JP2005036983A - Resin boot for constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin boot for a triport type joint, which is formed by integrally moulding a resin material to reduce the cost, which can be uniformly tightened and fixed to the outer circumference of an outer case of irregular form along the whole circumference, and in which assemblage performance and seal performance are favorable. <P>SOLUTION: A large diameter side mounting part 2 to be mounted on the circumference of the outer case 21, a small diameter side mounting part 3 to be mounted on a shaft 10 on the side of a triport 13, and a bellows part 4 between both mounting parts are integrally molded with a resin material. The inner circumference of the large diameter side mounting part 2 is formed in a non-circular form corresponding to irregular form of the outer circumference of the outer case 21, forming a thick part 2a protruded inward. A volume absorbing means 7 is provided in the thick part 2a. It can be roughly equally tightened and fixed along the whole circumference to the outer circumference of the outer case. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin boot used in a constant velocity joint including a tripart on one of an input side and an output side and an outer case on the other side.

  One of the constant velocity joints used for vehicle drive shafts and the like is a triport type joint, which is used, for example, for driving a front-wheel drive automobile.

  As shown in FIGS. 9 and 10, this triport type constant velocity joint has three trunnions (12) having rollers (11) on one shaft (10) on the input side and the output side. A triport (13) projecting in the direction and an outer case (21) provided at the end of the other shaft (20), and the outer case (21) is formed on the inner periphery of the triport (13). And the three sliding grooves (22) in the axial direction corresponding to the roller, and the roller (11) of the tripod (13) is fitted into the sliding groove (22), so that the axial sliding and both shafts The rotation torque can be transmitted while the angle can be angled.

  Also in this constant velocity joint, in order to prevent dust and foreign matter from entering the inside of the joint, it is generally extended or contracted or bent appropriately so as to cover the portion of the shaft (10) on the tripod (13) side from the outer case (21). A bellows-shaped boot (51) is provided.

  The boot (51) is formed as a large-diameter attachment portion (52) in which one end portion in the axial direction is fitted to the outer periphery of the outer case (21) and is fixed by a fastening member (25) such as a ring-shaped band. Further, the other end portion is formed as a small-diameter mounting portion (53) fixed to the triport side shaft (10). (54) indicates a bellows portion.

  Incidentally, the outer case (21) has an irregular shape in the circumferential direction corresponding to the arrangement of the inner peripheral sliding groove (22) as shown in FIG. The large-diameter side mounting portion (52) of the boot (51) must be fastened and fixed with its inner periphery corresponding to the shape of the outer case outer periphery in order to ensure the stability of the assembled state and the sealing performance. .

  When the boot is made of a rubber material such as chloroprene (CR), the inner periphery of the large-diameter side mounting portion can be integrally formed so as to have a shape corresponding to the irregular shape of the outer case outer periphery, A rubber material is limited in heat resistance and swingability and inferior in durability.

  Therefore, the use of a boot made of a molded product made of a resin material is increasing. However, when made of a resin material, it is more rigid than a rubber material and hardly elastically deforms. Therefore, in order to keep the sealing performance of the tightening force evenly, the large diameter side mounting portion ( 52) is interposed between the inner circumference of the outer case (21) and a ring-shaped inner circumference member (55) formed in a shape corresponding to the irregular shape of the outer circumference of the outer case by a rubber material or the like. It is tightened and fixed as if attached. Therefore, the assembling operation becomes troublesome, and the cost is high due to the use of the inner peripheral member (55) separate from the boot.

  The present invention has been made in view of the above, and as a boot in a triport type constant velocity joint, the entire structure including the large-diameter side mounting portion to the outer case is integrally formed of a resin material, so that the cost is low. In addition, it is possible to provide a resin boot that can be uniformly tightened and fixed over the outer periphery of the outer shape of the odd-shaped outer case and has good assembling and sealing properties.

  The present invention is a boot used in a constant velocity joint including a tripart on one of the input side and the output side and an outer case on the other side, and a large-diameter side attachment portion on one end side in the axial direction attached to the outer periphery of the outer case; A small-diameter side mounting portion that is attached to the triport-side shaft, and a bellows portion between the two mounting portions, each of which is integrally formed of a resin material, and the inner periphery of the large-diameter side mounting portion is the outer A non-circular shape corresponding to the shape of the outer periphery of the case is formed, and a thick portion forming an inward convex shape is formed.

  Particularly, in the present invention, a volume relief means is provided in the thick part of the large-diameter side attachment portion, and the large-diameter side attachment portion is formed so as to be clamped and fixed substantially uniformly over the outer circumference of the outer case. It is characterized by becoming.

  This resin boot is used in a triport type constant velocity joint, and fits the inner periphery of the large-diameter side mounting portion of the corresponding shape to the outer periphery forming the uneven shape of the outer case, What is necessary is just to fix | tighten and fix with a fastening member, and it can assemble | attach easily, without using inner peripheral members, such as another rubber material.

  In addition, in the large-diameter side mounting portion, a thick-walled portion that is more rigid than the thin-walled portion due to the tightening is provided by providing a volume relief means in the thick-walled portion that protrudes inward. As a result, the thick part is tightened together with the thin part with a substantially uniform force along the thin part. Holds well.

  Preferably, the volume relief means comprises one or a plurality of grooves provided on the outer periphery of the thick wall portion, so that the excess volume at the time of tightening is released to the space of the grooves, and the tightening force Is equalized over the entire circumference.

  Further, it is preferable that one or a plurality of sealing protrusions are provided on the inner periphery of the large-diameter side mounting portion, and in combination with being tightened substantially uniformly over the entire periphery, Good sealing performance can be secured.

  The resin material is preferably a thermoplastic elastomer resin, especially one containing mineral oil or vegetable oil. Thereby, even if it is bent and displaced at a wide angle and continuously rotated, it is possible to suppress the generation of abnormal noise such as scratching noise. In addition, good sealing and durability can be secured. Further, as the thermoplastic elastomer resin, those containing a fatty acid amide or those containing a polyether can also be used.

  As described above, the present invention is a resin boot used for a tripart type constant velocity joint, including a large-diameter side mounting portion having a non-circular inner peripheral shape corresponding to the irregular shape on the outer periphery of the outer case. Since it is integrally formed of a resin material, it can be easily assembled without interposing an inner peripheral member such as another rubber material on the inner periphery, and can be manufactured and provided at low cost.

  Moreover, since the thick-walled portion of the large-diameter side mounting portion is provided with a volume escape means such as a groove, the thick-walled portion and the thin-walled portion can be tightened and fixed substantially uniformly over the entire circumference, and can be assembled and sealed. Satisfactory and excellent durability.

  In addition, when the constituent material is made of a thermoplastic elastomer resin, especially a thermoplastic elastomer resin blended with mineral oil or vegetable oil, even if it is continuously rotated in a state of being bent and displaced at a wide angle, the resin boot may be scratched. Generation of abnormal noise can be suppressed, and the effect can be favorably sustained.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  1 is a longitudinal sectional view of a resin boot according to an embodiment of the present invention attached to a joint, FIG. 2 is a front view of a part of the boot from the large diameter side, and FIG. FIG. 4 is a cross-sectional view taken along line XX in the previous figure. FIGS. 5 and 6 are partially enlarged sectional views showing other examples of the volume relief means, and FIGS. 7 and 8 are partially enlarged sectional views showing other examples of the sealing protrusions on the inner periphery. is there.

  The boot (1) of this embodiment has a large-diameter side attachment portion (2) that is attached to an outer case (21) that is attached to one of the input side and output side shafts (20) of a triport type joint. And a small-diameter side attachment portion (3) on the other end side attached to the shaft on the triport (13) side, and a tapered bellows portion (4) connecting these attachment portions (2) and (3). These are integrally formed of a resin material by injection molding or press blow molding.

  In particular, the large-diameter side mounting portion (2) has a substantially circular outer periphery and a non-circular shape corresponding to the irregular shape of the outer case (21) outer periphery, and has a required circumferential interval. A thick part (2a) that forms an inward convex shape corresponding to the concave part on the outer periphery of the outer case is formed. Thereby, the thick part (2a) and the thin part (2b) are formed alternately.

  In the case of the figure, a circumferential recess (5) is formed on the outer periphery of the large-diameter side mounting portion (2) for positioning (preventing retaining) of a tightening member (25) such as a ring-shaped band. Is circular. A concave portion (6) in the circumferential direction of the fastening member (15) is also formed on the outer periphery of the small diameter side attaching portion (3) in the same manner as described above.

  In particular, a volume relief means (7) at the time of tightening by the tightening member (25) is provided in the thick part (2a) of the large diameter side attaching part (2). As the volume escape means (7), in the case of the embodiment shown in FIGS. 1 to 4, one or more grooves (7a) in the circumferential direction are formed on the outer peripheral surface of the thick part (2a).

  That is, in the case of being made of a resin material, it is more rigid than a rubber material and hardly elastically deforms. Therefore, when tightening with the tightening member (25), the thick portion (2a) has too much volume, and this The tightening force between the portion and the thin portion (2b) becomes uneven. Therefore, the volume relief means (7) is provided at the time of tightening as described above, and the entire outer circumference of the outer case (21) where the large-diameter mounting portion (2) is uneven in the circumferential direction is provided. It is good to be able to tighten with a substantially equal force.

  In practice, it is desirable that the groove (7a) is formed deeper as the thickness increases, or the volume in the groove is increased by increasing the groove width.

  As the volume relief means (7), in addition to the groove (7a), for example, a relatively wide groove (7b) as shown in FIG. 5 is formed, or as shown in FIG. A groove (7c) having a substantially W-shaped cross section having a ridge (7d) inside is formed, or a groove that gradually deepens toward both sides is formed by leaving the central portion flat (not shown). Etc.), and the like can be carried out in various forms such as various grooves, recesses and the like that can release the volume during tightening. In any case, it is preferable to increase the volume of the groove or the concave portion as the thickness increases, so that the volume can be easily released.

  Further, one or a plurality of sealing protrusions (8) are provided on the inner periphery of the large-diameter side mounting portion (2). As the convex portion for sealing (8), as shown in the embodiment of FIGS. 1 to 4, tapering convex portions (8a) having a wedge-shaped cross section are provided on both side ends of the convex portion having a trapezoidal cross section, FIG. Various forms such as one provided with one or a plurality of ridges (8b), and a narrow groove (8c) formed in the center in the width direction of the convex portion having a trapezoidal cross section as shown in FIG. Can be implemented.

  The above-mentioned resin materials include thermoplastic elastomer resins (TPE), for example, thermoplastic elastomer resins such as polyester, polyolefin, and polyurethane that have grease resistance, bending fatigue resistance, and moderately deformable flexibility. Is preferably used. In particular, a blend of mineral oil or vegetable oil with 5 parts by weight or less, preferably 3 parts by weight or less, with respect to 100 parts by weight of the thermoplastic elastomer resin, using the resin as a base material. This is particularly effective because it is effective in preventing the generation of sound.

  Mineral oils added to the thermoplastic elastomer resin include paraffinic, naphthenic, and aromatic types. Among them, those using 100% paraffinic oil or those mainly composed of paraffinic oil are used. preferable. Examples of vegetable oils include rapeseed oil, linseed oil, soybean oil, castor oil and the like.

  Moreover, what mixed the fatty acid amide or the polyether with the thermoplastic elastomer resin similar to the above can be used as an above-described resin material.

Fatty acid amides having the following structural formula [A], those having a low melting point of 20 to 60 ° C., and blending 0.2 to 1.5 parts by weight with respect to 100 parts by weight of the elastomer resin, or The thing of the following structural formula [B], and melting | fusing point 80-150 degreeC high melting | fusing point can mix | blend 0.03-0.15 weight part with respect to 100 weight part of elastomer resins.

However, R < ₁ >, R < ₂ > is either an alicyclic hydrocarbon group, an aromatic hydrocarbon group, an aliphatic hydrocarbon group, and an unsaturated hydrocarbon group, respectively, Comprising: Carbon number is 6 or more. R ₃ is any one of an alicyclic hydrocarbon group, an aromatic hydrocarbon group, an aliphatic hydrocarbon group, and an unsaturated hydrocarbon group, and has 2 or more carbon atoms.

Moreover, as a polyether, the thing of the following structural formula [C]-[E], what blended 0.01-20 weight part with respect to 100 weight part of elastomer resins of the thing of number average molecular weight 10000-50000 Can be illustrated.

However, R ₄ , R ₆ , R ₉ , R ₁₀ are each a functional group obtained by removing 2 hydrogen from a hydrocarbon compound having 1 to 6 carbon atoms, and R ₅ and R ₇ are each hydrogen or a hydrocarbon having 1 to 20 carbon atoms. A functional group obtained by removing one hydrogen from a compound, R ₈ is a functional group obtained by removing one hydrogen from a hydrogen or hydrocarbon compound having 1 to 20 carbon atoms, or a functional group in which one hydroxyl group is bonded to R ₁₀ , and R ₁₁ is hydrogen or carbon. 1 hydroxyl groups from C 1 -C 20 hydrocarbon compound to a functional group or R ₉ except one hydrogen is bonded to a functional group. x, y, z represents an integer of 1-1000.

  For example, as shown in FIG. 1, the resin boot of the present invention includes a triport (13) on one shaft (10) on the input side and the output side, and an outer case (21) on the other shaft (20). In a so-called triport type constant velocity joint, the large-diameter side take-up portion (2) is fitted to the outer periphery of the outer case (21), and is fastened and fixed by a ring-shaped fastening member (25). The attachment portion (3) is used by being fastened and fixed by the fastening member (15) of the shaft (10) on the tripod (13) side.

  At the time of this assembly, in the large-diameter side attachment portion (2), the inner peripheral shape forms a non-circular shape corresponding to the concave and convex shape on the outer periphery of the outer case (21), and the inner convex shape is thick. Since the thick part (2a) is formed, the thick part (2a) is fitted so as to fit into the concave part on the outer periphery of the outer case (21). Thus, when the tightening member (25) is tightened from the outer peripheral portion, the thick-walled portion (2a) is provided with volume relief means (7), for example, a circumferential groove (7a). The volume of 2a) is appropriately released and tightened in substantially the same manner as the thin-walled portion (2b) and thick-walled portion (2a). It can be fastened and fixed with a substantially uniform tightening force.

  In addition, a sealing convex portion (8) is provided on the inner circumference over the entire circumference of the thick portion and the thin portion, and the convex portion (8) is compressed to further improve the sealing state. Can be retained.

It is a longitudinal cross-sectional view of the state attached to the joint which shows one Example of the resin-made boots concerning this invention. It is the front view which omitted a part from the diameter large side of a boot same as the above. It is a partial expanded sectional view of FIG. It is sectional drawing of the XX line of a previous figure. It is a partial expanded sectional view which shows the other example of a volume escape means. It is a partial expanded sectional view which shows the further another example of a volume escape means. It is a partial expanded sectional view which shows the other example of the convex part for a seal | sticker of an inner periphery. It is a partial expanded sectional view which shows the further another example of the convex part for sealing of an inner periphery. It is a longitudinal cross-sectional view which shows the triport type constant velocity joint which attached the conventional boot. It is sectional drawing of a YY line same as the above.

Explanation of symbols

(1) Boot (2) Large-diameter side mounting part (2a) Thick-walled part (2b) Thin-walled part (3) Small-diameter side mounting part (4) Bellows part (5) (6) Recessed part (7) Volume escape means ( 7a) (7b) Groove (7d) Convex strip (7c) Groove with substantially W-shaped cross section (8) Convex portion for sealing (8a) (8b) Convex strip (8c) Narrow groove (10) (20) Shaft (12) ) Trunnion (13) Tripod (21) Outer case (22) Sliding groove (15) (25) Tightening member

Claims (8)

  A boot used in a constant velocity joint having a tripart on one of the input side and the output side and an outer case on the other side, a large-diameter side attachment portion on one end in the axial direction attached to the outer periphery of the outer case, It consists of a small-diameter side attachment portion attached to the shaft and a bellows portion between the two attachment portions. These parts are integrally formed of a resin material, and the inner periphery of the large-diameter side attachment portion corresponds to the outer periphery of the outer case. A resin boot for a constant velocity joint, characterized in that it has a non-circular shape and is formed with a thick-walled portion that is convex inward.   The volume relief means is provided in the thick part of the large-diameter side attachment portion, and the large-diameter side attachment portion is formed so as to be clamped and fixed substantially uniformly over the outer circumference of the outer case. Resin boots for constant velocity joints as described.   The resin boot for a constant velocity joint according to claim 2, wherein the volume relief means comprises one or a plurality of grooves provided on the outer periphery of the thick portion.   The resin boot for a constant velocity joint according to any one of claims 1 to 3, wherein one or a plurality of sealing convex portions are provided on an inner periphery of the large-diameter mounting portion.   The resin boot for a constant velocity joint according to any one of claims 1 to 4, wherein the resin material is made of a thermoplastic elastomer resin.   The resin boot for a constant velocity joint according to claim 5, wherein the thermoplastic elastomer resin is a blend of mineral oil or vegetable oil.   The resin boot for a constant velocity joint according to claim 5, wherein the thermoplastic elastomer resin is a mixture of a fatty acid amide.   The resin boot for a constant velocity joint according to claim 5, wherein the thermoplastic elastomer resin is a mixture of polyether.

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