JPH031181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pedal in a motor vehicle. Accelerator pedals, clutch pedals, brake pedals, etc. installed in automobiles are used under harsh conditions, and are required to have enough durability and shock resistance to withstand frequent repeated depressions and sudden strong depressions. ing. Conventionally, therefore, pedals in automobiles are generally made of metal. However, metal pedals are heavy and have a large number of parts, making it difficult to manage each part and requiring welding at multiple locations, making them less suitable for mass production. In recent years, automobile bodies have been required to be made lighter in order to improve fuel efficiency, and from this point of view, there has also been a demand for lighter weight pedals. In view of the above-mentioned points, the present invention aims to provide a pedal that is lightweight and has high durability and impact resistance. That is, the present invention is a polyamide composition comprising polyamide, glass fiber, ethylene-propylene copolymer rubber, and ionomer resin, wherein the amount of glass fiber in the composition is 15 to 40% (wt%,
The same applies below), the amount of ethylene-propylene copolymer rubber is 2 to 10%, and the amount of ionomer resin is 5 to 20%.
% of a polyamide composition for automobiles. BACKGROUND ART So-called glass fiber-reinforced thermoplastic resins, which are made by blending glass fibers with thermoplastic resins such as polyamide, have been known. However, although glass fiber reinforced polyamide has sufficient strength, it has poor impact resistance, so it cannot be used as a material for automobile pedals. A possible method for improving the impact resistance of glass fiber reinforced polyamide is to incorporate a plasticizer or a rubber substance. However, when a plasticizer is blended, the plasticizer tends to bleed, and when a normal rubber substance such as styrene-butadiene rubber is blended, phase separation between the polyamide and the rubber substance tends to occur, resulting in the desired physical properties. In either case, there is little practical application. However, in the present invention, a specific rubber material called ethylene-propylene copolymer rubber and an ionomer resin are blended into glass fiber reinforced polyamide, and the proportions of the ethylene-propylene copolymer rubber, ionomer resin and glass fiber are adjusted respectively. 2-10%, 5-10% of the total amount
By specifying 20% and 15 to 40%, the impact resistance can be greatly improved without impairing other physical properties of glass fiber reinforced polyamide, and it is suitable as a molding resin material for pedals in automobiles. was discovered. The polyamides used in the present invention are aliphatic polyamides and aromatic polyamides having plastic moldability, and aliphatic polyamides are particularly preferred. As the aliphatic polyamide, nylon-6,
Examples include nylon-6,6, nylon-6,10, nylon-6,12, nylon-7, nylon-11, and nylon-12. Examples of aromatic polyamides include polyhexamethylene diamine terephthalamide and polyhexamethylene diamine isophthalamide. These polyamides can be used alone or as a mixture of two or more, and can also be used as a copolymer. The glass fibers used in the present invention include glass rovings, chopped strands, milled fibers, etc. which are commonly used in reinforced thermoplastic resins. Ethylene-propylene copolymer rubber is a rubbery copolymer consisting of ethylene and propylene monomer units. Furthermore, the ionomer resin has a structure in which some of the functional groups of the resin are crosslinked with metal cations. In the polyamide composition of the present invention,
It is necessary that the amount of glass fiber in the composition is 15-40%, the amount of ethylene-propylene copolymer rubber is 2-10%, and the amount of ionomer resin is 5-20%. If the amount of glass fiber is less than the above range, the rigidity of the molded product of the polyamide composition will be insufficient, and if it is more than the above range, the moldability of the polyamide composition will decrease and the appearance of the molded product will deteriorate. Also, impact resistance decreases. Ethylene-
If the amount of the propylene copolymer rubber and ionomer resin is less than the above range, the impact resistance will not be improved sufficiently, and if it is more than the above range, the tensile strength and heat distortion temperature will decrease and it cannot be put to practical use. The polyamide composition may optionally contain conventional additives such as stabilizers, plasticizers, pigments, flame retardants, etc. within a range that does not impair the physical properties. To produce a pedal from the polyamide composition, it may be molded by a molding method such as injection molding.
Molding conditions etc. are not particularly limited. Next, an example in which the present invention is applied to an accelerator pedal will be explained based on the drawings. FIG. 1 is a front view showing an embodiment of a polyamide accelerator pedal according to the present invention, and FIG. 2 is a side view thereof. In the drawing, an accelerator pedal 10 includes an arm portion 11, a pedal depression portion 12, and a pin portion 1 that is the center of rocking.
3. It consists of a pedal stopper part 14 and an accelerator cable attachment part 15, which are integrally molded from the polyamide composition. The arm portion 11 is bent in a dogleg shape from approximately the center in the front-rear direction, and is connected at the bottom in order to place the pedal in an optimal position relative to the vehicle body and to provide the driver with an optimal depression position. Part 1
1a in the same direction, and bend the transition part 11b to the pedal depression part 12 and the transition part 11c to the accelerator cable attachment part 15 in the horizontal direction to make the point of force A and the point of action B, respectively, relative to the fulcrum c. It has been offset. The pedal depression part 12 is connected to the lower joint part 1 of the arm part 11.
It is formed on the upper surface side of 1a, has an appropriate width dimension, and is curved in an arc shape, so that it can always be depressed in a constant state even if the depression position is different. Further, a convex portion 16 is formed on the tread surface 12a of the pedal tread portion 12 as necessary. The pin portion 13 is provided to protrude from the side surface of the approximately central portion of the arm portion 11 in a direction perpendicular thereto, and is formed with a diameter that can sufficiently withstand the load during pedal operation. This pin portion 13 is rotatably pivoted to a bracket 17 attached to the vehicle body, and supports the pedal 10 in a swingable manner. Further, a return spring 18 is attached to the pin portion 13, one end of which is locked to the bracket 17, and the other end of which is locked to the arm portion 11 to impart restoring force to the pedal 10. The pedal stop part 14 is provided protruding forward near the upper end of the arm part 11, and a reinforcing rib 19 is formed spanning between the back surface of the pedal stop part 14 and the arm part 11. When the pedal 10 is attached to the vehicle body, this pedal stop portion 14 comes into contact with the front wall (not shown) of the vehicle body to position the pedal 10 when the pedal 10 is not operated. It is formed to a length that corresponds to the stepping height. The accelerator cable attachment part 15 is formed in a bifurcated shape extending upward at the upper end of the arm part 11, and a fitting hole 21 into which the centerpiece 20a of the end of the accelerator cable 20 fits is bored in the bifurcated part 15a. . This accelerator pedal 10 is a pedal depression part 1.
A reinforcing heel portion 22 is integrally formed so as to straddle the back surface of 2 and the lower joint portion 11a of the arm portion 11. This heel portion 22 has a flange 22 in the vertical direction.
The flange a and 22b are cross-shaped, wider than the left and right flanges 22c and 22d, and taper to the front. The coupling portion 11a of the arm portion 11 and the pedal depression portion 12 are formed in orthogonal directions, and have sufficient strength to withstand the loads caused by frequently repeated stepping operations or sudden strong stepping operations. At the same time, when the accelerator pedal 10 is depressed to the full throttle position, the tip of the heel section 22 comes into contact with the front wall of the vehicle body and acts as a stopper, preventing breakage due to the load acting on the pedal depression section 12. This also prevents adverse effects on the pin portion 13, the accelerator cable attachment portion 15, and the throttle valve (not shown). Furthermore, a rib 23 is formed over an appropriate length on the side surface of the arm portion 11 opposite to the pin portion 13, and the amount of deformation is determined by the twisting force that acts on the arm portion 11 from the pin portion 13 when the pedal is depressed. I'm trying to reduce it. The accelerator pedal 10 configured as described above is swingably attached to the vehicle body using a pin portion 13, and is set at an optimal depression position by a pedal stopper 14. Further, the eye 20a of the accelerator cable 20 disposed from the engine side is fitted into the fitting hole 21 and connected to the accelerator cable attaching portion 15. Since the accelerator pedal 10 as described above is formed of a single component made of the polyamide composition, it is lightweight, easy to manage due to a reduction in the number of parts, and can be molded by injection molding etc., making it easy to manufacture. It is. In addition, the joint part between the lower joint part 11a of the arm part 11 and the pedal depression part 12 and the arm part 1 are subjected to a relatively large load when the accelerator pedal 10 is depressed.
A reinforcing heel 22 and ribs 23 are integrally formed in the vicinity of the joint between the pin 1 and the pin 13, which improves the strength of this part and prevents it from being damaged by frequently repeated or rapid depressing operations. It can withstand heavy loads and there is no risk of damage. Furthermore, the heel part 2 for reinforcement
2 acts as a stopper when the pedal is depressed suddenly, and prevents the arm part 11 and the pedal depression part 12 from breaking due to the sudden load, and also prevents the pedal 1 from breaking.
It is highly safe because it prevents excessive depression of the engine and prevents adverse effects on the pin portion 13, accelerator cable attachment portion 15, throttle valve, etc. Further, since the accelerator pedal 10 is entirely made of the polyamide composition and has appropriate elasticity, engine vibrations transmitted via the accelerator cable 20 are absorbed by the accelerator cable attachment part 15 and the arm part 11. and is not transmitted to the pedal depression section 12, improving the pedal feel.
Therefore, there is no need to attach an elastic body such as rubber to the tread surface 12a of the pedal tread portion 12, and the number of parts is also reduced. Although the present invention has been described above as applied to an accelerator pedal, the present invention can also be similarly applied to a clutch pedal or a brake pedal. Next, the polyamide pedal of the present invention will be explained with reference to Examples and Comparative Examples. Examples 1 to 3 and Comparative Examples The polyamide compositions shown in Table 1 were injection molded at a cylinder temperature of 26 to 280°C and a mold temperature of 50 to 60°C to obtain the shapes shown in Figures 1 and 2. I made an accelerator pedal. The impact strength of each accelerator pedal was measured. The results are also listed in Table 1. The impact strength is
Measurements were made on 0.5 x 0.5 x 2.5 inch test pieces according to ASTM D256 Notched Izot Impact Strength Test. 【table】

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the polyamide pedal of the present invention, and FIG. 2 is a side view thereof. Main symbols in the drawing, 10...Accelerator pedal, 1
1...Arm part, 12...Pedal depression part, 13...
Pin part, 14...Pedal stopper part, 15...Accelerator cable attachment part.

Claims (1)

[Claims] 1 A polyamide composition consisting of polyamide, glass fiber, ethylene-propylene copolymer rubber, and ionomer resin, wherein the amount of glass fiber in the composition is 15 to 40% by weight, and the amount of ethylene-propylene copolymer rubber A polyamide pedal for an automobile, characterized in that it is a molded product of a polyamide composition in which the amount of ionomer resin is 2 to 10% by weight and the amount of ionomer resin is 5 to 20% by weight.