JP2017087629A - Metal mold and sealing device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal mold and a sealing device manufacturing method that solve problems in manufacturing a sealing device capable of reducing the rotational torque.SOLUTION: There is provided a metal mold M for manufacturing a sealing device that seals an annular space S formed between relatively coaxially rotating two members (2, 3) and comprises: a core metal 11 attached to one of the two members; and an annular lip 122 made of an elastic material fixed to the core metal and in elastic contact with the other member. The metal mold comprises a first mold M1 and a second mold M2 that define a cavity including a lip shaped part M21 with a shape corresponding to the lip formed to extend in a direction different from a die cutting direction D. An internal corner part P21 in the lip shaped part, which corresponds to a tip corner part 1220 being an origin of the elastic contact of the lip with the other member, and a periphery thereof have a rough surface with a rugged part. A splitting position P of the first mold and the second mold is located at a prescribed distance away from the internal corner part in the die cutting direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a molding die for manufacturing a sealing device to be mounted on a bearing device in, for example, an automobile, and a method for manufacturing the sealing device.

Conventionally, as the sealing device as described above, the grease enclosed in the bearing device is prevented from leaking, and water, dust, etc. do not enter the annular space to be sealed formed between the outer ring and the inner ring. There is a known structure for preventing such a situation.
Patent Document 1 below discloses a sealing device having a sealing lip that is slidably in close contact with a mating member, in which a roughened portion is provided on a contact surface of the sealing lip with respect to the mating member. Japanese Patent Application Laid-Open No. H10-228688 discloses that the sliding surface of the seal lip is provided with irregularities and low base oil kinematic viscosity grease is supplied to the sliding surface.
According to these, the contact area of the seal lip with respect to the mating member is substantially reduced and the grease retaining property of the contact surface is enhanced, so that the lubricity is enhanced and the friction is reduced.

Japanese Patent Laid-Open No. 2004-267338 International Publication No. 2012/127895

When manufacturing a sealing device in which a part of such a lip is rough, a manufacturing method is known in which molding dies are shot blasted to transfer irregularities to the lip. The following issues have been pointed out.
If the media used for shot blasting on the mold surface is too large, the media may be clogged in the cavities forming the lips, and roughing as may be expected of a mold may not be performed. Further, when the sealing device is removed from the molding die, an excessive load is applied to the lip that faces in a direction different from the mold release direction, so that the lip may be cracked or broken. In addition to such a problem, if a part of the mold surface is roughened as described above, the part cannot be subjected to a sliding process for facilitating demolding on the part, Demolding becomes even more difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molding die and a method for manufacturing a sealing device that can solve the manufacturing problem of the sealing device that can reduce rotational torque.

The molding die according to the present invention seals an annular space formed between two members rotating relatively coaxially, and is fixed to the core metal member attached to one of the two members. A molding die for manufacturing a sealing device having an annular lip made of an elastic material that elastically contacts the other member, wherein the molding die is provided so as to be relatively contactable and separable and in a direction different from the die cutting direction A first mold and a second mold for defining a cavity including a lip shape portion having a shape corresponding to the lip formed to extend, and a resilient contact point with respect to the other member of the lip in the lip shape portion The corner angle portion corresponding to the tip corner portion and the periphery thereof is a rough surface having a concavo-convex portion, and the split positions of the first mold and the second mold are from the corner angle portion. It must be a predetermined distance away from the die cutting direction. The features.
According to the present invention, since the split position of the first mold and the second mold is a position separated by a predetermined distance in the mold release direction from the corner of the corner forming the lip of the sealing device, demolding At times, the molded lip can be prevented from cracking and tearing, and the tip corner of the lip can be roughened.

In the present invention, the predetermined distance may be a position of 0.1 to 0.4 mm.
According to the present invention, when the predetermined distance is less than 0.1 mm, the uneven transfer region applied to the tip corner of the lip becomes narrow, and the other mold (in the following embodiment, the first mold side) ) Also requires a rough surface portion to be formed. If the predetermined distance exceeds 0.4 mm, the lip portion tends to be difficult to remove.

In the present invention, the lip-shaped portion may be formed so that the elastic contact angle of the corner portion is 30 ° to 45 °.
According to the present invention, when the lip-shaped portion is configured as described above, the lip of the sealing device formed thereby can be prevented from turning over (preventing inversion). When the elastic contact angle is less than 30 °, the reaction force of the lip that elastically contacts the other member tends to be large. When the elastic contact angle exceeds 45 °, it tends to turn easily.

In the present invention, the concavo-convex portion is formed such that a surface roughness of a predetermined range of the front side portion including the tip corner portion of the lip by the transfer of the concavo-convex portion is Ra 0.4 to 2.0 μm. It is good as a thing.
According to the present invention, according to the sealing device provided with the lip formed by transferring the concavo-convex portion having the above configuration, the friction coefficient of the sliding surface with the other member can be reduced, and the retention property of the grease is also improved. be able to. Therefore, it is possible to improve the sealing performance and reduce the rotational torque. When the surface roughness of the predetermined range is less than Ra 0.4 μm, the uneven portion tends to be too fine to make the predetermined range of the lip difficult to roughen, and the above-described effects are reduced. When the surface roughness in the predetermined range is higher than Ra 2.0 μm, the roughness of the uneven portion becomes too rough, and there is a concern that the sealing performance is deteriorated.

In this invention, the range in which the said uneven | corrugated | grooved part was formed in the said lip-shaped part is good also as a surface area of 1/10-2/3 of the length range from the extension base part of the said lip to the said front-end | tip corner | angular part.
According to the present invention, when the range in which the uneven portion is formed is smaller than 1/10 of the length range from the extended base portion of the lip to the tip corner portion, the sliding end surface or the sliding circumferential surface of the lip Among them, the portion where the uneven portion is formed decreases, and the effect of improving the sealing performance and reducing the rotational torque tends to be low. In addition, when the range in which the concavo-convex portion is formed is larger than 2/3 of the length range from the extending base portion of the lip to the tip corner portion, the frictional resistance at the time of demolding is increased, and the lip is deformed or broken. Such a problem tends to occur.

The manufacturing method of the sealing device according to the present invention seals an annular space formed between two members rotating relatively coaxially, a metal core member attached to one of the two members, and the metal core member A method of manufacturing a sealing device having an annular lip made of an elastic material that is fixed and elastically contacted with the other member, wherein the sealing device is provided so as to be relatively contactable and separable and extends in a direction different from a die-cutting direction. A first die and a second die that define a cavity including a lip shape portion having a shape corresponding to the lip, and the split positions of the first die and the second die are the lip shape portion, A mold preparing step of preparing a molding die that is positioned at a predetermined distance in the mold releasing direction from the corner of the corner corresponding to the tip corner serving as an elastic contact point with respect to the other member of the lip; and the core Set the metal member at the predetermined position of the mold. And forming the mold by supplying and clamping the elastic material, and in the mold preparation process, particles having a particle diameter of 100 to 200 μm are projected with the corner of the corner as a target, The surface of the corner portion and the peripheral lip-shaped portion is a rough surface, and in the molding step, the rough surface is transferred to a predetermined range of the front portion including the tip corner portion of the lip to form irregularities. It is characterized by that.
According to the above manufacturing method, the split position of the first mold and the second mold is a predetermined distance away from the corner of the corner forming the lip of the sealing device in the mold drawing direction. It is possible to prevent tearing and cracking of the lip molded at the time of demolding, and to give a rough surface to the corner of the tip of the lip. Moreover, when the particle size projected in the mold preparation step is less than 100 μm, the tip corner portion of the lip tends to be a desired rough surface. When the particle size projected in the mold preparation step exceeds 200 μm, depending on the shape of the lip-shaped part, the particles do not reach the tip of the cavity, and the desired rough surface tends not to be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the subject on manufacture of the sealing device which can aim at reduction of rotational torque can be solved.

It is a schematic longitudinal cross-sectional view which shows an example of the bearing apparatus with which the sealing device manufactured with the molding die concerning this invention is applied. (a) is an enlarged view of a portion X in FIG. 1, showing a first embodiment of a sealing device manufactured with the same mold, and (b) assembling the sealing device to a bearing device. It is a schematic longitudinal cross-sectional view which shows the previous state. It is a schematic longitudinal cross-sectional view which shows one process which manufactures the sealing device using the same shaping | molding die. It is a schematic longitudinal cross-sectional view which shows the same shaping | molding die. It is a typical sectional view for explaining the metallic mold preparation process of the same metallic mold, and is a figure showing the state where shot blasting is performed. It is a flowchart which shows the manufacturing process of the manufacturing method of the sealing device using the molding die. (a) is an enlarged view of a Y portion in FIG. 1 and shows a second embodiment of the sealing device, and (b) is a schematic longitudinal section showing a state before the sealing device is assembled to the bearing device. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The sealing device 10 manufactured by the molding die M according to the present embodiment seals an annular space S formed between two members that rotate relatively coaxially, specifically, between the outer ring 2 and the hub ring 3. It is a device to do. The sealing device 10 includes a metal core member 11 attached to one of the two members, and an annular lip (122 or the like) made of an elastic material that is fixed to the metal core member 11 and elastically contacts the other member.
The molding die M is provided in a relatively detachable manner and extends in a direction different from the die-cutting direction D, and has a lip shape portion (M21) having a shape corresponding to the lip (122 etc.) of the sealing device 10 formed. Etc.) is provided with a first mold M1 and a second mold M2. The lip-shaped portion (M21, etc.) is a rough surface having a corner portion P21 corresponding to the tip corner portion (1220, etc.) serving as an elastic contact point with respect to the other member of the lip (122, etc.) and the periphery thereof having an uneven portion. Is formed. The split position of the first mold M1 and the second mold M2 is a position (P) that is separated from the entering corner portion P21 by a predetermined distance in the mold drawing direction D.
Below, the molding die M for manufacturing the sealing device 10 to be mounted on the bearing device 1 that supports the wheel of the automobile so as to be axially rotatable and the manufacturing method thereof will be described in detail.

  First, the bearing device 1 to which the sealing device 10 is mounted will be described with reference to FIG. The bearing device 1 is generally formed between an outer ring 2, a hub ring 3, an inner ring member 4 fitted and integrated on the vehicle body side of the hub ring 3, and between the outer ring 2, the hub ring 3, and the inner ring member 4. And two rows of rolling elements (balls) 6 interposed therebetween. In this example, the hub ring 3 and the inner ring member 4 constitute an inner ring 5 as an inner member. The outer ring 2 is fixed to a vehicle body (not shown) of the automobile. A drive shaft 7 is coaxially spline-fitted to the hub wheel 3, and the drive shaft 7 is connected to a drive source (drive transmission unit) (not shown) via a constant velocity joint 8. The drive shaft 7 is integrated with the hub wheel 3 by a nut 9 to prevent the hub wheel 3 from being detached from the drive shaft 7. The inner ring 5 (the hub ring 3 and the inner ring member 4) is rotatable around the axis L with respect to the outer ring 2, and the outer ring 2 and the inner ring 5 constitute two members that rotate relatively. An annular space S is formed between the members. In the annular space S, two rows of rolling elements 6 are held by the retainer 6a so that the races of the outer ring 2, the hub ring 3 and the races 3a and 4a of the inner ring member 4 can roll. It is disguised. The hub wheel 3 has a cylindrical hub wheel main body 30 and a hub flange 32 formed so as to extend radially outward from the hub wheel main body 30 via a rising base portion 31. The wheels are attached and fixed by nuts (not shown). Sealing devices 10 and 20 are mounted between the outer ring 2 and the hub ring 3 and between the outer ring 2 and the inner ring member 4, respectively, and the annular space S is sealed by the sealing devices 10 and 20.

Next, the sealing device 10 manufactured using the molding die M will be described with reference to FIG.
The sealing device 10 shown in FIG. 2A is an enlarged view of a portion X in FIG. The sealing device 10 includes a cored bar member 11 fitted into the inner peripheral surface 2 b of the outer ring 2 and an elastic lip member 12 fixed to the cored bar member 11.

  The metal core member 11 is a ring shape made of a metal material or the like and processed by sheet metal, and has a cylindrical portion 110 fitted into the inner peripheral surface 2b of the outer ring 2, and a flange extending from the one end portion 110a of the cylindrical portion 110 to the inner diameter side. And a shape portion 111. The shape of the hook-shaped portion 111 is set in accordance with the number and formation positions of the annular lips 121, 122, 123, and the hook-shaped portion 111 in the illustrated example is a first inclined portion 111a inclined from the one end portion 110a toward the inner diameter side. A first parallel portion 111b formed substantially parallel to the hub flange 32 from one end of the first inclined portion 111a, a second inclined portion 111c inclined from the first parallel portion 111b to the inner diameter side, and a second It has the 2nd parallel part 111d formed substantially parallel with respect to the hub flange 32 from the one end part of the inclination part 111c.

The lip member 12 is made of an elastic material selected from NBR, H-NBR, ACM, AEM, EPDM, FKM, and the like, and is integrally fixed to the core metal 11 by vulcanization molding.
The lip member 12 includes a lip base 120 fixed to a surface of the flange 111 on the side of the hub flange 32 when mounted between the outer ring 2 and the hub ring 3, and an axis L of the bearing device 1 from the lip base 120. Lip (axial lip) 121 formed so as to be inclined and extended in a direction along the direction of the lip, and a lip (radial lip) formed so as to extend while being inclined in the radial direction with respect to the direction of the axis L 122 and a lip 123 (grease lip) formed toward the rolling element 6 side. Grease (not shown) is applied in advance to the sliding contact surfaces of the lips 121, 122, 123 with the hub flange 32, the rising base 31, and the hub wheel body 30.
Among the plurality of lips 121, 122, and 123 thus provided, the lip 121 that is an axial lip is formed to extend in the mold releasing direction D of the first mold M1, while the lip 122 that is a radial lip is The first mold M1 is formed to extend in a direction different from the die cutting direction D. The lip 122 extends in the same direction as the lip 121 in the axial center L direction, and extends in the opposite direction to the lip 123 in the axial center L direction.

The tip corners 1210 and 1220 of the lips 121 and 122 (specifically, the corners on the inner diameter side of the tips of the lips 121 and 122) are respectively attached to the hub flange 32 and the rising base 31 when mounted on the bearing device 1. Is assembled in a state of elastic contact. When the bearing device 1 is rotated, the lips 121 and 122 are slidably contacted with the hub flange 32 and the rising base 31, whereby the gap between the outer ring 2 and the hub ring 3, specifically, the end surface 2 e of the outer ring 2 and the hub flange 32. Intrusion of muddy water or the like into the gap 2c is prevented. The lip 123 formed toward the rolling element 6 is in sliding contact with the hub wheel main body 30 to prevent leakage of grease applied and enclosed in the rolling element 6.
The predetermined range of the front side portion including the tip corners 1210 and 1220 of the lips 121 and 122 is subjected to a roughening process to which fine irregularities of the molding die M are transferred, and has a so-called satin finish. . As a result, the contact area (the true contact area) of the lip 121, 122 with the hub flange 32 and the rising base 31 is reduced, and the grease retention of the contact surface is improved, so that the lubricity is improved and the friction is reduced. This can contribute to reduction of rotational torque.

  In the figure, 121a indicates a sliding peripheral surface of the lip 121, 121b indicates a sliding end surface of the lip 121, and the lip 121 is formed in a tapered shape whose tip is smaller in thickness than the base. In FIG. 2 (b), a roughening process having a concavo-convex portion in the range A1 is performed on the sliding peripheral surface 121a. The range of A1 in the illustrated example shows an example in which the entire length of the lip 121 (the length from the extending base 1212 to the base of the lip 121 to the tip corner 1210) is approximately 2/3, but is limited to this. In short, the surface of the lip 121 that is in sliding contact with the hub flange 32 (sliding contact surface) may be roughened. Therefore, 1/10 to 2/3 of the lip 121 may be in the range of A1, that is, the roughening processing range. The sliding end surface 121b of the lip 121 is roughened in the entire area of the end surface, that is, the range A2 shown in FIG.

Similarly, in the figure, 122a indicates the sliding peripheral surface of the lip 122, and 122b indicates the sliding end surface of the lip 122. The lip 122 has a tip shape that is thicker at the tip than the base, and has a cross-sectional shape that resembles a trapezoid. In FIG. 2 (b), a roughening process having a concavo-convex portion in the range B1 is performed on the sliding peripheral surface 122a. In the range of B1 in the figure, approximately 2/3 of the entire length of the lip 122 (the length from the extended base portion 1222 to the base of the lip 122 to the tip corner portion 1220) is roughened, but this is limited to this. In short, it is only necessary that the sliding contact surface of the lip 122 is roughened. Therefore, 1/10 to 2/3 of the lip 122 may be in the range of B1, that is, the roughening processing range. Further, the sliding end surface 122b of the lip 122 is roughened in the entire region of the end surface, that is, the range B2 shown in FIG. 2B, and the roughened processing is not performed in the range B3. . Therefore, the tip corner portion 1220 of the lip 122 is roughened, but the corner portion 1221 of the lip 122 existing on the outer diameter side of the tip corner portion 1220 is not roughened. .
In addition, in the sliding end surfaces 121b and 122b, the range to be roughened is not limited to the range of A2 and B2 in the illustrated example, but since this is an area of several millimeters, roughening is applied to all the end surfaces. ing.

Next, with reference to FIGS. 3 and 4, the molding die M for manufacturing the sealing device 10 including the lips 121 and 122 having the ranges of the partially roughening process and the partially non-roughening process as described above will be described. explain. 3 is a schematic diagram illustrating a state before the sealing device 10 manufactured by the molding die M is taken out, in which a part of the reference numeral of the sealing device 10 is omitted. FIG. 4 shows a state in which the mold is clamped in a state where there is nothing inside the cavity in order to explain the configuration of the molding die M.
The illustrated mold M includes an upper mold first mold M1 (movable mold) that is movable up and down, and a lower mold second mold M2 (fixed mold) that is fixedly installed. The first mold M1 moves up and down and is relatively movable. In the first mold M1, the tapered shape of the lip 121 is imitated, and a concave lip-shaped portion M12 is formed so that the elastic material is distributed. Further, in order to make the range of A1 and A2 of the lip 121 rough, a predetermined range of the lip shape portion M12, that is, 1/10 of the length range from the extended base portion 1212 to the tip corner portion 1210 of the lip 121 is used. The surface area of ˜2 / 3 is a rough surface having uneven portions. In FIG. 3 and FIG. 4, “x” marks are given to the roughened portions. The rough surface processing will be described later.
The first mold M1 is formed with a concave lip-shaped portion M13 in which only the front-side portion of the lip 122 (the outer-diameter-side thick portion) is imitated. That is, the corner angle portion M14 of the first mold M1 corresponds to the corner portion 1221 of the lip 122. Further, the first mold M1 is formed with a burr groove M11 adjacent to the lip-shaped portion M13. The lip shape portion M13 is not roughened.

  The second die M2 is formed by imitating the shape of the cored bar member 11 where the cored bar member 11 is disposed (the cylindrical part 110, the bowl-shaped part 111, etc.) and the first mold. It is formed so as to have a space in which the lip base 120 is formed when joined to M1. Further, a burr groove M10 that is generated when the lip base 120 is formed is formed in the first mold M1. The cored bar shape part M22 is designed in consideration of the space where the surface of the first parallel part 111b on the hub flange 32 side is covered with an elastic material and the lip base part 120 is formed when the cored bar member 11 is placed. Is formed.

  In the second mold M2, the shape of the lip 123 is imitated, and a concave lip-shaped portion M23 is formed so that the elastic material is distributed. Above that, a lip-shaped portion M21 that is shaped like a thick tip on the inner diameter side of the lip 122 is formed. The lip 122 is a lip formed to extend in a direction different from the mold release direction D of the first mold M1, and the lip shape part M13 of the first mold M1 and the lip shape part of the second mold M2. The mold is clamped in a state where M21 is joined to form a cavity.

The lip-shaped portion M21 has a rough surface with an indented corner portion P21 and its periphery having a concavo-convex portion. In FIG. It is marked.
The split position at which the molding die M is divided into the first die M1 and the second die M2 is a predetermined distance away from the corner corner portion P21 in the mold drawing direction D, in other words, from the corner corner portion P21. A predetermined position P (see FIG. 3) between the corner 1221 and the tip corner 1220 is reached. That is, the dimension (predetermined distance) from the predetermined position P, which is the split position (upper surface in the example) of the second mold M2, to the corner corner P21 is the range of B2 in the left enlarged view of FIG. Same size.
As described above, the split positions of the first mold M1 and the second mold M2 are predetermined in the mold release direction D (corner part 1221 side) from the entering corner part P21 forming the lip 122 which is the radial lip of the sealing device 10. Since the distance and the position are separated, the lip 122 molded at the time of demolding is prevented from cracking and tearing, and the desired rough surface in the range of B1 and B2 with the tip corner 1220 of the lip 122 interposed therebetween Can be applied. Conventionally, when the sealing device 10 is removed from the molding die M1, such as the lip 122, a lip (radial lip) facing in a direction different from the die-cutting direction D is excessively loaded, so that the lip is cracked. However, according to the above, such a problem can be solved.

  At this time, in the sealing device 10 shown in FIG. 2 and the like, it is desirable that the predetermined distance between the split positions of the first mold M1 and the second mold M2 is 0.1 to 0.4 mm, as shown in FIG. Thus, the dimension from the predetermined position P to the corner angle portion P21 corresponds to the range of B2 of the lip 122. When the predetermined distance is less than 0.1 mm, the uneven transfer region applied to the tip corner 1220 of the lip 122 becomes narrow, and depending on the case, the other mold (in the example shown, the first mold M1) is used. However, it becomes necessary to form a rough surface portion. When the predetermined distance exceeds 0.4 mm, when the sealing device 10 is removed from the second mold M2, the sliding peripheral surface 122b of the lip 122 extends from the predetermined position P of the second mold M2 to the corner corner P21. It becomes easy to get caught in the part, and tends to be difficult to remove.

  Further, the lip shape portion M21 is formed so that the elastic contact angle α (see the enlarged view on the left side of FIG. 3) of the entrance corner portion P21 that becomes the elastic contact point of the lip 122 is 30 ° to 45 °. desirable. If it is set as the above structure, the lip | rip 122 of the sealing device 10 formed by this can make it hard to turn over at the time of the mounting | wearing to the bearing apparatus 1 (inversion prevention). More specifically, when the elastic contact angle α is less than 30 °, the reaction force of the lip 122 elastically contacting the rising base portion 31 tends to be large. When the elastic contact angle α exceeds 45 °, it tends to be turned over when mounted on the bearing device 1, and if it is mounted in the turned-up state, a desired sealing function cannot be exhibited.

The concavo-convex portions formed on the first mold M1 and the second mold M2 are a predetermined range (A1, A2, B1) of the front side portion including the tip corner portions 1210, 1220 of the lips 121, 122 by the transfer of the concavo-convex portions. , B2) has a surface roughness Ra (arithmetic mean roughness) of 0.4 to 2.0 μm. Ra (arithmetic mean roughness) is the sum of the absolute values of deviations from the average line extracted from the roughness curve to the measurement curve, and the average value is obtained. That is, the average value obtained by dividing the area obtained by the average roughness and the average line by the length L is expressed in micrometers (μm), and is a value based on JIS B 0601.
When the surface roughness of the predetermined range is less than Ra 0.4 μm, the uneven portion is too fine and the predetermined range of the lip tends not to be roughened. If the surface roughness in the predetermined range is higher than Ra 2.0 μm, the roughness of the concavo-convex portion becomes too rough, and there is a concern that the sealing performance is reduced.

And the range in which the uneven | corrugated | grooved part was formed in the lip-shaped parts M12 and M21 is 1/10 to 2/3 of the length range from the extended base parts 1212 and 1222 of the lips 121 and 122 to the tip corner parts 1210 and 1220, The surface area is preferably 1/10 to 1/2 of the length range.
With the above configuration, when the range where the concavo-convex portions are formed is smaller than 1/10 of the length range from the extended base portions 1212 and 1222 of the lips 121 and 122 to the tip corner portions 1210 and 1220, Of the sliding end surfaces 121b and 122b or the sliding peripheral surfaces 121a and 122a of 122, the portion where the uneven portion is formed decreases, the sealing performance tends to be lowered, and the rotational torque reduction effect also tends to be low. Become. In addition, when the range where the concavo-convex portions are formed is larger than 2/3 of the length range from the extended base portions 1212 and 1222 of the lips 121 and 122 to the tip corner portions 1210 and 1220, the frictional resistance at the time of demolding increases. Problems such as deformation and breakage of the lips 121 and 122 tend to occur.

Next, a method for manufacturing the sealing device 10 according to the present embodiment will be described with reference to FIGS. As shown in FIG. 6, the manufacturing process is largely divided into “mold preparation process (S 100, S 101)” and “molding process (S 102 to S 104)”. An example will be described in which the elastic material placed is pressed against the cavity with the first mold M1.
<Mold preparation process>
In the mold preparation step, first, the first mold M1 and the second mold M2 that are in the above-described split position are prepared. Then, a roughening process is performed on predetermined portions of the first mold M1 and the second mold M2 (rough surface processing). Specifically, particles having a particle diameter of 100 to 200 μm, more specifically, for example, particles having an ASTM standard of 140 to 70 mesh are projected on the corners P12 and P21 of the lip-shaped parts M12 and M21. The corners P12 and P21 and the surrounding surfaces are roughened. As shown in FIG. 5 and FIG. 6, the portion where the roughening treatment is not desired may be covered with the sheet S and masked before the particles are projected (FIG. 6, S100, S101).

  In FIG. 5, the example by drive last is shown as a rough surface processing method of the 2nd metal mold | die M2. In this case, the fine particles as described above are sprayed into the cavity M20 of the lip-shaped portion M21 by using a projection gun using air to form fine uneven portions in the cavity M20. At this time, the strength and time of the shot, time, and the like are not particularly limited, but the processing is performed so that the surface roughness of the predetermined range of the lip shape portion M21 is approximately Ra 0.7 to 2.3 μm. When the lip 122 is formed by the lip shape portion M21 thus processed, a surface roughness of Ra in a predetermined range of the front side portion including the tip corner portion 1220 of the lip 122 is obtained from Ra 0.4 to 2.0 μm. it can.

  When the particle size of the particles projected in the mold preparation step is less than 100 μm, the tip corners 1210 and 1220 of the lips 121 and 122 tend not to have a desired rough surface. That is, in the case of a sealing device manufactured with such a molding die, the surface roughness of the predetermined range of the lip is less than Ra 0.4 μm, and the uneven portion tends to be too fine to make the predetermined range of the lip rough. It becomes difficult to exhibit effects such as improvement in sealing performance and reduction in rotational torque. When the particle size of the particles projected in the mold preparation process exceeds 200 μm, for example, the particles do not reach the tip of the tapered cavity like the lip shape portion M12 shown in FIG. It becomes clogged and tends to be unable to have a desired rough surface. Further, in this case, even in the lip-shaped portion where the particles reach the tip of the cavity, the surface roughness in a predetermined range exceeds Ra 2.0 μm, and the roughness of the uneven portion becomes too rough, The effect tends to decrease.

<Molding process>
After finishing the rough surface processing to a desired portion of the molding die M through the die preparation step, if masking is performed, the sheet body S is taken, and then the molding step is performed.
In the molding step, the above-mentioned rough surface is transferred to a predetermined range (a range of A1, A2, B1, and B2) of the front side portion including the tip corner portions 1210 and 1220 of the lips 121 and 122 to form irregularities.
Specifically, the core metal member 11 is installed in the core metal shape portion M22 of the second mold M2 that has been opened (S102). Then, an unvulcanized elastic material is placed on the upper surface of the core metal member 11, the heated first mold M1 is lowered, and the mold is clamped, and the lip-shaped parts M12, M13, M21, M23, etc. An elastic material is supplied to the cavity (S103). Then, vulcanization is performed for a predetermined time, and compression molding is performed until the elastic material is cured (S104). And if predetermined time passes, the 1st metal mold | die M1 will be raised, a mold opening will be performed, it will demold, and if the burr | flash is removed, the sealing device 10 can be obtained. As described above, the lips 121 and 122 molded at the time of demolding are hardly cracked or broken.
Note that the manufacturing method of the sealing device 10 is not limited to the above, and the manufacturing method of the present embodiment can also be applied to the case where an injection path of an elastic material is provided in a molding die and injection molding is performed. The shape, configuration, and the like of the molding die M are not limited to the illustrated example, and may be prepared according to the shape of the sealing device, and may be divided into a plurality of parts such as a middle die. In short, the first mold M1 and the second mold M2 are provided, and the corner angle portion P21 of the lip shape portion M21 and the periphery thereof have a rough surface with uneven portions, and the first mold M1 and the second mold M2 The split position P of the two molds M2 only needs to be a predetermined position between the tip corner 1220 and the corner 1221 different from the tip corner 1220.

Next, the sealing device 20 will be described with reference to FIGS. 7 (a) and 7 (b).
The sealing device 20 differs from the above in the shape and constituent members of the lip member, but the split position P of the first mold M1 and the second mold M2 for manufacturing the same and the formation method and setting of the rough surface are substantially the same. A manufacturing method using such a molding die M can also be applied to the sealing device 20 in the same manner, and the same effects as described above can be obtained. FIG. 7B omits the illustration of the L-shaped slinger 23 in order to explain the configuration of the lip. This will be described in detail below.

A sealing device 20 shown in FIG. 7A corresponds to an enlarged view of the Y part in FIG. 1 and is mounted between the outer ring 2 and the inner ring member 4 to seal the annular space S.
The sealing device 20 is configured by a pack seal type, and a slinger 23 fitted to the outer diameter surface 4b of the inner ring member 4, a core metal member 21 fitted to the inner peripheral surface 2b of the outer ring 2, and a core metal member And a lip member 22 having a plurality of (four in the illustrated example) lips 220, 221, 222, and 223 that are fixed to 21 and elastically slidably contact the slinger 23. The slinger 23 is fitted to and integrated with the outer diameter surface 4b of the inner ring member 4 and the one end portion on the opposite side to the annular space S of the cylindrical portion 231 toward the outer ring 2 side along the radial direction. And an annular outward flange portion 230 that are coupled in this manner. The metal core member 21 includes a cylindrical portion 210 that is fitted to the inner peripheral surface 2 b of the outer ring 2, and a disk portion 211 that is formed so as to extend radially inward (centripetal direction) from the cylindrical portion 210. Yes.
Here, an example in which a magnetic ring made of an annular multipolar magnet is not fixed to the outward flange portion 230 is shown, but the magnetic sensor installed on the vehicle body side and the magnetic ring are installed so as to face each other. Rotational state data such as the rotational speed of a wheel (not shown) attached to the hub wheel 3 may be obtained by detecting a magnetic change.

Of the lips 220, 221, 222, 223 of the lip member 22, two lips 220, 221 (axial lips) are formed so as to be inclined and extend in a direction along the axis L of the bearing device 1, It arrange | positions so that the outward flange part 230 of the slinger 23 may contact elastically. The lip 222 (radial lip) of the lip member 22 is formed in the radial direction (radial direction) with respect to the axial center L direction, and the lip 223 (grease lip) is formed toward the rolling element 6 side. These are arranged so as to be in sliding contact with the cylindrical portion 231 of the slinger 23 elastically.
Grease (not shown) is applied in advance to the sliding surfaces of the lips 220, 221, 222, and 223 to the slinger 23.
Among the plurality of lips 220, 221, 222, and 223 thus provided, the lip 222, which is a radial lip, is formed to extend in a direction different from the die-cutting direction D of the first mold serving as a movable mold. Corresponds to the lip.

The sliding contact surfaces of the lips 220, 221, and 222 of the sealing device 20 to the slinger 23, specifically, sliding peripheral surfaces 220a, 221a, and 222a and sliding end surfaces 220b, 221b, as shown in FIG. Similar to the sealing device 10 and the lips 121 and 122, the roughening process is applied to 222b.
At this time, the range (C1, C2, D1, D2, E1, E2) to which the roughening process is applied to the lips 220, 221, 222 is the range of the lips 121, 122 (A1, A2, B1, B2). The same can be said. Specifically, for example, a range in which the roughening treatment of the lip 220 is performed is a surface area of 1/10 to 2/3 of a length range from the extended base portion 2201 to the tip corner portion 2200 of the lip 220, The sliding end surface 220b is the entire end surface. The surface roughness is the same as that of the sealing device 10 in that Ra is 0.4 to 2.0 μm.

  If the molding die M of this embodiment is applied to the manufacture of the sealing device 20 shown in FIG. 7, it is possible to prevent an excessive load from being applied to the lip 222 (radial lip) that faces in a direction different from the die-cutting direction D. Therefore, cracking and tearing of the lip 222 can be prevented, and the problems of the manufacturing method can be solved as described above. Further, a desired rough surface can be formed in a desired range across the tip corners 2200, 2210, and 2220 of the lips 220, 221, and 222, and the sealing device 20 that can improve the sealing performance and reduce the rotational torque. Can be obtained.

  As described above, not only the shape and configuration of the molding die, but also the sealing devices 10 and 20 manufactured thereby, the shape and configuration of the core metal member and lip member constituting them are not limited to the illustrated examples. Absent. The sealing device may be any device that seals an annular space formed between two members that rotate relatively coaxially and has a cored bar member and a lip, and the number of lips is not particularly limited. For example, one lip (radial lip) facing in a direction different from the die cutting direction D when demolding may be provided in the outer diameter direction and one in the inner diameter direction with an annular core member interposed therebetween. .

2 Outer ring (outer member)
3 Hub wheel (inner member)
DESCRIPTION OF SYMBOLS 10 Sealing device 11 Core metal member 122 Lip 1220 Tip corner part 1221 Corner part S Annular space M Molding mold M1 First mold M2 Second mold M21 Lip shape part P21 Corner corner part P Predetermined position D Die cutting direction

Claims (6)

An annular space formed between two members rotating relatively coaxially is sealed, and a metal core member attached to one of the two members and an elastic material fixed to the metal core member and elastically contacting the other member A mold for producing a sealing device having an annular lip of
The molding die is a first die that divides a cavity including a lip-shaped portion having a shape corresponding to the lip formed so as to be relatively contactable and separable and extending in a direction different from a die-cutting direction. And a second mold,
In the lip-shaped part, the corner of the corner corresponding to the tip corner that becomes the elastic contact point with respect to the other member of the lip and the periphery thereof are rough surfaces having irregularities,
The molding die characterized in that the split position of the first die and the second die is a predetermined distance away from the entering corner portion in the die-cutting direction. In the molding die according to claim 1,
The molding die characterized in that the predetermined distance is 0.1 to 0.4 mm. In the molding die according to claim 1 or 2,
The molding die, wherein the lip-shaped part is formed so that the elastic contact angle of the corner part is 30 ° to 45 °. In the molding die described in any one of Claims 1-3,
The concavo-convex portion is formed such that a surface roughness of a predetermined range of the front side portion including the tip corner portion of the lip by the transfer of the concavo-convex portion is Ra 0.4 to 2.0 μm. Mold to mold. In the molding die described in any one of Claims 1-4,
The area where the concavo-convex part is formed in the lip-shaped part is a surface area of 1/10 to 2/3 of the length range from the extended base part of the lip to the tip corner part. Mold. An annular space formed between two members rotating relatively coaxially is sealed, and a metal core member attached to one of the two members and an elastic material fixed to the metal core member and elastically contacting the other member A manufacturing method of a sealing device having an annular lip,
A first mold and a second mold that define a cavity including a lip-shaped portion having a shape corresponding to the lip that is provided so as to be relatively contactable and separable and extends in a direction different from a die-cutting direction; The cutting position of the first mold and the second mold is in the die-cutting direction from the corner of the lip-shaped part corresponding to the tip corner that becomes the elastic contact point with respect to the other member of the lip. A mold preparation step of preparing a molding mold that is a predetermined distance away from the mold,
A molding step in which the core member is installed at a predetermined position of the molding die, and the elastic material is supplied and clamped to mold;
In the mold preparation step, the particles with a particle diameter of 100 to 200 μm are projected with the corners at the corners as targets, and the surfaces of the corners at the corners and the peripheral lip-shaped portions are rough surfaces.
In the molding step, the rough surface is transferred to a predetermined range of the front side portion including the tip corner portion of the lip to form irregularities.

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