JP6478765B2 - Flexible boots - Google Patents

Description

  The present invention relates to a flexible boot made of a rubber-like elastic body. More specifically, the mechanical element is covered by attaching it to a mechanical element such as a steering mechanism of an automobile, a constant velocity joint, an air cylinder device of an industrial machine, etc. to protect the mechanical element from external dust, water, etc. and around the mechanical element. The present invention relates to a flexible boot used to prevent the lubricant and the like from leaking to the outside.

  Conventionally, as shown in FIG. 3, the small diameter fixing portion 102 is fitted in the fitting groove portion 105a of the one end side counterpart member (hereinafter referred to as "tie rod 105") as in FIG. The large diameter fixing portion 103 is fitted on the outer peripheral surface of the other end side counterpart member (hereinafter referred to as "housing 106"), and the boot bands 107 and 108 are pressed from the outer peripheral side of each fixing portion. By doing this, the sealability with the other member was secured. With this configuration, it is possible to prevent dust, water, and the like from invading the inside of the flexible boot and to prevent the lubricant in the flexible boot from leaking to the outside.

  Furthermore, by forming a plurality of annular projections 102 a on the inner peripheral surface of the small diameter fixing portion 102, there are also some in which the contact area with the tie rod 105 is reduced to reduce the frictional resistance. In this case, when the toe-in adjustment of the wheel is performed by rotating the tie rod 105, it can be suppressed that the small diameter fixing portion 102 rotates together with the tie rod 105 (see Patent Document 1). .

  In addition, depending on the type of the flexible boot for reciprocating movement, the air pressure inside the flexible boot changes rapidly at the time of operation, and the flexible boot may be deformed. For this reason, by forming an annular protrusion or an annular groove in a spiral on the inner peripheral surface of the small diameter fixing portion 102 and providing a communication path enabling ventilation inside the flexible boot, the flexible boot by the air pressure change inside the flexible boot Deformation is prevented (see Patent Document 2).

Japanese Patent Application No. 60-006320 (Japanese Patent Application Laid-Open No. 61-167781) The micro film of Japanese Patent Application No. 02-008018 (Japanese Patent Application No. 03-099685)

  However, if a plurality of annular projections 102a are formed in the small diameter fixing portion 102 as shown in the configuration of FIG. 3, molding defects such as defects occur when the mold is removed from the small diameter fixing portion 102 after molding the flexible boot 101. It is easy to occur.

  Further, in the case where a communication passage for ventilating the inside and the outside of the flexible boot is formed by an annular protrusion or an annular groove on the inner peripheral surface of the small diameter fixing portion 102, intrusion of foreign matter from the outside from the communication passage is permitted. There is a risk that the lubricant of the above may leak from the communication passage.

The present invention, while maintaining low friction of the small-diameter fixing portion 102 so that the tie rod 105 and the small-diameter fixing unit 102 during toe adjustment is not rotating together, reducing molding defects, also secured inside and outside the ventilation An object of the present invention is to provide a flexible boot that can ensure the sealing performance of the small diameter fixing portion 102 above.

In order to achieve the above object, the invention according to claim 1 is characterized in that the small diameter fixing portion 2 and the large diameter fixing portion 3 respectively provided at one end and the other end in the axial direction and the position between these fixing portions in the flexible boot 1 having a bellows portion 4, together with the flexible boot body is constituted by a rubber-like elastic material, laminating a resin film 2a having low friction on the inner peripheral surface of the small-diameter fixing part 2, the resin film 2a In advance, a crease is provided to connect the inside and the outside of the flexible boot in the axial direction . With this configuration, the frictional force of the contact surface between the small diameter fixing portion 2 and the tie rod 5 can be reduced by the resin film 2a having low friction and laminated on the inner peripheral surface of the small diameter fixing portion 102. Further, since the small diameter fixing portion 2 does not have the annular protrusion 102a in the small diameter fixing portion 102 of the flexible boot 101, when removing the mold from the small diameter fixing portion 2, there is no annular protrusion 102a contacting the mold. It is possible to suppress the occurrence of molding defects such as defects that have occurred on the inner peripheral surface of the small diameter fixing portion 102 when the flexible boot 1 is molded. Further, wrinkles provided in advance on the inner peripheral surface of the small diameter fixing portion 2 serve as fine communication paths for ventilating the inside and the outside of the flexible boot 1. At this time, a force is applied to the resin film 2a in the compression direction by the compression of the boot band 7, so that the shape of a fine wrinkle can be maintained. For this reason, it becomes a structure which the foreign substance from the outside can not easily invade, and it can make a lubricant hard to leak from the inside of flexible boots.

The invention according to claim 2 is a flexible having a small diameter fixing portion 2 and a large diameter fixing portion 3 respectively provided at one end and the other end in the axial direction, and a bellows 4 at a position between these fixing portions. In the boot 1, the flexible boot main body is made of a rubber-like elastic body, and the resin film 2a having low friction is laminated on the inner peripheral surface of the small diameter fixing portion 2, and the resin film having low friction in the axial direction A portion where 2a is not laminated is provided, and the non-laminated portion forms a communication passage capable of ventilating the flexible boot inside and outside. With this configuration, even if the resin film 2 does not generate wrinkles, the non-laminated portion can form a fine communication path of a thickness not laminated with the resin film. For this reason, it becomes a structure which the foreign substance from the outside can not easily invade, and it can make a lubricant hard to leak from the inside of flexible boots.

  The low friction resin film laminated on the inner peripheral surface of the small diameter fixing portion can reduce the frictional force between the small diameter fixing portion and the contact surface between the tie rod and the inner diameter of the small diameter fixing portion at the time of forming the flexible boot. It is possible to suppress the occurrence of molding defects such as surface defects. Therefore, it is possible to provide a flexible boot capable of reducing defects during molding while maintaining the low friction of the small diameter fixing portion so that the tie rod and the small diameter fixing portion do not rotate together during toe-in adjustment.

  In addition, on the inner peripheral surface of the small diameter fixing portion, a fine communication path that allows the flexible boot inside and outside to be ventilated by forming a fine crease connecting the inside and outside of the flexible boot in the axial direction or a non-laminated portion of a resin film. Can be formed. Furthermore, since the communication passage is minute, the foreign matter from the outside air hardly penetrates, and the lubricant can be made less likely to leak from the inside of the flexible boot.

FIG. 6 is a cross-sectional view showing an example of an embodiment after attaching the reciprocating flexible boot of the present invention to a counterpart member. It is sectional drawing which shows an example of the natural state of the boots for reciprocation of this invention. FIG. 7 is a cross-sectional view showing an example of an embodiment after attaching a counterpart member to a reciprocating boot according to the prior art.

  Hereinafter, the configuration of the present invention will be described in detail based on the embodiments shown in the drawings.

  An example of embodiment of the flexible boot 1 for reciprocation of this invention is shown to FIG. 1, FIG. The flexible flexible boot 1 according to the present invention has a small diameter fixing portion 2 fitted to be in contact with the annular groove 5a of the tie rod 5 and a large diameter fixing portion 3 fitted to be in contact with the housing 6; A serpentine portion 4 is formed between the fixing portions 2 and 3 and these are formed of a rubber-like elastic body. The reciprocating flexible boot 1 is provided to prevent water, dust and the like from entering the device from between the tie rod 5 of the steering device and the housing 6. In the present embodiment, although the present invention is applied to the reciprocating boot 1 used for the steering device, the present invention is not limited to this.

  The boot bands 7 and 8 are clamped from the outer peripheral side of the small diameter fixing portion 2 and the large diameter fixing portion 3. In the present embodiment, the groove for holding the boot bands 7 and 8 is provided on the outer peripheral side of each fixing portion, but it is only necessary to be able to clamp the boot band from the outer peripheral surface of each fixing portion. The groove may not be provided.

  The inner peripheral surface of the small diameter fixing portion 2 is laminated with a resin film 2a having lower friction than the rubber-like elastic body. In the present embodiment, although a film made of ultrahigh molecular weight polyethylene is used as the resin film, any film made of a resin having low friction such as a fluorocarbon resin, polyacetal, etc. may be used. Further, the laminating method is not particularly limited by the resin film 2a having low friction, and the resin film is attached to a resin film pasted after forming the flexible boot, or in a mold for forming the inner peripheral surface side of the small diameter fixing portion 2 in advance. After being disposed, they may be integrally molded with the rubber-like elastic body.

  Although not shown, the resin film 2a having low friction is provided with a crease extending in the axial direction in advance, and a non-laminated portion of the resin film 2a is provided on the inner peripheral surface of the small diameter fixing portion 2. A plurality of the axially extending wrinkles and the non-laminated portion may be formed in a spiral shape or a labyrinth shape.

  According to the reciprocating flexible boot 1 of the embodiment of the present invention, the following effects can be obtained.

  In order to fit the small diameter fixing portion 2 in which the resin film 2a having low friction property is laminated on the inner peripheral surface as shown in FIG. 1 into the annular groove portion 5a of the tie rod 5, as shown in FIG. The boot band 7 is pressed from the outer peripheral side of the portion 2. According to this configuration, the contact surface between the small diameter fixing portion 2 and the tie rod 5 can reduce the frictional force. Further, since the small diameter fixing portion 2 does not have the annular protrusion 102 a in the small diameter fixing portion 102 of the flexible boot 101, when removing the mold from the small diameter fixing portion 2, such as the annular protrusion 102 a contacting the mold Since there is no part, it is possible to suppress the occurrence of molding defects such as defects that have occurred on the inner peripheral surface of the small diameter fixing part 102 when molding the flexible boot 1.

  Although not shown, in the reciprocating flexible boot 1 of the embodiment, a low friction resin film 2a provided with wrinkles connecting the flexible boot in the axial direction in advance in the axial direction is laminated on the inner peripheral surface of the small diameter fixing portion 2. With this configuration, the wrinkles provided in advance on the inner circumferential surface of the small diameter fixing portion 2 become fine communication paths for ventilating the inside and the outside of the flexible boot 1. At this time, a force is applied to the resin film 2a in the compression direction by the compression of the boot band 7, so that the shape of a fine wrinkle can be maintained. For this reason, it becomes a structure which the foreign substance from the outside can not easily invade, and it can make a lubricant hard to leak from the inside of flexible boots.

  Further, although not shown, on the inner peripheral surface of the small diameter fixing portion 2 of the reciprocating flexible boot 1 of the embodiment, there is provided a portion where the resin film 2a having low friction in the axial direction is not laminated. To form a communication passage that can be ventilated. With this configuration, even if the resin film 2 does not generate wrinkles, the non-laminated portion can form a fine communication path of a thickness not laminated with the resin film. For this reason, it becomes a structure which the foreign substance from the outside can not easily invade, and it can make a lubricant hard to leak from the inside of flexible boots.

  Before the flexible boot fitting, the diameter dimension h2 of the fitting groove portion 5a of the tie rod 5 fitted with the small diameter fixing portion 2 is a wrinkle which connects the inside and the outside of the flexible boot in the axial direction in advance. Even if it is equal to or more than the diameter dimension h1 of the inner peripheral surface of the small diameter fixing portion 2 in the above, a fine communication passage can be configured. Further, by forming the wrinkle or the non-laminated portion in a spiral shape or a labyrinth shape, it is possible to make the lubricant less likely to leak from the inside of the flexible boot. Furthermore, air permeability of the flexible boot inside and outside can be further enhanced by forming a plurality of the wrinkles or the non-laminated portions.

1,101 Reciprocating flexible boots 2,102 Small diameter fixing portion 2a Resin film 102a Annular projection 3,103 Large diameter fixing portion 4,104 Bellows 5,105 Tie rod 5a, 105a Annular groove 6,106 Housing 7,107 (Small diameter fixing portion For) boot band 8, 108 (for large diameter fixed part) boot band h1 diameter of inner peripheral surface of small diameter fixed part h2 diameter of outer peripheral surface of annular groove

Claims (2)

A flexible boot having a rubber-like elastic body in a flexible boot having a small diameter fixing portion and a large diameter fixing portion respectively provided at one end and the other end in the axial direction and a bellows portion at a position between these fixing portions. A resin film having a lower friction than that of the rubber-like elastic body is laminated on the inner peripheral surface of the small diameter fixing portion, and the resin film is provided in advance with a crease connecting the inside and outside of the flexible boot in the axial direction. Flexible boots. A flexible boot having a rubber-like elastic body in a flexible boot having a small diameter fixing portion and a large diameter fixing portion respectively provided at one end and the other end in the axial direction and a bellows portion at a position between these fixing portions. A portion to be laminated with a resin film having lower friction than the rubbery elastic body on the inner peripheral surface of the small diameter fixing portion, and a portion not to laminate a resin film having low friction in the axial direction A flexible boot characterized by forming a communicating passage which can ventilate inside and outside of the flexible boot by a laminating section.

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