JP2009287690A - Ball joint structure for wiper device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ball joint structure for wiper device having high safety and reduced in costs by eliminating a process for deflashing a resin ball retainer. <P>SOLUTION: This ball joint structure for wiper device is structured by fixing each ball pin 11 to a crank arm 3 fixed to an output shaft of a wiper motor in one end thereof and to a pivot arm 13 fixed to a pivot shaft for swinging the wiper arm in one end thereof, and freely slidably fitting a resin ball retainer 12, which is fitted to a link connecting rod 6 connecting the crank arm 3 and the pivot arm 13 to each other, on a spherical part 11a of each ball pin 11 freely to slide by spherical and diagonal arrangement. A recessed part 12b is formed at a position opposite to a runner in injection molding of a ceiling part 12a of the resin ball retainer 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ball joint structure suitable for use in a wiper device for wiping rainwater from a windshield glass of an automobile.

  A wiper device of this type is shown in FIG. 3, and a ball joint structure thereof is shown in FIG. 4 (see, for example, Patent Document 1).

  As shown in FIG. 3, the wiper device 1 includes a wiper motor 2 with a speed reduction mechanism as a drive source, and a crank arm 3 is fixed to an output shaft 2 a of the wiper motor 2. As shown in FIGS. 3 and 4, a ball pin 4 is projected on the crank arm 3. The spherical surface 4b of the spherical portion 4a of the ball pin 4 is slidable by a spherical pair (sliding pair) of a sliding surface 5a of a ball retainer 5 made of resin and having a reverse concave shape attached to one end of a link connecting rod 6. It is fitted.

  One end of the pivot arm 13 is fixed to one end of the pivot shaft 8 that swings the wiper arm 7. A ball pin 4 protrudes from the other end of the pivot arm 13. The sliding surface 5a of the ball retainer 5 made of a resin and having a reverse concave shape is attached to the other end of the link connecting rod 6 for connecting the crank arm 3 and the pivot arm 13 to the spherical surface 4b of the spherical portion 4a of the ball pin 4. It is slidably fitted by a kinematic pair.

  The pivot shaft 8 is swingably supported by a pivot holder 9 attached to a vehicle body (not shown). These ball pins 4 and the ball retainer 5 constitute a ball joint.

  The rainwater on the windshield glass 14 is wiped off by a wiper blade 7 a attached to the wiper arm 7.

JP2003-247526A (FIG. 1)

  However, in the ball joint structure of the conventional wiper device 1, since the ceiling portion 5b of the resin ball retainer 5 is disk-shaped, when the ball retainer 5 is injection-molded from the upper side of the ceiling portion 5b, The remaining burr protrudes from the upper surface of the ceiling portion 5b, and deburring is indispensable from the viewpoint of safety.

  Further, in the type in which the rotation retaining projection 5c is provided on the lower surface (inner surface) of the ceiling portion 5b of the ball retainer 5, the thickness of the ceiling portion 5b is not uniform. Became bulky and expensive.

  Accordingly, the present invention has been made to solve the above-described problems, and has a highly safe wiper device ball joint structure that can reduce the cost by eliminating the need to deburr a resin ball retainer. The purpose is to provide.

  According to the first aspect of the present invention, the ball pin is fixed to the other end of the crank arm whose one end is fixed to the output shaft of the wiper motor and the other end of the pivot arm whose one end is fixed to the pivot shaft for swinging the wiper arm. Then, the sliding surfaces of the resin ball retainers attached to both ends of the link connecting rod connecting the crank arm and the pivot arm are slidably fitted to the spherical surface of each ball pin by a spherical pair. In the ball joint structure of the combined wiper device, the concave portion is formed at a position facing the runner at the time of injection molding of the resin ball retainer.

  A second aspect of the invention is the ball joint structure of the wiper device according to the first aspect, wherein the concave portion is formed at the center of the ceiling portion of the resin ball retainer.

  A third aspect of the invention is the ball joint structure of the wiper device according to the second aspect, wherein a rotation-preventing protrusion is integrally formed on the lower surface of the ball retainer facing the concave portion of the ceiling portion.

  As described above, according to the first aspect of the present invention, since the recess is formed at a position facing the runner at the time of injection molding of the resin ball retainer, the burr residue of the runner is located in the recess of the ball retainer. In addition, since it does not protrude outside, deburring is not necessary, cost can be reduced, and safety and layout can be improved.

  According to the invention of claim 2, since the recess is formed in the center of the ceiling portion of the resin ball retainer, the burr residue of the runner is located in the recess of the center of the ceiling portion of the ball retainer and does not protrude outward. For this reason, deburring is not required, the cost can be reduced, and safety and layout can be improved.

  According to the third aspect of the present invention, the rotation-preventing protrusion is integrally formed on the lower surface facing the concave portion of the ceiling portion of the resin-made ball retainer so that the burr residue of the runner is in the central concave portion of the ceiling portion of the ball retainer. Because it is located in the position and does not protrude outward, deburring is not required, cost can be reduced, safety and layout can be improved, and the wall thickness of the ceiling is made uniform. Thus, the occurrence of sink marks and the like can be prevented, and the material cost can be reduced and the cost can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a ball joint structure of a wiper device according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part of the ball joint structure, and the wiper device shown in FIG.

  As shown in FIGS. 1 and 3, a crank arm 3 having one end fixed to the output shaft 2 a of the wiper motor 2 of the wiper device 1 and a pivot arm 13 having one end fixed to a pivot shaft 8 that swings the wiper arm 7. At the other end, a metal ball pin 11 is projected and fixed. In the spherical portion 11a of each ball pin 11, a ball retainer 12 made of a resin and having a reverse concave shape attached to both ends of a link connecting rod 6 for connecting the crank arm 3 and the pivot arm 13 is slidable by a spherical pair. It is fitted. These ball pins 11 and ball retainers 12 constitute a ball joint 10.

  As shown in FIG. 1, the ball pin 11 includes a spherical portion 11a having a concave portion 11b for stopping rotation on the top (upper side), a large-diameter shaft portion 11d integrally formed below the spherical portion 11a, A small-diameter shaft portion 11e integrally formed in a step shape below the large-diameter shaft portion 11d is formed into a spherical pin shape, and the small-diameter shaft portion 11e is attached to the mounting hole 3a of the crank arm 3 and the pivot arm 13. It is fixed by being inserted into the hole 13a and caulking. Then, the sliding surface 12f of the ball retainer 12 made of resin and having a reverse concave shape is slidably fitted to the spherical surface 11c of the spherical portion 11a of the ball pin 11 by a spherical pair (sliding pair).

  As shown in FIG. 1, the resin-made ball retainer 12 has a cross-section of a ceiling portion 12a having an arcuate section (spherical shape) and a thick peripheral wall portion 12d extending in a substantially cylindrical shape below the periphery of the ceiling portion 12a. It is concave and the bottom surface is open. An inverted conical recess 12b is formed at the center (top) of the top surface of the ceiling-shaped portion 12a having a circular arc cross section of the resin ball retainer 12. As shown in FIG. 2, the most depressed bottom portion of the inverted conical recess 12b is the position of the runner L when the resin ball retainer 12 is injection molded. Further, a rotation-preventing protrusion 12c is integrally formed on the lower surface (inner surface) facing the concave portion 12b of the ceiling portion 12a having an arcuate cross section. The rotation of the ball retainer 12 is regulated by the protrusion 12c for stopping rotation of the ball retainer 12 coming into contact with the peripheral wall of the recess 11b for stopping rotation of the ball pin 11.

  As shown in FIG. 1, an annular recess 12e is formed on the outer periphery of the thick peripheral wall portion 12d of the ball retainer 12, and the annular recess 12e is formed at both ends of the link connecting rod 6. It is attached to the peripheral edge of the attachment hole 6a by fitting or outsert molding. Then, the arc-shaped concave sliding surface 12f which is the inner peripheral surface of the ceiling portion 12a and the peripheral wall portion 12d of the ball retainer 12 is slidable on the spherical surface 11c of the spherical portion 11a of the ball pin 11 by a spherical pair (sliding pair). Is fitted.

  According to the ball joint structure of the wiper device 1 of the above embodiment, when the ball retainer 12 is injection-molded from the upper side of the ceiling portion 12a by a molding die (not shown), as shown in FIG. 2, a resin ball retainer is used. Since the inverted conical recess 12b is formed on the top of the ceiling section 12a having an arcuate cross section, the burr remaining B of the runner L is positioned at the most depressed bottom of the inverted cone recess 12b. It does not protrude outward from the uppermost end. As a result, safety can be improved, deburring is not required, and cost can be reduced.

  Further, the protrusion 12c for rotation prevention is integrally formed on the lower surface of the ball retainer 12 facing the recess 12b of the ceiling portion 12a having an arcuate cross section, whereby the thickness of the ceiling portion 12a can be made uniform. Thereby, the occurrence of sink marks and the like can be prevented, and the material cost can be reduced to reduce the cost. Further, the layout can be improved.

It is sectional drawing of the ball joint structure of the wiper apparatus which is one Embodiment of this invention. It is an expanded sectional view of the important section of the above-mentioned ball joint structure. It is a schematic explanatory drawing which shows the whole structure of a wiper apparatus. It is sectional drawing of the ball joint structure of the conventional wiper apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wiper apparatus 2 Wiper motor 2a Output shaft 3 Crank arm 6 Link connecting rod 7 Wiper arm 8 Pivot shaft 10 Ball joint 11 Ball pin 11a Spherical part
11c Spherical surface 12 Resin ball retainer 12a Ceiling part 12b Recessed part 12c Anti-rotation protrusion 12f Sliding surface 13 Pivot arm L Runner B Burr remaining

Claims (3)

A ball pin is fixed to the other end of the crank arm having one end fixed to the output shaft of the wiper motor and the other end of the pivot arm having one end fixed to the pivot shaft for swinging the wiper arm. A wiper device comprising a spherical spherical surface and a sliding surface of a resin ball retainer attached to both ends of a link connecting rod for connecting the crank arm and the pivot arm to each other so as to be slidable by a spherical pair. In the ball joint structure,
A ball joint structure for a wiper device, wherein a recess is formed at a position facing a runner at the time of injection molding of the resin ball retainer. The ball joint structure of the wiper device according to claim 1,
A ball joint structure for a wiper device, wherein the concave portion is formed at a center of a ceiling portion of the resin ball retainer. A ball joint structure for a wiper device according to claim 2,
A ball joint structure for a wiper device, wherein a rotation-preventing protrusion is integrally formed on a lower surface of the ball retainer facing a concave portion of a ceiling portion.

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