindrical surface.

This arrangement of an electrode with an upper pointed tip 18 aligned with an electrode with a single lower rounded tip increases the life of the spark gap unit, while at the same time keeping the oil in the gap 20 due to surface tension. It is possible to prevent malfunctions due to being captured.

When the oil skewer goes down, the oil level in the sensing chamber also changes to gap 2.
decreases below the level of 0. However, due to surface tension phenomena associated with the oil 7, the oil tends to adhere and remain between the electrode tips 18 and 19, in which case the oil actually reaches zero.
A small spark gap 20 of about 0.004 to a few thousandths of an inch is connected. In the present invention, such a phenomenon can be practically eliminated due to the sharp tip 18, so that when the oil level of the sensing stroke falls below the level of the gap 20, the gap becomes exposed to the outside world, and the ignition caused by the ignition unit Conduction occurs when a high voltage signal is applied.

Terminal ends 30 and 31 of electrodes 15 and 16 project axially outwardly from mounting block support member 27. A high voltage tower 44 is molded integrally with the mounting block 27 around the high voltage side terminal 30 of the high voltage electrode 15.

Tower 44 is formed with a plurality of circumferential recesses forming circumferential or annular surface extensions 45 . This tower then forms a significantly extended outer surface between the crankcase 6 and the outer terminal 30 of the electrode 15. This results in a long creep path that substantially reduces parasitic currents flowing from the high voltage electrode to the crankcase and ground.

A connecting U-shaped loop terminal 46 is formed on the outer terminal 30 of the high voltage side electrode 15, and the corresponding end of the high voltage wire connector 24 is plug-in connected. In this manner, the high voltage end is configured differently with respect to the ground terminal 31 of the electrode 16 to prevent incorrect connections of the high voltage lead 24 and the ground return lead 25. High voltage lead wire 24
has a boot 47 at one end having an inner tubular connector 48 that resiliently engages the loop terminal 46, and the connector 48 pressably engages the terminal 46. boot 47 is tower 4
4 and tightly engages the connecting portion 48. The return electrodes and return or ground leads 25 are connected by four simple pin and socket connector assemblies with mechanical slip-type latches 50.

A cross-shaped portion including a vertical wall 51 slightly thicker than the embedded electrode and a short intersecting wall 52 is formed in the inner portion of the support member 27 . Further, an elliptical mounting wall 53 is integrally formed with the outer ends of this cross-shaped portion, and a central protruding wall 54 extends further outward from the center of this mounting wall 53. The ends of this central projecting wall 54 terminate at a location spaced apart from the electrode tips 18 and 19. The mounting wall 53 has a conical surface, and a circular recess 55 is formed at its inner end. The outer enclosure 32 has a similar shape and has a conical wall 54.
adapted to extend beyond.

The housing 32 has an inner end ridge 56 that elastically engages the recess 55 and serves to removably secure the housing. As can be seen from FIGS. 4 and 5, both the walls 54 of the housing 32 have an elongated shape, and a pair of relatively long and flat side walls 57 have a flat top wall 58 and a curved bottom wall. 59, respectively. The housing 32 includes an outer end wall 33, which is also planar and integrally formed with other walls. The side walls 57 are spaced apart from each other by a distance only slightly greater than the thickness of the mounting and projecting walls, the spacing being equal to the distance between the electrodes 15 and 16.
The diameter of the electrode is selected so that the outer wall is sufficiently close to the electrode. Similarly, the flat top wall 58 and curved bottom wall 59 are also spaced apart from the corresponding upper and lower J poles. The lengths of the side walls and end walls are selected such that when the housing is extended beyond the mounting ridge, the flat end walls 33 are spaced outwardly from the electrode ends 18 and 19, as best shown in FIG. Ru.

A plurality of flow ii+ control openings 222 and 23 are formed in the end wall 33 and are vertically separated. Openings 21-23
Generally, all openings are circular, and a thank-you portion is further formed on the outer side of the end wall 33 of the opening. The inlet opening 22 is generally aligned with the spark gap of the electrodes. The opening 22 is relatively large compared to the lower discharge opening 21. The inlet opening 22 allows relatively free movement of the oil 7 between the sump and the sensing chamber. The upper opening 23 is provided for the purpose of preventing air from becoming trapped within the chamber, particularly between the inlet opening and the upper end of the chamber. The upper opening 23 is preferably slightly smaller than the inlet opening so as to restrict the flow of oil through the top of the chamber while not impeding the movement of air exiting the chamber.

In the illustrated example, the air release opening is approximately 2/3 the size of the oil inlet opening.

The lower discharge opening 21 is substantially smaller than the inlet opening 22 and the air exchange opening. The dimensions of the exhaust opening 21 are the most important of these openings and control the flow of oil out of the sensing chamber. This controls the response characteristics of the sensor 14. In conventional engine operation, by providing a relatively large, unrestricted inlet, the supply of oil to the chamber is substantially constant as long as the supply of oil is adequate. In such conditions the oil supply is sufficient to keep the spark gap 20 submerged in oil 7.

The drain opening must be small enough so that the oil exits the chamber at a slower rate than it enters.

The dimensions of the drain opening are not critical if there is adequate oil 7 in the engine. In such a case, sufficient oil is maintained without flooding the gap, regardless of the size of the opening. However, if the m of the oil decreases, the discharge opening 2
Size 1 must be configured to prevent oil from flowing out of the sensing mold too quickly. At critical mass, the discharge flow rate must be slightly larger than the supply flow rate, so that the oil level in the special small sensing chamber drops rapidly below the gap position in the sensing chamber. By using a relatively small sensing chamber that closely surrounds the tip of the electrode and the spark gap 20, small changes in oil level can be reproducibly and accurately detected. In this manner, the system of the present invention can continuously and reliably monitor that the oil supply is adequate.

A flat end wall 33 on the outside of the housing is spaced from the electrode tips 18 and one. Inside the housing, a baffle unit 34 is connected to the end wall 33.
and mounted away from the tip 18, 19, gap 2
An intermediate chamber is formed adjacent to the sensing chamber surrounding 0.

In the illustrated embodiment of the invention, the baffle units i-34 have a baffle plate 61 whose outer shape substantially corresponds to the inner cross-section of the sensor housing 32. Upper and lower mounting arms 62 and 6
3 are fixed to the upper and lower ends of the plate 61 and extend on both sides of the plate 61. The arms 62 and 63 have a cross-sectional shape that matches the upper wall 58 and lower wall 59 of the housing 32, and the baffle unit 34 is inserted into the housing by pressing lightly by hand. The arms 62 and 63 project toward one side of the plate 61 to form a positioning member that engages the flat end wall 33 of the housing, and the baffle plate 61 is positioned within the housing in a generally spaced relationship from the end wall 33. Correctly placed, as a result of which an intermediate chamber is formed.

Further, the baffle plate 61 is installed at an appropriate distance from the electrode tips 18 and 19 by arms 62 and 63 extending oppositely, and a sensing chamber is formed between the electrode tips and the gap 20.

A similar rectangular notch 64 is formed at the edge of the baffle plate 61, and openings 35 and 36 connecting the outer chamber and the sensing chamber are formed between adjacent housing side walls. Notch 64
is formed at a position such that its lower end substantially coincides with the vertical level of the spark gap 20. The cutout 64 is dimensioned to allow free conventional movement of oil between the outer chamber and the sensing chamber. On the other hand, the baffle plate 61 forms a substantial laterally directed cover plate covering the portion of the spark gap 20 that is aligned with the inlet opening of the housing, thereby allowing the oil 7 to pass from the sump to the spark gap. This prevents it from entering directly.

The baffle plate 61 may be formed from the same plastic material as the outer housing to conveniently provide a baffle to the housing when attaching the housing to the support member. Of course, the baffle may be fixed in the housing by a suitable means such as a force fit or adhesive using an adhesive.

The baffle plate 61 further includes a small opening 65 adjacent to the lower arm, so that this opening 65 is aligned with the oil outlet or drain opening 21.

The discharge opening 65 in the baffle plate 61 is connected to the enclosure end wall 3.
Preferably, it is slightly smaller than the discharge opening in No. 3.

This further restricts oil flow and ensures that the oil level outside the gap area is at least as low as the level in the gap area, substantially eliminating backflow into the sensing chamber. Furthermore, a somewhat large opening 66 is formed in the baffle plate 61 at the intersection of the baffle plate 61 and the upper arm 62. The baffle plate openings 65 and 66 provide the desired movement of oil to the drainage control outlet opening 21 and the air release opening 23.

In the actual configuration, one sensor is installed in the engine where the normal oil level should be maintained between and fort. The electrodes are configured such that the tips are vertically spaced about 0.25 inches apart and the tips extend outwardly from the insulating block by about 0.125 inches. This amount of outward extension is selected in particular to accommodate the fact that the gap 20 is located essentially in the center of the sump chamber. The internal vertical dimension of the housing is approximately 0.650 inches and the width is approximately 0.3 inches.
It is 10 inches. The openings in the outer end wall are formed with maximum spacing as shown. The diameter of the center opening is 0.120 inches. The diameter of the air outlet or outlet opening is 0.08
It is 0 inches. The more important exhaust opening is formed in the inner wall to have a diameter of about 0.025 inch. The baffle plate is spaced 0.093 inch from the end wall and 0.093 inch from the electrode tip. Rectangular edge notches have a height of 0
．． 135 inches and a depth or width of 0.050 inches. It has been found that the sensor unit 14 is capable of very accurately, reliably and reproducibly sensing a drop in oil level or an oil addition before or after a predetermined operating level.

To summarize the operation of the illustrated embodiment of the invention, a small, internally baffled enclosure defines a sensing chamber that closely surrounds sensing gap 20 and electrodes 18 and 19. The baffle chamber is large enough to prevent oil from flowing straight into and engaging the electrodes 15-16, and the oil sump 7
Slightly slows the movement of oil from the to the sensing chamber.

The speed of this oil movement is related to the drop of oil below a predetermined safe level, and the electrode gap 20 is immersed in oil as long as the oil is properly supplied to the sensing chamber and there is a minimum amount of oil. It is set to a value that allows it to maintain its current state. If the oil level is less than a predetermined minimum amount, the opening 21
The initial velocity through the oil supply exceeds the oil supply velocity, and the sensor detects changes in the oil level in the small sensing chamber, especially the spark gear 1.
? It quickly responds to a drop below the level of the knob 20, creating a current path through the spark gap that is responsive to the high voltage in the high voltage ignition wire. This amount of current operationally shorts out the ignition system and shuts down the engine. By centrally locating the sensing gap as shown, complete control can be achieved even if the engine leans too far during operation.

At the same time, if indicator light 37 is used, indicator light 37 is energized to indicate to the operator that the engine has been shut down due to improper lubricating oil level.

Also, if the indicator light element has sufficient resistance, or if a suitable resistance is added in series with the circuit containing the indicator light, the indicator light will respond without causing engine stalling.

For example, a lamp unit 67 is connected in series with a current limiting resistor 68 instead of lead wire 24 and lamp 37, as shown by the dashed line in FIG. Resistor 68 limits the current level to a level that prevents shorting of the ignition current to ground. Thus, the present invention is easily adapted as a low level display device and can also function as a visual or audible display device.

In the illustrated embodiment, lead 24 is connected to lead 10 by a tap connector 70. The connection to lead 10 must be hermetically sealed to prevent the ingress of moisture or foreign substances that would interfere with proper ignition of the engine. Examples of particularly suitable compression connections are shown in FIGS. 1, 6, and 7. Here, the connection includes a two-piece collar 71 surrounding lead 10 and an integral tubular stem 72 connected to lead 24 . The collar 71 includes a connecting base 73 integrally formed with a stem 72 which is a tubular member. A two-point contact 74 is embedded in the wall between the stem 72 and the base 73. Contacts 74 have oppositely projecting, sturdy, sharp-pointed elements 75 and 76 that pierce the insulation coating of each lead 10 and 24 and connect to the inner conductor to form a connection. An outer clamp 77 is removably coupled to the base to press the lead (AIO) at the connection and hermetically seal the elastic insulation sheath of the lead wire 10.

The base 73 and the clamp 77 are elongated members having a curved inner surface that corresponds to the outer shape of the lead wire 10 but has a slightly smaller diameter. The base 73 and the clamp 77 are removably connected by a sliding concave and convex connecting part 78, and the lead wire 1
0 can be connected and disconnected. The conductor 24 projects tightly into the tubular stem 72 and the outer end is sealed with a sealant such as epoxy at location 78 to form a hermetic enclosure of the connection.

While the tap connections described above are useful, connections to the ignition wire or ignition system may be undesirable in some designs. In that case, lead wire 24 is connected directly to the power source. For example, in FIG. 8, leads 10 and 24 are connected directly and separately to coil 11 of magneto unit 12.

Each lead thread 10 and 24 is connected by seven similar hermetic connections. The coil 11 includes a waterproof cover 80 on the outside. A tubular hub 81 of the connection 79 projects from this and a corresponding readhead is sealed within the hub. An epoxy coating or other sealant 82 covers the connections and the face of the coil to form an effective seal.
maintain.

Since the electrode tips 18 and 19 have opposing pointed and flat tips, the opening 20 can prevent the sensing unit 14 from malfunctioning when the oil level in the sensing chamber drops.6 The tip of the electrode 18 is sharp. A conical shape is preferred, but other shapes can also produce a fil-like response. For example, when a flat conductive strap is used as a high voltage side electrode, forming the tip into a generally wedge shape reduces the width of the end and reduces the effect of surface tension. Such a configuration is collectively referred to as a tip element or means.

The high voltage connection properly connects the sensor to the high voltage ignition circuit, and fitting the sensor into the keyhole properly orients the sensor in the desired orientation and orients the electrode arrangement. The present invention can also be used to monitor the presence of a conductive medium such as water in a non-conductive medium such as a lubricant in drive gears, transmissions or other enclosed lubrication systems. Although the system described in the present 1M example can be driven directly by an ignition system such as a magneto coil, the system can also be driven by a separate power source to obtain a similar response to changes in immersion liquid volume. For example, a battery powered oscillator and converter unit may be used as a separate and independent power supply for the sensor, eliminating the need for connection to an existing ignition system.

Further, other display devices or control devices may be inserted into the return circuit.

The sensor of the invention may further include suitable interlocking means, such as reset control means operated by a discharge in the sensing gap. When the engine is shut down, a high voltage, but low current surge forms in the return lead,
As a result, the control means is activated. Preferably, the control means is connected to prevent restart of the engine in the absence of a reset of the control means. In this way, the operator can be alerted to the fact that the oil level is decreasing.

The illustrated embodiment of the invention utilizes unique separate sensing chambers to provide an improved multi-sensor system that can monitor oil level changes as described above, as well as the associated presence of non-conductive and conductive media. A sensor having the following characteristics is provided. Within the scope of the invention, different types of modified sensors using essentially the same sensing chamber can be produced depending on the application and the different specifications required.

Various embodiments of the invention are possible within the scope of the invention.

[Brief explanation of drawings]

1 is a schematic side view of a four-stroke internal combustion engine using a vertical rank shaft and a splash lubrication system; FIG. 2 is an enlarged section of the internal combustion engine to illustrate the installation of an oil sensor according to the invention; FIG. 3 is an enlarged sectional view of the sensing unit shown in FIG. 2, and FIG. 4 is a longitudinal section of the sensor shown in FIGS. 5 is a cross-sectional view of the sensor shown in FIGS. 2 and 3 taken along line 5-5 in FIG. 3, FIG. 6 is a side view of the high voltage lead wire connector, and FIG. 8 is a cross-sectional view taken approximately along the center line 7-7, FIG. 8 is a diagram showing another connection of the high voltage lead wire for the sensor, FIG. 9 is a diagram showing the installation of the sensor with the bracket attached, FIG. 10 is an enlarged view of a part of the figure, and is a view of the bracket with the central part removed to not clearly show the structure of the bracket. 1... Engine, 2... Head, 3... Piston, 4... Crank, 5... Crankshaft, 6...
... Oil cover, 7... Oil, 9... Spark plug, 10... High voltage lead wire, 11... High voltage source, 12... Magneto, 13... Magnetic core unit,
14...Sensor, 15.16...Electrode, 17...
Enclosure, 18.19... Electrode tip, 20... Gap, 21-23, 28° 35.36, 65.66... Opening, 24.25... Lead wire, 27... Block , 29... Bracket, 30.31.46... Terminal, 32... Housing, 33... Outer end wall, 34.61...
・Baffle plate, 37... Light unit, 39... Seal, 40... Flange, 442.55... Recessed part,
43...Protrusion, 44...Protrusion part, 45...Extension part, 47...Boot, 48.49.70...Connector, 50...Latch, 51...Vertical wall, 52 ... Cross wall, 53 ... Mounting wall, 54 ... Conical wall, 56 ...
・Ridge, 57...Side wall, 58...Top wall, 59...
・Bottom wall, 62.63... Arm, 64... Notch,
67...Lamp unit, 68...Resistor, 71.
...Collar, 72°73...Stem, 74...Contact, 75.76...Element, 77...Clamp, 78.
79... Connection portion, 80... Cover, 81... Hub, 82... Sealant.

Claims (47)

[Claims] (1) A sensor adapted to be immersed in a liquid and used while being immersed in a liquid, which senses the presence of a medium contained in a liquid and having a different conductivity from the liquid; , first and second spaced apart from each other forming a sensing gap therebetween.
an electrode within the sensing gap between the electrodes, means for varying the conductivity of the gap in response to the conductivity of the medium in the gap, and mounted around the ends of the electrodes forming the gap. a flow control enclosure defining a chamber, the flow control enclosure including a plurality of openings for forming a flow of the liquid into the chamber and bathing the opposing electrode; a sensor configured to retard the flow of the liquid from the chamber in response to movement of the liquid at the chamber. (2) The sensor according to claim 1, wherein the first electrode has a sharp tip and the second electrode has a blunt tip. (3) The first electrode is connected to a high voltage source, the second electrode is connected to a ground return path, and the control means is connected in series with the return path. The sensor described in item 1. (4) further comprising a support member supporting the electrode and the control enclosure, wherein the tips of the electrodes are arranged perpendicularly to each other;
2. A sensor according to claim 1, wherein key means formed in said support member vertically aligns said electrode tips. (5) the enclosure has an inlet opening substantially aligned with the gap;
2. A sensor according to claim 1, further comprising means inserted between the inlet opening and the gap to prevent direct entry of liquid into the gap from outside the enclosure. . (6) The means inserted between the inlet opening and the gap includes baffle plate means for diverting incoming fluid flow to opposite sides of the electrode and the gap. The sensor according to item 5. (7) the baffle plate means has a further discharge opening extending below and aligned with the discharge opening, the further discharge opening in the baffle plate; Claim 6, characterized in that the flow rate of liquid flowing through the enclosure is made smaller than the flow rate of liquid flowing through the discharge opening in the enclosure at a given liquid level in the enclosure. Detector described in section. (8) The cross-section of the further discharge opening in the baffle plate is made slightly smaller than the cross-section of the discharge opening in the enclosure to create the flow rate difference. The sensor described in item 7. (9) A sensor adapted to be immersed in a liquid, which senses the presence of a medium in a liquid that has a different conductivity from the liquid, and which is an insulated sensor. a high voltage side electrode fixed in the support member and protruding from the support member and having an L-shaped portion at one end and a pointed tip at the other end; a second reference electrode tipped with a blunt end disposed in spaced and opposing directions to form a sensing gap therebetween; and a second reference electrode having a blunt end mounted to the support member and disposed around the electrode; a flow control enclosure defining a chamber to include;
The flow control enclosure includes a plurality of openings for forming a flow of the liquid into the chamber and bathing opposite ends of the electrode, and the enclosure accommodates movement of the liquid around the enclosure. The sensor is configured to slow the flow of the liquid from the chamber. (10) The sensor according to claim 9, wherein the electrode is vertically oriented at its end, and the support member has key means for vertically orienting the electrode. . (11) The opening in the enclosure includes an inlet opening substantially aligned with the gap, and a baffle plate is provided between the inlet opening and the gap to direct liquid from outside the enclosure into the gap. 10. The sensor according to claim 9, wherein the sensor is prevented from directly flowing into the sensor. (12) the baffle plate is a plate shaped substantially to correspond to the inner surface of the enclosure, the plate having laterally spaced openings aligned with the level of the inlet opening and the discharge opening; and another discharge opening in the baffle plate, the flow rate through the other opening in the baffle plate being greater than the flow rate through the discharge opening in the enclosure for a given liquid level in the enclosure. 12. A method according to claim 11, characterized in that the size is also reduced. 13. The sensor according to claim 12, wherein the other discharge opening in the baffle plate has a slightly smaller cross section than the discharge opening in the enclosure. (14) a high voltage lead connected to said first electrode having a pointed end and a return lead connected to said second electrode having a blunt end, and a return lead connected directly to said return lead and said gap; 10. The sensor according to claim 9, further comprising signal detection means for detecting a change in conductivity of the sensor. (15) The signal means includes a resistor that limits the current flowing through the gap, so that even if the gap is conductive, the engine continues to operate. sensor. (16) The sensor according to claim 9, wherein the high-voltage electrode and the reference electrode have connection end shapes that are different from each other. (17) The sensor according to claim 9, wherein the support means is a molded member in which the electrode is embedded, and the electrode projects outward from the inside of the support means. . (18) The high voltage side electrode is a rod-shaped member, and the end forming the outer terminal is a spring means that can be elastically engaged with a tubular terminal, and the reference electrode has a different end. 18. The sensor according to claim 17, wherein the sensor is a shaped terminal. (19) having an insulating protrusion integrally formed with the support member and extending outwardly along the high voltage electrode, the protrusion further having an annular protrusion around the periphery; 19. The sensor according to claim 18, wherein the high voltage side electrode includes an insulating cover made of an elastic material, and this cover is removably covered along the outer surface of the protrusion. (20) A sensor for use when immersed in a liquid, the sensor being adapted to be immersed in a liquid within a housing and sensing the presence of a different electrically conductive medium in the liquid, the insulating support member being immersed in a liquid. a first high voltage electrode affixed to the support member; and a spark gap affixed within the support member and further disposed opposite to the first electrode and responsive to the conductivity of the medium. a second reference electrode forming a second reference electrode; and a flow control enclosure secured to the support member to define a chamber proximately surrounding the electrode, including the gap, the flow control enclosure including at least a gap in the chamber. a first aperture forming a flow of the liquid entering and bathing the opposing electrode ends, and a second aperture causing a restricted discharge from the aperture; the opening is configured to retard the flow of the liquid from the chamber in response to movement of the liquid around the enclosure;
The sensor further characterized in that a baffle plate is inserted between the opening and the gap to prevent the liquid from flowing directly into the gap from outside the enclosure through the inlet opening. (21) The electrode is vertically oriented at its end, and the upper electrode has a tip configured in opposing relationship with the second electrode. sensor. (22) the enclosure has an exterior planar wall having three vertically spaced openings including an opening generally aligned with the gap, a lower exhaust opening, and an upper degassing opening; 22. The sensor according to claim 21, comprising: (23) A baffle plate is a solid plate that substantially corresponds to the inner surface shape of the enclosure adjacent the spark gap and is spaced apart from the electrode and the end wall and has a spark gap and an inlet opening on the side edge. has a notch substantially aligned with the
23. The sensor of claim 22, further comprising an aperture aligned with the exhaust aperture and the degassing aperture. 24. The sensor of claim 23, wherein the opening in the baffle plate aligned with the exhaust opening has a smaller cross-section than the exhaust opening. (25) The enclosure includes a rectangular cup-shaped housing having a width slightly larger than the thickness of the electrodes and a height slightly larger than the electrode spacing, and the housing forms the enclosure by being removably mounted on the support member. and also has a flat outer end wall;
an opening is provided in the center of the end wall to form an oil inlet opening, the second opening defines a small lower opening, a restricted discharge opening; 21. The sensor according to claim 20, wherein an upper opening is formed as an air escape opening. (26) The baffle means includes a baffle plate fixed in a position between the electrode within the housing and the outer end wall of the housing, the baffle plate having a lower edge on a side edge thereof aligned with the inlet opening. A cutout is provided to allow free flow of oil around the baffle plate, and the lower end of the baffle plate has a small opening aligned with the exhaust opening, and the upper end of the baffle plate has a small opening for the air escape. 26. A sensor according to claim 25, further comprising an aperture aligned with the aperture for use in the sensor. (27) the support member is a molded plastic member adapted to be removably secured in an opening in the sump sidewall, and the electrode is embedded in the molded support member and extends through the support member; elongated rod-shaped electrodes, the inner ends of which are bent close together, the first electrode having a substantially pointed tip and the second electrode having a relatively blunt tip; Claims characterized in that the support member has a tip, and the support member is configured to cooperate with the mounting opening to vertically align the electrodes, with the pointed electrodes on top. The sensor according to item 20. (28) The support member is integrally formed with a protrusion that surrounds the first electrode and extends outward, and the protrusion includes a plurality of adjacent annular radially protruding parts. A patent claim characterized in that the surface creep path leading to the high-voltage side electrode is significantly lengthened by the formation of a protrusion, thereby minimizing the probability of generation of parasitic current from the high-voltage side electrode. The sensor according to item 20. (29) The sensor according to claim 20, wherein the high voltage side electrode has a U-shaped end, and the reference electrode has an end with a distinctly different shape. (30) the sensor is adapted to be mounted within a correspondingly shaped opening in the housing and includes fastening bracket means for mounting the fastening bracket to the housing adjacent the sensor opening; , wherein the bracket and the sensor support member have a plurality of correspondingly engaging members that limit attachment of the sensor support member to the opening in a single direction. The sensor according to item 20. (31) The bracket includes oppositely extending arms mounted on the support member and having protrusions with distinctly different cross-sectional shapes formed at both ends, and the support member receives the protrusions. the bracket cover has first and second recesses aligned with each other, the recess having a shape corresponding to one of the protrusions, such that the bracket cover is aligned in one direction of the support member with respect to the housing; 31. The sensor according to claim 30, wherein the sensor is adapted to be mounted only in a direction facing. (32) An internal combustion engine comprising a high voltage source for an ignition system, an oil sump, splash lubrication means for transferring oil from the oil sump to operating parts, and a sensor, the engine comprising:
The sensor is a sensor that is attached to the oil sump and is immersed in the liquid to sense the oil, and is fixed to the support member and is connected to a high voltage source for the ignition system. a high voltage side electrode connected to the support member; a second reference electrode fixed to the support member and provided opposite and spaced apart from the tip to form a sensing gap responsive to the conductivity of the oil therebetween; a flow control enclosure affixed to the member defining a chamber surrounding the electrode including the opposing end, the flow control enclosure causing oil to flow into the chamber and bathe the opposing end; the support member and the oil sump include a plurality of opening means configured to form a flow and retard the exit of oil from the chamber in response to movement of oil around the enclosure; An internal combustion engine configured to center the oil in an oil sump. (33) The opposing electrode ends are arranged vertically, and the support member has key means for vertically aligning the electrode ends when the support member is attached to the oil reservoir. An internal combustion engine according to claim 32. (34) the enclosure has an inlet opening generally aligned with the gap and a baffle inserted between the inlet opening and the gap to prevent oil from flowing directly into the gap from outside the enclosure; 33. An internal combustion engine as claimed in claim 32, characterized in that it comprises means. (35) The internal combustion engine of claim 32, wherein the support member includes a molded plastic member in which the embedded electrode is embedded. (36) The engine includes a magneto that generates a high voltage to ignite a spark plug, the magneto having an output coil having a moisture-proof cover, and first and second high voltages connected to the coil and passing through the cover. a lead wire and a seal means secured to the cover and the lead wire for hermetically sealing a connection of the lead wire to the coil, the first high voltage lead wire being connected to the spark plug; 33. The internal combustion engine of claim 32, wherein the second high voltage lead is connected to the high voltage side electrode of the sensor. (37) The ignition system includes a high voltage spark plug wire having an external insulating cover and an elongated base having a laterally directed tubular extension secured to the spark plug wire to form a lateral connection. a T-shaped connector including a T-shaped base member having a T-shaped base member; a conductor in the tubular extension having a solid tip at one end extending outwardly from the base; a removable clamping member that securely fastens to the spark plug wire and hermetically seals the base to the wire and moves the sturdy tip through the outer insulating cover. The internal combustion engine according to item 32. (38) Claim 1, which includes a spark plug lead wire connected to the high voltage source, and another sensor lead wire connected to the high voltage source and the high voltage side electrode. The internal combustion engine according to item 32. 39. A low level indicating means connected between the reference lead and ground and having a resistance sufficient to prevent shorting of the ignition system. internal combustion engine. (40) The high-voltage side electrode is a rod-like member formed with spring means adapted to elastically engage a tubular terminal at its outer end, and the reference side electrode is a rod-like member formed with a spring means adapted to elastically engage a tubular terminal, and the reference side electrode is a rod-like member formed with a spring means adapted to elastically engage a tubular terminal. Claim 32, characterized by having a terminal
Internal combustion engine as described in section. (41) an insulating protrusion fixed to the support member and extending outward along the high voltage side electrode, the protrusion having a plurality of annular protrusions; 33. An internal combustion engine as claimed in claim 32, including an insulating sleeve of resilient material removably placed over said insulating projection. (42) a fastening bracket and means for attaching the fastening bracket to the oil sump housing adjacent to the sensor mounting opening; the bracket and the sensor support member are connected to the sensor; 33. Internal combustion engine according to claim 32, characterized in that it has a plurality of cooperating engagement means for restricting attachment to the opening to be possible only in a single orientation. (43) the bracket is mounted on the support member;
a pair of oppositely extending arms having a pair of laterally projecting ends of distinctly different cross-sectional shapes, the support member having first and second arms aligned to receive the projecting ends;
a recessed portion, wherein the recessed portion has a cross-sectional shape corresponding to the protruding end, so that when the bracket cover is installed on the housing, the support member is installed facing only in one direction. 43. An internal combustion engine according to claim 42. (44) comprising an indicating means, a current limiting means, and a means for connecting the indicating means between the reference electrode and ground, the current limiting means limiting the current flowing through the gap to limit the current flowing through the ignition means; 33. Internal combustion engine according to claim 32, characterized in that the ignition function is maintained. (45) An internal combustion engine including a splash lubrication system, a closed-bottom sump, and an electrically responsive sensing means, the sensing means being configured in a pair of spaced-apart configurations and sensing between the an enclosure surrounding a pair of rod-shaped electrodes comprising a high-voltage side electrode connected to the high-voltage side of the igniter and another return electrode forming a gap, and removably mounted in a side wall opening of the sump cover; The rod-shaped electrode consists of an upper electrode having a sharp tip and a lower electrode having a flat tip, which are vertically spaced apart and whose inner ends are bent so as to be close to each other. a molded plastic embedded therein and having an engagement member that cooperates with the bracket to orient the electrodes so that the electrodes with the pointed tips are always on the top and the electrodes with the flat tips are on the bottom; a support member; a housing having a flat outer end wall secured to the support member and forming an end wall of the enclosure and spaced slightly apart from the electrode; and a sensing gap in the flat outer end wall of the housing. an inlet opening formed at substantially the same level as that for allowing oil to flow into the interior of the enclosure; and a second inlet opening formed in the lower end of the flat outer end wall to provide a restricted outflow of oil from the enclosure. three vertically spaced openings including an exhaust opening and a third vent opening formed in the upper end of the flat wall to allow air and other fumes in the enclosure to escape;
The housing includes a baffle plate inserted between the flat wall and the spark gap, and the housing has a substantially rectangular shape, a width slightly larger than the thickness of the electrode, and a height slightly larger than the electrode gap. the baffle plate includes a small notch in the side edge with the lower edge generally aligned with the spark gap and the inlet opening; upper and lower mounting arms that engage and secure a baffle plate spaced apart from the flat wall and the electrode, the baffle plate having a cross section that is slightly smaller than the lower opening in the flat wall; a lower opening in the planar wall and an upper opening aligned with the upper opening in the flat wall, the support member having an integral projection extending outwardly along the upper electrode; The target protrusion has a plurality of adjacent annular protrusions, and the sensing means is further adapted to be sleeved over the spring end and has a resilient member adapted to be fitted over and into engagement with the integral protrusion. a cylindrical contact having an outer sleeve, the support member positions the spark gap at a predetermined safe minimum oil level position in the center of the sump, and a high voltage source is connected to the high voltage lead. and a high voltage spark slag lead wire is connected to the high voltage source. (46) The high voltage source is a magnet driven in synchronization with the engine, and includes an output coil, a spark plug lead wire, and a first hermetic seal connection means for connecting the spark plug lead wire and the coil. and second hermetically sealed connection means for connecting the high voltage lead to the coil.
The engine mentioned in section. (47) The connecting means includes a two-piece connector surrounding the high voltage spark plug lead, a T-shaped base member having a base wall having a curvature corresponding to the high voltage spark plug lead, and a T-shaped base member extending through the base member. including an extending conductor bar in the stem having sharp points at both ends, and an outer fastening member removably secured to the base member and having a curve corresponding to the high voltage spark plug lead wire. The engine according to claim 45, characterized in that: