JP2004231105A - Cup seal and hydraulic master cylinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cup seal for a hydraulic master cylinder capable of maintaining the slidability of a piston by preventing a cup seal from being caught in by contact with a relief port while the piston is moving, and capable of realizing excellent toughness. <P>SOLUTION: The cup seals 32a, 32b are fitted onto the piston 31 of the hydraulic master cylinder 23. The cup seals 32a, 32b are formed of rubber including at least either carbon fiber or fullerene. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cup seal mounted on a piston of a hydraulic master cylinder, and a hydraulic master cylinder including the cup seal.
[0002]
[Background Art]
A hydraulic brake device for a vehicle includes a hydraulic master cylinder and a hydraulic brake. The hydraulic master cylinder and the hydraulic brake are connected by hydraulic piping.
[0003]
In this hydraulic brake device, the hydraulic pressure generated in the hydraulic master cylinder is supplied to the hydraulic brake by operating a brake lever or a pedal to brake the wheels.
[0004]
The hydraulic master cylinder includes a cylinder hole and a piston movably insertable into the cylinder hole. The cylinder hole and the piston constitute a hydraulic pressure generation chamber. A relief port is provided on the inner peripheral wall of the cylinder hole. The relief port includes an opening, and communicates the working fluid storage chamber with the cylinder via the opening.
[0005]
Further, a cup seal is mounted on the piston (for example, see Patent Document 1). The cup seal is configured such that, as the piston moves toward the hydraulic pressure generating chamber, the cup seal passes through the opening, and the hydraulic pressure generating chamber and the hydraulic fluid pass through the opening. The communication with the liquid storage chamber is cut off, and a hydraulic pressure is generated in the hydraulic pressure generating chamber. Therefore, the cup seal is required to have sufficient toughness to withstand erosion of the seal when passing through the relief port and pressure of the hydraulic fluid in the hydraulic pressure generating chamber.
[0006]
In some cases, the hydraulic master cylinder is applied to a brake system provided with a so-called ABS device (anti-skid control device). The brake system provided with the ABS device includes a pump for pressurizing and returning hydraulic fluid from the hydraulic brake side to the hydraulic master cylinder side.
[0007]
When the ABS device is operated, the piston receives the hydraulic pressure from the pump in a direction to push the piston back in a non-operation direction. At this time, since the cup seal is mounted on the piston, the cup seal receives a large hydraulic pressure. In order to provide durability against the liquid pressure, the cup seal is made of a material mainly composed of a material having a large elastic modulus (for example, rubber). However, generally, a material having a high elastic modulus such as rubber becomes brittle as the elastic modulus increases. Therefore, the cup seal is brittle because it is made of a material having a large elastic modulus. For this reason, when the piston is pushed back and the cup seal contacts the relief port, the cup seal is easily eroded by the relief port. In order to prevent the cup seal from being eroded, the cup seal needs to have sufficient toughness.
[0008]
[Patent Document 1]
JP-A-11-227600
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide a cup seal for a hydraulic master cylinder which can prevent erosion when contacting a relief port during movement of a piston, maintain slidability of the piston, and have excellent toughness. Is to do.
[0010]
Another object of the present invention is to provide a hydraulic master cylinder including the cup seal.
[0011]
[Means for Solving the Problems]
The cup seal of the present invention is a cup seal attached to a piston of a hydraulic master cylinder, and is made of rubber containing at least one of carbon fiber and fullerene.
[0012]
According to the cup seal of the present invention, the elastic modulus of the cup seal is maintained within a predetermined range while maintaining toughness and slidability by being made of a rubber containing at least one of carbon fiber and fullerene. Therefore, it is possible to prevent the cup seal from being eroded when the piston comes into contact with the relief port.
[0013]
In the cup seal of the present invention, the carbon fiber and the fullerene are preferably contained in a total amount of 0.01 to 50% by weight. If the ratio of the carbon fiber and the fullerene exceeds 50% by weight, sufficient elasticity may not be ensured, and if it is less than 0.01% by weight, sufficient toughness may not be ensured. In the case where the carbon fiber and the fullerene are individually contained, the weight is the weight of the carbon fiber and the fullerene alone.
[0014]
In the above-mentioned cup seal of the present invention, the carbon fiber may be made of carbon nanofiber having an average diameter of 0.7 to 500 nm and an average length of 0.01 to 1000 μm.
[0015]
With such a configuration, the carbon fiber has an ultrafine fiber structure called carbon nanofiber, and the toughness of the cup seal can be further improved while maintaining elasticity. In addition, by using ultrafine carbon nanofibers, rubber molding can be facilitated.
[0016]
In the above-mentioned cup seal of the present invention, the carbon nanofibers may be subjected to an ion implantation treatment.
[0017]
By adopting such a configuration, the ion-implanted carbon nanofiber has at least a change in the chemical composition of its surface, thereby improving the adhesiveness and wettability between the rubber and the carbon nanofiber and improving the cup seal. The mechanical strength can be further improved. Further, by chemically modifying the surface of the carbon nanofiber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. This makes it possible to obtain a cup seal having uniform performance throughout.
[0018]
In the cup seal of the present invention, the carbon nanofiber may be subjected to a sputter etching process.
[0019]
With such a configuration, the sputter-etched carbon nanofibers have fine irregularities formed on the surface thereof, so that the contact area of the carbon nanofibers with rubber can be increased. As a result, the adhesiveness and wetting of the rubber to the carbon nanofiber can be improved, so that the mechanical strength of the cup seal can be further improved. Further, by improving the adhesiveness and wetting property of the carbon nanofiber with the rubber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. This makes it possible to obtain a cup seal having uniform performance throughout.
[0020]
In the cup seal of the present invention, the carbon nanofibers may be subjected to a plasma treatment.
[0021]
With such a configuration, the plasma-treated carbon nanofiber has fine irregularities on its surface, so that the contact area of the carbon nanofiber with rubber can be increased. As a result, the adhesiveness and wetting of the rubber to the carbon nanofiber can be improved, so that the mechanical strength of the cup seal can be further improved. Further, by improving the adhesiveness and wetting property of the carbon nanofiber with the rubber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. This makes it possible to obtain a cup seal having uniform performance throughout.
[0022]
In the cup seal of the present invention, the fullerene includes carbon 60 and carbon 70, and may include the carbon 60 more than the carbon 70.
[0023]
With such a configuration, the toughness of the cup seal can be further improved while maintaining the elasticity. Further, rubber molding can be facilitated.
[0024]
The above-described cup seal of the present invention may further include a carbon compound obtained in a synthesis process of any one of the carbon nanofiber and the fullerene.
[0025]
Further, the hydraulic master cylinder of the present invention includes the cup seal of the present invention,
A cylinder bore,
A piston that can be inserted into the cylinder hole,
A hydraulic pressure generation chamber partitioned by the cylinder hole and the piston,
Including
On the inner peripheral wall of the cylinder hole, an opening is provided, and a relief port that connects the hydraulic fluid storage chamber and the cylinder hole is provided,
The cup seal is mounted on the piston,
As the piston moves toward the hydraulic pressure generation chamber side, the cup seal passes through the opening, whereby the hydraulic pressure generation chamber and the hydraulic fluid storage chamber through the opening are connected. Cut off contact.
[0026]
According to the hydraulic master cylinder of the present invention, the slidability of the piston can be maintained by mounting the cup seal of the present invention on the piston.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0028]
[First Embodiment]
FIG. 1 is a cross-sectional view schematically showing a hydraulic master cylinder 23 including cup seals 32a and 32b according to the first embodiment of the present invention. The hydraulic master cylinder 23 forms a part of a hydraulic brake device 21 for a two-wheeled vehicle. The hydraulic brake device 21 includes a hydraulic master cylinder 23 and a hydraulic brake (not shown). FIG. 1 shows only the hydraulic master cylinder 23 of the hydraulic brake device 21.
[0029]
As shown in FIG. 1, a brake lever 22 is attached to the hydraulic master cylinder 23. Further, the hydraulic master cylinder 23 and the hydraulic brake are connected by a hydraulic pipe 25 (illustrated by using arrows).
[0030]
In the hydraulic brake device 21, the hydraulic pressure generated in the hydraulic master cylinder 23 by the brake operation by gripping the brake lever 22 is supplied to a hydraulic brake (not shown) via a hydraulic pipe 25. By doing so, the wheels are braked.
[0031]
In this hydraulic master cylinder 23, the inside of the cylinder body 26 is partitioned into a cylinder hole 27 and a hydraulic fluid storage chamber 28 by a partition wall 26a.
[0032]
The hydraulic master cylinder 23 includes a cylinder hole 27 and a piston 31. The piston 31 is movably insertable into the cylinder hole 27. The cylinder hole 27 and the piston 31 constitute a hydraulic pressure generation chamber 33. That is, the hydraulic pressure generation chamber 33 is an area defined by the cylinder hole 27 and the piston 31.
[0033]
The hydraulic pressure generation chamber 33 is in communication with the hydraulic liquid storage chamber 78 via the relief port 29 when the master cylinder 23 is not operating (see FIG. 1). That is, the relief port 29 includes the opening 29a, and connects the hydraulic fluid storage chamber 28 and the cylinder hole 27 via the opening 29a when the master cylinder 23 is not operating. The opening 29 a is provided on the inner peripheral wall of the cylinder hole 27.
[0034]
The working fluid stored in the working fluid storage chamber 28 is directly supplied to the cylinder hole 27 through the relief port 29 and the supply port 30.
[0035]
In the hydraulic master cylinder 23 of the present embodiment, when a brake operation is performed by gripping the brake lever 22, the piston 31 moves in the direction of the output port 47 (to the left in FIG. 1), so that the cylinder hole is opened. The outer peripheral portion of the cup seal 32 a slidingly contacting the inner peripheral wall of the 26 passes through the opening 29 a of the relief port 29. Thus, the communication of the liquid between the hydraulic pressure generation chamber 33 and the hydraulic liquid storage chamber 28 through the opening 29a is shut off. Then, when the piston 31 further moves, a hydraulic pressure is generated in the hydraulic pressure generation chamber 33. The hydraulic pressure generated here is supplied to a hydraulic brake via a hydraulic pipe 25.
[0036]
The cup seals 32a and 32b are mounted on the piston 31. Specifically, the cup seal 32a is provided on the side of the piston 31 facing the hydraulic pressure generation chamber 33, and the cup seal 32b is provided on the opposite side of the piston 31 from the cup seal 32a. The material of the cup seals 32a and 32b will be described later.
[0037]
In the present embodiment, the hydraulic master cylinder 23 can be applied to a brake system provided with a so-called ABS device (not shown). The brake system provided with the ABS device includes a pump (not shown) for pressurizing and returning the hydraulic fluid from the hydraulic brake side to the hydraulic master cylinder 23 side.
[0038]
Next, the material of the cup seals 32a and 32b will be described.
[0039]
The cup seals 32a and 32b are made of rubber containing at least one of carbon fiber and fullerene. Specifically, the cup seals 32a and 32b can provide the following effects (a) and (b).
[0040]
(A) When this brake system is operated, when the piston 31 is inserted into the cylinder hole 27 and the cup seals 32a and 32b pass through the opening 29, the cup seals 32a and 32b are locally May be pushed inside. In this case, since the cup seals 32a and 32b of the present embodiment are made of rubber containing at least one of carbon fiber and fullerene, the elasticity of the cup seals 32a and 32b is maintained at a predetermined value while maintaining toughness and slidability. Can be maintained within the range. Thereby, the cup seals 32a and 32b can sufficiently withstand the pressure of the hydraulic fluid in the hydraulic pressure generation chamber 30. Therefore, even when the cup seals 32a, 32b are locally pushed into the relief port 29, the cup seals 32a, 32b are not eroded.
[0041]
(B) As described above, when the hydraulic master cylinder 23 is applied to a brake system including an ABS device, the hydraulic fluid is pressurized and returned from the hydraulic brake side to the hydraulic master cylinder 23 side. Pumps are installed. When the ABS device is operated, a very high hydraulic pressure may be applied to the cup seals 32a and 32b due to the pressure from the pump. Also in this case, since the cup seals 32a and 32b of the present embodiment are made of the above-mentioned materials, they can sufficiently withstand the pressure from the pump. Therefore, even when the cup seals 32a and 32b are locally pushed into the relief port 29 by the pressure from the pump, the cup seals 32a and 32b are not eroded.
[0042]
Examples of the rubber constituting the cup seals 32a and 32b include styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPR), and ethylene-propylene-diene-methylene linkage (EPDM). ), Natural rubber (NR), butadiene rubber (BR), chloroprene rubber (CR), silicone rubber, fluorine rubber, and blends thereof.
[0043]
The cup seals 32a and 32b preferably contain 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, sufficient elasticity may not be ensured, and if less than 0.01% by weight, sufficient toughness may not be ensured. In the case where the carbon fiber and the fullerene are contained alone, the weight is the weight of the carbon fiber and the fullerene alone. The cup seals 32a and 32b can further contain a carbon compound obtained in the process of synthesizing one of carbon fiber and carbon nanofiber.
[0044]
(Carbon fiber)
When forming cup seals 32a and 32b in which rubber is mixed with carbon fiber, mixing of the rubber and carbon fiber is performed by mixing the mixture of raw materials with a single-screw or twin-screw extruder, Banbury mixer, kneader, and mixing. A method of kneading by supplying the mixture to a commonly known mixer such as a roll can be exemplified. The mixing order of the rubber and the carbon fiber is such that all the materials are blended and then kneaded by the above-mentioned method, a part of the carbon fiber is blended and then kneaded by the above-mentioned method, and the remaining carbon fiber is blended and kneaded. A method such as a method of mixing carbon fibers using a side feeder while kneading rubber with a single-screw or twin-screw extruder can be used.
[0045]
As the carbon fibers to be mixed into the rubber, pitch-based carbon fibers made from pitch, which is a residue at the time of petroleum refining, and polyacrylonitrile (PAN) -based carbon fibers made from polyacryl fibers can be used.
[0046]
It is preferable to use carbon nanofibers having an average diameter of 0.7 to 500 nm and an average length of 0.01 to 1000 μm as the carbon fibers to be mixed into the rubber. The amount of the carbon nanofiber is 0.01 to 50% by weight in the rubber that is the main component of the cup seals 32a and 32b, from the viewpoint of fluidity during molding, specific gravity and strength of the molded article, and elasticity. Is preferably included in the range. Examples of such carbon nanofibers include, for example, so-called carbon nanotubes. The carbon nanotube has a single-layer structure in which a graphene sheet of carbon hexagonal mesh is closed in a cylindrical shape or a multilayer structure in which these cylindrical structures are nested. That is, the carbon nanotube may be composed of only a single-layer structure or a multilayer structure alone, and may have a mixture of a single-layer structure and a multilayer 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.
[0047]
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.
[0048]
The arc discharge method is a method of obtaining multi-walled carbon nanotubes deposited on a cathode by performing arc discharge between electrode materials made of carbon rods in an argon or hydrogen atmosphere at a pressure slightly lower than the 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.
[0049]
In the laser ablation method, a strong pulsed laser beam of a YAG laser is applied to a carbon surface mixed with a catalyst such as nickel / cobalt in a rare gas (eg, argon) to melt and evaporate the carbon surface. And obtaining single-walled carbon nanotubes.
[0050]
The vapor phase growth method synthesizes carbon nanotubes by thermally decomposing hydrocarbons such as benzene and toluene in the gas phase, and more specifically, a fluidized catalyst method and a zeolite-supported catalyst method can be exemplified.
[0051]
In forming the cup seals 32a and 32b, the carbon nanofibers are subjected to a surface treatment, for example, an ion implantation treatment, a sputter etching treatment, a plasma treatment or the like before kneading with the rubber, so that the main components of the cup seals 32a and 32b can be formed. Adhesion and wettability with rubber as a component can be improved.
[0052]
(Ion implantation processing)
In ion implantation, an element (eg, oxygen) ionized by an ion source is supplied with necessary energy by an accelerator, and a surface of the carbon nanofiber is placed in a vacuum chamber maintained in a high vacuum state by a vacuum pump. Ions are implanted inside.
[0053]
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.
[0054]
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.
[0055]
Further, the rotary table 53 of the omnidirectional ion implanter 50 may be 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.
[0056]
The surface of the ion-implanted carbon nanofiber is chemically modified, and the adhesiveness and wettability between the rubber and the carbon nanofiber, which are the main components of the cup seals 32a and 32b, are improved. 32b can be further improved in toughness. Further, by chemically modifying the surface of the carbon nanofiber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. As a result, the cup seals 32a and 32b having uniform performance throughout can be obtained.
[0057]
The element used for the ion implantation can be appropriately selected depending on the compatibility with the rubber which is the main component of the cup seals 32a and 32b. For example, oxygen (O), nitrogen (N), chlorine (Cl), chromium ( Cr), carbon (C), boron (B), titanium (Ti), molybdenum (Mo), phosphorus (P), aluminum (Al) and the like.
[0058]
(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.
[0059]
The surface of the carbon nanofiber that has been subjected to the sputter etching treatment is physically etched to form fine (nano-sized) irregularities. Due to the irregularities on the surface of the carbon nanofiber, the contact area of the carbon nanofiber with the rubber as the main component of the cup seals 32a and 32b can be increased. As a result, the adhesiveness and wettability of the carbon nanofiber with the rubber can be improved, so that the cup seals 32a and 32b formed by mixing the carbon nanofiber with the rubber (for example, injection molding) can be improved. Toughness Can be improved. In addition, by improving the adhesion and wetting properties of the carbon nanofiber to the rubber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. As a result, the cup seals 32a and 32b having uniform performance throughout can be obtained.
[0060]
(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.
[0061]
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.
[0062]
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.
[0063]
Since fine irregularities are formed on the surface of the carbon nanofiber subjected to the plasma treatment in this way, the contact area of the carbon nanofiber with rubber can be increased. As a result, the adhesiveness and wettability of the rubber with the carbon nanofibers can be improved, so that the mechanical strength of the cup seals 32a and 32b can be further improved. Further, by improving the adhesiveness and wetting property of the carbon nanofiber with the rubber, the carbon nanofiber is easily impregnated into the rubber, and the dispersibility of the carbon nanofiber in the rubber is improved. As a result, the cup seals 32a and 32b having uniform performance throughout can be obtained.
[0064]
(Fullerene)
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, C78, C82, C720, and C860. It is preferable that Further, it is preferable that C60 is contained as a main component and C70 is contained more than C60. Furthermore, C60 may be the main component, and may contain other fullerenes, or may contain other carbon compounds produced simultaneously with the production of fullerenes. The form of the fullerenes may be, for example, a soccer ball shape, a bucky ball shape, or the like. Fullerene can be mixed with rubber in the same manner as in the case of carbon fiber.
[0065]
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, which may be modified by introducing a liquid crystal polymer, a dye, polyethylene oxide, or the like. . Modification of fullerenes makes it possible to improve affinity with the curable resin and disperse fullerenes.
[0066]
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 subjected to column separation using basic activated alumina as a carrier and hexane as a developing solvent. It was adjusted by purification. The method of obtaining fullerene is not limited to the arc discharge method, and other methods can be used.
[0067]
[Second embodiment]
FIG. 2 is a sectional view schematically showing a hydraulic master cylinder 73 including cup seals 82a, 82b, 92a, 92b according to a second embodiment of the present invention. The hydraulic master cylinder 73 is a brake device for a four-wheeled vehicle, and forms a part of the hydraulic brake device 71. The hydraulic brake device 71 includes a hydraulic master cylinder 73 and a hydraulic brake (not shown). FIG. 2 shows only the hydraulic master cylinder 73 of the hydraulic brake device 71.
[0068]
As shown in FIG. 2, a brake pedal (not shown) is attached to the hydraulic master cylinder 73. The hydraulic master cylinder 73 and the hydraulic brake are connected by a hydraulic pipe 75 (illustrated by using arrows).
[0069]
In the hydraulic brake device 71, the hydraulic pressure generated in the hydraulic master cylinder 73 by the brake operation by depressing the brake pedal is supplied to a hydraulic brake (not shown) via a hydraulic pipe 75. Thus, the wheels are braked.
[0070]
In the hydraulic master cylinder 73, the inside of the cylinder body 76 is partitioned into a cylinder hole 77 and a hydraulic fluid storage chamber 78 by a partition wall 76a.
[0071]
The hydraulic master cylinder 73 includes a cylinder hole 77. The pistons 81 and 91 can be movably inserted into the cylinder holes 77.
[0072]
The hydraulic pressure generating chamber 83 is an area defined by the cylinder hole 77 and the piston 81, and the hydraulic pressure generating chamber 93 is an area defined by the cylinder hole 77 and the pistons 81 and 91. The hydraulic pressure is supplied from each of the hydraulic pressure generating chambers 83 and 93 to the hydraulic brake.
[0073]
Each of the hydraulic pressure generating chambers 83 and 93 is in communication with the hydraulic fluid storage chamber 78 via the relief ports 79 and 89 when the master cylinder 73 is not operating (see FIG. 2). That is, the relief port 79 includes the opening 79a, and connects the hydraulic fluid storage chamber 78 and the cylinder hole 77 via the opening 79a when the master cylinder 73 is not operating. The relief port 89 includes an opening 89a, and connects the working fluid storage chamber 78 and the cylinder hole 77 via the opening 89a when the master cylinder 73 is not operating. The openings 79a and 89a are provided on the inner peripheral wall of the cylinder hole 77.
[0074]
The working fluid stored in the working fluid storage chamber 78 is directly supplied to the cylinder hole 77 through the relief ports 79 and 89 and the supply ports 80 and 90.
[0075]
Annular cup seals 82a and 82b and cup seals 92a and 92b are mounted on the outer peripheral portions of the pistons 81 and 91, respectively.
[0076]
The cup seals 82a and 82b are mounted on the piston 81. That is, as shown in FIG. 2, the cup seal 82a is provided on the side of the piston 81 facing the hydraulic pressure generation chamber 83, and the cup seal 82b is provided on the opposite side of the piston 81 from the cup seal 82a. Have been.
[0077]
Further, the cup seals 92 a and 92 b are mounted on the piston 91. That is, as shown in FIG. 2, the cup seal 92a is provided on the side of the piston 91 facing the hydraulic pressure generation chamber 93, and the cup seal 92b is provided on the opposite side of the piston 91 from the cup seal 92a. Have been.
[0078]
In the hydraulic master cylinder 73 of the present embodiment, when the brake operation is performed by depressing the brake pedal, both the pistons 81 and 91 move in the direction of the side wall 76b (to the left in FIG. 2). The outer peripheral portions of the cup seals 82a and 92a slidingly contacting the inner peripheral wall of the cylinder hole 77 pass through the openings 79a and 89a of the relief ports 79 and 89, respectively. Thereby, the communication of the fluid between the hydraulic pressure generation chambers 83 and 93 and the hydraulic fluid storage chamber 78 via the openings 79a and 89a is cut off. When the pistons 81 and 91 further move, a hydraulic pressure is generated in the hydraulic pressure generating chambers 83 and 93. The hydraulic pressure generated here is supplied to a hydraulic brake via a hydraulic pipe 75.
[0079]
Further, springs 88 and 98 are provided in the respective hydraulic pressure generating chambers 83 and 93, respectively. When the depression operation of the brake pedal is released or weakened, the pistons 81, 91 move to return to the installation position shown in FIG. Then, with the return operation of the pistons 81, 91, the hydraulic pressure in the hydraulic pressure generation chambers 83, 93 temporarily becomes lower than the pressure of the hydraulic fluid in the hydraulic fluid storage chamber 78. As a result, the outer peripheral portions of the cup seals 82a and 92a move away from the inner peripheral wall of the cylinder hole 77, and the supply ports 80 and 90 are always in communication with the hydraulic fluid storage chamber 78 through the openings 79a and 89a. The hydraulic fluid is supplied to the hydraulic pressure generating chambers 83 and 93 from the hydraulic pump.
[0080]
Like the hydraulic master cylinder 23 of the first embodiment, the hydraulic master cylinder 73 of the present embodiment can be applied to a brake system provided with an ABS device (not shown). In this case, the hydraulic master cylinder 73 of the present embodiment performs the same operation as when the hydraulic master cylinder 23 of the first embodiment is provided in a brake system including an ABS device, and performs the same operation. The effect of the present invention can be obtained. That is, in this case, in order to prevent the wheels from being locked, when the ABS device is operated, the hydraulic fluid is released from the wheel cylinder by the pump included in the ABS device after being released from the wheel cylinder and pressurized. It is returned to the hydraulic pressure generating chambers 83, 93.
[0081]
In the present embodiment, the cup seals 82a, 82b, 92a, 92b can be made of the same material as the cup seals 32a, 32b of the first embodiment. Therefore, detailed description is omitted.
[0082]
According to the cup seals 82a, 82b, 92a, and 92b of the present embodiment, the same effects as those of the cup seals 32a and 32b of the first embodiment can be obtained. That is, according to the cup seals 82a, 82b, 92a, and 92b of the present embodiment, the elasticity of the cup seal is maintained while maintaining toughness and slidability by being made of rubber containing at least one of carbon fiber and fullerene. Since the ratio can be maintained within a predetermined range, it is possible to prevent the cup seal from being eroded when coming into contact with the relief port when the piston moves.
[0083]
It should be noted that the present invention is not limited to the above embodiment, and can be modified into various forms within the scope of the present invention.
[Brief description of the drawings]
FIG. 1 is a sectional view schematically showing a hydraulic master cylinder including a cup seal according to a first embodiment of the present invention.
FIG. 2 is a sectional view schematically showing a hydraulic master cylinder including a cup seal according to a second embodiment of the present invention.
FIG. 3 is a schematic explanatory view of an omnidirectional ion implantation apparatus used in one embodiment of the present invention.
FIG. 4 is a partial sectional view showing another embodiment of the rotary table of the omnidirectional ion implantation apparatus.
[Explanation of symbols]
21,71 Hydraulic brake device
22 Brake lever
23, 73 Hydraulic master cylinder
25,75 hydraulic piping
26,76 Cylinder body
26a, 76a Partition wall
26b, 76b Bottom wall
27, 77 Cylinder hole
28,78 Hydraulic fluid storage chamber
29, 79, 89 relief port
29a, 79a, 89a Opening
30,80,90 supply port
31, 81, 91 piston
32a, 32b, 82a, 82b, 92a, 92b Cup seal
33, 83, 93 Hydraulic pressure generation chamber
47 output port
50 Omnidirectional ion implanter
53 turntable
53a stirring blade
53b container
88,98 spring

Claims (9)

A cup seal attached to a piston of a hydraulic master cylinder,
A cup seal made of rubber containing at least one of carbon fiber and fullerene. In claim 1,
A cup seal containing 0.01 to 50% by weight of the carbon fiber and the fullerene in total. In claim 1 or 2,
The cup seal, wherein the carbon fibers are carbon nanofibers having an average diameter of 0.7 to 500 nm and an average length of 0.01 to 1000 μm. In claim 3,
A cup seal, wherein the carbon nanofiber is subjected to an ion implantation process. In claim 3,
A cup seal, wherein the carbon nanofiber is sputter-etched. In claim 3,
A cup seal, wherein the carbon nanofiber is plasma-treated. The cup seal according to any one of claims 1 to 6,
The fullerene includes carbon 60 and carbon 70,
A cup seal containing more of the carbon 60 than the carbon 70. In claims 1 to 6,
Further, a cup seal containing a carbon compound obtained in a process of synthesizing one of the carbon nanofiber and the fullerene. A cup seal according to any one of claims 1 to 8,
A cylinder bore,
A piston that can be inserted into the cylinder hole,
A hydraulic pressure generation chamber partitioned by the cylinder hole and the piston,
Including
On the inner peripheral wall of the cylinder hole, an opening is provided, and a relief port that connects the hydraulic fluid storage chamber and the cylinder hole is provided,
The cup seal is mounted on the piston,
As the piston moves toward the hydraulic pressure generation chamber side, the cup seal passes through the opening, whereby the hydraulic pressure generation chamber and the hydraulic fluid storage chamber through the opening are connected. A hydraulic master cylinder that cuts off communication.

Images