JP2004285400A - Vehicle mount members - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight mounting member for a vehicle whose rigidity is improved or retained. <P>SOLUTION: The mounting member 10 for the vehicle is formed from a metal containing at least one chosen from a carbon fiber and fullerene, i.e. a spherical cage-shaped carbon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle mount member that supports various devices and the like in an automobile.
[0002]
[Background Art]
The vehicle mount member is a vehicle component that connects and supports an engine or an engine peripheral device of an automobile with a vehicle body, and includes, for example, an engine mount that supports an engine and a transmission mount that supports a transmission. The engine mount has a bracket fixed to a plurality of portions of an automobile engine with bolts, and a damper for connecting the bracket to the vehicle body, and supports the engine with vibration damping to the vehicle body (for example, See Patent Document 1.). The transmission mount also supports the vehicle body with vibration isolation in the same manner as the engine mount. In the case of an automobile having a power unit in which an engine and a transmission are integrated, the transmission mount may be one of a plurality of engine mounts. As for the brackets of these engine mounts and transmission mounts, there is a cast product made of an aluminum alloy while automobile parts are required to be reduced in weight (for example, see Patent Document 2).
[0003]
However, in the case of a conventional lightweight aluminum alloy vehicle mount member, for example, an engine mount, aluminum itself has lower rigidity, particularly toughness, than iron, and therefore requires a rib structure or a padding for reinforcement. Was. These rib structures and build-up reduce not only the design difficulty of the vehicle mount member but also the effect of reducing the weight of the material by that much. In addition, the bracket of the engine mount is required to have a heat radiation property for the heat of the engine.
[0004]
[Patent Document 1]
JP-A-2002-127762 (page 1-10, FIG. 1-2)
[Patent Document 2]
JP 2001-131669 A (page 1-6, FIG. 1)
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle mount member capable of improving rigidity and reducing the weight while maintaining the rigidity. Another object of the present invention is to provide a vehicle mount member having improved heat dissipation.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a vehicle mount member according to a first aspect of the present invention is formed of a metal containing at least one of carbon fiber and fullerene which is spherical shell-like carbon.
[0007]
According to the first aspect of the present invention, the rigidity, particularly the fracture toughness, can be improved by being formed of a metal containing at least one of carbon fiber and fullerene, and a vehicle mount member while maintaining the rigidity. Can be reduced in weight. Further, according to the first aspect of the present invention, the heat radiation of the vehicle mount member can be improved.
[0008]
Here, in the vehicle mount member according to the first aspect of the present invention,
The carbon fibers may be carbon nanofibers having an average diameter of 0.7 to 500 nm and an average length of 0.01 to 1000 μm.
[0009]
With such a configuration, the rigidity, particularly toughness, of the vehicle mount member can be improved. Further, with such a configuration, the heat radiation of the vehicle mount member can be improved.
[0010]
Here, in the vehicle mount member according to the first aspect of the present invention,
The metal can be aluminum or an aluminum alloy.
[0011]
With such a configuration, the rigidity can be improved, and the weight can be reduced while maintaining the rigidity. As a result, it is possible to contribute to reducing the weight of the vehicle body of the vehicle, and it is possible to reduce carbon dioxide by improving the fuel efficiency of the vehicle.
[0012]
Here, in the vehicle mount member according to the first aspect of the present invention,
The metal can be magnesium or a magnesium alloy.
[0013]
With such a configuration, the rigidity can be improved, and the weight can be reduced while maintaining the rigidity. As a result, it is possible to contribute to reducing the weight of the vehicle body of the vehicle, and it is possible to reduce carbon dioxide by improving the fuel efficiency of the vehicle.
[0014]
Here, in the vehicle mount member according to the first aspect of the present invention,
The carbon nanofiber may be subjected to an ion implantation process.
[0015]
By adopting such a configuration, the ion-implanted carbon nanofiber has at least a change in the chemical composition of its surface, and thus the adhesiveness between the metal (aluminum, magnesium, etc.) constituting the bracket and the carbon nanofiber is improved. The wetting property is improved, and the rigidity, particularly toughness, of the vehicle mount member can be further improved. In addition, the dispersibility of the carbon nanofibers in the metal is improved, so that uniform performance can be obtained as a whole.
[0016]
Here, in the vehicle mount member according to the first aspect of the present invention,
The carbon nanofiber may be subjected to a sputter etching process.
[0017]
With such a configuration, the sputter-etched carbon nanofibers have fine irregularities on the surface thereof, so that the metal (aluminum, magnesium, etc.) that constitutes the bracket and the carbon nanofiber have an improved adhesion. The wetting property is improved, and the rigidity, particularly toughness, of the vehicle mount member can be further improved. In addition, the dispersibility of the carbon nanofibers in the metal is improved, so that uniform performance can be obtained as a whole.
[0018]
Here, in the vehicle mount member according to the first aspect of the present invention,
The carbon nanofiber can be plasma-treated.
[0019]
With such a configuration, the carbon nanofibers subjected to the plasma treatment are subjected to surface modification such as formation of fine irregularities on the surface thereof, and thus the metal (aluminum, magnesium, etc.) constituting the vehicle mount member is formed. The adhesion and wettability of carbon nanofibers are improved, and the rigidity, especially toughness, of vehicle mount members can be further improved. Performance.
[0020]
Here, in the vehicle mount member according to the first aspect of the present invention,
The fullerene includes carbon 60 and carbon 70,
The carbon 60 may be contained more than the carbon 70.
[0021]
With such a configuration, in the process of synthesizing fullerene, carbon 60 synthesized more than carbon 70 can be effectively used. In particular, since fullerene has high dispersibility in metal, uniform characteristics can be obtained in the entire vehicle mount member.
[0022]
Here, in the vehicle mount member according to the first aspect of the present invention,
The metal may contain carbon and a carbon compound obtained in a synthesis process of at least one of the carbon nanofiber and the fullerene.
[0023]
With such a configuration, carbon and carbon compounds, which are impurities synthesized, can be effectively used in the process of synthesizing carbon nanofibers and / or fullerenes.
[0024]
Here, the vehicle mount member according to the first aspect of the present invention may be a bracket of an engine mount that connects an engine and a vehicle body.
[0025]
With such a configuration, the rigidity of the bracket of the engine mount, particularly the fracture toughness, can be improved, and the weight can be reduced while maintaining the rigidity. Furthermore, since the heat radiation of the bracket of the engine mount can be improved, the heat of the engine can be efficiently dissipated, and deterioration of the rubber of the damper connected to the bracket can be prevented.
[0026]
Here, the vehicle mount member according to the first aspect of the present invention may be a transmission mount bracket that connects a transmission and a vehicle body.
[0027]
With such a configuration, the rigidity of the bracket of the transmission mount, particularly the fracture toughness, can be improved, and the weight can be reduced while maintaining the rigidity. Furthermore, since the heat radiation of the bracket of the transmission mount can be improved, the heat of the transmission can be efficiently radiated, and the rubber of the damper connected to the bracket is prevented from deteriorating.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0029]
FIG. 1 is a perspective view of a vehicle mount member according to one embodiment of the present invention. FIG. 2 is a schematic configuration diagram of an omnidirectional ion implantation apparatus, and FIG. 3 is a partial cross-sectional view showing another embodiment of the turntable.
[0030]
A vehicle mount member according to an embodiment of the present invention is, for example, as shown in FIG. 1, an engine mount bracket 10 for supporting an engine, which is fixed to a vehicle engine (not shown) via a bolt. Attachment holes 20 are formed at a plurality of locations. Further, the bracket 10 has a damper mounting hole 30 for connecting to a damper (not shown) made of a vibration isolating rubber or the like mounted on the vehicle body. Although the bracket 10 of the engine mount is directly connected to the engine, vibrations and the like generated by an increase or decrease in the number of revolutions of the engine are damped by the damper to reduce the influence on the vehicle body. In the present embodiment, the bracket 10 is made of aluminum for ease of manufacture and the like. It can be appropriately selected from among them.
[0031]
The method for forming the bracket 10 of the present invention is not particularly limited, but it can be manufactured by forging, casting, powder metallurgy, metal injection molding (MIM), or the like. In the present embodiment, manufactured by gravity casting, first, at least one of carbon nanofiber and fullerene is mixed into a metal melt (aluminum melt), and the metal melt (aluminum melt) is placed in a cavity formed by a mold. Fill and press. After the molten metal is solidified, the bracket 10 is taken out of the cavity and subjected to a desired cutting process to obtain a bracket 10 as a final product.
[0032]
The bracket 10 preferably contains 0.01 to 50% by weight of carbon fiber and fullerene in total. If the proportion of carbon fiber and fullerene exceeds 50% by weight, moldability is not preferred. If it is less than 0.01% by weight, toughness may not be sufficiently improved. When the carbon fiber and the fullerene are each independently contained, the above weight ratio is the weight percentage of the carbon fiber and the fullerene alone.
[0033]
Further, it is preferable to use carbon nanofibers having an average diameter of 0.7 nm to 500 nm and an average length of 0.01 to 1000 μm as the carbon fibers to be mixed with the metal such as aluminum. The amount of the carbon nanofibers contained in the metal of the bracket 10, for example, aluminum is in the range of 0.01 to 50% by weight from the viewpoints of fluidity during molding, rigidity of the obtained bracket, particularly toughness, and the like. Is preferred. Such a carbon nanofiber is a so-called carbon nanotube having a single-layer structure in which a graphene sheet having a carbon hexagonal mesh surface is closed in a cylindrical shape or a multilayer structure in which these cylindrical structures are nested. The carbon nanotube may be composed of only a single-layer structure or only a multi-layer structure, and may be a mixture of a single-layer structure and a multi-layer structure. Further, a carbon material partially having a carbon nanotube structure can also be used. In addition, it may be called by a name such as graphite fibril nanotube other than the name carbon nanotube.
[0034]
The single-walled carbon nanotube or the multi-walled carbon nanotube is manufactured to a desired size by an arc discharge method, a laser ablation method, a vapor phase growth method, or the like.
[0035]
The arc discharge method is to obtain multi-walled carbon nanotubes deposited on a cathode by performing arc discharge between electrode materials made of carbon rods in an atmosphere of argon or hydrogen at a pressure slightly lower than atmospheric pressure. Further, the single-walled carbon nanotube is obtained by mixing a catalyst such as nickel / cobalt into the carbon rod, performing arc discharge, and soot adhering to the inner surface of the processing container.
[0036]
In the laser ablation method, a carbon surface mixed with a catalyst such as nickel / cobalt as a target is irradiated with a strong pulsed laser beam of a YAG laser in a rare gas (eg, argon) to melt and evaporate the carbon surface. This is to obtain a single-walled carbon nanotube.
[0037]
The vapor phase growth method is a method in which hydrocarbons such as benzene and toluene are thermally decomposed in a gas phase to synthesize carbon nanotubes, and examples thereof include a fluidized catalyst method and a zeolite supported catalyst method.
[0038]
Before the carbon nanofiber is mixed with a metal such as aluminum, a surface treatment such as an ion implantation treatment, a sputter etching treatment, and a plasma treatment can be performed in advance to improve the adhesiveness and wettability with aluminum.
[0039]
(Ion implantation processing)
Ion implantation is a process in which necessary energy is given to an element ionized by an ion source, such as oxygen, by an accelerator, and ions are implanted in the surface of a carbon nanofiber in a vacuum chamber maintained in a high vacuum state by a vacuum pump. It is something to drive.
[0040]
The ion implantation processing according to one embodiment of the present invention will be described with reference to the schematic configuration diagram of the omnidirectional ion implantation apparatus shown in FIG. In the omnidirectional ion implantation apparatus 50, a rotary table 53 for placing a sample (for example, carbon nanofiber 52) to be subjected to an ion implantation process is rotatably arranged in a vacuum chamber 51 made of, for example, stainless steel connected to a vacuum pump 57. I have. The turntable 53 is connected to a pulse bias power supply 54, and is insulated from the vacuum chamber 51 by an insulator 55. The vacuum chamber 51 is connected to a process gas supply device 58, a coil 60 connected to a high frequency power supply 59, an arc evaporation source 61, and an infrared radiation thermometer 62 for measuring the temperature inside the vacuum chamber 51.
[0041]
In the ion implantation process, a gas is supplied from a process gas supply device 58 into a vacuum chamber 51 which is brought into an appropriate vacuum state by a vacuum pump 57, and a plasma is generated around a coil 60 by a high frequency power supply 59. The gas ionized thereby is drawn into a sample, for example, the carbon nanofiber 52 connected to the negative electrode of the pulse bias power supply 54 and injected. Further, metal ions can be injected into the sample, for example, the carbon nanofibers 52 by the arc evaporation source 61 connected to the vacuum chamber 51. In this case, the metal evaporation source in the arc evaporation source 61 is connected to a DC arc power supply (not shown), and is evaporated by arc discharge. At this time, since the rotating table 53 and the sample, for example, the carbon nanofibers 52 are applied by the negative DC bias power source 56 switched by the switch 63, the metal ions are injected into the sample, for example, the carbon nanofibers 52.
[0042]
Further, the rotary table 53 of the omnidirectional ion implanter 50 may have a structure having a stirring blade 53a and a container 53b as shown in FIG. The container 53b has a wide opening at the top, and a sample such as the carbon nanofiber 52 can be arranged in the container 53b. During the ion implantation process, the powder sample such as the carbon nanofibers 52 can be uniformly and entirely subjected to the ion implantation process by being stirred by the rotation of the stirring blades 53a. The rotation speed of the stirring blade 53a can be appropriately adjusted depending on the amount of the carbon nanofibers 52, the ion implantation processing time, and the like.
[0043]
The surface of the ion-implanted carbon nanofiber is chemically modified, so that the bracket 10 has improved wettability and adhesion to a metal such as aluminum, and the bracket 10 has improved rigidity, particularly fracture toughness. .
[0044]
Elements used for the ion implantation treatment include, for example, oxygen (O), nitrogen (N), chlorine (Cl), chromium (Cr), carbon (C), boron (B), titanium (Ti), and molybdenum (Mo). , Phosphorus (P), aluminum (Al), etc., can be appropriately selected depending on the compatibility with the metal of the bracket 10, for example, aluminum.
[0045]
(Sputter etching treatment)
In the dry etching sputter etching process, glow discharge is performed by applying an alternating current in an etching gas or an ultra-low pressure inert gas atmosphere such as argon (Ar) in a vacuum chamber maintained in a high vacuum state by a vacuum pump. In addition, etching is performed by colliding ions with the surface of the carbon nanofiber in contact with the electrode exposed in the plasma generated by the glow discharge.
[0046]
The surface of the carbon nanofiber that has been subjected to the sputter etching treatment is physically etched to form fine (nano-sized) irregularities. The irregularities on the surface of the carbon nanofibers increase the contact area of the bracket 10 with the metal, for example, aluminum, and can improve the adhesive strength between aluminum and the carbon nanofibers. The rigidity, especially the fracture toughness, of the bracket 10 manufactured by mixing carbon nanofibers in aluminum can be improved. In addition, the bracket 10 manufactured by mixing carbon nanofibers into aluminum as described above has improved heat dissipation and efficiently radiates heat from the engine, thereby reducing the influence of heat on the damper and the vehicle body. be able to.
[0047]
(Plasma treatment)
The plasma treatment modifies the surface by irradiating the carbon nanofibers with plasma. As the plasma processing, general glow discharge processing, corona discharge processing, or the like can be employed.
[0048]
For example, a plasma applies a high-voltage / high-frequency pulse voltage generated by a pulse generation circuit between a discharge electrode and a counter electrode facing each other, causing a corona discharge between the two electrodes and causing a plasma in the air. Is caused to occur. The object to be processed is arranged in a stationary state or a moving state between the two electrodes, and its surface is subjected to plasma processing.
[0049]
The method of plasma generation is a bipolar discharge type in which a voltage of several hundred to several thousand volts is applied to two parallel flat electrodes to discharge them. A large amount of electrons emitted from a hot cathode collide with gas molecules before entering the anode. Thermionic discharge type that generates plasma, magnetron discharge type that discharges in a high vacuum using a magnetic field, electrodeless discharge type that generates plasma by high-frequency electromagnetic induction, ECR that sends microwaves to a resonance chamber with a magnetic field to resonate electrons (Electron Cyclotron Resonance) discharge type and the like can be selected as appropriate.
[0050]
The surface of the carbon nanofibers thus plasma-treated has improved adhesiveness and wettability with the metal of the bracket 10 such as aluminum, and the rigidity, particularly fracture toughness, of the bracket 10 manufactured by mixing carbon nanofibers into aluminum. Is obtained. In addition, the bracket 10 manufactured by mixing carbon nanofibers into aluminum as described above has improved heat dissipation and efficiently radiates heat from the engine, thereby reducing the influence of heat on the damper and the vehicle body. be able to.
[0051]
The fullerene used in the present embodiment includes spherical shell carbon such as fullerenes such as carbon 60 (hereinafter referred to as C60), C70, C74, C76, C78, C82, C84, C720, and C860. Is preferably a main component. Further, it is preferable to use fullerene containing C60 as a main component and containing C70 in a smaller amount than C60. Further, C60 may be the main component, and may include other fullerenes, or may include other carbon and carbon compounds simultaneously generated when fullerene other than fullerene is generated. The form of the fullerenes may be, for example, a soccer ball shape, a bucky ball shape, or the like.
[0052]
Further, the fullerenes may be modified by introducing a substituent or the like. The modification method is not particularly limited, and for example, a 5-membered carbon ring portion of a fullerene having high reactivity can be chemically modified. The type of the substituent is not particularly limited, and examples thereof include an alkyl group, an aryl group, an aralkyl group, a dioxolane unit, a halogen or an oxygen atom, and the like, and the modification may be performed by introducing a liquid crystal polymer, a dye, polyethylene oxide, or the like. Good. Modification of fullerenes allows for improved affinity with selected metals, such as aluminum, and dispersion of fullerenes.
[0053]
C60 fullerene was subjected to arc discharge in a helium atmosphere using a graphite electrode, the resulting soot was extracted with benzene, and the resulting C60 mixture was purified by column separation using basic activated alumina as a carrier and hexane as a developing solvent. Prepared. The method for obtaining fullerene is not limited to the arc discharge method, but may be another method.
[0054]
As described above, the rigidity, particularly the fracture toughness, of the bracket 10 manufactured by mixing fullerene into the metal of the bracket 10, such as aluminum, can be improved.
[0055]
It should be noted that the present invention is not limited to the present embodiment, and can be modified into various forms within the scope of the present invention.
[0056]
For example, a composite material in which magnesium or a magnesium alloy is mixed with aluminum or an aluminum alloy constituting the bracket 10 by several percent may be mixed with another metal, for example, a metal mainly containing aluminum or magnesium. .
[0057]
In the above embodiment, the bracket 10 for the engine mount has been described. However, the bracket 10 may be a bracket for a transmission. In a motor vehicle using a power unit in which an engine and a transmission are integrated, an engine mount bracket that supports the power unit may be used.
[Brief description of the drawings]
FIG. 1 is a perspective view of a vehicle mount member according to an embodiment of the present invention.
FIG. 2 is a schematic explanatory view of an omnidirectional ion implantation apparatus used in one embodiment of the present invention.
FIG. 3 is a partial sectional view showing another embodiment of the turntable of the omnidirectional ion implantation apparatus.
[Explanation of symbols]
Reference Signs List 10 bracket 20 mounting hole 30 damper mounting hole 50 omnidirectional ion implanter 53 rotating table 53a stirring blade 53b container

Claims (11)

In a vehicle mounting member,
A vehicle mount member formed of a metal containing at least one of carbon fiber and fullerene that is spherical shell carbon. The vehicle mounting member according to claim 1,
The vehicle mount member, wherein the carbon fiber is a carbon nanofiber having an average diameter of 0.7 to 500 nm and an average length of 0.01 to 1000 μm. The vehicle mount member according to claim 1 or 2,
The vehicle mounting member, wherein the metal is aluminum or an aluminum alloy. The vehicle mount member according to claim 1 or 2,
The vehicle mounting member, wherein the metal is magnesium or a magnesium alloy. In any of the vehicle mounting members according to claims 2 to 4,
The vehicle mount member, wherein the carbon nanofiber is subjected to an ion implantation process. In any of the vehicle mounting members according to claims 2 to 4,
The vehicle mount member, wherein the carbon nanofiber is subjected to a sputter etching process. In any of the vehicle mounting members according to claims 2 to 4,
A vehicle mount member, wherein the carbon nanofiber is plasma-treated. The vehicle mounting member according to any one of claims 1 to 7,
The fullerene includes carbon 60 and carbon 70,
A mount member for a vehicle, wherein the mount member contains more carbon 60 than carbon 70. The vehicle mounting member according to any one of claims 2 to 8,
The vehicle mount member, wherein the metal contains carbon and a carbon compound obtained in a synthesis process of at least one of the carbon nanofiber and the fullerene. In any one of claims 1 to 9,
The vehicle mount member, wherein the vehicle mount member is an engine mount bracket for connecting an engine and a vehicle body. In any one of claims 1 to 9,
The vehicle mount member, wherein the vehicle mount member is a transmission mount bracket that connects a transmission and a vehicle body.

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