JP5122218B2 - Boot installation method - Google Patents

Description

  The present invention relates to a method for mounting a boot used in a drive shaft of an automobile or various industrial machines and mounted on a constant velocity universal joint that transmits rotational torque.

  A boot for a constant velocity universal joint is attached to a joint body in order to prevent leakage of a lubricating component filled in the joint to the outside and entry of foreign matter from the outside into the joint. As these boots, resin boots and CR (chloroprene) boots are widely known, but in recent years, resin boots are often employed from the viewpoint of bending durability and the like.

  FIG. 3 shows an example of a constant velocity universal joint (a ball-fixed fixed type constant velocity universal joint, referred to as BJ). The constant velocity universal joint 101 includes an outer ring 102, an inner ring 103, a ball 104, and a cage 105 as main parts. Inside the outer ring 102, an internal part 106 including the inner ring 103, the ball 104, and the cage 105 is accommodated. .

  The outer ring 102 has an opening at one end, and a plurality of curved track grooves 107 are formed on the inner spherical surface. The inner ring 103 has a shaft 115 spline-fitted into the center hole 117 and is prevented from coming off by a circlip 116, and a plurality of curved track grooves 108 that are paired with the track grooves 107 of the outer ring 102 are formed on the outer spherical surface. ing. A plurality of balls 104 are interposed between the track groove 107 of the outer ring 102 and the track groove 108 of the inner ring 103, and these balls 104 are pockets of a cage 105 disposed between the outer ring 102 and the inner ring 103. 109. The track grooves (107, 108) are formed in a curved shape over the entire length in the axial direction, which is a feature of the ball fixture type constant velocity universal joint.

  In such a constant velocity universal joint 101, the opening of the outer ring 102 is covered with a resin boot 110, and the lubricating component enclosed in the outer ring 102 leaks out of the joint by the boot 110. In addition, it is possible to prevent foreign matter from entering the outer ring 102.

The boot 110 has a large-diameter end 111 and a small-diameter end 112 and a bellows 118 that connects the large-diameter end 111 and the small-diameter end 112. The large-diameter end portion 111 is attached to the outer peripheral surface 120 of the open end portion 119 of the outer ring 102, the small-diameter end portion 112 is attached to the outer peripheral surface 121 of the shaft 115, and each attachment portion adds a boot band (113, 114). It is fastened and fixed (see Patent Document 1).
JP 2007-155002 A

  In the constant velocity universal joint described in Patent Document 1 shown in FIG. 3, the boot 110 is attached and fixed by attaching the large-diameter end 111 to the outer peripheral surface 120 of the outer ring 102 and the small-diameter end 112 to the outer peripheral surface of the shaft 115. It attaches to 121, Furthermore, each attachment part is performed by crimping a boot band (113,114).

  However, in this case, since the boot band (113, 114) must be used as a separate part, the number of parts increases, and there is a problem that the manufacturing cost necessary for assembling the constant velocity universal joint 101 increases. Further, since the work of crimping the boot bands (113, 114) is also required, there is a problem that the time required for assembling the constant velocity universal joint 101 becomes long.

  The present invention has been made in view of the above circumstances, omitting the boot band, making the constant velocity universal joint compact and lightweight, and reducing the cost required for assembling the constant velocity universal joint. An object of the present invention is to provide a boot mounting method that can be used.

The boot mounting method of the present invention for solving the above-described problem is a mounting method for a resin constant velocity universal joint boot whose end is fixedly attached to a metal mating member, wherein the end of the boot mounted fixed to the mating member, only the surface portion of the mounting surface of the mating member and the attachment surface of the mating member and the mounting surface of the end portion of the boot and heated by high frequency induction, contact with the metal The boundary portion of the resin is decomposed by rapid heating at a temperature equal to or higher than the decomposition temperature, and bubbles are generated so as to be joined and integrated.

  In this case, the mounting surface of the metal mating member is indirectly heated, and the mounting surface of the end of the boot and the mounting surface of the mating member can be joined and integrated with the heat. The end can be attached and fixed to the mating member. Here, “indirectly heating the mounting surface of the mating member” means heating the mounting surface of the mating member without directly applying heat. In addition, the “attachment and fixation” here means that the end of the boot can be attached and fixed to the mating member without depending on other parts.

The indirect heating of the attachment surface of the mating member, intends row by high frequency induction.

  This high-frequency induction is a method that can heat only a conductive material, and the mounting surface of the end of the boot and the mounted surface of the mating member are brought into close contact with the end of the boot in the coil. In this state, a high frequency current is passed through the coil. In this case, the mounted surface of the metal, that is, the conductive mating member is indirectly heated by the high frequency via the end of the boot, and the end of the boot contacting the mating surface of the mating member with the heat. Bubbles are generated at the boundary portion of the mounting surface, and the mounting surface at the end of the boot and the mounted surface of the mating member are joined and integrated. As a result, the end of the boot can be attached and fixed to the mating member without using a fixing part such as a boot band.

In the high frequency induction, the mounting surface of the mating member heat only the surface layer portion.

  This is because when the heating depth of the mounting surface of the mating member (depth from the surface layer of the heated part) is deep, that is, when the heating part of the mating surface of the mating member is not only the surface layer part, it was heated. The mounted surface of the mating member cannot be self-cooled (naturally cooled) and melts the resin component of the boot with heat, so that it can be joined and integrated with the mounting surface of the boot end. This is because it disappears.

  The material for the mounting surface of the boot end is preferably a thermoplastic polyester elastomer.

  Thermoplastic polyester elastomers are excellent as mechanical strength, moldability and elasticity, and are preferable as a material having functions such as bending durability required for boots. In addition, since thermoplastic polyester elastomers are not easily heat-deformed and have a high heat-resistant temperature, if this material is applied to boots that are exposed to high temperatures such as during the operation of constant velocity universal joints, the durability of the boots will decrease due to high temperatures. Can be prevented.

  It is desirable to add carbon black to the material of the mounting surface of the boot end.

  When carbon black is added to the material of the mounting surface of the boot end, the end of the boot can be colored black and the strength of the end of the boot can be improved. In addition, when carbon black is added to the mounting surface at the end of the boot, as described above, carbon is also used when the mounting surface of the boot end and the mounted surface of the mating member are joined and integrated by high frequency induction. Since black does not affect high frequency, it does not hinder bonding by high frequency induction.

According to the boot mounting method of the present invention, the fixing of the end of the boot to the mating member is performed by induction of only the surface layer portion of the mating surface of the mating member between the mounting surface of the boot end and the mating surface of the mating member. by heating with, carried out by the boundary of the resin which is in contact with the metal is decomposed by rapid heating above the decomposition temperature integrally bonding by foam generated. In this case, the fixing of the boot to the mating member can be performed without using a fixing part such as a boot band, so the number of parts is reduced and the cost required for assembling the constant velocity universal joint is reduced. Can do. Moreover, since it is not necessary to use fixed parts, such as a boot band, the structure of the constant velocity universal joint can be simplified, and the constant velocity universal joint can be made compact and light.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows an undercut-free type constant velocity universal joint (UJ) which is one of fixed type constant velocity universal joints to which the boot mounting method of the present invention is applied.

  The constant velocity universal joint 1 includes an outer ring 2 that is an outer joint member, an inner ring 3 that is an inner joint member, a ball 4 and a cage 5, and the inner ring 3, the ball 4, and the cage 5 are disposed inside the outer ring 2. An internal component 6 is accommodated and arranged.

  The outer ring 2 is made of metal, has an opening at one end, and a plurality of curved track grooves 7 are formed on the inner spherical surface. The inner ring 3 is formed with a plurality of curved track grooves 8 that are paired with the track grooves 7 of the outer ring 2 on the outer spherical surface, and a metal shaft 15 is spline-fitted into the center hole 14. It is prevented from coming off by a circlip 20 fitted in a fitting groove 16 formed on the outer peripheral surface of the tip portion. A plurality of balls 4 are interposed between the track grooves 7 of the outer ring 2 and the track grooves 8 of the inner ring 3. These balls 4 are pockets of the cage 5 disposed between the outer ring 2 and the inner ring 3. 9 is held. Since the curved track grooves (7, 8) are formed flat on the outer ring opening side and curved on the outer ring opposite opening side, this constant velocity universal joint 1 has a high operating angle. The shaft 15 and the inner peripheral surface of the open end 17 of the outer ring 2 are less likely to interfere with each other. This is a feature of a fixed type constant velocity universal joint of an undercut free type.

  The opening of the outer ring 2 is covered with a resin boot 10, and this boot 10 can prevent the lubricating component enclosed in the outer ring 2 from leaking to the outside of the joint, and can also be connected to the outside of the outer ring 2. It is possible to prevent foreign matter from entering from.

  The boot 10 has a large-diameter end portion 11 and a small-diameter end portion 12 and a bellows portion 13 that connects the large-diameter end portion 11 and the small-diameter end portion 12. The large-diameter end portion 11 is attached to the outer peripheral surface of the opening end portion 17 of the outer ring 2 that is the counterpart member, and the small-diameter end portion 12 is attached to the outer peripheral surface of the shaft 15 that is the counterpart member.

  Here, the mounting and fixing of the large diameter end portion 11 to the outer ring 2 is performed by attaching the mounting surface 21 which is the inner peripheral surface of the large diameter end portion 11 and the mounting surface 18 which is the outer peripheral surface of the outer ring 2 to the outer ring 2. The surface 18 is heated indirectly and integrated. The small diameter end 12 is fixedly attached to the shaft 15 by attaching the mounting surface 22 which is the inner peripheral surface of the small diameter end 12 and the mounted surface 19 which is the outer peripheral surface of the shaft 15 to the mounting surface 19 of the shaft 15. It is performed by indirectly heating and integrating them.

  In this case, the large-diameter end 11 and the outer ring 2 of the boot 10 and the small-diameter end 12 and the shaft 15 of the boot 10 can be mounted and fixed without using a fixing component such as a boot band as shown in FIG. Therefore, the number of parts can be reduced and the cost required for assembling the constant velocity universal joint 1 can be reduced. In addition, since the fixed parts such as the boot band can be omitted, the entire structure of the constant velocity universal joint 1 can be simplified, so that the constant velocity universal joint 1 can be reduced in weight and size.

  Here, the attachment surface 21 of the large-diameter end portion 11 of the boot 10 and the attachment surface 18 of the outer ring 2 are joined and integrated, and the attachment surface 22 of the small-diameter end portion 12 of the boot 10 and the attachment surface 19 of the shaft 15 are integration and integration. As a means for indirectly heating the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15, a joining method using high frequency induction is employed. Here, “directly heating” means heating the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15 without directly applying heat.

  This high frequency induction joining method is a method of heating a conductive material at high frequency. First, as shown in FIG. 2, the mounting surface of the large-diameter end 11 of the boot 10 is placed in an annular metal coil 150. 21 and the mounted surface 18 of the outer ring 2 made of metal are placed in close contact with each other, and the mounting surface 22 of the small-diameter end 12 of the boot 10 and the shaft made of metal are placed in an annular metal coil 160. The 15 attached surfaces 19 are arranged in close contact with each other, and a high-frequency current is passed through the metal coils (150, 160).

At this time, the metal (conductor mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15), which is a conductor, generates heat due to iron loss (the sum of eddy current loss and hysteresis loss) due to electromagnetic induction. , Resin (mounting surface 21 of large-diameter end 11 of boot 10, mounting surface 22 of small-diameter end 12 of boot 10) in contact with metal (mounted surface 18 of outer ring 2 and mounted surface 19 of shaft 15) The boundary is heated rapidly above the decomposition temperature and decomposes, generating bubbles. As a result, high-temperature and high-pressure conditions are generated on the surfaces of the high-temperature melt and metal (the attached surface 18 of the outer ring 2 and the attached surface 19 of the shaft 15) in the peripheral portion of the foam, as shown in FIG. As described above, between the attachment surface 21 of the large-diameter end portion 11 of the boot 10 and the attachment surface 18 of the outer ring 2 and between the attachment surface 22 of the small-diameter end portion 12 of the boot 10 and the attachment surface 19 of the shaft 15. Can obtain invisible joints (23, 24).
As a result, the attachment surface 21 of the large-diameter end portion 11, the attachment surface 18 of the outer ring 2, the attachment surface 22 of the small-diameter end portion 12, and the attachment surface 19 of the shaft 15 are joined and integrated, respectively. The small diameter end 12 can be fixedly attached to the shaft 15 by being fixedly attached to the outer ring 2.

  In this way, when the attachment surface 21 of the large-diameter end portion 11 and the attachment surface 18 of the outer ring 2 and the attachment surface 22 of the small-diameter end portion 12 and the attachment surface 19 of the shaft 15 are respectively joined and integrated by high frequency induction, the outer ring The heating of the mounting surface 18 of 2 and the mounting surface 19 of the shaft 15 is performed only on the surface layer portion, specifically, the heating depth from the surface is 0.1 mm or less.

  As a result, the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15 are self-cooled (naturally cooled) immediately after heating. The mounted surface 19 melts the mounting surface 21 of the large-diameter end portion 11 and the mounting surface 22 of the small-diameter end portion 12 with the heat, so that the mounting surface 21 of the large-diameter end portion 11 and the outer ring 2 are covered. The attachment surface 18 and the attachment surface 22 of the small-diameter end 12 and the attachment surface 19 of the shaft 15 cannot be joined and integrated.

  As a means for heating only the surface portion of the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15, there is a method of increasing the frequency of the apparatus for performing high-frequency induction or shortening the heating time.

  In this embodiment, the frequency of the high-frequency induction device is 200 kHz, the high-frequency output is 160 kW, and the heating time is 0.2 seconds, so that only the surface layer portions of the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15 are covered. By heating at about 600 ° C., the mounting surface 21 of the large-diameter end 11, the mounted surface 18 of the outer ring 2, the mounting surface 22 of the small-diameter end 12 and the mounted surface 19 of the shaft 15 are joined and integrated.

  In addition, when the frequency of the apparatus for performing high frequency induction is 200 kHz as in this embodiment, the high frequency output needs to be 15 kW or more and less than 250 kW.

  If the high frequency output is less than 15 kW, the heating temperature of the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15 tends to be lower than 250 ° C. In this case, the mounted surface 18 of the outer ring 2 and The mounting surface 19 of the shaft 15 is not sufficiently heated, and the boundary portion of the mounting surface 21 of the large-diameter end portion 11 that is in contact with the mounting surface 18 of the outer ring 2 and the small diameter that is in contact with the mounting surface 19 of the shaft 15. The boundary portion of the attachment surface 22 of the end portion 12 is heated to a decomposition temperature or higher so that the attachment surface 21 of the large-diameter end portion 11 and the attachment surface 18 of the outer ring 2 and the attachment surface 22 of the small-diameter end portion 12 and the shaft 15 are covered. The attachment surface 19 cannot be joined and integrated.

  When the high frequency output is 250 kw or more, the heating temperature of the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15 tends to be 700 ° C. or more. In this case, the mounting surface of the heated outer ring 2 18 and the attached surface 19 of the heated shaft 15 melt the attachment surface 21 of the large-diameter end portion 11 and the attachment surface 22 of the small-diameter end portion 12 by the heat, and the attachment surface 21 of the large-diameter end portion 11. The attached surface 18 of the outer ring 2 and the attached surface 22 of the small-diameter end 12 and the attached surface 19 of the shaft 15 cannot be joined and integrated.

  In addition, like this embodiment, when the frequency of the apparatus which performs high frequency induction shall be 200 kHz and a high frequency output shall be 15 kW or more and less than 250 kW, heating time will be controlled to 1 second or less. As a result, the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15 can be naturally cooled immediately after heating with a shallow heating depth, so that the mounted surface 18 of the heated outer ring 2 and Since the mounted surface 19 of the shaft 15 does not melt the mounting surface 21 of the large-diameter end portion 11 and the mounting surface 22 of the small-diameter end portion 12 by the heat, the mounting surface 21 of the large-diameter end portion 11 The mounted surface 18 of the outer ring 2 and the mounting surface 22 of the small diameter end portion 12 and the mounted surface 19 of the shaft 15 can be joined and integrated.

  The boot 10 of this embodiment forms the whole including the attachment surface 21 of the large-diameter end portion 11 and the attachment surface 22 of the small-diameter end portion 12 using a thermoplastic polyester elastomer as a material.

  The thermoplastic polyester-based elastomer is excellent in mechanical strength and elasticity, has a high heat deformation temperature and a heat-resistant temperature, and is excellent in moldability. Therefore, the boot 10 has these functions. In particular, since the boot 10 is exposed to a high temperature environment when the constant velocity universal joint 1 is operated, the boot 10 is molded from a thermoplastic polyester elastomer as a material to have heat resistance as in this embodiment. This is an effective means for improving the durability of the boot 10.

  Further, carbon black is added to the entire material of the boot 10 including the material of the mounting surface 21 of the large diameter end portion 11 and the material of the mounting surface 22 of the small diameter end portion 12.

  Carbon black is a fine particle of carbon having a diameter of about 3500 nm, is used as a black pigment, and functions as a reinforcing material for resin and rubber. Therefore, when carbon black is added to the boot 10 as in this embodiment, the boot 10 can be colored black and the strength of the boot 10 can be improved. When carbon black is added to the material of the mounting surface 21 of the large-diameter end portion 11 and the material of the mounting surface 22 of the small-diameter end portion 12, the large-diameter end is obtained by means of high-frequency induction as in this embodiment. When the attachment surface 21 of the portion 11 and the attachment surface 18 of the outer ring 2 and the attachment surface 22 of the small diameter end portion 12 and the attachment surface 19 of the shaft 15 are joined and integrated, the high frequency is not affected by carbon black. Therefore, joining and integration can be performed normally.

  Further, in the present embodiment, in the boot 10, a coating process is performed on the mounted surface 18 of the outer ring 2 and the mounted surface 19 of the shaft 15.

  As this coating treatment, means such as Parker treatment (zinc phosphate chemical conversion treatment) can be employed. By this coating treatment, a coating film such as a phosphate coating is formed on the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15, and the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15 are formed. Rust can be prevented from occurring. As a result, due to the rust generated on the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15, the mounting surface 18 of the outer ring 2 and the mounting surface 19 of the shaft 15 are indirectly connected by means of high frequency induction or the like already described. When heating automatically, such a situation that this work cannot be performed normally can be avoided.

  In the present embodiment, the entire outer ring 2 including the mounted surface 18 is formed from S53C (JIS number: G4051) mechanical structural carbon steel as a material. However, the present invention is not limited thereto. A material that satisfies the conditions of the following material components can be used for forming the mounting surface 18 of the outer ring 2. All units are weight (%).

  Carbon (C): 0.50 to 0.56, Silicon (Si): 0.10 to 0.40, Manganese (Mn): 0.97 to 1.10, Phosphorus (P): 0.03 or less, Sulfur (S): 0.04 or less, chromium (Cr): 0.1-0.25, copper (Cu): 0.3 or less, nickel (Ni): 0.2 or less.

  Moreover, in this embodiment, the shaft 15 is made of carbon steel for machine structural use of SBM40 in which boron is contained in S40C (JIS number: G4051) or S40C as a whole and the manganese content is increased. However, the present invention is not limited thereto, and when the present invention is carried out, a material that satisfies the conditions of the following material components can be used for forming the mounting surface 19 of the shaft 15. All units are weight (%).

  Carbon (C): 0.30 to 0.45, Silicon (Si): 0.35 or less, Manganese (Mn): 0.80 to 1.40, Phosphorus (P): 0.03 or less, Sulfur (S) : 0.01 to 0.04, chromium (Cr): 0.2 or less, copper (Cu): 0.4 or less, boron (B): 0.004 or less, nickel (Ni): 0.3 or less.

  As mentioned above, although embodiment of this invention was described, this is an illustration to the last, and is not restrict | limited to this embodiment at all, A various change is possible within the meaning and content of a claim. It is.

  For example, in the present embodiment, the present invention is applied to an undercut-free type constant velocity universal joint (UJ) which is one of fixed type constant velocity universal joints. However, the ball fixture type fixed type constant velocity shown in FIG. The present invention can also be applied to a universal joint (BJ). The present invention can be applied not only to a fixed type constant velocity universal joint but also to a known sliding type constant velocity universal joint.

It is sectional drawing which shows the constant velocity universal joint to which the boot attachment method of this invention is applied. In the embodiment shown in FIG. 1, it is sectional drawing explaining the joining method by a high frequency induction. It is sectional drawing which shows the constant velocity universal joint to which the conventional boot attachment method is applied.

Explanation of symbols

1 Fixed type constant velocity universal joint (UJ)
2 Outer ring (mating member)
10 Resin boot 11 Large diameter end 12 Small diameter end 15 Shaft (mating member)
18 Mounted surface (outer ring outer peripheral surface)
19 Mounted surface (shaft outer peripheral surface)
21 Mounting surface (Inner peripheral surface of large diameter end)
22 Mounting surface (Small diameter end inner peripheral surface)
150, 160 metal coil

Claims (3)

It is a mounting method of a boot made of a resin constant velocity universal joint whose end is attached and fixed to a metal counterpart member,
The fixing of the end of the boot to the mating member involves heating the mounting surface of the end of the boot and the mounting surface of the mating member by high-frequency induction only on the surface portion of the mounting surface of the mating member. A boot mounting method characterized in that it is performed by joining and integrating by causing a boundary portion of the resin in contact with the metal to be decomposed by rapid heating at a temperature equal to or higher than a decomposition temperature to generate bubbles . The boot mounting method according to claim 1 , wherein a material of a mounting surface of the boot end is a thermoplastic polyester elastomer. The boot attachment method according to claim 1 or 2 , wherein carbon black is added to a material of an attachment surface of the boot end.

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