JP3529031B2 - Automobile steering dust seal and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering dust seal for covering a column hole for inserting a steering shaft, which is formed in a dash panel for partitioning an engine room and a vehicle compartment of an automobile.

[0002]

2. Description of the Related Art FIG. 35 is a sectional view showing a conventional steering dust seal cut by a vertical plane including the central axis of a steering shaft. Referring to FIG.
A conventional dust seal will be described. A dash panel 300 partitions the engine room 100 and the vehicle room 200 of the automobile. The dash panel 300 has a column hole 302 formed therein.
A steering shaft 401 is inserted through the. A steering wheel (not shown) is attached to one end of the steering shaft 401 (end located on the vehicle compartment 200 side), and the front wheel is steered to the other end (end located on the engine room 100 side). A steering gear box (not shown) is attached to the steering shaft, and the steering shaft 401 transmits the rotational movement of the steering wheel (not shown) to the steering gear box (not shown) to enable steering. There is.

The column hole 302 thus formed in the dash panel 300 is indispensable,
This column hall 302 allows the engine room 100
In the state where the vehicle and the vehicle compartment 200 are communicated with each other, the engine room 1
From 00 to the passenger compartment 200, rainwater, dust, noise, and outside air including hot air and cold air intrude, and the comfort of the passenger compartment 200 is significantly impaired. To prevent this, a dust seal 501 for covering the column hole 302 is attached as shown in FIG. For a detailed understanding of the dust seal 501, an enlarged view of the inside of the circle A indicated by the dotted line in FIG. 35 is shown in FIG.
6 shows. The structure of the dust seal 501 will be described with reference to FIGS. 35 and 36.

The dust seal 501 has a hole through which the rotating steering shaft 401 passes. The dust seal 501 has a cylindrical shape (here, a cylindrical shape, which is a kind of cylindrical shape).
Has a sliding portion 511, a seal portion 521, and a dust seal body portion 531 (note that the seal portion 521
In order to clarify the dust seal body portion 531 and FIG.
Although the boundary between the two is shown by a dotted line, the actual dust seal 501 does not have such a boundary and is integrally formed. ). The tubular (here, cylindrical) sliding portion 511 is formed by a cylindrical resin ring. A lip 517a (see FIG. 36) is formed on the inner peripheral surface of the sliding portion 511 so as to extend in the circumferential direction. Outer peripheral surface 403 of the steering shaft 401 (see FIG. 36)
Is slidable on the inner peripheral surface 513 (see FIG. 36) of the sliding portion 511, and the sliding portion 511 pivotally supports the steering shaft 401. 35 and 36, there is a gap between the inner peripheral surface 513 of the sliding portion 511 and the outer peripheral surface 403 of the steering shaft 401,
The clearance disappears due to the force generated by the vibration caused by traveling, the acceleration caused by acceleration / deceleration, and the acceleration caused by right / left turning, etc.
The inner peripheral surface 513 and the outer peripheral surface 403 of the steering shaft 401 may come into contact with and slide against each other. Thus, the inner peripheral surface 513 of the sliding portion 511 and the outer peripheral surface 403 of the steering shaft 401 may be in constant contact with each other or may be in temporary contact with each other.

The seal portion 521 is provided to reduce the flow of foreign matter between the outer peripheral surface 403 of the steering shaft 401 and the inner peripheral surface 513 of the sliding portion 511. The entire outer edge 523 of the seal portion 521 is fixed to the dust seal body portion 531 and the inner edge portion 52 of the seal portion 521 is fixed.
5 The entire circumference is in close contact with the outer peripheral surface 403 of the steering shaft 401. Note that, here, the outer edge portion 52 of the seal portion 521 is
Although the entire circumference of 3 is fixed to the dust seal main body portion 531, it may be fixed to the sliding portion 511. The “foreign matter” referred to here is the engine room 100 of the automobile.
It is not desirable to enter the vehicle interior 200 from the vehicle interior, for example, rainwater, dust, and outside air including hot air and cold air. The seal portion 521 serves as a partition wall that blocks foreign matter, and reduces the flow of foreign matter through the outer circumferential surface 403 of the steering shaft 401 and the inner circumferential surface 513 of the sliding portion 511 even if a gap is formed between them. Let The dust seal body portion 531 is for closing the column hole 302, and has a flange 533 attached to the dash panel 300 around the column hole 302, and the dust seal body portion 531 covers the entire outer peripheral surface 515 of the sliding portion 511. To the entire circumference of the inner edge 535 of the flange 533.

The conventional dust seal 501 described above is used.
In the above, the sliding portion 511 is formed of a resin material, and the seal portion 521 and the dust seal body portion 531 are integrally formed of the same rubber material. In addition,
The outer peripheral surface 403 of the steering shaft 401 is the sliding portion 5.
The sliding portion 511 is formed of a resin material (a resin material such as polyacetal resin (POM) having a small friction coefficient) so that the sliding portion 511 can smoothly slide on the inner peripheral surface 513. The reason why the seal portion 521 and the dust seal body portion 531 are made of a rubber material is that the column hole 302
This is to allow the positional relationship between the steering shaft 401 and the steering shaft 401 to change within a certain range and prevent vibration from being transmitted between the dash panel 300 and the steering shaft 401.

[0007]

However, these conventional dust seals have a problem in that the outer peripheral surface 403 of the steering shaft 401 slides on the seal portion 521 to cause abnormal noise. To solve the problem of this abnormal noise, there is a method of reducing the friction coefficient of the portion of the seal portion 521 that is in close contact with the outer peripheral surface 403 of the steering shaft 401. On the other hand, the seal portion 521 needs to have sufficient flexibility because it needs to be kept in close contact with the outer peripheral surface 403 of the steering shaft 401, and thus is preferably formed of a flexible material. For this reason, flexible materials such as fluororubber, silicone rubber, and urethane rubber that have a small coefficient of friction (hereinafter,
It is called "low friction soft material". ) Using the seal portion 52
1 and the dust seal body 531 are integrally formed (that is, a low-friction flexible material is used instead of the rubber material), but these low-friction flexible materials are expensive. The cost will increase significantly.

Therefore, it is an object of the present invention to provide a dust seal which is low in cost and does not generate an abnormal noise when the steering shaft is rotated, and a manufacturing method thereof.

[0009]

SUMMARY OF THE INVENTION The present invention is a steering dust seal for covering a column hole for inserting a steering shaft, which is formed in a dash panel for partitioning an engine room and a vehicle compartment of an automobile. Through the dust seal body for closing the column hole, the cylindrical sliding portion that pivotally supports the steering shaft, and the outer peripheral surface of the steering shaft and the inner peripheral surface of the sliding portion. In a dust seal having a seal portion for reducing the flow of foreign matter, at least a portion of the seal portion that is in close contact with the outer peripheral surface of the steering shaft has a friction coefficient smaller than that of the dust seal main body portion. It is a dust seal.

In the dust seal of the present invention (hereinafter referred to as "the present dust seal"), at least a portion of the seal portion which is in close contact with the outer peripheral surface of the steering shaft has a friction coefficient smaller than that of the dust seal main body ( The lower limit of the friction coefficient of the portion is not particularly limited as long as the seal portion can reduce the flow of foreign matter between the outer peripheral surface of the steering shaft and the inner peripheral surface of the sliding portion at a desired level.) . By doing so, there is no problem that an abnormal noise is generated due to the outer peripheral surface of the steering shaft rubbing against the seal portion as the steering shaft rotates, and an expensive low friction flexible material is used only for the seal portion. By using it to reduce the usage amount or not using the low friction soft material, the cost increase is suppressed. The “friction coefficient” referred to in the present specification means a dynamic friction coefficient with respect to the material forming the outer peripheral surface of the steering shaft, unless otherwise specified, for example, the outer peripheral surface of the steering shaft is formed of stainless steel. If so, it refers to the dynamic friction coefficient for stainless steel. In addition, the comparison of the friction coefficient of the portion of the seal portion that is in close contact with the outer peripheral surface of the steering shaft (close contact portion) and the friction coefficient of the dust seal main body portion (main body portion) is based on the material forming the close contact portion and the main body portion. The material being formed is compared under the same conditions.

At least a portion of the seal portion, which is in close contact with the outer peripheral surface of the steering shaft, has a friction coefficient smaller than that of the dust seal main body portion. The seal part is
Since flexibility is required to improve the sealing performance with the outer peripheral surface of the steering shaft, it is made of a flexible rubber material as usual, and at the outer periphery of at least the steering shaft of the seal portion in order to prevent noise generation. The portion in close contact with the surface has a friction coefficient smaller than that of the dust seal body. That is, the friction coefficient of the portion of the seal portion that is in close contact with the outer peripheral surface of the steering shaft may be low enough to prevent the generation of abnormal noise at a desired level. The portion having a friction coefficient smaller than the friction coefficient of the dust seal body may be only the portion of the seal portion that is in close contact with the outer peripheral surface of the steering shaft, but other portions may also be so, for example, The entire seal portion may have a friction coefficient smaller than that of the dust seal body portion.

Various flexible rubber materials can be used as the material for forming the seal portion, but silicone rubber, fluororubber, urethane rubber, NR (natural rubber), EPDM rubber (ethylene-propylene-diene ternary) Polymer rubber), CR (chloroprene rubber), NBR (nitrile butadiene rubber), NBR / PVC (blend of NBR and polyvinyl chloride (PVC)), CM (chlorinated polyethylene), ECO (epichlorohydrin rubber), PVC
Examples thereof include blends (alloys) thereof and the like. In particular, if a low friction flexible material such as silicone rubber, fluororubber, urethane rubber, etc., which itself has a friction coefficient sufficiently smaller than the friction coefficient of the dust seal body, is used, the outer peripheral surface of the steering shaft is It is possible to configure the close contact portion to have a friction coefficient smaller than that of the dust seal main body portion without any special treatment. In this case, the entire seal part is made of expensive low-friction flexible material, but the amount of low-friction flexible material used is much larger than in the conventional case where the entire dust seal is made of low-friction flexible material. Therefore, the manufacturing cost of the dust seal can be significantly reduced.

On the other hand, NR, EPDM rubber, CR, NB
R, NBR / PVC, CM, ECO, PVC, and their blends (alloys), etc. themselves do not have a coefficient of friction sufficiently smaller than that of the dust seal body (that is, sufficient by itself). If it is impossible to prevent the generation of abnormal noise), it is necessary to reduce the friction coefficient of the portion in close contact with the outer peripheral surface of the steering shaft. As the first method, there is a method of coating a portion of the seal portion, which is in close contact with the outer peripheral surface of the steering shaft, with a substance having a friction coefficient lower than that of the dust seal main body portion. The substance to be coated may be appropriately selected according to the type of material forming the seal portion, and the like. For example, silicone resin, fluororesin, graphite, polyamide,
And a mixture of these may be mentioned. According to this first method, it is sufficient to coat the substance only on the small and intimate contact portion without using an expensive low friction soft material. Therefore, the amount of the normally expensive substance used can be reduced, and the manufacturing cost of the present dust seal can be significantly reduced. The coating of these substances on the intimate part can be performed by various known methods.

Further, as a second method of reducing the friction coefficient of the portion of the seal portion which is in close contact with the outer peripheral surface of the steering shaft, a material containing a lubricant which reduces the friction coefficient by mixing it in the material is used. There is a method of forming the portion. The lubricant used may be appropriately selected according to the type of material forming the seal portion, etc., but fluororesin particles, silicone resin particles, glass particles, polyamide fibers,
Examples thereof include a single substance or a mixture selected from the group consisting of polyethylene terephthalate fibers, aramid fibers, oils and fats (fatty acids etc.) and plasticizers (amide etc.). According to this second method, the portion (small portion) of the seal portion, which is in close contact with the outer peripheral surface of the steering shaft, is made of a material mixed with an expensive lubricant, without using an expensive low friction soft material. It only needs to be formed. (Not only the portion of the seal portion that is in close contact with the outer peripheral surface of the steering shaft, but also the portion (for example, the entire seal portion) beyond that may be formed of a material containing these lubricants.). Therefore, it is possible to reduce the amount of expensive lubricant used (when the entire seal part is made of a lubricant compound material, compared to the conventional case where the entire dust seal is made of this material. If only the part of the seal part that is in close contact with the outer peripheral surface of the steering shaft is made of a material containing a lubricant, the entire seal part will be made of a material containing a lubricant. The amount of lubricant used can be further reduced compared to the case where it is formed.), And the manufacturing cost of the present dust seal can be significantly reduced. In order to form the part of the seal part that is in close contact with the outer peripheral surface of the steering shaft with a material that contains a lubricant, mix the lubricant into the material or mix the lubricant in the rubber kneading process (mastication process). After forming the part formed by the above-mentioned material and the part formed by the material in which the lubricant is not mixed (either unvulcanized or vulcanized), both parts may be pasted together. .

As described above, in the present dust seal, the seal portion (at least the portion of the seal portion, which is in close contact with the outer peripheral surface of the steering shaft) is formed of different materials for the dust seal main body portion and the sliding portion. ,
The seal portion may be a separate body from the dust seal body portion and the sliding portion, and the seal portion may be fitted and fixed to the dust seal body portion and / or the sliding portion. By doing so, the seal portion manufactured as a separate body is replaced with the dust seal main body portion and / or
Alternatively, it can be easily and surely joined to the sliding portion, and when the dust seal is discarded after the dust seal has been used, the mating can be released to separate the materials as different materials, facilitating recycling. it can. The method for fitting and fixing the separate seal part to the dust seal main body part and / or the sliding part may be any method as long as it can be easily and surely fitted and fixed. Between the seal portion and the sliding portion, a protrusion protruding toward the other side is formed between the seal portion and the sliding portion, and a concave portion that engages with the protrusion is formed on the other side, and the protrusion and the concave portion are formed. May be fitted together. By doing so, the seal part manufactured as a separate body can be easily and surely joined to the sliding part, and when the dust seal is discarded after the dust seal has been used, the mating is released to dissimilar materials. It can be separated as and can be easily recycled. In addition, the recessed portion may be any as long as it can be fitted with the protrusion, and includes, for example, a through hole having no bottom. If a plurality of protrusions and recesses are formed between the seal portion and the sliding portion, all the protrusions are formed on one of the seal portion and the sliding portion and all the recesses are formed on the other. Is not required to be formed, one part is formed with a projection, the other part is formed with a remaining projection, one part is formed with a part recessed part that fits with the remaining projection, and the other part is formed. The remaining recess may be formed to fit with the protrusion.

Any structure may be used as long as the projection and the recess are fitted to each other and the sliding portion and the seal portion can be joined with each other with sufficient strength. The protrusion is an annular protrusion extending in the circumferential direction,
The recess may be an annular groove extending in the circumferential direction. By doing so, the sliding portion and the seal portion are in the direction perpendicular to the circumferential direction (that is, in the direction parallel to the central axis of the steering shaft).
Is preferable because it is firmly fixed.

Further, in the present dust seal, since the sliding portion and the dust seal main body are made of different materials, the separately manufactured both are easily and surely joined together, and after the present dust seal is used. Considering the convenience of recycling, a cylindrical central shaft formed between the outer peripheral surface of the sliding part and the dust seal body part, where the sliding part is formed on one of the sliding part and the dust seal body part. Alternatively, a rod-shaped projection may be formed so as to extend substantially parallel to, and a rod-shaped groove that fits the rod-shaped projection may be formed on the other side, and the rod-shaped projection and the rod-shaped groove may be fitted. By doing so, the separately manufactured sliding portion and the dust seal main body can be easily and reliably joined by fitting the rod-shaped projection and the rod-shaped groove, and the dust seal is discarded. In doing so, the materials can be separated as different materials by releasing the fitting, and recycling can be facilitated. It should be noted that the rod-shaped projection and the rod-shaped groove are fitted substantially parallel to the cylindrical central axis formed by the sliding portion in this manner, whereby the sliding portion unexpectedly rotates with respect to the dust seal body portion (for example, It is possible to effectively prevent the sliding portion from rotating with the rotation of the steering shaft. If a plurality of rod-shaped protrusions and rod-shaped grooves are formed between the outer peripheral surface of the sliding portion and the dust seal body, all rod-shaped protrusions are formed on one of the sliding portion and the dust seal body. , It is not necessary to form all the rod-shaped grooves on the other side, one rod-shaped protrusion is formed on one side, the remaining rod-shaped protrusion is formed on the other side, and the rod-shaped protrusion is fitted on one side A part of the bar-shaped groove may be formed, and the other bar-shaped groove may be formed on the other side so as to fit with the part of the bar-shaped protrusion.

Only by fitting the rod-shaped projection and the rod-shaped groove, it is sufficient for any one of them to move in the longitudinal direction (that is, in the direction substantially parallel to the central axis of the tubular shape formed by the sliding portion). Cannot be prevented. In order to prevent the movement in the longitudinal direction (that is, in the direction substantially parallel to the central axis of the cylinder formed by the sliding portion) and to fix the rod-shaped projection and the rod-shaped groove in the longitudinal direction, the rod-shaped projection is removed from the rod-shaped groove. A return portion may be formed on the rod-shaped projection so as not to come off in a direction substantially parallel to the central axis. The return portion has a shape such that it is possible to easily fit the rod-shaped projection into the rod-shaped groove along the longitudinal direction, while making it difficult to extract the rod-shaped projection from the rod-shaped groove along the longitudinal direction. Any material may be used. Usually, in a state where the rod-shaped projection is fitted in the rod-shaped groove, it is outside the shape of the rod-shaped groove in any cross section perpendicular to the longitudinal direction (the direction away from the center of the rod-shaped groove in the cross section). .) Protruding away from the cross section in the direction of the tip of the rod-shaped projection (the portion leading when the rod-shaped projection is fitted into the rod-shaped groove) from the cross section, which is perpendicular to the longitudinal direction. The shape of the rod-shaped protrusion in the cross section may have, for example, an inverted wedge shape may be formed on the outer surface of the rod-shaped protrusion.

The sealing portion of the present dust seal may be provided outside the sliding portion as shown in FIGS. 35 and 36, but the sealing portion extends in the circumferential direction on the inner circumference of the sliding portion. It may have an annular seal portion buried in. With such an annular seal portion, the distance from the portion that comes into close contact with the outer peripheral surface of the steering shaft and slides to the mounting position on the sliding portion (the inner periphery of the sliding portion) can be made extremely small, and It enables downsizing, reduces the material required for forming the seal portion, and reduces the manufacturing cost of the dust seal. Furthermore, since the seal portion is formed inside the sliding portion and is not exposed to the outside, the dust seal can be downsized and damage to the seal portion can be prevented.

Even when the seal portion has an annular seal portion embedded in the inner periphery of the sliding portion so as to extend in the circumferential direction, the sliding portion is provided between the outer peripheral surface of the sliding portion and the dust seal main body portion. A rod-shaped protrusion is formed on one of the dust seal body and the dust-seal main body so as to extend substantially parallel to the central axis of the cylindrical portion formed by the sliding portion, and a rod-shaped groove fitted to the rod-shaped protrusion is formed on the other of The rod-shaped protrusion and the rod-shaped groove may be fitted together. Further, in this case, a return portion may be formed on the rod-shaped projection so that the rod-shaped projection does not come out of the rod-shaped groove in a direction substantially parallel to the central axis. The rod-shaped projections, rod-shaped grooves, and return portions are the same as those described above.

The present dust seal may be manufactured by any manufacturing method. Between the seal portion and the sliding portion, one of the seal portion and the sliding portion has a protrusion protruding toward the other side. The present dust seal (the dust seal according to any one of claims 8 to 11) in which a concave portion fitted to the protrusion is formed on the other side, the first step of preparing the sliding portion and the sealing portion, and the protrusion Second step of assembling the sliding part and the seal part by fitting the recess and the recess, and the sliding part and the seal part assembled in the second step at a predetermined position in the molding die for the entire dust seal. And the third step of fixing, and the material forming the dust seal body (unvulcanized)
A fourth step of injecting into the mold, a fifth step of raising the temperature in the mold to carry out a vulcanization reaction, and a sixth step of taking out a dust seal from the mold,
It may be manufactured by a method (claim 15: hereinafter, referred to as “projection-recess fitting method”).

In the first step, both the sliding portion and the seal portion (vulcanized) are prepared. This "preparation" uses raw materials and the like to produce both or one of them (for example, molding with a molding die). , Machining such as shaving), or both may be obtained by purchase or other transfer. A protrusion or a recess is formed at a predetermined position in the sliding part (both the protrusion and the recess may be formed between the seal part and the sliding part if a plurality of protrusions or recesses are formed) Prepare what was done. The seal part must be vulcanized,
It may be prepared by any method, and may be manufactured by various conventional methods for manufacturing a rubber product having a predetermined shape. The seal part has a protrusion or a recess formed at a predetermined position that fits with a protrusion or a recess formed on the sliding part (if a plurality of protrusions or recesses are formed between the seal part and the sliding part, Both protrusions and recesses may be formed) are prepared.

In the second step, the projection and the recess are fitted together, and the sliding portion and the seal portion prepared in the first step are assembled. At this time, an adhesive may be applied between the sliding portion and the sealing portion so that the sliding portion and the sealing portion are bonded together, if necessary.

In the third step, the sliding portion and the seal portion, which are assembled with each other in the second step, are arranged and fixed at predetermined positions in the mold of the entire dust seal. That is, in this state, the portion that becomes the dust seal main body portion becomes hollow inside the molding die. Next, in the fourth step, the material (unvulcanized rubber material) forming the dust seal body is injected into the molding die. As a result, a material (unvulcanized rubber material) for forming the dust seal body is filled in the cavity existing in the molding die, and a portion to be the dust seal body is formed by the material. It should be noted that the dust seal main body and the sliding portion, the seal portion, or the like are more firmly joined to each other. If necessary, the sliding surface or the seal portion disposed in the molding die becomes a boundary surface with the dust seal main body portion. You may apply an adhesive agent to a part. In the fifth step, the vulcanization reaction is performed by raising the temperature inside the molding die.
The vulcanization conditions were injected into the mold in the fourth step,
Material forming the dust seal body (unvulcanized rubber material)
It may be appropriately determined as usual according to the type and the like. In the sixth step, the dust seal is taken out from the mold as in the conventional case, and the dust seal is completed.

According to this manufacturing method (projection / recess fitting method), after the sliding part and the sealing part are manufactured separately, the sliding part and the sealing part can be easily and quickly mounted by fitting the projection and the recess. In addition, since they can be reliably joined, complicated steps such as screwing and fusion are not required. Further, when disposing of the present dust seal, the protrusion and the recess are disengaged from each other, so that the sliding portion and the seal portion can be easily separated and separated as different materials, which facilitates recycling and use. ..

Between the seal portion and the sliding portion, a protrusion protruding toward the other side is formed on one of the seal portion and the sliding portion, and on the other of the seal portion and the sliding portion. A cylindrical center formed with a recess fitted to the projection, and between the outer peripheral surface of the sliding part and the dust seal body, the sliding part being formed on one of the sliding part and the dust seal body. The present dust seal in which a rod-shaped projection is formed so as to extend substantially parallel to the axis, and a rod-shaped groove fitted with the rod-shaped projection is formed on the other of the sliding portion and the dust seal main body (claim 10 or 11). The first step of preparing the sliding portion, the sealing portion, and the dust seal main body portion respectively, the second step of fitting the projection and the concave portion to assemble the sliding portion and the sealing portion, and the rod shape Sliding with the dust seal body by fitting the protrusion and the rod-shaped groove Is intended to include, a third step of assembling the bets, method (Claim 16:. Hereinafter referred to as "rod-like protrusion rod-shaped groove fitting method") may be prepared by.

In the first step, the sliding portion, the seal portion, and the dust seal main body portion are prepared. In this "preparation", these materials are manufactured by using raw materials and the like (for example, molding by a molding die, shaving). Etc.) or may be obtained by transfer such as purchase. The sliding part and the seal part are prepared in the same manner as in the first step of the projection / recess fitting method (the seal part is vulcanized). In addition, a rod-shaped protrusion or a rod-shaped groove is formed on the outer peripheral surface of the sliding portion (if a plurality of rod-shaped protrusions or rod-shaped grooves are formed between the sliding portion and the dust seal main body, the rod-shaped protrusion or the rod-shaped protrusion is formed). Both the rod-shaped groove may be formed). On the other hand, the dust seal main body needs to be vulcanized, but may be prepared by any method and may be manufactured by various conventional methods for manufacturing a rubber product having a predetermined shape. The prepared dust seal body is provided with a rod-shaped groove or rod-shaped protrusion that fits with the rod-shaped protrusion or rod-shaped groove formed on the outer peripheral surface of the sliding portion.

In the second step, as in the second step of the projection / recess fitting method, the projection and the recess are fitted to each other, and the sliding portion and the seal portion prepared in the first step are assembled. At this time, an adhesive may be applied between the sliding portion and the sealing portion so that the sliding portion and the sealing portion are bonded together, if necessary.

In the third step, the rod-shaped projection and the rod-shaped groove are fitted to each other to assemble the dust seal body and the sliding portion. At this time, if necessary, an adhesive may be applied between the dust seal body and the sliding portion so that the dust seal body and the sliding portion are bonded to each other. Also, if necessary, between the dust seal body and the sliding part,
And / or between the dust seal body and the seal,
Sealant (For example, Three Bond Co., Ltd. product name 1
207B) may be used. By using the sealant, the sealability (airtightness, liquid tightness) between the sliding portion and / or the sealing portion and the dust seal body portion can be improved (of the dust seal body portion, the sliding portion, and the seal portion). Even if a gap is created between the dust seal body and the sliding part and / or between the dust seal body and the seal part due to manufacturing error or assembly error, the sealant closes the gap and seals Is kept).

This manufacturing method (rod-shaped projection rod-shaped groove fitting method)
According to this, after the sliding portion, the sealing portion and the dust seal main body portion are manufactured separately, the sliding portion and the sealing portion can be easily, quickly and surely joined by fitting the projection and the concave portion, and the rod-shaped projection Since the dust seal main body and the sliding portion can be easily, quickly and surely joined by fitting of the rod groove with the rod-shaped groove, complicated steps such as screwing and fusion are not required. Further, when disposing of the present dust seal, the sliding portion, the seal portion, and the dust seal main body portion can be easily separated by releasing the fitting between the projection and the recess and the fitting between the rod-shaped projection and the rod-shaped groove. It can be separated and separated as different materials, facilitating recycling.

The seal portion has an annular seal portion embedded in the inner periphery of the sliding portion so as to extend in the circumferential direction.
The present dust seal (the dust seal according to any one of claims 12 to 14) is a sliding portion, and an annular seal groove formed on an inner peripheral surface of the sliding portion so as to extend in the circumferential direction,
A first step of preparing a sliding part having a recess formed on the outer peripheral surface of the sliding part, the recess communicating with the annular seal groove to the bottom of the recess; and forming the annular seal part. A second step of arranging a predetermined amount of unvulcanized material in the recess, and a sliding portion on which the unvulcanized material for forming the annular seal portion is arranged in the second step. The third step of arranging and fixing it in a predetermined position in the molding die, and the material for forming the dust seal body (at a temperature at which the unvulcanized material for forming the annular seal can be thermally softened) Vulcanization) into the mold,
The material forming the dust seal main body is in a heat-softened state in the depression, and unvulcanized material for forming the annular seal portion is extruded from the bottom portion into the annular seal groove to form the annular seal portion. A fourth step, a fifth step of raising the temperature in the mold to cause a vulcanization reaction, and a sixth step of taking out a dust seal from the mold,
Method (Claim 17: hereinafter referred to as "extrusion method")
May be manufactured by

In the first step, the sliding portion is prepared. The sliding portion is an annular seal groove formed on the inner peripheral surface of the sliding portion so as to extend in the circumferential direction, and a recess formed on the outer peripheral surface of the sliding portion, the recess being formed from the annular seal groove. And a recess communicating with the bottom of the. The annular seal groove fixes the outer edge portion of the annular seal portion to the inner peripheral surface of the sliding portion (the outer peripheral surface of the steering shaft is in close contact with the entire inner edge portion of the annular seal portion and slides). The term "formed so as to extend in the circumferential direction" as used herein means that the groove is formed so as to belong to one plane perpendicular to the central axis of the cylinder formed by the sliding portion. Depth of the annular seal groove (means the height difference between the inner peripheral surface of the sliding part where the annular seal groove is not formed and the bottom of the annular seal groove)
Is too small, the annular seal part cannot be fixed to the sliding part with sufficient strength, and if too large, the strength of the sliding part is reduced. The width of the annular seal groove (which is the dimension in the direction parallel to the central axis of the cylinder formed by the sliding portion) corresponds to the thickness of the annular seal portion sandwiched between the annular seal grooves, and therefore is too small. If the annular seal part cannot be fixed to the sliding part with sufficient strength, and if it is too large, the frictional force with the outer peripheral surface of the steering shaft will increase and the smooth turning motion of the steering shaft will be hindered. It is preferable that

The recess is formed on the outer peripheral surface of the sliding portion, and the bottom of the recess (the deepest portion from the outer peripheral surface of the sliding portion) communicates with the annular seal groove. Therefore, when the fluid is injected toward the bottom of the depression, the fluid flows out from the annular seal groove.
The depression should be sized and shaped so that the amount of unvulcanized material to form the annular seal can be placed in the second step to form the annular seal. Further, in the fourth step, the unvulcanized material for forming the annular seal portion, which has been heated and softened by the high temperature material (unvulcanized) for forming the dust seal body portion, is used. Material that forms (unvulcanized)
Preferably, the shape of the depression is such that it is pushed by and pushed out from the bottom of the depression to the annular seal groove.
Further, the recess may be only one, or a plurality of recesses may be formed. Further, the recess may communicate with the annular seal groove at a plurality of portions (for example, the sliding portion may be parallel to the annular seal groove). An annular recess is formed on the outer peripheral surface, and the annular seal groove and the annular recess are communicated by a plurality of communication passages)
May be The preparation of such a sliding portion can be done by manufacturing these materials using raw materials (for example, molding with a molding die, machining such as shaving), or obtaining by transfer such as purchase. Good.

In the second step, a predetermined amount of unvulcanized material for forming the annular seal portion is placed in the recess. At this time, in the fourth step (described later in detail), the material is easily in a heat-softened state and easily flows (extruded from the bottom of the depression into the annular seal groove) (the material is quickly discharged in the fourth step). Since it is softened by heat, the time required for the fourth step can be shortened), the material is preheated as necessary, for example, to arrange the material along the recess to soften the material. You may keep it. The unvulcanized material for forming the annular seal portion is placed in the recess in a predetermined amount, which is a sufficient amount for forming the annular seal portion. The unvulcanized material for forming the annular seal portion is heated by the material forming the dust seal body portion to be softened by heat,
It is placed so that it stays inside the recess.

In the third step, the sliding portion on which the unvulcanized material for forming the annular seal portion is arranged in the second step is arranged and fixed at a predetermined position in the molding die of the entire dust seal. That is, in this state, the portion that becomes the dust seal main body portion becomes hollow inside the molding die. Further, a cavity having a shape corresponding to the annular seal portion is formed between the inner peripheral surface of the sliding portion and the molding die so as to continue from the annular seal groove.

In the fourth step, the material for forming the dust seal body portion having a temperature at which the unvulcanized material for forming the annular seal portion can be thermally softened is poured into the mold to generate the dust seal. An unvulcanized material for forming the annular seal portion, which is in a heat-softened state in the recess, is extruded from the bottom portion into the annular seal groove to form the annular seal portion. First, a high temperature heat-softened material for forming the dust seal body is injected into the mold to form the material for forming the dust seal body and the annular seal disposed in the recess. Contact with unvulcanized material. By this contact, heat is transferred from the high-temperature material forming the dust seal body to the unvulcanized low-temperature material for forming the annular seal portion, and the unvulcanized material for forming the annular seal portion The temperature rises, and eventually the unvulcanized material for forming the annular seal portion becomes a heat softened state inside the depression. Therefore,
The material forming the dust seal body, which is poured into the mold, must be at a temperature that allows the unvulcanized material to form the annular seal to be heat softened. The term "thermosoftening" is sometimes called simply softening, but the ratio of the plastic flow velocity and the stress (the reciprocal of the viscosity) of an indeterminate trait (unvulcanized rubber here) increases with increasing temperature. It rapidly increases and becomes a soft state with remarkable fluidity when passing through a certain relatively narrow temperature range (softening temperature). The "heat-softened state" means a heat-softened state. Therefore, the "temperature at which the unvulcanized material for forming the annular seal portion can be thermally softened" means at least a temperature higher than the softening temperature of the unvulcanized material for forming the annular seal portion. is there. Injected into the mold,
The temperature of the material forming the dust seal body is at least higher than the softening temperature of the unvulcanized material for forming the annular seal, and within the moldable temperature range (if the temperature is too high, the material is There is a problem such as deterioration)
May be determined as appropriate. The unvulcanized material for forming the annular seal portion, which is in the heat-softened state in the depression in this way, is pushed by the material for forming the dust seal body portion, which is injected into the mold. Extrusion from the bottom of the depression into the annular seal groove. Since a cavity having a shape corresponding to the annular seal portion is formed so as to be continuous to the annular seal groove, the unvulcanized material extruded into the annular seal groove to form the annular seal portion is stored in the cavity. A shape corresponding to the annular seal portion is formed by the unvulcanized material that is filled and that forms the annular seal portion. The term “molding the annular seal portion” as used herein means to form a shape corresponding to the annular seal portion with an unvulcanized material for forming the annular seal portion.

In the fifth step, the vulcanization reaction is carried out by raising the temperature inside the molding die. The vulcanization condition is the material (unvulcanized) that is injected into the mold in the fourth step and forms the dust seal main body.
It may be appropriately determined in the same manner as in the past according to the type of the above. In the sixth step, the dust seal is taken out from the mold as in the conventional case, and the dust seal is completed.

In the extrusion method, the portion of the annular seal portion that is in close contact with the outer peripheral surface of the steering shaft is made of a low friction soft material having a friction coefficient smaller than that of the dust seal body portion after being vulcanized. Which is formed of an unvulcanized material for forming the annular seal portion, or is covered with a substance having a friction coefficient lower than that of the dust seal body portion (the coating step depends on the nature of the substance, etc. The friction coefficient of the dust seal body may be smaller than that of the dust seal body by either forming the portion with a material containing a lubricant or combining these methods. May be.

According to this manufacturing method (extrusion method),
The seal portion (annular seal portion) can be easily formed without requiring a separate manufacturing process for the seal portion, and the seal portion and the sliding portion can be joined securely and firmly. Besides,
Since the seal portion can be miniaturized, the material required for forming the seal portion can be reduced and the manufacturing cost of the dust seal can be reduced.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a partial cross-sectional view showing the main dust seal of the first embodiment, showing the main dust seal 11 inserted through the steering shaft 401, cut along a vertical plane including the central axis of the steering shaft 401. (The steering shaft 401 is not a cut surface). 2 is a sectional view taken along line XX of FIG. 1, and FIG.
2 is a cross-sectional view taken along line Y-Y (in FIGS. 2 and 3, the diameter of the steering shaft 401 is shown small in order to easily illustrate the structure of the dust seal 11). FIG. 4 is an enlarged detailed view of a portion surrounded by a circle B shown by a dotted line in FIG.

The dust seal 11 is attached similarly to the conventional dust seal shown in FIG. The dust seal 11 has a hole through which the rotating steering shaft 401 passes. The dust seal 11 includes a dust seal body 61 for closing the column hole 302, a cylindrical (a kind of tubular) sliding portion 21 that pivotally supports the steering shaft 401, an outer peripheral surface 403 of the steering shaft 401, and a sliding portion. And a seal portion 41 for reducing the flow of foreign matter passing through between the inner peripheral surface 21 and the inner peripheral surface 25. A plurality of parallel lips 23 (see FIG. 4) are formed on the inner peripheral surface of the cylindrical sliding portion 21 so as to extend in the circumferential direction.

The entire circumference of the outer edge portion 43 of the seal portion 41 is the sliding portion 2.
1, the entire inner edge portion 45 of the seal portion 41 is in close contact with the outer peripheral surface 403 of the steering shaft 401,
The outer peripheral surface 403 of the steering shaft 401 is slidable around the entire inner edge portion 45 of the seal portion 41. The seal portion 41 serves as a partition wall for blocking foreign matter, and reduces the flow of foreign matter through the outer circumferential surface 403 of the steering shaft 401 and the inner circumferential surface 25 of the sliding portion 21 even if a gap is formed between them. Let The dust seal main body 61 has a flange 63 to be attached to the dash panel 300 around the column hole 302, and the dust seal main body 61 extends from the entire outer peripheral surface 27 of the sliding portion 21 to the entire inner edge 65 of the flange 63. It is connected to.

The dust seal body 61 needs to use a material having properties such as flexibility, oil resistance and impact resistance, and requires a large amount of material (most of the volume occupied by this dust seal is the dust seal. Since the volume of the main body portion occupies), it is preferable to use a particularly inexpensive material, and it is preferable to use a rubber material that satisfies these conditions. As this rubber material, various rubber materials that have been conventionally used for forming a dust seal can be used.
M rubber, CR, CM, NBR / PVC, etc. can be enumerated (in the first embodiment, the dust seal body 61 is made of EPDM rubber).

The sliding portion 21 is the steering shaft 401.
At least the inner peripheral surface 25 of the sliding portion 21
It is preferable that the outer peripheral surface 403 of the steering shaft 401 can slide smoothly. Therefore, as a material for forming at least the inner peripheral surface 25 of the sliding portion 21, it is preferable to use a material having sufficient strength against a force received from the outer peripheral surface 403 of the steering shaft 401 and having a low friction coefficient. , Various resin materials, inorganic materials (for example, ceramic materials such as silicon nitride used for bearings, etc.), metal materials, etc. can be used, but durability,
It is preferable to use a resin material because of its low cost, light weight, and ease of molding. Although various materials can be used as the resin material, polyester resins such as polyacetal resin (POM), polyolefin resin (TPO), polyamide resin (PA), and polyethylene terephthalate (PET),
Examples thereof include fluorine resin, polyurethane resin, phenol resin, and the like, or a mixture thereof. It is not necessary that only the inner peripheral surface 25 of the sliding portion 21 be formed of these materials.
The whole may be formed of these materials. Also,
The sliding portion 21 may be one in which the inner peripheral surface of a tubular metal ring made of stainless steel or the like is coated with these materials (see the third embodiment).

The seal portion 41 is entirely formed of silicon rubber. Silicon rubber has a friction coefficient sufficiently smaller than that of the dust seal body 61 (made of EPDM rubber). Therefore, the seal portion 41 (the inner edge portion 4
The portion of 5) that is in close contact with the outer peripheral surface 403 of the steering shaft 401 has a friction coefficient that is sufficiently smaller than the friction coefficient of the dust seal body 61 (the entire seal portion 41 is sufficiently smaller than the friction coefficient of the dust seal body 61). Has a coefficient of friction.)

On the other hand, the seal portion 41 is a separate body from the dust seal body portion 61 and the sliding portion 21.
1 is fitted and fixed to the sliding portion 21. That is, between the seal portion 41 and the sliding portion 21, the sliding portion 21 is attached to the seal portion 41.
An annular projection 49 is formed so as to protrude toward the outside and extends in the circumferential direction, and an annular groove 29 is formed in the sliding portion 21 that is fitted to the annular projection 49 and extends in the circumferential direction. The annular protrusion 49 and the annular groove 29 are fitted to each other. The annular protrusion 49 and the annular groove 29 are
As shown in FIG. 3, they are fitted over the entire circumference. Also,
Sliding between the outer peripheral surface 27 of the sliding portion 21 and the dust seal main body portion 61 so as to extend substantially parallel to the central axis of the cylinder formed by the sliding portion 21 (corresponding to the central axis of the steering shaft 401). A rod-shaped projection 31 is formed on the portion 21, a rod-shaped groove 67 that fits with the rod-shaped projection 31 is formed on the dust seal body portion 61, and the rod-shaped projection 31 and the rod-shaped groove 67 are fitted. Further, a return portion 33 is formed at the tip end portion of the rod-shaped protrusion 31, whereby the rod-shaped protrusion 31 is abruptly removed from the rod-shaped groove 67 in a direction substantially parallel to the cylindrical central axis formed by the sliding portion 21. Not only is it not provided, but the return portion 33 also serves as a rotation stopper so that the sliding portion 21 does not follow the rotation of the steering shaft.

Next, a manufacturing method (a rod-shaped projection rod-shaped groove fitting method) for manufacturing the present dust seal (the dust seal shown in FIGS. 1 to 4) of the first embodiment will be described. As a first step, a sliding part, a seal part, and a dust seal body part are prepared. First, the sliding portion 21 shown in FIGS. 5 to 7 is manufactured by an injection molding method using the resin material (for example, polyacetal resin (POM)) suitable for forming the sliding portion 21. prepare. Figure 5 shows the sliding part 2
1 is a front view of FIG. 1, and FIG. 6 is a left side view of the sliding portion 21 (see FIG.
7 is a right side view of the sliding portion 21 (viewed from the direction of arrow E in FIG. 5). The prepared sliding portion 21 will be described with reference to FIGS. 5 to 7. The sliding portion 21 has a cylindrical shape, and an annular groove 29 is formed so as to extend in the circumferential direction around the center axis 21c of the cylinder. A rod-shaped projection 31 is formed on the sliding portion 21 so as to extend substantially parallel to a cylindrical central axis 21c formed by the sliding portion 21. Rod-shaped projection 3
A return portion 33 is formed at the tip portion of 1. Next, the seal portion 41 shown in FIGS. 8 to 10 is manufactured and prepared from silicon rubber. FIG. 8 is a cross-sectional view showing a cut surface by a plane including a central axis 41c of a seal portion 41 having a shape in which a hollow frustoconical top surface and a lower surface (bottom surface) are removed, and FIG. 9 is a right side of the seal portion 41. 8 is a plan view (viewed in the direction of arrow G in FIG. 8), and FIG. 10 is a left side view of the seal portion 41 (viewed in the direction of arrow F in FIG. 8). Seal part 41 prepared in the first step
Is vulcanized and is manufactured by known techniques for manufacturing rubber products. The seal portion 41 has an upper surface opening 41d and a lower surface opening 41f, and an annular projection 49 is formed around the lower surface opening 41f so as to extend in the circumferential direction.
Have. The entire seal portion 41 (including the portion of the seal portion 41 that comes into close contact with the outer peripheral surface 403 of the steering shaft 401) is the dust seal main body portion 61.
It is made of silicon resin, which is a substance having a lower friction coefficient than that of EPDM rubber. Then, the dust seal body 61 shown in FIG. 11 is manufactured and prepared from EPDM rubber. FIG. 11 shows the dust seal body 61.
FIG. 6 is a cross-sectional view showing a dust seal body 61 cut along a vertical plane that includes the central axis of the steering shaft 401 when the steering shaft 401 is inserted through a dust seal that will be composed of The dust seal body 61 prepared in the first step is vulcanized and is manufactured by a known technique for manufacturing a rubber product. In the dust seal main body 61,
A rod-shaped groove 67 for fitting with the rod-shaped projection 31 formed on the sliding portion 21 is formed. Further, at one end in the longitudinal direction of the rod-shaped groove 67, a return accommodating portion 67b for fitting with the return portion 33 formed at the tip portion of the rod-shaped projection 31 is formed.

As a second step, the annular projection 49 (projection) of the seal portion 41 and the annular groove 29 (recess) of the sliding portion 21 are fitted to each other to assemble the sliding portion 21 and the sealing portion 41. FIG. 12 is a sectional view showing a state in which the annular protrusion 49 and the annular groove 29 are fitted together. The annular protrusion 49 and the annular groove 29 are fitted tightly over the entire circumference, so that the sliding portion 21 and the sealing portion 41 are securely joined firmly. That is, before the annular groove 29 (recess) and the annular protrusion 49 (projection) are fitted to each other, the outer peripheral length of the annular groove 29 (recess) is equal to the annular protrusion 49.
The annular groove 29 (recess) and the annular protrusion 49 (protrusion) are formed so as to be about 10 to 30% larger than the inner peripheral length of the (protrusion). By moving the seal portion 41 in the arrow J direction with respect to the sliding portion 21, the elasticity of the seal portion 41 (made of flexible silicon rubber) is utilized (the annular protrusion 49 (of the seal portion 41). It is possible to fit the annular protrusion 49 and the annular groove 29 while pushing the protrusion) apart. In this fitted state, the seal portion 41
The annular protrusion 49 (projection) of the annular groove 29 of the sliding portion 21 is
Since it is pushed out by the (concave portion), the annular projection 49 (projection) of the seal portion 41 tightens the annular groove 29 (concave portion) of the sliding portion 21, so that the annular projection 49 and the annular groove 29 are completely covered. Fits snugly around the circumference. At this time, if necessary, an adhesive may be applied between the annular protrusion 49 and the annular groove 29 so that the sliding portion 21 and the seal portion 41 are firmly joined.

As a third step, the rod-shaped projection 3 of the sliding portion 21
1 and the rod-shaped groove 67 of the dust seal main body 61 are fitted to each other to assemble the dust seal main body 61 and the sliding portion 21. In the second step, the sliding portion 21 to which the seal portion 41 is assembled is moved so that the rod-shaped projection 31 formed on the sliding portion 21 slides along the rod-shaped groove 67 of the dust seal main body portion 61, whereby the rod-shaped projection 31 is smoothly moved. And rod groove 67
And can be fitted together. At this time, if necessary, an adhesive may be applied between the dust seal body 61 and the sliding portion 21 so as to bond them together. In FIG.
The sectional view of the present dust seal 11 of the first embodiment which is completed after the third step is shown. The dust seal 11 is constructed by assembling the seal portion 41, the sliding portion 21, and the dust seal body portion 61. After this, this dust seal 1
When 1 is used, the steering shaft 401 is inserted into the sliding portion 21, and the structure shown in FIG. 1 is obtained.

FIG. 14 is a partially enlarged sectional view showing the present dust seal of the second embodiment, showing the same portion as FIG. 4 in the first embodiment. Further, FIG. 15 is an enlarged detailed view of a portion surrounded by a circle C shown by a dotted line in FIG. The present dust seal of the second embodiment will be described with reference to FIGS. 14 and 15. The differences between the dust seal of the second embodiment and the dust seal of the first embodiment will be described, and the description of the same points will be omitted (the same reference numerals as those used in the first embodiment are given. The element shows the same element as the element of the first embodiment.). Compared to the first embodiment, in the second embodiment, the material of the seal part 41, that part of the seal part 41 is coated with silicone resin, and the material of the dust seal body part 61 are different. That is, the seal portion 4
1 is made of NBR / PVC. As shown in FIG. 15, in the portion of the seal portion 41 (inner edge portion 45) in close contact with the outer peripheral surface 403 of the steering shaft 401, a substance having a lower friction coefficient than the dust seal body portion 61 (made of NBR / PVC). Silicone resin 47 is coated.

The method of attaching the seal portion 41, the dust seal main body portion 61, and the sliding portion 21 and the shape and structure of each portion are completely the same as those in the first embodiment, and therefore the description thereof is omitted here. The present dust seal of the second embodiment can be manufactured by a method similar to that of the present dust seal of the first embodiment (rod-shaped projection rod-shaped groove fitting method). That is, as the first step, the sliding portion, the seal portion, and the dust seal main body portion are prepared. First, similarly to the first embodiment, the sliding portion 21 shown in FIGS. 5 to 7 is manufactured and prepared by the injection molding method using the resin material (the sliding portion 21 in the first embodiment is prepared. The description is omitted because it is the same as the one used.) Then, in FIG.
The seal portion 41 shown in 1 is manufactured and prepared by NBR / PVC. FIG. 16 shows a cross section at the same position as that of FIG. 8 showing the seal portion 41 used in the first embodiment, and the center of the seal portion 41 having a shape in which the upper surface and the lower surface (bottom surface) of the hollow truncated cone shape are removed. It is sectional drawing which shows the cut surface by the plane containing the axis | shaft 41c. The seal portion 4 shown in FIG.
1 has the same shape as the seal portion 41 (shown in FIGS. 8 to 10) used in the first embodiment, and therefore,
Right side view (viewed from the direction of arrow G in FIG. 16)
10 is the same as FIG. 10 and its left side view (arrow F in FIG. 16).
(When viewed from the direction of) is the same as FIG. 11. The seal part 41 prepared in the first step is vulcanized and manufactured by a known technique for manufacturing a rubber product. The seal portion 41 has an upper surface opening 41d and a lower surface opening 41f, and has an annular projection 49 formed around the lower surface opening 41f so as to extend in the circumferential direction. The dust seal main body portion 61 is provided in a portion (of the inner edge portion 45 defining the upper surface opening 41d) of the seal portion 41, which comes into close contact with the outer peripheral surface 403 of the steering shaft 401.
Silicone resin 47, which is a substance having a lower friction coefficient than that of NBR / PVC, is coated. Silicone resin 47
The coating can be performed by various known methods. For example, the sealing part (vulcanized) before coating is immersed in acetone to degrease it, and a multi-liquid mixed baking type silicone liquid is used. (For example, "Tore SRX", a trade name of Toray, Dow Corning, Silicone Co., Ltd., which is commercially available.
290 "and the like can be preferably used. ) Is dried at room temperature for a predetermined time (usually about 10 to 30 minutes), and then baked at a predetermined temperature for a predetermined time (usually 1
It can be carried out at 00 ° C. for 10 to 60 minutes).
Then, similarly to the first embodiment, the dust seal body 61 shown in FIG. 11 is manufactured and prepared by NBR / PVC (the dust seal body 61 is used in the first embodiment except that the material used is different). The description is omitted because it is the same as the one). The dust seal body 61 prepared in the first step is vulcanized and is manufactured by a known technique for manufacturing a rubber product. After that, the second step and the third step are performed in the same manner as in the case of manufacturing the present dust seal of the first embodiment, and the present dust seal of the second embodiment is completed.

FIG. 17 is a partially enlarged sectional view showing the present dust seal of the third embodiment, and shows the same portion as FIG. 4 in the first embodiment. 18 is a ZZ cross-sectional view of FIG. The dust seal of the third embodiment will be described with reference to FIGS. 17 and 18. In addition,
The present dust seal of the third embodiment has the same structure as the dust seal of the first embodiment except for the portions shown in FIGS. 17 and 18. The seal portion 41 of the third embodiment has an annular seal portion 42 embedded in the inner periphery of the sliding portion 21 so as to extend in the circumferential direction. The annular seal portion 42 is formed so that a part thereof protrudes inward from the inner peripheral surface of the sliding portion 21, and the inner edge portion 45 of the seal portion 41 is formed by the protruding portion. The entire circumference of the outer edge portion 43 of the seal portion 41 is fixed to the sliding portion 21 (see a communication passage 37 (see FIG.
(Refer to (see FIG. 3) to firmly fix the seal portion 41 by filling the seal portion 41)). In the third embodiment, the entire seal portion 41 is made of CR mixed with fluororesin particles as a lubricant. The CR containing the fluorine resin particles has a friction coefficient smaller than that of the dust seal body 61 (made of CR). Therefore, the seal portion 41 (inner edge portion 45)
The portion 51 of the steering shaft 401, which is in close contact with the outer peripheral surface 403, has a friction coefficient sufficiently smaller than the friction coefficient of the dust seal body 61 (the entire seal portion 41 has a friction coefficient sufficiently smaller than the friction coefficient of the dust seal body 61). Has a coefficient.)

A cylindrical central axis formed by the sliding portion 21 between the outer peripheral surface 27 of the sliding portion 21 and the dust seal body 61 (corresponding to the central axis of the steering shaft 401).
A bar-shaped protrusion 31 is formed on the sliding portion 21 so as to extend substantially parallel to the bar-shaped protrusion 31 on the dust seal body 61.
Is formed, and the rod-shaped projection 31 and the rod-shaped groove 67 are fitted together. Furthermore, a return portion 33 is formed at the tip of the rod-shaped projection 31,
As a result, the rod-shaped projection 31 is prevented from being abruptly removed from the rod-shaped groove 67 in the direction substantially parallel to the cylindrical central axis formed by the sliding portion 21. These rod-shaped protrusions 31 and rod-shaped grooves 67
Both are formed similarly to those of the first embodiment.

A manufacturing method (extrusion method) for manufacturing the present dust seal (the dust seal shown in FIGS. 17 and 18) of the third embodiment will be described. As the first step,
The sliding part 21 is prepared. The sliding portion 21 to be prepared is shown in FIGS. 19 and 20. FIG. 19 is a cross-sectional view showing a cross section taken along a plane including the central axis 21c of the cylinder formed by the sliding portion 21, and FIG. 20 is a P-P cross-sectional view of FIG. The sliding portion 21 will be described with reference to FIGS. 19 and 20. An annular seal groove 35 is formed on the inner peripheral surface 25 of the sliding portion 21 so as to extend in the circumferential direction. The annular seal groove 35 has a substantially trapezoidal cross-sectional shape (refers to the cross-sectional shape when cut by a plane perpendicular to the longitudinal direction of the groove. Therefore, it is the same as the shape of the annular seal groove 35 appearing on the cut surface in FIG. 19). Since the upper base (which is the shorter of the upper base and the lower base parallel to each other among the four sides of the trapezoid) is along the inner peripheral surface 25 of the sliding portion 21, The formed annular seal portion 42 is securely fixed to the inner peripheral surface 25 and is prevented from falling off. The annular seal groove 35 is formed continuously over the entire circumference of the inner peripheral surface 25 of the sliding portion 21, as shown in FIG. On the other hand, the outer peripheral surface 2 of the sliding portion 21
A recess 36 is formed in 7. A plurality (here, 6
The individual communication passages 37 are formed at equal intervals along the circumference (see FIG. 20). The cross-sectional shape of the dent 36 (the cross-sectional shape when cut by a plane perpendicular to the longitudinal direction of the dent 36. Therefore, the shape of the dent 36 shown in the cut surface of FIG. 19 is substantially trapezoidal). . Here, the upper base (the shorter one of the upper base and the lower base parallel to each other among the four sides of the trapezoid) is communicated with the communication passage 37, so that the recess 36 is thermally softened in the fourth step. Became a state,
The material for forming the annular seal portion 42 is smoothly extruded into the annular seal groove 35 through the communication passage 37, and the depression 36 is formed.
The material remaining inside can be reduced. Further, since the lower bottom (which is the longer one of the four sides of the trapezoid which is parallel to each other) is along the outer peripheral surface 27, it is injected into the molding die in the fourth step. The material forming the dust seal main body easily enters the recess 36, so that the material forming the annular seal portion 42 can be effectively softened and extruded by the material forming the dust seal main body. In addition, in the sliding portion 21,
A rod-shaped projection 31 is formed so as to extend substantially parallel to the cylindrical central axis 21c formed by the sliding portion 21. A return portion 33 is formed at the tip of the rod-shaped protrusion 31.
Such a sliding portion 21 as a whole is made of the resin material (for example,
Although it is formed of a polyacetal resin (POM), any method may be used, and examples thereof include an injection molding method and a machining method such as cutting.

As a second step, a predetermined amount of unvulcanized material for forming the annular seal portion 42 is placed in the recess 36.
21 and 22 show a state where CR (unvulcanized) 38 containing fluororesin particles (lubricant), which is an unvulcanized material for forming the annular seal portion 42, is placed in the recess 36. ing. FIG. 21 shows the same cross section as FIG.
22 is a QQ sectional view of FIG. 21 (that is, FIG. 22 shows the same section as FIG. 20). The second step will be described with reference to FIGS. 21 and 22. Cross-sectional shape of CR (unvulcanized) 38 containing fluororesin particles (lubricant) (when cut by a plane perpendicular to the longitudinal direction of CR (unvulcanized) 38 containing fluororesin particles (lubricant)) 21. Therefore, the CR (unvulcanized) 38 blended with the fluororesin particles (lubricant) that appears on the cut surface in FIG. 21 has the substantially oval or trapezoidal shape. It is substantially along the cross-sectional shape of the depression 36. The CR (unvulcanized) 38 containing the fluororesin particles (lubricant) has an annular shape as a whole (see FIG. 22), and is arranged along the entire circumference of the annular recess 36. Here, although an annular material was used as the unvulcanized material for forming the annular seal portion 42, the depression 36
Any shape can be used as long as it can be arranged in, for example, a rod shape or a spherical shape can be used. Further, the “predetermined amount” in which the CR (unvulcanized) 38 containing the fluororesin particles (lubricant) is arranged means the amount required to form the annular seal portion 42. In addition, CR (non-vulcanized) containing fluororesin particles (lubricant)
38 may be preheated and then placed in the recess 36. By doing so, the CR (unvulcanized) 38 containing the fluororesin particles (lubricant) is easily and quickly brought into a heat-softened state in the fourth step, so that the time required for the fourth step can be shortened. .

As the third step, CR (unvulcanized) 38 (unvulcanized material for forming the annular seal portion 42) containing fluororesin particles (lubricant) was placed in the second step. The sliding part 21 is formed into a molding die 701 for the entire dust seal.
Place and secure in place. FIG. 23 is a cross-sectional view showing that the sliding portion 21 in which the CR (unvulcanized) 38 containing the fluororesin particles (lubricant) is arranged is arranged in the molding die 701. FIG. 24 is an enlarged cross-sectional view of a portion of a circle M indicated by a dotted line in FIG. 25 is a sectional view taken along line RR of FIG. The third step will be described with reference to FIGS. 23 to 25. As described in FIGS. 21 and 22, CR (unvulcanized) containing fluororesin particles (lubricant)
The sliding portion 21 in which 38 is arranged is arranged and fixed at a predetermined position (position where the sliding portion 21 should be arranged) in the molding die 701 of the entire dust seal. A cavity 70 is formed around the sliding portion 21 in a portion that should be the dust seal body 61.
3 is formed. The outer peripheral surface 27 of the sliding portion 21 is the cavity 7
Surrounded by 03. Therefore, the cavity 36 in which the CR (unvulcanized) 38 containing the fluororesin particles (lubricant) is arranged is also surrounded by the cavity 703 over the entire circumference. Between the inner peripheral surface 25 of the sliding portion 21 and the molding die 701, a cavity 39 having a shape corresponding to the annular seal portion (not shown) is formed so as to continue from the annular seal groove 35. When it is necessary to firmly bond the sliding portion 21 and the dust seal main body portion, an adhesive may be applied to the outer peripheral surface 27 of the sliding portion 21 before being placed in the molding die 701. .

As a fourth step, an unvulcanized material (here, CR (unvulcanized) 38 containing fluorine resin particles (lubricant)) for forming the annular seal portion 42 can be thermally softened. The material for forming the dust seal body 61 at a temperature is injected into the molding die 701, and the material for forming the dust seal body 61 is used to form the annular seal portion 42 that is in the heat-softened state in the depression 36. Unvulcanized material (here CR mixed with fluororesin particles (lubricant))
(Unvulcanized) 38) is extruded from the bottom into the annular seal groove 35 to form the annular seal portion 42. High temperature (ring seal 4
2 is a heat-softened dust seal body part of an unvulcanized material (here, a temperature at which CR (unvulcanized) 38 containing fluorine resin particles (lubricant)) can be thermally softened). Material forming 61 (here unvulcanized CR)
Is injected into the molding die 701, and the dust seal main body 61
(Here, unvulcanized CR) and the unvulcanized material (here, fluororesin particles (lubricant)) for forming the annular seal portion 42, which is disposed in the depression 36, are mixed.
And R (unvulcanized) 38). This contact (part,
Radiant heat transfer and convective heat transfer are also generated) from a high temperature material (here, unvulcanized CR) forming the dust seal body 61 to an unvulcanized low temperature material for forming the annular seal portion 42. The heat is transferred to (here, CR (unvulcanized) 38 containing fluororesin particles (lubricant)), and an unvulcanized material for forming the annular seal portion 42 (here, fluororesin particles (lubricant) The temperature of CR (unvulcanized) 38) is increased, and an unvulcanized material for forming the annular seal portion 42 (here, CR (unvulcanized) mixed with fluororesin particles (lubricant)) is formed. (Sulfuric acid) 38) becomes a heat softened state inside the recess 36. In this state, a material (here, unvulcanized CR) that forms the dust seal body 61 is further injected into the molding die 701 (cavity 703) to form the depression 36.
An unvulcanized material (here, CR (unvulcanized) 38 mixed with fluororesin particles (lubricant)) for forming the annular seal portion 42, which is in a heat-softened state inside, is introduced from the bottom of the depression 36. It is pushed out to the annular seal groove 35 via the communication passage 37. The annular seal portion 4 is continuous with the annular seal groove 35.
Since the cavity 39 having a shape corresponding to 2 is formed, an unvulcanized material (here, fluororesin particles (lubricant)) extruded into the annular seal groove 35 to form the annular seal portion 42 is formed. The mixed CR (unvulcanized) 38) is filled in the cavity 39, and the unvulcanized material for forming the annular seal portion 42 (here, CR mixed with fluororesin particles (lubricant)).
By (unvulcanized) 38), a shape corresponding to the annular seal portion 42 is formed. The state in which this fourth step is completed is shown in FIG.
6 and FIG. 27. 26 is a sectional view showing the same section as FIG. 24, and FIG. 27 is an SS sectional view of FIG. 26 (FIG. 27 shows the same section as FIG. 25).
A state in which the fourth step is completed will be described with reference to FIGS. 26 and 27. The material that forms the dust seal body 61 (here, unvulcanized CR707) is filled in the portion that was the cavity 703 in FIGS. 24 and 25. 24 (FIG. 24 and FIG. 2), CR (unvulcanized) 38 mixed with fluororesin particles (lubricant) is heat-softened.
5 is filled with the annular seal groove 35 and the cavity 39 having a shape corresponding to the annular seal portion (the annular seal groove 35).
And the rest of the fluororesin particles (lubricant) that fill the cavity 39
CR (unvulcanized) mixed with is present in the communication passage 37 and the bottom of the recess 36. ). As a result, an unvulcanized annular seal portion 42a having a shape corresponding to the annular seal portion 42 is formed.

In the fifth step, the temperature inside the molding die 701 is raised,
The material forming the dust seal body 61 (here, unvulcanized CR707) and the material forming the unvulcanized annular seal portion 42a (here, C mixed with fluororesin particles (lubricant))
R (unvulcanized)) is vulcanized. Here, the vulcanization reaction was carried out at 170 ° C. for about 3 minutes. In the sixth step, the dust seal was taken out from the molding die 701 and the dust seal 11 was completed by the extrusion method as in the conventional method.

FIG. 28 is a partially enlarged sectional view showing the present dust seal of the fourth embodiment, and shows the same portion as FIG. 4 in the first embodiment. 29 is an enlarged detailed view of a portion surrounded by a circle D shown by a dotted line in FIG. The present dust seal of the fourth embodiment will be described with reference to FIGS. 28 and 29. The differences between the dust seal of the fourth embodiment and the dust seal of the first embodiment will be described, and description of the same points will be omitted (the same reference numerals as the reference numerals used in the first embodiment are given. The element shows the same element as the element of the first embodiment.). In the fourth embodiment, compared with the dust seal of the first embodiment, the shape of the seal portion 41 and the steering shaft 401 of the seal portion 41 (inner edge portion 45).
Of the nitrile butadiene rubber (NB) in which the portion 51 that is in close contact with the outer peripheral surface 403 of the rubber is compounded with fluororesin particles as a lubricant.
R) is different (see FIG. 29). The fluororesin particles have a NBR content of about 10
It is blended in a weight percentage. Therefore, the seal portion 41
The portion 51 of the (inner edge portion 45) that is in close contact with the outer peripheral surface 403 of the steering shaft 401 is the dust seal main body portion 6.
It has a friction coefficient sufficiently smaller than the friction coefficient of 1 (made by CR).

The seal portion 41 is the dust seal body portion 61.
And the sliding portion 21 are separate bodies, and the seal portion 41 is fitted and fixed to the sliding portion 21. That is, similarly to the first embodiment, an annular protrusion 49 is formed between the seal portion 41 and the sliding portion 21 so as to project to the slide portion 21 and extend in the circumferential direction in the seal portion 41. Is formed, and an annular groove 29 is formed in the sliding portion 21 so as to fit with the annular protrusion 49 and extend in the circumferential direction.
And the annular groove 29 are fitted to each other. The annular protrusion 49 and the annular groove 29 are fitted over the entire circumference. Also,
Sliding between the outer peripheral surface 27 of the sliding portion 21 and the dust seal main body portion 61 so as to extend substantially parallel to the central axis of the cylinder formed by the sliding portion 21 (corresponding to the central axis of the steering shaft 401). A rod-shaped projection 31 is formed on the portion 21, a rod-shaped groove 67 that fits with the rod-shaped projection 31 is formed on the dust seal body portion 61, and the rod-shaped projection 31 and the rod-shaped groove 67 are fitted. Further, a return portion 33 is formed at the tip end portion of the rod-shaped protrusion 31, whereby the rod-shaped protrusion 31 is abruptly pulled out from the rod-shaped groove 67 in a direction substantially parallel to the cylindrical central axis formed by the sliding portion 21. It is supposed not to. The annular protrusion 49 and the annular groove 29,
Both the rod-shaped protrusion 31 and the rod-shaped groove 67 are configured similarly to those in the first embodiment.

A manufacturing method (projection / recess fitting method) for manufacturing the present dust seal (the dust seal shown in FIGS. 28 and 29) of the fourth embodiment will be described. As the first step, the sliding portion 21 and the sealing portion 41 are prepared respectively.
The sliding portion 21 is a rod-shaped projection rod-shaped groove fitting method (method shown as a method for manufacturing the dust seal of the first embodiment).
Manufactured by the injection molding method or the like (the above-mentioned resin material suitable for forming the sliding portion 21, for example, a material such as a polyamide resin is used. And prepare. On the other hand, FIG.
The seal part 41 shown in the cross-sectional view of FIG.
Nitrile butadiene rubber (N
A material such as BR) may be used. ) And prepare. Figure 30
Shows a cut surface of a hollow substantially cylindrical seal portion 41 having openings in an upper bottom surface and a lower bottom surface by a plane including a cylindrical center axis 41c. The seal part 41 prepared in the first step is vulcanized and manufactured by a known technique for manufacturing a rubber product. The seal portion 41 has an upper surface opening 41d and a lower surface opening 41f, and the lower surface opening 41d.
An annular protrusion 49 formed so as to extend in the circumferential direction is provided around f. Of the inner edge portion 45 that defines the upper surface opening 41d of the seal portion 41, the portion 51 that comes into close contact with the outer peripheral surface 403 of the steering shaft 401 has about 10% by weight of fluororesin particles as a lubricant on the NBR (versus NB).
It is formed of the material compounded in R). The method of forming the seal portion 41 with two different kinds of materials as described above can be freely performed by a known technique. For example, a two-color molding method (which is then vulcanized) or a different material portion is separately formed. And then gluing (either vulcanizing before gluing or vulcanizing after gluing) or one of the dissimilar material parts first and then insert it into the other mold and insert the other. A method of molding (then, followed by vulcanization) and the like can be mentioned.

In the second step, the annular projection 49 (projection) of the seal portion 41 and the annular groove 29 (recess) of the slide portion 21 are fitted to each other to assemble the slide portion 21 and the seal portion 41. FIG. 31 is a cross-sectional view showing a state where the annular protrusion 49 and the annular groove 29 are fitted together. The annular protrusion 49 and the annular groove 29 are fitted tightly over the entire circumference, so that the sliding portion 21 and the sealing portion 41 are securely joined firmly. That is, before the annular groove 29 (recess) and the annular protrusion 49 (projection) are fitted to each other, the outer peripheral length of the annular groove 29 (recess) is equal to the annular protrusion 49.
The annular groove 29 (recess) and the annular protrusion 49 (protrusion) are formed so as to be about 10 to 30% larger than the inner peripheral length of the (protrusion). By moving the seal portion 41 in the direction of the sliding portion 21, the elasticity of the seal portion 41 (formed by the flexible NBR) is utilized (the annular protrusion 49 (projection) of the seal portion 41 is widened). The annular protrusion 49 and the annular groove 29 can be fitted together.
In this fitted state, the annular projection 49 (projection) of the seal portion 41 is expanded by the annular groove 29 (recess) of the sliding portion 21, so that the annular projection 4 of the seal portion 41 is formed.
9 (protrusion) tightens the annular groove 29 (recess) of the sliding portion 21, and the annular projection 49 and the annular groove 29 are fitted tightly over the entire circumference. At this time, if necessary, an adhesive may be applied between the annular protrusion 49 and the annular groove 29 so that the sliding portion 21 and the seal portion 41 are firmly joined.

In the third step, the sliding portion and the seal portion assembled in the second step are arranged and fixed at predetermined positions in the mold of the entire dust seal. FIG. 32 is a cross-sectional view showing the internal state of the molding die for the entire dust seal after the third step is completed. The sliding portion 21 and the sealing portion 41, which are assembled with each other, are arranged and fixed at predetermined positions (positions where the sliding portion and the sealing portion should be arranged) inside the molding die 701 of the entire dust seal. Mold 70
A cavity 703 corresponding to the dust seal main body 61 is formed inside the unit 1. The dust seal body 6
1 and the sliding portion 21 and the seal portion 41 are more firmly joined to each other, and the sliding portion 2 is disposed in the molding die 701 as necessary.
An adhesive may be applied to the portion of 1 or the seal portion 41 that becomes the boundary surface with the dust seal body portion 61.

As a fourth step, the inside of the molding die 701 (the cavity 7
03) is filled with the material (unvulcanized rubber) forming the dust seal body 61. The material (unvulcanized rubber) forming the dust seal body 61 may be appropriately selected as described above, and unvulcanized chloroprene rubber (CR) is used here. FIG. 33 shows an internal state of the molding die 701 in which the fourth step has been completed. In FIG. 32, an unvulcanized chloroprene rubber 705 is injected and filled into the portion which is the cavity 703. In the fifth step, the mold 70
The temperature inside 1 is raised to vulcanize the unvulcanized chloroprene rubber 705. Here, the vulcanization reaction was carried out at 170 ° C. for about 3 minutes. In the sixth step, the dust seal was taken out from the molding die 701 and the dust seal 11 was completed by the projection recess fitting method as in the conventional case.

FIG. 34 is a partially enlarged sectional view showing the present dust seal of the fifth embodiment, and shows the same portion as FIG. 4 in the first embodiment. The dust seal of the fifth embodiment will be described with reference to FIG. 34. The difference between the dust seal of the fifth embodiment and the dust seal of the first embodiment will be described, and the description of the same points will be omitted (the same reference numerals as the reference numerals used in the first embodiment are given. The element shows the same element as the element of the first embodiment.). In the fifth embodiment, compared with the dust seal of the first embodiment, the structure of the sliding portion 21 and the steering shaft 4 of the seal portion 41 (inner edge portion 45).
The difference is that the portion 51 of 01 that is in close contact with the outer peripheral surface 403 is formed of NBR / PVC mixed with silicon resin particles as a lubricant. The silicone resin particles are mixed in the NBR / PVC at a ratio of about 15% by weight. Therefore, the portion 51 of the seal portion 41 (inner edge portion 45) that is in close contact with the outer peripheral surface 403 of the steering shaft 401 has a dust seal body portion 61 (NBR / PVC).
Has a friction coefficient sufficiently smaller than the friction coefficient of (made by Japan).

The sliding portion 21 is made of the above-mentioned resin material (sliding portion 2
1. A cylindrical resin cylinder 21a made of, for example, polyethylene terephthalate (PET) or the like suitable for forming No. 1 and formed along the outer peripheral surface of the resin cylinder 21a so as to closely contact and cover the outer peripheral surface. Stainless steel metal tube 2
1b and. The seal portion 41 is a separate body from the dust seal main body portion 61 and the sliding portion 21.
1 is fitted and fixed to the sliding portion 21. That is, similarly to the first embodiment, an annular protrusion 49 is formed between the seal portion 41 and the sliding portion 21 so as to project to the slide portion 21 and extend in the circumferential direction in the seal portion 41. Is formed, and an annular groove 29 is formed in the sliding portion 21 so as to be fitted to the annular projection 49 and extend in the circumferential direction. The annular projection 49 and the annular groove 29 are fitted to each other. There is. Annular groove 2
Before the 9 (recess) and the annular projection 49 (projection) are fitted together, the outer peripheral length of the annular groove 29 (recess) is about 10 to 10 times the inner peripheral length of the annular projection 49 (projection). Since the annular groove 29 (recess) and the annular protrusion 49 (projection) are formed to be 30% larger, the annular protrusion 49 (projection) of the seal portion 41 is formed.
Tightens the annular groove 29 (recess) of the sliding portion 21, and the annular protrusion 49 and the annular groove 29 are fitted tightly over the entire circumference. (If necessary, an adhesive may be applied between the annular protrusion 49 and the annular groove 29 so that the sliding portion 21 and the seal portion 41 are firmly joined together.). An adhesive layer (not shown) that strongly adheres the metal tube 21b and the dust seal body 61 is interposed between the metal tube 21b and the dust seal body 61. The present dust seal of the fifth embodiment can be manufactured by various methods. For example, the projection recess fitting method (the method already described as the method of manufacturing the dust seal of the fourth embodiment) or the sliding portion 21 is used. After assembling with the seal portion 41 (vulcanized), an adhesive is applied to the outer peripheral surface of the sliding portion 21 (metal cylinder 21b) and inserted into the vulcanized dust seal body portion 61, or sliding. Part 21 and seal part 41
After assembling with (vulcanized), the sliding portion 21 (metal cylinder 21
An adhesive for vulcanization adhesion is applied to the outer peripheral surface of b), the sliding portion 21 and the seal portion 41 are arranged and fixed at predetermined positions in the molding die of the entire dust seal, and the dust seal main body portion is placed in the molding die. A material for forming 61 (unvulcanized) is injected, the temperature inside the mold is raised to cause a vulcanization reaction (at the same time, the metal which is the outer peripheral surface of the sliding portion 21 (metal cylinder 21b) and the dust seal main body 61
It is firmly vulcanized and adhered to the rubber. ), And by taking out a dust seal from the molding die or the like. The sliding portion 21 can be manufactured by various known methods. For example, the resin cylinder 21a is formed after the metal cylinder 21b is inserted into a molding die corresponding to the entire shape of the sliding portion 21. A method of injecting a material (melted state) into the molding die for molding, a method of separately manufacturing the resin cylinder 21a and the metal cylinder 21b, and then fixing the both by adhesion or the like may be exemplified. it can.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a present dust seal of a first embodiment.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line YY of FIG.

FIG. 4 is an enlarged detailed view of a portion surrounded by a circle B in FIG.

FIG. 5 is a front view of a sliding portion prepared when the present dust seal according to the first embodiment is manufactured by the rod-shaped projection rod-shaped groove fitting method.

FIG. 6 is a left side view of the sliding portion shown in FIG.

7 is a right side view of the sliding portion shown in FIG.

FIG. 8 is a cross-sectional view of a seal portion prepared when the present dust seal of the first embodiment is manufactured by the rod-shaped projection rod-shaped groove fitting method.

9 is a right side view of the seal portion shown in FIG.

FIG. 10 is a left side view of the seal portion shown in FIG.

FIG. 11 is a cross-sectional view of a dust seal main body portion prepared when the present dust seal according to the first embodiment is manufactured by the rod-shaped projection rod-shaped groove fitting method.

FIG. 12 is a cross-sectional view showing a state in which the annular projection and the annular groove are fitted (completion of the second step).

FIG. 13 is a cross-sectional view of the dust seal of the first embodiment manufactured by the rod-shaped projection rod-shaped groove fitting method.

FIG. 14 is a partially enlarged cross-sectional view showing the present dust seal of the second embodiment.

FIG. 15 is an enlarged detailed view of a portion surrounded by a circle C shown by a dotted line in FIG.

FIG. 16 is a cross-sectional view of a seal portion prepared when the present dust seal of the second embodiment is manufactured by the rod-shaped projection rod-shaped groove fitting method.

FIG. 17 is a partially enlarged cross-sectional view showing the present dust seal of the third embodiment.

18 is a sectional view taken along line ZZ of FIG.

FIG. 19 is a cross-sectional view of a sliding portion prepared when the dust seal according to the third embodiment is manufactured by an extrusion method.

20 is a cross-sectional view taken along the line P-P of FIG.

FIG. 21 is a cross-sectional view showing a CR (unvulcanized) compounded with fluororesin particles (lubricant), which is an unvulcanized material for forming the annular seal portion, disposed in the recess.

22 is a sectional view taken along line QQ of FIG.

FIG. 23 is a cross-sectional view showing a state where a sliding portion, in which CR (unvulcanized) mixed with fluororesin particles (lubricant) is arranged, is arranged in the molding die (after completion of the third step).

FIG. 24 is an enlarged sectional view of a portion of a circle M indicated by a dotted line in FIG.

25 is a cross-sectional view taken along line RR of FIG.

FIG. 26 is a cross-sectional view showing a state where the fourth step of the extrusion method has been completed.

27 is a sectional view taken along line S-S in FIG. 26.

FIG. 28 is a partially enlarged cross-sectional view showing the present dust seal of the fourth embodiment.

29 is an enlarged cross-sectional view of a portion of a circle D shown by a dotted line in FIG.

FIG. 30 is a cross-sectional view of a seal portion prepared when the present dust seal according to the fourth embodiment is manufactured by the projection recess fitting method.

FIG. 31 is a cross-sectional view showing a state in which the annular protrusion and the annular groove are fitted (second step is completed).

FIG. 32 is a cross-sectional view showing an internal state of the molding die for the entire dust seal after completion of the third step of the method of fitting a projection / recess.

FIG. 33 is a cross-sectional view showing an internal state of the molding die for the entire dust seal after completion of the fourth step of the method of fitting a projection / recess.

FIG. 34 is a partially enlarged cross-sectional view showing the present dust seal of the fifth embodiment.

FIG. 35 is a cross-sectional view showing a conventional steering dust seal.

FIG. 36 is an enlarged view of a portion surrounded by a circle A in FIG. 35.

[Description of Reference Signs] 11 dust seal 21 sliding portion 21a resin cylinder 21b metal cylinder 21c central axis 23 of sliding portion lip 25 inner peripheral surface 27 of sliding portion outer peripheral surface 29 of sliding portion annular groove 31 rod-shaped projection 33 return portion 35 annular seal groove 36 dent 37 communication passage 38 C mixed with fluororesin particles (lubricant)
R (unvulcanized) 39 Cavity 41 (shape corresponding to annular seal part) Seal part 41c Central axis 41d of seal part Upper surface opening 41f Lower surface opening 42 Annular seal part 42a Unvulcanized annular seal part 43 Outer edge part of seal part 45 Inner edge part 47 of seal part 47 (Coated) Silicon resin 49 Annular projection 51 Part closely contacting to outer peripheral surface of steering shaft 61 Dust seal main body part 63 Flange 65 Inner edge 67 of flange 67 Rod-like groove 67b Return storage part 100 Engine room 200 Cabin 300 Dash panel 302 Column hole 401 Steering shaft 403 Steering shaft outer peripheral surface 701 Mold 703 Cavities 705 and 707 (having a shape corresponding to the dust seal body) Unvulcanized chloroprene rubber (CR)

Continuation of the front page (56) Bibliography Sho 55-15137 (JP, U) Ribaku 63-45429 (JP, U) Ribaku Sho 62-68074 (JP, U) Rikai 4-56976 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 39/00-39/44 B62D 1/00-1/28 F16J 15/16-15/52

Claims (2)

(57) [Claims] 1. A steering dust seal for covering a column hole for inserting a steering shaft, which is formed on a dash panel for partitioning between an engine room and a vehicle room of an automobile, for closing the column hole. Dust seal body part of
A tubular sliding portion that pivotally supports the steering shaft, and a seal portion that reduces the flow of foreign matter between the outer peripheral surface of the steering shaft and the inner peripheral surface of the sliding portion. In the dust seal, at least a portion of the seal portion, which is in close contact with the outer peripheral surface of the steering shaft, has a friction coefficient smaller than that of the dust seal main body portion, and the seal portion and the dust seal main body portion slide with each other. A dust seal, which is separate from the moving part, and in which the seal part is fitted and fixed to the dust seal body part and / or the sliding part. 2. The seal portion is formed of a material selected from the group consisting of silicone rubber, fluororubber and urethane rubber, which has a friction coefficient smaller than that of the dust seal body. The dust seal according to 1.