Patent Application
20080053267
Various embodiments of the present invention will be described below with reference to the drawings.
A parking brake apparatus 10 pertaining to the present embodiment includes a braking section 11 which receives an operating force at the time of parking, and transmits the operating force to generate a braking force, and a releasing section 21 which cancels the constrained state in which the operating force is held. The knob structure providing the heart of the present invention is the portion that receives the operation releasing force in the releasing section 21.
As shown in
In
The releasing section 21 is made up of a releasing member 22 that is pushably/pullably connected to the pawl; a release cable 23 which is fastened to the nose end side of the releasing member 22; and a knob structure that is connected to the nose end side of the release cable 23, and receives the operation releasing force applied by the driver pulling the knob structure. The knob structure includes a rod 30 that is movably disposed on the vehicle body side, and a knob main body 32 that is connected to the nose end side of the rod 30.
The rod 30 is movably disposed in a guide member 24 that is disposed under the vehicle inner panel, and on the base end side of the rod 30, the nose end side of said release cable 23 is fastened. The rod 30 is made of a metal, for example, an iron mandrel. When the knob main body 32 is pulled, this operation releasing force rocks the pawl through the release cable 23 in the direction in which it is disengaged from the sector gear tooth, canceling the constrained state in which said operating force is held.
As shown in
As shown in
As shown in
The core part 32a is previously assembled to the rod 30 before insert molding of the surface layer part 32b, however, as shown in
Next, the function of the knob structure of the parking brake apparatus 10 pertaining to the present embodiment will be described. In order to manufacture the present knob structure, the rod 30 is assembled to the core part 32a of the knob main body 32 which has been already molded, as shown in
Thereafter, the surface layer part 32b of the knob main body 32 is provided by insert molding around the core part 32a which has been previously assembled to the nose end side of the rod 30. In other words, the core part 32a which has been assembled to the nose end side of the rod 30 is loaded in the mold before injecting the resin for enclosing the core part 32a with molten resin and solidifying it to coat the surface of the core part 32a with the surface layer part 32b with a substantially uniform coating thickness for integration.
As shown in
Yet, the surface layer part 32b can be formed such that the surface of the core part 32a is substantially uniformly coated in correspondence with the design geometry of the core part 32a, whereby a sink mark or a weld mark at the time of resin molding can be prevented from occurring, and thus the appearance quality of the knob main body 32 can be improved. In addition, at the time of manufacturing the knob structure, the insert molding can be performed in a single process, resulting in the manufacturing cost being reduced. Further, the engaged part 31 on the nose end side of the rod 30 is engaged with the engaging part 32a2 of the core part 32a, which can positively prevent the knob main body 32 from being dropped off from the rod 30.
Further, as shown in
Next, the operation of the foot lever 13 will be briefly described.
In
In order to cancel the constrained state, pulling the knob structure in the releasing section 21 forward by gripping the hand grip part 35 of the knob main body 32 with the finger ends being aligned will move the rod 30 forward in the guide member 24, resulting in the release cable 23 being strained and the releasing member 22 being turned. The cover part 34 eliminates a possibility of the operator finger touching the rod 30, enhancing the safety. With the releasing member 22 being turned, the pawl is rocked in the direction in which it is disengaged from the sector gear tooth; and the foot lever 13 is rocked in the return direction by the braking reaction force to be returned to the release state, the brake cable being loosened, which results in the braking force being released.
In the present embodiment, in the connection part 33 of the knob main body 32 into which the nose end side of the rod 30 is inserted, the base end of the core part 32a, from which the rod 30 is exposed, is formed as a protrusion part 32a3 that extends from the surface layer part 32b. The same portions as those in the first embodiment are provided with the same signs, and explanation is omitted.
In the present embodiment, at the time of insert molding of the surface layer part 32b, the protrusion part 32a3 of the core part 32a is held by a holder 40 in the mold as shown in
Hereinabove, the embodiments of the present invention have been described with reference to the drawings; however, the specific configuration is not limited to those as given in the above-described embodiments, and even if any alteration or addition is given within the scope of the spirit of the present invention, it would be included in the present invention. For example, the surface of the core part 32a may be provided with irregularities, such as grooves, or the like, for enhancing the integrity of the surface layer part 32b to the core part 32a.
Further, the core part 32a that is previously molded is designed to be downsized by a definite amount (for example, 2 to 3 mm) from the finished size of the knob main body 32, however, if, at the time of insert molding of the surface layer part 32b, the resin should have a poor fluidity, a weld mark or an unfilled portion might be produced Thus in such a case, the core part 32a may be more undersized, and inversely the resin thickness of the surface layer part 32b may be increased to improve the resin fluidity at the time of molding.
According to the knob structure for a parking brake apparatus that pertains to the present invention, the knob main body is made up of a core part that is previously assembled to the nose end side of the rod, and a surface layer part that coats the surface of the core part after the assembling with a substantially uniform coating thickness. Thus it can be molded to an optional design geometry, and allows prevention of occurrence of a sink mark or a weld mark at the time of resin molding, improving in appearance quality.
In addition, the surface layer part is provided by insert molding of resin around the core part that has been previously assembled to the nose end side of the rod. Thus at the time of manufacturing the knob structure, the insert molding can be performed in a single process, resulting in the manufacturing cost being reduced.
Further, a portion of the core part is exposed on the surface of the surface layer part to provide an information display part by the exposed portion. Thus the necessary information can be indicated by the information display part with no need for printing on the knob main body or applying a seal thereto, which allows an inexpensive resin material with a good moldability to be adopted.
