Pivot structure for vehicle wiper device

A pivot structure for a vehicle wiper device is provided. The pivot structure prevents foreign matters from invading through a body exterior sheet into a dash board area, for example. The pivot structure may be used in both left-side-drive vehicles and right-side-drive vehicles. A first regulating rib and second regulating rib are formed on respective fixing pieces, which extend from the outside periphery of a pivot holder. The first and second ribs are formed symmetrically with respect to an imaginary line X passing through the center axis of the pivot shaft on the right side and the left side.

BACKGROUND OF THE INVENTION
 1. Field of Invention
 The present invention relates to a pivot structure for a vehicle wiper
 device. In particular, the invention relates to a pivot structure for a
 vehicle wiper mounted on passenger cars, buses, and trucks, for example.
 2. Description of Related Art
 In general, vehicles are equipped with a wiper device for wiping the window
 surface of a windshield and the like. As shown in FIGS. 7(A) and 7(B), a
 known wiper device is arranged such that a pivot shaft 22 is rotatably
 supported by a pivot holder 21 fixed to a body, and specifically a body
 exterior sheet. A link arm 23, which is coupled with a motor (not shown),
 is fixed to the base end of the pivot shaft 22. A wiper arm 24 is fixed to
 the extreme end of the pivot shaft 22. With this arrangement, when the
 motor is driven, the wiper arm 24 is reciprocatingly circularly moved
 about the pivot shaft 22, as a swing support shaft, so as to perform a
 wiping motion.
 The wiper device is arranged such that a pivot holder 21 has a fixing piece
 21a formed in a collar shape and fixed to the body. The portion of the
 body above the fixing piece 21a is covered with a cowl top 25. With this
 arrangement, the cowl top 25 has a large diameter through-hole 25a so that
 the pivot holder 21 loosely passes therethrough.
 SUMMARY OF THE INVENTION
 However, known wiper devices have various problems. That is, rainwater may
 invade between the through-hole 25a and the pivot holder 21. The water may
 enter a wiper drive unit and splash on a drive link, for example. Also,
 foreign matter may be sucked in when a vehicle travels, i.e., by the
 negative pressure in an upper-section of a dash board where the wiper
 device is mounted. The foreign matter may invade the dash board upper
 section through a through-hole formed in a body exterior sheet, for
 example. The foreign matter may generate noise by interfering with a wiper
 link, a wiper arm, and the like, when the wiper device is operated.
 To overcome the above problems, there has been proposed to form a large
 diameter regulating section to the pivot holder fixing piece so as to
 surround the outside periphery of the pivot holder to regulate the
 invasion of rainwater and foreign matters, as well as to provide a guide
 path for guiding and discharging invaded rainwater. However, vehicles are
 manufactured in two types, that is, in a left-hand-drive type and a
 right-hand-drive type. As a result, two kinds of the pivot holders must be
 used to provide a driver side pivot holder and a passenger side pivot
 holder to accommodate left-hand-drive vehicles and right-hand-drive
 vehicles. Accordingly, there arises a problem to be solved by the present
 invention that not only the number of parts is increased, but also the
 management of the parts are troublesome.
 The present invention is directed to solving these problems in view of the
 above circumstances. In accordance with the invention, there is provided a
 pivot structure for a vehicle wiper device. A pivot holder, through which
 a pivot shaft having a wiper arm fixed thereto passes so as to rotate
 about the axis of the pivot shaft, is mounted by fixing a fixing piece.
 The fixing piece is formed on the pivot holder in a collar shape. The
 fixing piece is fixed to a body exterior sheet disposed below a cowl top
 in an inclined state. The pivot structure includes a regulating section
 formed on the upper surface of the fixing piece, which opposes the cowl
 top.
 The regulating section has a large diameter so as to surround the outside
 periphery of the pivot holder for restricting entry of foreign substance
 from the cowl top. The regulating section is formed symmetrically, with
 respect to an imaginary line passing through the axial center of the pivot
 shaft, on the right side and the left side.
 Further, according to the present invention, the regulating section may be
 divided into a plurality of portions.
 According to the pivot structure for the vehicle wiper device of the
 present invention as described above, the invasion of foreign matters such
 as rainwater, dead leaves, and the like, into a dash board upper section
 can be regulated. Additionally, in accordance with the invention, a guide
 path is formed to discharge entering rainwater. Further, the pivot holder
 can be employed to both left-hand-drive vehicles and right-hand-driver
 vehicles.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
 While the invention will hereinafter be described in connection with
 exemplary embodiments thereof, it will be understood that it is not
 intended to limit the invention to those embodiments. On the contrary, it
 is intended to cover all alternatives, modifications and equivalents that
 may be included within the spirit and scope of the invention.
 For a general understanding of the features of the invention, reference is
 made to the drawings. In the drawings, like reference numerals have been
 used throughout to designate like elements.
 A wiper device 1 is shown, in FIG. 1, for wiping the windshield of a
 vehicle. The wiper device 1 includes a driver side pivot holder 2 and a
 passenger side pivot holder 3. Pivot shafts 4, 5 pass through the pivot
 holders 2, 3 and are supported by the pivot holders 2, 3 so as to rotate
 about the axes thereof. Wiper arms 6 are fixed to the extreme ends of the
 pivot shafts 4, 5, respectively, whereas swing links 4a, 5a are fixed to
 the base ends of the pivot shafts 4, 5, respectively. As a result, the
 power from the output shaft 7 of a wiper motor (not shown) is transmitted
 to an output link 7a, a first rod 8, a passenger side swing link 4a, a
 second rod 9 and a driver side swing link 5a.
 The passenger side pivot holder 3 will first be described, although the
 invention is directed to each of the pivot holders 2, 3. As shown in FIG.
 2A and FIG. 4, the pivot holder 3 loosely passes through a through-hole
 10a, formed in a body exterior sheet 10, from the lower side (body side)
 thereof. The pivot holder 3 is fixed to the body exterior sheet 10 in such
 a manner that a fixing piece 3a which extends from the outside periphery
 of the pivot holder 3, in a collar shape, is fitted to the body exterior
 sheet 10 inclined in a forward/backward direction from the lower side
 thereof. The fixing piece 3a supported by a bolt 11 as an example of a
 fixture.
 Numeral 12 denotes a cowl top mounted above the body exterior sheet 10. The
 cowl top 12 has a through-hole 12a formed therein so that the pivot holder
 3 loosely passes through it. First and second regulating ribs 3b and 3c
 are formed to the fixing piece 3a of the pivot holder 3, which confront
 the lower surface of the cowl top 12, respectively. The first and second
 regulating ribs 3b and 3c regulate the invasion of foreign matters such as
 dead leaves and the like into the space between the lower surface of the
 cowl top 12 and the fixing piece 3a. The first regulating rib 3b is formed
 in a substantially cylindrical shape projecting toward the cowl top 12
 with a diameter larger than the outside shape of the pivot holder 3. The
 first regulating rib 3b has an opening formed thereto on the inclined side
 of the pivot holder 3. On the other hand, the second regulating rib 3c is
 formed linearly at the position of the opening of the first regulating rib
 3b with intervals S defined between both the ends of the first regulating
 rib 3b and both the ends of the second regulating rib and located in the
 tangential direction with respect to the imaginary arc C of the first
 regulating rib 3b. As a result, the second regulating rib 3c forms a
 discharge path for discharging invaded rainwater and the like to the
 outside of the regulating ribs. A pair of cutout portions between the
 first regulating rib 3b and the second regulating rib 3c are formed
 substantially symmetrically with respect to an imaginary line X as a
 symmetrical line passing through the axial center of the pivot shaft 5 on
 the right side and the left side thereof. As a result, the pivot structure
 can be used in any left-hand-drive vehicles or right-hand-drive vehicles.
 The driver side pivot holder 2 has the same mounting structure as that of
 the passenger side pivot holder 3 except that it is mounted at an end of
 the windshield of the vehicle at the lower portion thereof and fixedly
 supported by being also inclined in the right and left directions in
 conformity with the round shapes of the body and the windshield. The
 regulating ribs of the pivot holder 2 will hereinafter be described. As
 shown in FIG. 2B and FIG. 3, first and second regulating ribs 2b and 2c
 are formed to the fixing piece 2a of the pivot holder 2, which confronts
 the lower surface of a cowl top 12. The first regulating rib 2b includes a
 pair of substantially arc-shaped ribs having openings at the inclined
 upper and lower ends thereof. The second regulating rib 2c is formed
 linearly at the position of the opening at the lower end of the first
 regulating rib 2b with intervals S defined between both the ends of the
 first regulating rib 2b and both the ends of the second regulating rib 2c
 and located in the tangential direction with respect to the imaginary arc
 C of the first regulating rib 2b. As a result, a discharge path is formed
 for discharging invaded rainwater and the like.
 In the first and second driver side regulating ribs 2b and 2c, a pair of
 cutout portions are formed substantially symmetrically with respect to an
 imaginary line X as a symmetrical line passing through the axial center of
 the pivot shaft 4. The first and second passenger side regulating ribs 3b
 and 3c are likewise positioned on the right side and the left side.
 When the pivot holders 2, 3 are mounted on a left-hand-drive vehicle or a
 right-hand-drive vehicle whose inclinations in the right and left
 directions are opposite to each other symmetrically with respect to a
 line, a discharge path is formed by one of the pair of the cutout portions
 and the second regulating rib. The discharge path is formed in the
 tangential direction to discharge invaded rainwater through the discharge
 path, regardless of whether the vehicle is inclined in the right direction
 or in the left direction. As a result, the pivot holder can be easily
 formed without consideration of a difference in shape, depending on its
 use in a left-hand-drive vehicle or a right-hand-drive vehicle.
 In the wiper device arranged as described above, the window surface of the
 windshield is wiped by the wiper arms 6 which are swung by the
 reciprocating rotations of the pivot shafts 4, 5 driven by a motor (not
 shown). As a result of the invention, it is difficult for foreign matters
 such as rainwater, dead leaves and the like to invade the cowl top from
 the through-hole 12a. Even if foreign matter invades the cowl top, the
 invasion of it into a dash board upper section, located further inwardly
 of the cowl top, is regulated by the first and second regulating ribs 2b,
 2c, 3b and 3c. The rainwater is guided and discharged to a prescribed
 portion through the cutout. As a result, the problem of noise generated by
 contact of any invaded foreign materials with an inner portion of the
 drive link, and the like, of the wiper drive unit is prevented.
 In the wiper device to which the present invention is embodied, the
 invasion of the foreign matters into the inner portion of the wiper device
 can be prevented by the first and second regulating ribs 2b, 2c, 3b and
 3c. Further, the second regulating ribs 2c, 3c are linearly formed at the
 positions of the openings of the first regulating ribs 2b and 3b, with the
 intervals S defined between both the ends of the first regulating ribs 2b
 and 3b and both the ends of the second regulating ribs 2c and 3c. The
 second regulating ribs 2c and 3c are located in the tangential direction
 with respect to the imaginary arcs C of the first regulating rib 2b and 3b
 so as to form the discharge path of the rainwater. Thus, the passage of
 the rainwater, for example, can be regulated. Further, the regulating ribs
 2b, 2c, 3b and 3c are formed symmetrically with respect to the imaginary
 line X as a symmetrical line passing through the axial center of the pivot
 shaft on the right side and the left side. Therefore, the wiper device can
 be employed to any of a left-hand-drive vehicle and the right-hand-side
 vehicle. Further, the number of parts can be reduced and management of the
 parts can be simplified.
 The present invention is not limited to the above embodiment. The cowl top
 mounted above the body exterior sheet can be devised as shown in FIG. 5A
 and FIG. 5B, which illustrate the wiper device of another embodiment of
 the present invention. More specifically, as shown in FIG. 5A, a passenger
 side cowl top 13 is mounted to a body exterior sheet 10, a pivot holder 3,
 also mounted to the body exterior sheet 10, loosely passes through the
 through-hole 13a of the passenger side cowl top 13. The cowl top 13 has an
 extending section 13b which projects downward from the surface of the cowl
 top 13, which confronts first and second regulating ribs 3b and 3c and
 extends toward the second regulating rib 3c, around the outside periphery
 of a pivot holder 3. The extending section 13b has a covering section 13c
 formed to the lower end edge thereof. The covering section 13c has a
 substantially gate-shaped cross section. This is provided as a result of
 the extending section 13b bulging to have a large diameter. The covering
 section 13c is fitted over the second regulating rib 3c in a labyrinth
 fashion.
 With regard to a driver side cowl top 14, an extending section 14b projects
 from the through-hole 14a of the driver side cowl top 14, through which a
 pivot holder 2 loosely passes. The extending section 14b extends toward
 first and second regulating ribs 2b and 2c so as to surround the outside
 periphery of the pivot holder 2. The extending section 14b has a covering
 section 14c formed to the lower end edge thereof. The covering section 14c
 has a substantially gate-shaped cross section. This is provided as a
 result of the extending section 14b bulging to have a large diameter. The
 covering section 14c is fitted over the second regulating rib 2c in a
 labyrinth fashion.
 With the above arrangements, even if foreign matters, such as dead leaves
 and the like, invade from the through-holes 13a and 14a of the cowl tops
 13 and 14, the invasion can be regulated by not only the regulating ribs,
 but also the covering sections 13c and 14c of the cowl tops 13 and 14. As
 a result, the invasion of the foreign matters can be more reliably
 regulated.
 Further, as shown in FIG. 6, an annular groove 16 may be formed on the
 fixing piece 15 of the pivot holder in place of the regulating rib. With
 this arrangement, discharge grooves 16a are formed from the annular groove
 16 in a radial direction symmetrically with respect to the right and left
 sides. The invasion of foreign matters such as dead leaves and the like
 can be regulated by arranging the annular groove 16 and a projecting
 section extending from a cowl top downward in the labyrinth fashion.
 While the invention has been described in conjunction with specific
 embodiments thereof, it is evident that many alternatives, modifications
 and variations may be apparent to those skilled in the art. Accordingly,
 the exemplary embodiments of the invention as set forth herein are
 intended to be illustrative, not limiting. Various changes may be made
 without departing from the spirit and scope of the invention.