JPH0725635Y2 - Oil sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an oil sensor for detecting the presence or absence of lubricating oil from the difference between the resistance values of air and lubricating oil.

[Problems to be solved by conventional techniques and devices] Generally, in a general-purpose engine, an in-vehicle engine, etc., if an operating state is maintained without noticing that the lubricating oil is insufficient, it causes damage such as seizure. In many cases, the oil amount is constantly monitored, and when the amount of lubricating oil is insufficient, the engine is stopped or a warning light is turned on to prevent the engine from being damaged before it is damaged.

By the way, as an oil sensor provided in the above-mentioned lubricating oil shortage detection device, for example, JP-A-62-93417, JP-A-62-93417 can be used.
-26379, there is a float switch type for monitoring the lubricating oil surface as disclosed in Japanese Patent Publication, or a hydraulic switch type for monitoring the lubricating oil pressure.
Due to its function, it is necessary to install each component (float, reed switch, etc.) inside the engine, and when installing it later, it is necessary to make a mounting hole in the bottom of the oil pan and assemble it.

As a result, not only the maintenance becomes complicated, but in the case of retrofitting, it is necessary to sufficiently ensure the sealability with the retrofitting hole formed in the bottom of the oil pan, and the structure and
There is a problem that assembly becomes complicated.

In addition, the hydraulic oil sensor cannot be used in a splash lubrication type engine that is not equipped with an oil pump, which not only has a problem in versatility, but also must be installed in the lubricating oil passage in advance. Similar to the above, there are problems in handling and maintenance.

Therefore, the applicant of the present application, in the earlier application (Japanese Patent Application No. 1-132087) to the same applicant,
The oil sensor composed of the sensor inner electrode inserted through the shaft center of the sensor outer electrode is inserted into the oil pan, and the resistance value detected by the distance between both electrodes and the space insulation resistance value are compared to determine the distance between the electrodes. In this paper, we proposed a technique to judge that the lubricating oil is present when the resistance value of the lubricating oil is detected, and to judge that the lubricating oil is insufficient when the space insulation resistance value is detected.

However, in the above-mentioned application, since the insulating member that insulates the sensor inner electrode and the sensor outer electrode is integrally formed with the sensor inner electrode, for example, the length of the sensor inner electrode is different for each engine type. In this case, it is necessary to individually provide an insert jig, a mold, etc. for integral molding, which not only increases the equipment cost but also significantly increases the man-hours required for molding.

In particular, it is difficult to quickly deal with the flexible process that accompanies the recent trend of user's needs and high-mix low-volume production, and parts management becomes complicated.

[Purpose of Invention] The present invention has been made in view of the above circumstances.
It is possible to quickly respond to the flexibility of the process associated with high-mix low-volume production without increasing the number of molding operations.
Moreover, it aims at providing the oil sensor which can simplify component management.

[Means for Solving the Problems] In the oil sensor according to the present invention, an insulating member is inserted and fixed to the hollow base side of a cylindrical sensor body that also serves as an outer electrode of the sensor, and the inner electrode of the sensor is located at the shaft center of the insulating member. Through the sensor body, the insulating sleeve is attached to the exposed surface of the insulating member on the hollow base side of the sensor body, and the proximal end of the sensor inner electrode is supported and fixed to the insulating sleeve, and the core wire of the shield wire is Formed on the upper surface side of the insulating sleeve by connecting the sensor inner electrode through the insulating sleeve and the insulating member, and further connecting the shield wire of the shield wire from the upper surface side of the insulating sleeve to the sensor body. The hollow concave portion of the sensor body is filled with a sealing material having adhesiveness with the insulating sleeve.

[Operation] In the above configuration, first, the sensor internal electrode is inserted through the shaft center of the insulating member, and the core wire of the shield wire is penetrated through the insulating sleeve, and then the core wire of the shield wire is connected to the sensor internal electrode. .

Then, the insulating member is inserted and fixed to the hollow base of the cylindrical sensor body that also serves as the sensor outer electrode.

Then, the base end of the sensor internal electrode is supported and fixed to the insulating sleeve, and the shield wire of the shield wire is connected to the sensor body from the upper surface side of the insulating sleeve. Then, a hollow recess formed between the hollow body proximal end side of the sensor body and the upper surface of the insulating sleeve is filled with a sealing material having adhesiveness with the insulating sleeve. Then, the sealing material permeates the surface of the insulating sleeve, covers the shield wire, and seals between the insulating sleeve and the shield wire and the base end of the sensor inner electrode.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional view of an oil sensor, Fig. 2 is a sectional view taken along line II-II of Fig. 1, and Fig. 3 shows a state in which the oil sensor is mounted on an oil pan. It is a fragmentary sectional view shown.

(Structure) Reference numeral A in the drawing is an oil sensor, and the sensor body 1 which also serves as the sensor outer electrode of the oil sensor A is injection molded from a conductive resin containing a conductive material such as carbon.

A screw head 1a is formed on the head of the sensor body 1, a flange 1b is formed on the lower portion thereof, and a screw portion 1c is formed on the lower portion of the neck. Also, the sensor body 1
A hollow portion 1e penetrating from the head (base portion) side to the tip portion 1d is formed in the above, and an air vent hole 1f opening to the hollow portion 1e is formed in the middle of the sensor body 1. .

Further, a step portion 1g is formed on the base side of the hollow portion 1e of the sensor body 1, and the flange portion of the insulating member 2 is formed on the step portion 1g.
2a is hooked. The insulating member 2 is made of a high resistance insulating resin material having heat resistance.

In addition, a groove is formed in the lower part of the neck of the flange 2a of the insulating member 2.
2b is provided in an annular manner, and an O-ring 3a that seals between the inner wall of the hollow portion 1e of the sensor body 1 and the groove 2b is interposed in the groove 2b. Further, the tip of the insulating member 2 forms a tapered surface 2c that converges in the tip direction, and the diameter of the body between the tapered surface 2c of the insulating member 2 and the groove 2b is equal to that of the sensor body 1. It is formed to be equal to or slightly smaller than the inner diameter of the hollow portion 1e.

Further, in order to prevent adsorption of lubricating oil to the entire circumference of the insulating member 2, or at least the portion exposed to the tip 1d side of the hollow portion 1e, that is, the tapered surface 2c and the tip surface thereof, fluorine is adsorbed. A member having heat resistance, insulation and non-lipophilicity such as resin is coated.

Further, a base portion of the sensor inner electrode 4 made of a metal pipe or the like is fitted in the center of the insulating member 2, and a flange 4a provided on the base portion is brought into contact with the upper surface of the insulating member 2 to prevent the same from coming off, and the bottom surface thereof. Is a groove formed on the upper surface of the insulating member 2
It is in contact with the O-ring 3b attached to 2d.

Further, a solder impregnation small hole 4c communicating with the hollow portion 4b is formed on the tip surface of the in-sensor electrode 4.

An insulating sleeve 16 is attached to the base end of the hollow portion 1e of the sensor body 1, the tip end surface of which is brought into contact with the upper surface of the flange portion 2a of the insulating member 2, and the tip end surface is provided with the in-sensor electrode. The base end of 4 is supported and fixed. This insulating sleeve 16 has a high insulation resistance and the sealing material 8
It is formed of a material having close adhesion to

Further, the inner wire 5a of the heat-resistant shield wire 5 is inserted into the hollow portion 4b of the sensor inner electrode 4, and the core wire 5b protruding from the tip of the inner wire 5a is brought into contact with the bottom portion of the hollow portion 4b. During the automatic soldering process, it is connected and fixed to the bottom portion of the hollow portion 4b by the solder that has permeated through the small hole 4c formed in the tip end surface of the in-sensor electrode 4.

Further, the shield wire 5d exposed from the tip of the jacket 5c of the shield wire 5 is spread on the upper surface of the insulating sleeve 16, and the conductive washer 6 is brought into contact with the upper surface thereof, and the upper surface of the conductive washer 6 is The outer circumference is the sensor body 1
The conductive clip washer 7 which bites into the inner wall of the hollow portion 1e to prevent it from coming off is abutted, and the shield wire 5d and the sensor body 1 are electrically connected to each other through the biting portion of the clip washer 7.

Further, a sealing material 8 such as an epoxy resin is filled from the base end side of the hollow portion 1e of the sensor body 1, the sealing material 8 is on the upper surface of the insulating sleeve 16, the inner wall surface of the hollow portion 1e of the sensor body 1, Also, the hollow portion 1e of the sensor body 1 is in close contact with the outer sheath 5c of the shield wire 5.
And the outer sheath 5c of the shield wire 5 are sealed.

On the other hand, at the other end of the shield wire 5, a pin connector 9
Is connected, and the outer periphery of the pin connector 9 is a waterproof cap.
It is coated with 10.

Reference numeral 11 denotes an oil pan provided at the bottom of the crankcase of the engine, and a sensor mounting port 11a for screwing and fixing the oil sensor A through a packing 12 is formed on one side of the oil pan 11.

Further, reference numeral 15 is a control means, and the pin connector 9 of the oil sensor A is connected to the control means 15, and whether or not the lubricating oil is insufficient is internally provided based on the resistance value detected by the oil sensor A. Lubricant shortage determination means 15a
And a lubricating oil shortage display means 15b for giving an alarm display such as lighting of a lamp when the lubricating oil shortage determination means 15a determines that the lubricating oil is insufficient.

(Operation) Next, the operation of the embodiment having the above configuration will be described.

(Assembly procedure) First, the clip washer 7, the conductive washer 6, and the insulating sleeve are attached to the inner cover 5a, which has been peeled off in advance, at the other end of the heat resistant shield wire 5 having the pin connector 9 and the waterproof cap 10 assembled at one end. The shield wire 5d, which is inserted through the shield wire 5 and exposed from the middle of the tip of the shield wire 5, is spread on the upper surface of the insulating sleeve 16, and the conductive washer 6 is brought into contact with the upper surface.

After that, the inner wire 5a of the shield wire 5 is inserted into the hollow portion 4b of the sensor inner electrode 4, and the core wire exposed from the tip thereof.
5b is brought into contact with the bottom of the hollow portion 4b.

Then, in this state, the sensor internal electrode 4 is conveyed to the automatic solder bath, and the tip of the sensor internal electrode 4 is immersed in the solder bath. Then, the solder is immersed into the inside of the small hole 4c formed at the tip of the in-sensor electrode 4, and the core wire 5b is connected and fixed to the bottom of the hollow portion 4b of the in-sensor electrode 4.

Next, the groove formed in the body portion of the insulating member 2 and the flange portion 2a
After mounting the O-rings 3a, 3b on the 2b, 2d, the insulating member 2 is inserted through the sensor inner electrode 4, and the flange portion 4a provided on the sensor inner electrode 4 is attached to the upper surface of the flange portion 2a of the insulating member 2. Hang up.

Then, the insulating member 2 is inserted into the hollow portion 1e of the sensor body 1, and the flange portion 2a of the insulating member 2 is inserted into the hollow portion 1e.
Hook on 1g of step.

After that, the base portion side of the hollow portion 1e of the sensor body 1 is filled with a sealing material 8 such as epoxy resin, and the base portion side is sealed to complete the assembly of the oil sensor A.

By the way, although the pipe lengths of the sensor inner electrode 4 and the sensor body 1 are different depending on the engine model, the insulating member 2, the insulating sleeve 16 and the like can be managed as common parts, and the parts management is easy. Or, since the parts are shared, the number of types of molding dies is reduced and the equipment cost is reduced.

Further, since the parts are commonly used, not only can the high-mix low-volume production be promptly dealt with, but the cost does not increase.

(Lubricant shortage detection) After that, the oil sensor A assembled in a predetermined manner is inserted through the packing 12 into the sensor mounting port 11a formed on one side of the engine oil pan 11, and screwed by the threaded portion 1c of the sensor body 1. Fix (state of Fig. 3).

Further, the pin connector 9 is connected to the control means 15.

Next, when a key switch (not shown) is turned on to start the engine, the lubricating oil shortage determination means 15a of the control means 15 is
A voltage is applied to the oil sensor A, and the oil sensor A starts detecting the lack of lubricating oil.

When the lubricating oil is sufficiently stored in the oil pan 11 during engine operation, the tip ends of the sensor body 1 and the sensor inner electrode 4 are immersed in the lubricating oil, and the electrodes of the sensor body 1 and the sensor inner electrode 4 are formed. The resistance value of the lubricating oil is detected at the distance.

Since the resistance value of the lubricating oil is smaller than the space insulation resistance value between the electrodes, the lubricating oil shortage determination means 15 of the control means 15 is
At a, since there is a large difference between the two resistance values, it is determined that there is lubricating oil.

Further, the core wire 5b of the shield wire 5 and the shield wire 5d are electrically separated by the insulating sleeve 16 having a high insulating property,
Insulation is fully guaranteed.

Further, since the oil sensor A does not detect the amount of lubricating oil but detects whether or not the lubricating oil reaches the specified level in the oil pan, the oil sensor A is not required to have high detection accuracy. The volume resistance value of the sensor body 1 is extremely smaller than the resistance value of the lubricating oil because it contains a conductive material such as carbon.
The resistance value of is included in the range of detection error.

On the other hand, since the material of the sensor body 1 is made of a conductive resin, not only weight saving can be realized, but also injection molding is possible, handling becomes easy, and the die manufacturing cost becomes low.

Further, since the sensor body 1 is formed by using resin as the material, the draft can be reduced, and the distance between the electrodes between the sensor inner electrode 4 and the inner wall surface of the hollow portion 1e of the sensor body 1 is from the base of the shaft to the tip. The detection accuracy can be improved because the resistance value of the lubricating oil can be maintained at a substantially constant value and the resistance value of the lubricating oil can be detected at a substantially constant value.

Further, since the sensor body 1 is a resin product, the surface roughness is small, and therefore, for example, the O-ring 3a of the hollow portion 1e is used.
Not only is post-processing unnecessary for the sliding contact surface with respect to, but the surface roughness is included in the error range of the inter-electrode distance, and the detection accuracy is further improved.

Moreover, since the sensor body 1 contains carbon, sufficient mechanical strength can be secured, and vibration resistance and durability are improved.

On the other hand, when the lubricating oil stored in the oil pan 11 is insufficient and the tip of the oil sensor A is exposed from the surface of the lubricating oil, the space insulation resistance increases depending on the distance between the sensor body 1 and the sensor inner electrode 4. The value is detected, and the lubricating oil shortage determination means 15a of the control means 15 drives the lubricating oil shortage display means 15b to display an alarm or stops the engine to inform the operator of the lubricating oil shortage. At the same time, it prevents the engine from burning.

Further, if the mounting level of the tip end surface of the oil sensor A is variably set, only the warning display can be operated without stopping the engine before the lack of lubricating oil occurs.

The present invention is not limited to the above-mentioned embodiment, and for example, the sensor internal electrode 4 may be formed of a conductive resin, and the sensor internal electrode 4 may be a hollow material.

[Advantage of the Invention] As described above, according to the present invention, the insulating member is inserted and fixed to the hollow base side of the cylindrical sensor body that also serves as the sensor outer electrode, and the inside of the sensor is attached to the shaft center of the insulating member. Insert the electrode, attach the insulating sleeve to the hollow body proximal end side of the sensor body, support and fix the proximal end of the sensor inner electrode to the insulating sleeve, and also pass the shield wire core wire through the insulating sleeve. And connect to the electrode inside the sensor,
Furthermore, since the shield wire of the shield wire is connected to the sensor body from the upper surface side of the insulating sleeve, the parts can be shared, the facility cost and the molding work man-hours are not increased, and the steps involved in the production of a wide variety of products in small quantities can be performed. It has excellent effects such as being able to quickly cope with the flexibility and simplifying the parts management.

Further, by loading a sealing material having adhesiveness with the insulating sleeve on the upper surface of the insulating sleeve, the sealing material penetrates into the surface of the insulating sleeve to cover the shielded wire and the insulating sleeve. , The shield wire and the base end of the sensor inner electrode are sealed to prevent oil from entering, and as a result, the insulation between the sensor inner electrode and the sensor outer electrode connected to the shield wire is achieved. Is sufficiently secured.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional view of an oil sensor, Fig. 2 is a sectional view taken along line II-II of Fig. 1, and Fig. 3 shows a state in which the oil sensor is mounted on an oil pan. It is a fragmentary sectional view shown. 1 ... Sensor body, 1e ... hollow part, 2 ... insulating member,
4 ... Electrode in sensor, 5 ... Shield wire, 5b ... Core wire, 5d ... Shield wire, 8 ... Sealing material, 16 ... Insulating sleeve.

Claims (1)

[Scope of utility model registration request] 1. A hollow base of the sensor body, wherein an insulating member is inserted and fixed on the hollow base side of a cylindrical sensor body which also serves as an outer electrode of the sensor, and an inner electrode of the sensor is inserted around the shaft center of the insulating member. Side, the insulating sleeve is mounted on the exposed surface of the insulating member, and the base end of the sensor inner electrode is supported and fixed to the insulating sleeve, and the core wire of the shield wire is penetrated through the insulating sleeve and the insulating member. The shield wire of the shield wire is connected to the electrode inside the sensor, and the shield wire of the shield wire is connected to the sensor body from the upper surface side of the insulating sleeve, and the insulating sleeve is connected to the hollow recess of the sensor body formed on the upper surface side of the insulating sleeve. An oil sensor filled with a sealing material having adhesiveness.