JPH03146555A - Vibration-damping resin molded article for engine - Google Patents

Abstract

PURPOSE:To provide a molded article composed of a copolymer produced by the copolymerization of two or more kinds of monomers constituting polyamide resin, having excellent vibration-damping property and suitable for an engine or its peripheral devices. CONSTITUTION:The objective molded article is a part mechanically attached to an engine or its peripheral devices and composed of a copolymer produced by the copolymerization of two or more kinds of monomers constituting a polyamide resin. The copolymer is produced by copolymerizing two or more kinds of monomers constituting nylon 6, nylon 66, nylon 12, etc., for example, a 6-66 copolymer produced by copolymerizing three kinds of monomers consisting of epsilon-caprolactam, adipic acid and hexamethylenediamine.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cylinder throat cover. This article relates to resin molded products for engines with excellent vibration damping properties used in gear cases, etc.

[Prior art]

In recent years, in response to the social demand for improved fuel efficiency in automobiles, research has been carried out on replacing metal components with plastics, and progress is being made in practical applications.

Compared to metal materials, nylon resin products are lighter in weight, and have better vibration damping, rigidity, and heat resistance.

It has various excellent performances in terms of oil resistance, etc.

Therefore, in recent years, it has been used as a vibration-damping material that is mechanically attached to automobile parts, especially engines or engine peripheral equipment such as cylinder head cover gear cases, etc., for the purpose of weight reduction and noise reduction.

In general, resin materials have superior vibration damping performance in parts compared to metal materials. However, in terms of noise reduction effect, solid-borne sound, that is, sound based on the vibration of the component itself, is reduced, but air-transmitted sound due to the small specific gravity increases.

Therefore, in order to obtain an effective noise reduction effect by changing materials, it is required to reduce structure-borne sound more than the increase in air-transmitted sound. In other words, high vibration damping performance is required.

Generally, resin materials have strong viscoelastic properties,
The damping performance is highest around the maximum temperature of the loss tangent (tan δ) of mechanical dispersion, which is mainly based on the glass transition of the polymer material. 1 Usually, the temperature is in the range of 10 to 30°C higher than the glass transition temperature (Tg) observed by differential scanning calorimetry (DSC).

For example, nylon 6, nylon 66, nylon 12, nylon 11. Linear aliphatic nylon such as nylon 610 has a Tg of 40 to 60°C, and a damping performance of 60 to 80°C.
It reaches a maximum around °C.

Other nylon resins include crystalline metaxylylene resin (MXD), which has an aromatic ring in two molecular chains.
Aromatic nylons such as amorphous nylons, which are copolymers of one or more diamines and one or more dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), have a Tg of 120°C or higher. Therefore, the damping performance reaches its maximum in a high temperature region of 130°C or higher.

On the other hand, in automobiles, there is a growing demand for improved ride comfort as well as weight reduction. One of the ways to improve riding comfort is to reduce vibration and noise. This vibration noise is caused by the vibration of peripheral equipment caused by engine vibration.

It also occurs in various resin molded products that are mechanically attached to peripheral equipment using bolts, nuts, screws, etc. (see below for details).

Moreover, since these resin molded products are placed near the engine, they are mainly heated to 80 to 120°C. Therefore, it is required to have particularly excellent vibration damping properties in this temperature range.

In view of these conventional problems, the present invention has particularly excellent vibration damping performance in the above temperature range. The aim is to provide nylon resin molded products.

[Means for solving problems]

The present invention is a resonant resin molded product that is mechanically attached to an engine and its peripheral equipment, and the resin molded product is a copolymer obtained by copolymerizing two similar monomers constituting a polyamide resin. Coalescence (hereinafter referred to as copolymerized nylon)
A damping resin molded product for engines is characterized by the following.

In the present invention, the copolymerized nylon refers to nylon 6
It is a copolymer obtained by copolymerizing two types of monomers constituting polyamide resins, such as , nylon 66, and nylon 12.

For example, by copolymerizing three monomers: ε-caprolactam, which is a monomer that makes up nylon 6, and adipic acid and hexamethylene diamine, which are monomers that make up nylon 66, a 6-66 copolymer (copolymer) is produced. is obtained.

In addition to nylon 6-66, the copolymerized nylon mentioned above includes conventionally known nylon 6-12, nylon 6
-610. Nylon 66-12゜Nylon 66-610
．． Nylon 6-12-66゜Nylon 6-12-610
．． Nylon 6-66610 Nylon 6-66-610
-12 etc.

In addition, in the resin molded article of the present invention, 10 to 150 parts of the inorganic filler is added to 100 parts by weight of the nylon mixture.
11 parts can also be blended. Thereby, the mechanical strength of the resin molded product can be improved.

If the inorganic filler is less than 10 parts by weight, the effect of blending will be low, while if it exceeds 150 parts by weight, moldability will deteriorate,
This is because the gloss of the surface of the molded product decreases.

Examples of the above inorganic filler include glass fiber and mica.

Talc, wollastonite, barium sulfate, clay calcium carbonate, carbon fiber, silicon carbide fiber, potassium titanate whisker (, calcium hydride whisker, etc.) are used.

In the present invention, antioxidants, ultraviolet absorbers, lubricants,
Antistatic agents, nucleating agents, mold release agents, plasticizers, additives, flame retardants, fillers, other resin materials, etc. can be added.

The above copolymer is molded into a desired shape using an injection molding machine or the like.
Molded into a structural resin molded product.

The damping resin molded product for engines according to the present invention is as follows.

It is used as a resin molded product that is mechanically attached to the engine and its peripheral equipment. Such resin molded products include cylinder head covers, gear covers, timing belt covers, oil pans, mission covers, air cleaner cases, resonators, exhaust pipes, and the like.

[Action and effect]

The resin molded article in the present invention is made from a copolymerized nylon obtained by using two types of the monomers as described above. Therefore, especially 80~120'C
Excellent vibration damping performance.

Therefore, one resin molded article of the present invention is as described above. As a vibration-damping resin molded product that is mechanically attached to the engine and its peripheral equipment, it exhibits excellent vibration-damping effects.

〔Example〕

An example according to the present invention will be described below along with a comparative example.

[Sample preparation, measurement method]

For both Examples and Comparative Examples, pellets of each nylon shown in Table 9 were used, and test pieces of predetermined shapes were produced by injection molding, and these were used as samples.

In addition, before measuring the physical properties, the sample was placed in a vacuum at lOO°C18
Annealed for a time.

0 Measurement of loss coefficient (note: a measure of damping performance) is 2
This was done by the following method.

Sample shape: 150mX 150ak, thickness 3IIn.

Measurement method: The transfer function was measured by vibrating the center of the sample at 0.1 G in a constant temperature bath, and the loss coefficient η was calculated from the secondary resonance point using the half-width method.

The measurement results are shown in the table below.

The ingredients in the comparative example are:

In addition, each of the above examples The following were used.

06-66 COBORIMER NOVAMID 2420A ○ 6-12 copolymer: Grillon CA6 0 Nylon 6 resin: Grillon A28 0 Nylon 66 resin: (EMS) (Mitsubishi Kasei) (EMS) Grillon T-300CM (EMS) O Nylon 12 resin: Dia Poison de L2140 (Daicel Huls) As known from the above table 1 Examples 1 and 2 of the present invention
It can be seen that all of the resin molded articles have superior vibration damping performance compared to Comparative Examples 1 to 3 in which each nylon component was used alone.

As described above, the nine resin molded products according to the present invention are as follows.

It can be seen that the damping performance is excellent, especially the damping performance under high temperature conditions of 80 to 120°C.

"Example 3" Next, a cylinder cover molded using the nylon copolymer according to the present invention will be described.

As shown in FIGS. 1 and 2, the cylinder rad cover is comprised of a cylinder rad cover 1 and a heat-resistant rubber gasket 2 attached to its lower end surface. The cylinder cover 1 is box-shaped with its bottom open, and has an oil inlet 11 above it.

It has an EGR nozzle 12 on the side. Further, it has mounting bolt holes 15 on the lower side.

The cylinder cover 1 is for a diesel engine, and is injection molded using each of the nylons of Example 1 and Comparative Example 1 at a cylinder temperature of about 290°C and a mold temperature of about 80°C.

The size of the rad cover for this cylinder was 48 cm long, 25 cm wide, and 8 cm deep (0.4 cm thick).

A bench test was conducted by assembling the rad cover to the cylinder under the same conditions as above to the engine, and a microphone was installed at a position 100 cm away from the cylinder head cover to measure the sound pressure level. The salinity of the cylinder head cover at the time of measurement was approximately 100'C.

As a result, the cylinder rad cover according to Example 1 was as follows:
Compared to that of Comparative Example 1, the noise reduction effect was approximately 1 to 2 dB (decibel).

[Brief explanation of the drawing]

1 is a perspective view of a cylinder cover according to a third embodiment, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1. 110. Bolt hole for mounting rad cover 15 to cylinder.

Claims (1)

[Claims] A damping resin molded product that is mechanically attached to an engine and its peripheral equipment, and the resin molded product is made of a copolymer obtained by copolymerizing two similar monomers that make up polyamide resin. A vibration damping resin molded product for engines.