JP2009019710A - Axial displacement absorbing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial displacement absorbing structure capable of effectively preventing invasion of muddy water and rain water into a connection section without causing increase of manufacturing cost. <P>SOLUTION: This axial displacement absorbing structure A includes a shaft part 1, a tube part 2 enveloping outside of the shaft part 1 and connected to the shaft part 1 in such a manner that the same can relatively displace in the axial direction, a first and a second sealing means 3, 4 preventing invasion of rain water into the connection parts 1a, 2a between the shaft part 1 and the tube part 2. Axial gap between the first sealing means 3 and the second sealing means 4 is not less than the maximum axial displacement S of the shaft part 1 in relation to the tube part 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an axial displacement absorbing structure suitable for use in vehicles such as passenger cars, trucks, and buses.

  As an axial direction displacement absorption structure applied to a vehicle, for example, there is one applied to a vehicle steering device. A vehicle steering system generally includes a steering wheel, a column main shaft, an intermediate shaft, and a rack and pinion mechanism. The column main shaft is rotatably supported by a column assembly, and the column main shaft and intermediate shaft are connected via a universal joint. Connected. Furthermore, the intermediate shaft has an axial displacement absorbing structure in which the intermediate shaft pipe portion and the intermediate shaft shaft portion are connected to each other so as to be relatively displaceable by serration or the like in the axial direction, and the intermediate shaft portion is connected via a universal joint. Connected to the gear of the rack and pinion mechanism.

  In such a steering apparatus, the column assembly is fixed to a steering support that is connected to the vehicle body and extends in the vehicle width direction, and the rack and pinion mechanism is fixed to the vehicle frame side. Due to the fact that a body mount is interposed between the body and the frame for the purpose of vibration absorption, the body and the frame undergo relative displacement, and the axial displacement between the intermediate shaft and the intermediate shaft pipe The relative displacement is absorbed in the absorbing structure.

  However, in the axial displacement absorbing structure having such a configuration, the axial displacement absorbing structure constituted by the intermediate shaft pipe portion and the intermediate shaft shaft portion is located outside the dashboard of the vehicle and the hole cover of the vehicle. Therefore, if muddy water or rainwater enters the serration from the outside, the serration may be rusted or fouled. As a result, the function of absorbing the relative displacement between the body and the frame is lowered, and the serration portion is promoted to wear, causing unpleasant vibration noise and deteriorating the steering feeling.

In order to prevent the occurrence of these problems, for example, muddy water or rainwater permeates into the axial displacement absorbing structure between the shaft shaft and the shaft shaft using a seal as described in Patent Document 1, for example. It is conceivable to prevent this.
JP 2003-194230 A

  However, in the prior art described in Patent Document 1, the seal is in sliding contact with the outer peripheral surface of the intermediate shaft portion, and muddy water or rainwater is attached to the intermediate shaft portion. Since the shaft shaft and the seal are in sliding contact with each other, the seal is required to have higher durability. Therefore, it is necessary to use an expensive material for the seal, resulting in an increase in manufacturing cost.

  Alternatively, instead of such a configuration, a configuration in which the seal is in a bellows shape and both ends thereof are joined to the outer peripheral surface of the intermediate shaft shaft portion and the outer peripheral surface of the intermediate shaft pipe portion is also conceivable. The size in the radial direction becomes large, the separation distance from the engine and the exhaust manifold cannot be secured in the engine room, the heat resistance needs to be increased, and it is also necessary to use expensive materials, and the seal is bellows Therefore, the amount of material necessary for the shape of the seal also increases, and this also increases the manufacturing cost of the seal.

  In view of the above problems, an object of the present invention is to provide an axial displacement absorbing structure that can effectively prevent intrusion of muddy water and rainwater into a connecting portion without increasing the manufacturing cost.

In order to solve the above problem, the axial displacement absorbing structure according to the present invention is:
A shaft portion, a cylindrical portion that encloses the shaft portion and is connected to the shaft portion so as to be relatively displaceable in the axial direction, and a first portion that prevents rainwater from entering the connecting portion between the shaft portion and the cylindrical portion. And the second sealing means, and the axial interval between the first sealing means and the second sealing means is greater than or equal to the maximum axial displacement of the shaft portion with respect to the cylindrical portion. It is characterized by that.

  Here, the shaft portion is typically an intermediate shaft portion of a steering device, the cylindrical portion is an intermediate shaft pipe portion, and the connecting portion is an outer peripheral surface of the intermediate shaft portion and an intermediate shaft pipe. The first and second sealing means are dust seals that are in sliding contact with the outer peripheral surface of the shaft shaft.

Here, in the axial displacement absorbing structure,
The maximum displacement amount is preferably an amount obtained by adding the displacement amount from the neutral position when the frame bounces to the body constituting the vehicle and the displacement amount from the neutral position when the frame rebounds.

In addition, in the axial displacement absorbing structure,
It is preferable that the axial interval is an amount obtained by adding a predetermined amount to the maximum displacement amount.

Furthermore, in the axial displacement absorbing structure,
Preferably, the predetermined amount is determined by variations in specifications of a body mount interposed between the body and the frame.

  Thus, by setting the axial interval to be equal to or greater than the maximum displacement amount, the outer peripheral surface of the shaft portion is soiled by muddy water or rainwater, which is located outside the vehicle with respect to the dashboard and the hole cover described above. Due to the axial displacement of the shaft portion with respect to the cylindrical portion, the sliding contact surface with respect to the shaft portion of the sealing means located outside of the first sealing means and the second sealing means is soiled. Even if the sealing performance of the sealing means with respect to the shaft portion is lowered, the sealing means located on the inner side of the first sealing means and the second sealing means has an outer peripheral surface of the shaft portion. It is possible to prevent the adhering muddy water and rainwater from reaching.

  Further, the axial interval is an amount obtained by adding the predetermined amount to the maximum displacement amount, and the maximum displacement amount is a displacement amount from a neutral position when the frame bounces against the body constituting the vehicle, The amount of displacement from the neutral position when rebounding is added, and the predetermined amount is determined by the variation in the specifications of the body mount interposed between the body and the frame. The effect of preventing the muddy water and rain water adhering to the outer peripheral surface of the shaft portion from reaching the sealing means positioned can be made more reliable.

  By these, the sealing means which is located on the inner side of either the first sealing means or the second sealing means guarantees the sealing performance with respect to the outside to the connecting portion, and the muddy water to the connecting portion. And rainwater intrusion can be prevented. In addition, since the need for the first sealing means and the second sealing means to have high durability against muddy water and rainwater can be eliminated, the manufacturing cost of the first and second sealing means is increased. Can be prevented.

  In addition, since it is possible to eliminate the need for the first sealing means and the second sealing means to be bellows-like, the material used in order to provide durability against heat sources such as engines and exhaust manifolds. Can be made expensive and the amount of material used can be increased, which also prevents an increase in manufacturing cost.

Furthermore, in the axial displacement absorbing structure,
It is preferable to have first fixing means for fixing the first sealing means to the cylindrical portion and second fixing means for fixing the second sealing means to the cylindrical portion.

Alternatively, in the axial displacement absorbing structure,
The first sealing means and the second sealing means are formed integrally, and the first sealing means and the third sealing means are fixed to the cylindrical portion. Also good.

Alternatively, in the axial displacement absorbing structure,
The first sealing means or the second sealing means may be directly fixed to the inner peripheral surface of the cylindrical portion.

  With any of the above-described configurations, the axial displacement absorbing structure can be easily configured.

Furthermore, in the axial displacement absorbing structure,
It is preferable to position the shaft portion below the cylindrical portion.

  According to this, the muddy water and rainwater adhering to the outer peripheral surface of the shaft portion enter the connecting portion by gravity through the first sealing means and the second sealing means by a simpler method. Further, it can be effectively prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the axial direction displacement absorption structure which can prevent effectively intrusion of muddy water and rain water to a connection part can be provided, without causing the increase in manufacturing cost.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing a steering apparatus including an axial displacement absorbing structure according to the present invention. FIG. 2 is a schematic view showing an embodiment of the axial displacement absorbing structure according to the present invention.

  As shown in FIGS. 1 and 2, the steering device including the axial displacement absorbing structure of the present embodiment includes an intermediate shaft portion 1, an intermediate shaft pipe portion 2, an outer dust seal 3, an inner dust seal 4, and a rack. An and pinion mechanism 5, a column ASSY 6, and a steering wheel 7 are included. The intermediate shaft portion 1 and the intermediate shaft pipe portion 2 constitute an intermediate shaft 8.

  As shown in FIG. 1, the column assembly 6 rotatably supports a column main shaft 9, and the column main shaft 9 and the intermediate shaft 8 are connected via a universal joint 10. Further, as shown in FIG. 2, the intermediate shaft 8 includes an intermediate shaft pipe portion 2 and an intermediate shaft portion 1 which are axially displaced so as to be relatively displaceable from the serrations 1a and 1b. The intermediate shaft portion 1 is connected to the gear of the rack and pinion mechanism 5 via the universal joint 11.

  In such a steering apparatus, the column ASSY 6 is connected to a body (not shown) of the vehicle and fixed to the steering support 12 extending in the vehicle width direction, and the rack and pinion mechanism 5 is fixed to the frame side (not shown) of the vehicle. A body mount (not shown) is interposed between the vehicle body and the frame for the purpose of absorbing vibration. As a result, the body and the frame are relatively displaced, and a relative displacement is generated between the intermediate shaft portion 1 and the intermediate shaft pipe portion 2. Relative displacement is absorbed.

  Among the elements constituting the steering device described above, the steering wheel 7, the column ASSY 6, the column main shaft 9, and the universal joint 10 are arranged on the vehicle inner side of the dashboard 13 that defines the vehicle inner side and the vehicle outer side, The intermediate shaft pipe portion 2 is inserted into a hole provided in the dashboard 13, and the hole cover 14 seals between the outer peripheral surface of the intermediate shaft pipe portion 2 and the dashboard 13.

  Further, a cylindrical bracket 15 is fitted to the end of the intermediate shaft pipe portion 2 on the rack and pinion mechanism 5 side, and the end of the bracket 15 on the rack and pinion mechanism 5 side is oriented toward the inner peripheral side. The outer dust seal 3 is joined to this end, and the inner peripheral surface of the outer dust seal 3 is in sliding contact with the outer peripheral surface of the intermediate shaft portion 1. The outer dust seal 3 constitutes a first sealing means for preventing intrusion of muddy water and rainwater from the outside into the serrations 2a and 1a which are connected portions.

  A bracket 16 is fitted on the inner peripheral side of the bracket 15, and the end of the bracket 16 on the rack and pinion mechanism 5 side is also formed in a collar shape so as to be directed toward the inner peripheral side. The inner dust seal 4 is joined to the portion, and the inner peripheral surface of the inner dust seal 4 is in sliding contact with the outer peripheral surface of the intermediate shaft portion 1. The inner dust seal 4 also constitutes a second sealing means for preventing intrusion of muddy water and rainwater from the outside into the serrations 2a and 1a which are connected portions, and seals the lubricating oil of the serrations 2a and 2a so as not to leak to the outside. A seal portion 4a that protrudes to the right in FIG.

  Here, the intermediate shaft portion 1 constitutes a shaft portion, the intermediate shaft portion 2 constitutes a cylindrical portion, and the serration 1a of the intermediate shaft portion 1 and the serration 2a of the intermediate shaft portion 2 constitute a connecting portion. The bracket 15 constitutes a first fixing means, and the bracket 16 constitutes a second fixing means.

  In addition, the axial interval between the outer dust seal 3 and the inner dust seal 4 is an amount S + α obtained by adding a predetermined amount α to the maximum axial displacement amount S of the intermediate shaft shaft portion 1 relative to the intermediate shaft pipe portion 2. Here, the axial interval is an axial distance between a sliding contact position of the outer dust seal 3 with respect to the outer peripheral surface of the intermediate shaft shaft portion 1 and a sliding contact position of the inner dust seal 4 with respect to the outer peripheral surface of the intermediate shaft shaft portion 1. .

  This maximum displacement amount S is an amount S1 + S2 obtained by adding the displacement amount S1 from the neutral position when the frame bounces to the body constituting the vehicle and the displacement amount S2 from the neutral position when the frame rebounds. . The predetermined amount α is a margin determined by variations in specifications such as the spring constant and hardness of the body mount interposed between the body and the frame.

  The intermediate shaft shaft portion 1 and the intermediate shaft pipe portion 2 constituting the axial displacement structure A described above are disposed outside the dashboard 13 and exposed to muddy water and rainwater. Due to the relative displacement in the axial direction of the shaft pipe portion 2, the muddy water and rainwater adhering to the outer peripheral surface of the intermediate shaft shaft 1 get over the sliding contact position between the outer dust seal 3 and the outer peripheral surface of the intermediate shaft portion 1, and the serration 2 a Invade in the direction.

  Therefore, as in this embodiment, the axial distance between the outer dust seal 3 and the inner dust seal 4 is an amount obtained by adding a predetermined amount α to the axial maximum displacement amount S of the intermediate shaft shaft portion 1 with respect to the intermediate shaft pipe portion 2. By setting S + α, the following operational effects can be obtained. Hereinafter, the function and effect will be described with reference to FIGS. 3 and 4 are schematic views showing the operational effects of an embodiment of the axial displacement absorbing structure according to the present invention. Here, the outer dust seal 3 and the inner dust seal 4 are schematically indicated by arrows.

  That is, as shown in FIG. 4, after the outer peripheral surface of the intermediate shaft 1 located on the vehicle outer side with respect to the dashboard 13 and the hole cover 14 is soiled by muddy water or rain water, as shown in FIG. In addition, even when muddy water or rainwater on the outer peripheral surface is conveyed to the serration 2a side due to the displacement of the maximum displacement amount S in the axial direction with respect to the intermediate shaft pipe portion 2 of the intermediate shaft portion 1, the inner dust seal is as follows. 4 can be prevented from reaching muddy water and rainwater.

  That is, as shown in FIG. 4, the sliding contact surface of the outer dust seal 3 located on the outer side of the outer dust seal 3 and the inner dust seal 4 with respect to the intermediate shaft shaft 1 is fouled, and the outer dust seal 3 against the intermediate shaft shaft 1. Even if the sealing performance is reduced, the axial distance between the outer dust seal 3 and the inner dust seal 4 is not less than the maximum displacement amount S, that is, S + α, so that the inner dust seal 4 on the inner side has the intermediate shaft shaft portion 1. Since the end a on the intermediate shaft pipe portion 2 side of the muddy water and rainwater adhering to the outer peripheral surface of the water reaches only a point separated by a predetermined amount α from the front of the inner dust seal 4, muddy water and rainwater must reach the inner dust seal 4. Can be prevented.

  Further, the axial interval between the outer dust seal 3 and the inner dust seal 4 is set to an amount S + α obtained by adding a predetermined amount α to the maximum displacement amount S, and the maximum displacement amount S is neutral when the frame bounces against the body constituting the vehicle. The amount S1 + S2 is obtained by adding the displacement amount S1 from the position and the displacement amount S2 from the neutral position when rebounding, and the predetermined amount α is determined by variations in the specifications of the body mount interposed between the body and the frame. By using the margin, the muddy water and rain water attached to the outer peripheral surface of the intermediate shaft portion 1 can be surely prevented from reaching the inner dust seal 4 located inside.

  By these things, the inner dust seal 4 located inside the outer dust seal 3 and the inner dust seal 4 ensures the sealing property to the outside to the serrations 2a and the serrations 1a which are the connection parts, and mud water and rainwater to the connection parts. Intrusion can be prevented. In addition, since the need for the outer dust seal 3 and the inner dust seal 4 to have high durability against muddy water and rainwater can be eliminated, it is possible to prevent the manufacturing cost of the outer dust seal 3 and the inner dust seal 4 from being increased. Can do.

  In addition, since it is possible to eliminate the need for the outer dust seal 3 and the inner dust seal 4 to be accordion-like, the materials used are expensive in order to provide durability against heat sources such as engines and exhaust manifolds. It is also possible to prevent an increase in the manufacturing cost by increasing the amount of material used.

  Further, the axial displacement absorbing structure A has a bracket 15 for fixing the outer dust seal 3 to the intermediate shaft pipe portion 2 and a bracket 16 for fixing the inner dust seal 4 to the intermediate shaft pipe portion 2, so that the axial direction can be simplified. The displacement absorbing structure A can be configured.

  Further, in the axial displacement absorbing structure A, by positioning the intermediate shaft portion 1 below the intermediate shaft pipe portion 2, muddy water and rainwater adhering to the outer peripheral surface of the intermediate shaft portion 1 are separated from the outer dust seal by gravity. 3 and the inner dust seal 4 can be more effectively prevented from entering the serration 2a and the serration 1a.

  In the above-described embodiment, the outer dust seal 3 is fixed to the intermediate shaft pipe portion 2 by the bracket 15 and the inner dust seal 4 is fixed to the intermediate shaft pipe portion 2 by the bracket 16. However, the outer dust seal 3 and the inter dust seal 4 are It is not restricted to such a form, It can also be set as the following forms.

  FIG. 5 is a schematic view showing an embodiment of the axial displacement absorbing structure according to the present invention. In this axial displacement absorbing structure B, the outer dust seal 23 as the first sealing means and the inner dust seal 24 as the second sealing means are connected and formed integrally by the cylindrical portion 25, and the outer dust seal 23. And a bracket 26 as a third fixing means for fixing the inner dust seal 24 to the intermediate shaft pipe portion 2. In addition, about the structure similar to the axial direction displacement absorption structure A shown in FIG. 2, the same code | symbol is attached | subjected and the overlapping description is omitted.

  FIG. 6 is a schematic view showing an embodiment of the axial displacement absorbing structure according to the present invention. In this axial displacement absorbing structure C, the outer dust seal 33 as the first sealing means is fixed to the intermediate shaft pipe portion 2 by the bracket 34, and the inner dust seal 34 as the second sealing means is fixed to the intermediate shaft pipe portion 2. It is directly fixed to the serration 2a on the inner peripheral surface. In addition, about the structure similar to the axial direction displacement absorption structure A shown in FIG. 2, the same code | symbol is attached | subjected and the overlapping description is omitted.

  The axial displacement absorbing structure according to the present invention can be easily configured by any of the configurations shown in FIGS. Since the function and effect are the same as those of the axial displacement absorbing structure A shown in FIG. 2, the overlapping description is omitted.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  For example, in the above-described embodiment, the intermediate shaft 8 has the intermediate wheel pipe portion 2 on the steering wheel 7 side and the intermediate shaft shaft portion 1 on the rack and pinion mechanism 5 side, but the intermediate shaft shaft portion 1 on the steering wheel 7 side. Further, the intermediate shaft pipe portion 2 may be provided on the rack and pinion mechanism 5 side.

  Further, the axial displacement absorbing structure according to the present invention is not limited to being applied to a steering device, and has a shaft portion and a cylindrical portion that encloses the shaft portion, so that the shaft portion and the cylindrical portion can be relatively displaced in the axial direction. It can be applied to other devices as long as they are connected and exposed to the outside of the vehicle.

  The present invention relates to an axial displacement absorbing structure for a vehicle, and effectively prevents intrusion of muddy water and rainwater into a connecting portion without causing an increase in manufacturing cost due to a relatively simple configuration and minor changes. Therefore, it is useful when applied to various vehicles such as ordinary passenger cars, trucks, and buses.

It is a schematic diagram which shows one Embodiment of the axial direction displacement absorption structure concerning this invention. It is a schematic diagram which shows one Embodiment of the axial direction displacement absorption structure concerning this invention. It is a schematic diagram which shows the effect of one Embodiment of the axial direction displacement absorption structure concerning this invention. It is a schematic diagram which shows the effect of one Embodiment of the axial direction displacement absorption structure concerning this invention. It is a schematic diagram which shows one Embodiment of the axial direction displacement absorption structure concerning this invention. It is a schematic diagram which shows one Embodiment of the axial direction displacement absorption structure concerning this invention.

Explanation of symbols

A Axial displacement absorbing structure 1 Intermediate shaft shaft 2 Intermediate shaft pipe 3 Outer dust seal 4 Inner dust seal 5 Rack and pinion mechanism 6 Column assembly
7 Steering wheel 8 Intermediate shaft 9 Column main shaft 10 Universal joint 11 Universal joint 12 Steering support 13 Dashboard 14 Hole cover 15 Bracket 16 Bracket B Axial displacement absorbing structure 23 Outer dust seal 24 Inner dust seal 25 Cylindrical portion 26 Bracket C Axial displacement Absorption structure 33 Outer dust seal 34 Inner dust seal 35 Bracket

Claims (8)

  A shaft portion, a cylindrical portion that encloses the shaft portion and is connected to the shaft portion so as to be relatively displaceable in the axial direction, and a first portion that prevents rainwater from entering the connecting portion between the shaft portion and the cylindrical portion. And the second sealing means, and the axial interval between the first sealing means and the second sealing means is greater than or equal to the maximum axial displacement of the shaft portion with respect to the cylindrical portion. An axial displacement absorbing structure characterized by that.   The maximum displacement amount is an amount obtained by adding a displacement amount from a neutral position when the frame bounces to a body constituting the vehicle and a displacement amount from a neutral position when the frame rebounds. The axial displacement absorbing structure according to claim 1.   The axial displacement absorbing structure according to claim 1 or 2, wherein the axial interval is an amount obtained by adding a predetermined amount to the maximum displacement amount.   The axial displacement absorbing structure according to claim 3, wherein the predetermined amount is determined by variation in specifications of a body mount interposed between the body and the frame.   The first fixing means for fixing the first sealing means to the cylindrical portion, and the second fixing means for fixing the second sealing means to the cylindrical portion. The axial direction displacement absorption structure as described in any one of these.   The first sealing means and the second sealing means are integrally formed, and the first sealing means and the third sealing means are fixed to the cylindrical portion. The axial direction displacement absorption structure according to any one of claims 1 to 4 characterized by things.   The axial displacement absorbing structure according to any one of claims 1 to 4, wherein the first sealing means or the second sealing means is directly fixed to the inner peripheral surface of the cylindrical portion.   The axial displacement absorbing structure according to any one of claims 1 to 7, wherein the shaft portion is positioned below the cylindrical portion.

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