JP2572007B2 - Sliding part structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member constituting a sliding member with a mating member, and more particularly, to a sliding surface forming region and the sliding surface forming region. The present invention relates to a sliding portion structure provided with a flank forming area that continues to retreat.

[0002]

2. Description of the Related Art Heretofore, as this kind of sliding portion structure, for example, a chromium plating layer formed on an outer peripheral surface of a piston ring for an internal combustion engine has been known. The main purpose of the chromium plating layer is to improve the wear resistance of the piston ring.

[0003]

However, since the chromium plating layer has a smooth surface and poor wettability with oil, the chromium plating layer does not have sufficient oil holding properties, that is, oil holding properties, and furthermore has poor initial adaptability. Because of the bad situation, the seizure resistance is poor under the current situation where the internal combustion engine tends to increase in speed and output. Also, due to the poor wettability, an oil film having a high sealing property cannot be sufficiently formed between the chromium plating layer and the inner wall surface of the cylinder.

[0004] In view of the above, the present invention improves the wettability of the sliding surface forming area to oil and the conformability to the mating member, and also has an oil reservoir function in the flank forming area and an oil supply function to the sliding surface forming area. An object of the present invention is to provide the above-mentioned sliding portion structure, which can significantly improve seizure resistance by providing the same, and furthermore can sufficiently form an oil film having a high sealing property with a mating member. And

[0005]

SUMMARY OF THE INVENTION The present invention comprises a sliding surface formed region, on the sliding surface forming regions, and a flank forming region continuing to be recessed from the sliding surface thereof forming zone, mating member Tosuri
In the sliding portion forming body constituting the moving portion, the sliding surface forming region and the flank forming region are formed of an aggregate of metal crystals, and the aggregate is formed on the sliding surface side in the sliding surface forming region. The flank forming region includes an oriented metal crystal whose crystal faces are directed to the flank side and the abundance S is S ≧ 40%, and the sliding surface is formed flat. A large number of the oriented metal crystals present on the flank have at least one of a pyramid shape and a truncated pyramid shape.

[0006]

When the oriented metal crystal is present at the above-mentioned abundance S in the sliding surface forming area and the sliding surface is formed flat, the wettability of the sliding surface with the oil and the familiarity of the sliding surface with the mating member are obtained. The property becomes good.

If a large number of oriented metal crystals present on the flank have a pyramid shape or the like, a valley between adjacent two oriented metal crystals forms an oil reservoir, and the oil is deposited on the sliding surface. Supplied sequentially.

As described above, since the adaptability of the sliding surface can be improved and oil can be supplied to the sliding surface from the flank side,
Since the sliding surface has good wettability with respect to oil, the sliding surface has a sufficient oil retaining property, whereby the seizure resistance of the sliding surface can be improved.

With the improvement of the oil retaining property, it is possible to sufficiently form an oil film having a high sealing property between the mating member and the sliding surface.

In addition, the abundance S of the oriented metal crystal is S <4.
At 0%, the wettability of the sliding surface to the oil and the conformability of the sliding surface to the mating member decrease, and it is difficult to give the oriented metal crystal a pyramidal shape or the like in the flank forming region. Become.

[0011]

1 and 2, a piston ring 1 for an internal combustion engine comprises a ring main body 3 having an abutment 2 and a layered sliding member 5 covering an outer peripheral surface 4 of the ring main body 3. The ring main body 3 is made of cast iron, and its outer peripheral surface 4 has an annular flat surface 6 occupying a central region in the ring width direction, and a pair of annular arc surfaces 7 connected to both sides of the flat surface 6 so as to recede therefrom. Have.

The sliding portion structure 5 is formed on the outer peripheral surface 4 of the ring body 3.
It is formed by performing a plating process on the substrate. The sliding portion structure 5 includes a sliding surface forming area 8 that covers the flat surface 6, and a pair of flank faces that are connected to the sliding surface forming area 8 so as to recede from the sliding surface 8 and cover both arc surfaces 7. And a formation area 9.

The sliding surface forming area 8 and each flank forming area 9 are composed of an aggregate of metal crystals. The aggregate is located on the sliding surface a side in the sliding surface forming region 8 and the flank forming region 9
Includes oriented metal crystals whose specific crystal faces are directed to the flank b side and whose abundance S is S ≧ 40%.
The sliding surface a is formed flat, and the many oriented metal crystals 10 present on the flank b have at least one of a pyramid shape or a truncated pyramid shape, and have a triangular pyramid shape in the illustrated example.

Such a sliding portion constituting body 5 is composed of a large number of triangular pyramid oriented metal crystals 10 on the entire outer peripheral surface 4 of the ring main body 3.
Is formed, and the surface of the plating layer corresponding to the sliding surface forming area 8 covering the flat surface 6 is formed flat by polishing to obtain the sliding surface a.

If the oriented metal crystal 10 is present in the sliding surface forming area 8 at the above-mentioned abundance S and the sliding surface a is formed flat, the wettability of the sliding surface a to oil and the mating member
The adaptability of the sliding surface a to the cylinder inner wall surface 11 is improved.

When a large number of oriented metal crystals 10 present on the flank b have a triangular pyramid shape, as shown in FIG. It becomes a pool, and the oil is sequentially supplied to the sliding surface a.

As described above, since it is possible to improve the conformability of the sliding surface a and supply oil to the sliding surface a from the flank b, the wettability of the sliding surface a with oil is good. The sliding surface a has a sufficient oil retaining property, whereby the seizure resistance of the sliding surface a can be improved.

Further, with the improvement of the oil retaining property, it is possible to sufficiently form an oil film having a high sealing effect between the inner wall surface 11 of the cylinder and the sliding surface a, whereby the amount of blow-by gas can be reduced. it can.

The oriented metal crystal 10 has a body-centered cubic structure (bc
In the case of having the (c structure), the crystal plane is a (hhh) plane with a Miller index as shown in FIG. 4, and the sliding surface a having this (hhh) plane has good oil wettability.

As shown in FIG. 5, the inclination of the (hhh) plane with respect to the imaginary plane 13 along the flank b appears as the inclination of the triangular pyramid, which affects the oil reservoir function of the flank forming area 9. Therefore, the inclination angle θ formed by the (hhh) plane with respect to the virtual plane 13 is set to 0 ° ≦ θ ≦ 15 °. In this case, the inclination direction of the (hhh) plane is not limited.
When the inclination angle θ becomes θ> 15 °, the oil reservoir function of the flank forming area 9 decreases. In addition, (hh
h) The inclination angle θ of the surface is also set to 0 ° ≦ θ ≦ 15 ° in order to maintain good wettability to oil.

As a metal crystal having a bcc structure, F
e, Cr, Mo, W, Ta, Zr, Nb, V, etc., or a crystal of a simple substance or alloy.

On the other hand, when the oriented metal crystal 10 has a face-centered cubic structure (fcc structure), the crystal plane in the sliding surface formation region 8 is a (hh0) plane with a Miller index as shown in FIG. The sliding surface a having the (hh0) surface has good wettability to oil. Such a (hh0) oriented metal crystal forms a quadrangular pyramid on the sliding surface a after plating, but is removed when the sliding surface a is polished flat.
The crystal plane in the flank forming area 9 is a (3hhh) plane with a Miller index as shown in FIG. Such a (3hhh) oriented metal crystal 10 forms a quadrangular pyramid on the flank b as shown in FIG.

As shown in FIG. 8, the inclination of the (3hhh) plane with respect to the virtual plane 13 along the flank b appears as the inclination of a quadrangular pyramid, which affects the oil reservoir function of the flank forming area 9. Therefore, the inclination angle θ formed by the (3hhh) plane with respect to the virtual plane 13 is set to 0 ° ≦ θ ≦ 15 ° as described above. In this case, the inclination direction of the (3hhh) plane is not limited. When the inclination angle θ becomes θ> 15 °, the oil reservoir function of the flank forming area 9 decreases. The inclination angle θ of the (hh0) plane in the sliding surface a is also set to 0 ° ≦ θ ≦ 15 ° in order to maintain good wettability to oil.

As the metal crystal having the fcc structure, P
b, Ni, Cu, Pt, Al, Ag, Au and the like, or a crystal of a simple substance or alloy.

Tables 1 and 2 show the basic conditions for performing the electric Fe plating process in the plating process for forming the sliding portion constituting member 5 composed of an aggregate of metal crystals having a bcc structure. .

As the energization method, a DC method or a pulse current method is applied. In the pulse current method, as shown in FIG. 9, the maximum current density CDmax is 1 A / dm ² ≦ CDma
x ≦ 40 A / dm ² , the output time T _ON from the start of the output rise to the start of the fall is 0.1 msec ≦ T _ON ≦ 6 msec, and the cycle from the start of the previous rise to the start of the next rise is one cycle. When the cycle time is T _c , the time ratio T _ON
/ T _c is T _ON / T _c ≦ 0.45 and therefore Table 2
Is the average cathode current density CDm in the pulse current method.

[0027]

[Table 1]

Urea, saccharin and the like are used as organic additives.

[0029]

[Table 2]

In the electric Fe plating process performed under the above conditions, the precipitation of the (hh) oriented Fe crystal having the (hhh) plane and the abundance thereof are controlled by the cathode current density, the plating bath pH and the like. I do. In this case, under the application of the DC method, the (hhh) -oriented Fe crystal 10 grows in a columnar shape and usually forms a triangular pyramid on the flank b. on the other hand,
Under the application of the pulse current method, the (hhh) oriented Fe crystal 1
0 grows in a columnar shape, and on the flank b, triangular pyramid-shaped and hexagonal pyramid-shaped Fe crystals exist as shown in FIG. 10, or only hexagonal pyramid-shaped Fe crystals exist.

The sliding portion structure 5 according to the present invention is
Table 3 shows the basic conditions when forming by r plating.
4 The energization method is the same as in the case of the Fe plating process.

[0032]

[Table 3]

[0033]

[Table 4]

As the plating process, in addition to the electroplating process, for example, a vapor phase plating process such as a PVD process, a CVD process, a sputtering process, and an ion plating process can be used. Conditions for performing W and Mo plating by the sputtering method include, for example, an Ar pressure of 0.2 to 1 Pa and an Ar accelerating power.
DC 1 to 1.5 kW, base material temperature 150 to 300 ° C. Conditions for performing W plating by the CVD method include, for example, raw material WF ₆ , WF ₆ gas flow rate 2 to 15 cc / min.
, Chamber pressure 50-300 Pa, base material temperature 4
00-600 ° C.

Tables 5 and 6 show the basic conditions for performing the electric Ni plating process in the plating process for forming the sliding portion constituting member 5 composed of an aggregate of metal crystals having the fcc structure. . The energization method is the same as in the case of the Fe plating process.

[0036]

[Table 5]

[0037]

[Table 6]

In the electric Ni plating treatment performed under the above conditions, (h) depends on the cathode current density, the plating bath pH, and the like.
h0), (3hhh) Precipitation of oriented Ni crystals and their abundance are controlled.

As the plating process, in addition to the electroplating process, the same vapor phase plating method as described above can be used. For example, conditions for performing Pt and Al plating by a sputtering method are Ar pressure 0.8 to 1 Pa, Ar acceleration power DC 200 to 1000 W, and base material temperature 80 to 300 ° C. Conditions for Al plating by the CVD method are as follows: raw material Al (CH ₃ ) ₃ , Al (CH ₃ ) ₃ gas flow rate 1 to 10 cc / min, chamber pressure 50 to 30
0 Pa and a base material temperature of 300 to 600 ° C.

Example I The outer peripheral surface 4 of a plurality of stainless steel ring bodies 3 was subjected to an electric Fe plating process using a DC method or a pulse current method to form a thickness composed of an aggregate of Fe crystals. A 15 μm plating layer was formed. The ring body 3 and the plating layer are referred to as a piston ring 1 for convenience.

Tables 7 and 8 show the conditions of the electric Fe plating treatment in Examples 1 to 5 of the plating layer. The plating time was varied in the range of 10 to 120 minutes in order to set the thickness in Examples 1 to 5 to 15 μm as described above.

[0042]

[Table 7]

[0043]

[Table 8]

Table 9 shows the crystal morphology of the surface, the average grain size of the Fe crystal, the abundance S of each oriented Fe crystal, and the hardness in Examples 1 to 5 of the plating layer.

[0045]

[Table 9]

The average grain size of the trigonal pyramidal Fe crystal is a distance from each corner to each of the opposite sides through the vertex, that is, an average of three distances. Is
It is the distance between the two corners facing each other across the vertex, that is, the average value of the three distances.

The abundance S is determined by the following method based on the X-ray diffraction patterns of Examples 1 to 5 (the X-ray irradiation direction is a direction perpendicular to the surface of the plating layer). As an example,
Describing Example 1, FIG. 11 is an X-ray diffraction diagram of Example 1, and the abundance S of each oriented Fe crystal was obtained from the following equation. Note that, for example, {110} oriented Fe crystal means {1}
It means an oriented Fe crystal with the 10 ° plane facing the front side. {110} oriented Fe crystal: S ₁₁₀ = {(I ₁₁₀ / IA)
₁₁₀ ) / T} × 100, {200} oriented Fe crystal: S ₂₀₀ = {(I ₂₀₀ / IA)
₂₀₀ ) / T} × 100, {211} oriented Fe crystal: S ₂₁₁ = {(I ₂₁₁ / IA)
₂₁₁ ) / T} × 100, {310} oriented Fe crystal: S ₃₁₀ = {(I ₃₁₀ / IA)
₃₁₀ ) / T} × 100, {222} oriented Fe crystal: S ₂₂₂ = {(I ₂₂₂ / IA)
₂₂₂ ) / T｝ × 100 where I ₁₁₀ , I ₂₀₀ , I ₂₁₁ , I ₃₁₀ , and I ₂₂₂ are the measured values (cps) of the X-ray reflection intensity of each crystal plane, and IA ₁₁₀ , IA ₂₀₀ , and IA ₂₁₁ , IA ₃₁₀ and IA ₂₂₂ are the X-ray reflection intensity ratios of each crystal plane in the ASTM card,
IA ₁₁₀ = 100, IA ₂₀₀ = 20, IA ₂₁₁ = 30,
IA ₃₁₀ = 12 and IA ₂₂₂ = 6. Further, T is T
_{= (I 110 / IA 110)} + (I 200 / IA 200) + (I
_{211 / IA 211) + (I} 310 / IA 310) + (I 222 /
IA ₂₂₂ ).

FIG. 12 is a micrograph showing the crystal structure of the surface in Example 1. In FIG. 12, a large number of triangular pyramidal Fe crystals are observed. This triangular pyramidal Fe crystal is (h
hh) plane, that is, a {222} oriented Fe crystal with the {222} plane facing the surface side. In this case, $ 22
As shown in Table 9 and FIG. 11, the abundance S of the 2Ｆｅ-oriented Fe crystal is S = 43%.

FIG. 13 is an X-ray diffraction diagram of Example 3, and FIG.
4 is a micrograph showing the crystal structure of the surface in Example 3. In FIG. 14, a number of hexagonal pyramidal Fe crystals are observed. These hexagonal pyramidal Fe crystals are {222} oriented Fe crystals with the {222} plane facing the surface side, and the abundance S is 94% as shown in Table 9 and FIG.

Next, in the piston ring 1 having the plating layer of Examples 1 to 3, the surface corresponding to the sliding surface forming area 8 of the plating layer is formed flat by polishing to form the sliding surface a.
I got The plated layers after this processing are referred to as Examples 1 to 3 of the sliding portion constituting body. In the first embodiment, as shown in FIG. 2, a flank b having a large number of triangular pyramid-shaped {222} oriented Fe crystals is provided so as to be continuous with a flat sliding surface a. In the second embodiment, the flank b has a hexagonal pyramid shape and a triangular pyramid shape.
In Example 3, it has a hexagonal pyramidal {222} oriented Fe crystal.

Further, in the piston rings having the plated layers of Examples 4 and 5, the plated layers are not polished at all, and therefore have unprocessed, having a large number of granular Fe crystals on the sliding surface a and the flank b. The plating layers are Comparative Examples 1 and 2 of the sliding portion structure.

Next, a burn-in test by the chip-on-disk method was performed on Examples 1 to 3 and Comparative Examples 1 and 2, and the results shown in Table 10 and FIG. 15 were obtained. The test conditions are as follows. Disc material Cast iron, disc rotation speed 15m / sec, oil supply 0.3ml / min,
The area of the sliding surface a of the chip manufactured from the piston ring is 1 cm ² .

[0053]

[Table 10]

FIG. 15 is based on Tables 9 and 10,
2 is a graph showing the relationship between the abundance S of 2｝ -oriented Fe crystals and the seizure load. As is clear from Tables 9, 10 and FIG. 15, in Examples 1 to 3, {222}
Since the abundance S of the oriented Fe crystal is S ≧ 40% and the sliding surface a is flat, the wettability of the sliding surface a with the oil and the conformability of the sliding surface a with the disk are reduced. Oil is supplied to the sliding surface a from the oil pool by the triangular pyramidal and / or hexagonal pyramid-shaped {222} oriented Fe crystals of the flank b, so that the seizure is more likely than in Comparative Examples 1 and 2. The generated load is greatly improved. The hexagonal pyramid-shaped Fe crystal aggregate is superior to the triangular pyramid-shaped Fe crystal aggregate in the oil reservoir function and the oil supply function.

In Comparative Examples 1 and 2, the abundance S of the {222} oriented Fe crystal was S <40%, and the wettability of the sliding surface a to oil and the conformability to the disk were poor. Since it does not have the oil reservoir function and the oil supply function as described above, the seizure resistance is extremely low.

Next, the oil storage function of the triangular pyramid-shaped {222} oriented Fe crystal and the like are described.
The following experiment was conducted in order to investigate the wettability and the like of the 2Ｆｅ-oriented Fe crystal.

In the piston ring having the plating layer of Example 1, the plating layer is not machined at all, so that the sliding surface a and the flank b have a large number of triangular pyramids # 22.
The unprocessed plating layer having the 2｝ -oriented Fe crystal is referred to as Comparative Example 3 of the sliding portion structure.

In the piston ring having the plating layer of Example 1, the sliding surface a and the flank b were formed flat by polishing the entire surface of the plating layer. The plated layer after this processing is referred to as Comparative Example 4 of the sliding portion structure.

Next, a burn-in test by the chip-on-disk method was performed on Comparative Examples 3 and 4 under the same conditions as above, and the results shown in Table 11 and FIG. 16 were obtained. For comparison, Table 11 and FIG. 16 also show the measured values of Example 1 and Comparative Example 1.

[0060]

[Table 11]

FIG. 16 is a graph of Table 11. As is clear from Table 11 and FIG. 16, in Comparative Example 3, the presence of triangular pyramid-shaped {222} oriented Fe crystals on the sliding surface a provided an oil sump function, so that the same fire resistance as in Example 1 was obtained. Has stickiness. Comparative Example 4 has no oil reservoir function because the flank b is flat, but the existence ratio S ≧
Since good wettability and conformability are obtained by the 40% {222} oriented Fe crystal as described above, seizure resistance is improved as compared with Comparative Example 1.

Next, each of the piston rings 1 having the sliding portion constituting example 1 and the comparative examples 1, 3, and 4 was used as a top ring, which was incorporated into a 2000 cc in-line four-cylinder internal combustion engine, and When the blow-by gas amount was measured under the conditions of a rotation speed of 6000 rpm (constant) and an outside temperature of room temperature, the results shown in Table 12 and FIG. 17 were obtained.

[0063]

[Table 12]

FIG. 17 is a graph of Table 12. As is clear from Table 12 and FIG. 17, in Example 1, the oil wettability of the sliding surface a was good because the oil wettability was good, and accordingly the seal between the sliding surface a and the cylinder inner wall surface 11 was improved. Since an oil film having high property is sufficiently formed, the blow-by gas amount is significantly reduced as compared with Comparative Examples 1 and 3.

In Comparative Example 1, the amount of blow-by gas was large because of poor wettability to oil as described above. In Comparative Example 3, a large number of triangular pyramids {222} orientation F
The sealing property is poor due to the presence of the e crystal, and as a result,
Blow-by gas amount is the largest. Since the sliding surface a in Comparative Example 4 has the same properties as in Example 1, the amount of blow-by gas is also the same as in Example 1.

EXAMPLE II An outer peripheral surface 4 of a plurality of ring bodies 3 made of stainless steel was subjected to an electric Ni plating process using a DC method to form a plated layer having a thickness of 15 μm formed of an aggregate of Ni crystals. Was formed. This ring body 3
The piston ring 1 is made up of a metal layer and a plating layer for convenience.

Tables 13 and 14 show the conditions of the electric Ni plating process in Examples 1 to 4 of the plating layer. In Example 1, the conditions for the electric Ni plating process are different between the sliding surface forming region 8 and the flank forming region 9. Also, the plating processing time was as shown in Examples 1 to
In order to set the thickness at 4 to 15 μm as described above,
Various changes were made within a range of 10 to 120 minutes.

[0068]

[Table 13]

[0069]

[Table 14]

Table 15 shows the crystal morphology of the surface, the average grain size of the Ni crystal, the abundance S of each oriented Ni crystal and the hardness in Examples 1 to 4 of the plating layer.

[0071]

[Table 15]

The average grain size of the quadrangular pyramid-shaped Ni crystal is a distance from each corner to each opposing corner through the vertex, that is, an average value of two distances.

The abundance S was determined from the following equation based on the X-ray diffraction patterns of Examples 1 to 4 (the X-ray irradiation direction was perpendicular to the surface of the plating layer). Note that, for example, {111} orientation N
An i-crystal is an oriented Ni with the {111} plane facing the surface.
Means crystal. {111} oriented Ni crystal: S ₁₁₁ = {(I ₁₁₁ / IA)
₁₁₁ ) / T} × 100, {200} oriented Ni crystal: S ₂₀₀ = {(I ₂₀₀ / IA)
₂₀₀ ) / T} × 100, {220} oriented Ni crystal: S ₂₂₀ = {(I ₂₂₀ / IA)
₂₂₀ ) / T} × 100, {311} oriented Ni crystal: S ₃₁₁ = {(I ₃₁₁ / IA)
₃₁₁ ) / T｝ × 100 where I ₁₁₁ , I ₂₀₀ , I ₂₂₀ , and I ₃₁₁ are measured values (cps) of the X-ray reflection intensity of each crystal plane.
A ₁₁₁ , IA ₂₀₀ , IA ₂₂₀ , and IA ₃₁₁ are X-ray reflection intensity ratios of each crystal plane in the ASTM card, and IA ₁₁₁ = 1
00, IA ₂₀₀ = 42, IA ₂₂₀ = 21, IA ₃₁₁ = 2
0. Further, T is T = (I ₁₁₁ / IA ₁₁₁ ) +
(I ₂₀₀ / IA ₂₀₀ ) + (I ₂₂₀ / IA ₂₂₀ ) + (I
₃₁₁ / IA ₃₁₁ ).

Next, in the piston ring 1 having the plating layer of Example 1, the surface corresponding to the sliding surface forming area 8 of the plating layer was formed flat by polishing to obtain the sliding surface a. The plated layer after this processing is referred to as an example of the sliding portion constituting body. This embodiment is provided with a flank b having a large number of pyramidal {311} oriented Ni crystals connected to a flat sliding surface a as shown in FIG.

In the piston ring 1 having the plating layer of Example 2, the entire surface of the plating layer was polished to form the sliding surface a and the flank b flat. The plated layer after this processing is referred to as Comparative Example 1 of the sliding portion structure.

Piston ring 1 having plated layer of Example 3
In this case, the plating layer is not polished at all, so that a large number of square pyramids # 3 are formed on the sliding surface a and the flank b.
The unprocessed plating layer having 11 ° oriented Ni crystal is referred to as Comparative Example 2 of the sliding portion structure.

Further, in the piston ring 1 having the plated layer of Example 4, the plated layer is not polished at all, so that a large number of granular N
The unprocessed plating layer having the i crystal is referred to as Comparative Example 3 of the sliding portion constituting body.

Next, a burn-in test was performed on the example and comparative examples 1 to 3 by the chip-on-disk method under the same conditions as in Example I, and the results shown in Table 16 and FIG. 18 were obtained.

[0079]

[Table 16]

FIG. 18 is a graph of Table 16. As is clear from Table 16 and FIG. 18, in the sliding surface forming region 8 of the example, the abundance S of {220} oriented Ni crystal is S ≧ 40%, and the sliding surface a is flat. Because of this, the wettability of the sliding surface a to the oil and the conformability of the sliding surface a to the disk are improved, and the sliding surface b slides out of the oil pool formed by the pyramidal {311} oriented Ni crystal of the flank b. Since the oil is supplied to the surface a, the seizure load is significantly improved as compared with Comparative Examples 1 and 3.

In Comparative Example 2, a square pyramid {311} was formed on the sliding surface a.
Since the oil reservoir function is obtained by the presence of the oriented Ni crystal, the same seizure resistance as that of the embodiment is obtained. Comparative Example 1 has no oil reservoir function because the flank b is flat, but {220} oriented Ni with an abundance S ≧ 40%.
The crystal provides good wettability and conformability as described above, so that seizure resistance is improved as compared with Comparative Example 3.

Next, Examples of the sliding portion constituting body, Comparative Examples 1 to
Each piston ring 1 having 3 is used as a top ring, which is incorporated in an in-line four-cylinder internal combustion engine similar to that described above,
When the blow-by gas amount was measured under the same conditions, the results shown in Table 17 and FIG. 19 were obtained.

[0083]

[Table 17]

FIG. 19 is a graph of Table 17. As is clear from Table 17 and FIG. 19, in the embodiment, since the wettability of the sliding surface a to the oil is good, the oil retention is improved, and accordingly, the seal between the sliding surface a and the cylinder inner wall surface 11 is formed. Since an oil film having a high property is sufficiently formed, the amount of blow-by gas is significantly reduced as compared with Comparative Examples 2 and 3.

Since the sliding surface a in Comparative Example 1 has the same properties as those of the embodiment, the blow-by gas amount is also the same as that of the embodiment. In Comparative Example 2, a large number of pyramid-shaped
Since the 1｝ -oriented Ni crystal is present, the sealing property is poor, and as a result, the blow-by gas amount is the largest. Comparative Example 3 has a large amount of blow-by gas because of poor wettability to oil as described above.

The present invention is not limited to the piston ring, but is also applicable to a piston skirt or the like.

[0087]

According to the present invention, by forming the sliding surface forming area and the flank forming area as described above, an oil film having excellent seizure resistance and a high sealing property with a mating member is provided. Can be provided sufficiently.

[Brief description of the drawings]

FIG. 1 is a plan view of a piston ring.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a perspective view showing an example of a flank.

FIG. 4 is a perspective view showing a body-centered cubic structure and its (hhh) plane.

FIG. 5 is an explanatory diagram showing an inclination of a (hhh) plane in a body-centered cubic structure.

FIG. 6 shows a face-centered cubic structure and its (3hhh) plane, (h
It is a perspective view which shows the h0) surface.

FIG. 7 is a plan view showing another example of a flank.

FIG. 8 is an explanatory diagram showing the inclination of the (3hhh) plane in the face-centered cubic structure.

FIG. 9 is an output waveform diagram of a power supply for electroplating.

FIG. 10 is a perspective view showing still another example of the flank.

FIG. 11 is an X-ray diffraction diagram of an example of a plating layer.

FIG. 12 is a micrograph showing a crystal structure of an example of a plating layer surface.

FIG. 13 is an X-ray diffraction diagram of another example of the plating layer.

FIG. 14 is a micrograph showing a crystal structure of another example of a plating layer surface.

FIG. 15 is a graph showing the relationship between the abundance of {222} oriented Fe crystals and the seizure load.

FIG. 16 is a graph showing the seizure generation load of Example 1 and the like.

FIG. 17 is a graph showing the amount of blow-by gas when Example 1 and the like are used.

FIG. 18 is a graph showing the seizure load in Examples and the like.

FIG. 19 is a graph showing the amount of blow-by gas when an example or the like is used.

[Explanation of symbols]

Reference Signs List 5 sliding surface structure 8 sliding surface forming region 9 flank forming region 10 oriented metal crystal 11 cylinder inner wall surface (partner member) a sliding surface b flank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C25D 3/12 101 C25D 3/12 101 3/20 3/20 (72) Inventor Katsumune Tabata Saitama 1-4-1 Chuo, Wako-shi, Japan Inside Honda R & D Co., Ltd. (56) References JP-A-60-149768 (JP, A)

Claims (3)

(57) [Claims] 1. A sliding surface forming area (8) and a flank forming area (9) connected to the sliding surface forming area (8) so as to recede from the sliding surface forming area (8). Equipped, mating member (1
In the sliding portion constituting the sliding portion with 1), the sliding surface forming region (8) and the flank forming region (9) are composed of an aggregate of metal crystals, and the aggregate is In the sliding surface forming region (8), the crystal surface is directed to the sliding surface (a) side, and in the flank forming region (9), the crystal surface is directed to the flank surface (b) side. The sliding surface (a) is formed to be flat, and a large number of the oriented metal crystals (10) present on the flank (b) are pyramidal or pyramidal. A sliding part structure having at least one form of a truncated pyramid. 2. The sliding part structure according to claim 1, wherein said oriented metal crystal has a body-centered cubic structure, and said crystal plane is a (hhh) plane with a Miller index. 3. The oriented metal crystal (10) has a face-centered cubic structure, the crystal plane in the sliding surface formation region (8) has a Miller index (hh0) surface, and the flank surface formation. The crystal plane in the region (9) has a Miller index of (3h
The sliding portion structure according to claim 1, which is an hh) surface.