JPH03267599A - Internal combustion engine part - Google Patents

Abstract

PURPOSE:To increase strength of molded parts and improve a joint force by reinforcing an aromatic polyether ketone resin covered by an aromatic polyether sulfone resin with a carbon fiber so as to increase fiber orientation distribution in the direction in parallel to the straight line connecting joint parts with each other. CONSTITUTION:Using a polyacrylonitrile carbon fiber to which surface treatment has been given, after covering the surface by a polyether sulfone converging agent in which a low molecular weight polyether sulfone resin and a solvent are prepared with xylene as a diluent, it is cut to obtain a chopped carbon fiber, and heat treatment is given to it. Next, a polyether ketone resin as a matrix resin is blended with the above carbon fiber, and it is extruded at the cylinder temperature of 300 to 400 deg.C to have a pellet-state molding material. By this method, wettability of the carbon fiber and the matrix resin as well as strength is improved, and the fiber orientation distribution in which more orientation distribution is in parallel to the straight line connecting joint parts at both ends of a boss part improves creep strength and prevents loosening of a nut.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to internal combustion engine parts made of fiber-reinforced resin, particularly impellers, power transmission gears, etc. used in centrifugal compressors.

(Prior Art) Conventional impellers made of fiber-reinforced resin include, for example, Japanese Patent Publication No. 52-48684, Japanese Patent Application Laid-open No. 135132-1982, Japanese Patent Application Publication No. 119105-1980, Japanese Patent Application Laid-open No. 18296-1989, There are impellers described in Japanese Patent No. 61-283797, but the resin materials that make up these impellers are
It is characterized by using carbon fiber as a reinforcing material for the resin. In particular, JP-A-57-119105 describes that a carbon fiber reinforced resin using a heat-resistant thermoplastic resin or a thermosetting resin as a matrix resin is used for an impeller. Also, JP-A-57-1
In Publication No. 35132 and Japanese Utility Model Application Publication No. 60-6839,
It is described that the connection to the shaft is via a boss made of a metal material.

(Problem to be Solved by the Invention) However, the centrifugal compressor impeller is fastened to the shaft via a nut, and the fastening torque at that time is 1 kgm to 1.4 kgm (seat surface pressure of about 10 to 14 kgm).
kg/garden2). Furthermore, its usage conditions are -50℃ to 200''C (maximum temperature during regular use is 150℃), maximum rotation speed is 13 x 10'r
Furthermore, the stress generated at maximum rotation is approximately 20 kg/cm for the current product (made of aluminum alloy, outer diameter approximately 60 mm).
The root part of the wing weighs about 10 kg/kaku2.

By using fiber-reinforced resin with low specific gravity,
The maximum stress during rotation can be reduced to about 1/2. However, there is a problem in the fastening part that the fastening stress caused by the nut causes creep deformation, causing the nut to loosen.
Part of the idea of inserting metal into the fastening part as a countermeasure was proposed in Japanese Patent Application Laid-open No. 57-135132 and Japanese Utility Model Application No. 60-6.
Seen in issue 839.

Considering the current usage conditions, heat resistance, strength (tensile, bending, pressure wl), elastic modulus (tension, bending), durability fatigue resistance (tension, bending), creep properties (tension, pressure ta>, etc.) are taken into account to determine the material. , the thermoplastic resin or thermosetting resin disclosed in JP-A-57-119105 cannot be used as is for the impeller; The fastening creep countermeasures disclosed in Publication No. 6839 cannot be directly applied to impellers.

Fiber-reinforced resin compositions that satisfy these conditions include:
Polyether sulfone (PES), polyetherimide (PHI), polyether ether ketone (PEE)
K), polyetherketone (PEK), polyetherketoneketone (PEKK), polyketone sulfide (
PKS), polyallyletherketone (PARK),
Aromatic polyamide (PA), polyamideimide (FAI)
), heat-resistant resin such as polyimide (PI) and carbon fiber,
Composites with glass fibers, whiskers, etc. may be considered.

However, the above-mentioned resin has a high melting temperature, and it is necessary to mold the resin at a considerably high melting temperature of 350° C. to 430° C. during molding. In particular, regarding carbon fibers, currently commercially available carbon fibers for resin reinforcement use polyamide resins (decomposition temperature 280°C) for thermoplastic resins and epoxy resins (decomposition temperature 280°C) for thermosetting resins as binding agents.
The decomposition temperature (300°C) is mainly used, and the above-mentioned resin melting temperature during molding (350°C to 430°C) easily decomposes, resulting in a decrease in interfacial strength due to insufficient wetting between carbon fiber and matrix resin. Moreover, variations in strength tend to occur, and when used as an impeller material for a centrifugal compressor made of fiber-reinforced resin, there is a problem in that the reinforcing effect of carbon fibers is not effectively utilized and the strength is low.

In addition, for impellers in which a metal boss is press-fitted, glued, or integrally molded into the shaft hole of the impeller, a static long-term creep test (temperature of the fastened part = 120°C) is not sufficient to prevent fastening creep. Although it is effective, it is not effective in dynamic long-term durability in the highest temperature range (approximately 150℃) during practical use.In other words, when the compressed air temperature at the impeller outlet is 150℃ and the maximum rotation speed is 13X10' r
When a continuous durability test was conducted on p-, there was a problem in that peeling occurred at the interface between the boss made of a metal material and the resin, and this interfacial peeling became the starting point of breakage, resulting in breakage in a short period of time.

Furthermore, in an impeller made only of fiber-reinforced resin without using a boss made of a metal material in the shaft portion of the impeller, the bearing surface of the impeller undergoes creep deformation due to the fastening stress caused by the nut, causing the nut to loosen. When rotating at high speed, the rotational balance becomes unstable, causing vibrations and abnormal noises. There was also the problem that the looseness caused the impeller to spin idly, making it unable to perform its original function of compressing air and sending it into the combustion chamber of the engine.

(Means for Solving the Problems) The present invention has been made by focusing on such conventional problems, and has been made in the impeller of an integrated centrifugal compressor made of fiber-reinforced resin, a power transmission gear, etc. Use a resin composition in which an aromatic polyetherketone resin is used as a matrix resin, the surface of this matrix resin is coated with an aromatic polyethersulfone resin, and then reinforced with carbon fiber heated at 300 to 400°C. The above-mentioned problem was solved by further oriented the fiber orientation distribution of the fastening boss part of the part so that more fibers were aligned parallel to the straight line connecting the two fastening parts at both ends of the boss part. .

That is, this invention uses a resin composition consisting of an aromatic polyetherketone resin and carbon fibers subjected to the above treatment,
An integrated centrifugal compression product made of fiber-reinforced resin, characterized in that the fiber orientation distribution in the fastening boss part of the part is oriented so that more fibers are aligned parallel to the straight line connecting the two fastening parts at both ends of the boss part. These include aircraft impellers and power transmission gears.

The aromatic polyether sulfone resin used as a binding agent for carbon fibers used in the present invention is a linear polymer having arylene bonds, ether bonds, and sulfone bonds as bonding units. Particularly preferred are those represented by the following general formula.

Generally, it is sold by ICI in the UK under the trademark VICTREX ■Polyethersulfone (pH! It is commercially available as.

As the matrix resin, polyether sulfone (P
ES), polyetherimide (PH1), polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK)
, polyketone sulfide (PKS), polyallyletherketone (PAEK), aromatic polyamide (PA)
, polyamideimide (FAI), polyimide (PI)
etc. are used, but it is easy to mold, has high heat resistance strength,
Furthermore, aromatic polyetherketone resins, such as polyetheretherketone (PEEK
), polyetherketone (PEK), polyetherketoneketone (PEKK), polyallyletherketone (
It is a single resin such as PAEK) or a polymer alloy resin with other resins based on these resins.

The aromatic polyetherketone resin used as the matrix resin can be selected from various types depending on the operating temperature conditions, and it is clear that the glass transition temperature (Tg) of the matrix resin is an important guideline for selection. As aromatic polyetherketone resins, those consisting of repeating units as shown in the following formula are known.

In addition, carbon fiber is polyacrylonitrile filament,
It is obtained by firing rayon filament or petroleum pitch, and acrylonitrile filament is particularly suitable.

These carbon fibers are preferably surface-treated with ozone or electrolytic oxidation, coated with an aromatic polyethersulfone resin, and then heat-treated at 300 to 400°C. In addition, as aromatic polyether sulfone resin,
Low molecular weight compounds having a hydroxyl group at the end of the molecule are preferred. The blending ratio of reinforcing fibers is 25 to 45 to the total weight of matrix resin and reinforcing fibers! i amount% is preferable, 25
This effect is small when the weight percentage is not dropped. On the other hand, 46-47
If the blending ratio exceeds % by weight, the adhesion with the matrix resin will deteriorate, the strength will decrease, and the moldability will deteriorate significantly, which is not practical.

The carbon fiber-reinforced aromatic polyetherketone resin composition used in this invention is usually subjected to an injection molding process as an easy-to-handle pellet-shaped molding material, but these can be processed using a known single-screw or two-wheel extruder. Aromatic polyetherketone resin and carbon fiber are blended, and the cylinder temperature is 350°C to 410°C, preferably 370°C to 39°C.
It is obtained by extrusion shaping at 0°C with a compression ratio of 2 to 3 in the nozzle of an extruder.

Injection molding is carried out using a normal multi-stage control injection molding machine at a cylinder temperature of 380°C to 430°C, preferably 390°C to
410'C, the mold temperature is 160'C to 230'C, preferably 190'C to 210'C, and can be carried out while controlling the material filling rate into the mold, and carbon fibers with complex shapes can be processed. Impellers for centrifugal compressors made of reinforced resin, power transmission gears, etc. can be easily obtained.

The present invention will be explained below based on the drawings.

FIG. 1 is a diagram showing a centrifugal compressor impeller according to an embodiment of the present invention.

First, the configuration will be explained. As shown in the figure, an impeller 1 of a centrifugal compressor has a complicated shape and requires precise dimensional accuracy. This impeller 1 is fixed to a shaft portion 5 by a collar 2, a sleeve 3, and a nut 4, as shown in FIG. The fiber orientation distribution near the fastening portion is also shown in the figure.

The impeller of the present invention can be manufactured using the resin composition by a well-known method such as extrusion molding or injection molding. For example, an impeller can be molded using the mold shown in FIG.

That is, the bottle 7 is attached to the lower mold 10 combined with the assembly cost mold 6 in which the impeller shape is engraved, and then,
The upper mold 8 is tightly fixed, and the molding material is injected or extruded from the direction A through the gate 9 and filled into the impeller shaped part (cavity part) 11 and molded.

(Example) Next, the present invention will be explained with reference to Examples and Comparative Examples.

Polyacrylonitrile carbon fiber (manufactured by Toho Rayon ■, HTA type) that has been surface-treated by single-layer electrolytic oxidation is used, and low molecular weight polyether sulfone resin (manufactured by Mitsui Toatsu Chemical ■, 5003P) having a hydroxyl group at the end group is used. ) and N-methylpyrrolidone as a melting material at a mixing ratio of 10 to 30.
After coating the surface with a polyether sulfone-based sizing agent using xylene as a diluent, the chopped carbon fibers were cut into 5 m lengths and then heated at 370°C in a heat treatment furnace in an air atmosphere. Heat treatment was performed for 10 hours.

Next, a polyether ketone resin (PEK manufactured by Mitsui Toatsu Chemical Company Ltd.) as a matrix resin and the carbon fiber treated above were blended so that the carbon fiber content was 30% by weight. This one has a diameter of 65 m with L/D = 23 and compression ratio of 3.
- Since a shaft vent type extruder is used, the cylinder temperature is 390
'C, It was extruded at a screw rotation speed of 45 rpa+, and the strand was cut to obtain a pellet-shaped molding material. After drying the pellets with hot air at 180°C for 5 hours, they were molded using an 80TON (mold clamping pressure) multi-stage control injection molding machine manufactured by Nisshin Jushi Kogyo ■, with a cylinder temperature of 390°C and a mold temperature of 210"C.
1. Under the molding conditions of 2100 kg/cm" injection pressure, the injection speed was slowed, and the holding pressure switching timing and holding pressure were controlled in multiple stages, and the product was injected into a mold having the structure shown in Figure 3 to obtain an impeller-shaped object. The obtained shape was heat-treated at 230°C for 5 hours, and then machined such as deburring, shaft hole drilling, and balance check. It was attached to a fastening creep test jig that can be fixed to the shaft with a fastening torque of 1 kgm, and left in a hot air circulation dryer with an internal temperature of 120°C to determine the correlation between the elapsed time and the degree of decrease in fastening torque. The results are shown in Figure 4 and Table 1.The impeller shape obtained as described above was machined to correct the balance, and was assembled with a part of the rotor to form a turbocharger. This turbocharger was installed in a turbocharger continuous durability test equipment equipped with an air heating device, heated air of 900"C was blown onto the rotor side, the rotor and impeller were rotated at 130,000 rpm, and the air was compressed by the impeller and released. A continuous durability test was conducted while controlling the inlet air temperature so that the temperature of the incoming air was 150°C. The results obtained are shown in Table 1. Those that withstood 200 hours of continuous durability, had no decrease in fastening torque, and had no deformation of the fastened portion were judged to be acceptable.

After coating the surface of polyacrylonitrile carbon fiber (manufactured by Toho Rayon, HTA type) that had been surface-treated by electrolytic oxidation with aromatic polyether sulfone resin, 61
The carbon fibers were cut into 1II+ lengths to obtain chopped carbon fibers, and heat treated at 370°C for 10 hours in a heat treatment furnace in an air atmosphere. Next, a polyether ether ketone resin (PEEK manufactured by Mitsui Toatsu Chemical Co., Ltd.) was used as a matrix resin and kneaded with the carbon fiber treated above, and the blend was adjusted so that the carbon fiber content was 30% by weight. .

This material was made into pellets in the same manner as described in Example 1, and injection molding was carried out using an 80TON (mold clamping pressure) multi-stage control injection molding machine manufactured by Nisshin Jushi Kogyo ■ at a cylinder temperature of 390°C and a mold temperature of 200°C. The impeller-shaped product was obtained by injecting it into a mold having a structure as shown in Fig. 3 under molding conditions of 2100 cg/as'' pressure.After post-processing such as heat treatment and deburring, the product was as described in Example 1. A fastening creep test and a continuous durability test were conducted under exactly the same conditions.The fastening creep test results are shown in Figure 4 and Table 1, and the continuous durability test results are shown in Table 1.Continuous durability test The tips of the blades are deformed in this case, but this is due to durability at temperatures above the glass transition temperature (Tg = 145°C) of polyetheretherketone resin, and durability at temperatures below 140°C at the outlet air temperature. No deformation occurs.

1 vessel 1 The matrix resin is an aromatic polyetherketone polymer alloy resin with a blending ratio of polyetherketone resin (PEK manufactured by Mitsui Toatsu Chemical Co., Ltd.) and polyetherimide resin (PHI manufactured by GE Corporation) in a ratio of 80/20. Example 1
A pellet-shaped resin composition was prepared by kneading with chopped carbon fibers that had been subjected to the same surface treatment as described above, and blending them so that the carbon fiber content was 30% by weight. Using this resin composition, injection molding and post-processing were carried out in exactly the same manner as described in Example 1, and a fastening creep test and a continuous durability experiment were conducted. The results are shown in FIG. 4 and Table 1.

As the matrix resin, polyamideimide resin (A
Torlon (manufactured by Co., Ltd.) and chopped carbon fibers subjected to the same surface treatment as in Example 1 were kneaded and blended so that the carbon fiber content was 30% by weight to prepare a pellet-shaped resin composition. did. This resin composition was heated at 120°C for 1
After drying with hot air for 0 hours, 50TON manufactured by ARBURG
(Mold clamping pressure) Using an injection molding machine, cylinder temperature 350°C
1 mold temperature 210°C 1 injection pressure 2000kg/am
An impeller-shaped object was obtained by injecting it into a mold with the structure shown in Figure 3 under the molding conditions of ``.This impeller-shaped object was placed in a hot air circulation oven that allows precise temperature control. The following (149°C x 24Hr) + (216°C x 2
4Hr) + (243°CX 24Hr) + (26
After-cure was performed using a continuous temperature control pattern (0°C x 168 hours). The resulting shape was subjected to machining such as deburring, shaft hole drilling, and balance checking, and a fastening creep test and continuous durability test were conducted. The results are shown in FIG. 4 and Table 1.

Comparison Example 1 Using the resin composition used in Main Comparative Example 2 and using exactly the same molding conditions, an aluminum metal boss with a low-left finish on the surface was integrally molded with an insert to obtain an impeller-shaped article. This impeller-shaped product was subjected to after-curing and post-processing in exactly the same manner as described in Comparative Example 2, and was subjected to a fastening creep test and a continuous durability test. The results are shown in FIG. 4 and Table 1.

As a matrix resin, polyether sulfone resin (4100G manufactured by Mitsui Toatsu Chemical Co., Ltd.) was kneaded with chopped carbon fibers that had been subjected to the same surface treatment as in Example 1, and the carbon fiber content was 30% by weight. A pellet-shaped resin composition was prepared by blending the following ingredients.

After drying this resin composition with hot air at 180°C for 5 hours,
Using a Nippon Steel injection molding machine with a rupture of 75 TON (mold clamping pressure), injection was made into a mold with the structure shown in Figure 3 under the following molding conditions: cylinder temperature 380°C, mold temperature 200°C, injection pressure 1600 kg/cm2. , an impeller shape was obtained. The obtained shape was after-cured for 5 hours at 210°C, and after machining such as deburring, shaft hole machining, and balance check, fastening creep was performed in exactly the same manner as described in Example 1. We conducted tests as well as continuous durability tests. The results are shown in FIG. 4 and Table 1.

Hokkaido I Using the resin composition used in Comparative Example 4 and using exactly the same molding conditions, an impeller-shaped object was obtained by insert-molding an aluminum metal boss whose surface was knurled. The obtained impeller shape was subjected to machining such as after-curing, deburring, shaft hole machining, and balance check in the same manner as in Comparative Example 4, and was subjected to the same fastening creep test as described in Example 1, and continuous A durability test was conducted. The results are shown in FIG. 4 and Table 1.

Table 1 ($1) Initial tightening torque is constant at 1.0 kg-m;
The test piece was placed in an oven at 12oC for durability, and the torque was measured after the jig and impeller were removed from the oven and the temperature of the jig and impeller had cooled to room temperature.

(Book 2) Control the impeller outlet air temperature to 150"C, keep the rotation speed constant at 13 x 104 rpm, and
A time endurance test was carried out.

○: Pass No damage Δ: Semi-pass No damage, but deformation at the blade tip ×: Fail Damage From the results in Table 1, the impellers molded in the examples had better heat resistance strength and better strength than those in the comparative examples. It can be seen that the fastening creep properties are excellent.

(Effects of the Invention) As explained above, according to the present invention, aromatic resin is used as a matrix resin in internal combustion engine parts such as an integral centrifugal compressor impeller and power transmission gear made of fiber-reinforced resin. A resin composition was used in which a polyetherketone resin was used, the surface of this matrix resin was coated with an aromatic polyethersulfone resin, and then reinforced with carbon fibers heated at 300°C to 400°C.
The wettability of the carbon fibers and the matrix resin is improved, and the strength is improved.Furthermore, the fiber orientation distribution at the fastening boss part of the part is oriented parallel to the straight line connecting the two fastening parts at both ends of the boss part. By orienting it so that the distribution is large, the creep strength against fastening stress is improved, the fastening torque does not decrease, the nut does not loosen, and the loosening of the nut prevents the rotational balance from being out of balance. It is possible to prevent the generation of vibrations and abnormal noises, and it also has the effect of being able to withstand continuous high-speed durability without being damaged.

In addition to the above-mentioned common effects, each of the embodiments also has the following effects. Reducing the weight of the impeller improves its ability to follow engine load fluctuations. Furthermore, since the precision of the product surface is significantly improved compared to aluminum alloy products, it is possible to reduce the separation phenomenon of intake air from the blade surface during high-speed rotation, and has the effect of improving intake compression efficiency. can get.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an invera as an example of the present invention, Fig. 2 is a sectional view of an impeller attached to a shaft, Fig. 3 is a sectional view of a mold for forming the impeller, and Fig. 4 shows a carbon fiber content of 30%. It is a curve diagram showing the change over time of the fastening torque in a 120°C atmosphere of impellers manufactured with various resin compositions expressed as weight %. 1... Impeller 2... Color 3...
Sleeve 5...Shaft 7...Bin 9...Gate 11...Impeller shape part 4...Nut 6...Assembly fee mold 8...Upper mold 10...Lower mold ( cavity)

Claims (1)

[Claims] 1. In internal combustion engine parts made of fiber-reinforced resin, an aromatic polyetherketone resin is used as the matrix resin, and after coating the surface of this matrix resin with an aromatic polyethersulfone resin, By using a resin composition reinforced with carbon fibers heated at ~400°C, the fiber orientation distribution in the fastening boss part of the part is increased so that the fiber orientation distribution is often parallel to the straight line connecting the fastening parts at the two ends of the boss part. An internal combustion engine part made of fiber-reinforced resin characterized by being oriented in a similar manner. 2. The internal combustion engine component according to claim 2, wherein the internal combustion engine component is an impeller of an integrated centrifugal compressor that does not require a boss made of a metal material inside the component.