JPS5893840A - Combination of member - Google Patents

Abstract

PURPOSE:To enhance the specific strength and wear resistance of 2 members which contact with each other and slide relatively by forming the sliding surface part of one member with a fiber reinforced metallic composite material contg. alumina-silica fibers having a specified composition and contg. a specified amount of alpha-alumina as a reinforcing material and the sliding surface part of the other member with cast iron. CONSTITUTION:For example, a piston for an engine is combined with a piston ring. At this time, the sliding surface of the piston facing to the piston ring is formed with a composite material composed of alumina-silica fibers consisting of >=80wt% alumina and the balance silica and contg. 5-55, especially 10- 45wt% alpha-alumina as a reinforcing material and Al, Mg or an alloy thereof as a matrix. The sliding surface of the piston ring facing to the piston is formed with cast iron. It is desirable to subject the sliding surface to rubellite treament.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combination of two members that abut each other and slide relative to each other, and more specifically, one member is made of a composite material and the other member is made of cast iron. It relates to a combination of two configured members.

Components and members of various machines often require special mechanical properties. For example, in automobile engines, as demands for engine performance become higher, members such as pistons not only have excellent specific strength and rigidity, but also require that their sliding surfaces have excellent wear resistance. There is now a strong demand to be present. As a means of improving the specific strength, wear resistance, etc. of such members, attempts have been made to construct these members from composite materials in which various inorganic materials such as 1iI1 are used as reinforcement materials and light metals such as aluminum alloys are used as a matrix. ing. As one such fiber-reinforced metal composite material, a fiber-reinforced metal composite material that uses alumina fiber as a reinforcing material and aluminum, magnesium, or an alloy thereof as a matrix is already known. Accordingly, it is possible to improve the specific strength, purity resistance, etc. of a member made of them.

However, in a combination of two members that are in contact with each other and slide relative to each other, if one of the members is made of a fiber-reinforced metal composite material as described above, depending on the material of the other member, The wear of the other member increases significantly, so that they cannot be used as a combination of sliding members that abut and slide relative to each other.

The inventors of the present application have proposed an llll1 reinforced metal composite material, which is a combination of two members that come into contact with each other and slide relatively, one of which is made of alumina fiber as a reinforcing material and a light metal such as an aluminum alloy as a matrix. In order to minimize the amount of wear on both parts in a combination of parts where the other part is made of cast iron, what is the composition and combination of materials? As a result of conducting various experimental studies on the appropriateness of these methods, we found that each of them must have specific characteristics.

The present invention is based on the knowledge obtained as a result of the above-mentioned experimental research conducted by the inventors of the present invention, and is based on the findings of the present invention, which is based on the findings of the present inventors. It is a combination of two members that are in contact with each other and slide relatively, the other member being made of cast iron, and the wear resistance of both members as they slide relative to each other. The objective is to provide a combination of two components with improved properties.

According to the present invention, this object is achieved by combining a first member and a second member that abut each other and slide relative to each other,
The sliding surface portion of the first member relative to at least the second member is made of alumina of more than aowt% and silica as the balance, and is reinforced with alumina fibers having an α-alumina content of 5 to 5Elt%, and is made of aluminum and magnesium. , and is made of a composite material having a matrix of a metal selected from the group consisting of alloys thereof, and at least the sliding surface portion of the second member relative to the first member is made of cast iron. This is achieved by a combination of members characterized by:

According to the present invention, it is a combination of two members that come into contact with each other and slide relative to each other, and the sliding surfaces of both members relative to each other have excellent wear resistance. It is possible to obtain a combination of members in which the amount of wear in each sliding motion can be minimized, and one member has excellent specific strength and rigidity.

According to one detailed feature of the invention, the alumina fibers have an alpha alumina content (ratio of alpha alumina weight to total alumina weight in the alumina fibers) of 10 to 45.
Preferably, it is wt%.

According to another detailed feature of the present invention, it is preferable that the sliding surface of the second member relative to the first member is treated with a lubrite treatment, and the sliding surface of the second member The cast iron constituting the dynamic surface portion is preferably spheroidal graphite cast iron.

According to another detailed feature of the present invention, the other member is a piston ring, and the one member is an engine piston in which a ring groove for receiving a similar piston ring is made of a fiber-reinforced metal composite material. It may be. According to such a combination of a piston and a piston ring, it is possible to minimize the amount of wear on both the ring groove W surface of the piston and the upper and lower surfaces of the piston ring, thereby ensuring long-term wear and normal operation of the engine. be able to.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

First, it is a combination of two members that come into contact with each other and slide relative to each other, one of which is a fiber-reinforced metal composite material with alumina fibers as a reinforcement and a light metal such as an aluminum alloy as a matrix. The inventors of the present invention have examined the appropriate composition and material of each member by combining members in which the other member is made of cast iron. The following describes the wear test.

゛Alumina fiber with a fiber diameter of 3.0μ (95wt%A1t
O@, 5wt%810! ＞The bulk density is 0.15+1/
A composite material was manufactured using a randomly oriented fiber molded body as a reinforcing material and an aluminum alloy (J Is standard AC8A> as a matrix), and the size was 16 x 6 x 1.
0-1, one face (161-X101-),
A block test piece was prepared using the test surface as the test surface. In this case, the α-alumina content of the alumina fiber is Qvt%, 5wt%,
Five types of block test pieces were created, each containing 30 wt%, 55'llt%, and 65 wt%.

In addition, for comparison, a block test piece having the same dimensions as the above-mentioned block test piece was prepared, which was made only of an aluminum alloy (JISI rating AC8A) that was not reinforced with fibers.

These test pieces were sequentially set in the wear tester, and the outer diameter of the mating member was 35-1. ! 30m5, width 1011 (
F) Spherical Jll lead casting 11t (J l811FCD70
) was brought into contact with the outer circumferential surface of a cylindrical test piece made of ), and while supplying high m1 (150°C) refined oil (castle motor oil 5W-30) to the contact portion of the test piece, a pressing force of 60 ko;
A wear test was conducted by rotating a cylindrical test piece for 1 hour at a rotation speed of 160 rpm. The combinations of block test pieces and cylindrical test pieces in this wear test were as shown in Table 1 below.

1: Note: 1) α alumina content (35wt%2) α plumina content 55wt% 3) α alumina content 3Qwt% 4) α alumina content set% 5) α alumina content Qwt% The above wear Figure 1 shows the test @prefectures. In Fig. 1, the upper half shows the wear amount of the block test piece (lI wear scar depth μ).
The lower half represents the wear amount (wear loss -9) of the cylindrical test piece that is the mating material, and the symbols A-H correspond to the test piece combinations A-H in Table 1. Compatible.

From this Figure 1, it can be seen that the block test pieces made only of aluminum alloy (G and H) have a very large amount of wear, whereas the block test pieces made of aluminum alloy reinforced with reinforcing fibers (A-F) The wear amount is very small compared to the block test pieces (G and H) made only of aluminum alloy, and in particular, the block test pieces (A-E) for the cylindrical test pieces treated with luplite are hard chromium plated. Block test for a cylindrical test piece The composition and material of each member are A wear test conducted by the inventors of the present invention will be explained to determine what kind of material is appropriate.

Alumina fiber (95wt%Al*O) with a fiber diameter of 3.0μ
s, 5 t%810, bulk density 0.15 + 1/a
s'' randomly oriented Il miscellaneous molded body as a reinforcing material,
Made of a composite material with aluminum alloy (JIS standard AC8A) as a matrix, and the size is 16 x 6 x 10 m.
-, and a block test piece was prepared with one surface (16a-xloa-) as the test surface. In this case, the α-alumina content of the alumina fiber is 0t%, 5wt%, 30v
Five types of block test specimens were prepared: t%, 55wt%, and 65wt%.

For comparison, the above-mentioned 1 made of aluminum alloy (JIS standard AC8A) that is not reinforced with fibers
A block test piece having the same dimensions as the 0tsuk test piece was prepared.

These test pieces were sequentially set in a friction and wear tester and brought into contact with the outer peripheral surface of a cylindrical test piece made of spheroidal graphite cast iron (J l8111FCD70) with an outer diameter of 35-1 and a width of 10 mm and a width of 10 mm. , high I at the contact area of these test pieces
I (150℃) lubricating oil (castle motor oil 5W
-30), pressing force 60ko, rotation speed 160
A wear test was conducted by rotating a cylindrical test piece for 1 hour at rEI-. The combinations of block test pieces and cylindrical test pieces in this wear test were as shown in Table 1 below.

1: Note = 1) α alumina content 55wt% 2) α alumina content 55wt% 3) α alumina content 3Qwt% 4) α alumina content aVt% 5) α alumina content 9wt% The above wear test The results are shown in Figure 1. In Figure 1, the upper half represents the wear amount (wear scar depth μ) of the block test piece, and the lower half represents the wear amount (wear loss SO) of the cylindrical test piece, which is the mating material. The symbols A to H correspond to the test piece combinations A to H in Table 1.

From this Figure 1, it can be seen that the block test pieces made only of aluminum alloy (G and H) have a very large amount of wear, whereas the block test pieces made of aluminum alloy reinforced with reinforcing fibers (A-F) The wear amount is very small compared to the block test pieces (G and H) made only of aluminum alloy, and in particular, the block test pieces (A-E) for the cylindrical test pieces treated with luplite are hard chromium plated. The block test piece (
It can be seen that the amount of wear is smaller than that of F).

Regarding the wear of the cylindrical test piece as a mating material, the wear amount of the cylindrical test piece of combinations A, E, and F is the same as that of combinations G and H.
while the combination 8 according to the invention is larger than in the case of
It can be seen that the wear amount of the cylindrical test piece of C1D was suppressed to the same level as that of combinations G and H, or to a very slightly larger extent than that of combinations G and H.

In addition, block test specimens were prepared using composite materials containing aluminum, magnesium, and magnesium alloy as a matrix, using alumina fibers of various α-alumina compositions as reinforcement materials, and containing 80 vt% or more of alumina and the remainder of silica. Cylindrical specimens of various cast irons, including cored malleable iron (both with and without leuprite treatment)
When a wear test similar to the above-mentioned wear test was conducted, the results showed substantially the same tendency as shown in Figure 1 (however, the amount of wear on the cylindrical test piece in this case was greater than that on the spheroidal graphite cast iron). Test results were obtained that showed a slightly larger value.

From the results of these wear tests, it was found that this is a combination of two members that come into contact with each other and slide relative to each other, one of which has alumina fiber as a reinforcement and a light metal such as an aluminum alloy as a matrix. In the case of a combination of two parts, such as one made of a composite material and the other part made of cast iron, the composite material making up one of the parts contains 80 wt% or more of alumina. The balance is silica, and the alpha alumina content is 5 to 55111t.
% alumina fiber as a reinforcing material and a matrix of metal selected from the group consisting of aluminum, magnesium, and alloys thereof, and the cast iron constituting the other member is luprite-treated cast iron, It can be seen that spheroidal graphite cast iron treated with leuprite is particularly preferable.

Next, a specific example of a combination of members according to the present invention applied to a combination of an engine piston and a piston ring will be described.

Fig. 2 is a vertical sectional view showing the above-mentioned embodiment, Fig. 3 is an enlarged longitudinal sectional view of the main part thereof, and Fig. 4 is an enlarged longitudinal sectional view showing the piston ring. It is a 51mm view. In these figures, 1 is a piston, which is made of aluminum alloy (J18m grade AC8A). On the side outer circumferential surface 2 of the piston 1, **Gas flows into the piston 1 and the cylinder block 3! two ring grooves 6 and 7 that receive compression rings 4 and 5 that prevent water from leaking from the m* chamber of the engine through the surface and the surface;
A ring groove 9 is formed to receive an oil ring 8 for scraping off excess oil. In the illustrated embodiment, τ is a portion from the piston head 10 along the side outer surface 2 of the piston 1 to below the lower surface 11 of the top ring groove 6.
! 3.0 μ, α-alumina content of 30 wt% alumina fibers (95 wt% A:!0・, 5++yt% 5 lots) are randomly oriented with a bulk density of 0°159/cl” as a reinforcing material. The other parts of the piston 1 are made of a composite material 12 having an aluminum alloy (J15I14@AC8A) as a matrix.

This composite material 12 defines the wall surface of the top ring groove 6 that receives the top ring 4, and also defines a part of the top land 13 and second land 14 in the portion exposed to the side outer peripheral surface 2 of the piston. are doing.

In addition, such a piston is made by placing a molded body on the bottom wall of a mold cavity of a mold for casting the piston, pouring molten aluminum alloy into the mold, and fitting it into the mold in a fluid-tight manner. The aluminum alloy is solidified while being pressurized by a plunger to form a piston preform, which is then heat-treated
1 (T6 treatment), then processed to a predetermined size, and further formed by forming ring grooves 6.7.9.

The top ring 4, which contacts the piston 1 as described above and slides relative to it, is made of spheroidal graphite cast iron (JIsle grade FC).
C70), and has been subjected to a leuprite treatment as a surface treatment.

In particular, the illustrated embodiment is configured as a 7° keystone ring, and a molybdenum sprayed layer 15 is formed on the sliding surface of the cylinder block 3 with the cylinder wall surface.

Piston and piston ring configured as described above (corresponding to combination C in Table 1 listed above), and combination A in Table 1 listed above
, the piston and piston ring composed of E-H are 4
It was installed in a 4-cylinder diesel engine, and an actual wear test was conducted under the test conditions shown in Table 2 below.

Color λ2” ΔOtori JJL Engine used: 4-cylinder 4-stroke diesel engine cylinder bore! : 90+n Stroke: 86g+a Compression ratio: 21.5 Displacement: 2188cc Cylinder material: Gray cast iron (JIS standard FC25> Fuel used: Light oil Engine speed: 5200 rpm Engine load =
Full load test time: 500 hours The results of the wear test using this actual machine are shown in Figure 5.

In Fig. 5, the upper half and the lower half represent the wear amount (wear scar depth μ) of the top ring groove lower surface 11 and the top ring lower surface 17, respectively, and are designated by symbols A, C, E, F, G.
, H are combinations A, C, and ES in Table 1, respectively.
Compatible with F, G, and H.

From this FIG. 5, in the case of combinations I C, E, and F, the lower surface of the top ring groove of the piston is more difficult than in the case of combination H.
It can be seen that the amount of wear on both the bottom surface of the top ring 17 is small, and in particular, in the case of combination C of the present invention, the amount of wear on the bottom surface of the ring groove and the bottom surface of the piston ring is smaller than in any of the combinations. Furthermore, the oil consumption and blow-by gas amount in the case of combination C of the present invention were stable and lower than in any other combination.

Although the present invention has been described above in detail with respect to one embodiment applied to a combination of a piston and a piston ring, the present invention is not limited to such an embodiment. It will be appreciated that other combinations of sliding members are also applicable.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the results of a wear test conducted by the inventors of the present application, and Fig. 2 is a graph showing an example of a combination of members according to the present invention applied to a combination of a piston and a piston ring. FIG. 3 is an enlarged partial longitudinal sectional view of the embodiment shown in FIG. 2, and FIG. 4 is an enlarged longitudinal sectional view of the piston ring (top ring). The enlarged vertical cross-sectional view of FIG. 5 is a graph showing the results of a wear test using an actual machine. DESCRIPTION OF SYMBOLS 1... Piston, 2... Side outer peripheral surface, 3... Cylinder liner, 4... Top ring, 5... Second land.

Claims (1)

[Scope of Claims] (1) In a combination of a first member and a second member that are in contact with each other and slide relative to each other, at least the 1III1 surface portion of the first member with respect to the second member is sowt%
A composite material consisting of the above alumina and silica as the balance, alumina fiber with an α-alumina content of 5 to 55 wt% as a reinforcing material, and a matrix of a metal selected from the group consisting of aluminum, magnesium, and their alloys. A combination of members, characterized in that at least both of the impulse parts of the second member relative to the first member are made of cast iron. (2. In the combination of members set forth in claim 1, the α-alumina content of the alumina 5Ill is 10 to 45W.
A combination of members characterized in that t%. (3) In the combination of members according to claim 1 or 2, the sliding surface of the second member relative to the first member is treated with Leuprite. A combination of (4) In the combination of members according to claims 1 to 3, the first member is an engine piston;
A combination of members, characterized in that the second member is a piston ring.