JP2008240782A - Sealing structure for ball joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing structure for a ball joint capable of always ensuring an air-tight property by certainly sealing a shaft part of a ball pin from a periphery of an annular recession part of a peripheral wall part of a retainer. <P>SOLUTION: The sealing structure for the ball joint 10 is provided with: the ball pin 20 in which a shaft part 22 is fixed to a mounting hole 11a of a link arm 11; and a retainer 30 for slidably fitting a spherical part 21 of the ball pin to a slide surface 32b of an inner periphery of a peripheral wall part 32 mounted to one end 12a side of a link connecting rod 12 by spherical surface kinematic pair, in which the ball pin and the retainer are sealed by a joint seal 40. The joint seal is formed of: a retainer covering part 41 of C shape ring-like cross section for covering one end side of the retainer; and a cylindrical seal body 42 integrally formed from an intermediate opening part 44 at a lower side of the retainer covering part to a lower side and formed with a lower end opening part 45 fitted in the shaft part of the ball pin at a lower end. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to, for example, a seal structure of a ball joint that connects a crank arm (motor arm) of a wiper device of an automobile and a link connecting rod, or a link connecting rod and a pivot arm.

  As this type of ball joint seal structure, there is one shown in FIG. 6 (see, for example, Patent Document 1). The ball joint 1 is used when a motor arm 8 as a link arm of a wiper device of an automobile and a link connecting rod 9 are connected to each other. The ball joint 1 is made of a metal spherical pin-shaped ball pin 2 and a resin cross section. A reverse concave retainer 3 is used.

  The ball pin 2 has a spherical portion 2a and shaft portions 2b and 2c protruding from the lower surface of the spherical portion 2a. The shaft portion 2 c of the ball pin 2 is fixed to the mounting hole 8 a of the motor arm 8. An annular recess 3b formed on the outer periphery of the peripheral wall portion 3a of the retainer 3 is attached to an attachment hole 9a formed on one end side of the link connecting rod 9, and the inner peripheral sliding surface 3c of the peripheral wall portion 3a is attached. The spherical portion 2a of the ball pin 2 is slidably fitted by a spherical pair.

  The lower end 3d of the peripheral wall 3a of the retainer 3 and the shaft 2b of the ball pin 2 are sealed between the upper end opening 4b and the lower end opening 4c of the seal body 4a of the cylindrical joint seal 4 made of rubber. It has come to be.

JP-A-10-169639

  However, in the conventional seal structure of the ball joint 1, the upper end opening 4 b of the seal body 4 a of the joint seal 4 is fitted into the lower end 3 d of the peripheral wall 3 a of the retainer 3 and the seal is attached to the shaft 2 b of the ball pin 2. Since the lower end opening 4c of the main body 4a is fitted, the periphery of the annular recess 3b of the peripheral wall 3a of the retainer 3 attached to one end of the link connecting rod 9 cannot be sealed. When a load such as an external force is applied to the seal body 4a of the joint seal 4, a gap is generated between the upper end opening 4b of the seal body 4a of the joint seal 4 and the lower end 3d of the peripheral wall 3a of the retainer 3. It was difficult to ensure the airtightness of the seal 4.

  Accordingly, the present invention has been made to solve the above-described problems, can be easily incorporated, and reliably seals the shaft portion of the ball pin from the periphery of the annular recess of the peripheral wall portion of the retainer. It is an object of the present invention to provide a ball joint sealing structure capable of always ensuring airtightness.

  The invention of claim 1 includes a ball pin having a spherical portion and a shaft portion protruding from the lower surface of the spherical portion, the ball pin fixed to the attachment portion of the link arm, and an annular recess on the outer periphery of the peripheral wall portion And a retainer having a reverse concave shape in which the spherical portion of the ball pin is slidably fitted to the inner sliding surface of the peripheral wall portion by a spherical pair. A ball joint sealing structure in which the ball pin and the retainer are sealed through a rubber-made cylindrical joint seal, wherein the joint seal includes the upper side of the annular recess of the retainer and the link connecting rod. A retainer covering portion covering one end side and a lower intermediate opening on the lower side of the retainer covering portion are integrally formed downward and fitted to the shaft portion of the ball pin at the lower end. A cylindrical sealing body having a lower end opening formed thereon, and a sealing convex portion is formed around the upper end opening on the upper side of the retainer covering portion and around the intermediate opening, respectively. To do.

  According to a second aspect of the present invention, there is provided the ball joint seal structure according to the first aspect, wherein a side end opening portion into which one end side of the link connecting rod is inserted is provided on a side portion of the retainer covering portion of the joint seal, A structure in which gripping pieces for a handle protrude from the upper and lower edges of the side end opening.

  A third aspect of the invention is the ball joint seal structure according to the first or second aspect, wherein a sealing convex portion is formed around the side end opening.

  As described above, according to the first aspect of the present invention, the joint seal is formed with a U-shaped retainer covering portion covering the upper side of the annular concave portion of the retainer and one end side of the link connecting rod, and the lower portion of the retainer covering portion. The upper end opening on the upper side of the retainer covering portion is formed with a cylindrical seal body integrally formed downward from the intermediate opening portion on the side and having a lower end opening portion fitted to the shaft portion of the ball pin at the lower end. By forming the sealing protrusions around the periphery and the intermediate opening, the ball pin shaft is securely sealed from the one end side of the link connecting rod and the periphery of the annular recess in the peripheral wall of the retainer. Airtightness can always be ensured.

  According to the second aspect of the present invention, the side end opening portion into which one end side of the link connecting rod is inserted is provided at the side portion of the retainer covering portion of the joint seal, and the upper edge and the lower edge of the side end opening portion are used for the handle. By projecting the gripping piece portions, the retainer covering portion of the joint seal can be easily incorporated around the one end side of the link connecting rod and the periphery of the annular concave portion of the peripheral wall portion of the retainer, and workability can be improved. .

  According to the third aspect of the present invention, the airtightness of the link connecting rod can always be reliably ensured by forming the sealing convex portion around the side end opening.

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

  1 is a cross-sectional view showing a state where a ball joint according to an embodiment of the present invention is sealed with a joint seal, FIG. 2 is a perspective view of the joint seal, and FIG. 3 is a cross-sectional view taken along line XX in FIG. 4 is a perspective view showing a state before the joint seal is attached to one end side of the link connecting rod, and FIG. 5 is a perspective view showing a state where the joint seal is attached to one end side of the link connecting rod.

  As shown in FIG. 1, the ball joint 10 is used when a crank arm (link arm) 11 and a link connecting rod 12 of a wiper device of an automobile are connected to each other. And a retainer 30 made of resin and having a reverse concave shape in cross section. The ball pin 20 and the retainer 30 are sealed with a rubber-made cylindrical joint seal 40.

  The ball pin 20 includes a spherical portion 21 whose bottom surface is cut out to form a circular plane, a large-diameter shaft portion (shaft portion) 22 integrally formed in a step shape on the lower surface 21 b of the spherical portion 21, A small-diameter shaft portion (shaft portion) 23 integrally formed in a step shape on the lower surface of the large-diameter shaft portion 22 has a spherical pin shape. The small-diameter shaft portion 23 is fixed by being inserted into an attachment hole (attachment portion) 11a of the crank arm 11 and caulking.

  The retainer 30 has a disk-shaped ceiling portion 31 and a thick peripheral wall portion 32 extending in a substantially cylindrical shape below the peripheral edge of the ceiling portion 31 and has a reverse concave shape in cross section, and the lower surface side is open. An annular recess 33 is formed in the outer peripheral surface 32 a of the thick peripheral wall portion 32 of the retainer 30, and the annular recess 33 is fitted to the peripheral portion of the mounting hole 13 formed in the one end 12 a of the link connecting rod 12. Or by outsert molding or the like. The spherical surface 21a of the spherical portion 21 of the ball pin 20 is slidably fitted to the sliding surface 32b, which is the inner peripheral surface of the peripheral wall portion 32 of the retainer 30, by a spherical pair (sliding pair).

  As shown in FIGS. 1 to 5, the joint seal 40 includes a retainer covering portion 41 having a U-shaped cross section covering the upper side of the annular recess 33 of the retainer 30 and the one end 12 a side of the link connecting rod 12, and the retainer covering portion 41. A cylindrical seal body 42 integrally formed downward from the lower intermediate opening 44 and having a lower end opening 45 fitted to the large-diameter shaft portion 22 of the ball pin 20 at the lower end. Yes.

  A circular upper opening 43 is formed on the upper side of the retainer covering portion 41 of the joint seal 40, and a circular intermediate opening 44 is formed on the lower side thereof. These upper end opening 43 and intermediate opening 44 are formed to have the same diameter. Further, around the upper end opening 43 of the retainer covering portion 41, a sealing convex portion 43a is doubled. Further, around the intermediate opening 44 of the retainer covering portion 41, a sealing convex portion 44a is doubled.

  Further, the side end 41 a of the retainer covering portion 41 is formed with a square flat cylindrical side end opening 46 into which the one end 12 a side of the link connecting rod 12 is inserted. A pair of upper and lower gripping pieces 47 and 48 for a handle are integrally formed at the center of the upper edge 46a and the center of the lower edge 46b of the side end opening 46 of the square flat cylindrical shape. Further, a sealing convex portion 46c is formed around the side end opening 46 having a rectangular flat cylindrical shape.

  Around the lower end opening 45 of the seal main body 42 of the joint seal 40, an oil sump groove 45a is formed. The inner diameter dimension of the lower end opening 45 is slightly smaller than the outer diameter dimension of the large diameter shaft portion 22 of the ball pin 20, and the lower end opening 45 is fitted to the large diameter shaft portion 22 of the ball pin 20. Sometimes, the elastic restoring force allows the large diameter shaft portion 22 to be fitted with no gap.

  The thickness of the body portion 42a of the seal body 42 of the joint seal 40 is formed to be thin, for example, 0.8 mm in consideration of elastic deformation, and the lower end opening 45 and the retainer covering portion of the seal body 42 other than that are formed. The thickness of 41 is formed to a thickness of, for example, 1.0 mm in order to maintain rigidity.

  According to the ball joint 10 of the above-described embodiment, the joint seal 40 for sealing the ball joint 10 is provided with a retainer covering portion having a U-shaped cross section that covers the upper side of the annular recess 33 of the retainer 30 and the one end 12a side of the link connecting rod 12. 41 and a cylindrical shape in which a lower end opening 45 that is fitted to the large-diameter shaft portion 22 of the ball pin 20 is formed at the lower end while being integrally formed downward from the lower intermediate opening 44 of the retainer covering portion 41. And the sealing protrusions 43a and 44a are integrally formed around the upper end opening 43 on the upper side of the retainer covering part 41 and around the lower intermediate opening 44, respectively. The end of the link connecting rod 12 and the periphery of the annular concave portion 33 of the peripheral wall portion 32 of the retainer 30 to the large-diameter shaft portion 22 of the ball pin 20 are securely inserted. It is possible to secure airtightness always easily and reliably by Le.

  Further, a side end opening 46 into which the one end 12a side of the link connecting rod 12 is inserted is formed in the side portion 41a of the retainer covering portion 41 of the joint seal 40, and the center and lower edges of the upper edge 46a of the side end opening 46 are formed. Since a pair of upper and lower gripping piece portions 47 and 48 for the handle are integrally projected at the center of 46b, the pair of upper and lower gripping piece portions 47 and 48 are gripped as shown in FIG. When the one end 12a side of the link connecting rod 12 is inserted into the side end opening 46 of 41a, the peripheral wall 32 of the retainer 30 is easily fitted into the upper end opening 43 on the upper side of the retainer covering portion 41 as shown in FIG. The one end 12a side of the link connecting rod 12 can be easily fitted into the side portion 41a of the retainer covering portion 41. Thereby, the retainer coating | coated part 41 of the joint seal 40 can be easily integrated in the one end 12a side of the link connecting rod 12, and the periphery of the annular recessed part 33 of the peripheral wall part 32 of the retainer 30, and an assembly workability | operativity is improved. it can. After this assembly, the airtightness of the upper side of the annular recess 33 of the peripheral wall portion 32 of the retainer 30 is always reliably ensured by the sealing convex portion 43a of the upper end opening 43 of the retainer covering portion 41 of the joint seal 40. One end 12a side of the link connecting rod 12 inserted into the side end opening 46 by the sealing convex part 46c formed around the side end opening 46 of the side part 41a of the retainer covering part 41. The airtightness of the can always be ensured.

  Further, as shown in FIG. 1, the sliding surface 32 b of the peripheral wall portion 32 of the retainer 30 and the joint seal 40 are formed on the spherical portion 21 and the large-diameter shaft portion 22 of the ball pin 20 fixed in the mounting hole 11 a of the crank arm 11. After the lower end opening 45 of the seal body 42 is fitted and assembled, the cylindrical seal body 42 in which the lower end opening 45 is formed is formed integrally with the lower intermediate opening 44 of the retainer covering portion 41. Accordingly, even when a load such as an external force is applied to the seal main body 42 of the joint seal 40 as in the prior art, the intermediate opening 44 on the lower side of the retainer covering portion 41 that also serves as the upper end opening of the seal main body 42 and the retainer 30. A gap is not generated between the peripheral wall portion 32 and the lower end portion 32c of the peripheral wall portion 32, and the airtightness of the joint seal 40 can always be ensured easily and reliably.

  In addition, according to the said embodiment, although the seal structure of the ball joint which connects the crank arm and link connecting rod as a link arm of the wiper apparatus of a motor vehicle was demonstrated, the ball joint which connects a link connecting rod and the pivot arm as a link arm was demonstrated. Of course, the above embodiment can be applied to the seal structure.

It is sectional drawing which shows the state which sealed the ball joint of one Embodiment of this invention with the joint seal. It is a perspective view of the joint seal. It is sectional drawing which follows the XX line in FIG. It is a perspective view which shows the state before attaching the said joint seal to the one end side of a link connecting rod. It is a perspective view which shows the state which attached the said joint seal to the one end side of a link connecting rod. It is sectional drawing which shows the state which sealed the conventional ball joint with the joint seal.

Explanation of symbols

10 Ball joint 11 Crank arm 11a Mounting hole (mounting part)
12 Link connecting rod 12a One end 13 Mounting hole 20 Ball pin 21 Spherical part 21b Lower surface 22 Large diameter shaft part (shaft part)
23 Small-diameter shaft (shaft)
30 retainer 32 peripheral wall portion 32b sliding surface 33 annular recess 40 joint seal 41 retainer covering portion 41a side portion 43 upper end opening portion 43a sealing convex portion 44 intermediate opening portion 44a sealing convex portion 45 lower end opening portion 46 side end Opening 46a Upper edge 46b Lower edge 46c Convex portion 47, 48 A pair of upper and lower grip pieces

Claims (3)

A ball pin having a spherical portion and a shaft projecting from the lower surface of the spherical portion, a ball pin fixed to the attachment portion of the link arm, and an annular recess on the outer periphery of the peripheral wall portion on one end side of the link connecting rod The ball pin and the retainer are provided with a retainer having an inverted concave section in which the spherical portion of the ball pin is slidably fitted to the inner peripheral sliding surface of the peripheral wall portion by a spherical pair. In a ball joint seal structure in which a rubber joint is sealed through a cylindrical joint seal,
The joint seal is formed integrally with a retainer covering portion that covers the upper side of the annular recess of the retainer and one end side of the link connecting rod, and a lower intermediate opening on the lower side of the retainer covering portion. A cylindrical sealing body having a lower end opening that is fitted to the shaft of the ball pin, and a sealing protrusion around the upper end opening on the upper side of the retainer covering portion and around the intermediate opening. A ball joint seal structure characterized in that each part is formed.   The ball joint seal structure according to claim 1, wherein a side end opening into which one end side of the link connecting rod is inserted is provided at a side of the retainer covering portion of the joint seal, and an upper edge of the side end opening. And a ball joint seal structure characterized in that a grip piece for a handle protrudes from the lower edge.   3. The ball joint seal structure according to claim 1, wherein a sealing convex portion is formed around the side end opening.

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