JP2003139732A - Instrument and method for measuring oil film-forming condition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument and a method for measuring an oil film forming state between a piston ring and a cylinder liner in an internal combustion engine enhanced in reliability for attaching to the cylinder liner, reduced in an attaching cost, and enhanced in reliability for a measured data generated caused by friction of the piston ring. SOLUTION: In this instrument for measuring the oil film forming state between the piston ring and the cylinder liner in the internal combustion engine attached with a continuity sensor 5 drilled with a through-hole 11 from a liner outer circumferential side toward a sliding face side in a piston ring sliding part of the cylinder liner 3, and having an electrode in the sliding face side in the through hole, the through-hole drilled in the cylinder liner is formed into a tapered through-hole of which at least the sliding face side is reduced in its inside diameter from the siding face side toward its deep side, and the electrode of the continuity sensor is stored in the tapered through-hole via an insulating material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device and a measuring method for an oil film formation state between a piston ring and a cylinder liner of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, a contact resistance type is used for measuring an oil film forming state of a sliding portion between a piston ring and a cylinder liner of an internal combustion engine by utilizing the fact that the oil film is insulating and the piston ring is conductive. A technique using an electrical continuity sensor (hereinafter referred to as continuity sensor) has been proposed. This type of sensor structure is disclosed in JP-A-7-43329, JP-A-8-35412, and the like.
The conventional continuity sensor concerning this is shown. The upper part of FIG. 7 shows an overall view of an internal combustion engine in which a piston 01 having a piston ring 02 is reciprocally slid in a cylinder liner 03. Piston ring 02
A through hole is formed in the upper portion of the cylinder liner 03 corresponding to the sliding surface, and a conduction sensor 05 is attached to the through hole so as to face the piston ring 02.

As shown in the lower part of FIG. 7, such a sensor has an electrode (sensor body) 06 located flush with the cylinder liner sliding surface 04, and a lead extending outside from the rear surface of the electrode 06. A wire 07, a mounting jig 08 for holding the electrode, a lead wire through hole in the mounting jig 08, and an adhesive 09 that fills the periphery of the electrode and is fixed by insulation. It is fixed to the through hole of the liner 03 with a screw 010 engraved on a mounting jig 08.

That is, the adhesive 09 is provided between the mounting jig 08 and the electrode 09 and between the cylinder liner 03 and the electrode 06 in order to insulate the cylinder liner 03 main body from the electrode 06 and maintain the strength under high temperature. The material of high temperature specification is used for the gap.

According to the continuity sensor 05 having such a configuration, the electrode 06 electrically insulated by the adhesive 09 is processed so as to be flush with the sliding surface 04 of the cylinder liner 03, An applied voltage is applied to the electrode 06. When there is no oil film when the piston ring 02 passes over the surface of the electrode 06 of the conduction sensor 05, the electricity applied to the electrode 06 is transferred to the cylinder liner 03 via the conductive piston ring 02.
Flowing to the side. On the other hand, when an oil film that is an insulator is present, electricity does not flow due to the insulating property of the oil film. Therefore, the presence / absence of oil film formation on the piston ring is determined based on the electrical output (conduction / insulation) of the sensor.

[0006]

The conventional conduction sensor using such an adhesive has the following problems. Normally, the high temperature adhesive 09 is a thermosetting type, and therefore the temperature must be raised when it is cured. Therefore, since it is not possible to heat only the adhesive portion, when fixing the continuity sensor 05 to the cylinder liner 03 via the adhesive, an electric furnace that is a temperature raising device according to the size of the cylinder liner 03 is used. is necessary. This means that when applied to a large cylinder liner, it is necessary to use a large electric furnace according to its size.
Costs of capital investment and equipment usage fees increase.

Further, the electrode 06 of the continuity sensor 05 attached to the cylinder liner 03 is machined at room temperature so as to be flush with the sliding surface of the cylinder liner 03, while the ambient temperature at the time of actual measurement is May reach a high temperature of around 200 ° C. However, at this time, since the adhesive 09 used for insulation has a larger linear expansion coefficient than the material of the cylinder liner 03, the electrode 06 may stick out from the sliding surface and cannot maintain the same surface, which may prevent measurement work. is there.

Further, in terms of the performance of the adhesive 09, mechanical properties such as tensile strength are deteriorated in a high temperature state, and deterioration is a problem when it is exposed to a high temperature state for a long time. In such a case, the strength of the adhesive 09 that fixes the electrode 06 may be reduced, and the electrode 06 may fall off to make measurement impossible.

Further, the piston ring 02 is worn by sliding on the cylinder liner 03, but since the piston ring is generally formed in a tapered shape, the piston ring 02 and the cylinder liner 03 are worn when worn. The contact width gradually increases. As a result, it takes a long time for the piston ring 02 to pass over the conduction sensor 05, which may cause an error in the measurement data.

In view of the above problems of the prior art, an object of the present invention is to improve the reliability of mounting on a cylinder liner, to reduce the mounting cost, and to improve the reliability of measurement data caused by wear of a piston ring. An object of the present invention is to provide an apparatus for measuring an oil film formation state between a piston ring and a cylinder liner of an internal combustion engine and a measuring method therefor.

[0011]

In order to solve such a problem, the first aspect of the present invention is to form a through hole in the piston ring sliding portion of the cylinder liner from the liner outer peripheral side toward the sliding surface side, In an oil film formation state measuring device between a piston ring and a cylinder liner of an internal combustion engine, in which a conduction sensor having an electrode on the sliding surface side is attached to the through hole, at least sliding through the through hole formed in the cylinder liner. It is characterized in that the surface side is a tapered through hole whose diameter is reduced as it goes deeper than the sliding surface side, and the electrode of the conduction sensor is housed in the tapered through hole via an insulating material.

In this case, there is provided a taper pin mounted in the taper through hole as described in claim 2, and the electrode of the continuity sensor is housed in the shaft hole of the taper pin via an insulating material. preferable. The insulating material may be one or more members selected from an adhesive, a hollow insulator, and an insulating coating.

The specific construction is that the tapered hole and the tapered pin are tapered over the entire length,
It may be supported by a pressing jig screwed to the taper pin inner diameter screw via an insulating material located on the rear surface side of the electrode, or the electrode of the continuity sensor mounted in the through hole without providing the taper pin. May be accommodated via an insulating material, and the electrode may be supported by a pressing jig screwed to a screw.

Furthermore, the sliding surface side is tapered at the front side, and the back side is formed in a cylindrical shape or a convex circular shape having a seat surface at the step portion, and is located in the shaft hole on the electrode rear surface side. It may be supported by a holding jig that is screwed to the inner diameter screw via an insulating material, and is provided on the outer peripheral side of the cylinder liner by providing a screw portion on the cylindrical or convex circular outer diameter portion on the inner side of the pin. The pin may be screwed and fixed by a nut or a screw provided in the cylinder liner through hole.

As shown in FIG. 1, the first aspect of the present invention is such that the taper pin 12 whose diameter is enlarged on the sliding surface side of the cylinder liner 3 and the continuity sensor fixed to the taper pin 12 with an adhesive 9 are used. 5 and a taper hole 11 for mounting the taper pin 12 formed in the cylinder liner 3 can also be adopted, and as shown in FIG.
Has a tapered taper portion and is attached via a taper insulating material 16A, and is attached so as to be pressed by a holding jig 17 from the outside of the cylinder liner 3 via an insulating material 16B. Further, as shown in FIG. 4, the cylinder liner 3 is formed with a taper hole 11 whose diameter is enlarged on the sliding surface 4 side, and the taper pin 12 is attached with a mounting screw 36 at the rear of the taper hole 11. It is fastened and fixed with a nut 37, and the electrode 6 has a convex circular shape inside the taper pin 12,
The conduction sensor 5 is attached to the hole 32 with the tip sheet surface of 2 through the hollow insulating material 33, and is attached so as to be pressed from the outside of the taper pin 12 by the holding jig 34 through the insulating material 35. May be configured,
Further, as shown in FIG. 5, the electrode 6 has a tapered portion, is provided with an insulating coating 41, is attached via a spacer 42, and is pressed from the outside of the cylinder liner 3 via an insulating material 46. In the case where the electrode 6 is mounted so as to be pressed by, a coating 41 of an insulating material is applied to almost the entire circumference of the electrode 6 except the tip thereof, and a tapered conical cylindrical spacer 42 is provided at the tip of the tapered electrode. The spacer may be adhered and an insulating coating may be applied to the outer periphery of the spacer.

According to a second aspect of the invention, as described in claim 8, a through hole is formed in the piston ring sliding portion of the cylinder liner from the liner outer peripheral side toward the sliding surface side, and the through hole is slid. In a device for measuring an oil film formation state between a piston ring and a cylinder liner of an internal combustion engine in which a conduction sensor having an electrode on the moving surface side is mounted, a step portion is formed at least on a sliding surface side of a through hole formed in the cylinder liner. The sliding surface side having the seat surface is a through hole formed in a small-diameter convex circular shape, and the electrode of the convex circular conduction sensor is housed in the convex circular portion on the front side of the through hole via an insulating material. At the same time, the electrode is fixed and supported by a pressing jig further behind the electrode via an insulating material located on the rear surface side of the electrode. In such a configuration, as shown in FIG.
It has a convex shape, is attached to the tip sheet surface hole 22 of the cylinder liner 3 via the insulating material 23, and is pressed by the pressing jig 24 from the outside of the cylinder liner 3 via the insulating material 16B. It is installed and configured.

According to a ninth aspect of the present invention, a through hole is formed in a portion of the cylinder liner facing the piston ring sliding position from the outer peripheral side of the liner toward the sliding surface side, and the through hole has an electrode on the sliding surface side. A conduction signal of the conduction sensor according to a third aspect of the invention, which is an oil film formation state measuring method for mounting a conduction sensor and measuring an oil film formation state at each stroke between a piston ring and a cylinder liner of an internal combustion engine by an output signal of the conduction sensor. At the same time, it is set so that the crankshaft rotation pulse signal and the cylinder pressure signal that exceed the trigger level can be obtained, and the turning data, the cylinder pressure, and the contact signal contact signal of the conduction sensor are output during the turning operation in which the oil film is difficult to form. When the oil film formation state during the piston reciprocating stroke is measured, it is stored or recorded, and the stroke is discriminated from the rotation signal and the cylinder internal pressure. The Gudeta output is characterized in that so as to determine the measurement timing of the conduction sensor based on,
Specifically, when the rotation signal of the crankshaft and the in-cylinder pressure signal each exceed the trigger level at the same time, it is determined as the combustion stroke, the measurement timing is zero, and the timing at which the piston ring passes over the conduction sensor at each stroke, It is characterized in that the piston ring passing signal during operation is detected by measuring from the turning data with reference to the measurement timing zero (the AND of the rotation signal and the in-cylinder pressure signal).

Thus, for example, when measuring the oil film formation state at each stroke in a 4-cycle engine, the stroke is discriminated from the rotation signal and the in-cylinder pressure, and the data processing is performed so as to determine the measurement timing based on the turning data. Therefore, it is possible to perform measurement while considering the wear of the piston ring.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, unless otherwise specified, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. FIG. 1 is a sectional view showing a state in which a taper pin type continuity sensor according to a first embodiment of the present invention is attached to a cylinder liner. FIG. 1A shows a state in which the continuity sensor and the cylinder liner are disassembled,
(B) shows a state in which both are assembled.

In the figure, as the cylinder liner 3 advances from the piston ring sliding surface side 4 (inner diameter side) to the inner side (outer diameter side), the taper hole 11 (frustum-shaped through hole) is formed in the direction of decreasing the diameter. Are formed. On the other hand, the continuity sensor 5 has a straight through hole 13a having a circular shaft shape along the axial direction in a tapered pin 12 having a truncated cone shape corresponding to the tapered hole 11.
An electrode (sensor main body) 6 which is located flush with the cylinder liner sliding surface 4 in the through hole 13a;
A lead wire 7 extending from the rear surface to the outside, a mounting jig 13 for holding the electrode, a lead wire through hole 7a in the mounting jig 13, and an adhesive 9 for filling the periphery of the electrode 6 and insulatingly fixing the electrode 6 are provided. The conduction sensor 5 is stored in the taper hole 11 (through hole) of the cylinder liner 3 with a screw engraved on the mounting jig 13 and is hermetically sealed by a packing 14.

Next, a method of attaching the continuity sensor 5 to the cylinder liner 3 will be described with reference to FIG. First, at the mounting position of the continuity sensor 5 of the cylinder liner 3, a taper hole 11 whose diameter is enlarged on the sliding surface 4 side is formed. The taper angle of the taper hole 11 is the same as the taper angle of the taper pin 12. On the other hand, an attachment jig 7 for holding the electrode 6 is screwed into the taper pin 12 and the taper hole 11, and an adhesive 9 is filled in the gap between the electrode 6 and the lead wire 7 and the attachment jig 13 and the straight through hole 13a of the taper pin 12. ing. In addition, 14 is a packing that seals between the taper pin 12 and the mounting jig 13.
The taper pin 12 is preferably made of the same material as the cylinder liner 3.

After the taper pin 12 thus mounted inside the continuity sensor 5 is driven into the taper hole 11 to be fixed, the tip of the electrode 6 is slid on the sliding surface 4 of the cylinder liner 3.
Finish processing so that it is on the same surface as.

The effects of this embodiment will be described. In the prior art shown in FIG. 7, when attaching the continuity sensor 05 to the large cylinder liner 03, a large electric furnace is required to cure the adhesive 09. In the present embodiment, the continuity sensor 5 is built in the taper pin 12 to cure the adhesive. After that, after the taper pin 12 is driven into the taper hole 11 of the cylinder liner 3 to be fixed, finishing is performed so that the tip of the electrode 6 is flush with the sliding surface 4 of the cylinder liner 3. Therefore, a large electric furnace is not required, and the continuity sensor 5 can be attached regardless of the size of the cylinder liner 3.

Particularly in the explosion process of an internal combustion engine, even if high pressure acts from the inside of the cylinder liner 3, the taper pin 1
2 works in the direction of being caulked in the taper hole, and the continuity sensor 5
However, there is no worry of falling out.

FIG. 2 is a sectional view of a continuity sensor 5 according to a second embodiment of the present invention in which a hollow taper insulating material 16A is interposed between the tip of the electrode having a tapered tip and the tip of the cylinder liner 3. In FIG. 2, a through hole 11A as a mounting hole for the conduction sensor 5 of the cylinder liner 3 has a convex hole portion having a larger diameter / step / medium diameter than the outer diameter side, and the tip side thereof is the piston ring sliding surface side ( It is formed so as to open on the sliding surface of the piston ring by means of a tapered taper hole which is tapered on the inner diameter side). On the other hand, the continuity sensor 5 includes a taper ring-shaped insulating material 16A that matches the inner circumferential shape of the tapered tapered hole portion of the through hole 11A, and a taper tip portion that matches the inner circumferential side of the taper ring circular insulating material 16A. The electrode (sensor body) 6 having a cylindrical base portion connected to the electrode 6, a disc-shaped insulating material 16B located on the rear surface of the electrode 6, and the insulating material 16
The electrode 6 via the lead wire 7 extending from the rear surface of the electrode 6 to the outside through the center hole of B, and the disk-shaped insulating material 16B.
Holding jig 17, which has a convex cylindrical circular shape corresponding to the convex hole, and packing 14 interposed in the convex circular step portion of the holding jig 17, and the continuity sensor 05 is a cylinder liner. It is fixed to the convex hole 3 of the jig 3 with a screw 15 engraved on the outer circumference of the pressing jig, and is kept airtight by the packing 14.

That is, roughly, in the mounting portion of the cylinder liner 3 for the continuity sensor 5, the threaded portion 15 is formed in a convex hole from the outer peripheral side.
Further, the tip tapered hole 18 having a tapered tip is processed.
The electrode 6 having a tapered front end is inserted into the tapered tapered hole 18 via an insulating material 16A having a circular tapered shape having the same taper angle as the tip tapered hole 18. The electrode 6 is pressed and fixed from the rear while being screwed in from the outer peripheral surface side of the cylinder liner 3 with the holding jig 17. At this time, in order to insulate the holding jig 17 and the tapered electrode 6 from each other, a disk-shaped insulating material 16B is inserted in the middle. Further, in order to prevent the gas in the combustion chamber from blowing through, sealing is performed by the packing 14 provided on the convex circular step portion of the tip tapered hole 18.
The lead wire 7 is guided to the outside through a through hole in the pressing jig 17.

After mounting the continuity sensor 5 in this way, finishing is performed so that the tip of the electrode 6 is flush with the sliding surface of the cylinder liner 3.

According to this embodiment, the tip taper hole 18 functioning as the mounting hole for the conduction sensor 5 to the cylinder liner 3 is machined so as to taper toward the sliding surface 4, and the tip taper hole is formed. Since the electrode 6 having a tapered tip is fitted in 18, it is possible to prevent the electrode 6 from popping out due to the difference in linear expansion coefficient and from dropping into the combustion chamber. Further, by using the insulating material 16 as the insulating means for the electrode 6 and the cylinder liner 3, the continuity sensor 5 can be attached without using an adhesive. Therefore, problems such as the characteristics and deterioration of the adhesive and the use of an electric furnace can be avoided.

FIG. 3 shows a tip seal in which a hollow insulating material is interposed between the tip of the electrode having a stepped tip shape and the tip small diameter portion of the tip sheet surface-attaching hole 22 of the cylinder liner 3 according to the third embodiment of the present invention. It is a sectional view of the continuity sensor 5 using a convex electrode.

In FIG. 3, the leading end sheet surface-attaching hole 22 that functions as a continuity sensor mounting hole of the cylinder liner 3
Forms a seat surface in a step shape on the front side of the straight cylindrical hole from the outer diameter side, and then opens to the piston ring sliding surface 4 via the step having a reduced diameter. On the other hand, the continuity sensor 5 includes a hollow insulating material 23 having a hollow convex shape that conforms to the inner peripheral shape of the step hole, a step front portion that matches the inner peripheral side of the hollow convex insulating material, and a cylindrical shape that is connected to this. The convex electrode (sensor body) 6 having a base, a disk-shaped insulating material 16B located on the rear surface of the electrode 6, and a lead wire extending from the rear surface of the electrode 6 to the outside through a central hole of the insulating material 16B. 7. A pressing jig 24 having a convex cylindrical shape corresponding to the front end sheet surface hole 22 for holding the electrode 6 through the disc-shaped insulating material. The continuity sensor 5 has a cylinder liner 3 The front end sheet surface-attaching hole 22 and the pressing jig jig 24 are fixed by screws engraved on the outer periphery thereof.

That is, in the cylinder liner 3, the screw hole 21 and the stepped hole 2 in which the stepped portion functions as a seat surface from the outer peripheral side.
Process 2. In addition to this, a hollow convex insulating material 23
The convex-shaped electrode 6 is inserted through, and the electrode 6 is pressed from the outer peripheral surface of the cylinder liner 3 while the pressing jig 24 is screwed into the screw hole 21. At this time, in order to insulate the pressing jig 24 and the convex electrode 6 from each other, the disk-shaped insulating material 16 is inserted in the middle of them. The lead wire 7 is guided to the outside through a through hole in the pressing jig 24. After mounting the continuity sensor 5 in this way, finishing is performed so that the tip end surface of the electrode 6 is flush with the sliding surface 4 of the cylinder liner 3.

According to this embodiment, the hole in the cylinder liner 3 is formed into the hole 22 with the tip sheet surface, and the convex electrode 6 is pressed through the hollow convex insulating material 23.
By pressing with, the insulation of the electrode 6 and the sealing of combustion gas can be achieved at the same time. Further, the number of man-hours for processing the hole 22 and the electrodes 6 and the insulating material 23 can be remarkably reduced as compared with the taper method of the second embodiment.

FIG. 4 is a sectional view of a taper pin type continuity sensor 5 using an insulating material and a tip seal type electrode according to a fourth embodiment of the present invention. In the figure, as the cylinder liner 3 advances from the sliding surface side (inner diameter side) of the piston ring to the inner side (outer diameter side), a hole 32 with a tip sheet surface (a truncated cone-shaped hole) is formed in the direction of decreasing the diameter. Has been done. On the other hand, the continuity sensor 5
A conical trapezoidal taper pin 12 is formed from the piston ring sliding surface 4 side (inner diameter side) of the tip seat surface hole 32 to an intermediate position on the inner side, and the inner diameter is reduced to a thin cylindrical shape and the inner diameter of the axial line is a circular axis. Shaped through-hole 32A having a step-like straight through-hole and a small diameter at the tip side of the step-like through-hole,
A convex circular electrode (sensor main body) housed in a stepped portion on the front side in the through hole 32A via a hollow insulating material 33 having a convex hollow circular shape.
6, a disk-shaped insulating material 35 located on the rear surface of the electrode 6, a lead wire 7 extending from the rear surface of the electrode 6 to the outside through a central hole of the insulating material 35, and the disk-shaped insulating material 35. From the holding jig 34 that is screwed into the inner diameter screw hole of the rear portion of the taper pin 12 for holding the electrode 6, and the mounting nut 37 that is screwed into the inner diameter screw hole of the rear portion of the taper pin 12 Composed. The taper pin 12 is fixed by a hole 36 with a seat surface on the front end of the cylinder liner 3, a screw 36 engraved on the outer periphery of the holding jig jig 34, and the mounting nut 37.

That is, the cylinder liner 3 is formed with a hole 32 with a tip sheet surface which spreads to the sliding surface 4 side, and the hole 32 with a tip sheet surface has a taper pin 12 having a cylindrical portion on the inner side of the taper portion. Is fitted. Screws are engraved on the inner and outer diameters of the small-diameter cylindrical portion on the rear side of the taper portion of the taper pin 12.
From the taper rear side of the taper pin 12 on the small diameter side, screw 31
The hole 32 with a seat surface is machined by utilizing the convex circular stepped surface on the side and the tip side. This seat surface hole 32
The insulating material 33 having a hollow convex shape and the electrode 6 having a convex circular shape are put in the above, and are pressed from the outer peripheral surface of the cylinder liner 3 while being screwed into the screw 31 portion by the holding jig 34. At this time,
In order to insulate the pressing jig 34 and the convex electrode 6 from each other, a disk-shaped insulating material 35 is interposed between the pressing jig 34 and the convex electrode 6. In addition, a hole 3 with a convex circular tip surface
A hollow convex circular insulation material 33 is interposed between the electrode 2 and the electrode 6.

In such a structure, a mounting screw 36 is formed on the outer diameter of the rear small-diameter cylindrical portion of the taper pin 12, and a mounting nut 37 is screwed to the screw 36 to firmly fix the taper pin 12 to the cylinder liner 3. The lead wire 7 is guided to the outside through a through hole in the pressing jig 34. First, the electrode 6 is fixed in the taper pin 12 by the jig 34, and then the taper pin 12 is attached to the seat surface hole 32 of the cylinder liner 3 and the nut 37 is fixed on the outer peripheral side of the cylinder liner 3. After that, finishing is performed so that the tip end surface of the electrode 6 is flush with the sliding surface 4 of the cylinder liner 3.

The continuity sensor 5 having such a structure is installed inside the taper pin 12, and the taper pin 12 is provided with the hole 3 with the seat surface.
In the state of being installed in 2, the mounting screw is tightened from the outer peripheral side of the cylinder liner 3 with the nut 37, and then finishing is performed so that the tip surface of the electrode 6 is flush with the sliding surface 4 of the cylinder liner 3. It is possible to reduce the processing man-hours for the cylinder liner 3. In particular, when the continuity sensor 5 is attached to the large cylinder liner 3, a large machine is required and a problem of processing accuracy occurs, but this can be avoided by adopting the taper pin method.
By configuring the continuity sensor 5 in the small-sized taper pin 12, it is possible to improve the processing accuracy, quality control, and confirm the seat surface sealing performance as a single unit, which leads to the improvement of reliability. Also, if a material such as ceramics that is weak against impact is used as the insulating material 33, 35, there is a risk of damage due to the force applied when the taper pin 12 is driven. It can be avoided.

FIG. 5 is a cross-sectional view of a continuity sensor 5 according to a fifth embodiment of the present invention, which maintains insulation between the tip of the cylinder liner 3 and the tip of the cylinder liner 3 having an insulating coating on the tip of the electrode. . In FIG. 5, the cylinder liner 3
The mounting hole for the continuity sensor 5 is larger than the outer diameter side / step /
The convex hole 45 having a medium diameter is opened on the piston ring sliding surface through a tapered tapered hole that is tapered on the piston ring sliding surface side (inner diameter side) side. On the other hand, the continuity sensor 5 is provided with a tapered conical cylindrical spacer 42 corresponding to the tapered tapered portion of the electrode 6 and a tapered tip portion which matches the inner peripheral side of the tapered ring insulating material of the spacer. The electrode (sensor body) having a cylindrical base portion connected to the
6, an insulating coating 41 coated on substantially the entire circumference of the electrode 6 excluding the front surface of the electrode 6, a disc-shaped insulating material 46 located on the rear surface of the electrode 6, and the electrode 6 through the center hole of the insulating material 46. A holding jig 1 having a convex cylindrical shape corresponding to the convex hole 45 for holding the electrode 6 via the lead wire 7 extending from the rear surface to the outside and the disc-shaped insulating material 46.
7, the packing 14 interposed in the convex circular step portion of the pressing jig 17, the conduction sensor 05 is the cylinder liner 3
It is fixed to the convex hole 45 by a screw 09 engraved on the outer circumference of the pressing jig, and is kept airtight by the packing 14.

Therefore, the basic construction of this embodiment is the same as that of the second embodiment, except that the electrode 41 is coated with an insulating material 41 almost all around the electrode 6 except the front surface. Tapered conical cylindrical spacer 42 on the taper taper
And an insulating coating 43 on the outer periphery of the spacer.
Is being applied. Then, after the spacer 42 with the insulating coating 43 is covered on the tip of the electrode 6, the pressing jig 17 is screwed into the threaded portion on the cylinder liner 3 side to attach the electrode 6 as in FIG. is there. At this time, the packing 14 is attached to the stepped portion of the tapered hole.
Can be inserted at the same time to seal at the same time.

Therefore, according to this embodiment, the electrode 6 can be insulated by coating the electrode 6 with the insulating film 41.
However, since the usual coating layer is thin, there is a risk of energization due to cutting dust generated when honing the surface of the cylinder liner 3, abrasion of adjacent cylinder liner 3 main body, abrasion dust caused by sliding, and the like. for that reason,
Similarly, a spacer 42 whose outer peripheral surface is an insulating coating 43
To establish a backup. By coating the insulation of the electrode 6 with a thin thickness, the area of different materials on the surface of the cylinder liner 3 can be reduced, and the influence of the attachment of the conduction sensor 5 on the sliding can be reduced.

In FIG. 6, the contact width between the piston ring 2 and the cylinder liner 3 is gradually widened due to wear of the piston ring 2 in the case of a four-cycle internal combustion engine using the conduction sensor 5 as described above. As a result, the piston ring 2
FIG. 6 is an explanatory diagram of a data processing method capable of eliminating the risk of causing an error in the measurement data in consideration of the piston ring passage timing even when the time when the vehicle passes the conduction sensor 5 becomes long. FIG. 6 (A) is a timing chart of the measurement signal. The upper part is a crankshaft rotation pulse (hereinafter abbreviated as rotation signal) signal, which is at the top dead center of the piston between the compression stroke and the explosion stroke, and the exhaust stroke and the intake stroke. The trigger level is set so that a trigger signal can be obtained during each stroke.
The middle stage is an in-cylinder pressure signal, and an in-cylinder pressure signal that exceeds the trigger level is obtained every cycle between the compression stroke and the explosion process. Further, the lower stage is a contact signal of the piston ring located on the uppermost stage side of the piston, and when there is no oil film, a trigger signal is obtained immediately before and after the top dead center of the piston.

That is, in the case of measuring the contact conduction between the piston ring and the cylinder liner 3 in the internal combustion engine, FIG.
As shown in (A), the crankshaft rotation pulse signal (hereinafter abbreviated as rotation signal) set so that a pulse is generated at the top dead center, the cylinder pressure, and the output of the conduction sensor 5 are measured. Of these, trigger levels are set for the rotation signal and the in-cylinder pressure (force) signal, respectively.

As the measurement data processing method, as shown in the flowchart of the data processing method of FIG. 6B, the rotation signal and the cylinder pressure during the turning operation in which the oil film between the piston ring and the cylinder liner 3 is difficult to form. The turning data output of the contact signal of the continuity sensor 5 is recorded (S1). Based on this signal, the piston ring is the continuity sensor 5
The timing of passing the data is measured (S2), and the data acquisition timing is set (S3). Piston ring passage timing during turning obtained in this way A sampling frequency is set by the rotation signal of the crankshaft (S4), and the passage timing during operation is converted based on this frequency to operate the presence / absence of an oil film by the conduction sensor 5. The inside data is measured (S5).

FIG. 6C is an explanatory diagram showing the difference in the output of the continuity sensor 5 due to wear of the piston ring. FIG. 6 (C)
As shown in, the wear of the piston ring progresses as the usage time increases. Therefore, compared with the initial state, the ring contact signal has a longer time (contact signal pulse width) to pass while contacting the conduction sensor 5 even though the wear progressing state is the same operating state. That is, the complete contact time (contact signal pulse width) when the piston ring passes over the continuity sensor 5 becomes long.

Therefore, in the present invention, as shown in FIG. 6 (A), the crankshaft rotation signal and the in-cylinder pressure signal are respectively provided with trigger levels, and when both of them simultaneously exceed the trigger level, it is determined that the combustion process is performed. Set the measurement timing to zero. The timing at which the piston ring 2 passes over the conduction sensor 5 in each stroke is sampled from turning data based on the measurement timing zero (AND of the rotation signal and the in-cylinder pressure signal) (for example, the piston ring passage timing in the combustion stroke is , The sampling frequency is 25 with reference to the measurement timing zero.
It is 10 points after 35 points). By correcting the rotation speed and the frequency of the data sampling time, the piston ring passage signal during operation is detected to detect the presence or absence of an oil film, that is, the trigger signal in the lower part of FIG. 6A. The presence or absence of is detected.

The correction of the data acquisition timing during turning and during operation is performed using the following equation. Rotation speed RT x sampling piston ring frequency SPT
(At turning) = rotational speed RG × sampling piston ring frequency SPG (at measurement) That is, “RT × SPT” is known data obtained from turning data, and RG is obtained from crankshaft rotation signal (measured value). Therefore, SPG-= “RT × SPT” / RG can be easily obtained.

In a power generating engine or the like which is often used in DSS operation, the progress of wear of the piston ring is considered without recording all data by organizing using turning data before each operation. In this state, only the data when passing the piston ring can be measured, and the data storage capacity can be significantly reduced.

[0047]

As described above, according to the present invention, the reliability of mounting on the cylinder liner is improved, the mounting cost is reduced, and the reliability of the measurement data generated by the wear of the piston ring is improved. Further, it is possible to obtain a measuring device and a measuring method for an oil film formation state between a piston ring and a cylinder liner of an internal combustion engine.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a taper pin type continuity sensor according to a first embodiment of the present invention is attached to a cylinder liner, (A) a state where the continuity sensor and the cylinder liner are disassembled, and (B) a figure. The state where both are assembled is shown.

FIG. 2 is a cross-sectional view of a continuity sensor according to a second embodiment of the present invention in which an insulating material is interposed between a tip of the electrode having a tapered tip and a taper of the tip of the cylinder liner.

FIG. 3 is a cross-sectional view of a continuity sensor using an end-sealed electrode in which a hollow insulating material is interposed between an electrode tip side having a stepped tip shape and a small diameter portion of a cylinder liner tip according to a third embodiment of the present invention. is there.

FIG. 4 is a sectional view of a taper pin type continuity sensor using a tip seal type electrode according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view of a continuity sensor according to a fifth embodiment of the present invention, which maintains insulation between a tip end taper of a cylinder liner having a tip-tapered electrode tip side provided with an insulation coating.

FIG. 6A is a timing chart of measurement signals.
A crankshaft rotation pulse (hereinafter abbreviated as rotation signal) signal from the upper stage, an in-cylinder pressure signal in the middle stage, and an output signal of the conduction sensor during the turning operation in the lower stage. (B) is a flow chart of the data processing method, and (C) is an explanatory diagram of a difference in the output of the continuity sensor 5 due to wear of the piston ring.

FIG. 7 shows a continuity sensor according to the prior art, the upper part of which is provided with a through hole in the upper part of the cylinder liner of the internal combustion engine corresponding to the sliding surface of the piston ring so that the through hole can face the piston ring. Exploded view before mounting the continuity sensor, the lower part shows the assembled state.

[Explanation of symbols]

2 piston ring 3 cylinder liner 4 Sliding surface 5 Continuity sensor 6 electrodes 9 Adhesive Through holes 11, 18, 22, 32, 45 12 Taper pin 13, 17, 34 pressing jig 16A, 23, 33, 42, hollow insulator 41 Insulating coating

Claims (10)

[Claims] 1. A through hole is formed in a piston ring sliding portion of a cylinder liner from the liner outer peripheral side toward the sliding surface side,
In an oil film formation state measuring device between a piston ring and a cylinder liner of an internal combustion engine, in which a conduction sensor having an electrode on the sliding surface side is attached to the through hole, at least the sliding through hole formed in the cylinder liner slides. The oil film is characterized in that the surface side is a tapered through hole whose diameter is reduced as it goes further from the sliding surface side, and the electrode of the continuity sensor is housed in the tapered through hole via an insulating material. Forming state measuring device. 2. A taper pin mounted in the taper through hole, wherein an electrode of the continuity sensor is housed in an axial hole of the taper pin via an insulating material. Oil film formation state measuring device. 3. The oil film formation state measuring device according to claim 1, wherein the insulating material is one or a plurality of members selected from an adhesive, a hollow insulator, and an insulating coating. 4. The taper hole and the taper pin have a taper shape over the entire length, and are supported by a holding jig screwed to a taper pin inner diameter screw through an insulating material located on the rear surface side of the electrode. Claim 1 characterized by the above-mentioned.
The oil film formation state measuring device described. 5. The electrode of the continuity sensor mounted in the tapered through hole is housed via an insulating material, and the electrode is supported by a pressing jig screwed to a screw. The oil film formation state measuring device according to claim 1. 6. The taper hole and the taper pin have a tapered shape on the sliding surface side, and the back side is formed into a cylindrical shape or a convex circular shape having a seat surface at a step portion, and the taper pin has a shaft hole, The oil film formation state measuring device according to claim 2, wherein the oil film formation state measuring device is supported by a pressing jig screwed to the taper pin inner diameter screw via an insulating material located on the rear surface side of the electrode. 7. A threaded portion is provided on the cylindrical or convex circular outer diameter portion on the inner side of the taper pin, and the taper pin is screwed and fixed by a nut located on the outer peripheral side of the cylinder liner or a screw provided in the cylinder liner through hole. The oil film formation state measuring device according to claim 2, wherein 8. A through hole is formed in the piston ring sliding portion of the cylinder liner from the liner outer peripheral side toward the sliding surface side,
In an oil film formation state measuring device between a piston ring and a cylinder liner of an internal combustion engine, in which a conduction sensor having an electrode on the sliding surface side is attached to the through hole, at least the sliding through hole formed in the cylinder liner slides. The surface side has a seat surface at the step portion and the sliding surface side is a through hole formed in a small diameter convex circular shape, and the electrode of the convex circular conduction sensor has an insulating material on the front side convex circular portion of the through hole. The oil film formation state measuring device is characterized in that the electrode is fixedly supported by a holding jig located behind the electrode via an insulating material located on the rear surface side of the electrode. 9. A through hole is formed in the piston ring sliding portion of the cylinder liner from the liner outer peripheral side toward the sliding surface side,
An oil film formation state measuring method in which a conduction sensor having an electrode on the sliding surface side is attached to the through hole and the oil film formation state at each stroke between the piston ring and the cylinder liner of the internal combustion engine is measured by the output signal of the conduction sensor. In the above, along with the conduction signal of the conduction sensor, the crankshaft rotation pulse signal exceeding the trigger level and the cylinder pressure signal are set so as to be obtained, and the rotation signal during the turning operation in which the oil film is difficult to form,
The turning data output of the contact signal of the in-cylinder pressure and the continuity sensor is stored or recorded, and when measuring the oil film formation state during the piston reciprocating stroke, the stroke is determined from the rotation signal and the in-cylinder pressure, and the turning data An oil film formation state measuring method characterized in that the measurement timing of the continuity sensor is determined based on the output. 10. The timing when the crankshaft rotation signal and the in-cylinder pressure signal simultaneously exceed the trigger level is determined to be the combustion stroke, the measurement timing is set to zero, and the timing at which the piston ring passes over the conduction sensor is set at each stroke. 10. The oil film formation state measuring method according to claim 9, wherein the piston ring passing signal during operation is detected by measuring from turning data with reference to the measurement timing zero.