JPH0460272A - Flexible boot - Google Patents

Abstract

PURPOSE:To make it easy to fit a flexible boot, to reduce the number of parts, and to reduce production costs by molding a boot body of synthetic resin and molding the securing section, which is connected to the end section of the boot body in a body, of rubber. CONSTITUTION:A flexible boot comprises a flexible boot 1, accordion fold boot body 2 having a large diameter, and the nearly cylindrical securing section 4 provided to the small diameter section 3 of the boot body 2. The boot body 2 is molded of soft synthetic resin comprising thermoplastic elastomer such as polyester, polyamide, polyurethane, etc., in a body, and the end section 5 of the boot 2 is fastened and fixed to the outer peripheral surface of the opening of the housing 6 of an isokinetic joint by a ring-like fastening device 7. The securing section 4 is molded of oil proof and ozone proof rubber material such as chloroprene rubber, hydrogenerated nitrile butadiene rubber, acrylic rubber, silicone rubber, fluoro rubber, etc., in a body, and the whole is fastened and fixed to the outer peripheral surface of a rotary shaft 9 by a ring-like fastening device 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flexible boot that is attached to, for example, a power transmission system of an automobile.

As is well known in the art, a flexible boot is attached to a constant velocity joint, steering mechanism, etc. located at the end of a drive shaft of an automobile.

This flexible boot consists of a bellows-shaped main body and a cylindrical mounting part provided at the end of the main body, and holds grease for lubricating the constant velocity joint etc. from the outside. This prevents the intrusion of debris such as dust and water. And these flexible boots are
The boot body and the entire mounting portion are generally integrally molded from synthetic rubber.

However, when the entire flexible boot is integrally molded from synthetic rubber in this way, there are problems in that the manufacturing work becomes complicated and productivity deteriorates.

Therefore, as in the technique described in Japanese Utility Model Publication No. 56-72963, the entire flexible boot is integrally molded from a soft synthetic resin material, and the boot body is attached to the outer periphery of the opening end of the housing, which is equipped with a joint mechanism inside. One end is tightened and fixed with a fastener, and the mounting part is tightened and fixed with a fastener via an O-ring-shaped sealing member to a rotating shaft fixed to an inner ring in the housing. There is.

Problems to be Solved by the Invention However, in the conventional example described in the above-mentioned publication, the mounting portion is also molded from a soft synthetic resin material, and therefore sufficient sealing performance cannot be obtained with the mounting portion alone.

That is, in general, soft synthetic resin materials have a property that the higher the environmental temperature in which they are used, the more their mechanical strength decreases significantly, that is, the compression set remains. Therefore, in order to ensure sufficient sealing performance, a sealing member made of a rubber material is interposed between the mounting portion and the rotating shaft as described above.

However, when a sealing member is used, not only does the sealing member itself have to be fitted in a predetermined position on the rotating shaft in advance when mounting the mounting portion over the outer circumferential surface of the rotating shaft.
When the mounting portion is placed over the sealing member, there is a risk that the sealing member may be twisted and misaligned, or in some cases, the sealing member may be pushed out by the tip of the mounting portion and be completely removed from the fitted position. As a result, the installation work of the flexible boots becomes extremely complicated, leading to a decrease in the efficiency of the installation work.

Furthermore, in addition to the sealing member, a support member for stably supporting the sealing member on the rotating shaft is required, which inevitably increases the number of parts and the manufacturing cost.

Means for Solving the Problems The present invention was devised in view of the above-mentioned conventional situation, and
In particular, the boot body is made of a synthetic resin material, and the mounting portion integrally connected to the end of the boot body is made of a rubber material.

Effects According to the above configuration, since the boot body is molded from a synthetic resin material, manufacturing workability is improved, and since the mounting portion is molded from a rubber material, the influence of heat load is reduced, and the boot can be mounted without using a conventional sealing member. can be attached directly to the rotating shaft.

Example Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of a flexible boot according to the present invention, which includes a bellows-shaped large-diameter boot body 2, and a substantially cylindrical boot body 2 provided at a small-diameter end 3 of the boot body 2. It is composed of a mounting section 4.

The boot body 2 is integrally molded with a soft synthetic resin material made of thermoplastic elastomer such as polyester, polyamide, polyurethane, etc., and the large diameter end 5 is annularly fastened to the outer peripheral surface of the open end of the housing 6, which is a constant velocity joint. While being tightened and fixed by a fitting 7, the small diameter end 3 has a substantially cylindrical shape, and an annular projection 8 is provided at the inner end of the inner circumferential surface 3a to restrict the maximum inward movement position of the mounting portion 4. is provided.

The mounting portion 4 is integrally molded from a rubber material having oil resistance and ozone resistance such as chloroprene rubber, hydrogenated nitrile butadiene rubber, acrylic rubber, silicone rubber, fluororubber, etc., and the entire mounting portion 4 is attached to the rotating shaft 9. The outer peripheral surface of the small diameter end 3 is tightened and fixed by an annular fastener 10, and the outer diameter L1 is set to be slightly smaller than the inner diameter of the small diameter end 3. The length is set to approximately twice the length of section 3. Further, a flange portion 11 is provided on the outer periphery of the front end portion to prevent the fastener 10 from being pulled out.

The boot body 2 and the mounting portion 4 are integrally connected to each other by adhesive or vulcanization bonding during the respective molding processes. That is, when the boot body 2 is molded first, the adhesive 12 is applied to the inner circumferential surface 3a of the small diameter end 3 in advance, and then when the mounting part 4 is vulcanized and molded within the small diameter end 3. In addition, the two parts 3 and 4 are integrally and firmly vulcanized and bonded via an adhesive 12. In addition, when the mounting part 4 is molded first, adhesive 12 is applied to the outer peripheral surface of the rear end of the mounting part 4.
is applied in advance, and then both 3 and 4 are integrally and firmly adhered via an adhesive 12 when the boot body 2 is molded. As the adhesive 12, a chlorinated rubber-based, phenol-based, or incyanate-based rubber vulcanized adhesive is used.

The operation of this embodiment will be explained below. That is, since the boot body 2 is made of a soft synthetic resin material, it is possible to ensure good manufacturing workability of the boot body 2.
Since the mounting portion 4 is molded from a rubber material, a decrease in mechanical strength due to thermal load can be sufficiently suppressed. For this reason,
Even if the mounting portion 4 is directly attached to the rotating shaft 9, good sealing performance can be maintained. As a result, there is no need for a conventional sealing member at all, making it easier to attach the flexible boot 1 to the constant velocity joint and reducing manufacturing costs.

2 to 4 show different connection structures between the boot body 2 and the mounting part 4. The structure shown in FIG. In addition, in FIGS. 3 and 4, grooves 14 or through holes 15 are formed intermittently in the circumferential direction in the small diameter end 3, while Fitting protrusions 1.6.17 are provided on the outer peripheral surface of the rear end portion to fit into each of the grooves 14 or through holes 15. This makes it possible to expand the contact area between both 3 and 4 and further strengthen the adhesive force of the adhesive 12.

5 and 6 show the manufacturing process of the flexible boot I, FIG. 5 shows the case where the boot body 2 is manufactured first, and FIG. 6 shows the case where the mounting part 4 is manufactured first. .

Specifically, when manufacturing the boot body 2 first, a polyester resin molded body that will become the boot body 2 is first formed by blow molding in a first step 2I, and then a small diameter end portion is formed in a second step 22. For example, a chlorinated rubber adhesive 12 is applied to the inner circumferential surface 3a of 3 by spraying or brushing. Subsequently, in a third step 23, the resin molded body of the boot body 2 is placed in a mold for molding the mounting portion shown in FIG. 7, that is, a lower mold 26, an upper mold 27. It is set at a predetermined position in a mold consisting of a medium mold 28, and the mold is clamped. Next, in the fourth step 24, a rubber material such as Rolobrene rubber is injected as described above into the cylindrical cavity 29 between the upper mold 27 and the middle mold 28 through the injection gate 30, and the rubber material is vulcanized. Shape.

The vulcanization temperature was set at approximately 150°C, and the vulcanization time was approximately 4
It was set to minutes. Therefore, the mounting portion 4 is integrally bonded within the small diameter end portion 3 via the adhesive I2 by this vulcanization heat. In this way, the flexible boot 1 in which the boot body 2 and the mounting portion 4 are integrally and firmly connected is completed. In addition, when performing the vulcanization molding, the mold is heated to 100°C in advance.
Keep it warm to a moderate degree (.

In such a manufacturing method, since the boot body 2 and the mounting part 4 are bonded together using vulcanization heat as described above,
Both 2 and 4 can be easily and organically combined. Further, since the mounting portion 4 is formed by vulcanization molding of rubber, it is possible to form a sealing lip on the mounting portion 4 and to freely change the shape.

Next, a case where the mounting portion 4 is manufactured first will be described.

First, in a first step 31, a rubber molded body that will become the attachment part 4 is molded from a rubber material such as chloroprene by injection molding, and then in a second step 32, a chlorinated rubber The adhesive 12 is applied by spraying or brushing. Subsequently, in a third step 33, the rubber molded body is set in a predetermined position inside a resin mold and the mold is clamped. Next, in a fourth step 34, a polyester resin molding which will become the boot body 2 is molded in the mold, and the rubber molded body is connected to the molded body. That is, a resin material heated to 180° C. or higher is injected into a resin mold kept at about 100° C., and this state is maintained for about 1 minute to form a resin molded body. In addition, the resin material that has flowed into the mold comes into contact with the rubber molded body, and the resin material 18
The rubber molded body and the resin molded body are integrally bonded via the adhesive 12 by heat of 0° C. or higher. In this way, the flexible boot 1 in which the boot body 2 and the mounting portion 4 are integrally and firmly connected is completed.

Therefore, in this manufacturing method as well, it is possible to obtain the same effects as the above-mentioned method.
In order to bond the and mounting part 4 at a high temperature of 180°C or higher,
The bonding strength is further improved.

In the above embodiments, a flexible boot used for a constant velocity joint has been described, but the present invention is not limited to this. Further, the shape, wall thickness, etc. of the boot body 2 and the mounting portion 4 can be sufficiently changed.

Effects of the Invention As is clear from the above explanation, according to the flexible boots of the present invention, the boot body is made of synthetic resin material, which not only facilitates manufacturing work, but also allows the mounting part to be made of rubber material. Since it is molded, a decrease in mechanical strength due to heat load can be sufficiently suppressed, and good sealing performance can be maintained only with the mounting portion. As a result, there is no need for a conventional sealing member, making it easier to attach the flexible boot to equipment, as well as reducing the number of parts and manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the flexible boot according to the present invention applied to a constant velocity joint, FIG. 2 is a sectional view showing another connection structure between the boot body and the mounting portion of the present invention, and FIG. 3 4 is a sectional view showing a further different connection structure, FIG. 5 is a block diagram showing an example of the manufacturing process of the flexible boot in this embodiment, and FIG. 6 is the same. A block diagram showing the other side of the manufacturing process;
FIG. 7 is a sectional view showing a mold apparatus used in the manufacturing method shown in FIG. 5. 1...Flexible boots, 2...Boots body, 3
... Small diameter end, 4... Mounting part. Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) In a flexible boot consisting of a boot body and an attachment part that are attached to the outer periphery of equipment, the boot body is formed of a synthetic resin material, and the flexible boot is integrally connected to the end of the boot body. Flexible boots characterized by a mounting part made of rubber material.