JP2011202760A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device securing followability to eccentricity of a rod and sound insulation performance against noise, and reducing a number of components and manufacturing man-hours.SOLUTION: The sealing device includes a cylindrical holding member fixed to a shaft hole inner periphery of a housing, and a seal body held by an inner peripheral side of the holding member. The seal body has a bellows part in which a plurality of crest parts and trough parts are alternately arranged in an axial direction. The crest parts of the bellows part contact the inner peripheral surface of the holding member on outside diameter end parts thereof to form annular air chambers surrounded by the bellows part and the holding part between the adjacent crest parts. The trough parts of the bellows part contact an outer peripheral surface of the rod on inside diameter end parts thereof to form annular air chambers surrounded by the bellows part and the rod between the adjacent trough parts. The sealed air chambers are axially arranged.

Description

  The present invention relates to a sealing device, and more particularly to a sealing device used as a steering dust seal or the like in a vehicle such as an automobile. The sealing device of the present invention is used in the field of the automobile industry, or in the field of other industrial machines (equipment).

  The sealing device shown in FIG. 5 previously proposed by the applicant of the present application is used as a dust seal for steering in a vehicle such as an automobile, and has a thin bellows portion 52, thereby being excellent in the eccentricity of the steering rod 53. In addition to exhibiting followability, it is possible to exhibit excellent sound insulation that makes it difficult to transmit the noise on the engine side A to the vehicle interior side B by having a double structure of the bellows portion 52.

  However, in the above prior art, two bellows-shaped seals 51, which are vulcanized molded products, are required to realize the double structure of the thin-walled bellows portion 52. Therefore, the number of parts and manufacturing man-hours are large, and the cost is low. It is high (see Patent Document 1).

JP-A-9-242880

  In view of the above, an object of the present invention is to provide a sealing device that can ensure the followability to the eccentricity of the rod and the sound insulation against noise, and can reduce the number of parts and the number of manufacturing steps.

  In order to achieve the above object, a sealing device according to claim 1 of the present invention is a sealing device that seals between a housing and a rod inserted through a shaft hole of the housing, and is fixed to the inner periphery of the shaft hole of the housing. A cylindrical holding member; and a seal body held on the inner peripheral side of the holding member, wherein the seal body includes a bellows portion having a shape in which a plurality of crests and troughs are alternately arranged in the axial direction. Each of the ridges of the bellows part has an annular shape surrounded by the bellows part and the holding member between the ridges adjacent to each other by contacting the inner peripheral surface of the holding member. The bellows portion of the bellows portion is annularly surrounded by the bellows portion and the rod between the valley portions adjacent to each other by contacting the outer peripheral surface of the rod. Form an air chamber of the A plurality of air chambers closed is characterized in that it is arranged in the axial direction.

  The sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein a connecting portion for connecting the seal body to the holding member is integrally formed at one end of the bellows portion. A lip portion that is slidably in close contact with the peripheral surface of the rod is formed integrally with the other end of the bellows portion, and the seal body having the bellows portion, the connecting portion, and the lip portion is a vulcanization made of only a rubber-like elastic body. It is characterized by being molded as a molded product.

  Further, the sealing device according to claim 3 of the present invention is the sealing device according to claim 1 or 2, wherein the bellows portion follows the slope between the adjacent ridges and valleys against the eccentricity of the rod. A step shape or a bellows shape having a small bellows amplitude for enhancing the performance is provided.

  The sealing device according to claim 4 of the present invention is the sealing device according to claim 1, 2, or 3, wherein either one of an outer diameter end portion of the peak portion and an inner diameter end portion of the valley portion in the bellows portion. Or both are provided with the concave shape for hold | maintaining grease and improving airtightness.

  Furthermore, the sealing device according to claim 5 of the present invention is the sealing device according to claim 1, 2, 3 or 4, wherein the sealing device is used as a dust seal for steering of a vehicle such as an automobile. To do.

  In the sealing device of FIG. 5 according to the above prior art, the bellows portion 52 has a shape in which crests and troughs are arranged in the radial direction. Therefore, in order to realize a double structure of the thin bellows portion 52 Two accordion-shaped seals 51 which are vulcanized molded products are required. On the other hand, in the present invention, the bellows part has a shape in which peaks and valleys are arranged in the axial direction rather than in the radial direction. For this reason, the thin bellows part 2 is formed by one vulcanized molded product (seal body). It is possible to realize a double structure (multiple structure).

  That is, in the present invention, the seal main body has a bellows portion having a shape in which a plurality of crests and troughs are alternately arranged in the axial direction. The crest portions of the bellows portion each have an outer diameter end portion in contact with the inner peripheral surface of the holding member, thereby forming an annular air chamber surrounded by the bellows portion and the holding member between adjacent crest portions. . In addition, each of the valley portions of the bellows portion has an inner diameter end portion in contact with the outer peripheral surface of the rod, thereby forming an annular air chamber surrounded by the bellows portion and the rod between adjacent valley portions. For this reason, since a plurality of sealed air chambers are provided side by side in the axial direction by one vulcanized molded product, a sound insulation effect is exhibited in each of the air chambers and in each of the inclined surfaces of the bellows that partition the air chambers. It is possible to do. Also, with respect to the eccentricity of the rod, the bellows part is elastically deformed to reduce the bellows amplitude at a part of the circumference according to the eccentric direction of the rod, so that it is possible to follow the eccentricity of the rod. Has been.

  In the present invention, the sealing device includes a cylindrical holding member fixed to the inner periphery of the shaft hole of the housing, and a seal body held on the inner peripheral side of the holding member. The cylindrical holding member surrounds the seal main body from the outer peripheral side, and holds and protects the seal main body, that is, the seal main body directly contacts the inner peripheral surface of the shaft hole of the housing and is damaged. To prevent. The seal body has a bellows portion as described above. Therefore, since the sealing device of the present invention is composed of the holding member and the seal main body and thus has only two parts, the number of parts is reduced as compared with the sealing device of FIG. Reduction in manufacturing man-hours has been realized. Incidentally, the number of parts of the sealing device of FIG. 5 according to the above prior art is five (the rubber-like elastic body constituting the bellows-like seal on the upper side in the figure and two metal fittings embedded therein, and the bellows-like shape on the upper and lower sides of the figure A rubber-like elastic body constituting the seal and one metal fitting embedded in the rubber-like elastic body.

  As the overall structure of the seal body, a connecting portion for connecting the seal body to the holding member is integrally formed at one end of the bellows portion, and a lip portion slidably in contact with the peripheral surface of the rod is formed at the other end of the bellows portion. It is preferable to form integrally, and thus, by molding the seal body having the bellows part, the connecting part and the lip part integrally as a vulcanized molded article only of a rubber-like elastic body, without increasing the number of parts. A bellows-like seal can be manufactured.

  In addition, in the bellows portion of the seal body, if a step shape or a small bellows shape having a small bellows amplitude is provided on the slope portion between the adjacent ridges and valleys, the bellows portion is elastically deformed by weighting them. It becomes easier to elastically deform in the radial direction, so that the followability to the eccentricity of the rod can be further enhanced.

  Further, in the bellows portion of the seal body, if a concave shape for holding grease is provided at the outer diameter end portion of the peak portion or the inner diameter end portion of the valley portion, this improves the airtightness of the air chamber, thereby further improving the sound insulation. It becomes possible to raise.

  The present invention has the following effects.

  That is, in the sealing device of the present invention, as described above, the seal body has a bellows portion having a shape in which a plurality of peak portions and valley portions are alternately arranged in the axial direction, and the peak portion of the bellows portion has an outer diameter. The end portion is in contact with the inner peripheral surface of the holding member to form an air chamber between the adjacent ridge portions, and the bellows portion of the bellows portion is in contact with the outer peripheral surface of the rod. An air chamber is formed between adjacent valleys. For this reason, since a plurality of sealed air chambers are provided side by side in the axial direction by one vulcanized molded product, a sound insulation effect is exhibited in each of the air chambers and in each of the inclined surfaces of the bellows that partition the air chambers. It is possible to do. Also, with respect to the eccentricity of the rod, the bellows part is elastically deformed to reduce the bellows amplitude at a part of the circumference according to the eccentric direction of the rod, so that it is possible to follow the eccentricity of the rod. Has been.

  In addition, as described above, the ability to follow the eccentricity of the rod and the sound insulation against noise can be secured, and the number of parts and, consequently, the number of manufacturing steps can be reduced. A sealing device with a bellows having a simple structure can be provided.

  In addition, in the bellows portion of the seal body, when a stepped shape or a small bellows shape having a small bellows amplitude is provided on the slope portion between the adjacent ridges and valleys, the bellows are elastically deformed by weighting them. The portion is more easily elastically deformed in the radial direction, so that the followability to the eccentricity of the rod can be further enhanced.

  In addition, in the bellows portion of the seal body, when providing a concave shape that holds grease at the outer diameter end portion of the peak portion or the inner diameter end portion of the valley portion, this improves the airtightness of the air chamber, and thus the sound insulation property. Can be further enhanced.

  In addition, when the sealing device of the present invention is used as a steering dust seal for a vehicle such as an automobile, the above-described effects can be obtained in the field of the steering dust seal.

Sectional drawing which shows the mounting state of the sealing device which concerns on 1st Example of this invention Half-cut sectional view showing the mounting state of the sealing device according to the second embodiment of the present invention Half-cut sectional view showing the mounting state of the sealing device according to the third embodiment of the present invention It is a figure which shows the sealing device which concerns on 4th Example of this invention, (A) is sectional drawing of the outer-diameter end part of the bellows mountain part in the sealing device, (B) is an internal diameter end of the bellows valley part in the sealing device Sectional view Half-cut sectional view showing the mounting state of the sealing device according to the conventional example

The present invention includes the following embodiments.
(1)
The sealing device shown in FIG. 5 according to the prior art is used for a steering rod or the like of an automobile, and is a sealing device (steering dust seal) particularly improved in sound insulation. The bellows (seal) characteristic has a thin rubber thickness to follow (seal) the eccentric motion of the steering rod. Since the thin wall cannot obtain sufficient sound insulation, the bellows (seal) portion has a double structure in order to obtain sound insulation. However, the vulcanized molded product requires two manufacturing steps and is expensive.

(2)
Therefore, in the present invention, the followability to the eccentric movement of the steering rod (sealing) is the same as before, and the seal has a bellows-like multiple structure (multiple rubber plates and multiple air chambers) in order to improve sound insulation, This is a low-cost steering dust seal that has one vulcanized molded product and can reduce the number of manufacturing steps.
(2-1) Improvement of sound insulation by multiple structure A rubber plate and an air chamber are formed between the engine side and the vehicle interior to form multiple bellows-like seals to improve the sound insulation (multiple chamber: ring side 3 chambers, steering rod side 3 rooms).
(2-2) Sealing property and followable structure when steering rod is eccentric A ring portion (holding member) in the bellows and a portion in contact with the steering rod are formed in a concave shape, and a grease filling portion is provided to improve the sealing property. When the steering rod is eccentric, the bellows-like seal (rubber thickness: thin) is flexibly deformed to ensure followability.

(3)
For inexpensive steering, the seals are bellows so that multiple structures (multiple rubber plates and multiple air chambers) can be formed to improve sound insulation, and the number of vulcanized molded products can be reduced by one point. It is a dust seal. The rubber thickness of the seal (bellows-shaped seal) is made thin so that it can cope with the eccentric movement of the steering rod.

(4)
A cylindrical ring (holding member) is provided with a vulcanized bellows-like seal (rubber thickness: thin wall). The bellows-shaped seal
(4-1) Multiple structure A bellows-like seal partitions between the ring and the steering rod to form a multi-plate (rubber) and multi-layer air chamber (multi-layer air chamber: ring side three chambers, steering rod side 3 Room).
(4-2) Sealing performance and followable structure at the time of shaft eccentricity The bellows-like seal portion that contacts the ring portion and the steering rod is formed in a concave shape, and the sealing property is secured by providing the grease filling portion. When the steering rod is eccentric, a bellows-like seal (rubber thickness: thin) follows flexibly.

(5)
The sealing device of the present invention is attached to the front dash panel, and the bellows-like seal (multiple structure) blocks the noise entering the vehicle interior from the engine side noise near the steering rod, thereby reducing the vehicle interior noise.

(6)
The vulcanized product (seal body) is rubber only.
The ring (holding member) and the bellows-like seal (seal body) are fitted.
The air chamber is formed between the ring and the seal and between the seal and the rod.
Even if the entire bellows does not follow the radial follow-up property, it is sufficient that one of the multiple layers follows (contacts the seal, the ring, and the rod).
The greatest point of the present invention is that an air chamber is provided.
Press the resin ring into the ring (for fixing to the dash panel), and fix the rubber to the ring with a band (the band also serves as a seal fixing to the dash panel).

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment ...
FIG. 1 shows a cross-section in a mounted state of the sealing device according to the first embodiment of the present invention. The sealing device according to the embodiment is used as a dust seal for steering in a vehicle such as an automobile, and is configured as follows. The upper side of the figure is the engine side, and the lower side is the vehicle interior side.

  That is, the sealing device seals an annular gap between a housing (dash panel) 1 and a rod (steering rod) 3 inserted through the shaft hole 2 of the housing 1. It has a cylindrical holding member (ring) 11 fixed to the periphery, and a similarly cylindrical seal body (bellows-like seal) 21 held on the inner peripheral side of the holding member 11.

  The holding member 11 is formed in a cylindrical shape from a hard material such as metal or resin, and is fitted to the inner peripheral surface of the shaft hole 2 of the housing 1. Also, a hook-shaped stopper portion 12 is integrally provided at the engine-side end portion of the holding member 11 so that the seal body 21 does not drop off to the engine side or extend to the engine side. Further, when a retaining or axial positioning means for the housing 1 is necessary, a ring 13 is separately fixed on the outer peripheral side of the engine side end of the holding member 11, and this ring 13 is used as an engaging portion for the housing 1. good. The ring 13 is also formed of a hard material such as metal or resin.

  On the other hand, the seal body 21 is formed into a cylindrical shape as a whole by a rubber-like elastic body, and has a bellows portion 22 in which a plurality of peak portions 23 and valley portions 24 are alternately arranged in the axial direction. A connecting portion 25 for connecting the seal body 21 to the holding member 11 is integrally formed at the vehicle interior side end portion, and slides on the peripheral surface of the rod 3 at the engine side end portion of the bellows portion 22. A lip portion 26 that is freely in close contact is integrally formed. In the figure, the peak portion 23 is repeatedly formed four times from the engine side to the vehicle interior side, and a connecting portion 25 is provided at the outer diameter end portion of the fourth peak portion 23. The valley portion 24 is repeatedly formed four times from the vehicle interior side to the engine side, and a lip portion 26 is provided at the inner diameter end portion of the fourth valley portion 24.

  Each of the peak portions 23 has an outer diameter end portion that contacts the inner peripheral surface of the holding member 11, and thus, an annular air chamber surrounded by the bellows portion 22 and the holding member 11 between the adjacent peak portions 23. 27 is formed. Further, the valley portions 24 of the bellows portion 22 each have an inner diameter end portion in contact with the outer peripheral surface of the rod 3, whereby an annular air chamber surrounded by the bellows portion 22 and the rod 3 between the valley portions 24 adjacent to each other. 28 is formed. As described above, in the figure, the crest portion 23 and the trough portion 24 are repeatedly formed four times, so that seven convenient slope portions 29 are provided side by side in the axial direction, and the seven slope portions 29 are provided. Between the two chambers, there are six air chambers 27 and 28 which are sealed and arranged side by side in the axial direction.

  The seal body 21 integrally including the bellows portion 22, the connecting portion 25, and the lip portion 26 is molded as a single unit as a vulcanized molded product made of only a rubber-like elastic body (rubber only). It is assembled to. Since the engaging portion 30 having an annular groove shape is provided on the connecting portion 25 toward the engine side, the engaging portion 30 is fitted to the vehicle interior side end portion of the holding member 11. If there is a concern about insufficient fitting force, a band 31 may be separately assembled on the outer peripheral side of the connecting portion 25 and the band 31 may be tightened. Since the band 31 sandwiches the housing 1 with the ring 13, this forms a strong and highly accurate fixing structure.

  In the sealing device having the above-described configuration, the seal main body 21 has a bellows portion 22 having a shape in which a plurality of peak portions 23 and valley portions 24 are alternately arranged in the axial direction. The crest portions 23 of the bellows portion 22 have their outer diameter end portions in contact with the inner peripheral surface of the holding member 11, whereby the crest portions 23 and the holding member 11 are surrounded by the bellows portion 22 and the holding member 11. The air chamber 27 is formed. In addition, each of the valley portions 24 of the bellows portion 22 has an inner diameter end portion in contact with the outer peripheral surface of the rod 3, so that the annular air surrounded by the bellows portion 22 and the rod 3 is located between the valley portions 24 adjacent to each other. A chamber 28 is formed. For this reason, since a plurality of sealed air chambers 27 and 28 are provided side by side in the axial direction by the seal body 21 which is a single vulcanized molded product, It is possible to exert a sound insulation effect in each of the slope portions 29 that partition the space 28, thereby ensuring sound insulation. Further, since the bellows portion 22 is elastically deformed so as to reduce the bellows amplitude at a part of the circumference according to the eccentric direction of the rod 3 with respect to the eccentricity of the rod 3, follow the eccentricity of the rod 3. As a result, followability to the eccentricity of the rod 3 is ensured.

  In addition, since the sealing device having the above-described configuration includes only the holding member 11 and the seal main body 21 and has only two parts, the number of parts can be reduced and the number of manufacturing steps can be reduced with a simple structure. Reduction has been realized.

  In addition, about the sealing device which concerns on the said 1st Example, it is possible to add or change the structure as follows.

Second embodiment ...
As shown in FIG. 2, a stepped shape 32 for improving the followability to the eccentricity of the rod 3 is provided on each of the slope portions 29 between the adjacent crest portions 23 and trough portions 24 in the bellows portion 22 of the seal body 21. Form. The stepped shape 32 has a unique cylindrical portion or a slope-like portion having a slope angle different from that of the slope portion 29, and these portions are integrally provided in the middle of the slope portion 29. A stepped shape 32 is provided on both sides in the axial direction of the outer diameter end portion of the peak portion 23 and on both sides in the axial direction of the inner diameter end portion of the valley portion 24.

  When the stepped shape 32 is formed on each of the slope portions 29 of the bellows portion 22 in this way, the stepped shape 32 is elastically deformed under load, so that the bellows portion 22 is more easily elastically deformed in the radial direction. The followability to the eccentricity of 3 can be further enhanced.

Third embodiment ...
As shown in FIG. 3, the bellows amplitude S ₂ for increasing the followability to the eccentricity of the rod 3 on each of the slope portions 29 between the adjacent peak portions 23 and valley portions 24 in the bellows portion 22 of the seal body 21. The small bellows shape 33 is formed. The small bellows shape 33 has an inherent cross-sectional arc-shaped portion (reversing portion) 34, a slope-shaped portion 35 and a re-circular cross-sectional arc-shaped portion (re-reversing portion) 36 in series, and has a substantially S-shaped cross section. the exhibits, there these sites which was formed integrally with the middle of the inclined surface portion 29 is set smaller than the bellows amplitude S ₁ of the entire bellows portion 22 its own bellows amplitude S _2.

  When the small bellows shapes 33 are formed on the slope portions 29 of the bellows portion 22 as described above, the bellows portions 22 are more easily elastically deformed in the radial direction because the small bellows shapes 33 are elastically deformed under load. The followability to the eccentricity of the rod 3 can be further enhanced.

Fourth embodiment ...
As shown in FIG. 4A, a concave shape 37 is formed on the outer diameter surface of the outer diameter end portion of the crest portion 23 in the bellows portion 22 of the seal body 21 to retain grease and improve the sealing performance. . The concave shape 37 is formed in an annular groove shape.

  And if the concave shape 37 is formed on the outer diameter surface of the outer diameter end portion of the peak portion 23 in the bellows portion 22 and filled with grease in this way, the airtightness of the air chamber 27 is enhanced, so that the sound insulation is improved. It can be further enhanced. Further, sliding wear of the outer diameter end portion of the peak portion 23 due to the lubricating action by the grease can be suppressed.

  Further, as shown in FIG. 4B, a concave shape 38 is formed on the inner diameter surface of the inner diameter end portion of the valley portion 24 in the bellows portion 22 of the seal body 21 to retain grease and improve the sealing performance. . The concave shape 38 is formed in an annular groove shape.

  When the concave shape 38 is formed on the inner diameter surface of the inner diameter end portion of the valley portion 24 in the bellows portion 22 and the grease is filled and held in this manner, the airtightness of the air chamber 28 is improved, so that the sound insulation is further improved. be able to. Further, sliding wear of the inner diameter end portion of the valley portion 24 can be suppressed by the lubricating action by the grease.

  The configuration according to the fourth embodiment can be applied to any of the sealing devices according to the first to third embodiments. Moreover, since the other structure of the sealing device which concerns on the said 2nd thru | or 4th Example is the same as the said 1st Example, it attaches | subjects the same code | symbol and omits the description.

DESCRIPTION OF SYMBOLS 1 Housing 2 Shaft hole 3 Rod 11 Holding member 12 Stopper part 13 Ring 21 Seal main body 22 Bellows part 23 Mountain part 24 Valley part 25 Connection part 26 Lip part 27, 28 Air chamber 29, 35 Slope part 30 Engagement part 31 Band 32 Step shape 33 Small bellows shape 34, 36 Reversing part 37, 38 Concave shape

Claims (5)

In a sealing device for sealing between a housing and a rod inserted through a shaft hole of the housing,
A cylindrical holding member fixed to the inner periphery of the shaft hole of the housing; and a seal body held on the inner peripheral side of the holding member;
The seal body has a bellows portion having a shape in which a plurality of peaks and valleys are alternately arranged in the axial direction,
An annular air chamber surrounded by the bellows portion and the holding member between the mountain portions adjacent to each other when the outer diameter end portions of the bellows portion are in contact with the inner peripheral surface of the holding member. Each of the bellows portions of the bellows portion is in contact with the outer peripheral surface of the rod, so that the annular air chamber surrounded by the bellows portion and the rod is located between the valley portions adjacent to each other. And, as a result, a plurality of sealed air chambers are provided side by side in the axial direction. The sealing device according to claim 1.
A connecting portion for connecting the seal body to the holding member is integrally formed at one end of the bellows portion, and a lip portion slidably in contact with the peripheral surface of the rod is integrally formed at the other end of the bellows portion. The sealing body having the bellows portion, the connecting portion, and the lip portion is formed as a vulcanized molded product made of only a rubber-like elastic body. The sealing device according to claim 1 or 2,
A sealing portion characterized in that a stepped shape or a small bellows shape having a small bellows amplitude is provided on a slope portion between adjacent peak portions and trough portions in the bellows portion to improve followability to the eccentricity of the rod. apparatus. The sealing device according to claim 1, 2 or 3,
One or both of the outer diameter end portion of the peak portion and the inner diameter end portion of the valley portion in the bellows portion are provided with a concave shape for retaining grease and enhancing the sealing performance. apparatus. The sealing device according to claim 1, 2, 3 or 4,
The sealing device is used as a dust seal for steering of a vehicle such as an automobile.

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