JPS6079142A - Frp engine parts - Google Patents

Abstract

PURPOSE:To improve the lubrication performance and abrasion resistance of engine parts mainly composed of FRP, by providing a coating layer of resin mixed with soft metal scale and fluorine resin on the outer face of base. CONSTITUTION:An engine part such as a piston 1 is formed with a top portion 2 made of heat resistant metal and skirt section 3 made of FRP. In the skirt section 3, the outer face of FRP base 4 is coated with resin layer 5 composed of such material as having excellent lubrication, high abrasion resistance and thermal expansion resistance. Said layer 5 is composed of 30-70wt% of resin added with 20-40wt% of soft metal scale and 10-30wt% of fluorine resin or molybdenum disulfide. Consequently, lubrication and abrasion resistance at the skirt section 3 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to engine parts such as piston skirts and valve stems formed entirely or partially using fiber-reinforced plastics.

C) Prior art) Examples of conventional engine parts made of fiber-reinforced plastics include, for example, Utsukai Showa 5J-/Otsu! ;93! As shown in the above publication, there is a piston whose skirt portion is made of WaS reinforced plastic.

However, since fiber-reinforced plastic has a material characteristic of poor lubricity, when this fiber-reinforced plastic is used for a sliding part such as a piston skirt as in the above-mentioned known example, the sliding part in the sliding part Problems such as an increase in dynamic resistance or an increase in WIi wear will occur.

OBJECT OF THE INVENTION The present invention provides an engine component that is manufactured entirely or partially from fiber-reinforced plastic as a material, and provides improved lubricity and jI resistance of the fiber-reinforced plastic portion. This was done with the aim of improving wear resistance.

(Structure of the Invention) The fiber-reinforced plastic engine component of the present invention has an outer surface of a base made of fiber-reinforced plastic, in which appropriate amounts of a fluororesin or molybdenum disulfide and a scale-like soft metal are added to the resin. The purpose is to improve the lubricity and wear resistance of the sliding surface of the m-cone reinforced plastic base by coating it with a coating 8 [made of], and to maintain the strength of the coating layer itself against thermal expansion. In that case, the material composition of the covered lII layer is expressed by the tree 11M.
70-30% by weight of fluororesin or molybdenum disulfide and 20-1% of scaly soft metal for 30-70% by weight.
They are characterized in that they are each specified at 10% by weight.

(Embodiment) FIG. 1 shows an embodiment in which the present invention is applied to a skirt portion of a piston of an engine.

The piston l of the station shown in the figure is made of heat-resistant metal, with the top and bottom parts 2 and wA.
#, It is constructed by bonding a skirt s3 formed by covering the outer surface of a base t made of reinforced plastic with a coating layer S to be described later. The skirt portion 3 of the piston is a semi-sliding part and requires particularly good lubricity and wear resistance. The outer surface of the skirt base is covered with a coating layer made of JlfffW, which is made of a material with excellent wear resistance, abrasion resistance, and thermal expansion resistance, as described below. The coating ensures the lubricity, wear resistance, and thermal expansion resistance (iljj durability) required for engine parts.

The material characteristics and structural structure of this coating layer S will be explained below. The present inventors have developed a coating material that has excellent lubricity, wear resistance, and thermal expansion resistance, and has good bonding strength to the fiber-reinforced plastic substrate. During our research, we first discovered that in order to improve lubricity, wear resistance, and bondability to fiber-reinforced plastic substrates, we added an appropriate amount of fluorine to the material resin, such as epoxy resin, which acts as a bonding agent with fiber-reinforced plastic substrates. It is preferable to add a solid lubricant such as M fat or molybdenum disulfide, and in order to improve the thermal expansion resistance of the atjii itself, an appropriate amount of scale-like soft metal is added to the above material resin. The soft metal suppresses the thermal expansion of the coating layer, thereby suppressing as much as possible the occurrence of cracks caused by the difference in thermal expansion between the coating layer and the fiber-reinforced plastic substrate. As a result of various tests, we have found the types of leaf materials and fats and various additives that are suitable for use as a coating layer to achieve the above objective, as well as the optimal amount of addition thereof.

That is, after conducting a number of tests on each M sample, the present inventors used epoxy 81N1 polyimide resin, polyether ether ketone 1 dB Ha, and phenol M resin 11 as applicable material M resins to achieve the above objective.
In addition, two types of soft metals, aluminum and copper, were selected as the soft metals to be added to the material I11!111W, and a fluororesin was selected as the solid lubricant to be added to the material I11!111W. Two types of solid lubricants were selected: molybdenum disulfide and molybdenum disulfide.

Next, in order to find the content ratio of the above-mentioned material resin, soft metal, and solid lubricant so as to obtain the optimum characteristics as a coating material, base UN lubricant was selected from among the above-mentioned material resin, soft metal, and solid lubricant. The epoxy N side (number 6 in Figure 2) is used as the epoxy N side, and the aluminum C subdivided into scales below the SOO mesh as the ldC metal is number 7 in Figure 2.
), and 0.0% as a solid lubricant. ! ; Adopts fluororesin (indicated by the symbol in Figure 2) with a particle size of -2μ,
Coating layer 5 with different content ratios and layer thicknesses of each of these additives
We have prepared many. Next, a motoring test was conducted using a piston l equipped with a piston skirt 3 in which the outer surface of the skirt base t was coated with each of these coating layers S..., and it was found that there was no abnormal wear or damage to the coating layer j. Check the operating time until abnormalities such as peeling or cracking appear, and
The quality of the material of the coating layer S was determined based on the length of the operating time.

The test results are shown in FIG.

The test results shown in Figure 113 are based on the case where the epoxy resin is jOI%, the carbon fiber is 50% by weight, and the fiber wrapping angle is 4Zj.
The layer thickness is applied to the fiber-reinforced plastic skirt base t formed as ``''! ; These are the test results when the coating layer 5 of Oμ was formed. In addition, in FIG. 3, curve A is a characteristic diagram when the aluminum addition amount is expressed as ION amount % with respect to the total weight of the coating layer, and the following curve B1 curve C1 curve 1
The a o s curve pi is the aluminum addition amount, 2
It is a characteristic diagram in the case of oMm%, 30 weight%, 110 weight%, and 3O weight%.

From the test results shown in Figure 3, we will determine the optimal composition of the coating layer to achieve the above objective. In view of the fact that most engines for general use such as automobile engines are operated continuously for only 100 hours or less, the present inventors As a criterion for determining a coating layer that meets the purpose of the present invention, a test engine was tested for 10 years without any abnormal wear, peeling phenomenon, or cracking as described above in the coating layer S of the piston skirt 3.
If continuous operation was possible for 0 hours or more, it was determined that a coating layer having that material composition could be applied as a coating layer for the piston skirt. When we considered the test results in Figure 3 based on these criteria, we found that the amount of fluorinated liver fat added was 70 to 30% by weight, the amount of scale-like aluminum added was 2O-ION amount%, and the amount of epoxy resin was 70 to 30% by weight. 30% by weight (when fluororesin is 30% by weight and T-shaped aluminum is 40% by weight) - 70% by weight (fluororesin is 10% by weight)
It has been found that an aluminum coating layer having a composition within the range of 20% by weight of aluminum flakes is suitable as a coating layer for achieving the object of the present invention.

In this way, 20 to 70% by weight of epoxy resin contains 20 to 70% by weight of aluminum flakes and 10 to 10% by weight of fluororesin.
In the case of the coating layer S containing ~30% by weight, good results meeting the purpose of the present invention were obtained because, at this content ratio, the bonding strength between the epoxy resin and the skirt base (fiber-reinforced plastic) In other words, the flaky aluminum suppresses the thermal expansion of the epoxy resin constituting the coating layer S, resulting in a coefficient of thermal expansion of the epoxy resin α=30X/0−.
The effect of preventing cracks from occurring due to the difference in thermal expansion between the fiber-reinforced plastic (thermal expansion coefficient α=lOxlO,!/℃) that makes up the base of the skirt part) and the lubricity and wear resistance of the fluororesin It is surmised that the above-mentioned favorable results are obtained due to the mutually effective enhancing effects of .

In addition, if the content ratio between epoxy resin (material resin), flaky aluminum (soft metal), and fluororesin (solid lubricant) deviates from the above optimal content ratio, the following problems may occur. .

That is, when the amount of epoxy resin is 30% by weight or less, the bonding force between the covering layer 3 and the fiber-reinforced plastic skirt base t is reduced, and the peeling of the covering layer j is likely to occur; When the amount of epoxy M is 70% by weight or more, the bonding strength between the lla reinforced plastic skirt part base t and the coating layer S is good, but the amount of other additives added is small, so the coating layer j Cracks may occur.

In addition, if the amount of flaky aluminum is 20% by weight or less, the effect of suppressing cracks in the coating layer by the flaky aluminum cannot be expected to be significant, and as a result, cracks may occur in the M layer or the coating layer may be damaged. There is a problem that peeling M phenomenon occurs, and the amount of scaly aluminum is l/-O
When Mfjt exceeds 1%, the crack suppressing effect of the flaky aluminum reaches a peak, and conversely, the bonding force of the coating layer S to the skirt base t decreases, and the coating layer 5
There is a problem that it becomes easy to peel off from the skirt portion base t.

Furthermore, if the fluororesin content is 70% by weight or less, the lubricating effect of the fluororesin will be insufficient and the wear of the coating layer S will increase, causing problems in terms of durability. %, not only does the lubricating effect of the fluororesin reach a plateau, but also the bonding force to the skirt base t decreases, making it easy for the coating layer to peel off.

Also, regarding the thickness of the coating layer S, the same test as above was performed on the coating layer! As a result of trying various things by changing the thickness of
The best results are obtained when the thickness is -20μ to 100μ, whereas when the thickness t<20μ, the IWI of the coating layer exposes the surface of the fiber-reinforced plastic substrate in a short time, reducing the coating effect. In addition, test results have been obtained that in cases where the thickness t>100μ, excessive stress is generated in the coating layer due to wear between the coating layer and the cylinder sliding surface, making the coating layer likely to peel off. Ta.

It goes without saying that the present invention can be applied not only to the piston skirt as in the above embodiment, but also to other engine parts such as the stems of intake and exhaust valves.

(Effects of the Invention) The fiber-reinforced plastic engine parts of the present invention are coated with a solid lubricant such as 1-fluorine resin or molybdenum disulfide on the outer surface of the fiber-reinforced plastic base to suppress thermal expansion of the ND portion, thereby cracking cracks. By forming a coating layer made of lll1 fat containing a scale-like soft metal that acts to prevent the occurrence of In order to improve durability, the tree part of the fiber-reinforced plastic is left in contact with the sliding surface of the cylinder, etc.
//- Conventional engine parts C e.g.
This has the effect of reducing the sliding resistance and improving wear resistance and durability compared to Publication No. 35).

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of a 1m fiber-reinforced plastic engine part according to an embodiment of the present invention, and Fig. 2 is a partially cutaway front view of a 1m fiber-reinforced plastic engine part according to an embodiment of the present invention.
M enlarged view, Figure 3! FIG. 2 is a characteristic diagram of a coating layer covering the outer surface of the fiber-reinforced plastic expanded base of the engine component shown in FIG. 3-・- Piston Skirt...Skirt part base! -...Coating layer 2ζ ・ ・ ・ ・ -mi N 7... Slab-like soft metal l... Fluororesin or molybdenum disulfide application
People Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] / An engine part formed entirely or partially using fiber-reinforced plastic as a base, comprising 30-70% by weight of resin, 20-20% by weight of a soft metal and 10-10% by weight of a fluororesin or molybdenum disulfide. A fiber-reinforced plastic engine part, characterized in that the outer surface of the fiber-reinforced plastic base body is coated with a coating layer containing 30% by weight of the fiber-reinforced plastic base.