JP2013216292A - Sealing structure of steering shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure of a steering shaft capable of surely preventing ingress of water, dust, noise, etc. in a cabin while enhancing drainability of a sealing member.SOLUTION: An inner lip and an outer lip 4 formed on each of an inner periphery and an outer periphery at an upper end of a sealing member 2 are made to abut on an outer periphery of a steering shaft and a lower surface of a floor panel, respectively. A distal end of the inner lip penetrates a through-hole of the floor panel and is projected into a cabin. A drain groove 5 is formed between the inner lip and the outer lip 4 in a radial direction of the sealing member 2. A drain port 8 communicated with the drain groove 5 is opened in an outer peripheral surface of the sealing member 2, and the drain port 8 is covered with a bendable check valve 8a formed integrally with the sealing member 2. The check valve 8a is configured to open the drain port 8 by an internal pressure rise in the cabin.

Description

  The present invention relates to a structure in which a portion where a steering shaft of a vehicle passes through a through hole formed in a floor panel is sealed by a seal member.

  The steering shaft of a vehicle extends downward through a through hole formed in the floor panel, and its end is connected to the steering gear box, but water, dust, noise from the through hole of the floor panel to the vehicle interior In order to prevent the intrusion, etc., the portion of the through hole formed in the floor panel through which the steering shaft passes is sealed by a seal member made of an elastic body such as rubber.

  By the way, in the conventional seal structure, since the lip formed on the inner diameter portion of the seal member is brought into contact with the outer periphery of the steering shaft, water, dust, noise from the through hole of the floor panel to the vehicle interior In order to prevent the intrusion of the sealing member, it is necessary to increase the contact pressure of the lip of the seal member to the outer periphery of the steering shaft.

  However, if the contact pressure of the lip of the seal member on the outer periphery of the steering shaft is increased as described above, the steering shaft and the lip of the seal member rub against each other when the steering shaft is rotated by a steering operation. There was a problem.

  In order to solve the above problem, a structure may be employed in which the sealing member is brought into contact with the lower surface of the floor panel to seal with the floor panel, and the contact pressure of the sealing member lip to the steering shaft is lowered. (For example, refer to Patent Documents 1 and 2).

  However, in a vehicle in which the steering shaft penetrates the floor panel under the driver's feet, such as a cab-over type vehicle, the water may accumulate in the seal member. In order to prevent water from collecting in the seal member, as shown in FIG. 7 (see Patent Document 3), a lip 103 is formed on the inner periphery of the upper end of the cylindrical seal member 102, and the lip 103 is attached to the steering shaft. 101 is provided in contact with the outer periphery of the seal member 102, and a fitting support portion 102A is provided on the outer periphery of the upper end portion of the seal member 102. The seal groove 102a formed on the outer periphery of the fitting support portion 102A is fitted into the through hole 110a of the floor panel 110. A configuration may be adopted.

Japanese Patent No. 2558633 JP 2011-068164 A Japanese Utility Model Publication No. 1-63574

  However, when the seal structure as shown in FIG. 7 is adopted, there is a problem that the drainage of the seal member 102 is poor and water accumulates on the floor panel 110.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the object of the present invention is a steering shaft capable of reliably preventing water, dust, noise and the like from entering the vehicle compartment while improving the drainage performance of the seal member. It is in providing a sealing structure.

In order to achieve the above object, an invention according to claim 1 is a structure in which a through hole formed in a floor panel of a vehicle through which a steering shaft passes is sealed by a sealing member made of an elastic body.
An inner lip and an outer lip respectively formed on the inner periphery and outer periphery of the upper end of the seal member are brought into contact with the outer periphery of the steering shaft and the lower surface of the floor panel, respectively, and the tip of the inner lip passes through the through hole and is Projecting into the room and forming a drainage groove between the inner lip and the outer lip in the radial direction of the seal member;
A drainage port communicating with the drainage groove is opened on the outer peripheral surface of the seal member, the drainage port is covered with a bendable check valve formed integrally with the seal member, and the reverse is increased by increasing the internal pressure of the passenger compartment. The stop valve is configured to open the drain port.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the bottom surface of the drainage groove of the seal member is a slope inclined in a diagonally downward direction from the inner lip toward the outer lip in the radial direction. To do.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a ring-shaped abutting portion that abuts the lower surface of the floor panel is provided in the drain groove of the seal member so as to surround the corresponding portion. A notch is formed at a position different from the drain in the direction.

  The invention according to claim 4 is the invention according to claim 3, wherein a plurality of contact portions of the seal member are formed concentrically, and the notches formed in the contact portions are alternately arranged in the circumferential direction. It is characterized by that.

  According to the first aspect of the present invention, the water on the floor panel of the vehicle passes through the through hole of the floor panel and accumulates in the drainage groove of the seal member. However, since the passenger closes the door of the vehicle, Rises, the check valve that closed the drainage port of the seal member bends due to the pressure difference inside and outside the vehicle interior and opens the drainage port, so water that has accumulated in the drainage groove of the seal member moves from the drainage port to the outside of the seal member. And discharged. For this reason, the drainage of the sealing member is enhanced, and water does not accumulate on the through-hole portion of the floor panel or the sealing member. In this case, since the tip of the inner lip of the sealing member penetrates the through hole of the floor panel and protrudes into the vehicle interior, the water on the floor panel and the water accumulated in the drainage groove of the sealing member It does not enter the inside of the seal member from between the inner lips.

  Further, since the drainage port of the sealing member is normally closed by a check valve (except when the door is closed), water, dust, noise, etc. enter the vehicle interior from the drainage port through the drainage groove of the sealing member. There is nothing.

  According to the second aspect of the present invention, since the bottom surface of the drainage groove of the seal member is a slope inclined obliquely downward from the inner lip toward the outer lip in the radial direction, the water accumulated in the drainage groove can be checked. When is opened, it smoothly flows along the slope of the drainage groove to the drainage port, thereby further improving the drainage performance of the seal member.

  According to the third aspect of the present invention, the ring-shaped contact portion that contacts the lower surface of the floor panel is protruded in the drain groove of the seal member, and is cut out at a position different from the drain port in the circumferential direction of the contact portion. Therefore, water and dust from outside the vehicle compartment to the vehicle interior due to the labyrinth effect due to the ring-shaped contact portion of the seal member and the notch formed in the contact portion, while ensuring high drainage to the seal member, Intrusion of noise and the like can be reliably suppressed.

  In addition, the pressing force of the seal member to the floor panel can be received by the contact portion of the seal member, and by adjusting the pressing force of the outer lip of the seal member to the floor panel, the reverse of the outer lip is prevented, etc. The sealing performance of the sealing member can be stabilized, and the sealing performance of the sealing member can also be enhanced by the contact of the contact portion with the floor panel.

  According to the fourth aspect of the present invention, a plurality of contact portions of the seal member are formed concentrically, and the notches formed in these contact portions are alternately arranged in the circumferential direction. The effect is further enhanced, and the entry of water, dust, noise, and the like from outside the vehicle compartment into the vehicle compartment can be more reliably suppressed.

It is a sectional side view which shows the seal structure of the steering shaft which concerns on this invention. It is a side view of the seal member used for the seal structure of the steering shaft which concerns on this invention. It is a top view of the sealing member used for the seal structure of the steering shaft which concerns on this invention. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 5B is an enlarged detail view of part B of FIG. 4, wherein (a) shows a state where the check valve is closed, and (b) shows a state where the check valve is open. It is a figure of the arrow C direction of FIG. It is a sectional side view which shows the prior art example of the seal structure of a steering shaft.

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

  FIG. 1 is a side sectional view showing a seal structure of a steering shaft according to the present invention. As shown in the figure, a floor panel 10 of a vehicle is arranged substantially horizontally, and the floor panel 10 has a circular hole shape. A hole 10a is formed. The through hole 10a is formed in the vicinity of the occupant's foot, and the steering shaft 1 passes through the through hole 10a in the vertical direction of the vehicle. Here, the lower end portion of the steering shaft 1 extends through the through hole 10 a of the floor panel 10 to the outside of the passenger compartment, and the end portion thereof is connected to the steering gear box 11. A steering wheel is attached to the upper end of the steering shaft 1 facing the vehicle compartment via a joint and a steering column (not shown).

  Thus, in order to prevent water, dust, noise, and the like outside the passenger compartment from entering the passenger compartment through the through hole 10a of the floor panel 10, the portion of the through hole 10a of the floor panel 10 through which the steering shaft 1 passes is It is sealed by the seal member 2. The seal member 2 is attached to a steering gear box 11, and is interposed between the floor panel 10 and the steering gear box 11 in the vertical direction when the steering gear box 11 is attached to the vehicle body. The floor panel 10 and the steering gear box are in close contact with each other.

  Next, the detail of the structure of the sealing member 2 is demonstrated below based on FIGS.

  2 is a side view of the seal member, FIG. 3 is a plan view of the seal member, FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. Is a view showing a state where the check valve is closed, (b) is a view showing a state where the check valve is open, and FIG. 6 is a view taken in the direction of arrow C in FIG. 4, as shown in FIGS. The seal member 2 is integrally formed in a substantially cylindrical shape by an elastic body such as rubber.

  An inner lip 3 that contacts the steering shaft 1 and closes between the steering shaft 1 and the seal member 2 is integrated with the upper end of the seal member 2 (the end on the floor panel 10 side). The outer lip 4 closes the floor panel 10 and the seal member 2 (closes the through hole 10a) by contacting the back side (outside of the passenger compartment) of the periphery of the through hole 10a of the floor panel 10 on its outer periphery. Are integrally formed. In the state where the seal member 2 is assembled between the floor panel 10 and the steering gear box 11 as shown in FIG. 1, the inner lip 3 has its front end portion passing through the through hole 10a of the floor panel 10 outside the vehicle compartment. It penetrates from the (lower side) and protrudes into the vehicle compartment from the floor surface of the floor panel 10, and its inner peripheral surface is in contact with the outer peripheral surface of the steering shaft 1 to seal between them.

  Further, the outer lip 4 formed on the outer periphery of the upper end of the seal member 2 is formed on the floor panel 10 when the seal member 2 is assembled between the floor panel 10 and the steering gear box 11 as shown in FIG. It is elastically deformed by being pressed against the lower surface, and is in close contact with the lower surface of the floor panel 10 to seal between them.

  A drainage groove 5 that is recessed toward the steering gear box 11 so as to surround the inner lip 3 is formed between the inner lip 3 and the outer lip 4 in the radial direction of the upper surface of the seal member 2. In the drainage groove 5, two ring-shaped contact portions 6 and 7 that contact the lower surface of the floor panel 10 are concentrically provided so as to surround the inner lip 3. Here, as shown in FIG. 4, a plurality of protrusions 6a and 7a are concentrically formed on the upper surfaces (contact surfaces to the floor panel 10) of the contact portions 6 and 7, respectively.

  2-4, below the outer lip 4 on the outer peripheral surface of the seal member 2, there are four drain outlets 8 formed in a rectangular hole communicating with the drain groove 5 in the circumferential direction. Are opened at an equiangular pitch (90 ° pitch). Here, as shown in FIGS. 5 and 6, a thin and bendable check valve 8 a is integrally formed outside each drain port 8, and each drain port 8 a is formed by the check valve 8 a. Is normally closed (except when the vehicle door is closed) as shown in FIG. Here, each check valve 8a is formed integrally with the sealing member 2 with one end joined to the upper peripheral edge of the drain port 8, and is formed larger than the drain port 8, covering the entire drain port 8. ing. Then, the drain port 8 is opened and closed by bending from the state in contact with the peripheral edge of the drain port 8 from the upper end, and the weight of the water accumulated in the drain groove 5 and the pressure difference outside the vehicle interior (for example, When the door is closed, the internal pressure of the vehicle compartment is higher than the external pressure of the vehicle compartment), and as shown in FIG. 5B, water is discharged from the drain groove 5 to the outside of the seal member 2. On the other hand, the check valve 8a is shown in FIG. 5 (a) when the external pressure in the vehicle compartment is higher than the internal pressure (when trying to blow into the vehicle compartment through the drain port 8) or in a normal state. As shown in FIG. 4, the drain port 8 is closed without opening, and functions to prevent water, dust, noise and the like from entering the seal member 2 from outside the passenger compartment through the drain port 8. Each check valve 8a is not limited in size to cover the entire drainage port 8, but covers a part of the drainage port 8 to prevent water, dust, noise, etc. from entering the vehicle from the outside of the vehicle. May be.

  Incidentally, as shown in FIG. 4, the bottom surface of the drainage groove 5 of the seal member 2 extends from the inner lip 3 (specifically, the base end portion of the inner lip 3) to the outer lip 4 (specifically, the outer lip in the radial direction). 4 is a slope inclined obliquely downward toward the base end). Further, as shown in FIG. 3, notches 6b and 7b are respectively formed at two positions perpendicular to each other of the contact portions 6 and 7 of the seal member 2, and these notches 6b and 7b The four outlets 8 are formed at different positions in the circumferential direction, and the notches 6b and 7b and the drainage ports 8 are formed alternately in the circumferential direction. That is, the outer contact portion 7 formed on the upper surface of the seal member 2 is a location that is located between the two discharge ports 8 in the circumferential direction, and reaches the bottom surface of the drainage groove 5 to reach the outer contact portion 7. Notches 7b that communicate the inside and the outside are formed at two locations at a pitch of 180 °. The inner contact portion 6 formed on the upper surface of the seal member 2 which is the inner side of the outer contact portion 7 reaches the bottom surface of the drainage groove 5 and communicates the inner side and the outer side of the outer contact portion 6. Are formed at two positions in a direction shifted by 90 ° with respect to the notch 7b. Therefore, the notches 6b and 7b are alternately arranged in the circumferential direction.

  On the other hand, a ring-shaped abutting portion 9 is integrally protruded downward from the lower end portion of the seal member 2, and the seal member 2 is connected to the floor panel 10 and the steering gear box 11 as shown in FIG. In the state of being incorporated in between, the contact portion 9 is fitted in a ring-shaped groove 11 a formed in the steering gear box 11. Note that a plurality of protrusions 9a are formed concentrically on the contact portion 9 of the seal member 2 as shown in FIG. As described above, the sealing member 2 is integrally attached to the steering gear box 11 by the contact portion 9 being fitted into the groove 11 a formed in the steering gear box 11. And by this attachment, the edge part (lower end part) of the sealing member 2 by the side of the steering gear box 11 is sealed.

  Thus, the sealing member 2 configured as described above is incorporated between the floor panel 10 and the steering gear box 11 as shown in FIG. 1, and the steering shaft 1 passes through the center of the sealing member 2. However, as described above, the inner lip 3 of the seal member 2 is in contact with the outer peripheral surface of the tip end portion of the inner periphery of the steering shaft 1 located in the passenger compartment, and the outer lip 4 and the contact portions 6 and 7 are connected to the floor panel 10. By being pressed and elastically deformed by the lower surface (surface outside the passenger compartment), the lower surface of the floor panel 10 is in close contact. Further, the abutting portion 9 protruding from the lower end portion of the seal member 2 is pressed by the steering gear box 11 to be elastically deformed and is in close contact with the upper surface of the steering gear box 11.

  In the sealing structure of the steering shaft 1 by the sealing member 2 described above, the water that has flowed above the sealing member 2 through the through hole 10a of the floor panel 10 around the inner lip 3 of the sealing member 2 is the sealing member 2. 3 flows through the path indicated by the arrow in FIG. 3, and when the check valve 8a closes the drain port 8 as shown in FIG. That is, the water that flows into the drainage groove 5 of the seal member 2 from the gap between the through hole 10a of the floor panel 10 and the inner lip 3 of the seal member 2 is shown in FIG. After flowing into the drainage groove 5a between the two contact portions 6 and 7 through the notches 6b formed at two opposite positions of 6, the drainage groove 5a is divided into two directions and the drainage groove 5a is moved in the direction of the arrow. It flows and accumulates in the drain groove 5b outside the contact portion 7 through the notches 7b formed at two opposite positions of the outer contact portion 7.

  In the above state, when the passenger closes the door, the internal pressure of the passenger compartment increases, and when this internal pressure becomes higher than the external pressure (atmospheric pressure) of the passenger compartment, each check valve is caused by a differential pressure outside the passenger compartment. As shown in FIG. 5 (b), since 8a bends outward from the upper end edge of the drainage port 8 and opens each drainage port 8, the water accumulated in the drainage groove 5b is indicated by an arrow in FIG. As shown in FIG. 5B, the flow is divided into two directions and finally discharged from the four discharge ports 8 to the outside of the seal member 2 as shown in FIG.

  As described above, in the seal structure according to the present embodiment, water on the floor panel 10 of the vehicle passes through the through hole 10a of the floor panel 10 and accumulates in the drain groove 5 (5b) of the seal member 2. When the internal pressure of the passenger compartment rises because the passenger closes the door of the vehicle, the check valve 8a that has closed the drain port 8 of the seal member 2 as shown in FIG. As shown in FIG. 5 (b), the water outlet 8 is bent and opened, so that the water accumulated in the water drain groove 5 (5 b) of the seal member 2 is discharged from the water outlet 8 to the outside of the seal member 2. As a result, the drainage of the seal member 2 is enhanced, and water does not accumulate on the through hole 10a portion of the floor panel 10 or the seal member 2. In this case, since the tip of the inner lip 3 of the seal member 2 penetrates the through hole 10a of the floor panel 10 and protrudes into the vehicle interior, the water on the floor panel 10 and the drainage groove 5 (5b) of the seal member 2 The water accumulated in the inside of the seal member 2 does not enter from the space between the steering shaft 1 and the inner lip 3 of the seal member 2.

  Further, since the drain port 8 of the seal member 2 is normally closed by a check valve 8a as shown in FIG. 5A (except when the door is closed), the drain groove of the seal member 2 from the drain port 8 5, water, dust, noise, etc. do not enter the passenger compartment.

  In this embodiment, since only the tip of the small inner lip 3 of the seal member 2 protrudes into the vehicle interior, the inner lip of the seal member 2 is inserted into the through hole 10a having a diameter larger than the tip diameter of the inner lip 3. 3 can be easily penetrated, and the assembling workability of the seal member 2 is improved. Further, since the pressing force of the seal member 2 against the floor panel 10 can be received by the contact portions 6 and 7 of the seal member 2, the pressing force of the outer lip 4 of the seal member 2 against the floor panel 10 is adjusted. As a result, the sealing performance of the sealing member 2 can be stabilized, and the sealing performance of the sealing member 2 can also be enhanced by the contact of the contact portions 6 and 7 with the floor panel 10.

  Furthermore, in the present embodiment, the bottom surface of the drainage groove 5 of the seal member 2 is a slope that is inclined obliquely downward from the inner lip 3 toward the outer lip 4 in the radial direction. When the check valve 8a is opened, the check valve 8a smoothly flows along the slope of the drain groove 5 to the drain port 8, thereby further improving the drainage performance of the seal member 2.

  In the present embodiment, ring-shaped contact portions 6 and 7 that contact the lower surface of the floor panel 10 are provided in the drainage groove 5 of the seal member 2, and the circumferential directions of these contact portions 6 and 7 are provided. Since the notches 6b and 7b are respectively formed at positions different from the drain port 8, the ring-shaped abutting portions 6 and 7 of the seal member 2 and the abutting portions of the seal member 2 are secured while ensuring high drainage. The labyrinth effect by the notches 6b and 7b respectively formed in 6 and 7 can surely suppress the entry of water, dust, noise and the like from the outside of the vehicle compartment into the vehicle compartment. In the present embodiment, the notches 6b and 7b respectively formed in the concentric contact portions 6 and 7 of the seal member 2 are alternately arranged in the circumferential direction. Therefore, the labyrinth effect by the notches 6b and 7b is provided. Can be further increased, and the entry of water, dust, noise, etc. from outside the vehicle compartment into the vehicle compartment can be more reliably suppressed.

DESCRIPTION OF SYMBOLS 1 Steering shaft 2 Seal member 3 Inner lip of seal member 4 Outer lip of seal member 5 Drain groove 6 of seal member 6, 7 Contact portion 6b, 7b Notch of contact portion 8 Drain port 8a Check valve 9 Contact portion of seal member 10 Floor panel 10a Through hole in floor panel 11 Steering gear box

Claims (4)

A structure in which a through hole formed in a floor panel of a vehicle through which a steering shaft passes is sealed by a sealing member made of an elastic body,
An inner lip and an outer lip respectively formed on the inner periphery and outer periphery of the upper end of the seal member are brought into contact with the outer periphery of the steering shaft and the lower surface of the floor panel, respectively, and the tip of the inner lip passes through the through hole and is Projecting into the room and forming a drainage groove between the inner lip and the outer lip in the radial direction of the seal member;
A drainage port communicating with the drainage groove is opened on the outer peripheral surface of the seal member, the drainage port is covered with a bendable check valve formed integrally with the seal member, and the reverse is increased by increasing the internal pressure of the passenger compartment. A seal structure for a steering shaft, wherein the stop valve is configured to open the drain port.   2. The steering shaft seal structure according to claim 1, wherein a bottom surface of the drainage groove of the seal member is a slope inclined diagonally downward from the inner lip toward the outer lip in the radial direction.   A ring-shaped contact portion that contacts the lower surface of the floor panel protrudes from the drain groove of the seal member, and a notch is formed at a position different from the drain port in the circumferential direction of the contact portion. The steering shaft seal structure according to claim 1 or 2. The seal structure for a steering shaft according to claim 3, wherein a plurality of contact portions of the seal member are concentrically formed, and the notches formed in the contact portions are alternately arranged in the circumferential direction. .

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